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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Procedures for creating, accessing and interpreting the device tree.
4 *
5 * Paul Mackerras August 1996.
6 * Copyright (C) 1996-2005 Paul Mackerras.
7 *
8 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
9 * {engebret|bergner}@us.ibm.com
10 *
11 * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
12 *
13 * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
14 * Grant Likely.
15 */
16
17#define pr_fmt(fmt) "OF: " fmt
18
19#include <linux/console.h>
20#include <linux/ctype.h>
21#include <linux/cpu.h>
22#include <linux/module.h>
23#include <linux/of.h>
24#include <linux/of_device.h>
25#include <linux/of_graph.h>
26#include <linux/spinlock.h>
27#include <linux/slab.h>
28#include <linux/string.h>
29#include <linux/proc_fs.h>
30
31#include "of_private.h"
32
33LIST_HEAD(aliases_lookup);
34
35struct device_node *of_root;
36EXPORT_SYMBOL(of_root);
37struct device_node *of_chosen;
38EXPORT_SYMBOL(of_chosen);
39struct device_node *of_aliases;
40struct device_node *of_stdout;
41static const char *of_stdout_options;
42
43struct kset *of_kset;
44
45/*
46 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
47 * This mutex must be held whenever modifications are being made to the
48 * device tree. The of_{attach,detach}_node() and
49 * of_{add,remove,update}_property() helpers make sure this happens.
50 */
51DEFINE_MUTEX(of_mutex);
52
53/* use when traversing tree through the child, sibling,
54 * or parent members of struct device_node.
55 */
56DEFINE_RAW_SPINLOCK(devtree_lock);
57
58bool of_node_name_eq(const struct device_node *np, const char *name)
59{
60 const char *node_name;
61 size_t len;
62
63 if (!np)
64 return false;
65
66 node_name = kbasename(np->full_name);
67 len = strchrnul(node_name, '@') - node_name;
68
69 return (strlen(name) == len) && (strncmp(node_name, name, len) == 0);
70}
71EXPORT_SYMBOL(of_node_name_eq);
72
73bool of_node_name_prefix(const struct device_node *np, const char *prefix)
74{
75 if (!np)
76 return false;
77
78 return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0;
79}
80EXPORT_SYMBOL(of_node_name_prefix);
81
82static bool __of_node_is_type(const struct device_node *np, const char *type)
83{
84 const char *match = __of_get_property(np, "device_type", NULL);
85
86 return np && match && type && !strcmp(match, type);
87}
88
89int of_bus_n_addr_cells(struct device_node *np)
90{
91 u32 cells;
92
93 for (; np; np = np->parent)
94 if (!of_property_read_u32(np, "#address-cells", &cells))
95 return cells;
96
97 /* No #address-cells property for the root node */
98 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
99}
100
101int of_n_addr_cells(struct device_node *np)
102{
103 if (np->parent)
104 np = np->parent;
105
106 return of_bus_n_addr_cells(np);
107}
108EXPORT_SYMBOL(of_n_addr_cells);
109
110int of_bus_n_size_cells(struct device_node *np)
111{
112 u32 cells;
113
114 for (; np; np = np->parent)
115 if (!of_property_read_u32(np, "#size-cells", &cells))
116 return cells;
117
118 /* No #size-cells property for the root node */
119 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
120}
121
122int of_n_size_cells(struct device_node *np)
123{
124 if (np->parent)
125 np = np->parent;
126
127 return of_bus_n_size_cells(np);
128}
129EXPORT_SYMBOL(of_n_size_cells);
130
131#ifdef CONFIG_NUMA
132int __weak of_node_to_nid(struct device_node *np)
133{
134 return NUMA_NO_NODE;
135}
136#endif
137
138#define OF_PHANDLE_CACHE_BITS 7
139#define OF_PHANDLE_CACHE_SZ BIT(OF_PHANDLE_CACHE_BITS)
140
141static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ];
142
143static u32 of_phandle_cache_hash(phandle handle)
144{
145 return hash_32(handle, OF_PHANDLE_CACHE_BITS);
146}
147
148/*
149 * Caller must hold devtree_lock.
150 */
151void __of_phandle_cache_inv_entry(phandle handle)
152{
153 u32 handle_hash;
154 struct device_node *np;
155
156 if (!handle)
157 return;
158
159 handle_hash = of_phandle_cache_hash(handle);
160
161 np = phandle_cache[handle_hash];
162 if (np && handle == np->phandle)
163 phandle_cache[handle_hash] = NULL;
164}
165
166void __init of_core_init(void)
167{
168 struct device_node *np;
169
170
171 /* Create the kset, and register existing nodes */
172 mutex_lock(&of_mutex);
173 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
174 if (!of_kset) {
175 mutex_unlock(&of_mutex);
176 pr_err("failed to register existing nodes\n");
177 return;
178 }
179 for_each_of_allnodes(np) {
180 __of_attach_node_sysfs(np);
181 if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
182 phandle_cache[of_phandle_cache_hash(np->phandle)] = np;
183 }
184 mutex_unlock(&of_mutex);
185
186 /* Symlink in /proc as required by userspace ABI */
187 if (of_root)
188 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
189}
190
191static struct property *__of_find_property(const struct device_node *np,
192 const char *name, int *lenp)
193{
194 struct property *pp;
195
196 if (!np)
197 return NULL;
198
199 for (pp = np->properties; pp; pp = pp->next) {
200 if (of_prop_cmp(pp->name, name) == 0) {
201 if (lenp)
202 *lenp = pp->length;
203 break;
204 }
205 }
206
207 return pp;
208}
209
210struct property *of_find_property(const struct device_node *np,
211 const char *name,
212 int *lenp)
213{
214 struct property *pp;
215 unsigned long flags;
216
217 raw_spin_lock_irqsave(&devtree_lock, flags);
218 pp = __of_find_property(np, name, lenp);
219 raw_spin_unlock_irqrestore(&devtree_lock, flags);
220
221 return pp;
222}
223EXPORT_SYMBOL(of_find_property);
224
225struct device_node *__of_find_all_nodes(struct device_node *prev)
226{
227 struct device_node *np;
228 if (!prev) {
229 np = of_root;
230 } else if (prev->child) {
231 np = prev->child;
232 } else {
233 /* Walk back up looking for a sibling, or the end of the structure */
234 np = prev;
235 while (np->parent && !np->sibling)
236 np = np->parent;
237 np = np->sibling; /* Might be null at the end of the tree */
238 }
239 return np;
240}
241
242/**
243 * of_find_all_nodes - Get next node in global list
244 * @prev: Previous node or NULL to start iteration
245 * of_node_put() will be called on it
246 *
247 * Return: A node pointer with refcount incremented, use
248 * of_node_put() on it when done.
249 */
250struct device_node *of_find_all_nodes(struct device_node *prev)
251{
252 struct device_node *np;
253 unsigned long flags;
254
255 raw_spin_lock_irqsave(&devtree_lock, flags);
256 np = __of_find_all_nodes(prev);
257 of_node_get(np);
258 of_node_put(prev);
259 raw_spin_unlock_irqrestore(&devtree_lock, flags);
260 return np;
261}
262EXPORT_SYMBOL(of_find_all_nodes);
263
264/*
265 * Find a property with a given name for a given node
266 * and return the value.
267 */
268const void *__of_get_property(const struct device_node *np,
269 const char *name, int *lenp)
270{
271 struct property *pp = __of_find_property(np, name, lenp);
272
273 return pp ? pp->value : NULL;
274}
275
276/*
277 * Find a property with a given name for a given node
278 * and return the value.
279 */
280const void *of_get_property(const struct device_node *np, const char *name,
281 int *lenp)
282{
283 struct property *pp = of_find_property(np, name, lenp);
284
285 return pp ? pp->value : NULL;
286}
287EXPORT_SYMBOL(of_get_property);
288
289/**
290 * of_get_cpu_hwid - Get the hardware ID from a CPU device node
291 *
292 * @cpun: CPU number(logical index) for which device node is required
293 * @thread: The local thread number to get the hardware ID for.
294 *
295 * Return: The hardware ID for the CPU node or ~0ULL if not found.
296 */
297u64 of_get_cpu_hwid(struct device_node *cpun, unsigned int thread)
298{
299 const __be32 *cell;
300 int ac, len;
301
302 ac = of_n_addr_cells(cpun);
303 cell = of_get_property(cpun, "reg", &len);
304 if (!cell || !ac || ((sizeof(*cell) * ac * (thread + 1)) > len))
305 return ~0ULL;
306
307 cell += ac * thread;
308 return of_read_number(cell, ac);
309}
310
311/*
312 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
313 *
314 * @cpu: logical cpu index of a core/thread
315 * @phys_id: physical identifier of a core/thread
316 *
317 * CPU logical to physical index mapping is architecture specific.
318 * However this __weak function provides a default match of physical
319 * id to logical cpu index. phys_id provided here is usually values read
320 * from the device tree which must match the hardware internal registers.
321 *
322 * Returns true if the physical identifier and the logical cpu index
323 * correspond to the same core/thread, false otherwise.
324 */
325bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
326{
327 return (u32)phys_id == cpu;
328}
329
330/*
331 * Checks if the given "prop_name" property holds the physical id of the
332 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
333 * NULL, local thread number within the core is returned in it.
334 */
335static bool __of_find_n_match_cpu_property(struct device_node *cpun,
336 const char *prop_name, int cpu, unsigned int *thread)
337{
338 const __be32 *cell;
339 int ac, prop_len, tid;
340 u64 hwid;
341
342 ac = of_n_addr_cells(cpun);
343 cell = of_get_property(cpun, prop_name, &prop_len);
344 if (!cell && !ac && arch_match_cpu_phys_id(cpu, 0))
345 return true;
346 if (!cell || !ac)
347 return false;
348 prop_len /= sizeof(*cell) * ac;
349 for (tid = 0; tid < prop_len; tid++) {
350 hwid = of_read_number(cell, ac);
351 if (arch_match_cpu_phys_id(cpu, hwid)) {
352 if (thread)
353 *thread = tid;
354 return true;
355 }
356 cell += ac;
357 }
358 return false;
359}
360
361/*
362 * arch_find_n_match_cpu_physical_id - See if the given device node is
363 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
364 * else false. If 'thread' is non-NULL, the local thread number within the
365 * core is returned in it.
366 */
367bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
368 int cpu, unsigned int *thread)
369{
370 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
371 * for thread ids on PowerPC. If it doesn't exist fallback to
372 * standard "reg" property.
373 */
374 if (IS_ENABLED(CONFIG_PPC) &&
375 __of_find_n_match_cpu_property(cpun,
376 "ibm,ppc-interrupt-server#s",
377 cpu, thread))
378 return true;
379
380 return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
381}
382
383/**
384 * of_get_cpu_node - Get device node associated with the given logical CPU
385 *
386 * @cpu: CPU number(logical index) for which device node is required
387 * @thread: if not NULL, local thread number within the physical core is
388 * returned
389 *
390 * The main purpose of this function is to retrieve the device node for the
391 * given logical CPU index. It should be used to initialize the of_node in
392 * cpu device. Once of_node in cpu device is populated, all the further
393 * references can use that instead.
394 *
395 * CPU logical to physical index mapping is architecture specific and is built
396 * before booting secondary cores. This function uses arch_match_cpu_phys_id
397 * which can be overridden by architecture specific implementation.
398 *
399 * Return: A node pointer for the logical cpu with refcount incremented, use
400 * of_node_put() on it when done. Returns NULL if not found.
401 */
402struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
403{
404 struct device_node *cpun;
405
406 for_each_of_cpu_node(cpun) {
407 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
408 return cpun;
409 }
410 return NULL;
411}
412EXPORT_SYMBOL(of_get_cpu_node);
413
414/**
415 * of_cpu_node_to_id: Get the logical CPU number for a given device_node
416 *
417 * @cpu_node: Pointer to the device_node for CPU.
418 *
419 * Return: The logical CPU number of the given CPU device_node or -ENODEV if the
420 * CPU is not found.
421 */
422int of_cpu_node_to_id(struct device_node *cpu_node)
423{
424 int cpu;
425 bool found = false;
426 struct device_node *np;
427
428 for_each_possible_cpu(cpu) {
429 np = of_cpu_device_node_get(cpu);
430 found = (cpu_node == np);
431 of_node_put(np);
432 if (found)
433 return cpu;
434 }
435
436 return -ENODEV;
437}
438EXPORT_SYMBOL(of_cpu_node_to_id);
439
440/**
441 * of_get_cpu_state_node - Get CPU's idle state node at the given index
442 *
443 * @cpu_node: The device node for the CPU
444 * @index: The index in the list of the idle states
445 *
446 * Two generic methods can be used to describe a CPU's idle states, either via
447 * a flattened description through the "cpu-idle-states" binding or via the
448 * hierarchical layout, using the "power-domains" and the "domain-idle-states"
449 * bindings. This function check for both and returns the idle state node for
450 * the requested index.
451 *
452 * Return: An idle state node if found at @index. The refcount is incremented
453 * for it, so call of_node_put() on it when done. Returns NULL if not found.
454 */
455struct device_node *of_get_cpu_state_node(struct device_node *cpu_node,
456 int index)
457{
458 struct of_phandle_args args;
459 int err;
460
461 err = of_parse_phandle_with_args(cpu_node, "power-domains",
462 "#power-domain-cells", 0, &args);
463 if (!err) {
464 struct device_node *state_node =
465 of_parse_phandle(args.np, "domain-idle-states", index);
466
467 of_node_put(args.np);
468 if (state_node)
469 return state_node;
470 }
471
472 return of_parse_phandle(cpu_node, "cpu-idle-states", index);
473}
474EXPORT_SYMBOL(of_get_cpu_state_node);
475
476/**
477 * __of_device_is_compatible() - Check if the node matches given constraints
478 * @device: pointer to node
479 * @compat: required compatible string, NULL or "" for any match
480 * @type: required device_type value, NULL or "" for any match
481 * @name: required node name, NULL or "" for any match
482 *
483 * Checks if the given @compat, @type and @name strings match the
484 * properties of the given @device. A constraints can be skipped by
485 * passing NULL or an empty string as the constraint.
486 *
487 * Returns 0 for no match, and a positive integer on match. The return
488 * value is a relative score with larger values indicating better
489 * matches. The score is weighted for the most specific compatible value
490 * to get the highest score. Matching type is next, followed by matching
491 * name. Practically speaking, this results in the following priority
492 * order for matches:
493 *
494 * 1. specific compatible && type && name
495 * 2. specific compatible && type
496 * 3. specific compatible && name
497 * 4. specific compatible
498 * 5. general compatible && type && name
499 * 6. general compatible && type
500 * 7. general compatible && name
501 * 8. general compatible
502 * 9. type && name
503 * 10. type
504 * 11. name
505 */
506static int __of_device_is_compatible(const struct device_node *device,
507 const char *compat, const char *type, const char *name)
508{
509 struct property *prop;
510 const char *cp;
511 int index = 0, score = 0;
512
513 /* Compatible match has highest priority */
514 if (compat && compat[0]) {
515 prop = __of_find_property(device, "compatible", NULL);
516 for (cp = of_prop_next_string(prop, NULL); cp;
517 cp = of_prop_next_string(prop, cp), index++) {
518 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
519 score = INT_MAX/2 - (index << 2);
520 break;
521 }
522 }
523 if (!score)
524 return 0;
525 }
526
527 /* Matching type is better than matching name */
528 if (type && type[0]) {
529 if (!__of_node_is_type(device, type))
530 return 0;
531 score += 2;
532 }
533
534 /* Matching name is a bit better than not */
535 if (name && name[0]) {
536 if (!of_node_name_eq(device, name))
537 return 0;
538 score++;
539 }
540
541 return score;
542}
543
544/** Checks if the given "compat" string matches one of the strings in
545 * the device's "compatible" property
546 */
547int of_device_is_compatible(const struct device_node *device,
548 const char *compat)
549{
550 unsigned long flags;
551 int res;
552
553 raw_spin_lock_irqsave(&devtree_lock, flags);
554 res = __of_device_is_compatible(device, compat, NULL, NULL);
555 raw_spin_unlock_irqrestore(&devtree_lock, flags);
556 return res;
557}
558EXPORT_SYMBOL(of_device_is_compatible);
559
560/** Checks if the device is compatible with any of the entries in
561 * a NULL terminated array of strings. Returns the best match
562 * score or 0.
563 */
564int of_device_compatible_match(const struct device_node *device,
565 const char *const *compat)
566{
567 unsigned int tmp, score = 0;
568
569 if (!compat)
570 return 0;
571
572 while (*compat) {
573 tmp = of_device_is_compatible(device, *compat);
574 if (tmp > score)
575 score = tmp;
576 compat++;
577 }
578
579 return score;
580}
581EXPORT_SYMBOL_GPL(of_device_compatible_match);
582
583/**
584 * of_machine_is_compatible - Test root of device tree for a given compatible value
585 * @compat: compatible string to look for in root node's compatible property.
586 *
587 * Return: A positive integer if the root node has the given value in its
588 * compatible property.
589 */
590int of_machine_is_compatible(const char *compat)
591{
592 struct device_node *root;
593 int rc = 0;
594
595 root = of_find_node_by_path("/");
596 if (root) {
597 rc = of_device_is_compatible(root, compat);
598 of_node_put(root);
599 }
600 return rc;
601}
602EXPORT_SYMBOL(of_machine_is_compatible);
603
604/**
605 * __of_device_is_available - check if a device is available for use
606 *
607 * @device: Node to check for availability, with locks already held
608 *
609 * Return: True if the status property is absent or set to "okay" or "ok",
610 * false otherwise
611 */
612static bool __of_device_is_available(const struct device_node *device)
613{
614 const char *status;
615 int statlen;
616
617 if (!device)
618 return false;
619
620 status = __of_get_property(device, "status", &statlen);
621 if (status == NULL)
622 return true;
623
624 if (statlen > 0) {
625 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
626 return true;
627 }
628
629 return false;
630}
631
632/**
633 * of_device_is_available - check if a device is available for use
634 *
635 * @device: Node to check for availability
636 *
637 * Return: True if the status property is absent or set to "okay" or "ok",
638 * false otherwise
639 */
640bool of_device_is_available(const struct device_node *device)
641{
642 unsigned long flags;
643 bool res;
644
645 raw_spin_lock_irqsave(&devtree_lock, flags);
646 res = __of_device_is_available(device);
647 raw_spin_unlock_irqrestore(&devtree_lock, flags);
648 return res;
649
650}
651EXPORT_SYMBOL(of_device_is_available);
652
653/**
654 * __of_device_is_fail - check if a device has status "fail" or "fail-..."
655 *
656 * @device: Node to check status for, with locks already held
657 *
658 * Return: True if the status property is set to "fail" or "fail-..." (for any
659 * error code suffix), false otherwise
660 */
661static bool __of_device_is_fail(const struct device_node *device)
662{
663 const char *status;
664
665 if (!device)
666 return false;
667
668 status = __of_get_property(device, "status", NULL);
669 if (status == NULL)
670 return false;
671
672 return !strcmp(status, "fail") || !strncmp(status, "fail-", 5);
673}
674
675/**
676 * of_device_is_big_endian - check if a device has BE registers
677 *
678 * @device: Node to check for endianness
679 *
680 * Return: True if the device has a "big-endian" property, or if the kernel
681 * was compiled for BE *and* the device has a "native-endian" property.
682 * Returns false otherwise.
683 *
684 * Callers would nominally use ioread32be/iowrite32be if
685 * of_device_is_big_endian() == true, or readl/writel otherwise.
686 */
687bool of_device_is_big_endian(const struct device_node *device)
688{
689 if (of_property_read_bool(device, "big-endian"))
690 return true;
691 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
692 of_property_read_bool(device, "native-endian"))
693 return true;
694 return false;
695}
696EXPORT_SYMBOL(of_device_is_big_endian);
697
698/**
699 * of_get_parent - Get a node's parent if any
700 * @node: Node to get parent
701 *
702 * Return: A node pointer with refcount incremented, use
703 * of_node_put() on it when done.
704 */
705struct device_node *of_get_parent(const struct device_node *node)
706{
707 struct device_node *np;
708 unsigned long flags;
709
710 if (!node)
711 return NULL;
712
713 raw_spin_lock_irqsave(&devtree_lock, flags);
714 np = of_node_get(node->parent);
715 raw_spin_unlock_irqrestore(&devtree_lock, flags);
716 return np;
717}
718EXPORT_SYMBOL(of_get_parent);
719
720/**
721 * of_get_next_parent - Iterate to a node's parent
722 * @node: Node to get parent of
723 *
724 * This is like of_get_parent() except that it drops the
725 * refcount on the passed node, making it suitable for iterating
726 * through a node's parents.
727 *
728 * Return: A node pointer with refcount incremented, use
729 * of_node_put() on it when done.
730 */
731struct device_node *of_get_next_parent(struct device_node *node)
732{
733 struct device_node *parent;
734 unsigned long flags;
735
736 if (!node)
737 return NULL;
738
739 raw_spin_lock_irqsave(&devtree_lock, flags);
740 parent = of_node_get(node->parent);
741 of_node_put(node);
742 raw_spin_unlock_irqrestore(&devtree_lock, flags);
743 return parent;
744}
745EXPORT_SYMBOL(of_get_next_parent);
746
747static struct device_node *__of_get_next_child(const struct device_node *node,
748 struct device_node *prev)
749{
750 struct device_node *next;
751
752 if (!node)
753 return NULL;
754
755 next = prev ? prev->sibling : node->child;
756 of_node_get(next);
757 of_node_put(prev);
758 return next;
759}
760#define __for_each_child_of_node(parent, child) \
761 for (child = __of_get_next_child(parent, NULL); child != NULL; \
762 child = __of_get_next_child(parent, child))
763
764/**
765 * of_get_next_child - Iterate a node childs
766 * @node: parent node
767 * @prev: previous child of the parent node, or NULL to get first
768 *
769 * Return: A node pointer with refcount incremented, use of_node_put() on
770 * it when done. Returns NULL when prev is the last child. Decrements the
771 * refcount of prev.
772 */
773struct device_node *of_get_next_child(const struct device_node *node,
774 struct device_node *prev)
775{
776 struct device_node *next;
777 unsigned long flags;
778
779 raw_spin_lock_irqsave(&devtree_lock, flags);
780 next = __of_get_next_child(node, prev);
781 raw_spin_unlock_irqrestore(&devtree_lock, flags);
782 return next;
783}
784EXPORT_SYMBOL(of_get_next_child);
785
786/**
787 * of_get_next_available_child - Find the next available child node
788 * @node: parent node
789 * @prev: previous child of the parent node, or NULL to get first
790 *
791 * This function is like of_get_next_child(), except that it
792 * automatically skips any disabled nodes (i.e. status = "disabled").
793 */
794struct device_node *of_get_next_available_child(const struct device_node *node,
795 struct device_node *prev)
796{
797 struct device_node *next;
798 unsigned long flags;
799
800 if (!node)
801 return NULL;
802
803 raw_spin_lock_irqsave(&devtree_lock, flags);
804 next = prev ? prev->sibling : node->child;
805 for (; next; next = next->sibling) {
806 if (!__of_device_is_available(next))
807 continue;
808 if (of_node_get(next))
809 break;
810 }
811 of_node_put(prev);
812 raw_spin_unlock_irqrestore(&devtree_lock, flags);
813 return next;
814}
815EXPORT_SYMBOL(of_get_next_available_child);
816
817/**
818 * of_get_next_cpu_node - Iterate on cpu nodes
819 * @prev: previous child of the /cpus node, or NULL to get first
820 *
821 * Unusable CPUs (those with the status property set to "fail" or "fail-...")
822 * will be skipped.
823 *
824 * Return: A cpu node pointer with refcount incremented, use of_node_put()
825 * on it when done. Returns NULL when prev is the last child. Decrements
826 * the refcount of prev.
827 */
828struct device_node *of_get_next_cpu_node(struct device_node *prev)
829{
830 struct device_node *next = NULL;
831 unsigned long flags;
832 struct device_node *node;
833
834 if (!prev)
835 node = of_find_node_by_path("/cpus");
836
837 raw_spin_lock_irqsave(&devtree_lock, flags);
838 if (prev)
839 next = prev->sibling;
840 else if (node) {
841 next = node->child;
842 of_node_put(node);
843 }
844 for (; next; next = next->sibling) {
845 if (__of_device_is_fail(next))
846 continue;
847 if (!(of_node_name_eq(next, "cpu") ||
848 __of_node_is_type(next, "cpu")))
849 continue;
850 if (of_node_get(next))
851 break;
852 }
853 of_node_put(prev);
854 raw_spin_unlock_irqrestore(&devtree_lock, flags);
855 return next;
856}
857EXPORT_SYMBOL(of_get_next_cpu_node);
858
859/**
860 * of_get_compatible_child - Find compatible child node
861 * @parent: parent node
862 * @compatible: compatible string
863 *
864 * Lookup child node whose compatible property contains the given compatible
865 * string.
866 *
867 * Return: a node pointer with refcount incremented, use of_node_put() on it
868 * when done; or NULL if not found.
869 */
870struct device_node *of_get_compatible_child(const struct device_node *parent,
871 const char *compatible)
872{
873 struct device_node *child;
874
875 for_each_child_of_node(parent, child) {
876 if (of_device_is_compatible(child, compatible))
877 break;
878 }
879
880 return child;
881}
882EXPORT_SYMBOL(of_get_compatible_child);
883
884/**
885 * of_get_child_by_name - Find the child node by name for a given parent
886 * @node: parent node
887 * @name: child name to look for.
888 *
889 * This function looks for child node for given matching name
890 *
891 * Return: A node pointer if found, with refcount incremented, use
892 * of_node_put() on it when done.
893 * Returns NULL if node is not found.
894 */
895struct device_node *of_get_child_by_name(const struct device_node *node,
896 const char *name)
897{
898 struct device_node *child;
899
900 for_each_child_of_node(node, child)
901 if (of_node_name_eq(child, name))
902 break;
903 return child;
904}
905EXPORT_SYMBOL(of_get_child_by_name);
906
907struct device_node *__of_find_node_by_path(struct device_node *parent,
908 const char *path)
909{
910 struct device_node *child;
911 int len;
912
913 len = strcspn(path, "/:");
914 if (!len)
915 return NULL;
916
917 __for_each_child_of_node(parent, child) {
918 const char *name = kbasename(child->full_name);
919 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
920 return child;
921 }
922 return NULL;
923}
924
925struct device_node *__of_find_node_by_full_path(struct device_node *node,
926 const char *path)
927{
928 const char *separator = strchr(path, ':');
929
930 while (node && *path == '/') {
931 struct device_node *tmp = node;
932
933 path++; /* Increment past '/' delimiter */
934 node = __of_find_node_by_path(node, path);
935 of_node_put(tmp);
936 path = strchrnul(path, '/');
937 if (separator && separator < path)
938 break;
939 }
940 return node;
941}
942
943/**
944 * of_find_node_opts_by_path - Find a node matching a full OF path
945 * @path: Either the full path to match, or if the path does not
946 * start with '/', the name of a property of the /aliases
947 * node (an alias). In the case of an alias, the node
948 * matching the alias' value will be returned.
949 * @opts: Address of a pointer into which to store the start of
950 * an options string appended to the end of the path with
951 * a ':' separator.
952 *
953 * Valid paths:
954 * * /foo/bar Full path
955 * * foo Valid alias
956 * * foo/bar Valid alias + relative path
957 *
958 * Return: A node pointer with refcount incremented, use
959 * of_node_put() on it when done.
960 */
961struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
962{
963 struct device_node *np = NULL;
964 struct property *pp;
965 unsigned long flags;
966 const char *separator = strchr(path, ':');
967
968 if (opts)
969 *opts = separator ? separator + 1 : NULL;
970
971 if (strcmp(path, "/") == 0)
972 return of_node_get(of_root);
973
974 /* The path could begin with an alias */
975 if (*path != '/') {
976 int len;
977 const char *p = separator;
978
979 if (!p)
980 p = strchrnul(path, '/');
981 len = p - path;
982
983 /* of_aliases must not be NULL */
984 if (!of_aliases)
985 return NULL;
986
987 for_each_property_of_node(of_aliases, pp) {
988 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
989 np = of_find_node_by_path(pp->value);
990 break;
991 }
992 }
993 if (!np)
994 return NULL;
995 path = p;
996 }
997
998 /* Step down the tree matching path components */
999 raw_spin_lock_irqsave(&devtree_lock, flags);
1000 if (!np)
1001 np = of_node_get(of_root);
1002 np = __of_find_node_by_full_path(np, path);
1003 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1004 return np;
1005}
1006EXPORT_SYMBOL(of_find_node_opts_by_path);
1007
1008/**
1009 * of_find_node_by_name - Find a node by its "name" property
1010 * @from: The node to start searching from or NULL; the node
1011 * you pass will not be searched, only the next one
1012 * will. Typically, you pass what the previous call
1013 * returned. of_node_put() will be called on @from.
1014 * @name: The name string to match against
1015 *
1016 * Return: A node pointer with refcount incremented, use
1017 * of_node_put() on it when done.
1018 */
1019struct device_node *of_find_node_by_name(struct device_node *from,
1020 const char *name)
1021{
1022 struct device_node *np;
1023 unsigned long flags;
1024
1025 raw_spin_lock_irqsave(&devtree_lock, flags);
1026 for_each_of_allnodes_from(from, np)
1027 if (of_node_name_eq(np, name) && of_node_get(np))
1028 break;
1029 of_node_put(from);
1030 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1031 return np;
1032}
1033EXPORT_SYMBOL(of_find_node_by_name);
1034
1035/**
1036 * of_find_node_by_type - Find a node by its "device_type" property
1037 * @from: The node to start searching from, or NULL to start searching
1038 * the entire device tree. The node you pass will not be
1039 * searched, only the next one will; typically, you pass
1040 * what the previous call returned. of_node_put() will be
1041 * called on from for you.
1042 * @type: The type string to match against
1043 *
1044 * Return: A node pointer with refcount incremented, use
1045 * of_node_put() on it when done.
1046 */
1047struct device_node *of_find_node_by_type(struct device_node *from,
1048 const char *type)
1049{
1050 struct device_node *np;
1051 unsigned long flags;
1052
1053 raw_spin_lock_irqsave(&devtree_lock, flags);
1054 for_each_of_allnodes_from(from, np)
1055 if (__of_node_is_type(np, type) && of_node_get(np))
1056 break;
1057 of_node_put(from);
1058 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1059 return np;
1060}
1061EXPORT_SYMBOL(of_find_node_by_type);
1062
1063/**
1064 * of_find_compatible_node - Find a node based on type and one of the
1065 * tokens in its "compatible" property
1066 * @from: The node to start searching from or NULL, the node
1067 * you pass will not be searched, only the next one
1068 * will; typically, you pass what the previous call
1069 * returned. of_node_put() will be called on it
1070 * @type: The type string to match "device_type" or NULL to ignore
1071 * @compatible: The string to match to one of the tokens in the device
1072 * "compatible" list.
1073 *
1074 * Return: A node pointer with refcount incremented, use
1075 * of_node_put() on it when done.
1076 */
1077struct device_node *of_find_compatible_node(struct device_node *from,
1078 const char *type, const char *compatible)
1079{
1080 struct device_node *np;
1081 unsigned long flags;
1082
1083 raw_spin_lock_irqsave(&devtree_lock, flags);
1084 for_each_of_allnodes_from(from, np)
1085 if (__of_device_is_compatible(np, compatible, type, NULL) &&
1086 of_node_get(np))
1087 break;
1088 of_node_put(from);
1089 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1090 return np;
1091}
1092EXPORT_SYMBOL(of_find_compatible_node);
1093
1094/**
1095 * of_find_node_with_property - Find a node which has a property with
1096 * the given name.
1097 * @from: The node to start searching from or NULL, the node
1098 * you pass will not be searched, only the next one
1099 * will; typically, you pass what the previous call
1100 * returned. of_node_put() will be called on it
1101 * @prop_name: The name of the property to look for.
1102 *
1103 * Return: A node pointer with refcount incremented, use
1104 * of_node_put() on it when done.
1105 */
1106struct device_node *of_find_node_with_property(struct device_node *from,
1107 const char *prop_name)
1108{
1109 struct device_node *np;
1110 struct property *pp;
1111 unsigned long flags;
1112
1113 raw_spin_lock_irqsave(&devtree_lock, flags);
1114 for_each_of_allnodes_from(from, np) {
1115 for (pp = np->properties; pp; pp = pp->next) {
1116 if (of_prop_cmp(pp->name, prop_name) == 0) {
1117 of_node_get(np);
1118 goto out;
1119 }
1120 }
1121 }
1122out:
1123 of_node_put(from);
1124 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1125 return np;
1126}
1127EXPORT_SYMBOL(of_find_node_with_property);
1128
1129static
1130const struct of_device_id *__of_match_node(const struct of_device_id *matches,
1131 const struct device_node *node)
1132{
1133 const struct of_device_id *best_match = NULL;
1134 int score, best_score = 0;
1135
1136 if (!matches)
1137 return NULL;
1138
1139 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
1140 score = __of_device_is_compatible(node, matches->compatible,
1141 matches->type, matches->name);
1142 if (score > best_score) {
1143 best_match = matches;
1144 best_score = score;
1145 }
1146 }
1147
1148 return best_match;
1149}
1150
1151/**
1152 * of_match_node - Tell if a device_node has a matching of_match structure
1153 * @matches: array of of device match structures to search in
1154 * @node: the of device structure to match against
1155 *
1156 * Low level utility function used by device matching.
1157 */
1158const struct of_device_id *of_match_node(const struct of_device_id *matches,
1159 const struct device_node *node)
1160{
1161 const struct of_device_id *match;
1162 unsigned long flags;
1163
1164 raw_spin_lock_irqsave(&devtree_lock, flags);
1165 match = __of_match_node(matches, node);
1166 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1167 return match;
1168}
1169EXPORT_SYMBOL(of_match_node);
1170
1171/**
1172 * of_find_matching_node_and_match - Find a node based on an of_device_id
1173 * match table.
1174 * @from: The node to start searching from or NULL, the node
1175 * you pass will not be searched, only the next one
1176 * will; typically, you pass what the previous call
1177 * returned. of_node_put() will be called on it
1178 * @matches: array of of device match structures to search in
1179 * @match: Updated to point at the matches entry which matched
1180 *
1181 * Return: A node pointer with refcount incremented, use
1182 * of_node_put() on it when done.
1183 */
1184struct device_node *of_find_matching_node_and_match(struct device_node *from,
1185 const struct of_device_id *matches,
1186 const struct of_device_id **match)
1187{
1188 struct device_node *np;
1189 const struct of_device_id *m;
1190 unsigned long flags;
1191
1192 if (match)
1193 *match = NULL;
1194
1195 raw_spin_lock_irqsave(&devtree_lock, flags);
1196 for_each_of_allnodes_from(from, np) {
1197 m = __of_match_node(matches, np);
1198 if (m && of_node_get(np)) {
1199 if (match)
1200 *match = m;
1201 break;
1202 }
1203 }
1204 of_node_put(from);
1205 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1206 return np;
1207}
1208EXPORT_SYMBOL(of_find_matching_node_and_match);
1209
1210/**
1211 * of_modalias_node - Lookup appropriate modalias for a device node
1212 * @node: pointer to a device tree node
1213 * @modalias: Pointer to buffer that modalias value will be copied into
1214 * @len: Length of modalias value
1215 *
1216 * Based on the value of the compatible property, this routine will attempt
1217 * to choose an appropriate modalias value for a particular device tree node.
1218 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1219 * from the first entry in the compatible list property.
1220 *
1221 * Return: This routine returns 0 on success, <0 on failure.
1222 */
1223int of_modalias_node(struct device_node *node, char *modalias, int len)
1224{
1225 const char *compatible, *p;
1226 int cplen;
1227
1228 compatible = of_get_property(node, "compatible", &cplen);
1229 if (!compatible || strlen(compatible) > cplen)
1230 return -ENODEV;
1231 p = strchr(compatible, ',');
1232 strscpy(modalias, p ? p + 1 : compatible, len);
1233 return 0;
1234}
1235EXPORT_SYMBOL_GPL(of_modalias_node);
1236
1237/**
1238 * of_find_node_by_phandle - Find a node given a phandle
1239 * @handle: phandle of the node to find
1240 *
1241 * Return: A node pointer with refcount incremented, use
1242 * of_node_put() on it when done.
1243 */
1244struct device_node *of_find_node_by_phandle(phandle handle)
1245{
1246 struct device_node *np = NULL;
1247 unsigned long flags;
1248 u32 handle_hash;
1249
1250 if (!handle)
1251 return NULL;
1252
1253 handle_hash = of_phandle_cache_hash(handle);
1254
1255 raw_spin_lock_irqsave(&devtree_lock, flags);
1256
1257 if (phandle_cache[handle_hash] &&
1258 handle == phandle_cache[handle_hash]->phandle)
1259 np = phandle_cache[handle_hash];
1260
1261 if (!np) {
1262 for_each_of_allnodes(np)
1263 if (np->phandle == handle &&
1264 !of_node_check_flag(np, OF_DETACHED)) {
1265 phandle_cache[handle_hash] = np;
1266 break;
1267 }
1268 }
1269
1270 of_node_get(np);
1271 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1272 return np;
1273}
1274EXPORT_SYMBOL(of_find_node_by_phandle);
1275
1276void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1277{
1278 int i;
1279 printk("%s %pOF", msg, args->np);
1280 for (i = 0; i < args->args_count; i++) {
1281 const char delim = i ? ',' : ':';
1282
1283 pr_cont("%c%08x", delim, args->args[i]);
1284 }
1285 pr_cont("\n");
1286}
1287
1288int of_phandle_iterator_init(struct of_phandle_iterator *it,
1289 const struct device_node *np,
1290 const char *list_name,
1291 const char *cells_name,
1292 int cell_count)
1293{
1294 const __be32 *list;
1295 int size;
1296
1297 memset(it, 0, sizeof(*it));
1298
1299 /*
1300 * one of cell_count or cells_name must be provided to determine the
1301 * argument length.
1302 */
1303 if (cell_count < 0 && !cells_name)
1304 return -EINVAL;
1305
1306 list = of_get_property(np, list_name, &size);
1307 if (!list)
1308 return -ENOENT;
1309
1310 it->cells_name = cells_name;
1311 it->cell_count = cell_count;
1312 it->parent = np;
1313 it->list_end = list + size / sizeof(*list);
1314 it->phandle_end = list;
1315 it->cur = list;
1316
1317 return 0;
1318}
1319EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
1320
1321int of_phandle_iterator_next(struct of_phandle_iterator *it)
1322{
1323 uint32_t count = 0;
1324
1325 if (it->node) {
1326 of_node_put(it->node);
1327 it->node = NULL;
1328 }
1329
1330 if (!it->cur || it->phandle_end >= it->list_end)
1331 return -ENOENT;
1332
1333 it->cur = it->phandle_end;
1334
1335 /* If phandle is 0, then it is an empty entry with no arguments. */
1336 it->phandle = be32_to_cpup(it->cur++);
1337
1338 if (it->phandle) {
1339
1340 /*
1341 * Find the provider node and parse the #*-cells property to
1342 * determine the argument length.
1343 */
1344 it->node = of_find_node_by_phandle(it->phandle);
1345
1346 if (it->cells_name) {
1347 if (!it->node) {
1348 pr_err("%pOF: could not find phandle %d\n",
1349 it->parent, it->phandle);
1350 goto err;
1351 }
1352
1353 if (of_property_read_u32(it->node, it->cells_name,
1354 &count)) {
1355 /*
1356 * If both cell_count and cells_name is given,
1357 * fall back to cell_count in absence
1358 * of the cells_name property
1359 */
1360 if (it->cell_count >= 0) {
1361 count = it->cell_count;
1362 } else {
1363 pr_err("%pOF: could not get %s for %pOF\n",
1364 it->parent,
1365 it->cells_name,
1366 it->node);
1367 goto err;
1368 }
1369 }
1370 } else {
1371 count = it->cell_count;
1372 }
1373
1374 /*
1375 * Make sure that the arguments actually fit in the remaining
1376 * property data length
1377 */
1378 if (it->cur + count > it->list_end) {
1379 if (it->cells_name)
1380 pr_err("%pOF: %s = %d found %td\n",
1381 it->parent, it->cells_name,
1382 count, it->list_end - it->cur);
1383 else
1384 pr_err("%pOF: phandle %s needs %d, found %td\n",
1385 it->parent, of_node_full_name(it->node),
1386 count, it->list_end - it->cur);
1387 goto err;
1388 }
1389 }
1390
1391 it->phandle_end = it->cur + count;
1392 it->cur_count = count;
1393
1394 return 0;
1395
1396err:
1397 if (it->node) {
1398 of_node_put(it->node);
1399 it->node = NULL;
1400 }
1401
1402 return -EINVAL;
1403}
1404EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
1405
1406int of_phandle_iterator_args(struct of_phandle_iterator *it,
1407 uint32_t *args,
1408 int size)
1409{
1410 int i, count;
1411
1412 count = it->cur_count;
1413
1414 if (WARN_ON(size < count))
1415 count = size;
1416
1417 for (i = 0; i < count; i++)
1418 args[i] = be32_to_cpup(it->cur++);
1419
1420 return count;
1421}
1422
1423int __of_parse_phandle_with_args(const struct device_node *np,
1424 const char *list_name,
1425 const char *cells_name,
1426 int cell_count, int index,
1427 struct of_phandle_args *out_args)
1428{
1429 struct of_phandle_iterator it;
1430 int rc, cur_index = 0;
1431
1432 if (index < 0)
1433 return -EINVAL;
1434
1435 /* Loop over the phandles until all the requested entry is found */
1436 of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1437 /*
1438 * All of the error cases bail out of the loop, so at
1439 * this point, the parsing is successful. If the requested
1440 * index matches, then fill the out_args structure and return,
1441 * or return -ENOENT for an empty entry.
1442 */
1443 rc = -ENOENT;
1444 if (cur_index == index) {
1445 if (!it.phandle)
1446 goto err;
1447
1448 if (out_args) {
1449 int c;
1450
1451 c = of_phandle_iterator_args(&it,
1452 out_args->args,
1453 MAX_PHANDLE_ARGS);
1454 out_args->np = it.node;
1455 out_args->args_count = c;
1456 } else {
1457 of_node_put(it.node);
1458 }
1459
1460 /* Found it! return success */
1461 return 0;
1462 }
1463
1464 cur_index++;
1465 }
1466
1467 /*
1468 * Unlock node before returning result; will be one of:
1469 * -ENOENT : index is for empty phandle
1470 * -EINVAL : parsing error on data
1471 */
1472
1473 err:
1474 of_node_put(it.node);
1475 return rc;
1476}
1477EXPORT_SYMBOL(__of_parse_phandle_with_args);
1478
1479/**
1480 * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
1481 * @np: pointer to a device tree node containing a list
1482 * @list_name: property name that contains a list
1483 * @stem_name: stem of property names that specify phandles' arguments count
1484 * @index: index of a phandle to parse out
1485 * @out_args: optional pointer to output arguments structure (will be filled)
1486 *
1487 * This function is useful to parse lists of phandles and their arguments.
1488 * Returns 0 on success and fills out_args, on error returns appropriate errno
1489 * value. The difference between this function and of_parse_phandle_with_args()
1490 * is that this API remaps a phandle if the node the phandle points to has
1491 * a <@stem_name>-map property.
1492 *
1493 * Caller is responsible to call of_node_put() on the returned out_args->np
1494 * pointer.
1495 *
1496 * Example::
1497 *
1498 * phandle1: node1 {
1499 * #list-cells = <2>;
1500 * };
1501 *
1502 * phandle2: node2 {
1503 * #list-cells = <1>;
1504 * };
1505 *
1506 * phandle3: node3 {
1507 * #list-cells = <1>;
1508 * list-map = <0 &phandle2 3>,
1509 * <1 &phandle2 2>,
1510 * <2 &phandle1 5 1>;
1511 * list-map-mask = <0x3>;
1512 * };
1513 *
1514 * node4 {
1515 * list = <&phandle1 1 2 &phandle3 0>;
1516 * };
1517 *
1518 * To get a device_node of the ``node2`` node you may call this:
1519 * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
1520 */
1521int of_parse_phandle_with_args_map(const struct device_node *np,
1522 const char *list_name,
1523 const char *stem_name,
1524 int index, struct of_phandle_args *out_args)
1525{
1526 char *cells_name, *map_name = NULL, *mask_name = NULL;
1527 char *pass_name = NULL;
1528 struct device_node *cur, *new = NULL;
1529 const __be32 *map, *mask, *pass;
1530 static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
1531 static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 };
1532 __be32 initial_match_array[MAX_PHANDLE_ARGS];
1533 const __be32 *match_array = initial_match_array;
1534 int i, ret, map_len, match;
1535 u32 list_size, new_size;
1536
1537 if (index < 0)
1538 return -EINVAL;
1539
1540 cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
1541 if (!cells_name)
1542 return -ENOMEM;
1543
1544 ret = -ENOMEM;
1545 map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
1546 if (!map_name)
1547 goto free;
1548
1549 mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
1550 if (!mask_name)
1551 goto free;
1552
1553 pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
1554 if (!pass_name)
1555 goto free;
1556
1557 ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
1558 out_args);
1559 if (ret)
1560 goto free;
1561
1562 /* Get the #<list>-cells property */
1563 cur = out_args->np;
1564 ret = of_property_read_u32(cur, cells_name, &list_size);
1565 if (ret < 0)
1566 goto put;
1567
1568 /* Precalculate the match array - this simplifies match loop */
1569 for (i = 0; i < list_size; i++)
1570 initial_match_array[i] = cpu_to_be32(out_args->args[i]);
1571
1572 ret = -EINVAL;
1573 while (cur) {
1574 /* Get the <list>-map property */
1575 map = of_get_property(cur, map_name, &map_len);
1576 if (!map) {
1577 ret = 0;
1578 goto free;
1579 }
1580 map_len /= sizeof(u32);
1581
1582 /* Get the <list>-map-mask property (optional) */
1583 mask = of_get_property(cur, mask_name, NULL);
1584 if (!mask)
1585 mask = dummy_mask;
1586 /* Iterate through <list>-map property */
1587 match = 0;
1588 while (map_len > (list_size + 1) && !match) {
1589 /* Compare specifiers */
1590 match = 1;
1591 for (i = 0; i < list_size; i++, map_len--)
1592 match &= !((match_array[i] ^ *map++) & mask[i]);
1593
1594 of_node_put(new);
1595 new = of_find_node_by_phandle(be32_to_cpup(map));
1596 map++;
1597 map_len--;
1598
1599 /* Check if not found */
1600 if (!new)
1601 goto put;
1602
1603 if (!of_device_is_available(new))
1604 match = 0;
1605
1606 ret = of_property_read_u32(new, cells_name, &new_size);
1607 if (ret)
1608 goto put;
1609
1610 /* Check for malformed properties */
1611 if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
1612 goto put;
1613 if (map_len < new_size)
1614 goto put;
1615
1616 /* Move forward by new node's #<list>-cells amount */
1617 map += new_size;
1618 map_len -= new_size;
1619 }
1620 if (!match)
1621 goto put;
1622
1623 /* Get the <list>-map-pass-thru property (optional) */
1624 pass = of_get_property(cur, pass_name, NULL);
1625 if (!pass)
1626 pass = dummy_pass;
1627
1628 /*
1629 * Successfully parsed a <list>-map translation; copy new
1630 * specifier into the out_args structure, keeping the
1631 * bits specified in <list>-map-pass-thru.
1632 */
1633 match_array = map - new_size;
1634 for (i = 0; i < new_size; i++) {
1635 __be32 val = *(map - new_size + i);
1636
1637 if (i < list_size) {
1638 val &= ~pass[i];
1639 val |= cpu_to_be32(out_args->args[i]) & pass[i];
1640 }
1641
1642 out_args->args[i] = be32_to_cpu(val);
1643 }
1644 out_args->args_count = list_size = new_size;
1645 /* Iterate again with new provider */
1646 out_args->np = new;
1647 of_node_put(cur);
1648 cur = new;
1649 }
1650put:
1651 of_node_put(cur);
1652 of_node_put(new);
1653free:
1654 kfree(mask_name);
1655 kfree(map_name);
1656 kfree(cells_name);
1657 kfree(pass_name);
1658
1659 return ret;
1660}
1661EXPORT_SYMBOL(of_parse_phandle_with_args_map);
1662
1663/**
1664 * of_count_phandle_with_args() - Find the number of phandles references in a property
1665 * @np: pointer to a device tree node containing a list
1666 * @list_name: property name that contains a list
1667 * @cells_name: property name that specifies phandles' arguments count
1668 *
1669 * Return: The number of phandle + argument tuples within a property. It
1670 * is a typical pattern to encode a list of phandle and variable
1671 * arguments into a single property. The number of arguments is encoded
1672 * by a property in the phandle-target node. For example, a gpios
1673 * property would contain a list of GPIO specifies consisting of a
1674 * phandle and 1 or more arguments. The number of arguments are
1675 * determined by the #gpio-cells property in the node pointed to by the
1676 * phandle.
1677 */
1678int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1679 const char *cells_name)
1680{
1681 struct of_phandle_iterator it;
1682 int rc, cur_index = 0;
1683
1684 /*
1685 * If cells_name is NULL we assume a cell count of 0. This makes
1686 * counting the phandles trivial as each 32bit word in the list is a
1687 * phandle and no arguments are to consider. So we don't iterate through
1688 * the list but just use the length to determine the phandle count.
1689 */
1690 if (!cells_name) {
1691 const __be32 *list;
1692 int size;
1693
1694 list = of_get_property(np, list_name, &size);
1695 if (!list)
1696 return -ENOENT;
1697
1698 return size / sizeof(*list);
1699 }
1700
1701 rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
1702 if (rc)
1703 return rc;
1704
1705 while ((rc = of_phandle_iterator_next(&it)) == 0)
1706 cur_index += 1;
1707
1708 if (rc != -ENOENT)
1709 return rc;
1710
1711 return cur_index;
1712}
1713EXPORT_SYMBOL(of_count_phandle_with_args);
1714
1715/**
1716 * __of_add_property - Add a property to a node without lock operations
1717 * @np: Caller's Device Node
1718 * @prop: Property to add
1719 */
1720int __of_add_property(struct device_node *np, struct property *prop)
1721{
1722 struct property **next;
1723
1724 prop->next = NULL;
1725 next = &np->properties;
1726 while (*next) {
1727 if (strcmp(prop->name, (*next)->name) == 0)
1728 /* duplicate ! don't insert it */
1729 return -EEXIST;
1730
1731 next = &(*next)->next;
1732 }
1733 *next = prop;
1734
1735 return 0;
1736}
1737
1738/**
1739 * of_add_property - Add a property to a node
1740 * @np: Caller's Device Node
1741 * @prop: Property to add
1742 */
1743int of_add_property(struct device_node *np, struct property *prop)
1744{
1745 unsigned long flags;
1746 int rc;
1747
1748 mutex_lock(&of_mutex);
1749
1750 raw_spin_lock_irqsave(&devtree_lock, flags);
1751 rc = __of_add_property(np, prop);
1752 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1753
1754 if (!rc)
1755 __of_add_property_sysfs(np, prop);
1756
1757 mutex_unlock(&of_mutex);
1758
1759 if (!rc)
1760 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1761
1762 return rc;
1763}
1764EXPORT_SYMBOL_GPL(of_add_property);
1765
1766int __of_remove_property(struct device_node *np, struct property *prop)
1767{
1768 struct property **next;
1769
1770 for (next = &np->properties; *next; next = &(*next)->next) {
1771 if (*next == prop)
1772 break;
1773 }
1774 if (*next == NULL)
1775 return -ENODEV;
1776
1777 /* found the node */
1778 *next = prop->next;
1779 prop->next = np->deadprops;
1780 np->deadprops = prop;
1781
1782 return 0;
1783}
1784
1785/**
1786 * of_remove_property - Remove a property from a node.
1787 * @np: Caller's Device Node
1788 * @prop: Property to remove
1789 *
1790 * Note that we don't actually remove it, since we have given out
1791 * who-knows-how-many pointers to the data using get-property.
1792 * Instead we just move the property to the "dead properties"
1793 * list, so it won't be found any more.
1794 */
1795int of_remove_property(struct device_node *np, struct property *prop)
1796{
1797 unsigned long flags;
1798 int rc;
1799
1800 if (!prop)
1801 return -ENODEV;
1802
1803 mutex_lock(&of_mutex);
1804
1805 raw_spin_lock_irqsave(&devtree_lock, flags);
1806 rc = __of_remove_property(np, prop);
1807 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1808
1809 if (!rc)
1810 __of_remove_property_sysfs(np, prop);
1811
1812 mutex_unlock(&of_mutex);
1813
1814 if (!rc)
1815 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1816
1817 return rc;
1818}
1819EXPORT_SYMBOL_GPL(of_remove_property);
1820
1821int __of_update_property(struct device_node *np, struct property *newprop,
1822 struct property **oldpropp)
1823{
1824 struct property **next, *oldprop;
1825
1826 for (next = &np->properties; *next; next = &(*next)->next) {
1827 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1828 break;
1829 }
1830 *oldpropp = oldprop = *next;
1831
1832 if (oldprop) {
1833 /* replace the node */
1834 newprop->next = oldprop->next;
1835 *next = newprop;
1836 oldprop->next = np->deadprops;
1837 np->deadprops = oldprop;
1838 } else {
1839 /* new node */
1840 newprop->next = NULL;
1841 *next = newprop;
1842 }
1843
1844 return 0;
1845}
1846
1847/*
1848 * of_update_property - Update a property in a node, if the property does
1849 * not exist, add it.
1850 *
1851 * Note that we don't actually remove it, since we have given out
1852 * who-knows-how-many pointers to the data using get-property.
1853 * Instead we just move the property to the "dead properties" list,
1854 * and add the new property to the property list
1855 */
1856int of_update_property(struct device_node *np, struct property *newprop)
1857{
1858 struct property *oldprop;
1859 unsigned long flags;
1860 int rc;
1861
1862 if (!newprop->name)
1863 return -EINVAL;
1864
1865 mutex_lock(&of_mutex);
1866
1867 raw_spin_lock_irqsave(&devtree_lock, flags);
1868 rc = __of_update_property(np, newprop, &oldprop);
1869 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1870
1871 if (!rc)
1872 __of_update_property_sysfs(np, newprop, oldprop);
1873
1874 mutex_unlock(&of_mutex);
1875
1876 if (!rc)
1877 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1878
1879 return rc;
1880}
1881
1882static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1883 int id, const char *stem, int stem_len)
1884{
1885 ap->np = np;
1886 ap->id = id;
1887 strncpy(ap->stem, stem, stem_len);
1888 ap->stem[stem_len] = 0;
1889 list_add_tail(&ap->link, &aliases_lookup);
1890 pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
1891 ap->alias, ap->stem, ap->id, np);
1892}
1893
1894/**
1895 * of_alias_scan - Scan all properties of the 'aliases' node
1896 * @dt_alloc: An allocator that provides a virtual address to memory
1897 * for storing the resulting tree
1898 *
1899 * The function scans all the properties of the 'aliases' node and populates
1900 * the global lookup table with the properties. It returns the
1901 * number of alias properties found, or an error code in case of failure.
1902 */
1903void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1904{
1905 struct property *pp;
1906
1907 of_aliases = of_find_node_by_path("/aliases");
1908 of_chosen = of_find_node_by_path("/chosen");
1909 if (of_chosen == NULL)
1910 of_chosen = of_find_node_by_path("/chosen@0");
1911
1912 if (of_chosen) {
1913 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1914 const char *name = NULL;
1915
1916 if (of_property_read_string(of_chosen, "stdout-path", &name))
1917 of_property_read_string(of_chosen, "linux,stdout-path",
1918 &name);
1919 if (IS_ENABLED(CONFIG_PPC) && !name)
1920 of_property_read_string(of_aliases, "stdout", &name);
1921 if (name)
1922 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1923 if (of_stdout)
1924 of_stdout->fwnode.flags |= FWNODE_FLAG_BEST_EFFORT;
1925 }
1926
1927 if (!of_aliases)
1928 return;
1929
1930 for_each_property_of_node(of_aliases, pp) {
1931 const char *start = pp->name;
1932 const char *end = start + strlen(start);
1933 struct device_node *np;
1934 struct alias_prop *ap;
1935 int id, len;
1936
1937 /* Skip those we do not want to proceed */
1938 if (!strcmp(pp->name, "name") ||
1939 !strcmp(pp->name, "phandle") ||
1940 !strcmp(pp->name, "linux,phandle"))
1941 continue;
1942
1943 np = of_find_node_by_path(pp->value);
1944 if (!np)
1945 continue;
1946
1947 /* walk the alias backwards to extract the id and work out
1948 * the 'stem' string */
1949 while (isdigit(*(end-1)) && end > start)
1950 end--;
1951 len = end - start;
1952
1953 if (kstrtoint(end, 10, &id) < 0)
1954 continue;
1955
1956 /* Allocate an alias_prop with enough space for the stem */
1957 ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
1958 if (!ap)
1959 continue;
1960 memset(ap, 0, sizeof(*ap) + len + 1);
1961 ap->alias = start;
1962 of_alias_add(ap, np, id, start, len);
1963 }
1964}
1965
1966/**
1967 * of_alias_get_id - Get alias id for the given device_node
1968 * @np: Pointer to the given device_node
1969 * @stem: Alias stem of the given device_node
1970 *
1971 * The function travels the lookup table to get the alias id for the given
1972 * device_node and alias stem.
1973 *
1974 * Return: The alias id if found.
1975 */
1976int of_alias_get_id(struct device_node *np, const char *stem)
1977{
1978 struct alias_prop *app;
1979 int id = -ENODEV;
1980
1981 mutex_lock(&of_mutex);
1982 list_for_each_entry(app, &aliases_lookup, link) {
1983 if (strcmp(app->stem, stem) != 0)
1984 continue;
1985
1986 if (np == app->np) {
1987 id = app->id;
1988 break;
1989 }
1990 }
1991 mutex_unlock(&of_mutex);
1992
1993 return id;
1994}
1995EXPORT_SYMBOL_GPL(of_alias_get_id);
1996
1997/**
1998 * of_alias_get_highest_id - Get highest alias id for the given stem
1999 * @stem: Alias stem to be examined
2000 *
2001 * The function travels the lookup table to get the highest alias id for the
2002 * given alias stem. It returns the alias id if found.
2003 */
2004int of_alias_get_highest_id(const char *stem)
2005{
2006 struct alias_prop *app;
2007 int id = -ENODEV;
2008
2009 mutex_lock(&of_mutex);
2010 list_for_each_entry(app, &aliases_lookup, link) {
2011 if (strcmp(app->stem, stem) != 0)
2012 continue;
2013
2014 if (app->id > id)
2015 id = app->id;
2016 }
2017 mutex_unlock(&of_mutex);
2018
2019 return id;
2020}
2021EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2022
2023/**
2024 * of_console_check() - Test and setup console for DT setup
2025 * @dn: Pointer to device node
2026 * @name: Name to use for preferred console without index. ex. "ttyS"
2027 * @index: Index to use for preferred console.
2028 *
2029 * Check if the given device node matches the stdout-path property in the
2030 * /chosen node. If it does then register it as the preferred console.
2031 *
2032 * Return: TRUE if console successfully setup. Otherwise return FALSE.
2033 */
2034bool of_console_check(struct device_node *dn, char *name, int index)
2035{
2036 if (!dn || dn != of_stdout || console_set_on_cmdline)
2037 return false;
2038
2039 /*
2040 * XXX: cast `options' to char pointer to suppress complication
2041 * warnings: printk, UART and console drivers expect char pointer.
2042 */
2043 return !add_preferred_console(name, index, (char *)of_stdout_options);
2044}
2045EXPORT_SYMBOL_GPL(of_console_check);
2046
2047/**
2048 * of_find_next_cache_node - Find a node's subsidiary cache
2049 * @np: node of type "cpu" or "cache"
2050 *
2051 * Return: A node pointer with refcount incremented, use
2052 * of_node_put() on it when done. Caller should hold a reference
2053 * to np.
2054 */
2055struct device_node *of_find_next_cache_node(const struct device_node *np)
2056{
2057 struct device_node *child, *cache_node;
2058
2059 cache_node = of_parse_phandle(np, "l2-cache", 0);
2060 if (!cache_node)
2061 cache_node = of_parse_phandle(np, "next-level-cache", 0);
2062
2063 if (cache_node)
2064 return cache_node;
2065
2066 /* OF on pmac has nodes instead of properties named "l2-cache"
2067 * beneath CPU nodes.
2068 */
2069 if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu"))
2070 for_each_child_of_node(np, child)
2071 if (of_node_is_type(child, "cache"))
2072 return child;
2073
2074 return NULL;
2075}
2076
2077/**
2078 * of_find_last_cache_level - Find the level at which the last cache is
2079 * present for the given logical cpu
2080 *
2081 * @cpu: cpu number(logical index) for which the last cache level is needed
2082 *
2083 * Return: The level at which the last cache is present. It is exactly
2084 * same as the total number of cache levels for the given logical cpu.
2085 */
2086int of_find_last_cache_level(unsigned int cpu)
2087{
2088 u32 cache_level = 0;
2089 struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
2090
2091 while (np) {
2092 of_node_put(prev);
2093 prev = np;
2094 np = of_find_next_cache_node(np);
2095 }
2096
2097 of_property_read_u32(prev, "cache-level", &cache_level);
2098 of_node_put(prev);
2099
2100 return cache_level;
2101}
2102
2103/**
2104 * of_map_id - Translate an ID through a downstream mapping.
2105 * @np: root complex device node.
2106 * @id: device ID to map.
2107 * @map_name: property name of the map to use.
2108 * @map_mask_name: optional property name of the mask to use.
2109 * @target: optional pointer to a target device node.
2110 * @id_out: optional pointer to receive the translated ID.
2111 *
2112 * Given a device ID, look up the appropriate implementation-defined
2113 * platform ID and/or the target device which receives transactions on that
2114 * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
2115 * @id_out may be NULL if only the other is required. If @target points to
2116 * a non-NULL device node pointer, only entries targeting that node will be
2117 * matched; if it points to a NULL value, it will receive the device node of
2118 * the first matching target phandle, with a reference held.
2119 *
2120 * Return: 0 on success or a standard error code on failure.
2121 */
2122int of_map_id(struct device_node *np, u32 id,
2123 const char *map_name, const char *map_mask_name,
2124 struct device_node **target, u32 *id_out)
2125{
2126 u32 map_mask, masked_id;
2127 int map_len;
2128 const __be32 *map = NULL;
2129
2130 if (!np || !map_name || (!target && !id_out))
2131 return -EINVAL;
2132
2133 map = of_get_property(np, map_name, &map_len);
2134 if (!map) {
2135 if (target)
2136 return -ENODEV;
2137 /* Otherwise, no map implies no translation */
2138 *id_out = id;
2139 return 0;
2140 }
2141
2142 if (!map_len || map_len % (4 * sizeof(*map))) {
2143 pr_err("%pOF: Error: Bad %s length: %d\n", np,
2144 map_name, map_len);
2145 return -EINVAL;
2146 }
2147
2148 /* The default is to select all bits. */
2149 map_mask = 0xffffffff;
2150
2151 /*
2152 * Can be overridden by "{iommu,msi}-map-mask" property.
2153 * If of_property_read_u32() fails, the default is used.
2154 */
2155 if (map_mask_name)
2156 of_property_read_u32(np, map_mask_name, &map_mask);
2157
2158 masked_id = map_mask & id;
2159 for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
2160 struct device_node *phandle_node;
2161 u32 id_base = be32_to_cpup(map + 0);
2162 u32 phandle = be32_to_cpup(map + 1);
2163 u32 out_base = be32_to_cpup(map + 2);
2164 u32 id_len = be32_to_cpup(map + 3);
2165
2166 if (id_base & ~map_mask) {
2167 pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n",
2168 np, map_name, map_name,
2169 map_mask, id_base);
2170 return -EFAULT;
2171 }
2172
2173 if (masked_id < id_base || masked_id >= id_base + id_len)
2174 continue;
2175
2176 phandle_node = of_find_node_by_phandle(phandle);
2177 if (!phandle_node)
2178 return -ENODEV;
2179
2180 if (target) {
2181 if (*target)
2182 of_node_put(phandle_node);
2183 else
2184 *target = phandle_node;
2185
2186 if (*target != phandle_node)
2187 continue;
2188 }
2189
2190 if (id_out)
2191 *id_out = masked_id - id_base + out_base;
2192
2193 pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
2194 np, map_name, map_mask, id_base, out_base,
2195 id_len, id, masked_id - id_base + out_base);
2196 return 0;
2197 }
2198
2199 pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
2200 id, target && *target ? *target : NULL);
2201
2202 /* Bypasses translation */
2203 if (id_out)
2204 *id_out = id;
2205 return 0;
2206}
2207EXPORT_SYMBOL_GPL(of_map_id);
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Procedures for creating, accessing and interpreting the device tree.
4 *
5 * Paul Mackerras August 1996.
6 * Copyright (C) 1996-2005 Paul Mackerras.
7 *
8 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
9 * {engebret|bergner}@us.ibm.com
10 *
11 * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
12 *
13 * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
14 * Grant Likely.
15 */
16
17#define pr_fmt(fmt) "OF: " fmt
18
19#include <linux/console.h>
20#include <linux/ctype.h>
21#include <linux/cpu.h>
22#include <linux/module.h>
23#include <linux/of.h>
24#include <linux/of_device.h>
25#include <linux/of_graph.h>
26#include <linux/spinlock.h>
27#include <linux/slab.h>
28#include <linux/string.h>
29#include <linux/proc_fs.h>
30
31#include "of_private.h"
32
33LIST_HEAD(aliases_lookup);
34
35struct device_node *of_root;
36EXPORT_SYMBOL(of_root);
37struct device_node *of_chosen;
38struct device_node *of_aliases;
39struct device_node *of_stdout;
40static const char *of_stdout_options;
41
42struct kset *of_kset;
43
44/*
45 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
46 * This mutex must be held whenever modifications are being made to the
47 * device tree. The of_{attach,detach}_node() and
48 * of_{add,remove,update}_property() helpers make sure this happens.
49 */
50DEFINE_MUTEX(of_mutex);
51
52/* use when traversing tree through the child, sibling,
53 * or parent members of struct device_node.
54 */
55DEFINE_RAW_SPINLOCK(devtree_lock);
56
57int of_n_addr_cells(struct device_node *np)
58{
59 u32 cells;
60
61 do {
62 if (np->parent)
63 np = np->parent;
64 if (!of_property_read_u32(np, "#address-cells", &cells))
65 return cells;
66 } while (np->parent);
67 /* No #address-cells property for the root node */
68 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
69}
70EXPORT_SYMBOL(of_n_addr_cells);
71
72int of_n_size_cells(struct device_node *np)
73{
74 u32 cells;
75
76 do {
77 if (np->parent)
78 np = np->parent;
79 if (!of_property_read_u32(np, "#size-cells", &cells))
80 return cells;
81 } while (np->parent);
82 /* No #size-cells property for the root node */
83 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
84}
85EXPORT_SYMBOL(of_n_size_cells);
86
87#ifdef CONFIG_NUMA
88int __weak of_node_to_nid(struct device_node *np)
89{
90 return NUMA_NO_NODE;
91}
92#endif
93
94static struct device_node **phandle_cache;
95static u32 phandle_cache_mask;
96
97/*
98 * Assumptions behind phandle_cache implementation:
99 * - phandle property values are in a contiguous range of 1..n
100 *
101 * If the assumptions do not hold, then
102 * - the phandle lookup overhead reduction provided by the cache
103 * will likely be less
104 */
105static void of_populate_phandle_cache(void)
106{
107 unsigned long flags;
108 u32 cache_entries;
109 struct device_node *np;
110 u32 phandles = 0;
111
112 raw_spin_lock_irqsave(&devtree_lock, flags);
113
114 kfree(phandle_cache);
115 phandle_cache = NULL;
116
117 for_each_of_allnodes(np)
118 if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL)
119 phandles++;
120
121 cache_entries = roundup_pow_of_two(phandles);
122 phandle_cache_mask = cache_entries - 1;
123
124 phandle_cache = kcalloc(cache_entries, sizeof(*phandle_cache),
125 GFP_ATOMIC);
126 if (!phandle_cache)
127 goto out;
128
129 for_each_of_allnodes(np)
130 if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL)
131 phandle_cache[np->phandle & phandle_cache_mask] = np;
132
133out:
134 raw_spin_unlock_irqrestore(&devtree_lock, flags);
135}
136
137#ifndef CONFIG_MODULES
138static int __init of_free_phandle_cache(void)
139{
140 unsigned long flags;
141
142 raw_spin_lock_irqsave(&devtree_lock, flags);
143
144 kfree(phandle_cache);
145 phandle_cache = NULL;
146
147 raw_spin_unlock_irqrestore(&devtree_lock, flags);
148
149 return 0;
150}
151late_initcall_sync(of_free_phandle_cache);
152#endif
153
154void __init of_core_init(void)
155{
156 struct device_node *np;
157
158 of_populate_phandle_cache();
159
160 /* Create the kset, and register existing nodes */
161 mutex_lock(&of_mutex);
162 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
163 if (!of_kset) {
164 mutex_unlock(&of_mutex);
165 pr_err("failed to register existing nodes\n");
166 return;
167 }
168 for_each_of_allnodes(np)
169 __of_attach_node_sysfs(np);
170 mutex_unlock(&of_mutex);
171
172 /* Symlink in /proc as required by userspace ABI */
173 if (of_root)
174 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
175}
176
177static struct property *__of_find_property(const struct device_node *np,
178 const char *name, int *lenp)
179{
180 struct property *pp;
181
182 if (!np)
183 return NULL;
184
185 for (pp = np->properties; pp; pp = pp->next) {
186 if (of_prop_cmp(pp->name, name) == 0) {
187 if (lenp)
188 *lenp = pp->length;
189 break;
190 }
191 }
192
193 return pp;
194}
195
196struct property *of_find_property(const struct device_node *np,
197 const char *name,
198 int *lenp)
199{
200 struct property *pp;
201 unsigned long flags;
202
203 raw_spin_lock_irqsave(&devtree_lock, flags);
204 pp = __of_find_property(np, name, lenp);
205 raw_spin_unlock_irqrestore(&devtree_lock, flags);
206
207 return pp;
208}
209EXPORT_SYMBOL(of_find_property);
210
211struct device_node *__of_find_all_nodes(struct device_node *prev)
212{
213 struct device_node *np;
214 if (!prev) {
215 np = of_root;
216 } else if (prev->child) {
217 np = prev->child;
218 } else {
219 /* Walk back up looking for a sibling, or the end of the structure */
220 np = prev;
221 while (np->parent && !np->sibling)
222 np = np->parent;
223 np = np->sibling; /* Might be null at the end of the tree */
224 }
225 return np;
226}
227
228/**
229 * of_find_all_nodes - Get next node in global list
230 * @prev: Previous node or NULL to start iteration
231 * of_node_put() will be called on it
232 *
233 * Returns a node pointer with refcount incremented, use
234 * of_node_put() on it when done.
235 */
236struct device_node *of_find_all_nodes(struct device_node *prev)
237{
238 struct device_node *np;
239 unsigned long flags;
240
241 raw_spin_lock_irqsave(&devtree_lock, flags);
242 np = __of_find_all_nodes(prev);
243 of_node_get(np);
244 of_node_put(prev);
245 raw_spin_unlock_irqrestore(&devtree_lock, flags);
246 return np;
247}
248EXPORT_SYMBOL(of_find_all_nodes);
249
250/*
251 * Find a property with a given name for a given node
252 * and return the value.
253 */
254const void *__of_get_property(const struct device_node *np,
255 const char *name, int *lenp)
256{
257 struct property *pp = __of_find_property(np, name, lenp);
258
259 return pp ? pp->value : NULL;
260}
261
262/*
263 * Find a property with a given name for a given node
264 * and return the value.
265 */
266const void *of_get_property(const struct device_node *np, const char *name,
267 int *lenp)
268{
269 struct property *pp = of_find_property(np, name, lenp);
270
271 return pp ? pp->value : NULL;
272}
273EXPORT_SYMBOL(of_get_property);
274
275/*
276 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
277 *
278 * @cpu: logical cpu index of a core/thread
279 * @phys_id: physical identifier of a core/thread
280 *
281 * CPU logical to physical index mapping is architecture specific.
282 * However this __weak function provides a default match of physical
283 * id to logical cpu index. phys_id provided here is usually values read
284 * from the device tree which must match the hardware internal registers.
285 *
286 * Returns true if the physical identifier and the logical cpu index
287 * correspond to the same core/thread, false otherwise.
288 */
289bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
290{
291 return (u32)phys_id == cpu;
292}
293
294/**
295 * Checks if the given "prop_name" property holds the physical id of the
296 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
297 * NULL, local thread number within the core is returned in it.
298 */
299static bool __of_find_n_match_cpu_property(struct device_node *cpun,
300 const char *prop_name, int cpu, unsigned int *thread)
301{
302 const __be32 *cell;
303 int ac, prop_len, tid;
304 u64 hwid;
305
306 ac = of_n_addr_cells(cpun);
307 cell = of_get_property(cpun, prop_name, &prop_len);
308 if (!cell || !ac)
309 return false;
310 prop_len /= sizeof(*cell) * ac;
311 for (tid = 0; tid < prop_len; tid++) {
312 hwid = of_read_number(cell, ac);
313 if (arch_match_cpu_phys_id(cpu, hwid)) {
314 if (thread)
315 *thread = tid;
316 return true;
317 }
318 cell += ac;
319 }
320 return false;
321}
322
323/*
324 * arch_find_n_match_cpu_physical_id - See if the given device node is
325 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
326 * else false. If 'thread' is non-NULL, the local thread number within the
327 * core is returned in it.
328 */
329bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
330 int cpu, unsigned int *thread)
331{
332 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
333 * for thread ids on PowerPC. If it doesn't exist fallback to
334 * standard "reg" property.
335 */
336 if (IS_ENABLED(CONFIG_PPC) &&
337 __of_find_n_match_cpu_property(cpun,
338 "ibm,ppc-interrupt-server#s",
339 cpu, thread))
340 return true;
341
342 return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
343}
344
345/**
346 * of_get_cpu_node - Get device node associated with the given logical CPU
347 *
348 * @cpu: CPU number(logical index) for which device node is required
349 * @thread: if not NULL, local thread number within the physical core is
350 * returned
351 *
352 * The main purpose of this function is to retrieve the device node for the
353 * given logical CPU index. It should be used to initialize the of_node in
354 * cpu device. Once of_node in cpu device is populated, all the further
355 * references can use that instead.
356 *
357 * CPU logical to physical index mapping is architecture specific and is built
358 * before booting secondary cores. This function uses arch_match_cpu_phys_id
359 * which can be overridden by architecture specific implementation.
360 *
361 * Returns a node pointer for the logical cpu with refcount incremented, use
362 * of_node_put() on it when done. Returns NULL if not found.
363 */
364struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
365{
366 struct device_node *cpun;
367
368 for_each_node_by_type(cpun, "cpu") {
369 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
370 return cpun;
371 }
372 return NULL;
373}
374EXPORT_SYMBOL(of_get_cpu_node);
375
376/**
377 * of_cpu_node_to_id: Get the logical CPU number for a given device_node
378 *
379 * @cpu_node: Pointer to the device_node for CPU.
380 *
381 * Returns the logical CPU number of the given CPU device_node.
382 * Returns -ENODEV if the CPU is not found.
383 */
384int of_cpu_node_to_id(struct device_node *cpu_node)
385{
386 int cpu;
387 bool found = false;
388 struct device_node *np;
389
390 for_each_possible_cpu(cpu) {
391 np = of_cpu_device_node_get(cpu);
392 found = (cpu_node == np);
393 of_node_put(np);
394 if (found)
395 return cpu;
396 }
397
398 return -ENODEV;
399}
400EXPORT_SYMBOL(of_cpu_node_to_id);
401
402/**
403 * __of_device_is_compatible() - Check if the node matches given constraints
404 * @device: pointer to node
405 * @compat: required compatible string, NULL or "" for any match
406 * @type: required device_type value, NULL or "" for any match
407 * @name: required node name, NULL or "" for any match
408 *
409 * Checks if the given @compat, @type and @name strings match the
410 * properties of the given @device. A constraints can be skipped by
411 * passing NULL or an empty string as the constraint.
412 *
413 * Returns 0 for no match, and a positive integer on match. The return
414 * value is a relative score with larger values indicating better
415 * matches. The score is weighted for the most specific compatible value
416 * to get the highest score. Matching type is next, followed by matching
417 * name. Practically speaking, this results in the following priority
418 * order for matches:
419 *
420 * 1. specific compatible && type && name
421 * 2. specific compatible && type
422 * 3. specific compatible && name
423 * 4. specific compatible
424 * 5. general compatible && type && name
425 * 6. general compatible && type
426 * 7. general compatible && name
427 * 8. general compatible
428 * 9. type && name
429 * 10. type
430 * 11. name
431 */
432static int __of_device_is_compatible(const struct device_node *device,
433 const char *compat, const char *type, const char *name)
434{
435 struct property *prop;
436 const char *cp;
437 int index = 0, score = 0;
438
439 /* Compatible match has highest priority */
440 if (compat && compat[0]) {
441 prop = __of_find_property(device, "compatible", NULL);
442 for (cp = of_prop_next_string(prop, NULL); cp;
443 cp = of_prop_next_string(prop, cp), index++) {
444 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
445 score = INT_MAX/2 - (index << 2);
446 break;
447 }
448 }
449 if (!score)
450 return 0;
451 }
452
453 /* Matching type is better than matching name */
454 if (type && type[0]) {
455 if (!device->type || of_node_cmp(type, device->type))
456 return 0;
457 score += 2;
458 }
459
460 /* Matching name is a bit better than not */
461 if (name && name[0]) {
462 if (!device->name || of_node_cmp(name, device->name))
463 return 0;
464 score++;
465 }
466
467 return score;
468}
469
470/** Checks if the given "compat" string matches one of the strings in
471 * the device's "compatible" property
472 */
473int of_device_is_compatible(const struct device_node *device,
474 const char *compat)
475{
476 unsigned long flags;
477 int res;
478
479 raw_spin_lock_irqsave(&devtree_lock, flags);
480 res = __of_device_is_compatible(device, compat, NULL, NULL);
481 raw_spin_unlock_irqrestore(&devtree_lock, flags);
482 return res;
483}
484EXPORT_SYMBOL(of_device_is_compatible);
485
486/** Checks if the device is compatible with any of the entries in
487 * a NULL terminated array of strings. Returns the best match
488 * score or 0.
489 */
490int of_device_compatible_match(struct device_node *device,
491 const char *const *compat)
492{
493 unsigned int tmp, score = 0;
494
495 if (!compat)
496 return 0;
497
498 while (*compat) {
499 tmp = of_device_is_compatible(device, *compat);
500 if (tmp > score)
501 score = tmp;
502 compat++;
503 }
504
505 return score;
506}
507
508/**
509 * of_machine_is_compatible - Test root of device tree for a given compatible value
510 * @compat: compatible string to look for in root node's compatible property.
511 *
512 * Returns a positive integer if the root node has the given value in its
513 * compatible property.
514 */
515int of_machine_is_compatible(const char *compat)
516{
517 struct device_node *root;
518 int rc = 0;
519
520 root = of_find_node_by_path("/");
521 if (root) {
522 rc = of_device_is_compatible(root, compat);
523 of_node_put(root);
524 }
525 return rc;
526}
527EXPORT_SYMBOL(of_machine_is_compatible);
528
529/**
530 * __of_device_is_available - check if a device is available for use
531 *
532 * @device: Node to check for availability, with locks already held
533 *
534 * Returns true if the status property is absent or set to "okay" or "ok",
535 * false otherwise
536 */
537static bool __of_device_is_available(const struct device_node *device)
538{
539 const char *status;
540 int statlen;
541
542 if (!device)
543 return false;
544
545 status = __of_get_property(device, "status", &statlen);
546 if (status == NULL)
547 return true;
548
549 if (statlen > 0) {
550 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
551 return true;
552 }
553
554 return false;
555}
556
557/**
558 * of_device_is_available - check if a device is available for use
559 *
560 * @device: Node to check for availability
561 *
562 * Returns true if the status property is absent or set to "okay" or "ok",
563 * false otherwise
564 */
565bool of_device_is_available(const struct device_node *device)
566{
567 unsigned long flags;
568 bool res;
569
570 raw_spin_lock_irqsave(&devtree_lock, flags);
571 res = __of_device_is_available(device);
572 raw_spin_unlock_irqrestore(&devtree_lock, flags);
573 return res;
574
575}
576EXPORT_SYMBOL(of_device_is_available);
577
578/**
579 * of_device_is_big_endian - check if a device has BE registers
580 *
581 * @device: Node to check for endianness
582 *
583 * Returns true if the device has a "big-endian" property, or if the kernel
584 * was compiled for BE *and* the device has a "native-endian" property.
585 * Returns false otherwise.
586 *
587 * Callers would nominally use ioread32be/iowrite32be if
588 * of_device_is_big_endian() == true, or readl/writel otherwise.
589 */
590bool of_device_is_big_endian(const struct device_node *device)
591{
592 if (of_property_read_bool(device, "big-endian"))
593 return true;
594 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
595 of_property_read_bool(device, "native-endian"))
596 return true;
597 return false;
598}
599EXPORT_SYMBOL(of_device_is_big_endian);
600
601/**
602 * of_get_parent - Get a node's parent if any
603 * @node: Node to get parent
604 *
605 * Returns a node pointer with refcount incremented, use
606 * of_node_put() on it when done.
607 */
608struct device_node *of_get_parent(const struct device_node *node)
609{
610 struct device_node *np;
611 unsigned long flags;
612
613 if (!node)
614 return NULL;
615
616 raw_spin_lock_irqsave(&devtree_lock, flags);
617 np = of_node_get(node->parent);
618 raw_spin_unlock_irqrestore(&devtree_lock, flags);
619 return np;
620}
621EXPORT_SYMBOL(of_get_parent);
622
623/**
624 * of_get_next_parent - Iterate to a node's parent
625 * @node: Node to get parent of
626 *
627 * This is like of_get_parent() except that it drops the
628 * refcount on the passed node, making it suitable for iterating
629 * through a node's parents.
630 *
631 * Returns a node pointer with refcount incremented, use
632 * of_node_put() on it when done.
633 */
634struct device_node *of_get_next_parent(struct device_node *node)
635{
636 struct device_node *parent;
637 unsigned long flags;
638
639 if (!node)
640 return NULL;
641
642 raw_spin_lock_irqsave(&devtree_lock, flags);
643 parent = of_node_get(node->parent);
644 of_node_put(node);
645 raw_spin_unlock_irqrestore(&devtree_lock, flags);
646 return parent;
647}
648EXPORT_SYMBOL(of_get_next_parent);
649
650static struct device_node *__of_get_next_child(const struct device_node *node,
651 struct device_node *prev)
652{
653 struct device_node *next;
654
655 if (!node)
656 return NULL;
657
658 next = prev ? prev->sibling : node->child;
659 for (; next; next = next->sibling)
660 if (of_node_get(next))
661 break;
662 of_node_put(prev);
663 return next;
664}
665#define __for_each_child_of_node(parent, child) \
666 for (child = __of_get_next_child(parent, NULL); child != NULL; \
667 child = __of_get_next_child(parent, child))
668
669/**
670 * of_get_next_child - Iterate a node childs
671 * @node: parent node
672 * @prev: previous child of the parent node, or NULL to get first
673 *
674 * Returns a node pointer with refcount incremented, use of_node_put() on
675 * it when done. Returns NULL when prev is the last child. Decrements the
676 * refcount of prev.
677 */
678struct device_node *of_get_next_child(const struct device_node *node,
679 struct device_node *prev)
680{
681 struct device_node *next;
682 unsigned long flags;
683
684 raw_spin_lock_irqsave(&devtree_lock, flags);
685 next = __of_get_next_child(node, prev);
686 raw_spin_unlock_irqrestore(&devtree_lock, flags);
687 return next;
688}
689EXPORT_SYMBOL(of_get_next_child);
690
691/**
692 * of_get_next_available_child - Find the next available child node
693 * @node: parent node
694 * @prev: previous child of the parent node, or NULL to get first
695 *
696 * This function is like of_get_next_child(), except that it
697 * automatically skips any disabled nodes (i.e. status = "disabled").
698 */
699struct device_node *of_get_next_available_child(const struct device_node *node,
700 struct device_node *prev)
701{
702 struct device_node *next;
703 unsigned long flags;
704
705 if (!node)
706 return NULL;
707
708 raw_spin_lock_irqsave(&devtree_lock, flags);
709 next = prev ? prev->sibling : node->child;
710 for (; next; next = next->sibling) {
711 if (!__of_device_is_available(next))
712 continue;
713 if (of_node_get(next))
714 break;
715 }
716 of_node_put(prev);
717 raw_spin_unlock_irqrestore(&devtree_lock, flags);
718 return next;
719}
720EXPORT_SYMBOL(of_get_next_available_child);
721
722/**
723 * of_get_child_by_name - Find the child node by name for a given parent
724 * @node: parent node
725 * @name: child name to look for.
726 *
727 * This function looks for child node for given matching name
728 *
729 * Returns a node pointer if found, with refcount incremented, use
730 * of_node_put() on it when done.
731 * Returns NULL if node is not found.
732 */
733struct device_node *of_get_child_by_name(const struct device_node *node,
734 const char *name)
735{
736 struct device_node *child;
737
738 for_each_child_of_node(node, child)
739 if (child->name && (of_node_cmp(child->name, name) == 0))
740 break;
741 return child;
742}
743EXPORT_SYMBOL(of_get_child_by_name);
744
745struct device_node *__of_find_node_by_path(struct device_node *parent,
746 const char *path)
747{
748 struct device_node *child;
749 int len;
750
751 len = strcspn(path, "/:");
752 if (!len)
753 return NULL;
754
755 __for_each_child_of_node(parent, child) {
756 const char *name = kbasename(child->full_name);
757 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
758 return child;
759 }
760 return NULL;
761}
762
763struct device_node *__of_find_node_by_full_path(struct device_node *node,
764 const char *path)
765{
766 const char *separator = strchr(path, ':');
767
768 while (node && *path == '/') {
769 struct device_node *tmp = node;
770
771 path++; /* Increment past '/' delimiter */
772 node = __of_find_node_by_path(node, path);
773 of_node_put(tmp);
774 path = strchrnul(path, '/');
775 if (separator && separator < path)
776 break;
777 }
778 return node;
779}
780
781/**
782 * of_find_node_opts_by_path - Find a node matching a full OF path
783 * @path: Either the full path to match, or if the path does not
784 * start with '/', the name of a property of the /aliases
785 * node (an alias). In the case of an alias, the node
786 * matching the alias' value will be returned.
787 * @opts: Address of a pointer into which to store the start of
788 * an options string appended to the end of the path with
789 * a ':' separator.
790 *
791 * Valid paths:
792 * /foo/bar Full path
793 * foo Valid alias
794 * foo/bar Valid alias + relative path
795 *
796 * Returns a node pointer with refcount incremented, use
797 * of_node_put() on it when done.
798 */
799struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
800{
801 struct device_node *np = NULL;
802 struct property *pp;
803 unsigned long flags;
804 const char *separator = strchr(path, ':');
805
806 if (opts)
807 *opts = separator ? separator + 1 : NULL;
808
809 if (strcmp(path, "/") == 0)
810 return of_node_get(of_root);
811
812 /* The path could begin with an alias */
813 if (*path != '/') {
814 int len;
815 const char *p = separator;
816
817 if (!p)
818 p = strchrnul(path, '/');
819 len = p - path;
820
821 /* of_aliases must not be NULL */
822 if (!of_aliases)
823 return NULL;
824
825 for_each_property_of_node(of_aliases, pp) {
826 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
827 np = of_find_node_by_path(pp->value);
828 break;
829 }
830 }
831 if (!np)
832 return NULL;
833 path = p;
834 }
835
836 /* Step down the tree matching path components */
837 raw_spin_lock_irqsave(&devtree_lock, flags);
838 if (!np)
839 np = of_node_get(of_root);
840 np = __of_find_node_by_full_path(np, path);
841 raw_spin_unlock_irqrestore(&devtree_lock, flags);
842 return np;
843}
844EXPORT_SYMBOL(of_find_node_opts_by_path);
845
846/**
847 * of_find_node_by_name - Find a node by its "name" property
848 * @from: The node to start searching from or NULL; the node
849 * you pass will not be searched, only the next one
850 * will. Typically, you pass what the previous call
851 * returned. of_node_put() will be called on @from.
852 * @name: The name string to match against
853 *
854 * Returns a node pointer with refcount incremented, use
855 * of_node_put() on it when done.
856 */
857struct device_node *of_find_node_by_name(struct device_node *from,
858 const char *name)
859{
860 struct device_node *np;
861 unsigned long flags;
862
863 raw_spin_lock_irqsave(&devtree_lock, flags);
864 for_each_of_allnodes_from(from, np)
865 if (np->name && (of_node_cmp(np->name, name) == 0)
866 && of_node_get(np))
867 break;
868 of_node_put(from);
869 raw_spin_unlock_irqrestore(&devtree_lock, flags);
870 return np;
871}
872EXPORT_SYMBOL(of_find_node_by_name);
873
874/**
875 * of_find_node_by_type - Find a node by its "device_type" property
876 * @from: The node to start searching from, or NULL to start searching
877 * the entire device tree. The node you pass will not be
878 * searched, only the next one will; typically, you pass
879 * what the previous call returned. of_node_put() will be
880 * called on from for you.
881 * @type: The type string to match against
882 *
883 * Returns a node pointer with refcount incremented, use
884 * of_node_put() on it when done.
885 */
886struct device_node *of_find_node_by_type(struct device_node *from,
887 const char *type)
888{
889 struct device_node *np;
890 unsigned long flags;
891
892 raw_spin_lock_irqsave(&devtree_lock, flags);
893 for_each_of_allnodes_from(from, np)
894 if (np->type && (of_node_cmp(np->type, type) == 0)
895 && of_node_get(np))
896 break;
897 of_node_put(from);
898 raw_spin_unlock_irqrestore(&devtree_lock, flags);
899 return np;
900}
901EXPORT_SYMBOL(of_find_node_by_type);
902
903/**
904 * of_find_compatible_node - Find a node based on type and one of the
905 * tokens in its "compatible" property
906 * @from: The node to start searching from or NULL, the node
907 * you pass will not be searched, only the next one
908 * will; typically, you pass what the previous call
909 * returned. of_node_put() will be called on it
910 * @type: The type string to match "device_type" or NULL to ignore
911 * @compatible: The string to match to one of the tokens in the device
912 * "compatible" list.
913 *
914 * Returns a node pointer with refcount incremented, use
915 * of_node_put() on it when done.
916 */
917struct device_node *of_find_compatible_node(struct device_node *from,
918 const char *type, const char *compatible)
919{
920 struct device_node *np;
921 unsigned long flags;
922
923 raw_spin_lock_irqsave(&devtree_lock, flags);
924 for_each_of_allnodes_from(from, np)
925 if (__of_device_is_compatible(np, compatible, type, NULL) &&
926 of_node_get(np))
927 break;
928 of_node_put(from);
929 raw_spin_unlock_irqrestore(&devtree_lock, flags);
930 return np;
931}
932EXPORT_SYMBOL(of_find_compatible_node);
933
934/**
935 * of_find_node_with_property - Find a node which has a property with
936 * the given name.
937 * @from: The node to start searching from or NULL, the node
938 * you pass will not be searched, only the next one
939 * will; typically, you pass what the previous call
940 * returned. of_node_put() will be called on it
941 * @prop_name: The name of the property to look for.
942 *
943 * Returns a node pointer with refcount incremented, use
944 * of_node_put() on it when done.
945 */
946struct device_node *of_find_node_with_property(struct device_node *from,
947 const char *prop_name)
948{
949 struct device_node *np;
950 struct property *pp;
951 unsigned long flags;
952
953 raw_spin_lock_irqsave(&devtree_lock, flags);
954 for_each_of_allnodes_from(from, np) {
955 for (pp = np->properties; pp; pp = pp->next) {
956 if (of_prop_cmp(pp->name, prop_name) == 0) {
957 of_node_get(np);
958 goto out;
959 }
960 }
961 }
962out:
963 of_node_put(from);
964 raw_spin_unlock_irqrestore(&devtree_lock, flags);
965 return np;
966}
967EXPORT_SYMBOL(of_find_node_with_property);
968
969static
970const struct of_device_id *__of_match_node(const struct of_device_id *matches,
971 const struct device_node *node)
972{
973 const struct of_device_id *best_match = NULL;
974 int score, best_score = 0;
975
976 if (!matches)
977 return NULL;
978
979 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
980 score = __of_device_is_compatible(node, matches->compatible,
981 matches->type, matches->name);
982 if (score > best_score) {
983 best_match = matches;
984 best_score = score;
985 }
986 }
987
988 return best_match;
989}
990
991/**
992 * of_match_node - Tell if a device_node has a matching of_match structure
993 * @matches: array of of device match structures to search in
994 * @node: the of device structure to match against
995 *
996 * Low level utility function used by device matching.
997 */
998const struct of_device_id *of_match_node(const struct of_device_id *matches,
999 const struct device_node *node)
1000{
1001 const struct of_device_id *match;
1002 unsigned long flags;
1003
1004 raw_spin_lock_irqsave(&devtree_lock, flags);
1005 match = __of_match_node(matches, node);
1006 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1007 return match;
1008}
1009EXPORT_SYMBOL(of_match_node);
1010
1011/**
1012 * of_find_matching_node_and_match - Find a node based on an of_device_id
1013 * match table.
1014 * @from: The node to start searching from or NULL, the node
1015 * you pass will not be searched, only the next one
1016 * will; typically, you pass what the previous call
1017 * returned. of_node_put() will be called on it
1018 * @matches: array of of device match structures to search in
1019 * @match Updated to point at the matches entry which matched
1020 *
1021 * Returns a node pointer with refcount incremented, use
1022 * of_node_put() on it when done.
1023 */
1024struct device_node *of_find_matching_node_and_match(struct device_node *from,
1025 const struct of_device_id *matches,
1026 const struct of_device_id **match)
1027{
1028 struct device_node *np;
1029 const struct of_device_id *m;
1030 unsigned long flags;
1031
1032 if (match)
1033 *match = NULL;
1034
1035 raw_spin_lock_irqsave(&devtree_lock, flags);
1036 for_each_of_allnodes_from(from, np) {
1037 m = __of_match_node(matches, np);
1038 if (m && of_node_get(np)) {
1039 if (match)
1040 *match = m;
1041 break;
1042 }
1043 }
1044 of_node_put(from);
1045 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1046 return np;
1047}
1048EXPORT_SYMBOL(of_find_matching_node_and_match);
1049
1050/**
1051 * of_modalias_node - Lookup appropriate modalias for a device node
1052 * @node: pointer to a device tree node
1053 * @modalias: Pointer to buffer that modalias value will be copied into
1054 * @len: Length of modalias value
1055 *
1056 * Based on the value of the compatible property, this routine will attempt
1057 * to choose an appropriate modalias value for a particular device tree node.
1058 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1059 * from the first entry in the compatible list property.
1060 *
1061 * This routine returns 0 on success, <0 on failure.
1062 */
1063int of_modalias_node(struct device_node *node, char *modalias, int len)
1064{
1065 const char *compatible, *p;
1066 int cplen;
1067
1068 compatible = of_get_property(node, "compatible", &cplen);
1069 if (!compatible || strlen(compatible) > cplen)
1070 return -ENODEV;
1071 p = strchr(compatible, ',');
1072 strlcpy(modalias, p ? p + 1 : compatible, len);
1073 return 0;
1074}
1075EXPORT_SYMBOL_GPL(of_modalias_node);
1076
1077/**
1078 * of_find_node_by_phandle - Find a node given a phandle
1079 * @handle: phandle of the node to find
1080 *
1081 * Returns a node pointer with refcount incremented, use
1082 * of_node_put() on it when done.
1083 */
1084struct device_node *of_find_node_by_phandle(phandle handle)
1085{
1086 struct device_node *np = NULL;
1087 unsigned long flags;
1088 phandle masked_handle;
1089
1090 if (!handle)
1091 return NULL;
1092
1093 raw_spin_lock_irqsave(&devtree_lock, flags);
1094
1095 masked_handle = handle & phandle_cache_mask;
1096
1097 if (phandle_cache) {
1098 if (phandle_cache[masked_handle] &&
1099 handle == phandle_cache[masked_handle]->phandle)
1100 np = phandle_cache[masked_handle];
1101 }
1102
1103 if (!np) {
1104 for_each_of_allnodes(np)
1105 if (np->phandle == handle) {
1106 if (phandle_cache)
1107 phandle_cache[masked_handle] = np;
1108 break;
1109 }
1110 }
1111
1112 of_node_get(np);
1113 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1114 return np;
1115}
1116EXPORT_SYMBOL(of_find_node_by_phandle);
1117
1118void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1119{
1120 int i;
1121 printk("%s %pOF", msg, args->np);
1122 for (i = 0; i < args->args_count; i++) {
1123 const char delim = i ? ',' : ':';
1124
1125 pr_cont("%c%08x", delim, args->args[i]);
1126 }
1127 pr_cont("\n");
1128}
1129
1130int of_phandle_iterator_init(struct of_phandle_iterator *it,
1131 const struct device_node *np,
1132 const char *list_name,
1133 const char *cells_name,
1134 int cell_count)
1135{
1136 const __be32 *list;
1137 int size;
1138
1139 memset(it, 0, sizeof(*it));
1140
1141 list = of_get_property(np, list_name, &size);
1142 if (!list)
1143 return -ENOENT;
1144
1145 it->cells_name = cells_name;
1146 it->cell_count = cell_count;
1147 it->parent = np;
1148 it->list_end = list + size / sizeof(*list);
1149 it->phandle_end = list;
1150 it->cur = list;
1151
1152 return 0;
1153}
1154EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
1155
1156int of_phandle_iterator_next(struct of_phandle_iterator *it)
1157{
1158 uint32_t count = 0;
1159
1160 if (it->node) {
1161 of_node_put(it->node);
1162 it->node = NULL;
1163 }
1164
1165 if (!it->cur || it->phandle_end >= it->list_end)
1166 return -ENOENT;
1167
1168 it->cur = it->phandle_end;
1169
1170 /* If phandle is 0, then it is an empty entry with no arguments. */
1171 it->phandle = be32_to_cpup(it->cur++);
1172
1173 if (it->phandle) {
1174
1175 /*
1176 * Find the provider node and parse the #*-cells property to
1177 * determine the argument length.
1178 */
1179 it->node = of_find_node_by_phandle(it->phandle);
1180
1181 if (it->cells_name) {
1182 if (!it->node) {
1183 pr_err("%pOF: could not find phandle\n",
1184 it->parent);
1185 goto err;
1186 }
1187
1188 if (of_property_read_u32(it->node, it->cells_name,
1189 &count)) {
1190 pr_err("%pOF: could not get %s for %pOF\n",
1191 it->parent,
1192 it->cells_name,
1193 it->node);
1194 goto err;
1195 }
1196 } else {
1197 count = it->cell_count;
1198 }
1199
1200 /*
1201 * Make sure that the arguments actually fit in the remaining
1202 * property data length
1203 */
1204 if (it->cur + count > it->list_end) {
1205 pr_err("%pOF: arguments longer than property\n",
1206 it->parent);
1207 goto err;
1208 }
1209 }
1210
1211 it->phandle_end = it->cur + count;
1212 it->cur_count = count;
1213
1214 return 0;
1215
1216err:
1217 if (it->node) {
1218 of_node_put(it->node);
1219 it->node = NULL;
1220 }
1221
1222 return -EINVAL;
1223}
1224EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
1225
1226int of_phandle_iterator_args(struct of_phandle_iterator *it,
1227 uint32_t *args,
1228 int size)
1229{
1230 int i, count;
1231
1232 count = it->cur_count;
1233
1234 if (WARN_ON(size < count))
1235 count = size;
1236
1237 for (i = 0; i < count; i++)
1238 args[i] = be32_to_cpup(it->cur++);
1239
1240 return count;
1241}
1242
1243static int __of_parse_phandle_with_args(const struct device_node *np,
1244 const char *list_name,
1245 const char *cells_name,
1246 int cell_count, int index,
1247 struct of_phandle_args *out_args)
1248{
1249 struct of_phandle_iterator it;
1250 int rc, cur_index = 0;
1251
1252 /* Loop over the phandles until all the requested entry is found */
1253 of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1254 /*
1255 * All of the error cases bail out of the loop, so at
1256 * this point, the parsing is successful. If the requested
1257 * index matches, then fill the out_args structure and return,
1258 * or return -ENOENT for an empty entry.
1259 */
1260 rc = -ENOENT;
1261 if (cur_index == index) {
1262 if (!it.phandle)
1263 goto err;
1264
1265 if (out_args) {
1266 int c;
1267
1268 c = of_phandle_iterator_args(&it,
1269 out_args->args,
1270 MAX_PHANDLE_ARGS);
1271 out_args->np = it.node;
1272 out_args->args_count = c;
1273 } else {
1274 of_node_put(it.node);
1275 }
1276
1277 /* Found it! return success */
1278 return 0;
1279 }
1280
1281 cur_index++;
1282 }
1283
1284 /*
1285 * Unlock node before returning result; will be one of:
1286 * -ENOENT : index is for empty phandle
1287 * -EINVAL : parsing error on data
1288 */
1289
1290 err:
1291 of_node_put(it.node);
1292 return rc;
1293}
1294
1295/**
1296 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1297 * @np: Pointer to device node holding phandle property
1298 * @phandle_name: Name of property holding a phandle value
1299 * @index: For properties holding a table of phandles, this is the index into
1300 * the table
1301 *
1302 * Returns the device_node pointer with refcount incremented. Use
1303 * of_node_put() on it when done.
1304 */
1305struct device_node *of_parse_phandle(const struct device_node *np,
1306 const char *phandle_name, int index)
1307{
1308 struct of_phandle_args args;
1309
1310 if (index < 0)
1311 return NULL;
1312
1313 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1314 index, &args))
1315 return NULL;
1316
1317 return args.np;
1318}
1319EXPORT_SYMBOL(of_parse_phandle);
1320
1321/**
1322 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1323 * @np: pointer to a device tree node containing a list
1324 * @list_name: property name that contains a list
1325 * @cells_name: property name that specifies phandles' arguments count
1326 * @index: index of a phandle to parse out
1327 * @out_args: optional pointer to output arguments structure (will be filled)
1328 *
1329 * This function is useful to parse lists of phandles and their arguments.
1330 * Returns 0 on success and fills out_args, on error returns appropriate
1331 * errno value.
1332 *
1333 * Caller is responsible to call of_node_put() on the returned out_args->np
1334 * pointer.
1335 *
1336 * Example:
1337 *
1338 * phandle1: node1 {
1339 * #list-cells = <2>;
1340 * }
1341 *
1342 * phandle2: node2 {
1343 * #list-cells = <1>;
1344 * }
1345 *
1346 * node3 {
1347 * list = <&phandle1 1 2 &phandle2 3>;
1348 * }
1349 *
1350 * To get a device_node of the `node2' node you may call this:
1351 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1352 */
1353int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1354 const char *cells_name, int index,
1355 struct of_phandle_args *out_args)
1356{
1357 if (index < 0)
1358 return -EINVAL;
1359 return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
1360 index, out_args);
1361}
1362EXPORT_SYMBOL(of_parse_phandle_with_args);
1363
1364/**
1365 * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
1366 * @np: pointer to a device tree node containing a list
1367 * @list_name: property name that contains a list
1368 * @stem_name: stem of property names that specify phandles' arguments count
1369 * @index: index of a phandle to parse out
1370 * @out_args: optional pointer to output arguments structure (will be filled)
1371 *
1372 * This function is useful to parse lists of phandles and their arguments.
1373 * Returns 0 on success and fills out_args, on error returns appropriate errno
1374 * value. The difference between this function and of_parse_phandle_with_args()
1375 * is that this API remaps a phandle if the node the phandle points to has
1376 * a <@stem_name>-map property.
1377 *
1378 * Caller is responsible to call of_node_put() on the returned out_args->np
1379 * pointer.
1380 *
1381 * Example:
1382 *
1383 * phandle1: node1 {
1384 * #list-cells = <2>;
1385 * }
1386 *
1387 * phandle2: node2 {
1388 * #list-cells = <1>;
1389 * }
1390 *
1391 * phandle3: node3 {
1392 * #list-cells = <1>;
1393 * list-map = <0 &phandle2 3>,
1394 * <1 &phandle2 2>,
1395 * <2 &phandle1 5 1>;
1396 * list-map-mask = <0x3>;
1397 * };
1398 *
1399 * node4 {
1400 * list = <&phandle1 1 2 &phandle3 0>;
1401 * }
1402 *
1403 * To get a device_node of the `node2' node you may call this:
1404 * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
1405 */
1406int of_parse_phandle_with_args_map(const struct device_node *np,
1407 const char *list_name,
1408 const char *stem_name,
1409 int index, struct of_phandle_args *out_args)
1410{
1411 char *cells_name, *map_name = NULL, *mask_name = NULL;
1412 char *pass_name = NULL;
1413 struct device_node *cur, *new = NULL;
1414 const __be32 *map, *mask, *pass;
1415 static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
1416 static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 };
1417 __be32 initial_match_array[MAX_PHANDLE_ARGS];
1418 const __be32 *match_array = initial_match_array;
1419 int i, ret, map_len, match;
1420 u32 list_size, new_size;
1421
1422 if (index < 0)
1423 return -EINVAL;
1424
1425 cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
1426 if (!cells_name)
1427 return -ENOMEM;
1428
1429 ret = -ENOMEM;
1430 map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
1431 if (!map_name)
1432 goto free;
1433
1434 mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
1435 if (!mask_name)
1436 goto free;
1437
1438 pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
1439 if (!pass_name)
1440 goto free;
1441
1442 ret = __of_parse_phandle_with_args(np, list_name, cells_name, 0, index,
1443 out_args);
1444 if (ret)
1445 goto free;
1446
1447 /* Get the #<list>-cells property */
1448 cur = out_args->np;
1449 ret = of_property_read_u32(cur, cells_name, &list_size);
1450 if (ret < 0)
1451 goto put;
1452
1453 /* Precalculate the match array - this simplifies match loop */
1454 for (i = 0; i < list_size; i++)
1455 initial_match_array[i] = cpu_to_be32(out_args->args[i]);
1456
1457 ret = -EINVAL;
1458 while (cur) {
1459 /* Get the <list>-map property */
1460 map = of_get_property(cur, map_name, &map_len);
1461 if (!map) {
1462 ret = 0;
1463 goto free;
1464 }
1465 map_len /= sizeof(u32);
1466
1467 /* Get the <list>-map-mask property (optional) */
1468 mask = of_get_property(cur, mask_name, NULL);
1469 if (!mask)
1470 mask = dummy_mask;
1471 /* Iterate through <list>-map property */
1472 match = 0;
1473 while (map_len > (list_size + 1) && !match) {
1474 /* Compare specifiers */
1475 match = 1;
1476 for (i = 0; i < list_size; i++, map_len--)
1477 match &= !((match_array[i] ^ *map++) & mask[i]);
1478
1479 of_node_put(new);
1480 new = of_find_node_by_phandle(be32_to_cpup(map));
1481 map++;
1482 map_len--;
1483
1484 /* Check if not found */
1485 if (!new)
1486 goto put;
1487
1488 if (!of_device_is_available(new))
1489 match = 0;
1490
1491 ret = of_property_read_u32(new, cells_name, &new_size);
1492 if (ret)
1493 goto put;
1494
1495 /* Check for malformed properties */
1496 if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
1497 goto put;
1498 if (map_len < new_size)
1499 goto put;
1500
1501 /* Move forward by new node's #<list>-cells amount */
1502 map += new_size;
1503 map_len -= new_size;
1504 }
1505 if (!match)
1506 goto put;
1507
1508 /* Get the <list>-map-pass-thru property (optional) */
1509 pass = of_get_property(cur, pass_name, NULL);
1510 if (!pass)
1511 pass = dummy_pass;
1512
1513 /*
1514 * Successfully parsed a <list>-map translation; copy new
1515 * specifier into the out_args structure, keeping the
1516 * bits specified in <list>-map-pass-thru.
1517 */
1518 match_array = map - new_size;
1519 for (i = 0; i < new_size; i++) {
1520 __be32 val = *(map - new_size + i);
1521
1522 if (i < list_size) {
1523 val &= ~pass[i];
1524 val |= cpu_to_be32(out_args->args[i]) & pass[i];
1525 }
1526
1527 out_args->args[i] = be32_to_cpu(val);
1528 }
1529 out_args->args_count = list_size = new_size;
1530 /* Iterate again with new provider */
1531 out_args->np = new;
1532 of_node_put(cur);
1533 cur = new;
1534 }
1535put:
1536 of_node_put(cur);
1537 of_node_put(new);
1538free:
1539 kfree(mask_name);
1540 kfree(map_name);
1541 kfree(cells_name);
1542 kfree(pass_name);
1543
1544 return ret;
1545}
1546EXPORT_SYMBOL(of_parse_phandle_with_args_map);
1547
1548/**
1549 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1550 * @np: pointer to a device tree node containing a list
1551 * @list_name: property name that contains a list
1552 * @cell_count: number of argument cells following the phandle
1553 * @index: index of a phandle to parse out
1554 * @out_args: optional pointer to output arguments structure (will be filled)
1555 *
1556 * This function is useful to parse lists of phandles and their arguments.
1557 * Returns 0 on success and fills out_args, on error returns appropriate
1558 * errno value.
1559 *
1560 * Caller is responsible to call of_node_put() on the returned out_args->np
1561 * pointer.
1562 *
1563 * Example:
1564 *
1565 * phandle1: node1 {
1566 * }
1567 *
1568 * phandle2: node2 {
1569 * }
1570 *
1571 * node3 {
1572 * list = <&phandle1 0 2 &phandle2 2 3>;
1573 * }
1574 *
1575 * To get a device_node of the `node2' node you may call this:
1576 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1577 */
1578int of_parse_phandle_with_fixed_args(const struct device_node *np,
1579 const char *list_name, int cell_count,
1580 int index, struct of_phandle_args *out_args)
1581{
1582 if (index < 0)
1583 return -EINVAL;
1584 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1585 index, out_args);
1586}
1587EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1588
1589/**
1590 * of_count_phandle_with_args() - Find the number of phandles references in a property
1591 * @np: pointer to a device tree node containing a list
1592 * @list_name: property name that contains a list
1593 * @cells_name: property name that specifies phandles' arguments count
1594 *
1595 * Returns the number of phandle + argument tuples within a property. It
1596 * is a typical pattern to encode a list of phandle and variable
1597 * arguments into a single property. The number of arguments is encoded
1598 * by a property in the phandle-target node. For example, a gpios
1599 * property would contain a list of GPIO specifies consisting of a
1600 * phandle and 1 or more arguments. The number of arguments are
1601 * determined by the #gpio-cells property in the node pointed to by the
1602 * phandle.
1603 */
1604int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1605 const char *cells_name)
1606{
1607 struct of_phandle_iterator it;
1608 int rc, cur_index = 0;
1609
1610 rc = of_phandle_iterator_init(&it, np, list_name, cells_name, 0);
1611 if (rc)
1612 return rc;
1613
1614 while ((rc = of_phandle_iterator_next(&it)) == 0)
1615 cur_index += 1;
1616
1617 if (rc != -ENOENT)
1618 return rc;
1619
1620 return cur_index;
1621}
1622EXPORT_SYMBOL(of_count_phandle_with_args);
1623
1624/**
1625 * __of_add_property - Add a property to a node without lock operations
1626 */
1627int __of_add_property(struct device_node *np, struct property *prop)
1628{
1629 struct property **next;
1630
1631 prop->next = NULL;
1632 next = &np->properties;
1633 while (*next) {
1634 if (strcmp(prop->name, (*next)->name) == 0)
1635 /* duplicate ! don't insert it */
1636 return -EEXIST;
1637
1638 next = &(*next)->next;
1639 }
1640 *next = prop;
1641
1642 return 0;
1643}
1644
1645/**
1646 * of_add_property - Add a property to a node
1647 */
1648int of_add_property(struct device_node *np, struct property *prop)
1649{
1650 unsigned long flags;
1651 int rc;
1652
1653 mutex_lock(&of_mutex);
1654
1655 raw_spin_lock_irqsave(&devtree_lock, flags);
1656 rc = __of_add_property(np, prop);
1657 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1658
1659 if (!rc)
1660 __of_add_property_sysfs(np, prop);
1661
1662 mutex_unlock(&of_mutex);
1663
1664 if (!rc)
1665 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1666
1667 return rc;
1668}
1669
1670int __of_remove_property(struct device_node *np, struct property *prop)
1671{
1672 struct property **next;
1673
1674 for (next = &np->properties; *next; next = &(*next)->next) {
1675 if (*next == prop)
1676 break;
1677 }
1678 if (*next == NULL)
1679 return -ENODEV;
1680
1681 /* found the node */
1682 *next = prop->next;
1683 prop->next = np->deadprops;
1684 np->deadprops = prop;
1685
1686 return 0;
1687}
1688
1689/**
1690 * of_remove_property - Remove a property from a node.
1691 *
1692 * Note that we don't actually remove it, since we have given out
1693 * who-knows-how-many pointers to the data using get-property.
1694 * Instead we just move the property to the "dead properties"
1695 * list, so it won't be found any more.
1696 */
1697int of_remove_property(struct device_node *np, struct property *prop)
1698{
1699 unsigned long flags;
1700 int rc;
1701
1702 if (!prop)
1703 return -ENODEV;
1704
1705 mutex_lock(&of_mutex);
1706
1707 raw_spin_lock_irqsave(&devtree_lock, flags);
1708 rc = __of_remove_property(np, prop);
1709 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1710
1711 if (!rc)
1712 __of_remove_property_sysfs(np, prop);
1713
1714 mutex_unlock(&of_mutex);
1715
1716 if (!rc)
1717 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1718
1719 return rc;
1720}
1721
1722int __of_update_property(struct device_node *np, struct property *newprop,
1723 struct property **oldpropp)
1724{
1725 struct property **next, *oldprop;
1726
1727 for (next = &np->properties; *next; next = &(*next)->next) {
1728 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1729 break;
1730 }
1731 *oldpropp = oldprop = *next;
1732
1733 if (oldprop) {
1734 /* replace the node */
1735 newprop->next = oldprop->next;
1736 *next = newprop;
1737 oldprop->next = np->deadprops;
1738 np->deadprops = oldprop;
1739 } else {
1740 /* new node */
1741 newprop->next = NULL;
1742 *next = newprop;
1743 }
1744
1745 return 0;
1746}
1747
1748/*
1749 * of_update_property - Update a property in a node, if the property does
1750 * not exist, add it.
1751 *
1752 * Note that we don't actually remove it, since we have given out
1753 * who-knows-how-many pointers to the data using get-property.
1754 * Instead we just move the property to the "dead properties" list,
1755 * and add the new property to the property list
1756 */
1757int of_update_property(struct device_node *np, struct property *newprop)
1758{
1759 struct property *oldprop;
1760 unsigned long flags;
1761 int rc;
1762
1763 if (!newprop->name)
1764 return -EINVAL;
1765
1766 mutex_lock(&of_mutex);
1767
1768 raw_spin_lock_irqsave(&devtree_lock, flags);
1769 rc = __of_update_property(np, newprop, &oldprop);
1770 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1771
1772 if (!rc)
1773 __of_update_property_sysfs(np, newprop, oldprop);
1774
1775 mutex_unlock(&of_mutex);
1776
1777 if (!rc)
1778 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1779
1780 return rc;
1781}
1782
1783static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1784 int id, const char *stem, int stem_len)
1785{
1786 ap->np = np;
1787 ap->id = id;
1788 strncpy(ap->stem, stem, stem_len);
1789 ap->stem[stem_len] = 0;
1790 list_add_tail(&ap->link, &aliases_lookup);
1791 pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
1792 ap->alias, ap->stem, ap->id, np);
1793}
1794
1795/**
1796 * of_alias_scan - Scan all properties of the 'aliases' node
1797 *
1798 * The function scans all the properties of the 'aliases' node and populates
1799 * the global lookup table with the properties. It returns the
1800 * number of alias properties found, or an error code in case of failure.
1801 *
1802 * @dt_alloc: An allocator that provides a virtual address to memory
1803 * for storing the resulting tree
1804 */
1805void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1806{
1807 struct property *pp;
1808
1809 of_aliases = of_find_node_by_path("/aliases");
1810 of_chosen = of_find_node_by_path("/chosen");
1811 if (of_chosen == NULL)
1812 of_chosen = of_find_node_by_path("/chosen@0");
1813
1814 if (of_chosen) {
1815 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1816 const char *name = NULL;
1817
1818 if (of_property_read_string(of_chosen, "stdout-path", &name))
1819 of_property_read_string(of_chosen, "linux,stdout-path",
1820 &name);
1821 if (IS_ENABLED(CONFIG_PPC) && !name)
1822 of_property_read_string(of_aliases, "stdout", &name);
1823 if (name)
1824 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1825 }
1826
1827 if (!of_aliases)
1828 return;
1829
1830 for_each_property_of_node(of_aliases, pp) {
1831 const char *start = pp->name;
1832 const char *end = start + strlen(start);
1833 struct device_node *np;
1834 struct alias_prop *ap;
1835 int id, len;
1836
1837 /* Skip those we do not want to proceed */
1838 if (!strcmp(pp->name, "name") ||
1839 !strcmp(pp->name, "phandle") ||
1840 !strcmp(pp->name, "linux,phandle"))
1841 continue;
1842
1843 np = of_find_node_by_path(pp->value);
1844 if (!np)
1845 continue;
1846
1847 /* walk the alias backwards to extract the id and work out
1848 * the 'stem' string */
1849 while (isdigit(*(end-1)) && end > start)
1850 end--;
1851 len = end - start;
1852
1853 if (kstrtoint(end, 10, &id) < 0)
1854 continue;
1855
1856 /* Allocate an alias_prop with enough space for the stem */
1857 ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
1858 if (!ap)
1859 continue;
1860 memset(ap, 0, sizeof(*ap) + len + 1);
1861 ap->alias = start;
1862 of_alias_add(ap, np, id, start, len);
1863 }
1864}
1865
1866/**
1867 * of_alias_get_id - Get alias id for the given device_node
1868 * @np: Pointer to the given device_node
1869 * @stem: Alias stem of the given device_node
1870 *
1871 * The function travels the lookup table to get the alias id for the given
1872 * device_node and alias stem. It returns the alias id if found.
1873 */
1874int of_alias_get_id(struct device_node *np, const char *stem)
1875{
1876 struct alias_prop *app;
1877 int id = -ENODEV;
1878
1879 mutex_lock(&of_mutex);
1880 list_for_each_entry(app, &aliases_lookup, link) {
1881 if (strcmp(app->stem, stem) != 0)
1882 continue;
1883
1884 if (np == app->np) {
1885 id = app->id;
1886 break;
1887 }
1888 }
1889 mutex_unlock(&of_mutex);
1890
1891 return id;
1892}
1893EXPORT_SYMBOL_GPL(of_alias_get_id);
1894
1895/**
1896 * of_alias_get_highest_id - Get highest alias id for the given stem
1897 * @stem: Alias stem to be examined
1898 *
1899 * The function travels the lookup table to get the highest alias id for the
1900 * given alias stem. It returns the alias id if found.
1901 */
1902int of_alias_get_highest_id(const char *stem)
1903{
1904 struct alias_prop *app;
1905 int id = -ENODEV;
1906
1907 mutex_lock(&of_mutex);
1908 list_for_each_entry(app, &aliases_lookup, link) {
1909 if (strcmp(app->stem, stem) != 0)
1910 continue;
1911
1912 if (app->id > id)
1913 id = app->id;
1914 }
1915 mutex_unlock(&of_mutex);
1916
1917 return id;
1918}
1919EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
1920
1921/**
1922 * of_console_check() - Test and setup console for DT setup
1923 * @dn - Pointer to device node
1924 * @name - Name to use for preferred console without index. ex. "ttyS"
1925 * @index - Index to use for preferred console.
1926 *
1927 * Check if the given device node matches the stdout-path property in the
1928 * /chosen node. If it does then register it as the preferred console and return
1929 * TRUE. Otherwise return FALSE.
1930 */
1931bool of_console_check(struct device_node *dn, char *name, int index)
1932{
1933 if (!dn || dn != of_stdout || console_set_on_cmdline)
1934 return false;
1935
1936 /*
1937 * XXX: cast `options' to char pointer to suppress complication
1938 * warnings: printk, UART and console drivers expect char pointer.
1939 */
1940 return !add_preferred_console(name, index, (char *)of_stdout_options);
1941}
1942EXPORT_SYMBOL_GPL(of_console_check);
1943
1944/**
1945 * of_find_next_cache_node - Find a node's subsidiary cache
1946 * @np: node of type "cpu" or "cache"
1947 *
1948 * Returns a node pointer with refcount incremented, use
1949 * of_node_put() on it when done. Caller should hold a reference
1950 * to np.
1951 */
1952struct device_node *of_find_next_cache_node(const struct device_node *np)
1953{
1954 struct device_node *child, *cache_node;
1955
1956 cache_node = of_parse_phandle(np, "l2-cache", 0);
1957 if (!cache_node)
1958 cache_node = of_parse_phandle(np, "next-level-cache", 0);
1959
1960 if (cache_node)
1961 return cache_node;
1962
1963 /* OF on pmac has nodes instead of properties named "l2-cache"
1964 * beneath CPU nodes.
1965 */
1966 if (!strcmp(np->type, "cpu"))
1967 for_each_child_of_node(np, child)
1968 if (!strcmp(child->type, "cache"))
1969 return child;
1970
1971 return NULL;
1972}
1973
1974/**
1975 * of_find_last_cache_level - Find the level at which the last cache is
1976 * present for the given logical cpu
1977 *
1978 * @cpu: cpu number(logical index) for which the last cache level is needed
1979 *
1980 * Returns the the level at which the last cache is present. It is exactly
1981 * same as the total number of cache levels for the given logical cpu.
1982 */
1983int of_find_last_cache_level(unsigned int cpu)
1984{
1985 u32 cache_level = 0;
1986 struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
1987
1988 while (np) {
1989 prev = np;
1990 of_node_put(np);
1991 np = of_find_next_cache_node(np);
1992 }
1993
1994 of_property_read_u32(prev, "cache-level", &cache_level);
1995
1996 return cache_level;
1997}