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 | ||
86e03221 GL |
18 | #ifdef CONFIG_PPC |
19 | #include <asm/machdep.h> | |
20 | #endif /* CONFIG_PPC */ | |
21 | ||
f00abd94 GL |
22 | int __initdata dt_root_addr_cells; |
23 | int __initdata dt_root_size_cells; | |
24 | ||
e169cfbe GL |
25 | struct boot_param_header *initial_boot_params; |
26 | ||
27 | char *find_flat_dt_string(u32 offset) | |
28 | { | |
29 | return ((char *)initial_boot_params) + | |
30 | initial_boot_params->off_dt_strings + offset; | |
31 | } | |
c8cb7a59 GL |
32 | |
33 | /** | |
34 | * of_scan_flat_dt - scan flattened tree blob and call callback on each. | |
35 | * @it: callback function | |
36 | * @data: context data pointer | |
37 | * | |
38 | * This function is used to scan the flattened device-tree, it is | |
39 | * used to extract the memory information at boot before we can | |
40 | * unflatten the tree | |
41 | */ | |
42 | int __init of_scan_flat_dt(int (*it)(unsigned long node, | |
43 | const char *uname, int depth, | |
44 | void *data), | |
45 | void *data) | |
46 | { | |
47 | unsigned long p = ((unsigned long)initial_boot_params) + | |
48 | initial_boot_params->off_dt_struct; | |
49 | int rc = 0; | |
50 | int depth = -1; | |
51 | ||
52 | do { | |
53 | u32 tag = *((u32 *)p); | |
54 | char *pathp; | |
55 | ||
56 | p += 4; | |
57 | if (tag == OF_DT_END_NODE) { | |
58 | depth--; | |
59 | continue; | |
60 | } | |
61 | if (tag == OF_DT_NOP) | |
62 | continue; | |
63 | if (tag == OF_DT_END) | |
64 | break; | |
65 | if (tag == OF_DT_PROP) { | |
66 | u32 sz = *((u32 *)p); | |
67 | p += 8; | |
68 | if (initial_boot_params->version < 0x10) | |
69 | p = _ALIGN(p, sz >= 8 ? 8 : 4); | |
70 | p += sz; | |
71 | p = _ALIGN(p, 4); | |
72 | continue; | |
73 | } | |
74 | if (tag != OF_DT_BEGIN_NODE) { | |
75 | pr_err("Invalid tag %x in flat device tree!\n", tag); | |
76 | return -EINVAL; | |
77 | } | |
78 | depth++; | |
79 | pathp = (char *)p; | |
80 | p = _ALIGN(p + strlen(pathp) + 1, 4); | |
81 | if ((*pathp) == '/') { | |
82 | char *lp, *np; | |
83 | for (lp = NULL, np = pathp; *np; np++) | |
84 | if ((*np) == '/') | |
85 | lp = np+1; | |
86 | if (lp != NULL) | |
87 | pathp = lp; | |
88 | } | |
89 | rc = it(p, pathp, depth, data); | |
90 | if (rc != 0) | |
91 | break; | |
92 | } while (1); | |
93 | ||
94 | return rc; | |
95 | } | |
819d2819 GL |
96 | |
97 | /** | |
98 | * of_get_flat_dt_root - find the root node in the flat blob | |
99 | */ | |
100 | unsigned long __init of_get_flat_dt_root(void) | |
101 | { | |
102 | unsigned long p = ((unsigned long)initial_boot_params) + | |
103 | initial_boot_params->off_dt_struct; | |
104 | ||
105 | while (*((u32 *)p) == OF_DT_NOP) | |
106 | p += 4; | |
107 | BUG_ON(*((u32 *)p) != OF_DT_BEGIN_NODE); | |
108 | p += 4; | |
109 | return _ALIGN(p + strlen((char *)p) + 1, 4); | |
110 | } | |
111 | ||
ca900cfa GL |
112 | /** |
113 | * of_get_flat_dt_prop - Given a node in the flat blob, return the property ptr | |
114 | * | |
115 | * This function can be used within scan_flattened_dt callback to get | |
116 | * access to properties | |
117 | */ | |
118 | void *__init of_get_flat_dt_prop(unsigned long node, const char *name, | |
119 | unsigned long *size) | |
120 | { | |
121 | unsigned long p = node; | |
122 | ||
123 | do { | |
124 | u32 tag = *((u32 *)p); | |
125 | u32 sz, noff; | |
126 | const char *nstr; | |
127 | ||
128 | p += 4; | |
129 | if (tag == OF_DT_NOP) | |
130 | continue; | |
131 | if (tag != OF_DT_PROP) | |
132 | return NULL; | |
133 | ||
134 | sz = *((u32 *)p); | |
135 | noff = *((u32 *)(p + 4)); | |
136 | p += 8; | |
137 | if (initial_boot_params->version < 0x10) | |
138 | p = _ALIGN(p, sz >= 8 ? 8 : 4); | |
139 | ||
140 | nstr = find_flat_dt_string(noff); | |
141 | if (nstr == NULL) { | |
142 | pr_warning("Can't find property index name !\n"); | |
143 | return NULL; | |
144 | } | |
145 | if (strcmp(name, nstr) == 0) { | |
146 | if (size) | |
147 | *size = sz; | |
148 | return (void *)p; | |
149 | } | |
150 | p += sz; | |
151 | p = _ALIGN(p, 4); | |
152 | } while (1); | |
153 | } | |
154 | ||
00e38efd GL |
155 | /** |
156 | * of_flat_dt_is_compatible - Return true if given node has compat in compatible list | |
157 | * @node: node to test | |
158 | * @compat: compatible string to compare with compatible list. | |
159 | */ | |
160 | int __init of_flat_dt_is_compatible(unsigned long node, const char *compat) | |
161 | { | |
162 | const char *cp; | |
163 | unsigned long cplen, l; | |
164 | ||
165 | cp = of_get_flat_dt_prop(node, "compatible", &cplen); | |
166 | if (cp == NULL) | |
167 | return 0; | |
168 | while (cplen > 0) { | |
169 | if (strncasecmp(cp, compat, strlen(compat)) == 0) | |
170 | return 1; | |
171 | l = strlen(cp) + 1; | |
172 | cp += l; | |
173 | cplen -= l; | |
174 | } | |
175 | ||
176 | return 0; | |
177 | } | |
178 | ||
bbd33931 GL |
179 | static void *__init unflatten_dt_alloc(unsigned long *mem, unsigned long size, |
180 | unsigned long align) | |
181 | { | |
182 | void *res; | |
183 | ||
184 | *mem = _ALIGN(*mem, align); | |
185 | res = (void *)*mem; | |
186 | *mem += size; | |
187 | ||
188 | return res; | |
189 | } | |
190 | ||
191 | /** | |
192 | * unflatten_dt_node - Alloc and populate a device_node from the flat tree | |
193 | * @p: pointer to node in flat tree | |
194 | * @dad: Parent struct device_node | |
195 | * @allnextpp: pointer to ->allnext from last allocated device_node | |
196 | * @fpsize: Size of the node path up at the current depth. | |
197 | */ | |
198 | unsigned long __init unflatten_dt_node(unsigned long mem, | |
199 | unsigned long *p, | |
200 | struct device_node *dad, | |
201 | struct device_node ***allnextpp, | |
202 | unsigned long fpsize) | |
203 | { | |
204 | struct device_node *np; | |
205 | struct property *pp, **prev_pp = NULL; | |
206 | char *pathp; | |
207 | u32 tag; | |
208 | unsigned int l, allocl; | |
209 | int has_name = 0; | |
210 | int new_format = 0; | |
211 | ||
212 | tag = *((u32 *)(*p)); | |
213 | if (tag != OF_DT_BEGIN_NODE) { | |
214 | pr_err("Weird tag at start of node: %x\n", tag); | |
215 | return mem; | |
216 | } | |
217 | *p += 4; | |
218 | pathp = (char *)*p; | |
219 | l = allocl = strlen(pathp) + 1; | |
220 | *p = _ALIGN(*p + l, 4); | |
221 | ||
222 | /* version 0x10 has a more compact unit name here instead of the full | |
223 | * path. we accumulate the full path size using "fpsize", we'll rebuild | |
224 | * it later. We detect this because the first character of the name is | |
225 | * not '/'. | |
226 | */ | |
227 | if ((*pathp) != '/') { | |
228 | new_format = 1; | |
229 | if (fpsize == 0) { | |
230 | /* root node: special case. fpsize accounts for path | |
231 | * plus terminating zero. root node only has '/', so | |
232 | * fpsize should be 2, but we want to avoid the first | |
233 | * level nodes to have two '/' so we use fpsize 1 here | |
234 | */ | |
235 | fpsize = 1; | |
236 | allocl = 2; | |
237 | } else { | |
238 | /* account for '/' and path size minus terminal 0 | |
239 | * already in 'l' | |
240 | */ | |
241 | fpsize += l; | |
242 | allocl = fpsize; | |
243 | } | |
244 | } | |
245 | ||
246 | np = unflatten_dt_alloc(&mem, sizeof(struct device_node) + allocl, | |
247 | __alignof__(struct device_node)); | |
248 | if (allnextpp) { | |
249 | memset(np, 0, sizeof(*np)); | |
250 | np->full_name = ((char *)np) + sizeof(struct device_node); | |
251 | if (new_format) { | |
252 | char *fn = np->full_name; | |
253 | /* rebuild full path for new format */ | |
254 | if (dad && dad->parent) { | |
255 | strcpy(fn, dad->full_name); | |
256 | #ifdef DEBUG | |
257 | if ((strlen(fn) + l + 1) != allocl) { | |
258 | pr_debug("%s: p: %d, l: %d, a: %d\n", | |
259 | pathp, (int)strlen(fn), | |
260 | l, allocl); | |
261 | } | |
262 | #endif | |
263 | fn += strlen(fn); | |
264 | } | |
265 | *(fn++) = '/'; | |
266 | memcpy(fn, pathp, l); | |
267 | } else | |
268 | memcpy(np->full_name, pathp, l); | |
269 | prev_pp = &np->properties; | |
270 | **allnextpp = np; | |
271 | *allnextpp = &np->allnext; | |
272 | if (dad != NULL) { | |
273 | np->parent = dad; | |
274 | /* we temporarily use the next field as `last_child'*/ | |
275 | if (dad->next == NULL) | |
276 | dad->child = np; | |
277 | else | |
278 | dad->next->sibling = np; | |
279 | dad->next = np; | |
280 | } | |
281 | kref_init(&np->kref); | |
282 | } | |
283 | while (1) { | |
284 | u32 sz, noff; | |
285 | char *pname; | |
286 | ||
287 | tag = *((u32 *)(*p)); | |
288 | if (tag == OF_DT_NOP) { | |
289 | *p += 4; | |
290 | continue; | |
291 | } | |
292 | if (tag != OF_DT_PROP) | |
293 | break; | |
294 | *p += 4; | |
295 | sz = *((u32 *)(*p)); | |
296 | noff = *((u32 *)((*p) + 4)); | |
297 | *p += 8; | |
298 | if (initial_boot_params->version < 0x10) | |
299 | *p = _ALIGN(*p, sz >= 8 ? 8 : 4); | |
300 | ||
301 | pname = find_flat_dt_string(noff); | |
302 | if (pname == NULL) { | |
303 | pr_info("Can't find property name in list !\n"); | |
304 | break; | |
305 | } | |
306 | if (strcmp(pname, "name") == 0) | |
307 | has_name = 1; | |
308 | l = strlen(pname) + 1; | |
309 | pp = unflatten_dt_alloc(&mem, sizeof(struct property), | |
310 | __alignof__(struct property)); | |
311 | if (allnextpp) { | |
312 | if (strcmp(pname, "linux,phandle") == 0) { | |
6016a363 GL |
313 | if (np->phandle == 0) |
314 | np->phandle = *((u32 *)*p); | |
bbd33931 GL |
315 | } |
316 | if (strcmp(pname, "ibm,phandle") == 0) | |
6016a363 | 317 | np->phandle = *((u32 *)*p); |
bbd33931 GL |
318 | pp->name = pname; |
319 | pp->length = sz; | |
320 | pp->value = (void *)*p; | |
321 | *prev_pp = pp; | |
322 | prev_pp = &pp->next; | |
323 | } | |
324 | *p = _ALIGN((*p) + sz, 4); | |
325 | } | |
326 | /* with version 0x10 we may not have the name property, recreate | |
327 | * it here from the unit name if absent | |
328 | */ | |
329 | if (!has_name) { | |
330 | char *p1 = pathp, *ps = pathp, *pa = NULL; | |
331 | int sz; | |
332 | ||
333 | while (*p1) { | |
334 | if ((*p1) == '@') | |
335 | pa = p1; | |
336 | if ((*p1) == '/') | |
337 | ps = p1 + 1; | |
338 | p1++; | |
339 | } | |
340 | if (pa < ps) | |
341 | pa = p1; | |
342 | sz = (pa - ps) + 1; | |
343 | pp = unflatten_dt_alloc(&mem, sizeof(struct property) + sz, | |
344 | __alignof__(struct property)); | |
345 | if (allnextpp) { | |
346 | pp->name = "name"; | |
347 | pp->length = sz; | |
348 | pp->value = pp + 1; | |
349 | *prev_pp = pp; | |
350 | prev_pp = &pp->next; | |
351 | memcpy(pp->value, ps, sz - 1); | |
352 | ((char *)pp->value)[sz - 1] = 0; | |
353 | pr_debug("fixed up name for %s -> %s\n", pathp, | |
354 | (char *)pp->value); | |
355 | } | |
356 | } | |
357 | if (allnextpp) { | |
358 | *prev_pp = NULL; | |
359 | np->name = of_get_property(np, "name", NULL); | |
360 | np->type = of_get_property(np, "device_type", NULL); | |
361 | ||
362 | if (!np->name) | |
363 | np->name = "<NULL>"; | |
364 | if (!np->type) | |
365 | np->type = "<NULL>"; | |
366 | } | |
367 | while (tag == OF_DT_BEGIN_NODE) { | |
368 | mem = unflatten_dt_node(mem, p, np, allnextpp, fpsize); | |
369 | tag = *((u32 *)(*p)); | |
370 | } | |
371 | if (tag != OF_DT_END_NODE) { | |
372 | pr_err("Weird tag at end of node: %x\n", tag); | |
373 | return mem; | |
374 | } | |
375 | *p += 4; | |
376 | return mem; | |
377 | } | |
41f88009 | 378 | |
f7b3a835 GL |
379 | #ifdef CONFIG_BLK_DEV_INITRD |
380 | /** | |
381 | * early_init_dt_check_for_initrd - Decode initrd location from flat tree | |
382 | * @node: reference to node containing initrd location ('chosen') | |
383 | */ | |
384 | void __init early_init_dt_check_for_initrd(unsigned long node) | |
385 | { | |
386 | unsigned long len; | |
387 | u32 *prop; | |
388 | ||
389 | pr_debug("Looking for initrd properties... "); | |
390 | ||
391 | prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len); | |
392 | if (prop) { | |
393 | initrd_start = (unsigned long) | |
394 | __va(of_read_ulong(prop, len/4)); | |
395 | ||
396 | prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len); | |
397 | if (prop) { | |
398 | initrd_end = (unsigned long) | |
399 | __va(of_read_ulong(prop, len/4)); | |
400 | initrd_below_start_ok = 1; | |
401 | } else { | |
402 | initrd_start = 0; | |
403 | } | |
404 | } | |
405 | ||
406 | pr_debug("initrd_start=0x%lx initrd_end=0x%lx\n", | |
407 | initrd_start, initrd_end); | |
408 | } | |
409 | #else | |
410 | inline void early_init_dt_check_for_initrd(unsigned long node) | |
411 | { | |
412 | } | |
413 | #endif /* CONFIG_BLK_DEV_INITRD */ | |
414 | ||
f00abd94 GL |
415 | /** |
416 | * early_init_dt_scan_root - fetch the top level address and size cells | |
417 | */ | |
418 | int __init early_init_dt_scan_root(unsigned long node, const char *uname, | |
419 | int depth, void *data) | |
420 | { | |
421 | u32 *prop; | |
422 | ||
423 | if (depth != 0) | |
424 | return 0; | |
425 | ||
426 | prop = of_get_flat_dt_prop(node, "#size-cells", NULL); | |
427 | dt_root_size_cells = (prop == NULL) ? 1 : *prop; | |
428 | pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells); | |
429 | ||
430 | prop = of_get_flat_dt_prop(node, "#address-cells", NULL); | |
431 | dt_root_addr_cells = (prop == NULL) ? 2 : *prop; | |
432 | pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells); | |
433 | ||
434 | /* break now */ | |
435 | return 1; | |
436 | } | |
437 | ||
83f7a06e GL |
438 | u64 __init dt_mem_next_cell(int s, u32 **cellp) |
439 | { | |
440 | u32 *p = *cellp; | |
441 | ||
442 | *cellp = p + s; | |
443 | return of_read_number(p, s); | |
444 | } | |
445 | ||
86e03221 GL |
446 | int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, |
447 | int depth, void *data) | |
448 | { | |
449 | unsigned long l; | |
450 | char *p; | |
451 | ||
452 | pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname); | |
453 | ||
454 | if (depth != 1 || | |
455 | (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0)) | |
456 | return 0; | |
457 | ||
458 | early_init_dt_check_for_initrd(node); | |
459 | ||
460 | /* Retreive command line */ | |
461 | p = of_get_flat_dt_prop(node, "bootargs", &l); | |
462 | if (p != NULL && l > 0) | |
463 | strlcpy(cmd_line, p, min((int)l, COMMAND_LINE_SIZE)); | |
464 | ||
465 | #ifdef CONFIG_CMDLINE | |
466 | #ifndef CONFIG_CMDLINE_FORCE | |
467 | if (p == NULL || l == 0 || (l == 1 && (*p) == 0)) | |
468 | #endif | |
469 | strlcpy(cmd_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE); | |
470 | #endif /* CONFIG_CMDLINE */ | |
471 | ||
472 | early_init_dt_scan_chosen_arch(node); | |
473 | ||
474 | pr_debug("Command line is: %s\n", cmd_line); | |
475 | ||
476 | /* break now */ | |
477 | return 1; | |
478 | } | |
479 | ||
41f88009 GL |
480 | /** |
481 | * unflatten_device_tree - create tree of device_nodes from flat blob | |
482 | * | |
483 | * unflattens the device-tree passed by the firmware, creating the | |
484 | * tree of struct device_node. It also fills the "name" and "type" | |
485 | * pointers of the nodes so the normal device-tree walking functions | |
486 | * can be used. | |
487 | */ | |
488 | void __init unflatten_device_tree(void) | |
489 | { | |
490 | unsigned long start, mem, size; | |
491 | struct device_node **allnextp = &allnodes; | |
492 | ||
493 | pr_debug(" -> unflatten_device_tree()\n"); | |
494 | ||
495 | /* First pass, scan for size */ | |
496 | start = ((unsigned long)initial_boot_params) + | |
497 | initial_boot_params->off_dt_struct; | |
498 | size = unflatten_dt_node(0, &start, NULL, NULL, 0); | |
499 | size = (size | 3) + 1; | |
500 | ||
501 | pr_debug(" size is %lx, allocating...\n", size); | |
502 | ||
503 | /* Allocate memory for the expanded device tree */ | |
504 | mem = lmb_alloc(size + 4, __alignof__(struct device_node)); | |
505 | mem = (unsigned long) __va(mem); | |
506 | ||
507 | ((u32 *)mem)[size / 4] = 0xdeadbeef; | |
508 | ||
509 | pr_debug(" unflattening %lx...\n", mem); | |
510 | ||
511 | /* Second pass, do actual unflattening */ | |
512 | start = ((unsigned long)initial_boot_params) + | |
513 | initial_boot_params->off_dt_struct; | |
514 | unflatten_dt_node(mem, &start, NULL, &allnextp, 0); | |
515 | if (*((u32 *)start) != OF_DT_END) | |
516 | pr_warning("Weird tag at end of tree: %08x\n", *((u32 *)start)); | |
517 | if (((u32 *)mem)[size / 4] != 0xdeadbeef) | |
518 | pr_warning("End of tree marker overwritten: %08x\n", | |
519 | ((u32 *)mem)[size / 4]); | |
520 | *allnextp = NULL; | |
521 | ||
522 | /* Get pointer to OF "/chosen" node for use everywhere */ | |
523 | of_chosen = of_find_node_by_path("/chosen"); | |
524 | if (of_chosen == NULL) | |
525 | of_chosen = of_find_node_by_path("/chosen@0"); | |
526 | ||
527 | pr_debug(" <- unflatten_device_tree()\n"); | |
528 | } |