Commit | Line | Data |
---|---|---|
7941b27b PA |
1 | /* |
2 | * Functions for dealing with DT resolution | |
3 | * | |
4 | * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com> | |
5 | * Copyright (C) 2012 Texas Instruments Inc. | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * version 2 as published by the Free Software Foundation. | |
10 | */ | |
11 | ||
606ad42a RH |
12 | #define pr_fmt(fmt) "OF: resolver: " fmt |
13 | ||
7941b27b PA |
14 | #include <linux/kernel.h> |
15 | #include <linux/module.h> | |
16 | #include <linux/of.h> | |
17 | #include <linux/of_device.h> | |
18 | #include <linux/string.h> | |
19 | #include <linux/ctype.h> | |
20 | #include <linux/errno.h> | |
7941b27b PA |
21 | #include <linux/slab.h> |
22 | ||
27497e11 RH |
23 | #include "of_private.h" |
24 | ||
7941b27b PA |
25 | /* illegal phandle value (set when unresolved) */ |
26 | #define OF_PHANDLE_ILLEGAL 0xdeadbeef | |
27 | ||
f94823f2 | 28 | static phandle live_tree_max_phandle(void) |
7941b27b PA |
29 | { |
30 | struct device_node *node; | |
31 | phandle phandle; | |
32 | unsigned long flags; | |
33 | ||
7941b27b PA |
34 | raw_spin_lock_irqsave(&devtree_lock, flags); |
35 | phandle = 0; | |
36 | for_each_of_allnodes(node) { | |
37 | if (node->phandle != OF_PHANDLE_ILLEGAL && | |
38 | node->phandle > phandle) | |
39 | phandle = node->phandle; | |
40 | } | |
41 | raw_spin_unlock_irqrestore(&devtree_lock, flags); | |
42 | ||
43 | return phandle; | |
44 | } | |
45 | ||
25e16877 | 46 | static void adjust_overlay_phandles(struct device_node *overlay, |
7941b27b PA |
47 | int phandle_delta) |
48 | { | |
49 | struct device_node *child; | |
50 | struct property *prop; | |
51 | phandle phandle; | |
52 | ||
269f1a67 | 53 | /* adjust node's phandle in node */ |
25e16877 FR |
54 | if (overlay->phandle != 0 && overlay->phandle != OF_PHANDLE_ILLEGAL) |
55 | overlay->phandle += phandle_delta; | |
7941b27b | 56 | |
269f1a67 | 57 | /* copy adjusted phandle into *phandle properties */ |
25e16877 | 58 | for_each_property_of_node(overlay, prop) { |
7941b27b | 59 | |
9f27ede4 FR |
60 | if (of_prop_cmp(prop->name, "phandle") && |
61 | of_prop_cmp(prop->name, "linux,phandle")) | |
7941b27b PA |
62 | continue; |
63 | ||
7941b27b PA |
64 | if (prop->length < 4) |
65 | continue; | |
66 | ||
7941b27b | 67 | phandle = be32_to_cpup(prop->value); |
a67976ec | 68 | if (phandle == OF_PHANDLE_ILLEGAL) |
7941b27b PA |
69 | continue; |
70 | ||
17a70355 | 71 | *(__be32 *)prop->value = cpu_to_be32(overlay->phandle); |
7941b27b PA |
72 | } |
73 | ||
25e16877 | 74 | for_each_child_of_node(overlay, child) |
f94823f2 | 75 | adjust_overlay_phandles(child, phandle_delta); |
7941b27b PA |
76 | } |
77 | ||
25e16877 FR |
78 | static int update_usages_of_a_phandle_reference(struct device_node *overlay, |
79 | struct property *prop_fixup, phandle phandle) | |
7941b27b | 80 | { |
7941b27b | 81 | struct device_node *refnode; |
25e16877 FR |
82 | struct property *prop; |
83 | char *value, *cur, *end, *node_path, *prop_name, *s; | |
84 | int offset, len; | |
7941b27b PA |
85 | int err = 0; |
86 | ||
25e16877 FR |
87 | value = kmalloc(prop_fixup->length, GFP_KERNEL); |
88 | if (!value) | |
7941b27b | 89 | return -ENOMEM; |
25e16877 | 90 | memcpy(value, prop_fixup->value, prop_fixup->length); |
7941b27b | 91 | |
269f1a67 | 92 | /* prop_fixup contains a list of tuples of path:property_name:offset */ |
25e16877 FR |
93 | end = value + prop_fixup->length; |
94 | for (cur = value; cur < end; cur += len + 1) { | |
95 | len = strlen(cur); | |
7941b27b | 96 | |
25e16877 FR |
97 | node_path = cur; |
98 | s = strchr(cur, ':'); | |
7941b27b | 99 | if (!s) { |
7941b27b PA |
100 | err = -EINVAL; |
101 | goto err_fail; | |
102 | } | |
103 | *s++ = '\0'; | |
104 | ||
25e16877 | 105 | prop_name = s; |
7941b27b PA |
106 | s = strchr(s, ':'); |
107 | if (!s) { | |
7941b27b PA |
108 | err = -EINVAL; |
109 | goto err_fail; | |
110 | } | |
7941b27b | 111 | *s++ = '\0'; |
624ab2a4 | 112 | |
7941b27b | 113 | err = kstrtoint(s, 10, &offset); |
9f27ede4 | 114 | if (err) |
7941b27b | 115 | goto err_fail; |
7941b27b | 116 | |
27497e11 | 117 | refnode = __of_find_node_by_full_path(of_node_get(overlay), node_path); |
96d1c8e8 | 118 | if (!refnode) |
7941b27b | 119 | continue; |
7941b27b | 120 | |
25e16877 FR |
121 | for_each_property_of_node(refnode, prop) { |
122 | if (!of_prop_cmp(prop->name, prop_name)) | |
7941b27b PA |
123 | break; |
124 | } | |
82f68756 | 125 | of_node_put(refnode); |
7941b27b | 126 | |
25e16877 | 127 | if (!prop) { |
7941b27b PA |
128 | err = -ENOENT; |
129 | goto err_fail; | |
130 | } | |
131 | ||
25e16877 | 132 | *(__be32 *)(prop->value + offset) = cpu_to_be32(phandle); |
7941b27b PA |
133 | } |
134 | ||
135 | err_fail: | |
25e16877 | 136 | kfree(value); |
7941b27b PA |
137 | return err; |
138 | } | |
139 | ||
da56d04c | 140 | /* compare nodes taking into account that 'name' strips out the @ part */ |
fad556bf | 141 | static int node_name_cmp(const struct device_node *dn1, |
da56d04c PA |
142 | const struct device_node *dn2) |
143 | { | |
95e6b1fa RH |
144 | const char *n1 = kbasename(dn1->full_name); |
145 | const char *n2 = kbasename(dn2->full_name); | |
da56d04c PA |
146 | |
147 | return of_node_cmp(n1, n2); | |
148 | } | |
149 | ||
7941b27b PA |
150 | /* |
151 | * Adjust the local phandle references by the given phandle delta. | |
269f1a67 FR |
152 | * |
153 | * Subtree @local_fixups, which is overlay node __local_fixups__, | |
154 | * mirrors the fragment node structure at the root of the overlay. | |
155 | * | |
156 | * For each property in the fragments that contains a phandle reference, | |
157 | * @local_fixups has a property of the same name that contains a list | |
158 | * of offsets of the phandle reference(s) within the respective property | |
159 | * value(s). The values at these offsets will be fixed up. | |
7941b27b | 160 | */ |
25e16877 FR |
161 | static int adjust_local_phandle_references(struct device_node *local_fixups, |
162 | struct device_node *overlay, int phandle_delta) | |
7941b27b | 163 | { |
25e16877 FR |
164 | struct device_node *child, *overlay_child; |
165 | struct property *prop_fix, *prop; | |
da56d04c PA |
166 | int err, i, count; |
167 | unsigned int off; | |
168 | phandle phandle; | |
7941b27b | 169 | |
25e16877 | 170 | if (!local_fixups) |
7941b27b PA |
171 | return 0; |
172 | ||
25e16877 | 173 | for_each_property_of_node(local_fixups, prop_fix) { |
da56d04c | 174 | |
7941b27b | 175 | /* skip properties added automatically */ |
25e16877 FR |
176 | if (!of_prop_cmp(prop_fix->name, "name") || |
177 | !of_prop_cmp(prop_fix->name, "phandle") || | |
178 | !of_prop_cmp(prop_fix->name, "linux,phandle")) | |
7941b27b PA |
179 | continue; |
180 | ||
25e16877 | 181 | if ((prop_fix->length % 4) != 0 || prop_fix->length == 0) |
da56d04c | 182 | return -EINVAL; |
25e16877 | 183 | count = prop_fix->length / sizeof(__be32); |
da56d04c | 184 | |
25e16877 FR |
185 | for_each_property_of_node(overlay, prop) { |
186 | if (!of_prop_cmp(prop->name, prop_fix->name)) | |
da56d04c PA |
187 | break; |
188 | } | |
189 | ||
25e16877 | 190 | if (!prop) |
da56d04c | 191 | return -EINVAL; |
da56d04c PA |
192 | |
193 | for (i = 0; i < count; i++) { | |
25e16877 | 194 | off = be32_to_cpu(((__be32 *)prop_fix->value)[i]); |
ea8229b7 | 195 | if ((off + 4) > prop->length) |
da56d04c | 196 | return -EINVAL; |
da56d04c | 197 | |
624ab2a4 FR |
198 | phandle = be32_to_cpu(*(__be32 *)(prop->value + off)); |
199 | phandle += phandle_delta; | |
200 | *(__be32 *)(prop->value + off) = cpu_to_be32(phandle); | |
da56d04c PA |
201 | } |
202 | } | |
203 | ||
269f1a67 FR |
204 | /* |
205 | * These nested loops recurse down two subtrees in parallel, where the | |
206 | * node names in the two subtrees match. | |
207 | * | |
208 | * The roots of the subtrees are the overlay's __local_fixups__ node | |
209 | * and the overlay's root node. | |
210 | */ | |
25e16877 | 211 | for_each_child_of_node(local_fixups, child) { |
da56d04c | 212 | |
25e16877 FR |
213 | for_each_child_of_node(overlay, overlay_child) |
214 | if (!node_name_cmp(child, overlay_child)) | |
da56d04c PA |
215 | break; |
216 | ||
25e16877 | 217 | if (!overlay_child) |
da56d04c | 218 | return -EINVAL; |
da56d04c | 219 | |
25e16877 | 220 | err = adjust_local_phandle_references(child, overlay_child, |
da56d04c | 221 | phandle_delta); |
9f27ede4 | 222 | if (err) |
7941b27b PA |
223 | return err; |
224 | } | |
225 | ||
226 | return 0; | |
227 | } | |
228 | ||
229 | /** | |
269f1a67 FR |
230 | * of_resolve_phandles - Relocate and resolve overlay against live tree |
231 | * | |
232 | * @overlay: Pointer to devicetree overlay to relocate and resolve | |
233 | * | |
234 | * Modify (relocate) values of local phandles in @overlay to a range that | |
235 | * does not conflict with the live expanded devicetree. Update references | |
236 | * to the local phandles in @overlay. Update (resolve) phandle references | |
237 | * in @overlay that refer to the live expanded devicetree. | |
238 | * | |
239 | * Phandle values in the live tree are in the range of | |
240 | * 1 .. live_tree_max_phandle(). The range of phandle values in the overlay | |
241 | * also begin with at 1. Adjust the phandle values in the overlay to begin | |
242 | * at live_tree_max_phandle() + 1. Update references to the phandles to | |
243 | * the adjusted phandle values. | |
244 | * | |
245 | * The name of each property in the "__fixups__" node in the overlay matches | |
246 | * the name of a symbol (a label) in the live tree. The values of each | |
247 | * property in the "__fixups__" node is a list of the property values in the | |
248 | * overlay that need to be updated to contain the phandle reference | |
249 | * corresponding to that symbol in the live tree. Update the references in | |
250 | * the overlay with the phandle values in the live tree. | |
251 | * | |
252 | * @overlay must be detached. | |
7941b27b | 253 | * |
269f1a67 FR |
254 | * Resolving and applying @overlay to the live expanded devicetree must be |
255 | * protected by a mechanism to ensure that multiple overlays are processed | |
256 | * in a single threaded manner so that multiple overlays will not relocate | |
257 | * phandles to overlapping ranges. The mechanism to enforce this is not | |
258 | * yet implemented. | |
7941b27b | 259 | * |
269f1a67 | 260 | * Return: %0 on success or a negative error value on error. |
7941b27b | 261 | */ |
25e16877 | 262 | int of_resolve_phandles(struct device_node *overlay) |
7941b27b | 263 | { |
25e16877 | 264 | struct device_node *child, *local_fixups, *refnode; |
5581a95f | 265 | struct device_node *tree_symbols, *overlay_fixups; |
25e16877 | 266 | struct property *prop; |
7941b27b PA |
267 | const char *refpath; |
268 | phandle phandle, phandle_delta; | |
269 | int err; | |
270 | ||
d9181b20 FR |
271 | tree_symbols = NULL; |
272 | ||
624ab2a4 FR |
273 | if (!overlay) { |
274 | pr_err("null overlay\n"); | |
d9181b20 | 275 | err = -EINVAL; |
32bed310 | 276 | goto out; |
624ab2a4 FR |
277 | } |
278 | if (!of_node_check_flag(overlay, OF_DETACHED)) { | |
279 | pr_err("overlay not detached\n"); | |
d9181b20 | 280 | err = -EINVAL; |
32bed310 | 281 | goto out; |
624ab2a4 | 282 | } |
7941b27b | 283 | |
f94823f2 | 284 | phandle_delta = live_tree_max_phandle() + 1; |
25e16877 | 285 | adjust_overlay_phandles(overlay, phandle_delta); |
da56d04c | 286 | |
25e16877 FR |
287 | for_each_child_of_node(overlay, local_fixups) |
288 | if (!of_node_cmp(local_fixups->name, "__local_fixups__")) | |
da56d04c PA |
289 | break; |
290 | ||
624ab2a4 FR |
291 | err = adjust_local_phandle_references(local_fixups, overlay, phandle_delta); |
292 | if (err) | |
32bed310 | 293 | goto out; |
da56d04c | 294 | |
25e16877 | 295 | overlay_fixups = NULL; |
7941b27b | 296 | |
25e16877 | 297 | for_each_child_of_node(overlay, child) { |
624ab2a4 | 298 | if (!of_node_cmp(child->name, "__fixups__")) |
25e16877 | 299 | overlay_fixups = child; |
7941b27b PA |
300 | } |
301 | ||
25e16877 | 302 | if (!overlay_fixups) { |
a67976ec | 303 | err = 0; |
7941b27b PA |
304 | goto out; |
305 | } | |
306 | ||
4458db4c | 307 | tree_symbols = of_find_node_by_path("/__symbols__"); |
25e16877 | 308 | if (!tree_symbols) { |
624ab2a4 | 309 | pr_err("no symbols in root of device tree.\n"); |
7941b27b | 310 | err = -EINVAL; |
32bed310 | 311 | goto out; |
7941b27b PA |
312 | } |
313 | ||
25e16877 | 314 | for_each_property_of_node(overlay_fixups, prop) { |
7941b27b PA |
315 | |
316 | /* skip properties added automatically */ | |
25e16877 | 317 | if (!of_prop_cmp(prop->name, "name")) |
7941b27b PA |
318 | continue; |
319 | ||
25e16877 FR |
320 | err = of_property_read_string(tree_symbols, |
321 | prop->name, &refpath); | |
9f27ede4 | 322 | if (err) |
32bed310 | 323 | goto out; |
7941b27b PA |
324 | |
325 | refnode = of_find_node_by_path(refpath); | |
326 | if (!refnode) { | |
7941b27b | 327 | err = -ENOENT; |
32bed310 | 328 | goto out; |
7941b27b PA |
329 | } |
330 | ||
331 | phandle = refnode->phandle; | |
332 | of_node_put(refnode); | |
333 | ||
25e16877 | 334 | err = update_usages_of_a_phandle_reference(overlay, prop, phandle); |
7941b27b PA |
335 | if (err) |
336 | break; | |
337 | } | |
338 | ||
339 | out: | |
32bed310 MF |
340 | if (err) |
341 | pr_err("overlay phandle fixup failed: %d\n", err); | |
25e16877 | 342 | of_node_put(tree_symbols); |
7941b27b PA |
343 | |
344 | return err; | |
345 | } | |
346 | EXPORT_SYMBOL_GPL(of_resolve_phandles); |