Merging upstream version 6.9.7.

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

13 files changed, 380 insertions, 214 deletions

diff --git a/drivers/of/.kunitconfig b/drivers/of/.kunitconfig
new file mode 100644
index 0000000000..5a8fee1197
--- /dev/null
+++ b/drivers/of/.kunitconfig
@@ -0,0 +1,3 @@
+CONFIG_KUNIT=y
+CONFIG_OF=y
+CONFIG_OF_KUNIT_TEST=y
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index da9826accb..dd726c7056 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -14,9 +14,8 @@ if OF
 
 config OF_UNITTEST
 	bool "Device Tree runtime unit tests"
-	depends on !SPARC
+	depends on OF_EARLY_FLATTREE
 	select IRQ_DOMAIN
-	select OF_EARLY_FLATTREE
 	select OF_RESOLVE
 	help
 	  This option builds in test cases for the device tree infrastructure
@@ -37,6 +36,15 @@ config OF_UNITTEST
 
 	  If unsure, say N here. This option is not safe to enable.
 
+config OF_KUNIT_TEST
+	tristate "Devicetree KUnit Test" if !KUNIT_ALL_TESTS
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  This option builds KUnit unit tests for device tree infrastructure.
+
+	  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
@@ -54,7 +62,7 @@ config OF_FLATTREE
 	select CRC32
 
 config OF_EARLY_FLATTREE
-	bool
+	def_bool OF && !(SPARC || ALPHA || HEXAGON || M68K || PARISC || S390)
 	select DMA_DECLARE_COHERENT if HAS_DMA && HAS_IOMEM
 	select OF_FLATTREE
 
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index eff6248545..251d335321 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -2,7 +2,7 @@
 obj-y = base.o cpu.o device.o module.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_FLATTREE) += fdt.o empty_root.dtb.o
 obj-$(CONFIG_OF_EARLY_FLATTREE) += fdt_address.o
 obj-$(CONFIG_OF_PROMTREE) += pdt.o
 obj-$(CONFIG_OF_ADDRESS)  += address.o
@@ -19,4 +19,6 @@ obj-y	+= kexec.o
 endif
 endif
 
+obj-$(CONFIG_OF_KUNIT_TEST) += of_test.o
+
 obj-$(CONFIG_OF_UNITTEST) += unittest-data/
diff --git a/drivers/of/base.c b/drivers/of/base.c
index b0ad8fc06e..8856c67c46 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -395,25 +395,57 @@ int of_device_compatible_match(const struct device_node *device,
 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.
+ * of_machine_compatible_match - Test root of device tree against a compatible array
+ * @compats: NULL terminated array of compatible strings to look for in root node's compatible property.
  *
- * Return: A positive integer if the root node has the given value in its
+ * Returns true if the root node has any of the given compatible values in its
  * compatible property.
  */
-int of_machine_is_compatible(const char *compat)
+bool of_machine_compatible_match(const char *const *compats)
 {
 	struct device_node *root;
 	int rc = 0;
 
 	root = of_find_node_by_path("/");
 	if (root) {
-		rc = of_device_is_compatible(root, compat);
+		rc = of_device_compatible_match(root, compats);
 		of_node_put(root);
 	}
-	return rc;
+
+	return rc != 0;
+}
+EXPORT_SYMBOL(of_machine_compatible_match);
+
+static bool __of_device_is_status(const struct device_node *device,
+				  const char * const*strings)
+{
+	const char *status;
+	int statlen;
+
+	if (!device)
+		return false;
+
+	status = __of_get_property(device, "status", &statlen);
+	if (status == NULL)
+		return false;
+
+	if (statlen > 0) {
+		while (*strings) {
+			unsigned int len = strlen(*strings);
+
+			if ((*strings)[len - 1] == '-') {
+				if (!strncmp(status, *strings, len))
+					return true;
+			} else {
+				if (!strcmp(status, *strings))
+					return true;
+			}
+			strings++;
+		}
+	}
+
+	return false;
 }
-EXPORT_SYMBOL(of_machine_is_compatible);
 
 /**
  *  __of_device_is_available - check if a device is available for use
@@ -425,22 +457,27 @@ EXPORT_SYMBOL(of_machine_is_compatible);
  */
 static bool __of_device_is_available(const struct device_node *device)
 {
-	const char *status;
-	int statlen;
+	static const char * const ok[] = {"okay", "ok", NULL};
 
 	if (!device)
 		return false;
 
-	status = __of_get_property(device, "status", &statlen);
-	if (status == NULL)
-		return true;
+	return !__of_get_property(device, "status", NULL) ||
+		__of_device_is_status(device, ok);
+}
 
-	if (statlen > 0) {
-		if (!strcmp(status, "okay") || !strcmp(status, "ok"))
-			return true;
-	}
+/**
+ *  __of_device_is_reserved - check if a device is reserved
+ *
+ *  @device: Node to check for availability, with locks already held
+ *
+ *  Return: True if the status property is set to "reserved", false otherwise
+ */
+static bool __of_device_is_reserved(const struct device_node *device)
+{
+	static const char * const reserved[] = {"reserved", NULL};
 
-	return false;
+	return __of_device_is_status(device, reserved);
 }
 
 /**
@@ -474,16 +511,9 @@ EXPORT_SYMBOL(of_device_is_available);
  */
 static bool __of_device_is_fail(const struct device_node *device)
 {
-	const char *status;
+	static const char * const fail[] = {"fail", "fail-", NULL};
 
-	if (!device)
-		return false;
-
-	status = __of_get_property(device, "status", NULL);
-	if (status == NULL)
-		return false;
-
-	return !strcmp(status, "fail") || !strncmp(status, "fail-", 5);
+	return __of_device_is_status(device, fail);
 }
 
 /**
@@ -597,16 +627,9 @@ struct device_node *of_get_next_child(const struct device_node *node,
 }
 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)
+static struct device_node *of_get_next_status_child(const struct device_node *node,
+						    struct device_node *prev,
+						    bool (*checker)(const struct device_node *))
 {
 	struct device_node *next;
 	unsigned long flags;
@@ -617,7 +640,7 @@ struct device_node *of_get_next_available_child(const struct device_node *node,
 	raw_spin_lock_irqsave(&devtree_lock, flags);
 	next = prev ? prev->sibling : node->child;
 	for (; next; next = next->sibling) {
-		if (!__of_device_is_available(next))
+		if (!checker(next))
 			continue;
 		if (of_node_get(next))
 			break;
@@ -626,9 +649,38 @@ struct device_node *of_get_next_available_child(const struct device_node *node,
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 	return next;
 }
+
+/**
+ * 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)
+{
+	return of_get_next_status_child(node, prev, __of_device_is_available);
+}
 EXPORT_SYMBOL(of_get_next_available_child);
 
 /**
+ * of_get_next_reserved_child - Find the next reserved 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_reserved_child(const struct device_node *node,
+						struct device_node *prev)
+{
+	return of_get_next_status_child(node, prev, __of_device_is_reserved);
+}
+EXPORT_SYMBOL(of_get_next_reserved_child);
+
+/**
  * of_get_next_cpu_node - Iterate on cpu nodes
  * @prev:	previous child of the /cpus node, or NULL to get first
  *
@@ -1345,8 +1397,8 @@ int of_parse_phandle_with_args_map(const struct device_node *np,
 	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 };
+	static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = cpu_to_be32(~0) };
+	static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = cpu_to_be32(0) };
 	__be32 initial_match_array[MAX_PHANDLE_ARGS];
 	const __be32 *match_array = initial_match_array;
 	int i, ret, map_len, match;
diff --git a/drivers/of/empty_root.dts b/drivers/of/empty_root.dts
new file mode 100644
index 0000000000..cf9e97a60f
--- /dev/null
+++ b/drivers/of/empty_root.dts
@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/dts-v1/;
+
+/ {
+
+};
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index bf502ba8da..a8a04f2791 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -8,6 +8,7 @@
 
 #define pr_fmt(fmt)	"OF: fdt: " fmt
 
+#include <linux/acpi.h>
 #include <linux/crash_dump.h>
 #include <linux/crc32.h>
 #include <linux/kernel.h>
@@ -16,7 +17,6 @@
 #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>
@@ -33,6 +33,13 @@
 #include "of_private.h"
 
 /*
+ * __dtb_empty_root_begin[] and __dtb_empty_root_end[] magically created by
+ * cmd_dt_S_dtb in scripts/Makefile.lib
+ */
+extern uint8_t __dtb_empty_root_begin[];
+extern uint8_t __dtb_empty_root_end[];
+
+/*
  * of_fdt_limit_memory - limit the number of regions in the /memory node
  * @limit: maximum entries
  *
@@ -80,7 +87,7 @@ void __init of_fdt_limit_memory(int limit)
 	}
 }
 
-static bool of_fdt_device_is_available(const void *blob, unsigned long node)
+bool of_fdt_device_is_available(const void *blob, unsigned long node)
 {
 	const char *status = fdt_getprop(blob, node, "status", NULL);
 
@@ -476,126 +483,6 @@ void *initial_boot_params __ro_after_init;
 
 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
  *
@@ -1318,6 +1205,21 @@ bool __init early_init_dt_scan(void *params)
 	return true;
 }
 
+static void *__init copy_device_tree(void *fdt)
+{
+	int size;
+	void *dt;
+
+	size = fdt_totalsize(fdt);
+	dt = early_init_dt_alloc_memory_arch(size,
+					     roundup_pow_of_two(FDT_V17_SIZE));
+
+	if (dt)
+		memcpy(dt, fdt, size);
+
+	return dt;
+}
+
 /**
  * unflatten_device_tree - create tree of device_nodes from flat blob
  *
@@ -1328,7 +1230,29 @@ bool __init early_init_dt_scan(void *params)
  */
 void __init unflatten_device_tree(void)
 {
-	__unflatten_device_tree(initial_boot_params, NULL, &of_root,
+	void *fdt = initial_boot_params;
+
+	/* Don't use the bootloader provided DTB if ACPI is enabled */
+	if (!acpi_disabled)
+		fdt = NULL;
+
+	/*
+	 * Populate an empty root node when ACPI is enabled or bootloader
+	 * doesn't provide one.
+	 */
+	if (!fdt) {
+		fdt = (void *) __dtb_empty_root_begin;
+		/* fdt_totalsize() will be used for copy size */
+		if (fdt_totalsize(fdt) >
+		    __dtb_empty_root_end - __dtb_empty_root_begin) {
+			pr_err("invalid size in dtb_empty_root\n");
+			return;
+		}
+		of_fdt_crc32 = crc32_be(~0, fdt, fdt_totalsize(fdt));
+		fdt = copy_device_tree(fdt);
+	}
+
+	__unflatten_device_tree(fdt, NULL, &of_root,
 				early_init_dt_alloc_memory_arch, false);
 
 	/* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
@@ -1350,22 +1274,9 @@ void __init unflatten_device_tree(void)
  */
 void __init unflatten_and_copy_device_tree(void)
 {
-	int size;
-	void *dt;
+	if (initial_boot_params)
+		initial_boot_params = copy_device_tree(initial_boot_params);
 
-	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();
 }
 
diff --git a/drivers/of/kexec.c b/drivers/of/kexec.c
index 68278340ce..9ccde2fd77 100644
--- a/drivers/of/kexec.c
+++ b/drivers/of/kexec.c
@@ -395,6 +395,7 @@ void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
 		if (ret)
 			goto out;
 
+#ifdef CONFIG_CRASH_DUMP
 		/* add linux,usable-memory-range */
 		ret = fdt_appendprop_addrrange(fdt, 0, chosen_node,
 				"linux,usable-memory-range", crashk_res.start,
@@ -410,6 +411,7 @@ void *of_kexec_alloc_and_setup_fdt(const struct kimage *image,
 			if (ret)
 				goto out;
 		}
+#endif
 	}
 
 	/* add bootargs */
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index f38397c7b5..485483524b 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -175,8 +175,9 @@ static inline struct device_node *__of_get_dma_parent(const struct device_node *
 }
 #endif
 
+int fdt_scan_reserved_mem(void);
 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);
+
+bool of_fdt_device_is_available(const void *blob, unsigned long node);
 
 #endif /* _LINUX_OF_PRIVATE_H */
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 7ec94cfcbd..8236ecae29 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -12,6 +12,7 @@
 #define pr_fmt(fmt)	"OF: reserved mem: " fmt
 
 #include <linux/err.h>
+#include <linux/libfdt.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
 #include <linux/of_platform.h>
@@ -58,8 +59,8 @@ static int __init early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
 /*
  * 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)
+static 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];
 
@@ -77,6 +78,126 @@ void __init fdt_reserved_mem_save_node(unsigned long node, const char *uname,
 	return;
 }
 
+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
+ */
+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;
+}
+
 /*
  * __reserved_mem_alloc_in_range() - allocate reserved memory described with
  *	'alloc-ranges'. Choose bottom-up/top-down depending on nearby existing
diff --git a/drivers/of/of_test.c b/drivers/of/of_test.c
new file mode 100644
index 0000000000..a9301d293f
--- /dev/null
+++ b/drivers/of/of_test.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit tests for OF APIs
+ */
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include <kunit/test.h>
+
+/*
+ * Test that the root node "/" can be found by path.
+ */
+static void of_dtb_root_node_found_by_path(struct kunit *test)
+{
+	struct device_node *np;
+
+	np = of_find_node_by_path("/");
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, np);
+	of_node_put(np);
+}
+
+/*
+ * Test that the 'of_root' global variable is always populated when DT code is
+ * enabled. Remove this test once of_root is removed from global access.
+ */
+static void of_dtb_root_node_populates_of_root(struct kunit *test)
+{
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, of_root);
+}
+
+static struct kunit_case of_dtb_test_cases[] = {
+	KUNIT_CASE(of_dtb_root_node_found_by_path),
+	KUNIT_CASE(of_dtb_root_node_populates_of_root),
+	{}
+};
+
+static int of_dtb_test_init(struct kunit *test)
+{
+	if (!IS_ENABLED(CONFIG_OF_EARLY_FLATTREE))
+		kunit_skip(test, "requires CONFIG_OF_EARLY_FLATTREE");
+
+	return 0;
+}
+
+/*
+ * Test suite to confirm a DTB is loaded.
+ */
+static struct kunit_suite of_dtb_suite = {
+	.name = "of_dtb",
+	.test_cases = of_dtb_test_cases,
+	.init = of_dtb_test_init,
+};
+
+kunit_test_suites(
+	&of_dtb_suite,
+);
+MODULE_LICENSE("GPL");
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index b7708a06dc..389d4ea6bf 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -166,6 +166,8 @@ static struct platform_device *of_platform_device_create_pdata(
 {
 	struct platform_device *dev;
 
+	pr_debug("create platform device: %pOF\n", np);
+
 	if (!of_device_is_available(np) ||
 	    of_node_test_and_set_flag(np, OF_POPULATED))
 		return NULL;
@@ -510,9 +512,6 @@ static int __init of_platform_default_populate_init(void)
 
 	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;
diff --git a/drivers/of/property.c b/drivers/of/property.c
index fa8cd33be1..a6358ee99b 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -665,7 +665,7 @@ struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
 		of_node_put(node);
 
 		if (!port) {
-			pr_err("graph: no port node found in %pOF\n", parent);
+			pr_debug("graph: no port node found in %pOF\n", parent);
 			return NULL;
 		}
 	} else {
@@ -814,10 +814,16 @@ struct device_node *of_graph_get_remote_port(const struct device_node *node)
 }
 EXPORT_SYMBOL(of_graph_get_remote_port);
 
-int of_graph_get_endpoint_count(const struct device_node *np)
+/**
+ * of_graph_get_endpoint_count() - get the number of endpoints in a device node
+ * @np: parent device node containing ports and endpoints
+ *
+ * Return: count of endpoint of this device node
+ */
+unsigned int of_graph_get_endpoint_count(const struct device_node *np)
 {
 	struct device_node *endpoint;
-	int num = 0;
+	unsigned int num = 0;
 
 	for_each_endpoint_of_node(np, endpoint)
 		num++;
@@ -1066,7 +1072,8 @@ of_fwnode_device_get_match_data(const struct fwnode_handle *fwnode,
 }
 
 static void of_link_to_phandle(struct device_node *con_np,
-			      struct device_node *sup_np)
+			      struct device_node *sup_np,
+			      u8 flags)
 {
 	struct device_node *tmp_np = of_node_get(sup_np);
 
@@ -1085,7 +1092,7 @@ static void of_link_to_phandle(struct device_node *con_np,
 		tmp_np = of_get_next_parent(tmp_np);
 	}
 
-	fwnode_link_add(of_fwnode_handle(con_np), of_fwnode_handle(sup_np));
+	fwnode_link_add(of_fwnode_handle(con_np), of_fwnode_handle(sup_np), flags);
 }
 
 /**
@@ -1198,6 +1205,8 @@ static struct device_node *parse_##fname(struct device_node *np,	     \
  *		 to a struct device, implement this ops so fw_devlink can use it
  *		 to find the true consumer.
  * @optional: Describes whether a supplier is mandatory or not
+ * @fwlink_flags: Optional fwnode link flags to use when creating a fwnode link
+ *		  for this property.
  *
  * Returns:
  * parse_prop() return values are
@@ -1210,6 +1219,7 @@ struct supplier_bindings {
 					  const char *prop_name, int index);
 	struct device_node *(*get_con_dev)(struct device_node *np);
 	bool optional;
+	u8 fwlink_flags;
 };
 
 DEFINE_SIMPLE_PROP(clocks, "clocks", "#clock-cells")
@@ -1217,6 +1227,7 @@ 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-channels", "#io-channel-cells")
+DEFINE_SIMPLE_PROP(io_backends, "io-backends", "#io-backend-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")
@@ -1240,6 +1251,7 @@ DEFINE_SIMPLE_PROP(leds, "leds", NULL)
 DEFINE_SIMPLE_PROP(backlight, "backlight", NULL)
 DEFINE_SIMPLE_PROP(panel, "panel", NULL)
 DEFINE_SIMPLE_PROP(msi_parent, "msi-parent", "#msi-cells")
+DEFINE_SIMPLE_PROP(post_init_providers, "post-init-providers", NULL)
 DEFINE_SUFFIX_PROP(regulators, "-supply", NULL)
 DEFINE_SUFFIX_PROP(gpio, "-gpio", "#gpio-cells")
 
@@ -1317,6 +1329,7 @@ static const struct supplier_bindings of_supplier_bindings[] = {
 	{ .parse_prop = parse_iommu_maps, .optional = true, },
 	{ .parse_prop = parse_mboxes, },
 	{ .parse_prop = parse_io_channels, },
+	{ .parse_prop = parse_io_backends, },
 	{ .parse_prop = parse_interrupt_parent, },
 	{ .parse_prop = parse_dmas, .optional = true, },
 	{ .parse_prop = parse_power_domains, },
@@ -1349,6 +1362,10 @@ static const struct supplier_bindings of_supplier_bindings[] = {
 	{ .parse_prop = parse_regulators, },
 	{ .parse_prop = parse_gpio, },
 	{ .parse_prop = parse_gpios, },
+	{
+		.parse_prop = parse_post_init_providers,
+		.fwlink_flags = FWLINK_FLAG_IGNORE,
+	},
 	{}
 };
 
@@ -1393,7 +1410,7 @@ static int of_link_property(struct device_node *con_np, const char *prop_name)
 					: of_node_get(con_np);
 			matched = true;
 			i++;
-			of_link_to_phandle(con_dev_np, phandle);
+			of_link_to_phandle(con_dev_np, phandle, s->fwlink_flags);
 			of_node_put(phandle);
 			of_node_put(con_dev_np);
 		}
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index d7593bde2d..6b5c36b6a7 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -239,27 +239,22 @@ static void __init of_unittest_dynamic(void)
 
 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) {
+	for_each_child_of_node_scoped(np, child) {
 		if (child->parent != np) {
 			pr_err("Child node %pOFn links to wrong parent %pOFn\n",
 				 child, np);
-			rc = -EINVAL;
-			goto put_child;
+			return -EINVAL;
 		}
 
 		rc = of_unittest_check_node_linkage(child);
 		if (rc < 0)
-			goto put_child;
+			return rc;
 		count += rc;
 	}
 
 	return count + 1;
-put_child:
-	of_node_put(child);
-	return rc;
 }
 
 static void __init of_unittest_check_tree_linkage(void)
@@ -1750,20 +1745,16 @@ static int __init unittest_data_add(void)
 		return -EINVAL;
 	}
 
+	/* attach the sub-tree to live tree */
 	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;
+		pr_warn("%s: no live tree to attach sub-tree\n", __func__);
+		kfree(unittest_data);
+		return -ENODEV;
 	}
 
 	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;
@@ -4093,10 +4084,6 @@ static int __init of_unittest(void)
 	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;