Commit | Line | Data |
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e169cfbe GL |
1 | /* |
2 | * Functions for working with the Flattened Device Tree data format | |
3 | * | |
4 | * Copyright 2009 Benjamin Herrenschmidt, IBM Corp | |
5 | * benh@kernel.crashing.org | |
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 | ||
41f88009 GL |
12 | #include <linux/kernel.h> |
13 | #include <linux/lmb.h> | |
f7b3a835 | 14 | #include <linux/initrd.h> |
e169cfbe GL |
15 | #include <linux/of.h> |
16 | #include <linux/of_fdt.h> | |
17 | ||
f00abd94 GL |
18 | int __initdata dt_root_addr_cells; |
19 | int __initdata dt_root_size_cells; | |
20 | ||
e169cfbe GL |
21 | struct boot_param_header *initial_boot_params; |
22 | ||
23 | char *find_flat_dt_string(u32 offset) | |
24 | { | |
25 | return ((char *)initial_boot_params) + | |
26 | initial_boot_params->off_dt_strings + offset; | |
27 | } | |
c8cb7a59 GL |
28 | |
29 | /** | |
30 | * of_scan_flat_dt - scan flattened tree blob and call callback on each. | |
31 | * @it: callback function | |
32 | * @data: context data pointer | |
33 | * | |
34 | * This function is used to scan the flattened device-tree, it is | |
35 | * used to extract the memory information at boot before we can | |
36 | * unflatten the tree | |
37 | */ | |
38 | int __init of_scan_flat_dt(int (*it)(unsigned long node, | |
39 | const char *uname, int depth, | |
40 | void *data), | |
41 | void *data) | |
42 | { | |
43 | unsigned long p = ((unsigned long)initial_boot_params) + | |
44 | initial_boot_params->off_dt_struct; | |
45 | int rc = 0; | |
46 | int depth = -1; | |
47 | ||
48 | do { | |
49 | u32 tag = *((u32 *)p); | |
50 | char *pathp; | |
51 | ||
52 | p += 4; | |
53 | if (tag == OF_DT_END_NODE) { | |
54 | depth--; | |
55 | continue; | |
56 | } | |
57 | if (tag == OF_DT_NOP) | |
58 | continue; | |
59 | if (tag == OF_DT_END) | |
60 | break; | |
61 | if (tag == OF_DT_PROP) { | |
62 | u32 sz = *((u32 *)p); | |
63 | p += 8; | |
64 | if (initial_boot_params->version < 0x10) | |
65 | p = _ALIGN(p, sz >= 8 ? 8 : 4); | |
66 | p += sz; | |
67 | p = _ALIGN(p, 4); | |
68 | continue; | |
69 | } | |
70 | if (tag != OF_DT_BEGIN_NODE) { | |
71 | pr_err("Invalid tag %x in flat device tree!\n", tag); | |
72 | return -EINVAL; | |
73 | } | |
74 | depth++; | |
75 | pathp = (char *)p; | |
76 | p = _ALIGN(p + strlen(pathp) + 1, 4); | |
77 | if ((*pathp) == '/') { | |
78 | char *lp, *np; | |
79 | for (lp = NULL, np = pathp; *np; np++) | |
80 | if ((*np) == '/') | |
81 | lp = np+1; | |
82 | if (lp != NULL) | |
83 | pathp = lp; | |
84 | } | |
85 | rc = it(p, pathp, depth, data); | |
86 | if (rc != 0) | |
87 | break; | |
88 | } while (1); | |
89 | ||
90 | return rc; | |
91 | } | |
819d2819 GL |
92 | |
93 | /** | |
94 | * of_get_flat_dt_root - find the root node in the flat blob | |
95 | */ | |
96 | unsigned long __init of_get_flat_dt_root(void) | |
97 | { | |
98 | unsigned long p = ((unsigned long)initial_boot_params) + | |
99 | initial_boot_params->off_dt_struct; | |
100 | ||
101 | while (*((u32 *)p) == OF_DT_NOP) | |
102 | p += 4; | |
103 | BUG_ON(*((u32 *)p) != OF_DT_BEGIN_NODE); | |
104 | p += 4; | |
105 | return _ALIGN(p + strlen((char *)p) + 1, 4); | |
106 | } | |
107 | ||
ca900cfa GL |
108 | /** |
109 | * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr | |
110 | * | |
111 | * This function can be used within scan_flattened_dt callback to get | |
112 | * access to properties | |
113 | */ | |
114 | void *__init of_get_flat_dt_prop(unsigned long node, const char *name, | |
115 | unsigned long *size) | |
116 | { | |
117 | unsigned long p = node; | |
118 | ||
119 | do { | |
120 | u32 tag = *((u32 *)p); | |
121 | u32 sz, noff; | |
122 | const char *nstr; | |
123 | ||
124 | p += 4; | |
125 | if (tag == OF_DT_NOP) | |
126 | continue; | |
127 | if (tag != OF_DT_PROP) | |
128 | return NULL; | |
129 | ||
130 | sz = *((u32 *)p); | |
131 | noff = *((u32 *)(p + 4)); | |
132 | p += 8; | |
133 | if (initial_boot_params->version < 0x10) | |
134 | p = _ALIGN(p, sz >= 8 ? 8 : 4); | |
135 | ||
136 | nstr = find_flat_dt_string(noff); | |
137 | if (nstr == NULL) { | |
138 | pr_warning("Can't find property index name !\n"); | |
139 | return NULL; | |
140 | } | |
141 | if (strcmp(name, nstr) == 0) { | |
142 | if (size) | |
143 | *size = sz; | |
144 | return (void *)p; | |
145 | } | |
146 | p += sz; | |
147 | p = _ALIGN(p, 4); | |
148 | } while (1); | |
149 | } | |
150 | ||
00e38efd GL |
151 | /** |
152 | * of_flat_dt_is_compatible - Return true if given node has compat in compatible list | |
153 | * @node: node to test | |
154 | * @compat: compatible string to compare with compatible list. | |
155 | */ | |
156 | int __init of_flat_dt_is_compatible(unsigned long node, const char *compat) | |
157 | { | |
158 | const char *cp; | |
159 | unsigned long cplen, l; | |
160 | ||
161 | cp = of_get_flat_dt_prop(node, "compatible", &cplen); | |
162 | if (cp == NULL) | |
163 | return 0; | |
164 | while (cplen > 0) { | |
165 | if (strncasecmp(cp, compat, strlen(compat)) == 0) | |
166 | return 1; | |
167 | l = strlen(cp) + 1; | |
168 | cp += l; | |
169 | cplen -= l; | |
170 | } | |
171 | ||
172 | return 0; | |
173 | } | |
174 | ||
bbd33931 GL |
175 | static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size, |
176 | unsigned long align) | |
177 | { | |
178 | void *res; | |
179 | ||
180 | *mem = _ALIGN(*mem, align); | |
181 | res = (void *)*mem; | |
182 | *mem += size; | |
183 | ||
184 | return res; | |
185 | } | |
186 | ||
187 | /** | |
188 | * unflatten_dt_node - Alloc and populate a device_node from the flat tree | |
189 | * @p: pointer to node in flat tree | |
190 | * @dad: Parent struct device_node | |
191 | * @allnextpp: pointer to ->allnext from last allocated device_node | |
192 | * @fpsize: Size of the node path up at the current depth. | |
193 | */ | |
194 | unsigned long __init unflatten_dt_node(unsigned long mem, | |
195 | unsigned long *p, | |
196 | struct device_node *dad, | |
197 | struct device_node ***allnextpp, | |
198 | unsigned long fpsize) | |
199 | { | |
200 | struct device_node *np; | |
201 | struct property *pp, **prev_pp = NULL; | |
202 | char *pathp; | |
203 | u32 tag; | |
204 | unsigned int l, allocl; | |
205 | int has_name = 0; | |
206 | int new_format = 0; | |
207 | ||
208 | tag = *((u32 *)(*p)); | |
209 | if (tag != OF_DT_BEGIN_NODE) { | |
210 | pr_err("Weird tag at start of node: %x\n", tag); | |
211 | return mem; | |
212 | } | |
213 | *p += 4; | |
214 | pathp = (char *)*p; | |
215 | l = allocl = strlen(pathp) + 1; | |
216 | *p = _ALIGN(*p + l, 4); | |
217 | ||
218 | /* version 0x10 has a more compact unit name here instead of the full | |
219 | * path. we accumulate the full path size using "fpsize", we'll rebuild | |
220 | * it later. We detect this because the first character of the name is | |
221 | * not '/'. | |
222 | */ | |
223 | if ((*pathp) != '/') { | |
224 | new_format = 1; | |
225 | if (fpsize == 0) { | |
226 | /* root node: special case. fpsize accounts for path | |
227 | * plus terminating zero. root node only has '/', so | |
228 | * fpsize should be 2, but we want to avoid the first | |
229 | * level nodes to have two '/' so we use fpsize 1 here | |
230 | */ | |
231 | fpsize = 1; | |
232 | allocl = 2; | |
233 | } else { | |
234 | /* account for '/' and path size minus terminal 0 | |
235 | * already in 'l' | |
236 | */ | |
237 | fpsize += l; | |
238 | allocl = fpsize; | |
239 | } | |
240 | } | |
241 | ||
242 | np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl, | |
243 | __alignof__(struct device_node)); | |
244 | if (allnextpp) { | |
245 | memset(np, 0, sizeof(*np)); | |
246 | np->full_name = ((char *)np) + sizeof(struct device_node); | |
247 | if (new_format) { | |
248 | char *fn = np->full_name; | |
249 | /* rebuild full path for new format */ | |
250 | if (dad && dad->parent) { | |
251 | strcpy(fn, dad->full_name); | |
252 | #ifdef DEBUG | |
253 | if ((strlen(fn) + l + 1) != allocl) { | |
254 | pr_debug("%s: p: %d, l: %d, a: %d\n", | |
255 | pathp, (int)strlen(fn), | |
256 | l, allocl); | |
257 | } | |
258 | #endif | |
259 | fn += strlen(fn); | |
260 | } | |
261 | *(fn++) = '/'; | |
262 | memcpy(fn, pathp, l); | |
263 | } else | |
264 | memcpy(np->full_name, pathp, l); | |
265 | prev_pp = &np->properties; | |
266 | **allnextpp = np; | |
267 | *allnextpp = &np->allnext; | |
268 | if (dad != NULL) { | |
269 | np->parent = dad; | |
270 | /* we temporarily use the next field as `last_child'*/ | |
271 | if (dad->next == NULL) | |
272 | dad->child = np; | |
273 | else | |
274 | dad->next->sibling = np; | |
275 | dad->next = np; | |
276 | } | |
277 | kref_init(&np->kref); | |
278 | } | |
279 | while (1) { | |
280 | u32 sz, noff; | |
281 | char *pname; | |
282 | ||
283 | tag = *((u32 *)(*p)); | |
284 | if (tag == OF_DT_NOP) { | |
285 | *p += 4; | |
286 | continue; | |
287 | } | |
288 | if (tag != OF_DT_PROP) | |
289 | break; | |
290 | *p += 4; | |
291 | sz = *((u32 *)(*p)); | |
292 | noff = *((u32 *)((*p) + 4)); | |
293 | *p += 8; | |
294 | if (initial_boot_params->version < 0x10) | |
295 | *p = _ALIGN(*p, sz >= 8 ? 8 : 4); | |
296 | ||
297 | pname = find_flat_dt_string(noff); | |
298 | if (pname == NULL) { | |
299 | pr_info("Can't find property name in list !\n"); | |
300 | break; | |
301 | } | |
302 | if (strcmp(pname, "name") == 0) | |
303 | has_name = 1; | |
304 | l = strlen(pname) + 1; | |
305 | pp = unflatten_dt_alloc(&mem, sizeof(struct property), | |
306 | __alignof__(struct property)); | |
307 | if (allnextpp) { | |
308 | if (strcmp(pname, "linux,phandle") == 0) { | |
309 | np->node = *((u32 *)*p); | |
310 | if (np->linux_phandle == 0) | |
311 | np->linux_phandle = np->node; | |
312 | } | |
313 | if (strcmp(pname, "ibm,phandle") == 0) | |
314 | np->linux_phandle = *((u32 *)*p); | |
315 | pp->name = pname; | |
316 | pp->length = sz; | |
317 | pp->value = (void *)*p; | |
318 | *prev_pp = pp; | |
319 | prev_pp = &pp->next; | |
320 | } | |
321 | *p = _ALIGN((*p) + sz, 4); | |
322 | } | |
323 | /* with version 0x10 we may not have the name property, recreate | |
324 | * it here from the unit name if absent | |
325 | */ | |
326 | if (!has_name) { | |
327 | char *p1 = pathp, *ps = pathp, *pa = NULL; | |
328 | int sz; | |
329 | ||
330 | while (*p1) { | |
331 | if ((*p1) == '@') | |
332 | pa = p1; | |
333 | if ((*p1) == '/') | |
334 | ps = p1 + 1; | |
335 | p1++; | |
336 | } | |
337 | if (pa < ps) | |
338 | pa = p1; | |
339 | sz = (pa - ps) + 1; | |
340 | pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz, | |
341 | __alignof__(struct property)); | |
342 | if (allnextpp) { | |
343 | pp->name = "name"; | |
344 | pp->length = sz; | |
345 | pp->value = pp + 1; | |
346 | *prev_pp = pp; | |
347 | prev_pp = &pp->next; | |
348 | memcpy(pp->value, ps, sz - 1); | |
349 | ((char *)pp->value)[sz - 1] = 0; | |
350 | pr_debug("fixed up name for %s -> %s\n", pathp, | |
351 | (char *)pp->value); | |
352 | } | |
353 | } | |
354 | if (allnextpp) { | |
355 | *prev_pp = NULL; | |
356 | np->name = of_get_property(np, "name", NULL); | |
357 | np->type = of_get_property(np, "device_type", NULL); | |
358 | ||
359 | if (!np->name) | |
360 | np->name = "<NULL>"; | |
361 | if (!np->type) | |
362 | np->type = "<NULL>"; | |
363 | } | |
364 | while (tag == OF_DT_BEGIN_NODE) { | |
365 | mem = unflatten_dt_node(mem, p, np, allnextpp, fpsize); | |
366 | tag = *((u32 *)(*p)); | |
367 | } | |
368 | if (tag != OF_DT_END_NODE) { | |
369 | pr_err("Weird tag at end of node: %x\n", tag); | |
370 | return mem; | |
371 | } | |
372 | *p += 4; | |
373 | return mem; | |
374 | } | |
41f88009 | 375 | |
f7b3a835 GL |
376 | #ifdef CONFIG_BLK_DEV_INITRD |
377 | /** | |
378 | * early_init_dt_check_for_initrd - Decode initrd location from flat tree | |
379 | * @node: reference to node containing initrd location ('chosen') | |
380 | */ | |
381 | void __init early_init_dt_check_for_initrd(unsigned long node) | |
382 | { | |
383 | unsigned long len; | |
384 | u32 *prop; | |
385 | ||
386 | pr_debug("Looking for initrd properties... "); | |
387 | ||
388 | prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len); | |
389 | if (prop) { | |
390 | initrd_start = (unsigned long) | |
391 | __va(of_read_ulong(prop, len/4)); | |
392 | ||
393 | prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len); | |
394 | if (prop) { | |
395 | initrd_end = (unsigned long) | |
396 | __va(of_read_ulong(prop, len/4)); | |
397 | initrd_below_start_ok = 1; | |
398 | } else { | |
399 | initrd_start = 0; | |
400 | } | |
401 | } | |
402 | ||
403 | pr_debug("initrd_start=0x%lx initrd_end=0x%lx\n", | |
404 | initrd_start, initrd_end); | |
405 | } | |
406 | #else | |
407 | inline void early_init_dt_check_for_initrd(unsigned long node) | |
408 | { | |
409 | } | |
410 | #endif /* CONFIG_BLK_DEV_INITRD */ | |
411 | ||
f00abd94 GL |
412 | /** |
413 | * early_init_dt_scan_root - fetch the top level address and size cells | |
414 | */ | |
415 | int __init early_init_dt_scan_root(unsigned long node, const char *uname, | |
416 | int depth, void *data) | |
417 | { | |
418 | u32 *prop; | |
419 | ||
420 | if (depth != 0) | |
421 | return 0; | |
422 | ||
423 | prop = of_get_flat_dt_prop(node, "#size-cells", NULL); | |
424 | dt_root_size_cells = (prop == NULL) ? 1 : *prop; | |
425 | pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells); | |
426 | ||
427 | prop = of_get_flat_dt_prop(node, "#address-cells", NULL); | |
428 | dt_root_addr_cells = (prop == NULL) ? 2 : *prop; | |
429 | pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells); | |
430 | ||
431 | /* break now */ | |
432 | return 1; | |
433 | } | |
434 | ||
83f7a06e GL |
435 | u64 __init dt_mem_next_cell(int s, u32 **cellp) |
436 | { | |
437 | u32 *p = *cellp; | |
438 | ||
439 | *cellp = p + s; | |
440 | return of_read_number(p, s); | |
441 | } | |
442 | ||
41f88009 GL |
443 | /** |
444 | * unflatten_device_tree - create tree of device_nodes from flat blob | |
445 | * | |
446 | * unflattens the device-tree passed by the firmware, creating the | |
447 | * tree of struct device_node. It also fills the "name" and "type" | |
448 | * pointers of the nodes so the normal device-tree walking functions | |
449 | * can be used. | |
450 | */ | |
451 | void __init unflatten_device_tree(void) | |
452 | { | |
453 | unsigned long start, mem, size; | |
454 | struct device_node **allnextp = &allnodes; | |
455 | ||
456 | pr_debug(" -> unflatten_device_tree()\n"); | |
457 | ||
458 | /* First pass, scan for size */ | |
459 | start = ((unsigned long)initial_boot_params) + | |
460 | initial_boot_params->off_dt_struct; | |
461 | size = unflatten_dt_node(0, &start, NULL, NULL, 0); | |
462 | size = (size | 3) + 1; | |
463 | ||
464 | pr_debug(" size is %lx, allocating...\n", size); | |
465 | ||
466 | /* Allocate memory for the expanded device tree */ | |
467 | mem = lmb_alloc(size + 4, __alignof__(struct device_node)); | |
468 | mem = (unsigned long) __va(mem); | |
469 | ||
470 | ((u32 *)mem)[size / 4] = 0xdeadbeef; | |
471 | ||
472 | pr_debug(" unflattening %lx...\n", mem); | |
473 | ||
474 | /* Second pass, do actual unflattening */ | |
475 | start = ((unsigned long)initial_boot_params) + | |
476 | initial_boot_params->off_dt_struct; | |
477 | unflatten_dt_node(mem, &start, NULL, &allnextp, 0); | |
478 | if (*((u32 *)start) != OF_DT_END) | |
479 | pr_warning("Weird tag at end of tree: %08x\n", *((u32 *)start)); | |
480 | if (((u32 *)mem)[size / 4] != 0xdeadbeef) | |
481 | pr_warning("End of tree marker overwritten: %08x\n", | |
482 | ((u32 *)mem)[size / 4]); | |
483 | *allnextp = NULL; | |
484 | ||
485 | /* Get pointer to OF "/chosen" node for use everywhere */ | |
486 | of_chosen = of_find_node_by_path("/chosen"); | |
487 | if (of_chosen == NULL) | |
488 | of_chosen = of_find_node_by_path("/chosen@0"); | |
489 | ||
490 | pr_debug(" <- unflatten_device_tree()\n"); | |
491 | } |