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