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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Support for dynamic device trees.
4 *
5 * On some platforms, the device tree can be manipulated at runtime.
6 * The routines in this section support adding, removing and changing
7 * device tree nodes.
8 */
9
10#define pr_fmt(fmt) "OF: " fmt
11
12#include <linux/of.h>
13#include <linux/spinlock.h>
14#include <linux/slab.h>
15#include <linux/string.h>
16#include <linux/proc_fs.h>
17
18#include "of_private.h"
19
20static struct device_node *kobj_to_device_node(struct kobject *kobj)
21{
22 return container_of(kobj, struct device_node, kobj);
23}
24
25/**
26 * of_node_get() - Increment refcount of a node
27 * @node: Node to inc refcount, NULL is supported to simplify writing of
28 * callers
29 *
30 * Return: The node with refcount incremented.
31 */
32struct device_node *of_node_get(struct device_node *node)
33{
34 if (node)
35 kobject_get(&node->kobj);
36 return node;
37}
38EXPORT_SYMBOL(of_node_get);
39
40/**
41 * of_node_put() - Decrement refcount of a node
42 * @node: Node to dec refcount, NULL is supported to simplify writing of
43 * callers
44 */
45void of_node_put(struct device_node *node)
46{
47 if (node)
48 kobject_put(&node->kobj);
49}
50EXPORT_SYMBOL(of_node_put);
51
52static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
53
54int of_reconfig_notifier_register(struct notifier_block *nb)
55{
56 return blocking_notifier_chain_register(&of_reconfig_chain, nb);
57}
58EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
59
60int of_reconfig_notifier_unregister(struct notifier_block *nb)
61{
62 return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
63}
64EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
65
66#ifdef DEBUG
67const char *action_names[] = {
68 [OF_RECONFIG_ATTACH_NODE] = "ATTACH_NODE",
69 [OF_RECONFIG_DETACH_NODE] = "DETACH_NODE",
70 [OF_RECONFIG_ADD_PROPERTY] = "ADD_PROPERTY",
71 [OF_RECONFIG_REMOVE_PROPERTY] = "REMOVE_PROPERTY",
72 [OF_RECONFIG_UPDATE_PROPERTY] = "UPDATE_PROPERTY",
73};
74#endif
75
76int of_reconfig_notify(unsigned long action, struct of_reconfig_data *p)
77{
78 int rc;
79#ifdef DEBUG
80 struct of_reconfig_data *pr = p;
81
82 switch (action) {
83 case OF_RECONFIG_ATTACH_NODE:
84 case OF_RECONFIG_DETACH_NODE:
85 pr_debug("notify %-15s %pOF\n", action_names[action],
86 pr->dn);
87 break;
88 case OF_RECONFIG_ADD_PROPERTY:
89 case OF_RECONFIG_REMOVE_PROPERTY:
90 case OF_RECONFIG_UPDATE_PROPERTY:
91 pr_debug("notify %-15s %pOF:%s\n", action_names[action],
92 pr->dn, pr->prop->name);
93 break;
94
95 }
96#endif
97 rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
98 return notifier_to_errno(rc);
99}
100
101/*
102 * of_reconfig_get_state_change() - Returns new state of device
103 * @action - action of the of notifier
104 * @arg - argument of the of notifier
105 *
106 * Returns the new state of a device based on the notifier used.
107 *
108 * Return: 0 on device going from enabled to disabled, 1 on device
109 * going from disabled to enabled and -1 on no change.
110 */
111int of_reconfig_get_state_change(unsigned long action, struct of_reconfig_data *pr)
112{
113 struct property *prop, *old_prop = NULL;
114 int is_status, status_state, old_status_state, prev_state, new_state;
115
116 /* figure out if a device should be created or destroyed */
117 switch (action) {
118 case OF_RECONFIG_ATTACH_NODE:
119 case OF_RECONFIG_DETACH_NODE:
120 prop = of_find_property(pr->dn, "status", NULL);
121 break;
122 case OF_RECONFIG_ADD_PROPERTY:
123 case OF_RECONFIG_REMOVE_PROPERTY:
124 prop = pr->prop;
125 break;
126 case OF_RECONFIG_UPDATE_PROPERTY:
127 prop = pr->prop;
128 old_prop = pr->old_prop;
129 break;
130 default:
131 return OF_RECONFIG_NO_CHANGE;
132 }
133
134 is_status = 0;
135 status_state = -1;
136 old_status_state = -1;
137 prev_state = -1;
138 new_state = -1;
139
140 if (prop && !strcmp(prop->name, "status")) {
141 is_status = 1;
142 status_state = !strcmp(prop->value, "okay") ||
143 !strcmp(prop->value, "ok");
144 if (old_prop)
145 old_status_state = !strcmp(old_prop->value, "okay") ||
146 !strcmp(old_prop->value, "ok");
147 }
148
149 switch (action) {
150 case OF_RECONFIG_ATTACH_NODE:
151 prev_state = 0;
152 /* -1 & 0 status either missing or okay */
153 new_state = status_state != 0;
154 break;
155 case OF_RECONFIG_DETACH_NODE:
156 /* -1 & 0 status either missing or okay */
157 prev_state = status_state != 0;
158 new_state = 0;
159 break;
160 case OF_RECONFIG_ADD_PROPERTY:
161 if (is_status) {
162 /* no status property -> enabled (legacy) */
163 prev_state = 1;
164 new_state = status_state;
165 }
166 break;
167 case OF_RECONFIG_REMOVE_PROPERTY:
168 if (is_status) {
169 prev_state = status_state;
170 /* no status property -> enabled (legacy) */
171 new_state = 1;
172 }
173 break;
174 case OF_RECONFIG_UPDATE_PROPERTY:
175 if (is_status) {
176 prev_state = old_status_state != 0;
177 new_state = status_state != 0;
178 }
179 break;
180 }
181
182 if (prev_state == new_state)
183 return OF_RECONFIG_NO_CHANGE;
184
185 return new_state ? OF_RECONFIG_CHANGE_ADD : OF_RECONFIG_CHANGE_REMOVE;
186}
187EXPORT_SYMBOL_GPL(of_reconfig_get_state_change);
188
189int of_property_notify(int action, struct device_node *np,
190 struct property *prop, struct property *oldprop)
191{
192 struct of_reconfig_data pr;
193
194 /* only call notifiers if the node is attached */
195 if (!of_node_is_attached(np))
196 return 0;
197
198 pr.dn = np;
199 pr.prop = prop;
200 pr.old_prop = oldprop;
201 return of_reconfig_notify(action, &pr);
202}
203
204static void __of_attach_node(struct device_node *np)
205{
206 const __be32 *phandle;
207 int sz;
208
209 if (!of_node_check_flag(np, OF_OVERLAY)) {
210 np->name = __of_get_property(np, "name", NULL);
211 if (!np->name)
212 np->name = "<NULL>";
213
214 phandle = __of_get_property(np, "phandle", &sz);
215 if (!phandle)
216 phandle = __of_get_property(np, "linux,phandle", &sz);
217 if (IS_ENABLED(CONFIG_PPC_PSERIES) && !phandle)
218 phandle = __of_get_property(np, "ibm,phandle", &sz);
219 if (phandle && (sz >= 4))
220 np->phandle = be32_to_cpup(phandle);
221 else
222 np->phandle = 0;
223 }
224
225 np->child = NULL;
226 np->sibling = np->parent->child;
227 np->parent->child = np;
228 of_node_clear_flag(np, OF_DETACHED);
229}
230
231/**
232 * of_attach_node() - Plug a device node into the tree and global list.
233 * @np: Pointer to the caller's Device Node
234 */
235int of_attach_node(struct device_node *np)
236{
237 struct of_reconfig_data rd;
238 unsigned long flags;
239
240 memset(&rd, 0, sizeof(rd));
241 rd.dn = np;
242
243 mutex_lock(&of_mutex);
244 raw_spin_lock_irqsave(&devtree_lock, flags);
245 __of_attach_node(np);
246 raw_spin_unlock_irqrestore(&devtree_lock, flags);
247
248 __of_attach_node_sysfs(np);
249 mutex_unlock(&of_mutex);
250
251 of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, &rd);
252
253 return 0;
254}
255
256void __of_detach_node(struct device_node *np)
257{
258 struct device_node *parent;
259
260 if (WARN_ON(of_node_check_flag(np, OF_DETACHED)))
261 return;
262
263 parent = np->parent;
264 if (WARN_ON(!parent))
265 return;
266
267 if (parent->child == np)
268 parent->child = np->sibling;
269 else {
270 struct device_node *prevsib;
271 for (prevsib = np->parent->child;
272 prevsib->sibling != np;
273 prevsib = prevsib->sibling)
274 ;
275 prevsib->sibling = np->sibling;
276 }
277
278 of_node_set_flag(np, OF_DETACHED);
279
280 /* race with of_find_node_by_phandle() prevented by devtree_lock */
281 __of_phandle_cache_inv_entry(np->phandle);
282}
283
284/**
285 * of_detach_node() - "Unplug" a node from the device tree.
286 * @np: Pointer to the caller's Device Node
287 */
288int of_detach_node(struct device_node *np)
289{
290 struct of_reconfig_data rd;
291 unsigned long flags;
292
293 memset(&rd, 0, sizeof(rd));
294 rd.dn = np;
295
296 mutex_lock(&of_mutex);
297 raw_spin_lock_irqsave(&devtree_lock, flags);
298 __of_detach_node(np);
299 raw_spin_unlock_irqrestore(&devtree_lock, flags);
300
301 __of_detach_node_sysfs(np);
302 mutex_unlock(&of_mutex);
303
304 of_reconfig_notify(OF_RECONFIG_DETACH_NODE, &rd);
305
306 return 0;
307}
308EXPORT_SYMBOL_GPL(of_detach_node);
309
310static void property_list_free(struct property *prop_list)
311{
312 struct property *prop, *next;
313
314 for (prop = prop_list; prop != NULL; prop = next) {
315 next = prop->next;
316 kfree(prop->name);
317 kfree(prop->value);
318 kfree(prop);
319 }
320}
321
322/**
323 * of_node_release() - release a dynamically allocated node
324 * @kobj: kernel object of the node to be released
325 *
326 * In of_node_put() this function is passed to kref_put() as the destructor.
327 */
328void of_node_release(struct kobject *kobj)
329{
330 struct device_node *node = kobj_to_device_node(kobj);
331
332 /* We should never be releasing nodes that haven't been detached. */
333 if (!of_node_check_flag(node, OF_DETACHED)) {
334 pr_err("ERROR: Bad of_node_put() on %pOF\n", node);
335 dump_stack();
336 return;
337 }
338 if (!of_node_check_flag(node, OF_DYNAMIC))
339 return;
340
341 if (of_node_check_flag(node, OF_OVERLAY)) {
342
343 if (!of_node_check_flag(node, OF_OVERLAY_FREE_CSET)) {
344 /* premature refcount of zero, do not free memory */
345 pr_err("ERROR: memory leak before free overlay changeset, %pOF\n",
346 node);
347 return;
348 }
349
350 /*
351 * If node->properties non-empty then properties were added
352 * to this node either by different overlay that has not
353 * yet been removed, or by a non-overlay mechanism.
354 */
355 if (node->properties)
356 pr_err("ERROR: %s(), unexpected properties in %pOF\n",
357 __func__, node);
358 }
359
360 property_list_free(node->properties);
361 property_list_free(node->deadprops);
362 fwnode_links_purge(of_fwnode_handle(node));
363
364 kfree(node->full_name);
365 kfree(node->data);
366 kfree(node);
367}
368
369/**
370 * __of_prop_dup - Copy a property dynamically.
371 * @prop: Property to copy
372 * @allocflags: Allocation flags (typically pass GFP_KERNEL)
373 *
374 * Copy a property by dynamically allocating the memory of both the
375 * property structure and the property name & contents. The property's
376 * flags have the OF_DYNAMIC bit set so that we can differentiate between
377 * dynamically allocated properties and not.
378 *
379 * Return: The newly allocated property or NULL on out of memory error.
380 */
381struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags)
382{
383 struct property *new;
384
385 new = kzalloc(sizeof(*new), allocflags);
386 if (!new)
387 return NULL;
388
389 /*
390 * NOTE: There is no check for zero length value.
391 * In case of a boolean property, this will allocate a value
392 * of zero bytes. We do this to work around the use
393 * of of_get_property() calls on boolean values.
394 */
395 new->name = kstrdup(prop->name, allocflags);
396 new->value = kmemdup(prop->value, prop->length, allocflags);
397 new->length = prop->length;
398 if (!new->name || !new->value)
399 goto err_free;
400
401 /* mark the property as dynamic */
402 of_property_set_flag(new, OF_DYNAMIC);
403
404 return new;
405
406 err_free:
407 kfree(new->name);
408 kfree(new->value);
409 kfree(new);
410 return NULL;
411}
412
413/**
414 * __of_node_dup() - Duplicate or create an empty device node dynamically.
415 * @np: if not NULL, contains properties to be duplicated in new node
416 * @full_name: string value to be duplicated into new node's full_name field
417 *
418 * Create a device tree node, optionally duplicating the properties of
419 * another node. The node data are dynamically allocated and all the node
420 * flags have the OF_DYNAMIC & OF_DETACHED bits set.
421 *
422 * Return: The newly allocated node or NULL on out of memory error.
423 */
424struct device_node *__of_node_dup(const struct device_node *np,
425 const char *full_name)
426{
427 struct device_node *node;
428
429 node = kzalloc(sizeof(*node), GFP_KERNEL);
430 if (!node)
431 return NULL;
432 node->full_name = kstrdup(full_name, GFP_KERNEL);
433 if (!node->full_name) {
434 kfree(node);
435 return NULL;
436 }
437
438 of_node_set_flag(node, OF_DYNAMIC);
439 of_node_set_flag(node, OF_DETACHED);
440 of_node_init(node);
441
442 /* Iterate over and duplicate all properties */
443 if (np) {
444 struct property *pp, *new_pp;
445 for_each_property_of_node(np, pp) {
446 new_pp = __of_prop_dup(pp, GFP_KERNEL);
447 if (!new_pp)
448 goto err_prop;
449 if (__of_add_property(node, new_pp)) {
450 kfree(new_pp->name);
451 kfree(new_pp->value);
452 kfree(new_pp);
453 goto err_prop;
454 }
455 }
456 }
457 return node;
458
459 err_prop:
460 of_node_put(node); /* Frees the node and properties */
461 return NULL;
462}
463
464static void __of_changeset_entry_destroy(struct of_changeset_entry *ce)
465{
466 if (ce->action == OF_RECONFIG_ATTACH_NODE &&
467 of_node_check_flag(ce->np, OF_OVERLAY)) {
468 if (kref_read(&ce->np->kobj.kref) > 1) {
469 pr_err("ERROR: memory leak, expected refcount 1 instead of %d, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node %pOF\n",
470 kref_read(&ce->np->kobj.kref), ce->np);
471 } else {
472 of_node_set_flag(ce->np, OF_OVERLAY_FREE_CSET);
473 }
474 }
475
476 of_node_put(ce->np);
477 list_del(&ce->node);
478 kfree(ce);
479}
480
481#ifdef DEBUG
482static void __of_changeset_entry_dump(struct of_changeset_entry *ce)
483{
484 switch (ce->action) {
485 case OF_RECONFIG_ADD_PROPERTY:
486 case OF_RECONFIG_REMOVE_PROPERTY:
487 case OF_RECONFIG_UPDATE_PROPERTY:
488 pr_debug("cset<%p> %-15s %pOF/%s\n", ce, action_names[ce->action],
489 ce->np, ce->prop->name);
490 break;
491 case OF_RECONFIG_ATTACH_NODE:
492 case OF_RECONFIG_DETACH_NODE:
493 pr_debug("cset<%p> %-15s %pOF\n", ce, action_names[ce->action],
494 ce->np);
495 break;
496 }
497}
498#else
499static inline void __of_changeset_entry_dump(struct of_changeset_entry *ce)
500{
501 /* empty */
502}
503#endif
504
505static void __of_changeset_entry_invert(struct of_changeset_entry *ce,
506 struct of_changeset_entry *rce)
507{
508 memcpy(rce, ce, sizeof(*rce));
509
510 switch (ce->action) {
511 case OF_RECONFIG_ATTACH_NODE:
512 rce->action = OF_RECONFIG_DETACH_NODE;
513 break;
514 case OF_RECONFIG_DETACH_NODE:
515 rce->action = OF_RECONFIG_ATTACH_NODE;
516 break;
517 case OF_RECONFIG_ADD_PROPERTY:
518 rce->action = OF_RECONFIG_REMOVE_PROPERTY;
519 break;
520 case OF_RECONFIG_REMOVE_PROPERTY:
521 rce->action = OF_RECONFIG_ADD_PROPERTY;
522 break;
523 case OF_RECONFIG_UPDATE_PROPERTY:
524 rce->old_prop = ce->prop;
525 rce->prop = ce->old_prop;
526 /* update was used but original property did not exist */
527 if (!rce->prop) {
528 rce->action = OF_RECONFIG_REMOVE_PROPERTY;
529 rce->prop = ce->prop;
530 }
531 break;
532 }
533}
534
535static int __of_changeset_entry_notify(struct of_changeset_entry *ce,
536 bool revert)
537{
538 struct of_reconfig_data rd;
539 struct of_changeset_entry ce_inverted;
540 int ret = 0;
541
542 if (revert) {
543 __of_changeset_entry_invert(ce, &ce_inverted);
544 ce = &ce_inverted;
545 }
546
547 switch (ce->action) {
548 case OF_RECONFIG_ATTACH_NODE:
549 case OF_RECONFIG_DETACH_NODE:
550 memset(&rd, 0, sizeof(rd));
551 rd.dn = ce->np;
552 ret = of_reconfig_notify(ce->action, &rd);
553 break;
554 case OF_RECONFIG_ADD_PROPERTY:
555 case OF_RECONFIG_REMOVE_PROPERTY:
556 case OF_RECONFIG_UPDATE_PROPERTY:
557 ret = of_property_notify(ce->action, ce->np, ce->prop, ce->old_prop);
558 break;
559 default:
560 pr_err("invalid devicetree changeset action: %i\n",
561 (int)ce->action);
562 ret = -EINVAL;
563 }
564
565 if (ret)
566 pr_err("changeset notifier error @%pOF\n", ce->np);
567 return ret;
568}
569
570static int __of_changeset_entry_apply(struct of_changeset_entry *ce)
571{
572 struct property *old_prop, **propp;
573 unsigned long flags;
574 int ret = 0;
575
576 __of_changeset_entry_dump(ce);
577
578 raw_spin_lock_irqsave(&devtree_lock, flags);
579 switch (ce->action) {
580 case OF_RECONFIG_ATTACH_NODE:
581 __of_attach_node(ce->np);
582 break;
583 case OF_RECONFIG_DETACH_NODE:
584 __of_detach_node(ce->np);
585 break;
586 case OF_RECONFIG_ADD_PROPERTY:
587 /* If the property is in deadprops then it must be removed */
588 for (propp = &ce->np->deadprops; *propp; propp = &(*propp)->next) {
589 if (*propp == ce->prop) {
590 *propp = ce->prop->next;
591 ce->prop->next = NULL;
592 break;
593 }
594 }
595
596 ret = __of_add_property(ce->np, ce->prop);
597 if (ret) {
598 pr_err("changeset: add_property failed @%pOF/%s\n",
599 ce->np,
600 ce->prop->name);
601 break;
602 }
603 break;
604 case OF_RECONFIG_REMOVE_PROPERTY:
605 ret = __of_remove_property(ce->np, ce->prop);
606 if (ret) {
607 pr_err("changeset: remove_property failed @%pOF/%s\n",
608 ce->np,
609 ce->prop->name);
610 break;
611 }
612 break;
613
614 case OF_RECONFIG_UPDATE_PROPERTY:
615 /* If the property is in deadprops then it must be removed */
616 for (propp = &ce->np->deadprops; *propp; propp = &(*propp)->next) {
617 if (*propp == ce->prop) {
618 *propp = ce->prop->next;
619 ce->prop->next = NULL;
620 break;
621 }
622 }
623
624 ret = __of_update_property(ce->np, ce->prop, &old_prop);
625 if (ret) {
626 pr_err("changeset: update_property failed @%pOF/%s\n",
627 ce->np,
628 ce->prop->name);
629 break;
630 }
631 break;
632 default:
633 ret = -EINVAL;
634 }
635 raw_spin_unlock_irqrestore(&devtree_lock, flags);
636
637 if (ret)
638 return ret;
639
640 switch (ce->action) {
641 case OF_RECONFIG_ATTACH_NODE:
642 __of_attach_node_sysfs(ce->np);
643 break;
644 case OF_RECONFIG_DETACH_NODE:
645 __of_detach_node_sysfs(ce->np);
646 break;
647 case OF_RECONFIG_ADD_PROPERTY:
648 /* ignore duplicate names */
649 __of_add_property_sysfs(ce->np, ce->prop);
650 break;
651 case OF_RECONFIG_REMOVE_PROPERTY:
652 __of_remove_property_sysfs(ce->np, ce->prop);
653 break;
654 case OF_RECONFIG_UPDATE_PROPERTY:
655 __of_update_property_sysfs(ce->np, ce->prop, ce->old_prop);
656 break;
657 }
658
659 return 0;
660}
661
662static inline int __of_changeset_entry_revert(struct of_changeset_entry *ce)
663{
664 struct of_changeset_entry ce_inverted;
665
666 __of_changeset_entry_invert(ce, &ce_inverted);
667 return __of_changeset_entry_apply(&ce_inverted);
668}
669
670/**
671 * of_changeset_init - Initialize a changeset for use
672 *
673 * @ocs: changeset pointer
674 *
675 * Initialize a changeset structure
676 */
677void of_changeset_init(struct of_changeset *ocs)
678{
679 memset(ocs, 0, sizeof(*ocs));
680 INIT_LIST_HEAD(&ocs->entries);
681}
682EXPORT_SYMBOL_GPL(of_changeset_init);
683
684/**
685 * of_changeset_destroy - Destroy a changeset
686 *
687 * @ocs: changeset pointer
688 *
689 * Destroys a changeset. Note that if a changeset is applied,
690 * its changes to the tree cannot be reverted.
691 */
692void of_changeset_destroy(struct of_changeset *ocs)
693{
694 struct of_changeset_entry *ce, *cen;
695
696 list_for_each_entry_safe_reverse(ce, cen, &ocs->entries, node)
697 __of_changeset_entry_destroy(ce);
698}
699EXPORT_SYMBOL_GPL(of_changeset_destroy);
700
701/*
702 * Apply the changeset entries in @ocs.
703 * If apply fails, an attempt is made to revert the entries that were
704 * successfully applied.
705 *
706 * If multiple revert errors occur then only the final revert error is reported.
707 *
708 * Returns 0 on success, a negative error value in case of an error.
709 * If a revert error occurs, it is returned in *ret_revert.
710 */
711int __of_changeset_apply_entries(struct of_changeset *ocs, int *ret_revert)
712{
713 struct of_changeset_entry *ce;
714 int ret, ret_tmp;
715
716 pr_debug("changeset: applying...\n");
717 list_for_each_entry(ce, &ocs->entries, node) {
718 ret = __of_changeset_entry_apply(ce);
719 if (ret) {
720 pr_err("Error applying changeset (%d)\n", ret);
721 list_for_each_entry_continue_reverse(ce, &ocs->entries,
722 node) {
723 ret_tmp = __of_changeset_entry_revert(ce);
724 if (ret_tmp)
725 *ret_revert = ret_tmp;
726 }
727 return ret;
728 }
729 }
730
731 return 0;
732}
733
734/*
735 * Returns 0 on success, a negative error value in case of an error.
736 *
737 * If multiple changeset entry notification errors occur then only the
738 * final notification error is reported.
739 */
740int __of_changeset_apply_notify(struct of_changeset *ocs)
741{
742 struct of_changeset_entry *ce;
743 int ret = 0, ret_tmp;
744
745 pr_debug("changeset: emitting notifiers.\n");
746
747 /* drop the global lock while emitting notifiers */
748 mutex_unlock(&of_mutex);
749 list_for_each_entry(ce, &ocs->entries, node) {
750 ret_tmp = __of_changeset_entry_notify(ce, 0);
751 if (ret_tmp)
752 ret = ret_tmp;
753 }
754 mutex_lock(&of_mutex);
755 pr_debug("changeset: notifiers sent.\n");
756
757 return ret;
758}
759
760/*
761 * Returns 0 on success, a negative error value in case of an error.
762 *
763 * If a changeset entry apply fails, an attempt is made to revert any
764 * previous entries in the changeset. If any of the reverts fails,
765 * that failure is not reported. Thus the state of the device tree
766 * is unknown if an apply error occurs.
767 */
768static int __of_changeset_apply(struct of_changeset *ocs)
769{
770 int ret, ret_revert = 0;
771
772 ret = __of_changeset_apply_entries(ocs, &ret_revert);
773 if (!ret)
774 ret = __of_changeset_apply_notify(ocs);
775
776 return ret;
777}
778
779/**
780 * of_changeset_apply - Applies a changeset
781 *
782 * @ocs: changeset pointer
783 *
784 * Applies a changeset to the live tree.
785 * Any side-effects of live tree state changes are applied here on
786 * success, like creation/destruction of devices and side-effects
787 * like creation of sysfs properties and directories.
788 *
789 * Return: 0 on success, a negative error value in case of an error.
790 * On error the partially applied effects are reverted.
791 */
792int of_changeset_apply(struct of_changeset *ocs)
793{
794 int ret;
795
796 mutex_lock(&of_mutex);
797 ret = __of_changeset_apply(ocs);
798 mutex_unlock(&of_mutex);
799
800 return ret;
801}
802EXPORT_SYMBOL_GPL(of_changeset_apply);
803
804/*
805 * Revert the changeset entries in @ocs.
806 * If revert fails, an attempt is made to re-apply the entries that were
807 * successfully removed.
808 *
809 * If multiple re-apply errors occur then only the final apply error is
810 * reported.
811 *
812 * Returns 0 on success, a negative error value in case of an error.
813 * If an apply error occurs, it is returned in *ret_apply.
814 */
815int __of_changeset_revert_entries(struct of_changeset *ocs, int *ret_apply)
816{
817 struct of_changeset_entry *ce;
818 int ret, ret_tmp;
819
820 pr_debug("changeset: reverting...\n");
821 list_for_each_entry_reverse(ce, &ocs->entries, node) {
822 ret = __of_changeset_entry_revert(ce);
823 if (ret) {
824 pr_err("Error reverting changeset (%d)\n", ret);
825 list_for_each_entry_continue(ce, &ocs->entries, node) {
826 ret_tmp = __of_changeset_entry_apply(ce);
827 if (ret_tmp)
828 *ret_apply = ret_tmp;
829 }
830 return ret;
831 }
832 }
833
834 return 0;
835}
836
837/*
838 * If multiple changeset entry notification errors occur then only the
839 * final notification error is reported.
840 */
841int __of_changeset_revert_notify(struct of_changeset *ocs)
842{
843 struct of_changeset_entry *ce;
844 int ret = 0, ret_tmp;
845
846 pr_debug("changeset: emitting notifiers.\n");
847
848 /* drop the global lock while emitting notifiers */
849 mutex_unlock(&of_mutex);
850 list_for_each_entry_reverse(ce, &ocs->entries, node) {
851 ret_tmp = __of_changeset_entry_notify(ce, 1);
852 if (ret_tmp)
853 ret = ret_tmp;
854 }
855 mutex_lock(&of_mutex);
856 pr_debug("changeset: notifiers sent.\n");
857
858 return ret;
859}
860
861static int __of_changeset_revert(struct of_changeset *ocs)
862{
863 int ret, ret_reply;
864
865 ret_reply = 0;
866 ret = __of_changeset_revert_entries(ocs, &ret_reply);
867
868 if (!ret)
869 ret = __of_changeset_revert_notify(ocs);
870
871 return ret;
872}
873
874/**
875 * of_changeset_revert - Reverts an applied changeset
876 *
877 * @ocs: changeset pointer
878 *
879 * Reverts a changeset returning the state of the tree to what it
880 * was before the application.
881 * Any side-effects like creation/destruction of devices and
882 * removal of sysfs properties and directories are applied.
883 *
884 * Return: 0 on success, a negative error value in case of an error.
885 */
886int of_changeset_revert(struct of_changeset *ocs)
887{
888 int ret;
889
890 mutex_lock(&of_mutex);
891 ret = __of_changeset_revert(ocs);
892 mutex_unlock(&of_mutex);
893
894 return ret;
895}
896EXPORT_SYMBOL_GPL(of_changeset_revert);
897
898/**
899 * of_changeset_action - Add an action to the tail of the changeset list
900 *
901 * @ocs: changeset pointer
902 * @action: action to perform
903 * @np: Pointer to device node
904 * @prop: Pointer to property
905 *
906 * On action being one of:
907 * + OF_RECONFIG_ATTACH_NODE
908 * + OF_RECONFIG_DETACH_NODE,
909 * + OF_RECONFIG_ADD_PROPERTY
910 * + OF_RECONFIG_REMOVE_PROPERTY,
911 * + OF_RECONFIG_UPDATE_PROPERTY
912 *
913 * Return: 0 on success, a negative error value in case of an error.
914 */
915int of_changeset_action(struct of_changeset *ocs, unsigned long action,
916 struct device_node *np, struct property *prop)
917{
918 struct of_changeset_entry *ce;
919
920 ce = kzalloc(sizeof(*ce), GFP_KERNEL);
921 if (!ce)
922 return -ENOMEM;
923
924 /* get a reference to the node */
925 ce->action = action;
926 ce->np = of_node_get(np);
927 ce->prop = prop;
928
929 if (action == OF_RECONFIG_UPDATE_PROPERTY && prop)
930 ce->old_prop = of_find_property(np, prop->name, NULL);
931
932 /* add it to the list */
933 list_add_tail(&ce->node, &ocs->entries);
934 return 0;
935}
936EXPORT_SYMBOL_GPL(of_changeset_action);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Support for dynamic device trees.
4 *
5 * On some platforms, the device tree can be manipulated at runtime.
6 * The routines in this section support adding, removing and changing
7 * device tree nodes.
8 */
9
10#define pr_fmt(fmt) "OF: " fmt
11
12#include <linux/of.h>
13#include <linux/spinlock.h>
14#include <linux/slab.h>
15#include <linux/string.h>
16#include <linux/proc_fs.h>
17
18#include "of_private.h"
19
20static struct device_node *kobj_to_device_node(struct kobject *kobj)
21{
22 return container_of(kobj, struct device_node, kobj);
23}
24
25/**
26 * of_node_get() - Increment refcount of a node
27 * @node: Node to inc refcount, NULL is supported to simplify writing of
28 * callers
29 *
30 * Return: The node with refcount incremented.
31 */
32struct device_node *of_node_get(struct device_node *node)
33{
34 if (node)
35 kobject_get(&node->kobj);
36 return node;
37}
38EXPORT_SYMBOL(of_node_get);
39
40/**
41 * of_node_put() - Decrement refcount of a node
42 * @node: Node to dec refcount, NULL is supported to simplify writing of
43 * callers
44 */
45void of_node_put(struct device_node *node)
46{
47 if (node)
48 kobject_put(&node->kobj);
49}
50EXPORT_SYMBOL(of_node_put);
51
52static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
53
54int of_reconfig_notifier_register(struct notifier_block *nb)
55{
56 return blocking_notifier_chain_register(&of_reconfig_chain, nb);
57}
58EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
59
60int of_reconfig_notifier_unregister(struct notifier_block *nb)
61{
62 return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
63}
64EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
65
66static const char *action_names[] = {
67 [0] = "INVALID",
68 [OF_RECONFIG_ATTACH_NODE] = "ATTACH_NODE",
69 [OF_RECONFIG_DETACH_NODE] = "DETACH_NODE",
70 [OF_RECONFIG_ADD_PROPERTY] = "ADD_PROPERTY",
71 [OF_RECONFIG_REMOVE_PROPERTY] = "REMOVE_PROPERTY",
72 [OF_RECONFIG_UPDATE_PROPERTY] = "UPDATE_PROPERTY",
73};
74
75#define _do_print(func, prefix, action, node, prop, ...) ({ \
76 func("changeset: " prefix "%-15s %pOF%s%s\n", \
77 ##__VA_ARGS__, action_names[action], node, \
78 prop ? ":" : "", prop ? prop->name : ""); \
79})
80#define of_changeset_action_err(...) _do_print(pr_err, __VA_ARGS__)
81#define of_changeset_action_debug(...) _do_print(pr_debug, __VA_ARGS__)
82
83int of_reconfig_notify(unsigned long action, struct of_reconfig_data *p)
84{
85 int rc;
86 struct of_reconfig_data *pr = p;
87
88 of_changeset_action_debug("notify: ", action, pr->dn, pr->prop);
89
90 rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
91 return notifier_to_errno(rc);
92}
93
94/*
95 * of_reconfig_get_state_change() - Returns new state of device
96 * @action - action of the of notifier
97 * @arg - argument of the of notifier
98 *
99 * Returns the new state of a device based on the notifier used.
100 *
101 * Return: OF_RECONFIG_CHANGE_REMOVE on device going from enabled to
102 * disabled, OF_RECONFIG_CHANGE_ADD on device going from disabled to
103 * enabled and OF_RECONFIG_NO_CHANGE on no change.
104 */
105int of_reconfig_get_state_change(unsigned long action, struct of_reconfig_data *pr)
106{
107 struct property *prop, *old_prop = NULL;
108 int is_status, status_state, old_status_state, prev_state, new_state;
109
110 /* figure out if a device should be created or destroyed */
111 switch (action) {
112 case OF_RECONFIG_ATTACH_NODE:
113 case OF_RECONFIG_DETACH_NODE:
114 prop = of_find_property(pr->dn, "status", NULL);
115 break;
116 case OF_RECONFIG_ADD_PROPERTY:
117 case OF_RECONFIG_REMOVE_PROPERTY:
118 prop = pr->prop;
119 break;
120 case OF_RECONFIG_UPDATE_PROPERTY:
121 prop = pr->prop;
122 old_prop = pr->old_prop;
123 break;
124 default:
125 return OF_RECONFIG_NO_CHANGE;
126 }
127
128 is_status = 0;
129 status_state = -1;
130 old_status_state = -1;
131 prev_state = -1;
132 new_state = -1;
133
134 if (prop && !strcmp(prop->name, "status")) {
135 is_status = 1;
136 status_state = !strcmp(prop->value, "okay") ||
137 !strcmp(prop->value, "ok");
138 if (old_prop)
139 old_status_state = !strcmp(old_prop->value, "okay") ||
140 !strcmp(old_prop->value, "ok");
141 }
142
143 switch (action) {
144 case OF_RECONFIG_ATTACH_NODE:
145 prev_state = 0;
146 /* -1 & 0 status either missing or okay */
147 new_state = status_state != 0;
148 break;
149 case OF_RECONFIG_DETACH_NODE:
150 /* -1 & 0 status either missing or okay */
151 prev_state = status_state != 0;
152 new_state = 0;
153 break;
154 case OF_RECONFIG_ADD_PROPERTY:
155 if (is_status) {
156 /* no status property -> enabled (legacy) */
157 prev_state = 1;
158 new_state = status_state;
159 }
160 break;
161 case OF_RECONFIG_REMOVE_PROPERTY:
162 if (is_status) {
163 prev_state = status_state;
164 /* no status property -> enabled (legacy) */
165 new_state = 1;
166 }
167 break;
168 case OF_RECONFIG_UPDATE_PROPERTY:
169 if (is_status) {
170 prev_state = old_status_state != 0;
171 new_state = status_state != 0;
172 }
173 break;
174 }
175
176 if (prev_state == new_state)
177 return OF_RECONFIG_NO_CHANGE;
178
179 return new_state ? OF_RECONFIG_CHANGE_ADD : OF_RECONFIG_CHANGE_REMOVE;
180}
181EXPORT_SYMBOL_GPL(of_reconfig_get_state_change);
182
183int of_property_notify(int action, struct device_node *np,
184 struct property *prop, struct property *oldprop)
185{
186 struct of_reconfig_data pr;
187
188 /* only call notifiers if the node is attached */
189 if (!of_node_is_attached(np))
190 return 0;
191
192 pr.dn = np;
193 pr.prop = prop;
194 pr.old_prop = oldprop;
195 return of_reconfig_notify(action, &pr);
196}
197
198static void __of_attach_node(struct device_node *np)
199{
200 const __be32 *phandle;
201 int sz;
202 unsigned long flags;
203
204 raw_spin_lock_irqsave(&devtree_lock, flags);
205
206 if (!of_node_check_flag(np, OF_OVERLAY)) {
207 np->name = __of_get_property(np, "name", NULL);
208 if (!np->name)
209 np->name = "<NULL>";
210
211 phandle = __of_get_property(np, "phandle", &sz);
212 if (!phandle)
213 phandle = __of_get_property(np, "linux,phandle", &sz);
214 if (IS_ENABLED(CONFIG_PPC_PSERIES) && !phandle)
215 phandle = __of_get_property(np, "ibm,phandle", &sz);
216 if (phandle && (sz >= 4))
217 np->phandle = be32_to_cpup(phandle);
218 else
219 np->phandle = 0;
220 }
221
222 np->child = NULL;
223 np->sibling = np->parent->child;
224 np->parent->child = np;
225 of_node_clear_flag(np, OF_DETACHED);
226 np->fwnode.flags |= FWNODE_FLAG_NOT_DEVICE;
227
228 raw_spin_unlock_irqrestore(&devtree_lock, flags);
229
230 __of_attach_node_sysfs(np);
231}
232
233/**
234 * of_attach_node() - Plug a device node into the tree and global list.
235 * @np: Pointer to the caller's Device Node
236 */
237int of_attach_node(struct device_node *np)
238{
239 struct of_reconfig_data rd;
240
241 memset(&rd, 0, sizeof(rd));
242 rd.dn = np;
243
244 mutex_lock(&of_mutex);
245 __of_attach_node(np);
246 mutex_unlock(&of_mutex);
247
248 of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, &rd);
249
250 return 0;
251}
252
253void __of_detach_node(struct device_node *np)
254{
255 struct device_node *parent;
256 unsigned long flags;
257
258 raw_spin_lock_irqsave(&devtree_lock, flags);
259
260 parent = np->parent;
261 if (WARN_ON(of_node_check_flag(np, OF_DETACHED) || !parent)) {
262 raw_spin_unlock_irqrestore(&devtree_lock, flags);
263 return;
264 }
265
266 if (parent->child == np)
267 parent->child = np->sibling;
268 else {
269 struct device_node *prevsib;
270 for (prevsib = np->parent->child;
271 prevsib->sibling != np;
272 prevsib = prevsib->sibling)
273 ;
274 prevsib->sibling = np->sibling;
275 }
276
277 of_node_set_flag(np, OF_DETACHED);
278
279 /* race with of_find_node_by_phandle() prevented by devtree_lock */
280 __of_phandle_cache_inv_entry(np->phandle);
281
282 raw_spin_unlock_irqrestore(&devtree_lock, flags);
283
284 __of_detach_node_sysfs(np);
285}
286
287/**
288 * of_detach_node() - "Unplug" a node from the device tree.
289 * @np: Pointer to the caller's Device Node
290 */
291int of_detach_node(struct device_node *np)
292{
293 struct of_reconfig_data rd;
294
295 memset(&rd, 0, sizeof(rd));
296 rd.dn = np;
297
298 mutex_lock(&of_mutex);
299 __of_detach_node(np);
300 mutex_unlock(&of_mutex);
301
302 of_reconfig_notify(OF_RECONFIG_DETACH_NODE, &rd);
303
304 return 0;
305}
306EXPORT_SYMBOL_GPL(of_detach_node);
307
308static void property_list_free(struct property *prop_list)
309{
310 struct property *prop, *next;
311
312 for (prop = prop_list; prop != NULL; prop = next) {
313 next = prop->next;
314 kfree(prop->name);
315 kfree(prop->value);
316 kfree(prop);
317 }
318}
319
320/**
321 * of_node_release() - release a dynamically allocated node
322 * @kobj: kernel object of the node to be released
323 *
324 * In of_node_put() this function is passed to kref_put() as the destructor.
325 */
326void of_node_release(struct kobject *kobj)
327{
328 struct device_node *node = kobj_to_device_node(kobj);
329
330 /*
331 * can not use '"%pOF", node' in pr_err() calls from this function
332 * because an of_node_get(node) when refcount is already zero
333 * will result in an error and a stack dump
334 */
335
336 /* We should never be releasing nodes that haven't been detached. */
337 if (!of_node_check_flag(node, OF_DETACHED)) {
338
339 pr_err("ERROR: %s() detected bad of_node_put() on %pOF/%s\n",
340 __func__, node->parent, node->full_name);
341
342 /*
343 * of unittests will test this path. Do not print the stack
344 * trace when the error is caused by unittest so that we do
345 * not display what a normal developer might reasonably
346 * consider a real bug.
347 */
348 if (!IS_ENABLED(CONFIG_OF_UNITTEST) ||
349 strcmp(node->parent->full_name, "testcase-data")) {
350 dump_stack();
351 pr_err("ERROR: next of_node_put() on this node will result in a kobject warning 'refcount_t: underflow; use-after-free.'\n");
352 }
353
354 return;
355 }
356 if (!of_node_check_flag(node, OF_DYNAMIC))
357 return;
358
359 if (of_node_check_flag(node, OF_OVERLAY)) {
360
361 if (!of_node_check_flag(node, OF_OVERLAY_FREE_CSET)) {
362 /* premature refcount of zero, do not free memory */
363 pr_err("ERROR: memory leak before free overlay changeset, %pOF\n",
364 node);
365 return;
366 }
367
368 /*
369 * If node->properties non-empty then properties were added
370 * to this node either by different overlay that has not
371 * yet been removed, or by a non-overlay mechanism.
372 */
373 if (node->properties)
374 pr_err("ERROR: %s(), unexpected properties in %pOF\n",
375 __func__, node);
376 }
377
378 if (node->child)
379 pr_err("ERROR: %s() unexpected children for %pOF/%s\n",
380 __func__, node->parent, node->full_name);
381
382 property_list_free(node->properties);
383 property_list_free(node->deadprops);
384 fwnode_links_purge(of_fwnode_handle(node));
385
386 kfree(node->full_name);
387 kfree(node->data);
388 kfree(node);
389}
390
391/**
392 * __of_prop_dup - Copy a property dynamically.
393 * @prop: Property to copy
394 * @allocflags: Allocation flags (typically pass GFP_KERNEL)
395 *
396 * Copy a property by dynamically allocating the memory of both the
397 * property structure and the property name & contents. The property's
398 * flags have the OF_DYNAMIC bit set so that we can differentiate between
399 * dynamically allocated properties and not.
400 *
401 * Return: The newly allocated property or NULL on out of memory error.
402 */
403struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags)
404{
405 struct property *new;
406
407 new = kzalloc(sizeof(*new), allocflags);
408 if (!new)
409 return NULL;
410
411 /*
412 * NOTE: There is no check for zero length value.
413 * In case of a boolean property, this will allocate a value
414 * of zero bytes. We do this to work around the use
415 * of of_get_property() calls on boolean values.
416 */
417 new->name = kstrdup(prop->name, allocflags);
418 new->value = kmemdup(prop->value, prop->length, allocflags);
419 new->length = prop->length;
420 if (!new->name || !new->value)
421 goto err_free;
422
423 /* mark the property as dynamic */
424 of_property_set_flag(new, OF_DYNAMIC);
425
426 return new;
427
428 err_free:
429 kfree(new->name);
430 kfree(new->value);
431 kfree(new);
432 return NULL;
433}
434
435/**
436 * __of_node_dup() - Duplicate or create an empty device node dynamically.
437 * @np: if not NULL, contains properties to be duplicated in new node
438 * @full_name: string value to be duplicated into new node's full_name field
439 *
440 * Create a device tree node, optionally duplicating the properties of
441 * another node. The node data are dynamically allocated and all the node
442 * flags have the OF_DYNAMIC & OF_DETACHED bits set.
443 *
444 * Return: The newly allocated node or NULL on out of memory error. Use
445 * of_node_put() on it when done to free the memory allocated for it.
446 */
447struct device_node *__of_node_dup(const struct device_node *np,
448 const char *full_name)
449{
450 struct device_node *node;
451
452 node = kzalloc(sizeof(*node), GFP_KERNEL);
453 if (!node)
454 return NULL;
455 node->full_name = kstrdup(full_name, GFP_KERNEL);
456 if (!node->full_name) {
457 kfree(node);
458 return NULL;
459 }
460
461 of_node_set_flag(node, OF_DYNAMIC);
462 of_node_set_flag(node, OF_DETACHED);
463 of_node_init(node);
464
465 /* Iterate over and duplicate all properties */
466 if (np) {
467 struct property *pp, *new_pp;
468 for_each_property_of_node(np, pp) {
469 new_pp = __of_prop_dup(pp, GFP_KERNEL);
470 if (!new_pp)
471 goto err_prop;
472 if (__of_add_property(node, new_pp)) {
473 kfree(new_pp->name);
474 kfree(new_pp->value);
475 kfree(new_pp);
476 goto err_prop;
477 }
478 }
479 }
480 return node;
481
482 err_prop:
483 of_node_put(node); /* Frees the node and properties */
484 return NULL;
485}
486
487/**
488 * of_changeset_create_node - Dynamically create a device node and attach to
489 * a given changeset.
490 *
491 * @ocs: Pointer to changeset
492 * @parent: Pointer to parent device node
493 * @full_name: Node full name
494 *
495 * Return: Pointer to the created device node or NULL in case of an error.
496 */
497struct device_node *of_changeset_create_node(struct of_changeset *ocs,
498 struct device_node *parent,
499 const char *full_name)
500{
501 struct device_node *np;
502 int ret;
503
504 np = __of_node_dup(NULL, full_name);
505 if (!np)
506 return NULL;
507 np->parent = parent;
508
509 ret = of_changeset_attach_node(ocs, np);
510 if (ret) {
511 of_node_put(np);
512 return NULL;
513 }
514
515 return np;
516}
517EXPORT_SYMBOL(of_changeset_create_node);
518
519static void __of_changeset_entry_destroy(struct of_changeset_entry *ce)
520{
521 if (ce->action == OF_RECONFIG_ATTACH_NODE &&
522 of_node_check_flag(ce->np, OF_OVERLAY)) {
523 if (kref_read(&ce->np->kobj.kref) > 1) {
524 pr_err("ERROR: memory leak, expected refcount 1 instead of %d, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node %pOF\n",
525 kref_read(&ce->np->kobj.kref), ce->np);
526 } else {
527 of_node_set_flag(ce->np, OF_OVERLAY_FREE_CSET);
528 }
529 }
530
531 of_node_put(ce->np);
532 list_del(&ce->node);
533 kfree(ce);
534}
535
536static void __of_changeset_entry_invert(struct of_changeset_entry *ce,
537 struct of_changeset_entry *rce)
538{
539 memcpy(rce, ce, sizeof(*rce));
540
541 switch (ce->action) {
542 case OF_RECONFIG_ATTACH_NODE:
543 rce->action = OF_RECONFIG_DETACH_NODE;
544 break;
545 case OF_RECONFIG_DETACH_NODE:
546 rce->action = OF_RECONFIG_ATTACH_NODE;
547 break;
548 case OF_RECONFIG_ADD_PROPERTY:
549 rce->action = OF_RECONFIG_REMOVE_PROPERTY;
550 break;
551 case OF_RECONFIG_REMOVE_PROPERTY:
552 rce->action = OF_RECONFIG_ADD_PROPERTY;
553 break;
554 case OF_RECONFIG_UPDATE_PROPERTY:
555 rce->old_prop = ce->prop;
556 rce->prop = ce->old_prop;
557 /* update was used but original property did not exist */
558 if (!rce->prop) {
559 rce->action = OF_RECONFIG_REMOVE_PROPERTY;
560 rce->prop = ce->prop;
561 }
562 break;
563 }
564}
565
566static int __of_changeset_entry_notify(struct of_changeset_entry *ce,
567 bool revert)
568{
569 struct of_reconfig_data rd;
570 struct of_changeset_entry ce_inverted;
571 int ret = 0;
572
573 if (revert) {
574 __of_changeset_entry_invert(ce, &ce_inverted);
575 ce = &ce_inverted;
576 }
577
578 switch (ce->action) {
579 case OF_RECONFIG_ATTACH_NODE:
580 case OF_RECONFIG_DETACH_NODE:
581 memset(&rd, 0, sizeof(rd));
582 rd.dn = ce->np;
583 ret = of_reconfig_notify(ce->action, &rd);
584 break;
585 case OF_RECONFIG_ADD_PROPERTY:
586 case OF_RECONFIG_REMOVE_PROPERTY:
587 case OF_RECONFIG_UPDATE_PROPERTY:
588 ret = of_property_notify(ce->action, ce->np, ce->prop, ce->old_prop);
589 break;
590 default:
591 pr_err("invalid devicetree changeset action: %i\n",
592 (int)ce->action);
593 ret = -EINVAL;
594 }
595
596 if (ret)
597 pr_err("changeset notifier error @%pOF\n", ce->np);
598 return ret;
599}
600
601static int __of_changeset_entry_apply(struct of_changeset_entry *ce)
602{
603 int ret = 0;
604
605 of_changeset_action_debug("apply: ", ce->action, ce->np, ce->prop);
606
607 switch (ce->action) {
608 case OF_RECONFIG_ATTACH_NODE:
609 __of_attach_node(ce->np);
610 break;
611 case OF_RECONFIG_DETACH_NODE:
612 __of_detach_node(ce->np);
613 break;
614 case OF_RECONFIG_ADD_PROPERTY:
615 ret = __of_add_property(ce->np, ce->prop);
616 break;
617 case OF_RECONFIG_REMOVE_PROPERTY:
618 ret = __of_remove_property(ce->np, ce->prop);
619 break;
620
621 case OF_RECONFIG_UPDATE_PROPERTY:
622 ret = __of_update_property(ce->np, ce->prop, &ce->old_prop);
623 break;
624 default:
625 ret = -EINVAL;
626 }
627
628 if (ret) {
629 of_changeset_action_err("apply failed: ", ce->action, ce->np, ce->prop);
630 return ret;
631 }
632
633 return 0;
634}
635
636static inline int __of_changeset_entry_revert(struct of_changeset_entry *ce)
637{
638 struct of_changeset_entry ce_inverted;
639
640 __of_changeset_entry_invert(ce, &ce_inverted);
641 return __of_changeset_entry_apply(&ce_inverted);
642}
643
644/**
645 * of_changeset_init - Initialize a changeset for use
646 *
647 * @ocs: changeset pointer
648 *
649 * Initialize a changeset structure
650 */
651void of_changeset_init(struct of_changeset *ocs)
652{
653 memset(ocs, 0, sizeof(*ocs));
654 INIT_LIST_HEAD(&ocs->entries);
655}
656EXPORT_SYMBOL_GPL(of_changeset_init);
657
658/**
659 * of_changeset_destroy - Destroy a changeset
660 *
661 * @ocs: changeset pointer
662 *
663 * Destroys a changeset. Note that if a changeset is applied,
664 * its changes to the tree cannot be reverted.
665 */
666void of_changeset_destroy(struct of_changeset *ocs)
667{
668 struct of_changeset_entry *ce, *cen;
669
670 list_for_each_entry_safe_reverse(ce, cen, &ocs->entries, node)
671 __of_changeset_entry_destroy(ce);
672}
673EXPORT_SYMBOL_GPL(of_changeset_destroy);
674
675/*
676 * Apply the changeset entries in @ocs.
677 * If apply fails, an attempt is made to revert the entries that were
678 * successfully applied.
679 *
680 * If multiple revert errors occur then only the final revert error is reported.
681 *
682 * Returns 0 on success, a negative error value in case of an error.
683 * If a revert error occurs, it is returned in *ret_revert.
684 */
685int __of_changeset_apply_entries(struct of_changeset *ocs, int *ret_revert)
686{
687 struct of_changeset_entry *ce;
688 int ret, ret_tmp;
689
690 pr_debug("changeset: applying...\n");
691 list_for_each_entry(ce, &ocs->entries, node) {
692 ret = __of_changeset_entry_apply(ce);
693 if (ret) {
694 pr_err("Error applying changeset (%d)\n", ret);
695 list_for_each_entry_continue_reverse(ce, &ocs->entries,
696 node) {
697 ret_tmp = __of_changeset_entry_revert(ce);
698 if (ret_tmp)
699 *ret_revert = ret_tmp;
700 }
701 return ret;
702 }
703 }
704
705 return 0;
706}
707
708/*
709 * Returns 0 on success, a negative error value in case of an error.
710 *
711 * If multiple changeset entry notification errors occur then only the
712 * final notification error is reported.
713 */
714int __of_changeset_apply_notify(struct of_changeset *ocs)
715{
716 struct of_changeset_entry *ce;
717 int ret = 0, ret_tmp;
718
719 pr_debug("changeset: emitting notifiers.\n");
720
721 /* drop the global lock while emitting notifiers */
722 mutex_unlock(&of_mutex);
723 list_for_each_entry(ce, &ocs->entries, node) {
724 ret_tmp = __of_changeset_entry_notify(ce, 0);
725 if (ret_tmp)
726 ret = ret_tmp;
727 }
728 mutex_lock(&of_mutex);
729 pr_debug("changeset: notifiers sent.\n");
730
731 return ret;
732}
733
734/*
735 * Returns 0 on success, a negative error value in case of an error.
736 *
737 * If a changeset entry apply fails, an attempt is made to revert any
738 * previous entries in the changeset. If any of the reverts fails,
739 * that failure is not reported. Thus the state of the device tree
740 * is unknown if an apply error occurs.
741 */
742static int __of_changeset_apply(struct of_changeset *ocs)
743{
744 int ret, ret_revert = 0;
745
746 ret = __of_changeset_apply_entries(ocs, &ret_revert);
747 if (!ret)
748 ret = __of_changeset_apply_notify(ocs);
749
750 return ret;
751}
752
753/**
754 * of_changeset_apply - Applies a changeset
755 *
756 * @ocs: changeset pointer
757 *
758 * Applies a changeset to the live tree.
759 * Any side-effects of live tree state changes are applied here on
760 * success, like creation/destruction of devices and side-effects
761 * like creation of sysfs properties and directories.
762 *
763 * Return: 0 on success, a negative error value in case of an error.
764 * On error the partially applied effects are reverted.
765 */
766int of_changeset_apply(struct of_changeset *ocs)
767{
768 int ret;
769
770 mutex_lock(&of_mutex);
771 ret = __of_changeset_apply(ocs);
772 mutex_unlock(&of_mutex);
773
774 return ret;
775}
776EXPORT_SYMBOL_GPL(of_changeset_apply);
777
778/*
779 * Revert the changeset entries in @ocs.
780 * If revert fails, an attempt is made to re-apply the entries that were
781 * successfully removed.
782 *
783 * If multiple re-apply errors occur then only the final apply error is
784 * reported.
785 *
786 * Returns 0 on success, a negative error value in case of an error.
787 * If an apply error occurs, it is returned in *ret_apply.
788 */
789int __of_changeset_revert_entries(struct of_changeset *ocs, int *ret_apply)
790{
791 struct of_changeset_entry *ce;
792 int ret, ret_tmp;
793
794 pr_debug("changeset: reverting...\n");
795 list_for_each_entry_reverse(ce, &ocs->entries, node) {
796 ret = __of_changeset_entry_revert(ce);
797 if (ret) {
798 pr_err("Error reverting changeset (%d)\n", ret);
799 list_for_each_entry_continue(ce, &ocs->entries, node) {
800 ret_tmp = __of_changeset_entry_apply(ce);
801 if (ret_tmp)
802 *ret_apply = ret_tmp;
803 }
804 return ret;
805 }
806 }
807
808 return 0;
809}
810
811/*
812 * If multiple changeset entry notification errors occur then only the
813 * final notification error is reported.
814 */
815int __of_changeset_revert_notify(struct of_changeset *ocs)
816{
817 struct of_changeset_entry *ce;
818 int ret = 0, ret_tmp;
819
820 pr_debug("changeset: emitting notifiers.\n");
821
822 /* drop the global lock while emitting notifiers */
823 mutex_unlock(&of_mutex);
824 list_for_each_entry_reverse(ce, &ocs->entries, node) {
825 ret_tmp = __of_changeset_entry_notify(ce, 1);
826 if (ret_tmp)
827 ret = ret_tmp;
828 }
829 mutex_lock(&of_mutex);
830 pr_debug("changeset: notifiers sent.\n");
831
832 return ret;
833}
834
835static int __of_changeset_revert(struct of_changeset *ocs)
836{
837 int ret, ret_reply;
838
839 ret_reply = 0;
840 ret = __of_changeset_revert_entries(ocs, &ret_reply);
841
842 if (!ret)
843 ret = __of_changeset_revert_notify(ocs);
844
845 return ret;
846}
847
848/**
849 * of_changeset_revert - Reverts an applied changeset
850 *
851 * @ocs: changeset pointer
852 *
853 * Reverts a changeset returning the state of the tree to what it
854 * was before the application.
855 * Any side-effects like creation/destruction of devices and
856 * removal of sysfs properties and directories are applied.
857 *
858 * Return: 0 on success, a negative error value in case of an error.
859 */
860int of_changeset_revert(struct of_changeset *ocs)
861{
862 int ret;
863
864 mutex_lock(&of_mutex);
865 ret = __of_changeset_revert(ocs);
866 mutex_unlock(&of_mutex);
867
868 return ret;
869}
870EXPORT_SYMBOL_GPL(of_changeset_revert);
871
872/**
873 * of_changeset_action - Add an action to the tail of the changeset list
874 *
875 * @ocs: changeset pointer
876 * @action: action to perform
877 * @np: Pointer to device node
878 * @prop: Pointer to property
879 *
880 * On action being one of:
881 * + OF_RECONFIG_ATTACH_NODE
882 * + OF_RECONFIG_DETACH_NODE,
883 * + OF_RECONFIG_ADD_PROPERTY
884 * + OF_RECONFIG_REMOVE_PROPERTY,
885 * + OF_RECONFIG_UPDATE_PROPERTY
886 *
887 * Return: 0 on success, a negative error value in case of an error.
888 */
889int of_changeset_action(struct of_changeset *ocs, unsigned long action,
890 struct device_node *np, struct property *prop)
891{
892 struct of_changeset_entry *ce;
893
894 if (WARN_ON(action >= ARRAY_SIZE(action_names)))
895 return -EINVAL;
896
897 ce = kzalloc(sizeof(*ce), GFP_KERNEL);
898 if (!ce)
899 return -ENOMEM;
900
901 /* get a reference to the node */
902 ce->action = action;
903 ce->np = of_node_get(np);
904 ce->prop = prop;
905
906 /* add it to the list */
907 list_add_tail(&ce->node, &ocs->entries);
908 return 0;
909}
910EXPORT_SYMBOL_GPL(of_changeset_action);
911
912static int of_changeset_add_prop_helper(struct of_changeset *ocs,
913 struct device_node *np,
914 const struct property *pp)
915{
916 struct property *new_pp;
917 int ret;
918
919 new_pp = __of_prop_dup(pp, GFP_KERNEL);
920 if (!new_pp)
921 return -ENOMEM;
922
923 ret = of_changeset_add_property(ocs, np, new_pp);
924 if (ret) {
925 kfree(new_pp->name);
926 kfree(new_pp->value);
927 kfree(new_pp);
928 }
929
930 return ret;
931}
932
933/**
934 * of_changeset_add_prop_string - Add a string property to a changeset
935 *
936 * @ocs: changeset pointer
937 * @np: device node pointer
938 * @prop_name: name of the property to be added
939 * @str: pointer to null terminated string
940 *
941 * Create a string property and add it to a changeset.
942 *
943 * Return: 0 on success, a negative error value in case of an error.
944 */
945int of_changeset_add_prop_string(struct of_changeset *ocs,
946 struct device_node *np,
947 const char *prop_name, const char *str)
948{
949 struct property prop;
950
951 prop.name = (char *)prop_name;
952 prop.length = strlen(str) + 1;
953 prop.value = (void *)str;
954
955 return of_changeset_add_prop_helper(ocs, np, &prop);
956}
957EXPORT_SYMBOL_GPL(of_changeset_add_prop_string);
958
959/**
960 * of_changeset_add_prop_string_array - Add a string list property to
961 * a changeset
962 *
963 * @ocs: changeset pointer
964 * @np: device node pointer
965 * @prop_name: name of the property to be added
966 * @str_array: pointer to an array of null terminated strings
967 * @sz: number of string array elements
968 *
969 * Create a string list property and add it to a changeset.
970 *
971 * Return: 0 on success, a negative error value in case of an error.
972 */
973int of_changeset_add_prop_string_array(struct of_changeset *ocs,
974 struct device_node *np,
975 const char *prop_name,
976 const char **str_array, size_t sz)
977{
978 struct property prop;
979 int i, ret;
980 char *vp;
981
982 prop.name = (char *)prop_name;
983
984 prop.length = 0;
985 for (i = 0; i < sz; i++)
986 prop.length += strlen(str_array[i]) + 1;
987
988 prop.value = kmalloc(prop.length, GFP_KERNEL);
989 if (!prop.value)
990 return -ENOMEM;
991
992 vp = prop.value;
993 for (i = 0; i < sz; i++) {
994 vp += snprintf(vp, (char *)prop.value + prop.length - vp, "%s",
995 str_array[i]) + 1;
996 }
997 ret = of_changeset_add_prop_helper(ocs, np, &prop);
998 kfree(prop.value);
999
1000 return ret;
1001}
1002EXPORT_SYMBOL_GPL(of_changeset_add_prop_string_array);
1003
1004/**
1005 * of_changeset_add_prop_u32_array - Add a property of 32 bit integers
1006 * property to a changeset
1007 *
1008 * @ocs: changeset pointer
1009 * @np: device node pointer
1010 * @prop_name: name of the property to be added
1011 * @array: pointer to an array of 32 bit integers
1012 * @sz: number of array elements
1013 *
1014 * Create a property of 32 bit integers and add it to a changeset.
1015 *
1016 * Return: 0 on success, a negative error value in case of an error.
1017 */
1018int of_changeset_add_prop_u32_array(struct of_changeset *ocs,
1019 struct device_node *np,
1020 const char *prop_name,
1021 const u32 *array, size_t sz)
1022{
1023 struct property prop;
1024 __be32 *val;
1025 int i, ret;
1026
1027 val = kcalloc(sz, sizeof(__be32), GFP_KERNEL);
1028 if (!val)
1029 return -ENOMEM;
1030
1031 for (i = 0; i < sz; i++)
1032 val[i] = cpu_to_be32(array[i]);
1033 prop.name = (char *)prop_name;
1034 prop.length = sizeof(u32) * sz;
1035 prop.value = (void *)val;
1036
1037 ret = of_changeset_add_prop_helper(ocs, np, &prop);
1038 kfree(val);
1039
1040 return ret;
1041}
1042EXPORT_SYMBOL_GPL(of_changeset_add_prop_u32_array);