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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Functions for working with the Flattened Device Tree data format
4 *
5 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
6 * benh@kernel.crashing.org
7 */
8
9#define pr_fmt(fmt) "OF: fdt: " fmt
10
11#include <linux/crash_dump.h>
12#include <linux/crc32.h>
13#include <linux/kernel.h>
14#include <linux/initrd.h>
15#include <linux/memblock.h>
16#include <linux/mutex.h>
17#include <linux/of.h>
18#include <linux/of_fdt.h>
19#include <linux/sizes.h>
20#include <linux/string.h>
21#include <linux/errno.h>
22#include <linux/slab.h>
23#include <linux/libfdt.h>
24#include <linux/debugfs.h>
25#include <linux/serial_core.h>
26#include <linux/sysfs.h>
27#include <linux/random.h>
28
29#include <asm/setup.h> /* for COMMAND_LINE_SIZE */
30#include <asm/page.h>
31
32#include "of_private.h"
33
34/*
35 * __dtb_empty_root_begin[] and __dtb_empty_root_end[] magically created by
36 * cmd_wrap_S_dtb in scripts/Makefile.dtbs
37 */
38extern uint8_t __dtb_empty_root_begin[];
39extern uint8_t __dtb_empty_root_end[];
40
41/*
42 * of_fdt_limit_memory - limit the number of regions in the /memory node
43 * @limit: maximum entries
44 *
45 * Adjust the flattened device tree to have at most 'limit' number of
46 * memory entries in the /memory node. This function may be called
47 * any time after initial_boot_param is set.
48 */
49void __init of_fdt_limit_memory(int limit)
50{
51 int memory;
52 int len;
53 const void *val;
54 int cell_size = sizeof(uint32_t)*(dt_root_addr_cells + dt_root_size_cells);
55
56 memory = fdt_path_offset(initial_boot_params, "/memory");
57 if (memory > 0) {
58 val = fdt_getprop(initial_boot_params, memory, "reg", &len);
59 if (len > limit*cell_size) {
60 len = limit*cell_size;
61 pr_debug("Limiting number of entries to %d\n", limit);
62 fdt_setprop(initial_boot_params, memory, "reg", val,
63 len);
64 }
65 }
66}
67
68bool of_fdt_device_is_available(const void *blob, unsigned long node)
69{
70 const char *status = fdt_getprop(blob, node, "status", NULL);
71
72 if (!status)
73 return true;
74
75 if (!strcmp(status, "ok") || !strcmp(status, "okay"))
76 return true;
77
78 return false;
79}
80
81static void *unflatten_dt_alloc(void **mem, unsigned long size,
82 unsigned long align)
83{
84 void *res;
85
86 *mem = PTR_ALIGN(*mem, align);
87 res = *mem;
88 *mem += size;
89
90 return res;
91}
92
93static void populate_properties(const void *blob,
94 int offset,
95 void **mem,
96 struct device_node *np,
97 const char *nodename,
98 bool dryrun)
99{
100 struct property *pp, **pprev = NULL;
101 int cur;
102 bool has_name = false;
103
104 pprev = &np->properties;
105 for (cur = fdt_first_property_offset(blob, offset);
106 cur >= 0;
107 cur = fdt_next_property_offset(blob, cur)) {
108 const __be32 *val;
109 const char *pname;
110 u32 sz;
111
112 val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
113 if (!val) {
114 pr_warn("Cannot locate property at 0x%x\n", cur);
115 continue;
116 }
117
118 if (!pname) {
119 pr_warn("Cannot find property name at 0x%x\n", cur);
120 continue;
121 }
122
123 if (!strcmp(pname, "name"))
124 has_name = true;
125
126 pp = unflatten_dt_alloc(mem, sizeof(struct property),
127 __alignof__(struct property));
128 if (dryrun)
129 continue;
130
131 /* We accept flattened tree phandles either in
132 * ePAPR-style "phandle" properties, or the
133 * legacy "linux,phandle" properties. If both
134 * appear and have different values, things
135 * will get weird. Don't do that.
136 */
137 if (!strcmp(pname, "phandle") ||
138 !strcmp(pname, "linux,phandle")) {
139 if (!np->phandle)
140 np->phandle = be32_to_cpup(val);
141 }
142
143 /* And we process the "ibm,phandle" property
144 * used in pSeries dynamic device tree
145 * stuff
146 */
147 if (!strcmp(pname, "ibm,phandle"))
148 np->phandle = be32_to_cpup(val);
149
150 pp->name = (char *)pname;
151 pp->length = sz;
152 pp->value = (__be32 *)val;
153 *pprev = pp;
154 pprev = &pp->next;
155 }
156
157 /* With version 0x10 we may not have the name property,
158 * recreate it here from the unit name if absent
159 */
160 if (!has_name) {
161 const char *p = nodename, *ps = p, *pa = NULL;
162 int len;
163
164 while (*p) {
165 if ((*p) == '@')
166 pa = p;
167 else if ((*p) == '/')
168 ps = p + 1;
169 p++;
170 }
171
172 if (pa < ps)
173 pa = p;
174 len = (pa - ps) + 1;
175 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
176 __alignof__(struct property));
177 if (!dryrun) {
178 pp->name = "name";
179 pp->length = len;
180 pp->value = pp + 1;
181 *pprev = pp;
182 memcpy(pp->value, ps, len - 1);
183 ((char *)pp->value)[len - 1] = 0;
184 pr_debug("fixed up name for %s -> %s\n",
185 nodename, (char *)pp->value);
186 }
187 }
188}
189
190static int populate_node(const void *blob,
191 int offset,
192 void **mem,
193 struct device_node *dad,
194 struct device_node **pnp,
195 bool dryrun)
196{
197 struct device_node *np;
198 const char *pathp;
199 int len;
200
201 pathp = fdt_get_name(blob, offset, &len);
202 if (!pathp) {
203 *pnp = NULL;
204 return len;
205 }
206
207 len++;
208
209 np = unflatten_dt_alloc(mem, sizeof(struct device_node) + len,
210 __alignof__(struct device_node));
211 if (!dryrun) {
212 char *fn;
213 of_node_init(np);
214 np->full_name = fn = ((char *)np) + sizeof(*np);
215
216 memcpy(fn, pathp, len);
217
218 if (dad != NULL) {
219 np->parent = dad;
220 np->sibling = dad->child;
221 dad->child = np;
222 }
223 }
224
225 populate_properties(blob, offset, mem, np, pathp, dryrun);
226 if (!dryrun) {
227 np->name = of_get_property(np, "name", NULL);
228 if (!np->name)
229 np->name = "<NULL>";
230 }
231
232 *pnp = np;
233 return 0;
234}
235
236static void reverse_nodes(struct device_node *parent)
237{
238 struct device_node *child, *next;
239
240 /* In-depth first */
241 child = parent->child;
242 while (child) {
243 reverse_nodes(child);
244
245 child = child->sibling;
246 }
247
248 /* Reverse the nodes in the child list */
249 child = parent->child;
250 parent->child = NULL;
251 while (child) {
252 next = child->sibling;
253
254 child->sibling = parent->child;
255 parent->child = child;
256 child = next;
257 }
258}
259
260/**
261 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
262 * @blob: The parent device tree blob
263 * @mem: Memory chunk to use for allocating device nodes and properties
264 * @dad: Parent struct device_node
265 * @nodepp: The device_node tree created by the call
266 *
267 * Return: The size of unflattened device tree or error code
268 */
269static int unflatten_dt_nodes(const void *blob,
270 void *mem,
271 struct device_node *dad,
272 struct device_node **nodepp)
273{
274 struct device_node *root;
275 int offset = 0, depth = 0, initial_depth = 0;
276#define FDT_MAX_DEPTH 64
277 struct device_node *nps[FDT_MAX_DEPTH];
278 void *base = mem;
279 bool dryrun = !base;
280 int ret;
281
282 if (nodepp)
283 *nodepp = NULL;
284
285 /*
286 * We're unflattening device sub-tree if @dad is valid. There are
287 * possibly multiple nodes in the first level of depth. We need
288 * set @depth to 1 to make fdt_next_node() happy as it bails
289 * immediately when negative @depth is found. Otherwise, the device
290 * nodes except the first one won't be unflattened successfully.
291 */
292 if (dad)
293 depth = initial_depth = 1;
294
295 root = dad;
296 nps[depth] = dad;
297
298 for (offset = 0;
299 offset >= 0 && depth >= initial_depth;
300 offset = fdt_next_node(blob, offset, &depth)) {
301 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH - 1))
302 continue;
303
304 if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
305 !of_fdt_device_is_available(blob, offset))
306 continue;
307
308 ret = populate_node(blob, offset, &mem, nps[depth],
309 &nps[depth+1], dryrun);
310 if (ret < 0)
311 return ret;
312
313 if (!dryrun && nodepp && !*nodepp)
314 *nodepp = nps[depth+1];
315 if (!dryrun && !root)
316 root = nps[depth+1];
317 }
318
319 if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
320 pr_err("Error %d processing FDT\n", offset);
321 return -EINVAL;
322 }
323
324 /*
325 * Reverse the child list. Some drivers assumes node order matches .dts
326 * node order
327 */
328 if (!dryrun)
329 reverse_nodes(root);
330
331 return mem - base;
332}
333
334/**
335 * __unflatten_device_tree - create tree of device_nodes from flat blob
336 * @blob: The blob to expand
337 * @dad: Parent device node
338 * @mynodes: The device_node tree created by the call
339 * @dt_alloc: An allocator that provides a virtual address to memory
340 * for the resulting tree
341 * @detached: if true set OF_DETACHED on @mynodes
342 *
343 * unflattens a device-tree, creating the tree of struct device_node. It also
344 * fills the "name" and "type" pointers of the nodes so the normal device-tree
345 * walking functions can be used.
346 *
347 * Return: NULL on failure or the memory chunk containing the unflattened
348 * device tree on success.
349 */
350void *__unflatten_device_tree(const void *blob,
351 struct device_node *dad,
352 struct device_node **mynodes,
353 void *(*dt_alloc)(u64 size, u64 align),
354 bool detached)
355{
356 int size;
357 void *mem;
358 int ret;
359
360 if (mynodes)
361 *mynodes = NULL;
362
363 pr_debug(" -> unflatten_device_tree()\n");
364
365 if (!blob) {
366 pr_debug("No device tree pointer\n");
367 return NULL;
368 }
369
370 pr_debug("Unflattening device tree:\n");
371 pr_debug("magic: %08x\n", fdt_magic(blob));
372 pr_debug("size: %08x\n", fdt_totalsize(blob));
373 pr_debug("version: %08x\n", fdt_version(blob));
374
375 if (fdt_check_header(blob)) {
376 pr_err("Invalid device tree blob header\n");
377 return NULL;
378 }
379
380 /* First pass, scan for size */
381 size = unflatten_dt_nodes(blob, NULL, dad, NULL);
382 if (size <= 0)
383 return NULL;
384
385 size = ALIGN(size, 4);
386 pr_debug(" size is %d, allocating...\n", size);
387
388 /* Allocate memory for the expanded device tree */
389 mem = dt_alloc(size + 4, __alignof__(struct device_node));
390 if (!mem)
391 return NULL;
392
393 memset(mem, 0, size);
394
395 *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
396
397 pr_debug(" unflattening %p...\n", mem);
398
399 /* Second pass, do actual unflattening */
400 ret = unflatten_dt_nodes(blob, mem, dad, mynodes);
401
402 if (be32_to_cpup(mem + size) != 0xdeadbeef)
403 pr_warn("End of tree marker overwritten: %08x\n",
404 be32_to_cpup(mem + size));
405
406 if (ret <= 0)
407 return NULL;
408
409 if (detached && mynodes && *mynodes) {
410 of_node_set_flag(*mynodes, OF_DETACHED);
411 pr_debug("unflattened tree is detached\n");
412 }
413
414 pr_debug(" <- unflatten_device_tree()\n");
415 return mem;
416}
417
418static void *kernel_tree_alloc(u64 size, u64 align)
419{
420 return kzalloc(size, GFP_KERNEL);
421}
422
423static DEFINE_MUTEX(of_fdt_unflatten_mutex);
424
425/**
426 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
427 * @blob: Flat device tree blob
428 * @dad: Parent device node
429 * @mynodes: The device tree created by the call
430 *
431 * unflattens the device-tree passed by the firmware, creating the
432 * tree of struct device_node. It also fills the "name" and "type"
433 * pointers of the nodes so the normal device-tree walking functions
434 * can be used.
435 *
436 * Return: NULL on failure or the memory chunk containing the unflattened
437 * device tree on success.
438 */
439void *of_fdt_unflatten_tree(const unsigned long *blob,
440 struct device_node *dad,
441 struct device_node **mynodes)
442{
443 void *mem;
444
445 mutex_lock(&of_fdt_unflatten_mutex);
446 mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
447 true);
448 mutex_unlock(&of_fdt_unflatten_mutex);
449
450 return mem;
451}
452EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
453
454/* Everything below here references initial_boot_params directly. */
455int __initdata dt_root_addr_cells;
456int __initdata dt_root_size_cells;
457
458void *initial_boot_params __ro_after_init;
459phys_addr_t initial_boot_params_pa __ro_after_init;
460
461#ifdef CONFIG_OF_EARLY_FLATTREE
462
463static u32 of_fdt_crc32;
464
465/*
466 * fdt_reserve_elfcorehdr() - reserves memory for elf core header
467 *
468 * This function reserves the memory occupied by an elf core header
469 * described in the device tree. This region contains all the
470 * information about primary kernel's core image and is used by a dump
471 * capture kernel to access the system memory on primary kernel.
472 */
473static void __init fdt_reserve_elfcorehdr(void)
474{
475 if (!IS_ENABLED(CONFIG_CRASH_DUMP) || !elfcorehdr_size)
476 return;
477
478 if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) {
479 pr_warn("elfcorehdr is overlapped\n");
480 return;
481 }
482
483 memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
484
485 pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n",
486 elfcorehdr_size >> 10, elfcorehdr_addr);
487}
488
489/**
490 * early_init_fdt_scan_reserved_mem() - create reserved memory regions
491 *
492 * This function grabs memory from early allocator for device exclusive use
493 * defined in device tree structures. It should be called by arch specific code
494 * once the early allocator (i.e. memblock) has been fully activated.
495 */
496void __init early_init_fdt_scan_reserved_mem(void)
497{
498 int n;
499 u64 base, size;
500
501 if (!initial_boot_params)
502 return;
503
504 fdt_scan_reserved_mem();
505 fdt_reserve_elfcorehdr();
506
507 /* Process header /memreserve/ fields */
508 for (n = 0; ; n++) {
509 fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
510 if (!size)
511 break;
512 memblock_reserve(base, size);
513 }
514}
515
516/**
517 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
518 */
519void __init early_init_fdt_reserve_self(void)
520{
521 if (!initial_boot_params)
522 return;
523
524 /* Reserve the dtb region */
525 memblock_reserve(__pa(initial_boot_params),
526 fdt_totalsize(initial_boot_params));
527}
528
529/**
530 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
531 * @it: callback function
532 * @data: context data pointer
533 *
534 * This function is used to scan the flattened device-tree, it is
535 * used to extract the memory information at boot before we can
536 * unflatten the tree
537 */
538int __init of_scan_flat_dt(int (*it)(unsigned long node,
539 const char *uname, int depth,
540 void *data),
541 void *data)
542{
543 const void *blob = initial_boot_params;
544 const char *pathp;
545 int offset, rc = 0, depth = -1;
546
547 if (!blob)
548 return 0;
549
550 for (offset = fdt_next_node(blob, -1, &depth);
551 offset >= 0 && depth >= 0 && !rc;
552 offset = fdt_next_node(blob, offset, &depth)) {
553
554 pathp = fdt_get_name(blob, offset, NULL);
555 rc = it(offset, pathp, depth, data);
556 }
557 return rc;
558}
559
560/**
561 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
562 * @parent: parent node
563 * @it: callback function
564 * @data: context data pointer
565 *
566 * This function is used to scan sub-nodes of a node.
567 */
568int __init of_scan_flat_dt_subnodes(unsigned long parent,
569 int (*it)(unsigned long node,
570 const char *uname,
571 void *data),
572 void *data)
573{
574 const void *blob = initial_boot_params;
575 int node;
576
577 fdt_for_each_subnode(node, blob, parent) {
578 const char *pathp;
579 int rc;
580
581 pathp = fdt_get_name(blob, node, NULL);
582 rc = it(node, pathp, data);
583 if (rc)
584 return rc;
585 }
586 return 0;
587}
588
589/**
590 * of_get_flat_dt_subnode_by_name - get the subnode by given name
591 *
592 * @node: the parent node
593 * @uname: the name of subnode
594 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
595 */
596
597int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
598{
599 return fdt_subnode_offset(initial_boot_params, node, uname);
600}
601
602/*
603 * of_get_flat_dt_root - find the root node in the flat blob
604 */
605unsigned long __init of_get_flat_dt_root(void)
606{
607 return 0;
608}
609
610/*
611 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
612 *
613 * This function can be used within scan_flattened_dt callback to get
614 * access to properties
615 */
616const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
617 int *size)
618{
619 return fdt_getprop(initial_boot_params, node, name, size);
620}
621
622/**
623 * of_fdt_is_compatible - Return true if given node from the given blob has
624 * compat in its compatible list
625 * @blob: A device tree blob
626 * @node: node to test
627 * @compat: compatible string to compare with compatible list.
628 *
629 * Return: a non-zero value on match with smaller values returned for more
630 * specific compatible values.
631 */
632static int of_fdt_is_compatible(const void *blob,
633 unsigned long node, const char *compat)
634{
635 const char *cp;
636 int cplen;
637 unsigned long l, score = 0;
638
639 cp = fdt_getprop(blob, node, "compatible", &cplen);
640 if (cp == NULL)
641 return 0;
642 while (cplen > 0) {
643 score++;
644 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
645 return score;
646 l = strlen(cp) + 1;
647 cp += l;
648 cplen -= l;
649 }
650
651 return 0;
652}
653
654/**
655 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
656 * @node: node to test
657 * @compat: compatible string to compare with compatible list.
658 */
659int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
660{
661 return of_fdt_is_compatible(initial_boot_params, node, compat);
662}
663
664/*
665 * of_flat_dt_match - Return true if node matches a list of compatible values
666 */
667static int __init of_flat_dt_match(unsigned long node, const char *const *compat)
668{
669 unsigned int tmp, score = 0;
670
671 if (!compat)
672 return 0;
673
674 while (*compat) {
675 tmp = of_fdt_is_compatible(initial_boot_params, node, *compat);
676 if (tmp && (score == 0 || (tmp < score)))
677 score = tmp;
678 compat++;
679 }
680
681 return score;
682}
683
684/*
685 * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle
686 */
687uint32_t __init of_get_flat_dt_phandle(unsigned long node)
688{
689 return fdt_get_phandle(initial_boot_params, node);
690}
691
692const char * __init of_flat_dt_get_machine_name(void)
693{
694 const char *name;
695 unsigned long dt_root = of_get_flat_dt_root();
696
697 name = of_get_flat_dt_prop(dt_root, "model", NULL);
698 if (!name)
699 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
700 return name;
701}
702
703/**
704 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
705 *
706 * @default_match: A machine specific ptr to return in case of no match.
707 * @get_next_compat: callback function to return next compatible match table.
708 *
709 * Iterate through machine match tables to find the best match for the machine
710 * compatible string in the FDT.
711 */
712const void * __init of_flat_dt_match_machine(const void *default_match,
713 const void * (*get_next_compat)(const char * const**))
714{
715 const void *data = NULL;
716 const void *best_data = default_match;
717 const char *const *compat;
718 unsigned long dt_root;
719 unsigned int best_score = ~1, score = 0;
720
721 dt_root = of_get_flat_dt_root();
722 while ((data = get_next_compat(&compat))) {
723 score = of_flat_dt_match(dt_root, compat);
724 if (score > 0 && score < best_score) {
725 best_data = data;
726 best_score = score;
727 }
728 }
729 if (!best_data) {
730 const char *prop;
731 int size;
732
733 pr_err("\n unrecognized device tree list:\n[ ");
734
735 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
736 if (prop) {
737 while (size > 0) {
738 printk("'%s' ", prop);
739 size -= strlen(prop) + 1;
740 prop += strlen(prop) + 1;
741 }
742 }
743 printk("]\n\n");
744 return NULL;
745 }
746
747 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
748
749 return best_data;
750}
751
752static void __early_init_dt_declare_initrd(unsigned long start,
753 unsigned long end)
754{
755 /*
756 * __va() is not yet available this early on some platforms. In that
757 * case, the platform uses phys_initrd_start/phys_initrd_size instead
758 * and does the VA conversion itself.
759 */
760 if (!IS_ENABLED(CONFIG_ARM64) &&
761 !(IS_ENABLED(CONFIG_RISCV) && IS_ENABLED(CONFIG_64BIT))) {
762 initrd_start = (unsigned long)__va(start);
763 initrd_end = (unsigned long)__va(end);
764 initrd_below_start_ok = 1;
765 }
766}
767
768/**
769 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
770 * @node: reference to node containing initrd location ('chosen')
771 */
772static void __init early_init_dt_check_for_initrd(unsigned long node)
773{
774 u64 start, end;
775 int len;
776 const __be32 *prop;
777
778 if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
779 return;
780
781 pr_debug("Looking for initrd properties... ");
782
783 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
784 if (!prop)
785 return;
786 start = of_read_number(prop, len/4);
787
788 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
789 if (!prop)
790 return;
791 end = of_read_number(prop, len/4);
792 if (start > end)
793 return;
794
795 __early_init_dt_declare_initrd(start, end);
796 phys_initrd_start = start;
797 phys_initrd_size = end - start;
798
799 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", start, end);
800}
801
802/**
803 * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat
804 * tree
805 * @node: reference to node containing elfcorehdr location ('chosen')
806 */
807static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
808{
809 const __be32 *prop;
810 int len;
811
812 if (!IS_ENABLED(CONFIG_CRASH_DUMP))
813 return;
814
815 pr_debug("Looking for elfcorehdr property... ");
816
817 prop = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len);
818 if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells)))
819 return;
820
821 elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
822 elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &prop);
823
824 pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n",
825 elfcorehdr_addr, elfcorehdr_size);
826}
827
828static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
829
830/*
831 * The main usage of linux,usable-memory-range is for crash dump kernel.
832 * Originally, the number of usable-memory regions is one. Now there may
833 * be two regions, low region and high region.
834 * To make compatibility with existing user-space and older kdump, the low
835 * region is always the last range of linux,usable-memory-range if exist.
836 */
837#define MAX_USABLE_RANGES 2
838
839/**
840 * early_init_dt_check_for_usable_mem_range - Decode usable memory range
841 * location from flat tree
842 */
843void __init early_init_dt_check_for_usable_mem_range(void)
844{
845 struct memblock_region rgn[MAX_USABLE_RANGES] = {0};
846 const __be32 *prop, *endp;
847 int len, i;
848 unsigned long node = chosen_node_offset;
849
850 if ((long)node < 0)
851 return;
852
853 pr_debug("Looking for usable-memory-range property... ");
854
855 prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len);
856 if (!prop || (len % (dt_root_addr_cells + dt_root_size_cells)))
857 return;
858
859 endp = prop + (len / sizeof(__be32));
860 for (i = 0; i < MAX_USABLE_RANGES && prop < endp; i++) {
861 rgn[i].base = dt_mem_next_cell(dt_root_addr_cells, &prop);
862 rgn[i].size = dt_mem_next_cell(dt_root_size_cells, &prop);
863
864 pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n",
865 i, &rgn[i].base, &rgn[i].size);
866 }
867
868 memblock_cap_memory_range(rgn[0].base, rgn[0].size);
869 for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++)
870 memblock_add(rgn[i].base, rgn[i].size);
871}
872
873#ifdef CONFIG_SERIAL_EARLYCON
874
875int __init early_init_dt_scan_chosen_stdout(void)
876{
877 int offset;
878 const char *p, *q, *options = NULL;
879 int l;
880 const struct earlycon_id *match;
881 const void *fdt = initial_boot_params;
882 int ret;
883
884 offset = fdt_path_offset(fdt, "/chosen");
885 if (offset < 0)
886 offset = fdt_path_offset(fdt, "/chosen@0");
887 if (offset < 0)
888 return -ENOENT;
889
890 p = fdt_getprop(fdt, offset, "stdout-path", &l);
891 if (!p)
892 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
893 if (!p || !l)
894 return -ENOENT;
895
896 q = strchrnul(p, ':');
897 if (*q != '\0')
898 options = q + 1;
899 l = q - p;
900
901 /* Get the node specified by stdout-path */
902 offset = fdt_path_offset_namelen(fdt, p, l);
903 if (offset < 0) {
904 pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
905 return 0;
906 }
907
908 for (match = __earlycon_table; match < __earlycon_table_end; match++) {
909 if (!match->compatible[0])
910 continue;
911
912 if (fdt_node_check_compatible(fdt, offset, match->compatible))
913 continue;
914
915 ret = of_setup_earlycon(match, offset, options);
916 if (!ret || ret == -EALREADY)
917 return 0;
918 }
919 return -ENODEV;
920}
921#endif
922
923/*
924 * early_init_dt_scan_root - fetch the top level address and size cells
925 */
926int __init early_init_dt_scan_root(void)
927{
928 const __be32 *prop;
929 const void *fdt = initial_boot_params;
930 int node = fdt_path_offset(fdt, "/");
931
932 if (node < 0)
933 return -ENODEV;
934
935 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
936 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
937
938 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
939 if (!WARN(!prop, "No '#size-cells' in root node\n"))
940 dt_root_size_cells = be32_to_cpup(prop);
941 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
942
943 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
944 if (!WARN(!prop, "No '#address-cells' in root node\n"))
945 dt_root_addr_cells = be32_to_cpup(prop);
946 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
947
948 return 0;
949}
950
951u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
952{
953 const __be32 *p = *cellp;
954
955 *cellp = p + s;
956 return of_read_number(p, s);
957}
958
959/*
960 * early_init_dt_scan_memory - Look for and parse memory nodes
961 */
962int __init early_init_dt_scan_memory(void)
963{
964 int node, found_memory = 0;
965 const void *fdt = initial_boot_params;
966
967 fdt_for_each_subnode(node, fdt, 0) {
968 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
969 const __be32 *reg, *endp;
970 int l;
971 bool hotpluggable;
972
973 /* We are scanning "memory" nodes only */
974 if (type == NULL || strcmp(type, "memory") != 0)
975 continue;
976
977 if (!of_fdt_device_is_available(fdt, node))
978 continue;
979
980 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
981 if (reg == NULL)
982 reg = of_get_flat_dt_prop(node, "reg", &l);
983 if (reg == NULL)
984 continue;
985
986 endp = reg + (l / sizeof(__be32));
987 hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
988
989 pr_debug("memory scan node %s, reg size %d,\n",
990 fdt_get_name(fdt, node, NULL), l);
991
992 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
993 u64 base, size;
994
995 base = dt_mem_next_cell(dt_root_addr_cells, ®);
996 size = dt_mem_next_cell(dt_root_size_cells, ®);
997
998 if (size == 0)
999 continue;
1000 pr_debug(" - %llx, %llx\n", base, size);
1001
1002 early_init_dt_add_memory_arch(base, size);
1003
1004 found_memory = 1;
1005
1006 if (!hotpluggable)
1007 continue;
1008
1009 if (memblock_mark_hotplug(base, size))
1010 pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1011 base, base + size);
1012 }
1013 }
1014 return found_memory;
1015}
1016
1017int __init early_init_dt_scan_chosen(char *cmdline)
1018{
1019 int l, node;
1020 const char *p;
1021 const void *rng_seed;
1022 const void *fdt = initial_boot_params;
1023
1024 node = fdt_path_offset(fdt, "/chosen");
1025 if (node < 0)
1026 node = fdt_path_offset(fdt, "/chosen@0");
1027 if (node < 0)
1028 /* Handle the cmdline config options even if no /chosen node */
1029 goto handle_cmdline;
1030
1031 chosen_node_offset = node;
1032
1033 early_init_dt_check_for_initrd(node);
1034 early_init_dt_check_for_elfcorehdr(node);
1035
1036 rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
1037 if (rng_seed && l > 0) {
1038 add_bootloader_randomness(rng_seed, l);
1039
1040 /* try to clear seed so it won't be found. */
1041 fdt_nop_property(initial_boot_params, node, "rng-seed");
1042
1043 /* update CRC check value */
1044 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1045 fdt_totalsize(initial_boot_params));
1046 }
1047
1048 /* Retrieve command line */
1049 p = of_get_flat_dt_prop(node, "bootargs", &l);
1050 if (p != NULL && l > 0)
1051 strscpy(cmdline, p, min(l, COMMAND_LINE_SIZE));
1052
1053handle_cmdline:
1054 /*
1055 * CONFIG_CMDLINE is meant to be a default in case nothing else
1056 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1057 * is set in which case we override whatever was found earlier.
1058 */
1059#ifdef CONFIG_CMDLINE
1060#if defined(CONFIG_CMDLINE_EXTEND)
1061 strlcat(cmdline, " ", COMMAND_LINE_SIZE);
1062 strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1063#elif defined(CONFIG_CMDLINE_FORCE)
1064 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1065#else
1066 /* No arguments from boot loader, use kernel's cmdl*/
1067 if (!((char *)cmdline)[0])
1068 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1069#endif
1070#endif /* CONFIG_CMDLINE */
1071
1072 pr_debug("Command line is: %s\n", (char *)cmdline);
1073
1074 return 0;
1075}
1076
1077#ifndef MIN_MEMBLOCK_ADDR
1078#define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET)
1079#endif
1080#ifndef MAX_MEMBLOCK_ADDR
1081#define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0)
1082#endif
1083
1084void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1085{
1086 const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1087
1088 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1089 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1090 base, base + size);
1091 return;
1092 }
1093
1094 if (!PAGE_ALIGNED(base)) {
1095 size -= PAGE_SIZE - (base & ~PAGE_MASK);
1096 base = PAGE_ALIGN(base);
1097 }
1098 size &= PAGE_MASK;
1099
1100 if (base > MAX_MEMBLOCK_ADDR) {
1101 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1102 base, base + size);
1103 return;
1104 }
1105
1106 if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1107 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1108 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1109 size = MAX_MEMBLOCK_ADDR - base + 1;
1110 }
1111
1112 if (base + size < phys_offset) {
1113 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1114 base, base + size);
1115 return;
1116 }
1117 if (base < phys_offset) {
1118 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1119 base, phys_offset);
1120 size -= phys_offset - base;
1121 base = phys_offset;
1122 }
1123 memblock_add(base, size);
1124}
1125
1126static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
1127{
1128 void *ptr = memblock_alloc(size, align);
1129
1130 if (!ptr)
1131 panic("%s: Failed to allocate %llu bytes align=0x%llx\n",
1132 __func__, size, align);
1133
1134 return ptr;
1135}
1136
1137bool __init early_init_dt_verify(void *dt_virt, phys_addr_t dt_phys)
1138{
1139 if (!dt_virt)
1140 return false;
1141
1142 /* check device tree validity */
1143 if (fdt_check_header(dt_virt))
1144 return false;
1145
1146 /* Setup flat device-tree pointer */
1147 initial_boot_params = dt_virt;
1148 initial_boot_params_pa = dt_phys;
1149 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1150 fdt_totalsize(initial_boot_params));
1151
1152 /* Initialize {size,address}-cells info */
1153 early_init_dt_scan_root();
1154
1155 return true;
1156}
1157
1158
1159void __init early_init_dt_scan_nodes(void)
1160{
1161 int rc;
1162
1163 /* Retrieve various information from the /chosen node */
1164 rc = early_init_dt_scan_chosen(boot_command_line);
1165 if (rc)
1166 pr_warn("No chosen node found, continuing without\n");
1167
1168 /* Setup memory, calling early_init_dt_add_memory_arch */
1169 early_init_dt_scan_memory();
1170
1171 /* Handle linux,usable-memory-range property */
1172 early_init_dt_check_for_usable_mem_range();
1173}
1174
1175bool __init early_init_dt_scan(void *dt_virt, phys_addr_t dt_phys)
1176{
1177 bool status;
1178
1179 status = early_init_dt_verify(dt_virt, dt_phys);
1180 if (!status)
1181 return false;
1182
1183 early_init_dt_scan_nodes();
1184 return true;
1185}
1186
1187static void *__init copy_device_tree(void *fdt)
1188{
1189 int size;
1190 void *dt;
1191
1192 size = fdt_totalsize(fdt);
1193 dt = early_init_dt_alloc_memory_arch(size,
1194 roundup_pow_of_two(FDT_V17_SIZE));
1195
1196 if (dt)
1197 memcpy(dt, fdt, size);
1198
1199 return dt;
1200}
1201
1202/**
1203 * unflatten_device_tree - create tree of device_nodes from flat blob
1204 *
1205 * unflattens the device-tree passed by the firmware, creating the
1206 * tree of struct device_node. It also fills the "name" and "type"
1207 * pointers of the nodes so the normal device-tree walking functions
1208 * can be used.
1209 */
1210void __init unflatten_device_tree(void)
1211{
1212 void *fdt = initial_boot_params;
1213
1214 /* Save the statically-placed regions in the reserved_mem array */
1215 fdt_scan_reserved_mem_reg_nodes();
1216
1217 /* Populate an empty root node when bootloader doesn't provide one */
1218 if (!fdt) {
1219 fdt = (void *) __dtb_empty_root_begin;
1220 /* fdt_totalsize() will be used for copy size */
1221 if (fdt_totalsize(fdt) >
1222 __dtb_empty_root_end - __dtb_empty_root_begin) {
1223 pr_err("invalid size in dtb_empty_root\n");
1224 return;
1225 }
1226 of_fdt_crc32 = crc32_be(~0, fdt, fdt_totalsize(fdt));
1227 fdt = copy_device_tree(fdt);
1228 }
1229
1230 __unflatten_device_tree(fdt, NULL, &of_root,
1231 early_init_dt_alloc_memory_arch, false);
1232
1233 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1234 of_alias_scan(early_init_dt_alloc_memory_arch);
1235
1236 unittest_unflatten_overlay_base();
1237}
1238
1239/**
1240 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1241 *
1242 * Copies and unflattens the device-tree passed by the firmware, creating the
1243 * tree of struct device_node. It also fills the "name" and "type"
1244 * pointers of the nodes so the normal device-tree walking functions
1245 * can be used. This should only be used when the FDT memory has not been
1246 * reserved such is the case when the FDT is built-in to the kernel init
1247 * section. If the FDT memory is reserved already then unflatten_device_tree
1248 * should be used instead.
1249 */
1250void __init unflatten_and_copy_device_tree(void)
1251{
1252 if (initial_boot_params)
1253 initial_boot_params = copy_device_tree(initial_boot_params);
1254
1255 unflatten_device_tree();
1256}
1257
1258#ifdef CONFIG_SYSFS
1259static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1260 struct bin_attribute *bin_attr,
1261 char *buf, loff_t off, size_t count)
1262{
1263 memcpy(buf, initial_boot_params + off, count);
1264 return count;
1265}
1266
1267static int __init of_fdt_raw_init(void)
1268{
1269 static struct bin_attribute of_fdt_raw_attr =
1270 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1271
1272 if (!initial_boot_params)
1273 return 0;
1274
1275 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1276 fdt_totalsize(initial_boot_params))) {
1277 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1278 return 0;
1279 }
1280 of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1281 return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1282}
1283late_initcall(of_fdt_raw_init);
1284#endif
1285
1286#endif /* CONFIG_OF_EARLY_FLATTREE */
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 */