xref: /linux/scripts/dtc/libfdt/fdt_rw.c (revision 1bdd44579a54f73b87aff21d3b53f0f4e20b679c)
1 /*
2  * libfdt - Flat Device Tree manipulation
3  * Copyright (C) 2006 David Gibson, IBM Corporation.
4  *
5  * libfdt is dual licensed: you can use it either under the terms of
6  * the GPL, or the BSD license, at your option.
7  *
8  *  a) This library is free software; you can redistribute it and/or
9  *     modify it under the terms of the GNU General Public License as
10  *     published by the Free Software Foundation; either version 2 of the
11  *     License, or (at your option) any later version.
12  *
13  *     This library is distributed in the hope that it will be useful,
14  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *     GNU General Public License for more details.
17  *
18  *     You should have received a copy of the GNU General Public
19  *     License along with this library; if not, write to the Free
20  *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
21  *     MA 02110-1301 USA
22  *
23  * Alternatively,
24  *
25  *  b) Redistribution and use in source and binary forms, with or
26  *     without modification, are permitted provided that the following
27  *     conditions are met:
28  *
29  *     1. Redistributions of source code must retain the above
30  *        copyright notice, this list of conditions and the following
31  *        disclaimer.
32  *     2. Redistributions in binary form must reproduce the above
33  *        copyright notice, this list of conditions and the following
34  *        disclaimer in the documentation and/or other materials
35  *        provided with the distribution.
36  *
37  *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
38  *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
39  *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
40  *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
41  *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
42  *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
43  *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
44  *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
45  *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
46  *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
47  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
48  *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
49  *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
50  */
51 #include "libfdt_env.h"
52 
53 #include <fdt.h>
54 #include <libfdt.h>
55 
56 #include "libfdt_internal.h"
57 
58 static int fdt_blocks_misordered_(const void *fdt,
59 				  int mem_rsv_size, int struct_size)
60 {
61 	return (fdt_off_mem_rsvmap(fdt) < FDT_ALIGN(sizeof(struct fdt_header), 8))
62 		|| (fdt_off_dt_struct(fdt) <
63 		    (fdt_off_mem_rsvmap(fdt) + mem_rsv_size))
64 		|| (fdt_off_dt_strings(fdt) <
65 		    (fdt_off_dt_struct(fdt) + struct_size))
66 		|| (fdt_totalsize(fdt) <
67 		    (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt)));
68 }
69 
70 static int fdt_rw_probe_(void *fdt)
71 {
72 	FDT_RO_PROBE(fdt);
73 
74 	if (fdt_version(fdt) < 17)
75 		return -FDT_ERR_BADVERSION;
76 	if (fdt_blocks_misordered_(fdt, sizeof(struct fdt_reserve_entry),
77 				   fdt_size_dt_struct(fdt)))
78 		return -FDT_ERR_BADLAYOUT;
79 	if (fdt_version(fdt) > 17)
80 		fdt_set_version(fdt, 17);
81 
82 	return 0;
83 }
84 
85 #define FDT_RW_PROBE(fdt) \
86 	{ \
87 		int err_; \
88 		if ((err_ = fdt_rw_probe_(fdt)) != 0) \
89 			return err_; \
90 	}
91 
92 static inline int fdt_data_size_(void *fdt)
93 {
94 	return fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
95 }
96 
97 static int fdt_splice_(void *fdt, void *splicepoint, int oldlen, int newlen)
98 {
99 	char *p = splicepoint;
100 	char *end = (char *)fdt + fdt_data_size_(fdt);
101 
102 	if (((p + oldlen) < p) || ((p + oldlen) > end))
103 		return -FDT_ERR_BADOFFSET;
104 	if ((p < (char *)fdt) || ((end - oldlen + newlen) < (char *)fdt))
105 		return -FDT_ERR_BADOFFSET;
106 	if ((end - oldlen + newlen) > ((char *)fdt + fdt_totalsize(fdt)))
107 		return -FDT_ERR_NOSPACE;
108 	memmove(p + newlen, p + oldlen, end - p - oldlen);
109 	return 0;
110 }
111 
112 static int fdt_splice_mem_rsv_(void *fdt, struct fdt_reserve_entry *p,
113 			       int oldn, int newn)
114 {
115 	int delta = (newn - oldn) * sizeof(*p);
116 	int err;
117 	err = fdt_splice_(fdt, p, oldn * sizeof(*p), newn * sizeof(*p));
118 	if (err)
119 		return err;
120 	fdt_set_off_dt_struct(fdt, fdt_off_dt_struct(fdt) + delta);
121 	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
122 	return 0;
123 }
124 
125 static int fdt_splice_struct_(void *fdt, void *p,
126 			      int oldlen, int newlen)
127 {
128 	int delta = newlen - oldlen;
129 	int err;
130 
131 	if ((err = fdt_splice_(fdt, p, oldlen, newlen)))
132 		return err;
133 
134 	fdt_set_size_dt_struct(fdt, fdt_size_dt_struct(fdt) + delta);
135 	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
136 	return 0;
137 }
138 
139 /* Must only be used to roll back in case of error */
140 static void fdt_del_last_string_(void *fdt, const char *s)
141 {
142 	int newlen = strlen(s) + 1;
143 
144 	fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) - newlen);
145 }
146 
147 static int fdt_splice_string_(void *fdt, int newlen)
148 {
149 	void *p = (char *)fdt
150 		+ fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
151 	int err;
152 
153 	if ((err = fdt_splice_(fdt, p, 0, newlen)))
154 		return err;
155 
156 	fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) + newlen);
157 	return 0;
158 }
159 
160 static int fdt_find_add_string_(void *fdt, const char *s, int *allocated)
161 {
162 	char *strtab = (char *)fdt + fdt_off_dt_strings(fdt);
163 	const char *p;
164 	char *new;
165 	int len = strlen(s) + 1;
166 	int err;
167 
168 	*allocated = 0;
169 
170 	p = fdt_find_string_(strtab, fdt_size_dt_strings(fdt), s);
171 	if (p)
172 		/* found it */
173 		return (p - strtab);
174 
175 	new = strtab + fdt_size_dt_strings(fdt);
176 	err = fdt_splice_string_(fdt, len);
177 	if (err)
178 		return err;
179 
180 	*allocated = 1;
181 
182 	memcpy(new, s, len);
183 	return (new - strtab);
184 }
185 
186 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size)
187 {
188 	struct fdt_reserve_entry *re;
189 	int err;
190 
191 	FDT_RW_PROBE(fdt);
192 
193 	re = fdt_mem_rsv_w_(fdt, fdt_num_mem_rsv(fdt));
194 	err = fdt_splice_mem_rsv_(fdt, re, 0, 1);
195 	if (err)
196 		return err;
197 
198 	re->address = cpu_to_fdt64(address);
199 	re->size = cpu_to_fdt64(size);
200 	return 0;
201 }
202 
203 int fdt_del_mem_rsv(void *fdt, int n)
204 {
205 	struct fdt_reserve_entry *re = fdt_mem_rsv_w_(fdt, n);
206 
207 	FDT_RW_PROBE(fdt);
208 
209 	if (n >= fdt_num_mem_rsv(fdt))
210 		return -FDT_ERR_NOTFOUND;
211 
212 	return fdt_splice_mem_rsv_(fdt, re, 1, 0);
213 }
214 
215 static int fdt_resize_property_(void *fdt, int nodeoffset, const char *name,
216 				int len, struct fdt_property **prop)
217 {
218 	int oldlen;
219 	int err;
220 
221 	*prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
222 	if (!*prop)
223 		return oldlen;
224 
225 	if ((err = fdt_splice_struct_(fdt, (*prop)->data, FDT_TAGALIGN(oldlen),
226 				      FDT_TAGALIGN(len))))
227 		return err;
228 
229 	(*prop)->len = cpu_to_fdt32(len);
230 	return 0;
231 }
232 
233 static int fdt_add_property_(void *fdt, int nodeoffset, const char *name,
234 			     int len, struct fdt_property **prop)
235 {
236 	int proplen;
237 	int nextoffset;
238 	int namestroff;
239 	int err;
240 	int allocated;
241 
242 	if ((nextoffset = fdt_check_node_offset_(fdt, nodeoffset)) < 0)
243 		return nextoffset;
244 
245 	namestroff = fdt_find_add_string_(fdt, name, &allocated);
246 	if (namestroff < 0)
247 		return namestroff;
248 
249 	*prop = fdt_offset_ptr_w_(fdt, nextoffset);
250 	proplen = sizeof(**prop) + FDT_TAGALIGN(len);
251 
252 	err = fdt_splice_struct_(fdt, *prop, 0, proplen);
253 	if (err) {
254 		if (allocated)
255 			fdt_del_last_string_(fdt, name);
256 		return err;
257 	}
258 
259 	(*prop)->tag = cpu_to_fdt32(FDT_PROP);
260 	(*prop)->nameoff = cpu_to_fdt32(namestroff);
261 	(*prop)->len = cpu_to_fdt32(len);
262 	return 0;
263 }
264 
265 int fdt_set_name(void *fdt, int nodeoffset, const char *name)
266 {
267 	char *namep;
268 	int oldlen, newlen;
269 	int err;
270 
271 	FDT_RW_PROBE(fdt);
272 
273 	namep = (char *)(uintptr_t)fdt_get_name(fdt, nodeoffset, &oldlen);
274 	if (!namep)
275 		return oldlen;
276 
277 	newlen = strlen(name);
278 
279 	err = fdt_splice_struct_(fdt, namep, FDT_TAGALIGN(oldlen+1),
280 				 FDT_TAGALIGN(newlen+1));
281 	if (err)
282 		return err;
283 
284 	memcpy(namep, name, newlen+1);
285 	return 0;
286 }
287 
288 int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name,
289 			    int len, void **prop_data)
290 {
291 	struct fdt_property *prop;
292 	int err;
293 
294 	FDT_RW_PROBE(fdt);
295 
296 	err = fdt_resize_property_(fdt, nodeoffset, name, len, &prop);
297 	if (err == -FDT_ERR_NOTFOUND)
298 		err = fdt_add_property_(fdt, nodeoffset, name, len, &prop);
299 	if (err)
300 		return err;
301 
302 	*prop_data = prop->data;
303 	return 0;
304 }
305 
306 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
307 		const void *val, int len)
308 {
309 	void *prop_data;
310 	int err;
311 
312 	err = fdt_setprop_placeholder(fdt, nodeoffset, name, len, &prop_data);
313 	if (err)
314 		return err;
315 
316 	if (len)
317 		memcpy(prop_data, val, len);
318 	return 0;
319 }
320 
321 int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
322 		   const void *val, int len)
323 {
324 	struct fdt_property *prop;
325 	int err, oldlen, newlen;
326 
327 	FDT_RW_PROBE(fdt);
328 
329 	prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
330 	if (prop) {
331 		newlen = len + oldlen;
332 		err = fdt_splice_struct_(fdt, prop->data,
333 					 FDT_TAGALIGN(oldlen),
334 					 FDT_TAGALIGN(newlen));
335 		if (err)
336 			return err;
337 		prop->len = cpu_to_fdt32(newlen);
338 		memcpy(prop->data + oldlen, val, len);
339 	} else {
340 		err = fdt_add_property_(fdt, nodeoffset, name, len, &prop);
341 		if (err)
342 			return err;
343 		memcpy(prop->data, val, len);
344 	}
345 	return 0;
346 }
347 
348 int fdt_delprop(void *fdt, int nodeoffset, const char *name)
349 {
350 	struct fdt_property *prop;
351 	int len, proplen;
352 
353 	FDT_RW_PROBE(fdt);
354 
355 	prop = fdt_get_property_w(fdt, nodeoffset, name, &len);
356 	if (!prop)
357 		return len;
358 
359 	proplen = sizeof(*prop) + FDT_TAGALIGN(len);
360 	return fdt_splice_struct_(fdt, prop, proplen, 0);
361 }
362 
363 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
364 			    const char *name, int namelen)
365 {
366 	struct fdt_node_header *nh;
367 	int offset, nextoffset;
368 	int nodelen;
369 	int err;
370 	uint32_t tag;
371 	fdt32_t *endtag;
372 
373 	FDT_RW_PROBE(fdt);
374 
375 	offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
376 	if (offset >= 0)
377 		return -FDT_ERR_EXISTS;
378 	else if (offset != -FDT_ERR_NOTFOUND)
379 		return offset;
380 
381 	/* Try to place the new node after the parent's properties */
382 	fdt_next_tag(fdt, parentoffset, &nextoffset); /* skip the BEGIN_NODE */
383 	do {
384 		offset = nextoffset;
385 		tag = fdt_next_tag(fdt, offset, &nextoffset);
386 	} while ((tag == FDT_PROP) || (tag == FDT_NOP));
387 
388 	nh = fdt_offset_ptr_w_(fdt, offset);
389 	nodelen = sizeof(*nh) + FDT_TAGALIGN(namelen+1) + FDT_TAGSIZE;
390 
391 	err = fdt_splice_struct_(fdt, nh, 0, nodelen);
392 	if (err)
393 		return err;
394 
395 	nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
396 	memset(nh->name, 0, FDT_TAGALIGN(namelen+1));
397 	memcpy(nh->name, name, namelen);
398 	endtag = (fdt32_t *)((char *)nh + nodelen - FDT_TAGSIZE);
399 	*endtag = cpu_to_fdt32(FDT_END_NODE);
400 
401 	return offset;
402 }
403 
404 int fdt_add_subnode(void *fdt, int parentoffset, const char *name)
405 {
406 	return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name));
407 }
408 
409 int fdt_del_node(void *fdt, int nodeoffset)
410 {
411 	int endoffset;
412 
413 	FDT_RW_PROBE(fdt);
414 
415 	endoffset = fdt_node_end_offset_(fdt, nodeoffset);
416 	if (endoffset < 0)
417 		return endoffset;
418 
419 	return fdt_splice_struct_(fdt, fdt_offset_ptr_w_(fdt, nodeoffset),
420 				  endoffset - nodeoffset, 0);
421 }
422 
423 static void fdt_packblocks_(const char *old, char *new,
424 			    int mem_rsv_size, int struct_size)
425 {
426 	int mem_rsv_off, struct_off, strings_off;
427 
428 	mem_rsv_off = FDT_ALIGN(sizeof(struct fdt_header), 8);
429 	struct_off = mem_rsv_off + mem_rsv_size;
430 	strings_off = struct_off + struct_size;
431 
432 	memmove(new + mem_rsv_off, old + fdt_off_mem_rsvmap(old), mem_rsv_size);
433 	fdt_set_off_mem_rsvmap(new, mem_rsv_off);
434 
435 	memmove(new + struct_off, old + fdt_off_dt_struct(old), struct_size);
436 	fdt_set_off_dt_struct(new, struct_off);
437 	fdt_set_size_dt_struct(new, struct_size);
438 
439 	memmove(new + strings_off, old + fdt_off_dt_strings(old),
440 		fdt_size_dt_strings(old));
441 	fdt_set_off_dt_strings(new, strings_off);
442 	fdt_set_size_dt_strings(new, fdt_size_dt_strings(old));
443 }
444 
445 int fdt_open_into(const void *fdt, void *buf, int bufsize)
446 {
447 	int err;
448 	int mem_rsv_size, struct_size;
449 	int newsize;
450 	const char *fdtstart = fdt;
451 	const char *fdtend = fdtstart + fdt_totalsize(fdt);
452 	char *tmp;
453 
454 	FDT_RO_PROBE(fdt);
455 
456 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
457 		* sizeof(struct fdt_reserve_entry);
458 
459 	if (fdt_version(fdt) >= 17) {
460 		struct_size = fdt_size_dt_struct(fdt);
461 	} else {
462 		struct_size = 0;
463 		while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END)
464 			;
465 		if (struct_size < 0)
466 			return struct_size;
467 	}
468 
469 	if (!fdt_blocks_misordered_(fdt, mem_rsv_size, struct_size)) {
470 		/* no further work necessary */
471 		err = fdt_move(fdt, buf, bufsize);
472 		if (err)
473 			return err;
474 		fdt_set_version(buf, 17);
475 		fdt_set_size_dt_struct(buf, struct_size);
476 		fdt_set_totalsize(buf, bufsize);
477 		return 0;
478 	}
479 
480 	/* Need to reorder */
481 	newsize = FDT_ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size
482 		+ struct_size + fdt_size_dt_strings(fdt);
483 
484 	if (bufsize < newsize)
485 		return -FDT_ERR_NOSPACE;
486 
487 	/* First attempt to build converted tree at beginning of buffer */
488 	tmp = buf;
489 	/* But if that overlaps with the old tree... */
490 	if (((tmp + newsize) > fdtstart) && (tmp < fdtend)) {
491 		/* Try right after the old tree instead */
492 		tmp = (char *)(uintptr_t)fdtend;
493 		if ((tmp + newsize) > ((char *)buf + bufsize))
494 			return -FDT_ERR_NOSPACE;
495 	}
496 
497 	fdt_packblocks_(fdt, tmp, mem_rsv_size, struct_size);
498 	memmove(buf, tmp, newsize);
499 
500 	fdt_set_magic(buf, FDT_MAGIC);
501 	fdt_set_totalsize(buf, bufsize);
502 	fdt_set_version(buf, 17);
503 	fdt_set_last_comp_version(buf, 16);
504 	fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt));
505 
506 	return 0;
507 }
508 
509 int fdt_pack(void *fdt)
510 {
511 	int mem_rsv_size;
512 
513 	FDT_RW_PROBE(fdt);
514 
515 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
516 		* sizeof(struct fdt_reserve_entry);
517 	fdt_packblocks_(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt));
518 	fdt_set_totalsize(fdt, fdt_data_size_(fdt));
519 
520 	return 0;
521 }
522