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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/module.h>
15#include <linux/of.h>
16#include <linux/of_fdt.h>
17#include <linux/string.h>
18#include <linux/errno.h>
19#include <linux/slab.h>
20
21#ifdef CONFIG_PPC
22#include <asm/machdep.h>
23#endif /* CONFIG_PPC */
24
25#include <asm/page.h>
26
27char *of_fdt_get_string(struct boot_param_header *blob, u32 offset)
28{
29 return ((char *)blob) +
30 be32_to_cpu(blob->off_dt_strings) + offset;
31}
32
33/**
34 * of_fdt_get_property - Given a node in the given flat blob, return
35 * the property ptr
36 */
37void *of_fdt_get_property(struct boot_param_header *blob,
38 unsigned long node, const char *name,
39 unsigned long *size)
40{
41 unsigned long p = node;
42
43 do {
44 u32 tag = be32_to_cpup((__be32 *)p);
45 u32 sz, noff;
46 const char *nstr;
47
48 p += 4;
49 if (tag == OF_DT_NOP)
50 continue;
51 if (tag != OF_DT_PROP)
52 return NULL;
53
54 sz = be32_to_cpup((__be32 *)p);
55 noff = be32_to_cpup((__be32 *)(p + 4));
56 p += 8;
57 if (be32_to_cpu(blob->version) < 0x10)
58 p = ALIGN(p, sz >= 8 ? 8 : 4);
59
60 nstr = of_fdt_get_string(blob, noff);
61 if (nstr == NULL) {
62 pr_warning("Can't find property index name !\n");
63 return NULL;
64 }
65 if (strcmp(name, nstr) == 0) {
66 if (size)
67 *size = sz;
68 return (void *)p;
69 }
70 p += sz;
71 p = ALIGN(p, 4);
72 } while (1);
73}
74
75/**
76 * of_fdt_is_compatible - Return true if given node from the given blob has
77 * compat in its compatible list
78 * @blob: A device tree blob
79 * @node: node to test
80 * @compat: compatible string to compare with compatible list.
81 *
82 * On match, returns a non-zero value with smaller values returned for more
83 * specific compatible values.
84 */
85int of_fdt_is_compatible(struct boot_param_header *blob,
86 unsigned long node, const char *compat)
87{
88 const char *cp;
89 unsigned long cplen, l, score = 0;
90
91 cp = of_fdt_get_property(blob, node, "compatible", &cplen);
92 if (cp == NULL)
93 return 0;
94 while (cplen > 0) {
95 score++;
96 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
97 return score;
98 l = strlen(cp) + 1;
99 cp += l;
100 cplen -= l;
101 }
102
103 return 0;
104}
105
106/**
107 * of_fdt_match - Return true if node matches a list of compatible values
108 */
109int of_fdt_match(struct boot_param_header *blob, unsigned long node,
110 const char **compat)
111{
112 unsigned int tmp, score = 0;
113
114 if (!compat)
115 return 0;
116
117 while (*compat) {
118 tmp = of_fdt_is_compatible(blob, node, *compat);
119 if (tmp && (score == 0 || (tmp < score)))
120 score = tmp;
121 compat++;
122 }
123
124 return score;
125}
126
127static void *unflatten_dt_alloc(unsigned long *mem, unsigned long size,
128 unsigned long align)
129{
130 void *res;
131
132 *mem = ALIGN(*mem, align);
133 res = (void *)*mem;
134 *mem += size;
135
136 return res;
137}
138
139/**
140 * unflatten_dt_node - Alloc and populate a device_node from the flat tree
141 * @blob: The parent device tree blob
142 * @mem: Memory chunk to use for allocating device nodes and properties
143 * @p: pointer to node in flat tree
144 * @dad: Parent struct device_node
145 * @allnextpp: pointer to ->allnext from last allocated device_node
146 * @fpsize: Size of the node path up at the current depth.
147 */
148static unsigned long unflatten_dt_node(struct boot_param_header *blob,
149 unsigned long mem,
150 unsigned long *p,
151 struct device_node *dad,
152 struct device_node ***allnextpp,
153 unsigned long fpsize)
154{
155 struct device_node *np;
156 struct property *pp, **prev_pp = NULL;
157 char *pathp;
158 u32 tag;
159 unsigned int l, allocl;
160 int has_name = 0;
161 int new_format = 0;
162
163 tag = be32_to_cpup((__be32 *)(*p));
164 if (tag != OF_DT_BEGIN_NODE) {
165 pr_err("Weird tag at start of node: %x\n", tag);
166 return mem;
167 }
168 *p += 4;
169 pathp = (char *)*p;
170 l = allocl = strlen(pathp) + 1;
171 *p = ALIGN(*p + l, 4);
172
173 /* version 0x10 has a more compact unit name here instead of the full
174 * path. we accumulate the full path size using "fpsize", we'll rebuild
175 * it later. We detect this because the first character of the name is
176 * not '/'.
177 */
178 if ((*pathp) != '/') {
179 new_format = 1;
180 if (fpsize == 0) {
181 /* root node: special case. fpsize accounts for path
182 * plus terminating zero. root node only has '/', so
183 * fpsize should be 2, but we want to avoid the first
184 * level nodes to have two '/' so we use fpsize 1 here
185 */
186 fpsize = 1;
187 allocl = 2;
188 } else {
189 /* account for '/' and path size minus terminal 0
190 * already in 'l'
191 */
192 fpsize += l;
193 allocl = fpsize;
194 }
195 }
196
197 np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
198 __alignof__(struct device_node));
199 if (allnextpp) {
200 memset(np, 0, sizeof(*np));
201 np->full_name = ((char *)np) + sizeof(struct device_node);
202 if (new_format) {
203 char *fn = np->full_name;
204 /* rebuild full path for new format */
205 if (dad && dad->parent) {
206 strcpy(fn, dad->full_name);
207#ifdef DEBUG
208 if ((strlen(fn) + l + 1) != allocl) {
209 pr_debug("%s: p: %d, l: %d, a: %d\n",
210 pathp, (int)strlen(fn),
211 l, allocl);
212 }
213#endif
214 fn += strlen(fn);
215 }
216 *(fn++) = '/';
217 memcpy(fn, pathp, l);
218 } else
219 memcpy(np->full_name, pathp, l);
220 prev_pp = &np->properties;
221 **allnextpp = np;
222 *allnextpp = &np->allnext;
223 if (dad != NULL) {
224 np->parent = dad;
225 /* we temporarily use the next field as `last_child'*/
226 if (dad->next == NULL)
227 dad->child = np;
228 else
229 dad->next->sibling = np;
230 dad->next = np;
231 }
232 kref_init(&np->kref);
233 }
234 /* process properties */
235 while (1) {
236 u32 sz, noff;
237 char *pname;
238
239 tag = be32_to_cpup((__be32 *)(*p));
240 if (tag == OF_DT_NOP) {
241 *p += 4;
242 continue;
243 }
244 if (tag != OF_DT_PROP)
245 break;
246 *p += 4;
247 sz = be32_to_cpup((__be32 *)(*p));
248 noff = be32_to_cpup((__be32 *)((*p) + 4));
249 *p += 8;
250 if (be32_to_cpu(blob->version) < 0x10)
251 *p = ALIGN(*p, sz >= 8 ? 8 : 4);
252
253 pname = of_fdt_get_string(blob, noff);
254 if (pname == NULL) {
255 pr_info("Can't find property name in list !\n");
256 break;
257 }
258 if (strcmp(pname, "name") == 0)
259 has_name = 1;
260 l = strlen(pname) + 1;
261 pp = unflatten_dt_alloc(&mem, sizeof(struct property),
262 __alignof__(struct property));
263 if (allnextpp) {
264 /* We accept flattened tree phandles either in
265 * ePAPR-style "phandle" properties, or the
266 * legacy "linux,phandle" properties. If both
267 * appear and have different values, things
268 * will get weird. Don't do that. */
269 if ((strcmp(pname, "phandle") == 0) ||
270 (strcmp(pname, "linux,phandle") == 0)) {
271 if (np->phandle == 0)
272 np->phandle = be32_to_cpup((__be32*)*p);
273 }
274 /* And we process the "ibm,phandle" property
275 * used in pSeries dynamic device tree
276 * stuff */
277 if (strcmp(pname, "ibm,phandle") == 0)
278 np->phandle = be32_to_cpup((__be32 *)*p);
279 pp->name = pname;
280 pp->length = sz;
281 pp->value = (void *)*p;
282 *prev_pp = pp;
283 prev_pp = &pp->next;
284 }
285 *p = ALIGN((*p) + sz, 4);
286 }
287 /* with version 0x10 we may not have the name property, recreate
288 * it here from the unit name if absent
289 */
290 if (!has_name) {
291 char *p1 = pathp, *ps = pathp, *pa = NULL;
292 int sz;
293
294 while (*p1) {
295 if ((*p1) == '@')
296 pa = p1;
297 if ((*p1) == '/')
298 ps = p1 + 1;
299 p1++;
300 }
301 if (pa < ps)
302 pa = p1;
303 sz = (pa - ps) + 1;
304 pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
305 __alignof__(struct property));
306 if (allnextpp) {
307 pp->name = "name";
308 pp->length = sz;
309 pp->value = pp + 1;
310 *prev_pp = pp;
311 prev_pp = &pp->next;
312 memcpy(pp->value, ps, sz - 1);
313 ((char *)pp->value)[sz - 1] = 0;
314 pr_debug("fixed up name for %s -> %s\n", pathp,
315 (char *)pp->value);
316 }
317 }
318 if (allnextpp) {
319 *prev_pp = NULL;
320 np->name = of_get_property(np, "name", NULL);
321 np->type = of_get_property(np, "device_type", NULL);
322
323 if (!np->name)
324 np->name = "<NULL>";
325 if (!np->type)
326 np->type = "<NULL>";
327 }
328 while (tag == OF_DT_BEGIN_NODE || tag == OF_DT_NOP) {
329 if (tag == OF_DT_NOP)
330 *p += 4;
331 else
332 mem = unflatten_dt_node(blob, mem, p, np, allnextpp,
333 fpsize);
334 tag = be32_to_cpup((__be32 *)(*p));
335 }
336 if (tag != OF_DT_END_NODE) {
337 pr_err("Weird tag at end of node: %x\n", tag);
338 return mem;
339 }
340 *p += 4;
341 return mem;
342}
343
344/**
345 * __unflatten_device_tree - create tree of device_nodes from flat blob
346 *
347 * unflattens a device-tree, creating the
348 * tree of struct device_node. It also fills the "name" and "type"
349 * pointers of the nodes so the normal device-tree walking functions
350 * can be used.
351 * @blob: The blob to expand
352 * @mynodes: The device_node tree created by the call
353 * @dt_alloc: An allocator that provides a virtual address to memory
354 * for the resulting tree
355 */
356static void __unflatten_device_tree(struct boot_param_header *blob,
357 struct device_node **mynodes,
358 void * (*dt_alloc)(u64 size, u64 align))
359{
360 unsigned long start, mem, size;
361 struct device_node **allnextp = mynodes;
362
363 pr_debug(" -> unflatten_device_tree()\n");
364
365 if (!blob) {
366 pr_debug("No device tree pointer\n");
367 return;
368 }
369
370 pr_debug("Unflattening device tree:\n");
371 pr_debug("magic: %08x\n", be32_to_cpu(blob->magic));
372 pr_debug("size: %08x\n", be32_to_cpu(blob->totalsize));
373 pr_debug("version: %08x\n", be32_to_cpu(blob->version));
374
375 if (be32_to_cpu(blob->magic) != OF_DT_HEADER) {
376 pr_err("Invalid device tree blob header\n");
377 return;
378 }
379
380 /* First pass, scan for size */
381 start = ((unsigned long)blob) +
382 be32_to_cpu(blob->off_dt_struct);
383 size = unflatten_dt_node(blob, 0, &start, NULL, NULL, 0);
384 size = (size | 3) + 1;
385
386 pr_debug(" size is %lx, allocating...\n", size);
387
388 /* Allocate memory for the expanded device tree */
389 mem = (unsigned long)
390 dt_alloc(size + 4, __alignof__(struct device_node));
391
392 ((__be32 *)mem)[size / 4] = cpu_to_be32(0xdeadbeef);
393
394 pr_debug(" unflattening %lx...\n", mem);
395
396 /* Second pass, do actual unflattening */
397 start = ((unsigned long)blob) +
398 be32_to_cpu(blob->off_dt_struct);
399 unflatten_dt_node(blob, mem, &start, NULL, &allnextp, 0);
400 if (be32_to_cpup((__be32 *)start) != OF_DT_END)
401 pr_warning("Weird tag at end of tree: %08x\n", *((u32 *)start));
402 if (be32_to_cpu(((__be32 *)mem)[size / 4]) != 0xdeadbeef)
403 pr_warning("End of tree marker overwritten: %08x\n",
404 be32_to_cpu(((__be32 *)mem)[size / 4]));
405 *allnextp = NULL;
406
407 pr_debug(" <- unflatten_device_tree()\n");
408}
409
410static void *kernel_tree_alloc(u64 size, u64 align)
411{
412 return kzalloc(size, GFP_KERNEL);
413}
414
415/**
416 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
417 *
418 * unflattens the device-tree passed by the firmware, creating the
419 * tree of struct device_node. It also fills the "name" and "type"
420 * pointers of the nodes so the normal device-tree walking functions
421 * can be used.
422 */
423void of_fdt_unflatten_tree(unsigned long *blob,
424 struct device_node **mynodes)
425{
426 struct boot_param_header *device_tree =
427 (struct boot_param_header *)blob;
428 __unflatten_device_tree(device_tree, mynodes, &kernel_tree_alloc);
429}
430EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
431
432/* Everything below here references initial_boot_params directly. */
433int __initdata dt_root_addr_cells;
434int __initdata dt_root_size_cells;
435
436struct boot_param_header *initial_boot_params;
437
438#ifdef CONFIG_OF_EARLY_FLATTREE
439
440/**
441 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
442 * @it: callback function
443 * @data: context data pointer
444 *
445 * This function is used to scan the flattened device-tree, it is
446 * used to extract the memory information at boot before we can
447 * unflatten the tree
448 */
449int __init of_scan_flat_dt(int (*it)(unsigned long node,
450 const char *uname, int depth,
451 void *data),
452 void *data)
453{
454 unsigned long p = ((unsigned long)initial_boot_params) +
455 be32_to_cpu(initial_boot_params->off_dt_struct);
456 int rc = 0;
457 int depth = -1;
458
459 do {
460 u32 tag = be32_to_cpup((__be32 *)p);
461 char *pathp;
462
463 p += 4;
464 if (tag == OF_DT_END_NODE) {
465 depth--;
466 continue;
467 }
468 if (tag == OF_DT_NOP)
469 continue;
470 if (tag == OF_DT_END)
471 break;
472 if (tag == OF_DT_PROP) {
473 u32 sz = be32_to_cpup((__be32 *)p);
474 p += 8;
475 if (be32_to_cpu(initial_boot_params->version) < 0x10)
476 p = ALIGN(p, sz >= 8 ? 8 : 4);
477 p += sz;
478 p = ALIGN(p, 4);
479 continue;
480 }
481 if (tag != OF_DT_BEGIN_NODE) {
482 pr_err("Invalid tag %x in flat device tree!\n", tag);
483 return -EINVAL;
484 }
485 depth++;
486 pathp = (char *)p;
487 p = ALIGN(p + strlen(pathp) + 1, 4);
488 if ((*pathp) == '/') {
489 char *lp, *np;
490 for (lp = NULL, np = pathp; *np; np++)
491 if ((*np) == '/')
492 lp = np+1;
493 if (lp != NULL)
494 pathp = lp;
495 }
496 rc = it(p, pathp, depth, data);
497 if (rc != 0)
498 break;
499 } while (1);
500
501 return rc;
502}
503
504/**
505 * of_get_flat_dt_root - find the root node in the flat blob
506 */
507unsigned long __init of_get_flat_dt_root(void)
508{
509 unsigned long p = ((unsigned long)initial_boot_params) +
510 be32_to_cpu(initial_boot_params->off_dt_struct);
511
512 while (be32_to_cpup((__be32 *)p) == OF_DT_NOP)
513 p += 4;
514 BUG_ON(be32_to_cpup((__be32 *)p) != OF_DT_BEGIN_NODE);
515 p += 4;
516 return ALIGN(p + strlen((char *)p) + 1, 4);
517}
518
519/**
520 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
521 *
522 * This function can be used within scan_flattened_dt callback to get
523 * access to properties
524 */
525void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
526 unsigned long *size)
527{
528 return of_fdt_get_property(initial_boot_params, node, name, size);
529}
530
531/**
532 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
533 * @node: node to test
534 * @compat: compatible string to compare with compatible list.
535 */
536int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
537{
538 return of_fdt_is_compatible(initial_boot_params, node, compat);
539}
540
541/**
542 * of_flat_dt_match - Return true if node matches a list of compatible values
543 */
544int __init of_flat_dt_match(unsigned long node, const char **compat)
545{
546 return of_fdt_match(initial_boot_params, node, compat);
547}
548
549#ifdef CONFIG_BLK_DEV_INITRD
550/**
551 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
552 * @node: reference to node containing initrd location ('chosen')
553 */
554void __init early_init_dt_check_for_initrd(unsigned long node)
555{
556 unsigned long start, end, len;
557 __be32 *prop;
558
559 pr_debug("Looking for initrd properties... ");
560
561 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
562 if (!prop)
563 return;
564 start = of_read_ulong(prop, len/4);
565
566 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
567 if (!prop)
568 return;
569 end = of_read_ulong(prop, len/4);
570
571 early_init_dt_setup_initrd_arch(start, end);
572 pr_debug("initrd_start=0x%lx initrd_end=0x%lx\n", start, end);
573}
574#else
575inline void early_init_dt_check_for_initrd(unsigned long node)
576{
577}
578#endif /* CONFIG_BLK_DEV_INITRD */
579
580/**
581 * early_init_dt_scan_root - fetch the top level address and size cells
582 */
583int __init early_init_dt_scan_root(unsigned long node, const char *uname,
584 int depth, void *data)
585{
586 __be32 *prop;
587
588 if (depth != 0)
589 return 0;
590
591 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
592 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
593
594 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
595 if (prop)
596 dt_root_size_cells = be32_to_cpup(prop);
597 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
598
599 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
600 if (prop)
601 dt_root_addr_cells = be32_to_cpup(prop);
602 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
603
604 /* break now */
605 return 1;
606}
607
608u64 __init dt_mem_next_cell(int s, __be32 **cellp)
609{
610 __be32 *p = *cellp;
611
612 *cellp = p + s;
613 return of_read_number(p, s);
614}
615
616/**
617 * early_init_dt_scan_memory - Look for an parse memory nodes
618 */
619int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
620 int depth, void *data)
621{
622 char *type = of_get_flat_dt_prop(node, "device_type", NULL);
623 __be32 *reg, *endp;
624 unsigned long l;
625
626 /* We are scanning "memory" nodes only */
627 if (type == NULL) {
628 /*
629 * The longtrail doesn't have a device_type on the
630 * /memory node, so look for the node called /memory@0.
631 */
632 if (depth != 1 || strcmp(uname, "memory@0") != 0)
633 return 0;
634 } else if (strcmp(type, "memory") != 0)
635 return 0;
636
637 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
638 if (reg == NULL)
639 reg = of_get_flat_dt_prop(node, "reg", &l);
640 if (reg == NULL)
641 return 0;
642
643 endp = reg + (l / sizeof(__be32));
644
645 pr_debug("memory scan node %s, reg size %ld, data: %x %x %x %x,\n",
646 uname, l, reg[0], reg[1], reg[2], reg[3]);
647
648 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
649 u64 base, size;
650
651 base = dt_mem_next_cell(dt_root_addr_cells, ®);
652 size = dt_mem_next_cell(dt_root_size_cells, ®);
653
654 if (size == 0)
655 continue;
656 pr_debug(" - %llx , %llx\n", (unsigned long long)base,
657 (unsigned long long)size);
658
659 early_init_dt_add_memory_arch(base, size);
660 }
661
662 return 0;
663}
664
665int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
666 int depth, void *data)
667{
668 unsigned long l;
669 char *p;
670
671 pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
672
673 if (depth != 1 || !data ||
674 (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
675 return 0;
676
677 early_init_dt_check_for_initrd(node);
678
679 /* Retrieve command line */
680 p = of_get_flat_dt_prop(node, "bootargs", &l);
681 if (p != NULL && l > 0)
682 strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
683
684#ifdef CONFIG_CMDLINE
685#ifndef CONFIG_CMDLINE_FORCE
686 if (p == NULL || l == 0 || (l == 1 && (*p) == 0))
687#endif
688 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
689#endif /* CONFIG_CMDLINE */
690
691 pr_debug("Command line is: %s\n", (char*)data);
692
693 /* break now */
694 return 1;
695}
696
697/**
698 * unflatten_device_tree - create tree of device_nodes from flat blob
699 *
700 * unflattens the device-tree passed by the firmware, creating the
701 * tree of struct device_node. It also fills the "name" and "type"
702 * pointers of the nodes so the normal device-tree walking functions
703 * can be used.
704 */
705void __init unflatten_device_tree(void)
706{
707 __unflatten_device_tree(initial_boot_params, &allnodes,
708 early_init_dt_alloc_memory_arch);
709
710 /* Get pointer to OF "/chosen" node for use everywhere */
711 of_chosen = of_find_node_by_path("/chosen");
712 if (of_chosen == NULL)
713 of_chosen = of_find_node_by_path("/chosen@0");
714}
715
716#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 */