1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Functions for working with the Flattened Device Tree data format
4 *
5 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
6 * benh@kernel.crashing.org
7 */
8
9#define pr_fmt(fmt) "OF: fdt: " fmt
10
11#include <linux/crash_dump.h>
12#include <linux/crc32.h>
13#include <linux/kernel.h>
14#include <linux/initrd.h>
15#include <linux/memblock.h>
16#include <linux/mutex.h>
17#include <linux/of.h>
18#include <linux/of_fdt.h>
19#include <linux/sizes.h>
20#include <linux/string.h>
21#include <linux/errno.h>
22#include <linux/slab.h>
23#include <linux/libfdt.h>
24#include <linux/debugfs.h>
25#include <linux/serial_core.h>
26#include <linux/sysfs.h>
27#include <linux/random.h>
28#include <linux/kexec_handover.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 by
37 * cmd_wrap_S_dtb in scripts/Makefile.dtbs
38 */
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 node
44 * @limit: maximum entries
45 *
46 * Adjust the flattened device tree to have at most 'limit' number of
47 * memory entries in the /memory node. This function may be called
48 * 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(fdt: initial_boot_params, path: "/memory");
58 if (memory > 0) {
59 val = fdt_getprop(fdt: initial_boot_params, nodeoffset: memory, name: "reg", lenp: &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(fdt: initial_boot_params, nodeoffset: memory, name: "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(fdt: blob, nodeoffset: node, name: "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(fdt: blob, nodeoffset: offset);
107 cur >= 0;
108 cur = fdt_next_property_offset(fdt: blob, offset: cur)) {
109 const __be32 *val;
110 const char *pname;
111 u32 sz;
112
113 val = fdt_getprop_by_offset(fdt: blob, offset: cur, namep: &pname, lenp: &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, size: sizeof(struct property),
128 align: __alignof__(struct property));
129 if (dryrun)
130 continue;
131
132 /* We accept flattened tree phandles either in
133 * ePAPR-style "phandle" properties, or the
134 * legacy "linux,phandle" properties. If both
135 * appear and have different values, things
136 * 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(p: val);
142 }
143
144 /* And we process the "ibm,phandle" property
145 * used in pSeries dynamic device tree
146 * stuff
147 */
148 if (!strcmp(pname, "ibm,phandle"))
149 np->phandle = be32_to_cpup(p: 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 absent
160 */
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, size: sizeof(struct property) + len,
177 align: __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(fdt: blob, nodeoffset: offset, lenp: &len);
203 if (!pathp) {
204 *pnp = NULL;
205 return len;
206 }
207
208 len++;
209
210 np = unflatten_dt_alloc(mem, size: sizeof(struct device_node) + len,
211 align: __alignof__(struct device_node));
212 if (!dryrun) {
213 char *fn;
214 of_node_init(node: 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, nodename: pathp, dryrun);
227 if (!dryrun) {
228 np->name = of_get_property(node: np, name: "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(parent: 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 tree
263 * @blob: The parent device tree blob
264 * @mem: Memory chunk to use for allocating device nodes and properties
265 * @dad: Parent struct device_node
266 * @nodepp: The device_node tree created by the call
267 *
268 * Return: The size of unflattened device tree or error code
269 */
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 64
278 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 are
288 * possibly multiple nodes in the first level of depth. We need
289 * set @depth to 1 to make fdt_next_node() happy as it bails
290 * immediately when negative @depth is found. Otherwise, the device
291 * 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(fdt: blob, offset, depth: &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, node: offset))
307 continue;
308
309 ret = populate_node(blob, offset, mem: &mem, dad: nps[depth],
310 pnp: &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 .dts
327 * node order
328 */
329 if (!dryrun)
330 reverse_nodes(parent: root);
331
332 return mem - base;
333}
334
335/**
336 * __unflatten_device_tree - create tree of device_nodes from flat blob
337 * @blob: The blob to expand
338 * @dad: Parent device node
339 * @mynodes: The device_node tree created by the call
340 * @dt_alloc: An allocator that provides a virtual address to memory
341 * for the resulting tree
342 * @detached: if true set OF_DETACHED on @mynodes
343 *
344 * unflattens a device-tree, creating the tree of struct device_node. It also
345 * fills the "name" and "type" pointers of the nodes so the normal device-tree
346 * walking functions can be used.
347 *
348 * Return: NULL on failure or the memory chunk containing the unflattened
349 * 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(fdt: 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, nodepp: mynodes);
402
403 if (be32_to_cpup(p: 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(n: *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 blob
428 * @blob: Flat device tree blob
429 * @dad: Parent device node
430 * @mynodes: The device tree created by the call
431 *
432 * unflattens the device-tree passed by the firmware, creating the
433 * tree of struct device_node. It also fills the "name" and "type"
434 * pointers of the nodes so the normal device-tree walking functions
435 * can be used.
436 *
437 * Return: NULL on failure or the memory chunk containing the unflattened
438 * 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, dt_alloc: &kernel_tree_alloc,
448 detached: true);
449 mutex_unlock(lock: &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;
460phys_addr_t initial_boot_params_pa __ro_after_init;
461
462#ifdef CONFIG_OF_EARLY_FLATTREE
463
464static u32 of_fdt_crc32;
465
466/*
467 * fdt_reserve_elfcorehdr() - reserves memory for elf core header
468 *
469 * This function reserves the memory occupied by an elf core header
470 * described in the device tree. This region contains all the
471 * information about primary kernel's core image and is used by a dump
472 * capture kernel to access the system memory on primary kernel.
473 */
474static void __init fdt_reserve_elfcorehdr(void)
475{
476 if (!IS_ENABLED(CONFIG_CRASH_DUMP) || !elfcorehdr_size)
477 return;
478
479 if (memblock_is_region_reserved(base: elfcorehdr_addr, size: elfcorehdr_size)) {
480 pr_warn("elfcorehdr is overlapped\n");
481 return;
482 }
483
484 memblock_reserve(base: elfcorehdr_addr, size: elfcorehdr_size);
485
486 pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n",
487 elfcorehdr_size >> 10, elfcorehdr_addr);
488}
489
490/**
491 * early_init_fdt_scan_reserved_mem() - create reserved memory regions
492 *
493 * This function grabs memory from early allocator for device exclusive use
494 * defined in device tree structures. It should be called by arch specific code
495 * once the early allocator (i.e. memblock) has been fully activated.
496 */
497void __init early_init_fdt_scan_reserved_mem(void)
498{
499 int n;
500 int res;
501 u64 base, size;
502
503 if (!initial_boot_params)
504 return;
505
506 fdt_scan_reserved_mem();
507 fdt_reserve_elfcorehdr();
508
509 /* Process header /memreserve/ fields */
510 for (n = 0; ; n++) {
511 res = fdt_get_mem_rsv(fdt: initial_boot_params, n, address: &base, size: &size);
512 if (res) {
513 pr_err("Invalid memory reservation block index %d\n", n);
514 break;
515 }
516 if (!size)
517 break;
518 memblock_reserve(base, size);
519 }
520}
521
522/**
523 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
524 */
525void __init early_init_fdt_reserve_self(void)
526{
527 if (!initial_boot_params)
528 return;
529
530 /* Reserve the dtb region */
531 memblock_reserve(__pa(initial_boot_params),
532 fdt_totalsize(initial_boot_params));
533}
534
535/**
536 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
537 * @it: callback function
538 * @data: context data pointer
539 *
540 * This function is used to scan the flattened device-tree, it is
541 * used to extract the memory information at boot before we can
542 * unflatten the tree
543 */
544int __init of_scan_flat_dt(int (*it)(unsigned long node,
545 const char *uname, int depth,
546 void *data),
547 void *data)
548{
549 const void *blob = initial_boot_params;
550 const char *pathp;
551 int offset, rc = 0, depth = -1;
552
553 if (!blob)
554 return 0;
555
556 for (offset = fdt_next_node(fdt: blob, offset: -1, depth: &depth);
557 offset >= 0 && depth >= 0 && !rc;
558 offset = fdt_next_node(fdt: blob, offset, depth: &depth)) {
559
560 pathp = fdt_get_name(fdt: blob, nodeoffset: offset, NULL);
561 rc = it(offset, pathp, depth, data);
562 }
563 return rc;
564}
565
566/**
567 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
568 * @parent: parent node
569 * @it: callback function
570 * @data: context data pointer
571 *
572 * This function is used to scan sub-nodes of a node.
573 */
574int __init of_scan_flat_dt_subnodes(unsigned long parent,
575 int (*it)(unsigned long node,
576 const char *uname,
577 void *data),
578 void *data)
579{
580 const void *blob = initial_boot_params;
581 int node;
582
583 fdt_for_each_subnode(node, blob, parent) {
584 const char *pathp;
585 int rc;
586
587 pathp = fdt_get_name(fdt: blob, nodeoffset: node, NULL);
588 rc = it(node, pathp, data);
589 if (rc)
590 return rc;
591 }
592 return 0;
593}
594
595/**
596 * of_get_flat_dt_subnode_by_name - get the subnode by given name
597 *
598 * @node: the parent node
599 * @uname: the name of subnode
600 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
601 */
602
603int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
604{
605 return fdt_subnode_offset(fdt: initial_boot_params, parentoffset: node, name: uname);
606}
607
608/*
609 * of_get_flat_dt_root - find the root node in the flat blob
610 */
611unsigned long __init of_get_flat_dt_root(void)
612{
613 return 0;
614}
615
616/*
617 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
618 *
619 * This function can be used within scan_flattened_dt callback to get
620 * access to properties
621 */
622const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
623 int *size)
624{
625 return fdt_getprop(fdt: initial_boot_params, nodeoffset: node, name, lenp: size);
626}
627
628/**
629 * of_fdt_is_compatible - Return true if given node from the given blob has
630 * compat in its compatible list
631 * @blob: A device tree blob
632 * @node: node to test
633 * @compat: compatible string to compare with compatible list.
634 *
635 * Return: a non-zero value on match with smaller values returned for more
636 * specific compatible values.
637 */
638static int of_fdt_is_compatible(const void *blob,
639 unsigned long node, const char *compat)
640{
641 const char *cp;
642 int cplen;
643 unsigned long l, score = 0;
644
645 cp = fdt_getprop(fdt: blob, nodeoffset: node, name: "compatible", lenp: &cplen);
646 if (cp == NULL)
647 return 0;
648 while (cplen > 0) {
649 score++;
650 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
651 return score;
652 l = strlen(cp) + 1;
653 cp += l;
654 cplen -= l;
655 }
656
657 return 0;
658}
659
660/**
661 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
662 * @node: node to test
663 * @compat: compatible string to compare with compatible list.
664 */
665int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
666{
667 return of_fdt_is_compatible(blob: initial_boot_params, node, compat);
668}
669
670/*
671 * of_flat_dt_match - Return true if node matches a list of compatible values
672 */
673static int __init of_flat_dt_match(unsigned long node, const char *const *compat)
674{
675 unsigned int tmp, score = 0;
676
677 if (!compat)
678 return 0;
679
680 while (*compat) {
681 tmp = of_fdt_is_compatible(blob: initial_boot_params, node, compat: *compat);
682 if (tmp && (score == 0 || (tmp < score)))
683 score = tmp;
684 compat++;
685 }
686
687 return score;
688}
689
690/*
691 * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle
692 */
693uint32_t __init of_get_flat_dt_phandle(unsigned long node)
694{
695 return fdt_get_phandle(fdt: initial_boot_params, nodeoffset: node);
696}
697
698const char * __init of_flat_dt_get_machine_name(void)
699{
700 const char *name;
701 unsigned long dt_root = of_get_flat_dt_root();
702
703 name = of_get_flat_dt_prop(node: dt_root, name: "model", NULL);
704 if (!name)
705 name = of_get_flat_dt_prop(node: dt_root, name: "compatible", NULL);
706 return name;
707}
708
709/**
710 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
711 *
712 * @default_match: A machine specific ptr to return in case of no match.
713 * @get_next_compat: callback function to return next compatible match table.
714 *
715 * Iterate through machine match tables to find the best match for the machine
716 * compatible string in the FDT.
717 */
718const void * __init of_flat_dt_match_machine(const void *default_match,
719 const void * (*get_next_compat)(const char * const**))
720{
721 const void *data = NULL;
722 const void *best_data = default_match;
723 const char *const *compat;
724 unsigned long dt_root;
725 unsigned int best_score = ~1, score = 0;
726
727 dt_root = of_get_flat_dt_root();
728 while ((data = get_next_compat(&compat))) {
729 score = of_flat_dt_match(node: dt_root, compat);
730 if (score > 0 && score < best_score) {
731 best_data = data;
732 best_score = score;
733 }
734 }
735 if (!best_data) {
736 const char *prop;
737 int size;
738
739 pr_err("\n unrecognized device tree list:\n[ ");
740
741 prop = of_get_flat_dt_prop(node: dt_root, name: "compatible", size: &size);
742 if (prop) {
743 while (size > 0) {
744 printk("'%s' ", prop);
745 size -= strlen(prop) + 1;
746 prop += strlen(prop) + 1;
747 }
748 }
749 printk("]\n\n");
750 return NULL;
751 }
752
753 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
754
755 return best_data;
756}
757
758static void __early_init_dt_declare_initrd(unsigned long start,
759 unsigned long end)
760{
761 /*
762 * __va() is not yet available this early on some platforms. In that
763 * case, the platform uses phys_initrd_start/phys_initrd_size instead
764 * and does the VA conversion itself.
765 */
766 if (!IS_ENABLED(CONFIG_ARM64) &&
767 !(IS_ENABLED(CONFIG_RISCV) && IS_ENABLED(CONFIG_64BIT))) {
768 initrd_start = (unsigned long)__va(start);
769 initrd_end = (unsigned long)__va(end);
770 initrd_below_start_ok = 1;
771 }
772}
773
774/**
775 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
776 * @node: reference to node containing initrd location ('chosen')
777 */
778static void __init early_init_dt_check_for_initrd(unsigned long node)
779{
780 u64 start, end;
781 int len;
782 const __be32 *prop;
783
784 if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
785 return;
786
787 pr_debug("Looking for initrd properties... ");
788
789 prop = of_get_flat_dt_prop(node, name: "linux,initrd-start", size: &len);
790 if (!prop)
791 return;
792 start = of_read_number(cell: prop, size: len/4);
793
794 prop = of_get_flat_dt_prop(node, name: "linux,initrd-end", size: &len);
795 if (!prop)
796 return;
797 end = of_read_number(cell: prop, size: len/4);
798 if (start > end)
799 return;
800
801 __early_init_dt_declare_initrd(start, end);
802 phys_initrd_start = start;
803 phys_initrd_size = end - start;
804
805 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", start, end);
806}
807
808/**
809 * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat
810 * tree
811 * @node: reference to node containing elfcorehdr location ('chosen')
812 */
813static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
814{
815 const __be32 *prop;
816 int len;
817
818 if (!IS_ENABLED(CONFIG_CRASH_DUMP))
819 return;
820
821 pr_debug("Looking for elfcorehdr property... ");
822
823 prop = of_get_flat_dt_prop(node, name: "linux,elfcorehdr", size: &len);
824 if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells)))
825 return;
826
827 elfcorehdr_addr = dt_mem_next_cell(s: dt_root_addr_cells, cellp: &prop);
828 elfcorehdr_size = dt_mem_next_cell(s: dt_root_size_cells, cellp: &prop);
829
830 pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n",
831 elfcorehdr_addr, elfcorehdr_size);
832}
833
834static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
835
836/*
837 * The main usage of linux,usable-memory-range is for crash dump kernel.
838 * Originally, the number of usable-memory regions is one. Now there may
839 * be two regions, low region and high region.
840 * To make compatibility with existing user-space and older kdump, the low
841 * region is always the last range of linux,usable-memory-range if exist.
842 */
843#define MAX_USABLE_RANGES 2
844
845/**
846 * early_init_dt_check_for_usable_mem_range - Decode usable memory range
847 * location from flat tree
848 */
849void __init early_init_dt_check_for_usable_mem_range(void)
850{
851 struct memblock_region rgn[MAX_USABLE_RANGES] = {0};
852 const __be32 *prop, *endp;
853 int len, i;
854 unsigned long node = chosen_node_offset;
855
856 if ((long)node < 0)
857 return;
858
859 pr_debug("Looking for usable-memory-range property... ");
860
861 prop = of_get_flat_dt_prop(node, name: "linux,usable-memory-range", size: &len);
862 if (!prop || (len % (dt_root_addr_cells + dt_root_size_cells)))
863 return;
864
865 endp = prop + (len / sizeof(__be32));
866 for (i = 0; i < MAX_USABLE_RANGES && prop < endp; i++) {
867 rgn[i].base = dt_mem_next_cell(s: dt_root_addr_cells, cellp: &prop);
868 rgn[i].size = dt_mem_next_cell(s: dt_root_size_cells, cellp: &prop);
869
870 pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n",
871 i, &rgn[i].base, &rgn[i].size);
872 }
873
874 memblock_cap_memory_range(base: rgn[0].base, size: rgn[0].size);
875 for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++)
876 memblock_add(base: rgn[i].base, size: rgn[i].size);
877}
878
879/**
880 * early_init_dt_check_kho - Decode info required for kexec handover from DT
881 */
882static void __init early_init_dt_check_kho(void)
883{
884 unsigned long node = chosen_node_offset;
885 u64 fdt_start, fdt_size, scratch_start, scratch_size;
886 const __be32 *p;
887 int l;
888
889 if (!IS_ENABLED(CONFIG_KEXEC_HANDOVER) || (long)node < 0)
890 return;
891
892 p = of_get_flat_dt_prop(node, name: "linux,kho-fdt", size: &l);
893 if (l != (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32))
894 return;
895
896 fdt_start = dt_mem_next_cell(s: dt_root_addr_cells, cellp: &p);
897 fdt_size = dt_mem_next_cell(s: dt_root_addr_cells, cellp: &p);
898
899 p = of_get_flat_dt_prop(node, name: "linux,kho-scratch", size: &l);
900 if (l != (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32))
901 return;
902
903 scratch_start = dt_mem_next_cell(s: dt_root_addr_cells, cellp: &p);
904 scratch_size = dt_mem_next_cell(s: dt_root_addr_cells, cellp: &p);
905
906 kho_populate(fdt_phys: fdt_start, fdt_len: fdt_size, scratch_phys: scratch_start, scratch_len: scratch_size);
907}
908
909#ifdef CONFIG_SERIAL_EARLYCON
910
911int __init early_init_dt_scan_chosen_stdout(void)
912{
913 int offset;
914 const char *p, *q, *options = NULL;
915 int l;
916 const struct earlycon_id *match;
917 const void *fdt = initial_boot_params;
918 int ret;
919
920 offset = fdt_path_offset(fdt, path: "/chosen");
921 if (offset < 0)
922 offset = fdt_path_offset(fdt, path: "/chosen@0");
923 if (offset < 0)
924 return -ENOENT;
925
926 p = fdt_getprop(fdt, nodeoffset: offset, name: "stdout-path", lenp: &l);
927 if (!p)
928 p = fdt_getprop(fdt, nodeoffset: offset, name: "linux,stdout-path", lenp: &l);
929 if (!p || !l)
930 return -ENOENT;
931
932 q = strchrnul(p, ':');
933 if (*q != '\0')
934 options = q + 1;
935 l = q - p;
936
937 /* Get the node specified by stdout-path */
938 offset = fdt_path_offset_namelen(fdt, path: p, namelen: l);
939 if (offset < 0) {
940 pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
941 return 0;
942 }
943
944 for (match = __earlycon_table; match < __earlycon_table_end; match++) {
945 if (!match->compatible[0])
946 continue;
947
948 if (fdt_node_check_compatible(fdt, nodeoffset: offset, compatible: match->compatible))
949 continue;
950
951 ret = of_setup_earlycon(match, node: offset, options);
952 if (!ret || ret == -EALREADY)
953 return 0;
954 }
955 return -ENODEV;
956}
957#endif
958
959/*
960 * early_init_dt_scan_root - fetch the top level address and size cells
961 */
962int __init early_init_dt_scan_root(void)
963{
964 const __be32 *prop;
965 const void *fdt = initial_boot_params;
966 int node = fdt_path_offset(fdt, path: "/");
967
968 if (node < 0)
969 return -ENODEV;
970
971 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
972 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
973
974 prop = of_get_flat_dt_prop(node, name: "#size-cells", NULL);
975 if (!WARN(!prop, "No '#size-cells' in root node\n"))
976 dt_root_size_cells = be32_to_cpup(p: prop);
977 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
978
979 prop = of_get_flat_dt_prop(node, name: "#address-cells", NULL);
980 if (!WARN(!prop, "No '#address-cells' in root node\n"))
981 dt_root_addr_cells = be32_to_cpup(p: prop);
982 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
983
984 return 0;
985}
986
987u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
988{
989 const __be32 *p = *cellp;
990
991 *cellp = p + s;
992 return of_read_number(cell: p, size: s);
993}
994
995/*
996 * early_init_dt_scan_memory - Look for and parse memory nodes
997 */
998int __init early_init_dt_scan_memory(void)
999{
1000 int node, found_memory = 0;
1001 const void *fdt = initial_boot_params;
1002
1003 fdt_for_each_subnode(node, fdt, 0) {
1004 const char *type = of_get_flat_dt_prop(node, name: "device_type", NULL);
1005 const __be32 *reg, *endp;
1006 int l;
1007 bool hotpluggable;
1008
1009 /* We are scanning "memory" nodes only */
1010 if (type == NULL || strcmp(type, "memory") != 0)
1011 continue;
1012
1013 if (!of_fdt_device_is_available(blob: fdt, node))
1014 continue;
1015
1016 reg = of_get_flat_dt_prop(node, name: "linux,usable-memory", size: &l);
1017 if (reg == NULL)
1018 reg = of_get_flat_dt_prop(node, name: "reg", size: &l);
1019 if (reg == NULL)
1020 continue;
1021
1022 endp = reg + (l / sizeof(__be32));
1023 hotpluggable = of_get_flat_dt_prop(node, name: "hotpluggable", NULL);
1024
1025 pr_debug("memory scan node %s, reg size %d,\n",
1026 fdt_get_name(fdt, node, NULL), l);
1027
1028 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
1029 u64 base, size;
1030
1031 base = dt_mem_next_cell(s: dt_root_addr_cells, cellp: &reg);
1032 size = dt_mem_next_cell(s: dt_root_size_cells, cellp: &reg);
1033
1034 if (size == 0)
1035 continue;
1036 pr_debug(" - %llx, %llx\n", base, size);
1037
1038 early_init_dt_add_memory_arch(base, size);
1039
1040 found_memory = 1;
1041
1042 if (!hotpluggable)
1043 continue;
1044
1045 if (memblock_mark_hotplug(base, size))
1046 pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1047 base, base + size);
1048 }
1049 }
1050 return found_memory;
1051}
1052
1053int __init early_init_dt_scan_chosen(char *cmdline)
1054{
1055 int l, node;
1056 const char *p;
1057 const void *rng_seed;
1058 const void *fdt = initial_boot_params;
1059
1060 node = fdt_path_offset(fdt, path: "/chosen");
1061 if (node < 0)
1062 node = fdt_path_offset(fdt, path: "/chosen@0");
1063 if (node < 0)
1064 /* Handle the cmdline config options even if no /chosen node */
1065 goto handle_cmdline;
1066
1067 chosen_node_offset = node;
1068
1069 early_init_dt_check_for_initrd(node);
1070 early_init_dt_check_for_elfcorehdr(node);
1071
1072 rng_seed = of_get_flat_dt_prop(node, name: "rng-seed", size: &l);
1073 if (rng_seed && l > 0) {
1074 add_bootloader_randomness(buf: rng_seed, len: l);
1075
1076 /* try to clear seed so it won't be found. */
1077 fdt_nop_property(fdt: initial_boot_params, nodeoffset: node, name: "rng-seed");
1078
1079 /* update CRC check value */
1080 of_fdt_crc32 = crc32_be(crc: ~0, p: initial_boot_params,
1081 fdt_totalsize(initial_boot_params));
1082 }
1083
1084 /* Retrieve command line */
1085 p = of_get_flat_dt_prop(node, name: "bootargs", size: &l);
1086 if (p != NULL && l > 0)
1087 strscpy(cmdline, p, min(l, COMMAND_LINE_SIZE));
1088
1089handle_cmdline:
1090 /*
1091 * CONFIG_CMDLINE is meant to be a default in case nothing else
1092 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1093 * is set in which case we override whatever was found earlier.
1094 */
1095#ifdef CONFIG_CMDLINE
1096#if defined(CONFIG_CMDLINE_EXTEND)
1097 strlcat(cmdline, " ", COMMAND_LINE_SIZE);
1098 strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1099#elif defined(CONFIG_CMDLINE_FORCE)
1100 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1101#else
1102 /* No arguments from boot loader, use kernel's cmdl*/
1103 if (!((char *)cmdline)[0])
1104 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1105#endif
1106#endif /* CONFIG_CMDLINE */
1107
1108 pr_debug("Command line is: %s\n", (char *)cmdline);
1109
1110 return 0;
1111}
1112
1113#ifndef MIN_MEMBLOCK_ADDR
1114#define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET)
1115#endif
1116#ifndef MAX_MEMBLOCK_ADDR
1117#define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0)
1118#endif
1119
1120void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1121{
1122 const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1123
1124 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1125 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1126 base, base + size);
1127 return;
1128 }
1129
1130 if (!PAGE_ALIGNED(base)) {
1131 size -= PAGE_SIZE - (base & ~PAGE_MASK);
1132 base = PAGE_ALIGN(base);
1133 }
1134 size &= PAGE_MASK;
1135
1136 if (base > MAX_MEMBLOCK_ADDR) {
1137 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1138 base, base + size);
1139 return;
1140 }
1141
1142 if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1143 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1144 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1145 size = MAX_MEMBLOCK_ADDR - base + 1;
1146 }
1147
1148 if (base + size < phys_offset) {
1149 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1150 base, base + size);
1151 return;
1152 }
1153 if (base < phys_offset) {
1154 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1155 base, phys_offset);
1156 size -= phys_offset - base;
1157 base = phys_offset;
1158 }
1159 memblock_add(base, size);
1160}
1161
1162static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
1163{
1164 return memblock_alloc_or_panic(size, align);
1165}
1166
1167bool __init early_init_dt_verify(void *dt_virt, phys_addr_t dt_phys)
1168{
1169 if (!dt_virt)
1170 return false;
1171
1172 /* check device tree validity */
1173 if (fdt_check_header(fdt: dt_virt))
1174 return false;
1175
1176 /* Setup flat device-tree pointer */
1177 initial_boot_params = dt_virt;
1178 initial_boot_params_pa = dt_phys;
1179 of_fdt_crc32 = crc32_be(crc: ~0, p: initial_boot_params,
1180 fdt_totalsize(initial_boot_params));
1181
1182 /* Initialize {size,address}-cells info */
1183 early_init_dt_scan_root();
1184
1185 return true;
1186}
1187
1188
1189void __init early_init_dt_scan_nodes(void)
1190{
1191 int rc;
1192
1193 /* Retrieve various information from the /chosen node */
1194 rc = early_init_dt_scan_chosen(cmdline: boot_command_line);
1195 if (rc)
1196 pr_warn("No chosen node found, continuing without\n");
1197
1198 /* Setup memory, calling early_init_dt_add_memory_arch */
1199 early_init_dt_scan_memory();
1200
1201 /* Handle linux,usable-memory-range property */
1202 early_init_dt_check_for_usable_mem_range();
1203
1204 /* Handle kexec handover */
1205 early_init_dt_check_kho();
1206}
1207
1208bool __init early_init_dt_scan(void *dt_virt, phys_addr_t dt_phys)
1209{
1210 bool status;
1211
1212 status = early_init_dt_verify(dt_virt, dt_phys);
1213 if (!status)
1214 return false;
1215
1216 early_init_dt_scan_nodes();
1217 return true;
1218}
1219
1220static void *__init copy_device_tree(void *fdt)
1221{
1222 int size;
1223 void *dt;
1224
1225 size = fdt_totalsize(fdt);
1226 dt = early_init_dt_alloc_memory_arch(size,
1227 roundup_pow_of_two(FDT_V17_SIZE));
1228
1229 if (dt)
1230 memcpy(dt, fdt, size);
1231
1232 return dt;
1233}
1234
1235/**
1236 * unflatten_device_tree - create tree of device_nodes from flat blob
1237 *
1238 * unflattens the device-tree passed by the firmware, creating the
1239 * tree of struct device_node. It also fills the "name" and "type"
1240 * pointers of the nodes so the normal device-tree walking functions
1241 * can be used.
1242 */
1243void __init unflatten_device_tree(void)
1244{
1245 void *fdt = initial_boot_params;
1246
1247 /* Save the statically-placed regions in the reserved_mem array */
1248 fdt_scan_reserved_mem_reg_nodes();
1249
1250 /* Populate an empty root node when bootloader doesn't provide one */
1251 if (!fdt) {
1252 fdt = (void *) __dtb_empty_root_begin;
1253 /* fdt_totalsize() will be used for copy size */
1254 if (fdt_totalsize(fdt) >
1255 __dtb_empty_root_end - __dtb_empty_root_begin) {
1256 pr_err("invalid size in dtb_empty_root\n");
1257 return;
1258 }
1259 of_fdt_crc32 = crc32_be(crc: ~0, p: fdt, fdt_totalsize(fdt));
1260 fdt = copy_device_tree(fdt);
1261 }
1262
1263 __unflatten_device_tree(blob: fdt, NULL, mynodes: &of_root,
1264 dt_alloc: early_init_dt_alloc_memory_arch, detached: false);
1265
1266 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1267 of_alias_scan(dt_alloc: early_init_dt_alloc_memory_arch);
1268
1269 unittest_unflatten_overlay_base();
1270}
1271
1272/**
1273 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1274 *
1275 * Copies and unflattens the device-tree passed by the firmware, creating the
1276 * tree of struct device_node. It also fills the "name" and "type"
1277 * pointers of the nodes so the normal device-tree walking functions
1278 * can be used. This should only be used when the FDT memory has not been
1279 * reserved such is the case when the FDT is built-in to the kernel init
1280 * section. If the FDT memory is reserved already then unflatten_device_tree
1281 * should be used instead.
1282 */
1283void __init unflatten_and_copy_device_tree(void)
1284{
1285 if (initial_boot_params)
1286 initial_boot_params = copy_device_tree(fdt: initial_boot_params);
1287
1288 unflatten_device_tree();
1289}
1290
1291#ifdef CONFIG_SYSFS
1292static int __init of_fdt_raw_init(void)
1293{
1294 static __ro_after_init BIN_ATTR_SIMPLE_ADMIN_RO(fdt);
1295
1296 if (!initial_boot_params)
1297 return 0;
1298
1299 if (of_fdt_crc32 != crc32_be(crc: ~0, p: initial_boot_params,
1300 fdt_totalsize(initial_boot_params))) {
1301 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1302 return 0;
1303 }
1304 bin_attr_fdt.private = initial_boot_params;
1305 bin_attr_fdt.size = fdt_totalsize(initial_boot_params);
1306 return sysfs_create_bin_file(kobj: firmware_kobj, attr: &bin_attr_fdt);
1307}
1308late_initcall(of_fdt_raw_init);
1309#endif
1310
1311#endif /* CONFIG_OF_EARLY_FLATTREE */
1312

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source code of linux/drivers/of/fdt.c