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1// SPDX-License-Identifier: GPL-2.02/*3 * Functions for working with the Flattened Device Tree data format4 *5 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp6 * benh@kernel.crashing.org7 */8 9#define pr_fmt(fmt) "OF: fdt: " fmt10 11#include <linux/acpi.h>12#include <linux/crash_dump.h>13#include <linux/crc32.h>14#include <linux/kernel.h>15#include <linux/initrd.h>16#include <linux/memblock.h>17#include <linux/mutex.h>18#include <linux/of.h>19#include <linux/of_fdt.h>20#include <linux/sizes.h>21#include <linux/string.h>22#include <linux/errno.h>23#include <linux/slab.h>24#include <linux/libfdt.h>25#include <linux/debugfs.h>26#include <linux/serial_core.h>27#include <linux/sysfs.h>28#include <linux/random.h>29 30#include <asm/setup.h> /* for COMMAND_LINE_SIZE */31#include <asm/page.h>32 33#include "of_private.h"34 35/*36 * __dtb_empty_root_begin[] and __dtb_empty_root_end[] magically created by37 * cmd_wrap_S_dtb in scripts/Makefile.dtbs38 */39extern uint8_t __dtb_empty_root_begin[];40extern uint8_t __dtb_empty_root_end[];41 42/*43 * of_fdt_limit_memory - limit the number of regions in the /memory node44 * @limit: maximum entries45 *46 * Adjust the flattened device tree to have at most 'limit' number of47 * memory entries in the /memory node. This function may be called48 * any time after initial_boot_param is set.49 */50void __init of_fdt_limit_memory(int limit)51{52 int memory;53 int len;54 const void *val;55 int cell_size = sizeof(uint32_t)*(dt_root_addr_cells + dt_root_size_cells);56 57 memory = fdt_path_offset(initial_boot_params, "/memory");58 if (memory > 0) {59 val = fdt_getprop(initial_boot_params, memory, "reg", &len);60 if (len > limit*cell_size) {61 len = limit*cell_size;62 pr_debug("Limiting number of entries to %d\n", limit);63 fdt_setprop(initial_boot_params, memory, "reg", val,64 len);65 }66 }67}68 69bool of_fdt_device_is_available(const void *blob, unsigned long node)70{71 const char *status = fdt_getprop(blob, node, "status", NULL);72 73 if (!status)74 return true;75 76 if (!strcmp(status, "ok") || !strcmp(status, "okay"))77 return true;78 79 return false;80}81 82static void *unflatten_dt_alloc(void **mem, unsigned long size,83 unsigned long align)84{85 void *res;86 87 *mem = PTR_ALIGN(*mem, align);88 res = *mem;89 *mem += size;90 91 return res;92}93 94static void populate_properties(const void *blob,95 int offset,96 void **mem,97 struct device_node *np,98 const char *nodename,99 bool dryrun)100{101 struct property *pp, **pprev = NULL;102 int cur;103 bool has_name = false;104 105 pprev = &np->properties;106 for (cur = fdt_first_property_offset(blob, offset);107 cur >= 0;108 cur = fdt_next_property_offset(blob, cur)) {109 const __be32 *val;110 const char *pname;111 u32 sz;112 113 val = fdt_getprop_by_offset(blob, cur, &pname, &sz);114 if (!val) {115 pr_warn("Cannot locate property at 0x%x\n", cur);116 continue;117 }118 119 if (!pname) {120 pr_warn("Cannot find property name at 0x%x\n", cur);121 continue;122 }123 124 if (!strcmp(pname, "name"))125 has_name = true;126 127 pp = unflatten_dt_alloc(mem, sizeof(struct property),128 __alignof__(struct property));129 if (dryrun)130 continue;131 132 /* We accept flattened tree phandles either in133 * ePAPR-style "phandle" properties, or the134 * legacy "linux,phandle" properties. If both135 * appear and have different values, things136 * will get weird. Don't do that.137 */138 if (!strcmp(pname, "phandle") ||139 !strcmp(pname, "linux,phandle")) {140 if (!np->phandle)141 np->phandle = be32_to_cpup(val);142 }143 144 /* And we process the "ibm,phandle" property145 * used in pSeries dynamic device tree146 * stuff147 */148 if (!strcmp(pname, "ibm,phandle"))149 np->phandle = be32_to_cpup(val);150 151 pp->name = (char *)pname;152 pp->length = sz;153 pp->value = (__be32 *)val;154 *pprev = pp;155 pprev = &pp->next;156 }157 158 /* With version 0x10 we may not have the name property,159 * recreate it here from the unit name if absent160 */161 if (!has_name) {162 const char *p = nodename, *ps = p, *pa = NULL;163 int len;164 165 while (*p) {166 if ((*p) == '@')167 pa = p;168 else if ((*p) == '/')169 ps = p + 1;170 p++;171 }172 173 if (pa < ps)174 pa = p;175 len = (pa - ps) + 1;176 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,177 __alignof__(struct property));178 if (!dryrun) {179 pp->name = "name";180 pp->length = len;181 pp->value = pp + 1;182 *pprev = pp;183 memcpy(pp->value, ps, len - 1);184 ((char *)pp->value)[len - 1] = 0;185 pr_debug("fixed up name for %s -> %s\n",186 nodename, (char *)pp->value);187 }188 }189}190 191static int populate_node(const void *blob,192 int offset,193 void **mem,194 struct device_node *dad,195 struct device_node **pnp,196 bool dryrun)197{198 struct device_node *np;199 const char *pathp;200 int len;201 202 pathp = fdt_get_name(blob, offset, &len);203 if (!pathp) {204 *pnp = NULL;205 return len;206 }207 208 len++;209 210 np = unflatten_dt_alloc(mem, sizeof(struct device_node) + len,211 __alignof__(struct device_node));212 if (!dryrun) {213 char *fn;214 of_node_init(np);215 np->full_name = fn = ((char *)np) + sizeof(*np);216 217 memcpy(fn, pathp, len);218 219 if (dad != NULL) {220 np->parent = dad;221 np->sibling = dad->child;222 dad->child = np;223 }224 }225 226 populate_properties(blob, offset, mem, np, pathp, dryrun);227 if (!dryrun) {228 np->name = of_get_property(np, "name", NULL);229 if (!np->name)230 np->name = "<NULL>";231 }232 233 *pnp = np;234 return 0;235}236 237static void reverse_nodes(struct device_node *parent)238{239 struct device_node *child, *next;240 241 /* In-depth first */242 child = parent->child;243 while (child) {244 reverse_nodes(child);245 246 child = child->sibling;247 }248 249 /* Reverse the nodes in the child list */250 child = parent->child;251 parent->child = NULL;252 while (child) {253 next = child->sibling;254 255 child->sibling = parent->child;256 parent->child = child;257 child = next;258 }259}260 261/**262 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree263 * @blob: The parent device tree blob264 * @mem: Memory chunk to use for allocating device nodes and properties265 * @dad: Parent struct device_node266 * @nodepp: The device_node tree created by the call267 *268 * Return: The size of unflattened device tree or error code269 */270static int unflatten_dt_nodes(const void *blob,271 void *mem,272 struct device_node *dad,273 struct device_node **nodepp)274{275 struct device_node *root;276 int offset = 0, depth = 0, initial_depth = 0;277#define FDT_MAX_DEPTH 64278 struct device_node *nps[FDT_MAX_DEPTH];279 void *base = mem;280 bool dryrun = !base;281 int ret;282 283 if (nodepp)284 *nodepp = NULL;285 286 /*287 * We're unflattening device sub-tree if @dad is valid. There are288 * possibly multiple nodes in the first level of depth. We need289 * set @depth to 1 to make fdt_next_node() happy as it bails290 * immediately when negative @depth is found. Otherwise, the device291 * nodes except the first one won't be unflattened successfully.292 */293 if (dad)294 depth = initial_depth = 1;295 296 root = dad;297 nps[depth] = dad;298 299 for (offset = 0;300 offset >= 0 && depth >= initial_depth;301 offset = fdt_next_node(blob, offset, &depth)) {302 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH - 1))303 continue;304 305 if (!IS_ENABLED(CONFIG_OF_KOBJ) &&306 !of_fdt_device_is_available(blob, offset))307 continue;308 309 ret = populate_node(blob, offset, &mem, nps[depth],310 &nps[depth+1], dryrun);311 if (ret < 0)312 return ret;313 314 if (!dryrun && nodepp && !*nodepp)315 *nodepp = nps[depth+1];316 if (!dryrun && !root)317 root = nps[depth+1];318 }319 320 if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {321 pr_err("Error %d processing FDT\n", offset);322 return -EINVAL;323 }324 325 /*326 * Reverse the child list. Some drivers assumes node order matches .dts327 * node order328 */329 if (!dryrun)330 reverse_nodes(root);331 332 return mem - base;333}334 335/**336 * __unflatten_device_tree - create tree of device_nodes from flat blob337 * @blob: The blob to expand338 * @dad: Parent device node339 * @mynodes: The device_node tree created by the call340 * @dt_alloc: An allocator that provides a virtual address to memory341 * for the resulting tree342 * @detached: if true set OF_DETACHED on @mynodes343 *344 * unflattens a device-tree, creating the tree of struct device_node. It also345 * fills the "name" and "type" pointers of the nodes so the normal device-tree346 * walking functions can be used.347 *348 * Return: NULL on failure or the memory chunk containing the unflattened349 * device tree on success.350 */351void *__unflatten_device_tree(const void *blob,352 struct device_node *dad,353 struct device_node **mynodes,354 void *(*dt_alloc)(u64 size, u64 align),355 bool detached)356{357 int size;358 void *mem;359 int ret;360 361 if (mynodes)362 *mynodes = NULL;363 364 pr_debug(" -> unflatten_device_tree()\n");365 366 if (!blob) {367 pr_debug("No device tree pointer\n");368 return NULL;369 }370 371 pr_debug("Unflattening device tree:\n");372 pr_debug("magic: %08x\n", fdt_magic(blob));373 pr_debug("size: %08x\n", fdt_totalsize(blob));374 pr_debug("version: %08x\n", fdt_version(blob));375 376 if (fdt_check_header(blob)) {377 pr_err("Invalid device tree blob header\n");378 return NULL;379 }380 381 /* First pass, scan for size */382 size = unflatten_dt_nodes(blob, NULL, dad, NULL);383 if (size <= 0)384 return NULL;385 386 size = ALIGN(size, 4);387 pr_debug(" size is %d, allocating...\n", size);388 389 /* Allocate memory for the expanded device tree */390 mem = dt_alloc(size + 4, __alignof__(struct device_node));391 if (!mem)392 return NULL;393 394 memset(mem, 0, size);395 396 *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);397 398 pr_debug(" unflattening %p...\n", mem);399 400 /* Second pass, do actual unflattening */401 ret = unflatten_dt_nodes(blob, mem, dad, mynodes);402 403 if (be32_to_cpup(mem + size) != 0xdeadbeef)404 pr_warn("End of tree marker overwritten: %08x\n",405 be32_to_cpup(mem + size));406 407 if (ret <= 0)408 return NULL;409 410 if (detached && mynodes && *mynodes) {411 of_node_set_flag(*mynodes, OF_DETACHED);412 pr_debug("unflattened tree is detached\n");413 }414 415 pr_debug(" <- unflatten_device_tree()\n");416 return mem;417}418 419static void *kernel_tree_alloc(u64 size, u64 align)420{421 return kzalloc(size, GFP_KERNEL);422}423 424static DEFINE_MUTEX(of_fdt_unflatten_mutex);425 426/**427 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob428 * @blob: Flat device tree blob429 * @dad: Parent device node430 * @mynodes: The device tree created by the call431 *432 * unflattens the device-tree passed by the firmware, creating the433 * tree of struct device_node. It also fills the "name" and "type"434 * pointers of the nodes so the normal device-tree walking functions435 * can be used.436 *437 * Return: NULL on failure or the memory chunk containing the unflattened438 * device tree on success.439 */440void *of_fdt_unflatten_tree(const unsigned long *blob,441 struct device_node *dad,442 struct device_node **mynodes)443{444 void *mem;445 446 mutex_lock(&of_fdt_unflatten_mutex);447 mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,448 true);449 mutex_unlock(&of_fdt_unflatten_mutex);450 451 return mem;452}453EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);454 455/* Everything below here references initial_boot_params directly. */456int __initdata dt_root_addr_cells;457int __initdata dt_root_size_cells;458 459void *initial_boot_params __ro_after_init;460 461#ifdef CONFIG_OF_EARLY_FLATTREE462 463static u32 of_fdt_crc32;464 465/*466 * fdt_reserve_elfcorehdr() - reserves memory for elf core header467 *468 * This function reserves the memory occupied by an elf core header469 * described in the device tree. This region contains all the470 * information about primary kernel's core image and is used by a dump471 * capture kernel to access the system memory on primary kernel.472 */473static void __init fdt_reserve_elfcorehdr(void)474{475 if (!IS_ENABLED(CONFIG_CRASH_DUMP) || !elfcorehdr_size)476 return;477 478 if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) {479 pr_warn("elfcorehdr is overlapped\n");480 return;481 }482 483 memblock_reserve(elfcorehdr_addr, elfcorehdr_size);484 485 pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n",486 elfcorehdr_size >> 10, elfcorehdr_addr);487}488 489/**490 * early_init_fdt_scan_reserved_mem() - create reserved memory regions491 *492 * This function grabs memory from early allocator for device exclusive use493 * defined in device tree structures. It should be called by arch specific code494 * once the early allocator (i.e. memblock) has been fully activated.495 */496void __init early_init_fdt_scan_reserved_mem(void)497{498 int n;499 u64 base, size;500 501 if (!initial_boot_params)502 return;503 504 fdt_scan_reserved_mem();505 fdt_reserve_elfcorehdr();506 507 /* Process header /memreserve/ fields */508 for (n = 0; ; n++) {509 fdt_get_mem_rsv(initial_boot_params, n, &base, &size);510 if (!size)511 break;512 memblock_reserve(base, size);513 }514 515 fdt_init_reserved_mem();516}517 518/**519 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob520 */521void __init early_init_fdt_reserve_self(void)522{523 if (!initial_boot_params)524 return;525 526 /* Reserve the dtb region */527 memblock_reserve(__pa(initial_boot_params),528 fdt_totalsize(initial_boot_params));529}530 531/**532 * of_scan_flat_dt - scan flattened tree blob and call callback on each.533 * @it: callback function534 * @data: context data pointer535 *536 * This function is used to scan the flattened device-tree, it is537 * used to extract the memory information at boot before we can538 * unflatten the tree539 */540int __init of_scan_flat_dt(int (*it)(unsigned long node,541 const char *uname, int depth,542 void *data),543 void *data)544{545 const void *blob = initial_boot_params;546 const char *pathp;547 int offset, rc = 0, depth = -1;548 549 if (!blob)550 return 0;551 552 for (offset = fdt_next_node(blob, -1, &depth);553 offset >= 0 && depth >= 0 && !rc;554 offset = fdt_next_node(blob, offset, &depth)) {555 556 pathp = fdt_get_name(blob, offset, NULL);557 rc = it(offset, pathp, depth, data);558 }559 return rc;560}561 562/**563 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.564 * @parent: parent node565 * @it: callback function566 * @data: context data pointer567 *568 * This function is used to scan sub-nodes of a node.569 */570int __init of_scan_flat_dt_subnodes(unsigned long parent,571 int (*it)(unsigned long node,572 const char *uname,573 void *data),574 void *data)575{576 const void *blob = initial_boot_params;577 int node;578 579 fdt_for_each_subnode(node, blob, parent) {580 const char *pathp;581 int rc;582 583 pathp = fdt_get_name(blob, node, NULL);584 rc = it(node, pathp, data);585 if (rc)586 return rc;587 }588 return 0;589}590 591/**592 * of_get_flat_dt_subnode_by_name - get the subnode by given name593 *594 * @node: the parent node595 * @uname: the name of subnode596 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none597 */598 599int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)600{601 return fdt_subnode_offset(initial_boot_params, node, uname);602}603 604/*605 * of_get_flat_dt_root - find the root node in the flat blob606 */607unsigned long __init of_get_flat_dt_root(void)608{609 return 0;610}611 612/*613 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr614 *615 * This function can be used within scan_flattened_dt callback to get616 * access to properties617 */618const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,619 int *size)620{621 return fdt_getprop(initial_boot_params, node, name, size);622}623 624/**625 * of_fdt_is_compatible - Return true if given node from the given blob has626 * compat in its compatible list627 * @blob: A device tree blob628 * @node: node to test629 * @compat: compatible string to compare with compatible list.630 *631 * Return: a non-zero value on match with smaller values returned for more632 * specific compatible values.633 */634static int of_fdt_is_compatible(const void *blob,635 unsigned long node, const char *compat)636{637 const char *cp;638 int cplen;639 unsigned long l, score = 0;640 641 cp = fdt_getprop(blob, node, "compatible", &cplen);642 if (cp == NULL)643 return 0;644 while (cplen > 0) {645 score++;646 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)647 return score;648 l = strlen(cp) + 1;649 cp += l;650 cplen -= l;651 }652 653 return 0;654}655 656/**657 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list658 * @node: node to test659 * @compat: compatible string to compare with compatible list.660 */661int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)662{663 return of_fdt_is_compatible(initial_boot_params, node, compat);664}665 666/*667 * of_flat_dt_match - Return true if node matches a list of compatible values668 */669static int __init of_flat_dt_match(unsigned long node, const char *const *compat)670{671 unsigned int tmp, score = 0;672 673 if (!compat)674 return 0;675 676 while (*compat) {677 tmp = of_fdt_is_compatible(initial_boot_params, node, *compat);678 if (tmp && (score == 0 || (tmp < score)))679 score = tmp;680 compat++;681 }682 683 return score;684}685 686/*687 * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle688 */689uint32_t __init of_get_flat_dt_phandle(unsigned long node)690{691 return fdt_get_phandle(initial_boot_params, node);692}693 694const char * __init of_flat_dt_get_machine_name(void)695{696 const char *name;697 unsigned long dt_root = of_get_flat_dt_root();698 699 name = of_get_flat_dt_prop(dt_root, "model", NULL);700 if (!name)701 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);702 return name;703}704 705/**706 * of_flat_dt_match_machine - Iterate match tables to find matching machine.707 *708 * @default_match: A machine specific ptr to return in case of no match.709 * @get_next_compat: callback function to return next compatible match table.710 *711 * Iterate through machine match tables to find the best match for the machine712 * compatible string in the FDT.713 */714const void * __init of_flat_dt_match_machine(const void *default_match,715 const void * (*get_next_compat)(const char * const**))716{717 const void *data = NULL;718 const void *best_data = default_match;719 const char *const *compat;720 unsigned long dt_root;721 unsigned int best_score = ~1, score = 0;722 723 dt_root = of_get_flat_dt_root();724 while ((data = get_next_compat(&compat))) {725 score = of_flat_dt_match(dt_root, compat);726 if (score > 0 && score < best_score) {727 best_data = data;728 best_score = score;729 }730 }731 if (!best_data) {732 const char *prop;733 int size;734 735 pr_err("\n unrecognized device tree list:\n[ ");736 737 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);738 if (prop) {739 while (size > 0) {740 printk("'%s' ", prop);741 size -= strlen(prop) + 1;742 prop += strlen(prop) + 1;743 }744 }745 printk("]\n\n");746 return NULL;747 }748 749 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());750 751 return best_data;752}753 754static void __early_init_dt_declare_initrd(unsigned long start,755 unsigned long end)756{757 /*758 * __va() is not yet available this early on some platforms. In that759 * case, the platform uses phys_initrd_start/phys_initrd_size instead760 * and does the VA conversion itself.761 */762 if (!IS_ENABLED(CONFIG_ARM64) &&763 !(IS_ENABLED(CONFIG_RISCV) && IS_ENABLED(CONFIG_64BIT))) {764 initrd_start = (unsigned long)__va(start);765 initrd_end = (unsigned long)__va(end);766 initrd_below_start_ok = 1;767 }768}769 770/**771 * early_init_dt_check_for_initrd - Decode initrd location from flat tree772 * @node: reference to node containing initrd location ('chosen')773 */774static void __init early_init_dt_check_for_initrd(unsigned long node)775{776 u64 start, end;777 int len;778 const __be32 *prop;779 780 if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))781 return;782 783 pr_debug("Looking for initrd properties... ");784 785 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);786 if (!prop)787 return;788 start = of_read_number(prop, len/4);789 790 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);791 if (!prop)792 return;793 end = of_read_number(prop, len/4);794 if (start > end)795 return;796 797 __early_init_dt_declare_initrd(start, end);798 phys_initrd_start = start;799 phys_initrd_size = end - start;800 801 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", start, end);802}803 804/**805 * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat806 * tree807 * @node: reference to node containing elfcorehdr location ('chosen')808 */809static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)810{811 const __be32 *prop;812 int len;813 814 if (!IS_ENABLED(CONFIG_CRASH_DUMP))815 return;816 817 pr_debug("Looking for elfcorehdr property... ");818 819 prop = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len);820 if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells)))821 return;822 823 elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &prop);824 elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &prop);825 826 pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n",827 elfcorehdr_addr, elfcorehdr_size);828}829 830static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;831 832/*833 * The main usage of linux,usable-memory-range is for crash dump kernel.834 * Originally, the number of usable-memory regions is one. Now there may835 * be two regions, low region and high region.836 * To make compatibility with existing user-space and older kdump, the low837 * region is always the last range of linux,usable-memory-range if exist.838 */839#define MAX_USABLE_RANGES 2840 841/**842 * early_init_dt_check_for_usable_mem_range - Decode usable memory range843 * location from flat tree844 */845void __init early_init_dt_check_for_usable_mem_range(void)846{847 struct memblock_region rgn[MAX_USABLE_RANGES] = {0};848 const __be32 *prop, *endp;849 int len, i;850 unsigned long node = chosen_node_offset;851 852 if ((long)node < 0)853 return;854 855 pr_debug("Looking for usable-memory-range property... ");856 857 prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len);858 if (!prop || (len % (dt_root_addr_cells + dt_root_size_cells)))859 return;860 861 endp = prop + (len / sizeof(__be32));862 for (i = 0; i < MAX_USABLE_RANGES && prop < endp; i++) {863 rgn[i].base = dt_mem_next_cell(dt_root_addr_cells, &prop);864 rgn[i].size = dt_mem_next_cell(dt_root_size_cells, &prop);865 866 pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n",867 i, &rgn[i].base, &rgn[i].size);868 }869 870 memblock_cap_memory_range(rgn[0].base, rgn[0].size);871 for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++)872 memblock_add(rgn[i].base, rgn[i].size);873}874 875#ifdef CONFIG_SERIAL_EARLYCON876 877int __init early_init_dt_scan_chosen_stdout(void)878{879 int offset;880 const char *p, *q, *options = NULL;881 int l;882 const struct earlycon_id *match;883 const void *fdt = initial_boot_params;884 int ret;885 886 offset = fdt_path_offset(fdt, "/chosen");887 if (offset < 0)888 offset = fdt_path_offset(fdt, "/chosen@0");889 if (offset < 0)890 return -ENOENT;891 892 p = fdt_getprop(fdt, offset, "stdout-path", &l);893 if (!p)894 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);895 if (!p || !l)896 return -ENOENT;897 898 q = strchrnul(p, ':');899 if (*q != '\0')900 options = q + 1;901 l = q - p;902 903 /* Get the node specified by stdout-path */904 offset = fdt_path_offset_namelen(fdt, p, l);905 if (offset < 0) {906 pr_warn("earlycon: stdout-path %.*s not found\n", l, p);907 return 0;908 }909 910 for (match = __earlycon_table; match < __earlycon_table_end; match++) {911 if (!match->compatible[0])912 continue;913 914 if (fdt_node_check_compatible(fdt, offset, match->compatible))915 continue;916 917 ret = of_setup_earlycon(match, offset, options);918 if (!ret || ret == -EALREADY)919 return 0;920 }921 return -ENODEV;922}923#endif924 925/*926 * early_init_dt_scan_root - fetch the top level address and size cells927 */928int __init early_init_dt_scan_root(void)929{930 const __be32 *prop;931 const void *fdt = initial_boot_params;932 int node = fdt_path_offset(fdt, "/");933 934 if (node < 0)935 return -ENODEV;936 937 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;938 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;939 940 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);941 if (prop)942 dt_root_size_cells = be32_to_cpup(prop);943 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);944 945 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);946 if (prop)947 dt_root_addr_cells = be32_to_cpup(prop);948 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);949 950 return 0;951}952 953u64 __init dt_mem_next_cell(int s, const __be32 **cellp)954{955 const __be32 *p = *cellp;956 957 *cellp = p + s;958 return of_read_number(p, s);959}960 961/*962 * early_init_dt_scan_memory - Look for and parse memory nodes963 */964int __init early_init_dt_scan_memory(void)965{966 int node, found_memory = 0;967 const void *fdt = initial_boot_params;968 969 fdt_for_each_subnode(node, fdt, 0) {970 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);971 const __be32 *reg, *endp;972 int l;973 bool hotpluggable;974 975 /* We are scanning "memory" nodes only */976 if (type == NULL || strcmp(type, "memory") != 0)977 continue;978 979 if (!of_fdt_device_is_available(fdt, node))980 continue;981 982 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);983 if (reg == NULL)984 reg = of_get_flat_dt_prop(node, "reg", &l);985 if (reg == NULL)986 continue;987 988 endp = reg + (l / sizeof(__be32));989 hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);990 991 pr_debug("memory scan node %s, reg size %d,\n",992 fdt_get_name(fdt, node, NULL), l);993 994 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {995 u64 base, size;996 997 base = dt_mem_next_cell(dt_root_addr_cells, ®);998 size = dt_mem_next_cell(dt_root_size_cells, ®);999 1000 if (size == 0)1001 continue;1002 pr_debug(" - %llx, %llx\n", base, size);1003 1004 early_init_dt_add_memory_arch(base, size);1005 1006 found_memory = 1;1007 1008 if (!hotpluggable)1009 continue;1010 1011 if (memblock_mark_hotplug(base, size))1012 pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",1013 base, base + size);1014 }1015 }1016 return found_memory;1017}1018 1019int __init early_init_dt_scan_chosen(char *cmdline)1020{1021 int l, node;1022 const char *p;1023 const void *rng_seed;1024 const void *fdt = initial_boot_params;1025 1026 node = fdt_path_offset(fdt, "/chosen");1027 if (node < 0)1028 node = fdt_path_offset(fdt, "/chosen@0");1029 if (node < 0)1030 /* Handle the cmdline config options even if no /chosen node */1031 goto handle_cmdline;1032 1033 chosen_node_offset = node;1034 1035 early_init_dt_check_for_initrd(node);1036 early_init_dt_check_for_elfcorehdr(node);1037 1038 rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);1039 if (rng_seed && l > 0) {1040 add_bootloader_randomness(rng_seed, l);1041 1042 /* try to clear seed so it won't be found. */1043 fdt_nop_property(initial_boot_params, node, "rng-seed");1044 1045 /* update CRC check value */1046 of_fdt_crc32 = crc32_be(~0, initial_boot_params,1047 fdt_totalsize(initial_boot_params));1048 }1049 1050 /* Retrieve command line */1051 p = of_get_flat_dt_prop(node, "bootargs", &l);1052 if (p != NULL && l > 0)1053 strscpy(cmdline, p, min(l, COMMAND_LINE_SIZE));1054 1055handle_cmdline:1056 /*1057 * CONFIG_CMDLINE is meant to be a default in case nothing else1058 * managed to set the command line, unless CONFIG_CMDLINE_FORCE1059 * is set in which case we override whatever was found earlier.1060 */1061#ifdef CONFIG_CMDLINE1062#if defined(CONFIG_CMDLINE_EXTEND)1063 strlcat(cmdline, " ", COMMAND_LINE_SIZE);1064 strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);1065#elif defined(CONFIG_CMDLINE_FORCE)1066 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);1067#else1068 /* No arguments from boot loader, use kernel's cmdl*/1069 if (!((char *)cmdline)[0])1070 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);1071#endif1072#endif /* CONFIG_CMDLINE */1073 1074 pr_debug("Command line is: %s\n", (char *)cmdline);1075 1076 return 0;1077}1078 1079#ifndef MIN_MEMBLOCK_ADDR1080#define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET)1081#endif1082#ifndef MAX_MEMBLOCK_ADDR1083#define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0)1084#endif1085 1086void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)1087{1088 const u64 phys_offset = MIN_MEMBLOCK_ADDR;1089 1090 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {1091 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",1092 base, base + size);1093 return;1094 }1095 1096 if (!PAGE_ALIGNED(base)) {1097 size -= PAGE_SIZE - (base & ~PAGE_MASK);1098 base = PAGE_ALIGN(base);1099 }1100 size &= PAGE_MASK;1101 1102 if (base > MAX_MEMBLOCK_ADDR) {1103 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",1104 base, base + size);1105 return;1106 }1107 1108 if (base + size - 1 > MAX_MEMBLOCK_ADDR) {1109 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",1110 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);1111 size = MAX_MEMBLOCK_ADDR - base + 1;1112 }1113 1114 if (base + size < phys_offset) {1115 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",1116 base, base + size);1117 return;1118 }1119 if (base < phys_offset) {1120 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",1121 base, phys_offset);1122 size -= phys_offset - base;1123 base = phys_offset;1124 }1125 memblock_add(base, size);1126}1127 1128static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)1129{1130 void *ptr = memblock_alloc(size, align);1131 1132 if (!ptr)1133 panic("%s: Failed to allocate %llu bytes align=0x%llx\n",1134 __func__, size, align);1135 1136 return ptr;1137}1138 1139bool __init early_init_dt_verify(void *params)1140{1141 if (!params)1142 return false;1143 1144 /* check device tree validity */1145 if (fdt_check_header(params))1146 return false;1147 1148 /* Setup flat device-tree pointer */1149 initial_boot_params = params;1150 of_fdt_crc32 = crc32_be(~0, initial_boot_params,1151 fdt_totalsize(initial_boot_params));1152 1153 /* Initialize {size,address}-cells info */1154 early_init_dt_scan_root();1155 1156 return true;1157}1158 1159 1160void __init early_init_dt_scan_nodes(void)1161{1162 int rc;1163 1164 /* Retrieve various information from the /chosen node */1165 rc = early_init_dt_scan_chosen(boot_command_line);1166 if (rc)1167 pr_warn("No chosen node found, continuing without\n");1168 1169 /* Setup memory, calling early_init_dt_add_memory_arch */1170 early_init_dt_scan_memory();1171 1172 /* Handle linux,usable-memory-range property */1173 early_init_dt_check_for_usable_mem_range();1174}1175 1176bool __init early_init_dt_scan(void *params)1177{1178 bool status;1179 1180 status = early_init_dt_verify(params);1181 if (!status)1182 return false;1183 1184 early_init_dt_scan_nodes();1185 return true;1186}1187 1188static void *__init copy_device_tree(void *fdt)1189{1190 int size;1191 void *dt;1192 1193 size = fdt_totalsize(fdt);1194 dt = early_init_dt_alloc_memory_arch(size,1195 roundup_pow_of_two(FDT_V17_SIZE));1196 1197 if (dt)1198 memcpy(dt, fdt, size);1199 1200 return dt;1201}1202 1203/**1204 * unflatten_device_tree - create tree of device_nodes from flat blob1205 *1206 * unflattens the device-tree passed by the firmware, creating the1207 * tree of struct device_node. It also fills the "name" and "type"1208 * pointers of the nodes so the normal device-tree walking functions1209 * can be used.1210 */1211void __init unflatten_device_tree(void)1212{1213 void *fdt = initial_boot_params;1214 1215 /* Don't use the bootloader provided DTB if ACPI is enabled */1216 if (!acpi_disabled)1217 fdt = NULL;1218 1219 /*1220 * Populate an empty root node when ACPI is enabled or bootloader1221 * doesn't provide one.1222 */1223 if (!fdt) {1224 fdt = (void *) __dtb_empty_root_begin;1225 /* fdt_totalsize() will be used for copy size */1226 if (fdt_totalsize(fdt) >1227 __dtb_empty_root_end - __dtb_empty_root_begin) {1228 pr_err("invalid size in dtb_empty_root\n");1229 return;1230 }1231 of_fdt_crc32 = crc32_be(~0, fdt, fdt_totalsize(fdt));1232 fdt = copy_device_tree(fdt);1233 }1234 1235 __unflatten_device_tree(fdt, NULL, &of_root,1236 early_init_dt_alloc_memory_arch, false);1237 1238 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */1239 of_alias_scan(early_init_dt_alloc_memory_arch);1240 1241 unittest_unflatten_overlay_base();1242}1243 1244/**1245 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob1246 *1247 * Copies and unflattens the device-tree passed by the firmware, creating the1248 * tree of struct device_node. It also fills the "name" and "type"1249 * pointers of the nodes so the normal device-tree walking functions1250 * can be used. This should only be used when the FDT memory has not been1251 * reserved such is the case when the FDT is built-in to the kernel init1252 * section. If the FDT memory is reserved already then unflatten_device_tree1253 * should be used instead.1254 */1255void __init unflatten_and_copy_device_tree(void)1256{1257 if (initial_boot_params)1258 initial_boot_params = copy_device_tree(initial_boot_params);1259 1260 unflatten_device_tree();1261}1262 1263#ifdef CONFIG_SYSFS1264static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,1265 struct bin_attribute *bin_attr,1266 char *buf, loff_t off, size_t count)1267{1268 memcpy(buf, initial_boot_params + off, count);1269 return count;1270}1271 1272static int __init of_fdt_raw_init(void)1273{1274 static struct bin_attribute of_fdt_raw_attr =1275 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);1276 1277 if (!initial_boot_params)1278 return 0;1279 1280 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,1281 fdt_totalsize(initial_boot_params))) {1282 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");1283 return 0;1284 }1285 of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);1286 return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);1287}1288late_initcall(of_fdt_raw_init);1289#endif1290 1291#endif /* CONFIG_OF_EARLY_FLATTREE */1292