xref: /optee_os/core/lib/libfdt/fdt_rw.c (revision 817466cb476de705a8e3dabe1ef165fe27a18c2f)
1 // SPDX-License-Identifier: (BSD-2-Clause OR GPL-2.0+)
2 /*
3  * libfdt - Flat Device Tree manipulation
4  * Copyright (C) 2006 David Gibson, IBM Corporation.
5  *
6  * libfdt is dual licensed: you can use it either under the terms of
7  * the GPL, or the BSD license, at your option.
8  *
9  *  a) This library is free software; you can redistribute it and/or
10  *     modify it under the terms of the GNU General Public License as
11  *     published by the Free Software Foundation; either version 2 of the
12  *     License, or (at your option) any later version.
13  *
14  *     This library is distributed in the hope that it will be useful,
15  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
16  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  *     GNU General Public License for more details.
18  *
19  *     You should have received a copy of the GNU General Public
20  *     License along with this library; if not, write to the Free
21  *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
22  *     MA 02110-1301 USA
23  *
24  * Alternatively,
25  *
26  *  b) Redistribution and use in source and binary forms, with or
27  *     without modification, are permitted provided that the following
28  *     conditions are met:
29  *
30  *     1. Redistributions of source code must retain the above
31  *        copyright notice, this list of conditions and the following
32  *        disclaimer.
33  *     2. Redistributions in binary form must reproduce the above
34  *        copyright notice, this list of conditions and the following
35  *        disclaimer in the documentation and/or other materials
36  *        provided with the distribution.
37  *
38  *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
39  *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
40  *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
41  *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
42  *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
43  *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44  *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45  *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46  *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
48  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
49  *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
50  *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
51  */
52 #include "libfdt_env.h"
53 
54 #include <fdt.h>
55 #include <libfdt.h>
56 
57 #include "libfdt_internal.h"
58 
59 static int _fdt_blocks_misordered(const void *fdt,
60 			      int mem_rsv_size, int struct_size)
61 {
62 	return (fdt_off_mem_rsvmap(fdt) < FDT_ALIGN(sizeof(struct fdt_header), 8))
63 		|| (fdt_off_dt_struct(fdt) <
64 		    (fdt_off_mem_rsvmap(fdt) + mem_rsv_size))
65 		|| (fdt_off_dt_strings(fdt) <
66 		    (fdt_off_dt_struct(fdt) + struct_size))
67 		|| (fdt_totalsize(fdt) <
68 		    (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt)));
69 }
70 
71 static int _fdt_rw_check_header(void *fdt)
72 {
73 	FDT_CHECK_HEADER(fdt);
74 
75 	if (fdt_version(fdt) < 17)
76 		return -FDT_ERR_BADVERSION;
77 	if (_fdt_blocks_misordered(fdt, sizeof(struct fdt_reserve_entry),
78 				   fdt_size_dt_struct(fdt)))
79 		return -FDT_ERR_BADLAYOUT;
80 	if (fdt_version(fdt) > 17)
81 		fdt_set_version(fdt, 17);
82 
83 	return 0;
84 }
85 
86 #define FDT_RW_CHECK_HEADER(fdt) \
87 	{ \
88 		int __err; \
89 		if ((__err = _fdt_rw_check_header(fdt)) != 0) \
90 			return __err; \
91 	}
92 
93 static inline int _fdt_data_size(void *fdt)
94 {
95 	return fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
96 }
97 
98 static int _fdt_splice(void *fdt, void *splicepoint, int oldlen, int newlen)
99 {
100 	char *p = splicepoint;
101 	char *end = (char *)fdt + _fdt_data_size(fdt);
102 
103 	if (((p + oldlen) < p) || ((p + oldlen) > end))
104 		return -FDT_ERR_BADOFFSET;
105 	if ((end - oldlen + newlen) > ((char *)fdt + fdt_totalsize(fdt)))
106 		return -FDT_ERR_NOSPACE;
107 	memmove(p + newlen, p + oldlen, end - p - oldlen);
108 	return 0;
109 }
110 
111 static int _fdt_splice_mem_rsv(void *fdt, struct fdt_reserve_entry *p,
112 			       int oldn, int newn)
113 {
114 	int delta = (newn - oldn) * sizeof(*p);
115 	int err;
116 	err = _fdt_splice(fdt, p, oldn * sizeof(*p), newn * sizeof(*p));
117 	if (err)
118 		return err;
119 	fdt_set_off_dt_struct(fdt, fdt_off_dt_struct(fdt) + delta);
120 	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
121 	return 0;
122 }
123 
124 static int _fdt_splice_struct(void *fdt, void *p,
125 			      int oldlen, int newlen)
126 {
127 	int delta = newlen - oldlen;
128 	int err;
129 
130 	if ((err = _fdt_splice(fdt, p, oldlen, newlen)))
131 		return err;
132 
133 	fdt_set_size_dt_struct(fdt, fdt_size_dt_struct(fdt) + delta);
134 	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
135 	return 0;
136 }
137 
138 static int _fdt_splice_string(void *fdt, int newlen)
139 {
140 	void *p = (char *)fdt
141 		+ fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
142 	int err;
143 
144 	if ((err = _fdt_splice(fdt, p, 0, newlen)))
145 		return err;
146 
147 	fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) + newlen);
148 	return 0;
149 }
150 
151 static int _fdt_find_add_string(void *fdt, const char *s)
152 {
153 	char *strtab = (char *)fdt + fdt_off_dt_strings(fdt);
154 	const char *p;
155 	char *new;
156 	int len = strlen(s) + 1;
157 	int err;
158 
159 	p = _fdt_find_string(strtab, fdt_size_dt_strings(fdt), s);
160 	if (p)
161 		/* found it */
162 		return (p - strtab);
163 
164 	new = strtab + fdt_size_dt_strings(fdt);
165 	err = _fdt_splice_string(fdt, len);
166 	if (err)
167 		return err;
168 
169 	memcpy(new, s, len);
170 	return (new - strtab);
171 }
172 
173 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size)
174 {
175 	struct fdt_reserve_entry *re;
176 	int err;
177 
178 	FDT_RW_CHECK_HEADER(fdt);
179 
180 	re = _fdt_mem_rsv_w(fdt, fdt_num_mem_rsv(fdt));
181 	err = _fdt_splice_mem_rsv(fdt, re, 0, 1);
182 	if (err)
183 		return err;
184 
185 	re->address = cpu_to_fdt64(address);
186 	re->size = cpu_to_fdt64(size);
187 	return 0;
188 }
189 
190 int fdt_del_mem_rsv(void *fdt, int n)
191 {
192 	struct fdt_reserve_entry *re = _fdt_mem_rsv_w(fdt, n);
193 	int err;
194 
195 	FDT_RW_CHECK_HEADER(fdt);
196 
197 	if (n >= fdt_num_mem_rsv(fdt))
198 		return -FDT_ERR_NOTFOUND;
199 
200 	err = _fdt_splice_mem_rsv(fdt, re, 1, 0);
201 	if (err)
202 		return err;
203 	return 0;
204 }
205 
206 static int _fdt_resize_property(void *fdt, int nodeoffset, const char *name,
207 				int len, struct fdt_property **prop)
208 {
209 	int oldlen;
210 	int err;
211 
212 	*prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
213 	if (! (*prop))
214 		return oldlen;
215 
216 	if ((err = _fdt_splice_struct(fdt, (*prop)->data, FDT_TAGALIGN(oldlen),
217 				      FDT_TAGALIGN(len))))
218 		return err;
219 
220 	(*prop)->len = cpu_to_fdt32(len);
221 	return 0;
222 }
223 
224 static int _fdt_add_property(void *fdt, int nodeoffset, const char *name,
225 			     int len, struct fdt_property **prop)
226 {
227 	int proplen;
228 	int nextoffset;
229 	int namestroff;
230 	int err;
231 
232 	if ((nextoffset = _fdt_check_node_offset(fdt, nodeoffset)) < 0)
233 		return nextoffset;
234 
235 	namestroff = _fdt_find_add_string(fdt, name);
236 	if (namestroff < 0)
237 		return namestroff;
238 
239 	*prop = _fdt_offset_ptr_w(fdt, nextoffset);
240 	proplen = sizeof(**prop) + FDT_TAGALIGN(len);
241 
242 	err = _fdt_splice_struct(fdt, *prop, 0, proplen);
243 	if (err)
244 		return err;
245 
246 	(*prop)->tag = cpu_to_fdt32(FDT_PROP);
247 	(*prop)->nameoff = cpu_to_fdt32(namestroff);
248 	(*prop)->len = cpu_to_fdt32(len);
249 	return 0;
250 }
251 
252 int fdt_set_name(void *fdt, int nodeoffset, const char *name)
253 {
254 	char *namep;
255 	int oldlen, newlen;
256 	int err;
257 
258 	FDT_RW_CHECK_HEADER(fdt);
259 
260 	namep = (char *)(uintptr_t)fdt_get_name(fdt, nodeoffset, &oldlen);
261 	if (!namep)
262 		return oldlen;
263 
264 	newlen = strlen(name);
265 
266 	err = _fdt_splice_struct(fdt, namep, FDT_TAGALIGN(oldlen+1),
267 				 FDT_TAGALIGN(newlen+1));
268 	if (err)
269 		return err;
270 
271 	memcpy(namep, name, newlen+1);
272 	return 0;
273 }
274 
275 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
276 		const void *val, int len)
277 {
278 	struct fdt_property *prop;
279 	int err;
280 
281 	FDT_RW_CHECK_HEADER(fdt);
282 
283 	err = _fdt_resize_property(fdt, nodeoffset, name, len, &prop);
284 	if (err == -FDT_ERR_NOTFOUND)
285 		err = _fdt_add_property(fdt, nodeoffset, name, len, &prop);
286 	if (err)
287 		return err;
288 
289 	if (len)
290 		memcpy(prop->data, val, len);
291 	return 0;
292 }
293 
294 int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
295 		   const void *val, int len)
296 {
297 	struct fdt_property *prop;
298 	int err, oldlen, newlen;
299 
300 	FDT_RW_CHECK_HEADER(fdt);
301 
302 	prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
303 	if (prop) {
304 		newlen = len + oldlen;
305 		err = _fdt_splice_struct(fdt, prop->data,
306 					 FDT_TAGALIGN(oldlen),
307 					 FDT_TAGALIGN(newlen));
308 		if (err)
309 			return err;
310 		prop->len = cpu_to_fdt32(newlen);
311 		memcpy(prop->data + oldlen, val, len);
312 	} else {
313 		err = _fdt_add_property(fdt, nodeoffset, name, len, &prop);
314 		if (err)
315 			return err;
316 		memcpy(prop->data, val, len);
317 	}
318 	return 0;
319 }
320 
321 int fdt_delprop(void *fdt, int nodeoffset, const char *name)
322 {
323 	struct fdt_property *prop;
324 	int len, proplen;
325 
326 	FDT_RW_CHECK_HEADER(fdt);
327 
328 	prop = fdt_get_property_w(fdt, nodeoffset, name, &len);
329 	if (! prop)
330 		return len;
331 
332 	proplen = sizeof(*prop) + FDT_TAGALIGN(len);
333 	return _fdt_splice_struct(fdt, prop, proplen, 0);
334 }
335 
336 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
337 			    const char *name, int namelen)
338 {
339 	struct fdt_node_header *nh;
340 	int offset, nextoffset;
341 	int nodelen;
342 	int err;
343 	uint32_t tag;
344 	fdt32_t *endtag;
345 
346 	FDT_RW_CHECK_HEADER(fdt);
347 
348 	offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
349 	if (offset >= 0)
350 		return -FDT_ERR_EXISTS;
351 	else if (offset != -FDT_ERR_NOTFOUND)
352 		return offset;
353 
354 	/* Try to place the new node after the parent's properties */
355 	fdt_next_tag(fdt, parentoffset, &nextoffset); /* skip the BEGIN_NODE */
356 	do {
357 		offset = nextoffset;
358 		tag = fdt_next_tag(fdt, offset, &nextoffset);
359 	} while ((tag == FDT_PROP) || (tag == FDT_NOP));
360 
361 	nh = _fdt_offset_ptr_w(fdt, offset);
362 	nodelen = sizeof(*nh) + FDT_TAGALIGN(namelen+1) + FDT_TAGSIZE;
363 
364 	err = _fdt_splice_struct(fdt, nh, 0, nodelen);
365 	if (err)
366 		return err;
367 
368 	nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
369 	memset(nh->name, 0, FDT_TAGALIGN(namelen+1));
370 	memcpy(nh->name, name, namelen);
371 	endtag = (fdt32_t *)((char *)nh + nodelen - FDT_TAGSIZE);
372 	*endtag = cpu_to_fdt32(FDT_END_NODE);
373 
374 	return offset;
375 }
376 
377 int fdt_add_subnode(void *fdt, int parentoffset, const char *name)
378 {
379 	return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name));
380 }
381 
382 int fdt_del_node(void *fdt, int nodeoffset)
383 {
384 	int endoffset;
385 
386 	FDT_RW_CHECK_HEADER(fdt);
387 
388 	endoffset = _fdt_node_end_offset(fdt, nodeoffset);
389 	if (endoffset < 0)
390 		return endoffset;
391 
392 	return _fdt_splice_struct(fdt, _fdt_offset_ptr_w(fdt, nodeoffset),
393 				  endoffset - nodeoffset, 0);
394 }
395 
396 static void _fdt_packblocks(const char *old, char *new,
397 			    int mem_rsv_size, int struct_size)
398 {
399 	int mem_rsv_off, struct_off, strings_off;
400 
401 	mem_rsv_off = FDT_ALIGN(sizeof(struct fdt_header), 8);
402 	struct_off = mem_rsv_off + mem_rsv_size;
403 	strings_off = struct_off + struct_size;
404 
405 	memmove(new + mem_rsv_off, old + fdt_off_mem_rsvmap(old), mem_rsv_size);
406 	fdt_set_off_mem_rsvmap(new, mem_rsv_off);
407 
408 	memmove(new + struct_off, old + fdt_off_dt_struct(old), struct_size);
409 	fdt_set_off_dt_struct(new, struct_off);
410 	fdt_set_size_dt_struct(new, struct_size);
411 
412 	memmove(new + strings_off, old + fdt_off_dt_strings(old),
413 		fdt_size_dt_strings(old));
414 	fdt_set_off_dt_strings(new, strings_off);
415 	fdt_set_size_dt_strings(new, fdt_size_dt_strings(old));
416 }
417 
418 int fdt_open_into(const void *fdt, void *buf, int bufsize)
419 {
420 	int err;
421 	int mem_rsv_size, struct_size;
422 	int newsize;
423 	const char *fdtstart = fdt;
424 	const char *fdtend = fdtstart + fdt_totalsize(fdt);
425 	char *tmp;
426 
427 	FDT_CHECK_HEADER(fdt);
428 
429 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
430 		* sizeof(struct fdt_reserve_entry);
431 
432 	if (fdt_version(fdt) >= 17) {
433 		struct_size = fdt_size_dt_struct(fdt);
434 	} else {
435 		struct_size = 0;
436 		while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END)
437 			;
438 		if (struct_size < 0)
439 			return struct_size;
440 	}
441 
442 	if (!_fdt_blocks_misordered(fdt, mem_rsv_size, struct_size)) {
443 		/* no further work necessary */
444 		err = fdt_move(fdt, buf, bufsize);
445 		if (err)
446 			return err;
447 		fdt_set_version(buf, 17);
448 		fdt_set_size_dt_struct(buf, struct_size);
449 		fdt_set_totalsize(buf, bufsize);
450 		return 0;
451 	}
452 
453 	/* Need to reorder */
454 	newsize = FDT_ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size
455 		+ struct_size + fdt_size_dt_strings(fdt);
456 
457 	if (bufsize < newsize)
458 		return -FDT_ERR_NOSPACE;
459 
460 	/* First attempt to build converted tree at beginning of buffer */
461 	tmp = buf;
462 	/* But if that overlaps with the old tree... */
463 	if (((tmp + newsize) > fdtstart) && (tmp < fdtend)) {
464 		/* Try right after the old tree instead */
465 		tmp = (char *)(uintptr_t)fdtend;
466 		if ((tmp + newsize) > ((char *)buf + bufsize))
467 			return -FDT_ERR_NOSPACE;
468 	}
469 
470 	_fdt_packblocks(fdt, tmp, mem_rsv_size, struct_size);
471 	memmove(buf, tmp, newsize);
472 
473 	fdt_set_magic(buf, FDT_MAGIC);
474 	fdt_set_totalsize(buf, bufsize);
475 	fdt_set_version(buf, 17);
476 	fdt_set_last_comp_version(buf, 16);
477 	fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt));
478 
479 	return 0;
480 }
481 
482 int fdt_pack(void *fdt)
483 {
484 	int mem_rsv_size;
485 
486 	FDT_RW_CHECK_HEADER(fdt);
487 
488 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
489 		* sizeof(struct fdt_reserve_entry);
490 	_fdt_packblocks(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt));
491 	fdt_set_totalsize(fdt, _fdt_data_size(fdt));
492 
493 	return 0;
494 }
495