Commit | Line | Data |
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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 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/of.h> | |
15 | #include <linux/of_device.h> | |
16 | #include <linux/string.h> | |
17 | #include <linux/ctype.h> | |
18 | #include <linux/errno.h> | |
19 | #include <linux/string.h> | |
20 | #include <linux/slab.h> | |
21 | ||
22 | /* illegal phandle value (set when unresolved) */ | |
23 | #define OF_PHANDLE_ILLEGAL 0xdeadbeef | |
24 | ||
25 | /** | |
26 | * Find a node with the give full name by recursively following any of | |
27 | * the child node links. | |
28 | */ | |
29 | static struct device_node *__of_find_node_by_full_name(struct device_node *node, | |
30 | const char *full_name) | |
31 | { | |
32 | struct device_node *child, *found; | |
33 | ||
34 | if (node == NULL) | |
35 | return NULL; | |
36 | ||
37 | /* check */ | |
38 | if (of_node_cmp(node->full_name, full_name) == 0) | |
39 | return node; | |
40 | ||
41 | for_each_child_of_node(node, child) { | |
42 | found = __of_find_node_by_full_name(child, full_name); | |
43 | if (found != NULL) | |
44 | return found; | |
45 | } | |
46 | ||
47 | return NULL; | |
48 | } | |
49 | ||
50 | /* | |
51 | * Find live tree's maximum phandle value. | |
52 | */ | |
53 | static phandle of_get_tree_max_phandle(void) | |
54 | { | |
55 | struct device_node *node; | |
56 | phandle phandle; | |
57 | unsigned long flags; | |
58 | ||
59 | /* now search recursively */ | |
60 | raw_spin_lock_irqsave(&devtree_lock, flags); | |
61 | phandle = 0; | |
62 | for_each_of_allnodes(node) { | |
63 | if (node->phandle != OF_PHANDLE_ILLEGAL && | |
64 | node->phandle > phandle) | |
65 | phandle = node->phandle; | |
66 | } | |
67 | raw_spin_unlock_irqrestore(&devtree_lock, flags); | |
68 | ||
69 | return phandle; | |
70 | } | |
71 | ||
72 | /* | |
73 | * Adjust a subtree's phandle values by a given delta. | |
74 | * Makes sure not to just adjust the device node's phandle value, | |
75 | * but modify the phandle properties values as well. | |
76 | */ | |
77 | static void __of_adjust_tree_phandles(struct device_node *node, | |
78 | int phandle_delta) | |
79 | { | |
80 | struct device_node *child; | |
81 | struct property *prop; | |
82 | phandle phandle; | |
83 | ||
84 | /* first adjust the node's phandle direct value */ | |
85 | if (node->phandle != 0 && node->phandle != OF_PHANDLE_ILLEGAL) | |
86 | node->phandle += phandle_delta; | |
87 | ||
88 | /* now adjust phandle & linux,phandle values */ | |
89 | for_each_property_of_node(node, prop) { | |
90 | ||
91 | /* only look for these two */ | |
92 | if (of_prop_cmp(prop->name, "phandle") != 0 && | |
93 | of_prop_cmp(prop->name, "linux,phandle") != 0) | |
94 | continue; | |
95 | ||
96 | /* must be big enough */ | |
97 | if (prop->length < 4) | |
98 | continue; | |
99 | ||
100 | /* read phandle value */ | |
101 | phandle = be32_to_cpup(prop->value); | |
102 | if (phandle == OF_PHANDLE_ILLEGAL) /* unresolved */ | |
103 | continue; | |
104 | ||
105 | /* adjust */ | |
106 | *(uint32_t *)prop->value = cpu_to_be32(node->phandle); | |
107 | } | |
108 | ||
109 | /* now do the children recursively */ | |
110 | for_each_child_of_node(node, child) | |
111 | __of_adjust_tree_phandles(child, phandle_delta); | |
112 | } | |
113 | ||
da56d04c PA |
114 | static int __of_adjust_phandle_ref(struct device_node *node, |
115 | struct property *rprop, int value) | |
7941b27b PA |
116 | { |
117 | phandle phandle; | |
118 | struct device_node *refnode; | |
119 | struct property *sprop; | |
120 | char *propval, *propcur, *propend, *nodestr, *propstr, *s; | |
121 | int offset, propcurlen; | |
122 | int err = 0; | |
123 | ||
124 | /* make a copy */ | |
125 | propval = kmalloc(rprop->length, GFP_KERNEL); | |
126 | if (!propval) { | |
127 | pr_err("%s: Could not copy value of '%s'\n", | |
128 | __func__, rprop->name); | |
129 | return -ENOMEM; | |
130 | } | |
131 | memcpy(propval, rprop->value, rprop->length); | |
132 | ||
133 | propend = propval + rprop->length; | |
134 | for (propcur = propval; propcur < propend; propcur += propcurlen + 1) { | |
135 | propcurlen = strlen(propcur); | |
136 | ||
137 | nodestr = propcur; | |
138 | s = strchr(propcur, ':'); | |
139 | if (!s) { | |
140 | pr_err("%s: Illegal symbol entry '%s' (1)\n", | |
141 | __func__, propcur); | |
142 | err = -EINVAL; | |
143 | goto err_fail; | |
144 | } | |
145 | *s++ = '\0'; | |
146 | ||
147 | propstr = s; | |
148 | s = strchr(s, ':'); | |
149 | if (!s) { | |
150 | pr_err("%s: Illegal symbol entry '%s' (2)\n", | |
151 | __func__, (char *)rprop->value); | |
152 | err = -EINVAL; | |
153 | goto err_fail; | |
154 | } | |
155 | ||
156 | *s++ = '\0'; | |
157 | err = kstrtoint(s, 10, &offset); | |
158 | if (err != 0) { | |
159 | pr_err("%s: Could get offset '%s'\n", | |
160 | __func__, (char *)rprop->value); | |
161 | goto err_fail; | |
162 | } | |
163 | ||
164 | /* look into the resolve node for the full path */ | |
165 | refnode = __of_find_node_by_full_name(node, nodestr); | |
166 | if (!refnode) { | |
167 | pr_warn("%s: Could not find refnode '%s'\n", | |
168 | __func__, (char *)rprop->value); | |
169 | continue; | |
170 | } | |
171 | ||
172 | /* now find the property */ | |
173 | for_each_property_of_node(refnode, sprop) { | |
174 | if (of_prop_cmp(sprop->name, propstr) == 0) | |
175 | break; | |
176 | } | |
177 | ||
178 | if (!sprop) { | |
179 | pr_err("%s: Could not find property '%s'\n", | |
180 | __func__, (char *)rprop->value); | |
181 | err = -ENOENT; | |
182 | goto err_fail; | |
183 | } | |
184 | ||
da56d04c | 185 | phandle = value; |
7941b27b PA |
186 | *(__be32 *)(sprop->value + offset) = cpu_to_be32(phandle); |
187 | } | |
188 | ||
189 | err_fail: | |
190 | kfree(propval); | |
191 | return err; | |
192 | } | |
193 | ||
da56d04c PA |
194 | /* compare nodes taking into account that 'name' strips out the @ part */ |
195 | static int __of_node_name_cmp(const struct device_node *dn1, | |
196 | const struct device_node *dn2) | |
197 | { | |
198 | const char *n1 = strrchr(dn1->full_name, '/') ? : "/"; | |
199 | const char *n2 = strrchr(dn2->full_name, '/') ? : "/"; | |
200 | ||
201 | return of_node_cmp(n1, n2); | |
202 | } | |
203 | ||
7941b27b PA |
204 | /* |
205 | * Adjust the local phandle references by the given phandle delta. | |
da56d04c PA |
206 | * Assumes the existances of a __local_fixups__ node at the root. |
207 | * Assumes that __of_verify_tree_phandle_references has been called. | |
208 | * Does not take any devtree locks so make sure you call this on a tree | |
209 | * which is at the detached state. | |
7941b27b PA |
210 | */ |
211 | static int __of_adjust_tree_phandle_references(struct device_node *node, | |
da56d04c | 212 | struct device_node *target, int phandle_delta) |
7941b27b | 213 | { |
da56d04c PA |
214 | struct device_node *child, *childtarget; |
215 | struct property *rprop, *sprop; | |
216 | int err, i, count; | |
217 | unsigned int off; | |
218 | phandle phandle; | |
7941b27b | 219 | |
da56d04c | 220 | if (node == NULL) |
7941b27b PA |
221 | return 0; |
222 | ||
da56d04c PA |
223 | for_each_property_of_node(node, rprop) { |
224 | ||
7941b27b | 225 | /* skip properties added automatically */ |
da56d04c PA |
226 | if (of_prop_cmp(rprop->name, "name") == 0 || |
227 | of_prop_cmp(rprop->name, "phandle") == 0 || | |
228 | of_prop_cmp(rprop->name, "linux,phandle") == 0) | |
7941b27b PA |
229 | continue; |
230 | ||
da56d04c PA |
231 | if ((rprop->length % 4) != 0 || rprop->length == 0) { |
232 | pr_err("%s: Illegal property (size) '%s' @%s\n", | |
233 | __func__, rprop->name, node->full_name); | |
234 | return -EINVAL; | |
235 | } | |
236 | count = rprop->length / sizeof(__be32); | |
237 | ||
238 | /* now find the target property */ | |
239 | for_each_property_of_node(target, sprop) { | |
240 | if (of_prop_cmp(sprop->name, rprop->name) == 0) | |
241 | break; | |
242 | } | |
243 | ||
244 | if (sprop == NULL) { | |
245 | pr_err("%s: Could not find target property '%s' @%s\n", | |
246 | __func__, rprop->name, node->full_name); | |
247 | return -EINVAL; | |
248 | } | |
249 | ||
250 | for (i = 0; i < count; i++) { | |
251 | off = be32_to_cpu(((__be32 *)rprop->value)[i]); | |
252 | /* make sure the offset doesn't overstep (even wrap) */ | |
253 | if (off >= sprop->length || | |
254 | (off + 4) > sprop->length) { | |
255 | pr_err("%s: Illegal property '%s' @%s\n", | |
256 | __func__, rprop->name, | |
257 | node->full_name); | |
258 | return -EINVAL; | |
259 | } | |
260 | ||
261 | if (phandle_delta) { | |
262 | /* adjust */ | |
263 | phandle = be32_to_cpu(*(__be32 *)(sprop->value + off)); | |
264 | phandle += phandle_delta; | |
265 | *(__be32 *)(sprop->value + off) = cpu_to_be32(phandle); | |
266 | } | |
267 | } | |
268 | } | |
269 | ||
270 | for_each_child_of_node(node, child) { | |
271 | ||
272 | for_each_child_of_node(target, childtarget) | |
273 | if (__of_node_name_cmp(child, childtarget) == 0) | |
274 | break; | |
275 | ||
276 | if (!childtarget) { | |
277 | pr_err("%s: Could not find target child '%s' @%s\n", | |
278 | __func__, child->name, node->full_name); | |
279 | return -EINVAL; | |
280 | } | |
281 | ||
282 | err = __of_adjust_tree_phandle_references(child, childtarget, | |
283 | phandle_delta); | |
284 | if (err != 0) | |
7941b27b PA |
285 | return err; |
286 | } | |
287 | ||
288 | return 0; | |
289 | } | |
290 | ||
291 | /** | |
292 | * of_resolve - Resolve the given node against the live tree. | |
293 | * | |
294 | * @resolve: Node to resolve | |
295 | * | |
296 | * Perform dynamic Device Tree resolution against the live tree | |
297 | * to the given node to resolve. This depends on the live tree | |
298 | * having a __symbols__ node, and the resolve node the __fixups__ & | |
299 | * __local_fixups__ nodes (if needed). | |
300 | * The result of the operation is a resolve node that it's contents | |
301 | * are fit to be inserted or operate upon the live tree. | |
302 | * Returns 0 on success or a negative error value on error. | |
303 | */ | |
304 | int of_resolve_phandles(struct device_node *resolve) | |
305 | { | |
da56d04c | 306 | struct device_node *child, *childroot, *refnode; |
7941b27b PA |
307 | struct device_node *root_sym, *resolve_sym, *resolve_fix; |
308 | struct property *rprop; | |
309 | const char *refpath; | |
310 | phandle phandle, phandle_delta; | |
311 | int err; | |
312 | ||
313 | /* the resolve node must exist, and be detached */ | |
314 | if (!resolve || !of_node_check_flag(resolve, OF_DETACHED)) | |
315 | return -EINVAL; | |
316 | ||
317 | /* first we need to adjust the phandles */ | |
318 | phandle_delta = of_get_tree_max_phandle() + 1; | |
319 | __of_adjust_tree_phandles(resolve, phandle_delta); | |
da56d04c PA |
320 | |
321 | /* locate the local fixups */ | |
322 | childroot = NULL; | |
323 | for_each_child_of_node(resolve, childroot) | |
324 | if (of_node_cmp(childroot->name, "__local_fixups__") == 0) | |
325 | break; | |
326 | ||
327 | if (childroot != NULL) { | |
328 | /* resolve root is guaranteed to be the '/' */ | |
329 | err = __of_adjust_tree_phandle_references(childroot, | |
330 | resolve, 0); | |
331 | if (err != 0) | |
332 | return err; | |
333 | ||
334 | BUG_ON(__of_adjust_tree_phandle_references(childroot, | |
335 | resolve, phandle_delta)); | |
336 | } | |
7941b27b PA |
337 | |
338 | root_sym = NULL; | |
339 | resolve_sym = NULL; | |
340 | resolve_fix = NULL; | |
341 | ||
342 | /* this may fail (if no fixups are required) */ | |
343 | root_sym = of_find_node_by_path("/__symbols__"); | |
344 | ||
345 | /* locate the symbols & fixups nodes on resolve */ | |
346 | for_each_child_of_node(resolve, child) { | |
347 | ||
348 | if (!resolve_sym && | |
349 | of_node_cmp(child->name, "__symbols__") == 0) | |
350 | resolve_sym = child; | |
351 | ||
352 | if (!resolve_fix && | |
353 | of_node_cmp(child->name, "__fixups__") == 0) | |
354 | resolve_fix = child; | |
355 | ||
356 | /* both found, don't bother anymore */ | |
357 | if (resolve_sym && resolve_fix) | |
358 | break; | |
359 | } | |
360 | ||
361 | /* we do allow for the case where no fixups are needed */ | |
362 | if (!resolve_fix) { | |
363 | err = 0; /* no error */ | |
364 | goto out; | |
365 | } | |
366 | ||
367 | /* we need to fixup, but no root symbols... */ | |
368 | if (!root_sym) { | |
369 | err = -EINVAL; | |
370 | goto out; | |
371 | } | |
372 | ||
373 | for_each_property_of_node(resolve_fix, rprop) { | |
374 | ||
375 | /* skip properties added automatically */ | |
376 | if (of_prop_cmp(rprop->name, "name") == 0) | |
377 | continue; | |
378 | ||
379 | err = of_property_read_string(root_sym, | |
380 | rprop->name, &refpath); | |
381 | if (err != 0) { | |
382 | pr_err("%s: Could not find symbol '%s'\n", | |
383 | __func__, rprop->name); | |
384 | goto out; | |
385 | } | |
386 | ||
387 | refnode = of_find_node_by_path(refpath); | |
388 | if (!refnode) { | |
389 | pr_err("%s: Could not find node by path '%s'\n", | |
390 | __func__, refpath); | |
391 | err = -ENOENT; | |
392 | goto out; | |
393 | } | |
394 | ||
395 | phandle = refnode->phandle; | |
396 | of_node_put(refnode); | |
397 | ||
398 | pr_debug("%s: %s phandle is 0x%08x\n", | |
399 | __func__, rprop->name, phandle); | |
400 | ||
da56d04c | 401 | err = __of_adjust_phandle_ref(resolve, rprop, phandle); |
7941b27b PA |
402 | if (err) |
403 | break; | |
404 | } | |
405 | ||
406 | out: | |
407 | /* NULL is handled by of_node_put as NOP */ | |
408 | of_node_put(root_sym); | |
409 | ||
410 | return err; | |
411 | } | |
412 | EXPORT_SYMBOL_GPL(of_resolve_phandles); |