summaryrefslogtreecommitdiffstats
path: root/drivers/of/fdt.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/of/fdt.c')
-rw-r--r--drivers/of/fdt.c1398
1 files changed, 1398 insertions, 0 deletions
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 */