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af6074fc 1// SPDX-License-Identifier: GPL-2.0
6afc0dc3
GL
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
606ad42a
RH
10#define pr_fmt(fmt) "OF: " fmt
11
6afc0dc3
GL
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
4c2bb574
RH
20static struct device_node *kobj_to_device_node(struct kobject *kobj)
21{
22 return container_of(kobj, struct device_node, kobj);
23}
24
6afc0dc3
GL
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 *
8c8239c2 30 * Return: The node with refcount incremented.
6afc0dc3
GL
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
6afc0dc3
GL
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
00aa3720
GL
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
f5242e5a 76int of_reconfig_notify(unsigned long action, struct of_reconfig_data *p)
6afc0dc3
GL
77{
78 int rc;
00aa3720 79#ifdef DEBUG
f5242e5a 80 struct of_reconfig_data *pr = p;
00aa3720
GL
81
82 switch (action) {
83 case OF_RECONFIG_ATTACH_NODE:
84 case OF_RECONFIG_DETACH_NODE:
0d638a07
RH
85 pr_debug("notify %-15s %pOF\n", action_names[action],
86 pr->dn);
00aa3720
GL
87 break;
88 case OF_RECONFIG_ADD_PROPERTY:
89 case OF_RECONFIG_REMOVE_PROPERTY:
90 case OF_RECONFIG_UPDATE_PROPERTY:
0d638a07
RH
91 pr_debug("notify %-15s %pOF:%s\n", action_names[action],
92 pr->dn, pr->prop->name);
00aa3720 93 break;
6afc0dc3 94
00aa3720
GL
95 }
96#endif
6afc0dc3
GL
97 rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
98 return notifier_to_errno(rc);
99}
100
b53a2340
PA
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.
8c8239c2
RH
107 *
108 * Return: 0 on device going from enabled to disabled, 1 on device
b53a2340
PA
109 * going from disabled to enabled and -1 on no change.
110 */
f5242e5a 111int of_reconfig_get_state_change(unsigned long action, struct of_reconfig_data *pr)
b53a2340 112{
f5242e5a 113 struct property *prop, *old_prop = NULL;
b53a2340
PA
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 */
b53a2340
PA
117 switch (action) {
118 case OF_RECONFIG_ATTACH_NODE:
119 case OF_RECONFIG_DETACH_NODE:
f5242e5a 120 prop = of_find_property(pr->dn, "status", NULL);
b53a2340
PA
121 break;
122 case OF_RECONFIG_ADD_PROPERTY:
123 case OF_RECONFIG_REMOVE_PROPERTY:
b53a2340
PA
124 prop = pr->prop;
125 break;
126 case OF_RECONFIG_UPDATE_PROPERTY:
b53a2340
PA
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
6afc0dc3 189int of_property_notify(int action, struct device_node *np,
259092a3 190 struct property *prop, struct property *oldprop)
6afc0dc3 191{
f5242e5a 192 struct of_reconfig_data pr;
6afc0dc3
GL
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;
259092a3 200 pr.old_prop = oldprop;
6afc0dc3
GL
201 return of_reconfig_notify(action, &pr);
202}
203
24996951 204static void __of_attach_node(struct device_node *np)
d8c50088 205{
a25095d4
GL
206 const __be32 *phandle;
207 int sz;
208
f9627881
FR
209 if (!of_node_check_flag(np, OF_OVERLAY)) {
210 np->name = __of_get_property(np, "name", NULL);
f9627881
FR
211 if (!np->name)
212 np->name = "<NULL>";
f9627881
FR
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 }
a25095d4 224
6162dbe4 225 np->child = NULL;
d8c50088 226 np->sibling = np->parent->child;
d8c50088
PA
227 np->parent->child = np;
228 of_node_clear_flag(np, OF_DETACHED);
229}
230
6afc0dc3
GL
231/**
232 * of_attach_node() - Plug a device node into the tree and global list.
3cb025d9 233 * @np: Pointer to the caller's Device Node
6afc0dc3
GL
234 */
235int of_attach_node(struct device_node *np)
236{
f5242e5a 237 struct of_reconfig_data rd;
6afc0dc3 238 unsigned long flags;
6afc0dc3 239
f5242e5a
GL
240 memset(&rd, 0, sizeof(rd));
241 rd.dn = np;
242
8a2b22a2 243 mutex_lock(&of_mutex);
6afc0dc3 244 raw_spin_lock_irqsave(&devtree_lock, flags);
d8c50088 245 __of_attach_node(np);
6afc0dc3
GL
246 raw_spin_unlock_irqrestore(&devtree_lock, flags);
247
8a2b22a2
GL
248 __of_attach_node_sysfs(np);
249 mutex_unlock(&of_mutex);
259092a3 250
f5242e5a 251 of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, &rd);
259092a3 252
6afc0dc3
GL
253 return 0;
254}
255
d8c50088 256void __of_detach_node(struct device_node *np)
6afc0dc3
GL
257{
258 struct device_node *parent;
6afc0dc3 259
d8c50088
PA
260 if (WARN_ON(of_node_check_flag(np, OF_DETACHED)))
261 return;
6afc0dc3
GL
262
263 parent = np->parent;
d8c50088
PA
264 if (WARN_ON(!parent))
265 return;
6afc0dc3 266
6afc0dc3
GL
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);
5801169a
FR
279
280 /* race with of_find_node_by_phandle() prevented by devtree_lock */
90dc0d1c 281 __of_phandle_cache_inv_entry(np->phandle);
d8c50088
PA
282}
283
284/**
285 * of_detach_node() - "Unplug" a node from the device tree.
3cb025d9 286 * @np: Pointer to the caller's Device Node
d8c50088
PA
287 */
288int of_detach_node(struct device_node *np)
289{
f5242e5a 290 struct of_reconfig_data rd;
d8c50088 291 unsigned long flags;
d8c50088 292
f5242e5a
GL
293 memset(&rd, 0, sizeof(rd));
294 rd.dn = np;
295
8a2b22a2 296 mutex_lock(&of_mutex);
d8c50088
PA
297 raw_spin_lock_irqsave(&devtree_lock, flags);
298 __of_detach_node(np);
6afc0dc3
GL
299 raw_spin_unlock_irqrestore(&devtree_lock, flags);
300
8a2b22a2
GL
301 __of_detach_node_sysfs(np);
302 mutex_unlock(&of_mutex);
259092a3 303
f5242e5a 304 of_reconfig_notify(OF_RECONFIG_DETACH_NODE, &rd);
259092a3 305
58fb82cc 306 return 0;
6afc0dc3 307}
bb91f923 308EXPORT_SYMBOL_GPL(of_detach_node);
6afc0dc3 309
070ea018
LW
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
6afc0dc3
GL
322/**
323 * of_node_release() - release a dynamically allocated node
3cb025d9 324 * @kobj: kernel object of the node to be released
6afc0dc3
GL
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);
6afc0dc3
GL
331
332 /* We should never be releasing nodes that haven't been detached. */
333 if (!of_node_check_flag(node, OF_DETACHED)) {
0d638a07 334 pr_err("ERROR: Bad of_node_put() on %pOF\n", node);
6afc0dc3
GL
335 dump_stack();
336 return;
337 }
6afc0dc3
GL
338 if (!of_node_check_flag(node, OF_DYNAMIC))
339 return;
340
144552c7
FR
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
070ea018
LW
360 property_list_free(node->properties);
361 property_list_free(node->deadprops);
7b337cb3 362 fwnode_links_purge(of_fwnode_handle(node));
6afc0dc3 363
6afc0dc3
GL
364 kfree(node->full_name);
365 kfree(node->data);
366 kfree(node);
367}
69843396
PA
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
27b3383a 375 * property structure and the property name & contents. The property's
69843396
PA
376 * flags have the OF_DYNAMIC bit set so that we can differentiate between
377 * dynamically allocated properties and not.
8c8239c2
RH
378 *
379 * Return: The newly allocated property or NULL on out of memory error.
69843396
PA
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.
b6ae5dc5 391 * In case of a boolean property, this will allocate a value
69843396
PA
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/**
e5179581 414 * __of_node_dup() - Duplicate or create an empty device node dynamically.
b89dae18
FR
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
69843396 417 *
b89dae18
FR
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 *
8c8239c2 422 * Return: The newly allocated node or NULL on out of memory error.
69843396 423 */
b89dae18
FR
424struct device_node *__of_node_dup(const struct device_node *np,
425 const char *full_name)
69843396
PA
426{
427 struct device_node *node;
428
ef8bbd73 429 node = kzalloc(sizeof(*node), GFP_KERNEL);
69843396
PA
430 if (!node)
431 return NULL;
b89dae18 432 node->full_name = kstrdup(full_name, GFP_KERNEL);
e5179581
GL
433 if (!node->full_name) {
434 kfree(node);
435 return NULL;
436 }
69843396 437
ef8bbd73
GL
438 of_node_set_flag(node, OF_DYNAMIC);
439 of_node_set_flag(node, OF_DETACHED);
69843396
PA
440 of_node_init(node);
441
e5179581
GL
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 }
69843396
PA
457 return node;
458
e5179581
GL
459 err_prop:
460 of_node_put(node); /* Frees the node and properties */
69843396
PA
461 return NULL;
462}
201c910b
PA
463
464static void __of_changeset_entry_destroy(struct of_changeset_entry *ce)
465{
144552c7
FR
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
201c910b
PA
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:
201c910b 486 case OF_RECONFIG_REMOVE_PROPERTY:
201c910b 487 case OF_RECONFIG_UPDATE_PROPERTY:
0d638a07
RH
488 pr_debug("cset<%p> %-15s %pOF/%s\n", ce, action_names[ce->action],
489 ce->np, ce->prop->name);
201c910b
PA
490 break;
491 case OF_RECONFIG_ATTACH_NODE:
201c910b 492 case OF_RECONFIG_DETACH_NODE:
0d638a07
RH
493 pr_debug("cset<%p> %-15s %pOF\n", ce, action_names[ce->action],
494 ce->np);
201c910b
PA
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;
b9c43856
PA
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 }
201c910b
PA
531 break;
532 }
533}
534
24789c5c
FR
535static int __of_changeset_entry_notify(struct of_changeset_entry *ce,
536 bool revert)
201c910b 537{
f5242e5a 538 struct of_reconfig_data rd;
201c910b 539 struct of_changeset_entry ce_inverted;
24789c5c 540 int ret = 0;
201c910b
PA
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:
f5242e5a
GL
550 memset(&rd, 0, sizeof(rd));
551 rd.dn = ce->np;
552 ret = of_reconfig_notify(ce->action, &rd);
201c910b
PA
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:
606ad42a 560 pr_err("invalid devicetree changeset action: %i\n",
201c910b 561 (int)ce->action);
24789c5c 562 ret = -EINVAL;
201c910b
PA
563 }
564
565 if (ret)
0d638a07 566 pr_err("changeset notifier error @%pOF\n", ce->np);
24789c5c 567 return ret;
201c910b
PA
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) {
0d638a07
RH
598 pr_err("changeset: add_property failed @%pOF/%s\n",
599 ce->np,
201c910b
PA
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) {
0d638a07
RH
607 pr_err("changeset: remove_property failed @%pOF/%s\n",
608 ce->np,
201c910b
PA
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) {
0d638a07
RH
626 pr_err("changeset: update_property failed @%pOF/%s\n",
627 ce->np,
201c910b
PA
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}
18322377 682EXPORT_SYMBOL_GPL(of_changeset_init);
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PA
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}
18322377 699EXPORT_SYMBOL_GPL(of_changeset_destroy);
201c910b 700
24789c5c
FR
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)
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PA
712{
713 struct of_changeset_entry *ce;
24789c5c 714 int ret, ret_tmp;
201c910b 715
606ad42a 716 pr_debug("changeset: applying...\n");
201c910b
PA
717 list_for_each_entry(ce, &ocs->entries, node) {
718 ret = __of_changeset_entry_apply(ce);
719 if (ret) {
606ad42a 720 pr_err("Error applying changeset (%d)\n", ret);
24789c5c
FR
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 }
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727 return ret;
728 }
729 }
24789c5c
FR
730
731 return 0;
732}
733
734/*
735 * Returns 0 on success, a negative error value in case of an error.
736 *
e9d92e40 737 * If multiple changeset entry notification errors occur then only the
24789c5c
FR
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");
201c910b
PA
746
747 /* drop the global lock while emitting notifiers */
748 mutex_unlock(&of_mutex);
24789c5c
FR
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 }
201c910b 754 mutex_lock(&of_mutex);
606ad42a 755 pr_debug("changeset: notifiers sent.\n");
201c910b 756
24789c5c
FR
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;
201c910b
PA
777}
778
779/**
18322377 780 * of_changeset_apply - Applies a changeset
201c910b
PA
781 *
782 * @ocs: changeset pointer
783 *
18322377
GS
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.
8c8239c2
RH
788 *
789 * Return: 0 on success, a negative error value in case of an error.
18322377 790 * On error the partially applied effects are reverted.
201c910b 791 */
18322377
GS
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
24789c5c
FR
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)
201c910b
PA
816{
817 struct of_changeset_entry *ce;
24789c5c 818 int ret, ret_tmp;
201c910b 819
606ad42a 820 pr_debug("changeset: reverting...\n");
201c910b
PA
821 list_for_each_entry_reverse(ce, &ocs->entries, node) {
822 ret = __of_changeset_entry_revert(ce);
823 if (ret) {
606ad42a 824 pr_err("Error reverting changeset (%d)\n", ret);
24789c5c
FR
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 }
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PA
830 return ret;
831 }
832 }
24789c5c
FR
833
834 return 0;
835}
836
837/*
e9d92e40 838 * If multiple changeset entry notification errors occur then only the
24789c5c
FR
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");
201c910b
PA
847
848 /* drop the global lock while emitting notifiers */
849 mutex_unlock(&of_mutex);
24789c5c
FR
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 }
201c910b 855 mutex_lock(&of_mutex);
606ad42a 856 pr_debug("changeset: notifiers sent.\n");
201c910b 857
24789c5c
FR
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;
201c910b
PA
872}
873
18322377
GS
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.
8c8239c2
RH
883 *
884 * Return: 0 on success, a negative error value in case of an error.
18322377
GS
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
201c910b 898/**
0290c4ca 899 * of_changeset_action - Add an action to the tail of the changeset list
201c910b
PA
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
8c8239c2
RH
912 *
913 * Return: 0 on success, a negative error value in case of an error.
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PA
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);
606ad42a 921 if (!ce)
201c910b 922 return -ENOMEM;
606ad42a 923
201c910b
PA
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}
18322377 936EXPORT_SYMBOL_GPL(of_changeset_action);