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/crc32.h>
12#include <linux/kernel.h>
13#include <linux/initrd.h>
14#include <linux/memblock.h>
15#include <linux/mutex.h>
16#include <linux/of.h>
17#include <linux/of_fdt.h>
18#include <linux/of_reserved_mem.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
28#include <asm/setup.h> /* for COMMAND_LINE_SIZE */
29#include <asm/page.h>
30
31#include "of_private.h"
32
33/*
34 * of_fdt_limit_memory - limit the number of regions in the /memory node
35 * @limit: maximum entries
36 *
37 * Adjust the flattened device tree to have at most 'limit' number of
38 * memory entries in the /memory node. This function may be called
39 * any time after initial_boot_param is set.
40 */
41void of_fdt_limit_memory(int limit)
42{
43 int memory;
44 int len;
45 const void *val;
46 int nr_address_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
47 int nr_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
48 const __be32 *addr_prop;
49 const __be32 *size_prop;
50 int root_offset;
51 int cell_size;
52
53 root_offset = fdt_path_offset(initial_boot_params, "/");
54 if (root_offset < 0)
55 return;
56
57 addr_prop = fdt_getprop(initial_boot_params, root_offset,
58 "#address-cells", NULL);
59 if (addr_prop)
60 nr_address_cells = fdt32_to_cpu(*addr_prop);
61
62 size_prop = fdt_getprop(initial_boot_params, root_offset,
63 "#size-cells", NULL);
64 if (size_prop)
65 nr_size_cells = fdt32_to_cpu(*size_prop);
66
67 cell_size = sizeof(uint32_t)*(nr_address_cells + nr_size_cells);
68
69 memory = fdt_path_offset(initial_boot_params, "/memory");
70 if (memory > 0) {
71 val = fdt_getprop(initial_boot_params, memory, "reg", &len);
72 if (len > limit*cell_size) {
73 len = limit*cell_size;
74 pr_debug("Limiting number of entries to %d\n", limit);
75 fdt_setprop(initial_boot_params, memory, "reg", val,
76 len);
77 }
78 }
79}
80
81/**
82 * of_fdt_is_compatible - Return true if given node from the given blob has
83 * compat in its compatible list
84 * @blob: A device tree blob
85 * @node: node to test
86 * @compat: compatible string to compare with compatible list.
87 *
88 * On match, returns a non-zero value with smaller values returned for more
89 * specific compatible values.
90 */
91static int of_fdt_is_compatible(const void *blob,
92 unsigned long node, const char *compat)
93{
94 const char *cp;
95 int cplen;
96 unsigned long l, score = 0;
97
98 cp = fdt_getprop(blob, node, "compatible", &cplen);
99 if (cp == NULL)
100 return 0;
101 while (cplen > 0) {
102 score++;
103 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
104 return score;
105 l = strlen(cp) + 1;
106 cp += l;
107 cplen -= l;
108 }
109
110 return 0;
111}
112
113/**
114 * of_fdt_is_big_endian - Return true if given node needs BE MMIO accesses
115 * @blob: A device tree blob
116 * @node: node to test
117 *
118 * Returns true if the node has a "big-endian" property, or if the kernel
119 * was compiled for BE *and* the node has a "native-endian" property.
120 * Returns false otherwise.
121 */
122bool of_fdt_is_big_endian(const void *blob, unsigned long node)
123{
124 if (fdt_getprop(blob, node, "big-endian", NULL))
125 return true;
126 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
127 fdt_getprop(blob, node, "native-endian", NULL))
128 return true;
129 return false;
130}
131
132static bool of_fdt_device_is_available(const void *blob, unsigned long node)
133{
134 const char *status = fdt_getprop(blob, node, "status", NULL);
135
136 if (!status)
137 return true;
138
139 if (!strcmp(status, "ok") || !strcmp(status, "okay"))
140 return true;
141
142 return false;
143}
144
145/**
146 * of_fdt_match - Return true if node matches a list of compatible values
147 */
148int of_fdt_match(const void *blob, unsigned long node,
149 const char *const *compat)
150{
151 unsigned int tmp, score = 0;
152
153 if (!compat)
154 return 0;
155
156 while (*compat) {
157 tmp = of_fdt_is_compatible(blob, node, *compat);
158 if (tmp && (score == 0 || (tmp < score)))
159 score = tmp;
160 compat++;
161 }
162
163 return score;
164}
165
166static void *unflatten_dt_alloc(void **mem, unsigned long size,
167 unsigned long align)
168{
169 void *res;
170
171 *mem = PTR_ALIGN(*mem, align);
172 res = *mem;
173 *mem += size;
174
175 return res;
176}
177
178static void populate_properties(const void *blob,
179 int offset,
180 void **mem,
181 struct device_node *np,
182 const char *nodename,
183 bool dryrun)
184{
185 struct property *pp, **pprev = NULL;
186 int cur;
187 bool has_name = false;
188
189 pprev = &np->properties;
190 for (cur = fdt_first_property_offset(blob, offset);
191 cur >= 0;
192 cur = fdt_next_property_offset(blob, cur)) {
193 const __be32 *val;
194 const char *pname;
195 u32 sz;
196
197 val = fdt_getprop_by_offset(blob, cur, &pname, &sz);
198 if (!val) {
199 pr_warn("Cannot locate property at 0x%x\n", cur);
200 continue;
201 }
202
203 if (!pname) {
204 pr_warn("Cannot find property name at 0x%x\n", cur);
205 continue;
206 }
207
208 if (!strcmp(pname, "name"))
209 has_name = true;
210
211 pp = unflatten_dt_alloc(mem, sizeof(struct property),
212 __alignof__(struct property));
213 if (dryrun)
214 continue;
215
216 /* We accept flattened tree phandles either in
217 * ePAPR-style "phandle" properties, or the
218 * legacy "linux,phandle" properties. If both
219 * appear and have different values, things
220 * will get weird. Don't do that.
221 */
222 if (!strcmp(pname, "phandle") ||
223 !strcmp(pname, "linux,phandle")) {
224 if (!np->phandle)
225 np->phandle = be32_to_cpup(val);
226 }
227
228 /* And we process the "ibm,phandle" property
229 * used in pSeries dynamic device tree
230 * stuff
231 */
232 if (!strcmp(pname, "ibm,phandle"))
233 np->phandle = be32_to_cpup(val);
234
235 pp->name = (char *)pname;
236 pp->length = sz;
237 pp->value = (__be32 *)val;
238 *pprev = pp;
239 pprev = &pp->next;
240 }
241
242 /* With version 0x10 we may not have the name property,
243 * recreate it here from the unit name if absent
244 */
245 if (!has_name) {
246 const char *p = nodename, *ps = p, *pa = NULL;
247 int len;
248
249 while (*p) {
250 if ((*p) == '@')
251 pa = p;
252 else if ((*p) == '/')
253 ps = p + 1;
254 p++;
255 }
256
257 if (pa < ps)
258 pa = p;
259 len = (pa - ps) + 1;
260 pp = unflatten_dt_alloc(mem, sizeof(struct property) + len,
261 __alignof__(struct property));
262 if (!dryrun) {
263 pp->name = "name";
264 pp->length = len;
265 pp->value = pp + 1;
266 *pprev = pp;
267 pprev = &pp->next;
268 memcpy(pp->value, ps, len - 1);
269 ((char *)pp->value)[len - 1] = 0;
270 pr_debug("fixed up name for %s -> %s\n",
271 nodename, (char *)pp->value);
272 }
273 }
274
275 if (!dryrun)
276 *pprev = NULL;
277}
278
279static bool populate_node(const void *blob,
280 int offset,
281 void **mem,
282 struct device_node *dad,
283 struct device_node **pnp,
284 bool dryrun)
285{
286 struct device_node *np;
287 const char *pathp;
288 unsigned int l, allocl;
289
290 pathp = fdt_get_name(blob, offset, &l);
291 if (!pathp) {
292 *pnp = NULL;
293 return false;
294 }
295
296 allocl = ++l;
297
298 np = unflatten_dt_alloc(mem, sizeof(struct device_node) + allocl,
299 __alignof__(struct device_node));
300 if (!dryrun) {
301 char *fn;
302 of_node_init(np);
303 np->full_name = fn = ((char *)np) + sizeof(*np);
304
305 memcpy(fn, pathp, l);
306
307 if (dad != NULL) {
308 np->parent = dad;
309 np->sibling = dad->child;
310 dad->child = np;
311 }
312 }
313
314 populate_properties(blob, offset, mem, np, pathp, dryrun);
315 if (!dryrun) {
316 np->name = of_get_property(np, "name", NULL);
317 if (!np->name)
318 np->name = "<NULL>";
319 }
320
321 *pnp = np;
322 return true;
323}
324
325static void reverse_nodes(struct device_node *parent)
326{
327 struct device_node *child, *next;
328
329 /* In-depth first */
330 child = parent->child;
331 while (child) {
332 reverse_nodes(child);
333
334 child = child->sibling;
335 }
336
337 /* Reverse the nodes in the child list */
338 child = parent->child;
339 parent->child = NULL;
340 while (child) {
341 next = child->sibling;
342
343 child->sibling = parent->child;
344 parent->child = child;
345 child = next;
346 }
347}
348
349/**
350 * unflatten_dt_nodes - Alloc and populate a device_node from the flat tree
351 * @blob: The parent device tree blob
352 * @mem: Memory chunk to use for allocating device nodes and properties
353 * @dad: Parent struct device_node
354 * @nodepp: The device_node tree created by the call
355 *
356 * It returns the size of unflattened device tree or error code
357 */
358static int unflatten_dt_nodes(const void *blob,
359 void *mem,
360 struct device_node *dad,
361 struct device_node **nodepp)
362{
363 struct device_node *root;
364 int offset = 0, depth = 0, initial_depth = 0;
365#define FDT_MAX_DEPTH 64
366 struct device_node *nps[FDT_MAX_DEPTH];
367 void *base = mem;
368 bool dryrun = !base;
369
370 if (nodepp)
371 *nodepp = NULL;
372
373 /*
374 * We're unflattening device sub-tree if @dad is valid. There are
375 * possibly multiple nodes in the first level of depth. We need
376 * set @depth to 1 to make fdt_next_node() happy as it bails
377 * immediately when negative @depth is found. Otherwise, the device
378 * nodes except the first one won't be unflattened successfully.
379 */
380 if (dad)
381 depth = initial_depth = 1;
382
383 root = dad;
384 nps[depth] = dad;
385
386 for (offset = 0;
387 offset >= 0 && depth >= initial_depth;
388 offset = fdt_next_node(blob, offset, &depth)) {
389 if (WARN_ON_ONCE(depth >= FDT_MAX_DEPTH))
390 continue;
391
392 if (!IS_ENABLED(CONFIG_OF_KOBJ) &&
393 !of_fdt_device_is_available(blob, offset))
394 continue;
395
396 if (!populate_node(blob, offset, &mem, nps[depth],
397 &nps[depth+1], dryrun))
398 return mem - base;
399
400 if (!dryrun && nodepp && !*nodepp)
401 *nodepp = nps[depth+1];
402 if (!dryrun && !root)
403 root = nps[depth+1];
404 }
405
406 if (offset < 0 && offset != -FDT_ERR_NOTFOUND) {
407 pr_err("Error %d processing FDT\n", offset);
408 return -EINVAL;
409 }
410
411 /*
412 * Reverse the child list. Some drivers assumes node order matches .dts
413 * node order
414 */
415 if (!dryrun)
416 reverse_nodes(root);
417
418 return mem - base;
419}
420
421/**
422 * __unflatten_device_tree - create tree of device_nodes from flat blob
423 *
424 * unflattens a device-tree, creating the
425 * tree of struct device_node. It also fills the "name" and "type"
426 * pointers of the nodes so the normal device-tree walking functions
427 * can be used.
428 * @blob: The blob to expand
429 * @dad: Parent device node
430 * @mynodes: The device_node tree created by the call
431 * @dt_alloc: An allocator that provides a virtual address to memory
432 * for the resulting tree
433 * @detached: if true set OF_DETACHED on @mynodes
434 *
435 * Returns NULL on failure or the memory chunk containing the unflattened
436 * device tree on success.
437 */
438void *__unflatten_device_tree(const void *blob,
439 struct device_node *dad,
440 struct device_node **mynodes,
441 void *(*dt_alloc)(u64 size, u64 align),
442 bool detached)
443{
444 int size;
445 void *mem;
446
447 pr_debug(" -> unflatten_device_tree()\n");
448
449 if (!blob) {
450 pr_debug("No device tree pointer\n");
451 return NULL;
452 }
453
454 pr_debug("Unflattening device tree:\n");
455 pr_debug("magic: %08x\n", fdt_magic(blob));
456 pr_debug("size: %08x\n", fdt_totalsize(blob));
457 pr_debug("version: %08x\n", fdt_version(blob));
458
459 if (fdt_check_header(blob)) {
460 pr_err("Invalid device tree blob header\n");
461 return NULL;
462 }
463
464 /* First pass, scan for size */
465 size = unflatten_dt_nodes(blob, NULL, dad, NULL);
466 if (size < 0)
467 return NULL;
468
469 size = ALIGN(size, 4);
470 pr_debug(" size is %d, allocating...\n", size);
471
472 /* Allocate memory for the expanded device tree */
473 mem = dt_alloc(size + 4, __alignof__(struct device_node));
474 if (!mem)
475 return NULL;
476
477 memset(mem, 0, size);
478
479 *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
480
481 pr_debug(" unflattening %p...\n", mem);
482
483 /* Second pass, do actual unflattening */
484 unflatten_dt_nodes(blob, mem, dad, mynodes);
485 if (be32_to_cpup(mem + size) != 0xdeadbeef)
486 pr_warning("End of tree marker overwritten: %08x\n",
487 be32_to_cpup(mem + size));
488
489 if (detached && mynodes) {
490 of_node_set_flag(*mynodes, OF_DETACHED);
491 pr_debug("unflattened tree is detached\n");
492 }
493
494 pr_debug(" <- unflatten_device_tree()\n");
495 return mem;
496}
497
498static void *kernel_tree_alloc(u64 size, u64 align)
499{
500 return kzalloc(size, GFP_KERNEL);
501}
502
503static DEFINE_MUTEX(of_fdt_unflatten_mutex);
504
505/**
506 * of_fdt_unflatten_tree - create tree of device_nodes from flat blob
507 * @blob: Flat device tree blob
508 * @dad: Parent device node
509 * @mynodes: The device tree created by the call
510 *
511 * unflattens the device-tree passed by the firmware, creating the
512 * tree of struct device_node. It also fills the "name" and "type"
513 * pointers of the nodes so the normal device-tree walking functions
514 * can be used.
515 *
516 * Returns NULL on failure or the memory chunk containing the unflattened
517 * device tree on success.
518 */
519void *of_fdt_unflatten_tree(const unsigned long *blob,
520 struct device_node *dad,
521 struct device_node **mynodes)
522{
523 void *mem;
524
525 mutex_lock(&of_fdt_unflatten_mutex);
526 mem = __unflatten_device_tree(blob, dad, mynodes, &kernel_tree_alloc,
527 true);
528 mutex_unlock(&of_fdt_unflatten_mutex);
529
530 return mem;
531}
532EXPORT_SYMBOL_GPL(of_fdt_unflatten_tree);
533
534/* Everything below here references initial_boot_params directly. */
535int __initdata dt_root_addr_cells;
536int __initdata dt_root_size_cells;
537
538void *initial_boot_params;
539
540#ifdef CONFIG_OF_EARLY_FLATTREE
541
542static u32 of_fdt_crc32;
543
544/**
545 * res_mem_reserve_reg() - reserve all memory described in 'reg' property
546 */
547static int __init __reserved_mem_reserve_reg(unsigned long node,
548 const char *uname)
549{
550 int t_len = (dt_root_addr_cells + dt_root_size_cells) * sizeof(__be32);
551 phys_addr_t base, size;
552 int len;
553 const __be32 *prop;
554 int nomap, first = 1;
555
556 prop = of_get_flat_dt_prop(node, "reg", &len);
557 if (!prop)
558 return -ENOENT;
559
560 if (len && len % t_len != 0) {
561 pr_err("Reserved memory: invalid reg property in '%s', skipping node.\n",
562 uname);
563 return -EINVAL;
564 }
565
566 nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
567
568 while (len >= t_len) {
569 base = dt_mem_next_cell(dt_root_addr_cells, &prop);
570 size = dt_mem_next_cell(dt_root_size_cells, &prop);
571
572 if (size &&
573 early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
574 pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
575 uname, &base, (unsigned long)size / SZ_1M);
576 else
577 pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
578 uname, &base, (unsigned long)size / SZ_1M);
579
580 len -= t_len;
581 if (first) {
582 fdt_reserved_mem_save_node(node, uname, base, size);
583 first = 0;
584 }
585 }
586 return 0;
587}
588
589/**
590 * __reserved_mem_check_root() - check if #size-cells, #address-cells provided
591 * in /reserved-memory matches the values supported by the current implementation,
592 * also check if ranges property has been provided
593 */
594static int __init __reserved_mem_check_root(unsigned long node)
595{
596 const __be32 *prop;
597
598 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
599 if (!prop || be32_to_cpup(prop) != dt_root_size_cells)
600 return -EINVAL;
601
602 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
603 if (!prop || be32_to_cpup(prop) != dt_root_addr_cells)
604 return -EINVAL;
605
606 prop = of_get_flat_dt_prop(node, "ranges", NULL);
607 if (!prop)
608 return -EINVAL;
609 return 0;
610}
611
612/**
613 * fdt_scan_reserved_mem() - scan a single FDT node for reserved memory
614 */
615static int __init __fdt_scan_reserved_mem(unsigned long node, const char *uname,
616 int depth, void *data)
617{
618 static int found;
619 int err;
620
621 if (!found && depth == 1 && strcmp(uname, "reserved-memory") == 0) {
622 if (__reserved_mem_check_root(node) != 0) {
623 pr_err("Reserved memory: unsupported node format, ignoring\n");
624 /* break scan */
625 return 1;
626 }
627 found = 1;
628 /* scan next node */
629 return 0;
630 } else if (!found) {
631 /* scan next node */
632 return 0;
633 } else if (found && depth < 2) {
634 /* scanning of /reserved-memory has been finished */
635 return 1;
636 }
637
638 if (!of_fdt_device_is_available(initial_boot_params, node))
639 return 0;
640
641 err = __reserved_mem_reserve_reg(node, uname);
642 if (err == -ENOENT && of_get_flat_dt_prop(node, "size", NULL))
643 fdt_reserved_mem_save_node(node, uname, 0, 0);
644
645 /* scan next node */
646 return 0;
647}
648
649/**
650 * early_init_fdt_scan_reserved_mem() - create reserved memory regions
651 *
652 * This function grabs memory from early allocator for device exclusive use
653 * defined in device tree structures. It should be called by arch specific code
654 * once the early allocator (i.e. memblock) has been fully activated.
655 */
656void __init early_init_fdt_scan_reserved_mem(void)
657{
658 int n;
659 u64 base, size;
660
661 if (!initial_boot_params)
662 return;
663
664 /* Process header /memreserve/ fields */
665 for (n = 0; ; n++) {
666 fdt_get_mem_rsv(initial_boot_params, n, &base, &size);
667 if (!size)
668 break;
669 early_init_dt_reserve_memory_arch(base, size, 0);
670 }
671
672 of_scan_flat_dt(__fdt_scan_reserved_mem, NULL);
673 fdt_init_reserved_mem();
674}
675
676/**
677 * early_init_fdt_reserve_self() - reserve the memory used by the FDT blob
678 */
679void __init early_init_fdt_reserve_self(void)
680{
681 if (!initial_boot_params)
682 return;
683
684 /* Reserve the dtb region */
685 early_init_dt_reserve_memory_arch(__pa(initial_boot_params),
686 fdt_totalsize(initial_boot_params),
687 0);
688}
689
690/**
691 * of_scan_flat_dt - scan flattened tree blob and call callback on each.
692 * @it: callback function
693 * @data: context data pointer
694 *
695 * This function is used to scan the flattened device-tree, it is
696 * used to extract the memory information at boot before we can
697 * unflatten the tree
698 */
699int __init of_scan_flat_dt(int (*it)(unsigned long node,
700 const char *uname, int depth,
701 void *data),
702 void *data)
703{
704 const void *blob = initial_boot_params;
705 const char *pathp;
706 int offset, rc = 0, depth = -1;
707
708 if (!blob)
709 return 0;
710
711 for (offset = fdt_next_node(blob, -1, &depth);
712 offset >= 0 && depth >= 0 && !rc;
713 offset = fdt_next_node(blob, offset, &depth)) {
714
715 pathp = fdt_get_name(blob, offset, NULL);
716 if (*pathp == '/')
717 pathp = kbasename(pathp);
718 rc = it(offset, pathp, depth, data);
719 }
720 return rc;
721}
722
723/**
724 * of_scan_flat_dt_subnodes - scan sub-nodes of a node call callback on each.
725 * @it: callback function
726 * @data: context data pointer
727 *
728 * This function is used to scan sub-nodes of a node.
729 */
730int __init of_scan_flat_dt_subnodes(unsigned long parent,
731 int (*it)(unsigned long node,
732 const char *uname,
733 void *data),
734 void *data)
735{
736 const void *blob = initial_boot_params;
737 int node;
738
739 fdt_for_each_subnode(node, blob, parent) {
740 const char *pathp;
741 int rc;
742
743 pathp = fdt_get_name(blob, node, NULL);
744 if (*pathp == '/')
745 pathp = kbasename(pathp);
746 rc = it(node, pathp, data);
747 if (rc)
748 return rc;
749 }
750 return 0;
751}
752
753/**
754 * of_get_flat_dt_subnode_by_name - get the subnode by given name
755 *
756 * @node: the parent node
757 * @uname: the name of subnode
758 * @return offset of the subnode, or -FDT_ERR_NOTFOUND if there is none
759 */
760
761int of_get_flat_dt_subnode_by_name(unsigned long node, const char *uname)
762{
763 return fdt_subnode_offset(initial_boot_params, node, uname);
764}
765
766/**
767 * of_get_flat_dt_root - find the root node in the flat blob
768 */
769unsigned long __init of_get_flat_dt_root(void)
770{
771 return 0;
772}
773
774/**
775 * of_get_flat_dt_size - Return the total size of the FDT
776 */
777int __init of_get_flat_dt_size(void)
778{
779 return fdt_totalsize(initial_boot_params);
780}
781
782/**
783 * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr
784 *
785 * This function can be used within scan_flattened_dt callback to get
786 * access to properties
787 */
788const void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
789 int *size)
790{
791 return fdt_getprop(initial_boot_params, node, name, size);
792}
793
794/**
795 * of_flat_dt_is_compatible - Return true if given node has compat in compatible list
796 * @node: node to test
797 * @compat: compatible string to compare with compatible list.
798 */
799int __init of_flat_dt_is_compatible(unsigned long node, const char *compat)
800{
801 return of_fdt_is_compatible(initial_boot_params, node, compat);
802}
803
804/**
805 * of_flat_dt_match - Return true if node matches a list of compatible values
806 */
807int __init of_flat_dt_match(unsigned long node, const char *const *compat)
808{
809 return of_fdt_match(initial_boot_params, node, compat);
810}
811
812/**
813 * of_get_flat_dt_prop - Given a node in the flat blob, return the phandle
814 */
815uint32_t __init of_get_flat_dt_phandle(unsigned long node)
816{
817 return fdt_get_phandle(initial_boot_params, node);
818}
819
820struct fdt_scan_status {
821 const char *name;
822 int namelen;
823 int depth;
824 int found;
825 int (*iterator)(unsigned long node, const char *uname, int depth, void *data);
826 void *data;
827};
828
829const char * __init of_flat_dt_get_machine_name(void)
830{
831 const char *name;
832 unsigned long dt_root = of_get_flat_dt_root();
833
834 name = of_get_flat_dt_prop(dt_root, "model", NULL);
835 if (!name)
836 name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
837 return name;
838}
839
840/**
841 * of_flat_dt_match_machine - Iterate match tables to find matching machine.
842 *
843 * @default_match: A machine specific ptr to return in case of no match.
844 * @get_next_compat: callback function to return next compatible match table.
845 *
846 * Iterate through machine match tables to find the best match for the machine
847 * compatible string in the FDT.
848 */
849const void * __init of_flat_dt_match_machine(const void *default_match,
850 const void * (*get_next_compat)(const char * const**))
851{
852 const void *data = NULL;
853 const void *best_data = default_match;
854 const char *const *compat;
855 unsigned long dt_root;
856 unsigned int best_score = ~1, score = 0;
857
858 dt_root = of_get_flat_dt_root();
859 while ((data = get_next_compat(&compat))) {
860 score = of_flat_dt_match(dt_root, compat);
861 if (score > 0 && score < best_score) {
862 best_data = data;
863 best_score = score;
864 }
865 }
866 if (!best_data) {
867 const char *prop;
868 int size;
869
870 pr_err("\n unrecognized device tree list:\n[ ");
871
872 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
873 if (prop) {
874 while (size > 0) {
875 printk("'%s' ", prop);
876 size -= strlen(prop) + 1;
877 prop += strlen(prop) + 1;
878 }
879 }
880 printk("]\n\n");
881 return NULL;
882 }
883
884 pr_info("Machine model: %s\n", of_flat_dt_get_machine_name());
885
886 return best_data;
887}
888
889#ifdef CONFIG_BLK_DEV_INITRD
890static void __early_init_dt_declare_initrd(unsigned long start,
891 unsigned long end)
892{
893 /* ARM64 would cause a BUG to occur here when CONFIG_DEBUG_VM is
894 * enabled since __va() is called too early. ARM64 does make use
895 * of phys_initrd_start/phys_initrd_size so we can skip this
896 * conversion.
897 */
898 if (!IS_ENABLED(CONFIG_ARM64)) {
899 initrd_start = (unsigned long)__va(start);
900 initrd_end = (unsigned long)__va(end);
901 initrd_below_start_ok = 1;
902 }
903}
904
905/**
906 * early_init_dt_check_for_initrd - Decode initrd location from flat tree
907 * @node: reference to node containing initrd location ('chosen')
908 */
909static void __init early_init_dt_check_for_initrd(unsigned long node)
910{
911 u64 start, end;
912 int len;
913 const __be32 *prop;
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
927 __early_init_dt_declare_initrd(start, end);
928 phys_initrd_start = start;
929 phys_initrd_size = end - start;
930
931 pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n",
932 (unsigned long long)start, (unsigned long long)end);
933}
934#else
935static inline void early_init_dt_check_for_initrd(unsigned long node)
936{
937}
938#endif /* CONFIG_BLK_DEV_INITRD */
939
940#ifdef CONFIG_SERIAL_EARLYCON
941
942int __init early_init_dt_scan_chosen_stdout(void)
943{
944 int offset;
945 const char *p, *q, *options = NULL;
946 int l;
947 const struct earlycon_id **p_match;
948 const void *fdt = initial_boot_params;
949
950 offset = fdt_path_offset(fdt, "/chosen");
951 if (offset < 0)
952 offset = fdt_path_offset(fdt, "/chosen@0");
953 if (offset < 0)
954 return -ENOENT;
955
956 p = fdt_getprop(fdt, offset, "stdout-path", &l);
957 if (!p)
958 p = fdt_getprop(fdt, offset, "linux,stdout-path", &l);
959 if (!p || !l)
960 return -ENOENT;
961
962 q = strchrnul(p, ':');
963 if (*q != '\0')
964 options = q + 1;
965 l = q - p;
966
967 /* Get the node specified by stdout-path */
968 offset = fdt_path_offset_namelen(fdt, p, l);
969 if (offset < 0) {
970 pr_warn("earlycon: stdout-path %.*s not found\n", l, p);
971 return 0;
972 }
973
974 for (p_match = __earlycon_table; p_match < __earlycon_table_end;
975 p_match++) {
976 const struct earlycon_id *match = *p_match;
977
978 if (!match->compatible[0])
979 continue;
980
981 if (fdt_node_check_compatible(fdt, offset, match->compatible))
982 continue;
983
984 of_setup_earlycon(match, offset, options);
985 return 0;
986 }
987 return -ENODEV;
988}
989#endif
990
991/**
992 * early_init_dt_scan_root - fetch the top level address and size cells
993 */
994int __init early_init_dt_scan_root(unsigned long node, const char *uname,
995 int depth, void *data)
996{
997 const __be32 *prop;
998
999 if (depth != 0)
1000 return 0;
1001
1002 dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
1003 dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
1004
1005 prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
1006 if (prop)
1007 dt_root_size_cells = be32_to_cpup(prop);
1008 pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
1009
1010 prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
1011 if (prop)
1012 dt_root_addr_cells = be32_to_cpup(prop);
1013 pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
1014
1015 /* break now */
1016 return 1;
1017}
1018
1019u64 __init dt_mem_next_cell(int s, const __be32 **cellp)
1020{
1021 const __be32 *p = *cellp;
1022
1023 *cellp = p + s;
1024 return of_read_number(p, s);
1025}
1026
1027/**
1028 * early_init_dt_scan_memory - Look for and parse memory nodes
1029 */
1030int __init early_init_dt_scan_memory(unsigned long node, const char *uname,
1031 int depth, void *data)
1032{
1033 const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
1034 const __be32 *reg, *endp;
1035 int l;
1036 bool hotpluggable;
1037
1038 /* We are scanning "memory" nodes only */
1039 if (type == NULL || strcmp(type, "memory") != 0)
1040 return 0;
1041
1042 reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
1043 if (reg == NULL)
1044 reg = of_get_flat_dt_prop(node, "reg", &l);
1045 if (reg == NULL)
1046 return 0;
1047
1048 endp = reg + (l / sizeof(__be32));
1049 hotpluggable = of_get_flat_dt_prop(node, "hotpluggable", NULL);
1050
1051 pr_debug("memory scan node %s, reg size %d,\n", uname, l);
1052
1053 while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
1054 u64 base, size;
1055
1056 base = dt_mem_next_cell(dt_root_addr_cells, &reg);
1057 size = dt_mem_next_cell(dt_root_size_cells, &reg);
1058
1059 if (size == 0)
1060 continue;
1061 pr_debug(" - %llx , %llx\n", (unsigned long long)base,
1062 (unsigned long long)size);
1063
1064 early_init_dt_add_memory_arch(base, size);
1065
1066 if (!hotpluggable)
1067 continue;
1068
1069 if (early_init_dt_mark_hotplug_memory_arch(base, size))
1070 pr_warn("failed to mark hotplug range 0x%llx - 0x%llx\n",
1071 base, base + size);
1072 }
1073
1074 return 0;
1075}
1076
1077int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
1078 int depth, void *data)
1079{
1080 int l;
1081 const char *p;
1082
1083 pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
1084
1085 if (depth != 1 || !data ||
1086 (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
1087 return 0;
1088
1089 early_init_dt_check_for_initrd(node);
1090
1091 /* Retrieve command line */
1092 p = of_get_flat_dt_prop(node, "bootargs", &l);
1093 if (p != NULL && l > 0)
1094 strlcpy(data, p, min((int)l, COMMAND_LINE_SIZE));
1095
1096 /*
1097 * CONFIG_CMDLINE is meant to be a default in case nothing else
1098 * managed to set the command line, unless CONFIG_CMDLINE_FORCE
1099 * is set in which case we override whatever was found earlier.
1100 */
1101#ifdef CONFIG_CMDLINE
1102#if defined(CONFIG_CMDLINE_EXTEND)
1103 strlcat(data, " ", COMMAND_LINE_SIZE);
1104 strlcat(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1105#elif defined(CONFIG_CMDLINE_FORCE)
1106 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1107#else
1108 /* No arguments from boot loader, use kernel's cmdl*/
1109 if (!((char *)data)[0])
1110 strlcpy(data, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
1111#endif
1112#endif /* CONFIG_CMDLINE */
1113
1114 pr_debug("Command line is: %s\n", (char*)data);
1115
1116 /* break now */
1117 return 1;
1118}
1119
1120#ifndef MIN_MEMBLOCK_ADDR
1121#define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET)
1122#endif
1123#ifndef MAX_MEMBLOCK_ADDR
1124#define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0)
1125#endif
1126
1127void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
1128{
1129 const u64 phys_offset = MIN_MEMBLOCK_ADDR;
1130
1131 if (size < PAGE_SIZE - (base & ~PAGE_MASK)) {
1132 pr_warn("Ignoring memory block 0x%llx - 0x%llx\n",
1133 base, base + size);
1134 return;
1135 }
1136
1137 if (!PAGE_ALIGNED(base)) {
1138 size -= PAGE_SIZE - (base & ~PAGE_MASK);
1139 base = PAGE_ALIGN(base);
1140 }
1141 size &= PAGE_MASK;
1142
1143 if (base > MAX_MEMBLOCK_ADDR) {
1144 pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1145 base, base + size);
1146 return;
1147 }
1148
1149 if (base + size - 1 > MAX_MEMBLOCK_ADDR) {
1150 pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1151 ((u64)MAX_MEMBLOCK_ADDR) + 1, base + size);
1152 size = MAX_MEMBLOCK_ADDR - base + 1;
1153 }
1154
1155 if (base + size < phys_offset) {
1156 pr_warning("Ignoring memory block 0x%llx - 0x%llx\n",
1157 base, base + size);
1158 return;
1159 }
1160 if (base < phys_offset) {
1161 pr_warning("Ignoring memory range 0x%llx - 0x%llx\n",
1162 base, phys_offset);
1163 size -= phys_offset - base;
1164 base = phys_offset;
1165 }
1166 memblock_add(base, size);
1167}
1168
1169int __init __weak early_init_dt_mark_hotplug_memory_arch(u64 base, u64 size)
1170{
1171 return memblock_mark_hotplug(base, size);
1172}
1173
1174int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
1175 phys_addr_t size, bool nomap)
1176{
1177 if (nomap)
1178 return memblock_remove(base, size);
1179 return memblock_reserve(base, size);
1180}
1181
1182static void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
1183{
1184 void *ptr = memblock_alloc(size, align);
1185
1186 if (!ptr)
1187 panic("%s: Failed to allocate %llu bytes align=0x%llx\n",
1188 __func__, size, align);
1189
1190 return ptr;
1191}
1192
1193bool __init early_init_dt_verify(void *params)
1194{
1195 if (!params)
1196 return false;
1197
1198 /* check device tree validity */
1199 if (fdt_check_header(params))
1200 return false;
1201
1202 /* Setup flat device-tree pointer */
1203 initial_boot_params = params;
1204 of_fdt_crc32 = crc32_be(~0, initial_boot_params,
1205 fdt_totalsize(initial_boot_params));
1206 return true;
1207}
1208
1209
1210void __init early_init_dt_scan_nodes(void)
1211{
1212 int rc = 0;
1213
1214 /* Retrieve various information from the /chosen node */
1215 rc = of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
1216 if (!rc)
1217 pr_warn("No chosen node found, continuing without\n");
1218
1219 /* Initialize {size,address}-cells info */
1220 of_scan_flat_dt(early_init_dt_scan_root, NULL);
1221
1222 /* Setup memory, calling early_init_dt_add_memory_arch */
1223 of_scan_flat_dt(early_init_dt_scan_memory, NULL);
1224}
1225
1226bool __init early_init_dt_scan(void *params)
1227{
1228 bool status;
1229
1230 status = early_init_dt_verify(params);
1231 if (!status)
1232 return false;
1233
1234 early_init_dt_scan_nodes();
1235 return true;
1236}
1237
1238/**
1239 * unflatten_device_tree - create tree of device_nodes from flat blob
1240 *
1241 * unflattens the device-tree passed by the firmware, creating the
1242 * tree of struct device_node. It also fills the "name" and "type"
1243 * pointers of the nodes so the normal device-tree walking functions
1244 * can be used.
1245 */
1246void __init unflatten_device_tree(void)
1247{
1248 __unflatten_device_tree(initial_boot_params, NULL, &of_root,
1249 early_init_dt_alloc_memory_arch, false);
1250
1251 /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
1252 of_alias_scan(early_init_dt_alloc_memory_arch);
1253
1254 unittest_unflatten_overlay_base();
1255}
1256
1257/**
1258 * unflatten_and_copy_device_tree - copy and create tree of device_nodes from flat blob
1259 *
1260 * Copies and unflattens the device-tree passed by the firmware, creating the
1261 * tree of struct device_node. It also fills the "name" and "type"
1262 * pointers of the nodes so the normal device-tree walking functions
1263 * can be used. This should only be used when the FDT memory has not been
1264 * reserved such is the case when the FDT is built-in to the kernel init
1265 * section. If the FDT memory is reserved already then unflatten_device_tree
1266 * should be used instead.
1267 */
1268void __init unflatten_and_copy_device_tree(void)
1269{
1270 int size;
1271 void *dt;
1272
1273 if (!initial_boot_params) {
1274 pr_warn("No valid device tree found, continuing without\n");
1275 return;
1276 }
1277
1278 size = fdt_totalsize(initial_boot_params);
1279 dt = early_init_dt_alloc_memory_arch(size,
1280 roundup_pow_of_two(FDT_V17_SIZE));
1281
1282 if (dt) {
1283 memcpy(dt, initial_boot_params, size);
1284 initial_boot_params = dt;
1285 }
1286 unflatten_device_tree();
1287}
1288
1289#ifdef CONFIG_SYSFS
1290static ssize_t of_fdt_raw_read(struct file *filp, struct kobject *kobj,
1291 struct bin_attribute *bin_attr,
1292 char *buf, loff_t off, size_t count)
1293{
1294 memcpy(buf, initial_boot_params + off, count);
1295 return count;
1296}
1297
1298static int __init of_fdt_raw_init(void)
1299{
1300 static struct bin_attribute of_fdt_raw_attr =
1301 __BIN_ATTR(fdt, S_IRUSR, of_fdt_raw_read, NULL, 0);
1302
1303 if (!initial_boot_params)
1304 return 0;
1305
1306 if (of_fdt_crc32 != crc32_be(~0, initial_boot_params,
1307 fdt_totalsize(initial_boot_params))) {
1308 pr_warn("not creating '/sys/firmware/fdt': CRC check failed\n");
1309 return 0;
1310 }
1311 of_fdt_raw_attr.size = fdt_totalsize(initial_boot_params);
1312 return sysfs_create_bin_file(firmware_kobj, &of_fdt_raw_attr);
1313}
1314late_initcall(of_fdt_raw_init);
1315#endif
1316
1317#endif /* CONFIG_OF_EARLY_FLATTREE */
1318