Commit | Line | Data |
---|---|---|
7518b589 PA |
1 | /* |
2 | * Functions for working with device tree overlays | |
3 | * | |
4 | * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com> | |
5 | * Copyright (C) 2012 Texas Instruments Inc. | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * version 2 as published by the Free Software Foundation. | |
10 | */ | |
606ad42a RH |
11 | |
12 | #define pr_fmt(fmt) "OF: overlay: " fmt | |
13 | ||
7518b589 PA |
14 | #include <linux/kernel.h> |
15 | #include <linux/module.h> | |
16 | #include <linux/of.h> | |
17 | #include <linux/of_device.h> | |
18 | #include <linux/string.h> | |
19 | #include <linux/ctype.h> | |
20 | #include <linux/errno.h> | |
7518b589 PA |
21 | #include <linux/slab.h> |
22 | #include <linux/err.h> | |
0d1886df | 23 | #include <linux/idr.h> |
7518b589 PA |
24 | |
25 | #include "of_private.h" | |
26 | ||
27 | /** | |
28 | * struct of_overlay_info - Holds a single overlay info | |
29 | * @target: target of the overlay operation | |
30 | * @overlay: pointer to the overlay contents node | |
31 | * | |
32 | * Holds a single overlay state, including all the overlay logs & | |
33 | * records. | |
34 | */ | |
35 | struct of_overlay_info { | |
36 | struct device_node *target; | |
37 | struct device_node *overlay; | |
d1651b03 | 38 | bool is_symbols_node; |
7518b589 PA |
39 | }; |
40 | ||
41 | /** | |
42 | * struct of_overlay - Holds a complete overlay transaction | |
43 | * @node: List on which we are located | |
44 | * @count: Count of ovinfo structures | |
45 | * @ovinfo_tab: Overlay info table (count sized) | |
46 | * @cset: Changeset to be used | |
47 | * | |
48 | * Holds a complete overlay transaction | |
49 | */ | |
50 | struct of_overlay { | |
51 | int id; | |
52 | struct list_head node; | |
53 | int count; | |
54 | struct of_overlay_info *ovinfo_tab; | |
55 | struct of_changeset cset; | |
56 | }; | |
57 | ||
58 | static int of_overlay_apply_one(struct of_overlay *ov, | |
d1651b03 FR |
59 | struct device_node *target, const struct device_node *overlay, |
60 | bool is_symbols_node); | |
7518b589 | 61 | |
39a842e2 AT |
62 | static BLOCKING_NOTIFIER_HEAD(of_overlay_chain); |
63 | ||
64 | int of_overlay_notifier_register(struct notifier_block *nb) | |
65 | { | |
66 | return blocking_notifier_chain_register(&of_overlay_chain, nb); | |
67 | } | |
68 | EXPORT_SYMBOL_GPL(of_overlay_notifier_register); | |
69 | ||
70 | int of_overlay_notifier_unregister(struct notifier_block *nb) | |
71 | { | |
72 | return blocking_notifier_chain_unregister(&of_overlay_chain, nb); | |
73 | } | |
74 | EXPORT_SYMBOL_GPL(of_overlay_notifier_unregister); | |
75 | ||
76 | static int of_overlay_notify(struct of_overlay *ov, | |
77 | enum of_overlay_notify_action action) | |
78 | { | |
79 | struct of_overlay_notify_data nd; | |
80 | int i, ret; | |
81 | ||
82 | for (i = 0; i < ov->count; i++) { | |
83 | struct of_overlay_info *ovinfo = &ov->ovinfo_tab[i]; | |
84 | ||
85 | nd.target = ovinfo->target; | |
86 | nd.overlay = ovinfo->overlay; | |
87 | ||
88 | ret = blocking_notifier_call_chain(&of_overlay_chain, | |
89 | action, &nd); | |
90 | if (ret) | |
91 | return notifier_to_errno(ret); | |
92 | } | |
93 | ||
94 | return 0; | |
95 | } | |
96 | ||
d1651b03 FR |
97 | static struct property *dup_and_fixup_symbol_prop(struct of_overlay *ov, |
98 | const struct property *prop) | |
99 | { | |
100 | struct of_overlay_info *ovinfo; | |
101 | struct property *new; | |
102 | const char *overlay_name; | |
103 | char *label_path; | |
104 | char *symbol_path; | |
105 | const char *target_path; | |
106 | int k; | |
107 | int label_path_len; | |
108 | int overlay_name_len; | |
109 | int target_path_len; | |
110 | ||
111 | if (!prop->value) | |
112 | return NULL; | |
113 | symbol_path = prop->value; | |
114 | ||
115 | new = kzalloc(sizeof(*new), GFP_KERNEL); | |
116 | if (!new) | |
117 | return NULL; | |
118 | ||
119 | for (k = 0; k < ov->count; k++) { | |
120 | ovinfo = &ov->ovinfo_tab[k]; | |
121 | overlay_name = ovinfo->overlay->full_name; | |
122 | overlay_name_len = strlen(overlay_name); | |
123 | if (!strncasecmp(symbol_path, overlay_name, overlay_name_len)) | |
124 | break; | |
125 | } | |
126 | ||
127 | if (k >= ov->count) | |
128 | goto err_free; | |
129 | ||
130 | target_path = ovinfo->target->full_name; | |
131 | target_path_len = strlen(target_path); | |
132 | ||
133 | label_path = symbol_path + overlay_name_len; | |
134 | label_path_len = strlen(label_path); | |
135 | ||
136 | new->name = kstrdup(prop->name, GFP_KERNEL); | |
137 | new->length = target_path_len + label_path_len + 1; | |
138 | new->value = kzalloc(new->length, GFP_KERNEL); | |
139 | ||
140 | if (!new->name || !new->value) | |
141 | goto err_free; | |
142 | ||
143 | strcpy(new->value, target_path); | |
144 | strcpy(new->value + target_path_len, label_path); | |
145 | ||
146 | /* mark the property as dynamic */ | |
147 | of_property_set_flag(new, OF_DYNAMIC); | |
148 | ||
149 | return new; | |
150 | ||
151 | err_free: | |
152 | kfree(new->name); | |
153 | kfree(new->value); | |
154 | kfree(new); | |
155 | return NULL; | |
156 | ||
157 | ||
158 | } | |
159 | ||
7518b589 | 160 | static int of_overlay_apply_single_property(struct of_overlay *ov, |
d1651b03 FR |
161 | struct device_node *target, struct property *prop, |
162 | bool is_symbols_node) | |
7518b589 | 163 | { |
d1651b03 | 164 | struct property *propn = NULL, *tprop; |
7518b589 PA |
165 | |
166 | /* NOTE: Multiple changes of single properties not supported */ | |
167 | tprop = of_find_property(target, prop->name, NULL); | |
168 | ||
169 | /* special properties are not meant to be updated (silent NOP) */ | |
170 | if (of_prop_cmp(prop->name, "name") == 0 || | |
171 | of_prop_cmp(prop->name, "phandle") == 0 || | |
172 | of_prop_cmp(prop->name, "linux,phandle") == 0) | |
173 | return 0; | |
174 | ||
d1651b03 FR |
175 | if (is_symbols_node) { |
176 | /* changing a property in __symbols__ node not allowed */ | |
177 | if (tprop) | |
178 | return -EINVAL; | |
179 | propn = dup_and_fixup_symbol_prop(ov, prop); | |
180 | } else { | |
181 | propn = __of_prop_dup(prop, GFP_KERNEL); | |
182 | } | |
183 | ||
7518b589 PA |
184 | if (propn == NULL) |
185 | return -ENOMEM; | |
186 | ||
187 | /* not found? add */ | |
188 | if (tprop == NULL) | |
189 | return of_changeset_add_property(&ov->cset, target, propn); | |
190 | ||
191 | /* found? update */ | |
192 | return of_changeset_update_property(&ov->cset, target, propn); | |
193 | } | |
194 | ||
195 | static int of_overlay_apply_single_device_node(struct of_overlay *ov, | |
196 | struct device_node *target, struct device_node *child) | |
197 | { | |
198 | const char *cname; | |
d3a89165 | 199 | struct device_node *tchild; |
7518b589 PA |
200 | int ret = 0; |
201 | ||
202 | cname = kbasename(child->full_name); | |
203 | if (cname == NULL) | |
204 | return -ENOMEM; | |
205 | ||
206 | /* NOTE: Multiple mods of created nodes not supported */ | |
c1cd1e01 FR |
207 | for_each_child_of_node(target, tchild) |
208 | if (!of_node_cmp(cname, kbasename(tchild->full_name))) | |
209 | break; | |
210 | ||
7518b589 | 211 | if (tchild != NULL) { |
7a12f459 FR |
212 | /* new overlay phandle value conflicts with existing value */ |
213 | if (child->phandle) | |
214 | return -EINVAL; | |
215 | ||
7518b589 | 216 | /* apply overlay recursively */ |
d1651b03 | 217 | ret = of_overlay_apply_one(ov, tchild, child, 0); |
7518b589 PA |
218 | of_node_put(tchild); |
219 | } else { | |
220 | /* create empty tree as a target */ | |
0d638a07 | 221 | tchild = __of_node_dup(child, "%pOF/%s", target, cname); |
7518b589 PA |
222 | if (!tchild) |
223 | return -ENOMEM; | |
224 | ||
225 | /* point to parent */ | |
226 | tchild->parent = target; | |
227 | ||
228 | ret = of_changeset_attach_node(&ov->cset, tchild); | |
229 | if (ret) | |
230 | return ret; | |
231 | ||
d1651b03 | 232 | ret = of_overlay_apply_one(ov, tchild, child, 0); |
7518b589 PA |
233 | if (ret) |
234 | return ret; | |
7518b589 PA |
235 | } |
236 | ||
237 | return ret; | |
238 | } | |
239 | ||
240 | /* | |
241 | * Apply a single overlay node recursively. | |
242 | * | |
243 | * Note that the in case of an error the target node is left | |
244 | * in a inconsistent state. Error recovery should be performed | |
245 | * by using the changeset. | |
246 | */ | |
247 | static int of_overlay_apply_one(struct of_overlay *ov, | |
d1651b03 FR |
248 | struct device_node *target, const struct device_node *overlay, |
249 | bool is_symbols_node) | |
7518b589 PA |
250 | { |
251 | struct device_node *child; | |
252 | struct property *prop; | |
253 | int ret; | |
254 | ||
255 | for_each_property_of_node(overlay, prop) { | |
d1651b03 FR |
256 | ret = of_overlay_apply_single_property(ov, target, prop, |
257 | is_symbols_node); | |
7518b589 | 258 | if (ret) { |
0d638a07 RH |
259 | pr_err("Failed to apply prop @%pOF/%s\n", |
260 | target, prop->name); | |
7518b589 PA |
261 | return ret; |
262 | } | |
263 | } | |
264 | ||
d1651b03 FR |
265 | /* do not allow symbols node to have any children */ |
266 | if (is_symbols_node) | |
267 | return 0; | |
268 | ||
7518b589 PA |
269 | for_each_child_of_node(overlay, child) { |
270 | ret = of_overlay_apply_single_device_node(ov, target, child); | |
271 | if (ret != 0) { | |
0d638a07 RH |
272 | pr_err("Failed to apply single node @%pOF/%s\n", |
273 | target, child->name); | |
001cf504 | 274 | of_node_put(child); |
7518b589 PA |
275 | return ret; |
276 | } | |
277 | } | |
278 | ||
279 | return 0; | |
280 | } | |
281 | ||
282 | /** | |
283 | * of_overlay_apply() - Apply @count overlays pointed at by @ovinfo_tab | |
284 | * @ov: Overlay to apply | |
285 | * | |
286 | * Applies the overlays given, while handling all error conditions | |
287 | * appropriately. Either the operation succeeds, or if it fails the | |
288 | * live tree is reverted to the state before the attempt. | |
289 | * Returns 0, or an error if the overlay attempt failed. | |
290 | */ | |
291 | static int of_overlay_apply(struct of_overlay *ov) | |
292 | { | |
293 | int i, err; | |
294 | ||
295 | /* first we apply the overlays atomically */ | |
296 | for (i = 0; i < ov->count; i++) { | |
297 | struct of_overlay_info *ovinfo = &ov->ovinfo_tab[i]; | |
298 | ||
d1651b03 FR |
299 | err = of_overlay_apply_one(ov, ovinfo->target, ovinfo->overlay, |
300 | ovinfo->is_symbols_node); | |
7518b589 | 301 | if (err != 0) { |
0d638a07 | 302 | pr_err("apply failed '%pOF'\n", ovinfo->target); |
7518b589 PA |
303 | return err; |
304 | } | |
305 | } | |
306 | ||
307 | return 0; | |
308 | } | |
309 | ||
310 | /* | |
311 | * Find the target node using a number of different strategies | |
312 | * in order of preference | |
313 | * | |
314 | * "target" property containing the phandle of the target | |
315 | * "target-path" property containing the path of the target | |
316 | */ | |
317 | static struct device_node *find_target_node(struct device_node *info_node) | |
318 | { | |
319 | const char *path; | |
320 | u32 val; | |
321 | int ret; | |
322 | ||
323 | /* first try to go by using the target as a phandle */ | |
324 | ret = of_property_read_u32(info_node, "target", &val); | |
325 | if (ret == 0) | |
326 | return of_find_node_by_phandle(val); | |
327 | ||
328 | /* now try to locate by path */ | |
329 | ret = of_property_read_string(info_node, "target-path", &path); | |
330 | if (ret == 0) | |
331 | return of_find_node_by_path(path); | |
332 | ||
606ad42a | 333 | pr_err("Failed to find target for node %p (%s)\n", |
7518b589 PA |
334 | info_node, info_node->name); |
335 | ||
336 | return NULL; | |
337 | } | |
338 | ||
339 | /** | |
340 | * of_fill_overlay_info() - Fill an overlay info structure | |
341 | * @ov Overlay to fill | |
342 | * @info_node: Device node containing the overlay | |
343 | * @ovinfo: Pointer to the overlay info structure to fill | |
344 | * | |
345 | * Fills an overlay info structure with the overlay information | |
346 | * from a device node. This device node must have a target property | |
347 | * which contains a phandle of the overlay target node, and an | |
348 | * __overlay__ child node which has the overlay contents. | |
349 | * Both ovinfo->target & ovinfo->overlay have their references taken. | |
350 | * | |
351 | * Returns 0 on success, or a negative error value. | |
352 | */ | |
353 | static int of_fill_overlay_info(struct of_overlay *ov, | |
354 | struct device_node *info_node, struct of_overlay_info *ovinfo) | |
355 | { | |
356 | ovinfo->overlay = of_get_child_by_name(info_node, "__overlay__"); | |
357 | if (ovinfo->overlay == NULL) | |
358 | goto err_fail; | |
359 | ||
360 | ovinfo->target = find_target_node(info_node); | |
361 | if (ovinfo->target == NULL) | |
362 | goto err_fail; | |
363 | ||
364 | return 0; | |
365 | ||
366 | err_fail: | |
367 | of_node_put(ovinfo->target); | |
368 | of_node_put(ovinfo->overlay); | |
369 | ||
370 | memset(ovinfo, 0, sizeof(*ovinfo)); | |
371 | return -EINVAL; | |
372 | } | |
373 | ||
374 | /** | |
375 | * of_build_overlay_info() - Build an overlay info array | |
376 | * @ov Overlay to build | |
377 | * @tree: Device node containing all the overlays | |
378 | * | |
379 | * Helper function that given a tree containing overlay information, | |
380 | * allocates and builds an overlay info array containing it, ready | |
381 | * for use using of_overlay_apply. | |
382 | * | |
383 | * Returns 0 on success with the @cntp @ovinfop pointers valid, | |
384 | * while on error a negative error value is returned. | |
385 | */ | |
386 | static int of_build_overlay_info(struct of_overlay *ov, | |
387 | struct device_node *tree) | |
388 | { | |
389 | struct device_node *node; | |
390 | struct of_overlay_info *ovinfo; | |
391 | int cnt, err; | |
392 | ||
393 | /* worst case; every child is a node */ | |
394 | cnt = 0; | |
395 | for_each_child_of_node(tree, node) | |
396 | cnt++; | |
397 | ||
d1651b03 FR |
398 | if (of_get_child_by_name(tree, "__symbols__")) |
399 | cnt++; | |
400 | ||
7518b589 PA |
401 | ovinfo = kcalloc(cnt, sizeof(*ovinfo), GFP_KERNEL); |
402 | if (ovinfo == NULL) | |
403 | return -ENOMEM; | |
404 | ||
405 | cnt = 0; | |
406 | for_each_child_of_node(tree, node) { | |
7518b589 PA |
407 | err = of_fill_overlay_info(ov, node, &ovinfo[cnt]); |
408 | if (err == 0) | |
409 | cnt++; | |
410 | } | |
411 | ||
d1651b03 FR |
412 | node = of_get_child_by_name(tree, "__symbols__"); |
413 | if (node) { | |
414 | ovinfo[cnt].overlay = node; | |
415 | ovinfo[cnt].target = of_find_node_by_path("/__symbols__"); | |
416 | ovinfo[cnt].is_symbols_node = 1; | |
417 | ||
418 | if (!ovinfo[cnt].target) { | |
419 | pr_err("no symbols in root of device tree.\n"); | |
420 | return -EINVAL; | |
421 | } | |
422 | ||
423 | cnt++; | |
424 | } | |
425 | ||
7518b589 PA |
426 | /* if nothing filled, return error */ |
427 | if (cnt == 0) { | |
428 | kfree(ovinfo); | |
429 | return -ENODEV; | |
430 | } | |
431 | ||
432 | ov->count = cnt; | |
433 | ov->ovinfo_tab = ovinfo; | |
434 | ||
435 | return 0; | |
436 | } | |
437 | ||
438 | /** | |
439 | * of_free_overlay_info() - Free an overlay info array | |
440 | * @ov Overlay to free the overlay info from | |
441 | * @ovinfo_tab: Array of overlay_info's to free | |
442 | * | |
443 | * Releases the memory of a previously allocated ovinfo array | |
444 | * by of_build_overlay_info. | |
445 | * Returns 0, or an error if the arguments are bogus. | |
446 | */ | |
447 | static int of_free_overlay_info(struct of_overlay *ov) | |
448 | { | |
449 | struct of_overlay_info *ovinfo; | |
450 | int i; | |
451 | ||
452 | /* do it in reverse */ | |
453 | for (i = ov->count - 1; i >= 0; i--) { | |
454 | ovinfo = &ov->ovinfo_tab[i]; | |
455 | ||
456 | of_node_put(ovinfo->target); | |
457 | of_node_put(ovinfo->overlay); | |
458 | } | |
459 | kfree(ov->ovinfo_tab); | |
460 | ||
461 | return 0; | |
462 | } | |
463 | ||
464 | static LIST_HEAD(ov_list); | |
465 | static DEFINE_IDR(ov_idr); | |
466 | ||
467 | /** | |
468 | * of_overlay_create() - Create and apply an overlay | |
469 | * @tree: Device node containing all the overlays | |
470 | * | |
471 | * Creates and applies an overlay while also keeping track | |
472 | * of the overlay in a list. This list can be used to prevent | |
473 | * illegal overlay removals. | |
474 | * | |
94a8bf97 | 475 | * Returns the id of the created overlay, or a negative error number |
7518b589 PA |
476 | */ |
477 | int of_overlay_create(struct device_node *tree) | |
478 | { | |
479 | struct of_overlay *ov; | |
480 | int err, id; | |
481 | ||
482 | /* allocate the overlay structure */ | |
483 | ov = kzalloc(sizeof(*ov), GFP_KERNEL); | |
484 | if (ov == NULL) | |
485 | return -ENOMEM; | |
486 | ov->id = -1; | |
487 | ||
488 | INIT_LIST_HEAD(&ov->node); | |
489 | ||
490 | of_changeset_init(&ov->cset); | |
491 | ||
492 | mutex_lock(&of_mutex); | |
493 | ||
494 | id = idr_alloc(&ov_idr, ov, 0, 0, GFP_KERNEL); | |
495 | if (id < 0) { | |
7518b589 PA |
496 | err = id; |
497 | goto err_destroy_trans; | |
498 | } | |
499 | ov->id = id; | |
500 | ||
501 | /* build the overlay info structures */ | |
502 | err = of_build_overlay_info(ov, tree); | |
503 | if (err) { | |
0d638a07 RH |
504 | pr_err("of_build_overlay_info() failed for tree@%pOF\n", |
505 | tree); | |
7518b589 PA |
506 | goto err_free_idr; |
507 | } | |
508 | ||
39a842e2 AT |
509 | err = of_overlay_notify(ov, OF_OVERLAY_PRE_APPLY); |
510 | if (err < 0) { | |
511 | pr_err("%s: Pre-apply notifier failed (err=%d)\n", | |
512 | __func__, err); | |
513 | goto err_free_idr; | |
514 | } | |
515 | ||
7518b589 PA |
516 | /* apply the overlay */ |
517 | err = of_overlay_apply(ov); | |
606ad42a | 518 | if (err) |
7518b589 | 519 | goto err_abort_trans; |
7518b589 PA |
520 | |
521 | /* apply the changeset */ | |
18322377 | 522 | err = __of_changeset_apply(&ov->cset); |
606ad42a | 523 | if (err) |
7518b589 | 524 | goto err_revert_overlay; |
606ad42a | 525 | |
7518b589 PA |
526 | |
527 | /* add to the tail of the overlay list */ | |
528 | list_add_tail(&ov->node, &ov_list); | |
529 | ||
39a842e2 AT |
530 | of_overlay_notify(ov, OF_OVERLAY_POST_APPLY); |
531 | ||
7518b589 PA |
532 | mutex_unlock(&of_mutex); |
533 | ||
534 | return id; | |
535 | ||
536 | err_revert_overlay: | |
537 | err_abort_trans: | |
538 | of_free_overlay_info(ov); | |
539 | err_free_idr: | |
540 | idr_remove(&ov_idr, ov->id); | |
541 | err_destroy_trans: | |
542 | of_changeset_destroy(&ov->cset); | |
543 | kfree(ov); | |
544 | mutex_unlock(&of_mutex); | |
545 | ||
546 | return err; | |
547 | } | |
548 | EXPORT_SYMBOL_GPL(of_overlay_create); | |
549 | ||
550 | /* check whether the given node, lies under the given tree */ | |
551 | static int overlay_subtree_check(struct device_node *tree, | |
552 | struct device_node *dn) | |
553 | { | |
554 | struct device_node *child; | |
555 | ||
556 | /* match? */ | |
557 | if (tree == dn) | |
558 | return 1; | |
559 | ||
560 | for_each_child_of_node(tree, child) { | |
001cf504 JL |
561 | if (overlay_subtree_check(child, dn)) { |
562 | of_node_put(child); | |
7518b589 | 563 | return 1; |
001cf504 | 564 | } |
7518b589 PA |
565 | } |
566 | ||
567 | return 0; | |
568 | } | |
569 | ||
570 | /* check whether this overlay is the topmost */ | |
571 | static int overlay_is_topmost(struct of_overlay *ov, struct device_node *dn) | |
572 | { | |
573 | struct of_overlay *ovt; | |
574 | struct of_changeset_entry *ce; | |
575 | ||
576 | list_for_each_entry_reverse(ovt, &ov_list, node) { | |
577 | /* if we hit ourselves, we're done */ | |
578 | if (ovt == ov) | |
579 | break; | |
580 | ||
581 | /* check against each subtree affected by this overlay */ | |
582 | list_for_each_entry(ce, &ovt->cset.entries, node) { | |
583 | if (overlay_subtree_check(ce->np, dn)) { | |
0d638a07 RH |
584 | pr_err("%s: #%d clashes #%d @%pOF\n", |
585 | __func__, ov->id, ovt->id, dn); | |
7518b589 PA |
586 | return 0; |
587 | } | |
588 | } | |
589 | } | |
590 | ||
591 | /* overlay is topmost */ | |
592 | return 1; | |
593 | } | |
594 | ||
595 | /* | |
596 | * We can safely remove the overlay only if it's the top-most one. | |
597 | * Newly applied overlays are inserted at the tail of the overlay list, | |
598 | * so a top most overlay is the one that is closest to the tail. | |
599 | * | |
600 | * The topmost check is done by exploiting this property. For each | |
601 | * affected device node in the log list we check if this overlay is | |
602 | * the one closest to the tail. If another overlay has affected this | |
603 | * device node and is closest to the tail, then removal is not permited. | |
604 | */ | |
605 | static int overlay_removal_is_ok(struct of_overlay *ov) | |
606 | { | |
607 | struct of_changeset_entry *ce; | |
608 | ||
609 | list_for_each_entry(ce, &ov->cset.entries, node) { | |
610 | if (!overlay_is_topmost(ov, ce->np)) { | |
606ad42a | 611 | pr_err("overlay #%d is not topmost\n", ov->id); |
7518b589 PA |
612 | return 0; |
613 | } | |
614 | } | |
615 | ||
616 | return 1; | |
617 | } | |
618 | ||
619 | /** | |
620 | * of_overlay_destroy() - Removes an overlay | |
621 | * @id: Overlay id number returned by a previous call to of_overlay_create | |
622 | * | |
623 | * Removes an overlay if it is permissible. | |
624 | * | |
94a8bf97 | 625 | * Returns 0 on success, or a negative error number |
7518b589 PA |
626 | */ |
627 | int of_overlay_destroy(int id) | |
628 | { | |
629 | struct of_overlay *ov; | |
630 | int err; | |
631 | ||
632 | mutex_lock(&of_mutex); | |
633 | ||
634 | ov = idr_find(&ov_idr, id); | |
635 | if (ov == NULL) { | |
636 | err = -ENODEV; | |
606ad42a | 637 | pr_err("destroy: Could not find overlay #%d\n", id); |
7518b589 PA |
638 | goto out; |
639 | } | |
640 | ||
641 | /* check whether the overlay is safe to remove */ | |
642 | if (!overlay_removal_is_ok(ov)) { | |
643 | err = -EBUSY; | |
7518b589 PA |
644 | goto out; |
645 | } | |
646 | ||
39a842e2 | 647 | of_overlay_notify(ov, OF_OVERLAY_PRE_REMOVE); |
7518b589 | 648 | list_del(&ov->node); |
18322377 | 649 | __of_changeset_revert(&ov->cset); |
39a842e2 | 650 | of_overlay_notify(ov, OF_OVERLAY_POST_REMOVE); |
7518b589 PA |
651 | of_free_overlay_info(ov); |
652 | idr_remove(&ov_idr, id); | |
653 | of_changeset_destroy(&ov->cset); | |
654 | kfree(ov); | |
655 | ||
656 | err = 0; | |
657 | ||
658 | out: | |
659 | mutex_unlock(&of_mutex); | |
660 | ||
661 | return err; | |
662 | } | |
663 | EXPORT_SYMBOL_GPL(of_overlay_destroy); | |
664 | ||
665 | /** | |
666 | * of_overlay_destroy_all() - Removes all overlays from the system | |
667 | * | |
668 | * Removes all overlays from the system in the correct order. | |
669 | * | |
94a8bf97 | 670 | * Returns 0 on success, or a negative error number |
7518b589 PA |
671 | */ |
672 | int of_overlay_destroy_all(void) | |
673 | { | |
674 | struct of_overlay *ov, *ovn; | |
675 | ||
676 | mutex_lock(&of_mutex); | |
677 | ||
678 | /* the tail of list is guaranteed to be safe to remove */ | |
679 | list_for_each_entry_safe_reverse(ov, ovn, &ov_list, node) { | |
680 | list_del(&ov->node); | |
18322377 | 681 | __of_changeset_revert(&ov->cset); |
7518b589 PA |
682 | of_free_overlay_info(ov); |
683 | idr_remove(&ov_idr, ov->id); | |
684 | kfree(ov); | |
685 | } | |
686 | ||
687 | mutex_unlock(&of_mutex); | |
688 | ||
689 | return 0; | |
690 | } | |
691 | EXPORT_SYMBOL_GPL(of_overlay_destroy_all); |