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af6074fc | 1 | // SPDX-License-Identifier: GPL-2.0 |
7518b589 PA |
2 | /* |
3 | * Functions for working with device tree overlays | |
4 | * | |
5 | * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com> | |
6 | * Copyright (C) 2012 Texas Instruments Inc. | |
7518b589 | 7 | */ |
606ad42a RH |
8 | |
9 | #define pr_fmt(fmt) "OF: overlay: " fmt | |
10 | ||
7518b589 PA |
11 | #include <linux/kernel.h> |
12 | #include <linux/module.h> | |
13 | #include <linux/of.h> | |
14 | #include <linux/of_device.h> | |
39a751a4 | 15 | #include <linux/of_fdt.h> |
7518b589 PA |
16 | #include <linux/string.h> |
17 | #include <linux/ctype.h> | |
18 | #include <linux/errno.h> | |
7518b589 | 19 | #include <linux/slab.h> |
39a751a4 | 20 | #include <linux/libfdt.h> |
7518b589 | 21 | #include <linux/err.h> |
0d1886df | 22 | #include <linux/idr.h> |
7518b589 PA |
23 | |
24 | #include "of_private.h" | |
25 | ||
6b4955ba FR |
26 | /** |
27 | * struct target - info about current target node as recursing through overlay | |
28 | * @np: node where current level of overlay will be applied | |
29 | * @in_livetree: @np is a node in the live devicetree | |
30 | * | |
31 | * Used in the algorithm to create the portion of a changeset that describes | |
32 | * an overlay fragment, which is a devicetree subtree. Initially @np is a node | |
33 | * in the live devicetree where the overlay subtree is targeted to be grafted | |
34 | * into. When recursing to the next level of the overlay subtree, the target | |
35 | * also recurses to the next level of the live devicetree, as long as overlay | |
36 | * subtree node also exists in the live devicetree. When a node in the overlay | |
37 | * subtree does not exist at the same level in the live devicetree, target->np | |
38 | * points to a newly allocated node, and all subsequent targets in the subtree | |
39 | * will be newly allocated nodes. | |
40 | */ | |
41 | struct target { | |
42 | struct device_node *np; | |
43 | bool in_livetree; | |
44 | }; | |
45 | ||
7518b589 | 46 | /** |
0290c4ca | 47 | * struct fragment - info about fragment nodes in overlay expanded device tree |
7518b589 | 48 | * @target: target of the overlay operation |
0290c4ca | 49 | * @overlay: pointer to the __overlay__ node |
7518b589 | 50 | */ |
0290c4ca | 51 | struct fragment { |
7518b589 PA |
52 | struct device_node *target; |
53 | struct device_node *overlay; | |
54 | }; | |
55 | ||
56 | /** | |
0290c4ca | 57 | * struct overlay_changeset |
39a751a4 | 58 | * @id: changeset identifier |
3912b791 | 59 | * @ovcs_list: list on which we are located |
39a751a4 | 60 | * @fdt: FDT that was unflattened to create @overlay_tree |
e0a58f3e | 61 | * @overlay_tree: expanded device tree that contains the fragment nodes |
3912b791 FR |
62 | * @count: count of fragment structures |
63 | * @fragments: fragment nodes in the overlay expanded device tree | |
64 | * @symbols_fragment: last element of @fragments[] is the __symbols__ node | |
65 | * @cset: changeset to apply fragments to live device tree | |
7518b589 | 66 | */ |
0290c4ca | 67 | struct overlay_changeset { |
7518b589 | 68 | int id; |
0290c4ca | 69 | struct list_head ovcs_list; |
39a751a4 | 70 | const void *fdt; |
e0a58f3e | 71 | struct device_node *overlay_tree; |
7518b589 | 72 | int count; |
0290c4ca | 73 | struct fragment *fragments; |
3912b791 | 74 | bool symbols_fragment; |
7518b589 PA |
75 | struct of_changeset cset; |
76 | }; | |
77 | ||
24789c5c FR |
78 | /* flags are sticky - once set, do not reset */ |
79 | static int devicetree_state_flags; | |
80 | #define DTSF_APPLY_FAIL 0x01 | |
81 | #define DTSF_REVERT_FAIL 0x02 | |
82 | ||
83 | /* | |
84 | * If a changeset apply or revert encounters an error, an attempt will | |
85 | * be made to undo partial changes, but may fail. If the undo fails | |
86 | * we do not know the state of the devicetree. | |
87 | */ | |
88 | static int devicetree_corrupt(void) | |
89 | { | |
90 | return devicetree_state_flags & | |
91 | (DTSF_APPLY_FAIL | DTSF_REVERT_FAIL); | |
92 | } | |
93 | ||
0290c4ca | 94 | static int build_changeset_next_level(struct overlay_changeset *ovcs, |
6b4955ba | 95 | struct target *target, const struct device_node *overlay_node); |
7518b589 | 96 | |
f948d6d8 FR |
97 | /* |
98 | * of_resolve_phandles() finds the largest phandle in the live tree. | |
99 | * of_overlay_apply() may add a larger phandle to the live tree. | |
100 | * Do not allow race between two overlays being applied simultaneously: | |
101 | * mutex_lock(&of_overlay_phandle_mutex) | |
102 | * of_resolve_phandles() | |
103 | * of_overlay_apply() | |
104 | * mutex_unlock(&of_overlay_phandle_mutex) | |
105 | */ | |
106 | static DEFINE_MUTEX(of_overlay_phandle_mutex); | |
107 | ||
108 | void of_overlay_mutex_lock(void) | |
109 | { | |
110 | mutex_lock(&of_overlay_phandle_mutex); | |
111 | } | |
112 | ||
113 | void of_overlay_mutex_unlock(void) | |
114 | { | |
115 | mutex_unlock(&of_overlay_phandle_mutex); | |
116 | } | |
117 | ||
118 | ||
61b4de4e FR |
119 | static LIST_HEAD(ovcs_list); |
120 | static DEFINE_IDR(ovcs_idr); | |
121 | ||
0290c4ca | 122 | static BLOCKING_NOTIFIER_HEAD(overlay_notify_chain); |
39a842e2 | 123 | |
83ef4777 JK |
124 | /** |
125 | * of_overlay_notifier_register() - Register notifier for overlay operations | |
126 | * @nb: Notifier block to register | |
127 | * | |
128 | * Register for notification on overlay operations on device tree nodes. The | |
129 | * reported actions definied by @of_reconfig_change. The notifier callback | |
130 | * furthermore receives a pointer to the affected device tree node. | |
131 | * | |
132 | * Note that a notifier callback is not supposed to store pointers to a device | |
133 | * tree node or its content beyond @OF_OVERLAY_POST_REMOVE corresponding to the | |
134 | * respective node it received. | |
135 | */ | |
39a842e2 AT |
136 | int of_overlay_notifier_register(struct notifier_block *nb) |
137 | { | |
0290c4ca | 138 | return blocking_notifier_chain_register(&overlay_notify_chain, nb); |
39a842e2 AT |
139 | } |
140 | EXPORT_SYMBOL_GPL(of_overlay_notifier_register); | |
141 | ||
83ef4777 JK |
142 | /** |
143 | * of_overlay_notifier_register() - Unregister notifier for overlay operations | |
144 | * @nb: Notifier block to unregister | |
145 | */ | |
39a842e2 AT |
146 | int of_overlay_notifier_unregister(struct notifier_block *nb) |
147 | { | |
0290c4ca | 148 | return blocking_notifier_chain_unregister(&overlay_notify_chain, nb); |
39a842e2 AT |
149 | } |
150 | EXPORT_SYMBOL_GPL(of_overlay_notifier_unregister); | |
151 | ||
24789c5c FR |
152 | static char *of_overlay_action_name[] = { |
153 | "pre-apply", | |
154 | "post-apply", | |
155 | "pre-remove", | |
156 | "post-remove", | |
157 | }; | |
158 | ||
0290c4ca FR |
159 | static int overlay_notify(struct overlay_changeset *ovcs, |
160 | enum of_overlay_notify_action action) | |
39a842e2 AT |
161 | { |
162 | struct of_overlay_notify_data nd; | |
163 | int i, ret; | |
164 | ||
0290c4ca FR |
165 | for (i = 0; i < ovcs->count; i++) { |
166 | struct fragment *fragment = &ovcs->fragments[i]; | |
39a842e2 | 167 | |
0290c4ca FR |
168 | nd.target = fragment->target; |
169 | nd.overlay = fragment->overlay; | |
39a842e2 | 170 | |
0290c4ca | 171 | ret = blocking_notifier_call_chain(&overlay_notify_chain, |
39a842e2 | 172 | action, &nd); |
a1d19bd4 | 173 | if (ret == NOTIFY_OK || ret == NOTIFY_STOP) |
24789c5c FR |
174 | return 0; |
175 | if (ret) { | |
176 | ret = notifier_to_errno(ret); | |
177 | pr_err("overlay changeset %s notifier error %d, target: %pOF\n", | |
178 | of_overlay_action_name[action], ret, nd.target); | |
179 | return ret; | |
180 | } | |
39a842e2 AT |
181 | } |
182 | ||
183 | return 0; | |
184 | } | |
185 | ||
42b2e94f | 186 | /* |
e0a58f3e FR |
187 | * The values of properties in the "/__symbols__" node are paths in |
188 | * the ovcs->overlay_tree. When duplicating the properties, the paths | |
189 | * need to be adjusted to be the correct path for the live device tree. | |
42b2e94f | 190 | * |
e0a58f3e FR |
191 | * The paths refer to a node in the subtree of a fragment node's "__overlay__" |
192 | * node, for example "/fragment@0/__overlay__/symbol_path_tail", | |
193 | * where symbol_path_tail can be a single node or it may be a multi-node path. | |
42b2e94f FR |
194 | * |
195 | * The duplicated property value will be modified by replacing the | |
196 | * "/fragment_name/__overlay/" portion of the value with the target | |
197 | * path from the fragment node. | |
198 | */ | |
0290c4ca FR |
199 | static struct property *dup_and_fixup_symbol_prop( |
200 | struct overlay_changeset *ovcs, const struct property *prop) | |
d1651b03 | 201 | { |
0290c4ca | 202 | struct fragment *fragment; |
e0a58f3e FR |
203 | struct property *new_prop; |
204 | struct device_node *fragment_node; | |
205 | struct device_node *overlay_node; | |
206 | const char *path; | |
207 | const char *path_tail; | |
d1651b03 FR |
208 | const char *target_path; |
209 | int k; | |
d1651b03 | 210 | int overlay_name_len; |
e0a58f3e FR |
211 | int path_len; |
212 | int path_tail_len; | |
d1651b03 FR |
213 | int target_path_len; |
214 | ||
215 | if (!prop->value) | |
216 | return NULL; | |
e0a58f3e FR |
217 | if (strnlen(prop->value, prop->length) >= prop->length) |
218 | return NULL; | |
219 | path = prop->value; | |
220 | path_len = strlen(path); | |
d1651b03 | 221 | |
e0a58f3e | 222 | if (path_len < 1) |
d1651b03 | 223 | return NULL; |
e0a58f3e FR |
224 | fragment_node = __of_find_node_by_path(ovcs->overlay_tree, path + 1); |
225 | overlay_node = __of_find_node_by_path(fragment_node, "__overlay__/"); | |
226 | of_node_put(fragment_node); | |
227 | of_node_put(overlay_node); | |
d1651b03 | 228 | |
0290c4ca FR |
229 | for (k = 0; k < ovcs->count; k++) { |
230 | fragment = &ovcs->fragments[k]; | |
e0a58f3e | 231 | if (fragment->overlay == overlay_node) |
d1651b03 FR |
232 | break; |
233 | } | |
0290c4ca | 234 | if (k >= ovcs->count) |
e0a58f3e FR |
235 | return NULL; |
236 | ||
237 | overlay_name_len = snprintf(NULL, 0, "%pOF", fragment->overlay); | |
d1651b03 | 238 | |
e0a58f3e FR |
239 | if (overlay_name_len > path_len) |
240 | return NULL; | |
241 | path_tail = path + overlay_name_len; | |
242 | path_tail_len = strlen(path_tail); | |
243 | ||
244 | target_path = kasprintf(GFP_KERNEL, "%pOF", fragment->target); | |
245 | if (!target_path) | |
246 | return NULL; | |
d1651b03 FR |
247 | target_path_len = strlen(target_path); |
248 | ||
e0a58f3e FR |
249 | new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL); |
250 | if (!new_prop) | |
251 | goto err_free_target_path; | |
d1651b03 | 252 | |
e0a58f3e FR |
253 | new_prop->name = kstrdup(prop->name, GFP_KERNEL); |
254 | new_prop->length = target_path_len + path_tail_len + 1; | |
255 | new_prop->value = kzalloc(new_prop->length, GFP_KERNEL); | |
256 | if (!new_prop->name || !new_prop->value) | |
257 | goto err_free_new_prop; | |
d1651b03 | 258 | |
e0a58f3e FR |
259 | strcpy(new_prop->value, target_path); |
260 | strcpy(new_prop->value + target_path_len, path_tail); | |
d1651b03 | 261 | |
e0a58f3e | 262 | of_property_set_flag(new_prop, OF_DYNAMIC); |
d1651b03 | 263 | |
e0a58f3e | 264 | return new_prop; |
d1651b03 | 265 | |
e0a58f3e FR |
266 | err_free_new_prop: |
267 | kfree(new_prop->name); | |
268 | kfree(new_prop->value); | |
269 | kfree(new_prop); | |
270 | err_free_target_path: | |
271 | kfree(target_path); | |
d1651b03 | 272 | |
d1651b03 | 273 | return NULL; |
d1651b03 FR |
274 | } |
275 | ||
0290c4ca FR |
276 | /** |
277 | * add_changeset_property() - add @overlay_prop to overlay changeset | |
278 | * @ovcs: overlay changeset | |
6b4955ba | 279 | * @target: where @overlay_prop will be placed |
0290c4ca | 280 | * @overlay_prop: property to add or update, from overlay tree |
3912b791 | 281 | * @is_symbols_prop: 1 if @overlay_prop is from node "/__symbols__" |
0290c4ca | 282 | * |
6b4955ba FR |
283 | * If @overlay_prop does not already exist in live devicetree, add changeset |
284 | * entry to add @overlay_prop in @target, else add changeset entry to update | |
0290c4ca FR |
285 | * value of @overlay_prop. |
286 | * | |
6b4955ba FR |
287 | * @target may be either in the live devicetree or in a new subtree that |
288 | * is contained in the changeset. | |
289 | * | |
646afc4a | 290 | * Some special properties are not updated (no error returned). |
0290c4ca | 291 | * |
646afc4a | 292 | * Update of property in symbols node is not allowed. |
0290c4ca FR |
293 | * |
294 | * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if | |
295 | * invalid @overlay. | |
646afc4a | 296 | */ |
0290c4ca | 297 | static int add_changeset_property(struct overlay_changeset *ovcs, |
6b4955ba | 298 | struct target *target, struct property *overlay_prop, |
3912b791 | 299 | bool is_symbols_prop) |
7518b589 | 300 | { |
0290c4ca | 301 | struct property *new_prop = NULL, *prop; |
ac0f3e30 | 302 | int ret = 0; |
7518b589 | 303 | |
0290c4ca FR |
304 | if (!of_prop_cmp(overlay_prop->name, "name") || |
305 | !of_prop_cmp(overlay_prop->name, "phandle") || | |
306 | !of_prop_cmp(overlay_prop->name, "linux,phandle")) | |
7518b589 PA |
307 | return 0; |
308 | ||
6b4955ba FR |
309 | if (target->in_livetree) |
310 | prop = of_find_property(target->np, overlay_prop->name, NULL); | |
311 | else | |
312 | prop = NULL; | |
313 | ||
3912b791 | 314 | if (is_symbols_prop) { |
0290c4ca | 315 | if (prop) |
d1651b03 | 316 | return -EINVAL; |
0290c4ca | 317 | new_prop = dup_and_fixup_symbol_prop(ovcs, overlay_prop); |
d1651b03 | 318 | } else { |
0290c4ca | 319 | new_prop = __of_prop_dup(overlay_prop, GFP_KERNEL); |
d1651b03 FR |
320 | } |
321 | ||
0290c4ca | 322 | if (!new_prop) |
7518b589 PA |
323 | return -ENOMEM; |
324 | ||
0290c4ca | 325 | if (!prop) |
6b4955ba | 326 | ret = of_changeset_add_property(&ovcs->cset, target->np, |
0290c4ca | 327 | new_prop); |
646afc4a | 328 | else |
6b4955ba | 329 | ret = of_changeset_update_property(&ovcs->cset, target->np, |
0290c4ca | 330 | new_prop); |
ac0f3e30 LW |
331 | |
332 | if (ret) { | |
0290c4ca FR |
333 | kfree(new_prop->name); |
334 | kfree(new_prop->value); | |
335 | kfree(new_prop); | |
ac0f3e30 LW |
336 | } |
337 | return ret; | |
7518b589 PA |
338 | } |
339 | ||
0290c4ca FR |
340 | /** |
341 | * add_changeset_node() - add @node (and children) to overlay changeset | |
6b4955ba FR |
342 | * @ovcs: overlay changeset |
343 | * @target: where @node will be placed in live tree or changeset | |
344 | * @node: node from within overlay device tree fragment | |
0290c4ca | 345 | * |
6b4955ba FR |
346 | * If @node does not already exist in @target, add changeset entry |
347 | * to add @node in @target. | |
0290c4ca | 348 | * |
6b4955ba | 349 | * If @node already exists in @target, and the existing node has |
0290c4ca FR |
350 | * a phandle, the overlay node is not allowed to have a phandle. |
351 | * | |
352 | * If @node has child nodes, add the children recursively via | |
353 | * build_changeset_next_level(). | |
354 | * | |
b89dae18 FR |
355 | * NOTE_1: A live devicetree created from a flattened device tree (FDT) will |
356 | * not contain the full path in node->full_name. Thus an overlay | |
357 | * created from an FDT also will not contain the full path in | |
358 | * node->full_name. However, a live devicetree created from Open | |
359 | * Firmware may have the full path in node->full_name. | |
360 | * | |
361 | * add_changeset_node() follows the FDT convention and does not include | |
362 | * the full path in node->full_name. Even though it expects the overlay | |
363 | * to not contain the full path, it uses kbasename() to remove the | |
364 | * full path should it exist. It also uses kbasename() in comparisons | |
365 | * to nodes in the live devicetree so that it can apply an overlay to | |
366 | * a live devicetree created from Open Firmware. | |
367 | * | |
368 | * NOTE_2: Multiple mods of created nodes not supported. | |
24789c5c FR |
369 | * If more than one fragment contains a node that does not already exist |
370 | * in the live tree, then for each fragment of_changeset_attach_node() | |
371 | * will add a changeset entry to add the node. When the changeset is | |
372 | * applied, __of_attach_node() will attach the node twice (once for | |
373 | * each fragment). At this point the device tree will be corrupted. | |
374 | * | |
375 | * TODO: add integrity check to ensure that multiple fragments do not | |
376 | * create the same node. | |
0290c4ca FR |
377 | * |
378 | * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if | |
379 | * invalid @overlay. | |
380 | */ | |
381 | static int add_changeset_node(struct overlay_changeset *ovcs, | |
6b4955ba | 382 | struct target *target, struct device_node *node) |
7518b589 | 383 | { |
0290c4ca | 384 | const char *node_kbasename; |
d3a89165 | 385 | struct device_node *tchild; |
6b4955ba | 386 | struct target target_child; |
7518b589 PA |
387 | int ret = 0; |
388 | ||
0290c4ca | 389 | node_kbasename = kbasename(node->full_name); |
7518b589 | 390 | |
6b4955ba | 391 | for_each_child_of_node(target->np, tchild) |
0290c4ca | 392 | if (!of_node_cmp(node_kbasename, kbasename(tchild->full_name))) |
c1cd1e01 FR |
393 | break; |
394 | ||
61b4de4e | 395 | if (!tchild) { |
b89dae18 | 396 | tchild = __of_node_dup(node, node_kbasename); |
7518b589 PA |
397 | if (!tchild) |
398 | return -ENOMEM; | |
399 | ||
6b4955ba | 400 | tchild->parent = target->np; |
144552c7 | 401 | of_node_set_flag(tchild, OF_OVERLAY); |
7518b589 | 402 | |
0290c4ca | 403 | ret = of_changeset_attach_node(&ovcs->cset, tchild); |
7518b589 PA |
404 | if (ret) |
405 | return ret; | |
406 | ||
6b4955ba FR |
407 | target_child.np = tchild; |
408 | target_child.in_livetree = false; | |
409 | ||
410 | ret = build_changeset_next_level(ovcs, &target_child, node); | |
7c528e45 FR |
411 | of_node_put(tchild); |
412 | return ret; | |
7518b589 PA |
413 | } |
414 | ||
6b4955ba | 415 | if (node->phandle && tchild->phandle) { |
6d0f5470 | 416 | ret = -EINVAL; |
6b4955ba FR |
417 | } else { |
418 | target_child.np = tchild; | |
419 | target_child.in_livetree = target->in_livetree; | |
420 | ret = build_changeset_next_level(ovcs, &target_child, node); | |
421 | } | |
61b4de4e FR |
422 | of_node_put(tchild); |
423 | ||
7518b589 PA |
424 | return ret; |
425 | } | |
426 | ||
0290c4ca FR |
427 | /** |
428 | * build_changeset_next_level() - add level of overlay changeset | |
429 | * @ovcs: overlay changeset | |
6b4955ba | 430 | * @target: where to place @overlay_node in live tree |
0290c4ca | 431 | * @overlay_node: node from within an overlay device tree fragment |
7518b589 | 432 | * |
0290c4ca FR |
433 | * Add the properties (if any) and nodes (if any) from @overlay_node to the |
434 | * @ovcs->cset changeset. If an added node has child nodes, they will | |
435 | * be added recursively. | |
646afc4a FR |
436 | * |
437 | * Do not allow symbols node to have any children. | |
0290c4ca FR |
438 | * |
439 | * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if | |
440 | * invalid @overlay_node. | |
7518b589 | 441 | */ |
0290c4ca | 442 | static int build_changeset_next_level(struct overlay_changeset *ovcs, |
6b4955ba | 443 | struct target *target, const struct device_node *overlay_node) |
7518b589 PA |
444 | { |
445 | struct device_node *child; | |
446 | struct property *prop; | |
447 | int ret; | |
448 | ||
0290c4ca | 449 | for_each_property_of_node(overlay_node, prop) { |
6b4955ba | 450 | ret = add_changeset_property(ovcs, target, prop, 0); |
7518b589 | 451 | if (ret) { |
24789c5c | 452 | pr_debug("Failed to apply prop @%pOF/%s, err=%d\n", |
6b4955ba | 453 | target->np, prop->name, ret); |
7518b589 PA |
454 | return ret; |
455 | } | |
456 | } | |
457 | ||
0290c4ca | 458 | for_each_child_of_node(overlay_node, child) { |
6b4955ba | 459 | ret = add_changeset_node(ovcs, target, child); |
bbed8794 | 460 | if (ret) { |
a613b26a | 461 | pr_debug("Failed to apply node @%pOF/%pOFn, err=%d\n", |
6b4955ba | 462 | target->np, child, ret); |
001cf504 | 463 | of_node_put(child); |
7518b589 PA |
464 | return ret; |
465 | } | |
466 | } | |
467 | ||
468 | return 0; | |
469 | } | |
470 | ||
3912b791 FR |
471 | /* |
472 | * Add the properties from __overlay__ node to the @ovcs->cset changeset. | |
473 | */ | |
474 | static int build_changeset_symbols_node(struct overlay_changeset *ovcs, | |
6b4955ba | 475 | struct target *target, |
3912b791 FR |
476 | const struct device_node *overlay_symbols_node) |
477 | { | |
478 | struct property *prop; | |
479 | int ret; | |
480 | ||
481 | for_each_property_of_node(overlay_symbols_node, prop) { | |
6b4955ba | 482 | ret = add_changeset_property(ovcs, target, prop, 1); |
3912b791 FR |
483 | if (ret) { |
484 | pr_debug("Failed to apply prop @%pOF/%s, err=%d\n", | |
6b4955ba | 485 | target->np, prop->name, ret); |
3912b791 FR |
486 | return ret; |
487 | } | |
488 | } | |
489 | ||
490 | return 0; | |
491 | } | |
492 | ||
7518b589 | 493 | /** |
0290c4ca FR |
494 | * build_changeset() - populate overlay changeset in @ovcs from @ovcs->fragments |
495 | * @ovcs: Overlay changeset | |
7518b589 | 496 | * |
0290c4ca FR |
497 | * Create changeset @ovcs->cset to contain the nodes and properties of the |
498 | * overlay device tree fragments in @ovcs->fragments[]. If an error occurs, | |
499 | * any portions of the changeset that were successfully created will remain | |
500 | * in @ovcs->cset. | |
501 | * | |
502 | * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if | |
503 | * invalid overlay in @ovcs->fragments[]. | |
7518b589 | 504 | */ |
0290c4ca | 505 | static int build_changeset(struct overlay_changeset *ovcs) |
7518b589 | 506 | { |
3912b791 | 507 | struct fragment *fragment; |
6b4955ba | 508 | struct target target; |
3912b791 | 509 | int fragments_count, i, ret; |
7518b589 | 510 | |
3912b791 FR |
511 | /* |
512 | * if there is a symbols fragment in ovcs->fragments[i] it is | |
513 | * the final element in the array | |
514 | */ | |
515 | if (ovcs->symbols_fragment) | |
516 | fragments_count = ovcs->count - 1; | |
517 | else | |
518 | fragments_count = ovcs->count; | |
519 | ||
520 | for (i = 0; i < fragments_count; i++) { | |
521 | fragment = &ovcs->fragments[i]; | |
7518b589 | 522 | |
6b4955ba FR |
523 | target.np = fragment->target; |
524 | target.in_livetree = true; | |
525 | ret = build_changeset_next_level(ovcs, &target, | |
3912b791 FR |
526 | fragment->overlay); |
527 | if (ret) { | |
528 | pr_debug("apply failed '%pOF'\n", fragment->target); | |
529 | return ret; | |
530 | } | |
531 | } | |
532 | ||
533 | if (ovcs->symbols_fragment) { | |
534 | fragment = &ovcs->fragments[ovcs->count - 1]; | |
6b4955ba FR |
535 | |
536 | target.np = fragment->target; | |
537 | target.in_livetree = true; | |
538 | ret = build_changeset_symbols_node(ovcs, &target, | |
3912b791 | 539 | fragment->overlay); |
0290c4ca | 540 | if (ret) { |
24789c5c | 541 | pr_debug("apply failed '%pOF'\n", fragment->target); |
0290c4ca | 542 | return ret; |
7518b589 PA |
543 | } |
544 | } | |
545 | ||
546 | return 0; | |
547 | } | |
548 | ||
549 | /* | |
550 | * Find the target node using a number of different strategies | |
646afc4a | 551 | * in order of preference: |
7518b589 | 552 | * |
646afc4a FR |
553 | * 1) "target" property containing the phandle of the target |
554 | * 2) "target-path" property containing the path of the target | |
7518b589 | 555 | */ |
6b4955ba | 556 | static struct device_node *find_target(struct device_node *info_node) |
7518b589 | 557 | { |
e547c003 | 558 | struct device_node *node; |
7518b589 PA |
559 | const char *path; |
560 | u32 val; | |
561 | int ret; | |
562 | ||
7518b589 | 563 | ret = of_property_read_u32(info_node, "target", &val); |
e547c003 FR |
564 | if (!ret) { |
565 | node = of_find_node_by_phandle(val); | |
566 | if (!node) | |
567 | pr_err("find target, node: %pOF, phandle 0x%x not found\n", | |
568 | info_node, val); | |
569 | return node; | |
570 | } | |
7518b589 | 571 | |
7518b589 | 572 | ret = of_property_read_string(info_node, "target-path", &path); |
e547c003 FR |
573 | if (!ret) { |
574 | node = of_find_node_by_path(path); | |
575 | if (!node) | |
576 | pr_err("find target, node: %pOF, path '%s' not found\n", | |
577 | info_node, path); | |
578 | return node; | |
579 | } | |
7518b589 | 580 | |
e547c003 | 581 | pr_err("find target, node: %pOF, no target property\n", info_node); |
7518b589 PA |
582 | |
583 | return NULL; | |
584 | } | |
585 | ||
7518b589 | 586 | /** |
0290c4ca | 587 | * init_overlay_changeset() - initialize overlay changeset from overlay tree |
39a751a4 FR |
588 | * @ovcs: Overlay changeset to build |
589 | * @fdt: the FDT that was unflattened to create @tree | |
0290c4ca | 590 | * @tree: Contains all the overlay fragments and overlay fixup nodes |
7518b589 | 591 | * |
0290c4ca FR |
592 | * Initialize @ovcs. Populate @ovcs->fragments with node information from |
593 | * the top level of @tree. The relevant top level nodes are the fragment | |
594 | * nodes and the __symbols__ node. Any other top level node will be ignored. | |
7518b589 | 595 | * |
0290c4ca | 596 | * Returns 0 on success, -ENOMEM if memory allocation failure, -EINVAL if error |
61b4de4e | 597 | * detected in @tree, or -ENOSPC if idr_alloc() error. |
7518b589 | 598 | */ |
0290c4ca | 599 | static int init_overlay_changeset(struct overlay_changeset *ovcs, |
39a751a4 | 600 | const void *fdt, struct device_node *tree) |
7518b589 | 601 | { |
61b4de4e | 602 | struct device_node *node, *overlay_node; |
0290c4ca FR |
603 | struct fragment *fragment; |
604 | struct fragment *fragments; | |
1352f09b | 605 | int cnt, id, ret; |
7518b589 | 606 | |
24789c5c FR |
607 | /* |
608 | * Warn for some issues. Can not return -EINVAL for these until | |
609 | * of_unittest_apply_overlay() is fixed to pass these checks. | |
610 | */ | |
611 | if (!of_node_check_flag(tree, OF_DYNAMIC)) | |
612 | pr_debug("%s() tree is not dynamic\n", __func__); | |
613 | ||
614 | if (!of_node_check_flag(tree, OF_DETACHED)) | |
615 | pr_debug("%s() tree is not detached\n", __func__); | |
616 | ||
617 | if (!of_node_is_root(tree)) | |
618 | pr_debug("%s() tree is not root\n", __func__); | |
619 | ||
e0a58f3e | 620 | ovcs->overlay_tree = tree; |
39a751a4 | 621 | ovcs->fdt = fdt; |
e0a58f3e | 622 | |
61b4de4e FR |
623 | INIT_LIST_HEAD(&ovcs->ovcs_list); |
624 | ||
625 | of_changeset_init(&ovcs->cset); | |
626 | ||
1352f09b GU |
627 | id = idr_alloc(&ovcs_idr, ovcs, 1, 0, GFP_KERNEL); |
628 | if (id <= 0) | |
629 | return id; | |
61b4de4e | 630 | |
7518b589 | 631 | cnt = 0; |
7518b589 | 632 | |
61b4de4e FR |
633 | /* fragment nodes */ |
634 | for_each_child_of_node(tree, node) { | |
635 | overlay_node = of_get_child_by_name(node, "__overlay__"); | |
636 | if (overlay_node) { | |
637 | cnt++; | |
638 | of_node_put(overlay_node); | |
639 | } | |
640 | } | |
641 | ||
642 | node = of_get_child_by_name(tree, "__symbols__"); | |
643 | if (node) { | |
d1651b03 | 644 | cnt++; |
61b4de4e FR |
645 | of_node_put(node); |
646 | } | |
d1651b03 | 647 | |
0290c4ca | 648 | fragments = kcalloc(cnt, sizeof(*fragments), GFP_KERNEL); |
61b4de4e FR |
649 | if (!fragments) { |
650 | ret = -ENOMEM; | |
651 | goto err_free_idr; | |
652 | } | |
7518b589 PA |
653 | |
654 | cnt = 0; | |
655 | for_each_child_of_node(tree, node) { | |
35e691ed | 656 | overlay_node = of_get_child_by_name(node, "__overlay__"); |
589b754d GU |
657 | if (!overlay_node) |
658 | continue; | |
6de67de3 | 659 | |
589b754d GU |
660 | fragment = &fragments[cnt]; |
661 | fragment->overlay = overlay_node; | |
6b4955ba | 662 | fragment->target = find_target(node); |
589b754d GU |
663 | if (!fragment->target) { |
664 | of_node_put(fragment->overlay); | |
665 | ret = -EINVAL; | |
666 | goto err_free_fragments; | |
61b4de4e | 667 | } |
589b754d GU |
668 | |
669 | cnt++; | |
7518b589 PA |
670 | } |
671 | ||
3912b791 FR |
672 | /* |
673 | * if there is a symbols fragment in ovcs->fragments[i] it is | |
674 | * the final element in the array | |
675 | */ | |
d1651b03 FR |
676 | node = of_get_child_by_name(tree, "__symbols__"); |
677 | if (node) { | |
3912b791 | 678 | ovcs->symbols_fragment = 1; |
0290c4ca FR |
679 | fragment = &fragments[cnt]; |
680 | fragment->overlay = node; | |
681 | fragment->target = of_find_node_by_path("/__symbols__"); | |
d1651b03 | 682 | |
0290c4ca | 683 | if (!fragment->target) { |
4ee7c0d9 | 684 | pr_err("symbols in overlay, but not in live tree\n"); |
61b4de4e FR |
685 | ret = -EINVAL; |
686 | goto err_free_fragments; | |
d1651b03 FR |
687 | } |
688 | ||
689 | cnt++; | |
690 | } | |
691 | ||
bbed8794 | 692 | if (!cnt) { |
39a751a4 | 693 | pr_err("no fragments or symbols in overlay\n"); |
61b4de4e FR |
694 | ret = -EINVAL; |
695 | goto err_free_fragments; | |
7518b589 PA |
696 | } |
697 | ||
1352f09b | 698 | ovcs->id = id; |
0290c4ca FR |
699 | ovcs->count = cnt; |
700 | ovcs->fragments = fragments; | |
7518b589 PA |
701 | |
702 | return 0; | |
61b4de4e | 703 | |
61b4de4e FR |
704 | err_free_fragments: |
705 | kfree(fragments); | |
706 | err_free_idr: | |
1352f09b | 707 | idr_remove(&ovcs_idr, id); |
61b4de4e | 708 | |
24789c5c FR |
709 | pr_err("%s() failed, ret = %d\n", __func__, ret); |
710 | ||
61b4de4e | 711 | return ret; |
7518b589 PA |
712 | } |
713 | ||
61b4de4e | 714 | static void free_overlay_changeset(struct overlay_changeset *ovcs) |
7518b589 | 715 | { |
7518b589 PA |
716 | int i; |
717 | ||
1352f09b GU |
718 | if (ovcs->cset.entries.next) |
719 | of_changeset_destroy(&ovcs->cset); | |
61b4de4e FR |
720 | |
721 | if (ovcs->id) | |
722 | idr_remove(&ovcs_idr, ovcs->id); | |
723 | ||
724 | for (i = 0; i < ovcs->count; i++) { | |
0290c4ca FR |
725 | of_node_put(ovcs->fragments[i].target); |
726 | of_node_put(ovcs->fragments[i].overlay); | |
7518b589 | 727 | } |
0290c4ca | 728 | kfree(ovcs->fragments); |
39a751a4 | 729 | /* |
83ef4777 JK |
730 | * There should be no live pointers into ovcs->overlay_tree and |
731 | * ovcs->fdt due to the policy that overlay notifiers are not allowed | |
732 | * to retain pointers into the overlay devicetree. | |
39a751a4 | 733 | */ |
83ef4777 JK |
734 | kfree(ovcs->overlay_tree); |
735 | kfree(ovcs->fdt); | |
61b4de4e FR |
736 | kfree(ovcs); |
737 | } | |
7518b589 | 738 | |
39a751a4 FR |
739 | /* |
740 | * internal documentation | |
741 | * | |
0290c4ca | 742 | * of_overlay_apply() - Create and apply an overlay changeset |
39a751a4 | 743 | * @fdt: the FDT that was unflattened to create @tree |
0290c4ca | 744 | * @tree: Expanded overlay device tree |
24789c5c FR |
745 | * @ovcs_id: Pointer to overlay changeset id |
746 | * | |
747 | * Creates and applies an overlay changeset. | |
7518b589 | 748 | * |
24789c5c FR |
749 | * If an error occurs in a pre-apply notifier, then no changes are made |
750 | * to the device tree. | |
7518b589 | 751 | * |
24789c5c FR |
752 | |
753 | * A non-zero return value will not have created the changeset if error is from: | |
754 | * - parameter checks | |
755 | * - building the changeset | |
e9d92e40 | 756 | * - overlay changeset pre-apply notifier |
24789c5c FR |
757 | * |
758 | * If an error is returned by an overlay changeset pre-apply notifier | |
759 | * then no further overlay changeset pre-apply notifier will be called. | |
760 | * | |
761 | * A non-zero return value will have created the changeset if error is from: | |
762 | * - overlay changeset entry notifier | |
e9d92e40 | 763 | * - overlay changeset post-apply notifier |
24789c5c FR |
764 | * |
765 | * If an error is returned by an overlay changeset post-apply notifier | |
766 | * then no further overlay changeset post-apply notifier will be called. | |
767 | * | |
768 | * If more than one notifier returns an error, then the last notifier | |
769 | * error to occur is returned. | |
770 | * | |
771 | * If an error occurred while applying the overlay changeset, then an | |
772 | * attempt is made to revert any changes that were made to the | |
773 | * device tree. If there were any errors during the revert attempt | |
774 | * then the state of the device tree can not be determined, and any | |
775 | * following attempt to apply or remove an overlay changeset will be | |
776 | * refused. | |
777 | * | |
778 | * Returns 0 on success, or a negative error number. Overlay changeset | |
779 | * id is returned to *ovcs_id. | |
7518b589 | 780 | */ |
24789c5c | 781 | |
39a751a4 FR |
782 | static int of_overlay_apply(const void *fdt, struct device_node *tree, |
783 | int *ovcs_id) | |
7518b589 | 784 | { |
0290c4ca | 785 | struct overlay_changeset *ovcs; |
24789c5c FR |
786 | int ret = 0, ret_revert, ret_tmp; |
787 | ||
39a751a4 FR |
788 | /* |
789 | * As of this point, fdt and tree belong to the overlay changeset. | |
790 | * overlay changeset code is responsible for freeing them. | |
791 | */ | |
24789c5c FR |
792 | |
793 | if (devicetree_corrupt()) { | |
794 | pr_err("devicetree state suspect, refuse to apply overlay\n"); | |
39a751a4 FR |
795 | kfree(fdt); |
796 | kfree(tree); | |
24789c5c FR |
797 | ret = -EBUSY; |
798 | goto out; | |
799 | } | |
7518b589 | 800 | |
0290c4ca | 801 | ovcs = kzalloc(sizeof(*ovcs), GFP_KERNEL); |
24789c5c | 802 | if (!ovcs) { |
39a751a4 FR |
803 | kfree(fdt); |
804 | kfree(tree); | |
24789c5c FR |
805 | ret = -ENOMEM; |
806 | goto out; | |
807 | } | |
7518b589 | 808 | |
f948d6d8 | 809 | of_overlay_mutex_lock(); |
5e474817 | 810 | mutex_lock(&of_mutex); |
f948d6d8 FR |
811 | |
812 | ret = of_resolve_phandles(tree); | |
813 | if (ret) | |
39a751a4 | 814 | goto err_free_tree; |
7518b589 | 815 | |
39a751a4 | 816 | ret = init_overlay_changeset(ovcs, fdt, tree); |
24789c5c | 817 | if (ret) |
39a751a4 | 818 | goto err_free_tree; |
7518b589 | 819 | |
39a751a4 FR |
820 | /* |
821 | * after overlay_notify(), ovcs->overlay_tree related pointers may have | |
822 | * leaked to drivers, so can not kfree() tree, aka ovcs->overlay_tree; | |
823 | * and can not free fdt, aka ovcs->fdt | |
824 | */ | |
0290c4ca | 825 | ret = overlay_notify(ovcs, OF_OVERLAY_PRE_APPLY); |
24789c5c FR |
826 | if (ret) { |
827 | pr_err("overlay changeset pre-apply notify error %d\n", ret); | |
61b4de4e | 828 | goto err_free_overlay_changeset; |
39a842e2 AT |
829 | } |
830 | ||
0290c4ca FR |
831 | ret = build_changeset(ovcs); |
832 | if (ret) | |
61b4de4e | 833 | goto err_free_overlay_changeset; |
606ad42a | 834 | |
24789c5c FR |
835 | ret_revert = 0; |
836 | ret = __of_changeset_apply_entries(&ovcs->cset, &ret_revert); | |
837 | if (ret) { | |
838 | if (ret_revert) { | |
839 | pr_debug("overlay changeset revert error %d\n", | |
840 | ret_revert); | |
841 | devicetree_state_flags |= DTSF_APPLY_FAIL; | |
842 | } | |
61b4de4e | 843 | goto err_free_overlay_changeset; |
24789c5c | 844 | } |
7518b589 | 845 | |
b9952b52 FR |
846 | of_populate_phandle_cache(); |
847 | ||
6de67de3 GU |
848 | ret = __of_changeset_apply_notify(&ovcs->cset); |
849 | if (ret) | |
850 | pr_err("overlay changeset entry notify error %d\n", ret); | |
851 | /* notify failure is not fatal, continue */ | |
852 | ||
0290c4ca | 853 | list_add_tail(&ovcs->ovcs_list, &ovcs_list); |
24789c5c FR |
854 | *ovcs_id = ovcs->id; |
855 | ||
856 | ret_tmp = overlay_notify(ovcs, OF_OVERLAY_POST_APPLY); | |
857 | if (ret_tmp) { | |
858 | pr_err("overlay changeset post-apply notify error %d\n", | |
859 | ret_tmp); | |
860 | if (!ret) | |
861 | ret = ret_tmp; | |
862 | } | |
39a842e2 | 863 | |
5e474817 | 864 | goto out_unlock; |
f948d6d8 | 865 | |
39a751a4 FR |
866 | err_free_tree: |
867 | kfree(fdt); | |
868 | kfree(tree); | |
869 | ||
61b4de4e FR |
870 | err_free_overlay_changeset: |
871 | free_overlay_changeset(ovcs); | |
7518b589 | 872 | |
5e474817 | 873 | out_unlock: |
7518b589 | 874 | mutex_unlock(&of_mutex); |
5e474817 | 875 | of_overlay_mutex_unlock(); |
7518b589 | 876 | |
24789c5c FR |
877 | out: |
878 | pr_debug("%s() err=%d\n", __func__, ret); | |
879 | ||
0290c4ca | 880 | return ret; |
7518b589 | 881 | } |
39a751a4 FR |
882 | |
883 | int of_overlay_fdt_apply(const void *overlay_fdt, u32 overlay_fdt_size, | |
884 | int *ovcs_id) | |
885 | { | |
886 | const void *new_fdt; | |
887 | int ret; | |
888 | u32 size; | |
889 | struct device_node *overlay_root; | |
890 | ||
891 | *ovcs_id = 0; | |
892 | ret = 0; | |
893 | ||
894 | if (overlay_fdt_size < sizeof(struct fdt_header) || | |
895 | fdt_check_header(overlay_fdt)) { | |
896 | pr_err("Invalid overlay_fdt header\n"); | |
897 | return -EINVAL; | |
898 | } | |
899 | ||
900 | size = fdt_totalsize(overlay_fdt); | |
901 | if (overlay_fdt_size < size) | |
902 | return -EINVAL; | |
903 | ||
904 | /* | |
905 | * Must create permanent copy of FDT because of_fdt_unflatten_tree() | |
906 | * will create pointers to the passed in FDT in the unflattened tree. | |
907 | */ | |
908 | new_fdt = kmemdup(overlay_fdt, size, GFP_KERNEL); | |
909 | if (!new_fdt) | |
910 | return -ENOMEM; | |
911 | ||
912 | of_fdt_unflatten_tree(new_fdt, NULL, &overlay_root); | |
913 | if (!overlay_root) { | |
914 | pr_err("unable to unflatten overlay_fdt\n"); | |
915 | ret = -EINVAL; | |
916 | goto out_free_new_fdt; | |
917 | } | |
918 | ||
919 | ret = of_overlay_apply(new_fdt, overlay_root, ovcs_id); | |
920 | if (ret < 0) { | |
921 | /* | |
922 | * new_fdt and overlay_root now belong to the overlay | |
923 | * changeset. | |
924 | * overlay changeset code is responsible for freeing them. | |
925 | */ | |
926 | goto out; | |
927 | } | |
928 | ||
929 | return 0; | |
930 | ||
931 | ||
932 | out_free_new_fdt: | |
933 | kfree(new_fdt); | |
934 | ||
935 | out: | |
936 | return ret; | |
937 | } | |
938 | EXPORT_SYMBOL_GPL(of_overlay_fdt_apply); | |
7518b589 | 939 | |
646afc4a | 940 | /* |
0290c4ca FR |
941 | * Find @np in @tree. |
942 | * | |
943 | * Returns 1 if @np is @tree or is contained in @tree, else 0 | |
646afc4a | 944 | */ |
0290c4ca | 945 | static int find_node(struct device_node *tree, struct device_node *np) |
7518b589 PA |
946 | { |
947 | struct device_node *child; | |
948 | ||
0290c4ca | 949 | if (tree == np) |
7518b589 PA |
950 | return 1; |
951 | ||
952 | for_each_child_of_node(tree, child) { | |
0290c4ca | 953 | if (find_node(child, np)) { |
001cf504 | 954 | of_node_put(child); |
7518b589 | 955 | return 1; |
001cf504 | 956 | } |
7518b589 PA |
957 | } |
958 | ||
959 | return 0; | |
960 | } | |
961 | ||
646afc4a | 962 | /* |
87f242c1 | 963 | * Is @remove_ce_node a child of, a parent of, or the same as any |
0290c4ca FR |
964 | * node in an overlay changeset more topmost than @remove_ovcs? |
965 | * | |
966 | * Returns 1 if found, else 0 | |
646afc4a | 967 | */ |
87f242c1 FR |
968 | static int node_overlaps_later_cs(struct overlay_changeset *remove_ovcs, |
969 | struct device_node *remove_ce_node) | |
7518b589 | 970 | { |
0290c4ca | 971 | struct overlay_changeset *ovcs; |
7518b589 PA |
972 | struct of_changeset_entry *ce; |
973 | ||
0290c4ca FR |
974 | list_for_each_entry_reverse(ovcs, &ovcs_list, ovcs_list) { |
975 | if (ovcs == remove_ovcs) | |
7518b589 PA |
976 | break; |
977 | ||
0290c4ca | 978 | list_for_each_entry(ce, &ovcs->cset.entries, node) { |
87f242c1 FR |
979 | if (find_node(ce->np, remove_ce_node)) { |
980 | pr_err("%s: #%d overlaps with #%d @%pOF\n", | |
0290c4ca | 981 | __func__, remove_ovcs->id, ovcs->id, |
87f242c1 FR |
982 | remove_ce_node); |
983 | return 1; | |
984 | } | |
985 | if (find_node(remove_ce_node, ce->np)) { | |
986 | pr_err("%s: #%d overlaps with #%d @%pOF\n", | |
987 | __func__, remove_ovcs->id, ovcs->id, | |
988 | remove_ce_node); | |
0290c4ca | 989 | return 1; |
7518b589 PA |
990 | } |
991 | } | |
992 | } | |
993 | ||
0290c4ca | 994 | return 0; |
7518b589 PA |
995 | } |
996 | ||
997 | /* | |
998 | * We can safely remove the overlay only if it's the top-most one. | |
999 | * Newly applied overlays are inserted at the tail of the overlay list, | |
1000 | * so a top most overlay is the one that is closest to the tail. | |
1001 | * | |
1002 | * The topmost check is done by exploiting this property. For each | |
1003 | * affected device node in the log list we check if this overlay is | |
1004 | * the one closest to the tail. If another overlay has affected this | |
1005 | * device node and is closest to the tail, then removal is not permited. | |
1006 | */ | |
0290c4ca | 1007 | static int overlay_removal_is_ok(struct overlay_changeset *remove_ovcs) |
7518b589 | 1008 | { |
0290c4ca | 1009 | struct of_changeset_entry *remove_ce; |
7518b589 | 1010 | |
0290c4ca | 1011 | list_for_each_entry(remove_ce, &remove_ovcs->cset.entries, node) { |
87f242c1 | 1012 | if (node_overlaps_later_cs(remove_ovcs, remove_ce->np)) { |
0290c4ca | 1013 | pr_err("overlay #%d is not topmost\n", remove_ovcs->id); |
7518b589 PA |
1014 | return 0; |
1015 | } | |
1016 | } | |
1017 | ||
1018 | return 1; | |
1019 | } | |
1020 | ||
1021 | /** | |
0290c4ca | 1022 | * of_overlay_remove() - Revert and free an overlay changeset |
24789c5c | 1023 | * @ovcs_id: Pointer to overlay changeset id |
7518b589 | 1024 | * |
24789c5c | 1025 | * Removes an overlay if it is permissible. @ovcs_id was previously returned |
a514266b | 1026 | * by of_overlay_fdt_apply(). |
7518b589 | 1027 | * |
24789c5c FR |
1028 | * If an error occurred while attempting to revert the overlay changeset, |
1029 | * then an attempt is made to re-apply any changeset entry that was | |
1030 | * reverted. If an error occurs on re-apply then the state of the device | |
1031 | * tree can not be determined, and any following attempt to apply or remove | |
1032 | * an overlay changeset will be refused. | |
1033 | * | |
1034 | * A non-zero return value will not revert the changeset if error is from: | |
1035 | * - parameter checks | |
e9d92e40 | 1036 | * - overlay changeset pre-remove notifier |
24789c5c FR |
1037 | * - overlay changeset entry revert |
1038 | * | |
1039 | * If an error is returned by an overlay changeset pre-remove notifier | |
1040 | * then no further overlay changeset pre-remove notifier will be called. | |
1041 | * | |
1042 | * If more than one notifier returns an error, then the last notifier | |
1043 | * error to occur is returned. | |
1044 | * | |
1045 | * A non-zero return value will revert the changeset if error is from: | |
1046 | * - overlay changeset entry notifier | |
e9d92e40 | 1047 | * - overlay changeset post-remove notifier |
24789c5c FR |
1048 | * |
1049 | * If an error is returned by an overlay changeset post-remove notifier | |
1050 | * then no further overlay changeset post-remove notifier will be called. | |
1051 | * | |
1052 | * Returns 0 on success, or a negative error number. *ovcs_id is set to | |
1053 | * zero after reverting the changeset, even if a subsequent error occurs. | |
7518b589 | 1054 | */ |
24789c5c | 1055 | int of_overlay_remove(int *ovcs_id) |
7518b589 | 1056 | { |
0290c4ca | 1057 | struct overlay_changeset *ovcs; |
24789c5c FR |
1058 | int ret, ret_apply, ret_tmp; |
1059 | ||
1060 | ret = 0; | |
1061 | ||
1062 | if (devicetree_corrupt()) { | |
1063 | pr_err("suspect devicetree state, refuse to remove overlay\n"); | |
1064 | ret = -EBUSY; | |
1065 | goto out; | |
1066 | } | |
7518b589 PA |
1067 | |
1068 | mutex_lock(&of_mutex); | |
1069 | ||
24789c5c | 1070 | ovcs = idr_find(&ovcs_idr, *ovcs_id); |
0290c4ca FR |
1071 | if (!ovcs) { |
1072 | ret = -ENODEV; | |
24789c5c FR |
1073 | pr_err("remove: Could not find overlay #%d\n", *ovcs_id); |
1074 | goto out_unlock; | |
7518b589 PA |
1075 | } |
1076 | ||
0290c4ca FR |
1077 | if (!overlay_removal_is_ok(ovcs)) { |
1078 | ret = -EBUSY; | |
24789c5c | 1079 | goto out_unlock; |
7518b589 PA |
1080 | } |
1081 | ||
24789c5c FR |
1082 | ret = overlay_notify(ovcs, OF_OVERLAY_PRE_REMOVE); |
1083 | if (ret) { | |
1084 | pr_err("overlay changeset pre-remove notify error %d\n", ret); | |
1085 | goto out_unlock; | |
1086 | } | |
61b4de4e | 1087 | |
0290c4ca | 1088 | list_del(&ovcs->ovcs_list); |
61b4de4e | 1089 | |
b9952b52 FR |
1090 | /* |
1091 | * Disable phandle cache. Avoids race condition that would arise | |
1092 | * from removing cache entry when the associated node is deleted. | |
1093 | */ | |
1094 | of_free_phandle_cache(); | |
1095 | ||
24789c5c FR |
1096 | ret_apply = 0; |
1097 | ret = __of_changeset_revert_entries(&ovcs->cset, &ret_apply); | |
b9952b52 FR |
1098 | |
1099 | of_populate_phandle_cache(); | |
1100 | ||
24789c5c FR |
1101 | if (ret) { |
1102 | if (ret_apply) | |
1103 | devicetree_state_flags |= DTSF_REVERT_FAIL; | |
1104 | goto out_unlock; | |
24789c5c | 1105 | } |
61b4de4e | 1106 | |
6de67de3 GU |
1107 | ret = __of_changeset_revert_notify(&ovcs->cset); |
1108 | if (ret) | |
1109 | pr_err("overlay changeset entry notify error %d\n", ret); | |
1110 | /* notify failure is not fatal, continue */ | |
1111 | ||
24789c5c FR |
1112 | *ovcs_id = 0; |
1113 | ||
1114 | ret_tmp = overlay_notify(ovcs, OF_OVERLAY_POST_REMOVE); | |
1115 | if (ret_tmp) { | |
1116 | pr_err("overlay changeset post-remove notify error %d\n", | |
1117 | ret_tmp); | |
1118 | if (!ret) | |
1119 | ret = ret_tmp; | |
1120 | } | |
61b4de4e FR |
1121 | |
1122 | free_overlay_changeset(ovcs); | |
7518b589 | 1123 | |
24789c5c | 1124 | out_unlock: |
7518b589 PA |
1125 | mutex_unlock(&of_mutex); |
1126 | ||
24789c5c FR |
1127 | out: |
1128 | pr_debug("%s() err=%d\n", __func__, ret); | |
1129 | ||
0290c4ca | 1130 | return ret; |
7518b589 | 1131 | } |
0290c4ca | 1132 | EXPORT_SYMBOL_GPL(of_overlay_remove); |
7518b589 PA |
1133 | |
1134 | /** | |
0290c4ca | 1135 | * of_overlay_remove_all() - Reverts and frees all overlay changesets |
7518b589 PA |
1136 | * |
1137 | * Removes all overlays from the system in the correct order. | |
1138 | * | |
94a8bf97 | 1139 | * Returns 0 on success, or a negative error number |
7518b589 | 1140 | */ |
0290c4ca | 1141 | int of_overlay_remove_all(void) |
7518b589 | 1142 | { |
0290c4ca | 1143 | struct overlay_changeset *ovcs, *ovcs_n; |
61b4de4e | 1144 | int ret; |
7518b589 PA |
1145 | |
1146 | /* the tail of list is guaranteed to be safe to remove */ | |
0290c4ca | 1147 | list_for_each_entry_safe_reverse(ovcs, ovcs_n, &ovcs_list, ovcs_list) { |
24789c5c | 1148 | ret = of_overlay_remove(&ovcs->id); |
61b4de4e FR |
1149 | if (ret) |
1150 | return ret; | |
7518b589 PA |
1151 | } |
1152 | ||
7518b589 PA |
1153 | return 0; |
1154 | } | |
0290c4ca | 1155 | EXPORT_SYMBOL_GPL(of_overlay_remove_all); |