xref: /openbmc/linux/scripts/dtc/libfdt/fdt_rw.c (revision 8c749ce9)
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_check_header(void *fdt)
71 {
72 	FDT_CHECK_HEADER(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_CHECK_HEADER(fdt) \
86 	{ \
87 		int __err; \
88 		if ((__err = _fdt_rw_check_header(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 ((end - oldlen + newlen) > ((char *)fdt + fdt_totalsize(fdt)))
105 		return -FDT_ERR_NOSPACE;
106 	memmove(p + newlen, p + oldlen, end - p - oldlen);
107 	return 0;
108 }
109 
110 static int _fdt_splice_mem_rsv(void *fdt, struct fdt_reserve_entry *p,
111 			       int oldn, int newn)
112 {
113 	int delta = (newn - oldn) * sizeof(*p);
114 	int err;
115 	err = _fdt_splice(fdt, p, oldn * sizeof(*p), newn * sizeof(*p));
116 	if (err)
117 		return err;
118 	fdt_set_off_dt_struct(fdt, fdt_off_dt_struct(fdt) + delta);
119 	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
120 	return 0;
121 }
122 
123 static int _fdt_splice_struct(void *fdt, void *p,
124 			      int oldlen, int newlen)
125 {
126 	int delta = newlen - oldlen;
127 	int err;
128 
129 	if ((err = _fdt_splice(fdt, p, oldlen, newlen)))
130 		return err;
131 
132 	fdt_set_size_dt_struct(fdt, fdt_size_dt_struct(fdt) + delta);
133 	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
134 	return 0;
135 }
136 
137 static int _fdt_splice_string(void *fdt, int newlen)
138 {
139 	void *p = (char *)fdt
140 		+ fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
141 	int err;
142 
143 	if ((err = _fdt_splice(fdt, p, 0, newlen)))
144 		return err;
145 
146 	fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) + newlen);
147 	return 0;
148 }
149 
150 static int _fdt_find_add_string(void *fdt, const char *s)
151 {
152 	char *strtab = (char *)fdt + fdt_off_dt_strings(fdt);
153 	const char *p;
154 	char *new;
155 	int len = strlen(s) + 1;
156 	int err;
157 
158 	p = _fdt_find_string(strtab, fdt_size_dt_strings(fdt), s);
159 	if (p)
160 		/* found it */
161 		return (p - strtab);
162 
163 	new = strtab + fdt_size_dt_strings(fdt);
164 	err = _fdt_splice_string(fdt, len);
165 	if (err)
166 		return err;
167 
168 	memcpy(new, s, len);
169 	return (new - strtab);
170 }
171 
172 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size)
173 {
174 	struct fdt_reserve_entry *re;
175 	int err;
176 
177 	FDT_RW_CHECK_HEADER(fdt);
178 
179 	re = _fdt_mem_rsv_w(fdt, fdt_num_mem_rsv(fdt));
180 	err = _fdt_splice_mem_rsv(fdt, re, 0, 1);
181 	if (err)
182 		return err;
183 
184 	re->address = cpu_to_fdt64(address);
185 	re->size = cpu_to_fdt64(size);
186 	return 0;
187 }
188 
189 int fdt_del_mem_rsv(void *fdt, int n)
190 {
191 	struct fdt_reserve_entry *re = _fdt_mem_rsv_w(fdt, n);
192 	int err;
193 
194 	FDT_RW_CHECK_HEADER(fdt);
195 
196 	if (n >= fdt_num_mem_rsv(fdt))
197 		return -FDT_ERR_NOTFOUND;
198 
199 	err = _fdt_splice_mem_rsv(fdt, re, 1, 0);
200 	if (err)
201 		return err;
202 	return 0;
203 }
204 
205 static int _fdt_resize_property(void *fdt, int nodeoffset, const char *name,
206 				int len, struct fdt_property **prop)
207 {
208 	int oldlen;
209 	int err;
210 
211 	*prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
212 	if (! (*prop))
213 		return oldlen;
214 
215 	if ((err = _fdt_splice_struct(fdt, (*prop)->data, FDT_TAGALIGN(oldlen),
216 				      FDT_TAGALIGN(len))))
217 		return err;
218 
219 	(*prop)->len = cpu_to_fdt32(len);
220 	return 0;
221 }
222 
223 static int _fdt_add_property(void *fdt, int nodeoffset, const char *name,
224 			     int len, struct fdt_property **prop)
225 {
226 	int proplen;
227 	int nextoffset;
228 	int namestroff;
229 	int err;
230 
231 	if ((nextoffset = _fdt_check_node_offset(fdt, nodeoffset)) < 0)
232 		return nextoffset;
233 
234 	namestroff = _fdt_find_add_string(fdt, name);
235 	if (namestroff < 0)
236 		return namestroff;
237 
238 	*prop = _fdt_offset_ptr_w(fdt, nextoffset);
239 	proplen = sizeof(**prop) + FDT_TAGALIGN(len);
240 
241 	err = _fdt_splice_struct(fdt, *prop, 0, proplen);
242 	if (err)
243 		return err;
244 
245 	(*prop)->tag = cpu_to_fdt32(FDT_PROP);
246 	(*prop)->nameoff = cpu_to_fdt32(namestroff);
247 	(*prop)->len = cpu_to_fdt32(len);
248 	return 0;
249 }
250 
251 int fdt_set_name(void *fdt, int nodeoffset, const char *name)
252 {
253 	char *namep;
254 	int oldlen, newlen;
255 	int err;
256 
257 	FDT_RW_CHECK_HEADER(fdt);
258 
259 	namep = (char *)(uintptr_t)fdt_get_name(fdt, nodeoffset, &oldlen);
260 	if (!namep)
261 		return oldlen;
262 
263 	newlen = strlen(name);
264 
265 	err = _fdt_splice_struct(fdt, namep, FDT_TAGALIGN(oldlen+1),
266 				 FDT_TAGALIGN(newlen+1));
267 	if (err)
268 		return err;
269 
270 	memcpy(namep, name, newlen+1);
271 	return 0;
272 }
273 
274 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
275 		const void *val, int len)
276 {
277 	struct fdt_property *prop;
278 	int err;
279 
280 	FDT_RW_CHECK_HEADER(fdt);
281 
282 	err = _fdt_resize_property(fdt, nodeoffset, name, len, &prop);
283 	if (err == -FDT_ERR_NOTFOUND)
284 		err = _fdt_add_property(fdt, nodeoffset, name, len, &prop);
285 	if (err)
286 		return err;
287 
288 	memcpy(prop->data, val, len);
289 	return 0;
290 }
291 
292 int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
293 		   const void *val, int len)
294 {
295 	struct fdt_property *prop;
296 	int err, oldlen, newlen;
297 
298 	FDT_RW_CHECK_HEADER(fdt);
299 
300 	prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
301 	if (prop) {
302 		newlen = len + oldlen;
303 		err = _fdt_splice_struct(fdt, prop->data,
304 					 FDT_TAGALIGN(oldlen),
305 					 FDT_TAGALIGN(newlen));
306 		if (err)
307 			return err;
308 		prop->len = cpu_to_fdt32(newlen);
309 		memcpy(prop->data + oldlen, val, len);
310 	} else {
311 		err = _fdt_add_property(fdt, nodeoffset, name, len, &prop);
312 		if (err)
313 			return err;
314 		memcpy(prop->data, val, len);
315 	}
316 	return 0;
317 }
318 
319 int fdt_delprop(void *fdt, int nodeoffset, const char *name)
320 {
321 	struct fdt_property *prop;
322 	int len, proplen;
323 
324 	FDT_RW_CHECK_HEADER(fdt);
325 
326 	prop = fdt_get_property_w(fdt, nodeoffset, name, &len);
327 	if (! prop)
328 		return len;
329 
330 	proplen = sizeof(*prop) + FDT_TAGALIGN(len);
331 	return _fdt_splice_struct(fdt, prop, proplen, 0);
332 }
333 
334 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
335 			    const char *name, int namelen)
336 {
337 	struct fdt_node_header *nh;
338 	int offset, nextoffset;
339 	int nodelen;
340 	int err;
341 	uint32_t tag;
342 	fdt32_t *endtag;
343 
344 	FDT_RW_CHECK_HEADER(fdt);
345 
346 	offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
347 	if (offset >= 0)
348 		return -FDT_ERR_EXISTS;
349 	else if (offset != -FDT_ERR_NOTFOUND)
350 		return offset;
351 
352 	/* Try to place the new node after the parent's properties */
353 	fdt_next_tag(fdt, parentoffset, &nextoffset); /* skip the BEGIN_NODE */
354 	do {
355 		offset = nextoffset;
356 		tag = fdt_next_tag(fdt, offset, &nextoffset);
357 	} while ((tag == FDT_PROP) || (tag == FDT_NOP));
358 
359 	nh = _fdt_offset_ptr_w(fdt, offset);
360 	nodelen = sizeof(*nh) + FDT_TAGALIGN(namelen+1) + FDT_TAGSIZE;
361 
362 	err = _fdt_splice_struct(fdt, nh, 0, nodelen);
363 	if (err)
364 		return err;
365 
366 	nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
367 	memset(nh->name, 0, FDT_TAGALIGN(namelen+1));
368 	memcpy(nh->name, name, namelen);
369 	endtag = (fdt32_t *)((char *)nh + nodelen - FDT_TAGSIZE);
370 	*endtag = cpu_to_fdt32(FDT_END_NODE);
371 
372 	return offset;
373 }
374 
375 int fdt_add_subnode(void *fdt, int parentoffset, const char *name)
376 {
377 	return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name));
378 }
379 
380 int fdt_del_node(void *fdt, int nodeoffset)
381 {
382 	int endoffset;
383 
384 	FDT_RW_CHECK_HEADER(fdt);
385 
386 	endoffset = _fdt_node_end_offset(fdt, nodeoffset);
387 	if (endoffset < 0)
388 		return endoffset;
389 
390 	return _fdt_splice_struct(fdt, _fdt_offset_ptr_w(fdt, nodeoffset),
391 				  endoffset - nodeoffset, 0);
392 }
393 
394 static void _fdt_packblocks(const char *old, char *new,
395 			    int mem_rsv_size, int struct_size)
396 {
397 	int mem_rsv_off, struct_off, strings_off;
398 
399 	mem_rsv_off = FDT_ALIGN(sizeof(struct fdt_header), 8);
400 	struct_off = mem_rsv_off + mem_rsv_size;
401 	strings_off = struct_off + struct_size;
402 
403 	memmove(new + mem_rsv_off, old + fdt_off_mem_rsvmap(old), mem_rsv_size);
404 	fdt_set_off_mem_rsvmap(new, mem_rsv_off);
405 
406 	memmove(new + struct_off, old + fdt_off_dt_struct(old), struct_size);
407 	fdt_set_off_dt_struct(new, struct_off);
408 	fdt_set_size_dt_struct(new, struct_size);
409 
410 	memmove(new + strings_off, old + fdt_off_dt_strings(old),
411 		fdt_size_dt_strings(old));
412 	fdt_set_off_dt_strings(new, strings_off);
413 	fdt_set_size_dt_strings(new, fdt_size_dt_strings(old));
414 }
415 
416 int fdt_open_into(const void *fdt, void *buf, int bufsize)
417 {
418 	int err;
419 	int mem_rsv_size, struct_size;
420 	int newsize;
421 	const char *fdtstart = fdt;
422 	const char *fdtend = fdtstart + fdt_totalsize(fdt);
423 	char *tmp;
424 
425 	FDT_CHECK_HEADER(fdt);
426 
427 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
428 		* sizeof(struct fdt_reserve_entry);
429 
430 	if (fdt_version(fdt) >= 17) {
431 		struct_size = fdt_size_dt_struct(fdt);
432 	} else {
433 		struct_size = 0;
434 		while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END)
435 			;
436 		if (struct_size < 0)
437 			return struct_size;
438 	}
439 
440 	if (!_fdt_blocks_misordered(fdt, mem_rsv_size, struct_size)) {
441 		/* no further work necessary */
442 		err = fdt_move(fdt, buf, bufsize);
443 		if (err)
444 			return err;
445 		fdt_set_version(buf, 17);
446 		fdt_set_size_dt_struct(buf, struct_size);
447 		fdt_set_totalsize(buf, bufsize);
448 		return 0;
449 	}
450 
451 	/* Need to reorder */
452 	newsize = FDT_ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size
453 		+ struct_size + fdt_size_dt_strings(fdt);
454 
455 	if (bufsize < newsize)
456 		return -FDT_ERR_NOSPACE;
457 
458 	/* First attempt to build converted tree at beginning of buffer */
459 	tmp = buf;
460 	/* But if that overlaps with the old tree... */
461 	if (((tmp + newsize) > fdtstart) && (tmp < fdtend)) {
462 		/* Try right after the old tree instead */
463 		tmp = (char *)(uintptr_t)fdtend;
464 		if ((tmp + newsize) > ((char *)buf + bufsize))
465 			return -FDT_ERR_NOSPACE;
466 	}
467 
468 	_fdt_packblocks(fdt, tmp, mem_rsv_size, struct_size);
469 	memmove(buf, tmp, newsize);
470 
471 	fdt_set_magic(buf, FDT_MAGIC);
472 	fdt_set_totalsize(buf, bufsize);
473 	fdt_set_version(buf, 17);
474 	fdt_set_last_comp_version(buf, 16);
475 	fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt));
476 
477 	return 0;
478 }
479 
480 int fdt_pack(void *fdt)
481 {
482 	int mem_rsv_size;
483 
484 	FDT_RW_CHECK_HEADER(fdt);
485 
486 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
487 		* sizeof(struct fdt_reserve_entry);
488 	_fdt_packblocks(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt));
489 	fdt_set_totalsize(fdt, _fdt_data_size(fdt));
490 
491 	return 0;
492 }
493