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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#include <asm/setup.h> /* for COMMAND_LINE_SIZE */
22#ifdef CONFIG_PPC
23#include <asm/machdep.h>
24#endif /* CONFIG_PPC */
25
26#include <asm/page.h>
27
28char *of_fdt_get_string(struct boot_param_header *blob, u32 offset)
29{
30 return ((char *)blob) +
31 be32_to_cpu(blob->off_dt_strings) + offset;
32}
33
34/**
35 * of_fdt_get_property - Given a node in the given flat blob, return
36 * the property ptr
37 */
38void *of_fdt_get_property(struct boot_param_header *blob,
39 unsigned long node, const char *name,
40 unsigned long *size)
41{
42 unsigned long p = node;
43
44 do {
45 u32 tag = be32_to_cpup((__be32 *)p);
46 u32 sz, noff;
47 const char *nstr;
48
49 p += 4;
50 if (tag == OF_DT_NOP)
51 continue;
52 if (tag != OF_DT_PROP)
53 return NULL;
54
55 sz = be32_to_cpup((__be32 *)p);
56 noff = be32_to_cpup((__be32 *)(p + 4));
57 p += 8;
58 if (be32_to_cpu(blob->version) < 0x10)
59 p = ALIGN(p, sz >= 8 ? 8 : 4);
60
61 nstr = of_fdt_get_string(blob, noff);
62 if (nstr == NULL) {
63 pr_warning("Can't find property index name !\n");
64 return NULL;
65 }
66 if (strcmp(name, nstr) == 0) {
67 if (size)
68 *size = sz;
69 return (void *)p;
70 }
71 p += sz;
72 p = ALIGN(p, 4);
73 } while (1);
74}
75
76/**
77 * of_fdt_is_compatible - Return true if given node from the given blob has
78 * compat in its compatible list
79 * @blob: A device tree blob
80 * @node: node to test
81 * @compat: compatible string to compare with compatible list.
82 *
83 * On match, returns a non-zero value with smaller values returned for more
84 * specific compatible values.
85 */
86int of_fdt_is_compatible(struct boot_param_header *blob,
87 unsigned long node, const char *compat)
88{
89 const char *cp;
90 unsigned long cplen, l, score = 0;
91
92 cp = of_fdt_get_property(blob, node, "compatible", &cplen);
93 if (cp == NULL)
94 return 0;
95 while (cplen > 0) {
96 score++;
97 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
98 return score;
99 l = strlen(cp) + 1;
100 cp += l;
101 cplen -= l;
102 }
103
104 return 0;
105}
106
107/**
108 * of_fdt_match - Return true if node matches a list of compatible values
109 */
110int of_fdt_match(struct boot_param_header *blob, unsigned long node,
111 const char *const *compat)
112{
113 unsigned int tmp, score = 0;
114
115 if (!compat)
116 return 0;
117
118 while (*compat) {
119 tmp = of_fdt_is_compatible(blob, node, *compat);
120 if (tmp && (score == 0 || (tmp < score)))
121 score = tmp;
122 compat++;
123 }
124
125 return score;
126}
127
128static void *unflatten_dt_alloc(unsigned long *mem, unsigned long size,
129 unsigned long align)
130{
131 void *res;
132
133 *mem = ALIGN(*mem, align);
134 res = (void *)*mem;
135 *mem += size;
136
137 return res;
138}
139
140/**
141 * unflatten_dt_node - Alloc and populate a device_node from the flat tree
142 * @blob: The parent device tree blob
143 * @mem: Memory chunk to use for allocating device nodes and properties
144 * @p: pointer to node in flat tree
145 * @dad: Parent struct device_node
146 * @allnextpp: pointer to ->allnext from last allocated device_node
147 * @fpsize: Size of the node path up at the current depth.
148 */
149static unsigned long unflatten_dt_node(struct boot_param_header *blob,
150 unsigned long mem,
151 unsigned long *p,
152 struct device_node *dad,
153 struct device_node ***allnextpp,
154 unsigned long fpsize)
155{
156 struct device_node *np;
157 struct property *pp, **prev_pp = NULL;
158 char *pathp;
159 u32 tag;
160 unsigned int l, allocl;
161 int has_name = 0;
162 int new_format = 0;
163
164 tag = be32_to_cpup((__be32 *)(*p));
165 if (tag != OF_DT_BEGIN_NODE) {
166 pr_err("Weird tag at start of node: %x\n", tag);
167 return mem;
168 }
169 *p += 4;
170 pathp = (char *)*p;
171 l = allocl = strlen(pathp) + 1;
172 *p = ALIGN(*p + l, 4);
173
174 /* version 0x10 has a more compact unit name here instead of the full
175 * path. we accumulate the full path size using "fpsize", we'll rebuild
176 * it later. We detect this because the first character of the name is
177 * not '/'.
178 */
179 if ((*pathp) != '/') {
180 new_format = 1;
181 if (fpsize == 0) {
182 /* root node: special case. fpsize accounts for path
183 * plus terminating zero. root node only has '/', so
184 * fpsize should be 2, but we want to avoid the first
185 * level nodes to have two '/' so we use fpsize 1 here
186 */
187 fpsize = 1;
188 allocl = 2;
189 } else {
190 /* account for '/' and path size minus terminal 0
191 * already in 'l'
192 */
193 fpsize += l;
194 allocl = fpsize;
195 }
196 }
197
198 np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl,
199 __alignof__(struct device_node));
200 if (allnextpp) {
201 memset(np, 0, sizeof(*np));
202 np->full_name = ((char *)np) + sizeof(struct device_node);
203 if (new_format) {
204 char *fn = np->full_name;
205 /* rebuild full path for new format */
206 if (dad && dad->parent) {
207 strcpy(fn, dad->full_name);
208#ifdef DEBUG
209 if ((strlen(fn) + l + 1) != allocl) {
210 pr_debug("%s: p: %d, l: %d, a: %d\n",
211 pathp, (int)strlen(fn),
212 l, allocl);
213 }
214#endif
215 fn += strlen(fn);
216 }
217 *(fn++) = '/';
218 memcpy(fn, pathp, l);
219 } else
220 memcpy(np->full_name, pathp, l);
221 prev_pp = &np->properties;
222 **allnextpp = np;
223 *allnextpp = &np->allnext;
224 if (dad != NULL) {
225 np->parent = dad;
226 /* we temporarily use the next field as `last_child'*/
227 if (dad->next == NULL)
228 dad->child = np;
229 else
230 dad->next->sibling = np;
231 dad->next = np;
232 }
233 kref_init(&np->kref);
234 }
235 /* process properties */
236 while (1) {
237 u32 sz, noff;
238 char *pname;
239
240 tag = be32_to_cpup((__be32 *)(*p));
241 if (tag == OF_DT_NOP) {
242 *p += 4;
243 continue;
244 }
245 if (tag != OF_DT_PROP)
246 break;
247 *p += 4;
248 sz = be32_to_cpup((__be32 *)(*p));
249 noff = be32_to_cpup((__be32 *)((*p) + 4));
250 *p += 8;
251 if (be32_to_cpu(blob->version) < 0x10)
252 *p = ALIGN(*p, sz >= 8 ? 8 : 4);
253
254 pname = of_fdt_get_string(blob, noff);
255 if (pname == NULL) {
256 pr_info("Can't find property name in list !\n");
257 break;
258 }
259 if (strcmp(pname, "name") == 0)
260 has_name = 1;
261 l = strlen(pname) + 1;
262 pp = unflatten_dt_alloc(&mem, sizeof(struct property),
263 __alignof__(struct property));
264 if (allnextpp) {
265 /* We accept flattened tree phandles either in
266 * ePAPR-style "phandle" properties, or the
267 * legacy "linux,phandle" properties. If both
268 * appear and have different values, things
269 * will get weird. Don't do that. */
270 if ((strcmp(pname, "phandle") == 0) ||
271 (strcmp(pname, "linux,phandle") == 0)) {
272 if (np->phandle == 0)
273 np->phandle = be32_to_cpup((__be32*)*p);
274 }
275 /* And we process the "ibm,phandle" property
276 * used in pSeries dynamic device tree
277 * stuff */
278 if (strcmp(pname, "ibm,phandle") == 0)
279 np->phandle = be32_to_cpup((__be32 *)*p);
280 pp->name = pname;
281 pp->length = sz;
282 pp->value = (void *)*p;
283 *prev_pp = pp;
284 prev_pp = &pp->next;
285 }
286 *p = ALIGN((*p) + sz, 4);
287 }
288 /* with version 0x10 we may not have the name property, recreate
289 * it here from the unit name if absent
290 */
291 if (!has_name) {
292 char *p1 = pathp, *ps = pathp, *pa = NULL;
293 int sz;
294
295 while (*p1) {
296 if ((*p1) == '@')
297 pa = p1;
298 if ((*p1) == '/')
299 ps = p1 + 1;
300 p1++;
301 }
302 if (pa < ps)
303 pa = p1;
304 sz = (pa - ps) + 1;
305 pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz,
306 __alignof__(struct property));
307 if (allnextpp) {
308 pp->name = "name";
309 pp->length = sz;
310 pp->value = pp + 1;
311 *prev_pp = pp;
312 prev_pp = &pp->next;
313 memcpy(pp->value, ps, sz - 1);
314 ((char *)pp->value)[sz - 1] = 0;
315 pr_debug("fixed up name for %s -> %s\n", pathp,
316 (char *)pp->value);
317 }
318 }
319 if (allnextpp) {
320 *prev_pp = NULL;
321 np->name = of_get_property(np, "name", NULL);
322 np->type = of_get_property(np, "device_type", NULL);
323
324 if (!np->name)
325 np->name = "<NULL>";
326 if (!np->type)
327 np->type = "<NULL>";
328 }
329 while (tag == OF_DT_BEGIN_NODE || tag == OF_DT_NOP) {
330 if (tag == OF_DT_NOP)
331 *p += 4;
332 else
333 mem = unflatten_dt_node(blob, mem, p, np, allnextpp,
334 fpsize);
335 tag = be32_to_cpup((__be32 *)(*p));
336 }
337 if (tag != OF_DT_END_NODE) {
338 pr_err("Weird tag at end of node: %x\n", tag);
339 return mem;
340 }
341 *p += 4;
342 return mem;
343}
344
345/**
346 * __unflatten_device_tree - create tree of device_nodes from flat blob
347 *
348 * unflattens a device-tree, creating the
349 * tree of struct device_node. It also fills the "name" and "type"
350 * pointers of the nodes so the normal device-tree walking functions
351 * can be used.
352 * @blob: The blob to expand
353 * @mynodes: The device_node tree created by the call
354 * @dt_alloc: An allocator that provides a virtual address to memory
355 * for the resulting tree
356 */
357static void __unflatten_device_tree(struct boot_param_header *blob,
358 struct device_node **mynodes,
359 void * (*dt_alloc)(u64 size, u64 align))
360{
361 unsigned long start, mem, size;
362 struct device_node **allnextp = mynodes;
363
364 pr_debug(" -> unflatten_device_tree()\n");
365
366 if (!blob) {
367 pr_debug("No device tree pointer\n");
368 return;
369 }
370
371 pr_debug("Unflattening device tree:\n");
372 pr_debug("magic: %08x\n", be32_to_cpu(blob->magic));
373 pr_debug("size: %08x\n", be32_to_cpu(blob->totalsize));
374 pr_debug("version: %08x\n", be32_to_cpu(blob->version));
375
376 if (be32_to_cpu(blob->magic) != OF_DT_HEADER) {
377 pr_err("Invalid device tree blob header\n");
378 return;
379 }
380
381 /* First pass, scan for size */
382 start = ((unsigned long)blob) +
383 be32_to_cpu(blob->off_dt_struct);
384 size = unflatten_dt_node(blob, 0, &start, NULL, NULL, 0);
385 size = (size | 3) + 1;
386
387 pr_debug(" size is %lx, allocating...\n", size);
388
389 /* Allocate memory for the expanded device tree */
390 mem = (unsigned long)
391 dt_alloc(size + 4, __alignof__(struct device_node));
392
393 ((__be32 *)mem)[size / 4] = cpu_to_be32(0xdeadbeef);
394
395 pr_debug(" unflattening %lx...\n", mem);
396
397 /* Second pass, do actual unflattening */
398 start = ((unsigned long)blob) +
399 be32_to_cpu(blob->off_dt_struct);
400 unflatten_dt_node(blob, mem, &start, NULL, &allnextp, 0);
401 if (be32_to_cpup((__be32 *)start) != OF_DT_END)
402 pr_warning("Weird tag at end of tree: %08x\n", *((u32 *)start));
403 if (be32_to_cpu(((__be32 *)mem)[size / 4]) != 0xdeadbeef)
404 pr_warning("End of tree marker overwritten: %08x\n",
405 be32_to_cpu(((__be32 *)mem)[size / 4]));
406 *allnextp = NULL;
407
408 pr_debug(" <- unflatten_device_tree()\n");
409}
410
411static void *kernel_tree_alloc(u64 size, u64 align)
412{
413 return kzalloc(size, GFP_KERNEL);
414}
415
416/**
417 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
418 *
419 * unflattens the device-tree passed by the firmware, creating the
420 * tree of struct device_node. It also fills the "name" and "type"
421 * pointers of the nodes so the normal device-tree walking functions
422 * can be used.
423 */
424void of_fdt_unflatten_tree(unsigned long *blob,
425 struct device_node **mynodes)
426{
427 struct boot_param_header *device_tree =
428 (struct boot_param_header *)blob;
429 __unflatten_device_tree(device_tree, mynodes, &kernel_tree_alloc);
430}
431EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
432
433/* Everything below here references initial_boot_params directly. */
434int __initdata dt_root_addr_cells;
435int __initdata dt_root_size_cells;
436
437struct boot_param_header *initial_boot_params;
438
439#ifdef CONFIG_OF_EARLY_FLATTREE
440
441/**
442 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
443 * @it: callback function
444 * @data: context data pointer
445 *
446 * This function is used to scan the flattened device-tree, it is
447 * used to extract the memory information at boot before we can
448 * unflatten the tree
449 */
450int __init of_scan_flat_dt(int (*it)(unsigned long node,
451 const char *uname, int depth,
452 void *data),
453 void *data)
454{
455 unsigned long p = ((unsigned long)initial_boot_params) +
456 be32_to_cpu(initial_boot_params->off_dt_struct);
457 int rc = 0;
458 int depth = -1;
459
460 do {
461 u32 tag = be32_to_cpup((__be32 *)p);
462 char *pathp;
463
464 p += 4;
465 if (tag == OF_DT_END_NODE) {
466 depth--;
467 continue;
468 }
469 if (tag == OF_DT_NOP)
470 continue;
471 if (tag == OF_DT_END)
472 break;
473 if (tag == OF_DT_PROP) {
474 u32 sz = be32_to_cpup((__be32 *)p);
475 p += 8;
476 if (be32_to_cpu(initial_boot_params->version) < 0x10)
477 p = ALIGN(p, sz >= 8 ? 8 : 4);
478 p += sz;
479 p = ALIGN(p, 4);
480 continue;
481 }
482 if (tag != OF_DT_BEGIN_NODE) {
483 pr_err("Invalid tag %x in flat device tree!\n", tag);
484 return -EINVAL;
485 }
486 depth++;
487 pathp = (char *)p;
488 p = ALIGN(p + strlen(pathp) + 1, 4);
489 if ((*pathp) == '/') {
490 char *lp, *np;
491 for (lp = NULL, np = pathp; *np; np++)
492 if ((*np) == '/')
493 lp = np+1;
494 if (lp != NULL)
495 pathp = lp;
496 }
497 rc = it(p, pathp, depth, data);
498 if (rc != 0)
499 break;
500 } while (1);
501
502 return rc;
503}
504
505/**
506 * of_get_flat_dt_root - find the root node in the flat blob
507 */
508unsigned long __init of_get_flat_dt_root(void)
509{
510 unsigned long p = ((unsigned long)initial_boot_params) +
511 be32_to_cpu(initial_boot_params->off_dt_struct);
512
513 while (be32_to_cpup((__be32 *)p) == OF_DT_NOP)
514 p += 4;
515 BUG_ON(be32_to_cpup((__be32 *)p) != OF_DT_BEGIN_NODE);
516 p += 4;
517 return ALIGN(p + strlen((char *)p) + 1, 4);
518}
519
520/**
521 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
522 *
523 * This function can be used within scan_flattened_dt callback to get
524 * access to properties
525 */
526void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
527 unsigned long *size)
528{
529 return of_fdt_get_property(initial_boot_params, node, name, size);
530}
531
532/**
533 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
534 * @node: node to test
535 * @compat: compatible string to compare with compatible list.
536 */
537int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
538{
539 return of_fdt_is_compatible(initial_boot_params, node, compat);
540}
541
542/**
543 * of_flat_dt_match - Return true if node matches a list of compatible values
544 */
545int __init of_flat_dt_match(unsigned long node, const char *const *compat)
546{
547 return of_fdt_match(initial_boot_params, node, compat);
548}
549
550#ifdef CONFIG_BLK_DEV_INITRD
551/**
552 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
553 * @node: reference to node containing initrd location ('chosen')
554 */
555void __init early_init_dt_check_for_initrd(unsigned long node)
556{
557 unsigned long start, end, len;
558 __be32 *prop;
559
560 pr_debug("Looking for initrd properties... ");
561
562 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
563 if (!prop)
564 return;
565 start = of_read_ulong(prop, len/4);
566
567 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
568 if (!prop)
569 return;
570 end = of_read_ulong(prop, len/4);
571
572 early_init_dt_setup_initrd_arch(start, end);
573 pr_debug("initrd_start=0x%lx initrd_end=0x%lx\n", start, end);
574}
575#else
576inline void early_init_dt_check_for_initrd(unsigned long node)
577{
578}
579#endif /* CONFIG_BLK_DEV_INITRD */
580
581/**
582 * early_init_dt_scan_root - fetch the top level address and size cells
583 */
584int __init early_init_dt_scan_root(unsigned long node, const char *uname,
585 int depth, void *data)
586{
587 __be32 *prop;
588
589 if (depth != 0)
590 return 0;
591
592 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
593 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
594
595 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
596 if (prop)
597 dt_root_size_cells = be32_to_cpup(prop);
598 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
599
600 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
601 if (prop)
602 dt_root_addr_cells = be32_to_cpup(prop);
603 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
604
605 /* break now */
606 return 1;
607}
608
609u64 __init dt_mem_next_cell(int s, __be32 **cellp)
610{
611 __be32 *p = *cellp;
612
613 *cellp = p + s;
614 return of_read_number(p, s);
615}
616
617/**
618 * early_init_dt_scan_memory - Look for an parse memory nodes
619 */
620int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
621 int depth, void *data)
622{
623 char *type = of_get_flat_dt_prop(node, "device_type", NULL);
624 __be32 *reg, *endp;
625 unsigned long l;
626
627 /* We are scanning "memory" nodes only */
628 if (type == NULL) {
629 /*
630 * The longtrail doesn't have a device_type on the
631 * /memory node, so look for the node called /memory@0.
632 */
633 if (depth != 1 || strcmp(uname, "memory@0") != 0)
634 return 0;
635 } else if (strcmp(type, "memory") != 0)
636 return 0;
637
638 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
639 if (reg == NULL)
640 reg = of_get_flat_dt_prop(node, "reg", &l);
641 if (reg == NULL)
642 return 0;
643
644 endp = reg + (l / sizeof(__be32));
645
646 pr_debug("memory scan node %s, reg size %ld, data: %x %x %x %x,\n",
647 uname, l, reg[0], reg[1], reg[2], reg[3]);
648
649 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
650 u64 base, size;
651
652 base = dt_mem_next_cell(dt_root_addr_cells, ®);
653 size = dt_mem_next_cell(dt_root_size_cells, ®);
654
655 if (size == 0)
656 continue;
657 pr_debug(" - %llx , %llx\n", (unsigned long long)base,
658 (unsigned long long)size);
659
660 early_init_dt_add_memory_arch(base, size);
661 }
662
663 return 0;
664}
665
666int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
667 int depth, void *data)
668{
669 unsigned long l;
670 char *p;
671
672 pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
673
674 if (depth != 1 || !data ||
675 (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
676 return 0;
677
678 early_init_dt_check_for_initrd(node);
679
680 /* Retrieve command line */
681 p = of_get_flat_dt_prop(node, "bootargs", &l);
682 if (p != NULL && l > 0)
683 strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
684
685 /*
686 * CONFIG_CMDLINE is meant to be a default in case nothing else
687 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
688 * is set in which case we override whatever was found earlier.
689 */
690#ifdef CONFIG_CMDLINE
691#ifndef CONFIG_CMDLINE_FORCE
692 if (!((char *)data)[0])
693#endif
694 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
695#endif /* CONFIG_CMDLINE */
696
697 pr_debug("Command line is: %s\n", (char*)data);
698
699 /* break now */
700 return 1;
701}
702
703/**
704 * unflatten_device_tree - create tree of device_nodes from flat blob
705 *
706 * unflattens the device-tree passed by the firmware, creating the
707 * tree of struct device_node. It also fills the "name" and "type"
708 * pointers of the nodes so the normal device-tree walking functions
709 * can be used.
710 */
711void __init unflatten_device_tree(void)
712{
713 __unflatten_device_tree(initial_boot_params, &allnodes,
714 early_init_dt_alloc_memory_arch);
715
716 /* Get pointer to "/chosen" and "/aliasas" nodes for use everywhere */
717 of_alias_scan(early_init_dt_alloc_memory_arch);
718}
719
720#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/crash_dump.h>
12#include <linux/crc32.h>
13#include <linux/kernel.h>
14#include <linux/initrd.h>
15#include <linux/memblock.h>
16#include <linux/mutex.h>
17#include <linux/of.h>
18#include <linux/of_fdt.h>
19#include <linux/of_reserved_mem.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 * of_fdt_limit_memory - limit the number of regions in the /memory node
37 * @limit: maximum entries
38 *
39 * Adjust the flattened device tree to have at most 'limit' number of
40 * memory entries in the /memory node. This function may be called
41 * any time after initial_boot_param is set.
42 */
43void __init of_fdt_limit_memory(int limit)
44{
45 int memory;
46 int len;
47 const void *val;
48 int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
49 int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
50 const __be32 *addr_prop;
51 const __be32 *size_prop;
52 int root_offset;
53 int cell_size;
54
55 root_offset = fdt_path_offset(initial_boot_params, "/");
56 if (root_offset < 0)
57 return;
58
59 addr_prop = fdt_getprop(initial_boot_params, root_offset,
60 "#address-cells", NULL);
61 if (addr_prop)
62 nr_address_cells = fdt32_to_cpu(*addr_prop);
63
64 size_prop = fdt_getprop(initial_boot_params, root_offset,
65 "#size-cells", NULL);
66 if (size_prop)
67 nr_size_cells = fdt32_to_cpu(*size_prop);
68
69 cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
70
71 memory = fdt_path_offset(initial_boot_params, "/memory");
72 if (memory > 0) {
73 val = fdt_getprop(initial_boot_params, memory, "reg", &len);
74 if (len > limit*cell_size) {
75 len = limit*cell_size;
76 pr_debug("Limiting number of entries to %d\n", limit);
77 fdt_setprop(initial_boot_params, memory, "reg", val,
78 len);
79 }
80 }
81}
82
83static bool of_fdt_device_is_available(const void *blob, unsigned long node)
84{
85 const char *status = fdt_getprop(blob, node, "status", NULL);
86
87 if (!status)
88 return true;
89
90 if (!strcmp(status, "ok") || !strcmp(status, "okay"))
91 return true;
92
93 return false;
94}
95
96static void *unflatten_dt_alloc(void **mem, unsigned long size,
97 unsigned long align)
98{
99 void *res;
100
101 *mem = PTR_ALIGN(*mem, align);
102 res = *mem;
103 *mem += size;
104
105 return res;
106}
107
108static void populate_properties(const void *blob,
109 int offset,
110 void **mem,
111 struct device_node *np,
112 const char *nodename,
113 bool dryrun)
114{
115 struct property *pp, **pprev = NULL;
116 int cur;
117 bool has_name = false;
118
119 pprev = &np->properties;
120 for (cur = fdt_first_property_offset(blob, offset);
121 cur >= 0;
122 cur = fdt_next_property_offset(blob, cur)) {
123 const __be32 *val;
124 const char *pname;
125 u32 sz;
126
127 val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
128 if (!val) {
129 pr_warn("Cannot locate property at 0x%x\n", cur);
130 continue;
131 }
132
133 if (!pname) {
134 pr_warn("Cannot find property name at 0x%x\n", cur);
135 continue;
136 }
137
138 if (!strcmp(pname, "name"))
139 has_name = true;
140
141 pp = unflatten_dt_alloc(mem, sizeof(struct property),
142 __alignof__(struct property));
143 if (dryrun)
144 continue;
145
146 /* We accept flattened tree phandles either in
147 * ePAPR-style "phandle" properties, or the
148 * legacy "linux,phandle" properties. If both
149 * appear and have different values, things
150 * will get weird. Don't do that.
151 */
152 if (!strcmp(pname, "phandle") ||
153 !strcmp(pname, "linux,phandle")) {
154 if (!np->phandle)
155 np->phandle = be32_to_cpup(val);
156 }
157
158 /* And we process the "ibm,phandle" property
159 * used in pSeries dynamic device tree
160 * stuff
161 */
162 if (!strcmp(pname, "ibm,phandle"))
163 np->phandle = be32_to_cpup(val);
164
165 pp->name = (char *)pname;
166 pp->length = sz;
167 pp->value = (__be32 *)val;
168 *pprev = pp;
169 pprev = &pp->next;
170 }
171
172 /* With version 0x10 we may not have the name property,
173 * recreate it here from the unit name if absent
174 */
175 if (!has_name) {
176 const char *p = nodename, *ps = p, *pa = NULL;
177 int len;
178
179 while (*p) {
180 if ((*p) == '@')
181 pa = p;
182 else if ((*p) == '/')
183 ps = p + 1;
184 p++;
185 }
186
187 if (pa < ps)
188 pa = p;
189 len = (pa - ps) + 1;
190 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
191 __alignof__(struct property));
192 if (!dryrun) {
193 pp->name = "name";
194 pp->length = len;
195 pp->value = pp + 1;
196 *pprev = pp;
197 memcpy(pp->value, ps, len - 1);
198 ((char *)pp->value)[len - 1] = 0;
199 pr_debug("fixed up name for %s -> %s\n",
200 nodename, (char *)pp->value);
201 }
202 }
203}
204
205static int populate_node(const void *blob,
206 int offset,
207 void **mem,
208 struct device_node *dad,
209 struct device_node **pnp,
210 bool dryrun)
211{
212 struct device_node *np;
213 const char *pathp;
214 int len;
215
216 pathp = fdt_get_name(blob, offset, &len);
217 if (!pathp) {
218 *pnp = NULL;
219 return len;
220 }
221
222 len++;
223
224 np = unflatten_dt_alloc(mem, sizeof(struct device_node) + len,
225 __alignof__(struct device_node));
226 if (!dryrun) {
227 char *fn;
228 of_node_init(np);
229 np->full_name = fn = ((char *)np) + sizeof(*np);
230
231 memcpy(fn, pathp, len);
232
233 if (dad != NULL) {
234 np->parent = dad;
235 np->sibling = dad->child;
236 dad->child = np;
237 }
238 }
239
240 populate_properties(blob, offset, mem, np, pathp, dryrun);
241 if (!dryrun) {
242 np->name = of_get_property(np, "name", NULL);
243 if (!np->name)
244 np->name = "<NULL>";
245 }
246
247 *pnp = np;
248 return 0;
249}
250
251static void reverse_nodes(struct device_node *parent)
252{
253 struct device_node *child, *next;
254
255 /* In-depth first */
256 child = parent->child;
257 while (child) {
258 reverse_nodes(child);
259
260 child = child->sibling;
261 }
262
263 /* Reverse the nodes in the child list */
264 child = parent->child;
265 parent->child = NULL;
266 while (child) {
267 next = child->sibling;
268
269 child->sibling = parent->child;
270 parent->child = child;
271 child = next;
272 }
273}
274
275/**
276 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
277 * @blob: The parent device tree blob
278 * @mem: Memory chunk to use for allocating device nodes and properties
279 * @dad: Parent struct device_node
280 * @nodepp: The device_node tree created by the call
281 *
282 * Return: The size of unflattened device tree or error code
283 */
284static int unflatten_dt_nodes(const void *blob,
285 void *mem,
286 struct device_node *dad,
287 struct device_node **nodepp)
288{
289 struct device_node *root;
290 int offset = 0, depth = 0, initial_depth = 0;
291#define FDT_MAX_DEPTH 64
292 struct device_node *nps[FDT_MAX_DEPTH];
293 void *base = mem;
294 bool dryrun = !base;
295 int ret;
296
297 if (nodepp)
298 *nodepp = NULL;
299
300 /*
301 * We're unflattening device sub-tree if @dad is valid. There are
302 * possibly multiple nodes in the first level of depth. We need
303 * set @depth to 1 to make fdt_next_node() happy as it bails
304 * immediately when negative @depth is found. Otherwise, the device
305 * nodes except the first one won't be unflattened successfully.
306 */
307 if (dad)
308 depth = initial_depth = 1;
309
310 root = dad;
311 nps[depth] = dad;
312
313 for (offset = 0;
314 offset >= 0 && depth >= initial_depth;
315 offset = fdt_next_node(blob, offset, &depth)) {
316 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH - 1))
317 continue;
318
319 if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
320 !of_fdt_device_is_available(blob, offset))
321 continue;
322
323 ret = populate_node(blob, offset, &mem, nps[depth],
324 &nps[depth+1], dryrun);
325 if (ret < 0)
326 return ret;
327
328 if (!dryrun && nodepp && !*nodepp)
329 *nodepp = nps[depth+1];
330 if (!dryrun && !root)
331 root = nps[depth+1];
332 }
333
334 if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
335 pr_err("Error %d processing FDT\n", offset);
336 return -EINVAL;
337 }
338
339 /*
340 * Reverse the child list. Some drivers assumes node order matches .dts
341 * node order
342 */
343 if (!dryrun)
344 reverse_nodes(root);
345
346 return mem - base;
347}
348
349/**
350 * __unflatten_device_tree - create tree of device_nodes from flat blob
351 * @blob: The blob to expand
352 * @dad: Parent device node
353 * @mynodes: The device_node tree created by the call
354 * @dt_alloc: An allocator that provides a virtual address to memory
355 * for the resulting tree
356 * @detached: if true set OF_DETACHED on @mynodes
357 *
358 * unflattens a device-tree, creating the tree of struct device_node. It also
359 * fills the "name" and "type" pointers of the nodes so the normal device-tree
360 * walking functions can be used.
361 *
362 * Return: NULL on failure or the memory chunk containing the unflattened
363 * device tree on success.
364 */
365void *__unflatten_device_tree(const void *blob,
366 struct device_node *dad,
367 struct device_node **mynodes,
368 void *(*dt_alloc)(u64 size, u64 align),
369 bool detached)
370{
371 int size;
372 void *mem;
373 int ret;
374
375 if (mynodes)
376 *mynodes = NULL;
377
378 pr_debug(" -> unflatten_device_tree()\n");
379
380 if (!blob) {
381 pr_debug("No device tree pointer\n");
382 return NULL;
383 }
384
385 pr_debug("Unflattening device tree:\n");
386 pr_debug("magic: %08x\n", fdt_magic(blob));
387 pr_debug("size: %08x\n", fdt_totalsize(blob));
388 pr_debug("version: %08x\n", fdt_version(blob));
389
390 if (fdt_check_header(blob)) {
391 pr_err("Invalid device tree blob header\n");
392 return NULL;
393 }
394
395 /* First pass, scan for size */
396 size = unflatten_dt_nodes(blob, NULL, dad, NULL);
397 if (size <= 0)
398 return NULL;
399
400 size = ALIGN(size, 4);
401 pr_debug(" size is %d, allocating...\n", size);
402
403 /* Allocate memory for the expanded device tree */
404 mem = dt_alloc(size + 4, __alignof__(struct device_node));
405 if (!mem)
406 return NULL;
407
408 memset(mem, 0, size);
409
410 *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
411
412 pr_debug(" unflattening %p...\n", mem);
413
414 /* Second pass, do actual unflattening */
415 ret = unflatten_dt_nodes(blob, mem, dad, mynodes);
416
417 if (be32_to_cpup(mem + size) != 0xdeadbeef)
418 pr_warn("End of tree marker overwritten: %08x\n",
419 be32_to_cpup(mem + size));
420
421 if (ret <= 0)
422 return NULL;
423
424 if (detached && mynodes && *mynodes) {
425 of_node_set_flag(*mynodes, OF_DETACHED);
426 pr_debug("unflattened tree is detached\n");
427 }
428
429 pr_debug(" <- unflatten_device_tree()\n");
430 return mem;
431}
432
433static void *kernel_tree_alloc(u64 size, u64 align)
434{
435 return kzalloc(size, GFP_KERNEL);
436}
437
438static DEFINE_MUTEX(of_fdt_unflatten_mutex);
439
440/**
441 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
442 * @blob: Flat device tree blob
443 * @dad: Parent device node
444 * @mynodes: The device tree created by the call
445 *
446 * unflattens the device-tree passed by the firmware, creating the
447 * tree of struct device_node. It also fills the "name" and "type"
448 * pointers of the nodes so the normal device-tree walking functions
449 * can be used.
450 *
451 * Return: NULL on failure or the memory chunk containing the unflattened
452 * device tree on success.
453 */
454void *of_fdt_unflatten_tree(const unsigned long *blob,
455 struct device_node *dad,
456 struct device_node **mynodes)
457{
458 void *mem;
459
460 mutex_lock(&of_fdt_unflatten_mutex);
461 mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
462 true);
463 mutex_unlock(&of_fdt_unflatten_mutex);
464
465 return mem;
466}
467EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
468
469/* Everything below here references initial_boot_params directly. */
470int __initdata dt_root_addr_cells;
471int __initdata dt_root_size_cells;
472
473void *initial_boot_params __ro_after_init;
474
475#ifdef CONFIG_OF_EARLY_FLATTREE
476
477static u32 of_fdt_crc32;
478
479static int __init early_init_dt_reserve_memory(phys_addr_t base,
480 phys_addr_t size, bool nomap)
481{
482 if (nomap) {
483 /*
484 * If the memory is already reserved (by another region), we
485 * should not allow it to be marked nomap, but don't worry
486 * if the region isn't memory as it won't be mapped.
487 */
488 if (memblock_overlaps_region(&memblock.memory, base, size) &&
489 memblock_is_region_reserved(base, size))
490 return -EBUSY;
491
492 return memblock_mark_nomap(base, size);
493 }
494 return memblock_reserve(base, size);
495}
496
497/*
498 * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property
499 */
500static int __init __reserved_mem_reserve_reg(unsigned long node,
501 const char *uname)
502{
503 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
504 phys_addr_t base, size;
505 int len;
506 const __be32 *prop;
507 int first = 1;
508 bool nomap;
509
510 prop = of_get_flat_dt_prop(node, "reg", &len);
511 if (!prop)
512 return -ENOENT;
513
514 if (len && len % t_len != 0) {
515 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
516 uname);
517 return -EINVAL;
518 }
519
520 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
521
522 while (len >= t_len) {
523 base = dt_mem_next_cell(dt_root_addr_cells, &prop);
524 size = dt_mem_next_cell(dt_root_size_cells, &prop);
525
526 if (size &&
527 early_init_dt_reserve_memory(base, size, nomap) == 0)
528 pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n",
529 uname, &base, (unsigned long)(size / SZ_1M));
530 else
531 pr_err("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n",
532 uname, &base, (unsigned long)(size / SZ_1M));
533
534 len -= t_len;
535 if (first) {
536 fdt_reserved_mem_save_node(node, uname, base, size);
537 first = 0;
538 }
539 }
540 return 0;
541}
542
543/*
544 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
545 * in /reserved-memory matches the values supported by the current implementation,
546 * also check if ranges property has been provided
547 */
548static int __init __reserved_mem_check_root(unsigned long node)
549{
550 const __be32 *prop;
551
552 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
553 if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
554 return -EINVAL;
555
556 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
557 if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
558 return -EINVAL;
559
560 prop = of_get_flat_dt_prop(node, "ranges", NULL);
561 if (!prop)
562 return -EINVAL;
563 return 0;
564}
565
566/*
567 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
568 */
569static int __init fdt_scan_reserved_mem(void)
570{
571 int node, child;
572 const void *fdt = initial_boot_params;
573
574 node = fdt_path_offset(fdt, "/reserved-memory");
575 if (node < 0)
576 return -ENODEV;
577
578 if (__reserved_mem_check_root(node) != 0) {
579 pr_err("Reserved memory: unsupported node format, ignoring\n");
580 return -EINVAL;
581 }
582
583 fdt_for_each_subnode(child, fdt, node) {
584 const char *uname;
585 int err;
586
587 if (!of_fdt_device_is_available(fdt, child))
588 continue;
589
590 uname = fdt_get_name(fdt, child, NULL);
591
592 err = __reserved_mem_reserve_reg(child, uname);
593 if (err == -ENOENT && of_get_flat_dt_prop(child, "size", NULL))
594 fdt_reserved_mem_save_node(child, uname, 0, 0);
595 }
596 return 0;
597}
598
599/*
600 * fdt_reserve_elfcorehdr() - reserves memory for elf core header
601 *
602 * This function reserves the memory occupied by an elf core header
603 * described in the device tree. This region contains all the
604 * information about primary kernel's core image and is used by a dump
605 * capture kernel to access the system memory on primary kernel.
606 */
607static void __init fdt_reserve_elfcorehdr(void)
608{
609 if (!IS_ENABLED(CONFIG_CRASH_DUMP) || !elfcorehdr_size)
610 return;
611
612 if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) {
613 pr_warn("elfcorehdr is overlapped\n");
614 return;
615 }
616
617 memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
618
619 pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n",
620 elfcorehdr_size >> 10, elfcorehdr_addr);
621}
622
623/**
624 * early_init_fdt_scan_reserved_mem() - create reserved memory regions
625 *
626 * This function grabs memory from early allocator for device exclusive use
627 * defined in device tree structures. It should be called by arch specific code
628 * once the early allocator (i.e. memblock) has been fully activated.
629 */
630void __init early_init_fdt_scan_reserved_mem(void)
631{
632 int n;
633 u64 base, size;
634
635 if (!initial_boot_params)
636 return;
637
638 fdt_scan_reserved_mem();
639 fdt_reserve_elfcorehdr();
640
641 /* Process header /memreserve/ fields */
642 for (n = 0; ; n++) {
643 fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
644 if (!size)
645 break;
646 memblock_reserve(base, size);
647 }
648
649 fdt_init_reserved_mem();
650}
651
652/**
653 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
654 */
655void __init early_init_fdt_reserve_self(void)
656{
657 if (!initial_boot_params)
658 return;
659
660 /* Reserve the dtb region */
661 memblock_reserve(__pa(initial_boot_params),
662 fdt_totalsize(initial_boot_params));
663}
664
665/**
666 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
667 * @it: callback function
668 * @data: context data pointer
669 *
670 * This function is used to scan the flattened device-tree, it is
671 * used to extract the memory information at boot before we can
672 * unflatten the tree
673 */
674int __init of_scan_flat_dt(int (*it)(unsigned long node,
675 const char *uname, int depth,
676 void *data),
677 void *data)
678{
679 const void *blob = initial_boot_params;
680 const char *pathp;
681 int offset, rc = 0, depth = -1;
682
683 if (!blob)
684 return 0;
685
686 for (offset = fdt_next_node(blob, -1, &depth);
687 offset >= 0 && depth >= 0 && !rc;
688 offset = fdt_next_node(blob, offset, &depth)) {
689
690 pathp = fdt_get_name(blob, offset, NULL);
691 rc = it(offset, pathp, depth, data);
692 }
693 return rc;
694}
695
696/**
697 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
698 * @parent: parent node
699 * @it: callback function
700 * @data: context data pointer
701 *
702 * This function is used to scan sub-nodes of a node.
703 */
704int __init of_scan_flat_dt_subnodes(unsigned long parent,
705 int (*it)(unsigned long node,
706 const char *uname,
707 void *data),
708 void *data)
709{
710 const void *blob = initial_boot_params;
711 int node;
712
713 fdt_for_each_subnode(node, blob, parent) {
714 const char *pathp;
715 int rc;
716
717 pathp = fdt_get_name(blob, node, NULL);
718 rc = it(node, pathp, data);
719 if (rc)
720 return rc;
721 }
722 return 0;
723}
724
725/**
726 * of_get_flat_dt_subnode_by_name - get the subnode by given name
727 *
728 * @node: the parent node
729 * @uname: the name of subnode
730 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
731 */
732
733int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
734{
735 return fdt_subnode_offset(initial_boot_params, node, uname);
736}
737
738/*
739 * of_get_flat_dt_root - find the root node in the flat blob
740 */
741unsigned long __init of_get_flat_dt_root(void)
742{
743 return 0;
744}
745
746/*
747 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
748 *
749 * This function can be used within scan_flattened_dt callback to get
750 * access to properties
751 */
752const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
753 int *size)
754{
755 return fdt_getprop(initial_boot_params, node, name, size);
756}
757
758/**
759 * of_fdt_is_compatible - Return true if given node from the given blob has
760 * compat in its compatible list
761 * @blob: A device tree blob
762 * @node: node to test
763 * @compat: compatible string to compare with compatible list.
764 *
765 * Return: a non-zero value on match with smaller values returned for more
766 * specific compatible values.
767 */
768static int of_fdt_is_compatible(const void *blob,
769 unsigned long node, const char *compat)
770{
771 const char *cp;
772 int cplen;
773 unsigned long l, score = 0;
774
775 cp = fdt_getprop(blob, node, "compatible", &cplen);
776 if (cp == NULL)
777 return 0;
778 while (cplen > 0) {
779 score++;
780 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
781 return score;
782 l = strlen(cp) + 1;
783 cp += l;
784 cplen -= l;
785 }
786
787 return 0;
788}
789
790/**
791 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
792 * @node: node to test
793 * @compat: compatible string to compare with compatible list.
794 */
795int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
796{
797 return of_fdt_is_compatible(initial_boot_params, node, compat);
798}
799
800/*
801 * of_flat_dt_match - Return true if node matches a list of compatible values
802 */
803static int __init of_flat_dt_match(unsigned long node, const char *const *compat)
804{
805 unsigned int tmp, score = 0;
806
807 if (!compat)
808 return 0;
809
810 while (*compat) {
811 tmp = of_fdt_is_compatible(initial_boot_params, node, *compat);
812 if (tmp && (score == 0 || (tmp < score)))
813 score = tmp;
814 compat++;
815 }
816
817 return score;
818}
819
820/*
821 * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle
822 */
823uint32_t __init of_get_flat_dt_phandle(unsigned long node)
824{
825 return fdt_get_phandle(initial_boot_params, node);
826}
827
828const char * __init of_flat_dt_get_machine_name(void)
829{
830 const char *name;
831 unsigned long dt_root = of_get_flat_dt_root();
832
833 name = of_get_flat_dt_prop(dt_root, "model", NULL);
834 if (!name)
835 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
836 return name;
837}
838
839/**
840 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
841 *
842 * @default_match: A machine specific ptr to return in case of no match.
843 * @get_next_compat: callback function to return next compatible match table.
844 *
845 * Iterate through machine match tables to find the best match for the machine
846 * compatible string in the FDT.
847 */
848const void * __init of_flat_dt_match_machine(const void *default_match,
849 const void * (*get_next_compat)(const char * const**))
850{
851 const void *data = NULL;
852 const void *best_data = default_match;
853 const char *const *compat;
854 unsigned long dt_root;
855 unsigned int best_score = ~1, score = 0;
856
857 dt_root = of_get_flat_dt_root();
858 while ((data = get_next_compat(&compat))) {
859 score = of_flat_dt_match(dt_root, compat);
860 if (score > 0 && score < best_score) {
861 best_data = data;
862 best_score = score;
863 }
864 }
865 if (!best_data) {
866 const char *prop;
867 int size;
868
869 pr_err("\n unrecognized device tree list:\n[ ");
870
871 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
872 if (prop) {
873 while (size > 0) {
874 printk("'%s' ", prop);
875 size -= strlen(prop) + 1;
876 prop += strlen(prop) + 1;
877 }
878 }
879 printk("]\n\n");
880 return NULL;
881 }
882
883 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
884
885 return best_data;
886}
887
888static void __early_init_dt_declare_initrd(unsigned long start,
889 unsigned long end)
890{
891 /*
892 * __va() is not yet available this early on some platforms. In that
893 * case, the platform uses phys_initrd_start/phys_initrd_size instead
894 * and does the VA conversion itself.
895 */
896 if (!IS_ENABLED(CONFIG_ARM64) &&
897 !(IS_ENABLED(CONFIG_RISCV) && IS_ENABLED(CONFIG_64BIT))) {
898 initrd_start = (unsigned long)__va(start);
899 initrd_end = (unsigned long)__va(end);
900 initrd_below_start_ok = 1;
901 }
902}
903
904/**
905 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
906 * @node: reference to node containing initrd location ('chosen')
907 */
908static void __init early_init_dt_check_for_initrd(unsigned long node)
909{
910 u64 start, end;
911 int len;
912 const __be32 *prop;
913
914 if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
915 return;
916
917 pr_debug("Looking for initrd properties... ");
918
919 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
920 if (!prop)
921 return;
922 start = of_read_number(prop, len/4);
923
924 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
925 if (!prop)
926 return;
927 end = of_read_number(prop, len/4);
928 if (start > end)
929 return;
930
931 __early_init_dt_declare_initrd(start, end);
932 phys_initrd_start = start;
933 phys_initrd_size = end - start;
934
935 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", start, end);
936}
937
938/**
939 * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat
940 * tree
941 * @node: reference to node containing elfcorehdr location ('chosen')
942 */
943static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
944{
945 const __be32 *prop;
946 int len;
947
948 if (!IS_ENABLED(CONFIG_CRASH_DUMP))
949 return;
950
951 pr_debug("Looking for elfcorehdr property... ");
952
953 prop = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len);
954 if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells)))
955 return;
956
957 elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
958 elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &prop);
959
960 pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n",
961 elfcorehdr_addr, elfcorehdr_size);
962}
963
964static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
965
966/*
967 * The main usage of linux,usable-memory-range is for crash dump kernel.
968 * Originally, the number of usable-memory regions is one. Now there may
969 * be two regions, low region and high region.
970 * To make compatibility with existing user-space and older kdump, the low
971 * region is always the last range of linux,usable-memory-range if exist.
972 */
973#define MAX_USABLE_RANGES 2
974
975/**
976 * early_init_dt_check_for_usable_mem_range - Decode usable memory range
977 * location from flat tree
978 */
979void __init early_init_dt_check_for_usable_mem_range(void)
980{
981 struct memblock_region rgn[MAX_USABLE_RANGES] = {0};
982 const __be32 *prop, *endp;
983 int len, i;
984 unsigned long node = chosen_node_offset;
985
986 if ((long)node < 0)
987 return;
988
989 pr_debug("Looking for usable-memory-range property... ");
990
991 prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len);
992 if (!prop || (len % (dt_root_addr_cells + dt_root_size_cells)))
993 return;
994
995 endp = prop + (len / sizeof(__be32));
996 for (i = 0; i < MAX_USABLE_RANGES && prop < endp; i++) {
997 rgn[i].base = dt_mem_next_cell(dt_root_addr_cells, &prop);
998 rgn[i].size = dt_mem_next_cell(dt_root_size_cells, &prop);
999
1000 pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n",
1001 i, &rgn[i].base, &rgn[i].size);
1002 }
1003
1004 memblock_cap_memory_range(rgn[0].base, rgn[0].size);
1005 for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++)
1006 memblock_add(rgn[i].base, rgn[i].size);
1007}
1008
1009#ifdef CONFIG_SERIAL_EARLYCON
1010
1011int __init early_init_dt_scan_chosen_stdout(void)
1012{
1013 int offset;
1014 const char *p, *q, *options = NULL;
1015 int l;
1016 const struct earlycon_id *match;
1017 const void *fdt = initial_boot_params;
1018 int ret;
1019
1020 offset = fdt_path_offset(fdt, "/chosen");
1021 if (offset < 0)
1022 offset = fdt_path_offset(fdt, "/chosen@0");
1023 if (offset < 0)
1024 return -ENOENT;
1025
1026 p = fdt_getprop(fdt, offset, "stdout-path", &l);
1027 if (!p)
1028 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
1029 if (!p || !l)
1030 return -ENOENT;
1031
1032 q = strchrnul(p, ':');
1033 if (*q != '\0')
1034 options = q + 1;
1035 l = q - p;
1036
1037 /* Get the node specified by stdout-path */
1038 offset = fdt_path_offset_namelen(fdt, p, l);
1039 if (offset < 0) {
1040 pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
1041 return 0;
1042 }
1043
1044 for (match = __earlycon_table; match < __earlycon_table_end; match++) {
1045 if (!match->compatible[0])
1046 continue;
1047
1048 if (fdt_node_check_compatible(fdt, offset, match->compatible))
1049 continue;
1050
1051 ret = of_setup_earlycon(match, offset, options);
1052 if (!ret || ret == -EALREADY)
1053 return 0;
1054 }
1055 return -ENODEV;
1056}
1057#endif
1058
1059/*
1060 * early_init_dt_scan_root - fetch the top level address and size cells
1061 */
1062int __init early_init_dt_scan_root(void)
1063{
1064 const __be32 *prop;
1065 const void *fdt = initial_boot_params;
1066 int node = fdt_path_offset(fdt, "/");
1067
1068 if (node < 0)
1069 return -ENODEV;
1070
1071 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
1072 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
1073
1074 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
1075 if (prop)
1076 dt_root_size_cells = be32_to_cpup(prop);
1077 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
1078
1079 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
1080 if (prop)
1081 dt_root_addr_cells = be32_to_cpup(prop);
1082 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
1083
1084 return 0;
1085}
1086
1087u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
1088{
1089 const __be32 *p = *cellp;
1090
1091 *cellp = p + s;
1092 return of_read_number(p, s);
1093}
1094
1095/*
1096 * early_init_dt_scan_memory - Look for and parse memory nodes
1097 */
1098int __init early_init_dt_scan_memory(void)
1099{
1100 int node, found_memory = 0;
1101 const void *fdt = initial_boot_params;
1102
1103 fdt_for_each_subnode(node, fdt, 0) {
1104 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
1105 const __be32 *reg, *endp;
1106 int l;
1107 bool hotpluggable;
1108
1109 /* We are scanning "memory" nodes only */
1110 if (type == NULL || strcmp(type, "memory") != 0)
1111 continue;
1112
1113 if (!of_fdt_device_is_available(fdt, node))
1114 continue;
1115
1116 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
1117 if (reg == NULL)
1118 reg = of_get_flat_dt_prop(node, "reg", &l);
1119 if (reg == NULL)
1120 continue;
1121
1122 endp = reg + (l / sizeof(__be32));
1123 hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
1124
1125 pr_debug("memory scan node %s, reg size %d,\n",
1126 fdt_get_name(fdt, node, NULL), l);
1127
1128 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
1129 u64 base, size;
1130
1131 base = dt_mem_next_cell(dt_root_addr_cells, ®);
1132 size = dt_mem_next_cell(dt_root_size_cells, ®);
1133
1134 if (size == 0)
1135 continue;
1136 pr_debug(" - %llx, %llx\n", base, size);
1137
1138 early_init_dt_add_memory_arch(base, size);
1139
1140 found_memory = 1;
1141
1142 if (!hotpluggable)
1143 continue;
1144
1145 if (memblock_mark_hotplug(base, size))
1146 pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1147 base, base + size);
1148 }
1149 }
1150 return found_memory;
1151}
1152
1153int __init early_init_dt_scan_chosen(char *cmdline)
1154{
1155 int l, node;
1156 const char *p;
1157 const void *rng_seed;
1158 const void *fdt = initial_boot_params;
1159
1160 node = fdt_path_offset(fdt, "/chosen");
1161 if (node < 0)
1162 node = fdt_path_offset(fdt, "/chosen@0");
1163 if (node < 0)
1164 /* Handle the cmdline config options even if no /chosen node */
1165 goto handle_cmdline;
1166
1167 chosen_node_offset = node;
1168
1169 early_init_dt_check_for_initrd(node);
1170 early_init_dt_check_for_elfcorehdr(node);
1171
1172 rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
1173 if (rng_seed && l > 0) {
1174 add_bootloader_randomness(rng_seed, l);
1175
1176 /* try to clear seed so it won't be found. */
1177 fdt_nop_property(initial_boot_params, node, "rng-seed");
1178
1179 /* update CRC check value */
1180 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1181 fdt_totalsize(initial_boot_params));
1182 }
1183
1184 /* Retrieve command line */
1185 p = of_get_flat_dt_prop(node, "bootargs", &l);
1186 if (p != NULL && l > 0)
1187 strscpy(cmdline, p, min(l, COMMAND_LINE_SIZE));
1188
1189handle_cmdline:
1190 /*
1191 * CONFIG_CMDLINE is meant to be a default in case nothing else
1192 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1193 * is set in which case we override whatever was found earlier.
1194 */
1195#ifdef CONFIG_CMDLINE
1196#if defined(CONFIG_CMDLINE_EXTEND)
1197 strlcat(cmdline, " ", COMMAND_LINE_SIZE);
1198 strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1199#elif defined(CONFIG_CMDLINE_FORCE)
1200 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1201#else
1202 /* No arguments from boot loader, use kernel's cmdl*/
1203 if (!((char *)cmdline)[0])
1204 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1205#endif
1206#endif /* CONFIG_CMDLINE */
1207
1208 pr_debug("Command line is: %s\n", (char *)cmdline);
1209
1210 return 0;
1211}
1212
1213#ifndef MIN_MEMBLOCK_ADDR
1214#define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET)
1215#endif
1216#ifndef MAX_MEMBLOCK_ADDR
1217#define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0)
1218#endif
1219
1220void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1221{
1222 const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1223
1224 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1225 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1226 base, base + size);
1227 return;
1228 }
1229
1230 if (!PAGE_ALIGNED(base)) {
1231 size -= PAGE_SIZE - (base & ~PAGE_MASK);
1232 base = PAGE_ALIGN(base);
1233 }
1234 size &= PAGE_MASK;
1235
1236 if (base > MAX_MEMBLOCK_ADDR) {
1237 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1238 base, base + size);
1239 return;
1240 }
1241
1242 if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1243 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1244 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1245 size = MAX_MEMBLOCK_ADDR - base + 1;
1246 }
1247
1248 if (base + size < phys_offset) {
1249 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1250 base, base + size);
1251 return;
1252 }
1253 if (base < phys_offset) {
1254 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1255 base, phys_offset);
1256 size -= phys_offset - base;
1257 base = phys_offset;
1258 }
1259 memblock_add(base, size);
1260}
1261
1262static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
1263{
1264 void *ptr = memblock_alloc(size, align);
1265
1266 if (!ptr)
1267 panic("%s: Failed to allocate %llu bytes align=0x%llx\n",
1268 __func__, size, align);
1269
1270 return ptr;
1271}
1272
1273bool __init early_init_dt_verify(void *params)
1274{
1275 if (!params)
1276 return false;
1277
1278 /* check device tree validity */
1279 if (fdt_check_header(params))
1280 return false;
1281
1282 /* Setup flat device-tree pointer */
1283 initial_boot_params = params;
1284 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1285 fdt_totalsize(initial_boot_params));
1286 return true;
1287}
1288
1289
1290void __init early_init_dt_scan_nodes(void)
1291{
1292 int rc;
1293
1294 /* Initialize {size,address}-cells info */
1295 early_init_dt_scan_root();
1296
1297 /* Retrieve various information from the /chosen node */
1298 rc = early_init_dt_scan_chosen(boot_command_line);
1299 if (rc)
1300 pr_warn("No chosen node found, continuing without\n");
1301
1302 /* Setup memory, calling early_init_dt_add_memory_arch */
1303 early_init_dt_scan_memory();
1304
1305 /* Handle linux,usable-memory-range property */
1306 early_init_dt_check_for_usable_mem_range();
1307}
1308
1309bool __init early_init_dt_scan(void *params)
1310{
1311 bool status;
1312
1313 status = early_init_dt_verify(params);
1314 if (!status)
1315 return false;
1316
1317 early_init_dt_scan_nodes();
1318 return true;
1319}
1320
1321/**
1322 * unflatten_device_tree - create tree of device_nodes from flat blob
1323 *
1324 * unflattens the device-tree passed by the firmware, creating the
1325 * tree of struct device_node. It also fills the "name" and "type"
1326 * pointers of the nodes so the normal device-tree walking functions
1327 * can be used.
1328 */
1329void __init unflatten_device_tree(void)
1330{
1331 __unflatten_device_tree(initial_boot_params, NULL, &of_root,
1332 early_init_dt_alloc_memory_arch, false);
1333
1334 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1335 of_alias_scan(early_init_dt_alloc_memory_arch);
1336
1337 unittest_unflatten_overlay_base();
1338}
1339
1340/**
1341 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1342 *
1343 * Copies and unflattens the device-tree passed by the firmware, creating the
1344 * tree of struct device_node. It also fills the "name" and "type"
1345 * pointers of the nodes so the normal device-tree walking functions
1346 * can be used. This should only be used when the FDT memory has not been
1347 * reserved such is the case when the FDT is built-in to the kernel init
1348 * section. If the FDT memory is reserved already then unflatten_device_tree
1349 * should be used instead.
1350 */
1351void __init unflatten_and_copy_device_tree(void)
1352{
1353 int size;
1354 void *dt;
1355
1356 if (!initial_boot_params) {
1357 pr_warn("No valid device tree found, continuing without\n");
1358 return;
1359 }
1360
1361 size = fdt_totalsize(initial_boot_params);
1362 dt = early_init_dt_alloc_memory_arch(size,
1363 roundup_pow_of_two(FDT_V17_SIZE));
1364
1365 if (dt) {
1366 memcpy(dt, initial_boot_params, size);
1367 initial_boot_params = dt;
1368 }
1369 unflatten_device_tree();
1370}
1371
1372#ifdef CONFIG_SYSFS
1373static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1374 struct bin_attribute *bin_attr,
1375 char *buf, loff_t off, size_t count)
1376{
1377 memcpy(buf, initial_boot_params + off, count);
1378 return count;
1379}
1380
1381static int __init of_fdt_raw_init(void)
1382{
1383 static struct bin_attribute of_fdt_raw_attr =
1384 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1385
1386 if (!initial_boot_params)
1387 return 0;
1388
1389 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1390 fdt_totalsize(initial_boot_params))) {
1391 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1392 return 0;
1393 }
1394 of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1395 return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1396}
1397late_initcall(of_fdt_raw_init);
1398#endif
1399
1400#endif /* CONFIG_OF_EARLY_FLATTREE */