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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 * [email protected]
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(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_stringlist_get(blob, node, "status", 0, 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 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(val);
142 }
143
144 /* And we process the "ibm,phandle" property
145 * used in pSeries dynamic device tree
146 * stuff
147 */
148 if (IS_ENABLED(CONFIG_PPC_PSERIES) && !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 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, 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 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(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 .dts
327 * node order
328 */
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 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(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 *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
395
396 pr_debug(" unflattening %p...\n", mem);
397
398 /* Second pass, do actual unflattening */
399 ret = unflatten_dt_nodes(blob, mem, dad, mynodes);
400
401 if (be32_to_cpup(mem + size) != 0xdeadbeef)
402 pr_warn("End of tree marker overwritten: %08x\n",
403 be32_to_cpup(mem + size));
404
405 if (ret <= 0)
406 return NULL;
407
408 if (detached && mynodes && *mynodes) {
409 of_node_set_flag(*mynodes, OF_DETACHED);
410 pr_debug("unflattened tree is detached\n");
411 }
412
413 pr_debug(" <- unflatten_device_tree()\n");
414 return mem;
415}
416
417static void *kernel_tree_alloc(u64 size, u64 align)
418{
419 return kzalloc(size, GFP_KERNEL);
420}
421
422static DEFINE_MUTEX(of_fdt_unflatten_mutex);
423
424/**
425 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
426 * @blob: Flat device tree blob
427 * @dad: Parent device node
428 * @mynodes: The device tree created by the call
429 *
430 * unflattens the device-tree passed by the firmware, creating the
431 * tree of struct device_node. It also fills the "name" and "type"
432 * pointers of the nodes so the normal device-tree walking functions
433 * can be used.
434 *
435 * Return: NULL on failure or the memory chunk containing the unflattened
436 * device tree on success.
437 */
438void *of_fdt_unflatten_tree(const unsigned long *blob,
439 struct device_node *dad,
440 struct device_node **mynodes)
441{
442 void *mem;
443
444 mutex_lock(&of_fdt_unflatten_mutex);
445 mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
446 true);
447 mutex_unlock(&of_fdt_unflatten_mutex);
448
449 return mem;
450}
451EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
452
453/* Everything below here references initial_boot_params directly. */
454int __initdata dt_root_addr_cells;
455int __initdata dt_root_size_cells;
456
457void *initial_boot_params __ro_after_init;
458phys_addr_t initial_boot_params_pa __ro_after_init;
459
460#ifdef CONFIG_OF_EARLY_FLATTREE
461
462static u32 of_fdt_crc32;
463
464/*
465 * fdt_reserve_elfcorehdr() - reserves memory for elf core header
466 *
467 * This function reserves the memory occupied by an elf core header
468 * described in the device tree. This region contains all the
469 * information about primary kernel's core image and is used by a dump
470 * capture kernel to access the system memory on primary kernel.
471 */
472static void __init fdt_reserve_elfcorehdr(void)
473{
474 if (!IS_ENABLED(CONFIG_CRASH_DUMP) || !elfcorehdr_size)
475 return;
476
477 if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) {
478 pr_warn("elfcorehdr is overlapped\n");
479 return;
480 }
481
482 memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
483
484 pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n",
485 elfcorehdr_size >> 10, elfcorehdr_addr);
486}
487
488/**
489 * early_init_fdt_scan_reserved_mem() - create reserved memory regions
490 *
491 * This function grabs memory from early allocator for device exclusive use
492 * defined in device tree structures. It should be called by arch specific code
493 * once the early allocator (i.e. memblock) has been fully activated.
494 */
495void __init early_init_fdt_scan_reserved_mem(void)
496{
497 int n;
498 int res;
499 u64 base, size;
500
501 if (!initial_boot_params)
502 return;
503
504 fdt_reserve_elfcorehdr();
505 fdt_scan_reserved_mem();
506
507 /* Process header /memreserve/ fields */
508 for (n = 0; ; n++) {
509 res = fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
510 if (res) {
511 pr_err("Invalid memory reservation block index %d\n", n);
512 break;
513 }
514 if (!size)
515 break;
516 memblock_reserve(base, size);
517 }
518}
519
520/**
521 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
522 */
523void __init early_init_fdt_reserve_self(void)
524{
525 if (!initial_boot_params)
526 return;
527
528 /* Reserve the dtb region */
529 memblock_reserve(__pa(initial_boot_params),
530 fdt_totalsize(initial_boot_params));
531}
532
533/**
534 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
535 * @it: callback function
536 * @data: context data pointer
537 *
538 * This function is used to scan the flattened device-tree, it is
539 * used to extract the memory information at boot before we can
540 * unflatten the tree
541 */
542int __init of_scan_flat_dt(int (*it)(unsigned long node,
543 const char *uname, int depth,
544 void *data),
545 void *data)
546{
547 const void *blob = initial_boot_params;
548 const char *pathp;
549 int offset, rc = 0, depth = -1;
550
551 if (!blob)
552 return 0;
553
554 for (offset = fdt_next_node(blob, -1, &depth);
555 offset >= 0 && depth >= 0 && !rc;
556 offset = fdt_next_node(blob, offset, &depth)) {
557
558 pathp = fdt_get_name(blob, offset, NULL);
559 rc = it(offset, pathp, depth, data);
560 }
561 return rc;
562}
563
564/**
565 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
566 * @parent: parent node
567 * @it: callback function
568 * @data: context data pointer
569 *
570 * This function is used to scan sub-nodes of a node.
571 */
572int __init of_scan_flat_dt_subnodes(unsigned long parent,
573 int (*it)(unsigned long node,
574 const char *uname,
575 void *data),
576 void *data)
577{
578 const void *blob = initial_boot_params;
579 int node;
580
581 fdt_for_each_subnode(node, blob, parent) {
582 const char *pathp;
583 int rc;
584
585 pathp = fdt_get_name(blob, node, NULL);
586 rc = it(node, pathp, data);
587 if (rc)
588 return rc;
589 }
590 return 0;
591}
592
593/**
594 * of_get_flat_dt_subnode_by_name - get the subnode by given name
595 *
596 * @node: the parent node
597 * @uname: the name of subnode
598 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
599 */
600
601int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
602{
603 return fdt_subnode_offset(initial_boot_params, node, uname);
604}
605
606/*
607 * of_get_flat_dt_root - find the root node in the flat blob
608 */
609unsigned long __init of_get_flat_dt_root(void)
610{
611 return 0;
612}
613
614/*
615 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
616 *
617 * This function can be used within scan_flattened_dt callback to get
618 * access to properties
619 */
620const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
621 int *size)
622{
623 return fdt_getprop(initial_boot_params, node, name, size);
624}
625
626const __be32 *__init of_flat_dt_get_addr_size_prop(unsigned long node,
627 const char *name,
628 int *entries)
629{
630 const __be32 *prop;
631 int len, elen = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
632
633 prop = of_get_flat_dt_prop(node, name, &len);
634 if (!prop || len % elen) {
635 *entries = 0;
636 return NULL;
637 }
638
639 *entries = len / elen;
640 return prop;
641}
642
643bool __init of_flat_dt_get_addr_size(unsigned long node, const char *name,
644 u64 *addr, u64 *size)
645{
646 const __be32 *prop;
647 int entries;
648
649 prop = of_flat_dt_get_addr_size_prop(node, name, &entries);
650 if (!prop || entries != 1)
651 return false;
652
653 of_flat_dt_read_addr_size(prop, 0, addr, size);
654 return true;
655}
656
657void __init of_flat_dt_read_addr_size(const __be32 *prop, int entry_index,
658 u64 *addr, u64 *size)
659{
660 int entry_cells = dt_root_addr_cells + dt_root_size_cells;
661 prop += entry_cells * entry_index;
662
663 *addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
664 *size = dt_mem_next_cell(dt_root_size_cells, &prop);
665}
666
667/**
668 * of_fdt_is_compatible - Return true if given node from the given blob has
669 * compat in its compatible list
670 * @blob: A device tree blob
671 * @node: node to test
672 * @compat: compatible string to compare with compatible list.
673 *
674 * Return: a non-zero value on match with smaller values returned for more
675 * specific compatible values.
676 */
677static int of_fdt_is_compatible(const void *blob,
678 unsigned long node, const char *compat)
679{
680 const char *cp;
681 int idx = 0, score = 0;
682
683 while ((cp = fdt_stringlist_get(blob, node, "compatible", idx++, NULL))) {
684 score++;
685 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
686 return score;
687 }
688
689 return 0;
690}
691
692/**
693 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
694 * @node: node to test
695 * @compat: compatible string to compare with compatible list.
696 */
697int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
698{
699 return of_fdt_is_compatible(initial_boot_params, node, compat);
700}
701
702/*
703 * of_flat_dt_match - Return true if node matches a list of compatible values
704 */
705static int __init of_flat_dt_match(unsigned long node, const char *const *compat)
706{
707 unsigned int tmp, score = 0;
708
709 if (!compat)
710 return 0;
711
712 while (*compat) {
713 tmp = of_fdt_is_compatible(initial_boot_params, node, *compat);
714 if (tmp && (score == 0 || (tmp < score)))
715 score = tmp;
716 compat++;
717 }
718
719 return score;
720}
721
722/*
723 * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle
724 */
725uint32_t __init of_get_flat_dt_phandle(unsigned long node)
726{
727 return fdt_get_phandle(initial_boot_params, node);
728}
729
730const char * __init of_flat_dt_get_machine_name(void)
731{
732 const char *name;
733 unsigned long dt_root = of_get_flat_dt_root();
734
735 name = fdt_stringlist_get(initial_boot_params, dt_root, "model", 0, NULL);
736 if (!name)
737 name = fdt_stringlist_get(initial_boot_params, dt_root,
738 "compatible", 0, NULL);
739 return name;
740}
741
742/**
743 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
744 *
745 * @default_match: A machine specific ptr to return in case of no match.
746 * @get_next_compat: callback function to return next compatible match table.
747 *
748 * Iterate through machine match tables to find the best match for the machine
749 * compatible string in the FDT.
750 */
751const void * __init of_flat_dt_match_machine(const void *default_match,
752 const void * (*get_next_compat)(const char * const**))
753{
754 const void *data = NULL;
755 const void *best_data = default_match;
756 const char *const *compat;
757 unsigned long dt_root;
758 unsigned int best_score = ~1, score = 0;
759
760 dt_root = of_get_flat_dt_root();
761 while ((data = get_next_compat(&compat))) {
762 score = of_flat_dt_match(dt_root, compat);
763 if (score > 0 && score < best_score) {
764 best_data = data;
765 best_score = score;
766 }
767 }
768 if (!best_data) {
769 const char *prop;
770 int idx = 0, size;
771
772 pr_err("\n unrecognized device tree list:\n[ ");
773
774 while ((prop = fdt_stringlist_get(initial_boot_params, dt_root,
775 "compatible", idx++, &size)))
776 pr_err("'%s' ", prop);
777 pr_err("]\n\n");
778 return NULL;
779 }
780
781 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
782
783 return best_data;
784}
785
786static void __early_init_dt_declare_initrd(unsigned long start,
787 unsigned long end)
788{
789 /*
790 * __va() is not yet available this early on some platforms. In that
791 * case, the platform uses phys_initrd_start/phys_initrd_size instead
792 * and does the VA conversion itself.
793 */
794 if (!IS_ENABLED(CONFIG_ARM64) &&
795 !(IS_ENABLED(CONFIG_RISCV) && IS_ENABLED(CONFIG_64BIT))) {
796 initrd_start = (unsigned long)__va(start);
797 initrd_end = (unsigned long)__va(end);
798 initrd_below_start_ok = 1;
799 }
800}
801
802/**
803 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
804 * @node: reference to node containing initrd location ('chosen')
805 */
806static void __init early_init_dt_check_for_initrd(unsigned long node)
807{
808 u64 start, end;
809 int len;
810 const __be32 *prop;
811
812 if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
813 return;
814
815 pr_debug("Looking for initrd properties... ");
816
817 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
818 if (!prop)
819 return;
820 start = of_read_number(prop, len/4);
821
822 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
823 if (!prop)
824 return;
825 end = of_read_number(prop, len/4);
826 if (start > end)
827 return;
828
829 __early_init_dt_declare_initrd(start, end);
830 phys_initrd_start = start;
831 phys_initrd_size = end - start;
832
833 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", start, end);
834}
835
836/**
837 * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat
838 * tree
839 * @node: reference to node containing elfcorehdr location ('chosen')
840 */
841static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
842{
843 if (!IS_ENABLED(CONFIG_CRASH_DUMP))
844 return;
845
846 pr_debug("Looking for elfcorehdr property... ");
847
848 if (!of_flat_dt_get_addr_size(node, "linux,elfcorehdr",
849 &elfcorehdr_addr, &elfcorehdr_size))
850 return;
851
852 pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n",
853 elfcorehdr_addr, elfcorehdr_size);
854}
855
856static void __init early_init_dt_check_for_dmcryptkeys(unsigned long node)
857{
858 const char *prop_name = "linux,dmcryptkeys";
859 const __be32 *prop;
860
861 if (!IS_ENABLED(CONFIG_CRASH_DM_CRYPT))
862 return;
863
864 pr_debug("Looking for dmcryptkeys property... ");
865
866 prop = of_get_flat_dt_prop(node, prop_name, NULL);
867 if (!prop)
868 return;
869
870 dm_crypt_keys_addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
871
872 /* Property only accessible to crash dump kernel */
873 fdt_delprop(initial_boot_params, node, prop_name);
874}
875
876static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
877
878/*
879 * The main usage of linux,usable-memory-range is for crash dump kernel.
880 * Originally, the number of usable-memory regions is one. Now there may
881 * be 2 + CRASHK_CMA_RANGES_MAX regions, low region, high region and cma
882 * regions. To make compatibility with existing user-space and older kdump,
883 * the high and low region are always the first two ranges of
884 * linux,usable-memory-range if exist.
885 */
886#define MAX_USABLE_RANGES (2 + CRASHK_CMA_RANGES_MAX)
887
888/**
889 * early_init_dt_check_for_usable_mem_range - Decode usable memory range
890 * location from flat tree
891 */
892void __init early_init_dt_check_for_usable_mem_range(void)
893{
894 struct memblock_region rgn[MAX_USABLE_RANGES] = {0};
895 const __be32 *prop;
896 int len, i;
897 u64 base, size;
898 unsigned long node = chosen_node_offset;
899
900 if ((long)node < 0)
901 return;
902
903 pr_debug("Looking for usable-memory-range property... ");
904
905 prop = of_flat_dt_get_addr_size_prop(node, "linux,usable-memory-range",
906 &len);
907 if (!prop)
908 return;
909
910 len = min(len, MAX_USABLE_RANGES);
911
912 for (i = 0; i < len; i++) {
913 of_flat_dt_read_addr_size(prop, i, &base, &size);
914 rgn[i].base = base;
915 rgn[i].size = size;
916
917 pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n",
918 i, &rgn[i].base, &rgn[i].size);
919 }
920
921 memblock_cap_memory_range(rgn[0].base, rgn[0].size);
922 for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++)
923 memblock_add(rgn[i].base, rgn[i].size);
924}
925
926/**
927 * early_init_dt_check_kho - Decode info required for kexec handover from DT
928 */
929static void __init early_init_dt_check_kho(void)
930{
931 unsigned long node = chosen_node_offset;
932 u64 fdt_start, fdt_size, scratch_start, scratch_size;
933
934 if (!IS_ENABLED(CONFIG_KEXEC_HANDOVER) || (long)node < 0)
935 return;
936
937 if (!of_flat_dt_get_addr_size(node, "linux,kho-fdt",
938 &fdt_start, &fdt_size))
939 return;
940
941 if (!of_flat_dt_get_addr_size(node, "linux,kho-scratch",
942 &scratch_start, &scratch_size))
943 return;
944
945 kho_populate(fdt_start, fdt_size, scratch_start, scratch_size);
946}
947
948#ifdef CONFIG_SERIAL_EARLYCON
949
950int __init early_init_dt_scan_chosen_stdout(void)
951{
952 int offset;
953 const char *p, *q, *options = NULL;
954 int l;
955 const struct earlycon_id *match;
956 const void *fdt = initial_boot_params;
957 int ret;
958
959 offset = fdt_path_offset(fdt, "/chosen");
960 if (offset < 0)
961 offset = fdt_path_offset(fdt, "/chosen@0");
962 if (offset < 0)
963 return -ENOENT;
964
965 p = fdt_stringlist_get(fdt, offset, "stdout-path", 0, &l);
966 if (!p)
967 p = fdt_stringlist_get(fdt, offset, "linux,stdout-path", 0, &l);
968 if (!p || !l)
969 return -ENOENT;
970
971 q = strchrnul(p, ':');
972 if (*q != '\0')
973 options = q + 1;
974 l = q - p;
975
976 /* Get the node specified by stdout-path */
977 offset = fdt_path_offset_namelen(fdt, p, l);
978 if (offset < 0) {
979 pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
980 return 0;
981 }
982
983 for (match = __earlycon_table; match < __earlycon_table_end; match++) {
984 if (!match->compatible[0])
985 continue;
986
987 if (fdt_node_check_compatible(fdt, offset, match->compatible))
988 continue;
989
990 ret = of_setup_earlycon(match, offset, options);
991 if (!ret || ret == -EALREADY)
992 return 0;
993 }
994 return -ENODEV;
995}
996#endif
997
998/*
999 * early_init_dt_scan_root - fetch the top level address and size cells
1000 */
1001int __init early_init_dt_scan_root(void)
1002{
1003 const __be32 *prop;
1004 const void *fdt = initial_boot_params;
1005 int node = fdt_path_offset(fdt, "/");
1006
1007 if (node < 0)
1008 return -ENODEV;
1009
1010 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
1011 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
1012
1013 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
1014 if (!WARN(!prop, "No '#size-cells' in root node\n"))
1015 dt_root_size_cells = be32_to_cpup(prop);
1016 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
1017
1018 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
1019 if (!WARN(!prop, "No '#address-cells' in root node\n"))
1020 dt_root_addr_cells = be32_to_cpup(prop);
1021 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
1022
1023 return 0;
1024}
1025
1026u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
1027{
1028 const __be32 *p = *cellp;
1029
1030 *cellp = p + s;
1031 return of_read_number(p, s);
1032}
1033
1034/*
1035 * early_init_dt_scan_memory - Look for and parse memory nodes
1036 */
1037int __init early_init_dt_scan_memory(void)
1038{
1039 int node, found_memory = 0;
1040 const void *fdt = initial_boot_params;
1041
1042 fdt_for_each_subnode(node, fdt, 0) {
1043 const char *type = fdt_stringlist_get(fdt, node,
1044 "device_type", 0, NULL);
1045 const __be32 *reg;
1046 int i, l;
1047 bool hotpluggable;
1048
1049 /* We are scanning "memory" nodes only */
1050 if (type == NULL || strcmp(type, "memory") != 0)
1051 continue;
1052
1053 if (!of_fdt_device_is_available(fdt, node))
1054 continue;
1055
1056 reg = of_flat_dt_get_addr_size_prop(node, "linux,usable-memory", &l);
1057 if (reg == NULL)
1058 reg = of_flat_dt_get_addr_size_prop(node, "reg", &l);
1059 if (reg == NULL)
1060 continue;
1061
1062 hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
1063
1064 pr_debug("memory scan node %s, reg {addr,size} entries %d,\n",
1065 fdt_get_name(fdt, node, NULL), l);
1066
1067 for (i = 0; i < l; i++) {
1068 u64 base, size;
1069
1070 of_flat_dt_read_addr_size(reg, i, &base, &size);
1071
1072 if (size == 0)
1073 continue;
1074 pr_debug(" - %llx, %llx\n", base, size);
1075
1076 early_init_dt_add_memory_arch(base, size);
1077
1078 found_memory = 1;
1079
1080 if (!hotpluggable)
1081 continue;
1082
1083 if (memblock_mark_hotplug(base, size))
1084 pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1085 base, base + size);
1086 }
1087 }
1088 return found_memory;
1089}
1090
1091int __init early_init_dt_scan_chosen(char *cmdline)
1092{
1093 int l, node;
1094 const char *p;
1095 const void *rng_seed;
1096 const void *fdt = initial_boot_params;
1097
1098 node = fdt_path_offset(fdt, "/chosen");
1099 if (node < 0)
1100 node = fdt_path_offset(fdt, "/chosen@0");
1101 if (node < 0)
1102 /* Handle the cmdline config options even if no /chosen node */
1103 goto handle_cmdline;
1104
1105 chosen_node_offset = node;
1106
1107 early_init_dt_check_for_initrd(node);
1108 early_init_dt_check_for_elfcorehdr(node);
1109 early_init_dt_check_for_dmcryptkeys(node);
1110
1111 rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
1112 if (rng_seed && l > 0) {
1113 add_bootloader_randomness(rng_seed, l);
1114
1115 /* try to clear seed so it won't be found. */
1116 fdt_nop_property(initial_boot_params, node, "rng-seed");
1117
1118 /* update CRC check value */
1119 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1120 fdt_totalsize(initial_boot_params));
1121 }
1122
1123 /* Retrieve command line */
1124 p = of_get_flat_dt_prop(node, "bootargs", &l);
1125 if (p != NULL && l > 0)
1126 strscpy(cmdline, p, min(l, COMMAND_LINE_SIZE));
1127
1128handle_cmdline:
1129 /*
1130 * CONFIG_CMDLINE is meant to be a default in case nothing else
1131 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1132 * is set in which case we override whatever was found earlier.
1133 */
1134#ifdef CONFIG_CMDLINE
1135#if defined(CONFIG_CMDLINE_EXTEND)
1136 strlcat(cmdline, " ", COMMAND_LINE_SIZE);
1137 strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1138#elif defined(CONFIG_CMDLINE_FORCE)
1139 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1140#else
1141 /* No arguments from boot loader, use kernel's cmdl*/
1142 if (!((char *)cmdline)[0])
1143 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1144#endif
1145#endif /* CONFIG_CMDLINE */
1146
1147 pr_debug("Command line is: %s\n", (char *)cmdline);
1148
1149 return 0;
1150}
1151
1152#ifndef MIN_MEMBLOCK_ADDR
1153#define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET)
1154#endif
1155#ifndef MAX_MEMBLOCK_ADDR
1156#define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0)
1157#endif
1158
1159void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1160{
1161 const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1162
1163 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1164 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1165 base, base + size);
1166 return;
1167 }
1168
1169 if (!PAGE_ALIGNED(base)) {
1170 size -= PAGE_SIZE - (base & ~PAGE_MASK);
1171 base = PAGE_ALIGN(base);
1172 }
1173 size &= PAGE_MASK;
1174
1175 if (base > MAX_MEMBLOCK_ADDR) {
1176 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1177 base, base + size);
1178 return;
1179 }
1180
1181 if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1182 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1183 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1184 size = MAX_MEMBLOCK_ADDR - base + 1;
1185 }
1186
1187 if (base + size < phys_offset) {
1188 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1189 base, base + size);
1190 return;
1191 }
1192 if (base < phys_offset) {
1193 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1194 base, phys_offset);
1195 size -= phys_offset - base;
1196 base = phys_offset;
1197 }
1198 memblock_add(base, size);
1199}
1200
1201static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
1202{
1203 return memblock_alloc_or_panic(size, align);
1204}
1205
1206bool __init early_init_dt_verify(void *dt_virt, phys_addr_t dt_phys)
1207{
1208 if (!dt_virt)
1209 return false;
1210
1211 /* check device tree validity */
1212 if (fdt_check_header(dt_virt))
1213 return false;
1214
1215 /* Setup flat device-tree pointer */
1216 initial_boot_params = dt_virt;
1217 initial_boot_params_pa = dt_phys;
1218 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1219 fdt_totalsize(initial_boot_params));
1220
1221 /* Initialize {size,address}-cells info */
1222 early_init_dt_scan_root();
1223
1224 return true;
1225}
1226
1227
1228void __init early_init_dt_scan_nodes(void)
1229{
1230 int rc;
1231
1232 /* Retrieve various information from the /chosen node */
1233 rc = early_init_dt_scan_chosen(boot_command_line);
1234 if (rc)
1235 pr_warn("No chosen node found, continuing without\n");
1236
1237 /* Setup memory, calling early_init_dt_add_memory_arch */
1238 early_init_dt_scan_memory();
1239
1240 /* Handle linux,usable-memory-range property */
1241 early_init_dt_check_for_usable_mem_range();
1242
1243 /* Handle kexec handover */
1244 early_init_dt_check_kho();
1245}
1246
1247bool __init early_init_dt_scan(void *dt_virt, phys_addr_t dt_phys)
1248{
1249 bool status;
1250
1251 status = early_init_dt_verify(dt_virt, dt_phys);
1252 if (!status)
1253 return false;
1254
1255 early_init_dt_scan_nodes();
1256 return true;
1257}
1258
1259static void *__init copy_device_tree(void *fdt)
1260{
1261 int size;
1262 void *dt;
1263
1264 size = fdt_totalsize(fdt);
1265 dt = early_init_dt_alloc_memory_arch(size,
1266 roundup_pow_of_two(FDT_V17_SIZE));
1267
1268 if (dt)
1269 memcpy(dt, fdt, size);
1270
1271 return dt;
1272}
1273
1274/**
1275 * unflatten_device_tree - create tree of device_nodes from flat blob
1276 *
1277 * unflattens the device-tree passed by the firmware, creating the
1278 * tree of struct device_node. It also fills the "name" and "type"
1279 * pointers of the nodes so the normal device-tree walking functions
1280 * can be used.
1281 */
1282void __init unflatten_device_tree(void)
1283{
1284 void *fdt = initial_boot_params;
1285
1286 /* Save the statically-placed regions in the reserved_mem array */
1287 fdt_scan_reserved_mem_late();
1288
1289 /* Populate an empty root node when bootloader doesn't provide one */
1290 if (!fdt) {
1291 fdt = (void *) __dtb_empty_root_begin;
1292 /* fdt_totalsize() will be used for copy size */
1293 if (fdt_totalsize(fdt) >
1294 __dtb_empty_root_end - __dtb_empty_root_begin) {
1295 pr_err("invalid size in dtb_empty_root\n");
1296 return;
1297 }
1298 of_fdt_crc32 = crc32_be(~0, fdt, fdt_totalsize(fdt));
1299 fdt = copy_device_tree(fdt);
1300 }
1301
1302 __unflatten_device_tree(fdt, NULL, &of_root,
1303 early_init_dt_alloc_memory_arch, false);
1304
1305 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1306 of_alias_scan(early_init_dt_alloc_memory_arch);
1307
1308 unittest_unflatten_overlay_base();
1309}
1310
1311/**
1312 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1313 *
1314 * Copies and unflattens the device-tree passed by the firmware, creating the
1315 * tree of struct device_node. It also fills the "name" and "type"
1316 * pointers of the nodes so the normal device-tree walking functions
1317 * can be used. This should only be used when the FDT memory has not been
1318 * reserved such is the case when the FDT is built-in to the kernel init
1319 * section. If the FDT memory is reserved already then unflatten_device_tree
1320 * should be used instead.
1321 */
1322void __init unflatten_and_copy_device_tree(void)
1323{
1324 if (initial_boot_params)
1325 initial_boot_params = copy_device_tree(initial_boot_params);
1326
1327 unflatten_device_tree();
1328}
1329
1330#ifdef CONFIG_SYSFS
1331static int __init of_fdt_raw_init(void)
1332{
1333 static __ro_after_init BIN_ATTR_SIMPLE_ADMIN_RO(fdt);
1334
1335 if (!initial_boot_params)
1336 return 0;
1337
1338 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1339 fdt_totalsize(initial_boot_params))) {
1340 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1341 return 0;
1342 }
1343 bin_attr_fdt.private = initial_boot_params;
1344 bin_attr_fdt.size = fdt_totalsize(initial_boot_params);
1345 return sysfs_create_bin_file(firmware_kobj, &bin_attr_fdt);
1346}
1347late_initcall(of_fdt_raw_init);
1348#endif
1349
1350#endif /* CONFIG_OF_EARLY_FLATTREE */