Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 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 | |
Rob Herring | 606ad42 | 2016-06-15 08:32:18 -0500 | [diff] [blame] | 12 | #define pr_fmt(fmt) "OF: resolver: " fmt |
| 13 | |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 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> |
| 21 | #include <linux/string.h> |
| 22 | #include <linux/slab.h> |
| 23 | |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 24 | /** |
| 25 | * Find a node with the give full name by recursively following any of |
| 26 | * the child node links. |
| 27 | */ |
| 28 | static struct device_node *__of_find_node_by_full_name(struct device_node *node, |
| 29 | const char *full_name) |
| 30 | { |
| 31 | struct device_node *child, *found; |
| 32 | |
| 33 | if (node == NULL) |
| 34 | return NULL; |
| 35 | |
| 36 | /* check */ |
| 37 | if (of_node_cmp(node->full_name, full_name) == 0) |
Amitoj Kaur Chawla | 82f6875 | 2016-02-03 23:39:01 +0530 | [diff] [blame] | 38 | return of_node_get(node); |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 39 | |
| 40 | for_each_child_of_node(node, child) { |
| 41 | found = __of_find_node_by_full_name(child, full_name); |
Amitoj Kaur Chawla | 82f6875 | 2016-02-03 23:39:01 +0530 | [diff] [blame] | 42 | if (found != NULL) { |
| 43 | of_node_put(child); |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 44 | return found; |
Amitoj Kaur Chawla | 82f6875 | 2016-02-03 23:39:01 +0530 | [diff] [blame] | 45 | } |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 46 | } |
| 47 | |
| 48 | return NULL; |
| 49 | } |
| 50 | |
| 51 | /* |
| 52 | * Find live tree's maximum phandle value. |
| 53 | */ |
| 54 | static phandle of_get_tree_max_phandle(void) |
| 55 | { |
| 56 | struct device_node *node; |
| 57 | phandle phandle; |
| 58 | unsigned long flags; |
| 59 | |
| 60 | /* now search recursively */ |
| 61 | raw_spin_lock_irqsave(&devtree_lock, flags); |
| 62 | phandle = 0; |
| 63 | for_each_of_allnodes(node) { |
| 64 | if (node->phandle != OF_PHANDLE_ILLEGAL && |
| 65 | node->phandle > phandle) |
| 66 | phandle = node->phandle; |
| 67 | } |
| 68 | raw_spin_unlock_irqrestore(&devtree_lock, flags); |
| 69 | |
| 70 | return phandle; |
| 71 | } |
| 72 | |
| 73 | /* |
| 74 | * Adjust a subtree's phandle values by a given delta. |
| 75 | * Makes sure not to just adjust the device node's phandle value, |
| 76 | * but modify the phandle properties values as well. |
| 77 | */ |
| 78 | static void __of_adjust_tree_phandles(struct device_node *node, |
| 79 | int phandle_delta) |
| 80 | { |
| 81 | struct device_node *child; |
| 82 | struct property *prop; |
| 83 | phandle phandle; |
| 84 | |
| 85 | /* first adjust the node's phandle direct value */ |
| 86 | if (node->phandle != 0 && node->phandle != OF_PHANDLE_ILLEGAL) |
| 87 | node->phandle += phandle_delta; |
| 88 | |
| 89 | /* now adjust phandle & linux,phandle values */ |
| 90 | for_each_property_of_node(node, prop) { |
| 91 | |
| 92 | /* only look for these two */ |
| 93 | if (of_prop_cmp(prop->name, "phandle") != 0 && |
| 94 | of_prop_cmp(prop->name, "linux,phandle") != 0) |
| 95 | continue; |
| 96 | |
| 97 | /* must be big enough */ |
| 98 | if (prop->length < 4) |
| 99 | continue; |
| 100 | |
| 101 | /* read phandle value */ |
| 102 | phandle = be32_to_cpup(prop->value); |
| 103 | if (phandle == OF_PHANDLE_ILLEGAL) /* unresolved */ |
| 104 | continue; |
| 105 | |
| 106 | /* adjust */ |
| 107 | *(uint32_t *)prop->value = cpu_to_be32(node->phandle); |
| 108 | } |
| 109 | |
| 110 | /* now do the children recursively */ |
| 111 | for_each_child_of_node(node, child) |
| 112 | __of_adjust_tree_phandles(child, phandle_delta); |
| 113 | } |
| 114 | |
Pantelis Antoniou | da56d04 | 2014-10-28 22:33:49 +0200 | [diff] [blame] | 115 | static int __of_adjust_phandle_ref(struct device_node *node, |
| 116 | struct property *rprop, int value) |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 117 | { |
| 118 | phandle phandle; |
| 119 | struct device_node *refnode; |
| 120 | struct property *sprop; |
| 121 | char *propval, *propcur, *propend, *nodestr, *propstr, *s; |
| 122 | int offset, propcurlen; |
| 123 | int err = 0; |
| 124 | |
| 125 | /* make a copy */ |
| 126 | propval = kmalloc(rprop->length, GFP_KERNEL); |
| 127 | if (!propval) { |
| 128 | pr_err("%s: Could not copy value of '%s'\n", |
| 129 | __func__, rprop->name); |
| 130 | return -ENOMEM; |
| 131 | } |
| 132 | memcpy(propval, rprop->value, rprop->length); |
| 133 | |
| 134 | propend = propval + rprop->length; |
| 135 | for (propcur = propval; propcur < propend; propcur += propcurlen + 1) { |
| 136 | propcurlen = strlen(propcur); |
| 137 | |
| 138 | nodestr = propcur; |
| 139 | s = strchr(propcur, ':'); |
| 140 | if (!s) { |
| 141 | pr_err("%s: Illegal symbol entry '%s' (1)\n", |
| 142 | __func__, propcur); |
| 143 | err = -EINVAL; |
| 144 | goto err_fail; |
| 145 | } |
| 146 | *s++ = '\0'; |
| 147 | |
| 148 | propstr = s; |
| 149 | s = strchr(s, ':'); |
| 150 | if (!s) { |
| 151 | pr_err("%s: Illegal symbol entry '%s' (2)\n", |
| 152 | __func__, (char *)rprop->value); |
| 153 | err = -EINVAL; |
| 154 | goto err_fail; |
| 155 | } |
| 156 | |
| 157 | *s++ = '\0'; |
| 158 | err = kstrtoint(s, 10, &offset); |
| 159 | if (err != 0) { |
| 160 | pr_err("%s: Could get offset '%s'\n", |
| 161 | __func__, (char *)rprop->value); |
| 162 | goto err_fail; |
| 163 | } |
| 164 | |
| 165 | /* look into the resolve node for the full path */ |
| 166 | refnode = __of_find_node_by_full_name(node, nodestr); |
| 167 | if (!refnode) { |
| 168 | pr_warn("%s: Could not find refnode '%s'\n", |
| 169 | __func__, (char *)rprop->value); |
| 170 | continue; |
| 171 | } |
| 172 | |
| 173 | /* now find the property */ |
| 174 | for_each_property_of_node(refnode, sprop) { |
| 175 | if (of_prop_cmp(sprop->name, propstr) == 0) |
| 176 | break; |
| 177 | } |
Amitoj Kaur Chawla | 82f6875 | 2016-02-03 23:39:01 +0530 | [diff] [blame] | 178 | of_node_put(refnode); |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 179 | |
| 180 | if (!sprop) { |
| 181 | pr_err("%s: Could not find property '%s'\n", |
| 182 | __func__, (char *)rprop->value); |
| 183 | err = -ENOENT; |
| 184 | goto err_fail; |
| 185 | } |
| 186 | |
Pantelis Antoniou | da56d04 | 2014-10-28 22:33:49 +0200 | [diff] [blame] | 187 | phandle = value; |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 188 | *(__be32 *)(sprop->value + offset) = cpu_to_be32(phandle); |
| 189 | } |
| 190 | |
| 191 | err_fail: |
| 192 | kfree(propval); |
| 193 | return err; |
| 194 | } |
| 195 | |
Pantelis Antoniou | da56d04 | 2014-10-28 22:33:49 +0200 | [diff] [blame] | 196 | /* compare nodes taking into account that 'name' strips out the @ part */ |
| 197 | static int __of_node_name_cmp(const struct device_node *dn1, |
| 198 | const struct device_node *dn2) |
| 199 | { |
| 200 | const char *n1 = strrchr(dn1->full_name, '/') ? : "/"; |
| 201 | const char *n2 = strrchr(dn2->full_name, '/') ? : "/"; |
| 202 | |
| 203 | return of_node_cmp(n1, n2); |
| 204 | } |
| 205 | |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 206 | /* |
| 207 | * Adjust the local phandle references by the given phandle delta. |
Pantelis Antoniou | da56d04 | 2014-10-28 22:33:49 +0200 | [diff] [blame] | 208 | * Assumes the existances of a __local_fixups__ node at the root. |
| 209 | * Assumes that __of_verify_tree_phandle_references has been called. |
| 210 | * Does not take any devtree locks so make sure you call this on a tree |
| 211 | * which is at the detached state. |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 212 | */ |
| 213 | static int __of_adjust_tree_phandle_references(struct device_node *node, |
Pantelis Antoniou | da56d04 | 2014-10-28 22:33:49 +0200 | [diff] [blame] | 214 | struct device_node *target, int phandle_delta) |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 215 | { |
Pantelis Antoniou | da56d04 | 2014-10-28 22:33:49 +0200 | [diff] [blame] | 216 | struct device_node *child, *childtarget; |
| 217 | struct property *rprop, *sprop; |
| 218 | int err, i, count; |
| 219 | unsigned int off; |
| 220 | phandle phandle; |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 221 | |
Pantelis Antoniou | da56d04 | 2014-10-28 22:33:49 +0200 | [diff] [blame] | 222 | if (node == NULL) |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 223 | return 0; |
| 224 | |
Pantelis Antoniou | da56d04 | 2014-10-28 22:33:49 +0200 | [diff] [blame] | 225 | for_each_property_of_node(node, rprop) { |
| 226 | |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 227 | /* skip properties added automatically */ |
Pantelis Antoniou | da56d04 | 2014-10-28 22:33:49 +0200 | [diff] [blame] | 228 | if (of_prop_cmp(rprop->name, "name") == 0 || |
| 229 | of_prop_cmp(rprop->name, "phandle") == 0 || |
| 230 | of_prop_cmp(rprop->name, "linux,phandle") == 0) |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 231 | continue; |
| 232 | |
Pantelis Antoniou | da56d04 | 2014-10-28 22:33:49 +0200 | [diff] [blame] | 233 | if ((rprop->length % 4) != 0 || rprop->length == 0) { |
| 234 | pr_err("%s: Illegal property (size) '%s' @%s\n", |
| 235 | __func__, rprop->name, node->full_name); |
| 236 | return -EINVAL; |
| 237 | } |
| 238 | count = rprop->length / sizeof(__be32); |
| 239 | |
| 240 | /* now find the target property */ |
| 241 | for_each_property_of_node(target, sprop) { |
| 242 | if (of_prop_cmp(sprop->name, rprop->name) == 0) |
| 243 | break; |
| 244 | } |
| 245 | |
| 246 | if (sprop == NULL) { |
| 247 | pr_err("%s: Could not find target property '%s' @%s\n", |
| 248 | __func__, rprop->name, node->full_name); |
| 249 | return -EINVAL; |
| 250 | } |
| 251 | |
| 252 | for (i = 0; i < count; i++) { |
| 253 | off = be32_to_cpu(((__be32 *)rprop->value)[i]); |
| 254 | /* make sure the offset doesn't overstep (even wrap) */ |
| 255 | if (off >= sprop->length || |
| 256 | (off + 4) > sprop->length) { |
| 257 | pr_err("%s: Illegal property '%s' @%s\n", |
| 258 | __func__, rprop->name, |
| 259 | node->full_name); |
| 260 | return -EINVAL; |
| 261 | } |
| 262 | |
| 263 | if (phandle_delta) { |
| 264 | /* adjust */ |
| 265 | phandle = be32_to_cpu(*(__be32 *)(sprop->value + off)); |
| 266 | phandle += phandle_delta; |
| 267 | *(__be32 *)(sprop->value + off) = cpu_to_be32(phandle); |
| 268 | } |
| 269 | } |
| 270 | } |
| 271 | |
| 272 | for_each_child_of_node(node, child) { |
| 273 | |
| 274 | for_each_child_of_node(target, childtarget) |
| 275 | if (__of_node_name_cmp(child, childtarget) == 0) |
| 276 | break; |
| 277 | |
| 278 | if (!childtarget) { |
| 279 | pr_err("%s: Could not find target child '%s' @%s\n", |
| 280 | __func__, child->name, node->full_name); |
| 281 | return -EINVAL; |
| 282 | } |
| 283 | |
| 284 | err = __of_adjust_tree_phandle_references(child, childtarget, |
| 285 | phandle_delta); |
| 286 | if (err != 0) |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 287 | return err; |
| 288 | } |
| 289 | |
| 290 | return 0; |
| 291 | } |
| 292 | |
| 293 | /** |
| 294 | * of_resolve - Resolve the given node against the live tree. |
| 295 | * |
| 296 | * @resolve: Node to resolve |
| 297 | * |
| 298 | * Perform dynamic Device Tree resolution against the live tree |
| 299 | * to the given node to resolve. This depends on the live tree |
| 300 | * having a __symbols__ node, and the resolve node the __fixups__ & |
| 301 | * __local_fixups__ nodes (if needed). |
| 302 | * The result of the operation is a resolve node that it's contents |
| 303 | * are fit to be inserted or operate upon the live tree. |
| 304 | * Returns 0 on success or a negative error value on error. |
| 305 | */ |
| 306 | int of_resolve_phandles(struct device_node *resolve) |
| 307 | { |
Pantelis Antoniou | da56d04 | 2014-10-28 22:33:49 +0200 | [diff] [blame] | 308 | struct device_node *child, *childroot, *refnode; |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 309 | struct device_node *root_sym, *resolve_sym, *resolve_fix; |
| 310 | struct property *rprop; |
| 311 | const char *refpath; |
| 312 | phandle phandle, phandle_delta; |
| 313 | int err; |
| 314 | |
Michal Suchanek | 5de3bbc | 2016-06-26 22:11:58 +0200 | [diff] [blame] | 315 | if (!resolve) |
| 316 | pr_err("%s: null node\n", __func__); |
| 317 | if (resolve && !of_node_check_flag(resolve, OF_DETACHED)) |
| 318 | pr_err("%s: node %s not detached\n", __func__, |
| 319 | resolve->full_name); |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 320 | /* the resolve node must exist, and be detached */ |
| 321 | if (!resolve || !of_node_check_flag(resolve, OF_DETACHED)) |
| 322 | return -EINVAL; |
| 323 | |
| 324 | /* first we need to adjust the phandles */ |
| 325 | phandle_delta = of_get_tree_max_phandle() + 1; |
| 326 | __of_adjust_tree_phandles(resolve, phandle_delta); |
Pantelis Antoniou | da56d04 | 2014-10-28 22:33:49 +0200 | [diff] [blame] | 327 | |
| 328 | /* locate the local fixups */ |
| 329 | childroot = NULL; |
| 330 | for_each_child_of_node(resolve, childroot) |
| 331 | if (of_node_cmp(childroot->name, "__local_fixups__") == 0) |
| 332 | break; |
| 333 | |
| 334 | if (childroot != NULL) { |
| 335 | /* resolve root is guaranteed to be the '/' */ |
| 336 | err = __of_adjust_tree_phandle_references(childroot, |
| 337 | resolve, 0); |
| 338 | if (err != 0) |
| 339 | return err; |
| 340 | |
| 341 | BUG_ON(__of_adjust_tree_phandle_references(childroot, |
| 342 | resolve, phandle_delta)); |
| 343 | } |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 344 | |
| 345 | root_sym = NULL; |
| 346 | resolve_sym = NULL; |
| 347 | resolve_fix = NULL; |
| 348 | |
| 349 | /* this may fail (if no fixups are required) */ |
| 350 | root_sym = of_find_node_by_path("/__symbols__"); |
| 351 | |
| 352 | /* locate the symbols & fixups nodes on resolve */ |
| 353 | for_each_child_of_node(resolve, child) { |
| 354 | |
| 355 | if (!resolve_sym && |
| 356 | of_node_cmp(child->name, "__symbols__") == 0) |
| 357 | resolve_sym = child; |
| 358 | |
| 359 | if (!resolve_fix && |
| 360 | of_node_cmp(child->name, "__fixups__") == 0) |
| 361 | resolve_fix = child; |
| 362 | |
| 363 | /* both found, don't bother anymore */ |
| 364 | if (resolve_sym && resolve_fix) |
| 365 | break; |
| 366 | } |
| 367 | |
| 368 | /* we do allow for the case where no fixups are needed */ |
| 369 | if (!resolve_fix) { |
| 370 | err = 0; /* no error */ |
| 371 | goto out; |
| 372 | } |
| 373 | |
| 374 | /* we need to fixup, but no root symbols... */ |
| 375 | if (!root_sym) { |
Michal Suchanek | 5de3bbc | 2016-06-26 22:11:58 +0200 | [diff] [blame] | 376 | pr_err("%s: no symbols in root of device tree.\n", __func__); |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 377 | err = -EINVAL; |
| 378 | goto out; |
| 379 | } |
| 380 | |
| 381 | for_each_property_of_node(resolve_fix, rprop) { |
| 382 | |
| 383 | /* skip properties added automatically */ |
| 384 | if (of_prop_cmp(rprop->name, "name") == 0) |
| 385 | continue; |
| 386 | |
| 387 | err = of_property_read_string(root_sym, |
| 388 | rprop->name, &refpath); |
| 389 | if (err != 0) { |
| 390 | pr_err("%s: Could not find symbol '%s'\n", |
| 391 | __func__, rprop->name); |
| 392 | goto out; |
| 393 | } |
| 394 | |
| 395 | refnode = of_find_node_by_path(refpath); |
| 396 | if (!refnode) { |
| 397 | pr_err("%s: Could not find node by path '%s'\n", |
| 398 | __func__, refpath); |
| 399 | err = -ENOENT; |
| 400 | goto out; |
| 401 | } |
| 402 | |
| 403 | phandle = refnode->phandle; |
| 404 | of_node_put(refnode); |
| 405 | |
| 406 | pr_debug("%s: %s phandle is 0x%08x\n", |
| 407 | __func__, rprop->name, phandle); |
| 408 | |
Pantelis Antoniou | da56d04 | 2014-10-28 22:33:49 +0200 | [diff] [blame] | 409 | err = __of_adjust_phandle_ref(resolve, rprop, phandle); |
Pantelis Antoniou | 7941b27 | 2014-07-04 19:59:20 +0300 | [diff] [blame] | 410 | if (err) |
| 411 | break; |
| 412 | } |
| 413 | |
| 414 | out: |
| 415 | /* NULL is handled by of_node_put as NOP */ |
| 416 | of_node_put(root_sym); |
| 417 | |
| 418 | return err; |
| 419 | } |
| 420 | EXPORT_SYMBOL_GPL(of_resolve_phandles); |