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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 | 52 | struct device_node *overlay; |
81225ea6 | 53 | struct device_node *target; |
7518b589 PA |
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 | * | |
6f751188 FR |
290 | * Some special properties are not added or updated (no error returned): |
291 | * "name", "phandle", "linux,phandle". | |
292 | * | |
293 | * Properties "#address-cells" and "#size-cells" are not updated if they | |
294 | * are already in the live tree, but if present in the live tree, the values | |
295 | * in the overlay must match the values in the live tree. | |
0290c4ca | 296 | * |
646afc4a | 297 | * Update of property in symbols node is not allowed. |
0290c4ca FR |
298 | * |
299 | * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if | |
300 | * invalid @overlay. | |
646afc4a | 301 | */ |
0290c4ca | 302 | static int add_changeset_property(struct overlay_changeset *ovcs, |
6b4955ba | 303 | struct target *target, struct property *overlay_prop, |
3912b791 | 304 | bool is_symbols_prop) |
7518b589 | 305 | { |
0290c4ca | 306 | struct property *new_prop = NULL, *prop; |
ac0f3e30 | 307 | int ret = 0; |
7518b589 | 308 | |
f9627881 FR |
309 | if (target->in_livetree) |
310 | if (!of_prop_cmp(overlay_prop->name, "name") || | |
311 | !of_prop_cmp(overlay_prop->name, "phandle") || | |
312 | !of_prop_cmp(overlay_prop->name, "linux,phandle")) | |
313 | return 0; | |
7518b589 | 314 | |
6b4955ba FR |
315 | if (target->in_livetree) |
316 | prop = of_find_property(target->np, overlay_prop->name, NULL); | |
317 | else | |
318 | prop = NULL; | |
319 | ||
637392a8 FR |
320 | if (prop) { |
321 | if (!of_prop_cmp(prop->name, "#address-cells")) { | |
322 | if (!of_prop_val_eq(prop, overlay_prop)) { | |
323 | pr_err("ERROR: changing value of #address-cells is not allowed in %pOF\n", | |
324 | target->np); | |
325 | ret = -EINVAL; | |
326 | } | |
327 | return ret; | |
328 | ||
329 | } else if (!of_prop_cmp(prop->name, "#size-cells")) { | |
330 | if (!of_prop_val_eq(prop, overlay_prop)) { | |
331 | pr_err("ERROR: changing value of #size-cells is not allowed in %pOF\n", | |
332 | target->np); | |
333 | ret = -EINVAL; | |
334 | } | |
335 | return ret; | |
336 | } | |
337 | } | |
338 | ||
3912b791 | 339 | if (is_symbols_prop) { |
0290c4ca | 340 | if (prop) |
d1651b03 | 341 | return -EINVAL; |
0290c4ca | 342 | new_prop = dup_and_fixup_symbol_prop(ovcs, overlay_prop); |
d1651b03 | 343 | } else { |
0290c4ca | 344 | new_prop = __of_prop_dup(overlay_prop, GFP_KERNEL); |
d1651b03 FR |
345 | } |
346 | ||
0290c4ca | 347 | if (!new_prop) |
7518b589 PA |
348 | return -ENOMEM; |
349 | ||
6f751188 | 350 | if (!prop) { |
f9627881 FR |
351 | if (!target->in_livetree) { |
352 | new_prop->next = target->np->deadprops; | |
353 | target->np->deadprops = new_prop; | |
354 | } | |
6b4955ba | 355 | ret = of_changeset_add_property(&ovcs->cset, target->np, |
0290c4ca | 356 | new_prop); |
6f751188 | 357 | } else { |
6b4955ba | 358 | ret = of_changeset_update_property(&ovcs->cset, target->np, |
0290c4ca | 359 | new_prop); |
6f751188 FR |
360 | } |
361 | ||
637392a8 | 362 | if (!of_node_check_flag(target->np, OF_OVERLAY)) |
6f751188 FR |
363 | pr_err("WARNING: memory leak will occur if overlay removed, property: %pOF/%s\n", |
364 | target->np, new_prop->name); | |
ac0f3e30 LW |
365 | |
366 | if (ret) { | |
0290c4ca FR |
367 | kfree(new_prop->name); |
368 | kfree(new_prop->value); | |
369 | kfree(new_prop); | |
ac0f3e30 LW |
370 | } |
371 | return ret; | |
7518b589 PA |
372 | } |
373 | ||
0290c4ca FR |
374 | /** |
375 | * add_changeset_node() - add @node (and children) to overlay changeset | |
6b4955ba FR |
376 | * @ovcs: overlay changeset |
377 | * @target: where @node will be placed in live tree or changeset | |
378 | * @node: node from within overlay device tree fragment | |
0290c4ca | 379 | * |
6b4955ba FR |
380 | * If @node does not already exist in @target, add changeset entry |
381 | * to add @node in @target. | |
0290c4ca | 382 | * |
6b4955ba | 383 | * If @node already exists in @target, and the existing node has |
0290c4ca FR |
384 | * a phandle, the overlay node is not allowed to have a phandle. |
385 | * | |
386 | * If @node has child nodes, add the children recursively via | |
387 | * build_changeset_next_level(). | |
388 | * | |
b89dae18 FR |
389 | * NOTE_1: A live devicetree created from a flattened device tree (FDT) will |
390 | * not contain the full path in node->full_name. Thus an overlay | |
391 | * created from an FDT also will not contain the full path in | |
392 | * node->full_name. However, a live devicetree created from Open | |
393 | * Firmware may have the full path in node->full_name. | |
394 | * | |
395 | * add_changeset_node() follows the FDT convention and does not include | |
396 | * the full path in node->full_name. Even though it expects the overlay | |
397 | * to not contain the full path, it uses kbasename() to remove the | |
398 | * full path should it exist. It also uses kbasename() in comparisons | |
399 | * to nodes in the live devicetree so that it can apply an overlay to | |
400 | * a live devicetree created from Open Firmware. | |
401 | * | |
402 | * NOTE_2: Multiple mods of created nodes not supported. | |
0290c4ca FR |
403 | * |
404 | * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if | |
405 | * invalid @overlay. | |
406 | */ | |
407 | static int add_changeset_node(struct overlay_changeset *ovcs, | |
6b4955ba | 408 | struct target *target, struct device_node *node) |
7518b589 | 409 | { |
0290c4ca | 410 | const char *node_kbasename; |
f9627881 | 411 | const __be32 *phandle; |
d3a89165 | 412 | struct device_node *tchild; |
6b4955ba | 413 | struct target target_child; |
f9627881 | 414 | int ret = 0, size; |
7518b589 | 415 | |
0290c4ca | 416 | node_kbasename = kbasename(node->full_name); |
7518b589 | 417 | |
6b4955ba | 418 | for_each_child_of_node(target->np, tchild) |
0290c4ca | 419 | if (!of_node_cmp(node_kbasename, kbasename(tchild->full_name))) |
c1cd1e01 FR |
420 | break; |
421 | ||
61b4de4e | 422 | if (!tchild) { |
8814dc46 | 423 | tchild = __of_node_dup(NULL, node_kbasename); |
7518b589 PA |
424 | if (!tchild) |
425 | return -ENOMEM; | |
426 | ||
6b4955ba | 427 | tchild->parent = target->np; |
f9627881 | 428 | tchild->name = __of_get_property(node, "name", NULL); |
f9627881 FR |
429 | |
430 | if (!tchild->name) | |
431 | tchild->name = "<NULL>"; | |
f9627881 FR |
432 | |
433 | /* ignore obsolete "linux,phandle" */ | |
434 | phandle = __of_get_property(node, "phandle", &size); | |
435 | if (phandle && (size == 4)) | |
436 | tchild->phandle = be32_to_cpup(phandle); | |
437 | ||
144552c7 | 438 | of_node_set_flag(tchild, OF_OVERLAY); |
7518b589 | 439 | |
0290c4ca | 440 | ret = of_changeset_attach_node(&ovcs->cset, tchild); |
7518b589 PA |
441 | if (ret) |
442 | return ret; | |
443 | ||
6b4955ba FR |
444 | target_child.np = tchild; |
445 | target_child.in_livetree = false; | |
446 | ||
447 | ret = build_changeset_next_level(ovcs, &target_child, node); | |
7c528e45 FR |
448 | of_node_put(tchild); |
449 | return ret; | |
7518b589 PA |
450 | } |
451 | ||
6b4955ba | 452 | if (node->phandle && tchild->phandle) { |
6d0f5470 | 453 | ret = -EINVAL; |
6b4955ba FR |
454 | } else { |
455 | target_child.np = tchild; | |
456 | target_child.in_livetree = target->in_livetree; | |
457 | ret = build_changeset_next_level(ovcs, &target_child, node); | |
458 | } | |
61b4de4e FR |
459 | of_node_put(tchild); |
460 | ||
7518b589 PA |
461 | return ret; |
462 | } | |
463 | ||
0290c4ca FR |
464 | /** |
465 | * build_changeset_next_level() - add level of overlay changeset | |
466 | * @ovcs: overlay changeset | |
6b4955ba | 467 | * @target: where to place @overlay_node in live tree |
0290c4ca | 468 | * @overlay_node: node from within an overlay device tree fragment |
7518b589 | 469 | * |
0290c4ca FR |
470 | * Add the properties (if any) and nodes (if any) from @overlay_node to the |
471 | * @ovcs->cset changeset. If an added node has child nodes, they will | |
472 | * be added recursively. | |
646afc4a FR |
473 | * |
474 | * Do not allow symbols node to have any children. | |
0290c4ca FR |
475 | * |
476 | * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if | |
477 | * invalid @overlay_node. | |
7518b589 | 478 | */ |
0290c4ca | 479 | static int build_changeset_next_level(struct overlay_changeset *ovcs, |
6b4955ba | 480 | struct target *target, const struct device_node *overlay_node) |
7518b589 PA |
481 | { |
482 | struct device_node *child; | |
483 | struct property *prop; | |
484 | int ret; | |
485 | ||
0290c4ca | 486 | for_each_property_of_node(overlay_node, prop) { |
6b4955ba | 487 | ret = add_changeset_property(ovcs, target, prop, 0); |
7518b589 | 488 | if (ret) { |
24789c5c | 489 | pr_debug("Failed to apply prop @%pOF/%s, err=%d\n", |
6b4955ba | 490 | target->np, prop->name, ret); |
7518b589 PA |
491 | return ret; |
492 | } | |
493 | } | |
494 | ||
0290c4ca | 495 | for_each_child_of_node(overlay_node, child) { |
6b4955ba | 496 | ret = add_changeset_node(ovcs, target, child); |
bbed8794 | 497 | if (ret) { |
a613b26a | 498 | pr_debug("Failed to apply node @%pOF/%pOFn, err=%d\n", |
6b4955ba | 499 | target->np, child, ret); |
001cf504 | 500 | of_node_put(child); |
7518b589 PA |
501 | return ret; |
502 | } | |
503 | } | |
504 | ||
505 | return 0; | |
506 | } | |
507 | ||
3912b791 FR |
508 | /* |
509 | * Add the properties from __overlay__ node to the @ovcs->cset changeset. | |
510 | */ | |
511 | static int build_changeset_symbols_node(struct overlay_changeset *ovcs, | |
6b4955ba | 512 | struct target *target, |
3912b791 FR |
513 | const struct device_node *overlay_symbols_node) |
514 | { | |
515 | struct property *prop; | |
516 | int ret; | |
517 | ||
518 | for_each_property_of_node(overlay_symbols_node, prop) { | |
6b4955ba | 519 | ret = add_changeset_property(ovcs, target, prop, 1); |
3912b791 | 520 | if (ret) { |
a15e824f | 521 | pr_debug("Failed to apply symbols prop @%pOF/%s, err=%d\n", |
6b4955ba | 522 | target->np, prop->name, ret); |
3912b791 FR |
523 | return ret; |
524 | } | |
525 | } | |
526 | ||
527 | return 0; | |
528 | } | |
529 | ||
2fe0e876 FR |
530 | static int find_dup_cset_node_entry(struct overlay_changeset *ovcs, |
531 | struct of_changeset_entry *ce_1) | |
532 | { | |
533 | struct of_changeset_entry *ce_2; | |
534 | char *fn_1, *fn_2; | |
535 | int node_path_match; | |
536 | ||
537 | if (ce_1->action != OF_RECONFIG_ATTACH_NODE && | |
538 | ce_1->action != OF_RECONFIG_DETACH_NODE) | |
539 | return 0; | |
540 | ||
541 | ce_2 = ce_1; | |
542 | list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) { | |
543 | if ((ce_2->action != OF_RECONFIG_ATTACH_NODE && | |
544 | ce_2->action != OF_RECONFIG_DETACH_NODE) || | |
545 | of_node_cmp(ce_1->np->full_name, ce_2->np->full_name)) | |
546 | continue; | |
547 | ||
548 | fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np); | |
549 | fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np); | |
550 | node_path_match = !strcmp(fn_1, fn_2); | |
551 | kfree(fn_1); | |
552 | kfree(fn_2); | |
553 | if (node_path_match) { | |
554 | pr_err("ERROR: multiple fragments add and/or delete node %pOF\n", | |
555 | ce_1->np); | |
556 | return -EINVAL; | |
557 | } | |
558 | } | |
559 | ||
560 | return 0; | |
561 | } | |
562 | ||
563 | static int find_dup_cset_prop(struct overlay_changeset *ovcs, | |
564 | struct of_changeset_entry *ce_1) | |
565 | { | |
566 | struct of_changeset_entry *ce_2; | |
567 | char *fn_1, *fn_2; | |
568 | int node_path_match; | |
569 | ||
570 | if (ce_1->action != OF_RECONFIG_ADD_PROPERTY && | |
571 | ce_1->action != OF_RECONFIG_REMOVE_PROPERTY && | |
572 | ce_1->action != OF_RECONFIG_UPDATE_PROPERTY) | |
573 | return 0; | |
574 | ||
575 | ce_2 = ce_1; | |
576 | list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) { | |
577 | if ((ce_2->action != OF_RECONFIG_ADD_PROPERTY && | |
578 | ce_2->action != OF_RECONFIG_REMOVE_PROPERTY && | |
579 | ce_2->action != OF_RECONFIG_UPDATE_PROPERTY) || | |
580 | of_node_cmp(ce_1->np->full_name, ce_2->np->full_name)) | |
581 | continue; | |
582 | ||
583 | fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np); | |
584 | fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np); | |
585 | node_path_match = !strcmp(fn_1, fn_2); | |
586 | kfree(fn_1); | |
587 | kfree(fn_2); | |
588 | if (node_path_match && | |
589 | !of_prop_cmp(ce_1->prop->name, ce_2->prop->name)) { | |
590 | pr_err("ERROR: multiple fragments add, update, and/or delete property %pOF/%s\n", | |
591 | ce_1->np, ce_1->prop->name); | |
592 | return -EINVAL; | |
593 | } | |
594 | } | |
595 | ||
596 | return 0; | |
597 | } | |
598 | ||
c168263b | 599 | /** |
2fe0e876 | 600 | * changeset_dup_entry_check() - check for duplicate entries |
c168263b FR |
601 | * @ovcs: Overlay changeset |
602 | * | |
2fe0e876 FR |
603 | * Check changeset @ovcs->cset for multiple {add or delete} node entries for |
604 | * the same node or duplicate {add, delete, or update} properties entries | |
605 | * for the same property. | |
c168263b | 606 | * |
2fe0e876 | 607 | * Returns 0 on success, or -EINVAL if duplicate changeset entry found. |
c168263b | 608 | */ |
2fe0e876 | 609 | static int changeset_dup_entry_check(struct overlay_changeset *ovcs) |
c168263b | 610 | { |
2fe0e876 FR |
611 | struct of_changeset_entry *ce_1; |
612 | int dup_entry = 0; | |
c168263b FR |
613 | |
614 | list_for_each_entry(ce_1, &ovcs->cset.entries, node) { | |
2fe0e876 FR |
615 | dup_entry |= find_dup_cset_node_entry(ovcs, ce_1); |
616 | dup_entry |= find_dup_cset_prop(ovcs, ce_1); | |
c168263b FR |
617 | } |
618 | ||
2fe0e876 | 619 | return dup_entry ? -EINVAL : 0; |
c168263b FR |
620 | } |
621 | ||
7518b589 | 622 | /** |
0290c4ca FR |
623 | * build_changeset() - populate overlay changeset in @ovcs from @ovcs->fragments |
624 | * @ovcs: Overlay changeset | |
7518b589 | 625 | * |
0290c4ca FR |
626 | * Create changeset @ovcs->cset to contain the nodes and properties of the |
627 | * overlay device tree fragments in @ovcs->fragments[]. If an error occurs, | |
628 | * any portions of the changeset that were successfully created will remain | |
629 | * in @ovcs->cset. | |
630 | * | |
631 | * Returns 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if | |
632 | * invalid overlay in @ovcs->fragments[]. | |
7518b589 | 633 | */ |
0290c4ca | 634 | static int build_changeset(struct overlay_changeset *ovcs) |
7518b589 | 635 | { |
3912b791 | 636 | struct fragment *fragment; |
6b4955ba | 637 | struct target target; |
3912b791 | 638 | int fragments_count, i, ret; |
7518b589 | 639 | |
3912b791 FR |
640 | /* |
641 | * if there is a symbols fragment in ovcs->fragments[i] it is | |
642 | * the final element in the array | |
643 | */ | |
644 | if (ovcs->symbols_fragment) | |
645 | fragments_count = ovcs->count - 1; | |
646 | else | |
647 | fragments_count = ovcs->count; | |
648 | ||
649 | for (i = 0; i < fragments_count; i++) { | |
650 | fragment = &ovcs->fragments[i]; | |
7518b589 | 651 | |
6b4955ba FR |
652 | target.np = fragment->target; |
653 | target.in_livetree = true; | |
654 | ret = build_changeset_next_level(ovcs, &target, | |
3912b791 FR |
655 | fragment->overlay); |
656 | if (ret) { | |
a15e824f FR |
657 | pr_debug("fragment apply failed '%pOF'\n", |
658 | fragment->target); | |
3912b791 FR |
659 | return ret; |
660 | } | |
661 | } | |
662 | ||
663 | if (ovcs->symbols_fragment) { | |
664 | fragment = &ovcs->fragments[ovcs->count - 1]; | |
6b4955ba FR |
665 | |
666 | target.np = fragment->target; | |
667 | target.in_livetree = true; | |
668 | ret = build_changeset_symbols_node(ovcs, &target, | |
3912b791 | 669 | fragment->overlay); |
0290c4ca | 670 | if (ret) { |
a15e824f FR |
671 | pr_debug("symbols fragment apply failed '%pOF'\n", |
672 | fragment->target); | |
0290c4ca | 673 | return ret; |
7518b589 PA |
674 | } |
675 | } | |
676 | ||
2fe0e876 | 677 | return changeset_dup_entry_check(ovcs); |
7518b589 PA |
678 | } |
679 | ||
680 | /* | |
681 | * Find the target node using a number of different strategies | |
646afc4a | 682 | * in order of preference: |
7518b589 | 683 | * |
646afc4a FR |
684 | * 1) "target" property containing the phandle of the target |
685 | * 2) "target-path" property containing the path of the target | |
7518b589 | 686 | */ |
6b4955ba | 687 | static struct device_node *find_target(struct device_node *info_node) |
7518b589 | 688 | { |
e547c003 | 689 | struct device_node *node; |
7518b589 PA |
690 | const char *path; |
691 | u32 val; | |
692 | int ret; | |
693 | ||
7518b589 | 694 | ret = of_property_read_u32(info_node, "target", &val); |
e547c003 FR |
695 | if (!ret) { |
696 | node = of_find_node_by_phandle(val); | |
697 | if (!node) | |
698 | pr_err("find target, node: %pOF, phandle 0x%x not found\n", | |
699 | info_node, val); | |
700 | return node; | |
701 | } | |
7518b589 | 702 | |
7518b589 | 703 | ret = of_property_read_string(info_node, "target-path", &path); |
e547c003 FR |
704 | if (!ret) { |
705 | node = of_find_node_by_path(path); | |
706 | if (!node) | |
707 | pr_err("find target, node: %pOF, path '%s' not found\n", | |
708 | info_node, path); | |
709 | return node; | |
710 | } | |
7518b589 | 711 | |
e547c003 | 712 | pr_err("find target, node: %pOF, no target property\n", info_node); |
7518b589 PA |
713 | |
714 | return NULL; | |
715 | } | |
716 | ||
7518b589 | 717 | /** |
0290c4ca | 718 | * init_overlay_changeset() - initialize overlay changeset from overlay tree |
39a751a4 FR |
719 | * @ovcs: Overlay changeset to build |
720 | * @fdt: the FDT that was unflattened to create @tree | |
0290c4ca | 721 | * @tree: Contains all the overlay fragments and overlay fixup nodes |
7518b589 | 722 | * |
0290c4ca FR |
723 | * Initialize @ovcs. Populate @ovcs->fragments with node information from |
724 | * the top level of @tree. The relevant top level nodes are the fragment | |
725 | * nodes and the __symbols__ node. Any other top level node will be ignored. | |
7518b589 | 726 | * |
0290c4ca | 727 | * Returns 0 on success, -ENOMEM if memory allocation failure, -EINVAL if error |
61b4de4e | 728 | * detected in @tree, or -ENOSPC if idr_alloc() error. |
7518b589 | 729 | */ |
0290c4ca | 730 | static int init_overlay_changeset(struct overlay_changeset *ovcs, |
39a751a4 | 731 | const void *fdt, struct device_node *tree) |
7518b589 | 732 | { |
61b4de4e | 733 | struct device_node *node, *overlay_node; |
0290c4ca FR |
734 | struct fragment *fragment; |
735 | struct fragment *fragments; | |
1352f09b | 736 | int cnt, id, ret; |
7518b589 | 737 | |
24789c5c FR |
738 | /* |
739 | * Warn for some issues. Can not return -EINVAL for these until | |
740 | * of_unittest_apply_overlay() is fixed to pass these checks. | |
741 | */ | |
742 | if (!of_node_check_flag(tree, OF_DYNAMIC)) | |
743 | pr_debug("%s() tree is not dynamic\n", __func__); | |
744 | ||
745 | if (!of_node_check_flag(tree, OF_DETACHED)) | |
746 | pr_debug("%s() tree is not detached\n", __func__); | |
747 | ||
748 | if (!of_node_is_root(tree)) | |
749 | pr_debug("%s() tree is not root\n", __func__); | |
750 | ||
e0a58f3e | 751 | ovcs->overlay_tree = tree; |
39a751a4 | 752 | ovcs->fdt = fdt; |
e0a58f3e | 753 | |
61b4de4e FR |
754 | INIT_LIST_HEAD(&ovcs->ovcs_list); |
755 | ||
756 | of_changeset_init(&ovcs->cset); | |
757 | ||
1352f09b GU |
758 | id = idr_alloc(&ovcs_idr, ovcs, 1, 0, GFP_KERNEL); |
759 | if (id <= 0) | |
760 | return id; | |
61b4de4e | 761 | |
7518b589 | 762 | cnt = 0; |
7518b589 | 763 | |
61b4de4e FR |
764 | /* fragment nodes */ |
765 | for_each_child_of_node(tree, node) { | |
766 | overlay_node = of_get_child_by_name(node, "__overlay__"); | |
767 | if (overlay_node) { | |
768 | cnt++; | |
769 | of_node_put(overlay_node); | |
770 | } | |
771 | } | |
772 | ||
773 | node = of_get_child_by_name(tree, "__symbols__"); | |
774 | if (node) { | |
d1651b03 | 775 | cnt++; |
61b4de4e FR |
776 | of_node_put(node); |
777 | } | |
d1651b03 | 778 | |
0290c4ca | 779 | fragments = kcalloc(cnt, sizeof(*fragments), GFP_KERNEL); |
61b4de4e FR |
780 | if (!fragments) { |
781 | ret = -ENOMEM; | |
782 | goto err_free_idr; | |
783 | } | |
7518b589 PA |
784 | |
785 | cnt = 0; | |
786 | for_each_child_of_node(tree, node) { | |
35e691ed | 787 | overlay_node = of_get_child_by_name(node, "__overlay__"); |
589b754d GU |
788 | if (!overlay_node) |
789 | continue; | |
6de67de3 | 790 | |
589b754d GU |
791 | fragment = &fragments[cnt]; |
792 | fragment->overlay = overlay_node; | |
6b4955ba | 793 | fragment->target = find_target(node); |
589b754d GU |
794 | if (!fragment->target) { |
795 | of_node_put(fragment->overlay); | |
796 | ret = -EINVAL; | |
797 | goto err_free_fragments; | |
61b4de4e | 798 | } |
589b754d GU |
799 | |
800 | cnt++; | |
7518b589 PA |
801 | } |
802 | ||
3912b791 FR |
803 | /* |
804 | * if there is a symbols fragment in ovcs->fragments[i] it is | |
805 | * the final element in the array | |
806 | */ | |
d1651b03 FR |
807 | node = of_get_child_by_name(tree, "__symbols__"); |
808 | if (node) { | |
3912b791 | 809 | ovcs->symbols_fragment = 1; |
0290c4ca FR |
810 | fragment = &fragments[cnt]; |
811 | fragment->overlay = node; | |
812 | fragment->target = of_find_node_by_path("/__symbols__"); | |
d1651b03 | 813 | |
0290c4ca | 814 | if (!fragment->target) { |
4ee7c0d9 | 815 | pr_err("symbols in overlay, but not in live tree\n"); |
61b4de4e FR |
816 | ret = -EINVAL; |
817 | goto err_free_fragments; | |
d1651b03 FR |
818 | } |
819 | ||
820 | cnt++; | |
821 | } | |
822 | ||
bbed8794 | 823 | if (!cnt) { |
39a751a4 | 824 | pr_err("no fragments or symbols in overlay\n"); |
61b4de4e FR |
825 | ret = -EINVAL; |
826 | goto err_free_fragments; | |
7518b589 PA |
827 | } |
828 | ||
1352f09b | 829 | ovcs->id = id; |
0290c4ca FR |
830 | ovcs->count = cnt; |
831 | ovcs->fragments = fragments; | |
7518b589 PA |
832 | |
833 | return 0; | |
61b4de4e | 834 | |
61b4de4e FR |
835 | err_free_fragments: |
836 | kfree(fragments); | |
837 | err_free_idr: | |
1352f09b | 838 | idr_remove(&ovcs_idr, id); |
61b4de4e | 839 | |
24789c5c FR |
840 | pr_err("%s() failed, ret = %d\n", __func__, ret); |
841 | ||
61b4de4e | 842 | return ret; |
7518b589 PA |
843 | } |
844 | ||
61b4de4e | 845 | static void free_overlay_changeset(struct overlay_changeset *ovcs) |
7518b589 | 846 | { |
7518b589 PA |
847 | int i; |
848 | ||
1352f09b GU |
849 | if (ovcs->cset.entries.next) |
850 | of_changeset_destroy(&ovcs->cset); | |
61b4de4e FR |
851 | |
852 | if (ovcs->id) | |
853 | idr_remove(&ovcs_idr, ovcs->id); | |
854 | ||
855 | for (i = 0; i < ovcs->count; i++) { | |
0290c4ca FR |
856 | of_node_put(ovcs->fragments[i].target); |
857 | of_node_put(ovcs->fragments[i].overlay); | |
7518b589 | 858 | } |
0290c4ca | 859 | kfree(ovcs->fragments); |
39a751a4 | 860 | /* |
83ef4777 JK |
861 | * There should be no live pointers into ovcs->overlay_tree and |
862 | * ovcs->fdt due to the policy that overlay notifiers are not allowed | |
863 | * to retain pointers into the overlay devicetree. | |
39a751a4 | 864 | */ |
83ef4777 JK |
865 | kfree(ovcs->overlay_tree); |
866 | kfree(ovcs->fdt); | |
61b4de4e FR |
867 | kfree(ovcs); |
868 | } | |
7518b589 | 869 | |
39a751a4 FR |
870 | /* |
871 | * internal documentation | |
872 | * | |
0290c4ca | 873 | * of_overlay_apply() - Create and apply an overlay changeset |
39a751a4 | 874 | * @fdt: the FDT that was unflattened to create @tree |
0290c4ca | 875 | * @tree: Expanded overlay device tree |
24789c5c FR |
876 | * @ovcs_id: Pointer to overlay changeset id |
877 | * | |
878 | * Creates and applies an overlay changeset. | |
7518b589 | 879 | * |
24789c5c FR |
880 | * If an error occurs in a pre-apply notifier, then no changes are made |
881 | * to the device tree. | |
7518b589 | 882 | * |
24789c5c FR |
883 | |
884 | * A non-zero return value will not have created the changeset if error is from: | |
885 | * - parameter checks | |
886 | * - building the changeset | |
e9d92e40 | 887 | * - overlay changeset pre-apply notifier |
24789c5c FR |
888 | * |
889 | * If an error is returned by an overlay changeset pre-apply notifier | |
890 | * then no further overlay changeset pre-apply notifier will be called. | |
891 | * | |
892 | * A non-zero return value will have created the changeset if error is from: | |
893 | * - overlay changeset entry notifier | |
e9d92e40 | 894 | * - overlay changeset post-apply notifier |
24789c5c FR |
895 | * |
896 | * If an error is returned by an overlay changeset post-apply notifier | |
897 | * then no further overlay changeset post-apply notifier will be called. | |
898 | * | |
899 | * If more than one notifier returns an error, then the last notifier | |
900 | * error to occur is returned. | |
901 | * | |
902 | * If an error occurred while applying the overlay changeset, then an | |
903 | * attempt is made to revert any changes that were made to the | |
904 | * device tree. If there were any errors during the revert attempt | |
905 | * then the state of the device tree can not be determined, and any | |
906 | * following attempt to apply or remove an overlay changeset will be | |
907 | * refused. | |
908 | * | |
909 | * Returns 0 on success, or a negative error number. Overlay changeset | |
910 | * id is returned to *ovcs_id. | |
7518b589 | 911 | */ |
24789c5c | 912 | |
39a751a4 FR |
913 | static int of_overlay_apply(const void *fdt, struct device_node *tree, |
914 | int *ovcs_id) | |
7518b589 | 915 | { |
0290c4ca | 916 | struct overlay_changeset *ovcs; |
24789c5c FR |
917 | int ret = 0, ret_revert, ret_tmp; |
918 | ||
39a751a4 FR |
919 | /* |
920 | * As of this point, fdt and tree belong to the overlay changeset. | |
921 | * overlay changeset code is responsible for freeing them. | |
922 | */ | |
24789c5c FR |
923 | |
924 | if (devicetree_corrupt()) { | |
925 | pr_err("devicetree state suspect, refuse to apply overlay\n"); | |
39a751a4 FR |
926 | kfree(fdt); |
927 | kfree(tree); | |
24789c5c FR |
928 | ret = -EBUSY; |
929 | goto out; | |
930 | } | |
7518b589 | 931 | |
0290c4ca | 932 | ovcs = kzalloc(sizeof(*ovcs), GFP_KERNEL); |
24789c5c | 933 | if (!ovcs) { |
39a751a4 FR |
934 | kfree(fdt); |
935 | kfree(tree); | |
24789c5c FR |
936 | ret = -ENOMEM; |
937 | goto out; | |
938 | } | |
7518b589 | 939 | |
f948d6d8 | 940 | of_overlay_mutex_lock(); |
5e474817 | 941 | mutex_lock(&of_mutex); |
f948d6d8 FR |
942 | |
943 | ret = of_resolve_phandles(tree); | |
944 | if (ret) | |
39a751a4 | 945 | goto err_free_tree; |
7518b589 | 946 | |
39a751a4 | 947 | ret = init_overlay_changeset(ovcs, fdt, tree); |
24789c5c | 948 | if (ret) |
39a751a4 | 949 | goto err_free_tree; |
7518b589 | 950 | |
39a751a4 FR |
951 | /* |
952 | * after overlay_notify(), ovcs->overlay_tree related pointers may have | |
953 | * leaked to drivers, so can not kfree() tree, aka ovcs->overlay_tree; | |
954 | * and can not free fdt, aka ovcs->fdt | |
955 | */ | |
0290c4ca | 956 | ret = overlay_notify(ovcs, OF_OVERLAY_PRE_APPLY); |
24789c5c FR |
957 | if (ret) { |
958 | pr_err("overlay changeset pre-apply notify error %d\n", ret); | |
61b4de4e | 959 | goto err_free_overlay_changeset; |
39a842e2 AT |
960 | } |
961 | ||
0290c4ca FR |
962 | ret = build_changeset(ovcs); |
963 | if (ret) | |
61b4de4e | 964 | goto err_free_overlay_changeset; |
606ad42a | 965 | |
24789c5c FR |
966 | ret_revert = 0; |
967 | ret = __of_changeset_apply_entries(&ovcs->cset, &ret_revert); | |
968 | if (ret) { | |
969 | if (ret_revert) { | |
970 | pr_debug("overlay changeset revert error %d\n", | |
971 | ret_revert); | |
972 | devicetree_state_flags |= DTSF_APPLY_FAIL; | |
973 | } | |
61b4de4e | 974 | goto err_free_overlay_changeset; |
24789c5c | 975 | } |
7518b589 | 976 | |
6de67de3 GU |
977 | ret = __of_changeset_apply_notify(&ovcs->cset); |
978 | if (ret) | |
a15e824f | 979 | pr_err("overlay apply changeset entry notify error %d\n", ret); |
6de67de3 GU |
980 | /* notify failure is not fatal, continue */ |
981 | ||
0290c4ca | 982 | list_add_tail(&ovcs->ovcs_list, &ovcs_list); |
24789c5c FR |
983 | *ovcs_id = ovcs->id; |
984 | ||
985 | ret_tmp = overlay_notify(ovcs, OF_OVERLAY_POST_APPLY); | |
986 | if (ret_tmp) { | |
987 | pr_err("overlay changeset post-apply notify error %d\n", | |
988 | ret_tmp); | |
989 | if (!ret) | |
990 | ret = ret_tmp; | |
991 | } | |
39a842e2 | 992 | |
5e474817 | 993 | goto out_unlock; |
f948d6d8 | 994 | |
39a751a4 FR |
995 | err_free_tree: |
996 | kfree(fdt); | |
997 | kfree(tree); | |
998 | ||
61b4de4e FR |
999 | err_free_overlay_changeset: |
1000 | free_overlay_changeset(ovcs); | |
7518b589 | 1001 | |
5e474817 | 1002 | out_unlock: |
7518b589 | 1003 | mutex_unlock(&of_mutex); |
5e474817 | 1004 | of_overlay_mutex_unlock(); |
7518b589 | 1005 | |
24789c5c FR |
1006 | out: |
1007 | pr_debug("%s() err=%d\n", __func__, ret); | |
1008 | ||
0290c4ca | 1009 | return ret; |
7518b589 | 1010 | } |
39a751a4 FR |
1011 | |
1012 | int of_overlay_fdt_apply(const void *overlay_fdt, u32 overlay_fdt_size, | |
1013 | int *ovcs_id) | |
1014 | { | |
1015 | const void *new_fdt; | |
1016 | int ret; | |
1017 | u32 size; | |
1018 | struct device_node *overlay_root; | |
1019 | ||
1020 | *ovcs_id = 0; | |
1021 | ret = 0; | |
1022 | ||
1023 | if (overlay_fdt_size < sizeof(struct fdt_header) || | |
1024 | fdt_check_header(overlay_fdt)) { | |
1025 | pr_err("Invalid overlay_fdt header\n"); | |
1026 | return -EINVAL; | |
1027 | } | |
1028 | ||
1029 | size = fdt_totalsize(overlay_fdt); | |
1030 | if (overlay_fdt_size < size) | |
1031 | return -EINVAL; | |
1032 | ||
1033 | /* | |
1034 | * Must create permanent copy of FDT because of_fdt_unflatten_tree() | |
1035 | * will create pointers to the passed in FDT in the unflattened tree. | |
1036 | */ | |
1037 | new_fdt = kmemdup(overlay_fdt, size, GFP_KERNEL); | |
1038 | if (!new_fdt) | |
1039 | return -ENOMEM; | |
1040 | ||
1041 | of_fdt_unflatten_tree(new_fdt, NULL, &overlay_root); | |
1042 | if (!overlay_root) { | |
1043 | pr_err("unable to unflatten overlay_fdt\n"); | |
1044 | ret = -EINVAL; | |
1045 | goto out_free_new_fdt; | |
1046 | } | |
1047 | ||
1048 | ret = of_overlay_apply(new_fdt, overlay_root, ovcs_id); | |
1049 | if (ret < 0) { | |
1050 | /* | |
1051 | * new_fdt and overlay_root now belong to the overlay | |
1052 | * changeset. | |
1053 | * overlay changeset code is responsible for freeing them. | |
1054 | */ | |
1055 | goto out; | |
1056 | } | |
1057 | ||
1058 | return 0; | |
1059 | ||
1060 | ||
1061 | out_free_new_fdt: | |
1062 | kfree(new_fdt); | |
1063 | ||
1064 | out: | |
1065 | return ret; | |
1066 | } | |
1067 | EXPORT_SYMBOL_GPL(of_overlay_fdt_apply); | |
7518b589 | 1068 | |
646afc4a | 1069 | /* |
0290c4ca FR |
1070 | * Find @np in @tree. |
1071 | * | |
1072 | * Returns 1 if @np is @tree or is contained in @tree, else 0 | |
646afc4a | 1073 | */ |
0290c4ca | 1074 | static int find_node(struct device_node *tree, struct device_node *np) |
7518b589 PA |
1075 | { |
1076 | struct device_node *child; | |
1077 | ||
0290c4ca | 1078 | if (tree == np) |
7518b589 PA |
1079 | return 1; |
1080 | ||
1081 | for_each_child_of_node(tree, child) { | |
0290c4ca | 1082 | if (find_node(child, np)) { |
001cf504 | 1083 | of_node_put(child); |
7518b589 | 1084 | return 1; |
001cf504 | 1085 | } |
7518b589 PA |
1086 | } |
1087 | ||
1088 | return 0; | |
1089 | } | |
1090 | ||
646afc4a | 1091 | /* |
87f242c1 | 1092 | * Is @remove_ce_node a child of, a parent of, or the same as any |
0290c4ca FR |
1093 | * node in an overlay changeset more topmost than @remove_ovcs? |
1094 | * | |
1095 | * Returns 1 if found, else 0 | |
646afc4a | 1096 | */ |
87f242c1 FR |
1097 | static int node_overlaps_later_cs(struct overlay_changeset *remove_ovcs, |
1098 | struct device_node *remove_ce_node) | |
7518b589 | 1099 | { |
0290c4ca | 1100 | struct overlay_changeset *ovcs; |
7518b589 PA |
1101 | struct of_changeset_entry *ce; |
1102 | ||
0290c4ca FR |
1103 | list_for_each_entry_reverse(ovcs, &ovcs_list, ovcs_list) { |
1104 | if (ovcs == remove_ovcs) | |
7518b589 PA |
1105 | break; |
1106 | ||
0290c4ca | 1107 | list_for_each_entry(ce, &ovcs->cset.entries, node) { |
87f242c1 FR |
1108 | if (find_node(ce->np, remove_ce_node)) { |
1109 | pr_err("%s: #%d overlaps with #%d @%pOF\n", | |
0290c4ca | 1110 | __func__, remove_ovcs->id, ovcs->id, |
87f242c1 FR |
1111 | remove_ce_node); |
1112 | return 1; | |
1113 | } | |
1114 | if (find_node(remove_ce_node, ce->np)) { | |
1115 | pr_err("%s: #%d overlaps with #%d @%pOF\n", | |
1116 | __func__, remove_ovcs->id, ovcs->id, | |
1117 | remove_ce_node); | |
0290c4ca | 1118 | return 1; |
7518b589 PA |
1119 | } |
1120 | } | |
1121 | } | |
1122 | ||
0290c4ca | 1123 | return 0; |
7518b589 PA |
1124 | } |
1125 | ||
1126 | /* | |
1127 | * We can safely remove the overlay only if it's the top-most one. | |
1128 | * Newly applied overlays are inserted at the tail of the overlay list, | |
1129 | * so a top most overlay is the one that is closest to the tail. | |
1130 | * | |
1131 | * The topmost check is done by exploiting this property. For each | |
1132 | * affected device node in the log list we check if this overlay is | |
1133 | * the one closest to the tail. If another overlay has affected this | |
1134 | * device node and is closest to the tail, then removal is not permited. | |
1135 | */ | |
0290c4ca | 1136 | static int overlay_removal_is_ok(struct overlay_changeset *remove_ovcs) |
7518b589 | 1137 | { |
0290c4ca | 1138 | struct of_changeset_entry *remove_ce; |
7518b589 | 1139 | |
0290c4ca | 1140 | list_for_each_entry(remove_ce, &remove_ovcs->cset.entries, node) { |
87f242c1 | 1141 | if (node_overlaps_later_cs(remove_ovcs, remove_ce->np)) { |
0290c4ca | 1142 | pr_err("overlay #%d is not topmost\n", remove_ovcs->id); |
7518b589 PA |
1143 | return 0; |
1144 | } | |
1145 | } | |
1146 | ||
1147 | return 1; | |
1148 | } | |
1149 | ||
1150 | /** | |
0290c4ca | 1151 | * of_overlay_remove() - Revert and free an overlay changeset |
24789c5c | 1152 | * @ovcs_id: Pointer to overlay changeset id |
7518b589 | 1153 | * |
24789c5c | 1154 | * Removes an overlay if it is permissible. @ovcs_id was previously returned |
a514266b | 1155 | * by of_overlay_fdt_apply(). |
7518b589 | 1156 | * |
24789c5c FR |
1157 | * If an error occurred while attempting to revert the overlay changeset, |
1158 | * then an attempt is made to re-apply any changeset entry that was | |
1159 | * reverted. If an error occurs on re-apply then the state of the device | |
1160 | * tree can not be determined, and any following attempt to apply or remove | |
1161 | * an overlay changeset will be refused. | |
1162 | * | |
1163 | * A non-zero return value will not revert the changeset if error is from: | |
1164 | * - parameter checks | |
e9d92e40 | 1165 | * - overlay changeset pre-remove notifier |
24789c5c FR |
1166 | * - overlay changeset entry revert |
1167 | * | |
1168 | * If an error is returned by an overlay changeset pre-remove notifier | |
1169 | * then no further overlay changeset pre-remove notifier will be called. | |
1170 | * | |
1171 | * If more than one notifier returns an error, then the last notifier | |
1172 | * error to occur is returned. | |
1173 | * | |
1174 | * A non-zero return value will revert the changeset if error is from: | |
1175 | * - overlay changeset entry notifier | |
e9d92e40 | 1176 | * - overlay changeset post-remove notifier |
24789c5c FR |
1177 | * |
1178 | * If an error is returned by an overlay changeset post-remove notifier | |
1179 | * then no further overlay changeset post-remove notifier will be called. | |
1180 | * | |
1181 | * Returns 0 on success, or a negative error number. *ovcs_id is set to | |
1182 | * zero after reverting the changeset, even if a subsequent error occurs. | |
7518b589 | 1183 | */ |
24789c5c | 1184 | int of_overlay_remove(int *ovcs_id) |
7518b589 | 1185 | { |
0290c4ca | 1186 | struct overlay_changeset *ovcs; |
24789c5c FR |
1187 | int ret, ret_apply, ret_tmp; |
1188 | ||
1189 | ret = 0; | |
1190 | ||
1191 | if (devicetree_corrupt()) { | |
1192 | pr_err("suspect devicetree state, refuse to remove overlay\n"); | |
1193 | ret = -EBUSY; | |
1194 | goto out; | |
1195 | } | |
7518b589 PA |
1196 | |
1197 | mutex_lock(&of_mutex); | |
1198 | ||
24789c5c | 1199 | ovcs = idr_find(&ovcs_idr, *ovcs_id); |
0290c4ca FR |
1200 | if (!ovcs) { |
1201 | ret = -ENODEV; | |
24789c5c FR |
1202 | pr_err("remove: Could not find overlay #%d\n", *ovcs_id); |
1203 | goto out_unlock; | |
7518b589 PA |
1204 | } |
1205 | ||
0290c4ca FR |
1206 | if (!overlay_removal_is_ok(ovcs)) { |
1207 | ret = -EBUSY; | |
24789c5c | 1208 | goto out_unlock; |
7518b589 PA |
1209 | } |
1210 | ||
24789c5c FR |
1211 | ret = overlay_notify(ovcs, OF_OVERLAY_PRE_REMOVE); |
1212 | if (ret) { | |
1213 | pr_err("overlay changeset pre-remove notify error %d\n", ret); | |
1214 | goto out_unlock; | |
1215 | } | |
61b4de4e | 1216 | |
0290c4ca | 1217 | list_del(&ovcs->ovcs_list); |
61b4de4e | 1218 | |
24789c5c FR |
1219 | ret_apply = 0; |
1220 | ret = __of_changeset_revert_entries(&ovcs->cset, &ret_apply); | |
1221 | if (ret) { | |
1222 | if (ret_apply) | |
1223 | devicetree_state_flags |= DTSF_REVERT_FAIL; | |
1224 | goto out_unlock; | |
24789c5c | 1225 | } |
61b4de4e | 1226 | |
6de67de3 GU |
1227 | ret = __of_changeset_revert_notify(&ovcs->cset); |
1228 | if (ret) | |
a15e824f | 1229 | pr_err("overlay remove changeset entry notify error %d\n", ret); |
6de67de3 GU |
1230 | /* notify failure is not fatal, continue */ |
1231 | ||
24789c5c FR |
1232 | *ovcs_id = 0; |
1233 | ||
1234 | ret_tmp = overlay_notify(ovcs, OF_OVERLAY_POST_REMOVE); | |
1235 | if (ret_tmp) { | |
1236 | pr_err("overlay changeset post-remove notify error %d\n", | |
1237 | ret_tmp); | |
1238 | if (!ret) | |
1239 | ret = ret_tmp; | |
1240 | } | |
61b4de4e FR |
1241 | |
1242 | free_overlay_changeset(ovcs); | |
7518b589 | 1243 | |
24789c5c | 1244 | out_unlock: |
7518b589 PA |
1245 | mutex_unlock(&of_mutex); |
1246 | ||
24789c5c FR |
1247 | out: |
1248 | pr_debug("%s() err=%d\n", __func__, ret); | |
1249 | ||
0290c4ca | 1250 | return ret; |
7518b589 | 1251 | } |
0290c4ca | 1252 | EXPORT_SYMBOL_GPL(of_overlay_remove); |
7518b589 PA |
1253 | |
1254 | /** | |
0290c4ca | 1255 | * of_overlay_remove_all() - Reverts and frees all overlay changesets |
7518b589 PA |
1256 | * |
1257 | * Removes all overlays from the system in the correct order. | |
1258 | * | |
94a8bf97 | 1259 | * Returns 0 on success, or a negative error number |
7518b589 | 1260 | */ |
0290c4ca | 1261 | int of_overlay_remove_all(void) |
7518b589 | 1262 | { |
0290c4ca | 1263 | struct overlay_changeset *ovcs, *ovcs_n; |
61b4de4e | 1264 | int ret; |
7518b589 PA |
1265 | |
1266 | /* the tail of list is guaranteed to be safe to remove */ | |
0290c4ca | 1267 | list_for_each_entry_safe_reverse(ovcs, ovcs_n, &ovcs_list, ovcs_list) { |
24789c5c | 1268 | ret = of_overlay_remove(&ovcs->id); |
61b4de4e FR |
1269 | if (ret) |
1270 | return ret; | |
7518b589 PA |
1271 | } |
1272 | ||
7518b589 PA |
1273 | return 0; |
1274 | } | |
0290c4ca | 1275 | EXPORT_SYMBOL_GPL(of_overlay_remove_all); |