Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

64 files changed, 17443 insertions, 0 deletions

diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
new file mode 100644
index 000000000..80b5fd44a
--- /dev/null
+++ b/drivers/of/Kconfig
@@ -0,0 +1,97 @@
+# SPDX-License-Identifier: GPL-2.0
+config DTC
+	bool
+
+menuconfig OF
+	bool "Device Tree and Open Firmware support"
+	help
+	  This option enables the device tree infrastructure.
+	  It is automatically selected by platforms that need it or can
+	  be enabled manually for unittests, overlays or
+	  compile-coverage.
+
+if OF
+
+config OF_UNITTEST
+	bool "Device Tree runtime unit tests"
+	depends on !SPARC
+	select IRQ_DOMAIN
+	select OF_EARLY_FLATTREE
+	select OF_RESOLVE
+	help
+	  This option builds in test cases for the device tree infrastructure
+	  that are executed once at boot time, and the results dumped to the
+	  console.
+
+	  If unsure, say N here, but this option is safe to enable.
+
+config OF_ALL_DTBS
+	bool "Build all Device Tree Blobs"
+	depends on COMPILE_TEST
+	select DTC
+	help
+	  This option builds all possible Device Tree Blobs (DTBs) for the
+	  current architecture.
+
+	  If unsure, say N here, but this option is safe to enable.
+
+config OF_FLATTREE
+	bool
+	select DTC
+	select LIBFDT
+	select CRC32
+
+config OF_EARLY_FLATTREE
+	bool
+	select DMA_DECLARE_COHERENT if HAS_DMA
+	select OF_FLATTREE
+
+config OF_PROMTREE
+	bool
+
+config OF_KOBJ
+	def_bool SYSFS
+
+# Hardly any platforms need this.  It is safe to select, but only do so if you
+# need it.
+config OF_DYNAMIC
+	bool "Support for dynamic device trees" if OF_UNITTEST
+	select OF_KOBJ
+	help
+	  On some platforms, the device tree can be manipulated at runtime.
+	  While this option is selected automatically on such platforms, you
+	  can enable it manually to improve device tree unit test coverage.
+
+config OF_ADDRESS
+	def_bool y
+	depends on !SPARC && (HAS_IOMEM || UML)
+
+config OF_IRQ
+	def_bool y
+	depends on !SPARC && IRQ_DOMAIN
+
+config OF_RESERVED_MEM
+	def_bool OF_EARLY_FLATTREE
+
+config OF_RESOLVE
+	bool
+
+config OF_OVERLAY
+	bool "Device Tree overlays"
+	select OF_DYNAMIC
+	select OF_FLATTREE
+	select OF_RESOLVE
+	help
+	  Overlays are a method to dynamically modify part of the kernel's
+	  device tree with dynamically loaded data.
+	  While this option is selected automatically when needed, you can
+	  enable it manually to improve device tree unit test coverage.
+
+config OF_NUMA
+	bool
+
+config OF_DMA_DEFAULT_COHERENT
+	# arches should select this if DMA is coherent by default for OF devices
+	bool
+
+endif # OF
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
new file mode 100644
index 000000000..e0360a443
--- /dev/null
+++ b/drivers/of/Makefile
@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-y = base.o device.o platform.o property.o
+obj-$(CONFIG_OF_KOBJ) += kobj.o
+obj-$(CONFIG_OF_DYNAMIC) += dynamic.o
+obj-$(CONFIG_OF_FLATTREE) += fdt.o
+obj-$(CONFIG_OF_EARLY_FLATTREE) += fdt_address.o
+obj-$(CONFIG_OF_PROMTREE) += pdt.o
+obj-$(CONFIG_OF_ADDRESS)  += address.o
+obj-$(CONFIG_OF_IRQ)    += irq.o
+obj-$(CONFIG_OF_UNITTEST) += unittest.o
+obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o
+obj-$(CONFIG_OF_RESOLVE)  += resolver.o
+obj-$(CONFIG_OF_OVERLAY) += overlay.o
+obj-$(CONFIG_OF_NUMA) += of_numa.o
+
+ifdef CONFIG_KEXEC_FILE
+ifdef CONFIG_OF_FLATTREE
+obj-y	+= kexec.o
+endif
+endif
+
+obj-$(CONFIG_OF_UNITTEST) += unittest-data/
diff --git a/drivers/of/address.c b/drivers/of/address.c
new file mode 100644
index 000000000..67763e5b8
--- /dev/null
+++ b/drivers/of/address.c
@@ -0,0 +1,1111 @@
+// SPDX-License-Identifier: GPL-2.0
+#define pr_fmt(fmt)	"OF: " fmt
+
+#include <linux/device.h>
+#include <linux/fwnode.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/logic_pio.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/pci.h>
+#include <linux/pci_regs.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/dma-direct.h> /* for bus_dma_region */
+
+#include "of_private.h"
+
+/* Max address size we deal with */
+#define OF_MAX_ADDR_CELLS	4
+#define OF_CHECK_ADDR_COUNT(na)	((na) > 0 && (na) <= OF_MAX_ADDR_CELLS)
+#define OF_CHECK_COUNTS(na, ns)	(OF_CHECK_ADDR_COUNT(na) && (ns) > 0)
+
+static struct of_bus *of_match_bus(struct device_node *np);
+static int __of_address_to_resource(struct device_node *dev, int index,
+		int bar_no, struct resource *r);
+static bool of_mmio_is_nonposted(struct device_node *np);
+
+/* Debug utility */
+#ifdef DEBUG
+static void of_dump_addr(const char *s, const __be32 *addr, int na)
+{
+	pr_debug("%s", s);
+	while (na--)
+		pr_cont(" %08x", be32_to_cpu(*(addr++)));
+	pr_cont("\n");
+}
+#else
+static void of_dump_addr(const char *s, const __be32 *addr, int na) { }
+#endif
+
+/* Callbacks for bus specific translators */
+struct of_bus {
+	const char	*name;
+	const char	*addresses;
+	int		(*match)(struct device_node *parent);
+	void		(*count_cells)(struct device_node *child,
+				       int *addrc, int *sizec);
+	u64		(*map)(__be32 *addr, const __be32 *range,
+				int na, int ns, int pna);
+	int		(*translate)(__be32 *addr, u64 offset, int na);
+	bool	has_flags;
+	unsigned int	(*get_flags)(const __be32 *addr);
+};
+
+/*
+ * Default translator (generic bus)
+ */
+
+static void of_bus_default_count_cells(struct device_node *dev,
+				       int *addrc, int *sizec)
+{
+	if (addrc)
+		*addrc = of_n_addr_cells(dev);
+	if (sizec)
+		*sizec = of_n_size_cells(dev);
+}
+
+static u64 of_bus_default_map(__be32 *addr, const __be32 *range,
+		int na, int ns, int pna)
+{
+	u64 cp, s, da;
+
+	cp = of_read_number(range, na);
+	s  = of_read_number(range + na + pna, ns);
+	da = of_read_number(addr, na);
+
+	pr_debug("default map, cp=%llx, s=%llx, da=%llx\n", cp, s, da);
+
+	if (da < cp || da >= (cp + s))
+		return OF_BAD_ADDR;
+	return da - cp;
+}
+
+static int of_bus_default_translate(__be32 *addr, u64 offset, int na)
+{
+	u64 a = of_read_number(addr, na);
+	memset(addr, 0, na * 4);
+	a += offset;
+	if (na > 1)
+		addr[na - 2] = cpu_to_be32(a >> 32);
+	addr[na - 1] = cpu_to_be32(a & 0xffffffffu);
+
+	return 0;
+}
+
+static unsigned int of_bus_default_get_flags(const __be32 *addr)
+{
+	return IORESOURCE_MEM;
+}
+
+#ifdef CONFIG_PCI
+static unsigned int of_bus_pci_get_flags(const __be32 *addr)
+{
+	unsigned int flags = 0;
+	u32 w = be32_to_cpup(addr);
+
+	if (!IS_ENABLED(CONFIG_PCI))
+		return 0;
+
+	switch((w >> 24) & 0x03) {
+	case 0x01:
+		flags |= IORESOURCE_IO;
+		break;
+	case 0x02: /* 32 bits */
+		flags |= IORESOURCE_MEM;
+		break;
+
+	case 0x03: /* 64 bits */
+		flags |= IORESOURCE_MEM | IORESOURCE_MEM_64;
+		break;
+	}
+	if (w & 0x40000000)
+		flags |= IORESOURCE_PREFETCH;
+	return flags;
+}
+
+/*
+ * PCI bus specific translator
+ */
+
+static bool of_node_is_pcie(struct device_node *np)
+{
+	bool is_pcie = of_node_name_eq(np, "pcie");
+
+	if (is_pcie)
+		pr_warn_once("%pOF: Missing device_type\n", np);
+
+	return is_pcie;
+}
+
+static int of_bus_pci_match(struct device_node *np)
+{
+	/*
+ 	 * "pciex" is PCI Express
+	 * "vci" is for the /chaos bridge on 1st-gen PCI powermacs
+	 * "ht" is hypertransport
+	 *
+	 * If none of the device_type match, and that the node name is
+	 * "pcie", accept the device as PCI (with a warning).
+	 */
+	return of_node_is_type(np, "pci") || of_node_is_type(np, "pciex") ||
+		of_node_is_type(np, "vci") || of_node_is_type(np, "ht") ||
+		of_node_is_pcie(np);
+}
+
+static void of_bus_pci_count_cells(struct device_node *np,
+				   int *addrc, int *sizec)
+{
+	if (addrc)
+		*addrc = 3;
+	if (sizec)
+		*sizec = 2;
+}
+
+static u64 of_bus_pci_map(__be32 *addr, const __be32 *range, int na, int ns,
+		int pna)
+{
+	u64 cp, s, da;
+	unsigned int af, rf;
+
+	af = of_bus_pci_get_flags(addr);
+	rf = of_bus_pci_get_flags(range);
+
+	/* Check address type match */
+	if ((af ^ rf) & (IORESOURCE_MEM | IORESOURCE_IO))
+		return OF_BAD_ADDR;
+
+	/* Read address values, skipping high cell */
+	cp = of_read_number(range + 1, na - 1);
+	s  = of_read_number(range + na + pna, ns);
+	da = of_read_number(addr + 1, na - 1);
+
+	pr_debug("PCI map, cp=%llx, s=%llx, da=%llx\n", cp, s, da);
+
+	if (da < cp || da >= (cp + s))
+		return OF_BAD_ADDR;
+	return da - cp;
+}
+
+static int of_bus_pci_translate(__be32 *addr, u64 offset, int na)
+{
+	return of_bus_default_translate(addr + 1, offset, na - 1);
+}
+#endif /* CONFIG_PCI */
+
+int of_pci_address_to_resource(struct device_node *dev, int bar,
+			       struct resource *r)
+{
+
+	if (!IS_ENABLED(CONFIG_PCI))
+		return -ENOSYS;
+
+	return __of_address_to_resource(dev, -1, bar, r);
+}
+EXPORT_SYMBOL_GPL(of_pci_address_to_resource);
+
+/*
+ * of_pci_range_to_resource - Create a resource from an of_pci_range
+ * @range:	the PCI range that describes the resource
+ * @np:		device node where the range belongs to
+ * @res:	pointer to a valid resource that will be updated to
+ *              reflect the values contained in the range.
+ *
+ * Returns EINVAL if the range cannot be converted to resource.
+ *
+ * Note that if the range is an IO range, the resource will be converted
+ * using pci_address_to_pio() which can fail if it is called too early or
+ * if the range cannot be matched to any host bridge IO space (our case here).
+ * To guard against that we try to register the IO range first.
+ * If that fails we know that pci_address_to_pio() will do too.
+ */
+int of_pci_range_to_resource(struct of_pci_range *range,
+			     struct device_node *np, struct resource *res)
+{
+	int err;
+	res->flags = range->flags;
+	res->parent = res->child = res->sibling = NULL;
+	res->name = np->full_name;
+
+	if (!IS_ENABLED(CONFIG_PCI))
+		return -ENOSYS;
+
+	if (res->flags & IORESOURCE_IO) {
+		unsigned long port;
+		err = pci_register_io_range(&np->fwnode, range->cpu_addr,
+				range->size);
+		if (err)
+			goto invalid_range;
+		port = pci_address_to_pio(range->cpu_addr);
+		if (port == (unsigned long)-1) {
+			err = -EINVAL;
+			goto invalid_range;
+		}
+		res->start = port;
+	} else {
+		if ((sizeof(resource_size_t) < 8) &&
+		    upper_32_bits(range->cpu_addr)) {
+			err = -EINVAL;
+			goto invalid_range;
+		}
+
+		res->start = range->cpu_addr;
+	}
+	res->end = res->start + range->size - 1;
+	return 0;
+
+invalid_range:
+	res->start = (resource_size_t)OF_BAD_ADDR;
+	res->end = (resource_size_t)OF_BAD_ADDR;
+	return err;
+}
+EXPORT_SYMBOL(of_pci_range_to_resource);
+
+/*
+ * ISA bus specific translator
+ */
+
+static int of_bus_isa_match(struct device_node *np)
+{
+	return of_node_name_eq(np, "isa");
+}
+
+static void of_bus_isa_count_cells(struct device_node *child,
+				   int *addrc, int *sizec)
+{
+	if (addrc)
+		*addrc = 2;
+	if (sizec)
+		*sizec = 1;
+}
+
+static u64 of_bus_isa_map(__be32 *addr, const __be32 *range, int na, int ns,
+		int pna)
+{
+	u64 cp, s, da;
+
+	/* Check address type match */
+	if ((addr[0] ^ range[0]) & cpu_to_be32(1))
+		return OF_BAD_ADDR;
+
+	/* Read address values, skipping high cell */
+	cp = of_read_number(range + 1, na - 1);
+	s  = of_read_number(range + na + pna, ns);
+	da = of_read_number(addr + 1, na - 1);
+
+	pr_debug("ISA map, cp=%llx, s=%llx, da=%llx\n", cp, s, da);
+
+	if (da < cp || da >= (cp + s))
+		return OF_BAD_ADDR;
+	return da - cp;
+}
+
+static int of_bus_isa_translate(__be32 *addr, u64 offset, int na)
+{
+	return of_bus_default_translate(addr + 1, offset, na - 1);
+}
+
+static unsigned int of_bus_isa_get_flags(const __be32 *addr)
+{
+	unsigned int flags = 0;
+	u32 w = be32_to_cpup(addr);
+
+	if (w & 1)
+		flags |= IORESOURCE_IO;
+	else
+		flags |= IORESOURCE_MEM;
+	return flags;
+}
+
+/*
+ * Array of bus specific translators
+ */
+
+static struct of_bus of_busses[] = {
+#ifdef CONFIG_PCI
+	/* PCI */
+	{
+		.name = "pci",
+		.addresses = "assigned-addresses",
+		.match = of_bus_pci_match,
+		.count_cells = of_bus_pci_count_cells,
+		.map = of_bus_pci_map,
+		.translate = of_bus_pci_translate,
+		.has_flags = true,
+		.get_flags = of_bus_pci_get_flags,
+	},
+#endif /* CONFIG_PCI */
+	/* ISA */
+	{
+		.name = "isa",
+		.addresses = "reg",
+		.match = of_bus_isa_match,
+		.count_cells = of_bus_isa_count_cells,
+		.map = of_bus_isa_map,
+		.translate = of_bus_isa_translate,
+		.has_flags = true,
+		.get_flags = of_bus_isa_get_flags,
+	},
+	/* Default */
+	{
+		.name = "default",
+		.addresses = "reg",
+		.match = NULL,
+		.count_cells = of_bus_default_count_cells,
+		.map = of_bus_default_map,
+		.translate = of_bus_default_translate,
+		.get_flags = of_bus_default_get_flags,
+	},
+};
+
+static struct of_bus *of_match_bus(struct device_node *np)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(of_busses); i++)
+		if (!of_busses[i].match || of_busses[i].match(np))
+			return &of_busses[i];
+	BUG();
+	return NULL;
+}
+
+static int of_empty_ranges_quirk(struct device_node *np)
+{
+	if (IS_ENABLED(CONFIG_PPC)) {
+		/* To save cycles, we cache the result for global "Mac" setting */
+		static int quirk_state = -1;
+
+		/* PA-SEMI sdc DT bug */
+		if (of_device_is_compatible(np, "1682m-sdc"))
+			return true;
+
+		/* Make quirk cached */
+		if (quirk_state < 0)
+			quirk_state =
+				of_machine_is_compatible("Power Macintosh") ||
+				of_machine_is_compatible("MacRISC");
+		return quirk_state;
+	}
+	return false;
+}
+
+static int of_translate_one(struct device_node *parent, struct of_bus *bus,
+			    struct of_bus *pbus, __be32 *addr,
+			    int na, int ns, int pna, const char *rprop)
+{
+	const __be32 *ranges;
+	unsigned int rlen;
+	int rone;
+	u64 offset = OF_BAD_ADDR;
+
+	/*
+	 * Normally, an absence of a "ranges" property means we are
+	 * crossing a non-translatable boundary, and thus the addresses
+	 * below the current cannot be converted to CPU physical ones.
+	 * Unfortunately, while this is very clear in the spec, it's not
+	 * what Apple understood, and they do have things like /uni-n or
+	 * /ht nodes with no "ranges" property and a lot of perfectly
+	 * useable mapped devices below them. Thus we treat the absence of
+	 * "ranges" as equivalent to an empty "ranges" property which means
+	 * a 1:1 translation at that level. It's up to the caller not to try
+	 * to translate addresses that aren't supposed to be translated in
+	 * the first place. --BenH.
+	 *
+	 * As far as we know, this damage only exists on Apple machines, so
+	 * This code is only enabled on powerpc. --gcl
+	 *
+	 * This quirk also applies for 'dma-ranges' which frequently exist in
+	 * child nodes without 'dma-ranges' in the parent nodes. --RobH
+	 */
+	ranges = of_get_property(parent, rprop, &rlen);
+	if (ranges == NULL && !of_empty_ranges_quirk(parent) &&
+	    strcmp(rprop, "dma-ranges")) {
+		pr_debug("no ranges; cannot translate\n");
+		return 1;
+	}
+	if (ranges == NULL || rlen == 0) {
+		offset = of_read_number(addr, na);
+		memset(addr, 0, pna * 4);
+		pr_debug("empty ranges; 1:1 translation\n");
+		goto finish;
+	}
+
+	pr_debug("walking ranges...\n");
+
+	/* Now walk through the ranges */
+	rlen /= 4;
+	rone = na + pna + ns;
+	for (; rlen >= rone; rlen -= rone, ranges += rone) {
+		offset = bus->map(addr, ranges, na, ns, pna);
+		if (offset != OF_BAD_ADDR)
+			break;
+	}
+	if (offset == OF_BAD_ADDR) {
+		pr_debug("not found !\n");
+		return 1;
+	}
+	memcpy(addr, ranges + na, 4 * pna);
+
+ finish:
+	of_dump_addr("parent translation for:", addr, pna);
+	pr_debug("with offset: %llx\n", offset);
+
+	/* Translate it into parent bus space */
+	return pbus->translate(addr, offset, pna);
+}
+
+/*
+ * Translate an address from the device-tree into a CPU physical address,
+ * this walks up the tree and applies the various bus mappings on the
+ * way.
+ *
+ * Note: We consider that crossing any level with #size-cells == 0 to mean
+ * that translation is impossible (that is we are not dealing with a value
+ * that can be mapped to a cpu physical address). This is not really specified
+ * that way, but this is traditionally the way IBM at least do things
+ *
+ * Whenever the translation fails, the *host pointer will be set to the
+ * device that had registered logical PIO mapping, and the return code is
+ * relative to that node.
+ */
+static u64 __of_translate_address(struct device_node *dev,
+				  struct device_node *(*get_parent)(const struct device_node *),
+				  const __be32 *in_addr, const char *rprop,
+				  struct device_node **host)
+{
+	struct device_node *parent = NULL;
+	struct of_bus *bus, *pbus;
+	__be32 addr[OF_MAX_ADDR_CELLS];
+	int na, ns, pna, pns;
+	u64 result = OF_BAD_ADDR;
+
+	pr_debug("** translation for device %pOF **\n", dev);
+
+	/* Increase refcount at current level */
+	of_node_get(dev);
+
+	*host = NULL;
+	/* Get parent & match bus type */
+	parent = get_parent(dev);
+	if (parent == NULL)
+		goto bail;
+	bus = of_match_bus(parent);
+
+	/* Count address cells & copy address locally */
+	bus->count_cells(dev, &na, &ns);
+	if (!OF_CHECK_COUNTS(na, ns)) {
+		pr_debug("Bad cell count for %pOF\n", dev);
+		goto bail;
+	}
+	memcpy(addr, in_addr, na * 4);
+
+	pr_debug("bus is %s (na=%d, ns=%d) on %pOF\n",
+	    bus->name, na, ns, parent);
+	of_dump_addr("translating address:", addr, na);
+
+	/* Translate */
+	for (;;) {
+		struct logic_pio_hwaddr *iorange;
+
+		/* Switch to parent bus */
+		of_node_put(dev);
+		dev = parent;
+		parent = get_parent(dev);
+
+		/* If root, we have finished */
+		if (parent == NULL) {
+			pr_debug("reached root node\n");
+			result = of_read_number(addr, na);
+			break;
+		}
+
+		/*
+		 * For indirectIO device which has no ranges property, get
+		 * the address from reg directly.
+		 */
+		iorange = find_io_range_by_fwnode(&dev->fwnode);
+		if (iorange && (iorange->flags != LOGIC_PIO_CPU_MMIO)) {
+			result = of_read_number(addr + 1, na - 1);
+			pr_debug("indirectIO matched(%pOF) 0x%llx\n",
+				 dev, result);
+			*host = of_node_get(dev);
+			break;
+		}
+
+		/* Get new parent bus and counts */
+		pbus = of_match_bus(parent);
+		pbus->count_cells(dev, &pna, &pns);
+		if (!OF_CHECK_COUNTS(pna, pns)) {
+			pr_err("Bad cell count for %pOF\n", dev);
+			break;
+		}
+
+		pr_debug("parent bus is %s (na=%d, ns=%d) on %pOF\n",
+		    pbus->name, pna, pns, parent);
+
+		/* Apply bus translation */
+		if (of_translate_one(dev, bus, pbus, addr, na, ns, pna, rprop))
+			break;
+
+		/* Complete the move up one level */
+		na = pna;
+		ns = pns;
+		bus = pbus;
+
+		of_dump_addr("one level translation:", addr, na);
+	}
+ bail:
+	of_node_put(parent);
+	of_node_put(dev);
+
+	return result;
+}
+
+u64 of_translate_address(struct device_node *dev, const __be32 *in_addr)
+{
+	struct device_node *host;
+	u64 ret;
+
+	ret = __of_translate_address(dev, of_get_parent,
+				     in_addr, "ranges", &host);
+	if (host) {
+		of_node_put(host);
+		return OF_BAD_ADDR;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(of_translate_address);
+
+#ifdef CONFIG_HAS_DMA
+struct device_node *__of_get_dma_parent(const struct device_node *np)
+{
+	struct of_phandle_args args;
+	int ret, index;
+
+	index = of_property_match_string(np, "interconnect-names", "dma-mem");
+	if (index < 0)
+		return of_get_parent(np);
+
+	ret = of_parse_phandle_with_args(np, "interconnects",
+					 "#interconnect-cells",
+					 index, &args);
+	if (ret < 0)
+		return of_get_parent(np);
+
+	return of_node_get(args.np);
+}
+#endif
+
+static struct device_node *of_get_next_dma_parent(struct device_node *np)
+{
+	struct device_node *parent;
+
+	parent = __of_get_dma_parent(np);
+	of_node_put(np);
+
+	return parent;
+}
+
+u64 of_translate_dma_address(struct device_node *dev, const __be32 *in_addr)
+{
+	struct device_node *host;
+	u64 ret;
+
+	ret = __of_translate_address(dev, __of_get_dma_parent,
+				     in_addr, "dma-ranges", &host);
+
+	if (host) {
+		of_node_put(host);
+		return OF_BAD_ADDR;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(of_translate_dma_address);
+
+const __be32 *__of_get_address(struct device_node *dev, int index, int bar_no,
+			       u64 *size, unsigned int *flags)
+{
+	const __be32 *prop;
+	unsigned int psize;
+	struct device_node *parent;
+	struct of_bus *bus;
+	int onesize, i, na, ns;
+
+	/* Get parent & match bus type */
+	parent = of_get_parent(dev);
+	if (parent == NULL)
+		return NULL;
+	bus = of_match_bus(parent);
+	if (strcmp(bus->name, "pci") && (bar_no >= 0)) {
+		of_node_put(parent);
+		return NULL;
+	}
+	bus->count_cells(dev, &na, &ns);
+	of_node_put(parent);
+	if (!OF_CHECK_ADDR_COUNT(na))
+		return NULL;
+
+	/* Get "reg" or "assigned-addresses" property */
+	prop = of_get_property(dev, bus->addresses, &psize);
+	if (prop == NULL)
+		return NULL;
+	psize /= 4;
+
+	onesize = na + ns;
+	for (i = 0; psize >= onesize; psize -= onesize, prop += onesize, i++) {
+		u32 val = be32_to_cpu(prop[0]);
+		/* PCI bus matches on BAR number instead of index */
+		if (((bar_no >= 0) && ((val & 0xff) == ((bar_no * 4) + PCI_BASE_ADDRESS_0))) ||
+		    ((index >= 0) && (i == index))) {
+			if (size)
+				*size = of_read_number(prop + na, ns);
+			if (flags)
+				*flags = bus->get_flags(prop);
+			return prop;
+		}
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(__of_get_address);
+
+static int parser_init(struct of_pci_range_parser *parser,
+			struct device_node *node, const char *name)
+{
+	int rlen;
+
+	parser->node = node;
+	parser->pna = of_n_addr_cells(node);
+	parser->na = of_bus_n_addr_cells(node);
+	parser->ns = of_bus_n_size_cells(node);
+	parser->dma = !strcmp(name, "dma-ranges");
+	parser->bus = of_match_bus(node);
+
+	parser->range = of_get_property(node, name, &rlen);
+	if (parser->range == NULL)
+		return -ENOENT;
+
+	parser->end = parser->range + rlen / sizeof(__be32);
+
+	return 0;
+}
+
+int of_pci_range_parser_init(struct of_pci_range_parser *parser,
+				struct device_node *node)
+{
+	return parser_init(parser, node, "ranges");
+}
+EXPORT_SYMBOL_GPL(of_pci_range_parser_init);
+
+int of_pci_dma_range_parser_init(struct of_pci_range_parser *parser,
+				struct device_node *node)
+{
+	return parser_init(parser, node, "dma-ranges");
+}
+EXPORT_SYMBOL_GPL(of_pci_dma_range_parser_init);
+#define of_dma_range_parser_init of_pci_dma_range_parser_init
+
+struct of_pci_range *of_pci_range_parser_one(struct of_pci_range_parser *parser,
+						struct of_pci_range *range)
+{
+	int na = parser->na;
+	int ns = parser->ns;
+	int np = parser->pna + na + ns;
+	int busflag_na = 0;
+
+	if (!range)
+		return NULL;
+
+	if (!parser->range || parser->range + np > parser->end)
+		return NULL;
+
+	range->flags = parser->bus->get_flags(parser->range);
+
+	/* A extra cell for resource flags */
+	if (parser->bus->has_flags)
+		busflag_na = 1;
+
+	range->bus_addr = of_read_number(parser->range + busflag_na, na - busflag_na);
+
+	if (parser->dma)
+		range->cpu_addr = of_translate_dma_address(parser->node,
+				parser->range + na);
+	else
+		range->cpu_addr = of_translate_address(parser->node,
+				parser->range + na);
+	range->size = of_read_number(parser->range + parser->pna + na, ns);
+
+	parser->range += np;
+
+	/* Now consume following elements while they are contiguous */
+	while (parser->range + np <= parser->end) {
+		u32 flags = 0;
+		u64 bus_addr, cpu_addr, size;
+
+		flags = parser->bus->get_flags(parser->range);
+		bus_addr = of_read_number(parser->range + busflag_na, na - busflag_na);
+		if (parser->dma)
+			cpu_addr = of_translate_dma_address(parser->node,
+					parser->range + na);
+		else
+			cpu_addr = of_translate_address(parser->node,
+					parser->range + na);
+		size = of_read_number(parser->range + parser->pna + na, ns);
+
+		if (flags != range->flags)
+			break;
+		if (bus_addr != range->bus_addr + range->size ||
+		    cpu_addr != range->cpu_addr + range->size)
+			break;
+
+		range->size += size;
+		parser->range += np;
+	}
+
+	return range;
+}
+EXPORT_SYMBOL_GPL(of_pci_range_parser_one);
+
+static u64 of_translate_ioport(struct device_node *dev, const __be32 *in_addr,
+			u64 size)
+{
+	u64 taddr;
+	unsigned long port;
+	struct device_node *host;
+
+	taddr = __of_translate_address(dev, of_get_parent,
+				       in_addr, "ranges", &host);
+	if (host) {
+		/* host-specific port access */
+		port = logic_pio_trans_hwaddr(&host->fwnode, taddr, size);
+		of_node_put(host);
+	} else {
+		/* memory-mapped I/O range */
+		port = pci_address_to_pio(taddr);
+	}
+
+	if (port == (unsigned long)-1)
+		return OF_BAD_ADDR;
+
+	return port;
+}
+
+static int __of_address_to_resource(struct device_node *dev, int index, int bar_no,
+		struct resource *r)
+{
+	u64 taddr;
+	const __be32	*addrp;
+	u64		size;
+	unsigned int	flags;
+	const char	*name = NULL;
+
+	addrp = __of_get_address(dev, index, bar_no, &size, &flags);
+	if (addrp == NULL)
+		return -EINVAL;
+
+	/* Get optional "reg-names" property to add a name to a resource */
+	if (index >= 0)
+		of_property_read_string_index(dev, "reg-names",	index, &name);
+
+	if (flags & IORESOURCE_MEM)
+		taddr = of_translate_address(dev, addrp);
+	else if (flags & IORESOURCE_IO)
+		taddr = of_translate_ioport(dev, addrp, size);
+	else
+		return -EINVAL;
+
+	if (taddr == OF_BAD_ADDR)
+		return -EINVAL;
+	memset(r, 0, sizeof(struct resource));
+
+	if (of_mmio_is_nonposted(dev))
+		flags |= IORESOURCE_MEM_NONPOSTED;
+
+	r->start = taddr;
+	r->end = taddr + size - 1;
+	r->flags = flags;
+	r->name = name ? name : dev->full_name;
+
+	return 0;
+}
+
+/**
+ * of_address_to_resource - Translate device tree address and return as resource
+ * @dev:	Caller's Device Node
+ * @index:	Index into the array
+ * @r:		Pointer to resource array
+ *
+ * Note that if your address is a PIO address, the conversion will fail if
+ * the physical address can't be internally converted to an IO token with
+ * pci_address_to_pio(), that is because it's either called too early or it
+ * can't be matched to any host bridge IO space
+ */
+int of_address_to_resource(struct device_node *dev, int index,
+			   struct resource *r)
+{
+	return __of_address_to_resource(dev, index, -1, r);
+}
+EXPORT_SYMBOL_GPL(of_address_to_resource);
+
+/**
+ * of_iomap - Maps the memory mapped IO for a given device_node
+ * @np:		the device whose io range will be mapped
+ * @index:	index of the io range
+ *
+ * Returns a pointer to the mapped memory
+ */
+void __iomem *of_iomap(struct device_node *np, int index)
+{
+	struct resource res;
+
+	if (of_address_to_resource(np, index, &res))
+		return NULL;
+
+	if (res.flags & IORESOURCE_MEM_NONPOSTED)
+		return ioremap_np(res.start, resource_size(&res));
+	else
+		return ioremap(res.start, resource_size(&res));
+}
+EXPORT_SYMBOL(of_iomap);
+
+/*
+ * of_io_request_and_map - Requests a resource and maps the memory mapped IO
+ *			   for a given device_node
+ * @device:	the device whose io range will be mapped
+ * @index:	index of the io range
+ * @name:	name "override" for the memory region request or NULL
+ *
+ * Returns a pointer to the requested and mapped memory or an ERR_PTR() encoded
+ * error code on failure. Usage example:
+ *
+ *	base = of_io_request_and_map(node, 0, "foo");
+ *	if (IS_ERR(base))
+ *		return PTR_ERR(base);
+ */
+void __iomem *of_io_request_and_map(struct device_node *np, int index,
+				    const char *name)
+{
+	struct resource res;
+	void __iomem *mem;
+
+	if (of_address_to_resource(np, index, &res))
+		return IOMEM_ERR_PTR(-EINVAL);
+
+	if (!name)
+		name = res.name;
+	if (!request_mem_region(res.start, resource_size(&res), name))
+		return IOMEM_ERR_PTR(-EBUSY);
+
+	if (res.flags & IORESOURCE_MEM_NONPOSTED)
+		mem = ioremap_np(res.start, resource_size(&res));
+	else
+		mem = ioremap(res.start, resource_size(&res));
+
+	if (!mem) {
+		release_mem_region(res.start, resource_size(&res));
+		return IOMEM_ERR_PTR(-ENOMEM);
+	}
+
+	return mem;
+}
+EXPORT_SYMBOL(of_io_request_and_map);
+
+#ifdef CONFIG_HAS_DMA
+/**
+ * of_dma_get_range - Get DMA range info and put it into a map array
+ * @np:		device node to get DMA range info
+ * @map:	dma range structure to return
+ *
+ * Look in bottom up direction for the first "dma-ranges" property
+ * and parse it.  Put the information into a DMA offset map array.
+ *
+ * dma-ranges format:
+ *	DMA addr (dma_addr)	: naddr cells
+ *	CPU addr (phys_addr_t)	: pna cells
+ *	size			: nsize cells
+ *
+ * It returns -ENODEV if "dma-ranges" property was not found for this
+ * device in the DT.
+ */
+int of_dma_get_range(struct device_node *np, const struct bus_dma_region **map)
+{
+	struct device_node *node = of_node_get(np);
+	const __be32 *ranges = NULL;
+	bool found_dma_ranges = false;
+	struct of_range_parser parser;
+	struct of_range range;
+	struct bus_dma_region *r;
+	int len, num_ranges = 0;
+	int ret = 0;
+
+	while (node) {
+		ranges = of_get_property(node, "dma-ranges", &len);
+
+		/* Ignore empty ranges, they imply no translation required */
+		if (ranges && len > 0)
+			break;
+
+		/* Once we find 'dma-ranges', then a missing one is an error */
+		if (found_dma_ranges && !ranges) {
+			ret = -ENODEV;
+			goto out;
+		}
+		found_dma_ranges = true;
+
+		node = of_get_next_dma_parent(node);
+	}
+
+	if (!node || !ranges) {
+		pr_debug("no dma-ranges found for node(%pOF)\n", np);
+		ret = -ENODEV;
+		goto out;
+	}
+
+	of_dma_range_parser_init(&parser, node);
+	for_each_of_range(&parser, &range) {
+		if (range.cpu_addr == OF_BAD_ADDR) {
+			pr_err("translation of DMA address(%llx) to CPU address failed node(%pOF)\n",
+			       range.bus_addr, node);
+			continue;
+		}
+		num_ranges++;
+	}
+
+	if (!num_ranges) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	r = kcalloc(num_ranges + 1, sizeof(*r), GFP_KERNEL);
+	if (!r) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/*
+	 * Record all info in the generic DMA ranges array for struct device,
+	 * returning an error if we don't find any parsable ranges.
+	 */
+	*map = r;
+	of_dma_range_parser_init(&parser, node);
+	for_each_of_range(&parser, &range) {
+		pr_debug("dma_addr(%llx) cpu_addr(%llx) size(%llx)\n",
+			 range.bus_addr, range.cpu_addr, range.size);
+		if (range.cpu_addr == OF_BAD_ADDR)
+			continue;
+		r->cpu_start = range.cpu_addr;
+		r->dma_start = range.bus_addr;
+		r->size = range.size;
+		r->offset = range.cpu_addr - range.bus_addr;
+		r++;
+	}
+out:
+	of_node_put(node);
+	return ret;
+}
+#endif /* CONFIG_HAS_DMA */
+
+/**
+ * of_dma_get_max_cpu_address - Gets highest CPU address suitable for DMA
+ * @np: The node to start searching from or NULL to start from the root
+ *
+ * Gets the highest CPU physical address that is addressable by all DMA masters
+ * in the sub-tree pointed by np, or the whole tree if NULL is passed. If no
+ * DMA constrained device is found, it returns PHYS_ADDR_MAX.
+ */
+phys_addr_t __init of_dma_get_max_cpu_address(struct device_node *np)
+{
+	phys_addr_t max_cpu_addr = PHYS_ADDR_MAX;
+	struct of_range_parser parser;
+	phys_addr_t subtree_max_addr;
+	struct device_node *child;
+	struct of_range range;
+	const __be32 *ranges;
+	u64 cpu_end = 0;
+	int len;
+
+	if (!np)
+		np = of_root;
+
+	ranges = of_get_property(np, "dma-ranges", &len);
+	if (ranges && len) {
+		of_dma_range_parser_init(&parser, np);
+		for_each_of_range(&parser, &range)
+			if (range.cpu_addr + range.size > cpu_end)
+				cpu_end = range.cpu_addr + range.size - 1;
+
+		if (max_cpu_addr > cpu_end)
+			max_cpu_addr = cpu_end;
+	}
+
+	for_each_available_child_of_node(np, child) {
+		subtree_max_addr = of_dma_get_max_cpu_address(child);
+		if (max_cpu_addr > subtree_max_addr)
+			max_cpu_addr = subtree_max_addr;
+	}
+
+	return max_cpu_addr;
+}
+
+/**
+ * of_dma_is_coherent - Check if device is coherent
+ * @np:	device node
+ *
+ * It returns true if "dma-coherent" property was found
+ * for this device in the DT, or if DMA is coherent by
+ * default for OF devices on the current platform and no
+ * "dma-noncoherent" property was found for this device.
+ */
+bool of_dma_is_coherent(struct device_node *np)
+{
+	struct device_node *node;
+	bool is_coherent = IS_ENABLED(CONFIG_OF_DMA_DEFAULT_COHERENT);
+
+	node = of_node_get(np);
+
+	while (node) {
+		if (of_property_read_bool(node, "dma-coherent")) {
+			is_coherent = true;
+			break;
+		}
+		if (of_property_read_bool(node, "dma-noncoherent")) {
+			is_coherent = false;
+			break;
+		}
+		node = of_get_next_dma_parent(node);
+	}
+	of_node_put(node);
+	return is_coherent;
+}
+EXPORT_SYMBOL_GPL(of_dma_is_coherent);
+
+/**
+ * of_mmio_is_nonposted - Check if device uses non-posted MMIO
+ * @np:	device node
+ *
+ * Returns true if the "nonposted-mmio" property was found for
+ * the device's bus.
+ *
+ * This is currently only enabled on builds that support Apple ARM devices, as
+ * an optimization.
+ */
+static bool of_mmio_is_nonposted(struct device_node *np)
+{
+	struct device_node *parent;
+	bool nonposted;
+
+	if (!IS_ENABLED(CONFIG_ARCH_APPLE))
+		return false;
+
+	parent = of_get_parent(np);
+	if (!parent)
+		return false;
+
+	nonposted = of_property_read_bool(parent, "nonposted-mmio");
+
+	of_node_put(parent);
+	return nonposted;
+}
diff --git a/drivers/of/base.c b/drivers/of/base.c
new file mode 100644
index 000000000..f849bbb9e
--- /dev/null
+++ b/drivers/of/base.c
@@ -0,0 +1,2208 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Procedures for creating, accessing and interpreting the device tree.
+ *
+ * Paul Mackerras	August 1996.
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ *
+ *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
+ *    {engebret|bergner}@us.ibm.com
+ *
+ *  Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
+ *
+ *  Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
+ *  Grant Likely.
+ */
+
+#define pr_fmt(fmt)	"OF: " fmt
+
+#include <linux/console.h>
+#include <linux/ctype.h>
+#include <linux/cpu.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_graph.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/proc_fs.h>
+
+#include "of_private.h"
+
+LIST_HEAD(aliases_lookup);
+
+struct device_node *of_root;
+EXPORT_SYMBOL(of_root);
+struct device_node *of_chosen;
+EXPORT_SYMBOL(of_chosen);
+struct device_node *of_aliases;
+struct device_node *of_stdout;
+static const char *of_stdout_options;
+
+struct kset *of_kset;
+
+/*
+ * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
+ * This mutex must be held whenever modifications are being made to the
+ * device tree. The of_{attach,detach}_node() and
+ * of_{add,remove,update}_property() helpers make sure this happens.
+ */
+DEFINE_MUTEX(of_mutex);
+
+/* use when traversing tree through the child, sibling,
+ * or parent members of struct device_node.
+ */
+DEFINE_RAW_SPINLOCK(devtree_lock);
+
+bool of_node_name_eq(const struct device_node *np, const char *name)
+{
+	const char *node_name;
+	size_t len;
+
+	if (!np)
+		return false;
+
+	node_name = kbasename(np->full_name);
+	len = strchrnul(node_name, '@') - node_name;
+
+	return (strlen(name) == len) && (strncmp(node_name, name, len) == 0);
+}
+EXPORT_SYMBOL(of_node_name_eq);
+
+bool of_node_name_prefix(const struct device_node *np, const char *prefix)
+{
+	if (!np)
+		return false;
+
+	return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0;
+}
+EXPORT_SYMBOL(of_node_name_prefix);
+
+static bool __of_node_is_type(const struct device_node *np, const char *type)
+{
+	const char *match = __of_get_property(np, "device_type", NULL);
+
+	return np && match && type && !strcmp(match, type);
+}
+
+int of_bus_n_addr_cells(struct device_node *np)
+{
+	u32 cells;
+
+	for (; np; np = np->parent)
+		if (!of_property_read_u32(np, "#address-cells", &cells))
+			return cells;
+
+	/* No #address-cells property for the root node */
+	return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
+}
+
+int of_n_addr_cells(struct device_node *np)
+{
+	if (np->parent)
+		np = np->parent;
+
+	return of_bus_n_addr_cells(np);
+}
+EXPORT_SYMBOL(of_n_addr_cells);
+
+int of_bus_n_size_cells(struct device_node *np)
+{
+	u32 cells;
+
+	for (; np; np = np->parent)
+		if (!of_property_read_u32(np, "#size-cells", &cells))
+			return cells;
+
+	/* No #size-cells property for the root node */
+	return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
+}
+
+int of_n_size_cells(struct device_node *np)
+{
+	if (np->parent)
+		np = np->parent;
+
+	return of_bus_n_size_cells(np);
+}
+EXPORT_SYMBOL(of_n_size_cells);
+
+#ifdef CONFIG_NUMA
+int __weak of_node_to_nid(struct device_node *np)
+{
+	return NUMA_NO_NODE;
+}
+#endif
+
+#define OF_PHANDLE_CACHE_BITS	7
+#define OF_PHANDLE_CACHE_SZ	BIT(OF_PHANDLE_CACHE_BITS)
+
+static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ];
+
+static u32 of_phandle_cache_hash(phandle handle)
+{
+	return hash_32(handle, OF_PHANDLE_CACHE_BITS);
+}
+
+/*
+ * Caller must hold devtree_lock.
+ */
+void __of_phandle_cache_inv_entry(phandle handle)
+{
+	u32 handle_hash;
+	struct device_node *np;
+
+	if (!handle)
+		return;
+
+	handle_hash = of_phandle_cache_hash(handle);
+
+	np = phandle_cache[handle_hash];
+	if (np && handle == np->phandle)
+		phandle_cache[handle_hash] = NULL;
+}
+
+void __init of_core_init(void)
+{
+	struct device_node *np;
+
+
+	/* Create the kset, and register existing nodes */
+	mutex_lock(&of_mutex);
+	of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
+	if (!of_kset) {
+		mutex_unlock(&of_mutex);
+		pr_err("failed to register existing nodes\n");
+		return;
+	}
+	for_each_of_allnodes(np) {
+		__of_attach_node_sysfs(np);
+		if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
+			phandle_cache[of_phandle_cache_hash(np->phandle)] = np;
+	}
+	mutex_unlock(&of_mutex);
+
+	/* Symlink in /proc as required by userspace ABI */
+	if (of_root)
+		proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
+}
+
+static struct property *__of_find_property(const struct device_node *np,
+					   const char *name, int *lenp)
+{
+	struct property *pp;
+
+	if (!np)
+		return NULL;
+
+	for (pp = np->properties; pp; pp = pp->next) {
+		if (of_prop_cmp(pp->name, name) == 0) {
+			if (lenp)
+				*lenp = pp->length;
+			break;
+		}
+	}
+
+	return pp;
+}
+
+struct property *of_find_property(const struct device_node *np,
+				  const char *name,
+				  int *lenp)
+{
+	struct property *pp;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	pp = __of_find_property(np, name, lenp);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	return pp;
+}
+EXPORT_SYMBOL(of_find_property);
+
+struct device_node *__of_find_all_nodes(struct device_node *prev)
+{
+	struct device_node *np;
+	if (!prev) {
+		np = of_root;
+	} else if (prev->child) {
+		np = prev->child;
+	} else {
+		/* Walk back up looking for a sibling, or the end of the structure */
+		np = prev;
+		while (np->parent && !np->sibling)
+			np = np->parent;
+		np = np->sibling; /* Might be null at the end of the tree */
+	}
+	return np;
+}
+
+/**
+ * of_find_all_nodes - Get next node in global list
+ * @prev:	Previous node or NULL to start iteration
+ *		of_node_put() will be called on it
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_all_nodes(struct device_node *prev)
+{
+	struct device_node *np;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = __of_find_all_nodes(prev);
+	of_node_get(np);
+	of_node_put(prev);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_all_nodes);
+
+/*
+ * Find a property with a given name for a given node
+ * and return the value.
+ */
+const void *__of_get_property(const struct device_node *np,
+			      const char *name, int *lenp)
+{
+	struct property *pp = __of_find_property(np, name, lenp);
+
+	return pp ? pp->value : NULL;
+}
+
+/*
+ * Find a property with a given name for a given node
+ * and return the value.
+ */
+const void *of_get_property(const struct device_node *np, const char *name,
+			    int *lenp)
+{
+	struct property *pp = of_find_property(np, name, lenp);
+
+	return pp ? pp->value : NULL;
+}
+EXPORT_SYMBOL(of_get_property);
+
+/**
+ * of_get_cpu_hwid - Get the hardware ID from a CPU device node
+ *
+ * @cpun: CPU number(logical index) for which device node is required
+ * @thread: The local thread number to get the hardware ID for.
+ *
+ * Return: The hardware ID for the CPU node or ~0ULL if not found.
+ */
+u64 of_get_cpu_hwid(struct device_node *cpun, unsigned int thread)
+{
+	const __be32 *cell;
+	int ac, len;
+
+	ac = of_n_addr_cells(cpun);
+	cell = of_get_property(cpun, "reg", &len);
+	if (!cell || !ac || ((sizeof(*cell) * ac * (thread + 1)) > len))
+		return ~0ULL;
+
+	cell += ac * thread;
+	return of_read_number(cell, ac);
+}
+
+/*
+ * arch_match_cpu_phys_id - Match the given logical CPU and physical id
+ *
+ * @cpu: logical cpu index of a core/thread
+ * @phys_id: physical identifier of a core/thread
+ *
+ * CPU logical to physical index mapping is architecture specific.
+ * However this __weak function provides a default match of physical
+ * id to logical cpu index. phys_id provided here is usually values read
+ * from the device tree which must match the hardware internal registers.
+ *
+ * Returns true if the physical identifier and the logical cpu index
+ * correspond to the same core/thread, false otherwise.
+ */
+bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
+{
+	return (u32)phys_id == cpu;
+}
+
+/*
+ * Checks if the given "prop_name" property holds the physical id of the
+ * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
+ * NULL, local thread number within the core is returned in it.
+ */
+static bool __of_find_n_match_cpu_property(struct device_node *cpun,
+			const char *prop_name, int cpu, unsigned int *thread)
+{
+	const __be32 *cell;
+	int ac, prop_len, tid;
+	u64 hwid;
+
+	ac = of_n_addr_cells(cpun);
+	cell = of_get_property(cpun, prop_name, &prop_len);
+	if (!cell && !ac && arch_match_cpu_phys_id(cpu, 0))
+		return true;
+	if (!cell || !ac)
+		return false;
+	prop_len /= sizeof(*cell) * ac;
+	for (tid = 0; tid < prop_len; tid++) {
+		hwid = of_read_number(cell, ac);
+		if (arch_match_cpu_phys_id(cpu, hwid)) {
+			if (thread)
+				*thread = tid;
+			return true;
+		}
+		cell += ac;
+	}
+	return false;
+}
+
+/*
+ * arch_find_n_match_cpu_physical_id - See if the given device node is
+ * for the cpu corresponding to logical cpu 'cpu'.  Return true if so,
+ * else false.  If 'thread' is non-NULL, the local thread number within the
+ * core is returned in it.
+ */
+bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
+					      int cpu, unsigned int *thread)
+{
+	/* Check for non-standard "ibm,ppc-interrupt-server#s" property
+	 * for thread ids on PowerPC. If it doesn't exist fallback to
+	 * standard "reg" property.
+	 */
+	if (IS_ENABLED(CONFIG_PPC) &&
+	    __of_find_n_match_cpu_property(cpun,
+					   "ibm,ppc-interrupt-server#s",
+					   cpu, thread))
+		return true;
+
+	return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
+}
+
+/**
+ * of_get_cpu_node - Get device node associated with the given logical CPU
+ *
+ * @cpu: CPU number(logical index) for which device node is required
+ * @thread: if not NULL, local thread number within the physical core is
+ *          returned
+ *
+ * The main purpose of this function is to retrieve the device node for the
+ * given logical CPU index. It should be used to initialize the of_node in
+ * cpu device. Once of_node in cpu device is populated, all the further
+ * references can use that instead.
+ *
+ * CPU logical to physical index mapping is architecture specific and is built
+ * before booting secondary cores. This function uses arch_match_cpu_phys_id
+ * which can be overridden by architecture specific implementation.
+ *
+ * Return: A node pointer for the logical cpu with refcount incremented, use
+ * of_node_put() on it when done. Returns NULL if not found.
+ */
+struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
+{
+	struct device_node *cpun;
+
+	for_each_of_cpu_node(cpun) {
+		if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
+			return cpun;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(of_get_cpu_node);
+
+/**
+ * of_cpu_node_to_id: Get the logical CPU number for a given device_node
+ *
+ * @cpu_node: Pointer to the device_node for CPU.
+ *
+ * Return: The logical CPU number of the given CPU device_node or -ENODEV if the
+ * CPU is not found.
+ */
+int of_cpu_node_to_id(struct device_node *cpu_node)
+{
+	int cpu;
+	bool found = false;
+	struct device_node *np;
+
+	for_each_possible_cpu(cpu) {
+		np = of_cpu_device_node_get(cpu);
+		found = (cpu_node == np);
+		of_node_put(np);
+		if (found)
+			return cpu;
+	}
+
+	return -ENODEV;
+}
+EXPORT_SYMBOL(of_cpu_node_to_id);
+
+/**
+ * of_get_cpu_state_node - Get CPU's idle state node at the given index
+ *
+ * @cpu_node: The device node for the CPU
+ * @index: The index in the list of the idle states
+ *
+ * Two generic methods can be used to describe a CPU's idle states, either via
+ * a flattened description through the "cpu-idle-states" binding or via the
+ * hierarchical layout, using the "power-domains" and the "domain-idle-states"
+ * bindings. This function check for both and returns the idle state node for
+ * the requested index.
+ *
+ * Return: An idle state node if found at @index. The refcount is incremented
+ * for it, so call of_node_put() on it when done. Returns NULL if not found.
+ */
+struct device_node *of_get_cpu_state_node(struct device_node *cpu_node,
+					  int index)
+{
+	struct of_phandle_args args;
+	int err;
+
+	err = of_parse_phandle_with_args(cpu_node, "power-domains",
+					"#power-domain-cells", 0, &args);
+	if (!err) {
+		struct device_node *state_node =
+			of_parse_phandle(args.np, "domain-idle-states", index);
+
+		of_node_put(args.np);
+		if (state_node)
+			return state_node;
+	}
+
+	return of_parse_phandle(cpu_node, "cpu-idle-states", index);
+}
+EXPORT_SYMBOL(of_get_cpu_state_node);
+
+/**
+ * __of_device_is_compatible() - Check if the node matches given constraints
+ * @device: pointer to node
+ * @compat: required compatible string, NULL or "" for any match
+ * @type: required device_type value, NULL or "" for any match
+ * @name: required node name, NULL or "" for any match
+ *
+ * Checks if the given @compat, @type and @name strings match the
+ * properties of the given @device. A constraints can be skipped by
+ * passing NULL or an empty string as the constraint.
+ *
+ * Returns 0 for no match, and a positive integer on match. The return
+ * value is a relative score with larger values indicating better
+ * matches. The score is weighted for the most specific compatible value
+ * to get the highest score. Matching type is next, followed by matching
+ * name. Practically speaking, this results in the following priority
+ * order for matches:
+ *
+ * 1. specific compatible && type && name
+ * 2. specific compatible && type
+ * 3. specific compatible && name
+ * 4. specific compatible
+ * 5. general compatible && type && name
+ * 6. general compatible && type
+ * 7. general compatible && name
+ * 8. general compatible
+ * 9. type && name
+ * 10. type
+ * 11. name
+ */
+static int __of_device_is_compatible(const struct device_node *device,
+				     const char *compat, const char *type, const char *name)
+{
+	struct property *prop;
+	const char *cp;
+	int index = 0, score = 0;
+
+	/* Compatible match has highest priority */
+	if (compat && compat[0]) {
+		prop = __of_find_property(device, "compatible", NULL);
+		for (cp = of_prop_next_string(prop, NULL); cp;
+		     cp = of_prop_next_string(prop, cp), index++) {
+			if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
+				score = INT_MAX/2 - (index << 2);
+				break;
+			}
+		}
+		if (!score)
+			return 0;
+	}
+
+	/* Matching type is better than matching name */
+	if (type && type[0]) {
+		if (!__of_node_is_type(device, type))
+			return 0;
+		score += 2;
+	}
+
+	/* Matching name is a bit better than not */
+	if (name && name[0]) {
+		if (!of_node_name_eq(device, name))
+			return 0;
+		score++;
+	}
+
+	return score;
+}
+
+/** Checks if the given "compat" string matches one of the strings in
+ * the device's "compatible" property
+ */
+int of_device_is_compatible(const struct device_node *device,
+		const char *compat)
+{
+	unsigned long flags;
+	int res;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	res = __of_device_is_compatible(device, compat, NULL, NULL);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return res;
+}
+EXPORT_SYMBOL(of_device_is_compatible);
+
+/** Checks if the device is compatible with any of the entries in
+ *  a NULL terminated array of strings. Returns the best match
+ *  score or 0.
+ */
+int of_device_compatible_match(const struct device_node *device,
+			       const char *const *compat)
+{
+	unsigned int tmp, score = 0;
+
+	if (!compat)
+		return 0;
+
+	while (*compat) {
+		tmp = of_device_is_compatible(device, *compat);
+		if (tmp > score)
+			score = tmp;
+		compat++;
+	}
+
+	return score;
+}
+EXPORT_SYMBOL_GPL(of_device_compatible_match);
+
+/**
+ * of_machine_is_compatible - Test root of device tree for a given compatible value
+ * @compat: compatible string to look for in root node's compatible property.
+ *
+ * Return: A positive integer if the root node has the given value in its
+ * compatible property.
+ */
+int of_machine_is_compatible(const char *compat)
+{
+	struct device_node *root;
+	int rc = 0;
+
+	root = of_find_node_by_path("/");
+	if (root) {
+		rc = of_device_is_compatible(root, compat);
+		of_node_put(root);
+	}
+	return rc;
+}
+EXPORT_SYMBOL(of_machine_is_compatible);
+
+/**
+ *  __of_device_is_available - check if a device is available for use
+ *
+ *  @device: Node to check for availability, with locks already held
+ *
+ *  Return: True if the status property is absent or set to "okay" or "ok",
+ *  false otherwise
+ */
+static bool __of_device_is_available(const struct device_node *device)
+{
+	const char *status;
+	int statlen;
+
+	if (!device)
+		return false;
+
+	status = __of_get_property(device, "status", &statlen);
+	if (status == NULL)
+		return true;
+
+	if (statlen > 0) {
+		if (!strcmp(status, "okay") || !strcmp(status, "ok"))
+			return true;
+	}
+
+	return false;
+}
+
+/**
+ *  of_device_is_available - check if a device is available for use
+ *
+ *  @device: Node to check for availability
+ *
+ *  Return: True if the status property is absent or set to "okay" or "ok",
+ *  false otherwise
+ */
+bool of_device_is_available(const struct device_node *device)
+{
+	unsigned long flags;
+	bool res;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	res = __of_device_is_available(device);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return res;
+
+}
+EXPORT_SYMBOL(of_device_is_available);
+
+/**
+ *  __of_device_is_fail - check if a device has status "fail" or "fail-..."
+ *
+ *  @device: Node to check status for, with locks already held
+ *
+ *  Return: True if the status property is set to "fail" or "fail-..." (for any
+ *  error code suffix), false otherwise
+ */
+static bool __of_device_is_fail(const struct device_node *device)
+{
+	const char *status;
+
+	if (!device)
+		return false;
+
+	status = __of_get_property(device, "status", NULL);
+	if (status == NULL)
+		return false;
+
+	return !strcmp(status, "fail") || !strncmp(status, "fail-", 5);
+}
+
+/**
+ *  of_device_is_big_endian - check if a device has BE registers
+ *
+ *  @device: Node to check for endianness
+ *
+ *  Return: True if the device has a "big-endian" property, or if the kernel
+ *  was compiled for BE *and* the device has a "native-endian" property.
+ *  Returns false otherwise.
+ *
+ *  Callers would nominally use ioread32be/iowrite32be if
+ *  of_device_is_big_endian() == true, or readl/writel otherwise.
+ */
+bool of_device_is_big_endian(const struct device_node *device)
+{
+	if (of_property_read_bool(device, "big-endian"))
+		return true;
+	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
+	    of_property_read_bool(device, "native-endian"))
+		return true;
+	return false;
+}
+EXPORT_SYMBOL(of_device_is_big_endian);
+
+/**
+ * of_get_parent - Get a node's parent if any
+ * @node:	Node to get parent
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_get_parent(const struct device_node *node)
+{
+	struct device_node *np;
+	unsigned long flags;
+
+	if (!node)
+		return NULL;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np = of_node_get(node->parent);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_get_parent);
+
+/**
+ * of_get_next_parent - Iterate to a node's parent
+ * @node:	Node to get parent of
+ *
+ * This is like of_get_parent() except that it drops the
+ * refcount on the passed node, making it suitable for iterating
+ * through a node's parents.
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_get_next_parent(struct device_node *node)
+{
+	struct device_node *parent;
+	unsigned long flags;
+
+	if (!node)
+		return NULL;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	parent = of_node_get(node->parent);
+	of_node_put(node);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return parent;
+}
+EXPORT_SYMBOL(of_get_next_parent);
+
+static struct device_node *__of_get_next_child(const struct device_node *node,
+						struct device_node *prev)
+{
+	struct device_node *next;
+
+	if (!node)
+		return NULL;
+
+	next = prev ? prev->sibling : node->child;
+	of_node_get(next);
+	of_node_put(prev);
+	return next;
+}
+#define __for_each_child_of_node(parent, child) \
+	for (child = __of_get_next_child(parent, NULL); child != NULL; \
+	     child = __of_get_next_child(parent, child))
+
+/**
+ * of_get_next_child - Iterate a node childs
+ * @node:	parent node
+ * @prev:	previous child of the parent node, or NULL to get first
+ *
+ * Return: A node pointer with refcount incremented, use of_node_put() on
+ * it when done. Returns NULL when prev is the last child. Decrements the
+ * refcount of prev.
+ */
+struct device_node *of_get_next_child(const struct device_node *node,
+	struct device_node *prev)
+{
+	struct device_node *next;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	next = __of_get_next_child(node, prev);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return next;
+}
+EXPORT_SYMBOL(of_get_next_child);
+
+/**
+ * of_get_next_available_child - Find the next available child node
+ * @node:	parent node
+ * @prev:	previous child of the parent node, or NULL to get first
+ *
+ * This function is like of_get_next_child(), except that it
+ * automatically skips any disabled nodes (i.e. status = "disabled").
+ */
+struct device_node *of_get_next_available_child(const struct device_node *node,
+	struct device_node *prev)
+{
+	struct device_node *next;
+	unsigned long flags;
+
+	if (!node)
+		return NULL;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	next = prev ? prev->sibling : node->child;
+	for (; next; next = next->sibling) {
+		if (!__of_device_is_available(next))
+			continue;
+		if (of_node_get(next))
+			break;
+	}
+	of_node_put(prev);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return next;
+}
+EXPORT_SYMBOL(of_get_next_available_child);
+
+/**
+ * of_get_next_cpu_node - Iterate on cpu nodes
+ * @prev:	previous child of the /cpus node, or NULL to get first
+ *
+ * Unusable CPUs (those with the status property set to "fail" or "fail-...")
+ * will be skipped.
+ *
+ * Return: A cpu node pointer with refcount incremented, use of_node_put()
+ * on it when done. Returns NULL when prev is the last child. Decrements
+ * the refcount of prev.
+ */
+struct device_node *of_get_next_cpu_node(struct device_node *prev)
+{
+	struct device_node *next = NULL;
+	unsigned long flags;
+	struct device_node *node;
+
+	if (!prev)
+		node = of_find_node_by_path("/cpus");
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	if (prev)
+		next = prev->sibling;
+	else if (node) {
+		next = node->child;
+		of_node_put(node);
+	}
+	for (; next; next = next->sibling) {
+		if (__of_device_is_fail(next))
+			continue;
+		if (!(of_node_name_eq(next, "cpu") ||
+		      __of_node_is_type(next, "cpu")))
+			continue;
+		if (of_node_get(next))
+			break;
+	}
+	of_node_put(prev);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return next;
+}
+EXPORT_SYMBOL(of_get_next_cpu_node);
+
+/**
+ * of_get_compatible_child - Find compatible child node
+ * @parent:	parent node
+ * @compatible:	compatible string
+ *
+ * Lookup child node whose compatible property contains the given compatible
+ * string.
+ *
+ * Return: a node pointer with refcount incremented, use of_node_put() on it
+ * when done; or NULL if not found.
+ */
+struct device_node *of_get_compatible_child(const struct device_node *parent,
+				const char *compatible)
+{
+	struct device_node *child;
+
+	for_each_child_of_node(parent, child) {
+		if (of_device_is_compatible(child, compatible))
+			break;
+	}
+
+	return child;
+}
+EXPORT_SYMBOL(of_get_compatible_child);
+
+/**
+ * of_get_child_by_name - Find the child node by name for a given parent
+ * @node:	parent node
+ * @name:	child name to look for.
+ *
+ * This function looks for child node for given matching name
+ *
+ * Return: A node pointer if found, with refcount incremented, use
+ * of_node_put() on it when done.
+ * Returns NULL if node is not found.
+ */
+struct device_node *of_get_child_by_name(const struct device_node *node,
+				const char *name)
+{
+	struct device_node *child;
+
+	for_each_child_of_node(node, child)
+		if (of_node_name_eq(child, name))
+			break;
+	return child;
+}
+EXPORT_SYMBOL(of_get_child_by_name);
+
+struct device_node *__of_find_node_by_path(struct device_node *parent,
+						const char *path)
+{
+	struct device_node *child;
+	int len;
+
+	len = strcspn(path, "/:");
+	if (!len)
+		return NULL;
+
+	__for_each_child_of_node(parent, child) {
+		const char *name = kbasename(child->full_name);
+		if (strncmp(path, name, len) == 0 && (strlen(name) == len))
+			return child;
+	}
+	return NULL;
+}
+
+struct device_node *__of_find_node_by_full_path(struct device_node *node,
+						const char *path)
+{
+	const char *separator = strchr(path, ':');
+
+	while (node && *path == '/') {
+		struct device_node *tmp = node;
+
+		path++; /* Increment past '/' delimiter */
+		node = __of_find_node_by_path(node, path);
+		of_node_put(tmp);
+		path = strchrnul(path, '/');
+		if (separator && separator < path)
+			break;
+	}
+	return node;
+}
+
+/**
+ * of_find_node_opts_by_path - Find a node matching a full OF path
+ * @path: Either the full path to match, or if the path does not
+ *       start with '/', the name of a property of the /aliases
+ *       node (an alias).  In the case of an alias, the node
+ *       matching the alias' value will be returned.
+ * @opts: Address of a pointer into which to store the start of
+ *       an options string appended to the end of the path with
+ *       a ':' separator.
+ *
+ * Valid paths:
+ *  * /foo/bar	Full path
+ *  * foo	Valid alias
+ *  * foo/bar	Valid alias + relative path
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
+{
+	struct device_node *np = NULL;
+	struct property *pp;
+	unsigned long flags;
+	const char *separator = strchr(path, ':');
+
+	if (opts)
+		*opts = separator ? separator + 1 : NULL;
+
+	if (strcmp(path, "/") == 0)
+		return of_node_get(of_root);
+
+	/* The path could begin with an alias */
+	if (*path != '/') {
+		int len;
+		const char *p = separator;
+
+		if (!p)
+			p = strchrnul(path, '/');
+		len = p - path;
+
+		/* of_aliases must not be NULL */
+		if (!of_aliases)
+			return NULL;
+
+		for_each_property_of_node(of_aliases, pp) {
+			if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
+				np = of_find_node_by_path(pp->value);
+				break;
+			}
+		}
+		if (!np)
+			return NULL;
+		path = p;
+	}
+
+	/* Step down the tree matching path components */
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	if (!np)
+		np = of_node_get(of_root);
+	np = __of_find_node_by_full_path(np, path);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_opts_by_path);
+
+/**
+ * of_find_node_by_name - Find a node by its "name" property
+ * @from:	The node to start searching from or NULL; the node
+ *		you pass will not be searched, only the next one
+ *		will. Typically, you pass what the previous call
+ *		returned. of_node_put() will be called on @from.
+ * @name:	The name string to match against
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_node_by_name(struct device_node *from,
+	const char *name)
+{
+	struct device_node *np;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for_each_of_allnodes_from(from, np)
+		if (of_node_name_eq(np, name) && of_node_get(np))
+			break;
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_by_name);
+
+/**
+ * of_find_node_by_type - Find a node by its "device_type" property
+ * @from:	The node to start searching from, or NULL to start searching
+ *		the entire device tree. The node you pass will not be
+ *		searched, only the next one will; typically, you pass
+ *		what the previous call returned. of_node_put() will be
+ *		called on from for you.
+ * @type:	The type string to match against
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_node_by_type(struct device_node *from,
+	const char *type)
+{
+	struct device_node *np;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for_each_of_allnodes_from(from, np)
+		if (__of_node_is_type(np, type) && of_node_get(np))
+			break;
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_by_type);
+
+/**
+ * of_find_compatible_node - Find a node based on type and one of the
+ *                                tokens in its "compatible" property
+ * @from:	The node to start searching from or NULL, the node
+ *		you pass will not be searched, only the next one
+ *		will; typically, you pass what the previous call
+ *		returned. of_node_put() will be called on it
+ * @type:	The type string to match "device_type" or NULL to ignore
+ * @compatible:	The string to match to one of the tokens in the device
+ *		"compatible" list.
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_compatible_node(struct device_node *from,
+	const char *type, const char *compatible)
+{
+	struct device_node *np;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for_each_of_allnodes_from(from, np)
+		if (__of_device_is_compatible(np, compatible, type, NULL) &&
+		    of_node_get(np))
+			break;
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_compatible_node);
+
+/**
+ * of_find_node_with_property - Find a node which has a property with
+ *                              the given name.
+ * @from:	The node to start searching from or NULL, the node
+ *		you pass will not be searched, only the next one
+ *		will; typically, you pass what the previous call
+ *		returned. of_node_put() will be called on it
+ * @prop_name:	The name of the property to look for.
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_node_with_property(struct device_node *from,
+	const char *prop_name)
+{
+	struct device_node *np;
+	struct property *pp;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for_each_of_allnodes_from(from, np) {
+		for (pp = np->properties; pp; pp = pp->next) {
+			if (of_prop_cmp(pp->name, prop_name) == 0) {
+				of_node_get(np);
+				goto out;
+			}
+		}
+	}
+out:
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_with_property);
+
+static
+const struct of_device_id *__of_match_node(const struct of_device_id *matches,
+					   const struct device_node *node)
+{
+	const struct of_device_id *best_match = NULL;
+	int score, best_score = 0;
+
+	if (!matches)
+		return NULL;
+
+	for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
+		score = __of_device_is_compatible(node, matches->compatible,
+						  matches->type, matches->name);
+		if (score > best_score) {
+			best_match = matches;
+			best_score = score;
+		}
+	}
+
+	return best_match;
+}
+
+/**
+ * of_match_node - Tell if a device_node has a matching of_match structure
+ * @matches:	array of of device match structures to search in
+ * @node:	the of device structure to match against
+ *
+ * Low level utility function used by device matching.
+ */
+const struct of_device_id *of_match_node(const struct of_device_id *matches,
+					 const struct device_node *node)
+{
+	const struct of_device_id *match;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	match = __of_match_node(matches, node);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return match;
+}
+EXPORT_SYMBOL(of_match_node);
+
+/**
+ * of_find_matching_node_and_match - Find a node based on an of_device_id
+ *				     match table.
+ * @from:	The node to start searching from or NULL, the node
+ *		you pass will not be searched, only the next one
+ *		will; typically, you pass what the previous call
+ *		returned. of_node_put() will be called on it
+ * @matches:	array of of device match structures to search in
+ * @match:	Updated to point at the matches entry which matched
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_matching_node_and_match(struct device_node *from,
+					const struct of_device_id *matches,
+					const struct of_device_id **match)
+{
+	struct device_node *np;
+	const struct of_device_id *m;
+	unsigned long flags;
+
+	if (match)
+		*match = NULL;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for_each_of_allnodes_from(from, np) {
+		m = __of_match_node(matches, np);
+		if (m && of_node_get(np)) {
+			if (match)
+				*match = m;
+			break;
+		}
+	}
+	of_node_put(from);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_matching_node_and_match);
+
+/**
+ * of_modalias_node - Lookup appropriate modalias for a device node
+ * @node:	pointer to a device tree node
+ * @modalias:	Pointer to buffer that modalias value will be copied into
+ * @len:	Length of modalias value
+ *
+ * Based on the value of the compatible property, this routine will attempt
+ * to choose an appropriate modalias value for a particular device tree node.
+ * It does this by stripping the manufacturer prefix (as delimited by a ',')
+ * from the first entry in the compatible list property.
+ *
+ * Return: This routine returns 0 on success, <0 on failure.
+ */
+int of_modalias_node(struct device_node *node, char *modalias, int len)
+{
+	const char *compatible, *p;
+	int cplen;
+
+	compatible = of_get_property(node, "compatible", &cplen);
+	if (!compatible || strlen(compatible) > cplen)
+		return -ENODEV;
+	p = strchr(compatible, ',');
+	strscpy(modalias, p ? p + 1 : compatible, len);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_modalias_node);
+
+/**
+ * of_find_node_by_phandle - Find a node given a phandle
+ * @handle:	phandle of the node to find
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.
+ */
+struct device_node *of_find_node_by_phandle(phandle handle)
+{
+	struct device_node *np = NULL;
+	unsigned long flags;
+	u32 handle_hash;
+
+	if (!handle)
+		return NULL;
+
+	handle_hash = of_phandle_cache_hash(handle);
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+
+	if (phandle_cache[handle_hash] &&
+	    handle == phandle_cache[handle_hash]->phandle)
+		np = phandle_cache[handle_hash];
+
+	if (!np) {
+		for_each_of_allnodes(np)
+			if (np->phandle == handle &&
+			    !of_node_check_flag(np, OF_DETACHED)) {
+				phandle_cache[handle_hash] = np;
+				break;
+			}
+	}
+
+	of_node_get(np);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return np;
+}
+EXPORT_SYMBOL(of_find_node_by_phandle);
+
+void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
+{
+	int i;
+	printk("%s %pOF", msg, args->np);
+	for (i = 0; i < args->args_count; i++) {
+		const char delim = i ? ',' : ':';
+
+		pr_cont("%c%08x", delim, args->args[i]);
+	}
+	pr_cont("\n");
+}
+
+int of_phandle_iterator_init(struct of_phandle_iterator *it,
+		const struct device_node *np,
+		const char *list_name,
+		const char *cells_name,
+		int cell_count)
+{
+	const __be32 *list;
+	int size;
+
+	memset(it, 0, sizeof(*it));
+
+	/*
+	 * one of cell_count or cells_name must be provided to determine the
+	 * argument length.
+	 */
+	if (cell_count < 0 && !cells_name)
+		return -EINVAL;
+
+	list = of_get_property(np, list_name, &size);
+	if (!list)
+		return -ENOENT;
+
+	it->cells_name = cells_name;
+	it->cell_count = cell_count;
+	it->parent = np;
+	it->list_end = list + size / sizeof(*list);
+	it->phandle_end = list;
+	it->cur = list;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
+
+int of_phandle_iterator_next(struct of_phandle_iterator *it)
+{
+	uint32_t count = 0;
+
+	if (it->node) {
+		of_node_put(it->node);
+		it->node = NULL;
+	}
+
+	if (!it->cur || it->phandle_end >= it->list_end)
+		return -ENOENT;
+
+	it->cur = it->phandle_end;
+
+	/* If phandle is 0, then it is an empty entry with no arguments. */
+	it->phandle = be32_to_cpup(it->cur++);
+
+	if (it->phandle) {
+
+		/*
+		 * Find the provider node and parse the #*-cells property to
+		 * determine the argument length.
+		 */
+		it->node = of_find_node_by_phandle(it->phandle);
+
+		if (it->cells_name) {
+			if (!it->node) {
+				pr_err("%pOF: could not find phandle %d\n",
+				       it->parent, it->phandle);
+				goto err;
+			}
+
+			if (of_property_read_u32(it->node, it->cells_name,
+						 &count)) {
+				/*
+				 * If both cell_count and cells_name is given,
+				 * fall back to cell_count in absence
+				 * of the cells_name property
+				 */
+				if (it->cell_count >= 0) {
+					count = it->cell_count;
+				} else {
+					pr_err("%pOF: could not get %s for %pOF\n",
+					       it->parent,
+					       it->cells_name,
+					       it->node);
+					goto err;
+				}
+			}
+		} else {
+			count = it->cell_count;
+		}
+
+		/*
+		 * Make sure that the arguments actually fit in the remaining
+		 * property data length
+		 */
+		if (it->cur + count > it->list_end) {
+			if (it->cells_name)
+				pr_err("%pOF: %s = %d found %td\n",
+					it->parent, it->cells_name,
+					count, it->list_end - it->cur);
+			else
+				pr_err("%pOF: phandle %s needs %d, found %td\n",
+					it->parent, of_node_full_name(it->node),
+					count, it->list_end - it->cur);
+			goto err;
+		}
+	}
+
+	it->phandle_end = it->cur + count;
+	it->cur_count = count;
+
+	return 0;
+
+err:
+	if (it->node) {
+		of_node_put(it->node);
+		it->node = NULL;
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
+
+int of_phandle_iterator_args(struct of_phandle_iterator *it,
+			     uint32_t *args,
+			     int size)
+{
+	int i, count;
+
+	count = it->cur_count;
+
+	if (WARN_ON(size < count))
+		count = size;
+
+	for (i = 0; i < count; i++)
+		args[i] = be32_to_cpup(it->cur++);
+
+	return count;
+}
+
+int __of_parse_phandle_with_args(const struct device_node *np,
+				 const char *list_name,
+				 const char *cells_name,
+				 int cell_count, int index,
+				 struct of_phandle_args *out_args)
+{
+	struct of_phandle_iterator it;
+	int rc, cur_index = 0;
+
+	if (index < 0)
+		return -EINVAL;
+
+	/* Loop over the phandles until all the requested entry is found */
+	of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
+		/*
+		 * All of the error cases bail out of the loop, so at
+		 * this point, the parsing is successful. If the requested
+		 * index matches, then fill the out_args structure and return,
+		 * or return -ENOENT for an empty entry.
+		 */
+		rc = -ENOENT;
+		if (cur_index == index) {
+			if (!it.phandle)
+				goto err;
+
+			if (out_args) {
+				int c;
+
+				c = of_phandle_iterator_args(&it,
+							     out_args->args,
+							     MAX_PHANDLE_ARGS);
+				out_args->np = it.node;
+				out_args->args_count = c;
+			} else {
+				of_node_put(it.node);
+			}
+
+			/* Found it! return success */
+			return 0;
+		}
+
+		cur_index++;
+	}
+
+	/*
+	 * Unlock node before returning result; will be one of:
+	 * -ENOENT : index is for empty phandle
+	 * -EINVAL : parsing error on data
+	 */
+
+ err:
+	of_node_put(it.node);
+	return rc;
+}
+EXPORT_SYMBOL(__of_parse_phandle_with_args);
+
+/**
+ * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
+ * @np:		pointer to a device tree node containing a list
+ * @list_name:	property name that contains a list
+ * @stem_name:	stem of property names that specify phandles' arguments count
+ * @index:	index of a phandle to parse out
+ * @out_args:	optional pointer to output arguments structure (will be filled)
+ *
+ * This function is useful to parse lists of phandles and their arguments.
+ * Returns 0 on success and fills out_args, on error returns appropriate errno
+ * value. The difference between this function and of_parse_phandle_with_args()
+ * is that this API remaps a phandle if the node the phandle points to has
+ * a <@stem_name>-map property.
+ *
+ * Caller is responsible to call of_node_put() on the returned out_args->np
+ * pointer.
+ *
+ * Example::
+ *
+ *  phandle1: node1 {
+ *  	#list-cells = <2>;
+ *  };
+ *
+ *  phandle2: node2 {
+ *  	#list-cells = <1>;
+ *  };
+ *
+ *  phandle3: node3 {
+ *  	#list-cells = <1>;
+ *  	list-map = <0 &phandle2 3>,
+ *  		   <1 &phandle2 2>,
+ *  		   <2 &phandle1 5 1>;
+ *  	list-map-mask = <0x3>;
+ *  };
+ *
+ *  node4 {
+ *  	list = <&phandle1 1 2 &phandle3 0>;
+ *  };
+ *
+ * To get a device_node of the ``node2`` node you may call this:
+ * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
+ */
+int of_parse_phandle_with_args_map(const struct device_node *np,
+				   const char *list_name,
+				   const char *stem_name,
+				   int index, struct of_phandle_args *out_args)
+{
+	char *cells_name, *map_name = NULL, *mask_name = NULL;
+	char *pass_name = NULL;
+	struct device_node *cur, *new = NULL;
+	const __be32 *map, *mask, *pass;
+	static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
+	static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 };
+	__be32 initial_match_array[MAX_PHANDLE_ARGS];
+	const __be32 *match_array = initial_match_array;
+	int i, ret, map_len, match;
+	u32 list_size, new_size;
+
+	if (index < 0)
+		return -EINVAL;
+
+	cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
+	if (!cells_name)
+		return -ENOMEM;
+
+	ret = -ENOMEM;
+	map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
+	if (!map_name)
+		goto free;
+
+	mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
+	if (!mask_name)
+		goto free;
+
+	pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
+	if (!pass_name)
+		goto free;
+
+	ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
+					   out_args);
+	if (ret)
+		goto free;
+
+	/* Get the #<list>-cells property */
+	cur = out_args->np;
+	ret = of_property_read_u32(cur, cells_name, &list_size);
+	if (ret < 0)
+		goto put;
+
+	/* Precalculate the match array - this simplifies match loop */
+	for (i = 0; i < list_size; i++)
+		initial_match_array[i] = cpu_to_be32(out_args->args[i]);
+
+	ret = -EINVAL;
+	while (cur) {
+		/* Get the <list>-map property */
+		map = of_get_property(cur, map_name, &map_len);
+		if (!map) {
+			ret = 0;
+			goto free;
+		}
+		map_len /= sizeof(u32);
+
+		/* Get the <list>-map-mask property (optional) */
+		mask = of_get_property(cur, mask_name, NULL);
+		if (!mask)
+			mask = dummy_mask;
+		/* Iterate through <list>-map property */
+		match = 0;
+		while (map_len > (list_size + 1) && !match) {
+			/* Compare specifiers */
+			match = 1;
+			for (i = 0; i < list_size; i++, map_len--)
+				match &= !((match_array[i] ^ *map++) & mask[i]);
+
+			of_node_put(new);
+			new = of_find_node_by_phandle(be32_to_cpup(map));
+			map++;
+			map_len--;
+
+			/* Check if not found */
+			if (!new)
+				goto put;
+
+			if (!of_device_is_available(new))
+				match = 0;
+
+			ret = of_property_read_u32(new, cells_name, &new_size);
+			if (ret)
+				goto put;
+
+			/* Check for malformed properties */
+			if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
+				goto put;
+			if (map_len < new_size)
+				goto put;
+
+			/* Move forward by new node's #<list>-cells amount */
+			map += new_size;
+			map_len -= new_size;
+		}
+		if (!match)
+			goto put;
+
+		/* Get the <list>-map-pass-thru property (optional) */
+		pass = of_get_property(cur, pass_name, NULL);
+		if (!pass)
+			pass = dummy_pass;
+
+		/*
+		 * Successfully parsed a <list>-map translation; copy new
+		 * specifier into the out_args structure, keeping the
+		 * bits specified in <list>-map-pass-thru.
+		 */
+		match_array = map - new_size;
+		for (i = 0; i < new_size; i++) {
+			__be32 val = *(map - new_size + i);
+
+			if (i < list_size) {
+				val &= ~pass[i];
+				val |= cpu_to_be32(out_args->args[i]) & pass[i];
+			}
+
+			out_args->args[i] = be32_to_cpu(val);
+		}
+		out_args->args_count = list_size = new_size;
+		/* Iterate again with new provider */
+		out_args->np = new;
+		of_node_put(cur);
+		cur = new;
+		new = NULL;
+	}
+put:
+	of_node_put(cur);
+	of_node_put(new);
+free:
+	kfree(mask_name);
+	kfree(map_name);
+	kfree(cells_name);
+	kfree(pass_name);
+
+	return ret;
+}
+EXPORT_SYMBOL(of_parse_phandle_with_args_map);
+
+/**
+ * of_count_phandle_with_args() - Find the number of phandles references in a property
+ * @np:		pointer to a device tree node containing a list
+ * @list_name:	property name that contains a list
+ * @cells_name:	property name that specifies phandles' arguments count
+ *
+ * Return: The number of phandle + argument tuples within a property. It
+ * is a typical pattern to encode a list of phandle and variable
+ * arguments into a single property. The number of arguments is encoded
+ * by a property in the phandle-target node. For example, a gpios
+ * property would contain a list of GPIO specifies consisting of a
+ * phandle and 1 or more arguments. The number of arguments are
+ * determined by the #gpio-cells property in the node pointed to by the
+ * phandle.
+ */
+int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
+				const char *cells_name)
+{
+	struct of_phandle_iterator it;
+	int rc, cur_index = 0;
+
+	/*
+	 * If cells_name is NULL we assume a cell count of 0. This makes
+	 * counting the phandles trivial as each 32bit word in the list is a
+	 * phandle and no arguments are to consider. So we don't iterate through
+	 * the list but just use the length to determine the phandle count.
+	 */
+	if (!cells_name) {
+		const __be32 *list;
+		int size;
+
+		list = of_get_property(np, list_name, &size);
+		if (!list)
+			return -ENOENT;
+
+		return size / sizeof(*list);
+	}
+
+	rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
+	if (rc)
+		return rc;
+
+	while ((rc = of_phandle_iterator_next(&it)) == 0)
+		cur_index += 1;
+
+	if (rc != -ENOENT)
+		return rc;
+
+	return cur_index;
+}
+EXPORT_SYMBOL(of_count_phandle_with_args);
+
+/**
+ * __of_add_property - Add a property to a node without lock operations
+ * @np:		Caller's Device Node
+ * @prop:	Property to add
+ */
+int __of_add_property(struct device_node *np, struct property *prop)
+{
+	struct property **next;
+
+	prop->next = NULL;
+	next = &np->properties;
+	while (*next) {
+		if (strcmp(prop->name, (*next)->name) == 0)
+			/* duplicate ! don't insert it */
+			return -EEXIST;
+
+		next = &(*next)->next;
+	}
+	*next = prop;
+
+	return 0;
+}
+
+/**
+ * of_add_property - Add a property to a node
+ * @np:		Caller's Device Node
+ * @prop:	Property to add
+ */
+int of_add_property(struct device_node *np, struct property *prop)
+{
+	unsigned long flags;
+	int rc;
+
+	mutex_lock(&of_mutex);
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	rc = __of_add_property(np, prop);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	if (!rc)
+		__of_add_property_sysfs(np, prop);
+
+	mutex_unlock(&of_mutex);
+
+	if (!rc)
+		of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(of_add_property);
+
+int __of_remove_property(struct device_node *np, struct property *prop)
+{
+	struct property **next;
+
+	for (next = &np->properties; *next; next = &(*next)->next) {
+		if (*next == prop)
+			break;
+	}
+	if (*next == NULL)
+		return -ENODEV;
+
+	/* found the node */
+	*next = prop->next;
+	prop->next = np->deadprops;
+	np->deadprops = prop;
+
+	return 0;
+}
+
+/**
+ * of_remove_property - Remove a property from a node.
+ * @np:		Caller's Device Node
+ * @prop:	Property to remove
+ *
+ * Note that we don't actually remove it, since we have given out
+ * who-knows-how-many pointers to the data using get-property.
+ * Instead we just move the property to the "dead properties"
+ * list, so it won't be found any more.
+ */
+int of_remove_property(struct device_node *np, struct property *prop)
+{
+	unsigned long flags;
+	int rc;
+
+	if (!prop)
+		return -ENODEV;
+
+	mutex_lock(&of_mutex);
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	rc = __of_remove_property(np, prop);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	if (!rc)
+		__of_remove_property_sysfs(np, prop);
+
+	mutex_unlock(&of_mutex);
+
+	if (!rc)
+		of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(of_remove_property);
+
+int __of_update_property(struct device_node *np, struct property *newprop,
+		struct property **oldpropp)
+{
+	struct property **next, *oldprop;
+
+	for (next = &np->properties; *next; next = &(*next)->next) {
+		if (of_prop_cmp((*next)->name, newprop->name) == 0)
+			break;
+	}
+	*oldpropp = oldprop = *next;
+
+	if (oldprop) {
+		/* replace the node */
+		newprop->next = oldprop->next;
+		*next = newprop;
+		oldprop->next = np->deadprops;
+		np->deadprops = oldprop;
+	} else {
+		/* new node */
+		newprop->next = NULL;
+		*next = newprop;
+	}
+
+	return 0;
+}
+
+/*
+ * of_update_property - Update a property in a node, if the property does
+ * not exist, add it.
+ *
+ * Note that we don't actually remove it, since we have given out
+ * who-knows-how-many pointers to the data using get-property.
+ * Instead we just move the property to the "dead properties" list,
+ * and add the new property to the property list
+ */
+int of_update_property(struct device_node *np, struct property *newprop)
+{
+	struct property *oldprop;
+	unsigned long flags;
+	int rc;
+
+	if (!newprop->name)
+		return -EINVAL;
+
+	mutex_lock(&of_mutex);
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	rc = __of_update_property(np, newprop, &oldprop);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	if (!rc)
+		__of_update_property_sysfs(np, newprop, oldprop);
+
+	mutex_unlock(&of_mutex);
+
+	if (!rc)
+		of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
+
+	return rc;
+}
+
+static void of_alias_add(struct alias_prop *ap, struct device_node *np,
+			 int id, const char *stem, int stem_len)
+{
+	ap->np = np;
+	ap->id = id;
+	strncpy(ap->stem, stem, stem_len);
+	ap->stem[stem_len] = 0;
+	list_add_tail(&ap->link, &aliases_lookup);
+	pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
+		 ap->alias, ap->stem, ap->id, np);
+}
+
+/**
+ * of_alias_scan - Scan all properties of the 'aliases' node
+ * @dt_alloc:	An allocator that provides a virtual address to memory
+ *		for storing the resulting tree
+ *
+ * The function scans all the properties of the 'aliases' node and populates
+ * the global lookup table with the properties.  It returns the
+ * number of alias properties found, or an error code in case of failure.
+ */
+void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
+{
+	struct property *pp;
+
+	of_aliases = of_find_node_by_path("/aliases");
+	of_chosen = of_find_node_by_path("/chosen");
+	if (of_chosen == NULL)
+		of_chosen = of_find_node_by_path("/chosen@0");
+
+	if (of_chosen) {
+		/* linux,stdout-path and /aliases/stdout are for legacy compatibility */
+		const char *name = NULL;
+
+		if (of_property_read_string(of_chosen, "stdout-path", &name))
+			of_property_read_string(of_chosen, "linux,stdout-path",
+						&name);
+		if (IS_ENABLED(CONFIG_PPC) && !name)
+			of_property_read_string(of_aliases, "stdout", &name);
+		if (name)
+			of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
+		if (of_stdout)
+			of_stdout->fwnode.flags |= FWNODE_FLAG_BEST_EFFORT;
+	}
+
+	if (!of_aliases)
+		return;
+
+	for_each_property_of_node(of_aliases, pp) {
+		const char *start = pp->name;
+		const char *end = start + strlen(start);
+		struct device_node *np;
+		struct alias_prop *ap;
+		int id, len;
+
+		/* Skip those we do not want to proceed */
+		if (!strcmp(pp->name, "name") ||
+		    !strcmp(pp->name, "phandle") ||
+		    !strcmp(pp->name, "linux,phandle"))
+			continue;
+
+		np = of_find_node_by_path(pp->value);
+		if (!np)
+			continue;
+
+		/* walk the alias backwards to extract the id and work out
+		 * the 'stem' string */
+		while (isdigit(*(end-1)) && end > start)
+			end--;
+		len = end - start;
+
+		if (kstrtoint(end, 10, &id) < 0)
+			continue;
+
+		/* Allocate an alias_prop with enough space for the stem */
+		ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
+		if (!ap)
+			continue;
+		memset(ap, 0, sizeof(*ap) + len + 1);
+		ap->alias = start;
+		of_alias_add(ap, np, id, start, len);
+	}
+}
+
+/**
+ * of_alias_get_id - Get alias id for the given device_node
+ * @np:		Pointer to the given device_node
+ * @stem:	Alias stem of the given device_node
+ *
+ * The function travels the lookup table to get the alias id for the given
+ * device_node and alias stem.
+ *
+ * Return: The alias id if found.
+ */
+int of_alias_get_id(struct device_node *np, const char *stem)
+{
+	struct alias_prop *app;
+	int id = -ENODEV;
+
+	mutex_lock(&of_mutex);
+	list_for_each_entry(app, &aliases_lookup, link) {
+		if (strcmp(app->stem, stem) != 0)
+			continue;
+
+		if (np == app->np) {
+			id = app->id;
+			break;
+		}
+	}
+	mutex_unlock(&of_mutex);
+
+	return id;
+}
+EXPORT_SYMBOL_GPL(of_alias_get_id);
+
+/**
+ * of_alias_get_highest_id - Get highest alias id for the given stem
+ * @stem:	Alias stem to be examined
+ *
+ * The function travels the lookup table to get the highest alias id for the
+ * given alias stem.  It returns the alias id if found.
+ */
+int of_alias_get_highest_id(const char *stem)
+{
+	struct alias_prop *app;
+	int id = -ENODEV;
+
+	mutex_lock(&of_mutex);
+	list_for_each_entry(app, &aliases_lookup, link) {
+		if (strcmp(app->stem, stem) != 0)
+			continue;
+
+		if (app->id > id)
+			id = app->id;
+	}
+	mutex_unlock(&of_mutex);
+
+	return id;
+}
+EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
+
+/**
+ * of_console_check() - Test and setup console for DT setup
+ * @dn: Pointer to device node
+ * @name: Name to use for preferred console without index. ex. "ttyS"
+ * @index: Index to use for preferred console.
+ *
+ * Check if the given device node matches the stdout-path property in the
+ * /chosen node. If it does then register it as the preferred console.
+ *
+ * Return: TRUE if console successfully setup. Otherwise return FALSE.
+ */
+bool of_console_check(struct device_node *dn, char *name, int index)
+{
+	if (!dn || dn != of_stdout || console_set_on_cmdline)
+		return false;
+
+	/*
+	 * XXX: cast `options' to char pointer to suppress complication
+	 * warnings: printk, UART and console drivers expect char pointer.
+	 */
+	return !add_preferred_console(name, index, (char *)of_stdout_options);
+}
+EXPORT_SYMBOL_GPL(of_console_check);
+
+/**
+ * of_find_next_cache_node - Find a node's subsidiary cache
+ * @np:	node of type "cpu" or "cache"
+ *
+ * Return: A node pointer with refcount incremented, use
+ * of_node_put() on it when done.  Caller should hold a reference
+ * to np.
+ */
+struct device_node *of_find_next_cache_node(const struct device_node *np)
+{
+	struct device_node *child, *cache_node;
+
+	cache_node = of_parse_phandle(np, "l2-cache", 0);
+	if (!cache_node)
+		cache_node = of_parse_phandle(np, "next-level-cache", 0);
+
+	if (cache_node)
+		return cache_node;
+
+	/* OF on pmac has nodes instead of properties named "l2-cache"
+	 * beneath CPU nodes.
+	 */
+	if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu"))
+		for_each_child_of_node(np, child)
+			if (of_node_is_type(child, "cache"))
+				return child;
+
+	return NULL;
+}
+
+/**
+ * of_find_last_cache_level - Find the level at which the last cache is
+ * 		present for the given logical cpu
+ *
+ * @cpu: cpu number(logical index) for which the last cache level is needed
+ *
+ * Return: The level at which the last cache is present. It is exactly
+ * same as  the total number of cache levels for the given logical cpu.
+ */
+int of_find_last_cache_level(unsigned int cpu)
+{
+	u32 cache_level = 0;
+	struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
+
+	while (np) {
+		of_node_put(prev);
+		prev = np;
+		np = of_find_next_cache_node(np);
+	}
+
+	of_property_read_u32(prev, "cache-level", &cache_level);
+	of_node_put(prev);
+
+	return cache_level;
+}
+
+/**
+ * of_map_id - Translate an ID through a downstream mapping.
+ * @np: root complex device node.
+ * @id: device ID to map.
+ * @map_name: property name of the map to use.
+ * @map_mask_name: optional property name of the mask to use.
+ * @target: optional pointer to a target device node.
+ * @id_out: optional pointer to receive the translated ID.
+ *
+ * Given a device ID, look up the appropriate implementation-defined
+ * platform ID and/or the target device which receives transactions on that
+ * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
+ * @id_out may be NULL if only the other is required. If @target points to
+ * a non-NULL device node pointer, only entries targeting that node will be
+ * matched; if it points to a NULL value, it will receive the device node of
+ * the first matching target phandle, with a reference held.
+ *
+ * Return: 0 on success or a standard error code on failure.
+ */
+int of_map_id(struct device_node *np, u32 id,
+	       const char *map_name, const char *map_mask_name,
+	       struct device_node **target, u32 *id_out)
+{
+	u32 map_mask, masked_id;
+	int map_len;
+	const __be32 *map = NULL;
+
+	if (!np || !map_name || (!target && !id_out))
+		return -EINVAL;
+
+	map = of_get_property(np, map_name, &map_len);
+	if (!map) {
+		if (target)
+			return -ENODEV;
+		/* Otherwise, no map implies no translation */
+		*id_out = id;
+		return 0;
+	}
+
+	if (!map_len || map_len % (4 * sizeof(*map))) {
+		pr_err("%pOF: Error: Bad %s length: %d\n", np,
+			map_name, map_len);
+		return -EINVAL;
+	}
+
+	/* The default is to select all bits. */
+	map_mask = 0xffffffff;
+
+	/*
+	 * Can be overridden by "{iommu,msi}-map-mask" property.
+	 * If of_property_read_u32() fails, the default is used.
+	 */
+	if (map_mask_name)
+		of_property_read_u32(np, map_mask_name, &map_mask);
+
+	masked_id = map_mask & id;
+	for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
+		struct device_node *phandle_node;
+		u32 id_base = be32_to_cpup(map + 0);
+		u32 phandle = be32_to_cpup(map + 1);
+		u32 out_base = be32_to_cpup(map + 2);
+		u32 id_len = be32_to_cpup(map + 3);
+
+		if (id_base & ~map_mask) {
+			pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n",
+				np, map_name, map_name,
+				map_mask, id_base);
+			return -EFAULT;
+		}
+
+		if (masked_id < id_base || masked_id >= id_base + id_len)
+			continue;
+
+		phandle_node = of_find_node_by_phandle(phandle);
+		if (!phandle_node)
+			return -ENODEV;
+
+		if (target) {
+			if (*target)
+				of_node_put(phandle_node);
+			else
+				*target = phandle_node;
+
+			if (*target != phandle_node)
+				continue;
+		}
+
+		if (id_out)
+			*id_out = masked_id - id_base + out_base;
+
+		pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
+			np, map_name, map_mask, id_base, out_base,
+			id_len, id, masked_id - id_base + out_base);
+		return 0;
+	}
+
+	pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
+		id, target && *target ? *target : NULL);
+
+	/* Bypasses translation */
+	if (id_out)
+		*id_out = id;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_map_id);
diff --git a/drivers/of/device.c b/drivers/of/device.c
new file mode 100644
index 000000000..ce225d259
--- /dev/null
+++ b/drivers/of/device.c
@@ -0,0 +1,397 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/of_iommu.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/dma-direct.h> /* for bus_dma_region */
+#include <linux/dma-map-ops.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+
+#include <asm/errno.h>
+#include "of_private.h"
+
+/**
+ * of_match_device - Tell if a struct device matches an of_device_id list
+ * @matches: array of of device match structures to search in
+ * @dev: the of device structure to match against
+ *
+ * Used by a driver to check whether an platform_device present in the
+ * system is in its list of supported devices.
+ */
+const struct of_device_id *of_match_device(const struct of_device_id *matches,
+					   const struct device *dev)
+{
+	if (!matches || !dev->of_node || dev->of_node_reused)
+		return NULL;
+	return of_match_node(matches, dev->of_node);
+}
+EXPORT_SYMBOL(of_match_device);
+
+int of_device_add(struct platform_device *ofdev)
+{
+	BUG_ON(ofdev->dev.of_node == NULL);
+
+	/* name and id have to be set so that the platform bus doesn't get
+	 * confused on matching */
+	ofdev->name = dev_name(&ofdev->dev);
+	ofdev->id = PLATFORM_DEVID_NONE;
+
+	/*
+	 * If this device has not binding numa node in devicetree, that is
+	 * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this
+	 * device is on the same node as the parent.
+	 */
+	set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
+
+	return device_add(&ofdev->dev);
+}
+
+static void
+of_dma_set_restricted_buffer(struct device *dev, struct device_node *np)
+{
+	struct device_node *node, *of_node = dev->of_node;
+	int count, i;
+
+	if (!IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL))
+		return;
+
+	count = of_property_count_elems_of_size(of_node, "memory-region",
+						sizeof(u32));
+	/*
+	 * If dev->of_node doesn't exist or doesn't contain memory-region, try
+	 * the OF node having DMA configuration.
+	 */
+	if (count <= 0) {
+		of_node = np;
+		count = of_property_count_elems_of_size(
+			of_node, "memory-region", sizeof(u32));
+	}
+
+	for (i = 0; i < count; i++) {
+		node = of_parse_phandle(of_node, "memory-region", i);
+		/*
+		 * There might be multiple memory regions, but only one
+		 * restricted-dma-pool region is allowed.
+		 */
+		if (of_device_is_compatible(node, "restricted-dma-pool") &&
+		    of_device_is_available(node)) {
+			of_node_put(node);
+			break;
+		}
+		of_node_put(node);
+	}
+
+	/*
+	 * Attempt to initialize a restricted-dma-pool region if one was found.
+	 * Note that count can hold a negative error code.
+	 */
+	if (i < count && of_reserved_mem_device_init_by_idx(dev, of_node, i))
+		dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n");
+}
+
+/**
+ * of_dma_configure_id - Setup DMA configuration
+ * @dev:	Device to apply DMA configuration
+ * @np:		Pointer to OF node having DMA configuration
+ * @force_dma:  Whether device is to be set up by of_dma_configure() even if
+ *		DMA capability is not explicitly described by firmware.
+ * @id:		Optional const pointer value input id
+ *
+ * Try to get devices's DMA configuration from DT and update it
+ * accordingly.
+ *
+ * If platform code needs to use its own special DMA configuration, it
+ * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
+ * to fix up DMA configuration.
+ */
+int of_dma_configure_id(struct device *dev, struct device_node *np,
+			bool force_dma, const u32 *id)
+{
+	const struct iommu_ops *iommu;
+	const struct bus_dma_region *map = NULL;
+	struct device_node *bus_np;
+	u64 dma_start = 0;
+	u64 mask, end, size = 0;
+	bool coherent;
+	int ret;
+
+	if (np == dev->of_node)
+		bus_np = __of_get_dma_parent(np);
+	else
+		bus_np = of_node_get(np);
+
+	ret = of_dma_get_range(bus_np, &map);
+	of_node_put(bus_np);
+	if (ret < 0) {
+		/*
+		 * For legacy reasons, we have to assume some devices need
+		 * DMA configuration regardless of whether "dma-ranges" is
+		 * correctly specified or not.
+		 */
+		if (!force_dma)
+			return ret == -ENODEV ? 0 : ret;
+	} else {
+		const struct bus_dma_region *r = map;
+		u64 dma_end = 0;
+
+		/* Determine the overall bounds of all DMA regions */
+		for (dma_start = ~0; r->size; r++) {
+			/* Take lower and upper limits */
+			if (r->dma_start < dma_start)
+				dma_start = r->dma_start;
+			if (r->dma_start + r->size > dma_end)
+				dma_end = r->dma_start + r->size;
+		}
+		size = dma_end - dma_start;
+
+		/*
+		 * Add a work around to treat the size as mask + 1 in case
+		 * it is defined in DT as a mask.
+		 */
+		if (size & 1) {
+			dev_warn(dev, "Invalid size 0x%llx for dma-range(s)\n",
+				 size);
+			size = size + 1;
+		}
+
+		if (!size) {
+			dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
+			kfree(map);
+			return -EINVAL;
+		}
+	}
+
+	/*
+	 * If @dev is expected to be DMA-capable then the bus code that created
+	 * it should have initialised its dma_mask pointer by this point. For
+	 * now, we'll continue the legacy behaviour of coercing it to the
+	 * coherent mask if not, but we'll no longer do so quietly.
+	 */
+	if (!dev->dma_mask) {
+		dev_warn(dev, "DMA mask not set\n");
+		dev->dma_mask = &dev->coherent_dma_mask;
+	}
+
+	if (!size && dev->coherent_dma_mask)
+		size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
+	else if (!size)
+		size = 1ULL << 32;
+
+	/*
+	 * Limit coherent and dma mask based on size and default mask
+	 * set by the driver.
+	 */
+	end = dma_start + size - 1;
+	mask = DMA_BIT_MASK(ilog2(end) + 1);
+	dev->coherent_dma_mask &= mask;
+	*dev->dma_mask &= mask;
+	/* ...but only set bus limit and range map if we found valid dma-ranges earlier */
+	if (!ret) {
+		dev->bus_dma_limit = end;
+		dev->dma_range_map = map;
+	}
+
+	coherent = of_dma_is_coherent(np);
+	dev_dbg(dev, "device is%sdma coherent\n",
+		coherent ? " " : " not ");
+
+	iommu = of_iommu_configure(dev, np, id);
+	if (PTR_ERR(iommu) == -EPROBE_DEFER) {
+		/* Don't touch range map if it wasn't set from a valid dma-ranges */
+		if (!ret)
+			dev->dma_range_map = NULL;
+		kfree(map);
+		return -EPROBE_DEFER;
+	}
+
+	dev_dbg(dev, "device is%sbehind an iommu\n",
+		iommu ? " " : " not ");
+
+	arch_setup_dma_ops(dev, dma_start, size, iommu, coherent);
+
+	if (!iommu)
+		of_dma_set_restricted_buffer(dev, np);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_dma_configure_id);
+
+int of_device_register(struct platform_device *pdev)
+{
+	device_initialize(&pdev->dev);
+	return of_device_add(pdev);
+}
+EXPORT_SYMBOL(of_device_register);
+
+void of_device_unregister(struct platform_device *ofdev)
+{
+	device_unregister(&ofdev->dev);
+}
+EXPORT_SYMBOL(of_device_unregister);
+
+const void *of_device_get_match_data(const struct device *dev)
+{
+	const struct of_device_id *match;
+
+	match = of_match_device(dev->driver->of_match_table, dev);
+	if (!match)
+		return NULL;
+
+	return match->data;
+}
+EXPORT_SYMBOL(of_device_get_match_data);
+
+static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
+{
+	const char *compat;
+	char *c;
+	struct property *p;
+	ssize_t csize;
+	ssize_t tsize;
+
+	if ((!dev) || (!dev->of_node))
+		return -ENODEV;
+
+	/* Name & Type */
+	/* %p eats all alphanum characters, so %c must be used here */
+	csize = snprintf(str, len, "of:N%pOFn%c%s", dev->of_node, 'T',
+			 of_node_get_device_type(dev->of_node));
+	tsize = csize;
+	len -= csize;
+	if (str)
+		str += csize;
+
+	of_property_for_each_string(dev->of_node, "compatible", p, compat) {
+		csize = strlen(compat) + 1;
+		tsize += csize;
+		if (csize > len)
+			continue;
+
+		csize = snprintf(str, len, "C%s", compat);
+		for (c = str; c; ) {
+			c = strchr(c, ' ');
+			if (c)
+				*c++ = '_';
+		}
+		len -= csize;
+		str += csize;
+	}
+
+	return tsize;
+}
+
+int of_device_request_module(struct device *dev)
+{
+	char *str;
+	ssize_t size;
+	int ret;
+
+	size = of_device_get_modalias(dev, NULL, 0);
+	if (size < 0)
+		return size;
+
+	/* Reserve an additional byte for the trailing '\0' */
+	size++;
+
+	str = kmalloc(size, GFP_KERNEL);
+	if (!str)
+		return -ENOMEM;
+
+	of_device_get_modalias(dev, str, size);
+	str[size - 1] = '\0';
+	ret = request_module(str);
+	kfree(str);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_device_request_module);
+
+/**
+ * of_device_modalias - Fill buffer with newline terminated modalias string
+ * @dev:	Calling device
+ * @str:	Modalias string
+ * @len:	Size of @str
+ */
+ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
+{
+	ssize_t sl = of_device_get_modalias(dev, str, len - 2);
+	if (sl < 0)
+		return sl;
+	if (sl > len - 2)
+		return -ENOMEM;
+
+	str[sl++] = '\n';
+	str[sl] = 0;
+	return sl;
+}
+EXPORT_SYMBOL_GPL(of_device_modalias);
+
+/**
+ * of_device_uevent - Display OF related uevent information
+ * @dev:	Device to apply DMA configuration
+ * @env:	Kernel object's userspace event reference
+ */
+void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	const char *compat, *type;
+	struct alias_prop *app;
+	struct property *p;
+	int seen = 0;
+
+	if ((!dev) || (!dev->of_node))
+		return;
+
+	add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node);
+	add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node);
+	type = of_node_get_device_type(dev->of_node);
+	if (type)
+		add_uevent_var(env, "OF_TYPE=%s", type);
+
+	/* Since the compatible field can contain pretty much anything
+	 * it's not really legal to split it out with commas. We split it
+	 * up using a number of environment variables instead. */
+	of_property_for_each_string(dev->of_node, "compatible", p, compat) {
+		add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
+		seen++;
+	}
+	add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
+
+	seen = 0;
+	mutex_lock(&of_mutex);
+	list_for_each_entry(app, &aliases_lookup, link) {
+		if (dev->of_node == app->np) {
+			add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
+				       app->alias);
+			seen++;
+		}
+	}
+	mutex_unlock(&of_mutex);
+}
+
+int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
+{
+	int sl;
+
+	if ((!dev) || (!dev->of_node))
+		return -ENODEV;
+
+	/* Devicetree modalias is tricky, we add it in 2 steps */
+	if (add_uevent_var(env, "MODALIAS="))
+		return -ENOMEM;
+
+	sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
+				    sizeof(env->buf) - env->buflen);
+	if (sl >= (sizeof(env->buf) - env->buflen))
+		return -ENOMEM;
+	env->buflen += sl;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_device_uevent_modalias);
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
new file mode 100644
index 000000000..9bb9fe0fa
--- /dev/null
+++ b/drivers/of/dynamic.c
@@ -0,0 +1,925 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Support for dynamic device trees.
+ *
+ * On some platforms, the device tree can be manipulated at runtime.
+ * The routines in this section support adding, removing and changing
+ * device tree nodes.
+ */
+
+#define pr_fmt(fmt)	"OF: " fmt
+
+#include <linux/of.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/proc_fs.h>
+
+#include "of_private.h"
+
+static struct device_node *kobj_to_device_node(struct kobject *kobj)
+{
+	return container_of(kobj, struct device_node, kobj);
+}
+
+/**
+ * of_node_get() - Increment refcount of a node
+ * @node:	Node to inc refcount, NULL is supported to simplify writing of
+ *		callers
+ *
+ * Return: The node with refcount incremented.
+ */
+struct device_node *of_node_get(struct device_node *node)
+{
+	if (node)
+		kobject_get(&node->kobj);
+	return node;
+}
+EXPORT_SYMBOL(of_node_get);
+
+/**
+ * of_node_put() - Decrement refcount of a node
+ * @node:	Node to dec refcount, NULL is supported to simplify writing of
+ *		callers
+ */
+void of_node_put(struct device_node *node)
+{
+	if (node)
+		kobject_put(&node->kobj);
+}
+EXPORT_SYMBOL(of_node_put);
+
+static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
+
+int of_reconfig_notifier_register(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&of_reconfig_chain, nb);
+}
+EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
+
+int of_reconfig_notifier_unregister(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
+}
+EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
+
+static const char *action_names[] = {
+	[0] = "INVALID",
+	[OF_RECONFIG_ATTACH_NODE] = "ATTACH_NODE",
+	[OF_RECONFIG_DETACH_NODE] = "DETACH_NODE",
+	[OF_RECONFIG_ADD_PROPERTY] = "ADD_PROPERTY",
+	[OF_RECONFIG_REMOVE_PROPERTY] = "REMOVE_PROPERTY",
+	[OF_RECONFIG_UPDATE_PROPERTY] = "UPDATE_PROPERTY",
+};
+
+int of_reconfig_notify(unsigned long action, struct of_reconfig_data *p)
+{
+	int rc;
+#ifdef DEBUG
+	struct of_reconfig_data *pr = p;
+
+	switch (action) {
+	case OF_RECONFIG_ATTACH_NODE:
+	case OF_RECONFIG_DETACH_NODE:
+		pr_debug("notify %-15s %pOF\n", action_names[action],
+			pr->dn);
+		break;
+	case OF_RECONFIG_ADD_PROPERTY:
+	case OF_RECONFIG_REMOVE_PROPERTY:
+	case OF_RECONFIG_UPDATE_PROPERTY:
+		pr_debug("notify %-15s %pOF:%s\n", action_names[action],
+			pr->dn, pr->prop->name);
+		break;
+
+	}
+#endif
+	rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
+	return notifier_to_errno(rc);
+}
+
+/*
+ * of_reconfig_get_state_change()	- Returns new state of device
+ * @action	- action of the of notifier
+ * @arg		- argument of the of notifier
+ *
+ * Returns the new state of a device based on the notifier used.
+ *
+ * Return: OF_RECONFIG_CHANGE_REMOVE on device going from enabled to
+ * disabled, OF_RECONFIG_CHANGE_ADD on device going from disabled to
+ * enabled and OF_RECONFIG_NO_CHANGE on no change.
+ */
+int of_reconfig_get_state_change(unsigned long action, struct of_reconfig_data *pr)
+{
+	struct property *prop, *old_prop = NULL;
+	int is_status, status_state, old_status_state, prev_state, new_state;
+
+	/* figure out if a device should be created or destroyed */
+	switch (action) {
+	case OF_RECONFIG_ATTACH_NODE:
+	case OF_RECONFIG_DETACH_NODE:
+		prop = of_find_property(pr->dn, "status", NULL);
+		break;
+	case OF_RECONFIG_ADD_PROPERTY:
+	case OF_RECONFIG_REMOVE_PROPERTY:
+		prop = pr->prop;
+		break;
+	case OF_RECONFIG_UPDATE_PROPERTY:
+		prop = pr->prop;
+		old_prop = pr->old_prop;
+		break;
+	default:
+		return OF_RECONFIG_NO_CHANGE;
+	}
+
+	is_status = 0;
+	status_state = -1;
+	old_status_state = -1;
+	prev_state = -1;
+	new_state = -1;
+
+	if (prop && !strcmp(prop->name, "status")) {
+		is_status = 1;
+		status_state = !strcmp(prop->value, "okay") ||
+			       !strcmp(prop->value, "ok");
+		if (old_prop)
+			old_status_state = !strcmp(old_prop->value, "okay") ||
+					   !strcmp(old_prop->value, "ok");
+	}
+
+	switch (action) {
+	case OF_RECONFIG_ATTACH_NODE:
+		prev_state = 0;
+		/* -1 & 0 status either missing or okay */
+		new_state = status_state != 0;
+		break;
+	case OF_RECONFIG_DETACH_NODE:
+		/* -1 & 0 status either missing or okay */
+		prev_state = status_state != 0;
+		new_state = 0;
+		break;
+	case OF_RECONFIG_ADD_PROPERTY:
+		if (is_status) {
+			/* no status property -> enabled (legacy) */
+			prev_state = 1;
+			new_state = status_state;
+		}
+		break;
+	case OF_RECONFIG_REMOVE_PROPERTY:
+		if (is_status) {
+			prev_state = status_state;
+			/* no status property -> enabled (legacy) */
+			new_state = 1;
+		}
+		break;
+	case OF_RECONFIG_UPDATE_PROPERTY:
+		if (is_status) {
+			prev_state = old_status_state != 0;
+			new_state = status_state != 0;
+		}
+		break;
+	}
+
+	if (prev_state == new_state)
+		return OF_RECONFIG_NO_CHANGE;
+
+	return new_state ? OF_RECONFIG_CHANGE_ADD : OF_RECONFIG_CHANGE_REMOVE;
+}
+EXPORT_SYMBOL_GPL(of_reconfig_get_state_change);
+
+int of_property_notify(int action, struct device_node *np,
+		       struct property *prop, struct property *oldprop)
+{
+	struct of_reconfig_data pr;
+
+	/* only call notifiers if the node is attached */
+	if (!of_node_is_attached(np))
+		return 0;
+
+	pr.dn = np;
+	pr.prop = prop;
+	pr.old_prop = oldprop;
+	return of_reconfig_notify(action, &pr);
+}
+
+static void __of_attach_node(struct device_node *np)
+{
+	const __be32 *phandle;
+	int sz;
+
+	if (!of_node_check_flag(np, OF_OVERLAY)) {
+		np->name = __of_get_property(np, "name", NULL);
+		if (!np->name)
+			np->name = "<NULL>";
+
+		phandle = __of_get_property(np, "phandle", &sz);
+		if (!phandle)
+			phandle = __of_get_property(np, "linux,phandle", &sz);
+		if (IS_ENABLED(CONFIG_PPC_PSERIES) && !phandle)
+			phandle = __of_get_property(np, "ibm,phandle", &sz);
+		if (phandle && (sz >= 4))
+			np->phandle = be32_to_cpup(phandle);
+		else
+			np->phandle = 0;
+	}
+
+	np->child = NULL;
+	np->sibling = np->parent->child;
+	np->parent->child = np;
+	of_node_clear_flag(np, OF_DETACHED);
+	np->fwnode.flags |= FWNODE_FLAG_NOT_DEVICE;
+}
+
+/**
+ * of_attach_node() - Plug a device node into the tree and global list.
+ * @np:		Pointer to the caller's Device Node
+ */
+int of_attach_node(struct device_node *np)
+{
+	struct of_reconfig_data rd;
+	unsigned long flags;
+
+	memset(&rd, 0, sizeof(rd));
+	rd.dn = np;
+
+	mutex_lock(&of_mutex);
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	__of_attach_node(np);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	__of_attach_node_sysfs(np);
+	mutex_unlock(&of_mutex);
+
+	of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, &rd);
+
+	return 0;
+}
+
+void __of_detach_node(struct device_node *np)
+{
+	struct device_node *parent;
+
+	if (WARN_ON(of_node_check_flag(np, OF_DETACHED)))
+		return;
+
+	parent = np->parent;
+	if (WARN_ON(!parent))
+		return;
+
+	if (parent->child == np)
+		parent->child = np->sibling;
+	else {
+		struct device_node *prevsib;
+		for (prevsib = np->parent->child;
+		     prevsib->sibling != np;
+		     prevsib = prevsib->sibling)
+			;
+		prevsib->sibling = np->sibling;
+	}
+
+	of_node_set_flag(np, OF_DETACHED);
+
+	/* race with of_find_node_by_phandle() prevented by devtree_lock */
+	__of_phandle_cache_inv_entry(np->phandle);
+}
+
+/**
+ * of_detach_node() - "Unplug" a node from the device tree.
+ * @np:		Pointer to the caller's Device Node
+ */
+int of_detach_node(struct device_node *np)
+{
+	struct of_reconfig_data rd;
+	unsigned long flags;
+
+	memset(&rd, 0, sizeof(rd));
+	rd.dn = np;
+
+	mutex_lock(&of_mutex);
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	__of_detach_node(np);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	__of_detach_node_sysfs(np);
+	mutex_unlock(&of_mutex);
+
+	of_reconfig_notify(OF_RECONFIG_DETACH_NODE, &rd);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_detach_node);
+
+static void property_list_free(struct property *prop_list)
+{
+	struct property *prop, *next;
+
+	for (prop = prop_list; prop != NULL; prop = next) {
+		next = prop->next;
+		kfree(prop->name);
+		kfree(prop->value);
+		kfree(prop);
+	}
+}
+
+/**
+ * of_node_release() - release a dynamically allocated node
+ * @kobj: kernel object of the node to be released
+ *
+ * In of_node_put() this function is passed to kref_put() as the destructor.
+ */
+void of_node_release(struct kobject *kobj)
+{
+	struct device_node *node = kobj_to_device_node(kobj);
+
+	/* We should never be releasing nodes that haven't been detached. */
+	if (!of_node_check_flag(node, OF_DETACHED)) {
+		pr_err("ERROR: Bad of_node_put() on %pOF\n", node);
+		dump_stack();
+		return;
+	}
+	if (!of_node_check_flag(node, OF_DYNAMIC))
+		return;
+
+	if (of_node_check_flag(node, OF_OVERLAY)) {
+
+		if (!of_node_check_flag(node, OF_OVERLAY_FREE_CSET)) {
+			/* premature refcount of zero, do not free memory */
+			pr_err("ERROR: memory leak before free overlay changeset,  %pOF\n",
+			       node);
+			return;
+		}
+
+		/*
+		 * If node->properties non-empty then properties were added
+		 * to this node either by different overlay that has not
+		 * yet been removed, or by a non-overlay mechanism.
+		 */
+		if (node->properties)
+			pr_err("ERROR: %s(), unexpected properties in %pOF\n",
+			       __func__, node);
+	}
+
+	property_list_free(node->properties);
+	property_list_free(node->deadprops);
+	fwnode_links_purge(of_fwnode_handle(node));
+
+	kfree(node->full_name);
+	kfree(node->data);
+	kfree(node);
+}
+
+/**
+ * __of_prop_dup - Copy a property dynamically.
+ * @prop:	Property to copy
+ * @allocflags:	Allocation flags (typically pass GFP_KERNEL)
+ *
+ * Copy a property by dynamically allocating the memory of both the
+ * property structure and the property name & contents. The property's
+ * flags have the OF_DYNAMIC bit set so that we can differentiate between
+ * dynamically allocated properties and not.
+ *
+ * Return: The newly allocated property or NULL on out of memory error.
+ */
+struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags)
+{
+	struct property *new;
+
+	new = kzalloc(sizeof(*new), allocflags);
+	if (!new)
+		return NULL;
+
+	/*
+	 * NOTE: There is no check for zero length value.
+	 * In case of a boolean property, this will allocate a value
+	 * of zero bytes. We do this to work around the use
+	 * of of_get_property() calls on boolean values.
+	 */
+	new->name = kstrdup(prop->name, allocflags);
+	new->value = kmemdup(prop->value, prop->length, allocflags);
+	new->length = prop->length;
+	if (!new->name || !new->value)
+		goto err_free;
+
+	/* mark the property as dynamic */
+	of_property_set_flag(new, OF_DYNAMIC);
+
+	return new;
+
+ err_free:
+	kfree(new->name);
+	kfree(new->value);
+	kfree(new);
+	return NULL;
+}
+
+/**
+ * __of_node_dup() - Duplicate or create an empty device node dynamically.
+ * @np:		if not NULL, contains properties to be duplicated in new node
+ * @full_name:	string value to be duplicated into new node's full_name field
+ *
+ * Create a device tree node, optionally duplicating the properties of
+ * another node.  The node data are dynamically allocated and all the node
+ * flags have the OF_DYNAMIC & OF_DETACHED bits set.
+ *
+ * Return: The newly allocated node or NULL on out of memory error.
+ */
+struct device_node *__of_node_dup(const struct device_node *np,
+				  const char *full_name)
+{
+	struct device_node *node;
+
+	node = kzalloc(sizeof(*node), GFP_KERNEL);
+	if (!node)
+		return NULL;
+	node->full_name = kstrdup(full_name, GFP_KERNEL);
+	if (!node->full_name) {
+		kfree(node);
+		return NULL;
+	}
+
+	of_node_set_flag(node, OF_DYNAMIC);
+	of_node_set_flag(node, OF_DETACHED);
+	of_node_init(node);
+
+	/* Iterate over and duplicate all properties */
+	if (np) {
+		struct property *pp, *new_pp;
+		for_each_property_of_node(np, pp) {
+			new_pp = __of_prop_dup(pp, GFP_KERNEL);
+			if (!new_pp)
+				goto err_prop;
+			if (__of_add_property(node, new_pp)) {
+				kfree(new_pp->name);
+				kfree(new_pp->value);
+				kfree(new_pp);
+				goto err_prop;
+			}
+		}
+	}
+	return node;
+
+ err_prop:
+	of_node_put(node); /* Frees the node and properties */
+	return NULL;
+}
+
+static void __of_changeset_entry_destroy(struct of_changeset_entry *ce)
+{
+	if (ce->action == OF_RECONFIG_ATTACH_NODE &&
+	    of_node_check_flag(ce->np, OF_OVERLAY)) {
+		if (kref_read(&ce->np->kobj.kref) > 1) {
+			pr_err("ERROR: memory leak, expected refcount 1 instead of %d, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node %pOF\n",
+			       kref_read(&ce->np->kobj.kref), ce->np);
+		} else {
+			of_node_set_flag(ce->np, OF_OVERLAY_FREE_CSET);
+		}
+	}
+
+	of_node_put(ce->np);
+	list_del(&ce->node);
+	kfree(ce);
+}
+
+#ifdef DEBUG
+static void __of_changeset_entry_dump(struct of_changeset_entry *ce)
+{
+	switch (ce->action) {
+	case OF_RECONFIG_ADD_PROPERTY:
+	case OF_RECONFIG_REMOVE_PROPERTY:
+	case OF_RECONFIG_UPDATE_PROPERTY:
+		pr_debug("cset<%p> %-15s %pOF/%s\n", ce, action_names[ce->action],
+			ce->np, ce->prop->name);
+		break;
+	case OF_RECONFIG_ATTACH_NODE:
+	case OF_RECONFIG_DETACH_NODE:
+		pr_debug("cset<%p> %-15s %pOF\n", ce, action_names[ce->action],
+			ce->np);
+		break;
+	}
+}
+#else
+static inline void __of_changeset_entry_dump(struct of_changeset_entry *ce)
+{
+	/* empty */
+}
+#endif
+
+static void __of_changeset_entry_invert(struct of_changeset_entry *ce,
+					  struct of_changeset_entry *rce)
+{
+	memcpy(rce, ce, sizeof(*rce));
+
+	switch (ce->action) {
+	case OF_RECONFIG_ATTACH_NODE:
+		rce->action = OF_RECONFIG_DETACH_NODE;
+		break;
+	case OF_RECONFIG_DETACH_NODE:
+		rce->action = OF_RECONFIG_ATTACH_NODE;
+		break;
+	case OF_RECONFIG_ADD_PROPERTY:
+		rce->action = OF_RECONFIG_REMOVE_PROPERTY;
+		break;
+	case OF_RECONFIG_REMOVE_PROPERTY:
+		rce->action = OF_RECONFIG_ADD_PROPERTY;
+		break;
+	case OF_RECONFIG_UPDATE_PROPERTY:
+		rce->old_prop = ce->prop;
+		rce->prop = ce->old_prop;
+		/* update was used but original property did not exist */
+		if (!rce->prop) {
+			rce->action = OF_RECONFIG_REMOVE_PROPERTY;
+			rce->prop = ce->prop;
+		}
+		break;
+	}
+}
+
+static int __of_changeset_entry_notify(struct of_changeset_entry *ce,
+		bool revert)
+{
+	struct of_reconfig_data rd;
+	struct of_changeset_entry ce_inverted;
+	int ret = 0;
+
+	if (revert) {
+		__of_changeset_entry_invert(ce, &ce_inverted);
+		ce = &ce_inverted;
+	}
+
+	switch (ce->action) {
+	case OF_RECONFIG_ATTACH_NODE:
+	case OF_RECONFIG_DETACH_NODE:
+		memset(&rd, 0, sizeof(rd));
+		rd.dn = ce->np;
+		ret = of_reconfig_notify(ce->action, &rd);
+		break;
+	case OF_RECONFIG_ADD_PROPERTY:
+	case OF_RECONFIG_REMOVE_PROPERTY:
+	case OF_RECONFIG_UPDATE_PROPERTY:
+		ret = of_property_notify(ce->action, ce->np, ce->prop, ce->old_prop);
+		break;
+	default:
+		pr_err("invalid devicetree changeset action: %i\n",
+			(int)ce->action);
+		ret = -EINVAL;
+	}
+
+	if (ret)
+		pr_err("changeset notifier error @%pOF\n", ce->np);
+	return ret;
+}
+
+static int __of_changeset_entry_apply(struct of_changeset_entry *ce)
+{
+	struct property *old_prop, **propp;
+	unsigned long flags;
+	int ret = 0;
+
+	__of_changeset_entry_dump(ce);
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	switch (ce->action) {
+	case OF_RECONFIG_ATTACH_NODE:
+		__of_attach_node(ce->np);
+		break;
+	case OF_RECONFIG_DETACH_NODE:
+		__of_detach_node(ce->np);
+		break;
+	case OF_RECONFIG_ADD_PROPERTY:
+		/* If the property is in deadprops then it must be removed */
+		for (propp = &ce->np->deadprops; *propp; propp = &(*propp)->next) {
+			if (*propp == ce->prop) {
+				*propp = ce->prop->next;
+				ce->prop->next = NULL;
+				break;
+			}
+		}
+
+		ret = __of_add_property(ce->np, ce->prop);
+		break;
+	case OF_RECONFIG_REMOVE_PROPERTY:
+		ret = __of_remove_property(ce->np, ce->prop);
+		break;
+
+	case OF_RECONFIG_UPDATE_PROPERTY:
+		/* If the property is in deadprops then it must be removed */
+		for (propp = &ce->np->deadprops; *propp; propp = &(*propp)->next) {
+			if (*propp == ce->prop) {
+				*propp = ce->prop->next;
+				ce->prop->next = NULL;
+				break;
+			}
+		}
+
+		ret = __of_update_property(ce->np, ce->prop, &old_prop);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	if (ret) {
+		pr_err("changeset: apply failed: %-15s %pOF:%s\n",
+		       action_names[ce->action], ce->np, ce->prop->name);
+		return ret;
+	}
+
+	switch (ce->action) {
+	case OF_RECONFIG_ATTACH_NODE:
+		__of_attach_node_sysfs(ce->np);
+		break;
+	case OF_RECONFIG_DETACH_NODE:
+		__of_detach_node_sysfs(ce->np);
+		break;
+	case OF_RECONFIG_ADD_PROPERTY:
+		/* ignore duplicate names */
+		__of_add_property_sysfs(ce->np, ce->prop);
+		break;
+	case OF_RECONFIG_REMOVE_PROPERTY:
+		__of_remove_property_sysfs(ce->np, ce->prop);
+		break;
+	case OF_RECONFIG_UPDATE_PROPERTY:
+		__of_update_property_sysfs(ce->np, ce->prop, ce->old_prop);
+		break;
+	}
+
+	return 0;
+}
+
+static inline int __of_changeset_entry_revert(struct of_changeset_entry *ce)
+{
+	struct of_changeset_entry ce_inverted;
+
+	__of_changeset_entry_invert(ce, &ce_inverted);
+	return __of_changeset_entry_apply(&ce_inverted);
+}
+
+/**
+ * of_changeset_init - Initialize a changeset for use
+ *
+ * @ocs:	changeset pointer
+ *
+ * Initialize a changeset structure
+ */
+void of_changeset_init(struct of_changeset *ocs)
+{
+	memset(ocs, 0, sizeof(*ocs));
+	INIT_LIST_HEAD(&ocs->entries);
+}
+EXPORT_SYMBOL_GPL(of_changeset_init);
+
+/**
+ * of_changeset_destroy - Destroy a changeset
+ *
+ * @ocs:	changeset pointer
+ *
+ * Destroys a changeset. Note that if a changeset is applied,
+ * its changes to the tree cannot be reverted.
+ */
+void of_changeset_destroy(struct of_changeset *ocs)
+{
+	struct of_changeset_entry *ce, *cen;
+
+	list_for_each_entry_safe_reverse(ce, cen, &ocs->entries, node)
+		__of_changeset_entry_destroy(ce);
+}
+EXPORT_SYMBOL_GPL(of_changeset_destroy);
+
+/*
+ * Apply the changeset entries in @ocs.
+ * If apply fails, an attempt is made to revert the entries that were
+ * successfully applied.
+ *
+ * If multiple revert errors occur then only the final revert error is reported.
+ *
+ * Returns 0 on success, a negative error value in case of an error.
+ * If a revert error occurs, it is returned in *ret_revert.
+ */
+int __of_changeset_apply_entries(struct of_changeset *ocs, int *ret_revert)
+{
+	struct of_changeset_entry *ce;
+	int ret, ret_tmp;
+
+	pr_debug("changeset: applying...\n");
+	list_for_each_entry(ce, &ocs->entries, node) {
+		ret = __of_changeset_entry_apply(ce);
+		if (ret) {
+			pr_err("Error applying changeset (%d)\n", ret);
+			list_for_each_entry_continue_reverse(ce, &ocs->entries,
+							     node) {
+				ret_tmp = __of_changeset_entry_revert(ce);
+				if (ret_tmp)
+					*ret_revert = ret_tmp;
+			}
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Returns 0 on success, a negative error value in case of an error.
+ *
+ * If multiple changeset entry notification errors occur then only the
+ * final notification error is reported.
+ */
+int __of_changeset_apply_notify(struct of_changeset *ocs)
+{
+	struct of_changeset_entry *ce;
+	int ret = 0, ret_tmp;
+
+	pr_debug("changeset: emitting notifiers.\n");
+
+	/* drop the global lock while emitting notifiers */
+	mutex_unlock(&of_mutex);
+	list_for_each_entry(ce, &ocs->entries, node) {
+		ret_tmp = __of_changeset_entry_notify(ce, 0);
+		if (ret_tmp)
+			ret = ret_tmp;
+	}
+	mutex_lock(&of_mutex);
+	pr_debug("changeset: notifiers sent.\n");
+
+	return ret;
+}
+
+/*
+ * Returns 0 on success, a negative error value in case of an error.
+ *
+ * If a changeset entry apply fails, an attempt is made to revert any
+ * previous entries in the changeset.  If any of the reverts fails,
+ * that failure is not reported.  Thus the state of the device tree
+ * is unknown if an apply error occurs.
+ */
+static int __of_changeset_apply(struct of_changeset *ocs)
+{
+	int ret, ret_revert = 0;
+
+	ret = __of_changeset_apply_entries(ocs, &ret_revert);
+	if (!ret)
+		ret = __of_changeset_apply_notify(ocs);
+
+	return ret;
+}
+
+/**
+ * of_changeset_apply - Applies a changeset
+ *
+ * @ocs:	changeset pointer
+ *
+ * Applies a changeset to the live tree.
+ * Any side-effects of live tree state changes are applied here on
+ * success, like creation/destruction of devices and side-effects
+ * like creation of sysfs properties and directories.
+ *
+ * Return: 0 on success, a negative error value in case of an error.
+ * On error the partially applied effects are reverted.
+ */
+int of_changeset_apply(struct of_changeset *ocs)
+{
+	int ret;
+
+	mutex_lock(&of_mutex);
+	ret = __of_changeset_apply(ocs);
+	mutex_unlock(&of_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_changeset_apply);
+
+/*
+ * Revert the changeset entries in @ocs.
+ * If revert fails, an attempt is made to re-apply the entries that were
+ * successfully removed.
+ *
+ * If multiple re-apply errors occur then only the final apply error is
+ * reported.
+ *
+ * Returns 0 on success, a negative error value in case of an error.
+ * If an apply error occurs, it is returned in *ret_apply.
+ */
+int __of_changeset_revert_entries(struct of_changeset *ocs, int *ret_apply)
+{
+	struct of_changeset_entry *ce;
+	int ret, ret_tmp;
+
+	pr_debug("changeset: reverting...\n");
+	list_for_each_entry_reverse(ce, &ocs->entries, node) {
+		ret = __of_changeset_entry_revert(ce);
+		if (ret) {
+			pr_err("Error reverting changeset (%d)\n", ret);
+			list_for_each_entry_continue(ce, &ocs->entries, node) {
+				ret_tmp = __of_changeset_entry_apply(ce);
+				if (ret_tmp)
+					*ret_apply = ret_tmp;
+			}
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * If multiple changeset entry notification errors occur then only the
+ * final notification error is reported.
+ */
+int __of_changeset_revert_notify(struct of_changeset *ocs)
+{
+	struct of_changeset_entry *ce;
+	int ret = 0, ret_tmp;
+
+	pr_debug("changeset: emitting notifiers.\n");
+
+	/* drop the global lock while emitting notifiers */
+	mutex_unlock(&of_mutex);
+	list_for_each_entry_reverse(ce, &ocs->entries, node) {
+		ret_tmp = __of_changeset_entry_notify(ce, 1);
+		if (ret_tmp)
+			ret = ret_tmp;
+	}
+	mutex_lock(&of_mutex);
+	pr_debug("changeset: notifiers sent.\n");
+
+	return ret;
+}
+
+static int __of_changeset_revert(struct of_changeset *ocs)
+{
+	int ret, ret_reply;
+
+	ret_reply = 0;
+	ret = __of_changeset_revert_entries(ocs, &ret_reply);
+
+	if (!ret)
+		ret = __of_changeset_revert_notify(ocs);
+
+	return ret;
+}
+
+/**
+ * of_changeset_revert - Reverts an applied changeset
+ *
+ * @ocs:	changeset pointer
+ *
+ * Reverts a changeset returning the state of the tree to what it
+ * was before the application.
+ * Any side-effects like creation/destruction of devices and
+ * removal of sysfs properties and directories are applied.
+ *
+ * Return: 0 on success, a negative error value in case of an error.
+ */
+int of_changeset_revert(struct of_changeset *ocs)
+{
+	int ret;
+
+	mutex_lock(&of_mutex);
+	ret = __of_changeset_revert(ocs);
+	mutex_unlock(&of_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_changeset_revert);
+
+/**
+ * of_changeset_action - Add an action to the tail of the changeset list
+ *
+ * @ocs:	changeset pointer
+ * @action:	action to perform
+ * @np:		Pointer to device node
+ * @prop:	Pointer to property
+ *
+ * On action being one of:
+ * + OF_RECONFIG_ATTACH_NODE
+ * + OF_RECONFIG_DETACH_NODE,
+ * + OF_RECONFIG_ADD_PROPERTY
+ * + OF_RECONFIG_REMOVE_PROPERTY,
+ * + OF_RECONFIG_UPDATE_PROPERTY
+ *
+ * Return: 0 on success, a negative error value in case of an error.
+ */
+int of_changeset_action(struct of_changeset *ocs, unsigned long action,
+		struct device_node *np, struct property *prop)
+{
+	struct of_changeset_entry *ce;
+
+	if (WARN_ON(action >= ARRAY_SIZE(action_names)))
+		return -EINVAL;
+
+	ce = kzalloc(sizeof(*ce), GFP_KERNEL);
+	if (!ce)
+		return -ENOMEM;
+
+	/* get a reference to the node */
+	ce->action = action;
+	ce->np = of_node_get(np);
+	ce->prop = prop;
+
+	if (action == OF_RECONFIG_UPDATE_PROPERTY && prop)
+		ce->old_prop = of_find_property(np, prop->name, NULL);
+
+	/* add it to the list */
+	list_add_tail(&ce->node, &ocs->entries);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_changeset_action);
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
new file mode 100644
index 000000000..d1a68b6d0
--- /dev/null
+++ b/drivers/of/fdt.c
@@ -0,0 +1,1398 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions for working with the Flattened Device Tree data format
+ *
+ * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
+ * benh@kernel.crashing.org
+ */
+
+#define pr_fmt(fmt)	"OF: fdt: " fmt
+
+#include <linux/crash_dump.h>
+#include <linux/crc32.h>
+#include <linux/kernel.h>
+#include <linux/initrd.h>
+#include <linux/memblock.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/sizes.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/libfdt.h>
+#include <linux/debugfs.h>
+#include <linux/serial_core.h>
+#include <linux/sysfs.h>
+#include <linux/random.h>
+
+#include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
+#include <asm/page.h>
+
+#include "of_private.h"
+
+/*
+ * of_fdt_limit_memory - limit the number of regions in the /memory node
+ * @limit: maximum entries
+ *
+ * Adjust the flattened device tree to have at most 'limit' number of
+ * memory entries in the /memory node. This function may be called
+ * any time after initial_boot_param is set.
+ */
+void __init of_fdt_limit_memory(int limit)
+{
+	int memory;
+	int len;
+	const void *val;
+	int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
+	int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
+	const __be32 *addr_prop;
+	const __be32 *size_prop;
+	int root_offset;
+	int cell_size;
+
+	root_offset = fdt_path_offset(initial_boot_params, "/");
+	if (root_offset < 0)
+		return;
+
+	addr_prop = fdt_getprop(initial_boot_params, root_offset,
+				"#address-cells", NULL);
+	if (addr_prop)
+		nr_address_cells = fdt32_to_cpu(*addr_prop);
+
+	size_prop = fdt_getprop(initial_boot_params, root_offset,
+				"#size-cells", NULL);
+	if (size_prop)
+		nr_size_cells = fdt32_to_cpu(*size_prop);
+
+	cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
+
+	memory = fdt_path_offset(initial_boot_params, "/memory");
+	if (memory > 0) {
+		val = fdt_getprop(initial_boot_params, memory, "reg", &len);
+		if (len > limit*cell_size) {
+			len = limit*cell_size;
+			pr_debug("Limiting number of entries to %d\n", limit);
+			fdt_setprop(initial_boot_params, memory, "reg", val,
+					len);
+		}
+	}
+}
+
+static bool of_fdt_device_is_available(const void *blob, unsigned long node)
+{
+	const char *status = fdt_getprop(blob, node, "status", NULL);
+
+	if (!status)
+		return true;
+
+	if (!strcmp(status, "ok") || !strcmp(status, "okay"))
+		return true;
+
+	return false;
+}
+
+static void *unflatten_dt_alloc(void **mem, unsigned long size,
+				       unsigned long align)
+{
+	void *res;
+
+	*mem = PTR_ALIGN(*mem, align);
+	res = *mem;
+	*mem += size;
+
+	return res;
+}
+
+static void populate_properties(const void *blob,
+				int offset,
+				void **mem,
+				struct device_node *np,
+				const char *nodename,
+				bool dryrun)
+{
+	struct property *pp, **pprev = NULL;
+	int cur;
+	bool has_name = false;
+
+	pprev = &np->properties;
+	for (cur = fdt_first_property_offset(blob, offset);
+	     cur >= 0;
+	     cur = fdt_next_property_offset(blob, cur)) {
+		const __be32 *val;
+		const char *pname;
+		u32 sz;
+
+		val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
+		if (!val) {
+			pr_warn("Cannot locate property at 0x%x\n", cur);
+			continue;
+		}
+
+		if (!pname) {
+			pr_warn("Cannot find property name at 0x%x\n", cur);
+			continue;
+		}
+
+		if (!strcmp(pname, "name"))
+			has_name = true;
+
+		pp = unflatten_dt_alloc(mem, sizeof(struct property),
+					__alignof__(struct property));
+		if (dryrun)
+			continue;
+
+		/* We accept flattened tree phandles either in
+		 * ePAPR-style "phandle" properties, or the
+		 * legacy "linux,phandle" properties.  If both
+		 * appear and have different values, things
+		 * will get weird. Don't do that.
+		 */
+		if (!strcmp(pname, "phandle") ||
+		    !strcmp(pname, "linux,phandle")) {
+			if (!np->phandle)
+				np->phandle = be32_to_cpup(val);
+		}
+
+		/* And we process the "ibm,phandle" property
+		 * used in pSeries dynamic device tree
+		 * stuff
+		 */
+		if (!strcmp(pname, "ibm,phandle"))
+			np->phandle = be32_to_cpup(val);
+
+		pp->name   = (char *)pname;
+		pp->length = sz;
+		pp->value  = (__be32 *)val;
+		*pprev     = pp;
+		pprev      = &pp->next;
+	}
+
+	/* With version 0x10 we may not have the name property,
+	 * recreate it here from the unit name if absent
+	 */
+	if (!has_name) {
+		const char *p = nodename, *ps = p, *pa = NULL;
+		int len;
+
+		while (*p) {
+			if ((*p) == '@')
+				pa = p;
+			else if ((*p) == '/')
+				ps = p + 1;
+			p++;
+		}
+
+		if (pa < ps)
+			pa = p;
+		len = (pa - ps) + 1;
+		pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
+					__alignof__(struct property));
+		if (!dryrun) {
+			pp->name   = "name";
+			pp->length = len;
+			pp->value  = pp + 1;
+			*pprev     = pp;
+			memcpy(pp->value, ps, len - 1);
+			((char *)pp->value)[len - 1] = 0;
+			pr_debug("fixed up name for %s -> %s\n",
+				 nodename, (char *)pp->value);
+		}
+	}
+}
+
+static int populate_node(const void *blob,
+			  int offset,
+			  void **mem,
+			  struct device_node *dad,
+			  struct device_node **pnp,
+			  bool dryrun)
+{
+	struct device_node *np;
+	const char *pathp;
+	int len;
+
+	pathp = fdt_get_name(blob, offset, &len);
+	if (!pathp) {
+		*pnp = NULL;
+		return len;
+	}
+
+	len++;
+
+	np = unflatten_dt_alloc(mem, sizeof(struct device_node) + len,
+				__alignof__(struct device_node));
+	if (!dryrun) {
+		char *fn;
+		of_node_init(np);
+		np->full_name = fn = ((char *)np) + sizeof(*np);
+
+		memcpy(fn, pathp, len);
+
+		if (dad != NULL) {
+			np->parent = dad;
+			np->sibling = dad->child;
+			dad->child = np;
+		}
+	}
+
+	populate_properties(blob, offset, mem, np, pathp, dryrun);
+	if (!dryrun) {
+		np->name = of_get_property(np, "name", NULL);
+		if (!np->name)
+			np->name = "<NULL>";
+	}
+
+	*pnp = np;
+	return 0;
+}
+
+static void reverse_nodes(struct device_node *parent)
+{
+	struct device_node *child, *next;
+
+	/* In-depth first */
+	child = parent->child;
+	while (child) {
+		reverse_nodes(child);
+
+		child = child->sibling;
+	}
+
+	/* Reverse the nodes in the child list */
+	child = parent->child;
+	parent->child = NULL;
+	while (child) {
+		next = child->sibling;
+
+		child->sibling = parent->child;
+		parent->child = child;
+		child = next;
+	}
+}
+
+/**
+ * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
+ * @blob: The parent device tree blob
+ * @mem: Memory chunk to use for allocating device nodes and properties
+ * @dad: Parent struct device_node
+ * @nodepp: The device_node tree created by the call
+ *
+ * Return: The size of unflattened device tree or error code
+ */
+static int unflatten_dt_nodes(const void *blob,
+			      void *mem,
+			      struct device_node *dad,
+			      struct device_node **nodepp)
+{
+	struct device_node *root;
+	int offset = 0, depth = 0, initial_depth = 0;
+#define FDT_MAX_DEPTH	64
+	struct device_node *nps[FDT_MAX_DEPTH];
+	void *base = mem;
+	bool dryrun = !base;
+	int ret;
+
+	if (nodepp)
+		*nodepp = NULL;
+
+	/*
+	 * We're unflattening device sub-tree if @dad is valid. There are
+	 * possibly multiple nodes in the first level of depth. We need
+	 * set @depth to 1 to make fdt_next_node() happy as it bails
+	 * immediately when negative @depth is found. Otherwise, the device
+	 * nodes except the first one won't be unflattened successfully.
+	 */
+	if (dad)
+		depth = initial_depth = 1;
+
+	root = dad;
+	nps[depth] = dad;
+
+	for (offset = 0;
+	     offset >= 0 && depth >= initial_depth;
+	     offset = fdt_next_node(blob, offset, &depth)) {
+		if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH - 1))
+			continue;
+
+		if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
+		    !of_fdt_device_is_available(blob, offset))
+			continue;
+
+		ret = populate_node(blob, offset, &mem, nps[depth],
+				   &nps[depth+1], dryrun);
+		if (ret < 0)
+			return ret;
+
+		if (!dryrun && nodepp && !*nodepp)
+			*nodepp = nps[depth+1];
+		if (!dryrun && !root)
+			root = nps[depth+1];
+	}
+
+	if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
+		pr_err("Error %d processing FDT\n", offset);
+		return -EINVAL;
+	}
+
+	/*
+	 * Reverse the child list. Some drivers assumes node order matches .dts
+	 * node order
+	 */
+	if (!dryrun)
+		reverse_nodes(root);
+
+	return mem - base;
+}
+
+/**
+ * __unflatten_device_tree - create tree of device_nodes from flat blob
+ * @blob: The blob to expand
+ * @dad: Parent device node
+ * @mynodes: The device_node tree created by the call
+ * @dt_alloc: An allocator that provides a virtual address to memory
+ * for the resulting tree
+ * @detached: if true set OF_DETACHED on @mynodes
+ *
+ * unflattens a device-tree, creating the tree of struct device_node. It also
+ * fills the "name" and "type" pointers of the nodes so the normal device-tree
+ * walking functions can be used.
+ *
+ * Return: NULL on failure or the memory chunk containing the unflattened
+ * device tree on success.
+ */
+void *__unflatten_device_tree(const void *blob,
+			      struct device_node *dad,
+			      struct device_node **mynodes,
+			      void *(*dt_alloc)(u64 size, u64 align),
+			      bool detached)
+{
+	int size;
+	void *mem;
+	int ret;
+
+	if (mynodes)
+		*mynodes = NULL;
+
+	pr_debug(" -> unflatten_device_tree()\n");
+
+	if (!blob) {
+		pr_debug("No device tree pointer\n");
+		return NULL;
+	}
+
+	pr_debug("Unflattening device tree:\n");
+	pr_debug("magic: %08x\n", fdt_magic(blob));
+	pr_debug("size: %08x\n", fdt_totalsize(blob));
+	pr_debug("version: %08x\n", fdt_version(blob));
+
+	if (fdt_check_header(blob)) {
+		pr_err("Invalid device tree blob header\n");
+		return NULL;
+	}
+
+	/* First pass, scan for size */
+	size = unflatten_dt_nodes(blob, NULL, dad, NULL);
+	if (size <= 0)
+		return NULL;
+
+	size = ALIGN(size, 4);
+	pr_debug("  size is %d, allocating...\n", size);
+
+	/* Allocate memory for the expanded device tree */
+	mem = dt_alloc(size + 4, __alignof__(struct device_node));
+	if (!mem)
+		return NULL;
+
+	memset(mem, 0, size);
+
+	*(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
+
+	pr_debug("  unflattening %p...\n", mem);
+
+	/* Second pass, do actual unflattening */
+	ret = unflatten_dt_nodes(blob, mem, dad, mynodes);
+
+	if (be32_to_cpup(mem + size) != 0xdeadbeef)
+		pr_warn("End of tree marker overwritten: %08x\n",
+			be32_to_cpup(mem + size));
+
+	if (ret <= 0)
+		return NULL;
+
+	if (detached && mynodes && *mynodes) {
+		of_node_set_flag(*mynodes, OF_DETACHED);
+		pr_debug("unflattened tree is detached\n");
+	}
+
+	pr_debug(" <- unflatten_device_tree()\n");
+	return mem;
+}
+
+static void *kernel_tree_alloc(u64 size, u64 align)
+{
+	return kzalloc(size, GFP_KERNEL);
+}
+
+static DEFINE_MUTEX(of_fdt_unflatten_mutex);
+
+/**
+ * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
+ * @blob: Flat device tree blob
+ * @dad: Parent device node
+ * @mynodes: The device tree created by the call
+ *
+ * unflattens the device-tree passed by the firmware, creating the
+ * tree of struct device_node. It also fills the "name" and "type"
+ * pointers of the nodes so the normal device-tree walking functions
+ * can be used.
+ *
+ * Return: NULL on failure or the memory chunk containing the unflattened
+ * device tree on success.
+ */
+void *of_fdt_unflatten_tree(const unsigned long *blob,
+			    struct device_node *dad,
+			    struct device_node **mynodes)
+{
+	void *mem;
+
+	mutex_lock(&of_fdt_unflatten_mutex);
+	mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
+				      true);
+	mutex_unlock(&of_fdt_unflatten_mutex);
+
+	return mem;
+}
+EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
+
+/* Everything below here references initial_boot_params directly. */
+int __initdata dt_root_addr_cells;
+int __initdata dt_root_size_cells;
+
+void *initial_boot_params __ro_after_init;
+
+#ifdef CONFIG_OF_EARLY_FLATTREE
+
+static u32 of_fdt_crc32;
+
+static int __init early_init_dt_reserve_memory(phys_addr_t base,
+					       phys_addr_t size, bool nomap)
+{
+	if (nomap) {
+		/*
+		 * If the memory is already reserved (by another region), we
+		 * should not allow it to be marked nomap, but don't worry
+		 * if the region isn't memory as it won't be mapped.
+		 */
+		if (memblock_overlaps_region(&memblock.memory, base, size) &&
+		    memblock_is_region_reserved(base, size))
+			return -EBUSY;
+
+		return memblock_mark_nomap(base, size);
+	}
+	return memblock_reserve(base, size);
+}
+
+/*
+ * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property
+ */
+static int __init __reserved_mem_reserve_reg(unsigned long node,
+					     const char *uname)
+{
+	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
+	phys_addr_t base, size;
+	int len;
+	const __be32 *prop;
+	int first = 1;
+	bool nomap;
+
+	prop = of_get_flat_dt_prop(node, "reg", &len);
+	if (!prop)
+		return -ENOENT;
+
+	if (len && len % t_len != 0) {
+		pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
+		       uname);
+		return -EINVAL;
+	}
+
+	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+
+	while (len >= t_len) {
+		base = dt_mem_next_cell(dt_root_addr_cells, &prop);
+		size = dt_mem_next_cell(dt_root_size_cells, &prop);
+
+		if (size &&
+		    early_init_dt_reserve_memory(base, size, nomap) == 0)
+			pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n",
+				uname, &base, (unsigned long)(size / SZ_1M));
+		else
+			pr_err("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n",
+			       uname, &base, (unsigned long)(size / SZ_1M));
+
+		len -= t_len;
+		if (first) {
+			fdt_reserved_mem_save_node(node, uname, base, size);
+			first = 0;
+		}
+	}
+	return 0;
+}
+
+/*
+ * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
+ * in /reserved-memory matches the values supported by the current implementation,
+ * also check if ranges property has been provided
+ */
+static int __init __reserved_mem_check_root(unsigned long node)
+{
+	const __be32 *prop;
+
+	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
+	if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
+		return -EINVAL;
+
+	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
+	if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
+		return -EINVAL;
+
+	prop = of_get_flat_dt_prop(node, "ranges", NULL);
+	if (!prop)
+		return -EINVAL;
+	return 0;
+}
+
+/*
+ * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
+ */
+static int __init fdt_scan_reserved_mem(void)
+{
+	int node, child;
+	const void *fdt = initial_boot_params;
+
+	node = fdt_path_offset(fdt, "/reserved-memory");
+	if (node < 0)
+		return -ENODEV;
+
+	if (__reserved_mem_check_root(node) != 0) {
+		pr_err("Reserved memory: unsupported node format, ignoring\n");
+		return -EINVAL;
+	}
+
+	fdt_for_each_subnode(child, fdt, node) {
+		const char *uname;
+		int err;
+
+		if (!of_fdt_device_is_available(fdt, child))
+			continue;
+
+		uname = fdt_get_name(fdt, child, NULL);
+
+		err = __reserved_mem_reserve_reg(child, uname);
+		if (err == -ENOENT && of_get_flat_dt_prop(child, "size", NULL))
+			fdt_reserved_mem_save_node(child, uname, 0, 0);
+	}
+	return 0;
+}
+
+/*
+ * fdt_reserve_elfcorehdr() - reserves memory for elf core header
+ *
+ * This function reserves the memory occupied by an elf core header
+ * described in the device tree. This region contains all the
+ * information about primary kernel's core image and is used by a dump
+ * capture kernel to access the system memory on primary kernel.
+ */
+static void __init fdt_reserve_elfcorehdr(void)
+{
+	if (!IS_ENABLED(CONFIG_CRASH_DUMP) || !elfcorehdr_size)
+		return;
+
+	if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) {
+		pr_warn("elfcorehdr is overlapped\n");
+		return;
+	}
+
+	memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
+
+	pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n",
+		elfcorehdr_size >> 10, elfcorehdr_addr);
+}
+
+/**
+ * early_init_fdt_scan_reserved_mem() - create reserved memory regions
+ *
+ * This function grabs memory from early allocator for device exclusive use
+ * defined in device tree structures. It should be called by arch specific code
+ * once the early allocator (i.e. memblock) has been fully activated.
+ */
+void __init early_init_fdt_scan_reserved_mem(void)
+{
+	int n;
+	u64 base, size;
+
+	if (!initial_boot_params)
+		return;
+
+	/* Process header /memreserve/ fields */
+	for (n = 0; ; n++) {
+		fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
+		if (!size)
+			break;
+		memblock_reserve(base, size);
+	}
+
+	fdt_scan_reserved_mem();
+	fdt_reserve_elfcorehdr();
+	fdt_init_reserved_mem();
+}
+
+/**
+ * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
+ */
+void __init early_init_fdt_reserve_self(void)
+{
+	if (!initial_boot_params)
+		return;
+
+	/* Reserve the dtb region */
+	memblock_reserve(__pa(initial_boot_params),
+			 fdt_totalsize(initial_boot_params));
+}
+
+/**
+ * of_scan_flat_dt - scan flattened tree blob and call callback on each.
+ * @it: callback function
+ * @data: context data pointer
+ *
+ * This function is used to scan the flattened device-tree, it is
+ * used to extract the memory information at boot before we can
+ * unflatten the tree
+ */
+int __init of_scan_flat_dt(int (*it)(unsigned long node,
+				     const char *uname, int depth,
+				     void *data),
+			   void *data)
+{
+	const void *blob = initial_boot_params;
+	const char *pathp;
+	int offset, rc = 0, depth = -1;
+
+	if (!blob)
+		return 0;
+
+	for (offset = fdt_next_node(blob, -1, &depth);
+	     offset >= 0 && depth >= 0 && !rc;
+	     offset = fdt_next_node(blob, offset, &depth)) {
+
+		pathp = fdt_get_name(blob, offset, NULL);
+		rc = it(offset, pathp, depth, data);
+	}
+	return rc;
+}
+
+/**
+ * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
+ * @parent: parent node
+ * @it: callback function
+ * @data: context data pointer
+ *
+ * This function is used to scan sub-nodes of a node.
+ */
+int __init of_scan_flat_dt_subnodes(unsigned long parent,
+				    int (*it)(unsigned long node,
+					      const char *uname,
+					      void *data),
+				    void *data)
+{
+	const void *blob = initial_boot_params;
+	int node;
+
+	fdt_for_each_subnode(node, blob, parent) {
+		const char *pathp;
+		int rc;
+
+		pathp = fdt_get_name(blob, node, NULL);
+		rc = it(node, pathp, data);
+		if (rc)
+			return rc;
+	}
+	return 0;
+}
+
+/**
+ * of_get_flat_dt_subnode_by_name - get the subnode by given name
+ *
+ * @node: the parent node
+ * @uname: the name of subnode
+ * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
+ */
+
+int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
+{
+	return fdt_subnode_offset(initial_boot_params, node, uname);
+}
+
+/*
+ * of_get_flat_dt_root - find the root node in the flat blob
+ */
+unsigned long __init of_get_flat_dt_root(void)
+{
+	return 0;
+}
+
+/*
+ * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
+ *
+ * This function can be used within scan_flattened_dt callback to get
+ * access to properties
+ */
+const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
+				       int *size)
+{
+	return fdt_getprop(initial_boot_params, node, name, size);
+}
+
+/**
+ * of_fdt_is_compatible - Return true if given node from the given blob has
+ * compat in its compatible list
+ * @blob: A device tree blob
+ * @node: node to test
+ * @compat: compatible string to compare with compatible list.
+ *
+ * Return: a non-zero value on match with smaller values returned for more
+ * specific compatible values.
+ */
+static int of_fdt_is_compatible(const void *blob,
+		      unsigned long node, const char *compat)
+{
+	const char *cp;
+	int cplen;
+	unsigned long l, score = 0;
+
+	cp = fdt_getprop(blob, node, "compatible", &cplen);
+	if (cp == NULL)
+		return 0;
+	while (cplen > 0) {
+		score++;
+		if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
+			return score;
+		l = strlen(cp) + 1;
+		cp += l;
+		cplen -= l;
+	}
+
+	return 0;
+}
+
+/**
+ * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
+ * @node: node to test
+ * @compat: compatible string to compare with compatible list.
+ */
+int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
+{
+	return of_fdt_is_compatible(initial_boot_params, node, compat);
+}
+
+/*
+ * of_flat_dt_match - Return true if node matches a list of compatible values
+ */
+static int __init of_flat_dt_match(unsigned long node, const char *const *compat)
+{
+	unsigned int tmp, score = 0;
+
+	if (!compat)
+		return 0;
+
+	while (*compat) {
+		tmp = of_fdt_is_compatible(initial_boot_params, node, *compat);
+		if (tmp && (score == 0 || (tmp < score)))
+			score = tmp;
+		compat++;
+	}
+
+	return score;
+}
+
+/*
+ * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle
+ */
+uint32_t __init of_get_flat_dt_phandle(unsigned long node)
+{
+	return fdt_get_phandle(initial_boot_params, node);
+}
+
+const char * __init of_flat_dt_get_machine_name(void)
+{
+	const char *name;
+	unsigned long dt_root = of_get_flat_dt_root();
+
+	name = of_get_flat_dt_prop(dt_root, "model", NULL);
+	if (!name)
+		name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
+	return name;
+}
+
+/**
+ * of_flat_dt_match_machine - Iterate match tables to find matching machine.
+ *
+ * @default_match: A machine specific ptr to return in case of no match.
+ * @get_next_compat: callback function to return next compatible match table.
+ *
+ * Iterate through machine match tables to find the best match for the machine
+ * compatible string in the FDT.
+ */
+const void * __init of_flat_dt_match_machine(const void *default_match,
+		const void * (*get_next_compat)(const char * const**))
+{
+	const void *data = NULL;
+	const void *best_data = default_match;
+	const char *const *compat;
+	unsigned long dt_root;
+	unsigned int best_score = ~1, score = 0;
+
+	dt_root = of_get_flat_dt_root();
+	while ((data = get_next_compat(&compat))) {
+		score = of_flat_dt_match(dt_root, compat);
+		if (score > 0 && score < best_score) {
+			best_data = data;
+			best_score = score;
+		}
+	}
+	if (!best_data) {
+		const char *prop;
+		int size;
+
+		pr_err("\n unrecognized device tree list:\n[ ");
+
+		prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
+		if (prop) {
+			while (size > 0) {
+				printk("'%s' ", prop);
+				size -= strlen(prop) + 1;
+				prop += strlen(prop) + 1;
+			}
+		}
+		printk("]\n\n");
+		return NULL;
+	}
+
+	pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
+
+	return best_data;
+}
+
+static void __early_init_dt_declare_initrd(unsigned long start,
+					   unsigned long end)
+{
+	/* ARM64 would cause a BUG to occur here when CONFIG_DEBUG_VM is
+	 * enabled since __va() is called too early. ARM64 does make use
+	 * of phys_initrd_start/phys_initrd_size so we can skip this
+	 * conversion.
+	 */
+	if (!IS_ENABLED(CONFIG_ARM64)) {
+		initrd_start = (unsigned long)__va(start);
+		initrd_end = (unsigned long)__va(end);
+		initrd_below_start_ok = 1;
+	}
+}
+
+/**
+ * early_init_dt_check_for_initrd - Decode initrd location from flat tree
+ * @node: reference to node containing initrd location ('chosen')
+ */
+static void __init early_init_dt_check_for_initrd(unsigned long node)
+{
+	u64 start, end;
+	int len;
+	const __be32 *prop;
+
+	if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
+		return;
+
+	pr_debug("Looking for initrd properties... ");
+
+	prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
+	if (!prop)
+		return;
+	start = of_read_number(prop, len/4);
+
+	prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
+	if (!prop)
+		return;
+	end = of_read_number(prop, len/4);
+	if (start > end)
+		return;
+
+	__early_init_dt_declare_initrd(start, end);
+	phys_initrd_start = start;
+	phys_initrd_size = end - start;
+
+	pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n", start, end);
+}
+
+/**
+ * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat
+ * tree
+ * @node: reference to node containing elfcorehdr location ('chosen')
+ */
+static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
+{
+	const __be32 *prop;
+	int len;
+
+	if (!IS_ENABLED(CONFIG_CRASH_DUMP))
+		return;
+
+	pr_debug("Looking for elfcorehdr property... ");
+
+	prop = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len);
+	if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells)))
+		return;
+
+	elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
+	elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &prop);
+
+	pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n",
+		 elfcorehdr_addr, elfcorehdr_size);
+}
+
+static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
+
+/*
+ * The main usage of linux,usable-memory-range is for crash dump kernel.
+ * Originally, the number of usable-memory regions is one. Now there may
+ * be two regions, low region and high region.
+ * To make compatibility with existing user-space and older kdump, the low
+ * region is always the last range of linux,usable-memory-range if exist.
+ */
+#define MAX_USABLE_RANGES		2
+
+/**
+ * early_init_dt_check_for_usable_mem_range - Decode usable memory range
+ * location from flat tree
+ */
+void __init early_init_dt_check_for_usable_mem_range(void)
+{
+	struct memblock_region rgn[MAX_USABLE_RANGES] = {0};
+	const __be32 *prop, *endp;
+	int len, i;
+	unsigned long node = chosen_node_offset;
+
+	if ((long)node < 0)
+		return;
+
+	pr_debug("Looking for usable-memory-range property... ");
+
+	prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len);
+	if (!prop || (len % (dt_root_addr_cells + dt_root_size_cells)))
+		return;
+
+	endp = prop + (len / sizeof(__be32));
+	for (i = 0; i < MAX_USABLE_RANGES && prop < endp; i++) {
+		rgn[i].base = dt_mem_next_cell(dt_root_addr_cells, &prop);
+		rgn[i].size = dt_mem_next_cell(dt_root_size_cells, &prop);
+
+		pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n",
+			 i, &rgn[i].base, &rgn[i].size);
+	}
+
+	memblock_cap_memory_range(rgn[0].base, rgn[0].size);
+	for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++)
+		memblock_add(rgn[i].base, rgn[i].size);
+}
+
+#ifdef CONFIG_SERIAL_EARLYCON
+
+int __init early_init_dt_scan_chosen_stdout(void)
+{
+	int offset;
+	const char *p, *q, *options = NULL;
+	int l;
+	const struct earlycon_id *match;
+	const void *fdt = initial_boot_params;
+	int ret;
+
+	offset = fdt_path_offset(fdt, "/chosen");
+	if (offset < 0)
+		offset = fdt_path_offset(fdt, "/chosen@0");
+	if (offset < 0)
+		return -ENOENT;
+
+	p = fdt_getprop(fdt, offset, "stdout-path", &l);
+	if (!p)
+		p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
+	if (!p || !l)
+		return -ENOENT;
+
+	q = strchrnul(p, ':');
+	if (*q != '\0')
+		options = q + 1;
+	l = q - p;
+
+	/* Get the node specified by stdout-path */
+	offset = fdt_path_offset_namelen(fdt, p, l);
+	if (offset < 0) {
+		pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
+		return 0;
+	}
+
+	for (match = __earlycon_table; match < __earlycon_table_end; match++) {
+		if (!match->compatible[0])
+			continue;
+
+		if (fdt_node_check_compatible(fdt, offset, match->compatible))
+			continue;
+
+		ret = of_setup_earlycon(match, offset, options);
+		if (!ret || ret == -EALREADY)
+			return 0;
+	}
+	return -ENODEV;
+}
+#endif
+
+/*
+ * early_init_dt_scan_root - fetch the top level address and size cells
+ */
+int __init early_init_dt_scan_root(void)
+{
+	const __be32 *prop;
+	const void *fdt = initial_boot_params;
+	int node = fdt_path_offset(fdt, "/");
+
+	if (node < 0)
+		return -ENODEV;
+
+	dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
+	dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
+
+	prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
+	if (prop)
+		dt_root_size_cells = be32_to_cpup(prop);
+	pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
+
+	prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
+	if (prop)
+		dt_root_addr_cells = be32_to_cpup(prop);
+	pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
+
+	return 0;
+}
+
+u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
+{
+	const __be32 *p = *cellp;
+
+	*cellp = p + s;
+	return of_read_number(p, s);
+}
+
+/*
+ * early_init_dt_scan_memory - Look for and parse memory nodes
+ */
+int __init early_init_dt_scan_memory(void)
+{
+	int node, found_memory = 0;
+	const void *fdt = initial_boot_params;
+
+	fdt_for_each_subnode(node, fdt, 0) {
+		const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+		const __be32 *reg, *endp;
+		int l;
+		bool hotpluggable;
+
+		/* We are scanning "memory" nodes only */
+		if (type == NULL || strcmp(type, "memory") != 0)
+			continue;
+
+		if (!of_fdt_device_is_available(fdt, node))
+			continue;
+
+		reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
+		if (reg == NULL)
+			reg = of_get_flat_dt_prop(node, "reg", &l);
+		if (reg == NULL)
+			continue;
+
+		endp = reg + (l / sizeof(__be32));
+		hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
+
+		pr_debug("memory scan node %s, reg size %d,\n",
+			 fdt_get_name(fdt, node, NULL), l);
+
+		while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
+			u64 base, size;
+
+			base = dt_mem_next_cell(dt_root_addr_cells, &reg);
+			size = dt_mem_next_cell(dt_root_size_cells, &reg);
+
+			if (size == 0)
+				continue;
+			pr_debug(" - %llx, %llx\n", base, size);
+
+			early_init_dt_add_memory_arch(base, size);
+
+			found_memory = 1;
+
+			if (!hotpluggable)
+				continue;
+
+			if (memblock_mark_hotplug(base, size))
+				pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
+					base, base + size);
+		}
+	}
+	return found_memory;
+}
+
+int __init early_init_dt_scan_chosen(char *cmdline)
+{
+	int l, node;
+	const char *p;
+	const void *rng_seed;
+	const void *fdt = initial_boot_params;
+
+	node = fdt_path_offset(fdt, "/chosen");
+	if (node < 0)
+		node = fdt_path_offset(fdt, "/chosen@0");
+	if (node < 0)
+		/* Handle the cmdline config options even if no /chosen node */
+		goto handle_cmdline;
+
+	chosen_node_offset = node;
+
+	early_init_dt_check_for_initrd(node);
+	early_init_dt_check_for_elfcorehdr(node);
+
+	rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
+	if (rng_seed && l > 0) {
+		add_bootloader_randomness(rng_seed, l);
+
+		/* try to clear seed so it won't be found. */
+		fdt_nop_property(initial_boot_params, node, "rng-seed");
+
+		/* update CRC check value */
+		of_fdt_crc32 = crc32_be(~0, initial_boot_params,
+				fdt_totalsize(initial_boot_params));
+	}
+
+	/* Retrieve command line */
+	p = of_get_flat_dt_prop(node, "bootargs", &l);
+	if (p != NULL && l > 0)
+		strscpy(cmdline, p, min(l, COMMAND_LINE_SIZE));
+
+handle_cmdline:
+	/*
+	 * CONFIG_CMDLINE is meant to be a default in case nothing else
+	 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
+	 * is set in which case we override whatever was found earlier.
+	 */
+#ifdef CONFIG_CMDLINE
+#if defined(CONFIG_CMDLINE_EXTEND)
+	strlcat(cmdline, " ", COMMAND_LINE_SIZE);
+	strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
+#elif defined(CONFIG_CMDLINE_FORCE)
+	strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
+#else
+	/* No arguments from boot loader, use kernel's  cmdl*/
+	if (!((char *)cmdline)[0])
+		strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
+#endif
+#endif /* CONFIG_CMDLINE */
+
+	pr_debug("Command line is: %s\n", (char *)cmdline);
+
+	return 0;
+}
+
+#ifndef MIN_MEMBLOCK_ADDR
+#define MIN_MEMBLOCK_ADDR	__pa(PAGE_OFFSET)
+#endif
+#ifndef MAX_MEMBLOCK_ADDR
+#define MAX_MEMBLOCK_ADDR	((phys_addr_t)~0)
+#endif
+
+void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
+{
+	const u64 phys_offset = MIN_MEMBLOCK_ADDR;
+
+	if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
+		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
+			base, base + size);
+		return;
+	}
+
+	if (!PAGE_ALIGNED(base)) {
+		size -= PAGE_SIZE - (base & ~PAGE_MASK);
+		base = PAGE_ALIGN(base);
+	}
+	size &= PAGE_MASK;
+
+	if (base > MAX_MEMBLOCK_ADDR) {
+		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
+			base, base + size);
+		return;
+	}
+
+	if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
+		pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
+			((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
+		size = MAX_MEMBLOCK_ADDR - base + 1;
+	}
+
+	if (base + size < phys_offset) {
+		pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
+			base, base + size);
+		return;
+	}
+	if (base < phys_offset) {
+		pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
+			base, phys_offset);
+		size -= phys_offset - base;
+		base = phys_offset;
+	}
+	memblock_add(base, size);
+}
+
+static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
+{
+	void *ptr = memblock_alloc(size, align);
+
+	if (!ptr)
+		panic("%s: Failed to allocate %llu bytes align=0x%llx\n",
+		      __func__, size, align);
+
+	return ptr;
+}
+
+bool __init early_init_dt_verify(void *params)
+{
+	if (!params)
+		return false;
+
+	/* check device tree validity */
+	if (fdt_check_header(params))
+		return false;
+
+	/* Setup flat device-tree pointer */
+	initial_boot_params = params;
+	of_fdt_crc32 = crc32_be(~0, initial_boot_params,
+				fdt_totalsize(initial_boot_params));
+	return true;
+}
+
+
+void __init early_init_dt_scan_nodes(void)
+{
+	int rc;
+
+	/* Initialize {size,address}-cells info */
+	early_init_dt_scan_root();
+
+	/* Retrieve various information from the /chosen node */
+	rc = early_init_dt_scan_chosen(boot_command_line);
+	if (rc)
+		pr_warn("No chosen node found, continuing without\n");
+
+	/* Setup memory, calling early_init_dt_add_memory_arch */
+	early_init_dt_scan_memory();
+
+	/* Handle linux,usable-memory-range property */
+	early_init_dt_check_for_usable_mem_range();
+}
+
+bool __init early_init_dt_scan(void *params)
+{
+	bool status;
+
+	status = early_init_dt_verify(params);
+	if (!status)
+		return false;
+
+	early_init_dt_scan_nodes();
+	return true;
+}
+
+/**
+ * unflatten_device_tree - create tree of device_nodes from flat blob
+ *
+ * unflattens the device-tree passed by the firmware, creating the
+ * tree of struct device_node. It also fills the "name" and "type"
+ * pointers of the nodes so the normal device-tree walking functions
+ * can be used.
+ */
+void __init unflatten_device_tree(void)
+{
+	__unflatten_device_tree(initial_boot_params, NULL, &of_root,
+				early_init_dt_alloc_memory_arch, false);
+
+	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
+	of_alias_scan(early_init_dt_alloc_memory_arch);
+
+	unittest_unflatten_overlay_base();
+}
+
+/**
+ * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
+ *
+ * Copies and unflattens the device-tree passed by the firmware, creating the
+ * tree of struct device_node. It also fills the "name" and "type"
+ * pointers of the nodes so the normal device-tree walking functions
+ * can be used. This should only be used when the FDT memory has not been
+ * reserved such is the case when the FDT is built-in to the kernel init
+ * section. If the FDT memory is reserved already then unflatten_device_tree
+ * should be used instead.
+ */
+void __init unflatten_and_copy_device_tree(void)
+{
+	int size;
+	void *dt;
+
+	if (!initial_boot_params) {
+		pr_warn("No valid device tree found, continuing without\n");
+		return;
+	}
+
+	size = fdt_totalsize(initial_boot_params);
+	dt = early_init_dt_alloc_memory_arch(size,
+					     roundup_pow_of_two(FDT_V17_SIZE));
+
+	if (dt) {
+		memcpy(dt, initial_boot_params, size);
+		initial_boot_params = dt;
+	}
+	unflatten_device_tree();
+}
+
+#ifdef CONFIG_SYSFS
+static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
+			       struct bin_attribute *bin_attr,
+			       char *buf, loff_t off, size_t count)
+{
+	memcpy(buf, initial_boot_params + off, count);
+	return count;
+}
+
+static int __init of_fdt_raw_init(void)
+{
+	static struct bin_attribute of_fdt_raw_attr =
+		__BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
+
+	if (!initial_boot_params)
+		return 0;
+
+	if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
+				     fdt_totalsize(initial_boot_params))) {
+		pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
+		return 0;
+	}
+	of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
+	return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
+}
+late_initcall(of_fdt_raw_init);
+#endif
+
+#endif /* CONFIG_OF_EARLY_FLATTREE */
diff --git a/drivers/of/fdt_address.c b/drivers/of/fdt_address.c
new file mode 100644
index 000000000..1dc15ab78
--- /dev/null
+++ b/drivers/of/fdt_address.c
@@ -0,0 +1,249 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * FDT Address translation based on u-boot fdt_support.c which in turn was
+ * based on the kernel unflattened DT address translation code.
+ *
+ * (C) Copyright 2007
+ * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com
+ *
+ * Copyright 2010-2011 Freescale Semiconductor, Inc.
+ */
+
+#define pr_fmt(fmt)	"OF: fdt: " fmt
+
+#include <linux/kernel.h>
+#include <linux/libfdt.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/sizes.h>
+
+/* Max address size we deal with */
+#define OF_MAX_ADDR_CELLS	4
+#define OF_CHECK_COUNTS(na, ns)	((na) > 0 && (na) <= OF_MAX_ADDR_CELLS && \
+			(ns) > 0)
+
+/* Debug utility */
+#ifdef DEBUG
+static void __init of_dump_addr(const char *s, const __be32 *addr, int na)
+{
+	pr_debug("%s", s);
+	while(na--)
+		pr_cont(" %08x", *(addr++));
+	pr_cont("\n");
+}
+#else
+static void __init of_dump_addr(const char *s, const __be32 *addr, int na) { }
+#endif
+
+/* Callbacks for bus specific translators */
+struct of_bus {
+	void		(*count_cells)(const void *blob, int parentoffset,
+				int *addrc, int *sizec);
+	u64		(*map)(__be32 *addr, const __be32 *range,
+				int na, int ns, int pna);
+	int		(*translate)(__be32 *addr, u64 offset, int na);
+};
+
+/* Default translator (generic bus) */
+static void __init fdt_bus_default_count_cells(const void *blob, int parentoffset,
+					       int *addrc, int *sizec)
+{
+	const __be32 *prop;
+
+	if (addrc) {
+		prop = fdt_getprop(blob, parentoffset, "#address-cells", NULL);
+		if (prop)
+			*addrc = be32_to_cpup(prop);
+		else
+			*addrc = dt_root_addr_cells;
+	}
+
+	if (sizec) {
+		prop = fdt_getprop(blob, parentoffset, "#size-cells", NULL);
+		if (prop)
+			*sizec = be32_to_cpup(prop);
+		else
+			*sizec = dt_root_size_cells;
+	}
+}
+
+static u64 __init fdt_bus_default_map(__be32 *addr, const __be32 *range,
+				      int na, int ns, int pna)
+{
+	u64 cp, s, da;
+
+	cp = of_read_number(range, na);
+	s  = of_read_number(range + na + pna, ns);
+	da = of_read_number(addr, na);
+
+	pr_debug("default map, cp=%llx, s=%llx, da=%llx\n",
+	    cp, s, da);
+
+	if (da < cp || da >= (cp + s))
+		return OF_BAD_ADDR;
+	return da - cp;
+}
+
+static int __init fdt_bus_default_translate(__be32 *addr, u64 offset, int na)
+{
+	u64 a = of_read_number(addr, na);
+	memset(addr, 0, na * 4);
+	a += offset;
+	if (na > 1)
+		addr[na - 2] = cpu_to_fdt32(a >> 32);
+	addr[na - 1] = cpu_to_fdt32(a & 0xffffffffu);
+
+	return 0;
+}
+
+/* Array of bus specific translators */
+static const struct of_bus of_busses[] __initconst = {
+	/* Default */
+	{
+		.count_cells = fdt_bus_default_count_cells,
+		.map = fdt_bus_default_map,
+		.translate = fdt_bus_default_translate,
+	},
+};
+
+static int __init fdt_translate_one(const void *blob, int parent,
+				    const struct of_bus *bus,
+				    const struct of_bus *pbus, __be32 *addr,
+				    int na, int ns, int pna, const char *rprop)
+{
+	const __be32 *ranges;
+	int rlen;
+	int rone;
+	u64 offset = OF_BAD_ADDR;
+
+	ranges = fdt_getprop(blob, parent, rprop, &rlen);
+	if (!ranges)
+		return 1;
+	if (rlen == 0) {
+		offset = of_read_number(addr, na);
+		memset(addr, 0, pna * 4);
+		pr_debug("empty ranges, 1:1 translation\n");
+		goto finish;
+	}
+
+	pr_debug("walking ranges...\n");
+
+	/* Now walk through the ranges */
+	rlen /= 4;
+	rone = na + pna + ns;
+	for (; rlen >= rone; rlen -= rone, ranges += rone) {
+		offset = bus->map(addr, ranges, na, ns, pna);
+		if (offset != OF_BAD_ADDR)
+			break;
+	}
+	if (offset == OF_BAD_ADDR) {
+		pr_debug("not found !\n");
+		return 1;
+	}
+	memcpy(addr, ranges + na, 4 * pna);
+
+ finish:
+	of_dump_addr("parent translation for:", addr, pna);
+	pr_debug("with offset: %llx\n", offset);
+
+	/* Translate it into parent bus space */
+	return pbus->translate(addr, offset, pna);
+}
+
+/*
+ * Translate an address from the device-tree into a CPU physical address,
+ * this walks up the tree and applies the various bus mappings on the
+ * way.
+ *
+ * Note: We consider that crossing any level with #size-cells == 0 to mean
+ * that translation is impossible (that is we are not dealing with a value
+ * that can be mapped to a cpu physical address). This is not really specified
+ * that way, but this is traditionally the way IBM at least do things
+ */
+static u64 __init fdt_translate_address(const void *blob, int node_offset)
+{
+	int parent, len;
+	const struct of_bus *bus, *pbus;
+	const __be32 *reg;
+	__be32 addr[OF_MAX_ADDR_CELLS];
+	int na, ns, pna, pns;
+	u64 result = OF_BAD_ADDR;
+
+	pr_debug("** translation for device %s **\n",
+		 fdt_get_name(blob, node_offset, NULL));
+
+	reg = fdt_getprop(blob, node_offset, "reg", &len);
+	if (!reg) {
+		pr_err("warning: device tree node '%s' has no address.\n",
+			fdt_get_name(blob, node_offset, NULL));
+		goto bail;
+	}
+
+	/* Get parent & match bus type */
+	parent = fdt_parent_offset(blob, node_offset);
+	if (parent < 0)
+		goto bail;
+	bus = &of_busses[0];
+
+	/* Cound address cells & copy address locally */
+	bus->count_cells(blob, parent, &na, &ns);
+	if (!OF_CHECK_COUNTS(na, ns)) {
+		pr_err("Bad cell count for %s\n",
+		       fdt_get_name(blob, node_offset, NULL));
+		goto bail;
+	}
+	memcpy(addr, reg, na * 4);
+
+	pr_debug("bus (na=%d, ns=%d) on %s\n",
+		 na, ns, fdt_get_name(blob, parent, NULL));
+	of_dump_addr("translating address:", addr, na);
+
+	/* Translate */
+	for (;;) {
+		/* Switch to parent bus */
+		node_offset = parent;
+		parent = fdt_parent_offset(blob, node_offset);
+
+		/* If root, we have finished */
+		if (parent < 0) {
+			pr_debug("reached root node\n");
+			result = of_read_number(addr, na);
+			break;
+		}
+
+		/* Get new parent bus and counts */
+		pbus = &of_busses[0];
+		pbus->count_cells(blob, parent, &pna, &pns);
+		if (!OF_CHECK_COUNTS(pna, pns)) {
+			pr_err("Bad cell count for %s\n",
+				fdt_get_name(blob, node_offset, NULL));
+			break;
+		}
+
+		pr_debug("parent bus (na=%d, ns=%d) on %s\n",
+			 pna, pns, fdt_get_name(blob, parent, NULL));
+
+		/* Apply bus translation */
+		if (fdt_translate_one(blob, node_offset, bus, pbus,
+					addr, na, ns, pna, "ranges"))
+			break;
+
+		/* Complete the move up one level */
+		na = pna;
+		ns = pns;
+		bus = pbus;
+
+		of_dump_addr("one level translation:", addr, na);
+	}
+ bail:
+	return result;
+}
+
+/**
+ * of_flat_dt_translate_address - translate DT addr into CPU phys addr
+ * @node: node in the flat blob
+ */
+u64 __init of_flat_dt_translate_address(unsigned long node)
+{
+	return fdt_translate_address(initial_boot_params, node);
+}
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
new file mode 100644
index 000000000..2bac44f09
--- /dev/null
+++ b/drivers/of/irq.c
@@ -0,0 +1,744 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Derived from arch/i386/kernel/irq.c
+ *    Copyright (C) 1992 Linus Torvalds
+ *  Adapted from arch/i386 by Gary Thomas
+ *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
+ *    Copyright (C) 1996-2001 Cort Dougan
+ *  Adapted for Power Macintosh by Paul Mackerras
+ *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
+ *
+ * This file contains the code used to make IRQ descriptions in the
+ * device tree to actual irq numbers on an interrupt controller
+ * driver.
+ */
+
+#define pr_fmt(fmt)	"OF: " fmt
+
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+
+/**
+ * irq_of_parse_and_map - Parse and map an interrupt into linux virq space
+ * @dev: Device node of the device whose interrupt is to be mapped
+ * @index: Index of the interrupt to map
+ *
+ * This function is a wrapper that chains of_irq_parse_one() and
+ * irq_create_of_mapping() to make things easier to callers
+ */
+unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
+{
+	struct of_phandle_args oirq;
+
+	if (of_irq_parse_one(dev, index, &oirq))
+		return 0;
+
+	return irq_create_of_mapping(&oirq);
+}
+EXPORT_SYMBOL_GPL(irq_of_parse_and_map);
+
+/**
+ * of_irq_find_parent - Given a device node, find its interrupt parent node
+ * @child: pointer to device node
+ *
+ * Return: A pointer to the interrupt parent node, or NULL if the interrupt
+ * parent could not be determined.
+ */
+struct device_node *of_irq_find_parent(struct device_node *child)
+{
+	struct device_node *p;
+	phandle parent;
+
+	if (!of_node_get(child))
+		return NULL;
+
+	do {
+		if (of_property_read_u32(child, "interrupt-parent", &parent)) {
+			p = of_get_parent(child);
+		} else	{
+			if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
+				p = of_node_get(of_irq_dflt_pic);
+			else
+				p = of_find_node_by_phandle(parent);
+		}
+		of_node_put(child);
+		child = p;
+	} while (p && of_get_property(p, "#interrupt-cells", NULL) == NULL);
+
+	return p;
+}
+EXPORT_SYMBOL_GPL(of_irq_find_parent);
+
+/*
+ * These interrupt controllers abuse interrupt-map for unspeakable
+ * reasons and rely on the core code to *ignore* it (the drivers do
+ * their own parsing of the property).
+ *
+ * If you think of adding to the list for something *new*, think
+ * again. There is a high chance that you will be sent back to the
+ * drawing board.
+ */
+static const char * const of_irq_imap_abusers[] = {
+	"CBEA,platform-spider-pic",
+	"sti,platform-spider-pic",
+	"realtek,rtl-intc",
+	"fsl,ls1021a-extirq",
+	"fsl,ls1043a-extirq",
+	"fsl,ls1088a-extirq",
+	"renesas,rza1-irqc",
+	NULL,
+};
+
+/**
+ * of_irq_parse_raw - Low level interrupt tree parsing
+ * @addr:	address specifier (start of "reg" property of the device) in be32 format
+ * @out_irq:	structure of_phandle_args updated by this function
+ *
+ * This function is a low-level interrupt tree walking function. It
+ * can be used to do a partial walk with synthetized reg and interrupts
+ * properties, for example when resolving PCI interrupts when no device
+ * node exist for the parent. It takes an interrupt specifier structure as
+ * input, walks the tree looking for any interrupt-map properties, translates
+ * the specifier for each map, and then returns the translated map.
+ *
+ * Return: 0 on success and a negative number on error
+ */
+int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
+{
+	struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL;
+	__be32 initial_match_array[MAX_PHANDLE_ARGS];
+	const __be32 *match_array = initial_match_array;
+	const __be32 *tmp, *imap, *imask, dummy_imask[] = { [0 ... MAX_PHANDLE_ARGS] = cpu_to_be32(~0) };
+	u32 intsize = 1, addrsize, newintsize = 0, newaddrsize = 0;
+	int imaplen, match, i, rc = -EINVAL;
+
+#ifdef DEBUG
+	of_print_phandle_args("of_irq_parse_raw: ", out_irq);
+#endif
+
+	ipar = of_node_get(out_irq->np);
+
+	/* First get the #interrupt-cells property of the current cursor
+	 * that tells us how to interpret the passed-in intspec. If there
+	 * is none, we are nice and just walk up the tree
+	 */
+	do {
+		if (!of_property_read_u32(ipar, "#interrupt-cells", &intsize))
+			break;
+		tnode = ipar;
+		ipar = of_irq_find_parent(ipar);
+		of_node_put(tnode);
+	} while (ipar);
+	if (ipar == NULL) {
+		pr_debug(" -> no parent found !\n");
+		goto fail;
+	}
+
+	pr_debug("of_irq_parse_raw: ipar=%pOF, size=%d\n", ipar, intsize);
+
+	if (out_irq->args_count != intsize)
+		goto fail;
+
+	/* Look for this #address-cells. We have to implement the old linux
+	 * trick of looking for the parent here as some device-trees rely on it
+	 */
+	old = of_node_get(ipar);
+	do {
+		tmp = of_get_property(old, "#address-cells", NULL);
+		tnode = of_get_parent(old);
+		of_node_put(old);
+		old = tnode;
+	} while (old && tmp == NULL);
+	of_node_put(old);
+	old = NULL;
+	addrsize = (tmp == NULL) ? 2 : be32_to_cpu(*tmp);
+
+	pr_debug(" -> addrsize=%d\n", addrsize);
+
+	/* Range check so that the temporary buffer doesn't overflow */
+	if (WARN_ON(addrsize + intsize > MAX_PHANDLE_ARGS)) {
+		rc = -EFAULT;
+		goto fail;
+	}
+
+	/* Precalculate the match array - this simplifies match loop */
+	for (i = 0; i < addrsize; i++)
+		initial_match_array[i] = addr ? addr[i] : 0;
+	for (i = 0; i < intsize; i++)
+		initial_match_array[addrsize + i] = cpu_to_be32(out_irq->args[i]);
+
+	/* Now start the actual "proper" walk of the interrupt tree */
+	while (ipar != NULL) {
+		/*
+		 * Now check if cursor is an interrupt-controller and
+		 * if it is then we are done, unless there is an
+		 * interrupt-map which takes precedence except on one
+		 * of these broken platforms that want to parse
+		 * interrupt-map themselves for $reason.
+		 */
+		bool intc = of_property_read_bool(ipar, "interrupt-controller");
+
+		imap = of_get_property(ipar, "interrupt-map", &imaplen);
+		if (intc &&
+		    (!imap || of_device_compatible_match(ipar, of_irq_imap_abusers))) {
+			pr_debug(" -> got it !\n");
+			return 0;
+		}
+
+		/*
+		 * interrupt-map parsing does not work without a reg
+		 * property when #address-cells != 0
+		 */
+		if (addrsize && !addr) {
+			pr_debug(" -> no reg passed in when needed !\n");
+			goto fail;
+		}
+
+		/* No interrupt map, check for an interrupt parent */
+		if (imap == NULL) {
+			pr_debug(" -> no map, getting parent\n");
+			newpar = of_irq_find_parent(ipar);
+			goto skiplevel;
+		}
+		imaplen /= sizeof(u32);
+
+		/* Look for a mask */
+		imask = of_get_property(ipar, "interrupt-map-mask", NULL);
+		if (!imask)
+			imask = dummy_imask;
+
+		/* Parse interrupt-map */
+		match = 0;
+		while (imaplen > (addrsize + intsize + 1) && !match) {
+			/* Compare specifiers */
+			match = 1;
+			for (i = 0; i < (addrsize + intsize); i++, imaplen--)
+				match &= !((match_array[i] ^ *imap++) & imask[i]);
+
+			pr_debug(" -> match=%d (imaplen=%d)\n", match, imaplen);
+
+			/* Get the interrupt parent */
+			if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
+				newpar = of_node_get(of_irq_dflt_pic);
+			else
+				newpar = of_find_node_by_phandle(be32_to_cpup(imap));
+			imap++;
+			--imaplen;
+
+			/* Check if not found */
+			if (newpar == NULL) {
+				pr_debug(" -> imap parent not found !\n");
+				goto fail;
+			}
+
+			if (!of_device_is_available(newpar))
+				match = 0;
+
+			/* Get #interrupt-cells and #address-cells of new
+			 * parent
+			 */
+			if (of_property_read_u32(newpar, "#interrupt-cells",
+						 &newintsize)) {
+				pr_debug(" -> parent lacks #interrupt-cells!\n");
+				goto fail;
+			}
+			if (of_property_read_u32(newpar, "#address-cells",
+						 &newaddrsize))
+				newaddrsize = 0;
+
+			pr_debug(" -> newintsize=%d, newaddrsize=%d\n",
+			    newintsize, newaddrsize);
+
+			/* Check for malformed properties */
+			if (WARN_ON(newaddrsize + newintsize > MAX_PHANDLE_ARGS)
+			    || (imaplen < (newaddrsize + newintsize))) {
+				rc = -EFAULT;
+				goto fail;
+			}
+
+			imap += newaddrsize + newintsize;
+			imaplen -= newaddrsize + newintsize;
+
+			pr_debug(" -> imaplen=%d\n", imaplen);
+		}
+		if (!match) {
+			if (intc) {
+				/*
+				 * The PASEMI Nemo is a known offender, so
+				 * let's only warn for anyone else.
+				 */
+				WARN(!IS_ENABLED(CONFIG_PPC_PASEMI),
+				     "%pOF interrupt-map failed, using interrupt-controller\n",
+				     ipar);
+				return 0;
+			}
+
+			goto fail;
+		}
+
+		/*
+		 * Successfully parsed an interrupt-map translation; copy new
+		 * interrupt specifier into the out_irq structure
+		 */
+		match_array = imap - newaddrsize - newintsize;
+		for (i = 0; i < newintsize; i++)
+			out_irq->args[i] = be32_to_cpup(imap - newintsize + i);
+		out_irq->args_count = intsize = newintsize;
+		addrsize = newaddrsize;
+
+		if (ipar == newpar) {
+			pr_debug("%pOF interrupt-map entry to self\n", ipar);
+			return 0;
+		}
+
+	skiplevel:
+		/* Iterate again with new parent */
+		out_irq->np = newpar;
+		pr_debug(" -> new parent: %pOF\n", newpar);
+		of_node_put(ipar);
+		ipar = newpar;
+		newpar = NULL;
+	}
+	rc = -ENOENT; /* No interrupt-map found */
+
+ fail:
+	of_node_put(ipar);
+	of_node_put(newpar);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(of_irq_parse_raw);
+
+/**
+ * of_irq_parse_one - Resolve an interrupt for a device
+ * @device: the device whose interrupt is to be resolved
+ * @index: index of the interrupt to resolve
+ * @out_irq: structure of_phandle_args filled by this function
+ *
+ * This function resolves an interrupt for a node by walking the interrupt tree,
+ * finding which interrupt controller node it is attached to, and returning the
+ * interrupt specifier that can be used to retrieve a Linux IRQ number.
+ */
+int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_args *out_irq)
+{
+	struct device_node *p;
+	const __be32 *addr;
+	u32 intsize;
+	int i, res;
+
+	pr_debug("of_irq_parse_one: dev=%pOF, index=%d\n", device, index);
+
+	/* OldWorld mac stuff is "special", handle out of line */
+	if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
+		return of_irq_parse_oldworld(device, index, out_irq);
+
+	/* Get the reg property (if any) */
+	addr = of_get_property(device, "reg", NULL);
+
+	/* Try the new-style interrupts-extended first */
+	res = of_parse_phandle_with_args(device, "interrupts-extended",
+					"#interrupt-cells", index, out_irq);
+	if (!res)
+		return of_irq_parse_raw(addr, out_irq);
+
+	/* Look for the interrupt parent. */
+	p = of_irq_find_parent(device);
+	if (p == NULL)
+		return -EINVAL;
+
+	/* Get size of interrupt specifier */
+	if (of_property_read_u32(p, "#interrupt-cells", &intsize)) {
+		res = -EINVAL;
+		goto out;
+	}
+
+	pr_debug(" parent=%pOF, intsize=%d\n", p, intsize);
+
+	/* Copy intspec into irq structure */
+	out_irq->np = p;
+	out_irq->args_count = intsize;
+	for (i = 0; i < intsize; i++) {
+		res = of_property_read_u32_index(device, "interrupts",
+						 (index * intsize) + i,
+						 out_irq->args + i);
+		if (res)
+			goto out;
+	}
+
+	pr_debug(" intspec=%d\n", *out_irq->args);
+
+
+	/* Check if there are any interrupt-map translations to process */
+	res = of_irq_parse_raw(addr, out_irq);
+ out:
+	of_node_put(p);
+	return res;
+}
+EXPORT_SYMBOL_GPL(of_irq_parse_one);
+
+/**
+ * of_irq_to_resource - Decode a node's IRQ and return it as a resource
+ * @dev: pointer to device tree node
+ * @index: zero-based index of the irq
+ * @r: pointer to resource structure to return result into.
+ */
+int of_irq_to_resource(struct device_node *dev, int index, struct resource *r)
+{
+	int irq = of_irq_get(dev, index);
+
+	if (irq < 0)
+		return irq;
+
+	/* Only dereference the resource if both the
+	 * resource and the irq are valid. */
+	if (r && irq) {
+		const char *name = NULL;
+
+		memset(r, 0, sizeof(*r));
+		/*
+		 * Get optional "interrupt-names" property to add a name
+		 * to the resource.
+		 */
+		of_property_read_string_index(dev, "interrupt-names", index,
+					      &name);
+
+		r->start = r->end = irq;
+		r->flags = IORESOURCE_IRQ | irqd_get_trigger_type(irq_get_irq_data(irq));
+		r->name = name ? name : of_node_full_name(dev);
+	}
+
+	return irq;
+}
+EXPORT_SYMBOL_GPL(of_irq_to_resource);
+
+/**
+ * of_irq_get - Decode a node's IRQ and return it as a Linux IRQ number
+ * @dev: pointer to device tree node
+ * @index: zero-based index of the IRQ
+ *
+ * Return: Linux IRQ number on success, or 0 on the IRQ mapping failure, or
+ * -EPROBE_DEFER if the IRQ domain is not yet created, or error code in case
+ * of any other failure.
+ */
+int of_irq_get(struct device_node *dev, int index)
+{
+	int rc;
+	struct of_phandle_args oirq;
+	struct irq_domain *domain;
+
+	rc = of_irq_parse_one(dev, index, &oirq);
+	if (rc)
+		return rc;
+
+	domain = irq_find_host(oirq.np);
+	if (!domain)
+		return -EPROBE_DEFER;
+
+	return irq_create_of_mapping(&oirq);
+}
+EXPORT_SYMBOL_GPL(of_irq_get);
+
+/**
+ * of_irq_get_byname - Decode a node's IRQ and return it as a Linux IRQ number
+ * @dev: pointer to device tree node
+ * @name: IRQ name
+ *
+ * Return: Linux IRQ number on success, or 0 on the IRQ mapping failure, or
+ * -EPROBE_DEFER if the IRQ domain is not yet created, or error code in case
+ * of any other failure.
+ */
+int of_irq_get_byname(struct device_node *dev, const char *name)
+{
+	int index;
+
+	if (unlikely(!name))
+		return -EINVAL;
+
+	index = of_property_match_string(dev, "interrupt-names", name);
+	if (index < 0)
+		return index;
+
+	return of_irq_get(dev, index);
+}
+EXPORT_SYMBOL_GPL(of_irq_get_byname);
+
+/**
+ * of_irq_count - Count the number of IRQs a node uses
+ * @dev: pointer to device tree node
+ */
+int of_irq_count(struct device_node *dev)
+{
+	struct of_phandle_args irq;
+	int nr = 0;
+
+	while (of_irq_parse_one(dev, nr, &irq) == 0)
+		nr++;
+
+	return nr;
+}
+
+/**
+ * of_irq_to_resource_table - Fill in resource table with node's IRQ info
+ * @dev: pointer to device tree node
+ * @res: array of resources to fill in
+ * @nr_irqs: the number of IRQs (and upper bound for num of @res elements)
+ *
+ * Return: The size of the filled in table (up to @nr_irqs).
+ */
+int of_irq_to_resource_table(struct device_node *dev, struct resource *res,
+		int nr_irqs)
+{
+	int i;
+
+	for (i = 0; i < nr_irqs; i++, res++)
+		if (of_irq_to_resource(dev, i, res) <= 0)
+			break;
+
+	return i;
+}
+EXPORT_SYMBOL_GPL(of_irq_to_resource_table);
+
+struct of_intc_desc {
+	struct list_head	list;
+	of_irq_init_cb_t	irq_init_cb;
+	struct device_node	*dev;
+	struct device_node	*interrupt_parent;
+};
+
+/**
+ * of_irq_init - Scan and init matching interrupt controllers in DT
+ * @matches: 0 terminated array of nodes to match and init function to call
+ *
+ * This function scans the device tree for matching interrupt controller nodes,
+ * and calls their initialization functions in order with parents first.
+ */
+void __init of_irq_init(const struct of_device_id *matches)
+{
+	const struct of_device_id *match;
+	struct device_node *np, *parent = NULL;
+	struct of_intc_desc *desc, *temp_desc;
+	struct list_head intc_desc_list, intc_parent_list;
+
+	INIT_LIST_HEAD(&intc_desc_list);
+	INIT_LIST_HEAD(&intc_parent_list);
+
+	for_each_matching_node_and_match(np, matches, &match) {
+		if (!of_property_read_bool(np, "interrupt-controller") ||
+				!of_device_is_available(np))
+			continue;
+
+		if (WARN(!match->data, "of_irq_init: no init function for %s\n",
+			 match->compatible))
+			continue;
+
+		/*
+		 * Here, we allocate and populate an of_intc_desc with the node
+		 * pointer, interrupt-parent device_node etc.
+		 */
+		desc = kzalloc(sizeof(*desc), GFP_KERNEL);
+		if (!desc) {
+			of_node_put(np);
+			goto err;
+		}
+
+		desc->irq_init_cb = match->data;
+		desc->dev = of_node_get(np);
+		/*
+		 * interrupts-extended can reference multiple parent domains.
+		 * Arbitrarily pick the first one; assume any other parents
+		 * are the same distance away from the root irq controller.
+		 */
+		desc->interrupt_parent = of_parse_phandle(np, "interrupts-extended", 0);
+		if (!desc->interrupt_parent)
+			desc->interrupt_parent = of_irq_find_parent(np);
+		if (desc->interrupt_parent == np) {
+			of_node_put(desc->interrupt_parent);
+			desc->interrupt_parent = NULL;
+		}
+		list_add_tail(&desc->list, &intc_desc_list);
+	}
+
+	/*
+	 * The root irq controller is the one without an interrupt-parent.
+	 * That one goes first, followed by the controllers that reference it,
+	 * followed by the ones that reference the 2nd level controllers, etc.
+	 */
+	while (!list_empty(&intc_desc_list)) {
+		/*
+		 * Process all controllers with the current 'parent'.
+		 * First pass will be looking for NULL as the parent.
+		 * The assumption is that NULL parent means a root controller.
+		 */
+		list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
+			int ret;
+
+			if (desc->interrupt_parent != parent)
+				continue;
+
+			list_del(&desc->list);
+
+			of_node_set_flag(desc->dev, OF_POPULATED);
+
+			pr_debug("of_irq_init: init %pOF (%p), parent %p\n",
+				 desc->dev,
+				 desc->dev, desc->interrupt_parent);
+			ret = desc->irq_init_cb(desc->dev,
+						desc->interrupt_parent);
+			if (ret) {
+				pr_err("%s: Failed to init %pOF (%p), parent %p\n",
+				       __func__, desc->dev, desc->dev,
+				       desc->interrupt_parent);
+				of_node_clear_flag(desc->dev, OF_POPULATED);
+				kfree(desc);
+				continue;
+			}
+
+			/*
+			 * This one is now set up; add it to the parent list so
+			 * its children can get processed in a subsequent pass.
+			 */
+			list_add_tail(&desc->list, &intc_parent_list);
+		}
+
+		/* Get the next pending parent that might have children */
+		desc = list_first_entry_or_null(&intc_parent_list,
+						typeof(*desc), list);
+		if (!desc) {
+			pr_err("of_irq_init: children remain, but no parents\n");
+			break;
+		}
+		list_del(&desc->list);
+		parent = desc->dev;
+		kfree(desc);
+	}
+
+	list_for_each_entry_safe(desc, temp_desc, &intc_parent_list, list) {
+		list_del(&desc->list);
+		kfree(desc);
+	}
+err:
+	list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
+		list_del(&desc->list);
+		of_node_put(desc->dev);
+		kfree(desc);
+	}
+}
+
+static u32 __of_msi_map_id(struct device *dev, struct device_node **np,
+			    u32 id_in)
+{
+	struct device *parent_dev;
+	u32 id_out = id_in;
+
+	/*
+	 * Walk up the device parent links looking for one with a
+	 * "msi-map" property.
+	 */
+	for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent)
+		if (!of_map_id(parent_dev->of_node, id_in, "msi-map",
+				"msi-map-mask", np, &id_out))
+			break;
+	return id_out;
+}
+
+/**
+ * of_msi_map_id - Map a MSI ID for a device.
+ * @dev: device for which the mapping is to be done.
+ * @msi_np: device node of the expected msi controller.
+ * @id_in: unmapped MSI ID for the device.
+ *
+ * Walk up the device hierarchy looking for devices with a "msi-map"
+ * property.  If found, apply the mapping to @id_in.
+ *
+ * Return: The mapped MSI ID.
+ */
+u32 of_msi_map_id(struct device *dev, struct device_node *msi_np, u32 id_in)
+{
+	return __of_msi_map_id(dev, &msi_np, id_in);
+}
+
+/**
+ * of_msi_map_get_device_domain - Use msi-map to find the relevant MSI domain
+ * @dev: device for which the mapping is to be done.
+ * @id: Device ID.
+ * @bus_token: Bus token
+ *
+ * Walk up the device hierarchy looking for devices with a "msi-map"
+ * property.
+ *
+ * Returns: the MSI domain for this device (or NULL on failure)
+ */
+struct irq_domain *of_msi_map_get_device_domain(struct device *dev, u32 id,
+						u32 bus_token)
+{
+	struct device_node *np = NULL;
+
+	__of_msi_map_id(dev, &np, id);
+	return irq_find_matching_host(np, bus_token);
+}
+
+/**
+ * of_msi_get_domain - Use msi-parent to find the relevant MSI domain
+ * @dev: device for which the domain is requested
+ * @np: device node for @dev
+ * @token: bus type for this domain
+ *
+ * Parse the msi-parent property (both the simple and the complex
+ * versions), and returns the corresponding MSI domain.
+ *
+ * Returns: the MSI domain for this device (or NULL on failure).
+ */
+struct irq_domain *of_msi_get_domain(struct device *dev,
+				     struct device_node *np,
+				     enum irq_domain_bus_token token)
+{
+	struct device_node *msi_np;
+	struct irq_domain *d;
+
+	/* Check for a single msi-parent property */
+	msi_np = of_parse_phandle(np, "msi-parent", 0);
+	if (msi_np && !of_property_read_bool(msi_np, "#msi-cells")) {
+		d = irq_find_matching_host(msi_np, token);
+		if (!d)
+			of_node_put(msi_np);
+		return d;
+	}
+
+	if (token == DOMAIN_BUS_PLATFORM_MSI) {
+		/* Check for the complex msi-parent version */
+		struct of_phandle_args args;
+		int index = 0;
+
+		while (!of_parse_phandle_with_args(np, "msi-parent",
+						   "#msi-cells",
+						   index, &args)) {
+			d = irq_find_matching_host(args.np, token);
+			if (d)
+				return d;
+
+			of_node_put(args.np);
+			index++;
+		}
+	}
+
+	return NULL;
+}
+
+/**
+ * of_msi_configure - Set the msi_domain field of a device
+ * @dev: device structure to associate with an MSI irq domain
+ * @np: device node for that device
+ */
+void of_msi_configure(struct device *dev, struct device_node *np)
+{
+	dev_set_msi_domain(dev,
+			   of_msi_get_domain(dev, np, DOMAIN_BUS_PLATFORM_MSI));
+}
+EXPORT_SYMBOL_GPL(of_msi_configure);
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
new file mode 100644
index 000000000..68278340c
--- /dev/null
+++ b/drivers/of/kexec.c
@@ -0,0 +1,472 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 Arm Limited
+ *
+ * Based on arch/arm64/kernel/machine_kexec_file.c:
+ *  Copyright (C) 2018 Linaro Limited
+ *
+ * And arch/powerpc/kexec/file_load.c:
+ *  Copyright (C) 2016  IBM Corporation
+ */
+
+#include <linux/ima.h>
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/memblock.h>
+#include <linux/libfdt.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#define RNG_SEED_SIZE		128
+
+/*
+ * Additional space needed for the FDT buffer so that we can add initrd,
+ * bootargs, kaslr-seed, rng-seed, useable-memory-range and elfcorehdr.
+ */
+#define FDT_EXTRA_SPACE 0x1000
+
+/**
+ * fdt_find_and_del_mem_rsv - delete memory reservation with given address and size
+ *
+ * @fdt:	Flattened device tree for the current kernel.
+ * @start:	Starting address of the reserved memory.
+ * @size:	Size of the reserved memory.
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+static int fdt_find_and_del_mem_rsv(void *fdt, unsigned long start, unsigned long size)
+{
+	int i, ret, num_rsvs = fdt_num_mem_rsv(fdt);
+
+	for (i = 0; i < num_rsvs; i++) {
+		u64 rsv_start, rsv_size;
+
+		ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
+		if (ret) {
+			pr_err("Malformed device tree.\n");
+			return -EINVAL;
+		}
+
+		if (rsv_start == start && rsv_size == size) {
+			ret = fdt_del_mem_rsv(fdt, i);
+			if (ret) {
+				pr_err("Error deleting device tree reservation.\n");
+				return -EINVAL;
+			}
+
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+
+/**
+ * get_addr_size_cells - Get address and size of root node
+ *
+ * @addr_cells: Return address of the root node
+ * @size_cells: Return size of the root node
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+static int get_addr_size_cells(int *addr_cells, int *size_cells)
+{
+	struct device_node *root;
+
+	root = of_find_node_by_path("/");
+	if (!root)
+		return -EINVAL;
+
+	*addr_cells = of_n_addr_cells(root);
+	*size_cells = of_n_size_cells(root);
+
+	of_node_put(root);
+
+	return 0;
+}
+
+/**
+ * do_get_kexec_buffer - Get address and size of device tree property
+ *
+ * @prop: Device tree property
+ * @len: Size of @prop
+ * @addr: Return address of the node
+ * @size: Return size of the node
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+static int do_get_kexec_buffer(const void *prop, int len, unsigned long *addr,
+			       size_t *size)
+{
+	int ret, addr_cells, size_cells;
+
+	ret = get_addr_size_cells(&addr_cells, &size_cells);
+	if (ret)
+		return ret;
+
+	if (len < 4 * (addr_cells + size_cells))
+		return -ENOENT;
+
+	*addr = of_read_number(prop, addr_cells);
+	*size = of_read_number(prop + 4 * addr_cells, size_cells);
+
+	return 0;
+}
+
+#ifdef CONFIG_HAVE_IMA_KEXEC
+/**
+ * ima_get_kexec_buffer - get IMA buffer from the previous kernel
+ * @addr:	On successful return, set to point to the buffer contents.
+ * @size:	On successful return, set to the buffer size.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int __init ima_get_kexec_buffer(void **addr, size_t *size)
+{
+	int ret, len;
+	unsigned long tmp_addr;
+	unsigned long start_pfn, end_pfn;
+	size_t tmp_size;
+	const void *prop;
+
+	prop = of_get_property(of_chosen, "linux,ima-kexec-buffer", &len);
+	if (!prop)
+		return -ENOENT;
+
+	ret = do_get_kexec_buffer(prop, len, &tmp_addr, &tmp_size);
+	if (ret)
+		return ret;
+
+	/* Do some sanity on the returned size for the ima-kexec buffer */
+	if (!tmp_size)
+		return -ENOENT;
+
+	/*
+	 * Calculate the PFNs for the buffer and ensure
+	 * they are with in addressable memory.
+	 */
+	start_pfn = PHYS_PFN(tmp_addr);
+	end_pfn = PHYS_PFN(tmp_addr + tmp_size - 1);
+	if (!page_is_ram(start_pfn) || !page_is_ram(end_pfn)) {
+		pr_warn("IMA buffer at 0x%lx, size = 0x%zx beyond memory\n",
+			tmp_addr, tmp_size);
+		return -EINVAL;
+	}
+
+	*addr = __va(tmp_addr);
+	*size = tmp_size;
+
+	return 0;
+}
+
+/**
+ * ima_free_kexec_buffer - free memory used by the IMA buffer
+ */
+int __init ima_free_kexec_buffer(void)
+{
+	int ret;
+	unsigned long addr;
+	size_t size;
+	struct property *prop;
+
+	prop = of_find_property(of_chosen, "linux,ima-kexec-buffer", NULL);
+	if (!prop)
+		return -ENOENT;
+
+	ret = do_get_kexec_buffer(prop->value, prop->length, &addr, &size);
+	if (ret)
+		return ret;
+
+	ret = of_remove_property(of_chosen, prop);
+	if (ret)
+		return ret;
+
+	memblock_free_late(addr, size);
+	return 0;
+}
+#endif
+
+/**
+ * remove_ima_buffer - remove the IMA buffer property and reservation from @fdt
+ *
+ * @fdt: Flattened Device Tree to update
+ * @chosen_node: Offset to the chosen node in the device tree
+ *
+ * The IMA measurement buffer is of no use to a subsequent kernel, so we always
+ * remove it from the device tree.
+ */
+static void remove_ima_buffer(void *fdt, int chosen_node)
+{
+	int ret, len;
+	unsigned long addr;
+	size_t size;
+	const void *prop;
+
+	if (!IS_ENABLED(CONFIG_HAVE_IMA_KEXEC))
+		return;
+
+	prop = fdt_getprop(fdt, chosen_node, "linux,ima-kexec-buffer", &len);
+	if (!prop)
+		return;
+
+	ret = do_get_kexec_buffer(prop, len, &addr, &size);
+	fdt_delprop(fdt, chosen_node, "linux,ima-kexec-buffer");
+	if (ret)
+		return;
+
+	ret = fdt_find_and_del_mem_rsv(fdt, addr, size);
+	if (!ret)
+		pr_debug("Removed old IMA buffer reservation.\n");
+}
+
+#ifdef CONFIG_IMA_KEXEC
+/**
+ * setup_ima_buffer - add IMA buffer information to the fdt
+ * @image:		kexec image being loaded.
+ * @fdt:		Flattened device tree for the next kernel.
+ * @chosen_node:	Offset to the chosen node.
+ *
+ * Return: 0 on success, or negative errno on error.
+ */
+static int setup_ima_buffer(const struct kimage *image, void *fdt,
+			    int chosen_node)
+{
+	int ret;
+
+	if (!image->ima_buffer_size)
+		return 0;
+
+	ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+				       "linux,ima-kexec-buffer",
+				       image->ima_buffer_addr,
+				       image->ima_buffer_size);
+	if (ret < 0)
+		return -EINVAL;
+
+	ret = fdt_add_mem_rsv(fdt, image->ima_buffer_addr,
+			      image->ima_buffer_size);
+	if (ret)
+		return -EINVAL;
+
+	pr_debug("IMA buffer at 0x%llx, size = 0x%zx\n",
+		 image->ima_buffer_addr, image->ima_buffer_size);
+
+	return 0;
+}
+#else /* CONFIG_IMA_KEXEC */
+static inline int setup_ima_buffer(const struct kimage *image, void *fdt,
+				   int chosen_node)
+{
+	return 0;
+}
+#endif /* CONFIG_IMA_KEXEC */
+
+/*
+ * of_kexec_alloc_and_setup_fdt - Alloc and setup a new Flattened Device Tree
+ *
+ * @image:		kexec image being loaded.
+ * @initrd_load_addr:	Address where the next initrd will be loaded.
+ * @initrd_len:		Size of the next initrd, or 0 if there will be none.
+ * @cmdline:		Command line for the next kernel, or NULL if there will
+ *			be none.
+ * @extra_fdt_size:	Additional size for the new FDT buffer.
+ *
+ * Return: fdt on success, or NULL errno on error.
+ */
+void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
+				   unsigned long initrd_load_addr,
+				   unsigned long initrd_len,
+				   const char *cmdline, size_t extra_fdt_size)
+{
+	void *fdt;
+	int ret, chosen_node, len;
+	const void *prop;
+	size_t fdt_size;
+
+	fdt_size = fdt_totalsize(initial_boot_params) +
+		   (cmdline ? strlen(cmdline) : 0) +
+		   FDT_EXTRA_SPACE +
+		   extra_fdt_size;
+	fdt = kvmalloc(fdt_size, GFP_KERNEL);
+	if (!fdt)
+		return NULL;
+
+	ret = fdt_open_into(initial_boot_params, fdt, fdt_size);
+	if (ret < 0) {
+		pr_err("Error %d setting up the new device tree.\n", ret);
+		goto out;
+	}
+
+	/* Remove memory reservation for the current device tree. */
+	ret = fdt_find_and_del_mem_rsv(fdt, __pa(initial_boot_params),
+				       fdt_totalsize(initial_boot_params));
+	if (ret == -EINVAL) {
+		pr_err("Error removing memory reservation.\n");
+		goto out;
+	}
+
+	chosen_node = fdt_path_offset(fdt, "/chosen");
+	if (chosen_node == -FDT_ERR_NOTFOUND)
+		chosen_node = fdt_add_subnode(fdt, fdt_path_offset(fdt, "/"),
+					      "chosen");
+	if (chosen_node < 0) {
+		ret = chosen_node;
+		goto out;
+	}
+
+	ret = fdt_delprop(fdt, chosen_node, "linux,elfcorehdr");
+	if (ret && ret != -FDT_ERR_NOTFOUND)
+		goto out;
+	ret = fdt_delprop(fdt, chosen_node, "linux,usable-memory-range");
+	if (ret && ret != -FDT_ERR_NOTFOUND)
+		goto out;
+
+	/* Did we boot using an initrd? */
+	prop = fdt_getprop(fdt, chosen_node, "linux,initrd-start", &len);
+	if (prop) {
+		u64 tmp_start, tmp_end, tmp_size;
+
+		tmp_start = of_read_number(prop, len / 4);
+
+		prop = fdt_getprop(fdt, chosen_node, "linux,initrd-end", &len);
+		if (!prop) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		tmp_end = of_read_number(prop, len / 4);
+
+		/*
+		 * kexec reserves exact initrd size, while firmware may
+		 * reserve a multiple of PAGE_SIZE, so check for both.
+		 */
+		tmp_size = tmp_end - tmp_start;
+		ret = fdt_find_and_del_mem_rsv(fdt, tmp_start, tmp_size);
+		if (ret == -ENOENT)
+			ret = fdt_find_and_del_mem_rsv(fdt, tmp_start,
+						       round_up(tmp_size, PAGE_SIZE));
+		if (ret == -EINVAL)
+			goto out;
+	}
+
+	/* add initrd-* */
+	if (initrd_load_addr) {
+		ret = fdt_setprop_u64(fdt, chosen_node, "linux,initrd-start",
+				      initrd_load_addr);
+		if (ret)
+			goto out;
+
+		ret = fdt_setprop_u64(fdt, chosen_node, "linux,initrd-end",
+				      initrd_load_addr + initrd_len);
+		if (ret)
+			goto out;
+
+		ret = fdt_add_mem_rsv(fdt, initrd_load_addr, initrd_len);
+		if (ret)
+			goto out;
+
+	} else {
+		ret = fdt_delprop(fdt, chosen_node, "linux,initrd-start");
+		if (ret && (ret != -FDT_ERR_NOTFOUND))
+			goto out;
+
+		ret = fdt_delprop(fdt, chosen_node, "linux,initrd-end");
+		if (ret && (ret != -FDT_ERR_NOTFOUND))
+			goto out;
+	}
+
+	if (image->type == KEXEC_TYPE_CRASH) {
+		/* add linux,elfcorehdr */
+		ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+				"linux,elfcorehdr", image->elf_load_addr,
+				image->elf_headers_sz);
+		if (ret)
+			goto out;
+
+		/*
+		 * Avoid elfcorehdr from being stomped on in kdump kernel by
+		 * setting up memory reserve map.
+		 */
+		ret = fdt_add_mem_rsv(fdt, image->elf_load_addr,
+				      image->elf_headers_sz);
+		if (ret)
+			goto out;
+
+		/* add linux,usable-memory-range */
+		ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+				"linux,usable-memory-range", crashk_res.start,
+				crashk_res.end - crashk_res.start + 1);
+		if (ret)
+			goto out;
+
+		if (crashk_low_res.end) {
+			ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
+					"linux,usable-memory-range",
+					crashk_low_res.start,
+					crashk_low_res.end - crashk_low_res.start + 1);
+			if (ret)
+				goto out;
+		}
+	}
+
+	/* add bootargs */
+	if (cmdline) {
+		ret = fdt_setprop_string(fdt, chosen_node, "bootargs", cmdline);
+		if (ret)
+			goto out;
+	} else {
+		ret = fdt_delprop(fdt, chosen_node, "bootargs");
+		if (ret && (ret != -FDT_ERR_NOTFOUND))
+			goto out;
+	}
+
+	/* add kaslr-seed */
+	ret = fdt_delprop(fdt, chosen_node, "kaslr-seed");
+	if (ret == -FDT_ERR_NOTFOUND)
+		ret = 0;
+	else if (ret)
+		goto out;
+
+	if (rng_is_initialized()) {
+		u64 seed = get_random_u64();
+
+		ret = fdt_setprop_u64(fdt, chosen_node, "kaslr-seed", seed);
+		if (ret)
+			goto out;
+	} else {
+		pr_notice("RNG is not initialised: omitting \"%s\" property\n",
+			  "kaslr-seed");
+	}
+
+	/* add rng-seed */
+	if (rng_is_initialized()) {
+		void *rng_seed;
+
+		ret = fdt_setprop_placeholder(fdt, chosen_node, "rng-seed",
+				RNG_SEED_SIZE, &rng_seed);
+		if (ret)
+			goto out;
+		get_random_bytes(rng_seed, RNG_SEED_SIZE);
+	} else {
+		pr_notice("RNG is not initialised: omitting \"%s\" property\n",
+			  "rng-seed");
+	}
+
+	ret = fdt_setprop(fdt, chosen_node, "linux,booted-from-kexec", NULL, 0);
+	if (ret)
+		goto out;
+
+	remove_ima_buffer(fdt, chosen_node);
+	ret = setup_ima_buffer(image, fdt, fdt_path_offset(fdt, "/chosen"));
+
+out:
+	if (ret) {
+		kvfree(fdt);
+		fdt = NULL;
+	}
+
+	return fdt;
+}
diff --git a/drivers/of/kobj.c b/drivers/of/kobj.c
new file mode 100644
index 000000000..7d3853a5a
--- /dev/null
+++ b/drivers/of/kobj.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/of.h>
+#include <linux/slab.h>
+
+#include "of_private.h"
+
+/* true when node is initialized */
+static int of_node_is_initialized(const struct device_node *node)
+{
+	return node && node->kobj.state_initialized;
+}
+
+/* true when node is attached (i.e. present on sysfs) */
+int of_node_is_attached(const struct device_node *node)
+{
+	return node && node->kobj.state_in_sysfs;
+}
+
+
+#ifndef CONFIG_OF_DYNAMIC
+static void of_node_release(struct kobject *kobj)
+{
+	/* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
+}
+#endif /* CONFIG_OF_DYNAMIC */
+
+struct kobj_type of_node_ktype = {
+	.release = of_node_release,
+};
+
+static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
+				struct bin_attribute *bin_attr, char *buf,
+				loff_t offset, size_t count)
+{
+	struct property *pp = container_of(bin_attr, struct property, attr);
+	return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
+}
+
+/* always return newly allocated name, caller must free after use */
+static const char *safe_name(struct kobject *kobj, const char *orig_name)
+{
+	const char *name = orig_name;
+	struct kernfs_node *kn;
+	int i = 0;
+
+	/* don't be a hero. After 16 tries give up */
+	while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {
+		sysfs_put(kn);
+		if (name != orig_name)
+			kfree(name);
+		name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
+	}
+
+	if (name == orig_name) {
+		name = kstrdup(orig_name, GFP_KERNEL);
+	} else {
+		pr_warn("Duplicate name in %s, renamed to \"%s\"\n",
+			kobject_name(kobj), name);
+	}
+	return name;
+}
+
+int __of_add_property_sysfs(struct device_node *np, struct property *pp)
+{
+	int rc;
+
+	/* Important: Don't leak passwords */
+	bool secure = strncmp(pp->name, "security-", 9) == 0;
+
+	if (!IS_ENABLED(CONFIG_SYSFS))
+		return 0;
+
+	if (!of_kset || !of_node_is_attached(np))
+		return 0;
+
+	sysfs_bin_attr_init(&pp->attr);
+	pp->attr.attr.name = safe_name(&np->kobj, pp->name);
+	pp->attr.attr.mode = secure ? 0400 : 0444;
+	pp->attr.size = secure ? 0 : pp->length;
+	pp->attr.read = of_node_property_read;
+
+	rc = sysfs_create_bin_file(&np->kobj, &pp->attr);
+	WARN(rc, "error adding attribute %s to node %pOF\n", pp->name, np);
+	return rc;
+}
+
+void __of_sysfs_remove_bin_file(struct device_node *np, struct property *prop)
+{
+	if (!IS_ENABLED(CONFIG_SYSFS))
+		return;
+
+	sysfs_remove_bin_file(&np->kobj, &prop->attr);
+	kfree(prop->attr.attr.name);
+}
+
+void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
+{
+	/* at early boot, bail here and defer setup to of_init() */
+	if (of_kset && of_node_is_attached(np))
+		__of_sysfs_remove_bin_file(np, prop);
+}
+
+void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
+		struct property *oldprop)
+{
+	/* At early boot, bail out and defer setup to of_init() */
+	if (!of_kset)
+		return;
+
+	if (oldprop)
+		__of_sysfs_remove_bin_file(np, oldprop);
+	__of_add_property_sysfs(np, newprop);
+}
+
+int __of_attach_node_sysfs(struct device_node *np)
+{
+	const char *name;
+	struct kobject *parent;
+	struct property *pp;
+	int rc;
+
+	if (!IS_ENABLED(CONFIG_SYSFS) || !of_kset)
+		return 0;
+
+	np->kobj.kset = of_kset;
+	if (!np->parent) {
+		/* Nodes without parents are new top level trees */
+		name = safe_name(&of_kset->kobj, "base");
+		parent = NULL;
+	} else {
+		name = safe_name(&np->parent->kobj, kbasename(np->full_name));
+		parent = &np->parent->kobj;
+	}
+	if (!name)
+		return -ENOMEM;
+
+	rc = kobject_add(&np->kobj, parent, "%s", name);
+	kfree(name);
+	if (rc)
+		return rc;
+
+	for_each_property_of_node(np, pp)
+		__of_add_property_sysfs(np, pp);
+
+	of_node_get(np);
+	return 0;
+}
+
+void __of_detach_node_sysfs(struct device_node *np)
+{
+	struct property *pp;
+
+	BUG_ON(!of_node_is_initialized(np));
+	if (!of_kset)
+		return;
+
+	/* only remove properties if on sysfs */
+	if (of_node_is_attached(np)) {
+		for_each_property_of_node(np, pp)
+			__of_sysfs_remove_bin_file(np, pp);
+		kobject_del(&np->kobj);
+	}
+
+	of_node_put(np);
+}
diff --git a/drivers/of/of_numa.c b/drivers/of/of_numa.c
new file mode 100644
index 000000000..5949829a1
--- /dev/null
+++ b/drivers/of/of_numa.c
@@ -0,0 +1,186 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * OF NUMA Parsing support.
+ *
+ * Copyright (C) 2015 - 2016 Cavium Inc.
+ */
+
+#define pr_fmt(fmt) "OF: NUMA: " fmt
+
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/nodemask.h>
+
+#include <asm/numa.h>
+
+/* define default numa node to 0 */
+#define DEFAULT_NODE 0
+
+/*
+ * Even though we connect cpus to numa domains later in SMP
+ * init, we need to know the node ids now for all cpus.
+*/
+static void __init of_numa_parse_cpu_nodes(void)
+{
+	u32 nid;
+	int r;
+	struct device_node *np;
+
+	for_each_of_cpu_node(np) {
+		r = of_property_read_u32(np, "numa-node-id", &nid);
+		if (r)
+			continue;
+
+		pr_debug("CPU on %u\n", nid);
+		if (nid >= MAX_NUMNODES)
+			pr_warn("Node id %u exceeds maximum value\n", nid);
+		else
+			node_set(nid, numa_nodes_parsed);
+	}
+}
+
+static int __init of_numa_parse_memory_nodes(void)
+{
+	struct device_node *np = NULL;
+	struct resource rsrc;
+	u32 nid;
+	int i, r;
+
+	for_each_node_by_type(np, "memory") {
+		r = of_property_read_u32(np, "numa-node-id", &nid);
+		if (r == -EINVAL)
+			/*
+			 * property doesn't exist if -EINVAL, continue
+			 * looking for more memory nodes with
+			 * "numa-node-id" property
+			 */
+			continue;
+
+		if (nid >= MAX_NUMNODES) {
+			pr_warn("Node id %u exceeds maximum value\n", nid);
+			r = -EINVAL;
+		}
+
+		for (i = 0; !r && !of_address_to_resource(np, i, &rsrc); i++)
+			r = numa_add_memblk(nid, rsrc.start, rsrc.end + 1);
+
+		if (!i || r) {
+			of_node_put(np);
+			pr_err("bad property in memory node\n");
+			return r ? : -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int __init of_numa_parse_distance_map_v1(struct device_node *map)
+{
+	const __be32 *matrix;
+	int entry_count;
+	int i;
+
+	pr_info("parsing numa-distance-map-v1\n");
+
+	matrix = of_get_property(map, "distance-matrix", NULL);
+	if (!matrix) {
+		pr_err("No distance-matrix property in distance-map\n");
+		return -EINVAL;
+	}
+
+	entry_count = of_property_count_u32_elems(map, "distance-matrix");
+	if (entry_count <= 0) {
+		pr_err("Invalid distance-matrix\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i + 2 < entry_count; i += 3) {
+		u32 nodea, nodeb, distance;
+
+		nodea = of_read_number(matrix, 1);
+		matrix++;
+		nodeb = of_read_number(matrix, 1);
+		matrix++;
+		distance = of_read_number(matrix, 1);
+		matrix++;
+
+		if ((nodea == nodeb && distance != LOCAL_DISTANCE) ||
+		    (nodea != nodeb && distance <= LOCAL_DISTANCE)) {
+			pr_err("Invalid distance[node%d -> node%d] = %d\n",
+			       nodea, nodeb, distance);
+			return -EINVAL;
+		}
+
+		node_set(nodea, numa_nodes_parsed);
+
+		numa_set_distance(nodea, nodeb, distance);
+
+		/* Set default distance of node B->A same as A->B */
+		if (nodeb > nodea)
+			numa_set_distance(nodeb, nodea, distance);
+	}
+
+	return 0;
+}
+
+static int __init of_numa_parse_distance_map(void)
+{
+	int ret = 0;
+	struct device_node *np;
+
+	np = of_find_compatible_node(NULL, NULL,
+				     "numa-distance-map-v1");
+	if (np)
+		ret = of_numa_parse_distance_map_v1(np);
+
+	of_node_put(np);
+	return ret;
+}
+
+int of_node_to_nid(struct device_node *device)
+{
+	struct device_node *np;
+	u32 nid;
+	int r = -ENODATA;
+
+	np = of_node_get(device);
+
+	while (np) {
+		r = of_property_read_u32(np, "numa-node-id", &nid);
+		/*
+		 * -EINVAL indicates the property was not found, and
+		 *  we walk up the tree trying to find a parent with a
+		 *  "numa-node-id".  Any other type of error indicates
+		 *  a bad device tree and we give up.
+		 */
+		if (r != -EINVAL)
+			break;
+
+		np = of_get_next_parent(np);
+	}
+	if (np && r)
+		pr_warn("Invalid \"numa-node-id\" property in node %pOFn\n",
+			np);
+	of_node_put(np);
+
+	/*
+	 * If numa=off passed on command line, or with a defective
+	 * device tree, the nid may not be in the set of possible
+	 * nodes.  Check for this case and return NUMA_NO_NODE.
+	 */
+	if (!r && nid < MAX_NUMNODES && node_possible(nid))
+		return nid;
+
+	return NUMA_NO_NODE;
+}
+
+int __init of_numa_init(void)
+{
+	int r;
+
+	of_numa_parse_cpu_nodes();
+	r = of_numa_parse_memory_nodes();
+	if (r)
+		return r;
+	return of_numa_parse_distance_map();
+}
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
new file mode 100644
index 000000000..fb6792d38
--- /dev/null
+++ b/drivers/of/of_private.h
@@ -0,0 +1,175 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+#ifndef _LINUX_OF_PRIVATE_H
+#define _LINUX_OF_PRIVATE_H
+/*
+ * Private symbols used by OF support code
+ *
+ * Paul Mackerras	August 1996.
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ */
+
+#define FDT_ALIGN_SIZE 8
+
+/**
+ * struct alias_prop - Alias property in 'aliases' node
+ * @link:	List node to link the structure in aliases_lookup list
+ * @alias:	Alias property name
+ * @np:		Pointer to device_node that the alias stands for
+ * @id:		Index value from end of alias name
+ * @stem:	Alias string without the index
+ *
+ * The structure represents one alias property of 'aliases' node as
+ * an entry in aliases_lookup list.
+ */
+struct alias_prop {
+	struct list_head link;
+	const char *alias;
+	struct device_node *np;
+	int id;
+	char stem[];
+};
+
+#if defined(CONFIG_SPARC)
+#define OF_ROOT_NODE_ADDR_CELLS_DEFAULT 2
+#else
+#define OF_ROOT_NODE_ADDR_CELLS_DEFAULT 1
+#endif
+
+#define OF_ROOT_NODE_SIZE_CELLS_DEFAULT 1
+
+extern struct mutex of_mutex;
+extern struct list_head aliases_lookup;
+extern struct kset *of_kset;
+
+#if defined(CONFIG_OF_DYNAMIC)
+extern int of_property_notify(int action, struct device_node *np,
+			      struct property *prop, struct property *old_prop);
+extern void of_node_release(struct kobject *kobj);
+extern int __of_changeset_apply_entries(struct of_changeset *ocs,
+					int *ret_revert);
+extern int __of_changeset_apply_notify(struct of_changeset *ocs);
+extern int __of_changeset_revert_entries(struct of_changeset *ocs,
+					 int *ret_apply);
+extern int __of_changeset_revert_notify(struct of_changeset *ocs);
+#else /* CONFIG_OF_DYNAMIC */
+static inline int of_property_notify(int action, struct device_node *np,
+				     struct property *prop, struct property *old_prop)
+{
+	return 0;
+}
+#endif /* CONFIG_OF_DYNAMIC */
+
+#if defined(CONFIG_OF_KOBJ)
+int of_node_is_attached(const struct device_node *node);
+int __of_add_property_sysfs(struct device_node *np, struct property *pp);
+void __of_remove_property_sysfs(struct device_node *np, struct property *prop);
+void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
+		struct property *oldprop);
+int __of_attach_node_sysfs(struct device_node *np);
+void __of_detach_node_sysfs(struct device_node *np);
+#else
+static inline int __of_add_property_sysfs(struct device_node *np, struct property *pp)
+{
+	return 0;
+}
+static inline void __of_remove_property_sysfs(struct device_node *np, struct property *prop) {}
+static inline void __of_update_property_sysfs(struct device_node *np,
+		struct property *newprop, struct property *oldprop) {}
+static inline int __of_attach_node_sysfs(struct device_node *np)
+{
+	return 0;
+}
+static inline void __of_detach_node_sysfs(struct device_node *np) {}
+#endif
+
+#if defined(CONFIG_OF_RESOLVE)
+int of_resolve_phandles(struct device_node *tree);
+#endif
+
+void __of_phandle_cache_inv_entry(phandle handle);
+
+#if defined(CONFIG_OF_OVERLAY)
+void of_overlay_mutex_lock(void);
+void of_overlay_mutex_unlock(void);
+#else
+static inline void of_overlay_mutex_lock(void) {};
+static inline void of_overlay_mutex_unlock(void) {};
+#endif
+
+#if defined(CONFIG_OF_UNITTEST) && defined(CONFIG_OF_OVERLAY)
+extern void __init unittest_unflatten_overlay_base(void);
+#else
+static inline void unittest_unflatten_overlay_base(void) {};
+#endif
+
+extern void *__unflatten_device_tree(const void *blob,
+			      struct device_node *dad,
+			      struct device_node **mynodes,
+			      void *(*dt_alloc)(u64 size, u64 align),
+			      bool detached);
+
+/**
+ * General utilities for working with live trees.
+ *
+ * All functions with two leading underscores operate
+ * without taking node references, so you either have to
+ * own the devtree lock or work on detached trees only.
+ */
+struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags);
+struct device_node *__of_node_dup(const struct device_node *np,
+				  const char *full_name);
+
+struct device_node *__of_find_node_by_path(struct device_node *parent,
+						const char *path);
+struct device_node *__of_find_node_by_full_path(struct device_node *node,
+						const char *path);
+
+extern const void *__of_get_property(const struct device_node *np,
+				     const char *name, int *lenp);
+extern int __of_add_property(struct device_node *np, struct property *prop);
+extern int __of_remove_property(struct device_node *np, struct property *prop);
+extern int __of_update_property(struct device_node *np,
+		struct property *newprop, struct property **oldprop);
+
+extern void __of_detach_node(struct device_node *np);
+
+extern void __of_sysfs_remove_bin_file(struct device_node *np,
+				       struct property *prop);
+
+/* illegal phandle value (set when unresolved) */
+#define OF_PHANDLE_ILLEGAL	0xdeadbeef
+
+/* iterators for transactions, used for overlays */
+/* forward iterator */
+#define for_each_transaction_entry(_oft, _te) \
+	list_for_each_entry(_te, &(_oft)->te_list, node)
+
+/* reverse iterator */
+#define for_each_transaction_entry_reverse(_oft, _te) \
+	list_for_each_entry_reverse(_te, &(_oft)->te_list, node)
+
+extern int of_bus_n_addr_cells(struct device_node *np);
+extern int of_bus_n_size_cells(struct device_node *np);
+
+struct bus_dma_region;
+#if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_HAS_DMA)
+int of_dma_get_range(struct device_node *np,
+		const struct bus_dma_region **map);
+struct device_node *__of_get_dma_parent(const struct device_node *np);
+#else
+static inline int of_dma_get_range(struct device_node *np,
+		const struct bus_dma_region **map)
+{
+	return -ENODEV;
+}
+static inline struct device_node *__of_get_dma_parent(const struct device_node *np)
+{
+	return of_get_parent(np);
+}
+#endif
+
+void fdt_init_reserved_mem(void);
+void fdt_reserved_mem_save_node(unsigned long node, const char *uname,
+			       phys_addr_t base, phys_addr_t size);
+
+#endif /* _LINUX_OF_PRIVATE_H */
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
new file mode 100644
index 000000000..f90975e00
--- /dev/null
+++ b/drivers/of/of_reserved_mem.c
@@ -0,0 +1,449 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Device tree based initialization code for reserved memory.
+ *
+ * Copyright (c) 2013, 2015 The Linux Foundation. All Rights Reserved.
+ * Copyright (c) 2013,2014 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ * Author: Marek Szyprowski <m.szyprowski@samsung.com>
+ * Author: Josh Cartwright <joshc@codeaurora.org>
+ */
+
+#define pr_fmt(fmt)	"OF: reserved mem: " fmt
+
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_platform.h>
+#include <linux/mm.h>
+#include <linux/sizes.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/sort.h>
+#include <linux/slab.h>
+#include <linux/memblock.h>
+#include <linux/kmemleak.h>
+#include <linux/cma.h>
+
+#include "of_private.h"
+
+#define MAX_RESERVED_REGIONS	64
+static struct reserved_mem reserved_mem[MAX_RESERVED_REGIONS];
+static int reserved_mem_count;
+
+static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
+	phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
+	phys_addr_t *res_base)
+{
+	phys_addr_t base;
+	int err = 0;
+
+	end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
+	align = !align ? SMP_CACHE_BYTES : align;
+	base = memblock_phys_alloc_range(size, align, start, end);
+	if (!base)
+		return -ENOMEM;
+
+	*res_base = base;
+	if (nomap) {
+		err = memblock_mark_nomap(base, size);
+		if (err)
+			memblock_phys_free(base, size);
+	}
+
+	kmemleak_ignore_phys(base);
+
+	return err;
+}
+
+/*
+ * fdt_reserved_mem_save_node() - save fdt node for second pass initialization
+ */
+void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
+				      phys_addr_t base, phys_addr_t size)
+{
+	struct reserved_mem *rmem = &reserved_mem[reserved_mem_count];
+
+	if (reserved_mem_count == ARRAY_SIZE(reserved_mem)) {
+		pr_err("not enough space for all defined regions.\n");
+		return;
+	}
+
+	rmem->fdt_node = node;
+	rmem->name = uname;
+	rmem->base = base;
+	rmem->size = size;
+
+	reserved_mem_count++;
+	return;
+}
+
+/*
+ * __reserved_mem_alloc_size() - allocate reserved memory described by
+ *	'size', 'alignment'  and 'alloc-ranges' properties.
+ */
+static int __init __reserved_mem_alloc_size(unsigned long node,
+	const char *uname, phys_addr_t *res_base, phys_addr_t *res_size)
+{
+	int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
+	phys_addr_t start = 0, end = 0;
+	phys_addr_t base = 0, align = 0, size;
+	int len;
+	const __be32 *prop;
+	bool nomap;
+	int ret;
+
+	prop = of_get_flat_dt_prop(node, "size", &len);
+	if (!prop)
+		return -EINVAL;
+
+	if (len != dt_root_size_cells * sizeof(__be32)) {
+		pr_err("invalid size property in '%s' node.\n", uname);
+		return -EINVAL;
+	}
+	size = dt_mem_next_cell(dt_root_size_cells, &prop);
+
+	prop = of_get_flat_dt_prop(node, "alignment", &len);
+	if (prop) {
+		if (len != dt_root_addr_cells * sizeof(__be32)) {
+			pr_err("invalid alignment property in '%s' node.\n",
+				uname);
+			return -EINVAL;
+		}
+		align = dt_mem_next_cell(dt_root_addr_cells, &prop);
+	}
+
+	nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+
+	/* Need adjust the alignment to satisfy the CMA requirement */
+	if (IS_ENABLED(CONFIG_CMA)
+	    && of_flat_dt_is_compatible(node, "shared-dma-pool")
+	    && of_get_flat_dt_prop(node, "reusable", NULL)
+	    && !nomap)
+		align = max_t(phys_addr_t, align, CMA_MIN_ALIGNMENT_BYTES);
+
+	prop = of_get_flat_dt_prop(node, "alloc-ranges", &len);
+	if (prop) {
+
+		if (len % t_len != 0) {
+			pr_err("invalid alloc-ranges property in '%s', skipping node.\n",
+			       uname);
+			return -EINVAL;
+		}
+
+		base = 0;
+
+		while (len > 0) {
+			start = dt_mem_next_cell(dt_root_addr_cells, &prop);
+			end = start + dt_mem_next_cell(dt_root_size_cells,
+						       &prop);
+
+			ret = early_init_dt_alloc_reserved_memory_arch(size,
+					align, start, end, nomap, &base);
+			if (ret == 0) {
+				pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
+					uname, &base,
+					(unsigned long)(size / SZ_1M));
+				break;
+			}
+			len -= t_len;
+		}
+
+	} else {
+		ret = early_init_dt_alloc_reserved_memory_arch(size, align,
+							0, 0, nomap, &base);
+		if (ret == 0)
+			pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
+				uname, &base, (unsigned long)(size / SZ_1M));
+	}
+
+	if (base == 0) {
+		pr_err("failed to allocate memory for node '%s': size %lu MiB\n",
+		       uname, (unsigned long)(size / SZ_1M));
+		return -ENOMEM;
+	}
+
+	*res_base = base;
+	*res_size = size;
+
+	return 0;
+}
+
+static const struct of_device_id __rmem_of_table_sentinel
+	__used __section("__reservedmem_of_table_end");
+
+/*
+ * __reserved_mem_init_node() - call region specific reserved memory init code
+ */
+static int __init __reserved_mem_init_node(struct reserved_mem *rmem)
+{
+	extern const struct of_device_id __reservedmem_of_table[];
+	const struct of_device_id *i;
+	int ret = -ENOENT;
+
+	for (i = __reservedmem_of_table; i < &__rmem_of_table_sentinel; i++) {
+		reservedmem_of_init_fn initfn = i->data;
+		const char *compat = i->compatible;
+
+		if (!of_flat_dt_is_compatible(rmem->fdt_node, compat))
+			continue;
+
+		ret = initfn(rmem);
+		if (ret == 0) {
+			pr_info("initialized node %s, compatible id %s\n",
+				rmem->name, compat);
+			break;
+		}
+	}
+	return ret;
+}
+
+static int __init __rmem_cmp(const void *a, const void *b)
+{
+	const struct reserved_mem *ra = a, *rb = b;
+
+	if (ra->base < rb->base)
+		return -1;
+
+	if (ra->base > rb->base)
+		return 1;
+
+	/*
+	 * Put the dynamic allocations (address == 0, size == 0) before static
+	 * allocations at address 0x0 so that overlap detection works
+	 * correctly.
+	 */
+	if (ra->size < rb->size)
+		return -1;
+	if (ra->size > rb->size)
+		return 1;
+
+	return 0;
+}
+
+static void __init __rmem_check_for_overlap(void)
+{
+	int i;
+
+	if (reserved_mem_count < 2)
+		return;
+
+	sort(reserved_mem, reserved_mem_count, sizeof(reserved_mem[0]),
+	     __rmem_cmp, NULL);
+	for (i = 0; i < reserved_mem_count - 1; i++) {
+		struct reserved_mem *this, *next;
+
+		this = &reserved_mem[i];
+		next = &reserved_mem[i + 1];
+
+		if (this->base + this->size > next->base) {
+			phys_addr_t this_end, next_end;
+
+			this_end = this->base + this->size;
+			next_end = next->base + next->size;
+			pr_err("OVERLAP DETECTED!\n%s (%pa--%pa) overlaps with %s (%pa--%pa)\n",
+			       this->name, &this->base, &this_end,
+			       next->name, &next->base, &next_end);
+		}
+	}
+}
+
+/**
+ * fdt_init_reserved_mem() - allocate and init all saved reserved memory regions
+ */
+void __init fdt_init_reserved_mem(void)
+{
+	int i;
+
+	/* check for overlapping reserved regions */
+	__rmem_check_for_overlap();
+
+	for (i = 0; i < reserved_mem_count; i++) {
+		struct reserved_mem *rmem = &reserved_mem[i];
+		unsigned long node = rmem->fdt_node;
+		int len;
+		const __be32 *prop;
+		int err = 0;
+		bool nomap;
+
+		nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
+		prop = of_get_flat_dt_prop(node, "phandle", &len);
+		if (!prop)
+			prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
+		if (prop)
+			rmem->phandle = of_read_number(prop, len/4);
+
+		if (rmem->size == 0)
+			err = __reserved_mem_alloc_size(node, rmem->name,
+						 &rmem->base, &rmem->size);
+		if (err == 0) {
+			err = __reserved_mem_init_node(rmem);
+			if (err != 0 && err != -ENOENT) {
+				pr_info("node %s compatible matching fail\n",
+					rmem->name);
+				if (nomap)
+					memblock_clear_nomap(rmem->base, rmem->size);
+				else
+					memblock_phys_free(rmem->base,
+							   rmem->size);
+			}
+		}
+	}
+}
+
+static inline struct reserved_mem *__find_rmem(struct device_node *node)
+{
+	unsigned int i;
+
+	if (!node->phandle)
+		return NULL;
+
+	for (i = 0; i < reserved_mem_count; i++)
+		if (reserved_mem[i].phandle == node->phandle)
+			return &reserved_mem[i];
+	return NULL;
+}
+
+struct rmem_assigned_device {
+	struct device *dev;
+	struct reserved_mem *rmem;
+	struct list_head list;
+};
+
+static LIST_HEAD(of_rmem_assigned_device_list);
+static DEFINE_MUTEX(of_rmem_assigned_device_mutex);
+
+/**
+ * of_reserved_mem_device_init_by_idx() - assign reserved memory region to
+ *					  given device
+ * @dev:	Pointer to the device to configure
+ * @np:		Pointer to the device_node with 'reserved-memory' property
+ * @idx:	Index of selected region
+ *
+ * This function assigns respective DMA-mapping operations based on reserved
+ * memory region specified by 'memory-region' property in @np node to the @dev
+ * device. When driver needs to use more than one reserved memory region, it
+ * should allocate child devices and initialize regions by name for each of
+ * child device.
+ *
+ * Returns error code or zero on success.
+ */
+int of_reserved_mem_device_init_by_idx(struct device *dev,
+				       struct device_node *np, int idx)
+{
+	struct rmem_assigned_device *rd;
+	struct device_node *target;
+	struct reserved_mem *rmem;
+	int ret;
+
+	if (!np || !dev)
+		return -EINVAL;
+
+	target = of_parse_phandle(np, "memory-region", idx);
+	if (!target)
+		return -ENODEV;
+
+	if (!of_device_is_available(target)) {
+		of_node_put(target);
+		return 0;
+	}
+
+	rmem = __find_rmem(target);
+	of_node_put(target);
+
+	if (!rmem || !rmem->ops || !rmem->ops->device_init)
+		return -EINVAL;
+
+	rd = kmalloc(sizeof(struct rmem_assigned_device), GFP_KERNEL);
+	if (!rd)
+		return -ENOMEM;
+
+	ret = rmem->ops->device_init(rmem, dev);
+	if (ret == 0) {
+		rd->dev = dev;
+		rd->rmem = rmem;
+
+		mutex_lock(&of_rmem_assigned_device_mutex);
+		list_add(&rd->list, &of_rmem_assigned_device_list);
+		mutex_unlock(&of_rmem_assigned_device_mutex);
+
+		dev_info(dev, "assigned reserved memory node %s\n", rmem->name);
+	} else {
+		kfree(rd);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_idx);
+
+/**
+ * of_reserved_mem_device_init_by_name() - assign named reserved memory region
+ *					   to given device
+ * @dev: pointer to the device to configure
+ * @np: pointer to the device node with 'memory-region' property
+ * @name: name of the selected memory region
+ *
+ * Returns: 0 on success or a negative error-code on failure.
+ */
+int of_reserved_mem_device_init_by_name(struct device *dev,
+					struct device_node *np,
+					const char *name)
+{
+	int idx = of_property_match_string(np, "memory-region-names", name);
+
+	return of_reserved_mem_device_init_by_idx(dev, np, idx);
+}
+EXPORT_SYMBOL_GPL(of_reserved_mem_device_init_by_name);
+
+/**
+ * of_reserved_mem_device_release() - release reserved memory device structures
+ * @dev:	Pointer to the device to deconfigure
+ *
+ * This function releases structures allocated for memory region handling for
+ * the given device.
+ */
+void of_reserved_mem_device_release(struct device *dev)
+{
+	struct rmem_assigned_device *rd, *tmp;
+	LIST_HEAD(release_list);
+
+	mutex_lock(&of_rmem_assigned_device_mutex);
+	list_for_each_entry_safe(rd, tmp, &of_rmem_assigned_device_list, list) {
+		if (rd->dev == dev)
+			list_move_tail(&rd->list, &release_list);
+	}
+	mutex_unlock(&of_rmem_assigned_device_mutex);
+
+	list_for_each_entry_safe(rd, tmp, &release_list, list) {
+		if (rd->rmem && rd->rmem->ops && rd->rmem->ops->device_release)
+			rd->rmem->ops->device_release(rd->rmem, dev);
+
+		kfree(rd);
+	}
+}
+EXPORT_SYMBOL_GPL(of_reserved_mem_device_release);
+
+/**
+ * of_reserved_mem_lookup() - acquire reserved_mem from a device node
+ * @np:		node pointer of the desired reserved-memory region
+ *
+ * This function allows drivers to acquire a reference to the reserved_mem
+ * struct based on a device node handle.
+ *
+ * Returns a reserved_mem reference, or NULL on error.
+ */
+struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
+{
+	const char *name;
+	int i;
+
+	if (!np->full_name)
+		return NULL;
+
+	name = kbasename(np->full_name);
+	for (i = 0; i < reserved_mem_count; i++)
+		if (!strcmp(reserved_mem[i].name, name))
+			return &reserved_mem[i];
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(of_reserved_mem_lookup);
diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
new file mode 100644
index 000000000..4402871b5
--- /dev/null
+++ b/drivers/of/overlay.c
@@ -0,0 +1,1266 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions for working with device tree overlays
+ *
+ * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com>
+ * Copyright (C) 2012 Texas Instruments Inc.
+ */
+
+#define pr_fmt(fmt)	"OF: overlay: " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_fdt.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/libfdt.h>
+#include <linux/err.h>
+#include <linux/idr.h>
+
+#include "of_private.h"
+
+/**
+ * struct target - info about current target node as recursing through overlay
+ * @np:			node where current level of overlay will be applied
+ * @in_livetree:	@np is a node in the live devicetree
+ *
+ * Used in the algorithm to create the portion of a changeset that describes
+ * an overlay fragment, which is a devicetree subtree.  Initially @np is a node
+ * in the live devicetree where the overlay subtree is targeted to be grafted
+ * into.  When recursing to the next level of the overlay subtree, the target
+ * also recurses to the next level of the live devicetree, as long as overlay
+ * subtree node also exists in the live devicetree.  When a node in the overlay
+ * subtree does not exist at the same level in the live devicetree, target->np
+ * points to a newly allocated node, and all subsequent targets in the subtree
+ * will be newly allocated nodes.
+ */
+struct target {
+	struct device_node *np;
+	bool in_livetree;
+};
+
+/**
+ * struct fragment - info about fragment nodes in overlay expanded device tree
+ * @target:	target of the overlay operation
+ * @overlay:	pointer to the __overlay__ node
+ */
+struct fragment {
+	struct device_node *overlay;
+	struct device_node *target;
+};
+
+/**
+ * struct overlay_changeset
+ * @id:			changeset identifier
+ * @ovcs_list:		list on which we are located
+ * @new_fdt:		Memory allocated to hold unflattened aligned FDT
+ * @overlay_mem:	the memory chunk that contains @overlay_root
+ * @overlay_root:	expanded device tree that contains the fragment nodes
+ * @notify_state:	most recent notify action used on overlay
+ * @count:		count of fragment structures
+ * @fragments:		fragment nodes in the overlay expanded device tree
+ * @symbols_fragment:	last element of @fragments[] is the  __symbols__ node
+ * @cset:		changeset to apply fragments to live device tree
+ */
+struct overlay_changeset {
+	int id;
+	struct list_head ovcs_list;
+	const void *new_fdt;
+	const void *overlay_mem;
+	struct device_node *overlay_root;
+	enum of_overlay_notify_action notify_state;
+	int count;
+	struct fragment *fragments;
+	bool symbols_fragment;
+	struct of_changeset cset;
+};
+
+/* flags are sticky - once set, do not reset */
+static int devicetree_state_flags;
+#define DTSF_APPLY_FAIL		0x01
+#define DTSF_REVERT_FAIL	0x02
+
+/*
+ * If a changeset apply or revert encounters an error, an attempt will
+ * be made to undo partial changes, but may fail.  If the undo fails
+ * we do not know the state of the devicetree.
+ */
+static int devicetree_corrupt(void)
+{
+	return devicetree_state_flags &
+		(DTSF_APPLY_FAIL | DTSF_REVERT_FAIL);
+}
+
+static int build_changeset_next_level(struct overlay_changeset *ovcs,
+		struct target *target, const struct device_node *overlay_node);
+
+/*
+ * of_resolve_phandles() finds the largest phandle in the live tree.
+ * of_overlay_apply() may add a larger phandle to the live tree.
+ * Do not allow race between two overlays being applied simultaneously:
+ *    mutex_lock(&of_overlay_phandle_mutex)
+ *    of_resolve_phandles()
+ *    of_overlay_apply()
+ *    mutex_unlock(&of_overlay_phandle_mutex)
+ */
+static DEFINE_MUTEX(of_overlay_phandle_mutex);
+
+void of_overlay_mutex_lock(void)
+{
+	mutex_lock(&of_overlay_phandle_mutex);
+}
+
+void of_overlay_mutex_unlock(void)
+{
+	mutex_unlock(&of_overlay_phandle_mutex);
+}
+
+static LIST_HEAD(ovcs_list);
+static DEFINE_IDR(ovcs_idr);
+
+static BLOCKING_NOTIFIER_HEAD(overlay_notify_chain);
+
+/**
+ * of_overlay_notifier_register() - Register notifier for overlay operations
+ * @nb:		Notifier block to register
+ *
+ * Register for notification on overlay operations on device tree nodes. The
+ * reported actions definied by @of_reconfig_change. The notifier callback
+ * furthermore receives a pointer to the affected device tree node.
+ *
+ * Note that a notifier callback is not supposed to store pointers to a device
+ * tree node or its content beyond @OF_OVERLAY_POST_REMOVE corresponding to the
+ * respective node it received.
+ */
+int of_overlay_notifier_register(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&overlay_notify_chain, nb);
+}
+EXPORT_SYMBOL_GPL(of_overlay_notifier_register);
+
+/**
+ * of_overlay_notifier_unregister() - Unregister notifier for overlay operations
+ * @nb:		Notifier block to unregister
+ */
+int of_overlay_notifier_unregister(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&overlay_notify_chain, nb);
+}
+EXPORT_SYMBOL_GPL(of_overlay_notifier_unregister);
+
+static int overlay_notify(struct overlay_changeset *ovcs,
+		enum of_overlay_notify_action action)
+{
+	struct of_overlay_notify_data nd;
+	int i, ret;
+
+	ovcs->notify_state = action;
+
+	for (i = 0; i < ovcs->count; i++) {
+		struct fragment *fragment = &ovcs->fragments[i];
+
+		nd.target = fragment->target;
+		nd.overlay = fragment->overlay;
+
+		ret = blocking_notifier_call_chain(&overlay_notify_chain,
+						   action, &nd);
+		if (notifier_to_errno(ret)) {
+			ret = notifier_to_errno(ret);
+			pr_err("overlay changeset %s notifier error %d, target: %pOF\n",
+			       of_overlay_action_name(action), ret, nd.target);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * The values of properties in the "/__symbols__" node are paths in
+ * the ovcs->overlay_root.  When duplicating the properties, the paths
+ * need to be adjusted to be the correct path for the live device tree.
+ *
+ * The paths refer to a node in the subtree of a fragment node's "__overlay__"
+ * node, for example "/fragment@0/__overlay__/symbol_path_tail",
+ * where symbol_path_tail can be a single node or it may be a multi-node path.
+ *
+ * The duplicated property value will be modified by replacing the
+ * "/fragment_name/__overlay/" portion of the value  with the target
+ * path from the fragment node.
+ */
+static struct property *dup_and_fixup_symbol_prop(
+		struct overlay_changeset *ovcs, const struct property *prop)
+{
+	struct fragment *fragment;
+	struct property *new_prop;
+	struct device_node *fragment_node;
+	struct device_node *overlay_node;
+	const char *path;
+	const char *path_tail;
+	const char *target_path;
+	int k;
+	int overlay_name_len;
+	int path_len;
+	int path_tail_len;
+	int target_path_len;
+
+	if (!prop->value)
+		return NULL;
+	if (strnlen(prop->value, prop->length) >= prop->length)
+		return NULL;
+	path = prop->value;
+	path_len = strlen(path);
+
+	if (path_len < 1)
+		return NULL;
+	fragment_node = __of_find_node_by_path(ovcs->overlay_root, path + 1);
+	overlay_node = __of_find_node_by_path(fragment_node, "__overlay__/");
+	of_node_put(fragment_node);
+	of_node_put(overlay_node);
+
+	for (k = 0; k < ovcs->count; k++) {
+		fragment = &ovcs->fragments[k];
+		if (fragment->overlay == overlay_node)
+			break;
+	}
+	if (k >= ovcs->count)
+		return NULL;
+
+	overlay_name_len = snprintf(NULL, 0, "%pOF", fragment->overlay);
+
+	if (overlay_name_len > path_len)
+		return NULL;
+	path_tail = path + overlay_name_len;
+	path_tail_len = strlen(path_tail);
+
+	target_path = kasprintf(GFP_KERNEL, "%pOF", fragment->target);
+	if (!target_path)
+		return NULL;
+	target_path_len = strlen(target_path);
+
+	new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
+	if (!new_prop)
+		goto err_free_target_path;
+
+	new_prop->name = kstrdup(prop->name, GFP_KERNEL);
+	new_prop->length = target_path_len + path_tail_len + 1;
+	new_prop->value = kzalloc(new_prop->length, GFP_KERNEL);
+	if (!new_prop->name || !new_prop->value)
+		goto err_free_new_prop;
+
+	strcpy(new_prop->value, target_path);
+	strcpy(new_prop->value + target_path_len, path_tail);
+
+	of_property_set_flag(new_prop, OF_DYNAMIC);
+
+	kfree(target_path);
+
+	return new_prop;
+
+err_free_new_prop:
+	kfree(new_prop->name);
+	kfree(new_prop->value);
+	kfree(new_prop);
+err_free_target_path:
+	kfree(target_path);
+
+	return NULL;
+}
+
+/**
+ * add_changeset_property() - add @overlay_prop to overlay changeset
+ * @ovcs:		overlay changeset
+ * @target:		where @overlay_prop will be placed
+ * @overlay_prop:	property to add or update, from overlay tree
+ * @is_symbols_prop:	1 if @overlay_prop is from node "/__symbols__"
+ *
+ * If @overlay_prop does not already exist in live devicetree, add changeset
+ * entry to add @overlay_prop in @target, else add changeset entry to update
+ * value of @overlay_prop.
+ *
+ * @target may be either in the live devicetree or in a new subtree that
+ * is contained in the changeset.
+ *
+ * Some special properties are not added or updated (no error returned):
+ * "name", "phandle", "linux,phandle".
+ *
+ * Properties "#address-cells" and "#size-cells" are not updated if they
+ * are already in the live tree, but if present in the live tree, the values
+ * in the overlay must match the values in the live tree.
+ *
+ * Update of property in symbols node is not allowed.
+ *
+ * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
+ * invalid @overlay.
+ */
+static int add_changeset_property(struct overlay_changeset *ovcs,
+		struct target *target, struct property *overlay_prop,
+		bool is_symbols_prop)
+{
+	struct property *new_prop = NULL, *prop;
+	int ret = 0;
+
+	if (target->in_livetree)
+		if (!of_prop_cmp(overlay_prop->name, "name") ||
+		    !of_prop_cmp(overlay_prop->name, "phandle") ||
+		    !of_prop_cmp(overlay_prop->name, "linux,phandle"))
+			return 0;
+
+	if (target->in_livetree)
+		prop = of_find_property(target->np, overlay_prop->name, NULL);
+	else
+		prop = NULL;
+
+	if (prop) {
+		if (!of_prop_cmp(prop->name, "#address-cells")) {
+			if (!of_prop_val_eq(prop, overlay_prop)) {
+				pr_err("ERROR: changing value of #address-cells is not allowed in %pOF\n",
+				       target->np);
+				ret = -EINVAL;
+			}
+			return ret;
+
+		} else if (!of_prop_cmp(prop->name, "#size-cells")) {
+			if (!of_prop_val_eq(prop, overlay_prop)) {
+				pr_err("ERROR: changing value of #size-cells is not allowed in %pOF\n",
+				       target->np);
+				ret = -EINVAL;
+			}
+			return ret;
+		}
+	}
+
+	if (is_symbols_prop) {
+		if (prop)
+			return -EINVAL;
+		new_prop = dup_and_fixup_symbol_prop(ovcs, overlay_prop);
+	} else {
+		new_prop = __of_prop_dup(overlay_prop, GFP_KERNEL);
+	}
+
+	if (!new_prop)
+		return -ENOMEM;
+
+	if (!prop) {
+		if (!target->in_livetree) {
+			new_prop->next = target->np->deadprops;
+			target->np->deadprops = new_prop;
+		}
+		ret = of_changeset_add_property(&ovcs->cset, target->np,
+						new_prop);
+	} else {
+		ret = of_changeset_update_property(&ovcs->cset, target->np,
+						   new_prop);
+	}
+
+	if (!of_node_check_flag(target->np, OF_OVERLAY))
+		pr_err("WARNING: memory leak will occur if overlay removed, property: %pOF/%s\n",
+		       target->np, new_prop->name);
+
+	if (ret) {
+		kfree(new_prop->name);
+		kfree(new_prop->value);
+		kfree(new_prop);
+	}
+	return ret;
+}
+
+/**
+ * add_changeset_node() - add @node (and children) to overlay changeset
+ * @ovcs:	overlay changeset
+ * @target:	where @node will be placed in live tree or changeset
+ * @node:	node from within overlay device tree fragment
+ *
+ * If @node does not already exist in @target, add changeset entry
+ * to add @node in @target.
+ *
+ * If @node already exists in @target, and the existing node has
+ * a phandle, the overlay node is not allowed to have a phandle.
+ *
+ * If @node has child nodes, add the children recursively via
+ * build_changeset_next_level().
+ *
+ * NOTE_1: A live devicetree created from a flattened device tree (FDT) will
+ *       not contain the full path in node->full_name.  Thus an overlay
+ *       created from an FDT also will not contain the full path in
+ *       node->full_name.  However, a live devicetree created from Open
+ *       Firmware may have the full path in node->full_name.
+ *
+ *       add_changeset_node() follows the FDT convention and does not include
+ *       the full path in node->full_name.  Even though it expects the overlay
+ *       to not contain the full path, it uses kbasename() to remove the
+ *       full path should it exist.  It also uses kbasename() in comparisons
+ *       to nodes in the live devicetree so that it can apply an overlay to
+ *       a live devicetree created from Open Firmware.
+ *
+ * NOTE_2: Multiple mods of created nodes not supported.
+ *
+ * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
+ * invalid @overlay.
+ */
+static int add_changeset_node(struct overlay_changeset *ovcs,
+		struct target *target, struct device_node *node)
+{
+	const char *node_kbasename;
+	const __be32 *phandle;
+	struct device_node *tchild;
+	struct target target_child;
+	int ret = 0, size;
+
+	node_kbasename = kbasename(node->full_name);
+
+	for_each_child_of_node(target->np, tchild)
+		if (!of_node_cmp(node_kbasename, kbasename(tchild->full_name)))
+			break;
+
+	if (!tchild) {
+		tchild = __of_node_dup(NULL, node_kbasename);
+		if (!tchild)
+			return -ENOMEM;
+
+		tchild->parent = target->np;
+		tchild->name = __of_get_property(node, "name", NULL);
+
+		if (!tchild->name)
+			tchild->name = "<NULL>";
+
+		/* ignore obsolete "linux,phandle" */
+		phandle = __of_get_property(node, "phandle", &size);
+		if (phandle && (size == 4))
+			tchild->phandle = be32_to_cpup(phandle);
+
+		of_node_set_flag(tchild, OF_OVERLAY);
+
+		ret = of_changeset_attach_node(&ovcs->cset, tchild);
+		if (ret)
+			return ret;
+
+		target_child.np = tchild;
+		target_child.in_livetree = false;
+
+		ret = build_changeset_next_level(ovcs, &target_child, node);
+		of_node_put(tchild);
+		return ret;
+	}
+
+	if (node->phandle && tchild->phandle) {
+		ret = -EINVAL;
+	} else {
+		target_child.np = tchild;
+		target_child.in_livetree = target->in_livetree;
+		ret = build_changeset_next_level(ovcs, &target_child, node);
+	}
+	of_node_put(tchild);
+
+	return ret;
+}
+
+/**
+ * build_changeset_next_level() - add level of overlay changeset
+ * @ovcs:		overlay changeset
+ * @target:		where to place @overlay_node in live tree
+ * @overlay_node:	node from within an overlay device tree fragment
+ *
+ * Add the properties (if any) and nodes (if any) from @overlay_node to the
+ * @ovcs->cset changeset.  If an added node has child nodes, they will
+ * be added recursively.
+ *
+ * Do not allow symbols node to have any children.
+ *
+ * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
+ * invalid @overlay_node.
+ */
+static int build_changeset_next_level(struct overlay_changeset *ovcs,
+		struct target *target, const struct device_node *overlay_node)
+{
+	struct device_node *child;
+	struct property *prop;
+	int ret;
+
+	for_each_property_of_node(overlay_node, prop) {
+		ret = add_changeset_property(ovcs, target, prop, 0);
+		if (ret) {
+			pr_debug("Failed to apply prop @%pOF/%s, err=%d\n",
+				 target->np, prop->name, ret);
+			return ret;
+		}
+	}
+
+	for_each_child_of_node(overlay_node, child) {
+		ret = add_changeset_node(ovcs, target, child);
+		if (ret) {
+			pr_debug("Failed to apply node @%pOF/%pOFn, err=%d\n",
+				 target->np, child, ret);
+			of_node_put(child);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Add the properties from __overlay__ node to the @ovcs->cset changeset.
+ */
+static int build_changeset_symbols_node(struct overlay_changeset *ovcs,
+		struct target *target,
+		const struct device_node *overlay_symbols_node)
+{
+	struct property *prop;
+	int ret;
+
+	for_each_property_of_node(overlay_symbols_node, prop) {
+		ret = add_changeset_property(ovcs, target, prop, 1);
+		if (ret) {
+			pr_debug("Failed to apply symbols prop @%pOF/%s, err=%d\n",
+				 target->np, prop->name, ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int find_dup_cset_node_entry(struct overlay_changeset *ovcs,
+		struct of_changeset_entry *ce_1)
+{
+	struct of_changeset_entry *ce_2;
+	char *fn_1, *fn_2;
+	int node_path_match;
+
+	if (ce_1->action != OF_RECONFIG_ATTACH_NODE &&
+	    ce_1->action != OF_RECONFIG_DETACH_NODE)
+		return 0;
+
+	ce_2 = ce_1;
+	list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) {
+		if ((ce_2->action != OF_RECONFIG_ATTACH_NODE &&
+		     ce_2->action != OF_RECONFIG_DETACH_NODE) ||
+		    of_node_cmp(ce_1->np->full_name, ce_2->np->full_name))
+			continue;
+
+		fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);
+		fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);
+		node_path_match = !fn_1 || !fn_2 || !strcmp(fn_1, fn_2);
+		kfree(fn_1);
+		kfree(fn_2);
+		if (node_path_match) {
+			pr_err("ERROR: multiple fragments add and/or delete node %pOF\n",
+			       ce_1->np);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int find_dup_cset_prop(struct overlay_changeset *ovcs,
+		struct of_changeset_entry *ce_1)
+{
+	struct of_changeset_entry *ce_2;
+	char *fn_1, *fn_2;
+	int node_path_match;
+
+	if (ce_1->action != OF_RECONFIG_ADD_PROPERTY &&
+	    ce_1->action != OF_RECONFIG_REMOVE_PROPERTY &&
+	    ce_1->action != OF_RECONFIG_UPDATE_PROPERTY)
+		return 0;
+
+	ce_2 = ce_1;
+	list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) {
+		if ((ce_2->action != OF_RECONFIG_ADD_PROPERTY &&
+		     ce_2->action != OF_RECONFIG_REMOVE_PROPERTY &&
+		     ce_2->action != OF_RECONFIG_UPDATE_PROPERTY) ||
+		    of_node_cmp(ce_1->np->full_name, ce_2->np->full_name))
+			continue;
+
+		fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);
+		fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);
+		node_path_match = !fn_1 || !fn_2 || !strcmp(fn_1, fn_2);
+		kfree(fn_1);
+		kfree(fn_2);
+		if (node_path_match &&
+		    !of_prop_cmp(ce_1->prop->name, ce_2->prop->name)) {
+			pr_err("ERROR: multiple fragments add, update, and/or delete property %pOF/%s\n",
+			       ce_1->np, ce_1->prop->name);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * changeset_dup_entry_check() - check for duplicate entries
+ * @ovcs:	Overlay changeset
+ *
+ * Check changeset @ovcs->cset for multiple {add or delete} node entries for
+ * the same node or duplicate {add, delete, or update} properties entries
+ * for the same property.
+ *
+ * Return: 0 on success, or -EINVAL if duplicate changeset entry found.
+ */
+static int changeset_dup_entry_check(struct overlay_changeset *ovcs)
+{
+	struct of_changeset_entry *ce_1;
+	int dup_entry = 0;
+
+	list_for_each_entry(ce_1, &ovcs->cset.entries, node) {
+		dup_entry |= find_dup_cset_node_entry(ovcs, ce_1);
+		dup_entry |= find_dup_cset_prop(ovcs, ce_1);
+	}
+
+	return dup_entry ? -EINVAL : 0;
+}
+
+/**
+ * build_changeset() - populate overlay changeset in @ovcs from @ovcs->fragments
+ * @ovcs:	Overlay changeset
+ *
+ * Create changeset @ovcs->cset to contain the nodes and properties of the
+ * overlay device tree fragments in @ovcs->fragments[].  If an error occurs,
+ * any portions of the changeset that were successfully created will remain
+ * in @ovcs->cset.
+ *
+ * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if
+ * invalid overlay in @ovcs->fragments[].
+ */
+static int build_changeset(struct overlay_changeset *ovcs)
+{
+	struct fragment *fragment;
+	struct target target;
+	int fragments_count, i, ret;
+
+	/*
+	 * if there is a symbols fragment in ovcs->fragments[i] it is
+	 * the final element in the array
+	 */
+	if (ovcs->symbols_fragment)
+		fragments_count = ovcs->count - 1;
+	else
+		fragments_count = ovcs->count;
+
+	for (i = 0; i < fragments_count; i++) {
+		fragment = &ovcs->fragments[i];
+
+		target.np = fragment->target;
+		target.in_livetree = true;
+		ret = build_changeset_next_level(ovcs, &target,
+						 fragment->overlay);
+		if (ret) {
+			pr_debug("fragment apply failed '%pOF'\n",
+				 fragment->target);
+			return ret;
+		}
+	}
+
+	if (ovcs->symbols_fragment) {
+		fragment = &ovcs->fragments[ovcs->count - 1];
+
+		target.np = fragment->target;
+		target.in_livetree = true;
+		ret = build_changeset_symbols_node(ovcs, &target,
+						   fragment->overlay);
+		if (ret) {
+			pr_debug("symbols fragment apply failed '%pOF'\n",
+				 fragment->target);
+			return ret;
+		}
+	}
+
+	return changeset_dup_entry_check(ovcs);
+}
+
+/*
+ * Find the target node using a number of different strategies
+ * in order of preference:
+ *
+ * 1) "target" property containing the phandle of the target
+ * 2) "target-path" property containing the path of the target
+ */
+static struct device_node *find_target(struct device_node *info_node)
+{
+	struct device_node *node;
+	const char *path;
+	u32 val;
+	int ret;
+
+	ret = of_property_read_u32(info_node, "target", &val);
+	if (!ret) {
+		node = of_find_node_by_phandle(val);
+		if (!node)
+			pr_err("find target, node: %pOF, phandle 0x%x not found\n",
+			       info_node, val);
+		return node;
+	}
+
+	ret = of_property_read_string(info_node, "target-path", &path);
+	if (!ret) {
+		node =  of_find_node_by_path(path);
+		if (!node)
+			pr_err("find target, node: %pOF, path '%s' not found\n",
+			       info_node, path);
+		return node;
+	}
+
+	pr_err("find target, node: %pOF, no target property\n", info_node);
+
+	return NULL;
+}
+
+/**
+ * init_overlay_changeset() - initialize overlay changeset from overlay tree
+ * @ovcs:		Overlay changeset to build
+ *
+ * Initialize @ovcs.  Populate @ovcs->fragments with node information from
+ * the top level of @overlay_root.  The relevant top level nodes are the
+ * fragment nodes and the __symbols__ node.  Any other top level node will
+ * be ignored.  Populate other @ovcs fields.
+ *
+ * Return: 0 on success, -ENOMEM if memory allocation failure, -EINVAL if error
+ * detected in @overlay_root.  On error return, the caller of
+ * init_overlay_changeset() must call free_overlay_changeset().
+ */
+static int init_overlay_changeset(struct overlay_changeset *ovcs)
+{
+	struct device_node *node, *overlay_node;
+	struct fragment *fragment;
+	struct fragment *fragments;
+	int cnt, ret;
+
+	/*
+	 * None of the resources allocated by this function will be freed in
+	 * the error paths.  Instead the caller of this function is required
+	 * to call free_overlay_changeset() (which will free the resources)
+	 * if error return.
+	 */
+
+	/*
+	 * Warn for some issues.  Can not return -EINVAL for these until
+	 * of_unittest_apply_overlay() is fixed to pass these checks.
+	 */
+	if (!of_node_check_flag(ovcs->overlay_root, OF_DYNAMIC))
+		pr_debug("%s() ovcs->overlay_root is not dynamic\n", __func__);
+
+	if (!of_node_check_flag(ovcs->overlay_root, OF_DETACHED))
+		pr_debug("%s() ovcs->overlay_root is not detached\n", __func__);
+
+	if (!of_node_is_root(ovcs->overlay_root))
+		pr_debug("%s() ovcs->overlay_root is not root\n", __func__);
+
+	cnt = 0;
+
+	/* fragment nodes */
+	for_each_child_of_node(ovcs->overlay_root, node) {
+		overlay_node = of_get_child_by_name(node, "__overlay__");
+		if (overlay_node) {
+			cnt++;
+			of_node_put(overlay_node);
+		}
+	}
+
+	node = of_get_child_by_name(ovcs->overlay_root, "__symbols__");
+	if (node) {
+		cnt++;
+		of_node_put(node);
+	}
+
+	fragments = kcalloc(cnt, sizeof(*fragments), GFP_KERNEL);
+	if (!fragments) {
+		ret = -ENOMEM;
+		goto err_out;
+	}
+	ovcs->fragments = fragments;
+
+	cnt = 0;
+	for_each_child_of_node(ovcs->overlay_root, node) {
+		overlay_node = of_get_child_by_name(node, "__overlay__");
+		if (!overlay_node)
+			continue;
+
+		fragment = &fragments[cnt];
+		fragment->overlay = overlay_node;
+		fragment->target = find_target(node);
+		if (!fragment->target) {
+			of_node_put(fragment->overlay);
+			ret = -EINVAL;
+			of_node_put(node);
+			goto err_out;
+		}
+
+		cnt++;
+	}
+
+	/*
+	 * if there is a symbols fragment in ovcs->fragments[i] it is
+	 * the final element in the array
+	 */
+	node = of_get_child_by_name(ovcs->overlay_root, "__symbols__");
+	if (node) {
+		ovcs->symbols_fragment = 1;
+		fragment = &fragments[cnt];
+		fragment->overlay = node;
+		fragment->target = of_find_node_by_path("/__symbols__");
+
+		if (!fragment->target) {
+			pr_err("symbols in overlay, but not in live tree\n");
+			ret = -EINVAL;
+			of_node_put(node);
+			goto err_out;
+		}
+
+		cnt++;
+	}
+
+	if (!cnt) {
+		pr_err("no fragments or symbols in overlay\n");
+		ret = -EINVAL;
+		goto err_out;
+	}
+
+	ovcs->count = cnt;
+
+	return 0;
+
+err_out:
+	pr_err("%s() failed, ret = %d\n", __func__, ret);
+
+	return ret;
+}
+
+static void free_overlay_changeset(struct overlay_changeset *ovcs)
+{
+	int i;
+
+	if (ovcs->cset.entries.next)
+		of_changeset_destroy(&ovcs->cset);
+
+	if (ovcs->id) {
+		idr_remove(&ovcs_idr, ovcs->id);
+		list_del(&ovcs->ovcs_list);
+		ovcs->id = 0;
+	}
+
+
+	for (i = 0; i < ovcs->count; i++) {
+		of_node_put(ovcs->fragments[i].target);
+		of_node_put(ovcs->fragments[i].overlay);
+	}
+	kfree(ovcs->fragments);
+
+	/*
+	 * There should be no live pointers into ovcs->overlay_mem and
+	 * ovcs->new_fdt due to the policy that overlay notifiers are not
+	 * allowed to retain pointers into the overlay devicetree other
+	 * than during the window from OF_OVERLAY_PRE_APPLY overlay
+	 * notifiers until the OF_OVERLAY_POST_REMOVE overlay notifiers.
+	 *
+	 * A memory leak will occur here if within the window.
+	 */
+
+	if (ovcs->notify_state == OF_OVERLAY_INIT ||
+	    ovcs->notify_state == OF_OVERLAY_POST_REMOVE) {
+		kfree(ovcs->overlay_mem);
+		kfree(ovcs->new_fdt);
+	}
+	kfree(ovcs);
+}
+
+/*
+ * internal documentation
+ *
+ * of_overlay_apply() - Create and apply an overlay changeset
+ * @ovcs:	overlay changeset
+ *
+ * Creates and applies an overlay changeset.
+ *
+ * If an error is returned by an overlay changeset pre-apply notifier
+ * then no further overlay changeset pre-apply notifier will be called.
+ *
+ * If an error is returned by an overlay changeset post-apply notifier
+ * then no further overlay changeset post-apply notifier will be called.
+ *
+ * If more than one notifier returns an error, then the last notifier
+ * error to occur is returned.
+ *
+ * If an error occurred while applying the overlay changeset, then an
+ * attempt is made to revert any changes that were made to the
+ * device tree.  If there were any errors during the revert attempt
+ * then the state of the device tree can not be determined, and any
+ * following attempt to apply or remove an overlay changeset will be
+ * refused.
+ *
+ * Returns 0 on success, or a negative error number.  On error return,
+ * the caller of of_overlay_apply() must call free_overlay_changeset().
+ */
+
+static int of_overlay_apply(struct overlay_changeset *ovcs)
+{
+	int ret = 0, ret_revert, ret_tmp;
+
+	ret = of_resolve_phandles(ovcs->overlay_root);
+	if (ret)
+		goto out;
+
+	ret = init_overlay_changeset(ovcs);
+	if (ret)
+		goto out;
+
+	ret = overlay_notify(ovcs, OF_OVERLAY_PRE_APPLY);
+	if (ret)
+		goto out;
+
+	ret = build_changeset(ovcs);
+	if (ret)
+		goto out;
+
+	ret_revert = 0;
+	ret = __of_changeset_apply_entries(&ovcs->cset, &ret_revert);
+	if (ret) {
+		if (ret_revert) {
+			pr_debug("overlay changeset revert error %d\n",
+				 ret_revert);
+			devicetree_state_flags |= DTSF_APPLY_FAIL;
+		}
+		goto out;
+	}
+
+	ret = __of_changeset_apply_notify(&ovcs->cset);
+	if (ret)
+		pr_err("overlay apply changeset entry notify error %d\n", ret);
+	/* notify failure is not fatal, continue */
+
+	ret_tmp = overlay_notify(ovcs, OF_OVERLAY_POST_APPLY);
+	if (ret_tmp)
+		if (!ret)
+			ret = ret_tmp;
+
+out:
+	pr_debug("%s() err=%d\n", __func__, ret);
+
+	return ret;
+}
+
+/*
+ * of_overlay_fdt_apply() - Create and apply an overlay changeset
+ * @overlay_fdt:	pointer to overlay FDT
+ * @overlay_fdt_size:	number of bytes in @overlay_fdt
+ * @ret_ovcs_id:	pointer for returning created changeset id
+ *
+ * Creates and applies an overlay changeset.
+ *
+ * See of_overlay_apply() for important behavior information.
+ *
+ * Return: 0 on success, or a negative error number.  *@ret_ovcs_id is set to
+ * the value of overlay changeset id, which can be passed to of_overlay_remove()
+ * to remove the overlay.
+ *
+ * On error return, the changeset may be partially applied.  This is especially
+ * likely if an OF_OVERLAY_POST_APPLY notifier returns an error.  In this case
+ * the caller should call of_overlay_remove() with the value in *@ret_ovcs_id.
+ */
+
+int of_overlay_fdt_apply(const void *overlay_fdt, u32 overlay_fdt_size,
+			 int *ret_ovcs_id)
+{
+	void *new_fdt;
+	void *new_fdt_align;
+	void *overlay_mem;
+	int ret;
+	u32 size;
+	struct overlay_changeset *ovcs;
+
+	*ret_ovcs_id = 0;
+
+	if (devicetree_corrupt()) {
+		pr_err("devicetree state suspect, refuse to apply overlay\n");
+		return -EBUSY;
+	}
+
+	if (overlay_fdt_size < sizeof(struct fdt_header) ||
+	    fdt_check_header(overlay_fdt)) {
+		pr_err("Invalid overlay_fdt header\n");
+		return -EINVAL;
+	}
+
+	size = fdt_totalsize(overlay_fdt);
+	if (overlay_fdt_size < size)
+		return -EINVAL;
+
+	ovcs = kzalloc(sizeof(*ovcs), GFP_KERNEL);
+	if (!ovcs)
+		return -ENOMEM;
+
+	of_overlay_mutex_lock();
+	mutex_lock(&of_mutex);
+
+	/*
+	 * ovcs->notify_state must be set to OF_OVERLAY_INIT before allocating
+	 * ovcs resources, implicitly set by kzalloc() of ovcs
+	 */
+
+	ovcs->id = idr_alloc(&ovcs_idr, ovcs, 1, 0, GFP_KERNEL);
+	if (ovcs->id <= 0) {
+		ret = ovcs->id;
+		goto err_free_ovcs;
+	}
+
+	INIT_LIST_HEAD(&ovcs->ovcs_list);
+	list_add_tail(&ovcs->ovcs_list, &ovcs_list);
+	of_changeset_init(&ovcs->cset);
+
+	/*
+	 * Must create permanent copy of FDT because of_fdt_unflatten_tree()
+	 * will create pointers to the passed in FDT in the unflattened tree.
+	 */
+	new_fdt = kmalloc(size + FDT_ALIGN_SIZE, GFP_KERNEL);
+	if (!new_fdt) {
+		ret = -ENOMEM;
+		goto err_free_ovcs;
+	}
+	ovcs->new_fdt = new_fdt;
+
+	new_fdt_align = PTR_ALIGN(new_fdt, FDT_ALIGN_SIZE);
+	memcpy(new_fdt_align, overlay_fdt, size);
+
+	overlay_mem = of_fdt_unflatten_tree(new_fdt_align, NULL,
+					    &ovcs->overlay_root);
+	if (!overlay_mem) {
+		pr_err("unable to unflatten overlay_fdt\n");
+		ret = -EINVAL;
+		goto err_free_ovcs;
+	}
+	ovcs->overlay_mem = overlay_mem;
+
+	ret = of_overlay_apply(ovcs);
+	/*
+	 * If of_overlay_apply() error, calling free_overlay_changeset() may
+	 * result in a memory leak if the apply partly succeeded, so do NOT
+	 * goto err_free_ovcs.  Instead, the caller of of_overlay_fdt_apply()
+	 * can call of_overlay_remove();
+	 */
+	*ret_ovcs_id = ovcs->id;
+	goto out_unlock;
+
+err_free_ovcs:
+	free_overlay_changeset(ovcs);
+
+out_unlock:
+	mutex_unlock(&of_mutex);
+	of_overlay_mutex_unlock();
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_overlay_fdt_apply);
+
+/*
+ * Find @np in @tree.
+ *
+ * Returns 1 if @np is @tree or is contained in @tree, else 0
+ */
+static int find_node(struct device_node *tree, struct device_node *np)
+{
+	struct device_node *child;
+
+	if (tree == np)
+		return 1;
+
+	for_each_child_of_node(tree, child) {
+		if (find_node(child, np)) {
+			of_node_put(child);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Is @remove_ce_node a child of, a parent of, or the same as any
+ * node in an overlay changeset more topmost than @remove_ovcs?
+ *
+ * Returns 1 if found, else 0
+ */
+static int node_overlaps_later_cs(struct overlay_changeset *remove_ovcs,
+		struct device_node *remove_ce_node)
+{
+	struct overlay_changeset *ovcs;
+	struct of_changeset_entry *ce;
+
+	list_for_each_entry_reverse(ovcs, &ovcs_list, ovcs_list) {
+		if (ovcs == remove_ovcs)
+			break;
+
+		list_for_each_entry(ce, &ovcs->cset.entries, node) {
+			if (find_node(ce->np, remove_ce_node)) {
+				pr_err("%s: #%d overlaps with #%d @%pOF\n",
+					__func__, remove_ovcs->id, ovcs->id,
+					remove_ce_node);
+				return 1;
+			}
+			if (find_node(remove_ce_node, ce->np)) {
+				pr_err("%s: #%d overlaps with #%d @%pOF\n",
+					__func__, remove_ovcs->id, ovcs->id,
+					remove_ce_node);
+				return 1;
+			}
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * We can safely remove the overlay only if it's the top-most one.
+ * Newly applied overlays are inserted at the tail of the overlay list,
+ * so a top most overlay is the one that is closest to the tail.
+ *
+ * The topmost check is done by exploiting this property. For each
+ * affected device node in the log list we check if this overlay is
+ * the one closest to the tail. If another overlay has affected this
+ * device node and is closest to the tail, then removal is not permited.
+ */
+static int overlay_removal_is_ok(struct overlay_changeset *remove_ovcs)
+{
+	struct of_changeset_entry *remove_ce;
+
+	list_for_each_entry(remove_ce, &remove_ovcs->cset.entries, node) {
+		if (node_overlaps_later_cs(remove_ovcs, remove_ce->np)) {
+			pr_err("overlay #%d is not topmost\n", remove_ovcs->id);
+			return 0;
+		}
+	}
+
+	return 1;
+}
+
+/**
+ * of_overlay_remove() - Revert and free an overlay changeset
+ * @ovcs_id:	Pointer to overlay changeset id
+ *
+ * Removes an overlay if it is permissible.  @ovcs_id was previously returned
+ * by of_overlay_fdt_apply().
+ *
+ * If an error occurred while attempting to revert the overlay changeset,
+ * then an attempt is made to re-apply any changeset entry that was
+ * reverted.  If an error occurs on re-apply then the state of the device
+ * tree can not be determined, and any following attempt to apply or remove
+ * an overlay changeset will be refused.
+ *
+ * A non-zero return value will not revert the changeset if error is from:
+ *   - parameter checks
+ *   - overlay changeset pre-remove notifier
+ *   - overlay changeset entry revert
+ *
+ * If an error is returned by an overlay changeset pre-remove notifier
+ * then no further overlay changeset pre-remove notifier will be called.
+ *
+ * If more than one notifier returns an error, then the last notifier
+ * error to occur is returned.
+ *
+ * A non-zero return value will revert the changeset if error is from:
+ *   - overlay changeset entry notifier
+ *   - overlay changeset post-remove notifier
+ *
+ * If an error is returned by an overlay changeset post-remove notifier
+ * then no further overlay changeset post-remove notifier will be called.
+ *
+ * Return: 0 on success, or a negative error number.  *@ovcs_id is set to
+ * zero after reverting the changeset, even if a subsequent error occurs.
+ */
+int of_overlay_remove(int *ovcs_id)
+{
+	struct overlay_changeset *ovcs;
+	int ret, ret_apply, ret_tmp;
+
+	if (devicetree_corrupt()) {
+		pr_err("suspect devicetree state, refuse to remove overlay\n");
+		ret = -EBUSY;
+		goto out;
+	}
+
+	mutex_lock(&of_mutex);
+
+	ovcs = idr_find(&ovcs_idr, *ovcs_id);
+	if (!ovcs) {
+		ret = -ENODEV;
+		pr_err("remove: Could not find overlay #%d\n", *ovcs_id);
+		goto err_unlock;
+	}
+
+	if (!overlay_removal_is_ok(ovcs)) {
+		ret = -EBUSY;
+		goto err_unlock;
+	}
+
+	ret = overlay_notify(ovcs, OF_OVERLAY_PRE_REMOVE);
+	if (ret)
+		goto err_unlock;
+
+	ret_apply = 0;
+	ret = __of_changeset_revert_entries(&ovcs->cset, &ret_apply);
+	if (ret) {
+		if (ret_apply)
+			devicetree_state_flags |= DTSF_REVERT_FAIL;
+		goto err_unlock;
+	}
+
+	ret = __of_changeset_revert_notify(&ovcs->cset);
+	if (ret)
+		pr_err("overlay remove changeset entry notify error %d\n", ret);
+	/* notify failure is not fatal, continue */
+
+	*ovcs_id = 0;
+
+	/*
+	 * Note that the overlay memory will be kfree()ed by
+	 * free_overlay_changeset() even if the notifier for
+	 * OF_OVERLAY_POST_REMOVE returns an error.
+	 */
+	ret_tmp = overlay_notify(ovcs, OF_OVERLAY_POST_REMOVE);
+	if (ret_tmp)
+		if (!ret)
+			ret = ret_tmp;
+
+	free_overlay_changeset(ovcs);
+
+err_unlock:
+	/*
+	 * If jumped over free_overlay_changeset(), then did not kfree()
+	 * overlay related memory.  This is a memory leak unless a subsequent
+	 * of_overlay_remove() of this overlay is successful.
+	 */
+	mutex_unlock(&of_mutex);
+
+out:
+	pr_debug("%s() err=%d\n", __func__, ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_overlay_remove);
+
+/**
+ * of_overlay_remove_all() - Reverts and frees all overlay changesets
+ *
+ * Removes all overlays from the system in the correct order.
+ *
+ * Return: 0 on success, or a negative error number
+ */
+int of_overlay_remove_all(void)
+{
+	struct overlay_changeset *ovcs, *ovcs_n;
+	int ret;
+
+	/* the tail of list is guaranteed to be safe to remove */
+	list_for_each_entry_safe_reverse(ovcs, ovcs_n, &ovcs_list, ovcs_list) {
+		ret = of_overlay_remove(&ovcs->id);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_overlay_remove_all);
diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c
new file mode 100644
index 000000000..7eda43c66
--- /dev/null
+++ b/drivers/of/pdt.c
@@ -0,0 +1,213 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* pdt.c: OF PROM device tree support code.
+ *
+ * Paul Mackerras	August 1996.
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ *
+ *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
+ *    {engebret|bergner}@us.ibm.com
+ *
+ *  Adapted for sparc by David S. Miller davem@davemloft.net
+ *  Adapted for multiple architectures by Andres Salomon <dilinger@queued.net>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_pdt.h>
+
+static struct of_pdt_ops *of_pdt_prom_ops __initdata;
+
+#if defined(CONFIG_SPARC)
+unsigned int of_pdt_unique_id __initdata;
+
+#define of_pdt_incr_unique_id(p) do { \
+	(p)->unique_id = of_pdt_unique_id++; \
+} while (0)
+
+static char * __init of_pdt_build_full_name(struct device_node *dp)
+{
+	return build_path_component(dp);
+}
+
+#else /* CONFIG_SPARC */
+
+static inline void of_pdt_incr_unique_id(void *p) { }
+static inline void irq_trans_init(struct device_node *dp) { }
+
+static char * __init of_pdt_build_full_name(struct device_node *dp)
+{
+	static int failsafe_id = 0; /* for generating unique names on failure */
+	const char *name;
+	char path[256];
+	char *buf;
+	int len;
+
+	if (!of_pdt_prom_ops->pkg2path(dp->phandle, path, sizeof(path), &len)) {
+		name = kbasename(path);
+		buf = prom_early_alloc(strlen(name) + 1);
+		strcpy(buf, name);
+		return buf;
+	}
+
+	name = of_get_property(dp, "name", &len);
+	buf = prom_early_alloc(len + 16);
+	sprintf(buf, "%s@unknown%i", name, failsafe_id++);
+	pr_err("%s: pkg2path failed; assigning %s\n", __func__, buf);
+	return buf;
+}
+
+#endif /* !CONFIG_SPARC */
+
+static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
+					       char *special_name,
+					       void *special_val,
+					       int special_len)
+{
+	static struct property *tmp = NULL;
+	struct property *p;
+	int err;
+
+	if (tmp) {
+		p = tmp;
+		memset(p, 0, sizeof(*p) + 32);
+		tmp = NULL;
+	} else {
+		p = prom_early_alloc(sizeof(struct property) + 32);
+		of_pdt_incr_unique_id(p);
+	}
+
+	p->name = (char *) (p + 1);
+	if (special_name) {
+		strcpy(p->name, special_name);
+		p->length = special_len;
+		p->value = prom_early_alloc(special_len);
+		memcpy(p->value, special_val, special_len);
+	} else {
+		err = of_pdt_prom_ops->nextprop(node, prev, p->name);
+		if (err) {
+			tmp = p;
+			return NULL;
+		}
+		p->length = of_pdt_prom_ops->getproplen(node, p->name);
+		if (p->length <= 0) {
+			p->length = 0;
+		} else {
+			int len;
+
+			p->value = prom_early_alloc(p->length + 1);
+			len = of_pdt_prom_ops->getproperty(node, p->name,
+					p->value, p->length);
+			if (len <= 0)
+				p->length = 0;
+			((unsigned char *)p->value)[p->length] = '\0';
+		}
+	}
+	return p;
+}
+
+static struct property * __init of_pdt_build_prop_list(phandle node)
+{
+	struct property *head, *tail;
+
+	head = tail = of_pdt_build_one_prop(node, NULL,
+				     ".node", &node, sizeof(node));
+
+	tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
+	tail = tail->next;
+	while(tail) {
+		tail->next = of_pdt_build_one_prop(node, tail->name,
+					    NULL, NULL, 0);
+		tail = tail->next;
+	}
+
+	return head;
+}
+
+static char * __init of_pdt_get_one_property(phandle node, const char *name)
+{
+	char *buf = "<NULL>";
+	int len;
+
+	len = of_pdt_prom_ops->getproplen(node, name);
+	if (len > 0) {
+		buf = prom_early_alloc(len);
+		len = of_pdt_prom_ops->getproperty(node, name, buf, len);
+	}
+
+	return buf;
+}
+
+static struct device_node * __init of_pdt_create_node(phandle node,
+						    struct device_node *parent)
+{
+	struct device_node *dp;
+
+	if (!node)
+		return NULL;
+
+	dp = prom_early_alloc(sizeof(*dp));
+	of_node_init(dp);
+	of_pdt_incr_unique_id(dp);
+	dp->parent = parent;
+
+	dp->name = of_pdt_get_one_property(node, "name");
+	dp->phandle = node;
+
+	dp->properties = of_pdt_build_prop_list(node);
+
+	dp->full_name = of_pdt_build_full_name(dp);
+
+	irq_trans_init(dp);
+
+	return dp;
+}
+
+static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
+						   phandle node)
+{
+	struct device_node *ret = NULL, *prev_sibling = NULL;
+	struct device_node *dp;
+
+	while (1) {
+		dp = of_pdt_create_node(node, parent);
+		if (!dp)
+			break;
+
+		if (prev_sibling)
+			prev_sibling->sibling = dp;
+
+		if (!ret)
+			ret = dp;
+		prev_sibling = dp;
+
+		dp->child = of_pdt_build_tree(dp, of_pdt_prom_ops->getchild(node));
+
+		node = of_pdt_prom_ops->getsibling(node);
+	}
+
+	return ret;
+}
+
+static void * __init kernel_tree_alloc(u64 size, u64 align)
+{
+	return prom_early_alloc(size);
+}
+
+void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
+{
+	BUG_ON(!ops);
+	of_pdt_prom_ops = ops;
+
+	of_root = of_pdt_create_node(root_node, NULL);
+	of_root->full_name = "/";
+
+	of_root->child = of_pdt_build_tree(of_root,
+				of_pdt_prom_ops->getchild(of_root->phandle));
+
+	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
+	of_alias_scan(kernel_tree_alloc);
+}
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
new file mode 100644
index 000000000..bf96862cb
--- /dev/null
+++ b/drivers/of/platform.c
@@ -0,0 +1,795 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *    Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
+ *			 <benh@kernel.crashing.org>
+ *    and		 Arnd Bergmann, IBM Corp.
+ *    Merged from powerpc/kernel/of_platform.c and
+ *    sparc{,64}/kernel/of_device.c by Stephen Rothwell
+ */
+
+#define pr_fmt(fmt)	"OF: " fmt
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/amba/bus.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+const struct of_device_id of_default_bus_match_table[] = {
+	{ .compatible = "simple-bus", },
+	{ .compatible = "simple-mfd", },
+	{ .compatible = "isa", },
+#ifdef CONFIG_ARM_AMBA
+	{ .compatible = "arm,amba-bus", },
+#endif /* CONFIG_ARM_AMBA */
+	{} /* Empty terminated list */
+};
+
+static const struct of_device_id of_skipped_node_table[] = {
+	{ .compatible = "operating-points-v2", },
+	{} /* Empty terminated list */
+};
+
+/**
+ * of_find_device_by_node - Find the platform_device associated with a node
+ * @np: Pointer to device tree node
+ *
+ * Takes a reference to the embedded struct device which needs to be dropped
+ * after use.
+ *
+ * Return: platform_device pointer, or NULL if not found
+ */
+struct platform_device *of_find_device_by_node(struct device_node *np)
+{
+	struct device *dev;
+
+	dev = bus_find_device_by_of_node(&platform_bus_type, np);
+	return dev ? to_platform_device(dev) : NULL;
+}
+EXPORT_SYMBOL(of_find_device_by_node);
+
+#ifdef CONFIG_OF_ADDRESS
+/*
+ * The following routines scan a subtree and registers a device for
+ * each applicable node.
+ *
+ * Note: sparc doesn't use these routines because it has a different
+ * mechanism for creating devices from device tree nodes.
+ */
+
+/**
+ * of_device_make_bus_id - Use the device node data to assign a unique name
+ * @dev: pointer to device structure that is linked to a device tree node
+ *
+ * This routine will first try using the translated bus address to
+ * derive a unique name. If it cannot, then it will prepend names from
+ * parent nodes until a unique name can be derived.
+ */
+static void of_device_make_bus_id(struct device *dev)
+{
+	struct device_node *node = dev->of_node;
+	const __be32 *reg;
+	u64 addr;
+	u32 mask;
+
+	/* Construct the name, using parent nodes if necessary to ensure uniqueness */
+	while (node->parent) {
+		/*
+		 * If the address can be translated, then that is as much
+		 * uniqueness as we need. Make it the first component and return
+		 */
+		reg = of_get_property(node, "reg", NULL);
+		if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
+			if (!of_property_read_u32(node, "mask", &mask))
+				dev_set_name(dev, dev_name(dev) ? "%llx.%x.%pOFn:%s" : "%llx.%x.%pOFn",
+					     addr, ffs(mask) - 1, node, dev_name(dev));
+
+			else
+				dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn",
+					     addr, node, dev_name(dev));
+			return;
+		}
+
+		/* format arguments only used if dev_name() resolves to NULL */
+		dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
+			     kbasename(node->full_name), dev_name(dev));
+		node = node->parent;
+	}
+}
+
+/**
+ * of_device_alloc - Allocate and initialize an of_device
+ * @np: device node to assign to device
+ * @bus_id: Name to assign to the device.  May be null to use default name.
+ * @parent: Parent device.
+ */
+struct platform_device *of_device_alloc(struct device_node *np,
+				  const char *bus_id,
+				  struct device *parent)
+{
+	struct platform_device *dev;
+	int rc, i, num_reg = 0;
+	struct resource *res, temp_res;
+
+	dev = platform_device_alloc("", PLATFORM_DEVID_NONE);
+	if (!dev)
+		return NULL;
+
+	/* count the io resources */
+	while (of_address_to_resource(np, num_reg, &temp_res) == 0)
+		num_reg++;
+
+	/* Populate the resource table */
+	if (num_reg) {
+		res = kcalloc(num_reg, sizeof(*res), GFP_KERNEL);
+		if (!res) {
+			platform_device_put(dev);
+			return NULL;
+		}
+
+		dev->num_resources = num_reg;
+		dev->resource = res;
+		for (i = 0; i < num_reg; i++, res++) {
+			rc = of_address_to_resource(np, i, res);
+			WARN_ON(rc);
+		}
+	}
+
+	dev->dev.of_node = of_node_get(np);
+	dev->dev.fwnode = &np->fwnode;
+	dev->dev.parent = parent ? : &platform_bus;
+
+	if (bus_id)
+		dev_set_name(&dev->dev, "%s", bus_id);
+	else
+		of_device_make_bus_id(&dev->dev);
+
+	return dev;
+}
+EXPORT_SYMBOL(of_device_alloc);
+
+/**
+ * of_platform_device_create_pdata - Alloc, initialize and register an of_device
+ * @np: pointer to node to create device for
+ * @bus_id: name to assign device
+ * @platform_data: pointer to populate platform_data pointer with
+ * @parent: Linux device model parent device.
+ *
+ * Return: Pointer to created platform device, or NULL if a device was not
+ * registered.  Unavailable devices will not get registered.
+ */
+static struct platform_device *of_platform_device_create_pdata(
+					struct device_node *np,
+					const char *bus_id,
+					void *platform_data,
+					struct device *parent)
+{
+	struct platform_device *dev;
+
+	if (!of_device_is_available(np) ||
+	    of_node_test_and_set_flag(np, OF_POPULATED))
+		return NULL;
+
+	dev = of_device_alloc(np, bus_id, parent);
+	if (!dev)
+		goto err_clear_flag;
+
+	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
+	if (!dev->dev.dma_mask)
+		dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
+	dev->dev.bus = &platform_bus_type;
+	dev->dev.platform_data = platform_data;
+	of_msi_configure(&dev->dev, dev->dev.of_node);
+
+	if (of_device_add(dev) != 0) {
+		platform_device_put(dev);
+		goto err_clear_flag;
+	}
+
+	return dev;
+
+err_clear_flag:
+	of_node_clear_flag(np, OF_POPULATED);
+	return NULL;
+}
+
+/**
+ * of_platform_device_create - Alloc, initialize and register an of_device
+ * @np: pointer to node to create device for
+ * @bus_id: name to assign device
+ * @parent: Linux device model parent device.
+ *
+ * Return: Pointer to created platform device, or NULL if a device was not
+ * registered.  Unavailable devices will not get registered.
+ */
+struct platform_device *of_platform_device_create(struct device_node *np,
+					    const char *bus_id,
+					    struct device *parent)
+{
+	return of_platform_device_create_pdata(np, bus_id, NULL, parent);
+}
+EXPORT_SYMBOL(of_platform_device_create);
+
+#ifdef CONFIG_ARM_AMBA
+static struct amba_device *of_amba_device_create(struct device_node *node,
+						 const char *bus_id,
+						 void *platform_data,
+						 struct device *parent)
+{
+	struct amba_device *dev;
+	const void *prop;
+	int ret;
+
+	pr_debug("Creating amba device %pOF\n", node);
+
+	if (!of_device_is_available(node) ||
+	    of_node_test_and_set_flag(node, OF_POPULATED))
+		return NULL;
+
+	dev = amba_device_alloc(NULL, 0, 0);
+	if (!dev)
+		goto err_clear_flag;
+
+	/* AMBA devices only support a single DMA mask */
+	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
+	dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
+
+	/* setup generic device info */
+	dev->dev.of_node = of_node_get(node);
+	dev->dev.fwnode = &node->fwnode;
+	dev->dev.parent = parent ? : &platform_bus;
+	dev->dev.platform_data = platform_data;
+	if (bus_id)
+		dev_set_name(&dev->dev, "%s", bus_id);
+	else
+		of_device_make_bus_id(&dev->dev);
+
+	/* Allow the HW Peripheral ID to be overridden */
+	prop = of_get_property(node, "arm,primecell-periphid", NULL);
+	if (prop)
+		dev->periphid = of_read_ulong(prop, 1);
+
+	ret = of_address_to_resource(node, 0, &dev->res);
+	if (ret) {
+		pr_err("amba: of_address_to_resource() failed (%d) for %pOF\n",
+		       ret, node);
+		goto err_free;
+	}
+
+	ret = amba_device_add(dev, &iomem_resource);
+	if (ret) {
+		pr_err("amba_device_add() failed (%d) for %pOF\n",
+		       ret, node);
+		goto err_free;
+	}
+
+	return dev;
+
+err_free:
+	amba_device_put(dev);
+err_clear_flag:
+	of_node_clear_flag(node, OF_POPULATED);
+	return NULL;
+}
+#else /* CONFIG_ARM_AMBA */
+static struct amba_device *of_amba_device_create(struct device_node *node,
+						 const char *bus_id,
+						 void *platform_data,
+						 struct device *parent)
+{
+	return NULL;
+}
+#endif /* CONFIG_ARM_AMBA */
+
+/*
+ * of_dev_lookup() - Given a device node, lookup the preferred Linux name
+ */
+static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
+				 struct device_node *np)
+{
+	const struct of_dev_auxdata *auxdata;
+	struct resource res;
+	int compatible = 0;
+
+	if (!lookup)
+		return NULL;
+
+	auxdata = lookup;
+	for (; auxdata->compatible; auxdata++) {
+		if (!of_device_is_compatible(np, auxdata->compatible))
+			continue;
+		compatible++;
+		if (!of_address_to_resource(np, 0, &res))
+			if (res.start != auxdata->phys_addr)
+				continue;
+		pr_debug("%pOF: devname=%s\n", np, auxdata->name);
+		return auxdata;
+	}
+
+	if (!compatible)
+		return NULL;
+
+	/* Try compatible match if no phys_addr and name are specified */
+	auxdata = lookup;
+	for (; auxdata->compatible; auxdata++) {
+		if (!of_device_is_compatible(np, auxdata->compatible))
+			continue;
+		if (!auxdata->phys_addr && !auxdata->name) {
+			pr_debug("%pOF: compatible match\n", np);
+			return auxdata;
+		}
+	}
+
+	return NULL;
+}
+
+/**
+ * of_platform_bus_create() - Create a device for a node and its children.
+ * @bus: device node of the bus to instantiate
+ * @matches: match table for bus nodes
+ * @lookup: auxdata table for matching id and platform_data with device nodes
+ * @parent: parent for new device, or NULL for top level.
+ * @strict: require compatible property
+ *
+ * Creates a platform_device for the provided device_node, and optionally
+ * recursively create devices for all the child nodes.
+ */
+static int of_platform_bus_create(struct device_node *bus,
+				  const struct of_device_id *matches,
+				  const struct of_dev_auxdata *lookup,
+				  struct device *parent, bool strict)
+{
+	const struct of_dev_auxdata *auxdata;
+	struct device_node *child;
+	struct platform_device *dev;
+	const char *bus_id = NULL;
+	void *platform_data = NULL;
+	int rc = 0;
+
+	/* Make sure it has a compatible property */
+	if (strict && (!of_get_property(bus, "compatible", NULL))) {
+		pr_debug("%s() - skipping %pOF, no compatible prop\n",
+			 __func__, bus);
+		return 0;
+	}
+
+	/* Skip nodes for which we don't want to create devices */
+	if (unlikely(of_match_node(of_skipped_node_table, bus))) {
+		pr_debug("%s() - skipping %pOF node\n", __func__, bus);
+		return 0;
+	}
+
+	if (of_node_check_flag(bus, OF_POPULATED_BUS)) {
+		pr_debug("%s() - skipping %pOF, already populated\n",
+			__func__, bus);
+		return 0;
+	}
+
+	auxdata = of_dev_lookup(lookup, bus);
+	if (auxdata) {
+		bus_id = auxdata->name;
+		platform_data = auxdata->platform_data;
+	}
+
+	if (of_device_is_compatible(bus, "arm,primecell")) {
+		/*
+		 * Don't return an error here to keep compatibility with older
+		 * device tree files.
+		 */
+		of_amba_device_create(bus, bus_id, platform_data, parent);
+		return 0;
+	}
+
+	dev = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);
+	if (!dev || !of_match_node(matches, bus))
+		return 0;
+
+	for_each_child_of_node(bus, child) {
+		pr_debug("   create child: %pOF\n", child);
+		rc = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);
+		if (rc) {
+			of_node_put(child);
+			break;
+		}
+	}
+	of_node_set_flag(bus, OF_POPULATED_BUS);
+	return rc;
+}
+
+/**
+ * of_platform_bus_probe() - Probe the device-tree for platform buses
+ * @root: parent of the first level to probe or NULL for the root of the tree
+ * @matches: match table for bus nodes
+ * @parent: parent to hook devices from, NULL for toplevel
+ *
+ * Note that children of the provided root are not instantiated as devices
+ * unless the specified root itself matches the bus list and is not NULL.
+ */
+int of_platform_bus_probe(struct device_node *root,
+			  const struct of_device_id *matches,
+			  struct device *parent)
+{
+	struct device_node *child;
+	int rc = 0;
+
+	root = root ? of_node_get(root) : of_find_node_by_path("/");
+	if (!root)
+		return -EINVAL;
+
+	pr_debug("%s()\n", __func__);
+	pr_debug(" starting at: %pOF\n", root);
+
+	/* Do a self check of bus type, if there's a match, create children */
+	if (of_match_node(matches, root)) {
+		rc = of_platform_bus_create(root, matches, NULL, parent, false);
+	} else for_each_child_of_node(root, child) {
+		if (!of_match_node(matches, child))
+			continue;
+		rc = of_platform_bus_create(child, matches, NULL, parent, false);
+		if (rc) {
+			of_node_put(child);
+			break;
+		}
+	}
+
+	of_node_put(root);
+	return rc;
+}
+EXPORT_SYMBOL(of_platform_bus_probe);
+
+/**
+ * of_platform_populate() - Populate platform_devices from device tree data
+ * @root: parent of the first level to probe or NULL for the root of the tree
+ * @matches: match table, NULL to use the default
+ * @lookup: auxdata table for matching id and platform_data with device nodes
+ * @parent: parent to hook devices from, NULL for toplevel
+ *
+ * Similar to of_platform_bus_probe(), this function walks the device tree
+ * and creates devices from nodes.  It differs in that it follows the modern
+ * convention of requiring all device nodes to have a 'compatible' property,
+ * and it is suitable for creating devices which are children of the root
+ * node (of_platform_bus_probe will only create children of the root which
+ * are selected by the @matches argument).
+ *
+ * New board support should be using this function instead of
+ * of_platform_bus_probe().
+ *
+ * Return: 0 on success, < 0 on failure.
+ */
+int of_platform_populate(struct device_node *root,
+			const struct of_device_id *matches,
+			const struct of_dev_auxdata *lookup,
+			struct device *parent)
+{
+	struct device_node *child;
+	int rc = 0;
+
+	root = root ? of_node_get(root) : of_find_node_by_path("/");
+	if (!root)
+		return -EINVAL;
+
+	pr_debug("%s()\n", __func__);
+	pr_debug(" starting at: %pOF\n", root);
+
+	device_links_supplier_sync_state_pause();
+	for_each_child_of_node(root, child) {
+		rc = of_platform_bus_create(child, matches, lookup, parent, true);
+		if (rc) {
+			of_node_put(child);
+			break;
+		}
+	}
+	device_links_supplier_sync_state_resume();
+
+	of_node_set_flag(root, OF_POPULATED_BUS);
+
+	of_node_put(root);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(of_platform_populate);
+
+int of_platform_default_populate(struct device_node *root,
+				 const struct of_dev_auxdata *lookup,
+				 struct device *parent)
+{
+	return of_platform_populate(root, of_default_bus_match_table, lookup,
+				    parent);
+}
+EXPORT_SYMBOL_GPL(of_platform_default_populate);
+
+static const struct of_device_id reserved_mem_matches[] = {
+	{ .compatible = "phram" },
+	{ .compatible = "qcom,rmtfs-mem" },
+	{ .compatible = "qcom,cmd-db" },
+	{ .compatible = "qcom,smem" },
+	{ .compatible = "ramoops" },
+	{ .compatible = "nvmem-rmem" },
+	{ .compatible = "google,open-dice" },
+	{}
+};
+
+static int __init of_platform_default_populate_init(void)
+{
+	struct device_node *node;
+
+	device_links_supplier_sync_state_pause();
+
+	if (!of_have_populated_dt())
+		return -ENODEV;
+
+	if (IS_ENABLED(CONFIG_PPC)) {
+		struct device_node *boot_display = NULL;
+		struct platform_device *dev;
+		int display_number = 0;
+		int ret;
+
+		/* Check if we have a MacOS display without a node spec */
+		if (of_get_property(of_chosen, "linux,bootx-noscreen", NULL)) {
+			/*
+			 * The old code tried to work out which node was the MacOS
+			 * display based on the address. I'm dropping that since the
+			 * lack of a node spec only happens with old BootX versions
+			 * (users can update) and with this code, they'll still get
+			 * a display (just not the palette hacks).
+			 */
+			dev = platform_device_alloc("bootx-noscreen", 0);
+			if (WARN_ON(!dev))
+				return -ENOMEM;
+			ret = platform_device_add(dev);
+			if (WARN_ON(ret)) {
+				platform_device_put(dev);
+				return ret;
+			}
+		}
+
+		/*
+		 * For OF framebuffers, first create the device for the boot display,
+		 * then for the other framebuffers. Only fail for the boot display;
+		 * ignore errors for the rest.
+		 */
+		for_each_node_by_type(node, "display") {
+			if (!of_get_property(node, "linux,opened", NULL) ||
+			    !of_get_property(node, "linux,boot-display", NULL))
+				continue;
+			dev = of_platform_device_create(node, "of-display", NULL);
+			of_node_put(node);
+			if (WARN_ON(!dev))
+				return -ENOMEM;
+			boot_display = node;
+			display_number++;
+			break;
+		}
+		for_each_node_by_type(node, "display") {
+			char buf[14];
+			const char *of_display_format = "of-display.%d";
+
+			if (!of_get_property(node, "linux,opened", NULL) || node == boot_display)
+				continue;
+			ret = snprintf(buf, sizeof(buf), of_display_format, display_number++);
+			if (ret < sizeof(buf))
+				of_platform_device_create(node, buf, NULL);
+		}
+
+	} else {
+		/*
+		 * Handle certain compatibles explicitly, since we don't want to create
+		 * platform_devices for every node in /reserved-memory with a
+		 * "compatible",
+		 */
+		for_each_matching_node(node, reserved_mem_matches)
+			of_platform_device_create(node, NULL, NULL);
+
+		node = of_find_node_by_path("/firmware");
+		if (node) {
+			of_platform_populate(node, NULL, NULL, NULL);
+			of_node_put(node);
+		}
+
+		node = of_get_compatible_child(of_chosen, "simple-framebuffer");
+		of_platform_device_create(node, NULL, NULL);
+		of_node_put(node);
+
+		/* Populate everything else. */
+		of_platform_default_populate(NULL, NULL, NULL);
+	}
+
+	return 0;
+}
+arch_initcall_sync(of_platform_default_populate_init);
+
+static int __init of_platform_sync_state_init(void)
+{
+	device_links_supplier_sync_state_resume();
+	return 0;
+}
+late_initcall_sync(of_platform_sync_state_init);
+
+int of_platform_device_destroy(struct device *dev, void *data)
+{
+	/* Do not touch devices not populated from the device tree */
+	if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
+		return 0;
+
+	/* Recurse for any nodes that were treated as busses */
+	if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
+		device_for_each_child(dev, NULL, of_platform_device_destroy);
+
+	of_node_clear_flag(dev->of_node, OF_POPULATED);
+	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
+
+	if (dev->bus == &platform_bus_type)
+		platform_device_unregister(to_platform_device(dev));
+#ifdef CONFIG_ARM_AMBA
+	else if (dev->bus == &amba_bustype)
+		amba_device_unregister(to_amba_device(dev));
+#endif
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_platform_device_destroy);
+
+/**
+ * of_platform_depopulate() - Remove devices populated from device tree
+ * @parent: device which children will be removed
+ *
+ * Complementary to of_platform_populate(), this function removes children
+ * of the given device (and, recurrently, their children) that have been
+ * created from their respective device tree nodes (and only those,
+ * leaving others - eg. manually created - unharmed).
+ */
+void of_platform_depopulate(struct device *parent)
+{
+	if (parent->of_node && of_node_check_flag(parent->of_node, OF_POPULATED_BUS)) {
+		device_for_each_child_reverse(parent, NULL, of_platform_device_destroy);
+		of_node_clear_flag(parent->of_node, OF_POPULATED_BUS);
+	}
+}
+EXPORT_SYMBOL_GPL(of_platform_depopulate);
+
+static void devm_of_platform_populate_release(struct device *dev, void *res)
+{
+	of_platform_depopulate(*(struct device **)res);
+}
+
+/**
+ * devm_of_platform_populate() - Populate platform_devices from device tree data
+ * @dev: device that requested to populate from device tree data
+ *
+ * Similar to of_platform_populate(), but will automatically call
+ * of_platform_depopulate() when the device is unbound from the bus.
+ *
+ * Return: 0 on success, < 0 on failure.
+ */
+int devm_of_platform_populate(struct device *dev)
+{
+	struct device **ptr;
+	int ret;
+
+	if (!dev)
+		return -EINVAL;
+
+	ptr = devres_alloc(devm_of_platform_populate_release,
+			   sizeof(*ptr), GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
+	if (ret) {
+		devres_free(ptr);
+	} else {
+		*ptr = dev;
+		devres_add(dev, ptr);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(devm_of_platform_populate);
+
+static int devm_of_platform_match(struct device *dev, void *res, void *data)
+{
+	struct device **ptr = res;
+
+	if (!ptr) {
+		WARN_ON(!ptr);
+		return 0;
+	}
+
+	return *ptr == data;
+}
+
+/**
+ * devm_of_platform_depopulate() - Remove devices populated from device tree
+ * @dev: device that requested to depopulate from device tree data
+ *
+ * Complementary to devm_of_platform_populate(), this function removes children
+ * of the given device (and, recurrently, their children) that have been
+ * created from their respective device tree nodes (and only those,
+ * leaving others - eg. manually created - unharmed).
+ */
+void devm_of_platform_depopulate(struct device *dev)
+{
+	int ret;
+
+	ret = devres_release(dev, devm_of_platform_populate_release,
+			     devm_of_platform_match, dev);
+
+	WARN_ON(ret);
+}
+EXPORT_SYMBOL_GPL(devm_of_platform_depopulate);
+
+#ifdef CONFIG_OF_DYNAMIC
+static int of_platform_notify(struct notifier_block *nb,
+				unsigned long action, void *arg)
+{
+	struct of_reconfig_data *rd = arg;
+	struct platform_device *pdev_parent, *pdev;
+	bool children_left;
+
+	switch (of_reconfig_get_state_change(action, rd)) {
+	case OF_RECONFIG_CHANGE_ADD:
+		/* verify that the parent is a bus */
+		if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
+			return NOTIFY_OK;	/* not for us */
+
+		/* already populated? (driver using of_populate manually) */
+		if (of_node_check_flag(rd->dn, OF_POPULATED))
+			return NOTIFY_OK;
+
+		/*
+		 * Clear the flag before adding the device so that fw_devlink
+		 * doesn't skip adding consumers to this device.
+		 */
+		rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
+		/* pdev_parent may be NULL when no bus platform device */
+		pdev_parent = of_find_device_by_node(rd->dn->parent);
+		pdev = of_platform_device_create(rd->dn, NULL,
+				pdev_parent ? &pdev_parent->dev : NULL);
+		platform_device_put(pdev_parent);
+
+		if (pdev == NULL) {
+			pr_err("%s: failed to create for '%pOF'\n",
+					__func__, rd->dn);
+			/* of_platform_device_create tosses the error code */
+			return notifier_from_errno(-EINVAL);
+		}
+		break;
+
+	case OF_RECONFIG_CHANGE_REMOVE:
+
+		/* already depopulated? */
+		if (!of_node_check_flag(rd->dn, OF_POPULATED))
+			return NOTIFY_OK;
+
+		/* find our device by node */
+		pdev = of_find_device_by_node(rd->dn);
+		if (pdev == NULL)
+			return NOTIFY_OK;	/* no? not meant for us */
+
+		/* unregister takes one ref away */
+		of_platform_device_destroy(&pdev->dev, &children_left);
+
+		/* and put the reference of the find */
+		platform_device_put(pdev);
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block platform_of_notifier = {
+	.notifier_call = of_platform_notify,
+};
+
+void of_platform_register_reconfig_notifier(void)
+{
+	WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
+}
+#endif /* CONFIG_OF_DYNAMIC */
+
+#endif /* CONFIG_OF_ADDRESS */
diff --git a/drivers/of/property.c b/drivers/of/property.c
new file mode 100644
index 000000000..b636777e6
--- /dev/null
+++ b/drivers/of/property.c
@@ -0,0 +1,1473 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * drivers/of/property.c - Procedures for accessing and interpreting
+ *			   Devicetree properties and graphs.
+ *
+ * Initially created by copying procedures from drivers/of/base.c. This
+ * file contains the OF property as well as the OF graph interface
+ * functions.
+ *
+ * Paul Mackerras	August 1996.
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ *
+ *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
+ *    {engebret|bergner}@us.ibm.com
+ *
+ *  Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
+ *
+ *  Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
+ *  Grant Likely.
+ */
+
+#define pr_fmt(fmt)	"OF: " fmt
+
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_graph.h>
+#include <linux/of_irq.h>
+#include <linux/string.h>
+#include <linux/moduleparam.h>
+
+#include "of_private.h"
+
+/**
+ * of_graph_is_present() - check graph's presence
+ * @node: pointer to device_node containing graph port
+ *
+ * Return: True if @node has a port or ports (with a port) sub-node,
+ * false otherwise.
+ */
+bool of_graph_is_present(const struct device_node *node)
+{
+	struct device_node *ports, *port;
+
+	ports = of_get_child_by_name(node, "ports");
+	if (ports)
+		node = ports;
+
+	port = of_get_child_by_name(node, "port");
+	of_node_put(ports);
+	of_node_put(port);
+
+	return !!port;
+}
+EXPORT_SYMBOL(of_graph_is_present);
+
+/**
+ * of_property_count_elems_of_size - Count the number of elements in a property
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @elem_size:	size of the individual element
+ *
+ * Search for a property in a device node and count the number of elements of
+ * size elem_size in it.
+ *
+ * Return: The number of elements on sucess, -EINVAL if the property does not
+ * exist or its length does not match a multiple of elem_size and -ENODATA if
+ * the property does not have a value.
+ */
+int of_property_count_elems_of_size(const struct device_node *np,
+				const char *propname, int elem_size)
+{
+	struct property *prop = of_find_property(np, propname, NULL);
+
+	if (!prop)
+		return -EINVAL;
+	if (!prop->value)
+		return -ENODATA;
+
+	if (prop->length % elem_size != 0) {
+		pr_err("size of %s in node %pOF is not a multiple of %d\n",
+		       propname, np, elem_size);
+		return -EINVAL;
+	}
+
+	return prop->length / elem_size;
+}
+EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
+
+/**
+ * of_find_property_value_of_size
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @min:	minimum allowed length of property value
+ * @max:	maximum allowed length of property value (0 means unlimited)
+ * @len:	if !=NULL, actual length is written to here
+ *
+ * Search for a property in a device node and valid the requested size.
+ *
+ * Return: The property value on success, -EINVAL if the property does not
+ * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data is too small or too large.
+ *
+ */
+static void *of_find_property_value_of_size(const struct device_node *np,
+			const char *propname, u32 min, u32 max, size_t *len)
+{
+	struct property *prop = of_find_property(np, propname, NULL);
+
+	if (!prop)
+		return ERR_PTR(-EINVAL);
+	if (!prop->value)
+		return ERR_PTR(-ENODATA);
+	if (prop->length < min)
+		return ERR_PTR(-EOVERFLOW);
+	if (max && prop->length > max)
+		return ERR_PTR(-EOVERFLOW);
+
+	if (len)
+		*len = prop->length;
+
+	return prop->value;
+}
+
+/**
+ * of_property_read_u32_index - Find and read a u32 from a multi-value property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @index:	index of the u32 in the list of values
+ * @out_value:	pointer to return value, modified only if no error.
+ *
+ * Search for a property in a device node and read nth 32-bit value from
+ * it.
+ *
+ * Return: 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_value is modified only if a valid u32 value can be decoded.
+ */
+int of_property_read_u32_index(const struct device_node *np,
+				       const char *propname,
+				       u32 index, u32 *out_value)
+{
+	const u32 *val = of_find_property_value_of_size(np, propname,
+					((index + 1) * sizeof(*out_value)),
+					0,
+					NULL);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	*out_value = be32_to_cpup(((__be32 *)val) + index);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u32_index);
+
+/**
+ * of_property_read_u64_index - Find and read a u64 from a multi-value property.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @index:	index of the u64 in the list of values
+ * @out_value:	pointer to return value, modified only if no error.
+ *
+ * Search for a property in a device node and read nth 64-bit value from
+ * it.
+ *
+ * Return: 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_value is modified only if a valid u64 value can be decoded.
+ */
+int of_property_read_u64_index(const struct device_node *np,
+				       const char *propname,
+				       u32 index, u64 *out_value)
+{
+	const u64 *val = of_find_property_value_of_size(np, propname,
+					((index + 1) * sizeof(*out_value)),
+					0, NULL);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	*out_value = be64_to_cpup(((__be64 *)val) + index);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u64_index);
+
+/**
+ * of_property_read_variable_u8_array - Find and read an array of u8 from a
+ * property, with bounds on the minimum and maximum array size.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to found values.
+ * @sz_min:	minimum number of array elements to read
+ * @sz_max:	maximum number of array elements to read, if zero there is no
+ *		upper limit on the number of elements in the dts entry but only
+ *		sz_min will be read.
+ *
+ * Search for a property in a device node and read 8-bit value(s) from
+ * it.
+ *
+ * dts entry of array should be like:
+ *  ``property = /bits/ 8 <0x50 0x60 0x70>;``
+ *
+ * Return: The number of elements read on success, -EINVAL if the property
+ * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
+ * if the property data is smaller than sz_min or longer than sz_max.
+ *
+ * The out_values is modified only if a valid u8 value can be decoded.
+ */
+int of_property_read_variable_u8_array(const struct device_node *np,
+					const char *propname, u8 *out_values,
+					size_t sz_min, size_t sz_max)
+{
+	size_t sz, count;
+	const u8 *val = of_find_property_value_of_size(np, propname,
+						(sz_min * sizeof(*out_values)),
+						(sz_max * sizeof(*out_values)),
+						&sz);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	if (!sz_max)
+		sz = sz_min;
+	else
+		sz /= sizeof(*out_values);
+
+	count = sz;
+	while (count--)
+		*out_values++ = *val++;
+
+	return sz;
+}
+EXPORT_SYMBOL_GPL(of_property_read_variable_u8_array);
+
+/**
+ * of_property_read_variable_u16_array - Find and read an array of u16 from a
+ * property, with bounds on the minimum and maximum array size.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to found values.
+ * @sz_min:	minimum number of array elements to read
+ * @sz_max:	maximum number of array elements to read, if zero there is no
+ *		upper limit on the number of elements in the dts entry but only
+ *		sz_min will be read.
+ *
+ * Search for a property in a device node and read 16-bit value(s) from
+ * it.
+ *
+ * dts entry of array should be like:
+ *  ``property = /bits/ 16 <0x5000 0x6000 0x7000>;``
+ *
+ * Return: The number of elements read on success, -EINVAL if the property
+ * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
+ * if the property data is smaller than sz_min or longer than sz_max.
+ *
+ * The out_values is modified only if a valid u16 value can be decoded.
+ */
+int of_property_read_variable_u16_array(const struct device_node *np,
+					const char *propname, u16 *out_values,
+					size_t sz_min, size_t sz_max)
+{
+	size_t sz, count;
+	const __be16 *val = of_find_property_value_of_size(np, propname,
+						(sz_min * sizeof(*out_values)),
+						(sz_max * sizeof(*out_values)),
+						&sz);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	if (!sz_max)
+		sz = sz_min;
+	else
+		sz /= sizeof(*out_values);
+
+	count = sz;
+	while (count--)
+		*out_values++ = be16_to_cpup(val++);
+
+	return sz;
+}
+EXPORT_SYMBOL_GPL(of_property_read_variable_u16_array);
+
+/**
+ * of_property_read_variable_u32_array - Find and read an array of 32 bit
+ * integers from a property, with bounds on the minimum and maximum array size.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to return found values.
+ * @sz_min:	minimum number of array elements to read
+ * @sz_max:	maximum number of array elements to read, if zero there is no
+ *		upper limit on the number of elements in the dts entry but only
+ *		sz_min will be read.
+ *
+ * Search for a property in a device node and read 32-bit value(s) from
+ * it.
+ *
+ * Return: The number of elements read on success, -EINVAL if the property
+ * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
+ * if the property data is smaller than sz_min or longer than sz_max.
+ *
+ * The out_values is modified only if a valid u32 value can be decoded.
+ */
+int of_property_read_variable_u32_array(const struct device_node *np,
+			       const char *propname, u32 *out_values,
+			       size_t sz_min, size_t sz_max)
+{
+	size_t sz, count;
+	const __be32 *val = of_find_property_value_of_size(np, propname,
+						(sz_min * sizeof(*out_values)),
+						(sz_max * sizeof(*out_values)),
+						&sz);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	if (!sz_max)
+		sz = sz_min;
+	else
+		sz /= sizeof(*out_values);
+
+	count = sz;
+	while (count--)
+		*out_values++ = be32_to_cpup(val++);
+
+	return sz;
+}
+EXPORT_SYMBOL_GPL(of_property_read_variable_u32_array);
+
+/**
+ * of_property_read_u64 - Find and read a 64 bit integer from a property
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_value:	pointer to return value, modified only if return value is 0.
+ *
+ * Search for a property in a device node and read a 64-bit value from
+ * it.
+ *
+ * Return: 0 on success, -EINVAL if the property does not exist,
+ * -ENODATA if property does not have a value, and -EOVERFLOW if the
+ * property data isn't large enough.
+ *
+ * The out_value is modified only if a valid u64 value can be decoded.
+ */
+int of_property_read_u64(const struct device_node *np, const char *propname,
+			 u64 *out_value)
+{
+	const __be32 *val = of_find_property_value_of_size(np, propname,
+						sizeof(*out_value),
+						0,
+						NULL);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	*out_value = of_read_number(val, 2);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_u64);
+
+/**
+ * of_property_read_variable_u64_array - Find and read an array of 64 bit
+ * integers from a property, with bounds on the minimum and maximum array size.
+ *
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_values:	pointer to found values.
+ * @sz_min:	minimum number of array elements to read
+ * @sz_max:	maximum number of array elements to read, if zero there is no
+ *		upper limit on the number of elements in the dts entry but only
+ *		sz_min will be read.
+ *
+ * Search for a property in a device node and read 64-bit value(s) from
+ * it.
+ *
+ * Return: The number of elements read on success, -EINVAL if the property
+ * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
+ * if the property data is smaller than sz_min or longer than sz_max.
+ *
+ * The out_values is modified only if a valid u64 value can be decoded.
+ */
+int of_property_read_variable_u64_array(const struct device_node *np,
+			       const char *propname, u64 *out_values,
+			       size_t sz_min, size_t sz_max)
+{
+	size_t sz, count;
+	const __be32 *val = of_find_property_value_of_size(np, propname,
+						(sz_min * sizeof(*out_values)),
+						(sz_max * sizeof(*out_values)),
+						&sz);
+
+	if (IS_ERR(val))
+		return PTR_ERR(val);
+
+	if (!sz_max)
+		sz = sz_min;
+	else
+		sz /= sizeof(*out_values);
+
+	count = sz;
+	while (count--) {
+		*out_values++ = of_read_number(val, 2);
+		val += 2;
+	}
+
+	return sz;
+}
+EXPORT_SYMBOL_GPL(of_property_read_variable_u64_array);
+
+/**
+ * of_property_read_string - Find and read a string from a property
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_string:	pointer to null terminated return string, modified only if
+ *		return value is 0.
+ *
+ * Search for a property in a device tree node and retrieve a null
+ * terminated string value (pointer to data, not a copy).
+ *
+ * Return: 0 on success, -EINVAL if the property does not exist, -ENODATA if
+ * property does not have a value, and -EILSEQ if the string is not
+ * null-terminated within the length of the property data.
+ *
+ * Note that the empty string "" has length of 1, thus -ENODATA cannot
+ * be interpreted as an empty string.
+ *
+ * The out_string pointer is modified only if a valid string can be decoded.
+ */
+int of_property_read_string(const struct device_node *np, const char *propname,
+				const char **out_string)
+{
+	const struct property *prop = of_find_property(np, propname, NULL);
+	if (!prop)
+		return -EINVAL;
+	if (!prop->length)
+		return -ENODATA;
+	if (strnlen(prop->value, prop->length) >= prop->length)
+		return -EILSEQ;
+	*out_string = prop->value;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_property_read_string);
+
+/**
+ * of_property_match_string() - Find string in a list and return index
+ * @np: pointer to node containing string list property
+ * @propname: string list property name
+ * @string: pointer to string to search for in string list
+ *
+ * This function searches a string list property and returns the index
+ * of a specific string value.
+ */
+int of_property_match_string(const struct device_node *np, const char *propname,
+			     const char *string)
+{
+	const struct property *prop = of_find_property(np, propname, NULL);
+	size_t l;
+	int i;
+	const char *p, *end;
+
+	if (!prop)
+		return -EINVAL;
+	if (!prop->value)
+		return -ENODATA;
+
+	p = prop->value;
+	end = p + prop->length;
+
+	for (i = 0; p < end; i++, p += l) {
+		l = strnlen(p, end - p) + 1;
+		if (p + l > end)
+			return -EILSEQ;
+		pr_debug("comparing %s with %s\n", string, p);
+		if (strcmp(string, p) == 0)
+			return i; /* Found it; return index */
+	}
+	return -ENODATA;
+}
+EXPORT_SYMBOL_GPL(of_property_match_string);
+
+/**
+ * of_property_read_string_helper() - Utility helper for parsing string properties
+ * @np:		device node from which the property value is to be read.
+ * @propname:	name of the property to be searched.
+ * @out_strs:	output array of string pointers.
+ * @sz:		number of array elements to read.
+ * @skip:	Number of strings to skip over at beginning of list.
+ *
+ * Don't call this function directly. It is a utility helper for the
+ * of_property_read_string*() family of functions.
+ */
+int of_property_read_string_helper(const struct device_node *np,
+				   const char *propname, const char **out_strs,
+				   size_t sz, int skip)
+{
+	const struct property *prop = of_find_property(np, propname, NULL);
+	int l = 0, i = 0;
+	const char *p, *end;
+
+	if (!prop)
+		return -EINVAL;
+	if (!prop->value)
+		return -ENODATA;
+	p = prop->value;
+	end = p + prop->length;
+
+	for (i = 0; p < end && (!out_strs || i < skip + sz); i++, p += l) {
+		l = strnlen(p, end - p) + 1;
+		if (p + l > end)
+			return -EILSEQ;
+		if (out_strs && i >= skip)
+			*out_strs++ = p;
+	}
+	i -= skip;
+	return i <= 0 ? -ENODATA : i;
+}
+EXPORT_SYMBOL_GPL(of_property_read_string_helper);
+
+const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
+			       u32 *pu)
+{
+	const void *curv = cur;
+
+	if (!prop)
+		return NULL;
+
+	if (!cur) {
+		curv = prop->value;
+		goto out_val;
+	}
+
+	curv += sizeof(*cur);
+	if (curv >= prop->value + prop->length)
+		return NULL;
+
+out_val:
+	*pu = be32_to_cpup(curv);
+	return curv;
+}
+EXPORT_SYMBOL_GPL(of_prop_next_u32);
+
+const char *of_prop_next_string(struct property *prop, const char *cur)
+{
+	const void *curv = cur;
+
+	if (!prop)
+		return NULL;
+
+	if (!cur)
+		return prop->value;
+
+	curv += strlen(cur) + 1;
+	if (curv >= prop->value + prop->length)
+		return NULL;
+
+	return curv;
+}
+EXPORT_SYMBOL_GPL(of_prop_next_string);
+
+/**
+ * of_graph_parse_endpoint() - parse common endpoint node properties
+ * @node: pointer to endpoint device_node
+ * @endpoint: pointer to the OF endpoint data structure
+ *
+ * The caller should hold a reference to @node.
+ */
+int of_graph_parse_endpoint(const struct device_node *node,
+			    struct of_endpoint *endpoint)
+{
+	struct device_node *port_node = of_get_parent(node);
+
+	WARN_ONCE(!port_node, "%s(): endpoint %pOF has no parent node\n",
+		  __func__, node);
+
+	memset(endpoint, 0, sizeof(*endpoint));
+
+	endpoint->local_node = node;
+	/*
+	 * It doesn't matter whether the two calls below succeed.
+	 * If they don't then the default value 0 is used.
+	 */
+	of_property_read_u32(port_node, "reg", &endpoint->port);
+	of_property_read_u32(node, "reg", &endpoint->id);
+
+	of_node_put(port_node);
+
+	return 0;
+}
+EXPORT_SYMBOL(of_graph_parse_endpoint);
+
+/**
+ * of_graph_get_port_by_id() - get the port matching a given id
+ * @parent: pointer to the parent device node
+ * @id: id of the port
+ *
+ * Return: A 'port' node pointer with refcount incremented. The caller
+ * has to use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
+{
+	struct device_node *node, *port;
+
+	node = of_get_child_by_name(parent, "ports");
+	if (node)
+		parent = node;
+
+	for_each_child_of_node(parent, port) {
+		u32 port_id = 0;
+
+		if (!of_node_name_eq(port, "port"))
+			continue;
+		of_property_read_u32(port, "reg", &port_id);
+		if (id == port_id)
+			break;
+	}
+
+	of_node_put(node);
+
+	return port;
+}
+EXPORT_SYMBOL(of_graph_get_port_by_id);
+
+/**
+ * of_graph_get_next_endpoint() - get next endpoint node
+ * @parent: pointer to the parent device node
+ * @prev: previous endpoint node, or NULL to get first
+ *
+ * Return: An 'endpoint' node pointer with refcount incremented. Refcount
+ * of the passed @prev node is decremented.
+ */
+struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
+					struct device_node *prev)
+{
+	struct device_node *endpoint;
+	struct device_node *port;
+
+	if (!parent)
+		return NULL;
+
+	/*
+	 * Start by locating the port node. If no previous endpoint is specified
+	 * search for the first port node, otherwise get the previous endpoint
+	 * parent port node.
+	 */
+	if (!prev) {
+		struct device_node *node;
+
+		node = of_get_child_by_name(parent, "ports");
+		if (node)
+			parent = node;
+
+		port = of_get_child_by_name(parent, "port");
+		of_node_put(node);
+
+		if (!port) {
+			pr_err("graph: no port node found in %pOF\n", parent);
+			return NULL;
+		}
+	} else {
+		port = of_get_parent(prev);
+		if (WARN_ONCE(!port, "%s(): endpoint %pOF has no parent node\n",
+			      __func__, prev))
+			return NULL;
+	}
+
+	while (1) {
+		/*
+		 * Now that we have a port node, get the next endpoint by
+		 * getting the next child. If the previous endpoint is NULL this
+		 * will return the first child.
+		 */
+		endpoint = of_get_next_child(port, prev);
+		if (endpoint) {
+			of_node_put(port);
+			return endpoint;
+		}
+
+		/* No more endpoints under this port, try the next one. */
+		prev = NULL;
+
+		do {
+			port = of_get_next_child(parent, port);
+			if (!port)
+				return NULL;
+		} while (!of_node_name_eq(port, "port"));
+	}
+}
+EXPORT_SYMBOL(of_graph_get_next_endpoint);
+
+/**
+ * of_graph_get_endpoint_by_regs() - get endpoint node of specific identifiers
+ * @parent: pointer to the parent device node
+ * @port_reg: identifier (value of reg property) of the parent port node
+ * @reg: identifier (value of reg property) of the endpoint node
+ *
+ * Return: An 'endpoint' node pointer which is identified by reg and at the same
+ * is the child of a port node identified by port_reg. reg and port_reg are
+ * ignored when they are -1. Use of_node_put() on the pointer when done.
+ */
+struct device_node *of_graph_get_endpoint_by_regs(
+	const struct device_node *parent, int port_reg, int reg)
+{
+	struct of_endpoint endpoint;
+	struct device_node *node = NULL;
+
+	for_each_endpoint_of_node(parent, node) {
+		of_graph_parse_endpoint(node, &endpoint);
+		if (((port_reg == -1) || (endpoint.port == port_reg)) &&
+			((reg == -1) || (endpoint.id == reg)))
+			return node;
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL(of_graph_get_endpoint_by_regs);
+
+/**
+ * of_graph_get_remote_endpoint() - get remote endpoint node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: Remote endpoint node associated with remote endpoint node linked
+ *	   to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_remote_endpoint(const struct device_node *node)
+{
+	/* Get remote endpoint node. */
+	return of_parse_phandle(node, "remote-endpoint", 0);
+}
+EXPORT_SYMBOL(of_graph_get_remote_endpoint);
+
+/**
+ * of_graph_get_port_parent() - get port's parent node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: device node associated with endpoint node linked
+ *	   to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_port_parent(struct device_node *node)
+{
+	unsigned int depth;
+
+	if (!node)
+		return NULL;
+
+	/*
+	 * Preserve usecount for passed in node as of_get_next_parent()
+	 * will do of_node_put() on it.
+	 */
+	of_node_get(node);
+
+	/* Walk 3 levels up only if there is 'ports' node. */
+	for (depth = 3; depth && node; depth--) {
+		node = of_get_next_parent(node);
+		if (depth == 2 && !of_node_name_eq(node, "ports"))
+			break;
+	}
+	return node;
+}
+EXPORT_SYMBOL(of_graph_get_port_parent);
+
+/**
+ * of_graph_get_remote_port_parent() - get remote port's parent node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: Remote device node associated with remote endpoint node linked
+ *	   to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_remote_port_parent(
+			       const struct device_node *node)
+{
+	struct device_node *np, *pp;
+
+	/* Get remote endpoint node. */
+	np = of_graph_get_remote_endpoint(node);
+
+	pp = of_graph_get_port_parent(np);
+
+	of_node_put(np);
+
+	return pp;
+}
+EXPORT_SYMBOL(of_graph_get_remote_port_parent);
+
+/**
+ * of_graph_get_remote_port() - get remote port node
+ * @node: pointer to a local endpoint device_node
+ *
+ * Return: Remote port node associated with remote endpoint node linked
+ * to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_remote_port(const struct device_node *node)
+{
+	struct device_node *np;
+
+	/* Get remote endpoint node. */
+	np = of_graph_get_remote_endpoint(node);
+	if (!np)
+		return NULL;
+	return of_get_next_parent(np);
+}
+EXPORT_SYMBOL(of_graph_get_remote_port);
+
+int of_graph_get_endpoint_count(const struct device_node *np)
+{
+	struct device_node *endpoint;
+	int num = 0;
+
+	for_each_endpoint_of_node(np, endpoint)
+		num++;
+
+	return num;
+}
+EXPORT_SYMBOL(of_graph_get_endpoint_count);
+
+/**
+ * of_graph_get_remote_node() - get remote parent device_node for given port/endpoint
+ * @node: pointer to parent device_node containing graph port/endpoint
+ * @port: identifier (value of reg property) of the parent port node
+ * @endpoint: identifier (value of reg property) of the endpoint node
+ *
+ * Return: Remote device node associated with remote endpoint node linked
+ * to @node. Use of_node_put() on it when done.
+ */
+struct device_node *of_graph_get_remote_node(const struct device_node *node,
+					     u32 port, u32 endpoint)
+{
+	struct device_node *endpoint_node, *remote;
+
+	endpoint_node = of_graph_get_endpoint_by_regs(node, port, endpoint);
+	if (!endpoint_node) {
+		pr_debug("no valid endpoint (%d, %d) for node %pOF\n",
+			 port, endpoint, node);
+		return NULL;
+	}
+
+	remote = of_graph_get_remote_port_parent(endpoint_node);
+	of_node_put(endpoint_node);
+	if (!remote) {
+		pr_debug("no valid remote node\n");
+		return NULL;
+	}
+
+	if (!of_device_is_available(remote)) {
+		pr_debug("not available for remote node\n");
+		of_node_put(remote);
+		return NULL;
+	}
+
+	return remote;
+}
+EXPORT_SYMBOL(of_graph_get_remote_node);
+
+static struct fwnode_handle *of_fwnode_get(struct fwnode_handle *fwnode)
+{
+	return of_fwnode_handle(of_node_get(to_of_node(fwnode)));
+}
+
+static void of_fwnode_put(struct fwnode_handle *fwnode)
+{
+	of_node_put(to_of_node(fwnode));
+}
+
+static bool of_fwnode_device_is_available(const struct fwnode_handle *fwnode)
+{
+	return of_device_is_available(to_of_node(fwnode));
+}
+
+static bool of_fwnode_device_dma_supported(const struct fwnode_handle *fwnode)
+{
+	return true;
+}
+
+static enum dev_dma_attr
+of_fwnode_device_get_dma_attr(const struct fwnode_handle *fwnode)
+{
+	if (of_dma_is_coherent(to_of_node(fwnode)))
+		return DEV_DMA_COHERENT;
+	else
+		return DEV_DMA_NON_COHERENT;
+}
+
+static bool of_fwnode_property_present(const struct fwnode_handle *fwnode,
+				       const char *propname)
+{
+	return of_property_read_bool(to_of_node(fwnode), propname);
+}
+
+static int of_fwnode_property_read_int_array(const struct fwnode_handle *fwnode,
+					     const char *propname,
+					     unsigned int elem_size, void *val,
+					     size_t nval)
+{
+	const struct device_node *node = to_of_node(fwnode);
+
+	if (!val)
+		return of_property_count_elems_of_size(node, propname,
+						       elem_size);
+
+	switch (elem_size) {
+	case sizeof(u8):
+		return of_property_read_u8_array(node, propname, val, nval);
+	case sizeof(u16):
+		return of_property_read_u16_array(node, propname, val, nval);
+	case sizeof(u32):
+		return of_property_read_u32_array(node, propname, val, nval);
+	case sizeof(u64):
+		return of_property_read_u64_array(node, propname, val, nval);
+	}
+
+	return -ENXIO;
+}
+
+static int
+of_fwnode_property_read_string_array(const struct fwnode_handle *fwnode,
+				     const char *propname, const char **val,
+				     size_t nval)
+{
+	const struct device_node *node = to_of_node(fwnode);
+
+	return val ?
+		of_property_read_string_array(node, propname, val, nval) :
+		of_property_count_strings(node, propname);
+}
+
+static const char *of_fwnode_get_name(const struct fwnode_handle *fwnode)
+{
+	return kbasename(to_of_node(fwnode)->full_name);
+}
+
+static const char *of_fwnode_get_name_prefix(const struct fwnode_handle *fwnode)
+{
+	/* Root needs no prefix here (its name is "/"). */
+	if (!to_of_node(fwnode)->parent)
+		return "";
+
+	return "/";
+}
+
+static struct fwnode_handle *
+of_fwnode_get_parent(const struct fwnode_handle *fwnode)
+{
+	return of_fwnode_handle(of_get_parent(to_of_node(fwnode)));
+}
+
+static struct fwnode_handle *
+of_fwnode_get_next_child_node(const struct fwnode_handle *fwnode,
+			      struct fwnode_handle *child)
+{
+	return of_fwnode_handle(of_get_next_available_child(to_of_node(fwnode),
+							    to_of_node(child)));
+}
+
+static struct fwnode_handle *
+of_fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
+			       const char *childname)
+{
+	const struct device_node *node = to_of_node(fwnode);
+	struct device_node *child;
+
+	for_each_available_child_of_node(node, child)
+		if (of_node_name_eq(child, childname))
+			return of_fwnode_handle(child);
+
+	return NULL;
+}
+
+static int
+of_fwnode_get_reference_args(const struct fwnode_handle *fwnode,
+			     const char *prop, const char *nargs_prop,
+			     unsigned int nargs, unsigned int index,
+			     struct fwnode_reference_args *args)
+{
+	struct of_phandle_args of_args;
+	unsigned int i;
+	int ret;
+
+	if (nargs_prop)
+		ret = of_parse_phandle_with_args(to_of_node(fwnode), prop,
+						 nargs_prop, index, &of_args);
+	else
+		ret = of_parse_phandle_with_fixed_args(to_of_node(fwnode), prop,
+						       nargs, index, &of_args);
+	if (ret < 0)
+		return ret;
+	if (!args) {
+		of_node_put(of_args.np);
+		return 0;
+	}
+
+	args->nargs = of_args.args_count;
+	args->fwnode = of_fwnode_handle(of_args.np);
+
+	for (i = 0; i < NR_FWNODE_REFERENCE_ARGS; i++)
+		args->args[i] = i < of_args.args_count ? of_args.args[i] : 0;
+
+	return 0;
+}
+
+static struct fwnode_handle *
+of_fwnode_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
+				  struct fwnode_handle *prev)
+{
+	return of_fwnode_handle(of_graph_get_next_endpoint(to_of_node(fwnode),
+							   to_of_node(prev)));
+}
+
+static struct fwnode_handle *
+of_fwnode_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
+{
+	return of_fwnode_handle(
+		of_graph_get_remote_endpoint(to_of_node(fwnode)));
+}
+
+static struct fwnode_handle *
+of_fwnode_graph_get_port_parent(struct fwnode_handle *fwnode)
+{
+	struct device_node *np;
+
+	/* Get the parent of the port */
+	np = of_get_parent(to_of_node(fwnode));
+	if (!np)
+		return NULL;
+
+	/* Is this the "ports" node? If not, it's the port parent. */
+	if (!of_node_name_eq(np, "ports"))
+		return of_fwnode_handle(np);
+
+	return of_fwnode_handle(of_get_next_parent(np));
+}
+
+static int of_fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
+					  struct fwnode_endpoint *endpoint)
+{
+	const struct device_node *node = to_of_node(fwnode);
+	struct device_node *port_node = of_get_parent(node);
+
+	endpoint->local_fwnode = fwnode;
+
+	of_property_read_u32(port_node, "reg", &endpoint->port);
+	of_property_read_u32(node, "reg", &endpoint->id);
+
+	of_node_put(port_node);
+
+	return 0;
+}
+
+static const void *
+of_fwnode_device_get_match_data(const struct fwnode_handle *fwnode,
+				const struct device *dev)
+{
+	return of_device_get_match_data(dev);
+}
+
+static struct device_node *of_get_compat_node(struct device_node *np)
+{
+	of_node_get(np);
+
+	while (np) {
+		if (!of_device_is_available(np)) {
+			of_node_put(np);
+			np = NULL;
+		}
+
+		if (of_find_property(np, "compatible", NULL))
+			break;
+
+		np = of_get_next_parent(np);
+	}
+
+	return np;
+}
+
+static struct device_node *of_get_compat_node_parent(struct device_node *np)
+{
+	struct device_node *parent, *node;
+
+	parent = of_get_parent(np);
+	node = of_get_compat_node(parent);
+	of_node_put(parent);
+
+	return node;
+}
+
+static void of_link_to_phandle(struct device_node *con_np,
+			      struct device_node *sup_np)
+{
+	struct device_node *tmp_np = of_node_get(sup_np);
+
+	/* Check that sup_np and its ancestors are available. */
+	while (tmp_np) {
+		if (of_fwnode_handle(tmp_np)->dev) {
+			of_node_put(tmp_np);
+			break;
+		}
+
+		if (!of_device_is_available(tmp_np)) {
+			of_node_put(tmp_np);
+			return;
+		}
+
+		tmp_np = of_get_next_parent(tmp_np);
+	}
+
+	fwnode_link_add(of_fwnode_handle(con_np), of_fwnode_handle(sup_np));
+}
+
+/**
+ * parse_prop_cells - Property parsing function for suppliers
+ *
+ * @np:		Pointer to device tree node containing a list
+ * @prop_name:	Name of property to be parsed. Expected to hold phandle values
+ * @index:	For properties holding a list of phandles, this is the index
+ *		into the list.
+ * @list_name:	Property name that is known to contain list of phandle(s) to
+ *		supplier(s)
+ * @cells_name:	property name that specifies phandles' arguments count
+ *
+ * This is a helper function to parse properties that have a known fixed name
+ * and are a list of phandles and phandle arguments.
+ *
+ * Returns:
+ * - phandle node pointer with refcount incremented. Caller must of_node_put()
+ *   on it when done.
+ * - NULL if no phandle found at index
+ */
+static struct device_node *parse_prop_cells(struct device_node *np,
+					    const char *prop_name, int index,
+					    const char *list_name,
+					    const char *cells_name)
+{
+	struct of_phandle_args sup_args;
+
+	if (strcmp(prop_name, list_name))
+		return NULL;
+
+	if (of_parse_phandle_with_args(np, list_name, cells_name, index,
+				       &sup_args))
+		return NULL;
+
+	return sup_args.np;
+}
+
+#define DEFINE_SIMPLE_PROP(fname, name, cells)				  \
+static struct device_node *parse_##fname(struct device_node *np,	  \
+					const char *prop_name, int index) \
+{									  \
+	return parse_prop_cells(np, prop_name, index, name, cells);	  \
+}
+
+static int strcmp_suffix(const char *str, const char *suffix)
+{
+	unsigned int len, suffix_len;
+
+	len = strlen(str);
+	suffix_len = strlen(suffix);
+	if (len <= suffix_len)
+		return -1;
+	return strcmp(str + len - suffix_len, suffix);
+}
+
+/**
+ * parse_suffix_prop_cells - Suffix property parsing function for suppliers
+ *
+ * @np:		Pointer to device tree node containing a list
+ * @prop_name:	Name of property to be parsed. Expected to hold phandle values
+ * @index:	For properties holding a list of phandles, this is the index
+ *		into the list.
+ * @suffix:	Property suffix that is known to contain list of phandle(s) to
+ *		supplier(s)
+ * @cells_name:	property name that specifies phandles' arguments count
+ *
+ * This is a helper function to parse properties that have a known fixed suffix
+ * and are a list of phandles and phandle arguments.
+ *
+ * Returns:
+ * - phandle node pointer with refcount incremented. Caller must of_node_put()
+ *   on it when done.
+ * - NULL if no phandle found at index
+ */
+static struct device_node *parse_suffix_prop_cells(struct device_node *np,
+					    const char *prop_name, int index,
+					    const char *suffix,
+					    const char *cells_name)
+{
+	struct of_phandle_args sup_args;
+
+	if (strcmp_suffix(prop_name, suffix))
+		return NULL;
+
+	if (of_parse_phandle_with_args(np, prop_name, cells_name, index,
+				       &sup_args))
+		return NULL;
+
+	return sup_args.np;
+}
+
+#define DEFINE_SUFFIX_PROP(fname, suffix, cells)			     \
+static struct device_node *parse_##fname(struct device_node *np,	     \
+					const char *prop_name, int index)    \
+{									     \
+	return parse_suffix_prop_cells(np, prop_name, index, suffix, cells); \
+}
+
+/**
+ * struct supplier_bindings - Property parsing functions for suppliers
+ *
+ * @parse_prop: function name
+ *	parse_prop() finds the node corresponding to a supplier phandle
+ * @parse_prop.np: Pointer to device node holding supplier phandle property
+ * @parse_prop.prop_name: Name of property holding a phandle value
+ * @parse_prop.index: For properties holding a list of phandles, this is the
+ *		      index into the list
+ * @optional: Describes whether a supplier is mandatory or not
+ * @node_not_dev: The consumer node containing the property is never converted
+ *		  to a struct device. Instead, parse ancestor nodes for the
+ *		  compatible property to find a node corresponding to a device.
+ *
+ * Returns:
+ * parse_prop() return values are
+ * - phandle node pointer with refcount incremented. Caller must of_node_put()
+ *   on it when done.
+ * - NULL if no phandle found at index
+ */
+struct supplier_bindings {
+	struct device_node *(*parse_prop)(struct device_node *np,
+					  const char *prop_name, int index);
+	bool optional;
+	bool node_not_dev;
+};
+
+DEFINE_SIMPLE_PROP(clocks, "clocks", "#clock-cells")
+DEFINE_SIMPLE_PROP(interconnects, "interconnects", "#interconnect-cells")
+DEFINE_SIMPLE_PROP(iommus, "iommus", "#iommu-cells")
+DEFINE_SIMPLE_PROP(mboxes, "mboxes", "#mbox-cells")
+DEFINE_SIMPLE_PROP(io_channels, "io-channel", "#io-channel-cells")
+DEFINE_SIMPLE_PROP(interrupt_parent, "interrupt-parent", NULL)
+DEFINE_SIMPLE_PROP(dmas, "dmas", "#dma-cells")
+DEFINE_SIMPLE_PROP(power_domains, "power-domains", "#power-domain-cells")
+DEFINE_SIMPLE_PROP(hwlocks, "hwlocks", "#hwlock-cells")
+DEFINE_SIMPLE_PROP(extcon, "extcon", NULL)
+DEFINE_SIMPLE_PROP(nvmem_cells, "nvmem-cells", NULL)
+DEFINE_SIMPLE_PROP(phys, "phys", "#phy-cells")
+DEFINE_SIMPLE_PROP(wakeup_parent, "wakeup-parent", NULL)
+DEFINE_SIMPLE_PROP(pinctrl0, "pinctrl-0", NULL)
+DEFINE_SIMPLE_PROP(pinctrl1, "pinctrl-1", NULL)
+DEFINE_SIMPLE_PROP(pinctrl2, "pinctrl-2", NULL)
+DEFINE_SIMPLE_PROP(pinctrl3, "pinctrl-3", NULL)
+DEFINE_SIMPLE_PROP(pinctrl4, "pinctrl-4", NULL)
+DEFINE_SIMPLE_PROP(pinctrl5, "pinctrl-5", NULL)
+DEFINE_SIMPLE_PROP(pinctrl6, "pinctrl-6", NULL)
+DEFINE_SIMPLE_PROP(pinctrl7, "pinctrl-7", NULL)
+DEFINE_SIMPLE_PROP(pinctrl8, "pinctrl-8", NULL)
+DEFINE_SIMPLE_PROP(remote_endpoint, "remote-endpoint", NULL)
+DEFINE_SIMPLE_PROP(pwms, "pwms", "#pwm-cells")
+DEFINE_SIMPLE_PROP(resets, "resets", "#reset-cells")
+DEFINE_SIMPLE_PROP(leds, "leds", NULL)
+DEFINE_SIMPLE_PROP(backlight, "backlight", NULL)
+DEFINE_SIMPLE_PROP(panel, "panel", NULL)
+DEFINE_SUFFIX_PROP(regulators, "-supply", NULL)
+DEFINE_SUFFIX_PROP(gpio, "-gpio", "#gpio-cells")
+
+static struct device_node *parse_gpios(struct device_node *np,
+				       const char *prop_name, int index)
+{
+	if (!strcmp_suffix(prop_name, ",nr-gpios"))
+		return NULL;
+
+	return parse_suffix_prop_cells(np, prop_name, index, "-gpios",
+				       "#gpio-cells");
+}
+
+static struct device_node *parse_iommu_maps(struct device_node *np,
+					    const char *prop_name, int index)
+{
+	if (strcmp(prop_name, "iommu-map"))
+		return NULL;
+
+	return of_parse_phandle(np, prop_name, (index * 4) + 1);
+}
+
+static struct device_node *parse_gpio_compat(struct device_node *np,
+					     const char *prop_name, int index)
+{
+	struct of_phandle_args sup_args;
+
+	if (strcmp(prop_name, "gpio") && strcmp(prop_name, "gpios"))
+		return NULL;
+
+	/*
+	 * Ignore node with gpio-hog property since its gpios are all provided
+	 * by its parent.
+	 */
+	if (of_find_property(np, "gpio-hog", NULL))
+		return NULL;
+
+	if (of_parse_phandle_with_args(np, prop_name, "#gpio-cells", index,
+				       &sup_args))
+		return NULL;
+
+	return sup_args.np;
+}
+
+static struct device_node *parse_interrupts(struct device_node *np,
+					    const char *prop_name, int index)
+{
+	struct of_phandle_args sup_args;
+
+	if (!IS_ENABLED(CONFIG_OF_IRQ) || IS_ENABLED(CONFIG_PPC))
+		return NULL;
+
+	if (strcmp(prop_name, "interrupts") &&
+	    strcmp(prop_name, "interrupts-extended"))
+		return NULL;
+
+	return of_irq_parse_one(np, index, &sup_args) ? NULL : sup_args.np;
+}
+
+static const struct supplier_bindings of_supplier_bindings[] = {
+	{ .parse_prop = parse_clocks, },
+	{ .parse_prop = parse_interconnects, },
+	{ .parse_prop = parse_iommus, .optional = true, },
+	{ .parse_prop = parse_iommu_maps, .optional = true, },
+	{ .parse_prop = parse_mboxes, },
+	{ .parse_prop = parse_io_channels, },
+	{ .parse_prop = parse_interrupt_parent, },
+	{ .parse_prop = parse_dmas, .optional = true, },
+	{ .parse_prop = parse_power_domains, },
+	{ .parse_prop = parse_hwlocks, },
+	{ .parse_prop = parse_extcon, },
+	{ .parse_prop = parse_nvmem_cells, },
+	{ .parse_prop = parse_phys, },
+	{ .parse_prop = parse_wakeup_parent, },
+	{ .parse_prop = parse_pinctrl0, },
+	{ .parse_prop = parse_pinctrl1, },
+	{ .parse_prop = parse_pinctrl2, },
+	{ .parse_prop = parse_pinctrl3, },
+	{ .parse_prop = parse_pinctrl4, },
+	{ .parse_prop = parse_pinctrl5, },
+	{ .parse_prop = parse_pinctrl6, },
+	{ .parse_prop = parse_pinctrl7, },
+	{ .parse_prop = parse_pinctrl8, },
+	{ .parse_prop = parse_remote_endpoint, .node_not_dev = true, },
+	{ .parse_prop = parse_pwms, },
+	{ .parse_prop = parse_resets, },
+	{ .parse_prop = parse_leds, },
+	{ .parse_prop = parse_backlight, },
+	{ .parse_prop = parse_panel, },
+	{ .parse_prop = parse_gpio_compat, },
+	{ .parse_prop = parse_interrupts, },
+	{ .parse_prop = parse_regulators, },
+	{ .parse_prop = parse_gpio, },
+	{ .parse_prop = parse_gpios, },
+	{}
+};
+
+/**
+ * of_link_property - Create device links to suppliers listed in a property
+ * @con_np: The consumer device tree node which contains the property
+ * @prop_name: Name of property to be parsed
+ *
+ * This function checks if the property @prop_name that is present in the
+ * @con_np device tree node is one of the known common device tree bindings
+ * that list phandles to suppliers. If @prop_name isn't one, this function
+ * doesn't do anything.
+ *
+ * If @prop_name is one, this function attempts to create fwnode links from the
+ * consumer device tree node @con_np to all the suppliers device tree nodes
+ * listed in @prop_name.
+ *
+ * Any failed attempt to create a fwnode link will NOT result in an immediate
+ * return.  of_link_property() must create links to all the available supplier
+ * device tree nodes even when attempts to create a link to one or more
+ * suppliers fail.
+ */
+static int of_link_property(struct device_node *con_np, const char *prop_name)
+{
+	struct device_node *phandle;
+	const struct supplier_bindings *s = of_supplier_bindings;
+	unsigned int i = 0;
+	bool matched = false;
+
+	/* Do not stop at first failed link, link all available suppliers. */
+	while (!matched && s->parse_prop) {
+		if (s->optional && !fw_devlink_is_strict()) {
+			s++;
+			continue;
+		}
+
+		while ((phandle = s->parse_prop(con_np, prop_name, i))) {
+			struct device_node *con_dev_np;
+
+			con_dev_np = s->node_not_dev
+					? of_get_compat_node_parent(con_np)
+					: of_node_get(con_np);
+			matched = true;
+			i++;
+			of_link_to_phandle(con_dev_np, phandle);
+			of_node_put(phandle);
+			of_node_put(con_dev_np);
+		}
+		s++;
+	}
+	return 0;
+}
+
+static void __iomem *of_fwnode_iomap(struct fwnode_handle *fwnode, int index)
+{
+#ifdef CONFIG_OF_ADDRESS
+	return of_iomap(to_of_node(fwnode), index);
+#else
+	return NULL;
+#endif
+}
+
+static int of_fwnode_irq_get(const struct fwnode_handle *fwnode,
+			     unsigned int index)
+{
+	return of_irq_get(to_of_node(fwnode), index);
+}
+
+static int of_fwnode_add_links(struct fwnode_handle *fwnode)
+{
+	struct property *p;
+	struct device_node *con_np = to_of_node(fwnode);
+
+	if (IS_ENABLED(CONFIG_X86))
+		return 0;
+
+	if (!con_np)
+		return -EINVAL;
+
+	for_each_property_of_node(con_np, p)
+		of_link_property(con_np, p->name);
+
+	return 0;
+}
+
+const struct fwnode_operations of_fwnode_ops = {
+	.get = of_fwnode_get,
+	.put = of_fwnode_put,
+	.device_is_available = of_fwnode_device_is_available,
+	.device_get_match_data = of_fwnode_device_get_match_data,
+	.device_dma_supported = of_fwnode_device_dma_supported,
+	.device_get_dma_attr = of_fwnode_device_get_dma_attr,
+	.property_present = of_fwnode_property_present,
+	.property_read_int_array = of_fwnode_property_read_int_array,
+	.property_read_string_array = of_fwnode_property_read_string_array,
+	.get_name = of_fwnode_get_name,
+	.get_name_prefix = of_fwnode_get_name_prefix,
+	.get_parent = of_fwnode_get_parent,
+	.get_next_child_node = of_fwnode_get_next_child_node,
+	.get_named_child_node = of_fwnode_get_named_child_node,
+	.get_reference_args = of_fwnode_get_reference_args,
+	.graph_get_next_endpoint = of_fwnode_graph_get_next_endpoint,
+	.graph_get_remote_endpoint = of_fwnode_graph_get_remote_endpoint,
+	.graph_get_port_parent = of_fwnode_graph_get_port_parent,
+	.graph_parse_endpoint = of_fwnode_graph_parse_endpoint,
+	.iomap = of_fwnode_iomap,
+	.irq_get = of_fwnode_irq_get,
+	.add_links = of_fwnode_add_links,
+};
+EXPORT_SYMBOL_GPL(of_fwnode_ops);
diff --git a/drivers/of/resolver.c b/drivers/of/resolver.c
new file mode 100644
index 000000000..b278ab433
--- /dev/null
+++ b/drivers/of/resolver.c
@@ -0,0 +1,351 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Functions for dealing with DT resolution
+ *
+ * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com>
+ * Copyright (C) 2012 Texas Instruments Inc.
+ */
+
+#define pr_fmt(fmt)	"OF: resolver: " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+
+#include "of_private.h"
+
+static phandle live_tree_max_phandle(void)
+{
+	struct device_node *node;
+	phandle phandle;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	phandle = 0;
+	for_each_of_allnodes(node) {
+		if (node->phandle != OF_PHANDLE_ILLEGAL &&
+				node->phandle > phandle)
+			phandle = node->phandle;
+	}
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	return phandle;
+}
+
+static void adjust_overlay_phandles(struct device_node *overlay,
+		int phandle_delta)
+{
+	struct device_node *child;
+	struct property *prop;
+	phandle phandle;
+
+	/* adjust node's phandle in node */
+	if (overlay->phandle != 0 && overlay->phandle != OF_PHANDLE_ILLEGAL)
+		overlay->phandle += phandle_delta;
+
+	/* copy adjusted phandle into *phandle properties */
+	for_each_property_of_node(overlay, prop) {
+
+		if (of_prop_cmp(prop->name, "phandle") &&
+		    of_prop_cmp(prop->name, "linux,phandle"))
+			continue;
+
+		if (prop->length < 4)
+			continue;
+
+		phandle = be32_to_cpup(prop->value);
+		if (phandle == OF_PHANDLE_ILLEGAL)
+			continue;
+
+		*(__be32 *)prop->value = cpu_to_be32(overlay->phandle);
+	}
+
+	for_each_child_of_node(overlay, child)
+		adjust_overlay_phandles(child, phandle_delta);
+}
+
+static int update_usages_of_a_phandle_reference(struct device_node *overlay,
+		struct property *prop_fixup, phandle phandle)
+{
+	struct device_node *refnode;
+	struct property *prop;
+	char *value, *cur, *end, *node_path, *prop_name, *s;
+	int offset, len;
+	int err = 0;
+
+	value = kmemdup(prop_fixup->value, prop_fixup->length, GFP_KERNEL);
+	if (!value)
+		return -ENOMEM;
+
+	/* prop_fixup contains a list of tuples of path:property_name:offset */
+	end = value + prop_fixup->length;
+	for (cur = value; cur < end; cur += len + 1) {
+		len = strlen(cur);
+
+		node_path = cur;
+		s = strchr(cur, ':');
+		if (!s) {
+			err = -EINVAL;
+			goto err_fail;
+		}
+		*s++ = '\0';
+
+		prop_name = s;
+		s = strchr(s, ':');
+		if (!s) {
+			err = -EINVAL;
+			goto err_fail;
+		}
+		*s++ = '\0';
+
+		err = kstrtoint(s, 10, &offset);
+		if (err)
+			goto err_fail;
+
+		refnode = __of_find_node_by_full_path(of_node_get(overlay), node_path);
+		if (!refnode)
+			continue;
+
+		for_each_property_of_node(refnode, prop) {
+			if (!of_prop_cmp(prop->name, prop_name))
+				break;
+		}
+		of_node_put(refnode);
+
+		if (!prop) {
+			err = -ENOENT;
+			goto err_fail;
+		}
+
+		if (offset < 0 || offset + sizeof(__be32) > prop->length) {
+			err = -EINVAL;
+			goto err_fail;
+		}
+
+		*(__be32 *)(prop->value + offset) = cpu_to_be32(phandle);
+	}
+
+err_fail:
+	kfree(value);
+	return err;
+}
+
+/* compare nodes taking into account that 'name' strips out the @ part */
+static int node_name_cmp(const struct device_node *dn1,
+		const struct device_node *dn2)
+{
+	const char *n1 = kbasename(dn1->full_name);
+	const char *n2 = kbasename(dn2->full_name);
+
+	return of_node_cmp(n1, n2);
+}
+
+/*
+ * Adjust the local phandle references by the given phandle delta.
+ *
+ * Subtree @local_fixups, which is overlay node __local_fixups__,
+ * mirrors the fragment node structure at the root of the overlay.
+ *
+ * For each property in the fragments that contains a phandle reference,
+ * @local_fixups has a property of the same name that contains a list
+ * of offsets of the phandle reference(s) within the respective property
+ * value(s).  The values at these offsets will be fixed up.
+ */
+static int adjust_local_phandle_references(struct device_node *local_fixups,
+		struct device_node *overlay, int phandle_delta)
+{
+	struct device_node *child, *overlay_child;
+	struct property *prop_fix, *prop;
+	int err, i, count;
+	unsigned int off;
+
+	if (!local_fixups)
+		return 0;
+
+	for_each_property_of_node(local_fixups, prop_fix) {
+
+		/* skip properties added automatically */
+		if (!of_prop_cmp(prop_fix->name, "name") ||
+		    !of_prop_cmp(prop_fix->name, "phandle") ||
+		    !of_prop_cmp(prop_fix->name, "linux,phandle"))
+			continue;
+
+		if ((prop_fix->length % 4) != 0 || prop_fix->length == 0)
+			return -EINVAL;
+		count = prop_fix->length / sizeof(__be32);
+
+		for_each_property_of_node(overlay, prop) {
+			if (!of_prop_cmp(prop->name, prop_fix->name))
+				break;
+		}
+
+		if (!prop)
+			return -EINVAL;
+
+		for (i = 0; i < count; i++) {
+			off = be32_to_cpu(((__be32 *)prop_fix->value)[i]);
+			if ((off + 4) > prop->length)
+				return -EINVAL;
+
+			be32_add_cpu(prop->value + off, phandle_delta);
+		}
+	}
+
+	/*
+	 * These nested loops recurse down two subtrees in parallel, where the
+	 * node names in the two subtrees match.
+	 *
+	 * The roots of the subtrees are the overlay's __local_fixups__ node
+	 * and the overlay's root node.
+	 */
+	for_each_child_of_node(local_fixups, child) {
+
+		for_each_child_of_node(overlay, overlay_child)
+			if (!node_name_cmp(child, overlay_child)) {
+				of_node_put(overlay_child);
+				break;
+			}
+
+		if (!overlay_child) {
+			of_node_put(child);
+			return -EINVAL;
+		}
+
+		err = adjust_local_phandle_references(child, overlay_child,
+				phandle_delta);
+		if (err) {
+			of_node_put(child);
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * of_resolve_phandles - Relocate and resolve overlay against live tree
+ *
+ * @overlay:	Pointer to devicetree overlay to relocate and resolve
+ *
+ * Modify (relocate) values of local phandles in @overlay to a range that
+ * does not conflict with the live expanded devicetree.  Update references
+ * to the local phandles in @overlay.  Update (resolve) phandle references
+ * in @overlay that refer to the live expanded devicetree.
+ *
+ * Phandle values in the live tree are in the range of
+ * 1 .. live_tree_max_phandle().  The range of phandle values in the overlay
+ * also begin with at 1.  Adjust the phandle values in the overlay to begin
+ * at live_tree_max_phandle() + 1.  Update references to the phandles to
+ * the adjusted phandle values.
+ *
+ * The name of each property in the "__fixups__" node in the overlay matches
+ * the name of a symbol (a label) in the live tree.  The values of each
+ * property in the "__fixups__" node is a list of the property values in the
+ * overlay that need to be updated to contain the phandle reference
+ * corresponding to that symbol in the live tree.  Update the references in
+ * the overlay with the phandle values in the live tree.
+ *
+ * @overlay must be detached.
+ *
+ * Resolving and applying @overlay to the live expanded devicetree must be
+ * protected by a mechanism to ensure that multiple overlays are processed
+ * in a single threaded manner so that multiple overlays will not relocate
+ * phandles to overlapping ranges.  The mechanism to enforce this is not
+ * yet implemented.
+ *
+ * Return: %0 on success or a negative error value on error.
+ */
+int of_resolve_phandles(struct device_node *overlay)
+{
+	struct device_node *child, *local_fixups, *refnode;
+	struct device_node *tree_symbols, *overlay_fixups;
+	struct property *prop;
+	const char *refpath;
+	phandle phandle, phandle_delta;
+	int err;
+
+	tree_symbols = NULL;
+
+	if (!overlay) {
+		pr_err("null overlay\n");
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (!of_node_check_flag(overlay, OF_DETACHED)) {
+		pr_err("overlay not detached\n");
+		err = -EINVAL;
+		goto out;
+	}
+
+	phandle_delta = live_tree_max_phandle() + 1;
+	adjust_overlay_phandles(overlay, phandle_delta);
+
+	for_each_child_of_node(overlay, local_fixups)
+		if (of_node_name_eq(local_fixups, "__local_fixups__"))
+			break;
+
+	err = adjust_local_phandle_references(local_fixups, overlay, phandle_delta);
+	if (err)
+		goto out;
+
+	overlay_fixups = NULL;
+
+	for_each_child_of_node(overlay, child) {
+		if (of_node_name_eq(child, "__fixups__"))
+			overlay_fixups = child;
+	}
+
+	if (!overlay_fixups) {
+		err = 0;
+		goto out;
+	}
+
+	tree_symbols = of_find_node_by_path("/__symbols__");
+	if (!tree_symbols) {
+		pr_err("no symbols in root of device tree.\n");
+		err = -EINVAL;
+		goto out;
+	}
+
+	for_each_property_of_node(overlay_fixups, prop) {
+
+		/* skip properties added automatically */
+		if (!of_prop_cmp(prop->name, "name"))
+			continue;
+
+		err = of_property_read_string(tree_symbols,
+				prop->name, &refpath);
+		if (err) {
+			pr_err("node label '%s' not found in live devicetree symbols table\n",
+			       prop->name);
+			goto out;
+		}
+
+		refnode = of_find_node_by_path(refpath);
+		if (!refnode) {
+			err = -ENOENT;
+			goto out;
+		}
+
+		phandle = refnode->phandle;
+		of_node_put(refnode);
+
+		err = update_usages_of_a_phandle_reference(overlay, prop, phandle);
+		if (err)
+			break;
+	}
+
+out:
+	if (err)
+		pr_err("overlay phandle fixup failed: %d\n", err);
+	of_node_put(tree_symbols);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(of_resolve_phandles);
diff --git a/drivers/of/unittest-data/Makefile b/drivers/of/unittest-data/Makefile
new file mode 100644
index 000000000..d072f3ba3
--- /dev/null
+++ b/drivers/of/unittest-data/Makefile
@@ -0,0 +1,104 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-y += testcases.dtb.o
+
+obj-$(CONFIG_OF_OVERLAY) += overlay.dtb.o \
+			    overlay_0.dtb.o \
+			    overlay_1.dtb.o \
+			    overlay_2.dtb.o \
+			    overlay_3.dtb.o \
+			    overlay_4.dtb.o \
+			    overlay_5.dtb.o \
+			    overlay_6.dtb.o \
+			    overlay_7.dtb.o \
+			    overlay_8.dtb.o \
+			    overlay_9.dtb.o \
+			    overlay_10.dtb.o \
+			    overlay_11.dtb.o \
+			    overlay_12.dtb.o \
+			    overlay_13.dtb.o \
+			    overlay_15.dtb.o \
+			    overlay_16.dtb.o \
+			    overlay_17.dtb.o \
+			    overlay_18.dtb.o \
+			    overlay_19.dtb.o \
+			    overlay_20.dtb.o \
+			    overlay_bad_add_dup_node.dtb.o \
+			    overlay_bad_add_dup_prop.dtb.o \
+			    overlay_bad_phandle.dtb.o \
+			    overlay_bad_symbol.dtb.o \
+			    overlay_base.dtb.o \
+			    overlay_gpio_01.dtb.o \
+			    overlay_gpio_02a.dtb.o \
+			    overlay_gpio_02b.dtb.o \
+			    overlay_gpio_03.dtb.o \
+			    overlay_gpio_04a.dtb.o \
+			    overlay_gpio_04b.dtb.o
+
+# enable creation of __symbols__ node
+DTC_FLAGS_overlay += -@
+DTC_FLAGS_overlay_bad_phandle += -@
+DTC_FLAGS_overlay_bad_symbol += -@
+DTC_FLAGS_overlay_base += -@
+DTC_FLAGS_testcases += -@
+
+# suppress warnings about intentional errors
+DTC_FLAGS_testcases += -Wno-interrupts_property \
+	-Wno-node_name_vs_property_name \
+	-Wno-interrupt_map
+
+# Apply overlays statically with fdtoverlay.  This is a build time test that
+# the overlays can be applied successfully by fdtoverlay.  This does not
+# guarantee that the overlays can be applied successfully at run time by
+# unittest, but it provides a bit of build time test coverage for those
+# who do not execute unittest.
+#
+# The overlays are applied on top of static_base_1.dtb and static_base_2.dtb to
+# create static_test_1.dtb and static_test_2.dtb.  If fdtoverlay detects an
+# error than the kernel build will fail.  static_test_1.dtb and
+# static_test_2.dtb are not consumed by unittest.
+#
+# Some unittest overlays deliberately contain errors that unittest checks for.
+# These overlays will cause fdtoverlay to fail, and are thus not included
+# in the static test:
+#			  overlay_bad_add_dup_node.dtbo \
+#			  overlay_bad_add_dup_prop.dtbo \
+#			  overlay_bad_phandle.dtbo \
+#			  overlay_bad_symbol.dtbo \
+
+apply_static_overlay_1 := overlay_0.dtbo \
+			  overlay_1.dtbo \
+			  overlay_2.dtbo \
+			  overlay_3.dtbo \
+			  overlay_4.dtbo \
+			  overlay_5.dtbo \
+			  overlay_6.dtbo \
+			  overlay_7.dtbo \
+			  overlay_8.dtbo \
+			  overlay_9.dtbo \
+			  overlay_10.dtbo \
+			  overlay_11.dtbo \
+			  overlay_12.dtbo \
+			  overlay_13.dtbo \
+			  overlay_15.dtbo \
+			  overlay_16.dtbo \
+			  overlay_17.dtbo \
+			  overlay_18.dtbo \
+			  overlay_19.dtbo \
+			  overlay_20.dtbo \
+			  overlay_gpio_01.dtbo \
+			  overlay_gpio_02a.dtbo \
+			  overlay_gpio_02b.dtbo \
+			  overlay_gpio_03.dtbo \
+			  overlay_gpio_04a.dtbo \
+			  overlay_gpio_04b.dtbo
+
+apply_static_overlay_2 := overlay.dtbo
+
+DTC_FLAGS_static_base_1 += -Wno-interrupts_property \
+	-Wno-node_name_vs_property_name \
+	-Wno-interrupt_map
+
+static_test_1-dtbs := static_base_1.dtb $(apply_static_overlay_1)
+static_test_2-dtbs := static_base_2.dtb $(apply_static_overlay_2)
+
+dtb-$(CONFIG_OF_OVERLAY) += static_test_1.dtb static_test_2.dtb
diff --git a/drivers/of/unittest-data/overlay.dts b/drivers/of/unittest-data/overlay.dts
new file mode 100644
index 000000000..3bbc59e92
--- /dev/null
+++ b/drivers/of/unittest-data/overlay.dts
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&electric_1 {
+
+	status = "okay";
+
+	hvac_2: hvac-large-1 {
+		compatible = "ot,hvac-large";
+		heat-range = < 40 75 >;
+		cool-range = < 65 80 >;
+	};
+};
+
+&rides_1 {
+
+	#address-cells = <1>;
+	#size-cells = <1>;
+	status = "okay";
+
+	ride@100 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		track@30 {
+			incline-up = < 48 32 16 >;
+		};
+
+		track@40 {
+			incline-up = < 47 31 15 >;
+		};
+	};
+
+	ride_200: ride@200 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "ot,ferris-wheel";
+		reg = < 0x00000200 0x100 >;
+		hvac-provider = < &hvac_2 >;
+		hvac-thermostat = < 27 32 > ;
+		hvac-zones = < 12 5 >;
+		hvac-zone-names = "operator", "snack-bar";
+		spin-controller = < &spin_ctrl_1 3 >;
+		spin-rph = < 30 >;
+		gondolas = < 16 >;
+		gondola-capacity = < 6 >;
+
+		ride_200_left: track@10 {
+			reg = < 0x00000010 0x10 >;
+		};
+
+		ride_200_right: track@20 {
+			reg = < 0x00000020 0x10 >;
+		};
+	};
+};
+
+&lights_2 {
+
+	status = "okay";
+	color = "purple", "white", "red", "green";
+	rate = < 3 256 >;
+};
diff --git a/drivers/of/unittest-data/overlay_0.dts b/drivers/of/unittest-data/overlay_0.dts
new file mode 100644
index 000000000..ac0f9e0fe
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_0.dts
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/ {
+	/* overlay_0 - enable using absolute target path */
+
+	fragment@0 {
+		target-path = "/testcase-data/overlay-node/test-bus/test-unittest0";
+		__overlay__ {
+			status = "okay";
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_1.dts b/drivers/of/unittest-data/overlay_1.dts
new file mode 100644
index 000000000..e92a626e2
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_1.dts
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/ {
+	/* overlay_1 - disable using absolute target path */
+
+	fragment@0 {
+		target-path = "/testcase-data/overlay-node/test-bus/test-unittest1";
+		__overlay__ {
+			status = "disabled";
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_10.dts b/drivers/of/unittest-data/overlay_10.dts
new file mode 100644
index 000000000..73993bf23
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_10.dts
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_10 */
+/* overlays 8, 9, 10, 11 application and removal in bad sequence */
+
+&unittest_test_bus {
+	/* suppress DTC warning */
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest10 {
+		compatible = "unittest";
+		status = "okay";
+		reg = <10>;
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		test-unittest101 {
+			compatible = "unittest";
+			status = "okay";
+			reg = <1>;
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_11.dts b/drivers/of/unittest-data/overlay_11.dts
new file mode 100644
index 000000000..9a79b253a
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_11.dts
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_11 */
+/* overlays 8, 9, 10, 11 application and removal in bad sequence */
+
+&unittest_test_bus {
+	/* suppress DTC warning */
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest11 {
+		compatible = "unittest";
+		status = "okay";
+		reg = <11>;
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		test-unittest111 {
+			compatible = "unittest";
+			status = "okay";
+			reg = <1>;
+		};
+
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_12.dts b/drivers/of/unittest-data/overlay_12.dts
new file mode 100644
index 000000000..ca3441e2c
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_12.dts
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/ {
+	/* overlay_12 - enable using absolute target path (i2c) */
+
+	fragment@0 {
+		target-path = "/testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest12";
+		__overlay__ {
+			status = "okay";
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_13.dts b/drivers/of/unittest-data/overlay_13.dts
new file mode 100644
index 000000000..3c30dec63
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_13.dts
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/ {
+	/* overlay_13 - disable using absolute target path (i2c) */
+
+	fragment@0 {
+		target-path = "/testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest13";
+		__overlay__ {
+			status = "disabled";
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_15.dts b/drivers/of/unittest-data/overlay_15.dts
new file mode 100644
index 000000000..572849047
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_15.dts
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_15 - mux overlay */
+
+&unittest_i2c_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+	test-unittest15 {
+		reg = <11>;
+		compatible = "unittest-i2c-mux";
+		status = "okay";
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		i2c@0 {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			reg = <0>;
+
+			test-mux-dev@20 {
+				reg = <0x20>;
+				compatible = "unittest-i2c-dev";
+				status = "okay";
+			};
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_16.dts b/drivers/of/unittest-data/overlay_16.dts
new file mode 100644
index 000000000..80a46dc02
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_16.dts
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_16 - notify test */
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest16 {
+		compatible = "unittest";
+		reg = <16>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_17.dts b/drivers/of/unittest-data/overlay_17.dts
new file mode 100644
index 000000000..5b8a22091
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_17.dts
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_17 - notify test */
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest17 {
+		compatible = "unittest";
+		reg = <17>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_18.dts b/drivers/of/unittest-data/overlay_18.dts
new file mode 100644
index 000000000..dcddd5f6d
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_18.dts
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_18 - notify test */
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest18 {
+		compatible = "unittest";
+		reg = <18>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_19.dts b/drivers/of/unittest-data/overlay_19.dts
new file mode 100644
index 000000000..32b3ba0b6
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_19.dts
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_19 - notify test */
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest19 {
+		compatible = "unittest";
+		reg = <19>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_2.dts b/drivers/of/unittest-data/overlay_2.dts
new file mode 100644
index 000000000..db8684ba8
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_2.dts
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_2 -  enable using label */
+
+&unittest2 {
+	status = "okay";
+};
diff --git a/drivers/of/unittest-data/overlay_20.dts b/drivers/of/unittest-data/overlay_20.dts
new file mode 100644
index 000000000..d4a4f2f32
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_20.dts
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_20 - notify test */
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest20 {
+		compatible = "unittest";
+		reg = <20>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_3.dts b/drivers/of/unittest-data/overlay_3.dts
new file mode 100644
index 000000000..40f289e7c
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_3.dts
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_3 - disable using label */
+
+&unittest3 {
+	status = "disabled";
+};
diff --git a/drivers/of/unittest-data/overlay_4.dts b/drivers/of/unittest-data/overlay_4.dts
new file mode 100644
index 000000000..a8a77ddf9
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_4.dts
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_4 - test insertion of a full node */
+
+&unittest_test_bus {
+
+	/* suppress DTC warning */
+	#address-cells = <1>;
+	#size-cells = <0>;
+
+	test-unittest4 {
+		compatible = "unittest";
+		status = "okay";
+		reg = <4>;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_5.dts b/drivers/of/unittest-data/overlay_5.dts
new file mode 100644
index 000000000..706f5f1b7
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_5.dts
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_5 - test overlay apply revert */
+
+&unittest5 {
+	status = "okay";
+};
diff --git a/drivers/of/unittest-data/overlay_6.dts b/drivers/of/unittest-data/overlay_6.dts
new file mode 100644
index 000000000..21a7fa4ca
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_6.dts
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_6 */
+/* overlays 6, 7 application and removal in sequence */
+
+&unittest6 {
+	status = "okay";
+};
diff --git a/drivers/of/unittest-data/overlay_7.dts b/drivers/of/unittest-data/overlay_7.dts
new file mode 100644
index 000000000..58ba1bb51
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_7.dts
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_7 */
+/* overlays 6, 7 application and removal in sequence */
+
+&unittest7 {
+	status = "okay";
+};
diff --git a/drivers/of/unittest-data/overlay_8.dts b/drivers/of/unittest-data/overlay_8.dts
new file mode 100644
index 000000000..e9718d118
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_8.dts
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_8 */
+/* overlays 8, 9, 10, 11 application and removal in bad sequence */
+
+&unittest8 {
+	status = "okay";
+};
diff --git a/drivers/of/unittest-data/overlay_9.dts b/drivers/of/unittest-data/overlay_9.dts
new file mode 100644
index 000000000..b35e23eda
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_9.dts
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/* overlay_9 */
+/* overlays 8, 9, 10, 11 application and removal in bad sequence */
+
+&unittest8 {
+	property-foo = "bar";
+};
diff --git a/drivers/of/unittest-data/overlay_bad_add_dup_node.dts b/drivers/of/unittest-data/overlay_bad_add_dup_node.dts
new file mode 100644
index 000000000..145dfc3b1
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_bad_add_dup_node.dts
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/*
+ * &electric_1/motor-1 and &spin_ctrl_1 are the same node:
+ *   /testcase-data-2/substation@100/motor-1
+ *
+ * Thus the new node "controller" in each fragment will
+ * result in an attempt to add the same node twice.
+ * This will result in an error and the overlay apply
+ * will fail.
+ */
+
+&electric_1 {
+
+	motor-1 {
+		controller {
+			power_bus = < 0x1 0x2 >;
+		};
+	};
+};
+
+&spin_ctrl_1 {
+		controller {
+			power_bus_emergency = < 0x101 0x102 >;
+		};
+};
diff --git a/drivers/of/unittest-data/overlay_bad_add_dup_prop.dts b/drivers/of/unittest-data/overlay_bad_add_dup_prop.dts
new file mode 100644
index 000000000..6327d1ffb
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_bad_add_dup_prop.dts
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+/*
+ * &electric_1/motor-1/electric and &spin_ctrl_1/electric are the same node:
+ *   /testcase-data-2/substation@100/motor-1/electric
+ *
+ * Thus the property "rpm_avail" in each fragment will
+ * result in an attempt to update the same property twice.
+ * This will result in an error and the overlay apply
+ * will fail.
+ *
+ * The previous version of this test did not include the extra
+ * level of node 'electric'.  That resulted in the 'rpm_avail'
+ * property being located in the pre-existing node 'motor-1'.
+ * Modifying a property results in a WARNING that a memory leak
+ * will occur if the overlay is removed.  Since the overlay apply
+ * fails, the memory leak does actually occur, and kmemleak will
+ * further report the memory leak if CONFIG_DEBUG_KMEMLEAK is
+ * enabled.  Adding the overlay node 'electric' avoids the
+ * memory leak and thus people who use kmemleak will not
+ * have to debug this non-problem again.
+ */
+
+&electric_1 {
+
+	motor-1 {
+		electric {
+			rpm_avail = < 100 >;
+		};
+	};
+};
+
+&spin_ctrl_1 {
+		electric {
+			rpm_avail = < 100 200 >;
+		};
+};
diff --git a/drivers/of/unittest-data/overlay_bad_phandle.dts b/drivers/of/unittest-data/overlay_bad_phandle.dts
new file mode 100644
index 000000000..83b797360
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_bad_phandle.dts
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&electric_1 {
+
+	// This label should cause an error when the overlay
+	// is applied.  There is already a phandle value
+	// in the base tree for motor-1.
+	spin_ctrl_1_conflict: motor-1 {
+		accelerate = < 3 >;
+		decelerate = < 5 >;
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_bad_symbol.dts b/drivers/of/unittest-data/overlay_bad_symbol.dts
new file mode 100644
index 000000000..98c6d1de1
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_bad_symbol.dts
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&electric_1 {
+
+	// This label should cause an error when the overlay
+	// is applied.  There is already a symbol hvac_1
+	// in the base tree
+	hvac_1: hvac-medium-2 {
+		compatible = "ot,hvac-medium";
+		heat-range = < 50 75 >;
+		cool-range = < 60 80 >;
+	};
+
+};
diff --git a/drivers/of/unittest-data/overlay_base.dts b/drivers/of/unittest-data/overlay_base.dts
new file mode 100644
index 000000000..ab9014589
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_base.dts
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+#include "overlay_common.dtsi"
diff --git a/drivers/of/unittest-data/overlay_common.dtsi b/drivers/of/unittest-data/overlay_common.dtsi
new file mode 100644
index 000000000..08874a725
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_common.dtsi
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Base device tree that overlays will be applied against.
+ *
+ * Do not add any properties in node "/".
+ * Do not add any nodes other than "/testcase-data-2" in node "/".
+ * Do not add anything that would result in dtc creating node "/__fixups__".
+ * dtc will create nodes "/__symbols__" and "/__local_fixups__".
+ */
+
+/ {
+	testcase-data-2 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		electric_1: substation@100 {
+			compatible = "ot,big-volts-control";
+			reg = < 0x00000100 0x100 >;
+			status = "disabled";
+
+			hvac_1: hvac-medium-1 {
+				compatible = "ot,hvac-medium";
+				heat-range = < 50 75 >;
+				cool-range = < 60 80 >;
+			};
+
+			spin_ctrl_1: motor-1 {
+				compatible = "ot,ferris-wheel-motor";
+				spin = "clockwise";
+				rpm_avail = < 50 >;
+			};
+
+			spin_ctrl_2: motor-8 {
+				compatible = "ot,roller-coaster-motor";
+			};
+		};
+
+		rides_1: fairway-1 {
+			#address-cells = <1>;
+			#size-cells = <1>;
+			compatible = "ot,rides";
+			status = "disabled";
+			orientation = < 127 >;
+
+			ride@100 {
+				#address-cells = <1>;
+				#size-cells = <1>;
+				compatible = "ot,roller-coaster";
+				reg = < 0x00000100 0x100 >;
+				hvac-provider = < &hvac_1 >;
+				hvac-thermostat = < 29 > ;
+				hvac-zones = < 14 >;
+				hvac-zone-names = "operator";
+				spin-controller = < &spin_ctrl_2 5 &spin_ctrl_2 7 >;
+				spin-controller-names = "track_1", "track_2";
+				queues = < 2 >;
+
+				track@30 {
+					reg = < 0x00000030 0x10 >;
+				};
+
+				track@40 {
+					reg = < 0x00000040 0x10 >;
+				};
+
+			};
+		};
+
+		lights_1: lights@30000 {
+			compatible = "ot,work-lights";
+			reg = < 0x00030000 0x1000 >;
+			status = "disabled";
+		};
+
+		lights_2: lights@40000 {
+			compatible = "ot,show-lights";
+			reg = < 0x00040000 0x1000 >;
+			status = "disabled";
+			rate = < 13 138 >;
+		};
+
+		retail_1: vending@50000 {
+			reg = < 0x00050000 0x1000 >;
+			compatible = "ot,tickets";
+			status = "disabled";
+		};
+
+	};
+};
+
diff --git a/drivers/of/unittest-data/overlay_gpio_01.dts b/drivers/of/unittest-data/overlay_gpio_01.dts
new file mode 100644
index 000000000..699ff104a
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_gpio_01.dts
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+	gpio@0 {
+		compatible = "unittest-gpio";
+		reg = <0>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		ngpios = <2>;
+		gpio-line-names = "line-A", "line-B";
+
+		line-b {
+			gpio-hog;
+			gpios = <2 0>;
+			input;
+			line-name = "line-B-input";
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_gpio_02a.dts b/drivers/of/unittest-data/overlay_gpio_02a.dts
new file mode 100644
index 000000000..ec59aff6e
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_gpio_02a.dts
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+	gpio@2 {
+		compatible = "unittest-gpio";
+		reg = <2>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		ngpios = <2>;
+		gpio-line-names = "line-A", "line-B";
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_gpio_02b.dts b/drivers/of/unittest-data/overlay_gpio_02b.dts
new file mode 100644
index 000000000..43ce111d4
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_gpio_02b.dts
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+	gpio@2 {
+		line-a {
+			gpio-hog;
+			gpios = <1 0>;
+			input;
+			line-name = "line-A-input";
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_gpio_03.dts b/drivers/of/unittest-data/overlay_gpio_03.dts
new file mode 100644
index 000000000..6e0312340
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_gpio_03.dts
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+	gpio@3 {
+		compatible = "unittest-gpio";
+		reg = <3>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		ngpios = <2>;
+		gpio-line-names = "line-A", "line-B", "line-C", "line-D";
+
+		line-d {
+			gpio-hog;
+			gpios = <4 0>;
+			input;
+			line-name = "line-D-input";
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_gpio_04a.dts b/drivers/of/unittest-data/overlay_gpio_04a.dts
new file mode 100644
index 000000000..7b1e04ebf
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_gpio_04a.dts
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+	gpio@4 {
+		compatible = "unittest-gpio";
+		reg = <4>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		ngpios = <2>;
+		gpio-line-names = "line-A", "line-B", "line-C", "line-D";
+	};
+};
diff --git a/drivers/of/unittest-data/overlay_gpio_04b.dts b/drivers/of/unittest-data/overlay_gpio_04b.dts
new file mode 100644
index 000000000..a14e95c66
--- /dev/null
+++ b/drivers/of/unittest-data/overlay_gpio_04b.dts
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&unittest_test_bus {
+	#address-cells = <1>;
+	#size-cells = <0>;
+	gpio@4 {
+		line-c {
+			gpio-hog;
+			gpios = <3 0>;
+			input;
+			line-name = "line-C-input";
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/static_base_1.dts b/drivers/of/unittest-data/static_base_1.dts
new file mode 100644
index 000000000..10556cb3f
--- /dev/null
+++ b/drivers/of/unittest-data/static_base_1.dts
@@ -0,0 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+
+#include "testcases_common.dtsi"
diff --git a/drivers/of/unittest-data/static_base_2.dts b/drivers/of/unittest-data/static_base_2.dts
new file mode 100644
index 000000000..b0ea9504d
--- /dev/null
+++ b/drivers/of/unittest-data/static_base_2.dts
@@ -0,0 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+
+#include "overlay_common.dtsi"
diff --git a/drivers/of/unittest-data/testcases.dts b/drivers/of/unittest-data/testcases.dts
new file mode 100644
index 000000000..61cdd3d5f
--- /dev/null
+++ b/drivers/of/unittest-data/testcases.dts
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+#include "testcases_common.dtsi"
+
+/ {
+	/*
+	 * testcase data that intentionally results in an error is located here
+	 * instead of in testcases_common.dtsi so that the static overlay apply
+	 * tests will not include the error.
+	 */
+	testcase-data {
+		testcase-device2 {
+			compatible = "testcase-device";
+			interrupt-parent = <&test_intc2>;
+			interrupts = <1>; /* invalid specifier - too short */
+		};
+	};
+
+};
diff --git a/drivers/of/unittest-data/testcases_common.dtsi b/drivers/of/unittest-data/testcases_common.dtsi
new file mode 100644
index 000000000..19292bbb4
--- /dev/null
+++ b/drivers/of/unittest-data/testcases_common.dtsi
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/ {
+	testcase-data {
+		changeset {
+			prop-update = "hello";
+			prop-remove = "world";
+			node-remove {
+			};
+		};
+	};
+};
+
+#include "tests-phandle.dtsi"
+#include "tests-interrupts.dtsi"
+#include "tests-match.dtsi"
+#include "tests-address.dtsi"
+#include "tests-platform.dtsi"
+#include "tests-overlay.dtsi"
diff --git a/drivers/of/unittest-data/tests-address.dtsi b/drivers/of/unittest-data/tests-address.dtsi
new file mode 100644
index 000000000..6604a52bf
--- /dev/null
+++ b/drivers/of/unittest-data/tests-address.dtsi
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	testcase-data {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		address-tests {
+			#address-cells = <1>;
+			#size-cells = <1>;
+			/* ranges here is to make sure we don't use it for
+			 * dma-ranges translation */
+			ranges = <0x70000000 0x70000000 0x40000000>,
+				 <0x00000000 0xd0000000 0x20000000>;
+			dma-ranges = <0x0 0x20000000 0x40000000>;
+
+			device@70000000 {
+				reg = <0x70000000 0x1000>;
+			};
+
+			bus@80000000 {
+				#address-cells = <2>;
+				#size-cells = <2>;
+				ranges = <0x0 0x0 0x80000000 0x0 0x100000>;
+				dma-ranges = <0x1 0x0 0x0 0x20 0x0>;
+
+				device@1000 {
+					reg = <0x0 0x1000 0x0 0x1000>;
+				};
+			};
+
+			pci@90000000 {
+				device_type = "pci";
+				#address-cells = <3>;
+				#size-cells = <2>;
+				reg = <0x90000000 0x1000>;
+				ranges = <0x42000000 0x0 0x40000000 0x40000000 0x0 0x10000000>;
+				dma-ranges = <0x42000000 0x0 0x80000000 0x00000000 0x0 0x10000000>,
+					     <0x42000000 0x0 0xc0000000 0x20000000 0x0 0x10000000>;
+			};
+
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/tests-interrupts.dtsi b/drivers/of/unittest-data/tests-interrupts.dtsi
new file mode 100644
index 000000000..ecc74dbcc
--- /dev/null
+++ b/drivers/of/unittest-data/tests-interrupts.dtsi
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/ {
+	testcase-data {
+		interrupts {
+			#address-cells = <1>;
+			#size-cells = <1>;
+			test_intc0: intc0 {
+				interrupt-controller;
+				#interrupt-cells = <1>;
+			};
+
+			test_intc1: intc1 {
+				interrupt-controller;
+				#interrupt-cells = <3>;
+			};
+
+			test_intc2: intc2 {
+				interrupt-controller;
+				#interrupt-cells = <2>;
+			};
+
+			test_intmap0: intmap0 {
+				#interrupt-cells = <1>;
+				#address-cells = <0>;
+				interrupt-map = <1 &test_intc0 9>,
+						<2 &test_intc1 10 11 12>,
+						<3 &test_intc2 13 14>,
+						<4 &test_intc2 15 16>;
+			};
+
+			test_intmap1: intmap1 {
+				#interrupt-cells = <2>;
+				/*
+				 * #address-cells is required
+				 *
+				 * The property is not provided in this node to
+				 * test that the code will properly handle
+				 * this case for legacy .dts files.
+				 *
+				 * Not having #address-cells will result in a
+				 * warning from dtc starting with
+				 * version v1.6.1-19-g0a3a9d3449c8
+				 * The warning is suppressed by adding
+				 * -Wno-interrupt_map to the Makefile for all
+				 * .dts files this include this .dtsi
+				#address-cells = <1>;
+				 */
+				interrupt-map = <0x5000 1 2 &test_intc0 15>;
+			};
+
+			interrupts0 {
+				interrupt-parent = <&test_intc0>;
+				interrupts = <1>, <2>, <3>, <4>;
+			};
+
+			interrupts1 {
+				interrupt-parent = <&test_intmap0>;
+				interrupts = <1>, <2>, <3>, <4>;
+			};
+
+			interrupts-extended0 {
+				reg = <0x5000 0x100>;
+				/*
+				 * Do not remove &test_intmap1 from this
+				 * property - see comment in node intmap1
+				 */
+				interrupts-extended = <&test_intc0 1>,
+						      <&test_intc1 2 3 4>,
+						      <&test_intc2 5 6>,
+						      <&test_intmap0 1>,
+						      <&test_intmap0 2>,
+						      <&test_intmap0 3>,
+						      <&test_intmap1 1 2>;
+			};
+		};
+
+		testcase-device1 {
+			compatible = "testcase-device";
+			interrupt-parent = <&test_intc0>;
+			interrupts = <1>;
+		};
+
+		/*
+		 * testcase data that intentionally results in an error is
+		 * located in testcases.dts instead of in this file so that the
+		 * static overlay apply tests will not include the error.
+		 */
+	};
+};
diff --git a/drivers/of/unittest-data/tests-match.dtsi b/drivers/of/unittest-data/tests-match.dtsi
new file mode 100644
index 000000000..1fd3b2131
--- /dev/null
+++ b/drivers/of/unittest-data/tests-match.dtsi
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/ {
+	testcase-data {
+		match-node {
+			name0 { };
+			name1 { device_type = "type1"; };
+			a { name2 { device_type = "type1"; }; };
+			b { name2 { }; };
+			c { name2 { device_type = "type2"; }; };
+			name3 { compatible = "compat3"; };
+			name4 { compatible = "compat2", "compat3"; };
+			name5 { compatible = "compat2", "compat3"; };
+			name6 { compatible = "compat1", "compat2", "compat3"; };
+			name7 { compatible = "compat2"; device_type = "type1"; };
+			name8 { compatible = "compat2"; device_type = "type1"; };
+			name9 { compatible = "compat2"; };
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/tests-overlay.dtsi b/drivers/of/unittest-data/tests-overlay.dtsi
new file mode 100644
index 000000000..4ea024d90
--- /dev/null
+++ b/drivers/of/unittest-data/tests-overlay.dtsi
@@ -0,0 +1,117 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/ {
+	testcase-data {
+		overlay-node {
+
+			/* test bus */
+			unittest_test_bus: test-bus {
+				compatible = "simple-bus";
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				unittest100: test-unittest100 {
+					compatible = "unittest";
+					status = "okay";
+					reg = <100>;
+				};
+
+				unittest101: test-unittest101 {
+					compatible = "unittest";
+					status = "disabled";
+					reg = <101>;
+				};
+
+				unittest0: test-unittest0 {
+					compatible = "unittest";
+					status = "disabled";
+					reg = <0>;
+				};
+
+				unittest1: test-unittest1 {
+					compatible = "unittest";
+					status = "okay";
+					reg = <1>;
+				};
+
+				unittest2: test-unittest2 {
+					compatible = "unittest";
+					status = "disabled";
+					reg = <2>;
+				};
+
+				unittest3: test-unittest3 {
+					compatible = "unittest";
+					status = "okay";
+					reg = <3>;
+				};
+
+				unittest5: test-unittest5 {
+					compatible = "unittest";
+					status = "disabled";
+					reg = <5>;
+				};
+
+				unittest6: test-unittest6 {
+					compatible = "unittest";
+					status = "disabled";
+					reg = <6>;
+				};
+
+				unittest7: test-unittest7 {
+					compatible = "unittest";
+					status = "disabled";
+					reg = <7>;
+				};
+
+				unittest8: test-unittest8 {
+					compatible = "unittest";
+					status = "disabled";
+					reg = <8>;
+				};
+
+				unittest_i2c_test_bus: i2c-test-bus {
+					compatible = "unittest-i2c-bus";
+					status = "okay";
+					reg = <50>;
+
+					#address-cells = <1>;
+					#size-cells = <0>;
+
+					test-unittest12 {
+						reg = <8>;
+						compatible = "unittest-i2c-dev";
+						status = "disabled";
+					};
+
+					test-unittest13 {
+						reg = <9>;
+						compatible = "unittest-i2c-dev";
+						status = "okay";
+					};
+
+					test-unittest14 {
+						reg = <10>;
+						compatible = "unittest-i2c-mux";
+						status = "okay";
+
+						#address-cells = <1>;
+						#size-cells = <0>;
+
+						i2c@0 {
+							#address-cells = <1>;
+							#size-cells = <0>;
+							reg = <0>;
+
+							test-mux-dev@20 {
+								reg = <0x20>;
+								compatible = "unittest-i2c-dev";
+								status = "okay";
+							};
+						};
+					};
+				};
+			};
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/tests-phandle.dtsi b/drivers/of/unittest-data/tests-phandle.dtsi
new file mode 100644
index 000000000..aa0d7027f
--- /dev/null
+++ b/drivers/of/unittest-data/tests-phandle.dtsi
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/ {
+	aliases {
+		testcase-alias = &testcase;
+	};
+
+	testcase: testcase-data {
+		security-password = "password";
+		duplicate-name = "duplicate";
+		duplicate-name { };
+		phandle-tests {
+			provider0: provider0 {
+				#phandle-cells = <0>;
+			};
+
+			provider1: provider1 {
+				#phandle-cells = <1>;
+			};
+
+			provider2: provider2 {
+				#phandle-cells = <2>;
+			};
+
+			provider3: provider3 {
+				#phandle-cells = <3>;
+			};
+
+			provider4: provider4 {
+				#phandle-cells = <2>;
+				phandle-map = <0 1 &provider1 3>,
+					      <4 0 &provider0>,
+					      <16 5 &provider3 3 5 0>,
+					      <200 8 &provider2 23 6>,
+					      <19 0 &provider2 15 0>,
+					      <2 3 &provider3 2 5 3>;
+				phandle-map-mask = <0xff 0xf>;
+				phandle-map-pass-thru = <0x0 0xf0>;
+			};
+
+			provider5: provider5 {
+				#phandle-cells = <2>;
+				phandle-map = <2 7 &provider4 2 3>;
+				phandle-map-mask = <0xff 0xf>;
+				phandle-map-pass-thru = <0x0 0xf0>;
+			};
+
+			consumer-a {
+				phandle-list =	<&provider1 1>,
+						<&provider2 2 0>,
+						<0>,
+						<&provider3 4 4 3>,
+						<&provider2 5 100>,
+						<&provider0>,
+						<&provider1 7>;
+				phandle-list-names = "first", "second", "third";
+
+				phandle-list-bad-phandle = <12345678 0 0>;
+				phandle-list-bad-args = <&provider2 1 0>,
+							<&provider3 0>;
+				empty-property;
+				string-property = "foobar";
+				unterminated-string = [40 41 42 43];
+				unterminated-string-list = "first", "second", [40 41 42 43];
+			};
+
+			consumer-b {
+				phandle-list =	<&provider1 1>,
+						<&provider4 2 3>,
+						<0>,
+						<&provider4 4 0x100>,
+						<&provider4 0 0x61>,
+						<&provider0>,
+						<&provider4 19 0x20>,
+						<&provider5 2 7>;
+				phandle-list-bad-phandle = <12345678 0 0>;
+				phandle-list-bad-args = <&provider2 1 0>,
+							<&provider4 0>;
+			};
+		};
+	};
+};
diff --git a/drivers/of/unittest-data/tests-platform.dtsi b/drivers/of/unittest-data/tests-platform.dtsi
new file mode 100644
index 000000000..fa3961107
--- /dev/null
+++ b/drivers/of/unittest-data/tests-platform.dtsi
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/ {
+	testcase-data {
+		platform-tests {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			test-device@0 {
+				compatible = "test-device";
+				reg = <0x0>;
+
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				dev@100 {
+					compatible = "test-sub-device";
+					reg = <0x100>;
+				};
+			};
+
+			test-device@1 {
+				compatible = "test-device";
+				reg = <0x1>;
+
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				dev@100 {
+					compatible = "test-sub-device",
+						     "test-compat2",
+						     "test-compat3";
+					reg = <0x100>;
+				};
+			};
+		};
+	};
+};
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
new file mode 100644
index 000000000..e541a8960
--- /dev/null
+++ b/drivers/of/unittest.c
@@ -0,0 +1,3532 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Self tests for device tree subsystem
+ */
+
+#define pr_fmt(fmt) "### dt-test ### " fmt
+
+#include <linux/memblock.h>
+#include <linux/clk.h>
+#include <linux/dma-direct.h> /* to test phys_to_dma/dma_to_phys */
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/hashtable.h>
+#include <linux/libfdt.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_fdt.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/kernel.h>
+
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/gpio/driver.h>
+
+#include <linux/bitops.h>
+
+#include "of_private.h"
+
+static struct unittest_results {
+	int passed;
+	int failed;
+} unittest_results;
+
+#define unittest(result, fmt, ...) ({ \
+	bool failed = !(result); \
+	if (failed) { \
+		unittest_results.failed++; \
+		pr_err("FAIL %s():%i " fmt, __func__, __LINE__, ##__VA_ARGS__); \
+	} else { \
+		unittest_results.passed++; \
+		pr_info("pass %s():%i\n", __func__, __LINE__); \
+	} \
+	failed; \
+})
+
+/*
+ * Expected message may have a message level other than KERN_INFO.
+ * Print the expected message only if the current loglevel will allow
+ * the actual message to print.
+ *
+ * Do not use EXPECT_BEGIN() or EXPECT_END() for messages generated by
+ * pr_debug().
+ */
+#define EXPECT_BEGIN(level, fmt, ...) \
+	printk(level pr_fmt("EXPECT \\ : ") fmt, ##__VA_ARGS__)
+
+#define EXPECT_END(level, fmt, ...) \
+	printk(level pr_fmt("EXPECT / : ") fmt, ##__VA_ARGS__)
+
+static void __init of_unittest_find_node_by_name(void)
+{
+	struct device_node *np;
+	const char *options, *name;
+
+	np = of_find_node_by_path("/testcase-data");
+	name = kasprintf(GFP_KERNEL, "%pOF", np);
+	unittest(np && name && !strcmp("/testcase-data", name),
+		"find /testcase-data failed\n");
+	of_node_put(np);
+	kfree(name);
+
+	/* Test if trailing '/' works */
+	np = of_find_node_by_path("/testcase-data/");
+	unittest(!np, "trailing '/' on /testcase-data/ should fail\n");
+
+	np = of_find_node_by_path("/testcase-data/phandle-tests/consumer-a");
+	name = kasprintf(GFP_KERNEL, "%pOF", np);
+	unittest(np && name && !strcmp("/testcase-data/phandle-tests/consumer-a", name),
+		"find /testcase-data/phandle-tests/consumer-a failed\n");
+	of_node_put(np);
+	kfree(name);
+
+	np = of_find_node_by_path("testcase-alias");
+	name = kasprintf(GFP_KERNEL, "%pOF", np);
+	unittest(np && name && !strcmp("/testcase-data", name),
+		"find testcase-alias failed\n");
+	of_node_put(np);
+	kfree(name);
+
+	/* Test if trailing '/' works on aliases */
+	np = of_find_node_by_path("testcase-alias/");
+	unittest(!np, "trailing '/' on testcase-alias/ should fail\n");
+
+	np = of_find_node_by_path("testcase-alias/phandle-tests/consumer-a");
+	name = kasprintf(GFP_KERNEL, "%pOF", np);
+	unittest(np && name && !strcmp("/testcase-data/phandle-tests/consumer-a", name),
+		"find testcase-alias/phandle-tests/consumer-a failed\n");
+	of_node_put(np);
+	kfree(name);
+
+	np = of_find_node_by_path("/testcase-data/missing-path");
+	unittest(!np, "non-existent path returned node %pOF\n", np);
+	of_node_put(np);
+
+	np = of_find_node_by_path("missing-alias");
+	unittest(!np, "non-existent alias returned node %pOF\n", np);
+	of_node_put(np);
+
+	np = of_find_node_by_path("testcase-alias/missing-path");
+	unittest(!np, "non-existent alias with relative path returned node %pOF\n", np);
+	of_node_put(np);
+
+	np = of_find_node_opts_by_path("/testcase-data:testoption", &options);
+	unittest(np && !strcmp("testoption", options),
+		 "option path test failed\n");
+	of_node_put(np);
+
+	np = of_find_node_opts_by_path("/testcase-data:test/option", &options);
+	unittest(np && !strcmp("test/option", options),
+		 "option path test, subcase #1 failed\n");
+	of_node_put(np);
+
+	np = of_find_node_opts_by_path("/testcase-data/testcase-device1:test/option", &options);
+	unittest(np && !strcmp("test/option", options),
+		 "option path test, subcase #2 failed\n");
+	of_node_put(np);
+
+	np = of_find_node_opts_by_path("/testcase-data:testoption", NULL);
+	unittest(np, "NULL option path test failed\n");
+	of_node_put(np);
+
+	np = of_find_node_opts_by_path("testcase-alias:testaliasoption",
+				       &options);
+	unittest(np && !strcmp("testaliasoption", options),
+		 "option alias path test failed\n");
+	of_node_put(np);
+
+	np = of_find_node_opts_by_path("testcase-alias:test/alias/option",
+				       &options);
+	unittest(np && !strcmp("test/alias/option", options),
+		 "option alias path test, subcase #1 failed\n");
+	of_node_put(np);
+
+	np = of_find_node_opts_by_path("testcase-alias:testaliasoption", NULL);
+	unittest(np, "NULL option alias path test failed\n");
+	of_node_put(np);
+
+	options = "testoption";
+	np = of_find_node_opts_by_path("testcase-alias", &options);
+	unittest(np && !options, "option clearing test failed\n");
+	of_node_put(np);
+
+	options = "testoption";
+	np = of_find_node_opts_by_path("/", &options);
+	unittest(np && !options, "option clearing root node test failed\n");
+	of_node_put(np);
+}
+
+static void __init of_unittest_dynamic(void)
+{
+	struct device_node *np;
+	struct property *prop;
+
+	np = of_find_node_by_path("/testcase-data");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	/* Array of 4 properties for the purpose of testing */
+	prop = kcalloc(4, sizeof(*prop), GFP_KERNEL);
+	if (!prop) {
+		unittest(0, "kzalloc() failed\n");
+		return;
+	}
+
+	/* Add a new property - should pass*/
+	prop->name = "new-property";
+	prop->value = "new-property-data";
+	prop->length = strlen(prop->value) + 1;
+	unittest(of_add_property(np, prop) == 0, "Adding a new property failed\n");
+
+	/* Try to add an existing property - should fail */
+	prop++;
+	prop->name = "new-property";
+	prop->value = "new-property-data-should-fail";
+	prop->length = strlen(prop->value) + 1;
+	unittest(of_add_property(np, prop) != 0,
+		 "Adding an existing property should have failed\n");
+
+	/* Try to modify an existing property - should pass */
+	prop->value = "modify-property-data-should-pass";
+	prop->length = strlen(prop->value) + 1;
+	unittest(of_update_property(np, prop) == 0,
+		 "Updating an existing property should have passed\n");
+
+	/* Try to modify non-existent property - should pass*/
+	prop++;
+	prop->name = "modify-property";
+	prop->value = "modify-missing-property-data-should-pass";
+	prop->length = strlen(prop->value) + 1;
+	unittest(of_update_property(np, prop) == 0,
+		 "Updating a missing property should have passed\n");
+
+	/* Remove property - should pass */
+	unittest(of_remove_property(np, prop) == 0,
+		 "Removing a property should have passed\n");
+
+	/* Adding very large property - should pass */
+	prop++;
+	prop->name = "large-property-PAGE_SIZEx8";
+	prop->length = PAGE_SIZE * 8;
+	prop->value = kzalloc(prop->length, GFP_KERNEL);
+	unittest(prop->value != NULL, "Unable to allocate large buffer\n");
+	if (prop->value)
+		unittest(of_add_property(np, prop) == 0,
+			 "Adding a large property should have passed\n");
+}
+
+static int __init of_unittest_check_node_linkage(struct device_node *np)
+{
+	struct device_node *child;
+	int count = 0, rc;
+
+	for_each_child_of_node(np, child) {
+		if (child->parent != np) {
+			pr_err("Child node %pOFn links to wrong parent %pOFn\n",
+				 child, np);
+			rc = -EINVAL;
+			goto put_child;
+		}
+
+		rc = of_unittest_check_node_linkage(child);
+		if (rc < 0)
+			goto put_child;
+		count += rc;
+	}
+
+	return count + 1;
+put_child:
+	of_node_put(child);
+	return rc;
+}
+
+static void __init of_unittest_check_tree_linkage(void)
+{
+	struct device_node *np;
+	int allnode_count = 0, child_count;
+
+	if (!of_root)
+		return;
+
+	for_each_of_allnodes(np)
+		allnode_count++;
+	child_count = of_unittest_check_node_linkage(of_root);
+
+	unittest(child_count > 0, "Device node data structure is corrupted\n");
+	unittest(child_count == allnode_count,
+		 "allnodes list size (%i) doesn't match sibling lists size (%i)\n",
+		 allnode_count, child_count);
+	pr_debug("allnodes list size (%i); sibling lists size (%i)\n", allnode_count, child_count);
+}
+
+static void __init of_unittest_printf_one(struct device_node *np, const char *fmt,
+					  const char *expected)
+{
+	unsigned char *buf;
+	int buf_size;
+	int size, i;
+
+	buf_size = strlen(expected) + 10;
+	buf = kmalloc(buf_size, GFP_KERNEL);
+	if (!buf)
+		return;
+
+	/* Baseline; check conversion with a large size limit */
+	memset(buf, 0xff, buf_size);
+	size = snprintf(buf, buf_size - 2, fmt, np);
+
+	/* use strcmp() instead of strncmp() here to be absolutely sure strings match */
+	unittest((strcmp(buf, expected) == 0) && (buf[size+1] == 0xff),
+		"sprintf failed; fmt='%s' expected='%s' rslt='%s'\n",
+		fmt, expected, buf);
+
+	/* Make sure length limits work */
+	size++;
+	for (i = 0; i < 2; i++, size--) {
+		/* Clear the buffer, and make sure it works correctly still */
+		memset(buf, 0xff, buf_size);
+		snprintf(buf, size+1, fmt, np);
+		unittest(strncmp(buf, expected, size) == 0 && (buf[size+1] == 0xff),
+			"snprintf failed; size=%i fmt='%s' expected='%s' rslt='%s'\n",
+			size, fmt, expected, buf);
+	}
+	kfree(buf);
+}
+
+static void __init of_unittest_printf(void)
+{
+	struct device_node *np;
+	const char *full_name = "/testcase-data/platform-tests/test-device@1/dev@100";
+	char phandle_str[16] = "";
+
+	np = of_find_node_by_path(full_name);
+	if (!np) {
+		unittest(np, "testcase data missing\n");
+		return;
+	}
+
+	num_to_str(phandle_str, sizeof(phandle_str), np->phandle, 0);
+
+	of_unittest_printf_one(np, "%pOF",  full_name);
+	of_unittest_printf_one(np, "%pOFf", full_name);
+	of_unittest_printf_one(np, "%pOFn", "dev");
+	of_unittest_printf_one(np, "%2pOFn", "dev");
+	of_unittest_printf_one(np, "%5pOFn", "  dev");
+	of_unittest_printf_one(np, "%pOFnc", "dev:test-sub-device");
+	of_unittest_printf_one(np, "%pOFp", phandle_str);
+	of_unittest_printf_one(np, "%pOFP", "dev@100");
+	of_unittest_printf_one(np, "ABC %pOFP ABC", "ABC dev@100 ABC");
+	of_unittest_printf_one(np, "%10pOFP", "   dev@100");
+	of_unittest_printf_one(np, "%-10pOFP", "dev@100   ");
+	of_unittest_printf_one(of_root, "%pOFP", "/");
+	of_unittest_printf_one(np, "%pOFF", "----");
+	of_unittest_printf_one(np, "%pOFPF", "dev@100:----");
+	of_unittest_printf_one(np, "%pOFPFPc", "dev@100:----:dev@100:test-sub-device");
+	of_unittest_printf_one(np, "%pOFc", "test-sub-device");
+	of_unittest_printf_one(np, "%pOFC",
+			"\"test-sub-device\",\"test-compat2\",\"test-compat3\"");
+}
+
+struct node_hash {
+	struct hlist_node node;
+	struct device_node *np;
+};
+
+static DEFINE_HASHTABLE(phandle_ht, 8);
+static void __init of_unittest_check_phandles(void)
+{
+	struct device_node *np;
+	struct node_hash *nh;
+	struct hlist_node *tmp;
+	int i, dup_count = 0, phandle_count = 0;
+
+	for_each_of_allnodes(np) {
+		if (!np->phandle)
+			continue;
+
+		hash_for_each_possible(phandle_ht, nh, node, np->phandle) {
+			if (nh->np->phandle == np->phandle) {
+				pr_info("Duplicate phandle! %i used by %pOF and %pOF\n",
+					np->phandle, nh->np, np);
+				dup_count++;
+				break;
+			}
+		}
+
+		nh = kzalloc(sizeof(*nh), GFP_KERNEL);
+		if (!nh)
+			return;
+
+		nh->np = np;
+		hash_add(phandle_ht, &nh->node, np->phandle);
+		phandle_count++;
+	}
+	unittest(dup_count == 0, "Found %i duplicates in %i phandles\n",
+		 dup_count, phandle_count);
+
+	/* Clean up */
+	hash_for_each_safe(phandle_ht, i, tmp, nh, node) {
+		hash_del(&nh->node);
+		kfree(nh);
+	}
+}
+
+static void __init of_unittest_parse_phandle_with_args(void)
+{
+	struct device_node *np;
+	struct of_phandle_args args;
+	int i, rc;
+
+	np = of_find_node_by_path("/testcase-data/phandle-tests/consumer-a");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	rc = of_count_phandle_with_args(np, "phandle-list", "#phandle-cells");
+	unittest(rc == 7, "of_count_phandle_with_args() returned %i, expected 7\n", rc);
+
+	for (i = 0; i < 8; i++) {
+		bool passed = true;
+
+		memset(&args, 0, sizeof(args));
+		rc = of_parse_phandle_with_args(np, "phandle-list",
+						"#phandle-cells", i, &args);
+
+		/* Test the values from tests-phandle.dtsi */
+		switch (i) {
+		case 0:
+			passed &= !rc;
+			passed &= (args.args_count == 1);
+			passed &= (args.args[0] == (i + 1));
+			break;
+		case 1:
+			passed &= !rc;
+			passed &= (args.args_count == 2);
+			passed &= (args.args[0] == (i + 1));
+			passed &= (args.args[1] == 0);
+			break;
+		case 2:
+			passed &= (rc == -ENOENT);
+			break;
+		case 3:
+			passed &= !rc;
+			passed &= (args.args_count == 3);
+			passed &= (args.args[0] == (i + 1));
+			passed &= (args.args[1] == 4);
+			passed &= (args.args[2] == 3);
+			break;
+		case 4:
+			passed &= !rc;
+			passed &= (args.args_count == 2);
+			passed &= (args.args[0] == (i + 1));
+			passed &= (args.args[1] == 100);
+			break;
+		case 5:
+			passed &= !rc;
+			passed &= (args.args_count == 0);
+			break;
+		case 6:
+			passed &= !rc;
+			passed &= (args.args_count == 1);
+			passed &= (args.args[0] == (i + 1));
+			break;
+		case 7:
+			passed &= (rc == -ENOENT);
+			break;
+		default:
+			passed = false;
+		}
+
+		unittest(passed, "index %i - data error on node %pOF rc=%i\n",
+			 i, args.np, rc);
+
+		if (rc == 0)
+			of_node_put(args.np);
+	}
+
+	/* Check for missing list property */
+	memset(&args, 0, sizeof(args));
+	rc = of_parse_phandle_with_args(np, "phandle-list-missing",
+					"#phandle-cells", 0, &args);
+	unittest(rc == -ENOENT, "expected:%i got:%i\n", -ENOENT, rc);
+	rc = of_count_phandle_with_args(np, "phandle-list-missing",
+					"#phandle-cells");
+	unittest(rc == -ENOENT, "expected:%i got:%i\n", -ENOENT, rc);
+
+	/* Check for missing cells property */
+	memset(&args, 0, sizeof(args));
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-a: could not get #phandle-cells-missing for /testcase-data/phandle-tests/provider1");
+
+	rc = of_parse_phandle_with_args(np, "phandle-list",
+					"#phandle-cells-missing", 0, &args);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-a: could not get #phandle-cells-missing for /testcase-data/phandle-tests/provider1");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-a: could not get #phandle-cells-missing for /testcase-data/phandle-tests/provider1");
+
+	rc = of_count_phandle_with_args(np, "phandle-list",
+					"#phandle-cells-missing");
+
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-a: could not get #phandle-cells-missing for /testcase-data/phandle-tests/provider1");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+
+	/* Check for bad phandle in list */
+	memset(&args, 0, sizeof(args));
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-a: could not find phandle");
+
+	rc = of_parse_phandle_with_args(np, "phandle-list-bad-phandle",
+					"#phandle-cells", 0, &args);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-a: could not find phandle");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-a: could not find phandle");
+
+	rc = of_count_phandle_with_args(np, "phandle-list-bad-phandle",
+					"#phandle-cells");
+
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-a: could not find phandle");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+
+	/* Check for incorrectly formed argument list */
+	memset(&args, 0, sizeof(args));
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-a: #phandle-cells = 3 found 1");
+
+	rc = of_parse_phandle_with_args(np, "phandle-list-bad-args",
+					"#phandle-cells", 1, &args);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-a: #phandle-cells = 3 found 1");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-a: #phandle-cells = 3 found 1");
+
+	rc = of_count_phandle_with_args(np, "phandle-list-bad-args",
+					"#phandle-cells");
+
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-a: #phandle-cells = 3 found 1");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+}
+
+static void __init of_unittest_parse_phandle_with_args_map(void)
+{
+	struct device_node *np, *p[6] = {};
+	struct of_phandle_args args;
+	unsigned int prefs[6];
+	int i, rc;
+
+	np = of_find_node_by_path("/testcase-data/phandle-tests/consumer-b");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	p[0] = of_find_node_by_path("/testcase-data/phandle-tests/provider0");
+	p[1] = of_find_node_by_path("/testcase-data/phandle-tests/provider1");
+	p[2] = of_find_node_by_path("/testcase-data/phandle-tests/provider2");
+	p[3] = of_find_node_by_path("/testcase-data/phandle-tests/provider3");
+	p[4] = of_find_node_by_path("/testcase-data/phandle-tests/provider4");
+	p[5] = of_find_node_by_path("/testcase-data/phandle-tests/provider5");
+	for (i = 0; i < ARRAY_SIZE(p); ++i) {
+		if (!p[i]) {
+			pr_err("missing testcase data\n");
+			return;
+		}
+		prefs[i] = kref_read(&p[i]->kobj.kref);
+	}
+
+	rc = of_count_phandle_with_args(np, "phandle-list", "#phandle-cells");
+	unittest(rc == 8, "of_count_phandle_with_args() returned %i, expected 8\n", rc);
+
+	for (i = 0; i < 9; i++) {
+		bool passed = true;
+
+		memset(&args, 0, sizeof(args));
+		rc = of_parse_phandle_with_args_map(np, "phandle-list",
+						    "phandle", i, &args);
+
+		/* Test the values from tests-phandle.dtsi */
+		switch (i) {
+		case 0:
+			passed &= !rc;
+			passed &= (args.np == p[1]);
+			passed &= (args.args_count == 1);
+			passed &= (args.args[0] == 1);
+			break;
+		case 1:
+			passed &= !rc;
+			passed &= (args.np == p[3]);
+			passed &= (args.args_count == 3);
+			passed &= (args.args[0] == 2);
+			passed &= (args.args[1] == 5);
+			passed &= (args.args[2] == 3);
+			break;
+		case 2:
+			passed &= (rc == -ENOENT);
+			break;
+		case 3:
+			passed &= !rc;
+			passed &= (args.np == p[0]);
+			passed &= (args.args_count == 0);
+			break;
+		case 4:
+			passed &= !rc;
+			passed &= (args.np == p[1]);
+			passed &= (args.args_count == 1);
+			passed &= (args.args[0] == 3);
+			break;
+		case 5:
+			passed &= !rc;
+			passed &= (args.np == p[0]);
+			passed &= (args.args_count == 0);
+			break;
+		case 6:
+			passed &= !rc;
+			passed &= (args.np == p[2]);
+			passed &= (args.args_count == 2);
+			passed &= (args.args[0] == 15);
+			passed &= (args.args[1] == 0x20);
+			break;
+		case 7:
+			passed &= !rc;
+			passed &= (args.np == p[3]);
+			passed &= (args.args_count == 3);
+			passed &= (args.args[0] == 2);
+			passed &= (args.args[1] == 5);
+			passed &= (args.args[2] == 3);
+			break;
+		case 8:
+			passed &= (rc == -ENOENT);
+			break;
+		default:
+			passed = false;
+		}
+
+		unittest(passed, "index %i - data error on node %s rc=%i\n",
+			 i, args.np->full_name, rc);
+
+		if (rc == 0)
+			of_node_put(args.np);
+	}
+
+	/* Check for missing list property */
+	memset(&args, 0, sizeof(args));
+	rc = of_parse_phandle_with_args_map(np, "phandle-list-missing",
+					    "phandle", 0, &args);
+	unittest(rc == -ENOENT, "expected:%i got:%i\n", -ENOENT, rc);
+
+	/* Check for missing cells,map,mask property */
+	memset(&args, 0, sizeof(args));
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-b: could not get #phandle-missing-cells for /testcase-data/phandle-tests/provider1");
+
+	rc = of_parse_phandle_with_args_map(np, "phandle-list",
+					    "phandle-missing", 0, &args);
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-b: could not get #phandle-missing-cells for /testcase-data/phandle-tests/provider1");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+
+	/* Check for bad phandle in list */
+	memset(&args, 0, sizeof(args));
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-b: could not find phandle 12345678");
+
+	rc = of_parse_phandle_with_args_map(np, "phandle-list-bad-phandle",
+					    "phandle", 0, &args);
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-b: could not find phandle 12345678");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+
+	/* Check for incorrectly formed argument list */
+	memset(&args, 0, sizeof(args));
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: /testcase-data/phandle-tests/consumer-b: #phandle-cells = 2 found 1");
+
+	rc = of_parse_phandle_with_args_map(np, "phandle-list-bad-args",
+					    "phandle", 1, &args);
+	EXPECT_END(KERN_INFO,
+		   "OF: /testcase-data/phandle-tests/consumer-b: #phandle-cells = 2 found 1");
+
+	unittest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc);
+
+	for (i = 0; i < ARRAY_SIZE(p); ++i) {
+		unittest(prefs[i] == kref_read(&p[i]->kobj.kref),
+			 "provider%d: expected:%d got:%d\n",
+			 i, prefs[i], kref_read(&p[i]->kobj.kref));
+		of_node_put(p[i]);
+	}
+}
+
+static void __init of_unittest_property_string(void)
+{
+	const char *strings[4];
+	struct device_node *np;
+	int rc;
+
+	np = of_find_node_by_path("/testcase-data/phandle-tests/consumer-a");
+	if (!np) {
+		pr_err("No testcase data in device tree\n");
+		return;
+	}
+
+	rc = of_property_match_string(np, "phandle-list-names", "first");
+	unittest(rc == 0, "first expected:0 got:%i\n", rc);
+	rc = of_property_match_string(np, "phandle-list-names", "second");
+	unittest(rc == 1, "second expected:1 got:%i\n", rc);
+	rc = of_property_match_string(np, "phandle-list-names", "third");
+	unittest(rc == 2, "third expected:2 got:%i\n", rc);
+	rc = of_property_match_string(np, "phandle-list-names", "fourth");
+	unittest(rc == -ENODATA, "unmatched string; rc=%i\n", rc);
+	rc = of_property_match_string(np, "missing-property", "blah");
+	unittest(rc == -EINVAL, "missing property; rc=%i\n", rc);
+	rc = of_property_match_string(np, "empty-property", "blah");
+	unittest(rc == -ENODATA, "empty property; rc=%i\n", rc);
+	rc = of_property_match_string(np, "unterminated-string", "blah");
+	unittest(rc == -EILSEQ, "unterminated string; rc=%i\n", rc);
+
+	/* of_property_count_strings() tests */
+	rc = of_property_count_strings(np, "string-property");
+	unittest(rc == 1, "Incorrect string count; rc=%i\n", rc);
+	rc = of_property_count_strings(np, "phandle-list-names");
+	unittest(rc == 3, "Incorrect string count; rc=%i\n", rc);
+	rc = of_property_count_strings(np, "unterminated-string");
+	unittest(rc == -EILSEQ, "unterminated string; rc=%i\n", rc);
+	rc = of_property_count_strings(np, "unterminated-string-list");
+	unittest(rc == -EILSEQ, "unterminated string array; rc=%i\n", rc);
+
+	/* of_property_read_string_index() tests */
+	rc = of_property_read_string_index(np, "string-property", 0, strings);
+	unittest(rc == 0 && !strcmp(strings[0], "foobar"), "of_property_read_string_index() failure; rc=%i\n", rc);
+	strings[0] = NULL;
+	rc = of_property_read_string_index(np, "string-property", 1, strings);
+	unittest(rc == -ENODATA && strings[0] == NULL, "of_property_read_string_index() failure; rc=%i\n", rc);
+	rc = of_property_read_string_index(np, "phandle-list-names", 0, strings);
+	unittest(rc == 0 && !strcmp(strings[0], "first"), "of_property_read_string_index() failure; rc=%i\n", rc);
+	rc = of_property_read_string_index(np, "phandle-list-names", 1, strings);
+	unittest(rc == 0 && !strcmp(strings[0], "second"), "of_property_read_string_index() failure; rc=%i\n", rc);
+	rc = of_property_read_string_index(np, "phandle-list-names", 2, strings);
+	unittest(rc == 0 && !strcmp(strings[0], "third"), "of_property_read_string_index() failure; rc=%i\n", rc);
+	strings[0] = NULL;
+	rc = of_property_read_string_index(np, "phandle-list-names", 3, strings);
+	unittest(rc == -ENODATA && strings[0] == NULL, "of_property_read_string_index() failure; rc=%i\n", rc);
+	strings[0] = NULL;
+	rc = of_property_read_string_index(np, "unterminated-string", 0, strings);
+	unittest(rc == -EILSEQ && strings[0] == NULL, "of_property_read_string_index() failure; rc=%i\n", rc);
+	rc = of_property_read_string_index(np, "unterminated-string-list", 0, strings);
+	unittest(rc == 0 && !strcmp(strings[0], "first"), "of_property_read_string_index() failure; rc=%i\n", rc);
+	strings[0] = NULL;
+	rc = of_property_read_string_index(np, "unterminated-string-list", 2, strings); /* should fail */
+	unittest(rc == -EILSEQ && strings[0] == NULL, "of_property_read_string_index() failure; rc=%i\n", rc);
+	strings[1] = NULL;
+
+	/* of_property_read_string_array() tests */
+	rc = of_property_read_string_array(np, "string-property", strings, 4);
+	unittest(rc == 1, "Incorrect string count; rc=%i\n", rc);
+	rc = of_property_read_string_array(np, "phandle-list-names", strings, 4);
+	unittest(rc == 3, "Incorrect string count; rc=%i\n", rc);
+	rc = of_property_read_string_array(np, "unterminated-string", strings, 4);
+	unittest(rc == -EILSEQ, "unterminated string; rc=%i\n", rc);
+	/* -- An incorrectly formed string should cause a failure */
+	rc = of_property_read_string_array(np, "unterminated-string-list", strings, 4);
+	unittest(rc == -EILSEQ, "unterminated string array; rc=%i\n", rc);
+	/* -- parsing the correctly formed strings should still work: */
+	strings[2] = NULL;
+	rc = of_property_read_string_array(np, "unterminated-string-list", strings, 2);
+	unittest(rc == 2 && strings[2] == NULL, "of_property_read_string_array() failure; rc=%i\n", rc);
+	strings[1] = NULL;
+	rc = of_property_read_string_array(np, "phandle-list-names", strings, 1);
+	unittest(rc == 1 && strings[1] == NULL, "Overwrote end of string array; rc=%i, str='%s'\n", rc, strings[1]);
+}
+
+#define propcmp(p1, p2) (((p1)->length == (p2)->length) && \
+			(p1)->value && (p2)->value && \
+			!memcmp((p1)->value, (p2)->value, (p1)->length) && \
+			!strcmp((p1)->name, (p2)->name))
+static void __init of_unittest_property_copy(void)
+{
+#ifdef CONFIG_OF_DYNAMIC
+	struct property p1 = { .name = "p1", .length = 0, .value = "" };
+	struct property p2 = { .name = "p2", .length = 5, .value = "abcd" };
+	struct property *new;
+
+	new = __of_prop_dup(&p1, GFP_KERNEL);
+	unittest(new && propcmp(&p1, new), "empty property didn't copy correctly\n");
+	kfree(new->value);
+	kfree(new->name);
+	kfree(new);
+
+	new = __of_prop_dup(&p2, GFP_KERNEL);
+	unittest(new && propcmp(&p2, new), "non-empty property didn't copy correctly\n");
+	kfree(new->value);
+	kfree(new->name);
+	kfree(new);
+#endif
+}
+
+static void __init of_unittest_changeset(void)
+{
+#ifdef CONFIG_OF_DYNAMIC
+	struct property *ppadd, padd = { .name = "prop-add", .length = 1, .value = "" };
+	struct property *ppname_n1,  pname_n1  = { .name = "name", .length = 3, .value = "n1"  };
+	struct property *ppname_n2,  pname_n2  = { .name = "name", .length = 3, .value = "n2"  };
+	struct property *ppname_n21, pname_n21 = { .name = "name", .length = 3, .value = "n21" };
+	struct property *ppupdate, pupdate = { .name = "prop-update", .length = 5, .value = "abcd" };
+	struct property *ppremove;
+	struct device_node *n1, *n2, *n21, *nchangeset, *nremove, *parent, *np;
+	struct of_changeset chgset;
+
+	n1 = __of_node_dup(NULL, "n1");
+	unittest(n1, "testcase setup failure\n");
+
+	n2 = __of_node_dup(NULL, "n2");
+	unittest(n2, "testcase setup failure\n");
+
+	n21 = __of_node_dup(NULL, "n21");
+	unittest(n21, "testcase setup failure %p\n", n21);
+
+	nchangeset = of_find_node_by_path("/testcase-data/changeset");
+	nremove = of_get_child_by_name(nchangeset, "node-remove");
+	unittest(nremove, "testcase setup failure\n");
+
+	ppadd = __of_prop_dup(&padd, GFP_KERNEL);
+	unittest(ppadd, "testcase setup failure\n");
+
+	ppname_n1  = __of_prop_dup(&pname_n1, GFP_KERNEL);
+	unittest(ppname_n1, "testcase setup failure\n");
+
+	ppname_n2  = __of_prop_dup(&pname_n2, GFP_KERNEL);
+	unittest(ppname_n2, "testcase setup failure\n");
+
+	ppname_n21 = __of_prop_dup(&pname_n21, GFP_KERNEL);
+	unittest(ppname_n21, "testcase setup failure\n");
+
+	ppupdate = __of_prop_dup(&pupdate, GFP_KERNEL);
+	unittest(ppupdate, "testcase setup failure\n");
+
+	parent = nchangeset;
+	n1->parent = parent;
+	n2->parent = parent;
+	n21->parent = n2;
+
+	ppremove = of_find_property(parent, "prop-remove", NULL);
+	unittest(ppremove, "failed to find removal prop");
+
+	of_changeset_init(&chgset);
+
+	unittest(!of_changeset_attach_node(&chgset, n1), "fail attach n1\n");
+	unittest(!of_changeset_add_property(&chgset, n1, ppname_n1), "fail add prop name\n");
+
+	unittest(!of_changeset_attach_node(&chgset, n2), "fail attach n2\n");
+	unittest(!of_changeset_add_property(&chgset, n2, ppname_n2), "fail add prop name\n");
+
+	unittest(!of_changeset_detach_node(&chgset, nremove), "fail remove node\n");
+	unittest(!of_changeset_add_property(&chgset, n21, ppname_n21), "fail add prop name\n");
+
+	unittest(!of_changeset_attach_node(&chgset, n21), "fail attach n21\n");
+
+	unittest(!of_changeset_add_property(&chgset, parent, ppadd), "fail add prop prop-add\n");
+	unittest(!of_changeset_update_property(&chgset, parent, ppupdate), "fail update prop\n");
+	unittest(!of_changeset_remove_property(&chgset, parent, ppremove), "fail remove prop\n");
+
+	unittest(!of_changeset_apply(&chgset), "apply failed\n");
+
+	of_node_put(nchangeset);
+
+	/* Make sure node names are constructed correctly */
+	unittest((np = of_find_node_by_path("/testcase-data/changeset/n2/n21")),
+		 "'%pOF' not added\n", n21);
+	of_node_put(np);
+
+	unittest(!of_changeset_revert(&chgset), "revert failed\n");
+
+	of_changeset_destroy(&chgset);
+
+	of_node_put(n1);
+	of_node_put(n2);
+	of_node_put(n21);
+#endif
+}
+
+static void __init of_unittest_dma_get_max_cpu_address(void)
+{
+	struct device_node *np;
+	phys_addr_t cpu_addr;
+
+	if (!IS_ENABLED(CONFIG_OF_ADDRESS))
+		return;
+
+	np = of_find_node_by_path("/testcase-data/address-tests");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	cpu_addr = of_dma_get_max_cpu_address(np);
+	unittest(cpu_addr == 0x4fffffff,
+		 "of_dma_get_max_cpu_address: wrong CPU addr %pad (expecting %x)\n",
+		 &cpu_addr, 0x4fffffff);
+}
+
+static void __init of_unittest_dma_ranges_one(const char *path,
+		u64 expect_dma_addr, u64 expect_paddr)
+{
+#ifdef CONFIG_HAS_DMA
+	struct device_node *np;
+	const struct bus_dma_region *map = NULL;
+	int rc;
+
+	np = of_find_node_by_path(path);
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	rc = of_dma_get_range(np, &map);
+
+	unittest(!rc, "of_dma_get_range failed on node %pOF rc=%i\n", np, rc);
+
+	if (!rc) {
+		phys_addr_t	paddr;
+		dma_addr_t	dma_addr;
+		struct device	*dev_bogus;
+
+		dev_bogus = kzalloc(sizeof(struct device), GFP_KERNEL);
+		if (!dev_bogus) {
+			unittest(0, "kzalloc() failed\n");
+			kfree(map);
+			return;
+		}
+
+		dev_bogus->dma_range_map = map;
+		paddr = dma_to_phys(dev_bogus, expect_dma_addr);
+		dma_addr = phys_to_dma(dev_bogus, expect_paddr);
+
+		unittest(paddr == expect_paddr,
+			 "of_dma_get_range: wrong phys addr %pap (expecting %llx) on node %pOF\n",
+			 &paddr, expect_paddr, np);
+		unittest(dma_addr == expect_dma_addr,
+			 "of_dma_get_range: wrong DMA addr %pad (expecting %llx) on node %pOF\n",
+			 &dma_addr, expect_dma_addr, np);
+
+		kfree(map);
+		kfree(dev_bogus);
+	}
+	of_node_put(np);
+#endif
+}
+
+static void __init of_unittest_parse_dma_ranges(void)
+{
+	of_unittest_dma_ranges_one("/testcase-data/address-tests/device@70000000",
+		0x0, 0x20000000);
+	if (IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT))
+		of_unittest_dma_ranges_one("/testcase-data/address-tests/bus@80000000/device@1000",
+			0x100000000, 0x20000000);
+	of_unittest_dma_ranges_one("/testcase-data/address-tests/pci@90000000",
+		0x80000000, 0x20000000);
+}
+
+static void __init of_unittest_pci_dma_ranges(void)
+{
+	struct device_node *np;
+	struct of_pci_range range;
+	struct of_pci_range_parser parser;
+	int i = 0;
+
+	if (!IS_ENABLED(CONFIG_PCI))
+		return;
+
+	np = of_find_node_by_path("/testcase-data/address-tests/pci@90000000");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	if (of_pci_dma_range_parser_init(&parser, np)) {
+		pr_err("missing dma-ranges property\n");
+		return;
+	}
+
+	/*
+	 * Get the dma-ranges from the device tree
+	 */
+	for_each_of_pci_range(&parser, &range) {
+		if (!i) {
+			unittest(range.size == 0x10000000,
+				 "for_each_of_pci_range wrong size on node %pOF size=%llx\n",
+				 np, range.size);
+			unittest(range.cpu_addr == 0x20000000,
+				 "for_each_of_pci_range wrong CPU addr (%llx) on node %pOF",
+				 range.cpu_addr, np);
+			unittest(range.pci_addr == 0x80000000,
+				 "for_each_of_pci_range wrong DMA addr (%llx) on node %pOF",
+				 range.pci_addr, np);
+		} else {
+			unittest(range.size == 0x10000000,
+				 "for_each_of_pci_range wrong size on node %pOF size=%llx\n",
+				 np, range.size);
+			unittest(range.cpu_addr == 0x40000000,
+				 "for_each_of_pci_range wrong CPU addr (%llx) on node %pOF",
+				 range.cpu_addr, np);
+			unittest(range.pci_addr == 0xc0000000,
+				 "for_each_of_pci_range wrong DMA addr (%llx) on node %pOF",
+				 range.pci_addr, np);
+		}
+		i++;
+	}
+
+	of_node_put(np);
+}
+
+static void __init of_unittest_parse_interrupts(void)
+{
+	struct device_node *np;
+	struct of_phandle_args args;
+	int i, rc;
+
+	if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
+		return;
+
+	np = of_find_node_by_path("/testcase-data/interrupts/interrupts0");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	for (i = 0; i < 4; i++) {
+		bool passed = true;
+
+		memset(&args, 0, sizeof(args));
+		rc = of_irq_parse_one(np, i, &args);
+
+		passed &= !rc;
+		passed &= (args.args_count == 1);
+		passed &= (args.args[0] == (i + 1));
+
+		unittest(passed, "index %i - data error on node %pOF rc=%i\n",
+			 i, args.np, rc);
+	}
+	of_node_put(np);
+
+	np = of_find_node_by_path("/testcase-data/interrupts/interrupts1");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	for (i = 0; i < 4; i++) {
+		bool passed = true;
+
+		memset(&args, 0, sizeof(args));
+		rc = of_irq_parse_one(np, i, &args);
+
+		/* Test the values from tests-phandle.dtsi */
+		switch (i) {
+		case 0:
+			passed &= !rc;
+			passed &= (args.args_count == 1);
+			passed &= (args.args[0] == 9);
+			break;
+		case 1:
+			passed &= !rc;
+			passed &= (args.args_count == 3);
+			passed &= (args.args[0] == 10);
+			passed &= (args.args[1] == 11);
+			passed &= (args.args[2] == 12);
+			break;
+		case 2:
+			passed &= !rc;
+			passed &= (args.args_count == 2);
+			passed &= (args.args[0] == 13);
+			passed &= (args.args[1] == 14);
+			break;
+		case 3:
+			passed &= !rc;
+			passed &= (args.args_count == 2);
+			passed &= (args.args[0] == 15);
+			passed &= (args.args[1] == 16);
+			break;
+		default:
+			passed = false;
+		}
+		unittest(passed, "index %i - data error on node %pOF rc=%i\n",
+			 i, args.np, rc);
+	}
+	of_node_put(np);
+}
+
+static void __init of_unittest_parse_interrupts_extended(void)
+{
+	struct device_node *np;
+	struct of_phandle_args args;
+	int i, rc;
+
+	if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
+		return;
+
+	np = of_find_node_by_path("/testcase-data/interrupts/interrupts-extended0");
+	if (!np) {
+		pr_err("missing testcase data\n");
+		return;
+	}
+
+	for (i = 0; i < 7; i++) {
+		bool passed = true;
+
+		memset(&args, 0, sizeof(args));
+		rc = of_irq_parse_one(np, i, &args);
+
+		/* Test the values from tests-phandle.dtsi */
+		switch (i) {
+		case 0:
+			passed &= !rc;
+			passed &= (args.args_count == 1);
+			passed &= (args.args[0] == 1);
+			break;
+		case 1:
+			passed &= !rc;
+			passed &= (args.args_count == 3);
+			passed &= (args.args[0] == 2);
+			passed &= (args.args[1] == 3);
+			passed &= (args.args[2] == 4);
+			break;
+		case 2:
+			passed &= !rc;
+			passed &= (args.args_count == 2);
+			passed &= (args.args[0] == 5);
+			passed &= (args.args[1] == 6);
+			break;
+		case 3:
+			passed &= !rc;
+			passed &= (args.args_count == 1);
+			passed &= (args.args[0] == 9);
+			break;
+		case 4:
+			passed &= !rc;
+			passed &= (args.args_count == 3);
+			passed &= (args.args[0] == 10);
+			passed &= (args.args[1] == 11);
+			passed &= (args.args[2] == 12);
+			break;
+		case 5:
+			passed &= !rc;
+			passed &= (args.args_count == 2);
+			passed &= (args.args[0] == 13);
+			passed &= (args.args[1] == 14);
+			break;
+		case 6:
+			/*
+			 * Tests child node that is missing property
+			 * #address-cells.  See the comments in
+			 * drivers/of/unittest-data/tests-interrupts.dtsi
+			 * nodes intmap1 and interrupts-extended0
+			 */
+			passed &= !rc;
+			passed &= (args.args_count == 1);
+			passed &= (args.args[0] == 15);
+			break;
+		default:
+			passed = false;
+		}
+
+		unittest(passed, "index %i - data error on node %pOF rc=%i\n",
+			 i, args.np, rc);
+	}
+	of_node_put(np);
+}
+
+static const struct of_device_id match_node_table[] = {
+	{ .data = "A", .name = "name0", }, /* Name alone is lowest priority */
+	{ .data = "B", .type = "type1", }, /* followed by type alone */
+
+	{ .data = "Ca", .name = "name2", .type = "type1", }, /* followed by both together */
+	{ .data = "Cb", .name = "name2", }, /* Only match when type doesn't match */
+	{ .data = "Cc", .name = "name2", .type = "type2", },
+
+	{ .data = "E", .compatible = "compat3" },
+	{ .data = "G", .compatible = "compat2", },
+	{ .data = "H", .compatible = "compat2", .name = "name5", },
+	{ .data = "I", .compatible = "compat2", .type = "type1", },
+	{ .data = "J", .compatible = "compat2", .type = "type1", .name = "name8", },
+	{ .data = "K", .compatible = "compat2", .name = "name9", },
+	{}
+};
+
+static struct {
+	const char *path;
+	const char *data;
+} match_node_tests[] = {
+	{ .path = "/testcase-data/match-node/name0", .data = "A", },
+	{ .path = "/testcase-data/match-node/name1", .data = "B", },
+	{ .path = "/testcase-data/match-node/a/name2", .data = "Ca", },
+	{ .path = "/testcase-data/match-node/b/name2", .data = "Cb", },
+	{ .path = "/testcase-data/match-node/c/name2", .data = "Cc", },
+	{ .path = "/testcase-data/match-node/name3", .data = "E", },
+	{ .path = "/testcase-data/match-node/name4", .data = "G", },
+	{ .path = "/testcase-data/match-node/name5", .data = "H", },
+	{ .path = "/testcase-data/match-node/name6", .data = "G", },
+	{ .path = "/testcase-data/match-node/name7", .data = "I", },
+	{ .path = "/testcase-data/match-node/name8", .data = "J", },
+	{ .path = "/testcase-data/match-node/name9", .data = "K", },
+};
+
+static void __init of_unittest_match_node(void)
+{
+	struct device_node *np;
+	const struct of_device_id *match;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(match_node_tests); i++) {
+		np = of_find_node_by_path(match_node_tests[i].path);
+		if (!np) {
+			unittest(0, "missing testcase node %s\n",
+				match_node_tests[i].path);
+			continue;
+		}
+
+		match = of_match_node(match_node_table, np);
+		if (!match) {
+			unittest(0, "%s didn't match anything\n",
+				match_node_tests[i].path);
+			continue;
+		}
+
+		if (strcmp(match->data, match_node_tests[i].data) != 0) {
+			unittest(0, "%s got wrong match. expected %s, got %s\n",
+				match_node_tests[i].path, match_node_tests[i].data,
+				(const char *)match->data);
+			continue;
+		}
+		unittest(1, "passed");
+	}
+}
+
+static struct resource test_bus_res = DEFINE_RES_MEM(0xfffffff8, 2);
+static const struct platform_device_info test_bus_info = {
+	.name = "unittest-bus",
+};
+static void __init of_unittest_platform_populate(void)
+{
+	int irq, rc;
+	struct device_node *np, *child, *grandchild;
+	struct platform_device *pdev, *test_bus;
+	const struct of_device_id match[] = {
+		{ .compatible = "test-device", },
+		{}
+	};
+
+	np = of_find_node_by_path("/testcase-data");
+	of_platform_default_populate(np, NULL, NULL);
+
+	/* Test that a missing irq domain returns -EPROBE_DEFER */
+	np = of_find_node_by_path("/testcase-data/testcase-device1");
+	pdev = of_find_device_by_node(np);
+	unittest(pdev, "device 1 creation failed\n");
+
+	if (!(of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)) {
+		irq = platform_get_irq(pdev, 0);
+		unittest(irq == -EPROBE_DEFER,
+			 "device deferred probe failed - %d\n", irq);
+
+		/* Test that a parsing failure does not return -EPROBE_DEFER */
+		np = of_find_node_by_path("/testcase-data/testcase-device2");
+		pdev = of_find_device_by_node(np);
+		unittest(pdev, "device 2 creation failed\n");
+
+		EXPECT_BEGIN(KERN_INFO,
+			     "platform testcase-data:testcase-device2: error -ENXIO: IRQ index 0 not found");
+
+		irq = platform_get_irq(pdev, 0);
+
+		EXPECT_END(KERN_INFO,
+			   "platform testcase-data:testcase-device2: error -ENXIO: IRQ index 0 not found");
+
+		unittest(irq < 0 && irq != -EPROBE_DEFER,
+			 "device parsing error failed - %d\n", irq);
+	}
+
+	np = of_find_node_by_path("/testcase-data/platform-tests");
+	unittest(np, "No testcase data in device tree\n");
+	if (!np)
+		return;
+
+	test_bus = platform_device_register_full(&test_bus_info);
+	rc = PTR_ERR_OR_ZERO(test_bus);
+	unittest(!rc, "testbus registration failed; rc=%i\n", rc);
+	if (rc) {
+		of_node_put(np);
+		return;
+	}
+	test_bus->dev.of_node = np;
+
+	/*
+	 * Add a dummy resource to the test bus node after it is
+	 * registered to catch problems with un-inserted resources. The
+	 * DT code doesn't insert the resources, and it has caused the
+	 * kernel to oops in the past. This makes sure the same bug
+	 * doesn't crop up again.
+	 */
+	platform_device_add_resources(test_bus, &test_bus_res, 1);
+
+	of_platform_populate(np, match, NULL, &test_bus->dev);
+	for_each_child_of_node(np, child) {
+		for_each_child_of_node(child, grandchild) {
+			pdev = of_find_device_by_node(grandchild);
+			unittest(pdev,
+				 "Could not create device for node '%pOFn'\n",
+				 grandchild);
+			platform_device_put(pdev);
+		}
+	}
+
+	of_platform_depopulate(&test_bus->dev);
+	for_each_child_of_node(np, child) {
+		for_each_child_of_node(child, grandchild)
+			unittest(!of_find_device_by_node(grandchild),
+				 "device didn't get destroyed '%pOFn'\n",
+				 grandchild);
+	}
+
+	platform_device_unregister(test_bus);
+	of_node_put(np);
+}
+
+/**
+ *	update_node_properties - adds the properties
+ *	of np into dup node (present in live tree) and
+ *	updates parent of children of np to dup.
+ *
+ *	@np:	node whose properties are being added to the live tree
+ *	@dup:	node present in live tree to be updated
+ */
+static void update_node_properties(struct device_node *np,
+					struct device_node *dup)
+{
+	struct property *prop;
+	struct property *save_next;
+	struct device_node *child;
+	int ret;
+
+	for_each_child_of_node(np, child)
+		child->parent = dup;
+
+	/*
+	 * "unittest internal error: unable to add testdata property"
+	 *
+	 *    If this message reports a property in node '/__symbols__' then
+	 *    the respective unittest overlay contains a label that has the
+	 *    same name as a label in the live devicetree.  The label will
+	 *    be in the live devicetree only if the devicetree source was
+	 *    compiled with the '-@' option.  If you encounter this error,
+	 *    please consider renaming __all__ of the labels in the unittest
+	 *    overlay dts files with an odd prefix that is unlikely to be
+	 *    used in a real devicetree.
+	 */
+
+	/*
+	 * open code for_each_property_of_node() because of_add_property()
+	 * sets prop->next to NULL
+	 */
+	for (prop = np->properties; prop != NULL; prop = save_next) {
+		save_next = prop->next;
+		ret = of_add_property(dup, prop);
+		if (ret) {
+			if (ret == -EEXIST && !strcmp(prop->name, "name"))
+				continue;
+			pr_err("unittest internal error: unable to add testdata property %pOF/%s",
+			       np, prop->name);
+		}
+	}
+}
+
+/**
+ *	attach_node_and_children - attaches nodes
+ *	and its children to live tree.
+ *	CAUTION: misleading function name - if node @np already exists in
+ *	the live tree then children of @np are *not* attached to the live
+ *	tree.  This works for the current test devicetree nodes because such
+ *	nodes do not have child nodes.
+ *
+ *	@np:	Node to attach to live tree
+ */
+static void attach_node_and_children(struct device_node *np)
+{
+	struct device_node *next, *dup, *child;
+	unsigned long flags;
+	const char *full_name;
+
+	full_name = kasprintf(GFP_KERNEL, "%pOF", np);
+	if (!full_name)
+		return;
+
+	if (!strcmp(full_name, "/__local_fixups__") ||
+	    !strcmp(full_name, "/__fixups__")) {
+		kfree(full_name);
+		return;
+	}
+
+	dup = of_find_node_by_path(full_name);
+	kfree(full_name);
+	if (dup) {
+		update_node_properties(np, dup);
+		return;
+	}
+
+	child = np->child;
+	np->child = NULL;
+
+	mutex_lock(&of_mutex);
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	np->sibling = np->parent->child;
+	np->parent->child = np;
+	of_node_clear_flag(np, OF_DETACHED);
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+	__of_attach_node_sysfs(np);
+	mutex_unlock(&of_mutex);
+
+	while (child) {
+		next = child->sibling;
+		attach_node_and_children(child);
+		child = next;
+	}
+}
+
+/**
+ *	unittest_data_add - Reads, copies data from
+ *	linked tree and attaches it to the live tree
+ */
+static int __init unittest_data_add(void)
+{
+	void *unittest_data;
+	void *unittest_data_align;
+	struct device_node *unittest_data_node = NULL, *np;
+	/*
+	 * __dtb_testcases_begin[] and __dtb_testcases_end[] are magically
+	 * created by cmd_dt_S_dtb in scripts/Makefile.lib
+	 */
+	extern uint8_t __dtb_testcases_begin[];
+	extern uint8_t __dtb_testcases_end[];
+	const int size = __dtb_testcases_end - __dtb_testcases_begin;
+	int rc;
+	void *ret;
+
+	if (!size) {
+		pr_warn("%s: testcases is empty\n", __func__);
+		return -ENODATA;
+	}
+
+	/* creating copy */
+	unittest_data = kmalloc(size + FDT_ALIGN_SIZE, GFP_KERNEL);
+	if (!unittest_data)
+		return -ENOMEM;
+
+	unittest_data_align = PTR_ALIGN(unittest_data, FDT_ALIGN_SIZE);
+	memcpy(unittest_data_align, __dtb_testcases_begin, size);
+
+	ret = of_fdt_unflatten_tree(unittest_data_align, NULL, &unittest_data_node);
+	if (!ret) {
+		pr_warn("%s: unflatten testcases tree failed\n", __func__);
+		kfree(unittest_data);
+		return -ENODATA;
+	}
+	if (!unittest_data_node) {
+		pr_warn("%s: testcases tree is empty\n", __func__);
+		kfree(unittest_data);
+		return -ENODATA;
+	}
+
+	/*
+	 * This lock normally encloses of_resolve_phandles()
+	 */
+	of_overlay_mutex_lock();
+
+	rc = of_resolve_phandles(unittest_data_node);
+	if (rc) {
+		pr_err("%s: Failed to resolve phandles (rc=%i)\n", __func__, rc);
+		of_overlay_mutex_unlock();
+		return -EINVAL;
+	}
+
+	if (!of_root) {
+		of_root = unittest_data_node;
+		for_each_of_allnodes(np)
+			__of_attach_node_sysfs(np);
+		of_aliases = of_find_node_by_path("/aliases");
+		of_chosen = of_find_node_by_path("/chosen");
+		of_overlay_mutex_unlock();
+		return 0;
+	}
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "Duplicate name in testcase-data, renamed to \"duplicate-name#1\"");
+
+	/* attach the sub-tree to live tree */
+	np = unittest_data_node->child;
+	while (np) {
+		struct device_node *next = np->sibling;
+
+		np->parent = of_root;
+		attach_node_and_children(np);
+		np = next;
+	}
+
+	EXPECT_END(KERN_INFO,
+		   "Duplicate name in testcase-data, renamed to \"duplicate-name#1\"");
+
+	of_overlay_mutex_unlock();
+
+	return 0;
+}
+
+#ifdef CONFIG_OF_OVERLAY
+static int __init overlay_data_apply(const char *overlay_name, int *ovcs_id);
+
+static int unittest_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+
+	if (np == NULL) {
+		dev_err(dev, "No OF data for device\n");
+		return -EINVAL;
+
+	}
+
+	dev_dbg(dev, "%s for node @%pOF\n", __func__, np);
+
+	of_platform_populate(np, NULL, NULL, &pdev->dev);
+
+	return 0;
+}
+
+static int unittest_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+
+	dev_dbg(dev, "%s for node @%pOF\n", __func__, np);
+	return 0;
+}
+
+static const struct of_device_id unittest_match[] = {
+	{ .compatible = "unittest", },
+	{},
+};
+
+static struct platform_driver unittest_driver = {
+	.probe			= unittest_probe,
+	.remove			= unittest_remove,
+	.driver = {
+		.name		= "unittest",
+		.of_match_table	= of_match_ptr(unittest_match),
+	},
+};
+
+/* get the platform device instantiated at the path */
+static struct platform_device *of_path_to_platform_device(const char *path)
+{
+	struct device_node *np;
+	struct platform_device *pdev;
+
+	np = of_find_node_by_path(path);
+	if (np == NULL)
+		return NULL;
+
+	pdev = of_find_device_by_node(np);
+	of_node_put(np);
+
+	return pdev;
+}
+
+/* find out if a platform device exists at that path */
+static int of_path_platform_device_exists(const char *path)
+{
+	struct platform_device *pdev;
+
+	pdev = of_path_to_platform_device(path);
+	platform_device_put(pdev);
+	return pdev != NULL;
+}
+
+#ifdef CONFIG_OF_GPIO
+
+struct unittest_gpio_dev {
+	struct gpio_chip chip;
+};
+
+static int unittest_gpio_chip_request_count;
+static int unittest_gpio_probe_count;
+static int unittest_gpio_probe_pass_count;
+
+static int unittest_gpio_chip_request(struct gpio_chip *chip, unsigned int offset)
+{
+	unittest_gpio_chip_request_count++;
+
+	pr_debug("%s(): %s %d %d\n", __func__, chip->label, offset,
+		 unittest_gpio_chip_request_count);
+	return 0;
+}
+
+static int unittest_gpio_probe(struct platform_device *pdev)
+{
+	struct unittest_gpio_dev *devptr;
+	int ret;
+
+	unittest_gpio_probe_count++;
+
+	devptr = kzalloc(sizeof(*devptr), GFP_KERNEL);
+	if (!devptr)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, devptr);
+
+	devptr->chip.fwnode = dev_fwnode(&pdev->dev);
+	devptr->chip.label = "of-unittest-gpio";
+	devptr->chip.base = -1; /* dynamic allocation */
+	devptr->chip.ngpio = 5;
+	devptr->chip.request = unittest_gpio_chip_request;
+
+	ret = gpiochip_add_data(&devptr->chip, NULL);
+
+	unittest(!ret,
+		 "gpiochip_add_data() for node @%pfw failed, ret = %d\n", devptr->chip.fwnode, ret);
+
+	if (!ret)
+		unittest_gpio_probe_pass_count++;
+	return ret;
+}
+
+static int unittest_gpio_remove(struct platform_device *pdev)
+{
+	struct unittest_gpio_dev *devptr = platform_get_drvdata(pdev);
+	struct device *dev = &pdev->dev;
+
+	dev_dbg(dev, "%s for node @%pfw\n", __func__, devptr->chip.fwnode);
+
+	if (!devptr)
+		return -EINVAL;
+
+	if (devptr->chip.base != -1)
+		gpiochip_remove(&devptr->chip);
+
+	platform_set_drvdata(pdev, NULL);
+	kfree(devptr);
+
+	return 0;
+}
+
+static const struct of_device_id unittest_gpio_id[] = {
+	{ .compatible = "unittest-gpio", },
+	{}
+};
+
+static struct platform_driver unittest_gpio_driver = {
+	.probe	= unittest_gpio_probe,
+	.remove	= unittest_gpio_remove,
+	.driver	= {
+		.name		= "unittest-gpio",
+		.of_match_table	= of_match_ptr(unittest_gpio_id),
+	},
+};
+
+static void __init of_unittest_overlay_gpio(void)
+{
+	int chip_request_count;
+	int probe_pass_count;
+	int ret;
+
+	/*
+	 * tests: apply overlays before registering driver
+	 * Similar to installing a driver as a module, the
+	 * driver is registered after applying the overlays.
+	 *
+	 * The overlays are applied by overlay_data_apply()
+	 * instead of of_unittest_apply_overlay() so that they
+	 * will not be tracked.  Thus they will not be removed
+	 * by of_unittest_remove_tracked_overlays().
+	 *
+	 * - apply overlay_gpio_01
+	 * - apply overlay_gpio_02a
+	 * - apply overlay_gpio_02b
+	 * - register driver
+	 *
+	 * register driver will result in
+	 *   - probe and processing gpio hog for overlay_gpio_01
+	 *   - probe for overlay_gpio_02a
+	 *   - processing gpio for overlay_gpio_02b
+	 */
+
+	probe_pass_count = unittest_gpio_probe_pass_count;
+	chip_request_count = unittest_gpio_chip_request_count;
+
+	/*
+	 * overlay_gpio_01 contains gpio node and child gpio hog node
+	 * overlay_gpio_02a contains gpio node
+	 * overlay_gpio_02b contains child gpio hog node
+	 */
+
+	unittest(overlay_data_apply("overlay_gpio_01", NULL),
+		 "Adding overlay 'overlay_gpio_01' failed\n");
+
+	unittest(overlay_data_apply("overlay_gpio_02a", NULL),
+		 "Adding overlay 'overlay_gpio_02a' failed\n");
+
+	unittest(overlay_data_apply("overlay_gpio_02b", NULL),
+		 "Adding overlay 'overlay_gpio_02b' failed\n");
+
+	/*
+	 * messages are the result of the probes, after the
+	 * driver is registered
+	 */
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "gpio-<<int>> (line-B-input): hogged as input\n");
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "gpio-<<int>> (line-A-input): hogged as input\n");
+
+	ret = platform_driver_register(&unittest_gpio_driver);
+	if (unittest(ret == 0, "could not register unittest gpio driver\n"))
+		return;
+
+	EXPECT_END(KERN_INFO,
+		   "gpio-<<int>> (line-A-input): hogged as input\n");
+	EXPECT_END(KERN_INFO,
+		   "gpio-<<int>> (line-B-input): hogged as input\n");
+
+	unittest(probe_pass_count + 2 == unittest_gpio_probe_pass_count,
+		 "unittest_gpio_probe() failed or not called\n");
+
+	unittest(chip_request_count + 2 == unittest_gpio_chip_request_count,
+		 "unittest_gpio_chip_request() called %d times (expected 1 time)\n",
+		 unittest_gpio_chip_request_count - chip_request_count);
+
+	/*
+	 * tests: apply overlays after registering driver
+	 *
+	 * Similar to a driver built-in to the kernel, the
+	 * driver is registered before applying the overlays.
+	 *
+	 * overlay_gpio_03 contains gpio node and child gpio hog node
+	 *
+	 * - apply overlay_gpio_03
+	 *
+	 * apply overlay will result in
+	 *   - probe and processing gpio hog.
+	 */
+
+	probe_pass_count = unittest_gpio_probe_pass_count;
+	chip_request_count = unittest_gpio_chip_request_count;
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "gpio-<<int>> (line-D-input): hogged as input\n");
+
+	/* overlay_gpio_03 contains gpio node and child gpio hog node */
+
+	unittest(overlay_data_apply("overlay_gpio_03", NULL),
+		 "Adding overlay 'overlay_gpio_03' failed\n");
+
+	EXPECT_END(KERN_INFO,
+		   "gpio-<<int>> (line-D-input): hogged as input\n");
+
+	unittest(probe_pass_count + 1 == unittest_gpio_probe_pass_count,
+		 "unittest_gpio_probe() failed or not called\n");
+
+	unittest(chip_request_count + 1 == unittest_gpio_chip_request_count,
+		 "unittest_gpio_chip_request() called %d times (expected 1 time)\n",
+		 unittest_gpio_chip_request_count - chip_request_count);
+
+	/*
+	 * overlay_gpio_04a contains gpio node
+	 *
+	 * - apply overlay_gpio_04a
+	 *
+	 * apply the overlay will result in
+	 *   - probe for overlay_gpio_04a
+	 */
+
+	probe_pass_count = unittest_gpio_probe_pass_count;
+	chip_request_count = unittest_gpio_chip_request_count;
+
+	/* overlay_gpio_04a contains gpio node */
+
+	unittest(overlay_data_apply("overlay_gpio_04a", NULL),
+		 "Adding overlay 'overlay_gpio_04a' failed\n");
+
+	unittest(probe_pass_count + 1 == unittest_gpio_probe_pass_count,
+		 "unittest_gpio_probe() failed or not called\n");
+
+	/*
+	 * overlay_gpio_04b contains child gpio hog node
+	 *
+	 * - apply overlay_gpio_04b
+	 *
+	 * apply the overlay will result in
+	 *   - processing gpio for overlay_gpio_04b
+	 */
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "gpio-<<int>> (line-C-input): hogged as input\n");
+
+	/* overlay_gpio_04b contains child gpio hog node */
+
+	unittest(overlay_data_apply("overlay_gpio_04b", NULL),
+		 "Adding overlay 'overlay_gpio_04b' failed\n");
+
+	EXPECT_END(KERN_INFO,
+		   "gpio-<<int>> (line-C-input): hogged as input\n");
+
+	unittest(chip_request_count + 1 == unittest_gpio_chip_request_count,
+		 "unittest_gpio_chip_request() called %d times (expected 1 time)\n",
+		 unittest_gpio_chip_request_count - chip_request_count);
+}
+
+#else
+
+static void __init of_unittest_overlay_gpio(void)
+{
+	/* skip tests */
+}
+
+#endif
+
+#if IS_BUILTIN(CONFIG_I2C)
+
+/* get the i2c client device instantiated at the path */
+static struct i2c_client *of_path_to_i2c_client(const char *path)
+{
+	struct device_node *np;
+	struct i2c_client *client;
+
+	np = of_find_node_by_path(path);
+	if (np == NULL)
+		return NULL;
+
+	client = of_find_i2c_device_by_node(np);
+	of_node_put(np);
+
+	return client;
+}
+
+/* find out if a i2c client device exists at that path */
+static int of_path_i2c_client_exists(const char *path)
+{
+	struct i2c_client *client;
+
+	client = of_path_to_i2c_client(path);
+	if (client)
+		put_device(&client->dev);
+	return client != NULL;
+}
+#else
+static int of_path_i2c_client_exists(const char *path)
+{
+	return 0;
+}
+#endif
+
+enum overlay_type {
+	PDEV_OVERLAY,
+	I2C_OVERLAY
+};
+
+static int of_path_device_type_exists(const char *path,
+		enum overlay_type ovtype)
+{
+	switch (ovtype) {
+	case PDEV_OVERLAY:
+		return of_path_platform_device_exists(path);
+	case I2C_OVERLAY:
+		return of_path_i2c_client_exists(path);
+	}
+	return 0;
+}
+
+static const char *unittest_path(int nr, enum overlay_type ovtype)
+{
+	const char *base;
+	static char buf[256];
+
+	switch (ovtype) {
+	case PDEV_OVERLAY:
+		base = "/testcase-data/overlay-node/test-bus";
+		break;
+	case I2C_OVERLAY:
+		base = "/testcase-data/overlay-node/test-bus/i2c-test-bus";
+		break;
+	default:
+		buf[0] = '\0';
+		return buf;
+	}
+	snprintf(buf, sizeof(buf) - 1, "%s/test-unittest%d", base, nr);
+	buf[sizeof(buf) - 1] = '\0';
+	return buf;
+}
+
+static int of_unittest_device_exists(int unittest_nr, enum overlay_type ovtype)
+{
+	const char *path;
+
+	path = unittest_path(unittest_nr, ovtype);
+
+	switch (ovtype) {
+	case PDEV_OVERLAY:
+		return of_path_platform_device_exists(path);
+	case I2C_OVERLAY:
+		return of_path_i2c_client_exists(path);
+	}
+	return 0;
+}
+
+static const char *overlay_name_from_nr(int nr)
+{
+	static char buf[256];
+
+	snprintf(buf, sizeof(buf) - 1,
+		"overlay_%d", nr);
+	buf[sizeof(buf) - 1] = '\0';
+
+	return buf;
+}
+
+static const char *bus_path = "/testcase-data/overlay-node/test-bus";
+
+#define MAX_TRACK_OVCS_IDS 256
+
+static int track_ovcs_id[MAX_TRACK_OVCS_IDS];
+static int track_ovcs_id_overlay_nr[MAX_TRACK_OVCS_IDS];
+static int track_ovcs_id_cnt;
+
+static void of_unittest_track_overlay(int ovcs_id, int overlay_nr)
+{
+	if (WARN_ON(track_ovcs_id_cnt >= MAX_TRACK_OVCS_IDS))
+		return;
+
+	track_ovcs_id[track_ovcs_id_cnt] = ovcs_id;
+	track_ovcs_id_overlay_nr[track_ovcs_id_cnt] = overlay_nr;
+	track_ovcs_id_cnt++;
+}
+
+static void of_unittest_untrack_overlay(int ovcs_id)
+{
+	if (WARN_ON(track_ovcs_id_cnt < 1))
+		return;
+
+	track_ovcs_id_cnt--;
+
+	/* If out of synch then test is broken.  Do not try to recover. */
+	WARN_ON(track_ovcs_id[track_ovcs_id_cnt] != ovcs_id);
+}
+
+static void of_unittest_remove_tracked_overlays(void)
+{
+	int ret, ovcs_id, overlay_nr, save_ovcs_id;
+	const char *overlay_name;
+
+	while (track_ovcs_id_cnt > 0) {
+
+		ovcs_id = track_ovcs_id[track_ovcs_id_cnt - 1];
+		overlay_nr = track_ovcs_id_overlay_nr[track_ovcs_id_cnt - 1];
+		save_ovcs_id = ovcs_id;
+		ret = of_overlay_remove(&ovcs_id);
+		if (ret == -ENODEV) {
+			overlay_name = overlay_name_from_nr(overlay_nr);
+			pr_warn("%s: of_overlay_remove() for overlay \"%s\" failed, ret = %d\n",
+				__func__, overlay_name, ret);
+		}
+		of_unittest_untrack_overlay(save_ovcs_id);
+	}
+
+}
+
+static int __init of_unittest_apply_overlay(int overlay_nr, int *ovcs_id)
+{
+	/*
+	 * The overlay will be tracked, thus it will be removed
+	 * by of_unittest_remove_tracked_overlays().
+	 */
+
+	const char *overlay_name;
+
+	overlay_name = overlay_name_from_nr(overlay_nr);
+
+	if (!overlay_data_apply(overlay_name, ovcs_id)) {
+		unittest(0, "could not apply overlay \"%s\"\n", overlay_name);
+		return -EFAULT;
+	}
+	of_unittest_track_overlay(*ovcs_id, overlay_nr);
+
+	return 0;
+}
+
+/* apply an overlay while checking before and after states */
+static int __init of_unittest_apply_overlay_check(int overlay_nr,
+		int unittest_nr, int before, int after,
+		enum overlay_type ovtype)
+{
+	int ret, ovcs_id;
+
+	/* unittest device must not be in before state */
+	if (of_unittest_device_exists(unittest_nr, ovtype) != before) {
+		unittest(0, "%s with device @\"%s\" %s\n",
+				overlay_name_from_nr(overlay_nr),
+				unittest_path(unittest_nr, ovtype),
+				!before ? "enabled" : "disabled");
+		return -EINVAL;
+	}
+
+	ovcs_id = 0;
+	ret = of_unittest_apply_overlay(overlay_nr, &ovcs_id);
+	if (ret != 0) {
+		/* of_unittest_apply_overlay already called unittest() */
+		return ret;
+	}
+
+	/* unittest device must be to set to after state */
+	if (of_unittest_device_exists(unittest_nr, ovtype) != after) {
+		unittest(0, "%s failed to create @\"%s\" %s\n",
+				overlay_name_from_nr(overlay_nr),
+				unittest_path(unittest_nr, ovtype),
+				!after ? "enabled" : "disabled");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/* apply an overlay and then revert it while checking before, after states */
+static int __init of_unittest_apply_revert_overlay_check(int overlay_nr,
+		int unittest_nr, int before, int after,
+		enum overlay_type ovtype)
+{
+	int ret, ovcs_id, save_ovcs_id;
+
+	/* unittest device must be in before state */
+	if (of_unittest_device_exists(unittest_nr, ovtype) != before) {
+		unittest(0, "%s with device @\"%s\" %s\n",
+				overlay_name_from_nr(overlay_nr),
+				unittest_path(unittest_nr, ovtype),
+				!before ? "enabled" : "disabled");
+		return -EINVAL;
+	}
+
+	/* apply the overlay */
+	ovcs_id = 0;
+	ret = of_unittest_apply_overlay(overlay_nr, &ovcs_id);
+	if (ret != 0) {
+		/* of_unittest_apply_overlay already called unittest() */
+		return ret;
+	}
+
+	/* unittest device must be in after state */
+	if (of_unittest_device_exists(unittest_nr, ovtype) != after) {
+		unittest(0, "%s failed to create @\"%s\" %s\n",
+				overlay_name_from_nr(overlay_nr),
+				unittest_path(unittest_nr, ovtype),
+				!after ? "enabled" : "disabled");
+		return -EINVAL;
+	}
+
+	save_ovcs_id = ovcs_id;
+	ret = of_overlay_remove(&ovcs_id);
+	if (ret != 0) {
+		unittest(0, "%s failed to be destroyed @\"%s\"\n",
+				overlay_name_from_nr(overlay_nr),
+				unittest_path(unittest_nr, ovtype));
+		return ret;
+	}
+	of_unittest_untrack_overlay(save_ovcs_id);
+
+	/* unittest device must be again in before state */
+	if (of_unittest_device_exists(unittest_nr, ovtype) != before) {
+		unittest(0, "%s with device @\"%s\" %s\n",
+				overlay_name_from_nr(overlay_nr),
+				unittest_path(unittest_nr, ovtype),
+				!before ? "enabled" : "disabled");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/* test activation of device */
+static void __init of_unittest_overlay_0(void)
+{
+	int ret;
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest0/status");
+
+	/* device should enable */
+	ret = of_unittest_apply_overlay_check(0, 0, 0, 1, PDEV_OVERLAY);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest0/status");
+
+	if (ret)
+		return;
+
+	unittest(1, "overlay test %d passed\n", 0);
+}
+
+/* test deactivation of device */
+static void __init of_unittest_overlay_1(void)
+{
+	int ret;
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest1/status");
+
+	/* device should disable */
+	ret = of_unittest_apply_overlay_check(1, 1, 1, 0, PDEV_OVERLAY);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest1/status");
+
+	if (ret)
+		return;
+
+	unittest(1, "overlay test %d passed\n", 1);
+
+}
+
+/* test activation of device */
+static void __init of_unittest_overlay_2(void)
+{
+	int ret;
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest2/status");
+
+	/* device should enable */
+	ret = of_unittest_apply_overlay_check(2, 2, 0, 1, PDEV_OVERLAY);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest2/status");
+
+	if (ret)
+		return;
+	unittest(1, "overlay test %d passed\n", 2);
+}
+
+/* test deactivation of device */
+static void __init of_unittest_overlay_3(void)
+{
+	int ret;
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest3/status");
+
+	/* device should disable */
+	ret = of_unittest_apply_overlay_check(3, 3, 1, 0, PDEV_OVERLAY);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest3/status");
+
+	if (ret)
+		return;
+
+	unittest(1, "overlay test %d passed\n", 3);
+}
+
+/* test activation of a full device node */
+static void __init of_unittest_overlay_4(void)
+{
+	/* device should disable */
+	if (of_unittest_apply_overlay_check(4, 4, 0, 1, PDEV_OVERLAY))
+		return;
+
+	unittest(1, "overlay test %d passed\n", 4);
+}
+
+/* test overlay apply/revert sequence */
+static void __init of_unittest_overlay_5(void)
+{
+	int ret;
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest5/status");
+
+	/* device should disable */
+	ret = of_unittest_apply_revert_overlay_check(5, 5, 0, 1, PDEV_OVERLAY);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest5/status");
+
+	if (ret)
+		return;
+
+	unittest(1, "overlay test %d passed\n", 5);
+}
+
+/* test overlay application in sequence */
+static void __init of_unittest_overlay_6(void)
+{
+	int i, save_ovcs_id[2], ovcs_id;
+	int overlay_nr = 6, unittest_nr = 6;
+	int before = 0, after = 1;
+	const char *overlay_name;
+
+	int ret;
+
+	/* unittest device must be in before state */
+	for (i = 0; i < 2; i++) {
+		if (of_unittest_device_exists(unittest_nr + i, PDEV_OVERLAY)
+				!= before) {
+			unittest(0, "%s with device @\"%s\" %s\n",
+					overlay_name_from_nr(overlay_nr + i),
+					unittest_path(unittest_nr + i,
+						PDEV_OVERLAY),
+					!before ? "enabled" : "disabled");
+			return;
+		}
+	}
+
+	/* apply the overlays */
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest6/status");
+
+	overlay_name = overlay_name_from_nr(overlay_nr + 0);
+
+	ret = overlay_data_apply(overlay_name, &ovcs_id);
+
+	if (!ret) {
+		unittest(0, "could not apply overlay \"%s\"\n", overlay_name);
+			return;
+	}
+	save_ovcs_id[0] = ovcs_id;
+	of_unittest_track_overlay(ovcs_id, overlay_nr + 0);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest6/status");
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest7/status");
+
+	overlay_name = overlay_name_from_nr(overlay_nr + 1);
+
+	ret = overlay_data_apply(overlay_name, &ovcs_id);
+
+	if (!ret) {
+		unittest(0, "could not apply overlay \"%s\"\n", overlay_name);
+			return;
+	}
+	save_ovcs_id[1] = ovcs_id;
+	of_unittest_track_overlay(ovcs_id, overlay_nr + 1);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest7/status");
+
+
+	for (i = 0; i < 2; i++) {
+		/* unittest device must be in after state */
+		if (of_unittest_device_exists(unittest_nr + i, PDEV_OVERLAY)
+				!= after) {
+			unittest(0, "overlay @\"%s\" failed @\"%s\" %s\n",
+					overlay_name_from_nr(overlay_nr + i),
+					unittest_path(unittest_nr + i,
+						PDEV_OVERLAY),
+					!after ? "enabled" : "disabled");
+			return;
+		}
+	}
+
+	for (i = 1; i >= 0; i--) {
+		ovcs_id = save_ovcs_id[i];
+		if (of_overlay_remove(&ovcs_id)) {
+			unittest(0, "%s failed destroy @\"%s\"\n",
+					overlay_name_from_nr(overlay_nr + i),
+					unittest_path(unittest_nr + i,
+						PDEV_OVERLAY));
+			return;
+		}
+		of_unittest_untrack_overlay(save_ovcs_id[i]);
+	}
+
+	for (i = 0; i < 2; i++) {
+		/* unittest device must be again in before state */
+		if (of_unittest_device_exists(unittest_nr + i, PDEV_OVERLAY)
+				!= before) {
+			unittest(0, "%s with device @\"%s\" %s\n",
+					overlay_name_from_nr(overlay_nr + i),
+					unittest_path(unittest_nr + i,
+						PDEV_OVERLAY),
+					!before ? "enabled" : "disabled");
+			return;
+		}
+	}
+
+	unittest(1, "overlay test %d passed\n", 6);
+
+}
+
+/* test overlay application in sequence */
+static void __init of_unittest_overlay_8(void)
+{
+	int i, save_ovcs_id[2], ovcs_id;
+	int overlay_nr = 8, unittest_nr = 8;
+	const char *overlay_name;
+	int ret;
+
+	/* we don't care about device state in this test */
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest8/status");
+
+	overlay_name = overlay_name_from_nr(overlay_nr + 0);
+
+	ret = overlay_data_apply(overlay_name, &ovcs_id);
+	if (!ret)
+		unittest(0, "could not apply overlay \"%s\"\n", overlay_name);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest8/status");
+
+	if (!ret)
+		return;
+
+	save_ovcs_id[0] = ovcs_id;
+	of_unittest_track_overlay(ovcs_id, overlay_nr + 0);
+
+	overlay_name = overlay_name_from_nr(overlay_nr + 1);
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest8/property-foo");
+
+	/* apply the overlays */
+	ret = overlay_data_apply(overlay_name, &ovcs_id);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/test-unittest8/property-foo");
+
+	if (!ret) {
+		unittest(0, "could not apply overlay \"%s\"\n", overlay_name);
+		return;
+	}
+
+	save_ovcs_id[1] = ovcs_id;
+	of_unittest_track_overlay(ovcs_id, overlay_nr + 1);
+
+	/* now try to remove first overlay (it should fail) */
+	ovcs_id = save_ovcs_id[0];
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: node_overlaps_later_cs: #6 overlaps with #7 @/testcase-data/overlay-node/test-bus/test-unittest8");
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: overlay #6 is not topmost");
+
+	ret = of_overlay_remove(&ovcs_id);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: overlay #6 is not topmost");
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: node_overlaps_later_cs: #6 overlaps with #7 @/testcase-data/overlay-node/test-bus/test-unittest8");
+
+	if (!ret) {
+		/*
+		 * Should never get here.  If we do, expect a lot of
+		 * subsequent tracking and overlay removal related errors.
+		 */
+		unittest(0, "%s was destroyed @\"%s\"\n",
+				overlay_name_from_nr(overlay_nr + 0),
+				unittest_path(unittest_nr,
+					PDEV_OVERLAY));
+		return;
+	}
+
+	/* removing them in order should work */
+	for (i = 1; i >= 0; i--) {
+		ovcs_id = save_ovcs_id[i];
+		if (of_overlay_remove(&ovcs_id)) {
+			unittest(0, "%s not destroyed @\"%s\"\n",
+					overlay_name_from_nr(overlay_nr + i),
+					unittest_path(unittest_nr,
+						PDEV_OVERLAY));
+			return;
+		}
+		of_unittest_untrack_overlay(save_ovcs_id[i]);
+	}
+
+	unittest(1, "overlay test %d passed\n", 8);
+}
+
+/* test insertion of a bus with parent devices */
+static void __init of_unittest_overlay_10(void)
+{
+	int ret;
+	char *child_path;
+
+	/* device should disable */
+	ret = of_unittest_apply_overlay_check(10, 10, 0, 1, PDEV_OVERLAY);
+
+	if (unittest(ret == 0,
+			"overlay test %d failed; overlay application\n", 10))
+		return;
+
+	child_path = kasprintf(GFP_KERNEL, "%s/test-unittest101",
+			unittest_path(10, PDEV_OVERLAY));
+	if (unittest(child_path, "overlay test %d failed; kasprintf\n", 10))
+		return;
+
+	ret = of_path_device_type_exists(child_path, PDEV_OVERLAY);
+	kfree(child_path);
+
+	unittest(ret, "overlay test %d failed; no child device\n", 10);
+}
+
+/* test insertion of a bus with parent devices (and revert) */
+static void __init of_unittest_overlay_11(void)
+{
+	int ret;
+
+	/* device should disable */
+	ret = of_unittest_apply_revert_overlay_check(11, 11, 0, 1,
+			PDEV_OVERLAY);
+
+	unittest(ret == 0, "overlay test %d failed; overlay apply\n", 11);
+}
+
+#if IS_BUILTIN(CONFIG_I2C) && IS_ENABLED(CONFIG_OF_OVERLAY)
+
+struct unittest_i2c_bus_data {
+	struct platform_device	*pdev;
+	struct i2c_adapter	adap;
+};
+
+static int unittest_i2c_master_xfer(struct i2c_adapter *adap,
+		struct i2c_msg *msgs, int num)
+{
+	struct unittest_i2c_bus_data *std = i2c_get_adapdata(adap);
+
+	(void)std;
+
+	return num;
+}
+
+static u32 unittest_i2c_functionality(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm unittest_i2c_algo = {
+	.master_xfer	= unittest_i2c_master_xfer,
+	.functionality	= unittest_i2c_functionality,
+};
+
+static int unittest_i2c_bus_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct unittest_i2c_bus_data *std;
+	struct i2c_adapter *adap;
+	int ret;
+
+	if (np == NULL) {
+		dev_err(dev, "No OF data for device\n");
+		return -EINVAL;
+
+	}
+
+	dev_dbg(dev, "%s for node @%pOF\n", __func__, np);
+
+	std = devm_kzalloc(dev, sizeof(*std), GFP_KERNEL);
+	if (!std)
+		return -ENOMEM;
+
+	/* link them together */
+	std->pdev = pdev;
+	platform_set_drvdata(pdev, std);
+
+	adap = &std->adap;
+	i2c_set_adapdata(adap, std);
+	adap->nr = -1;
+	strscpy(adap->name, pdev->name, sizeof(adap->name));
+	adap->class = I2C_CLASS_DEPRECATED;
+	adap->algo = &unittest_i2c_algo;
+	adap->dev.parent = dev;
+	adap->dev.of_node = dev->of_node;
+	adap->timeout = 5 * HZ;
+	adap->retries = 3;
+
+	ret = i2c_add_numbered_adapter(adap);
+	if (ret != 0) {
+		dev_err(dev, "Failed to add I2C adapter\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int unittest_i2c_bus_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct unittest_i2c_bus_data *std = platform_get_drvdata(pdev);
+
+	dev_dbg(dev, "%s for node @%pOF\n", __func__, np);
+	i2c_del_adapter(&std->adap);
+
+	return 0;
+}
+
+static const struct of_device_id unittest_i2c_bus_match[] = {
+	{ .compatible = "unittest-i2c-bus", },
+	{},
+};
+
+static struct platform_driver unittest_i2c_bus_driver = {
+	.probe			= unittest_i2c_bus_probe,
+	.remove			= unittest_i2c_bus_remove,
+	.driver = {
+		.name		= "unittest-i2c-bus",
+		.of_match_table	= of_match_ptr(unittest_i2c_bus_match),
+	},
+};
+
+static int unittest_i2c_dev_probe(struct i2c_client *client,
+		const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct device_node *np = client->dev.of_node;
+
+	if (!np) {
+		dev_err(dev, "No OF node\n");
+		return -EINVAL;
+	}
+
+	dev_dbg(dev, "%s for node @%pOF\n", __func__, np);
+
+	return 0;
+};
+
+static void unittest_i2c_dev_remove(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct device_node *np = client->dev.of_node;
+
+	dev_dbg(dev, "%s for node @%pOF\n", __func__, np);
+}
+
+static const struct i2c_device_id unittest_i2c_dev_id[] = {
+	{ .name = "unittest-i2c-dev" },
+	{ }
+};
+
+static struct i2c_driver unittest_i2c_dev_driver = {
+	.driver = {
+		.name = "unittest-i2c-dev",
+	},
+	.probe = unittest_i2c_dev_probe,
+	.remove = unittest_i2c_dev_remove,
+	.id_table = unittest_i2c_dev_id,
+};
+
+#if IS_BUILTIN(CONFIG_I2C_MUX)
+
+static int unittest_i2c_mux_select_chan(struct i2c_mux_core *muxc, u32 chan)
+{
+	return 0;
+}
+
+static int unittest_i2c_mux_probe(struct i2c_client *client,
+		const struct i2c_device_id *id)
+{
+	int i, nchans;
+	struct device *dev = &client->dev;
+	struct i2c_adapter *adap = client->adapter;
+	struct device_node *np = client->dev.of_node, *child;
+	struct i2c_mux_core *muxc;
+	u32 reg, max_reg;
+
+	dev_dbg(dev, "%s for node @%pOF\n", __func__, np);
+
+	if (!np) {
+		dev_err(dev, "No OF node\n");
+		return -EINVAL;
+	}
+
+	max_reg = (u32)-1;
+	for_each_child_of_node(np, child) {
+		if (of_property_read_u32(child, "reg", &reg))
+			continue;
+		if (max_reg == (u32)-1 || reg > max_reg)
+			max_reg = reg;
+	}
+	nchans = max_reg == (u32)-1 ? 0 : max_reg + 1;
+	if (nchans == 0) {
+		dev_err(dev, "No channels\n");
+		return -EINVAL;
+	}
+
+	muxc = i2c_mux_alloc(adap, dev, nchans, 0, 0,
+			     unittest_i2c_mux_select_chan, NULL);
+	if (!muxc)
+		return -ENOMEM;
+	for (i = 0; i < nchans; i++) {
+		if (i2c_mux_add_adapter(muxc, 0, i, 0)) {
+			dev_err(dev, "Failed to register mux #%d\n", i);
+			i2c_mux_del_adapters(muxc);
+			return -ENODEV;
+		}
+	}
+
+	i2c_set_clientdata(client, muxc);
+
+	return 0;
+};
+
+static void unittest_i2c_mux_remove(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct device_node *np = client->dev.of_node;
+	struct i2c_mux_core *muxc = i2c_get_clientdata(client);
+
+	dev_dbg(dev, "%s for node @%pOF\n", __func__, np);
+	i2c_mux_del_adapters(muxc);
+}
+
+static const struct i2c_device_id unittest_i2c_mux_id[] = {
+	{ .name = "unittest-i2c-mux" },
+	{ }
+};
+
+static struct i2c_driver unittest_i2c_mux_driver = {
+	.driver = {
+		.name = "unittest-i2c-mux",
+	},
+	.probe = unittest_i2c_mux_probe,
+	.remove = unittest_i2c_mux_remove,
+	.id_table = unittest_i2c_mux_id,
+};
+
+#endif
+
+static int of_unittest_overlay_i2c_init(void)
+{
+	int ret;
+
+	ret = i2c_add_driver(&unittest_i2c_dev_driver);
+	if (unittest(ret == 0,
+			"could not register unittest i2c device driver\n"))
+		return ret;
+
+	ret = platform_driver_register(&unittest_i2c_bus_driver);
+
+	if (unittest(ret == 0,
+			"could not register unittest i2c bus driver\n"))
+		return ret;
+
+#if IS_BUILTIN(CONFIG_I2C_MUX)
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "i2c i2c-1: Added multiplexed i2c bus 2");
+
+	ret = i2c_add_driver(&unittest_i2c_mux_driver);
+
+	EXPECT_END(KERN_INFO,
+		   "i2c i2c-1: Added multiplexed i2c bus 2");
+
+	if (unittest(ret == 0,
+			"could not register unittest i2c mux driver\n"))
+		return ret;
+#endif
+
+	return 0;
+}
+
+static void of_unittest_overlay_i2c_cleanup(void)
+{
+#if IS_BUILTIN(CONFIG_I2C_MUX)
+	i2c_del_driver(&unittest_i2c_mux_driver);
+#endif
+	platform_driver_unregister(&unittest_i2c_bus_driver);
+	i2c_del_driver(&unittest_i2c_dev_driver);
+}
+
+static void __init of_unittest_overlay_i2c_12(void)
+{
+	int ret;
+
+	/* device should enable */
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest12/status");
+
+	ret = of_unittest_apply_overlay_check(12, 12, 0, 1, I2C_OVERLAY);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest12/status");
+
+	if (ret)
+		return;
+
+	unittest(1, "overlay test %d passed\n", 12);
+}
+
+/* test deactivation of device */
+static void __init of_unittest_overlay_i2c_13(void)
+{
+	int ret;
+
+	EXPECT_BEGIN(KERN_INFO,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest13/status");
+
+	/* device should disable */
+	ret = of_unittest_apply_overlay_check(13, 13, 1, 0, I2C_OVERLAY);
+
+	EXPECT_END(KERN_INFO,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data/overlay-node/test-bus/i2c-test-bus/test-unittest13/status");
+
+	if (ret)
+		return;
+
+	unittest(1, "overlay test %d passed\n", 13);
+}
+
+/* just check for i2c mux existence */
+static void of_unittest_overlay_i2c_14(void)
+{
+}
+
+static void __init of_unittest_overlay_i2c_15(void)
+{
+	int ret;
+
+	/* device should enable */
+	EXPECT_BEGIN(KERN_INFO,
+		     "i2c i2c-1: Added multiplexed i2c bus 3");
+
+	ret = of_unittest_apply_overlay_check(15, 15, 0, 1, I2C_OVERLAY);
+
+	EXPECT_END(KERN_INFO,
+		   "i2c i2c-1: Added multiplexed i2c bus 3");
+
+	if (ret)
+		return;
+
+	unittest(1, "overlay test %d passed\n", 15);
+}
+
+#else
+
+static inline void of_unittest_overlay_i2c_14(void) { }
+static inline void of_unittest_overlay_i2c_15(void) { }
+
+#endif
+
+static int of_notify(struct notifier_block *nb, unsigned long action,
+		     void *arg)
+{
+	struct of_overlay_notify_data *nd = arg;
+	struct device_node *found;
+	int ret;
+
+	/*
+	 * For overlay_16 .. overlay_19, check that returning an error
+	 * works for each of the actions by setting an arbitrary return
+	 * error number that matches the test number.  e.g. for unittest16,
+	 * ret = -EBUSY which is -16.
+	 *
+	 * OVERLAY_INFO() for the overlays is declared to expect the same
+	 * error number, so overlay_data_apply() will return no error.
+	 *
+	 * overlay_20 will return NOTIFY_DONE
+	 */
+
+	ret = 0;
+	of_node_get(nd->overlay);
+
+	switch (action) {
+
+	case OF_OVERLAY_PRE_APPLY:
+		found = of_find_node_by_name(nd->overlay, "test-unittest16");
+		if (found) {
+			of_node_put(found);
+			ret = -EBUSY;
+		}
+		break;
+
+	case OF_OVERLAY_POST_APPLY:
+		found = of_find_node_by_name(nd->overlay, "test-unittest17");
+		if (found) {
+			of_node_put(found);
+			ret = -EEXIST;
+		}
+		break;
+
+	case OF_OVERLAY_PRE_REMOVE:
+		found = of_find_node_by_name(nd->overlay, "test-unittest18");
+		if (found) {
+			of_node_put(found);
+			ret = -EXDEV;
+		}
+		break;
+
+	case OF_OVERLAY_POST_REMOVE:
+		found = of_find_node_by_name(nd->overlay, "test-unittest19");
+		if (found) {
+			of_node_put(found);
+			ret = -ENODEV;
+		}
+		break;
+
+	default:			/* should not happen */
+		of_node_put(nd->overlay);
+		ret = -EINVAL;
+		break;
+	}
+
+	if (ret)
+		return notifier_from_errno(ret);
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block of_nb = {
+	.notifier_call = of_notify,
+};
+
+static void __init of_unittest_overlay_notify(void)
+{
+	int ovcs_id;
+	int ret;
+
+	ret = of_overlay_notifier_register(&of_nb);
+	unittest(!ret,
+		 "of_overlay_notifier_register() failed, ret = %d\n", ret);
+	if (ret)
+		return;
+
+	/*
+	 * The overlays are applied by overlay_data_apply()
+	 * instead of of_unittest_apply_overlay() so that they
+	 * will not be tracked.  Thus they will not be removed
+	 * by of_unittest_remove_tracked_overlays().
+	 *
+	 * Applying overlays 16 - 19 will each trigger an error for a
+	 * different action in of_notify().
+	 *
+	 * Applying overlay 20 will not trigger any error in of_notify().
+	 */
+
+	/* ---  overlay 16  --- */
+
+	EXPECT_BEGIN(KERN_INFO, "OF: overlay: overlay changeset pre-apply notifier error -16, target: /testcase-data/overlay-node/test-bus");
+
+	unittest(overlay_data_apply("overlay_16", &ovcs_id),
+		 "test OF_OVERLAY_PRE_APPLY notify injected error\n");
+
+	EXPECT_END(KERN_INFO, "OF: overlay: overlay changeset pre-apply notifier error -16, target: /testcase-data/overlay-node/test-bus");
+
+	unittest(ovcs_id, "ovcs_id not created for overlay_16\n");
+
+	/* ---  overlay 17  --- */
+
+	EXPECT_BEGIN(KERN_INFO, "OF: overlay: overlay changeset post-apply notifier error -17, target: /testcase-data/overlay-node/test-bus");
+
+	unittest(overlay_data_apply("overlay_17", &ovcs_id),
+		 "test OF_OVERLAY_POST_APPLY notify injected error\n");
+
+	EXPECT_END(KERN_INFO, "OF: overlay: overlay changeset post-apply notifier error -17, target: /testcase-data/overlay-node/test-bus");
+
+	unittest(ovcs_id, "ovcs_id not created for overlay_17\n");
+
+	if (ovcs_id) {
+		ret = of_overlay_remove(&ovcs_id);
+		unittest(!ret,
+			"overlay_17 of_overlay_remove(), ret = %d\n", ret);
+	}
+
+	/* ---  overlay 18  --- */
+
+	unittest(overlay_data_apply("overlay_18", &ovcs_id),
+		 "OF_OVERLAY_PRE_REMOVE notify injected error\n");
+
+	unittest(ovcs_id, "ovcs_id not created for overlay_18\n");
+
+	if (ovcs_id) {
+		EXPECT_BEGIN(KERN_INFO, "OF: overlay: overlay changeset pre-remove notifier error -18, target: /testcase-data/overlay-node/test-bus");
+
+		ret = of_overlay_remove(&ovcs_id);
+		EXPECT_END(KERN_INFO, "OF: overlay: overlay changeset pre-remove notifier error -18, target: /testcase-data/overlay-node/test-bus");
+		if (ret == -EXDEV) {
+			/*
+			 * change set ovcs_id should still exist
+			 */
+			unittest(1, "overlay_18 of_overlay_remove() injected error for OF_OVERLAY_PRE_REMOVE\n");
+		} else {
+			unittest(0, "overlay_18 of_overlay_remove() injected error for OF_OVERLAY_PRE_REMOVE not returned\n");
+		}
+	} else {
+		unittest(1, "ovcs_id not created for overlay_18\n");
+	}
+
+	unittest(ovcs_id, "ovcs_id removed for overlay_18\n");
+
+	/* ---  overlay 19  --- */
+
+	unittest(overlay_data_apply("overlay_19", &ovcs_id),
+		 "OF_OVERLAY_POST_REMOVE notify injected error\n");
+
+	unittest(ovcs_id, "ovcs_id not created for overlay_19\n");
+
+	if (ovcs_id) {
+		EXPECT_BEGIN(KERN_INFO, "OF: overlay: overlay changeset post-remove notifier error -19, target: /testcase-data/overlay-node/test-bus");
+		ret = of_overlay_remove(&ovcs_id);
+		EXPECT_END(KERN_INFO, "OF: overlay: overlay changeset post-remove notifier error -19, target: /testcase-data/overlay-node/test-bus");
+		if (ret == -ENODEV)
+			unittest(1, "overlay_19 of_overlay_remove() injected error for OF_OVERLAY_POST_REMOVE\n");
+		else
+			unittest(0, "overlay_19 of_overlay_remove() injected error for OF_OVERLAY_POST_REMOVE not returned\n");
+	} else {
+		unittest(1, "ovcs_id removed for overlay_19\n");
+	}
+
+	unittest(!ovcs_id, "changeset ovcs_id = %d not removed for overlay_19\n",
+		 ovcs_id);
+
+	/* ---  overlay 20  --- */
+
+	unittest(overlay_data_apply("overlay_20", &ovcs_id),
+		 "overlay notify no injected error\n");
+
+	if (ovcs_id) {
+		ret = of_overlay_remove(&ovcs_id);
+		if (ret)
+			unittest(1, "overlay_20 failed to be destroyed, ret = %d\n",
+				 ret);
+	} else {
+		unittest(1, "ovcs_id not created for overlay_20\n");
+	}
+
+	unittest(!of_overlay_notifier_unregister(&of_nb),
+		 "of_overlay_notifier_unregister() failed, ret = %d\n", ret);
+}
+
+static void __init of_unittest_overlay(void)
+{
+	struct device_node *bus_np = NULL;
+
+	if (platform_driver_register(&unittest_driver)) {
+		unittest(0, "could not register unittest driver\n");
+		goto out;
+	}
+
+	bus_np = of_find_node_by_path(bus_path);
+	if (bus_np == NULL) {
+		unittest(0, "could not find bus_path \"%s\"\n", bus_path);
+		goto out;
+	}
+
+	if (of_platform_default_populate(bus_np, NULL, NULL)) {
+		unittest(0, "could not populate bus @ \"%s\"\n", bus_path);
+		goto out;
+	}
+
+	if (!of_unittest_device_exists(100, PDEV_OVERLAY)) {
+		unittest(0, "could not find unittest0 @ \"%s\"\n",
+				unittest_path(100, PDEV_OVERLAY));
+		goto out;
+	}
+
+	if (of_unittest_device_exists(101, PDEV_OVERLAY)) {
+		unittest(0, "unittest1 @ \"%s\" should not exist\n",
+				unittest_path(101, PDEV_OVERLAY));
+		goto out;
+	}
+
+	unittest(1, "basic infrastructure of overlays passed");
+
+	/* tests in sequence */
+	of_unittest_overlay_0();
+	of_unittest_overlay_1();
+	of_unittest_overlay_2();
+	of_unittest_overlay_3();
+	of_unittest_overlay_4();
+	of_unittest_overlay_5();
+	of_unittest_overlay_6();
+	of_unittest_overlay_8();
+
+	of_unittest_overlay_10();
+	of_unittest_overlay_11();
+
+#if IS_BUILTIN(CONFIG_I2C)
+	if (unittest(of_unittest_overlay_i2c_init() == 0, "i2c init failed\n"))
+		goto out;
+
+	of_unittest_overlay_i2c_12();
+	of_unittest_overlay_i2c_13();
+	of_unittest_overlay_i2c_14();
+	of_unittest_overlay_i2c_15();
+
+	of_unittest_overlay_i2c_cleanup();
+#endif
+
+	of_unittest_overlay_gpio();
+
+	of_unittest_remove_tracked_overlays();
+
+	of_unittest_overlay_notify();
+
+out:
+	of_node_put(bus_np);
+}
+
+#else
+static inline void __init of_unittest_overlay(void) { }
+#endif
+
+#ifdef CONFIG_OF_OVERLAY
+
+/*
+ * __dtb_ot_begin[] and __dtb_ot_end[] are created by cmd_dt_S_dtb
+ * in scripts/Makefile.lib
+ */
+
+#define OVERLAY_INFO_EXTERN(name) \
+	extern uint8_t __dtb_##name##_begin[]; \
+	extern uint8_t __dtb_##name##_end[]
+
+#define OVERLAY_INFO(overlay_name, expected)             \
+{	.dtb_begin       = __dtb_##overlay_name##_begin, \
+	.dtb_end         = __dtb_##overlay_name##_end,   \
+	.expected_result = expected,                     \
+	.name            = #overlay_name,                \
+}
+
+struct overlay_info {
+	uint8_t		*dtb_begin;
+	uint8_t		*dtb_end;
+	int		expected_result;
+	int		ovcs_id;
+	char		*name;
+};
+
+OVERLAY_INFO_EXTERN(overlay_base);
+OVERLAY_INFO_EXTERN(overlay);
+OVERLAY_INFO_EXTERN(overlay_0);
+OVERLAY_INFO_EXTERN(overlay_1);
+OVERLAY_INFO_EXTERN(overlay_2);
+OVERLAY_INFO_EXTERN(overlay_3);
+OVERLAY_INFO_EXTERN(overlay_4);
+OVERLAY_INFO_EXTERN(overlay_5);
+OVERLAY_INFO_EXTERN(overlay_6);
+OVERLAY_INFO_EXTERN(overlay_7);
+OVERLAY_INFO_EXTERN(overlay_8);
+OVERLAY_INFO_EXTERN(overlay_9);
+OVERLAY_INFO_EXTERN(overlay_10);
+OVERLAY_INFO_EXTERN(overlay_11);
+OVERLAY_INFO_EXTERN(overlay_12);
+OVERLAY_INFO_EXTERN(overlay_13);
+OVERLAY_INFO_EXTERN(overlay_15);
+OVERLAY_INFO_EXTERN(overlay_16);
+OVERLAY_INFO_EXTERN(overlay_17);
+OVERLAY_INFO_EXTERN(overlay_18);
+OVERLAY_INFO_EXTERN(overlay_19);
+OVERLAY_INFO_EXTERN(overlay_20);
+OVERLAY_INFO_EXTERN(overlay_gpio_01);
+OVERLAY_INFO_EXTERN(overlay_gpio_02a);
+OVERLAY_INFO_EXTERN(overlay_gpio_02b);
+OVERLAY_INFO_EXTERN(overlay_gpio_03);
+OVERLAY_INFO_EXTERN(overlay_gpio_04a);
+OVERLAY_INFO_EXTERN(overlay_gpio_04b);
+OVERLAY_INFO_EXTERN(overlay_bad_add_dup_node);
+OVERLAY_INFO_EXTERN(overlay_bad_add_dup_prop);
+OVERLAY_INFO_EXTERN(overlay_bad_phandle);
+OVERLAY_INFO_EXTERN(overlay_bad_symbol);
+
+/* entries found by name */
+static struct overlay_info overlays[] = {
+	OVERLAY_INFO(overlay_base, -9999),
+	OVERLAY_INFO(overlay, 0),
+	OVERLAY_INFO(overlay_0, 0),
+	OVERLAY_INFO(overlay_1, 0),
+	OVERLAY_INFO(overlay_2, 0),
+	OVERLAY_INFO(overlay_3, 0),
+	OVERLAY_INFO(overlay_4, 0),
+	OVERLAY_INFO(overlay_5, 0),
+	OVERLAY_INFO(overlay_6, 0),
+	OVERLAY_INFO(overlay_7, 0),
+	OVERLAY_INFO(overlay_8, 0),
+	OVERLAY_INFO(overlay_9, 0),
+	OVERLAY_INFO(overlay_10, 0),
+	OVERLAY_INFO(overlay_11, 0),
+	OVERLAY_INFO(overlay_12, 0),
+	OVERLAY_INFO(overlay_13, 0),
+	OVERLAY_INFO(overlay_15, 0),
+	OVERLAY_INFO(overlay_16, -EBUSY),
+	OVERLAY_INFO(overlay_17, -EEXIST),
+	OVERLAY_INFO(overlay_18, 0),
+	OVERLAY_INFO(overlay_19, 0),
+	OVERLAY_INFO(overlay_20, 0),
+	OVERLAY_INFO(overlay_gpio_01, 0),
+	OVERLAY_INFO(overlay_gpio_02a, 0),
+	OVERLAY_INFO(overlay_gpio_02b, 0),
+	OVERLAY_INFO(overlay_gpio_03, 0),
+	OVERLAY_INFO(overlay_gpio_04a, 0),
+	OVERLAY_INFO(overlay_gpio_04b, 0),
+	OVERLAY_INFO(overlay_bad_add_dup_node, -EINVAL),
+	OVERLAY_INFO(overlay_bad_add_dup_prop, -EINVAL),
+	OVERLAY_INFO(overlay_bad_phandle, -EINVAL),
+	OVERLAY_INFO(overlay_bad_symbol, -EINVAL),
+	/* end marker */
+	{.dtb_begin = NULL, .dtb_end = NULL, .expected_result = 0, .name = NULL}
+};
+
+static struct device_node *overlay_base_root;
+
+static void * __init dt_alloc_memory(u64 size, u64 align)
+{
+	void *ptr = memblock_alloc(size, align);
+
+	if (!ptr)
+		panic("%s: Failed to allocate %llu bytes align=0x%llx\n",
+		      __func__, size, align);
+
+	return ptr;
+}
+
+/*
+ * Create base device tree for the overlay unittest.
+ *
+ * This is called from very early boot code.
+ *
+ * Do as much as possible the same way as done in __unflatten_device_tree
+ * and other early boot steps for the normal FDT so that the overlay base
+ * unflattened tree will have the same characteristics as the real tree
+ * (such as having memory allocated by the early allocator).  The goal
+ * is to test "the real thing" as much as possible, and test "test setup
+ * code" as little as possible.
+ *
+ * Have to stop before resolving phandles, because that uses kmalloc.
+ */
+void __init unittest_unflatten_overlay_base(void)
+{
+	struct overlay_info *info;
+	u32 data_size;
+	void *new_fdt;
+	u32 size;
+	int found = 0;
+	const char *overlay_name = "overlay_base";
+
+	for (info = overlays; info && info->name; info++) {
+		if (!strcmp(overlay_name, info->name)) {
+			found = 1;
+			break;
+		}
+	}
+	if (!found) {
+		pr_err("no overlay data for %s\n", overlay_name);
+		return;
+	}
+
+	info = &overlays[0];
+
+	if (info->expected_result != -9999) {
+		pr_err("No dtb 'overlay_base' to attach\n");
+		return;
+	}
+
+	data_size = info->dtb_end - info->dtb_begin;
+	if (!data_size) {
+		pr_err("No dtb 'overlay_base' to attach\n");
+		return;
+	}
+
+	size = fdt_totalsize(info->dtb_begin);
+	if (size != data_size) {
+		pr_err("dtb 'overlay_base' header totalsize != actual size");
+		return;
+	}
+
+	new_fdt = dt_alloc_memory(size, roundup_pow_of_two(FDT_V17_SIZE));
+	if (!new_fdt) {
+		pr_err("alloc for dtb 'overlay_base' failed");
+		return;
+	}
+
+	memcpy(new_fdt, info->dtb_begin, size);
+
+	__unflatten_device_tree(new_fdt, NULL, &overlay_base_root,
+				dt_alloc_memory, true);
+}
+
+/*
+ * The purpose of of_unittest_overlay_data_add is to add an
+ * overlay in the normal fashion.  This is a test of the whole
+ * picture, instead of testing individual elements.
+ *
+ * A secondary purpose is to be able to verify that the contents of
+ * /proc/device-tree/ contains the updated structure and values from
+ * the overlay.  That must be verified separately in user space.
+ *
+ * Return 0 on unexpected error.
+ */
+static int __init overlay_data_apply(const char *overlay_name, int *ovcs_id)
+{
+	struct overlay_info *info;
+	int found = 0;
+	int ret;
+	u32 size;
+
+	for (info = overlays; info && info->name; info++) {
+		if (!strcmp(overlay_name, info->name)) {
+			found = 1;
+			break;
+		}
+	}
+	if (!found) {
+		pr_err("no overlay data for %s\n", overlay_name);
+		return 0;
+	}
+
+	size = info->dtb_end - info->dtb_begin;
+	if (!size)
+		pr_err("no overlay data for %s\n", overlay_name);
+
+	ret = of_overlay_fdt_apply(info->dtb_begin, size, &info->ovcs_id);
+	if (ovcs_id)
+		*ovcs_id = info->ovcs_id;
+	if (ret < 0)
+		goto out;
+
+	pr_debug("%s applied\n", overlay_name);
+
+out:
+	if (ret != info->expected_result)
+		pr_err("of_overlay_fdt_apply() expected %d, ret=%d, %s\n",
+		       info->expected_result, ret, overlay_name);
+
+	return (ret == info->expected_result);
+}
+
+/*
+ * The purpose of of_unittest_overlay_high_level is to add an overlay
+ * in the normal fashion.  This is a test of the whole picture,
+ * instead of individual elements.
+ *
+ * The first part of the function is _not_ normal overlay usage; it is
+ * finishing splicing the base overlay device tree into the live tree.
+ */
+static __init void of_unittest_overlay_high_level(void)
+{
+	struct device_node *last_sibling;
+	struct device_node *np;
+	struct device_node *of_symbols;
+	struct device_node *overlay_base_symbols;
+	struct device_node **pprev;
+	struct property *prop;
+	int ret;
+
+	if (!overlay_base_root) {
+		unittest(0, "overlay_base_root not initialized\n");
+		return;
+	}
+
+	/*
+	 * Could not fixup phandles in unittest_unflatten_overlay_base()
+	 * because kmalloc() was not yet available.
+	 */
+	of_overlay_mutex_lock();
+	of_resolve_phandles(overlay_base_root);
+	of_overlay_mutex_unlock();
+
+
+	/*
+	 * do not allow overlay_base to duplicate any node already in
+	 * tree, this greatly simplifies the code
+	 */
+
+	/*
+	 * remove overlay_base_root node "__local_fixups", after
+	 * being used by of_resolve_phandles()
+	 */
+	pprev = &overlay_base_root->child;
+	for (np = overlay_base_root->child; np; np = np->sibling) {
+		if (of_node_name_eq(np, "__local_fixups__")) {
+			*pprev = np->sibling;
+			break;
+		}
+		pprev = &np->sibling;
+	}
+
+	/* remove overlay_base_root node "__symbols__" if in live tree */
+	of_symbols = of_get_child_by_name(of_root, "__symbols__");
+	if (of_symbols) {
+		/* will have to graft properties from node into live tree */
+		pprev = &overlay_base_root->child;
+		for (np = overlay_base_root->child; np; np = np->sibling) {
+			if (of_node_name_eq(np, "__symbols__")) {
+				overlay_base_symbols = np;
+				*pprev = np->sibling;
+				break;
+			}
+			pprev = &np->sibling;
+		}
+	}
+
+	for_each_child_of_node(overlay_base_root, np) {
+		struct device_node *base_child;
+		for_each_child_of_node(of_root, base_child) {
+			if (!strcmp(np->full_name, base_child->full_name)) {
+				unittest(0, "illegal node name in overlay_base %pOFn",
+					 np);
+				of_node_put(np);
+				of_node_put(base_child);
+				return;
+			}
+		}
+	}
+
+	/*
+	 * overlay 'overlay_base' is not allowed to have root
+	 * properties, so only need to splice nodes into main device tree.
+	 *
+	 * root node of *overlay_base_root will not be freed, it is lost
+	 * memory.
+	 */
+
+	for (np = overlay_base_root->child; np; np = np->sibling)
+		np->parent = of_root;
+
+	mutex_lock(&of_mutex);
+
+	for (last_sibling = np = of_root->child; np; np = np->sibling)
+		last_sibling = np;
+
+	if (last_sibling)
+		last_sibling->sibling = overlay_base_root->child;
+	else
+		of_root->child = overlay_base_root->child;
+
+	for_each_of_allnodes_from(overlay_base_root, np)
+		__of_attach_node_sysfs(np);
+
+	if (of_symbols) {
+		struct property *new_prop;
+		for_each_property_of_node(overlay_base_symbols, prop) {
+
+			new_prop = __of_prop_dup(prop, GFP_KERNEL);
+			if (!new_prop) {
+				unittest(0, "__of_prop_dup() of '%s' from overlay_base node __symbols__",
+					 prop->name);
+				goto err_unlock;
+			}
+			if (__of_add_property(of_symbols, new_prop)) {
+				kfree(new_prop->name);
+				kfree(new_prop->value);
+				kfree(new_prop);
+				/* "name" auto-generated by unflatten */
+				if (!strcmp(prop->name, "name"))
+					continue;
+				unittest(0, "duplicate property '%s' in overlay_base node __symbols__",
+					 prop->name);
+				goto err_unlock;
+			}
+			if (__of_add_property_sysfs(of_symbols, new_prop)) {
+				unittest(0, "unable to add property '%s' in overlay_base node __symbols__ to sysfs",
+					 prop->name);
+				goto err_unlock;
+			}
+		}
+	}
+
+	mutex_unlock(&of_mutex);
+
+
+	/* now do the normal overlay usage test */
+
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/substation@100/status");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/fairway-1/status");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/fairway-1/ride@100/track@30/incline-up");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/fairway-1/ride@100/track@40/incline-up");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/lights@40000/status");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/lights@40000/color");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/lights@40000/rate");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /__symbols__/hvac_2");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /__symbols__/ride_200");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /__symbols__/ride_200_left");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /__symbols__/ride_200_right");
+
+	ret = overlay_data_apply("overlay", NULL);
+
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /__symbols__/ride_200_right");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /__symbols__/ride_200_left");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /__symbols__/ride_200");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /__symbols__/hvac_2");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/lights@40000/rate");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/lights@40000/color");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/lights@40000/status");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/fairway-1/ride@100/track@40/incline-up");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/fairway-1/ride@100/track@30/incline-up");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/fairway-1/status");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: WARNING: memory leak will occur if overlay removed, property: /testcase-data-2/substation@100/status");
+
+	unittest(ret, "Adding overlay 'overlay' failed\n");
+
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: ERROR: multiple fragments add and/or delete node /testcase-data-2/substation@100/motor-1/controller");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: ERROR: multiple fragments add, update, and/or delete property /testcase-data-2/substation@100/motor-1/controller/name");
+
+	unittest(overlay_data_apply("overlay_bad_add_dup_node", NULL),
+		 "Adding overlay 'overlay_bad_add_dup_node' failed\n");
+
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: ERROR: multiple fragments add, update, and/or delete property /testcase-data-2/substation@100/motor-1/controller/name");
+	EXPECT_END(KERN_ERR,
+		   "OF: overlay: ERROR: multiple fragments add and/or delete node /testcase-data-2/substation@100/motor-1/controller");
+
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: ERROR: multiple fragments add and/or delete node /testcase-data-2/substation@100/motor-1/electric");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: ERROR: multiple fragments add, update, and/or delete property /testcase-data-2/substation@100/motor-1/electric/rpm_avail");
+	EXPECT_BEGIN(KERN_ERR,
+		     "OF: overlay: ERROR: multiple fragments add, update, and/or delete property /testcase-data-2/substation@100/motor-1/electric/name");
+
+	unittest(overlay_data_apply("overlay_bad_add_dup_prop", NULL),
+		 "Adding overlay 'overlay_bad_add_dup_prop' failed\n");
+
+	EXPECT_END(KERN_ERR,
+		     "OF: overlay: ERROR: multiple fragments add, update, and/or delete property /testcase-data-2/substation@100/motor-1/electric/name");
+	EXPECT_END(KERN_ERR,
+		     "OF: overlay: ERROR: multiple fragments add, update, and/or delete property /testcase-data-2/substation@100/motor-1/electric/rpm_avail");
+	EXPECT_END(KERN_ERR,
+		     "OF: overlay: ERROR: multiple fragments add and/or delete node /testcase-data-2/substation@100/motor-1/electric");
+
+	unittest(overlay_data_apply("overlay_bad_phandle", NULL),
+		 "Adding overlay 'overlay_bad_phandle' failed\n");
+
+	unittest(overlay_data_apply("overlay_bad_symbol", NULL),
+		 "Adding overlay 'overlay_bad_symbol' failed\n");
+
+	return;
+
+err_unlock:
+	mutex_unlock(&of_mutex);
+}
+
+#else
+
+static inline __init void of_unittest_overlay_high_level(void) {}
+
+#endif
+
+static int __init of_unittest(void)
+{
+	struct device_node *np;
+	int res;
+
+	pr_info("start of unittest - you will see error messages\n");
+
+	/* Taint the kernel so we know we've run tests. */
+	add_taint(TAINT_TEST, LOCKDEP_STILL_OK);
+
+	/* adding data for unittest */
+
+	if (IS_ENABLED(CONFIG_UML))
+		unittest_unflatten_overlay_base();
+
+	res = unittest_data_add();
+	if (res)
+		return res;
+	if (!of_aliases)
+		of_aliases = of_find_node_by_path("/aliases");
+
+	np = of_find_node_by_path("/testcase-data/phandle-tests/consumer-a");
+	if (!np) {
+		pr_info("No testcase data in device tree; not running tests\n");
+		return 0;
+	}
+	of_node_put(np);
+
+	of_unittest_check_tree_linkage();
+	of_unittest_check_phandles();
+	of_unittest_find_node_by_name();
+	of_unittest_dynamic();
+	of_unittest_parse_phandle_with_args();
+	of_unittest_parse_phandle_with_args_map();
+	of_unittest_printf();
+	of_unittest_property_string();
+	of_unittest_property_copy();
+	of_unittest_changeset();
+	of_unittest_parse_interrupts();
+	of_unittest_parse_interrupts_extended();
+	of_unittest_dma_get_max_cpu_address();
+	of_unittest_parse_dma_ranges();
+	of_unittest_pci_dma_ranges();
+	of_unittest_match_node();
+	of_unittest_platform_populate();
+	of_unittest_overlay();
+
+	/* Double check linkage after removing testcase data */
+	of_unittest_check_tree_linkage();
+
+	of_unittest_overlay_high_level();
+
+	pr_info("end of unittest - %i passed, %i failed\n",
+		unittest_results.passed, unittest_results.failed);
+
+	return 0;
+}
+late_initcall(of_unittest);