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1/*
2 * Functions for working with the Flattened Device Tree data format
3 *
4 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
5 * benh@kernel.crashing.org
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * version 2 as published by the Free Software Foundation.
10 */
11
12#include <linux/kernel.h>
13#include <linux/initrd.h>
14#include <linux/memblock.h>
15#include <linux/module.h>
16#include <linux/of.h>
17#include <linux/of_fdt.h>
18#include <linux/of_reserved_mem.h>
19#include <linux/sizes.h>
20#include <linux/string.h>
21#include <linux/errno.h>
22#include <linux/slab.h>
23
24#include <asm/setup.h> /* for COMMAND_LINE_SIZE */
25#ifdef CONFIG_PPC
26#include <asm/machdep.h>
27#endif /* CONFIG_PPC */
28
29#include <asm/page.h>
30
31char *of_fdt_get_string(struct boot_param_header *blob, u32 offset)
32{
33 return ((char *)blob) +
34 be32_to_cpu(blob->off_dt_strings) + offset;
35}
36
37/**
38 * of_fdt_get_property - Given a node in the given flat blob, return
39 * the property ptr
40 */
41void *of_fdt_get_property(struct boot_param_header *blob,
42 unsigned long node, const char *name,
43 unsigned long *size)
44{
45 unsigned long p = node;
46
47 do {
48 u32 tag = be32_to_cpup((__be32 *)p);
49 u32 sz, noff;
50 const char *nstr;
51
52 p += 4;
53 if (tag == OF_DT_NOP)
54 continue;
55 if (tag != OF_DT_PROP)
56 return NULL;
57
58 sz = be32_to_cpup((__be32 *)p);
59 noff = be32_to_cpup((__be32 *)(p + 4));
60 p += 8;
61 if (be32_to_cpu(blob->version) < 0x10)
62 p = ALIGN(p, sz >= 8 ? 8 : 4);
63
64 nstr = of_fdt_get_string(blob, noff);
65 if (nstr == NULL) {
66 pr_warning("Can't find property index name !\n");
67 return NULL;
68 }
69 if (strcmp(name, nstr) == 0) {
70 if (size)
71 *size = sz;
72 return (void *)p;
73 }
74 p += sz;
75 p = ALIGN(p, 4);
76 } while (1);
77}
78
79/**
80 * of_fdt_is_compatible - Return true if given node from the given blob has
81 * compat in its compatible list
82 * @blob: A device tree blob
83 * @node: node to test
84 * @compat: compatible string to compare with compatible list.
85 *
86 * On match, returns a non-zero value with smaller values returned for more
87 * specific compatible values.
88 */
89int of_fdt_is_compatible(struct boot_param_header *blob,
90 unsigned long node, const char *compat)
91{
92 const char *cp;
93 unsigned long cplen, l, score = 0;
94
95 cp = of_fdt_get_property(blob, node, "compatible", &cplen);
96 if (cp == NULL)
97 return 0;
98 while (cplen > 0) {
99 score++;
100 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
101 return score;
102 l = strlen(cp) + 1;
103 cp += l;
104 cplen -= l;
105 }
106
107 return 0;
108}
109
110/**
111 * of_fdt_match - Return true if node matches a list of compatible values
112 */
113int of_fdt_match(struct boot_param_header *blob, unsigned long node,
114 const char *const *compat)
115{
116 unsigned int tmp, score = 0;
117
118 if (!compat)
119 return 0;
120
121 while (*compat) {
122 tmp = of_fdt_is_compatible(blob, node, *compat);
123 if (tmp && (score == 0 || (tmp < score)))
124 score = tmp;
125 compat++;
126 }
127
128 return score;
129}
130
131static void *unflatten_dt_alloc(void **mem, unsigned long size,
132 unsigned long align)
133{
134 void *res;
135
136 *mem = PTR_ALIGN(*mem, align);
137 res = *mem;
138 *mem += size;
139
140 return res;
141}
142
143/**
144 * unflatten_dt_node - Alloc and populate a device_node from the flat tree
145 * @blob: The parent device tree blob
146 * @mem: Memory chunk to use for allocating device nodes and properties
147 * @p: pointer to node in flat tree
148 * @dad: Parent struct device_node
149 * @allnextpp: pointer to ->allnext from last allocated device_node
150 * @fpsize: Size of the node path up at the current depth.
151 */
152static void * unflatten_dt_node(struct boot_param_header *blob,
153 void *mem,
154 void **p,
155 struct device_node *dad,
156 struct device_node ***allnextpp,
157 unsigned long fpsize)
158{
159 struct device_node *np;
160 struct property *pp, **prev_pp = NULL;
161 char *pathp;
162 u32 tag;
163 unsigned int l, allocl;
164 int has_name = 0;
165 int new_format = 0;
166
167 tag = be32_to_cpup(*p);
168 if (tag != OF_DT_BEGIN_NODE) {
169 pr_err("Weird tag at start of node: %x\n", tag);
170 return mem;
171 }
172 *p += 4;
173 pathp = *p;
174 l = allocl = strlen(pathp) + 1;
175 *p = PTR_ALIGN(*p + l, 4);
176
177 /* version 0x10 has a more compact unit name here instead of the full
178 * path. we accumulate the full path size using "fpsize", we'll rebuild
179 * it later. We detect this because the first character of the name is
180 * not '/'.
181 */
182 if ((*pathp) != '/') {
183 new_format = 1;
184 if (fpsize == 0) {
185 /* root node: special case. fpsize accounts for path
186 * plus terminating zero. root node only has '/', so
187 * fpsize should be 2, but we want to avoid the first
188 * level nodes to have two '/' so we use fpsize 1 here
189 */
190 fpsize = 1;
191 allocl = 2;
192 l = 1;
193 *pathp = '\0';
194 } else {
195 /* account for '/' and path size minus terminal 0
196 * already in 'l'
197 */
198 fpsize += l;
199 allocl = fpsize;
200 }
201 }
202
203 np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
204 __alignof__(struct device_node));
205 if (allnextpp) {
206 char *fn;
207 of_node_init(np);
208 np->full_name = fn = ((char *)np) + sizeof(*np);
209 if (new_format) {
210 /* rebuild full path for new format */
211 if (dad && dad->parent) {
212 strcpy(fn, dad->full_name);
213#ifdef DEBUG
214 if ((strlen(fn) + l + 1) != allocl) {
215 pr_debug("%s: p: %d, l: %d, a: %d\n",
216 pathp, (int)strlen(fn),
217 l, allocl);
218 }
219#endif
220 fn += strlen(fn);
221 }
222 *(fn++) = '/';
223 }
224 memcpy(fn, pathp, l);
225
226 prev_pp = &np->properties;
227 **allnextpp = np;
228 *allnextpp = &np->allnext;
229 if (dad != NULL) {
230 np->parent = dad;
231 /* we temporarily use the next field as `last_child'*/
232 if (dad->next == NULL)
233 dad->child = np;
234 else
235 dad->next->sibling = np;
236 dad->next = np;
237 }
238 }
239 /* process properties */
240 while (1) {
241 u32 sz, noff;
242 char *pname;
243
244 tag = be32_to_cpup(*p);
245 if (tag == OF_DT_NOP) {
246 *p += 4;
247 continue;
248 }
249 if (tag != OF_DT_PROP)
250 break;
251 *p += 4;
252 sz = be32_to_cpup(*p);
253 noff = be32_to_cpup(*p + 4);
254 *p += 8;
255 if (be32_to_cpu(blob->version) < 0x10)
256 *p = PTR_ALIGN(*p, sz >= 8 ? 8 : 4);
257
258 pname = of_fdt_get_string(blob, noff);
259 if (pname == NULL) {
260 pr_info("Can't find property name in list !\n");
261 break;
262 }
263 if (strcmp(pname, "name") == 0)
264 has_name = 1;
265 l = strlen(pname) + 1;
266 pp = unflatten_dt_alloc(&mem, sizeof(struct property),
267 __alignof__(struct property));
268 if (allnextpp) {
269 /* We accept flattened tree phandles either in
270 * ePAPR-style "phandle" properties, or the
271 * legacy "linux,phandle" properties. If both
272 * appear and have different values, things
273 * will get weird. Don't do that. */
274 if ((strcmp(pname, "phandle") == 0) ||
275 (strcmp(pname, "linux,phandle") == 0)) {
276 if (np->phandle == 0)
277 np->phandle = be32_to_cpup((__be32*)*p);
278 }
279 /* And we process the "ibm,phandle" property
280 * used in pSeries dynamic device tree
281 * stuff */
282 if (strcmp(pname, "ibm,phandle") == 0)
283 np->phandle = be32_to_cpup((__be32 *)*p);
284 pp->name = pname;
285 pp->length = sz;
286 pp->value = *p;
287 *prev_pp = pp;
288 prev_pp = &pp->next;
289 }
290 *p = PTR_ALIGN((*p) + sz, 4);
291 }
292 /* with version 0x10 we may not have the name property, recreate
293 * it here from the unit name if absent
294 */
295 if (!has_name) {
296 char *p1 = pathp, *ps = pathp, *pa = NULL;
297 int sz;
298
299 while (*p1) {
300 if ((*p1) == '@')
301 pa = p1;
302 if ((*p1) == '/')
303 ps = p1 + 1;
304 p1++;
305 }
306 if (pa < ps)
307 pa = p1;
308 sz = (pa - ps) + 1;
309 pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
310 __alignof__(struct property));
311 if (allnextpp) {
312 pp->name = "name";
313 pp->length = sz;
314 pp->value = pp + 1;
315 *prev_pp = pp;
316 prev_pp = &pp->next;
317 memcpy(pp->value, ps, sz - 1);
318 ((char *)pp->value)[sz - 1] = 0;
319 pr_debug("fixed up name for %s -> %s\n", pathp,
320 (char *)pp->value);
321 }
322 }
323 if (allnextpp) {
324 *prev_pp = NULL;
325 np->name = of_get_property(np, "name", NULL);
326 np->type = of_get_property(np, "device_type", NULL);
327
328 if (!np->name)
329 np->name = "<NULL>";
330 if (!np->type)
331 np->type = "<NULL>";
332 }
333 while (tag == OF_DT_BEGIN_NODE || tag == OF_DT_NOP) {
334 if (tag == OF_DT_NOP)
335 *p += 4;
336 else
337 mem = unflatten_dt_node(blob, mem, p, np, allnextpp,
338 fpsize);
339 tag = be32_to_cpup(*p);
340 }
341 if (tag != OF_DT_END_NODE) {
342 pr_err("Weird tag at end of node: %x\n", tag);
343 return mem;
344 }
345 *p += 4;
346 return mem;
347}
348
349/**
350 * __unflatten_device_tree - create tree of device_nodes from flat blob
351 *
352 * unflattens a device-tree, creating the
353 * tree of struct device_node. It also fills the "name" and "type"
354 * pointers of the nodes so the normal device-tree walking functions
355 * can be used.
356 * @blob: The blob to expand
357 * @mynodes: The device_node tree created by the call
358 * @dt_alloc: An allocator that provides a virtual address to memory
359 * for the resulting tree
360 */
361static void __unflatten_device_tree(struct boot_param_header *blob,
362 struct device_node **mynodes,
363 void * (*dt_alloc)(u64 size, u64 align))
364{
365 unsigned long size;
366 void *start, *mem;
367 struct device_node **allnextp = mynodes;
368
369 pr_debug(" -> unflatten_device_tree()\n");
370
371 if (!blob) {
372 pr_debug("No device tree pointer\n");
373 return;
374 }
375
376 pr_debug("Unflattening device tree:\n");
377 pr_debug("magic: %08x\n", be32_to_cpu(blob->magic));
378 pr_debug("size: %08x\n", be32_to_cpu(blob->totalsize));
379 pr_debug("version: %08x\n", be32_to_cpu(blob->version));
380
381 if (be32_to_cpu(blob->magic) != OF_DT_HEADER) {
382 pr_err("Invalid device tree blob header\n");
383 return;
384 }
385
386 /* First pass, scan for size */
387 start = ((void *)blob) + be32_to_cpu(blob->off_dt_struct);
388 size = (unsigned long)unflatten_dt_node(blob, 0, &start, NULL, NULL, 0);
389 size = ALIGN(size, 4);
390
391 pr_debug(" size is %lx, allocating...\n", size);
392
393 /* Allocate memory for the expanded device tree */
394 mem = dt_alloc(size + 4, __alignof__(struct device_node));
395 memset(mem, 0, size);
396
397 *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
398
399 pr_debug(" unflattening %p...\n", mem);
400
401 /* Second pass, do actual unflattening */
402 start = ((void *)blob) + be32_to_cpu(blob->off_dt_struct);
403 unflatten_dt_node(blob, mem, &start, NULL, &allnextp, 0);
404 if (be32_to_cpup(start) != OF_DT_END)
405 pr_warning("Weird tag at end of tree: %08x\n", be32_to_cpup(start));
406 if (be32_to_cpup(mem + size) != 0xdeadbeef)
407 pr_warning("End of tree marker overwritten: %08x\n",
408 be32_to_cpup(mem + size));
409 *allnextp = NULL;
410
411 pr_debug(" <- unflatten_device_tree()\n");
412}
413
414static void *kernel_tree_alloc(u64 size, u64 align)
415{
416 return kzalloc(size, GFP_KERNEL);
417}
418
419/**
420 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
421 *
422 * unflattens the device-tree passed by the firmware, creating the
423 * tree of struct device_node. It also fills the "name" and "type"
424 * pointers of the nodes so the normal device-tree walking functions
425 * can be used.
426 */
427void of_fdt_unflatten_tree(unsigned long *blob,
428 struct device_node **mynodes)
429{
430 struct boot_param_header *device_tree =
431 (struct boot_param_header *)blob;
432 __unflatten_device_tree(device_tree, mynodes, &kernel_tree_alloc);
433}
434EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
435
436/* Everything below here references initial_boot_params directly. */
437int __initdata dt_root_addr_cells;
438int __initdata dt_root_size_cells;
439
440struct boot_param_header *initial_boot_params;
441
442#ifdef CONFIG_OF_EARLY_FLATTREE
443
444/**
445 * res_mem_reserve_reg() - reserve all memory described in 'reg' property
446 */
447static int __init __reserved_mem_reserve_reg(unsigned long node,
448 const char *uname)
449{
450 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
451 phys_addr_t base, size;
452 unsigned long len;
453 __be32 *prop;
454 int nomap, first = 1;
455
456 prop = of_get_flat_dt_prop(node, "reg", &len);
457 if (!prop)
458 return -ENOENT;
459
460 if (len && len % t_len != 0) {
461 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
462 uname);
463 return -EINVAL;
464 }
465
466 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
467
468 while (len >= t_len) {
469 base = dt_mem_next_cell(dt_root_addr_cells, &prop);
470 size = dt_mem_next_cell(dt_root_size_cells, &prop);
471
472 if (base && size &&
473 early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
474 pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
475 uname, &base, (unsigned long)size / SZ_1M);
476 else
477 pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
478 uname, &base, (unsigned long)size / SZ_1M);
479
480 len -= t_len;
481 if (first) {
482 fdt_reserved_mem_save_node(node, uname, base, size);
483 first = 0;
484 }
485 }
486 return 0;
487}
488
489/**
490 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
491 * in /reserved-memory matches the values supported by the current implementation,
492 * also check if ranges property has been provided
493 */
494static int __init __reserved_mem_check_root(unsigned long node)
495{
496 __be32 *prop;
497
498 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
499 if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
500 return -EINVAL;
501
502 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
503 if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
504 return -EINVAL;
505
506 prop = of_get_flat_dt_prop(node, "ranges", NULL);
507 if (!prop)
508 return -EINVAL;
509 return 0;
510}
511
512/**
513 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
514 */
515static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
516 int depth, void *data)
517{
518 static int found;
519 const char *status;
520 int err;
521
522 if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
523 if (__reserved_mem_check_root(node) != 0) {
524 pr_err("Reserved memory: unsupported node format, ignoring\n");
525 /* break scan */
526 return 1;
527 }
528 found = 1;
529 /* scan next node */
530 return 0;
531 } else if (!found) {
532 /* scan next node */
533 return 0;
534 } else if (found && depth < 2) {
535 /* scanning of /reserved-memory has been finished */
536 return 1;
537 }
538
539 status = of_get_flat_dt_prop(node, "status", NULL);
540 if (status && strcmp(status, "okay") != 0 && strcmp(status, "ok") != 0)
541 return 0;
542
543 err = __reserved_mem_reserve_reg(node, uname);
544 if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
545 fdt_reserved_mem_save_node(node, uname, 0, 0);
546
547 /* scan next node */
548 return 0;
549}
550
551/**
552 * early_init_fdt_scan_reserved_mem() - create reserved memory regions
553 *
554 * This function grabs memory from early allocator for device exclusive use
555 * defined in device tree structures. It should be called by arch specific code
556 * once the early allocator (i.e. memblock) has been fully activated.
557 */
558void __init early_init_fdt_scan_reserved_mem(void)
559{
560 if (!initial_boot_params)
561 return;
562
563 of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
564 fdt_init_reserved_mem();
565}
566
567/**
568 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
569 * @it: callback function
570 * @data: context data pointer
571 *
572 * This function is used to scan the flattened device-tree, it is
573 * used to extract the memory information at boot before we can
574 * unflatten the tree
575 */
576int __init of_scan_flat_dt(int (*it)(unsigned long node,
577 const char *uname, int depth,
578 void *data),
579 void *data)
580{
581 unsigned long p = ((unsigned long)initial_boot_params) +
582 be32_to_cpu(initial_boot_params->off_dt_struct);
583 int rc = 0;
584 int depth = -1;
585
586 do {
587 u32 tag = be32_to_cpup((__be32 *)p);
588 const char *pathp;
589
590 p += 4;
591 if (tag == OF_DT_END_NODE) {
592 depth--;
593 continue;
594 }
595 if (tag == OF_DT_NOP)
596 continue;
597 if (tag == OF_DT_END)
598 break;
599 if (tag == OF_DT_PROP) {
600 u32 sz = be32_to_cpup((__be32 *)p);
601 p += 8;
602 if (be32_to_cpu(initial_boot_params->version) < 0x10)
603 p = ALIGN(p, sz >= 8 ? 8 : 4);
604 p += sz;
605 p = ALIGN(p, 4);
606 continue;
607 }
608 if (tag != OF_DT_BEGIN_NODE) {
609 pr_err("Invalid tag %x in flat device tree!\n", tag);
610 return -EINVAL;
611 }
612 depth++;
613 pathp = (char *)p;
614 p = ALIGN(p + strlen(pathp) + 1, 4);
615 if (*pathp == '/')
616 pathp = kbasename(pathp);
617 rc = it(p, pathp, depth, data);
618 if (rc != 0)
619 break;
620 } while (1);
621
622 return rc;
623}
624
625/**
626 * of_get_flat_dt_root - find the root node in the flat blob
627 */
628unsigned long __init of_get_flat_dt_root(void)
629{
630 unsigned long p = ((unsigned long)initial_boot_params) +
631 be32_to_cpu(initial_boot_params->off_dt_struct);
632
633 while (be32_to_cpup((__be32 *)p) == OF_DT_NOP)
634 p += 4;
635 BUG_ON(be32_to_cpup((__be32 *)p) != OF_DT_BEGIN_NODE);
636 p += 4;
637 return ALIGN(p + strlen((char *)p) + 1, 4);
638}
639
640/**
641 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
642 *
643 * This function can be used within scan_flattened_dt callback to get
644 * access to properties
645 */
646void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
647 unsigned long *size)
648{
649 return of_fdt_get_property(initial_boot_params, node, name, size);
650}
651
652/**
653 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
654 * @node: node to test
655 * @compat: compatible string to compare with compatible list.
656 */
657int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
658{
659 return of_fdt_is_compatible(initial_boot_params, node, compat);
660}
661
662/**
663 * of_flat_dt_match - Return true if node matches a list of compatible values
664 */
665int __init of_flat_dt_match(unsigned long node, const char *const *compat)
666{
667 return of_fdt_match(initial_boot_params, node, compat);
668}
669
670struct fdt_scan_status {
671 const char *name;
672 int namelen;
673 int depth;
674 int found;
675 int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
676 void *data;
677};
678
679/**
680 * fdt_scan_node_by_path - iterator for of_scan_flat_dt_by_path function
681 */
682static int __init fdt_scan_node_by_path(unsigned long node, const char *uname,
683 int depth, void *data)
684{
685 struct fdt_scan_status *st = data;
686
687 /*
688 * if scan at the requested fdt node has been completed,
689 * return -ENXIO to abort further scanning
690 */
691 if (depth <= st->depth)
692 return -ENXIO;
693
694 /* requested fdt node has been found, so call iterator function */
695 if (st->found)
696 return st->iterator(node, uname, depth, st->data);
697
698 /* check if scanning automata is entering next level of fdt nodes */
699 if (depth == st->depth + 1 &&
700 strncmp(st->name, uname, st->namelen) == 0 &&
701 uname[st->namelen] == 0) {
702 st->depth += 1;
703 if (st->name[st->namelen] == 0) {
704 st->found = 1;
705 } else {
706 const char *next = st->name + st->namelen + 1;
707 st->name = next;
708 st->namelen = strcspn(next, "/");
709 }
710 return 0;
711 }
712
713 /* scan next fdt node */
714 return 0;
715}
716
717/**
718 * of_scan_flat_dt_by_path - scan flattened tree blob and call callback on each
719 * child of the given path.
720 * @path: path to start searching for children
721 * @it: callback function
722 * @data: context data pointer
723 *
724 * This function is used to scan the flattened device-tree starting from the
725 * node given by path. It is used to extract information (like reserved
726 * memory), which is required on ealy boot before we can unflatten the tree.
727 */
728int __init of_scan_flat_dt_by_path(const char *path,
729 int (*it)(unsigned long node, const char *name, int depth, void *data),
730 void *data)
731{
732 struct fdt_scan_status st = {path, 0, -1, 0, it, data};
733 int ret = 0;
734
735 if (initial_boot_params)
736 ret = of_scan_flat_dt(fdt_scan_node_by_path, &st);
737
738 if (!st.found)
739 return -ENOENT;
740 else if (ret == -ENXIO) /* scan has been completed */
741 return 0;
742 else
743 return ret;
744}
745
746const char * __init of_flat_dt_get_machine_name(void)
747{
748 const char *name;
749 unsigned long dt_root = of_get_flat_dt_root();
750
751 name = of_get_flat_dt_prop(dt_root, "model", NULL);
752 if (!name)
753 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
754 return name;
755}
756
757/**
758 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
759 *
760 * @default_match: A machine specific ptr to return in case of no match.
761 * @get_next_compat: callback function to return next compatible match table.
762 *
763 * Iterate through machine match tables to find the best match for the machine
764 * compatible string in the FDT.
765 */
766const void * __init of_flat_dt_match_machine(const void *default_match,
767 const void * (*get_next_compat)(const char * const**))
768{
769 const void *data = NULL;
770 const void *best_data = default_match;
771 const char *const *compat;
772 unsigned long dt_root;
773 unsigned int best_score = ~1, score = 0;
774
775 dt_root = of_get_flat_dt_root();
776 while ((data = get_next_compat(&compat))) {
777 score = of_flat_dt_match(dt_root, compat);
778 if (score > 0 && score < best_score) {
779 best_data = data;
780 best_score = score;
781 }
782 }
783 if (!best_data) {
784 const char *prop;
785 long size;
786
787 pr_err("\n unrecognized device tree list:\n[ ");
788
789 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
790 if (prop) {
791 while (size > 0) {
792 printk("'%s' ", prop);
793 size -= strlen(prop) + 1;
794 prop += strlen(prop) + 1;
795 }
796 }
797 printk("]\n\n");
798 return NULL;
799 }
800
801 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
802
803 return best_data;
804}
805
806#ifdef CONFIG_BLK_DEV_INITRD
807/**
808 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
809 * @node: reference to node containing initrd location ('chosen')
810 */
811static void __init early_init_dt_check_for_initrd(unsigned long node)
812{
813 u64 start, end;
814 unsigned long len;
815 __be32 *prop;
816
817 pr_debug("Looking for initrd properties... ");
818
819 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
820 if (!prop)
821 return;
822 start = of_read_number(prop, len/4);
823
824 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
825 if (!prop)
826 return;
827 end = of_read_number(prop, len/4);
828
829 initrd_start = (unsigned long)__va(start);
830 initrd_end = (unsigned long)__va(end);
831 initrd_below_start_ok = 1;
832
833 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n",
834 (unsigned long long)start, (unsigned long long)end);
835}
836#else
837static inline void early_init_dt_check_for_initrd(unsigned long node)
838{
839}
840#endif /* CONFIG_BLK_DEV_INITRD */
841
842/**
843 * early_init_dt_scan_root - fetch the top level address and size cells
844 */
845int __init early_init_dt_scan_root(unsigned long node, const char *uname,
846 int depth, void *data)
847{
848 __be32 *prop;
849
850 if (depth != 0)
851 return 0;
852
853 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
854 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
855
856 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
857 if (prop)
858 dt_root_size_cells = be32_to_cpup(prop);
859 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
860
861 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
862 if (prop)
863 dt_root_addr_cells = be32_to_cpup(prop);
864 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
865
866 /* break now */
867 return 1;
868}
869
870u64 __init dt_mem_next_cell(int s, __be32 **cellp)
871{
872 __be32 *p = *cellp;
873
874 *cellp = p + s;
875 return of_read_number(p, s);
876}
877
878/**
879 * early_init_dt_scan_memory - Look for an parse memory nodes
880 */
881int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
882 int depth, void *data)
883{
884 char *type = of_get_flat_dt_prop(node, "device_type", NULL);
885 __be32 *reg, *endp;
886 unsigned long l;
887
888 /* We are scanning "memory" nodes only */
889 if (type == NULL) {
890 /*
891 * The longtrail doesn't have a device_type on the
892 * /memory node, so look for the node called /memory@0.
893 */
894 if (depth != 1 || strcmp(uname, "memory@0") != 0)
895 return 0;
896 } else if (strcmp(type, "memory") != 0)
897 return 0;
898
899 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
900 if (reg == NULL)
901 reg = of_get_flat_dt_prop(node, "reg", &l);
902 if (reg == NULL)
903 return 0;
904
905 endp = reg + (l / sizeof(__be32));
906
907 pr_debug("memory scan node %s, reg size %ld, data: %x %x %x %x,\n",
908 uname, l, reg[0], reg[1], reg[2], reg[3]);
909
910 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
911 u64 base, size;
912
913 base = dt_mem_next_cell(dt_root_addr_cells, ®);
914 size = dt_mem_next_cell(dt_root_size_cells, ®);
915
916 if (size == 0)
917 continue;
918 pr_debug(" - %llx , %llx\n", (unsigned long long)base,
919 (unsigned long long)size);
920
921 early_init_dt_add_memory_arch(base, size);
922 }
923
924 return 0;
925}
926
927int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
928 int depth, void *data)
929{
930 unsigned long l;
931 char *p;
932
933 pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
934
935 if (depth != 1 || !data ||
936 (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
937 return 0;
938
939 early_init_dt_check_for_initrd(node);
940
941 /* Retrieve command line */
942 p = of_get_flat_dt_prop(node, "bootargs", &l);
943 if (p != NULL && l > 0)
944 strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
945
946 /*
947 * CONFIG_CMDLINE is meant to be a default in case nothing else
948 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
949 * is set in which case we override whatever was found earlier.
950 */
951#ifdef CONFIG_CMDLINE
952#ifndef CONFIG_CMDLINE_FORCE
953 if (!((char *)data)[0])
954#endif
955 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
956#endif /* CONFIG_CMDLINE */
957
958 pr_debug("Command line is: %s\n", (char*)data);
959
960 /* break now */
961 return 1;
962}
963
964#ifdef CONFIG_HAVE_MEMBLOCK
965void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
966{
967 const u64 phys_offset = __pa(PAGE_OFFSET);
968 base &= PAGE_MASK;
969 size &= PAGE_MASK;
970 if (base + size < phys_offset) {
971 pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
972 base, base + size);
973 return;
974 }
975 if (base < phys_offset) {
976 pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
977 base, phys_offset);
978 size -= phys_offset - base;
979 base = phys_offset;
980 }
981 memblock_add(base, size);
982}
983
984int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
985 phys_addr_t size, bool nomap)
986{
987 if (memblock_is_region_reserved(base, size))
988 return -EBUSY;
989 if (nomap)
990 return memblock_remove(base, size);
991 return memblock_reserve(base, size);
992}
993
994/*
995 * called from unflatten_device_tree() to bootstrap devicetree itself
996 * Architectures can override this definition if memblock isn't used
997 */
998void * __init __weak early_init_dt_alloc_memory_arch(u64 size, u64 align)
999{
1000 return __va(memblock_alloc(size, align));
1001}
1002#else
1003int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1004 phys_addr_t size, bool nomap)
1005{
1006 pr_err("Reserved memory not supported, ignoring range 0x%llx - 0x%llx%s\n",
1007 base, size, nomap ? " (nomap)" : "");
1008 return -ENOSYS;
1009}
1010#endif
1011
1012bool __init early_init_dt_scan(void *params)
1013{
1014 if (!params)
1015 return false;
1016
1017 /* Setup flat device-tree pointer */
1018 initial_boot_params = params;
1019
1020 /* check device tree validity */
1021 if (be32_to_cpu(initial_boot_params->magic) != OF_DT_HEADER) {
1022 initial_boot_params = NULL;
1023 return false;
1024 }
1025
1026 /* Retrieve various information from the /chosen node */
1027 of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
1028
1029 /* Initialize {size,address}-cells info */
1030 of_scan_flat_dt(early_init_dt_scan_root, NULL);
1031
1032 /* Setup memory, calling early_init_dt_add_memory_arch */
1033 of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1034
1035 return true;
1036}
1037
1038/**
1039 * unflatten_device_tree - create tree of device_nodes from flat blob
1040 *
1041 * unflattens the device-tree passed by the firmware, creating the
1042 * tree of struct device_node. It also fills the "name" and "type"
1043 * pointers of the nodes so the normal device-tree walking functions
1044 * can be used.
1045 */
1046void __init unflatten_device_tree(void)
1047{
1048 __unflatten_device_tree(initial_boot_params, &of_allnodes,
1049 early_init_dt_alloc_memory_arch);
1050
1051 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1052 of_alias_scan(early_init_dt_alloc_memory_arch);
1053}
1054
1055/**
1056 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1057 *
1058 * Copies and unflattens the device-tree passed by the firmware, creating the
1059 * tree of struct device_node. It also fills the "name" and "type"
1060 * pointers of the nodes so the normal device-tree walking functions
1061 * can be used. This should only be used when the FDT memory has not been
1062 * reserved such is the case when the FDT is built-in to the kernel init
1063 * section. If the FDT memory is reserved already then unflatten_device_tree
1064 * should be used instead.
1065 */
1066void __init unflatten_and_copy_device_tree(void)
1067{
1068 int size;
1069 void *dt;
1070
1071 if (!initial_boot_params) {
1072 pr_warn("No valid device tree found, continuing without\n");
1073 return;
1074 }
1075
1076 size = __be32_to_cpu(initial_boot_params->totalsize);
1077 dt = early_init_dt_alloc_memory_arch(size,
1078 __alignof__(struct boot_param_header));
1079
1080 if (dt) {
1081 memcpy(dt, initial_boot_params, size);
1082 initial_boot_params = dt;
1083 }
1084 unflatten_device_tree();
1085}
1086
1087#endif /* CONFIG_OF_EARLY_FLATTREE */
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/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 by
37 * cmd_dt_S_dtb in scripts/Makefile.lib
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 nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
56 int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
57 const __be32 *addr_prop;
58 const __be32 *size_prop;
59 int root_offset;
60 int cell_size;
61
62 root_offset = fdt_path_offset(initial_boot_params, "/");
63 if (root_offset < 0)
64 return;
65
66 addr_prop = fdt_getprop(initial_boot_params, root_offset,
67 "#address-cells", NULL);
68 if (addr_prop)
69 nr_address_cells = fdt32_to_cpu(*addr_prop);
70
71 size_prop = fdt_getprop(initial_boot_params, root_offset,
72 "#size-cells", NULL);
73 if (size_prop)
74 nr_size_cells = fdt32_to_cpu(*size_prop);
75
76 cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
77
78 memory = fdt_path_offset(initial_boot_params, "/memory");
79 if (memory > 0) {
80 val = fdt_getprop(initial_boot_params, memory, "reg", &len);
81 if (len > limit*cell_size) {
82 len = limit*cell_size;
83 pr_debug("Limiting number of entries to %d\n", limit);
84 fdt_setprop(initial_boot_params, memory, "reg", val,
85 len);
86 }
87 }
88}
89
90bool of_fdt_device_is_available(const void *blob, unsigned long node)
91{
92 const char *status = fdt_getprop(blob, node, "status", NULL);
93
94 if (!status)
95 return true;
96
97 if (!strcmp(status, "ok") || !strcmp(status, "okay"))
98 return true;
99
100 return false;
101}
102
103static void *unflatten_dt_alloc(void **mem, unsigned long size,
104 unsigned long align)
105{
106 void *res;
107
108 *mem = PTR_ALIGN(*mem, align);
109 res = *mem;
110 *mem += size;
111
112 return res;
113}
114
115static void populate_properties(const void *blob,
116 int offset,
117 void **mem,
118 struct device_node *np,
119 const char *nodename,
120 bool dryrun)
121{
122 struct property *pp, **pprev = NULL;
123 int cur;
124 bool has_name = false;
125
126 pprev = &np->properties;
127 for (cur = fdt_first_property_offset(blob, offset);
128 cur >= 0;
129 cur = fdt_next_property_offset(blob, cur)) {
130 const __be32 *val;
131 const char *pname;
132 u32 sz;
133
134 val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
135 if (!val) {
136 pr_warn("Cannot locate property at 0x%x\n", cur);
137 continue;
138 }
139
140 if (!pname) {
141 pr_warn("Cannot find property name at 0x%x\n", cur);
142 continue;
143 }
144
145 if (!strcmp(pname, "name"))
146 has_name = true;
147
148 pp = unflatten_dt_alloc(mem, sizeof(struct property),
149 __alignof__(struct property));
150 if (dryrun)
151 continue;
152
153 /* We accept flattened tree phandles either in
154 * ePAPR-style "phandle" properties, or the
155 * legacy "linux,phandle" properties. If both
156 * appear and have different values, things
157 * will get weird. Don't do that.
158 */
159 if (!strcmp(pname, "phandle") ||
160 !strcmp(pname, "linux,phandle")) {
161 if (!np->phandle)
162 np->phandle = be32_to_cpup(val);
163 }
164
165 /* And we process the "ibm,phandle" property
166 * used in pSeries dynamic device tree
167 * stuff
168 */
169 if (!strcmp(pname, "ibm,phandle"))
170 np->phandle = be32_to_cpup(val);
171
172 pp->name = (char *)pname;
173 pp->length = sz;
174 pp->value = (__be32 *)val;
175 *pprev = pp;
176 pprev = &pp->next;
177 }
178
179 /* With version 0x10 we may not have the name property,
180 * recreate it here from the unit name if absent
181 */
182 if (!has_name) {
183 const char *p = nodename, *ps = p, *pa = NULL;
184 int len;
185
186 while (*p) {
187 if ((*p) == '@')
188 pa = p;
189 else if ((*p) == '/')
190 ps = p + 1;
191 p++;
192 }
193
194 if (pa < ps)
195 pa = p;
196 len = (pa - ps) + 1;
197 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
198 __alignof__(struct property));
199 if (!dryrun) {
200 pp->name = "name";
201 pp->length = len;
202 pp->value = pp + 1;
203 *pprev = pp;
204 memcpy(pp->value, ps, len - 1);
205 ((char *)pp->value)[len - 1] = 0;
206 pr_debug("fixed up name for %s -> %s\n",
207 nodename, (char *)pp->value);
208 }
209 }
210}
211
212static int populate_node(const void *blob,
213 int offset,
214 void **mem,
215 struct device_node *dad,
216 struct device_node **pnp,
217 bool dryrun)
218{
219 struct device_node *np;
220 const char *pathp;
221 int len;
222
223 pathp = fdt_get_name(blob, offset, &len);
224 if (!pathp) {
225 *pnp = NULL;
226 return len;
227 }
228
229 len++;
230
231 np = unflatten_dt_alloc(mem, sizeof(struct device_node) + len,
232 __alignof__(struct device_node));
233 if (!dryrun) {
234 char *fn;
235 of_node_init(np);
236 np->full_name = fn = ((char *)np) + sizeof(*np);
237
238 memcpy(fn, pathp, len);
239
240 if (dad != NULL) {
241 np->parent = dad;
242 np->sibling = dad->child;
243 dad->child = np;
244 }
245 }
246
247 populate_properties(blob, offset, mem, np, pathp, dryrun);
248 if (!dryrun) {
249 np->name = of_get_property(np, "name", NULL);
250 if (!np->name)
251 np->name = "<NULL>";
252 }
253
254 *pnp = np;
255 return 0;
256}
257
258static void reverse_nodes(struct device_node *parent)
259{
260 struct device_node *child, *next;
261
262 /* In-depth first */
263 child = parent->child;
264 while (child) {
265 reverse_nodes(child);
266
267 child = child->sibling;
268 }
269
270 /* Reverse the nodes in the child list */
271 child = parent->child;
272 parent->child = NULL;
273 while (child) {
274 next = child->sibling;
275
276 child->sibling = parent->child;
277 parent->child = child;
278 child = next;
279 }
280}
281
282/**
283 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
284 * @blob: The parent device tree blob
285 * @mem: Memory chunk to use for allocating device nodes and properties
286 * @dad: Parent struct device_node
287 * @nodepp: The device_node tree created by the call
288 *
289 * Return: The size of unflattened device tree or error code
290 */
291static int unflatten_dt_nodes(const void *blob,
292 void *mem,
293 struct device_node *dad,
294 struct device_node **nodepp)
295{
296 struct device_node *root;
297 int offset = 0, depth = 0, initial_depth = 0;
298#define FDT_MAX_DEPTH 64
299 struct device_node *nps[FDT_MAX_DEPTH];
300 void *base = mem;
301 bool dryrun = !base;
302 int ret;
303
304 if (nodepp)
305 *nodepp = NULL;
306
307 /*
308 * We're unflattening device sub-tree if @dad is valid. There are
309 * possibly multiple nodes in the first level of depth. We need
310 * set @depth to 1 to make fdt_next_node() happy as it bails
311 * immediately when negative @depth is found. Otherwise, the device
312 * nodes except the first one won't be unflattened successfully.
313 */
314 if (dad)
315 depth = initial_depth = 1;
316
317 root = dad;
318 nps[depth] = dad;
319
320 for (offset = 0;
321 offset >= 0 && depth >= initial_depth;
322 offset = fdt_next_node(blob, offset, &depth)) {
323 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH - 1))
324 continue;
325
326 if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
327 !of_fdt_device_is_available(blob, offset))
328 continue;
329
330 ret = populate_node(blob, offset, &mem, nps[depth],
331 &nps[depth+1], dryrun);
332 if (ret < 0)
333 return ret;
334
335 if (!dryrun && nodepp && !*nodepp)
336 *nodepp = nps[depth+1];
337 if (!dryrun && !root)
338 root = nps[depth+1];
339 }
340
341 if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
342 pr_err("Error %d processing FDT\n", offset);
343 return -EINVAL;
344 }
345
346 /*
347 * Reverse the child list. Some drivers assumes node order matches .dts
348 * node order
349 */
350 if (!dryrun)
351 reverse_nodes(root);
352
353 return mem - base;
354}
355
356/**
357 * __unflatten_device_tree - create tree of device_nodes from flat blob
358 * @blob: The blob to expand
359 * @dad: Parent device node
360 * @mynodes: The device_node tree created by the call
361 * @dt_alloc: An allocator that provides a virtual address to memory
362 * for the resulting tree
363 * @detached: if true set OF_DETACHED on @mynodes
364 *
365 * unflattens a device-tree, creating the tree of struct device_node. It also
366 * fills the "name" and "type" pointers of the nodes so the normal device-tree
367 * walking functions can be used.
368 *
369 * Return: NULL on failure or the memory chunk containing the unflattened
370 * device tree on success.
371 */
372void *__unflatten_device_tree(const void *blob,
373 struct device_node *dad,
374 struct device_node **mynodes,
375 void *(*dt_alloc)(u64 size, u64 align),
376 bool detached)
377{
378 int size;
379 void *mem;
380 int ret;
381
382 if (mynodes)
383 *mynodes = NULL;
384
385 pr_debug(" -> unflatten_device_tree()\n");
386
387 if (!blob) {
388 pr_debug("No device tree pointer\n");
389 return NULL;
390 }
391
392 pr_debug("Unflattening device tree:\n");
393 pr_debug("magic: %08x\n", fdt_magic(blob));
394 pr_debug("size: %08x\n", fdt_totalsize(blob));
395 pr_debug("version: %08x\n", fdt_version(blob));
396
397 if (fdt_check_header(blob)) {
398 pr_err("Invalid device tree blob header\n");
399 return NULL;
400 }
401
402 /* First pass, scan for size */
403 size = unflatten_dt_nodes(blob, NULL, dad, NULL);
404 if (size <= 0)
405 return NULL;
406
407 size = ALIGN(size, 4);
408 pr_debug(" size is %d, allocating...\n", size);
409
410 /* Allocate memory for the expanded device tree */
411 mem = dt_alloc(size + 4, __alignof__(struct device_node));
412 if (!mem)
413 return NULL;
414
415 memset(mem, 0, size);
416
417 *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
418
419 pr_debug(" unflattening %p...\n", mem);
420
421 /* Second pass, do actual unflattening */
422 ret = unflatten_dt_nodes(blob, mem, dad, mynodes);
423
424 if (be32_to_cpup(mem + size) != 0xdeadbeef)
425 pr_warn("End of tree marker overwritten: %08x\n",
426 be32_to_cpup(mem + size));
427
428 if (ret <= 0)
429 return NULL;
430
431 if (detached && mynodes && *mynodes) {
432 of_node_set_flag(*mynodes, OF_DETACHED);
433 pr_debug("unflattened tree is detached\n");
434 }
435
436 pr_debug(" <- unflatten_device_tree()\n");
437 return mem;
438}
439
440static void *kernel_tree_alloc(u64 size, u64 align)
441{
442 return kzalloc(size, GFP_KERNEL);
443}
444
445static DEFINE_MUTEX(of_fdt_unflatten_mutex);
446
447/**
448 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
449 * @blob: Flat device tree blob
450 * @dad: Parent device node
451 * @mynodes: The device tree created by the call
452 *
453 * unflattens the device-tree passed by the firmware, creating the
454 * tree of struct device_node. It also fills the "name" and "type"
455 * pointers of the nodes so the normal device-tree walking functions
456 * can be used.
457 *
458 * Return: NULL on failure or the memory chunk containing the unflattened
459 * device tree on success.
460 */
461void *of_fdt_unflatten_tree(const unsigned long *blob,
462 struct device_node *dad,
463 struct device_node **mynodes)
464{
465 void *mem;
466
467 mutex_lock(&of_fdt_unflatten_mutex);
468 mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
469 true);
470 mutex_unlock(&of_fdt_unflatten_mutex);
471
472 return mem;
473}
474EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
475
476/* Everything below here references initial_boot_params directly. */
477int __initdata dt_root_addr_cells;
478int __initdata dt_root_size_cells;
479
480void *initial_boot_params __ro_after_init;
481
482#ifdef CONFIG_OF_EARLY_FLATTREE
483
484static u32 of_fdt_crc32;
485
486/*
487 * fdt_reserve_elfcorehdr() - reserves memory for elf core header
488 *
489 * This function reserves the memory occupied by an elf core header
490 * described in the device tree. This region contains all the
491 * information about primary kernel's core image and is used by a dump
492 * capture kernel to access the system memory on primary kernel.
493 */
494static void __init fdt_reserve_elfcorehdr(void)
495{
496 if (!IS_ENABLED(CONFIG_CRASH_DUMP) || !elfcorehdr_size)
497 return;
498
499 if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) {
500 pr_warn("elfcorehdr is overlapped\n");
501 return;
502 }
503
504 memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
505
506 pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n",
507 elfcorehdr_size >> 10, elfcorehdr_addr);
508}
509
510/**
511 * early_init_fdt_scan_reserved_mem() - create reserved memory regions
512 *
513 * This function grabs memory from early allocator for device exclusive use
514 * defined in device tree structures. It should be called by arch specific code
515 * once the early allocator (i.e. memblock) has been fully activated.
516 */
517void __init early_init_fdt_scan_reserved_mem(void)
518{
519 int n;
520 u64 base, size;
521
522 if (!initial_boot_params)
523 return;
524
525 fdt_scan_reserved_mem();
526 fdt_reserve_elfcorehdr();
527
528 /* Process header /memreserve/ fields */
529 for (n = 0; ; n++) {
530 fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
531 if (!size)
532 break;
533 memblock_reserve(base, size);
534 }
535
536 fdt_init_reserved_mem();
537}
538
539/**
540 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
541 */
542void __init early_init_fdt_reserve_self(void)
543{
544 if (!initial_boot_params)
545 return;
546
547 /* Reserve the dtb region */
548 memblock_reserve(__pa(initial_boot_params),
549 fdt_totalsize(initial_boot_params));
550}
551
552/**
553 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
554 * @it: callback function
555 * @data: context data pointer
556 *
557 * This function is used to scan the flattened device-tree, it is
558 * used to extract the memory information at boot before we can
559 * unflatten the tree
560 */
561int __init of_scan_flat_dt(int (*it)(unsigned long node,
562 const char *uname, int depth,
563 void *data),
564 void *data)
565{
566 const void *blob = initial_boot_params;
567 const char *pathp;
568 int offset, rc = 0, depth = -1;
569
570 if (!blob)
571 return 0;
572
573 for (offset = fdt_next_node(blob, -1, &depth);
574 offset >= 0 && depth >= 0 && !rc;
575 offset = fdt_next_node(blob, offset, &depth)) {
576
577 pathp = fdt_get_name(blob, offset, NULL);
578 rc = it(offset, pathp, depth, data);
579 }
580 return rc;
581}
582
583/**
584 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
585 * @parent: parent node
586 * @it: callback function
587 * @data: context data pointer
588 *
589 * This function is used to scan sub-nodes of a node.
590 */
591int __init of_scan_flat_dt_subnodes(unsigned long parent,
592 int (*it)(unsigned long node,
593 const char *uname,
594 void *data),
595 void *data)
596{
597 const void *blob = initial_boot_params;
598 int node;
599
600 fdt_for_each_subnode(node, blob, parent) {
601 const char *pathp;
602 int rc;
603
604 pathp = fdt_get_name(blob, node, NULL);
605 rc = it(node, pathp, data);
606 if (rc)
607 return rc;
608 }
609 return 0;
610}
611
612/**
613 * of_get_flat_dt_subnode_by_name - get the subnode by given name
614 *
615 * @node: the parent node
616 * @uname: the name of subnode
617 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
618 */
619
620int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
621{
622 return fdt_subnode_offset(initial_boot_params, node, uname);
623}
624
625/*
626 * of_get_flat_dt_root - find the root node in the flat blob
627 */
628unsigned long __init of_get_flat_dt_root(void)
629{
630 return 0;
631}
632
633/*
634 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
635 *
636 * This function can be used within scan_flattened_dt callback to get
637 * access to properties
638 */
639const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
640 int *size)
641{
642 return fdt_getprop(initial_boot_params, node, name, size);
643}
644
645/**
646 * of_fdt_is_compatible - Return true if given node from the given blob has
647 * compat in its compatible list
648 * @blob: A device tree blob
649 * @node: node to test
650 * @compat: compatible string to compare with compatible list.
651 *
652 * Return: a non-zero value on match with smaller values returned for more
653 * specific compatible values.
654 */
655static int of_fdt_is_compatible(const void *blob,
656 unsigned long node, const char *compat)
657{
658 const char *cp;
659 int cplen;
660 unsigned long l, score = 0;
661
662 cp = fdt_getprop(blob, node, "compatible", &cplen);
663 if (cp == NULL)
664 return 0;
665 while (cplen > 0) {
666 score++;
667 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
668 return score;
669 l = strlen(cp) + 1;
670 cp += l;
671 cplen -= l;
672 }
673
674 return 0;
675}
676
677/**
678 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
679 * @node: node to test
680 * @compat: compatible string to compare with compatible list.
681 */
682int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
683{
684 return of_fdt_is_compatible(initial_boot_params, node, compat);
685}
686
687/*
688 * of_flat_dt_match - Return true if node matches a list of compatible values
689 */
690static int __init of_flat_dt_match(unsigned long node, const char *const *compat)
691{
692 unsigned int tmp, score = 0;
693
694 if (!compat)
695 return 0;
696
697 while (*compat) {
698 tmp = of_fdt_is_compatible(initial_boot_params, node, *compat);
699 if (tmp && (score == 0 || (tmp < score)))
700 score = tmp;
701 compat++;
702 }
703
704 return score;
705}
706
707/*
708 * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle
709 */
710uint32_t __init of_get_flat_dt_phandle(unsigned long node)
711{
712 return fdt_get_phandle(initial_boot_params, node);
713}
714
715const char * __init of_flat_dt_get_machine_name(void)
716{
717 const char *name;
718 unsigned long dt_root = of_get_flat_dt_root();
719
720 name = of_get_flat_dt_prop(dt_root, "model", NULL);
721 if (!name)
722 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
723 return name;
724}
725
726/**
727 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
728 *
729 * @default_match: A machine specific ptr to return in case of no match.
730 * @get_next_compat: callback function to return next compatible match table.
731 *
732 * Iterate through machine match tables to find the best match for the machine
733 * compatible string in the FDT.
734 */
735const void * __init of_flat_dt_match_machine(const void *default_match,
736 const void * (*get_next_compat)(const char * const**))
737{
738 const void *data = NULL;
739 const void *best_data = default_match;
740 const char *const *compat;
741 unsigned long dt_root;
742 unsigned int best_score = ~1, score = 0;
743
744 dt_root = of_get_flat_dt_root();
745 while ((data = get_next_compat(&compat))) {
746 score = of_flat_dt_match(dt_root, compat);
747 if (score > 0 && score < best_score) {
748 best_data = data;
749 best_score = score;
750 }
751 }
752 if (!best_data) {
753 const char *prop;
754 int size;
755
756 pr_err("\n unrecognized device tree list:\n[ ");
757
758 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
759 if (prop) {
760 while (size > 0) {
761 printk("'%s' ", prop);
762 size -= strlen(prop) + 1;
763 prop += strlen(prop) + 1;
764 }
765 }
766 printk("]\n\n");
767 return NULL;
768 }
769
770 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
771
772 return best_data;
773}
774
775static void __early_init_dt_declare_initrd(unsigned long start,
776 unsigned long end)
777{
778 /*
779 * __va() is not yet available this early on some platforms. In that
780 * case, the platform uses phys_initrd_start/phys_initrd_size instead
781 * and does the VA conversion itself.
782 */
783 if (!IS_ENABLED(CONFIG_ARM64) &&
784 !(IS_ENABLED(CONFIG_RISCV) && IS_ENABLED(CONFIG_64BIT))) {
785 initrd_start = (unsigned long)__va(start);
786 initrd_end = (unsigned long)__va(end);
787 initrd_below_start_ok = 1;
788 }
789}
790
791/**
792 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
793 * @node: reference to node containing initrd location ('chosen')
794 */
795static void __init early_init_dt_check_for_initrd(unsigned long node)
796{
797 u64 start, end;
798 int len;
799 const __be32 *prop;
800
801 if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
802 return;
803
804 pr_debug("Looking for initrd properties... ");
805
806 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
807 if (!prop)
808 return;
809 start = of_read_number(prop, len/4);
810
811 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
812 if (!prop)
813 return;
814 end = of_read_number(prop, len/4);
815 if (start > end)
816 return;
817
818 __early_init_dt_declare_initrd(start, end);
819 phys_initrd_start = start;
820 phys_initrd_size = end - start;
821
822 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", start, end);
823}
824
825/**
826 * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat
827 * tree
828 * @node: reference to node containing elfcorehdr location ('chosen')
829 */
830static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
831{
832 const __be32 *prop;
833 int len;
834
835 if (!IS_ENABLED(CONFIG_CRASH_DUMP))
836 return;
837
838 pr_debug("Looking for elfcorehdr property... ");
839
840 prop = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len);
841 if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells)))
842 return;
843
844 elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
845 elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &prop);
846
847 pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n",
848 elfcorehdr_addr, elfcorehdr_size);
849}
850
851static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
852
853/*
854 * The main usage of linux,usable-memory-range is for crash dump kernel.
855 * Originally, the number of usable-memory regions is one. Now there may
856 * be two regions, low region and high region.
857 * To make compatibility with existing user-space and older kdump, the low
858 * region is always the last range of linux,usable-memory-range if exist.
859 */
860#define MAX_USABLE_RANGES 2
861
862/**
863 * early_init_dt_check_for_usable_mem_range - Decode usable memory range
864 * location from flat tree
865 */
866void __init early_init_dt_check_for_usable_mem_range(void)
867{
868 struct memblock_region rgn[MAX_USABLE_RANGES] = {0};
869 const __be32 *prop, *endp;
870 int len, i;
871 unsigned long node = chosen_node_offset;
872
873 if ((long)node < 0)
874 return;
875
876 pr_debug("Looking for usable-memory-range property... ");
877
878 prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len);
879 if (!prop || (len % (dt_root_addr_cells + dt_root_size_cells)))
880 return;
881
882 endp = prop + (len / sizeof(__be32));
883 for (i = 0; i < MAX_USABLE_RANGES && prop < endp; i++) {
884 rgn[i].base = dt_mem_next_cell(dt_root_addr_cells, &prop);
885 rgn[i].size = dt_mem_next_cell(dt_root_size_cells, &prop);
886
887 pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n",
888 i, &rgn[i].base, &rgn[i].size);
889 }
890
891 memblock_cap_memory_range(rgn[0].base, rgn[0].size);
892 for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++)
893 memblock_add(rgn[i].base, rgn[i].size);
894}
895
896#ifdef CONFIG_SERIAL_EARLYCON
897
898int __init early_init_dt_scan_chosen_stdout(void)
899{
900 int offset;
901 const char *p, *q, *options = NULL;
902 int l;
903 const struct earlycon_id *match;
904 const void *fdt = initial_boot_params;
905 int ret;
906
907 offset = fdt_path_offset(fdt, "/chosen");
908 if (offset < 0)
909 offset = fdt_path_offset(fdt, "/chosen@0");
910 if (offset < 0)
911 return -ENOENT;
912
913 p = fdt_getprop(fdt, offset, "stdout-path", &l);
914 if (!p)
915 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
916 if (!p || !l)
917 return -ENOENT;
918
919 q = strchrnul(p, ':');
920 if (*q != '\0')
921 options = q + 1;
922 l = q - p;
923
924 /* Get the node specified by stdout-path */
925 offset = fdt_path_offset_namelen(fdt, p, l);
926 if (offset < 0) {
927 pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
928 return 0;
929 }
930
931 for (match = __earlycon_table; match < __earlycon_table_end; match++) {
932 if (!match->compatible[0])
933 continue;
934
935 if (fdt_node_check_compatible(fdt, offset, match->compatible))
936 continue;
937
938 ret = of_setup_earlycon(match, offset, options);
939 if (!ret || ret == -EALREADY)
940 return 0;
941 }
942 return -ENODEV;
943}
944#endif
945
946/*
947 * early_init_dt_scan_root - fetch the top level address and size cells
948 */
949int __init early_init_dt_scan_root(void)
950{
951 const __be32 *prop;
952 const void *fdt = initial_boot_params;
953 int node = fdt_path_offset(fdt, "/");
954
955 if (node < 0)
956 return -ENODEV;
957
958 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
959 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
960
961 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
962 if (prop)
963 dt_root_size_cells = be32_to_cpup(prop);
964 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
965
966 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
967 if (prop)
968 dt_root_addr_cells = be32_to_cpup(prop);
969 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
970
971 return 0;
972}
973
974u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
975{
976 const __be32 *p = *cellp;
977
978 *cellp = p + s;
979 return of_read_number(p, s);
980}
981
982/*
983 * early_init_dt_scan_memory - Look for and parse memory nodes
984 */
985int __init early_init_dt_scan_memory(void)
986{
987 int node, found_memory = 0;
988 const void *fdt = initial_boot_params;
989
990 fdt_for_each_subnode(node, fdt, 0) {
991 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
992 const __be32 *reg, *endp;
993 int l;
994 bool hotpluggable;
995
996 /* We are scanning "memory" nodes only */
997 if (type == NULL || strcmp(type, "memory") != 0)
998 continue;
999
1000 if (!of_fdt_device_is_available(fdt, node))
1001 continue;
1002
1003 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
1004 if (reg == NULL)
1005 reg = of_get_flat_dt_prop(node, "reg", &l);
1006 if (reg == NULL)
1007 continue;
1008
1009 endp = reg + (l / sizeof(__be32));
1010 hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
1011
1012 pr_debug("memory scan node %s, reg size %d,\n",
1013 fdt_get_name(fdt, node, NULL), l);
1014
1015 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
1016 u64 base, size;
1017
1018 base = dt_mem_next_cell(dt_root_addr_cells, ®);
1019 size = dt_mem_next_cell(dt_root_size_cells, ®);
1020
1021 if (size == 0)
1022 continue;
1023 pr_debug(" - %llx, %llx\n", base, size);
1024
1025 early_init_dt_add_memory_arch(base, size);
1026
1027 found_memory = 1;
1028
1029 if (!hotpluggable)
1030 continue;
1031
1032 if (memblock_mark_hotplug(base, size))
1033 pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1034 base, base + size);
1035 }
1036 }
1037 return found_memory;
1038}
1039
1040int __init early_init_dt_scan_chosen(char *cmdline)
1041{
1042 int l, node;
1043 const char *p;
1044 const void *rng_seed;
1045 const void *fdt = initial_boot_params;
1046
1047 node = fdt_path_offset(fdt, "/chosen");
1048 if (node < 0)
1049 node = fdt_path_offset(fdt, "/chosen@0");
1050 if (node < 0)
1051 /* Handle the cmdline config options even if no /chosen node */
1052 goto handle_cmdline;
1053
1054 chosen_node_offset = node;
1055
1056 early_init_dt_check_for_initrd(node);
1057 early_init_dt_check_for_elfcorehdr(node);
1058
1059 rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
1060 if (rng_seed && l > 0) {
1061 add_bootloader_randomness(rng_seed, l);
1062
1063 /* try to clear seed so it won't be found. */
1064 fdt_nop_property(initial_boot_params, node, "rng-seed");
1065
1066 /* update CRC check value */
1067 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1068 fdt_totalsize(initial_boot_params));
1069 }
1070
1071 /* Retrieve command line */
1072 p = of_get_flat_dt_prop(node, "bootargs", &l);
1073 if (p != NULL && l > 0)
1074 strscpy(cmdline, p, min(l, COMMAND_LINE_SIZE));
1075
1076handle_cmdline:
1077 /*
1078 * CONFIG_CMDLINE is meant to be a default in case nothing else
1079 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1080 * is set in which case we override whatever was found earlier.
1081 */
1082#ifdef CONFIG_CMDLINE
1083#if defined(CONFIG_CMDLINE_EXTEND)
1084 strlcat(cmdline, " ", COMMAND_LINE_SIZE);
1085 strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1086#elif defined(CONFIG_CMDLINE_FORCE)
1087 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1088#else
1089 /* No arguments from boot loader, use kernel's cmdl*/
1090 if (!((char *)cmdline)[0])
1091 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1092#endif
1093#endif /* CONFIG_CMDLINE */
1094
1095 pr_debug("Command line is: %s\n", (char *)cmdline);
1096
1097 return 0;
1098}
1099
1100#ifndef MIN_MEMBLOCK_ADDR
1101#define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET)
1102#endif
1103#ifndef MAX_MEMBLOCK_ADDR
1104#define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0)
1105#endif
1106
1107void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1108{
1109 const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1110
1111 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1112 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1113 base, base + size);
1114 return;
1115 }
1116
1117 if (!PAGE_ALIGNED(base)) {
1118 size -= PAGE_SIZE - (base & ~PAGE_MASK);
1119 base = PAGE_ALIGN(base);
1120 }
1121 size &= PAGE_MASK;
1122
1123 if (base > MAX_MEMBLOCK_ADDR) {
1124 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1125 base, base + size);
1126 return;
1127 }
1128
1129 if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1130 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1131 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1132 size = MAX_MEMBLOCK_ADDR - base + 1;
1133 }
1134
1135 if (base + size < phys_offset) {
1136 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1137 base, base + size);
1138 return;
1139 }
1140 if (base < phys_offset) {
1141 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1142 base, phys_offset);
1143 size -= phys_offset - base;
1144 base = phys_offset;
1145 }
1146 memblock_add(base, size);
1147}
1148
1149static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
1150{
1151 void *ptr = memblock_alloc(size, align);
1152
1153 if (!ptr)
1154 panic("%s: Failed to allocate %llu bytes align=0x%llx\n",
1155 __func__, size, align);
1156
1157 return ptr;
1158}
1159
1160bool __init early_init_dt_verify(void *params)
1161{
1162 if (!params)
1163 return false;
1164
1165 /* check device tree validity */
1166 if (fdt_check_header(params))
1167 return false;
1168
1169 /* Setup flat device-tree pointer */
1170 initial_boot_params = params;
1171 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1172 fdt_totalsize(initial_boot_params));
1173 return true;
1174}
1175
1176
1177void __init early_init_dt_scan_nodes(void)
1178{
1179 int rc;
1180
1181 /* Initialize {size,address}-cells info */
1182 early_init_dt_scan_root();
1183
1184 /* Retrieve various information from the /chosen node */
1185 rc = early_init_dt_scan_chosen(boot_command_line);
1186 if (rc)
1187 pr_warn("No chosen node found, continuing without\n");
1188
1189 /* Setup memory, calling early_init_dt_add_memory_arch */
1190 early_init_dt_scan_memory();
1191
1192 /* Handle linux,usable-memory-range property */
1193 early_init_dt_check_for_usable_mem_range();
1194}
1195
1196bool __init early_init_dt_scan(void *params)
1197{
1198 bool status;
1199
1200 status = early_init_dt_verify(params);
1201 if (!status)
1202 return false;
1203
1204 early_init_dt_scan_nodes();
1205 return true;
1206}
1207
1208static void *__init copy_device_tree(void *fdt)
1209{
1210 int size;
1211 void *dt;
1212
1213 size = fdt_totalsize(fdt);
1214 dt = early_init_dt_alloc_memory_arch(size,
1215 roundup_pow_of_two(FDT_V17_SIZE));
1216
1217 if (dt)
1218 memcpy(dt, fdt, size);
1219
1220 return dt;
1221}
1222
1223/**
1224 * unflatten_device_tree - create tree of device_nodes from flat blob
1225 *
1226 * unflattens the device-tree passed by the firmware, creating the
1227 * tree of struct device_node. It also fills the "name" and "type"
1228 * pointers of the nodes so the normal device-tree walking functions
1229 * can be used.
1230 */
1231void __init unflatten_device_tree(void)
1232{
1233 void *fdt = initial_boot_params;
1234
1235 /* Don't use the bootloader provided DTB if ACPI is enabled */
1236 if (!acpi_disabled)
1237 fdt = NULL;
1238
1239 /*
1240 * Populate an empty root node when ACPI is enabled or bootloader
1241 * doesn't provide one.
1242 */
1243 if (!fdt) {
1244 fdt = (void *) __dtb_empty_root_begin;
1245 /* fdt_totalsize() will be used for copy size */
1246 if (fdt_totalsize(fdt) >
1247 __dtb_empty_root_end - __dtb_empty_root_begin) {
1248 pr_err("invalid size in dtb_empty_root\n");
1249 return;
1250 }
1251 of_fdt_crc32 = crc32_be(~0, fdt, fdt_totalsize(fdt));
1252 fdt = copy_device_tree(fdt);
1253 }
1254
1255 __unflatten_device_tree(fdt, NULL, &of_root,
1256 early_init_dt_alloc_memory_arch, false);
1257
1258 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1259 of_alias_scan(early_init_dt_alloc_memory_arch);
1260
1261 unittest_unflatten_overlay_base();
1262}
1263
1264/**
1265 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1266 *
1267 * Copies and unflattens the device-tree passed by the firmware, creating the
1268 * tree of struct device_node. It also fills the "name" and "type"
1269 * pointers of the nodes so the normal device-tree walking functions
1270 * can be used. This should only be used when the FDT memory has not been
1271 * reserved such is the case when the FDT is built-in to the kernel init
1272 * section. If the FDT memory is reserved already then unflatten_device_tree
1273 * should be used instead.
1274 */
1275void __init unflatten_and_copy_device_tree(void)
1276{
1277 if (initial_boot_params)
1278 initial_boot_params = copy_device_tree(initial_boot_params);
1279
1280 unflatten_device_tree();
1281}
1282
1283#ifdef CONFIG_SYSFS
1284static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1285 struct bin_attribute *bin_attr,
1286 char *buf, loff_t off, size_t count)
1287{
1288 memcpy(buf, initial_boot_params + off, count);
1289 return count;
1290}
1291
1292static int __init of_fdt_raw_init(void)
1293{
1294 static struct bin_attribute of_fdt_raw_attr =
1295 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1296
1297 if (!initial_boot_params)
1298 return 0;
1299
1300 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1301 fdt_totalsize(initial_boot_params))) {
1302 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1303 return 0;
1304 }
1305 of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1306 return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1307}
1308late_initcall(of_fdt_raw_init);
1309#endif
1310
1311#endif /* CONFIG_OF_EARLY_FLATTREE */