xref: /netbsd-src/sys/external/bsd/libfdt/dist/fdt_rw.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: fdt_rw.c,v 1.1.1.2 2017/06/08 15:53:12 skrll Exp $	*/
2 
3 /*
4  * libfdt - Flat Device Tree manipulation
5  * Copyright (C) 2006 David Gibson, IBM Corporation.
6  *
7  * libfdt is dual licensed: you can use it either under the terms of
8  * the GPL, or the BSD license, at your option.
9  *
10  *  a) This library is free software; you can redistribute it and/or
11  *     modify it under the terms of the GNU General Public License as
12  *     published by the Free Software Foundation; either version 2 of the
13  *     License, or (at your option) any later version.
14  *
15  *     This library is distributed in the hope that it will be useful,
16  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
17  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  *     GNU General Public License for more details.
19  *
20  *     You should have received a copy of the GNU General Public
21  *     License along with this library; if not, write to the Free
22  *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
23  *     MA 02110-1301 USA
24  *
25  * Alternatively,
26  *
27  *  b) Redistribution and use in source and binary forms, with or
28  *     without modification, are permitted provided that the following
29  *     conditions are met:
30  *
31  *     1. Redistributions of source code must retain the above
32  *        copyright notice, this list of conditions and the following
33  *        disclaimer.
34  *     2. Redistributions in binary form must reproduce the above
35  *        copyright notice, this list of conditions and the following
36  *        disclaimer in the documentation and/or other materials
37  *        provided with the distribution.
38  *
39  *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
40  *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
41  *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
42  *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
43  *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
44  *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45  *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46  *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47  *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
49  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
50  *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
51  *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
52  */
53 #include "libfdt_env.h"
54 
55 #include <fdt.h>
56 #include <libfdt.h>
57 
58 #include "libfdt_internal.h"
59 
60 static int _fdt_blocks_misordered(const void *fdt,
61 			      int mem_rsv_size, int struct_size)
62 {
63 	return (fdt_off_mem_rsvmap(fdt) < FDT_ALIGN(sizeof(struct fdt_header), 8))
64 		|| (fdt_off_dt_struct(fdt) <
65 		    (fdt_off_mem_rsvmap(fdt) + mem_rsv_size))
66 		|| (fdt_off_dt_strings(fdt) <
67 		    (fdt_off_dt_struct(fdt) + struct_size))
68 		|| (fdt_totalsize(fdt) <
69 		    (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt)));
70 }
71 
72 static int _fdt_rw_check_header(void *fdt)
73 {
74 	FDT_CHECK_HEADER(fdt);
75 
76 	if (fdt_version(fdt) < 17)
77 		return -FDT_ERR_BADVERSION;
78 	if (_fdt_blocks_misordered(fdt, sizeof(struct fdt_reserve_entry),
79 				   fdt_size_dt_struct(fdt)))
80 		return -FDT_ERR_BADLAYOUT;
81 	if (fdt_version(fdt) > 17)
82 		fdt_set_version(fdt, 17);
83 
84 	return 0;
85 }
86 
87 #define FDT_RW_CHECK_HEADER(fdt) \
88 	{ \
89 		int __err; \
90 		if ((__err = _fdt_rw_check_header(fdt)) != 0) \
91 			return __err; \
92 	}
93 
94 static inline int _fdt_data_size(void *fdt)
95 {
96 	return fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
97 }
98 
99 static int _fdt_splice(void *fdt, void *splicepoint, int oldlen, int newlen)
100 {
101 	char *p = splicepoint;
102 	char *end = (char *)fdt + _fdt_data_size(fdt);
103 
104 	if (((p + oldlen) < p) || ((p + oldlen) > end))
105 		return -FDT_ERR_BADOFFSET;
106 	if ((p < (char *)fdt) || ((end - oldlen + newlen) < (char *)fdt))
107 		return -FDT_ERR_BADOFFSET;
108 	if ((end - oldlen + newlen) > ((char *)fdt + fdt_totalsize(fdt)))
109 		return -FDT_ERR_NOSPACE;
110 	memmove(p + newlen, p + oldlen, end - p - oldlen);
111 	return 0;
112 }
113 
114 static int _fdt_splice_mem_rsv(void *fdt, struct fdt_reserve_entry *p,
115 			       int oldn, int newn)
116 {
117 	int delta = (newn - oldn) * sizeof(*p);
118 	int err;
119 	err = _fdt_splice(fdt, p, oldn * sizeof(*p), newn * sizeof(*p));
120 	if (err)
121 		return err;
122 	fdt_set_off_dt_struct(fdt, fdt_off_dt_struct(fdt) + delta);
123 	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
124 	return 0;
125 }
126 
127 static int _fdt_splice_struct(void *fdt, void *p,
128 			      int oldlen, int newlen)
129 {
130 	int delta = newlen - oldlen;
131 	int err;
132 
133 	if ((err = _fdt_splice(fdt, p, oldlen, newlen)))
134 		return err;
135 
136 	fdt_set_size_dt_struct(fdt, fdt_size_dt_struct(fdt) + delta);
137 	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
138 	return 0;
139 }
140 
141 static int _fdt_splice_string(void *fdt, int newlen)
142 {
143 	void *p = (char *)fdt
144 		+ fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
145 	int err;
146 
147 	if ((err = _fdt_splice(fdt, p, 0, newlen)))
148 		return err;
149 
150 	fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) + newlen);
151 	return 0;
152 }
153 
154 static int _fdt_find_add_string(void *fdt, const char *s)
155 {
156 	char *strtab = (char *)fdt + fdt_off_dt_strings(fdt);
157 	const char *p;
158 	char *new;
159 	int len = strlen(s) + 1;
160 	int err;
161 
162 	p = _fdt_find_string(strtab, fdt_size_dt_strings(fdt), s);
163 	if (p)
164 		/* found it */
165 		return (p - strtab);
166 
167 	new = strtab + fdt_size_dt_strings(fdt);
168 	err = _fdt_splice_string(fdt, len);
169 	if (err)
170 		return err;
171 
172 	memcpy(new, s, len);
173 	return (new - strtab);
174 }
175 
176 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size)
177 {
178 	struct fdt_reserve_entry *re;
179 	int err;
180 
181 	FDT_RW_CHECK_HEADER(fdt);
182 
183 	re = _fdt_mem_rsv_w(fdt, fdt_num_mem_rsv(fdt));
184 	err = _fdt_splice_mem_rsv(fdt, re, 0, 1);
185 	if (err)
186 		return err;
187 
188 	re->address = cpu_to_fdt64(address);
189 	re->size = cpu_to_fdt64(size);
190 	return 0;
191 }
192 
193 int fdt_del_mem_rsv(void *fdt, int n)
194 {
195 	struct fdt_reserve_entry *re = _fdt_mem_rsv_w(fdt, n);
196 
197 	FDT_RW_CHECK_HEADER(fdt);
198 
199 	if (n >= fdt_num_mem_rsv(fdt))
200 		return -FDT_ERR_NOTFOUND;
201 
202 	return _fdt_splice_mem_rsv(fdt, re, 1, 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 	if (len)
289 		memcpy(prop->data, val, len);
290 	return 0;
291 }
292 
293 int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
294 		   const void *val, int len)
295 {
296 	struct fdt_property *prop;
297 	int err, oldlen, newlen;
298 
299 	FDT_RW_CHECK_HEADER(fdt);
300 
301 	prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
302 	if (prop) {
303 		newlen = len + oldlen;
304 		err = _fdt_splice_struct(fdt, prop->data,
305 					 FDT_TAGALIGN(oldlen),
306 					 FDT_TAGALIGN(newlen));
307 		if (err)
308 			return err;
309 		prop->len = cpu_to_fdt32(newlen);
310 		memcpy(prop->data + oldlen, val, len);
311 	} else {
312 		err = _fdt_add_property(fdt, nodeoffset, name, len, &prop);
313 		if (err)
314 			return err;
315 		memcpy(prop->data, val, len);
316 	}
317 	return 0;
318 }
319 
320 int fdt_delprop(void *fdt, int nodeoffset, const char *name)
321 {
322 	struct fdt_property *prop;
323 	int len, proplen;
324 
325 	FDT_RW_CHECK_HEADER(fdt);
326 
327 	prop = fdt_get_property_w(fdt, nodeoffset, name, &len);
328 	if (! prop)
329 		return len;
330 
331 	proplen = sizeof(*prop) + FDT_TAGALIGN(len);
332 	return _fdt_splice_struct(fdt, prop, proplen, 0);
333 }
334 
335 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
336 			    const char *name, int namelen)
337 {
338 	struct fdt_node_header *nh;
339 	int offset, nextoffset;
340 	int nodelen;
341 	int err;
342 	uint32_t tag;
343 	fdt32_t *endtag;
344 
345 	FDT_RW_CHECK_HEADER(fdt);
346 
347 	offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
348 	if (offset >= 0)
349 		return -FDT_ERR_EXISTS;
350 	else if (offset != -FDT_ERR_NOTFOUND)
351 		return offset;
352 
353 	/* Try to place the new node after the parent's properties */
354 	fdt_next_tag(fdt, parentoffset, &nextoffset); /* skip the BEGIN_NODE */
355 	do {
356 		offset = nextoffset;
357 		tag = fdt_next_tag(fdt, offset, &nextoffset);
358 	} while ((tag == FDT_PROP) || (tag == FDT_NOP));
359 
360 	nh = _fdt_offset_ptr_w(fdt, offset);
361 	nodelen = sizeof(*nh) + FDT_TAGALIGN(namelen+1) + FDT_TAGSIZE;
362 
363 	err = _fdt_splice_struct(fdt, nh, 0, nodelen);
364 	if (err)
365 		return err;
366 
367 	nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
368 	memset(nh->name, 0, FDT_TAGALIGN(namelen+1));
369 	memcpy(nh->name, name, namelen);
370 	endtag = (fdt32_t *)((char *)nh + nodelen - FDT_TAGSIZE);
371 	*endtag = cpu_to_fdt32(FDT_END_NODE);
372 
373 	return offset;
374 }
375 
376 int fdt_add_subnode(void *fdt, int parentoffset, const char *name)
377 {
378 	return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name));
379 }
380 
381 int fdt_del_node(void *fdt, int nodeoffset)
382 {
383 	int endoffset;
384 
385 	FDT_RW_CHECK_HEADER(fdt);
386 
387 	endoffset = _fdt_node_end_offset(fdt, nodeoffset);
388 	if (endoffset < 0)
389 		return endoffset;
390 
391 	return _fdt_splice_struct(fdt, _fdt_offset_ptr_w(fdt, nodeoffset),
392 				  endoffset - nodeoffset, 0);
393 }
394 
395 static void _fdt_packblocks(const char *old, char *new,
396 			    int mem_rsv_size, int struct_size)
397 {
398 	int mem_rsv_off, struct_off, strings_off;
399 
400 	mem_rsv_off = FDT_ALIGN(sizeof(struct fdt_header), 8);
401 	struct_off = mem_rsv_off + mem_rsv_size;
402 	strings_off = struct_off + struct_size;
403 
404 	memmove(new + mem_rsv_off, old + fdt_off_mem_rsvmap(old), mem_rsv_size);
405 	fdt_set_off_mem_rsvmap(new, mem_rsv_off);
406 
407 	memmove(new + struct_off, old + fdt_off_dt_struct(old), struct_size);
408 	fdt_set_off_dt_struct(new, struct_off);
409 	fdt_set_size_dt_struct(new, struct_size);
410 
411 	memmove(new + strings_off, old + fdt_off_dt_strings(old),
412 		fdt_size_dt_strings(old));
413 	fdt_set_off_dt_strings(new, strings_off);
414 	fdt_set_size_dt_strings(new, fdt_size_dt_strings(old));
415 }
416 
417 int fdt_open_into(const void *fdt, void *buf, int bufsize)
418 {
419 	int err;
420 	int mem_rsv_size, struct_size;
421 	int newsize;
422 	const char *fdtstart = fdt;
423 	const char *fdtend = fdtstart + fdt_totalsize(fdt);
424 	char *tmp;
425 
426 	FDT_CHECK_HEADER(fdt);
427 
428 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
429 		* sizeof(struct fdt_reserve_entry);
430 
431 	if (fdt_version(fdt) >= 17) {
432 		struct_size = fdt_size_dt_struct(fdt);
433 	} else {
434 		struct_size = 0;
435 		while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END)
436 			;
437 		if (struct_size < 0)
438 			return struct_size;
439 	}
440 
441 	if (!_fdt_blocks_misordered(fdt, mem_rsv_size, struct_size)) {
442 		/* no further work necessary */
443 		err = fdt_move(fdt, buf, bufsize);
444 		if (err)
445 			return err;
446 		fdt_set_version(buf, 17);
447 		fdt_set_size_dt_struct(buf, struct_size);
448 		fdt_set_totalsize(buf, bufsize);
449 		return 0;
450 	}
451 
452 	/* Need to reorder */
453 	newsize = FDT_ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size
454 		+ struct_size + fdt_size_dt_strings(fdt);
455 
456 	if (bufsize < newsize)
457 		return -FDT_ERR_NOSPACE;
458 
459 	/* First attempt to build converted tree at beginning of buffer */
460 	tmp = buf;
461 	/* But if that overlaps with the old tree... */
462 	if (((tmp + newsize) > fdtstart) && (tmp < fdtend)) {
463 		/* Try right after the old tree instead */
464 		tmp = (char *)(uintptr_t)fdtend;
465 		if ((tmp + newsize) > ((char *)buf + bufsize))
466 			return -FDT_ERR_NOSPACE;
467 	}
468 
469 	_fdt_packblocks(fdt, tmp, mem_rsv_size, struct_size);
470 	memmove(buf, tmp, newsize);
471 
472 	fdt_set_magic(buf, FDT_MAGIC);
473 	fdt_set_totalsize(buf, bufsize);
474 	fdt_set_version(buf, 17);
475 	fdt_set_last_comp_version(buf, 16);
476 	fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt));
477 
478 	return 0;
479 }
480 
481 int fdt_pack(void *fdt)
482 {
483 	int mem_rsv_size;
484 
485 	FDT_RW_CHECK_HEADER(fdt);
486 
487 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
488 		* sizeof(struct fdt_reserve_entry);
489 	_fdt_packblocks(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt));
490 	fdt_set_totalsize(fdt, _fdt_data_size(fdt));
491 
492 	return 0;
493 }
494