// SPDX-License-Identifier: GPL-2.0
/*
* Functions for working with the Flattened Device Tree data format
*
* Copyright 2009 Benjamin Herrenschmidt, IBM Corp
* [email protected]
*/
#define pr_fmt(fmt) "OF: fdt: " fmt
#include <linux/acpi.h>
#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/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"
/*
* __dtb_empty_root_begin[] and __dtb_empty_root_end[] magically created by
* cmd_wrap_S_dtb in scripts/Makefile.dtbs
*/
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
*
* 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 cell_size = sizeof(uint32_t)*(dt_root_addr_cells + dt_root_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);
}
}
}
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;
/*
* 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;
fdt_scan_reserved_mem();
fdt_reserve_elfcorehdr();
/* 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_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)
{
/*
* __va() is not yet available this early on some platforms. In that
* case, the platform uses phys_initrd_start/phys_initrd_size instead
* and does the VA conversion itself.
*/
if (!IS_ENABLED(CONFIG_ARM64) &&
!(IS_ENABLED(CONFIG_RISCV) && IS_ENABLED(CONFIG_64BIT))) {
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, ®);
size = dt_mem_next_cell(dt_root_size_cells, ®);
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));
/* Initialize {size,address}-cells info */
early_init_dt_scan_root();
return true;
}
void __init early_init_dt_scan_nodes(void)
{
int rc;
/* 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;
}
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
*
* 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)
{
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 */
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)
{
if (initial_boot_params)
initial_boot_params = copy_device_tree(initial_boot_params);
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 */
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