xref: /openbmc/u-boot/lib/libfdt/fdt_rw.c (revision 4982f464)
1 /*
2  * libfdt - Flat Device Tree manipulation
3  * Copyright (C) 2006 David Gibson, IBM Corporation.
4  * SPDX-License-Identifier:	GPL-2.0+ BSD-2-Clause
5  */
6 #include <libfdt_env.h>
7 
8 #ifndef USE_HOSTCC
9 #include <fdt.h>
10 #include <libfdt.h>
11 #else
12 #include "fdt_host.h"
13 #endif
14 
15 #include "libfdt_internal.h"
16 
17 static int _fdt_blocks_misordered(const void *fdt,
18 			      int mem_rsv_size, int struct_size)
19 {
20 	return (fdt_off_mem_rsvmap(fdt) < FDT_ALIGN(sizeof(struct fdt_header), 8))
21 		|| (fdt_off_dt_struct(fdt) <
22 		    (fdt_off_mem_rsvmap(fdt) + mem_rsv_size))
23 		|| (fdt_off_dt_strings(fdt) <
24 		    (fdt_off_dt_struct(fdt) + struct_size))
25 		|| (fdt_totalsize(fdt) <
26 		    (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt)));
27 }
28 
29 static int _fdt_rw_check_header(void *fdt)
30 {
31 	FDT_CHECK_HEADER(fdt);
32 
33 	if (fdt_version(fdt) < 17)
34 		return -FDT_ERR_BADVERSION;
35 	if (_fdt_blocks_misordered(fdt, sizeof(struct fdt_reserve_entry),
36 				   fdt_size_dt_struct(fdt)))
37 		return -FDT_ERR_BADLAYOUT;
38 	if (fdt_version(fdt) > 17)
39 		fdt_set_version(fdt, 17);
40 
41 	return 0;
42 }
43 
44 #define FDT_RW_CHECK_HEADER(fdt) \
45 	{ \
46 		int __err; \
47 		if ((__err = _fdt_rw_check_header(fdt)) != 0) \
48 			return __err; \
49 	}
50 
51 static inline int _fdt_data_size(void *fdt)
52 {
53 	return fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
54 }
55 
56 static int _fdt_splice(void *fdt, void *splicepoint, int oldlen, int newlen)
57 {
58 	char *p = splicepoint;
59 	char *end = (char *)fdt + _fdt_data_size(fdt);
60 
61 	if (((p + oldlen) < p) || ((p + oldlen) > end))
62 		return -FDT_ERR_BADOFFSET;
63 	if ((end - oldlen + newlen) > ((char *)fdt + fdt_totalsize(fdt)))
64 		return -FDT_ERR_NOSPACE;
65 	memmove(p + newlen, p + oldlen, end - p - oldlen);
66 	return 0;
67 }
68 
69 static int _fdt_splice_mem_rsv(void *fdt, struct fdt_reserve_entry *p,
70 			       int oldn, int newn)
71 {
72 	int delta = (newn - oldn) * sizeof(*p);
73 	int err;
74 	err = _fdt_splice(fdt, p, oldn * sizeof(*p), newn * sizeof(*p));
75 	if (err)
76 		return err;
77 	fdt_set_off_dt_struct(fdt, fdt_off_dt_struct(fdt) + delta);
78 	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
79 	return 0;
80 }
81 
82 static int _fdt_splice_struct(void *fdt, void *p,
83 			      int oldlen, int newlen)
84 {
85 	int delta = newlen - oldlen;
86 	int err;
87 
88 	if ((err = _fdt_splice(fdt, p, oldlen, newlen)))
89 		return err;
90 
91 	fdt_set_size_dt_struct(fdt, fdt_size_dt_struct(fdt) + delta);
92 	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
93 	return 0;
94 }
95 
96 static int _fdt_splice_string(void *fdt, int newlen)
97 {
98 	void *p = (char *)fdt
99 		+ fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
100 	int err;
101 
102 	if ((err = _fdt_splice(fdt, p, 0, newlen)))
103 		return err;
104 
105 	fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) + newlen);
106 	return 0;
107 }
108 
109 static int _fdt_find_add_string(void *fdt, const char *s)
110 {
111 	char *strtab = (char *)fdt + fdt_off_dt_strings(fdt);
112 	const char *p;
113 	char *new;
114 	int len = strlen(s) + 1;
115 	int err;
116 
117 	p = _fdt_find_string(strtab, fdt_size_dt_strings(fdt), s);
118 	if (p)
119 		/* found it */
120 		return (p - strtab);
121 
122 	new = strtab + fdt_size_dt_strings(fdt);
123 	err = _fdt_splice_string(fdt, len);
124 	if (err)
125 		return err;
126 
127 	memcpy(new, s, len);
128 	return (new - strtab);
129 }
130 
131 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size)
132 {
133 	struct fdt_reserve_entry *re;
134 	int err;
135 
136 	FDT_RW_CHECK_HEADER(fdt);
137 
138 	re = _fdt_mem_rsv_w(fdt, fdt_num_mem_rsv(fdt));
139 	err = _fdt_splice_mem_rsv(fdt, re, 0, 1);
140 	if (err)
141 		return err;
142 
143 	re->address = cpu_to_fdt64(address);
144 	re->size = cpu_to_fdt64(size);
145 	return 0;
146 }
147 
148 int fdt_del_mem_rsv(void *fdt, int n)
149 {
150 	struct fdt_reserve_entry *re = _fdt_mem_rsv_w(fdt, n);
151 
152 	FDT_RW_CHECK_HEADER(fdt);
153 
154 	if (n >= fdt_num_mem_rsv(fdt))
155 		return -FDT_ERR_NOTFOUND;
156 
157 	return _fdt_splice_mem_rsv(fdt, re, 1, 0);
158 }
159 
160 static int _fdt_resize_property(void *fdt, int nodeoffset, const char *name,
161 				int len, struct fdt_property **prop)
162 {
163 	int oldlen;
164 	int err;
165 
166 	*prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
167 	if (!(*prop))
168 		return oldlen;
169 
170 	if ((err = _fdt_splice_struct(fdt, (*prop)->data, FDT_TAGALIGN(oldlen),
171 				      FDT_TAGALIGN(len))))
172 		return err;
173 
174 	(*prop)->len = cpu_to_fdt32(len);
175 	return 0;
176 }
177 
178 static int _fdt_add_property(void *fdt, int nodeoffset, const char *name,
179 			     int len, struct fdt_property **prop)
180 {
181 	int proplen;
182 	int nextoffset;
183 	int namestroff;
184 	int err;
185 
186 	if ((nextoffset = _fdt_check_node_offset(fdt, nodeoffset)) < 0)
187 		return nextoffset;
188 
189 	namestroff = _fdt_find_add_string(fdt, name);
190 	if (namestroff < 0)
191 		return namestroff;
192 
193 	*prop = _fdt_offset_ptr_w(fdt, nextoffset);
194 	proplen = sizeof(**prop) + FDT_TAGALIGN(len);
195 
196 	err = _fdt_splice_struct(fdt, *prop, 0, proplen);
197 	if (err)
198 		return err;
199 
200 	(*prop)->tag = cpu_to_fdt32(FDT_PROP);
201 	(*prop)->nameoff = cpu_to_fdt32(namestroff);
202 	(*prop)->len = cpu_to_fdt32(len);
203 	return 0;
204 }
205 
206 int fdt_set_name(void *fdt, int nodeoffset, const char *name)
207 {
208 	char *namep;
209 	int oldlen, newlen;
210 	int err;
211 
212 	FDT_RW_CHECK_HEADER(fdt);
213 
214 	namep = (char *)(uintptr_t)fdt_get_name(fdt, nodeoffset, &oldlen);
215 	if (!namep)
216 		return oldlen;
217 
218 	newlen = strlen(name);
219 
220 	err = _fdt_splice_struct(fdt, namep, FDT_TAGALIGN(oldlen+1),
221 				 FDT_TAGALIGN(newlen+1));
222 	if (err)
223 		return err;
224 
225 	memcpy(namep, name, newlen+1);
226 	return 0;
227 }
228 
229 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
230 		const void *val, int len)
231 {
232 	struct fdt_property *prop;
233 	int err;
234 
235 	FDT_RW_CHECK_HEADER(fdt);
236 
237 	err = _fdt_resize_property(fdt, nodeoffset, name, len, &prop);
238 	if (err == -FDT_ERR_NOTFOUND)
239 		err = _fdt_add_property(fdt, nodeoffset, name, len, &prop);
240 	if (err)
241 		return err;
242 
243 	memcpy(prop->data, val, len);
244 	return 0;
245 }
246 
247 int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
248 		   const void *val, int len)
249 {
250 	struct fdt_property *prop;
251 	int err, oldlen, newlen;
252 
253 	FDT_RW_CHECK_HEADER(fdt);
254 
255 	prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
256 	if (prop) {
257 		newlen = len + oldlen;
258 		err = _fdt_splice_struct(fdt, prop->data,
259 					 FDT_TAGALIGN(oldlen),
260 					 FDT_TAGALIGN(newlen));
261 		if (err)
262 			return err;
263 		prop->len = cpu_to_fdt32(newlen);
264 		memcpy(prop->data + oldlen, val, len);
265 	} else {
266 		err = _fdt_add_property(fdt, nodeoffset, name, len, &prop);
267 		if (err)
268 			return err;
269 		memcpy(prop->data, val, len);
270 	}
271 	return 0;
272 }
273 
274 int fdt_delprop(void *fdt, int nodeoffset, const char *name)
275 {
276 	struct fdt_property *prop;
277 	int len, proplen;
278 
279 	FDT_RW_CHECK_HEADER(fdt);
280 
281 	prop = fdt_get_property_w(fdt, nodeoffset, name, &len);
282 	if (!prop)
283 		return len;
284 
285 	proplen = sizeof(*prop) + FDT_TAGALIGN(len);
286 	return _fdt_splice_struct(fdt, prop, proplen, 0);
287 }
288 
289 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
290 			    const char *name, int namelen)
291 {
292 	struct fdt_node_header *nh;
293 	int offset, nextoffset;
294 	int nodelen;
295 	int err;
296 	uint32_t tag;
297 	fdt32_t *endtag;
298 
299 	FDT_RW_CHECK_HEADER(fdt);
300 
301 	offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
302 	if (offset >= 0)
303 		return -FDT_ERR_EXISTS;
304 	else if (offset != -FDT_ERR_NOTFOUND)
305 		return offset;
306 
307 	/* Try to place the new node after the parent's properties */
308 	fdt_next_tag(fdt, parentoffset, &nextoffset); /* skip the BEGIN_NODE */
309 	do {
310 		offset = nextoffset;
311 		tag = fdt_next_tag(fdt, offset, &nextoffset);
312 	} while ((tag == FDT_PROP) || (tag == FDT_NOP));
313 
314 	nh = _fdt_offset_ptr_w(fdt, offset);
315 	nodelen = sizeof(*nh) + FDT_TAGALIGN(namelen+1) + FDT_TAGSIZE;
316 
317 	err = _fdt_splice_struct(fdt, nh, 0, nodelen);
318 	if (err)
319 		return err;
320 
321 	nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
322 	memset(nh->name, 0, FDT_TAGALIGN(namelen+1));
323 	memcpy(nh->name, name, namelen);
324 	endtag = (fdt32_t *)((char *)nh + nodelen - FDT_TAGSIZE);
325 	*endtag = cpu_to_fdt32(FDT_END_NODE);
326 
327 	return offset;
328 }
329 
330 int fdt_add_subnode(void *fdt, int parentoffset, const char *name)
331 {
332 	return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name));
333 }
334 
335 int fdt_del_node(void *fdt, int nodeoffset)
336 {
337 	int endoffset;
338 
339 	FDT_RW_CHECK_HEADER(fdt);
340 
341 	endoffset = _fdt_node_end_offset(fdt, nodeoffset);
342 	if (endoffset < 0)
343 		return endoffset;
344 
345 	return _fdt_splice_struct(fdt, _fdt_offset_ptr_w(fdt, nodeoffset),
346 				  endoffset - nodeoffset, 0);
347 }
348 
349 static void _fdt_packblocks(const char *old, char *new,
350 			    int mem_rsv_size, int struct_size)
351 {
352 	int mem_rsv_off, struct_off, strings_off;
353 
354 	mem_rsv_off = FDT_ALIGN(sizeof(struct fdt_header), 8);
355 	struct_off = mem_rsv_off + mem_rsv_size;
356 	strings_off = struct_off + struct_size;
357 
358 	memmove(new + mem_rsv_off, old + fdt_off_mem_rsvmap(old), mem_rsv_size);
359 	fdt_set_off_mem_rsvmap(new, mem_rsv_off);
360 
361 	memmove(new + struct_off, old + fdt_off_dt_struct(old), struct_size);
362 	fdt_set_off_dt_struct(new, struct_off);
363 	fdt_set_size_dt_struct(new, struct_size);
364 
365 	memmove(new + strings_off, old + fdt_off_dt_strings(old),
366 		fdt_size_dt_strings(old));
367 	fdt_set_off_dt_strings(new, strings_off);
368 	fdt_set_size_dt_strings(new, fdt_size_dt_strings(old));
369 }
370 
371 int fdt_open_into(const void *fdt, void *buf, int bufsize)
372 {
373 	int err;
374 	int mem_rsv_size, struct_size;
375 	int newsize;
376 	const char *fdtstart = fdt;
377 	const char *fdtend = fdtstart + fdt_totalsize(fdt);
378 	char *tmp;
379 
380 	FDT_CHECK_HEADER(fdt);
381 
382 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
383 		* sizeof(struct fdt_reserve_entry);
384 
385 	if (fdt_version(fdt) >= 17) {
386 		struct_size = fdt_size_dt_struct(fdt);
387 	} else {
388 		struct_size = 0;
389 		while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END)
390 			;
391 		if (struct_size < 0)
392 			return struct_size;
393 	}
394 
395 	if (!_fdt_blocks_misordered(fdt, mem_rsv_size, struct_size)) {
396 		/* no further work necessary */
397 		err = fdt_move(fdt, buf, bufsize);
398 		if (err)
399 			return err;
400 		fdt_set_version(buf, 17);
401 		fdt_set_size_dt_struct(buf, struct_size);
402 		fdt_set_totalsize(buf, bufsize);
403 		return 0;
404 	}
405 
406 	/* Need to reorder */
407 	newsize = FDT_ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size
408 		+ struct_size + fdt_size_dt_strings(fdt);
409 
410 	if (bufsize < newsize)
411 		return -FDT_ERR_NOSPACE;
412 
413 	/* First attempt to build converted tree at beginning of buffer */
414 	tmp = buf;
415 	/* But if that overlaps with the old tree... */
416 	if (((tmp + newsize) > fdtstart) && (tmp < fdtend)) {
417 		/* Try right after the old tree instead */
418 		tmp = (char *)(uintptr_t)fdtend;
419 		if ((tmp + newsize) > ((char *)buf + bufsize))
420 			return -FDT_ERR_NOSPACE;
421 	}
422 
423 	_fdt_packblocks(fdt, tmp, mem_rsv_size, struct_size);
424 	memmove(buf, tmp, newsize);
425 
426 	fdt_set_magic(buf, FDT_MAGIC);
427 	fdt_set_totalsize(buf, bufsize);
428 	fdt_set_version(buf, 17);
429 	fdt_set_last_comp_version(buf, 16);
430 	fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt));
431 
432 	return 0;
433 }
434 
435 int fdt_pack(void *fdt)
436 {
437 	int mem_rsv_size;
438 
439 	FDT_RW_CHECK_HEADER(fdt);
440 
441 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
442 		* sizeof(struct fdt_reserve_entry);
443 	_fdt_packblocks(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt));
444 	fdt_set_totalsize(fdt, _fdt_data_size(fdt));
445 
446 	return 0;
447 }
448 
449 int fdt_remove_unused_strings(const void *old, void *new)
450 {
451 	const struct fdt_property *old_prop;
452 	struct fdt_property *new_prop;
453 	int size = fdt_totalsize(old);
454 	int next_offset, offset;
455 	const char *str;
456 	int ret;
457 	int tag = FDT_PROP;
458 
459 	/* Make a copy and remove the strings */
460 	memcpy(new, old, size);
461 	fdt_set_size_dt_strings(new, 0);
462 
463 	/* Add every property name back into the new string table */
464 	for (offset = 0; tag != FDT_END; offset = next_offset) {
465 		tag = fdt_next_tag(old, offset, &next_offset);
466 		if (tag != FDT_PROP)
467 			continue;
468 		old_prop = fdt_get_property_by_offset(old, offset, NULL);
469 		new_prop = (struct fdt_property *)(unsigned long)
470 			fdt_get_property_by_offset(new, offset, NULL);
471 		str = fdt_string(old, fdt32_to_cpu(old_prop->nameoff));
472 		ret = _fdt_find_add_string(new, str);
473 		if (ret < 0)
474 			return ret;
475 		new_prop->nameoff = cpu_to_fdt32(ret);
476 	}
477 
478 	return 0;
479 }
480