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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/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 /* Process header /memreserve/ fields */
639 for (n = 0; ; n++) {
640 fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
641 if (!size)
642 break;
643 memblock_reserve(base, size);
644 }
645
646 fdt_scan_reserved_mem();
647 fdt_reserve_elfcorehdr();
648 fdt_init_reserved_mem();
649}
650
651/**
652 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
653 */
654void __init early_init_fdt_reserve_self(void)
655{
656 if (!initial_boot_params)
657 return;
658
659 /* Reserve the dtb region */
660 memblock_reserve(__pa(initial_boot_params),
661 fdt_totalsize(initial_boot_params));
662}
663
664/**
665 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
666 * @it: callback function
667 * @data: context data pointer
668 *
669 * This function is used to scan the flattened device-tree, it is
670 * used to extract the memory information at boot before we can
671 * unflatten the tree
672 */
673int __init of_scan_flat_dt(int (*it)(unsigned long node,
674 const char *uname, int depth,
675 void *data),
676 void *data)
677{
678 const void *blob = initial_boot_params;
679 const char *pathp;
680 int offset, rc = 0, depth = -1;
681
682 if (!blob)
683 return 0;
684
685 for (offset = fdt_next_node(blob, -1, &depth);
686 offset >= 0 && depth >= 0 && !rc;
687 offset = fdt_next_node(blob, offset, &depth)) {
688
689 pathp = fdt_get_name(blob, offset, NULL);
690 rc = it(offset, pathp, depth, data);
691 }
692 return rc;
693}
694
695/**
696 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
697 * @parent: parent node
698 * @it: callback function
699 * @data: context data pointer
700 *
701 * This function is used to scan sub-nodes of a node.
702 */
703int __init of_scan_flat_dt_subnodes(unsigned long parent,
704 int (*it)(unsigned long node,
705 const char *uname,
706 void *data),
707 void *data)
708{
709 const void *blob = initial_boot_params;
710 int node;
711
712 fdt_for_each_subnode(node, blob, parent) {
713 const char *pathp;
714 int rc;
715
716 pathp = fdt_get_name(blob, node, NULL);
717 rc = it(node, pathp, data);
718 if (rc)
719 return rc;
720 }
721 return 0;
722}
723
724/**
725 * of_get_flat_dt_subnode_by_name - get the subnode by given name
726 *
727 * @node: the parent node
728 * @uname: the name of subnode
729 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
730 */
731
732int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
733{
734 return fdt_subnode_offset(initial_boot_params, node, uname);
735}
736
737/*
738 * of_get_flat_dt_root - find the root node in the flat blob
739 */
740unsigned long __init of_get_flat_dt_root(void)
741{
742 return 0;
743}
744
745/*
746 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
747 *
748 * This function can be used within scan_flattened_dt callback to get
749 * access to properties
750 */
751const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
752 int *size)
753{
754 return fdt_getprop(initial_boot_params, node, name, size);
755}
756
757/**
758 * of_fdt_is_compatible - Return true if given node from the given blob has
759 * compat in its compatible list
760 * @blob: A device tree blob
761 * @node: node to test
762 * @compat: compatible string to compare with compatible list.
763 *
764 * Return: a non-zero value on match with smaller values returned for more
765 * specific compatible values.
766 */
767static int of_fdt_is_compatible(const void *blob,
768 unsigned long node, const char *compat)
769{
770 const char *cp;
771 int cplen;
772 unsigned long l, score = 0;
773
774 cp = fdt_getprop(blob, node, "compatible", &cplen);
775 if (cp == NULL)
776 return 0;
777 while (cplen > 0) {
778 score++;
779 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
780 return score;
781 l = strlen(cp) + 1;
782 cp += l;
783 cplen -= l;
784 }
785
786 return 0;
787}
788
789/**
790 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
791 * @node: node to test
792 * @compat: compatible string to compare with compatible list.
793 */
794int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
795{
796 return of_fdt_is_compatible(initial_boot_params, node, compat);
797}
798
799/*
800 * of_flat_dt_match - Return true if node matches a list of compatible values
801 */
802static int __init of_flat_dt_match(unsigned long node, const char *const *compat)
803{
804 unsigned int tmp, score = 0;
805
806 if (!compat)
807 return 0;
808
809 while (*compat) {
810 tmp = of_fdt_is_compatible(initial_boot_params, node, *compat);
811 if (tmp && (score == 0 || (tmp < score)))
812 score = tmp;
813 compat++;
814 }
815
816 return score;
817}
818
819/*
820 * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle
821 */
822uint32_t __init of_get_flat_dt_phandle(unsigned long node)
823{
824 return fdt_get_phandle(initial_boot_params, node);
825}
826
827const char * __init of_flat_dt_get_machine_name(void)
828{
829 const char *name;
830 unsigned long dt_root = of_get_flat_dt_root();
831
832 name = of_get_flat_dt_prop(dt_root, "model", NULL);
833 if (!name)
834 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
835 return name;
836}
837
838/**
839 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
840 *
841 * @default_match: A machine specific ptr to return in case of no match.
842 * @get_next_compat: callback function to return next compatible match table.
843 *
844 * Iterate through machine match tables to find the best match for the machine
845 * compatible string in the FDT.
846 */
847const void * __init of_flat_dt_match_machine(const void *default_match,
848 const void * (*get_next_compat)(const char * const**))
849{
850 const void *data = NULL;
851 const void *best_data = default_match;
852 const char *const *compat;
853 unsigned long dt_root;
854 unsigned int best_score = ~1, score = 0;
855
856 dt_root = of_get_flat_dt_root();
857 while ((data = get_next_compat(&compat))) {
858 score = of_flat_dt_match(dt_root, compat);
859 if (score > 0 && score < best_score) {
860 best_data = data;
861 best_score = score;
862 }
863 }
864 if (!best_data) {
865 const char *prop;
866 int size;
867
868 pr_err("\n unrecognized device tree list:\n[ ");
869
870 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
871 if (prop) {
872 while (size > 0) {
873 printk("'%s' ", prop);
874 size -= strlen(prop) + 1;
875 prop += strlen(prop) + 1;
876 }
877 }
878 printk("]\n\n");
879 return NULL;
880 }
881
882 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
883
884 return best_data;
885}
886
887static void __early_init_dt_declare_initrd(unsigned long start,
888 unsigned long end)
889{
890 /* ARM64 would cause a BUG to occur here when CONFIG_DEBUG_VM is
891 * enabled since __va() is called too early. ARM64 does make use
892 * of phys_initrd_start/phys_initrd_size so we can skip this
893 * conversion.
894 */
895 if (!IS_ENABLED(CONFIG_ARM64)) {
896 initrd_start = (unsigned long)__va(start);
897 initrd_end = (unsigned long)__va(end);
898 initrd_below_start_ok = 1;
899 }
900}
901
902/**
903 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
904 * @node: reference to node containing initrd location ('chosen')
905 */
906static void __init early_init_dt_check_for_initrd(unsigned long node)
907{
908 u64 start, end;
909 int len;
910 const __be32 *prop;
911
912 if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
913 return;
914
915 pr_debug("Looking for initrd properties... ");
916
917 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
918 if (!prop)
919 return;
920 start = of_read_number(prop, len/4);
921
922 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
923 if (!prop)
924 return;
925 end = of_read_number(prop, len/4);
926 if (start > end)
927 return;
928
929 __early_init_dt_declare_initrd(start, end);
930 phys_initrd_start = start;
931 phys_initrd_size = end - start;
932
933 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", start, end);
934}
935
936/**
937 * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat
938 * tree
939 * @node: reference to node containing elfcorehdr location ('chosen')
940 */
941static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
942{
943 const __be32 *prop;
944 int len;
945
946 if (!IS_ENABLED(CONFIG_CRASH_DUMP))
947 return;
948
949 pr_debug("Looking for elfcorehdr property... ");
950
951 prop = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len);
952 if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells)))
953 return;
954
955 elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
956 elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &prop);
957
958 pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n",
959 elfcorehdr_addr, elfcorehdr_size);
960}
961
962static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
963
964/*
965 * The main usage of linux,usable-memory-range is for crash dump kernel.
966 * Originally, the number of usable-memory regions is one. Now there may
967 * be two regions, low region and high region.
968 * To make compatibility with existing user-space and older kdump, the low
969 * region is always the last range of linux,usable-memory-range if exist.
970 */
971#define MAX_USABLE_RANGES 2
972
973/**
974 * early_init_dt_check_for_usable_mem_range - Decode usable memory range
975 * location from flat tree
976 */
977void __init early_init_dt_check_for_usable_mem_range(void)
978{
979 struct memblock_region rgn[MAX_USABLE_RANGES] = {0};
980 const __be32 *prop, *endp;
981 int len, i;
982 unsigned long node = chosen_node_offset;
983
984 if ((long)node < 0)
985 return;
986
987 pr_debug("Looking for usable-memory-range property... ");
988
989 prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len);
990 if (!prop || (len % (dt_root_addr_cells + dt_root_size_cells)))
991 return;
992
993 endp = prop + (len / sizeof(__be32));
994 for (i = 0; i < MAX_USABLE_RANGES && prop < endp; i++) {
995 rgn[i].base = dt_mem_next_cell(dt_root_addr_cells, &prop);
996 rgn[i].size = dt_mem_next_cell(dt_root_size_cells, &prop);
997
998 pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n",
999 i, &rgn[i].base, &rgn[i].size);
1000 }
1001
1002 memblock_cap_memory_range(rgn[0].base, rgn[0].size);
1003 for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++)
1004 memblock_add(rgn[i].base, rgn[i].size);
1005}
1006
1007#ifdef CONFIG_SERIAL_EARLYCON
1008
1009int __init early_init_dt_scan_chosen_stdout(void)
1010{
1011 int offset;
1012 const char *p, *q, *options = NULL;
1013 int l;
1014 const struct earlycon_id *match;
1015 const void *fdt = initial_boot_params;
1016 int ret;
1017
1018 offset = fdt_path_offset(fdt, "/chosen");
1019 if (offset < 0)
1020 offset = fdt_path_offset(fdt, "/chosen@0");
1021 if (offset < 0)
1022 return -ENOENT;
1023
1024 p = fdt_getprop(fdt, offset, "stdout-path", &l);
1025 if (!p)
1026 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
1027 if (!p || !l)
1028 return -ENOENT;
1029
1030 q = strchrnul(p, ':');
1031 if (*q != '\0')
1032 options = q + 1;
1033 l = q - p;
1034
1035 /* Get the node specified by stdout-path */
1036 offset = fdt_path_offset_namelen(fdt, p, l);
1037 if (offset < 0) {
1038 pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
1039 return 0;
1040 }
1041
1042 for (match = __earlycon_table; match < __earlycon_table_end; match++) {
1043 if (!match->compatible[0])
1044 continue;
1045
1046 if (fdt_node_check_compatible(fdt, offset, match->compatible))
1047 continue;
1048
1049 ret = of_setup_earlycon(match, offset, options);
1050 if (!ret || ret == -EALREADY)
1051 return 0;
1052 }
1053 return -ENODEV;
1054}
1055#endif
1056
1057/*
1058 * early_init_dt_scan_root - fetch the top level address and size cells
1059 */
1060int __init early_init_dt_scan_root(void)
1061{
1062 const __be32 *prop;
1063 const void *fdt = initial_boot_params;
1064 int node = fdt_path_offset(fdt, "/");
1065
1066 if (node < 0)
1067 return -ENODEV;
1068
1069 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
1070 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
1071
1072 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
1073 if (prop)
1074 dt_root_size_cells = be32_to_cpup(prop);
1075 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
1076
1077 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
1078 if (prop)
1079 dt_root_addr_cells = be32_to_cpup(prop);
1080 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
1081
1082 return 0;
1083}
1084
1085u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
1086{
1087 const __be32 *p = *cellp;
1088
1089 *cellp = p + s;
1090 return of_read_number(p, s);
1091}
1092
1093/*
1094 * early_init_dt_scan_memory - Look for and parse memory nodes
1095 */
1096int __init early_init_dt_scan_memory(void)
1097{
1098 int node, found_memory = 0;
1099 const void *fdt = initial_boot_params;
1100
1101 fdt_for_each_subnode(node, fdt, 0) {
1102 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
1103 const __be32 *reg, *endp;
1104 int l;
1105 bool hotpluggable;
1106
1107 /* We are scanning "memory" nodes only */
1108 if (type == NULL || strcmp(type, "memory") != 0)
1109 continue;
1110
1111 if (!of_fdt_device_is_available(fdt, node))
1112 continue;
1113
1114 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
1115 if (reg == NULL)
1116 reg = of_get_flat_dt_prop(node, "reg", &l);
1117 if (reg == NULL)
1118 continue;
1119
1120 endp = reg + (l / sizeof(__be32));
1121 hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
1122
1123 pr_debug("memory scan node %s, reg size %d,\n",
1124 fdt_get_name(fdt, node, NULL), l);
1125
1126 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
1127 u64 base, size;
1128
1129 base = dt_mem_next_cell(dt_root_addr_cells, ®);
1130 size = dt_mem_next_cell(dt_root_size_cells, ®);
1131
1132 if (size == 0)
1133 continue;
1134 pr_debug(" - %llx, %llx\n", base, size);
1135
1136 early_init_dt_add_memory_arch(base, size);
1137
1138 found_memory = 1;
1139
1140 if (!hotpluggable)
1141 continue;
1142
1143 if (memblock_mark_hotplug(base, size))
1144 pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1145 base, base + size);
1146 }
1147 }
1148 return found_memory;
1149}
1150
1151int __init early_init_dt_scan_chosen(char *cmdline)
1152{
1153 int l, node;
1154 const char *p;
1155 const void *rng_seed;
1156 const void *fdt = initial_boot_params;
1157
1158 node = fdt_path_offset(fdt, "/chosen");
1159 if (node < 0)
1160 node = fdt_path_offset(fdt, "/chosen@0");
1161 if (node < 0)
1162 /* Handle the cmdline config options even if no /chosen node */
1163 goto handle_cmdline;
1164
1165 chosen_node_offset = node;
1166
1167 early_init_dt_check_for_initrd(node);
1168 early_init_dt_check_for_elfcorehdr(node);
1169
1170 rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
1171 if (rng_seed && l > 0) {
1172 add_bootloader_randomness(rng_seed, l);
1173
1174 /* try to clear seed so it won't be found. */
1175 fdt_nop_property(initial_boot_params, node, "rng-seed");
1176
1177 /* update CRC check value */
1178 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1179 fdt_totalsize(initial_boot_params));
1180 }
1181
1182 /* Retrieve command line */
1183 p = of_get_flat_dt_prop(node, "bootargs", &l);
1184 if (p != NULL && l > 0)
1185 strscpy(cmdline, p, min(l, COMMAND_LINE_SIZE));
1186
1187handle_cmdline:
1188 /*
1189 * CONFIG_CMDLINE is meant to be a default in case nothing else
1190 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1191 * is set in which case we override whatever was found earlier.
1192 */
1193#ifdef CONFIG_CMDLINE
1194#if defined(CONFIG_CMDLINE_EXTEND)
1195 strlcat(cmdline, " ", COMMAND_LINE_SIZE);
1196 strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1197#elif defined(CONFIG_CMDLINE_FORCE)
1198 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1199#else
1200 /* No arguments from boot loader, use kernel's cmdl*/
1201 if (!((char *)cmdline)[0])
1202 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1203#endif
1204#endif /* CONFIG_CMDLINE */
1205
1206 pr_debug("Command line is: %s\n", (char *)cmdline);
1207
1208 return 0;
1209}
1210
1211#ifndef MIN_MEMBLOCK_ADDR
1212#define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET)
1213#endif
1214#ifndef MAX_MEMBLOCK_ADDR
1215#define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0)
1216#endif
1217
1218void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1219{
1220 const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1221
1222 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1223 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1224 base, base + size);
1225 return;
1226 }
1227
1228 if (!PAGE_ALIGNED(base)) {
1229 size -= PAGE_SIZE - (base & ~PAGE_MASK);
1230 base = PAGE_ALIGN(base);
1231 }
1232 size &= PAGE_MASK;
1233
1234 if (base > MAX_MEMBLOCK_ADDR) {
1235 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1236 base, base + size);
1237 return;
1238 }
1239
1240 if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1241 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1242 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1243 size = MAX_MEMBLOCK_ADDR - base + 1;
1244 }
1245
1246 if (base + size < phys_offset) {
1247 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1248 base, base + size);
1249 return;
1250 }
1251 if (base < phys_offset) {
1252 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1253 base, phys_offset);
1254 size -= phys_offset - base;
1255 base = phys_offset;
1256 }
1257 memblock_add(base, size);
1258}
1259
1260static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
1261{
1262 void *ptr = memblock_alloc(size, align);
1263
1264 if (!ptr)
1265 panic("%s: Failed to allocate %llu bytes align=0x%llx\n",
1266 __func__, size, align);
1267
1268 return ptr;
1269}
1270
1271bool __init early_init_dt_verify(void *params)
1272{
1273 if (!params)
1274 return false;
1275
1276 /* check device tree validity */
1277 if (fdt_check_header(params))
1278 return false;
1279
1280 /* Setup flat device-tree pointer */
1281 initial_boot_params = params;
1282 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1283 fdt_totalsize(initial_boot_params));
1284 return true;
1285}
1286
1287
1288void __init early_init_dt_scan_nodes(void)
1289{
1290 int rc;
1291
1292 /* Initialize {size,address}-cells info */
1293 early_init_dt_scan_root();
1294
1295 /* Retrieve various information from the /chosen node */
1296 rc = early_init_dt_scan_chosen(boot_command_line);
1297 if (rc)
1298 pr_warn("No chosen node found, continuing without\n");
1299
1300 /* Setup memory, calling early_init_dt_add_memory_arch */
1301 early_init_dt_scan_memory();
1302
1303 /* Handle linux,usable-memory-range property */
1304 early_init_dt_check_for_usable_mem_range();
1305}
1306
1307bool __init early_init_dt_scan(void *params)
1308{
1309 bool status;
1310
1311 status = early_init_dt_verify(params);
1312 if (!status)
1313 return false;
1314
1315 early_init_dt_scan_nodes();
1316 return true;
1317}
1318
1319/**
1320 * unflatten_device_tree - create tree of device_nodes from flat blob
1321 *
1322 * unflattens the device-tree passed by the firmware, creating the
1323 * tree of struct device_node. It also fills the "name" and "type"
1324 * pointers of the nodes so the normal device-tree walking functions
1325 * can be used.
1326 */
1327void __init unflatten_device_tree(void)
1328{
1329 __unflatten_device_tree(initial_boot_params, NULL, &of_root,
1330 early_init_dt_alloc_memory_arch, false);
1331
1332 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1333 of_alias_scan(early_init_dt_alloc_memory_arch);
1334
1335 unittest_unflatten_overlay_base();
1336}
1337
1338/**
1339 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1340 *
1341 * Copies and unflattens the device-tree passed by the firmware, creating the
1342 * tree of struct device_node. It also fills the "name" and "type"
1343 * pointers of the nodes so the normal device-tree walking functions
1344 * can be used. This should only be used when the FDT memory has not been
1345 * reserved such is the case when the FDT is built-in to the kernel init
1346 * section. If the FDT memory is reserved already then unflatten_device_tree
1347 * should be used instead.
1348 */
1349void __init unflatten_and_copy_device_tree(void)
1350{
1351 int size;
1352 void *dt;
1353
1354 if (!initial_boot_params) {
1355 pr_warn("No valid device tree found, continuing without\n");
1356 return;
1357 }
1358
1359 size = fdt_totalsize(initial_boot_params);
1360 dt = early_init_dt_alloc_memory_arch(size,
1361 roundup_pow_of_two(FDT_V17_SIZE));
1362
1363 if (dt) {
1364 memcpy(dt, initial_boot_params, size);
1365 initial_boot_params = dt;
1366 }
1367 unflatten_device_tree();
1368}
1369
1370#ifdef CONFIG_SYSFS
1371static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1372 struct bin_attribute *bin_attr,
1373 char *buf, loff_t off, size_t count)
1374{
1375 memcpy(buf, initial_boot_params + off, count);
1376 return count;
1377}
1378
1379static int __init of_fdt_raw_init(void)
1380{
1381 static struct bin_attribute of_fdt_raw_attr =
1382 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1383
1384 if (!initial_boot_params)
1385 return 0;
1386
1387 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1388 fdt_totalsize(initial_boot_params))) {
1389 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1390 return 0;
1391 }
1392 of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1393 return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1394}
1395late_initcall(of_fdt_raw_init);
1396#endif
1397
1398#endif /* CONFIG_OF_EARLY_FLATTREE */
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Functions for working with the Flattened Device Tree data format
4 *
5 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
6 * benh@kernel.crashing.org
7 */
8
9#define pr_fmt(fmt) "OF: fdt: " fmt
10
11#include <linux/acpi.h>
12#include <linux/crash_dump.h>
13#include <linux/crc32.h>
14#include <linux/kernel.h>
15#include <linux/initrd.h>
16#include <linux/memblock.h>
17#include <linux/mutex.h>
18#include <linux/of.h>
19#include <linux/of_fdt.h>
20#include <linux/sizes.h>
21#include <linux/string.h>
22#include <linux/errno.h>
23#include <linux/slab.h>
24#include <linux/libfdt.h>
25#include <linux/debugfs.h>
26#include <linux/serial_core.h>
27#include <linux/sysfs.h>
28#include <linux/random.h>
29
30#include <asm/setup.h> /* for COMMAND_LINE_SIZE */
31#include <asm/page.h>
32
33#include "of_private.h"
34
35/*
36 * __dtb_empty_root_begin[] and __dtb_empty_root_end[] magically created by
37 * cmd_dt_S_dtb in scripts/Makefile.lib
38 */
39extern uint8_t __dtb_empty_root_begin[];
40extern uint8_t __dtb_empty_root_end[];
41
42/*
43 * of_fdt_limit_memory - limit the number of regions in the /memory node
44 * @limit: maximum entries
45 *
46 * Adjust the flattened device tree to have at most 'limit' number of
47 * memory entries in the /memory node. This function may be called
48 * any time after initial_boot_param is set.
49 */
50void __init of_fdt_limit_memory(int limit)
51{
52 int memory;
53 int len;
54 const void *val;
55 int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
56 int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
57 const __be32 *addr_prop;
58 const __be32 *size_prop;
59 int root_offset;
60 int cell_size;
61
62 root_offset = fdt_path_offset(initial_boot_params, "/");
63 if (root_offset < 0)
64 return;
65
66 addr_prop = fdt_getprop(initial_boot_params, root_offset,
67 "#address-cells", NULL);
68 if (addr_prop)
69 nr_address_cells = fdt32_to_cpu(*addr_prop);
70
71 size_prop = fdt_getprop(initial_boot_params, root_offset,
72 "#size-cells", NULL);
73 if (size_prop)
74 nr_size_cells = fdt32_to_cpu(*size_prop);
75
76 cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
77
78 memory = fdt_path_offset(initial_boot_params, "/memory");
79 if (memory > 0) {
80 val = fdt_getprop(initial_boot_params, memory, "reg", &len);
81 if (len > limit*cell_size) {
82 len = limit*cell_size;
83 pr_debug("Limiting number of entries to %d\n", limit);
84 fdt_setprop(initial_boot_params, memory, "reg", val,
85 len);
86 }
87 }
88}
89
90bool of_fdt_device_is_available(const void *blob, unsigned long node)
91{
92 const char *status = fdt_getprop(blob, node, "status", NULL);
93
94 if (!status)
95 return true;
96
97 if (!strcmp(status, "ok") || !strcmp(status, "okay"))
98 return true;
99
100 return false;
101}
102
103static void *unflatten_dt_alloc(void **mem, unsigned long size,
104 unsigned long align)
105{
106 void *res;
107
108 *mem = PTR_ALIGN(*mem, align);
109 res = *mem;
110 *mem += size;
111
112 return res;
113}
114
115static void populate_properties(const void *blob,
116 int offset,
117 void **mem,
118 struct device_node *np,
119 const char *nodename,
120 bool dryrun)
121{
122 struct property *pp, **pprev = NULL;
123 int cur;
124 bool has_name = false;
125
126 pprev = &np->properties;
127 for (cur = fdt_first_property_offset(blob, offset);
128 cur >= 0;
129 cur = fdt_next_property_offset(blob, cur)) {
130 const __be32 *val;
131 const char *pname;
132 u32 sz;
133
134 val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
135 if (!val) {
136 pr_warn("Cannot locate property at 0x%x\n", cur);
137 continue;
138 }
139
140 if (!pname) {
141 pr_warn("Cannot find property name at 0x%x\n", cur);
142 continue;
143 }
144
145 if (!strcmp(pname, "name"))
146 has_name = true;
147
148 pp = unflatten_dt_alloc(mem, sizeof(struct property),
149 __alignof__(struct property));
150 if (dryrun)
151 continue;
152
153 /* We accept flattened tree phandles either in
154 * ePAPR-style "phandle" properties, or the
155 * legacy "linux,phandle" properties. If both
156 * appear and have different values, things
157 * will get weird. Don't do that.
158 */
159 if (!strcmp(pname, "phandle") ||
160 !strcmp(pname, "linux,phandle")) {
161 if (!np->phandle)
162 np->phandle = be32_to_cpup(val);
163 }
164
165 /* And we process the "ibm,phandle" property
166 * used in pSeries dynamic device tree
167 * stuff
168 */
169 if (!strcmp(pname, "ibm,phandle"))
170 np->phandle = be32_to_cpup(val);
171
172 pp->name = (char *)pname;
173 pp->length = sz;
174 pp->value = (__be32 *)val;
175 *pprev = pp;
176 pprev = &pp->next;
177 }
178
179 /* With version 0x10 we may not have the name property,
180 * recreate it here from the unit name if absent
181 */
182 if (!has_name) {
183 const char *p = nodename, *ps = p, *pa = NULL;
184 int len;
185
186 while (*p) {
187 if ((*p) == '@')
188 pa = p;
189 else if ((*p) == '/')
190 ps = p + 1;
191 p++;
192 }
193
194 if (pa < ps)
195 pa = p;
196 len = (pa - ps) + 1;
197 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
198 __alignof__(struct property));
199 if (!dryrun) {
200 pp->name = "name";
201 pp->length = len;
202 pp->value = pp + 1;
203 *pprev = pp;
204 memcpy(pp->value, ps, len - 1);
205 ((char *)pp->value)[len - 1] = 0;
206 pr_debug("fixed up name for %s -> %s\n",
207 nodename, (char *)pp->value);
208 }
209 }
210}
211
212static int populate_node(const void *blob,
213 int offset,
214 void **mem,
215 struct device_node *dad,
216 struct device_node **pnp,
217 bool dryrun)
218{
219 struct device_node *np;
220 const char *pathp;
221 int len;
222
223 pathp = fdt_get_name(blob, offset, &len);
224 if (!pathp) {
225 *pnp = NULL;
226 return len;
227 }
228
229 len++;
230
231 np = unflatten_dt_alloc(mem, sizeof(struct device_node) + len,
232 __alignof__(struct device_node));
233 if (!dryrun) {
234 char *fn;
235 of_node_init(np);
236 np->full_name = fn = ((char *)np) + sizeof(*np);
237
238 memcpy(fn, pathp, len);
239
240 if (dad != NULL) {
241 np->parent = dad;
242 np->sibling = dad->child;
243 dad->child = np;
244 }
245 }
246
247 populate_properties(blob, offset, mem, np, pathp, dryrun);
248 if (!dryrun) {
249 np->name = of_get_property(np, "name", NULL);
250 if (!np->name)
251 np->name = "<NULL>";
252 }
253
254 *pnp = np;
255 return 0;
256}
257
258static void reverse_nodes(struct device_node *parent)
259{
260 struct device_node *child, *next;
261
262 /* In-depth first */
263 child = parent->child;
264 while (child) {
265 reverse_nodes(child);
266
267 child = child->sibling;
268 }
269
270 /* Reverse the nodes in the child list */
271 child = parent->child;
272 parent->child = NULL;
273 while (child) {
274 next = child->sibling;
275
276 child->sibling = parent->child;
277 parent->child = child;
278 child = next;
279 }
280}
281
282/**
283 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
284 * @blob: The parent device tree blob
285 * @mem: Memory chunk to use for allocating device nodes and properties
286 * @dad: Parent struct device_node
287 * @nodepp: The device_node tree created by the call
288 *
289 * Return: The size of unflattened device tree or error code
290 */
291static int unflatten_dt_nodes(const void *blob,
292 void *mem,
293 struct device_node *dad,
294 struct device_node **nodepp)
295{
296 struct device_node *root;
297 int offset = 0, depth = 0, initial_depth = 0;
298#define FDT_MAX_DEPTH 64
299 struct device_node *nps[FDT_MAX_DEPTH];
300 void *base = mem;
301 bool dryrun = !base;
302 int ret;
303
304 if (nodepp)
305 *nodepp = NULL;
306
307 /*
308 * We're unflattening device sub-tree if @dad is valid. There are
309 * possibly multiple nodes in the first level of depth. We need
310 * set @depth to 1 to make fdt_next_node() happy as it bails
311 * immediately when negative @depth is found. Otherwise, the device
312 * nodes except the first one won't be unflattened successfully.
313 */
314 if (dad)
315 depth = initial_depth = 1;
316
317 root = dad;
318 nps[depth] = dad;
319
320 for (offset = 0;
321 offset >= 0 && depth >= initial_depth;
322 offset = fdt_next_node(blob, offset, &depth)) {
323 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH - 1))
324 continue;
325
326 if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
327 !of_fdt_device_is_available(blob, offset))
328 continue;
329
330 ret = populate_node(blob, offset, &mem, nps[depth],
331 &nps[depth+1], dryrun);
332 if (ret < 0)
333 return ret;
334
335 if (!dryrun && nodepp && !*nodepp)
336 *nodepp = nps[depth+1];
337 if (!dryrun && !root)
338 root = nps[depth+1];
339 }
340
341 if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
342 pr_err("Error %d processing FDT\n", offset);
343 return -EINVAL;
344 }
345
346 /*
347 * Reverse the child list. Some drivers assumes node order matches .dts
348 * node order
349 */
350 if (!dryrun)
351 reverse_nodes(root);
352
353 return mem - base;
354}
355
356/**
357 * __unflatten_device_tree - create tree of device_nodes from flat blob
358 * @blob: The blob to expand
359 * @dad: Parent device node
360 * @mynodes: The device_node tree created by the call
361 * @dt_alloc: An allocator that provides a virtual address to memory
362 * for the resulting tree
363 * @detached: if true set OF_DETACHED on @mynodes
364 *
365 * unflattens a device-tree, creating the tree of struct device_node. It also
366 * fills the "name" and "type" pointers of the nodes so the normal device-tree
367 * walking functions can be used.
368 *
369 * Return: NULL on failure or the memory chunk containing the unflattened
370 * device tree on success.
371 */
372void *__unflatten_device_tree(const void *blob,
373 struct device_node *dad,
374 struct device_node **mynodes,
375 void *(*dt_alloc)(u64 size, u64 align),
376 bool detached)
377{
378 int size;
379 void *mem;
380 int ret;
381
382 if (mynodes)
383 *mynodes = NULL;
384
385 pr_debug(" -> unflatten_device_tree()\n");
386
387 if (!blob) {
388 pr_debug("No device tree pointer\n");
389 return NULL;
390 }
391
392 pr_debug("Unflattening device tree:\n");
393 pr_debug("magic: %08x\n", fdt_magic(blob));
394 pr_debug("size: %08x\n", fdt_totalsize(blob));
395 pr_debug("version: %08x\n", fdt_version(blob));
396
397 if (fdt_check_header(blob)) {
398 pr_err("Invalid device tree blob header\n");
399 return NULL;
400 }
401
402 /* First pass, scan for size */
403 size = unflatten_dt_nodes(blob, NULL, dad, NULL);
404 if (size <= 0)
405 return NULL;
406
407 size = ALIGN(size, 4);
408 pr_debug(" size is %d, allocating...\n", size);
409
410 /* Allocate memory for the expanded device tree */
411 mem = dt_alloc(size + 4, __alignof__(struct device_node));
412 if (!mem)
413 return NULL;
414
415 memset(mem, 0, size);
416
417 *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
418
419 pr_debug(" unflattening %p...\n", mem);
420
421 /* Second pass, do actual unflattening */
422 ret = unflatten_dt_nodes(blob, mem, dad, mynodes);
423
424 if (be32_to_cpup(mem + size) != 0xdeadbeef)
425 pr_warn("End of tree marker overwritten: %08x\n",
426 be32_to_cpup(mem + size));
427
428 if (ret <= 0)
429 return NULL;
430
431 if (detached && mynodes && *mynodes) {
432 of_node_set_flag(*mynodes, OF_DETACHED);
433 pr_debug("unflattened tree is detached\n");
434 }
435
436 pr_debug(" <- unflatten_device_tree()\n");
437 return mem;
438}
439
440static void *kernel_tree_alloc(u64 size, u64 align)
441{
442 return kzalloc(size, GFP_KERNEL);
443}
444
445static DEFINE_MUTEX(of_fdt_unflatten_mutex);
446
447/**
448 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
449 * @blob: Flat device tree blob
450 * @dad: Parent device node
451 * @mynodes: The device tree created by the call
452 *
453 * unflattens the device-tree passed by the firmware, creating the
454 * tree of struct device_node. It also fills the "name" and "type"
455 * pointers of the nodes so the normal device-tree walking functions
456 * can be used.
457 *
458 * Return: NULL on failure or the memory chunk containing the unflattened
459 * device tree on success.
460 */
461void *of_fdt_unflatten_tree(const unsigned long *blob,
462 struct device_node *dad,
463 struct device_node **mynodes)
464{
465 void *mem;
466
467 mutex_lock(&of_fdt_unflatten_mutex);
468 mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
469 true);
470 mutex_unlock(&of_fdt_unflatten_mutex);
471
472 return mem;
473}
474EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
475
476/* Everything below here references initial_boot_params directly. */
477int __initdata dt_root_addr_cells;
478int __initdata dt_root_size_cells;
479
480void *initial_boot_params __ro_after_init;
481
482#ifdef CONFIG_OF_EARLY_FLATTREE
483
484static u32 of_fdt_crc32;
485
486/*
487 * fdt_reserve_elfcorehdr() - reserves memory for elf core header
488 *
489 * This function reserves the memory occupied by an elf core header
490 * described in the device tree. This region contains all the
491 * information about primary kernel's core image and is used by a dump
492 * capture kernel to access the system memory on primary kernel.
493 */
494static void __init fdt_reserve_elfcorehdr(void)
495{
496 if (!IS_ENABLED(CONFIG_CRASH_DUMP) || !elfcorehdr_size)
497 return;
498
499 if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) {
500 pr_warn("elfcorehdr is overlapped\n");
501 return;
502 }
503
504 memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
505
506 pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n",
507 elfcorehdr_size >> 10, elfcorehdr_addr);
508}
509
510/**
511 * early_init_fdt_scan_reserved_mem() - create reserved memory regions
512 *
513 * This function grabs memory from early allocator for device exclusive use
514 * defined in device tree structures. It should be called by arch specific code
515 * once the early allocator (i.e. memblock) has been fully activated.
516 */
517void __init early_init_fdt_scan_reserved_mem(void)
518{
519 int n;
520 u64 base, size;
521
522 if (!initial_boot_params)
523 return;
524
525 fdt_scan_reserved_mem();
526 fdt_reserve_elfcorehdr();
527
528 /* Process header /memreserve/ fields */
529 for (n = 0; ; n++) {
530 fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
531 if (!size)
532 break;
533 memblock_reserve(base, size);
534 }
535
536 fdt_init_reserved_mem();
537}
538
539/**
540 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
541 */
542void __init early_init_fdt_reserve_self(void)
543{
544 if (!initial_boot_params)
545 return;
546
547 /* Reserve the dtb region */
548 memblock_reserve(__pa(initial_boot_params),
549 fdt_totalsize(initial_boot_params));
550}
551
552/**
553 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
554 * @it: callback function
555 * @data: context data pointer
556 *
557 * This function is used to scan the flattened device-tree, it is
558 * used to extract the memory information at boot before we can
559 * unflatten the tree
560 */
561int __init of_scan_flat_dt(int (*it)(unsigned long node,
562 const char *uname, int depth,
563 void *data),
564 void *data)
565{
566 const void *blob = initial_boot_params;
567 const char *pathp;
568 int offset, rc = 0, depth = -1;
569
570 if (!blob)
571 return 0;
572
573 for (offset = fdt_next_node(blob, -1, &depth);
574 offset >= 0 && depth >= 0 && !rc;
575 offset = fdt_next_node(blob, offset, &depth)) {
576
577 pathp = fdt_get_name(blob, offset, NULL);
578 rc = it(offset, pathp, depth, data);
579 }
580 return rc;
581}
582
583/**
584 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
585 * @parent: parent node
586 * @it: callback function
587 * @data: context data pointer
588 *
589 * This function is used to scan sub-nodes of a node.
590 */
591int __init of_scan_flat_dt_subnodes(unsigned long parent,
592 int (*it)(unsigned long node,
593 const char *uname,
594 void *data),
595 void *data)
596{
597 const void *blob = initial_boot_params;
598 int node;
599
600 fdt_for_each_subnode(node, blob, parent) {
601 const char *pathp;
602 int rc;
603
604 pathp = fdt_get_name(blob, node, NULL);
605 rc = it(node, pathp, data);
606 if (rc)
607 return rc;
608 }
609 return 0;
610}
611
612/**
613 * of_get_flat_dt_subnode_by_name - get the subnode by given name
614 *
615 * @node: the parent node
616 * @uname: the name of subnode
617 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
618 */
619
620int __init of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
621{
622 return fdt_subnode_offset(initial_boot_params, node, uname);
623}
624
625/*
626 * of_get_flat_dt_root - find the root node in the flat blob
627 */
628unsigned long __init of_get_flat_dt_root(void)
629{
630 return 0;
631}
632
633/*
634 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
635 *
636 * This function can be used within scan_flattened_dt callback to get
637 * access to properties
638 */
639const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
640 int *size)
641{
642 return fdt_getprop(initial_boot_params, node, name, size);
643}
644
645/**
646 * of_fdt_is_compatible - Return true if given node from the given blob has
647 * compat in its compatible list
648 * @blob: A device tree blob
649 * @node: node to test
650 * @compat: compatible string to compare with compatible list.
651 *
652 * Return: a non-zero value on match with smaller values returned for more
653 * specific compatible values.
654 */
655static int of_fdt_is_compatible(const void *blob,
656 unsigned long node, const char *compat)
657{
658 const char *cp;
659 int cplen;
660 unsigned long l, score = 0;
661
662 cp = fdt_getprop(blob, node, "compatible", &cplen);
663 if (cp == NULL)
664 return 0;
665 while (cplen > 0) {
666 score++;
667 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
668 return score;
669 l = strlen(cp) + 1;
670 cp += l;
671 cplen -= l;
672 }
673
674 return 0;
675}
676
677/**
678 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
679 * @node: node to test
680 * @compat: compatible string to compare with compatible list.
681 */
682int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
683{
684 return of_fdt_is_compatible(initial_boot_params, node, compat);
685}
686
687/*
688 * of_flat_dt_match - Return true if node matches a list of compatible values
689 */
690static int __init of_flat_dt_match(unsigned long node, const char *const *compat)
691{
692 unsigned int tmp, score = 0;
693
694 if (!compat)
695 return 0;
696
697 while (*compat) {
698 tmp = of_fdt_is_compatible(initial_boot_params, node, *compat);
699 if (tmp && (score == 0 || (tmp < score)))
700 score = tmp;
701 compat++;
702 }
703
704 return score;
705}
706
707/*
708 * of_get_flat_dt_phandle - Given a node in the flat blob, return the phandle
709 */
710uint32_t __init of_get_flat_dt_phandle(unsigned long node)
711{
712 return fdt_get_phandle(initial_boot_params, node);
713}
714
715const char * __init of_flat_dt_get_machine_name(void)
716{
717 const char *name;
718 unsigned long dt_root = of_get_flat_dt_root();
719
720 name = of_get_flat_dt_prop(dt_root, "model", NULL);
721 if (!name)
722 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
723 return name;
724}
725
726/**
727 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
728 *
729 * @default_match: A machine specific ptr to return in case of no match.
730 * @get_next_compat: callback function to return next compatible match table.
731 *
732 * Iterate through machine match tables to find the best match for the machine
733 * compatible string in the FDT.
734 */
735const void * __init of_flat_dt_match_machine(const void *default_match,
736 const void * (*get_next_compat)(const char * const**))
737{
738 const void *data = NULL;
739 const void *best_data = default_match;
740 const char *const *compat;
741 unsigned long dt_root;
742 unsigned int best_score = ~1, score = 0;
743
744 dt_root = of_get_flat_dt_root();
745 while ((data = get_next_compat(&compat))) {
746 score = of_flat_dt_match(dt_root, compat);
747 if (score > 0 && score < best_score) {
748 best_data = data;
749 best_score = score;
750 }
751 }
752 if (!best_data) {
753 const char *prop;
754 int size;
755
756 pr_err("\n unrecognized device tree list:\n[ ");
757
758 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
759 if (prop) {
760 while (size > 0) {
761 printk("'%s' ", prop);
762 size -= strlen(prop) + 1;
763 prop += strlen(prop) + 1;
764 }
765 }
766 printk("]\n\n");
767 return NULL;
768 }
769
770 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
771
772 return best_data;
773}
774
775static void __early_init_dt_declare_initrd(unsigned long start,
776 unsigned long end)
777{
778 /*
779 * __va() is not yet available this early on some platforms. In that
780 * case, the platform uses phys_initrd_start/phys_initrd_size instead
781 * and does the VA conversion itself.
782 */
783 if (!IS_ENABLED(CONFIG_ARM64) &&
784 !(IS_ENABLED(CONFIG_RISCV) && IS_ENABLED(CONFIG_64BIT))) {
785 initrd_start = (unsigned long)__va(start);
786 initrd_end = (unsigned long)__va(end);
787 initrd_below_start_ok = 1;
788 }
789}
790
791/**
792 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
793 * @node: reference to node containing initrd location ('chosen')
794 */
795static void __init early_init_dt_check_for_initrd(unsigned long node)
796{
797 u64 start, end;
798 int len;
799 const __be32 *prop;
800
801 if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
802 return;
803
804 pr_debug("Looking for initrd properties... ");
805
806 prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
807 if (!prop)
808 return;
809 start = of_read_number(prop, len/4);
810
811 prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
812 if (!prop)
813 return;
814 end = of_read_number(prop, len/4);
815 if (start > end)
816 return;
817
818 __early_init_dt_declare_initrd(start, end);
819 phys_initrd_start = start;
820 phys_initrd_size = end - start;
821
822 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", start, end);
823}
824
825/**
826 * early_init_dt_check_for_elfcorehdr - Decode elfcorehdr location from flat
827 * tree
828 * @node: reference to node containing elfcorehdr location ('chosen')
829 */
830static void __init early_init_dt_check_for_elfcorehdr(unsigned long node)
831{
832 const __be32 *prop;
833 int len;
834
835 if (!IS_ENABLED(CONFIG_CRASH_DUMP))
836 return;
837
838 pr_debug("Looking for elfcorehdr property... ");
839
840 prop = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len);
841 if (!prop || (len < (dt_root_addr_cells + dt_root_size_cells)))
842 return;
843
844 elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &prop);
845 elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &prop);
846
847 pr_debug("elfcorehdr_start=0x%llx elfcorehdr_size=0x%llx\n",
848 elfcorehdr_addr, elfcorehdr_size);
849}
850
851static unsigned long chosen_node_offset = -FDT_ERR_NOTFOUND;
852
853/*
854 * The main usage of linux,usable-memory-range is for crash dump kernel.
855 * Originally, the number of usable-memory regions is one. Now there may
856 * be two regions, low region and high region.
857 * To make compatibility with existing user-space and older kdump, the low
858 * region is always the last range of linux,usable-memory-range if exist.
859 */
860#define MAX_USABLE_RANGES 2
861
862/**
863 * early_init_dt_check_for_usable_mem_range - Decode usable memory range
864 * location from flat tree
865 */
866void __init early_init_dt_check_for_usable_mem_range(void)
867{
868 struct memblock_region rgn[MAX_USABLE_RANGES] = {0};
869 const __be32 *prop, *endp;
870 int len, i;
871 unsigned long node = chosen_node_offset;
872
873 if ((long)node < 0)
874 return;
875
876 pr_debug("Looking for usable-memory-range property... ");
877
878 prop = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len);
879 if (!prop || (len % (dt_root_addr_cells + dt_root_size_cells)))
880 return;
881
882 endp = prop + (len / sizeof(__be32));
883 for (i = 0; i < MAX_USABLE_RANGES && prop < endp; i++) {
884 rgn[i].base = dt_mem_next_cell(dt_root_addr_cells, &prop);
885 rgn[i].size = dt_mem_next_cell(dt_root_size_cells, &prop);
886
887 pr_debug("cap_mem_regions[%d]: base=%pa, size=%pa\n",
888 i, &rgn[i].base, &rgn[i].size);
889 }
890
891 memblock_cap_memory_range(rgn[0].base, rgn[0].size);
892 for (i = 1; i < MAX_USABLE_RANGES && rgn[i].size; i++)
893 memblock_add(rgn[i].base, rgn[i].size);
894}
895
896#ifdef CONFIG_SERIAL_EARLYCON
897
898int __init early_init_dt_scan_chosen_stdout(void)
899{
900 int offset;
901 const char *p, *q, *options = NULL;
902 int l;
903 const struct earlycon_id *match;
904 const void *fdt = initial_boot_params;
905 int ret;
906
907 offset = fdt_path_offset(fdt, "/chosen");
908 if (offset < 0)
909 offset = fdt_path_offset(fdt, "/chosen@0");
910 if (offset < 0)
911 return -ENOENT;
912
913 p = fdt_getprop(fdt, offset, "stdout-path", &l);
914 if (!p)
915 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
916 if (!p || !l)
917 return -ENOENT;
918
919 q = strchrnul(p, ':');
920 if (*q != '\0')
921 options = q + 1;
922 l = q - p;
923
924 /* Get the node specified by stdout-path */
925 offset = fdt_path_offset_namelen(fdt, p, l);
926 if (offset < 0) {
927 pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
928 return 0;
929 }
930
931 for (match = __earlycon_table; match < __earlycon_table_end; match++) {
932 if (!match->compatible[0])
933 continue;
934
935 if (fdt_node_check_compatible(fdt, offset, match->compatible))
936 continue;
937
938 ret = of_setup_earlycon(match, offset, options);
939 if (!ret || ret == -EALREADY)
940 return 0;
941 }
942 return -ENODEV;
943}
944#endif
945
946/*
947 * early_init_dt_scan_root - fetch the top level address and size cells
948 */
949int __init early_init_dt_scan_root(void)
950{
951 const __be32 *prop;
952 const void *fdt = initial_boot_params;
953 int node = fdt_path_offset(fdt, "/");
954
955 if (node < 0)
956 return -ENODEV;
957
958 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
959 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
960
961 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
962 if (prop)
963 dt_root_size_cells = be32_to_cpup(prop);
964 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
965
966 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
967 if (prop)
968 dt_root_addr_cells = be32_to_cpup(prop);
969 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
970
971 return 0;
972}
973
974u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
975{
976 const __be32 *p = *cellp;
977
978 *cellp = p + s;
979 return of_read_number(p, s);
980}
981
982/*
983 * early_init_dt_scan_memory - Look for and parse memory nodes
984 */
985int __init early_init_dt_scan_memory(void)
986{
987 int node, found_memory = 0;
988 const void *fdt = initial_boot_params;
989
990 fdt_for_each_subnode(node, fdt, 0) {
991 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
992 const __be32 *reg, *endp;
993 int l;
994 bool hotpluggable;
995
996 /* We are scanning "memory" nodes only */
997 if (type == NULL || strcmp(type, "memory") != 0)
998 continue;
999
1000 if (!of_fdt_device_is_available(fdt, node))
1001 continue;
1002
1003 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
1004 if (reg == NULL)
1005 reg = of_get_flat_dt_prop(node, "reg", &l);
1006 if (reg == NULL)
1007 continue;
1008
1009 endp = reg + (l / sizeof(__be32));
1010 hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
1011
1012 pr_debug("memory scan node %s, reg size %d,\n",
1013 fdt_get_name(fdt, node, NULL), l);
1014
1015 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
1016 u64 base, size;
1017
1018 base = dt_mem_next_cell(dt_root_addr_cells, ®);
1019 size = dt_mem_next_cell(dt_root_size_cells, ®);
1020
1021 if (size == 0)
1022 continue;
1023 pr_debug(" - %llx, %llx\n", base, size);
1024
1025 early_init_dt_add_memory_arch(base, size);
1026
1027 found_memory = 1;
1028
1029 if (!hotpluggable)
1030 continue;
1031
1032 if (memblock_mark_hotplug(base, size))
1033 pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1034 base, base + size);
1035 }
1036 }
1037 return found_memory;
1038}
1039
1040int __init early_init_dt_scan_chosen(char *cmdline)
1041{
1042 int l, node;
1043 const char *p;
1044 const void *rng_seed;
1045 const void *fdt = initial_boot_params;
1046
1047 node = fdt_path_offset(fdt, "/chosen");
1048 if (node < 0)
1049 node = fdt_path_offset(fdt, "/chosen@0");
1050 if (node < 0)
1051 /* Handle the cmdline config options even if no /chosen node */
1052 goto handle_cmdline;
1053
1054 chosen_node_offset = node;
1055
1056 early_init_dt_check_for_initrd(node);
1057 early_init_dt_check_for_elfcorehdr(node);
1058
1059 rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
1060 if (rng_seed && l > 0) {
1061 add_bootloader_randomness(rng_seed, l);
1062
1063 /* try to clear seed so it won't be found. */
1064 fdt_nop_property(initial_boot_params, node, "rng-seed");
1065
1066 /* update CRC check value */
1067 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1068 fdt_totalsize(initial_boot_params));
1069 }
1070
1071 /* Retrieve command line */
1072 p = of_get_flat_dt_prop(node, "bootargs", &l);
1073 if (p != NULL && l > 0)
1074 strscpy(cmdline, p, min(l, COMMAND_LINE_SIZE));
1075
1076handle_cmdline:
1077 /*
1078 * CONFIG_CMDLINE is meant to be a default in case nothing else
1079 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1080 * is set in which case we override whatever was found earlier.
1081 */
1082#ifdef CONFIG_CMDLINE
1083#if defined(CONFIG_CMDLINE_EXTEND)
1084 strlcat(cmdline, " ", COMMAND_LINE_SIZE);
1085 strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1086#elif defined(CONFIG_CMDLINE_FORCE)
1087 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1088#else
1089 /* No arguments from boot loader, use kernel's cmdl*/
1090 if (!((char *)cmdline)[0])
1091 strscpy(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1092#endif
1093#endif /* CONFIG_CMDLINE */
1094
1095 pr_debug("Command line is: %s\n", (char *)cmdline);
1096
1097 return 0;
1098}
1099
1100#ifndef MIN_MEMBLOCK_ADDR
1101#define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET)
1102#endif
1103#ifndef MAX_MEMBLOCK_ADDR
1104#define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0)
1105#endif
1106
1107void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1108{
1109 const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1110
1111 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1112 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1113 base, base + size);
1114 return;
1115 }
1116
1117 if (!PAGE_ALIGNED(base)) {
1118 size -= PAGE_SIZE - (base & ~PAGE_MASK);
1119 base = PAGE_ALIGN(base);
1120 }
1121 size &= PAGE_MASK;
1122
1123 if (base > MAX_MEMBLOCK_ADDR) {
1124 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1125 base, base + size);
1126 return;
1127 }
1128
1129 if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1130 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1131 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1132 size = MAX_MEMBLOCK_ADDR - base + 1;
1133 }
1134
1135 if (base + size < phys_offset) {
1136 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1137 base, base + size);
1138 return;
1139 }
1140 if (base < phys_offset) {
1141 pr_warn("Ignoring memory range 0x%llx - 0x%llx\n",
1142 base, phys_offset);
1143 size -= phys_offset - base;
1144 base = phys_offset;
1145 }
1146 memblock_add(base, size);
1147}
1148
1149static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
1150{
1151 void *ptr = memblock_alloc(size, align);
1152
1153 if (!ptr)
1154 panic("%s: Failed to allocate %llu bytes align=0x%llx\n",
1155 __func__, size, align);
1156
1157 return ptr;
1158}
1159
1160bool __init early_init_dt_verify(void *params)
1161{
1162 if (!params)
1163 return false;
1164
1165 /* check device tree validity */
1166 if (fdt_check_header(params))
1167 return false;
1168
1169 /* Setup flat device-tree pointer */
1170 initial_boot_params = params;
1171 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1172 fdt_totalsize(initial_boot_params));
1173 return true;
1174}
1175
1176
1177void __init early_init_dt_scan_nodes(void)
1178{
1179 int rc;
1180
1181 /* Initialize {size,address}-cells info */
1182 early_init_dt_scan_root();
1183
1184 /* Retrieve various information from the /chosen node */
1185 rc = early_init_dt_scan_chosen(boot_command_line);
1186 if (rc)
1187 pr_warn("No chosen node found, continuing without\n");
1188
1189 /* Setup memory, calling early_init_dt_add_memory_arch */
1190 early_init_dt_scan_memory();
1191
1192 /* Handle linux,usable-memory-range property */
1193 early_init_dt_check_for_usable_mem_range();
1194}
1195
1196bool __init early_init_dt_scan(void *params)
1197{
1198 bool status;
1199
1200 status = early_init_dt_verify(params);
1201 if (!status)
1202 return false;
1203
1204 early_init_dt_scan_nodes();
1205 return true;
1206}
1207
1208static void *__init copy_device_tree(void *fdt)
1209{
1210 int size;
1211 void *dt;
1212
1213 size = fdt_totalsize(fdt);
1214 dt = early_init_dt_alloc_memory_arch(size,
1215 roundup_pow_of_two(FDT_V17_SIZE));
1216
1217 if (dt)
1218 memcpy(dt, fdt, size);
1219
1220 return dt;
1221}
1222
1223/**
1224 * unflatten_device_tree - create tree of device_nodes from flat blob
1225 *
1226 * unflattens the device-tree passed by the firmware, creating the
1227 * tree of struct device_node. It also fills the "name" and "type"
1228 * pointers of the nodes so the normal device-tree walking functions
1229 * can be used.
1230 */
1231void __init unflatten_device_tree(void)
1232{
1233 void *fdt = initial_boot_params;
1234
1235 /* Don't use the bootloader provided DTB if ACPI is enabled */
1236 if (!acpi_disabled)
1237 fdt = NULL;
1238
1239 /*
1240 * Populate an empty root node when ACPI is enabled or bootloader
1241 * doesn't provide one.
1242 */
1243 if (!fdt) {
1244 fdt = (void *) __dtb_empty_root_begin;
1245 /* fdt_totalsize() will be used for copy size */
1246 if (fdt_totalsize(fdt) >
1247 __dtb_empty_root_end - __dtb_empty_root_begin) {
1248 pr_err("invalid size in dtb_empty_root\n");
1249 return;
1250 }
1251 of_fdt_crc32 = crc32_be(~0, fdt, fdt_totalsize(fdt));
1252 fdt = copy_device_tree(fdt);
1253 }
1254
1255 __unflatten_device_tree(fdt, NULL, &of_root,
1256 early_init_dt_alloc_memory_arch, false);
1257
1258 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1259 of_alias_scan(early_init_dt_alloc_memory_arch);
1260
1261 unittest_unflatten_overlay_base();
1262}
1263
1264/**
1265 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1266 *
1267 * Copies and unflattens the device-tree passed by the firmware, creating the
1268 * tree of struct device_node. It also fills the "name" and "type"
1269 * pointers of the nodes so the normal device-tree walking functions
1270 * can be used. This should only be used when the FDT memory has not been
1271 * reserved such is the case when the FDT is built-in to the kernel init
1272 * section. If the FDT memory is reserved already then unflatten_device_tree
1273 * should be used instead.
1274 */
1275void __init unflatten_and_copy_device_tree(void)
1276{
1277 if (initial_boot_params)
1278 initial_boot_params = copy_device_tree(initial_boot_params);
1279
1280 unflatten_device_tree();
1281}
1282
1283#ifdef CONFIG_SYSFS
1284static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1285 struct bin_attribute *bin_attr,
1286 char *buf, loff_t off, size_t count)
1287{
1288 memcpy(buf, initial_boot_params + off, count);
1289 return count;
1290}
1291
1292static int __init of_fdt_raw_init(void)
1293{
1294 static struct bin_attribute of_fdt_raw_attr =
1295 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1296
1297 if (!initial_boot_params)
1298 return 0;
1299
1300 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1301 fdt_totalsize(initial_boot_params))) {
1302 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1303 return 0;
1304 }
1305 of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1306 return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1307}
1308late_initcall(of_fdt_raw_init);
1309#endif
1310
1311#endif /* CONFIG_OF_EARLY_FLATTREE */