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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/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 */