Commit | Line | Data |
---|---|---|
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 |
48d499bd | 60 | * @fdt: base of memory allocated to hold aligned 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 | 142 | /** |
f957d5b7 | 143 | * of_overlay_notifier_unregister() - Unregister notifier for overlay operations |
83ef4777 JK |
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 | |
478ff649 FR |
264 | kfree(target_path); |
265 | ||
e0a58f3e | 266 | return new_prop; |
d1651b03 | 267 | |
e0a58f3e FR |
268 | err_free_new_prop: |
269 | kfree(new_prop->name); | |
270 | kfree(new_prop->value); | |
271 | kfree(new_prop); | |
272 | err_free_target_path: | |
273 | kfree(target_path); | |
d1651b03 | 274 | |
d1651b03 | 275 | return NULL; |
d1651b03 FR |
276 | } |
277 | ||
0290c4ca FR |
278 | /** |
279 | * add_changeset_property() - add @overlay_prop to overlay changeset | |
280 | * @ovcs: overlay changeset | |
6b4955ba | 281 | * @target: where @overlay_prop will be placed |
0290c4ca | 282 | * @overlay_prop: property to add or update, from overlay tree |
3912b791 | 283 | * @is_symbols_prop: 1 if @overlay_prop is from node "/__symbols__" |
0290c4ca | 284 | * |
6b4955ba FR |
285 | * If @overlay_prop does not already exist in live devicetree, add changeset |
286 | * entry to add @overlay_prop in @target, else add changeset entry to update | |
0290c4ca FR |
287 | * value of @overlay_prop. |
288 | * | |
6b4955ba FR |
289 | * @target may be either in the live devicetree or in a new subtree that |
290 | * is contained in the changeset. | |
291 | * | |
6f751188 FR |
292 | * Some special properties are not added or updated (no error returned): |
293 | * "name", "phandle", "linux,phandle". | |
294 | * | |
295 | * Properties "#address-cells" and "#size-cells" are not updated if they | |
296 | * are already in the live tree, but if present in the live tree, the values | |
297 | * in the overlay must match the values in the live tree. | |
0290c4ca | 298 | * |
646afc4a | 299 | * Update of property in symbols node is not allowed. |
0290c4ca | 300 | * |
8c8239c2 | 301 | * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if |
0290c4ca | 302 | * invalid @overlay. |
646afc4a | 303 | */ |
0290c4ca | 304 | static int add_changeset_property(struct overlay_changeset *ovcs, |
6b4955ba | 305 | struct target *target, struct property *overlay_prop, |
3912b791 | 306 | bool is_symbols_prop) |
7518b589 | 307 | { |
0290c4ca | 308 | struct property *new_prop = NULL, *prop; |
ac0f3e30 | 309 | int ret = 0; |
7518b589 | 310 | |
f9627881 FR |
311 | if (target->in_livetree) |
312 | if (!of_prop_cmp(overlay_prop->name, "name") || | |
313 | !of_prop_cmp(overlay_prop->name, "phandle") || | |
314 | !of_prop_cmp(overlay_prop->name, "linux,phandle")) | |
315 | return 0; | |
7518b589 | 316 | |
6b4955ba FR |
317 | if (target->in_livetree) |
318 | prop = of_find_property(target->np, overlay_prop->name, NULL); | |
319 | else | |
320 | prop = NULL; | |
321 | ||
637392a8 FR |
322 | if (prop) { |
323 | if (!of_prop_cmp(prop->name, "#address-cells")) { | |
324 | if (!of_prop_val_eq(prop, overlay_prop)) { | |
325 | pr_err("ERROR: changing value of #address-cells is not allowed in %pOF\n", | |
326 | target->np); | |
327 | ret = -EINVAL; | |
328 | } | |
329 | return ret; | |
330 | ||
331 | } else if (!of_prop_cmp(prop->name, "#size-cells")) { | |
332 | if (!of_prop_val_eq(prop, overlay_prop)) { | |
333 | pr_err("ERROR: changing value of #size-cells is not allowed in %pOF\n", | |
334 | target->np); | |
335 | ret = -EINVAL; | |
336 | } | |
337 | return ret; | |
338 | } | |
339 | } | |
340 | ||
3912b791 | 341 | if (is_symbols_prop) { |
0290c4ca | 342 | if (prop) |
d1651b03 | 343 | return -EINVAL; |
0290c4ca | 344 | new_prop = dup_and_fixup_symbol_prop(ovcs, overlay_prop); |
d1651b03 | 345 | } else { |
0290c4ca | 346 | new_prop = __of_prop_dup(overlay_prop, GFP_KERNEL); |
d1651b03 FR |
347 | } |
348 | ||
0290c4ca | 349 | if (!new_prop) |
7518b589 PA |
350 | return -ENOMEM; |
351 | ||
6f751188 | 352 | if (!prop) { |
f9627881 FR |
353 | if (!target->in_livetree) { |
354 | new_prop->next = target->np->deadprops; | |
355 | target->np->deadprops = new_prop; | |
356 | } | |
6b4955ba | 357 | ret = of_changeset_add_property(&ovcs->cset, target->np, |
0290c4ca | 358 | new_prop); |
6f751188 | 359 | } else { |
6b4955ba | 360 | ret = of_changeset_update_property(&ovcs->cset, target->np, |
0290c4ca | 361 | new_prop); |
6f751188 FR |
362 | } |
363 | ||
637392a8 | 364 | if (!of_node_check_flag(target->np, OF_OVERLAY)) |
6f751188 FR |
365 | pr_err("WARNING: memory leak will occur if overlay removed, property: %pOF/%s\n", |
366 | target->np, new_prop->name); | |
ac0f3e30 LW |
367 | |
368 | if (ret) { | |
0290c4ca FR |
369 | kfree(new_prop->name); |
370 | kfree(new_prop->value); | |
371 | kfree(new_prop); | |
ac0f3e30 LW |
372 | } |
373 | return ret; | |
7518b589 PA |
374 | } |
375 | ||
0290c4ca FR |
376 | /** |
377 | * add_changeset_node() - add @node (and children) to overlay changeset | |
6b4955ba FR |
378 | * @ovcs: overlay changeset |
379 | * @target: where @node will be placed in live tree or changeset | |
380 | * @node: node from within overlay device tree fragment | |
0290c4ca | 381 | * |
6b4955ba FR |
382 | * If @node does not already exist in @target, add changeset entry |
383 | * to add @node in @target. | |
0290c4ca | 384 | * |
6b4955ba | 385 | * If @node already exists in @target, and the existing node has |
0290c4ca FR |
386 | * a phandle, the overlay node is not allowed to have a phandle. |
387 | * | |
388 | * If @node has child nodes, add the children recursively via | |
389 | * build_changeset_next_level(). | |
390 | * | |
b89dae18 FR |
391 | * NOTE_1: A live devicetree created from a flattened device tree (FDT) will |
392 | * not contain the full path in node->full_name. Thus an overlay | |
393 | * created from an FDT also will not contain the full path in | |
394 | * node->full_name. However, a live devicetree created from Open | |
395 | * Firmware may have the full path in node->full_name. | |
396 | * | |
397 | * add_changeset_node() follows the FDT convention and does not include | |
398 | * the full path in node->full_name. Even though it expects the overlay | |
399 | * to not contain the full path, it uses kbasename() to remove the | |
400 | * full path should it exist. It also uses kbasename() in comparisons | |
401 | * to nodes in the live devicetree so that it can apply an overlay to | |
402 | * a live devicetree created from Open Firmware. | |
403 | * | |
404 | * NOTE_2: Multiple mods of created nodes not supported. | |
0290c4ca | 405 | * |
8c8239c2 | 406 | * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if |
0290c4ca FR |
407 | * invalid @overlay. |
408 | */ | |
409 | static int add_changeset_node(struct overlay_changeset *ovcs, | |
6b4955ba | 410 | struct target *target, struct device_node *node) |
7518b589 | 411 | { |
0290c4ca | 412 | const char *node_kbasename; |
f9627881 | 413 | const __be32 *phandle; |
d3a89165 | 414 | struct device_node *tchild; |
6b4955ba | 415 | struct target target_child; |
f9627881 | 416 | int ret = 0, size; |
7518b589 | 417 | |
0290c4ca | 418 | node_kbasename = kbasename(node->full_name); |
7518b589 | 419 | |
6b4955ba | 420 | for_each_child_of_node(target->np, tchild) |
0290c4ca | 421 | if (!of_node_cmp(node_kbasename, kbasename(tchild->full_name))) |
c1cd1e01 FR |
422 | break; |
423 | ||
61b4de4e | 424 | if (!tchild) { |
8814dc46 | 425 | tchild = __of_node_dup(NULL, node_kbasename); |
7518b589 PA |
426 | if (!tchild) |
427 | return -ENOMEM; | |
428 | ||
6b4955ba | 429 | tchild->parent = target->np; |
f9627881 | 430 | tchild->name = __of_get_property(node, "name", NULL); |
f9627881 FR |
431 | |
432 | if (!tchild->name) | |
433 | tchild->name = "<NULL>"; | |
f9627881 FR |
434 | |
435 | /* ignore obsolete "linux,phandle" */ | |
436 | phandle = __of_get_property(node, "phandle", &size); | |
437 | if (phandle && (size == 4)) | |
438 | tchild->phandle = be32_to_cpup(phandle); | |
439 | ||
144552c7 | 440 | of_node_set_flag(tchild, OF_OVERLAY); |
7518b589 | 441 | |
0290c4ca | 442 | ret = of_changeset_attach_node(&ovcs->cset, tchild); |
7518b589 PA |
443 | if (ret) |
444 | return ret; | |
445 | ||
6b4955ba FR |
446 | target_child.np = tchild; |
447 | target_child.in_livetree = false; | |
448 | ||
449 | ret = build_changeset_next_level(ovcs, &target_child, node); | |
7c528e45 FR |
450 | of_node_put(tchild); |
451 | return ret; | |
7518b589 PA |
452 | } |
453 | ||
6b4955ba | 454 | if (node->phandle && tchild->phandle) { |
6d0f5470 | 455 | ret = -EINVAL; |
6b4955ba FR |
456 | } else { |
457 | target_child.np = tchild; | |
458 | target_child.in_livetree = target->in_livetree; | |
459 | ret = build_changeset_next_level(ovcs, &target_child, node); | |
460 | } | |
61b4de4e FR |
461 | of_node_put(tchild); |
462 | ||
7518b589 PA |
463 | return ret; |
464 | } | |
465 | ||
0290c4ca FR |
466 | /** |
467 | * build_changeset_next_level() - add level of overlay changeset | |
468 | * @ovcs: overlay changeset | |
6b4955ba | 469 | * @target: where to place @overlay_node in live tree |
0290c4ca | 470 | * @overlay_node: node from within an overlay device tree fragment |
7518b589 | 471 | * |
0290c4ca FR |
472 | * Add the properties (if any) and nodes (if any) from @overlay_node to the |
473 | * @ovcs->cset changeset. If an added node has child nodes, they will | |
474 | * be added recursively. | |
646afc4a FR |
475 | * |
476 | * Do not allow symbols node to have any children. | |
0290c4ca | 477 | * |
8c8239c2 | 478 | * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if |
0290c4ca | 479 | * invalid @overlay_node. |
7518b589 | 480 | */ |
0290c4ca | 481 | static int build_changeset_next_level(struct overlay_changeset *ovcs, |
6b4955ba | 482 | struct target *target, const struct device_node *overlay_node) |
7518b589 PA |
483 | { |
484 | struct device_node *child; | |
485 | struct property *prop; | |
486 | int ret; | |
487 | ||
0290c4ca | 488 | for_each_property_of_node(overlay_node, prop) { |
6b4955ba | 489 | ret = add_changeset_property(ovcs, target, prop, 0); |
7518b589 | 490 | if (ret) { |
24789c5c | 491 | pr_debug("Failed to apply prop @%pOF/%s, err=%d\n", |
6b4955ba | 492 | target->np, prop->name, ret); |
7518b589 PA |
493 | return ret; |
494 | } | |
495 | } | |
496 | ||
0290c4ca | 497 | for_each_child_of_node(overlay_node, child) { |
6b4955ba | 498 | ret = add_changeset_node(ovcs, target, child); |
bbed8794 | 499 | if (ret) { |
a613b26a | 500 | pr_debug("Failed to apply node @%pOF/%pOFn, err=%d\n", |
6b4955ba | 501 | target->np, child, ret); |
001cf504 | 502 | of_node_put(child); |
7518b589 PA |
503 | return ret; |
504 | } | |
505 | } | |
506 | ||
507 | return 0; | |
508 | } | |
509 | ||
3912b791 FR |
510 | /* |
511 | * Add the properties from __overlay__ node to the @ovcs->cset changeset. | |
512 | */ | |
513 | static int build_changeset_symbols_node(struct overlay_changeset *ovcs, | |
6b4955ba | 514 | struct target *target, |
3912b791 FR |
515 | const struct device_node *overlay_symbols_node) |
516 | { | |
517 | struct property *prop; | |
518 | int ret; | |
519 | ||
520 | for_each_property_of_node(overlay_symbols_node, prop) { | |
6b4955ba | 521 | ret = add_changeset_property(ovcs, target, prop, 1); |
3912b791 | 522 | if (ret) { |
a15e824f | 523 | pr_debug("Failed to apply symbols prop @%pOF/%s, err=%d\n", |
6b4955ba | 524 | target->np, prop->name, ret); |
3912b791 FR |
525 | return ret; |
526 | } | |
527 | } | |
528 | ||
529 | return 0; | |
530 | } | |
531 | ||
2fe0e876 FR |
532 | static int find_dup_cset_node_entry(struct overlay_changeset *ovcs, |
533 | struct of_changeset_entry *ce_1) | |
534 | { | |
535 | struct of_changeset_entry *ce_2; | |
536 | char *fn_1, *fn_2; | |
537 | int node_path_match; | |
538 | ||
539 | if (ce_1->action != OF_RECONFIG_ATTACH_NODE && | |
540 | ce_1->action != OF_RECONFIG_DETACH_NODE) | |
541 | return 0; | |
542 | ||
543 | ce_2 = ce_1; | |
544 | list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) { | |
545 | if ((ce_2->action != OF_RECONFIG_ATTACH_NODE && | |
546 | ce_2->action != OF_RECONFIG_DETACH_NODE) || | |
547 | of_node_cmp(ce_1->np->full_name, ce_2->np->full_name)) | |
548 | continue; | |
549 | ||
550 | fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np); | |
551 | fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np); | |
552 | node_path_match = !strcmp(fn_1, fn_2); | |
553 | kfree(fn_1); | |
554 | kfree(fn_2); | |
555 | if (node_path_match) { | |
556 | pr_err("ERROR: multiple fragments add and/or delete node %pOF\n", | |
557 | ce_1->np); | |
558 | return -EINVAL; | |
559 | } | |
560 | } | |
561 | ||
562 | return 0; | |
563 | } | |
564 | ||
565 | static int find_dup_cset_prop(struct overlay_changeset *ovcs, | |
566 | struct of_changeset_entry *ce_1) | |
567 | { | |
568 | struct of_changeset_entry *ce_2; | |
569 | char *fn_1, *fn_2; | |
570 | int node_path_match; | |
571 | ||
572 | if (ce_1->action != OF_RECONFIG_ADD_PROPERTY && | |
573 | ce_1->action != OF_RECONFIG_REMOVE_PROPERTY && | |
574 | ce_1->action != OF_RECONFIG_UPDATE_PROPERTY) | |
575 | return 0; | |
576 | ||
577 | ce_2 = ce_1; | |
578 | list_for_each_entry_continue(ce_2, &ovcs->cset.entries, node) { | |
579 | if ((ce_2->action != OF_RECONFIG_ADD_PROPERTY && | |
580 | ce_2->action != OF_RECONFIG_REMOVE_PROPERTY && | |
581 | ce_2->action != OF_RECONFIG_UPDATE_PROPERTY) || | |
582 | of_node_cmp(ce_1->np->full_name, ce_2->np->full_name)) | |
583 | continue; | |
584 | ||
585 | fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np); | |
586 | fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np); | |
587 | node_path_match = !strcmp(fn_1, fn_2); | |
588 | kfree(fn_1); | |
589 | kfree(fn_2); | |
590 | if (node_path_match && | |
591 | !of_prop_cmp(ce_1->prop->name, ce_2->prop->name)) { | |
592 | pr_err("ERROR: multiple fragments add, update, and/or delete property %pOF/%s\n", | |
593 | ce_1->np, ce_1->prop->name); | |
594 | return -EINVAL; | |
595 | } | |
596 | } | |
597 | ||
598 | return 0; | |
599 | } | |
600 | ||
c168263b | 601 | /** |
2fe0e876 | 602 | * changeset_dup_entry_check() - check for duplicate entries |
c168263b FR |
603 | * @ovcs: Overlay changeset |
604 | * | |
2fe0e876 FR |
605 | * Check changeset @ovcs->cset for multiple {add or delete} node entries for |
606 | * the same node or duplicate {add, delete, or update} properties entries | |
607 | * for the same property. | |
c168263b | 608 | * |
8c8239c2 | 609 | * Return: 0 on success, or -EINVAL if duplicate changeset entry found. |
c168263b | 610 | */ |
2fe0e876 | 611 | static int changeset_dup_entry_check(struct overlay_changeset *ovcs) |
c168263b | 612 | { |
2fe0e876 FR |
613 | struct of_changeset_entry *ce_1; |
614 | int dup_entry = 0; | |
c168263b FR |
615 | |
616 | list_for_each_entry(ce_1, &ovcs->cset.entries, node) { | |
2fe0e876 FR |
617 | dup_entry |= find_dup_cset_node_entry(ovcs, ce_1); |
618 | dup_entry |= find_dup_cset_prop(ovcs, ce_1); | |
c168263b FR |
619 | } |
620 | ||
2fe0e876 | 621 | return dup_entry ? -EINVAL : 0; |
c168263b FR |
622 | } |
623 | ||
7518b589 | 624 | /** |
0290c4ca FR |
625 | * build_changeset() - populate overlay changeset in @ovcs from @ovcs->fragments |
626 | * @ovcs: Overlay changeset | |
7518b589 | 627 | * |
0290c4ca FR |
628 | * Create changeset @ovcs->cset to contain the nodes and properties of the |
629 | * overlay device tree fragments in @ovcs->fragments[]. If an error occurs, | |
630 | * any portions of the changeset that were successfully created will remain | |
631 | * in @ovcs->cset. | |
632 | * | |
8c8239c2 | 633 | * Return: 0 on success, -ENOMEM if memory allocation failure, or -EINVAL if |
0290c4ca | 634 | * invalid overlay in @ovcs->fragments[]. |
7518b589 | 635 | */ |
0290c4ca | 636 | static int build_changeset(struct overlay_changeset *ovcs) |
7518b589 | 637 | { |
3912b791 | 638 | struct fragment *fragment; |
6b4955ba | 639 | struct target target; |
3912b791 | 640 | int fragments_count, i, ret; |
7518b589 | 641 | |
3912b791 FR |
642 | /* |
643 | * if there is a symbols fragment in ovcs->fragments[i] it is | |
644 | * the final element in the array | |
645 | */ | |
646 | if (ovcs->symbols_fragment) | |
647 | fragments_count = ovcs->count - 1; | |
648 | else | |
649 | fragments_count = ovcs->count; | |
650 | ||
651 | for (i = 0; i < fragments_count; i++) { | |
652 | fragment = &ovcs->fragments[i]; | |
7518b589 | 653 | |
6b4955ba FR |
654 | target.np = fragment->target; |
655 | target.in_livetree = true; | |
656 | ret = build_changeset_next_level(ovcs, &target, | |
3912b791 FR |
657 | fragment->overlay); |
658 | if (ret) { | |
a15e824f FR |
659 | pr_debug("fragment apply failed '%pOF'\n", |
660 | fragment->target); | |
3912b791 FR |
661 | return ret; |
662 | } | |
663 | } | |
664 | ||
665 | if (ovcs->symbols_fragment) { | |
666 | fragment = &ovcs->fragments[ovcs->count - 1]; | |
6b4955ba FR |
667 | |
668 | target.np = fragment->target; | |
669 | target.in_livetree = true; | |
670 | ret = build_changeset_symbols_node(ovcs, &target, | |
3912b791 | 671 | fragment->overlay); |
0290c4ca | 672 | if (ret) { |
a15e824f FR |
673 | pr_debug("symbols fragment apply failed '%pOF'\n", |
674 | fragment->target); | |
0290c4ca | 675 | return ret; |
7518b589 PA |
676 | } |
677 | } | |
678 | ||
2fe0e876 | 679 | return changeset_dup_entry_check(ovcs); |
7518b589 PA |
680 | } |
681 | ||
682 | /* | |
683 | * Find the target node using a number of different strategies | |
646afc4a | 684 | * in order of preference: |
7518b589 | 685 | * |
646afc4a FR |
686 | * 1) "target" property containing the phandle of the target |
687 | * 2) "target-path" property containing the path of the target | |
7518b589 | 688 | */ |
6b4955ba | 689 | static struct device_node *find_target(struct device_node *info_node) |
7518b589 | 690 | { |
e547c003 | 691 | struct device_node *node; |
7518b589 PA |
692 | const char *path; |
693 | u32 val; | |
694 | int ret; | |
695 | ||
7518b589 | 696 | ret = of_property_read_u32(info_node, "target", &val); |
e547c003 FR |
697 | if (!ret) { |
698 | node = of_find_node_by_phandle(val); | |
699 | if (!node) | |
700 | pr_err("find target, node: %pOF, phandle 0x%x not found\n", | |
701 | info_node, val); | |
702 | return node; | |
703 | } | |
7518b589 | 704 | |
7518b589 | 705 | ret = of_property_read_string(info_node, "target-path", &path); |
e547c003 FR |
706 | if (!ret) { |
707 | node = of_find_node_by_path(path); | |
708 | if (!node) | |
709 | pr_err("find target, node: %pOF, path '%s' not found\n", | |
710 | info_node, path); | |
711 | return node; | |
712 | } | |
7518b589 | 713 | |
e547c003 | 714 | pr_err("find target, node: %pOF, no target property\n", info_node); |
7518b589 PA |
715 | |
716 | return NULL; | |
717 | } | |
718 | ||
7518b589 | 719 | /** |
0290c4ca | 720 | * init_overlay_changeset() - initialize overlay changeset from overlay tree |
39a751a4 | 721 | * @ovcs: Overlay changeset to build |
48d499bd FR |
722 | * @fdt: base of memory allocated to hold aligned FDT that was unflattened to create @tree |
723 | * @tree: Contains the overlay fragments and overlay fixup nodes | |
7518b589 | 724 | * |
0290c4ca FR |
725 | * Initialize @ovcs. Populate @ovcs->fragments with node information from |
726 | * the top level of @tree. The relevant top level nodes are the fragment | |
727 | * nodes and the __symbols__ node. Any other top level node will be ignored. | |
7518b589 | 728 | * |
8c8239c2 | 729 | * Return: 0 on success, -ENOMEM if memory allocation failure, -EINVAL if error |
61b4de4e | 730 | * detected in @tree, or -ENOSPC if idr_alloc() error. |
7518b589 | 731 | */ |
0290c4ca | 732 | static int init_overlay_changeset(struct overlay_changeset *ovcs, |
39a751a4 | 733 | const void *fdt, struct device_node *tree) |
7518b589 | 734 | { |
61b4de4e | 735 | struct device_node *node, *overlay_node; |
0290c4ca FR |
736 | struct fragment *fragment; |
737 | struct fragment *fragments; | |
1352f09b | 738 | int cnt, id, ret; |
7518b589 | 739 | |
24789c5c FR |
740 | /* |
741 | * Warn for some issues. Can not return -EINVAL for these until | |
742 | * of_unittest_apply_overlay() is fixed to pass these checks. | |
743 | */ | |
744 | if (!of_node_check_flag(tree, OF_DYNAMIC)) | |
745 | pr_debug("%s() tree is not dynamic\n", __func__); | |
746 | ||
747 | if (!of_node_check_flag(tree, OF_DETACHED)) | |
748 | pr_debug("%s() tree is not detached\n", __func__); | |
749 | ||
750 | if (!of_node_is_root(tree)) | |
751 | pr_debug("%s() tree is not root\n", __func__); | |
752 | ||
e0a58f3e | 753 | ovcs->overlay_tree = tree; |
39a751a4 | 754 | ovcs->fdt = fdt; |
e0a58f3e | 755 | |
61b4de4e FR |
756 | INIT_LIST_HEAD(&ovcs->ovcs_list); |
757 | ||
758 | of_changeset_init(&ovcs->cset); | |
759 | ||
1352f09b GU |
760 | id = idr_alloc(&ovcs_idr, ovcs, 1, 0, GFP_KERNEL); |
761 | if (id <= 0) | |
762 | return id; | |
61b4de4e | 763 | |
7518b589 | 764 | cnt = 0; |
7518b589 | 765 | |
61b4de4e FR |
766 | /* fragment nodes */ |
767 | for_each_child_of_node(tree, node) { | |
768 | overlay_node = of_get_child_by_name(node, "__overlay__"); | |
769 | if (overlay_node) { | |
770 | cnt++; | |
771 | of_node_put(overlay_node); | |
772 | } | |
773 | } | |
774 | ||
775 | node = of_get_child_by_name(tree, "__symbols__"); | |
776 | if (node) { | |
d1651b03 | 777 | cnt++; |
61b4de4e FR |
778 | of_node_put(node); |
779 | } | |
d1651b03 | 780 | |
0290c4ca | 781 | fragments = kcalloc(cnt, sizeof(*fragments), GFP_KERNEL); |
61b4de4e FR |
782 | if (!fragments) { |
783 | ret = -ENOMEM; | |
784 | goto err_free_idr; | |
785 | } | |
7518b589 PA |
786 | |
787 | cnt = 0; | |
788 | for_each_child_of_node(tree, node) { | |
35e691ed | 789 | overlay_node = of_get_child_by_name(node, "__overlay__"); |
589b754d GU |
790 | if (!overlay_node) |
791 | continue; | |
6de67de3 | 792 | |
589b754d GU |
793 | fragment = &fragments[cnt]; |
794 | fragment->overlay = overlay_node; | |
6b4955ba | 795 | fragment->target = find_target(node); |
589b754d GU |
796 | if (!fragment->target) { |
797 | of_node_put(fragment->overlay); | |
798 | ret = -EINVAL; | |
c4d74f0f | 799 | of_node_put(node); |
589b754d | 800 | goto err_free_fragments; |
61b4de4e | 801 | } |
589b754d GU |
802 | |
803 | cnt++; | |
7518b589 PA |
804 | } |
805 | ||
3912b791 FR |
806 | /* |
807 | * if there is a symbols fragment in ovcs->fragments[i] it is | |
808 | * the final element in the array | |
809 | */ | |
d1651b03 FR |
810 | node = of_get_child_by_name(tree, "__symbols__"); |
811 | if (node) { | |
3912b791 | 812 | ovcs->symbols_fragment = 1; |
0290c4ca FR |
813 | fragment = &fragments[cnt]; |
814 | fragment->overlay = node; | |
815 | fragment->target = of_find_node_by_path("/__symbols__"); | |
d1651b03 | 816 | |
0290c4ca | 817 | if (!fragment->target) { |
4ee7c0d9 | 818 | pr_err("symbols in overlay, but not in live tree\n"); |
61b4de4e FR |
819 | ret = -EINVAL; |
820 | goto err_free_fragments; | |
d1651b03 FR |
821 | } |
822 | ||
823 | cnt++; | |
824 | } | |
825 | ||
bbed8794 | 826 | if (!cnt) { |
39a751a4 | 827 | pr_err("no fragments or symbols in overlay\n"); |
61b4de4e FR |
828 | ret = -EINVAL; |
829 | goto err_free_fragments; | |
7518b589 PA |
830 | } |
831 | ||
1352f09b | 832 | ovcs->id = id; |
0290c4ca FR |
833 | ovcs->count = cnt; |
834 | ovcs->fragments = fragments; | |
7518b589 PA |
835 | |
836 | return 0; | |
61b4de4e | 837 | |
61b4de4e FR |
838 | err_free_fragments: |
839 | kfree(fragments); | |
840 | err_free_idr: | |
1352f09b | 841 | idr_remove(&ovcs_idr, id); |
61b4de4e | 842 | |
24789c5c FR |
843 | pr_err("%s() failed, ret = %d\n", __func__, ret); |
844 | ||
61b4de4e | 845 | return ret; |
7518b589 PA |
846 | } |
847 | ||
61b4de4e | 848 | static void free_overlay_changeset(struct overlay_changeset *ovcs) |
7518b589 | 849 | { |
7518b589 PA |
850 | int i; |
851 | ||
1352f09b GU |
852 | if (ovcs->cset.entries.next) |
853 | of_changeset_destroy(&ovcs->cset); | |
61b4de4e FR |
854 | |
855 | if (ovcs->id) | |
856 | idr_remove(&ovcs_idr, ovcs->id); | |
857 | ||
858 | for (i = 0; i < ovcs->count; i++) { | |
0290c4ca FR |
859 | of_node_put(ovcs->fragments[i].target); |
860 | of_node_put(ovcs->fragments[i].overlay); | |
7518b589 | 861 | } |
0290c4ca | 862 | kfree(ovcs->fragments); |
39a751a4 | 863 | /* |
83ef4777 JK |
864 | * There should be no live pointers into ovcs->overlay_tree and |
865 | * ovcs->fdt due to the policy that overlay notifiers are not allowed | |
866 | * to retain pointers into the overlay devicetree. | |
39a751a4 | 867 | */ |
83ef4777 JK |
868 | kfree(ovcs->overlay_tree); |
869 | kfree(ovcs->fdt); | |
61b4de4e FR |
870 | kfree(ovcs); |
871 | } | |
7518b589 | 872 | |
39a751a4 FR |
873 | /* |
874 | * internal documentation | |
875 | * | |
0290c4ca | 876 | * of_overlay_apply() - Create and apply an overlay changeset |
48d499bd | 877 | * @fdt: base of memory allocated to hold the aligned FDT |
0290c4ca | 878 | * @tree: Expanded overlay device tree |
24789c5c FR |
879 | * @ovcs_id: Pointer to overlay changeset id |
880 | * | |
881 | * Creates and applies an overlay changeset. | |
7518b589 | 882 | * |
24789c5c FR |
883 | * If an error occurs in a pre-apply notifier, then no changes are made |
884 | * to the device tree. | |
7518b589 | 885 | * |
24789c5c FR |
886 | |
887 | * A non-zero return value will not have created the changeset if error is from: | |
888 | * - parameter checks | |
889 | * - building the changeset | |
e9d92e40 | 890 | * - overlay changeset pre-apply notifier |
24789c5c FR |
891 | * |
892 | * If an error is returned by an overlay changeset pre-apply notifier | |
893 | * then no further overlay changeset pre-apply notifier will be called. | |
894 | * | |
895 | * A non-zero return value will have created the changeset if error is from: | |
896 | * - overlay changeset entry notifier | |
e9d92e40 | 897 | * - overlay changeset post-apply notifier |
24789c5c FR |
898 | * |
899 | * If an error is returned by an overlay changeset post-apply notifier | |
900 | * then no further overlay changeset post-apply notifier will be called. | |
901 | * | |
902 | * If more than one notifier returns an error, then the last notifier | |
903 | * error to occur is returned. | |
904 | * | |
905 | * If an error occurred while applying the overlay changeset, then an | |
906 | * attempt is made to revert any changes that were made to the | |
907 | * device tree. If there were any errors during the revert attempt | |
908 | * then the state of the device tree can not be determined, and any | |
909 | * following attempt to apply or remove an overlay changeset will be | |
910 | * refused. | |
911 | * | |
912 | * Returns 0 on success, or a negative error number. Overlay changeset | |
913 | * id is returned to *ovcs_id. | |
7518b589 | 914 | */ |
24789c5c | 915 | |
39a751a4 FR |
916 | static int of_overlay_apply(const void *fdt, struct device_node *tree, |
917 | int *ovcs_id) | |
7518b589 | 918 | { |
0290c4ca | 919 | struct overlay_changeset *ovcs; |
24789c5c FR |
920 | int ret = 0, ret_revert, ret_tmp; |
921 | ||
39a751a4 FR |
922 | /* |
923 | * As of this point, fdt and tree belong to the overlay changeset. | |
924 | * overlay changeset code is responsible for freeing them. | |
925 | */ | |
24789c5c FR |
926 | |
927 | if (devicetree_corrupt()) { | |
928 | pr_err("devicetree state suspect, refuse to apply overlay\n"); | |
39a751a4 FR |
929 | kfree(fdt); |
930 | kfree(tree); | |
24789c5c FR |
931 | ret = -EBUSY; |
932 | goto out; | |
933 | } | |
7518b589 | 934 | |
0290c4ca | 935 | ovcs = kzalloc(sizeof(*ovcs), GFP_KERNEL); |
24789c5c | 936 | if (!ovcs) { |
39a751a4 FR |
937 | kfree(fdt); |
938 | kfree(tree); | |
24789c5c FR |
939 | ret = -ENOMEM; |
940 | goto out; | |
941 | } | |
7518b589 | 942 | |
f948d6d8 | 943 | of_overlay_mutex_lock(); |
5e474817 | 944 | mutex_lock(&of_mutex); |
f948d6d8 FR |
945 | |
946 | ret = of_resolve_phandles(tree); | |
947 | if (ret) | |
39a751a4 | 948 | goto err_free_tree; |
7518b589 | 949 | |
39a751a4 | 950 | ret = init_overlay_changeset(ovcs, fdt, tree); |
24789c5c | 951 | if (ret) |
39a751a4 | 952 | goto err_free_tree; |
7518b589 | 953 | |
39a751a4 FR |
954 | /* |
955 | * after overlay_notify(), ovcs->overlay_tree related pointers may have | |
956 | * leaked to drivers, so can not kfree() tree, aka ovcs->overlay_tree; | |
48d499bd FR |
957 | * and can not free memory containing aligned fdt. The aligned fdt |
958 | * is contained within the memory at ovcs->fdt, possibly at an offset | |
959 | * from ovcs->fdt. | |
39a751a4 | 960 | */ |
0290c4ca | 961 | ret = overlay_notify(ovcs, OF_OVERLAY_PRE_APPLY); |
24789c5c FR |
962 | if (ret) { |
963 | pr_err("overlay changeset pre-apply notify error %d\n", ret); | |
61b4de4e | 964 | goto err_free_overlay_changeset; |
39a842e2 AT |
965 | } |
966 | ||
0290c4ca FR |
967 | ret = build_changeset(ovcs); |
968 | if (ret) | |
61b4de4e | 969 | goto err_free_overlay_changeset; |
606ad42a | 970 | |
24789c5c FR |
971 | ret_revert = 0; |
972 | ret = __of_changeset_apply_entries(&ovcs->cset, &ret_revert); | |
973 | if (ret) { | |
974 | if (ret_revert) { | |
975 | pr_debug("overlay changeset revert error %d\n", | |
976 | ret_revert); | |
977 | devicetree_state_flags |= DTSF_APPLY_FAIL; | |
978 | } | |
61b4de4e | 979 | goto err_free_overlay_changeset; |
24789c5c | 980 | } |
7518b589 | 981 | |
6de67de3 GU |
982 | ret = __of_changeset_apply_notify(&ovcs->cset); |
983 | if (ret) | |
a15e824f | 984 | pr_err("overlay apply changeset entry notify error %d\n", ret); |
6de67de3 GU |
985 | /* notify failure is not fatal, continue */ |
986 | ||
0290c4ca | 987 | list_add_tail(&ovcs->ovcs_list, &ovcs_list); |
24789c5c FR |
988 | *ovcs_id = ovcs->id; |
989 | ||
990 | ret_tmp = overlay_notify(ovcs, OF_OVERLAY_POST_APPLY); | |
991 | if (ret_tmp) { | |
992 | pr_err("overlay changeset post-apply notify error %d\n", | |
993 | ret_tmp); | |
994 | if (!ret) | |
995 | ret = ret_tmp; | |
996 | } | |
39a842e2 | 997 | |
5e474817 | 998 | goto out_unlock; |
f948d6d8 | 999 | |
39a751a4 FR |
1000 | err_free_tree: |
1001 | kfree(fdt); | |
1002 | kfree(tree); | |
1003 | ||
61b4de4e FR |
1004 | err_free_overlay_changeset: |
1005 | free_overlay_changeset(ovcs); | |
7518b589 | 1006 | |
5e474817 | 1007 | out_unlock: |
7518b589 | 1008 | mutex_unlock(&of_mutex); |
5e474817 | 1009 | of_overlay_mutex_unlock(); |
7518b589 | 1010 | |
24789c5c FR |
1011 | out: |
1012 | pr_debug("%s() err=%d\n", __func__, ret); | |
1013 | ||
0290c4ca | 1014 | return ret; |
7518b589 | 1015 | } |
39a751a4 FR |
1016 | |
1017 | int of_overlay_fdt_apply(const void *overlay_fdt, u32 overlay_fdt_size, | |
1018 | int *ovcs_id) | |
1019 | { | |
48d499bd FR |
1020 | void *new_fdt; |
1021 | void *new_fdt_align; | |
39a751a4 FR |
1022 | int ret; |
1023 | u32 size; | |
649cab56 | 1024 | struct device_node *overlay_root = NULL; |
39a751a4 FR |
1025 | |
1026 | *ovcs_id = 0; | |
1027 | ret = 0; | |
1028 | ||
1029 | if (overlay_fdt_size < sizeof(struct fdt_header) || | |
1030 | fdt_check_header(overlay_fdt)) { | |
1031 | pr_err("Invalid overlay_fdt header\n"); | |
1032 | return -EINVAL; | |
1033 | } | |
1034 | ||
1035 | size = fdt_totalsize(overlay_fdt); | |
1036 | if (overlay_fdt_size < size) | |
1037 | return -EINVAL; | |
1038 | ||
1039 | /* | |
1040 | * Must create permanent copy of FDT because of_fdt_unflatten_tree() | |
1041 | * will create pointers to the passed in FDT in the unflattened tree. | |
1042 | */ | |
48d499bd | 1043 | new_fdt = kmalloc(size + FDT_ALIGN_SIZE, GFP_KERNEL); |
39a751a4 FR |
1044 | if (!new_fdt) |
1045 | return -ENOMEM; | |
1046 | ||
48d499bd FR |
1047 | new_fdt_align = PTR_ALIGN(new_fdt, FDT_ALIGN_SIZE); |
1048 | memcpy(new_fdt_align, overlay_fdt, size); | |
1049 | ||
1050 | of_fdt_unflatten_tree(new_fdt_align, NULL, &overlay_root); | |
39a751a4 FR |
1051 | if (!overlay_root) { |
1052 | pr_err("unable to unflatten overlay_fdt\n"); | |
1053 | ret = -EINVAL; | |
1054 | goto out_free_new_fdt; | |
1055 | } | |
1056 | ||
1057 | ret = of_overlay_apply(new_fdt, overlay_root, ovcs_id); | |
1058 | if (ret < 0) { | |
1059 | /* | |
1060 | * new_fdt and overlay_root now belong to the overlay | |
1061 | * changeset. | |
1062 | * overlay changeset code is responsible for freeing them. | |
1063 | */ | |
1064 | goto out; | |
1065 | } | |
1066 | ||
1067 | return 0; | |
1068 | ||
1069 | ||
1070 | out_free_new_fdt: | |
1071 | kfree(new_fdt); | |
1072 | ||
1073 | out: | |
1074 | return ret; | |
1075 | } | |
1076 | EXPORT_SYMBOL_GPL(of_overlay_fdt_apply); | |
7518b589 | 1077 | |
646afc4a | 1078 | /* |
0290c4ca FR |
1079 | * Find @np in @tree. |
1080 | * | |
1081 | * Returns 1 if @np is @tree or is contained in @tree, else 0 | |
646afc4a | 1082 | */ |
0290c4ca | 1083 | static int find_node(struct device_node *tree, struct device_node *np) |
7518b589 PA |
1084 | { |
1085 | struct device_node *child; | |
1086 | ||
0290c4ca | 1087 | if (tree == np) |
7518b589 PA |
1088 | return 1; |
1089 | ||
1090 | for_each_child_of_node(tree, child) { | |
0290c4ca | 1091 | if (find_node(child, np)) { |
001cf504 | 1092 | of_node_put(child); |
7518b589 | 1093 | return 1; |
001cf504 | 1094 | } |
7518b589 PA |
1095 | } |
1096 | ||
1097 | return 0; | |
1098 | } | |
1099 | ||
646afc4a | 1100 | /* |
87f242c1 | 1101 | * Is @remove_ce_node a child of, a parent of, or the same as any |
0290c4ca FR |
1102 | * node in an overlay changeset more topmost than @remove_ovcs? |
1103 | * | |
1104 | * Returns 1 if found, else 0 | |
646afc4a | 1105 | */ |
87f242c1 FR |
1106 | static int node_overlaps_later_cs(struct overlay_changeset *remove_ovcs, |
1107 | struct device_node *remove_ce_node) | |
7518b589 | 1108 | { |
0290c4ca | 1109 | struct overlay_changeset *ovcs; |
7518b589 PA |
1110 | struct of_changeset_entry *ce; |
1111 | ||
0290c4ca FR |
1112 | list_for_each_entry_reverse(ovcs, &ovcs_list, ovcs_list) { |
1113 | if (ovcs == remove_ovcs) | |
7518b589 PA |
1114 | break; |
1115 | ||
0290c4ca | 1116 | list_for_each_entry(ce, &ovcs->cset.entries, node) { |
87f242c1 FR |
1117 | if (find_node(ce->np, remove_ce_node)) { |
1118 | pr_err("%s: #%d overlaps with #%d @%pOF\n", | |
0290c4ca | 1119 | __func__, remove_ovcs->id, ovcs->id, |
87f242c1 FR |
1120 | remove_ce_node); |
1121 | return 1; | |
1122 | } | |
1123 | if (find_node(remove_ce_node, ce->np)) { | |
1124 | pr_err("%s: #%d overlaps with #%d @%pOF\n", | |
1125 | __func__, remove_ovcs->id, ovcs->id, | |
1126 | remove_ce_node); | |
0290c4ca | 1127 | return 1; |
7518b589 PA |
1128 | } |
1129 | } | |
1130 | } | |
1131 | ||
0290c4ca | 1132 | return 0; |
7518b589 PA |
1133 | } |
1134 | ||
1135 | /* | |
1136 | * We can safely remove the overlay only if it's the top-most one. | |
1137 | * Newly applied overlays are inserted at the tail of the overlay list, | |
1138 | * so a top most overlay is the one that is closest to the tail. | |
1139 | * | |
1140 | * The topmost check is done by exploiting this property. For each | |
1141 | * affected device node in the log list we check if this overlay is | |
1142 | * the one closest to the tail. If another overlay has affected this | |
1143 | * device node and is closest to the tail, then removal is not permited. | |
1144 | */ | |
0290c4ca | 1145 | static int overlay_removal_is_ok(struct overlay_changeset *remove_ovcs) |
7518b589 | 1146 | { |
0290c4ca | 1147 | struct of_changeset_entry *remove_ce; |
7518b589 | 1148 | |
0290c4ca | 1149 | list_for_each_entry(remove_ce, &remove_ovcs->cset.entries, node) { |
87f242c1 | 1150 | if (node_overlaps_later_cs(remove_ovcs, remove_ce->np)) { |
0290c4ca | 1151 | pr_err("overlay #%d is not topmost\n", remove_ovcs->id); |
7518b589 PA |
1152 | return 0; |
1153 | } | |
1154 | } | |
1155 | ||
1156 | return 1; | |
1157 | } | |
1158 | ||
1159 | /** | |
0290c4ca | 1160 | * of_overlay_remove() - Revert and free an overlay changeset |
24789c5c | 1161 | * @ovcs_id: Pointer to overlay changeset id |
7518b589 | 1162 | * |
24789c5c | 1163 | * Removes an overlay if it is permissible. @ovcs_id was previously returned |
a514266b | 1164 | * by of_overlay_fdt_apply(). |
7518b589 | 1165 | * |
24789c5c FR |
1166 | * If an error occurred while attempting to revert the overlay changeset, |
1167 | * then an attempt is made to re-apply any changeset entry that was | |
1168 | * reverted. If an error occurs on re-apply then the state of the device | |
1169 | * tree can not be determined, and any following attempt to apply or remove | |
1170 | * an overlay changeset will be refused. | |
1171 | * | |
1172 | * A non-zero return value will not revert the changeset if error is from: | |
1173 | * - parameter checks | |
e9d92e40 | 1174 | * - overlay changeset pre-remove notifier |
24789c5c FR |
1175 | * - overlay changeset entry revert |
1176 | * | |
1177 | * If an error is returned by an overlay changeset pre-remove notifier | |
1178 | * then no further overlay changeset pre-remove notifier will be called. | |
1179 | * | |
1180 | * If more than one notifier returns an error, then the last notifier | |
1181 | * error to occur is returned. | |
1182 | * | |
1183 | * A non-zero return value will revert the changeset if error is from: | |
1184 | * - overlay changeset entry notifier | |
e9d92e40 | 1185 | * - overlay changeset post-remove notifier |
24789c5c FR |
1186 | * |
1187 | * If an error is returned by an overlay changeset post-remove notifier | |
1188 | * then no further overlay changeset post-remove notifier will be called. | |
1189 | * | |
aed4349c | 1190 | * Return: 0 on success, or a negative error number. *@ovcs_id is set to |
24789c5c | 1191 | * zero after reverting the changeset, even if a subsequent error occurs. |
7518b589 | 1192 | */ |
24789c5c | 1193 | int of_overlay_remove(int *ovcs_id) |
7518b589 | 1194 | { |
0290c4ca | 1195 | struct overlay_changeset *ovcs; |
24789c5c FR |
1196 | int ret, ret_apply, ret_tmp; |
1197 | ||
1198 | ret = 0; | |
1199 | ||
1200 | if (devicetree_corrupt()) { | |
1201 | pr_err("suspect devicetree state, refuse to remove overlay\n"); | |
1202 | ret = -EBUSY; | |
1203 | goto out; | |
1204 | } | |
7518b589 PA |
1205 | |
1206 | mutex_lock(&of_mutex); | |
1207 | ||
24789c5c | 1208 | ovcs = idr_find(&ovcs_idr, *ovcs_id); |
0290c4ca FR |
1209 | if (!ovcs) { |
1210 | ret = -ENODEV; | |
24789c5c FR |
1211 | pr_err("remove: Could not find overlay #%d\n", *ovcs_id); |
1212 | goto out_unlock; | |
7518b589 PA |
1213 | } |
1214 | ||
0290c4ca FR |
1215 | if (!overlay_removal_is_ok(ovcs)) { |
1216 | ret = -EBUSY; | |
24789c5c | 1217 | goto out_unlock; |
7518b589 PA |
1218 | } |
1219 | ||
24789c5c FR |
1220 | ret = overlay_notify(ovcs, OF_OVERLAY_PRE_REMOVE); |
1221 | if (ret) { | |
1222 | pr_err("overlay changeset pre-remove notify error %d\n", ret); | |
1223 | goto out_unlock; | |
1224 | } | |
61b4de4e | 1225 | |
0290c4ca | 1226 | list_del(&ovcs->ovcs_list); |
61b4de4e | 1227 | |
24789c5c FR |
1228 | ret_apply = 0; |
1229 | ret = __of_changeset_revert_entries(&ovcs->cset, &ret_apply); | |
1230 | if (ret) { | |
1231 | if (ret_apply) | |
1232 | devicetree_state_flags |= DTSF_REVERT_FAIL; | |
1233 | goto out_unlock; | |
24789c5c | 1234 | } |
61b4de4e | 1235 | |
6de67de3 GU |
1236 | ret = __of_changeset_revert_notify(&ovcs->cset); |
1237 | if (ret) | |
a15e824f | 1238 | pr_err("overlay remove changeset entry notify error %d\n", ret); |
6de67de3 GU |
1239 | /* notify failure is not fatal, continue */ |
1240 | ||
24789c5c FR |
1241 | *ovcs_id = 0; |
1242 | ||
1243 | ret_tmp = overlay_notify(ovcs, OF_OVERLAY_POST_REMOVE); | |
1244 | if (ret_tmp) { | |
1245 | pr_err("overlay changeset post-remove notify error %d\n", | |
1246 | ret_tmp); | |
1247 | if (!ret) | |
1248 | ret = ret_tmp; | |
1249 | } | |
61b4de4e FR |
1250 | |
1251 | free_overlay_changeset(ovcs); | |
7518b589 | 1252 | |
24789c5c | 1253 | out_unlock: |
7518b589 PA |
1254 | mutex_unlock(&of_mutex); |
1255 | ||
24789c5c FR |
1256 | out: |
1257 | pr_debug("%s() err=%d\n", __func__, ret); | |
1258 | ||
0290c4ca | 1259 | return ret; |
7518b589 | 1260 | } |
0290c4ca | 1261 | EXPORT_SYMBOL_GPL(of_overlay_remove); |
7518b589 PA |
1262 | |
1263 | /** | |
0290c4ca | 1264 | * of_overlay_remove_all() - Reverts and frees all overlay changesets |
7518b589 PA |
1265 | * |
1266 | * Removes all overlays from the system in the correct order. | |
1267 | * | |
8c8239c2 | 1268 | * Return: 0 on success, or a negative error number |
7518b589 | 1269 | */ |
0290c4ca | 1270 | int of_overlay_remove_all(void) |
7518b589 | 1271 | { |
0290c4ca | 1272 | struct overlay_changeset *ovcs, *ovcs_n; |
61b4de4e | 1273 | int ret; |
7518b589 PA |
1274 | |
1275 | /* the tail of list is guaranteed to be safe to remove */ | |
0290c4ca | 1276 | list_for_each_entry_safe_reverse(ovcs, ovcs_n, &ovcs_list, ovcs_list) { |
24789c5c | 1277 | ret = of_overlay_remove(&ovcs->id); |
61b4de4e FR |
1278 | if (ret) |
1279 | return ret; | |
7518b589 PA |
1280 | } |
1281 | ||
7518b589 PA |
1282 | return 0; |
1283 | } | |
0290c4ca | 1284 | EXPORT_SYMBOL_GPL(of_overlay_remove_all); |