xref: /openbmc/u-boot/lib/libfdt/fdt_rw.c (revision e895e996)
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 ((p < (char *)fdt) || ((end - oldlen + newlen) < (char *)fdt))
64 		return -FDT_ERR_BADOFFSET;
65 	if ((end - oldlen + newlen) > ((char *)fdt + fdt_totalsize(fdt)))
66 		return -FDT_ERR_NOSPACE;
67 	memmove(p + newlen, p + oldlen, end - p - oldlen);
68 	return 0;
69 }
70 
71 static int _fdt_splice_mem_rsv(void *fdt, struct fdt_reserve_entry *p,
72 			       int oldn, int newn)
73 {
74 	int delta = (newn - oldn) * sizeof(*p);
75 	int err;
76 	err = _fdt_splice(fdt, p, oldn * sizeof(*p), newn * sizeof(*p));
77 	if (err)
78 		return err;
79 	fdt_set_off_dt_struct(fdt, fdt_off_dt_struct(fdt) + delta);
80 	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
81 	return 0;
82 }
83 
84 static int _fdt_splice_struct(void *fdt, void *p,
85 			      int oldlen, int newlen)
86 {
87 	int delta = newlen - oldlen;
88 	int err;
89 
90 	if ((err = _fdt_splice(fdt, p, oldlen, newlen)))
91 		return err;
92 
93 	fdt_set_size_dt_struct(fdt, fdt_size_dt_struct(fdt) + delta);
94 	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
95 	return 0;
96 }
97 
98 static int _fdt_splice_string(void *fdt, int newlen)
99 {
100 	void *p = (char *)fdt
101 		+ fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
102 	int err;
103 
104 	if ((err = _fdt_splice(fdt, p, 0, newlen)))
105 		return err;
106 
107 	fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) + newlen);
108 	return 0;
109 }
110 
111 static int _fdt_find_add_string(void *fdt, const char *s)
112 {
113 	char *strtab = (char *)fdt + fdt_off_dt_strings(fdt);
114 	const char *p;
115 	char *new;
116 	int len = strlen(s) + 1;
117 	int err;
118 
119 	p = _fdt_find_string(strtab, fdt_size_dt_strings(fdt), s);
120 	if (p)
121 		/* found it */
122 		return (p - strtab);
123 
124 	new = strtab + fdt_size_dt_strings(fdt);
125 	err = _fdt_splice_string(fdt, len);
126 	if (err)
127 		return err;
128 
129 	memcpy(new, s, len);
130 	return (new - strtab);
131 }
132 
133 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size)
134 {
135 	struct fdt_reserve_entry *re;
136 	int err;
137 
138 	FDT_RW_CHECK_HEADER(fdt);
139 
140 	re = _fdt_mem_rsv_w(fdt, fdt_num_mem_rsv(fdt));
141 	err = _fdt_splice_mem_rsv(fdt, re, 0, 1);
142 	if (err)
143 		return err;
144 
145 	re->address = cpu_to_fdt64(address);
146 	re->size = cpu_to_fdt64(size);
147 	return 0;
148 }
149 
150 int fdt_del_mem_rsv(void *fdt, int n)
151 {
152 	struct fdt_reserve_entry *re = _fdt_mem_rsv_w(fdt, n);
153 
154 	FDT_RW_CHECK_HEADER(fdt);
155 
156 	if (n >= fdt_num_mem_rsv(fdt))
157 		return -FDT_ERR_NOTFOUND;
158 
159 	return _fdt_splice_mem_rsv(fdt, re, 1, 0);
160 }
161 
162 static int _fdt_resize_property(void *fdt, int nodeoffset, const char *name,
163 				int len, struct fdt_property **prop)
164 {
165 	int oldlen;
166 	int err;
167 
168 	*prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
169 	if (!*prop)
170 		return oldlen;
171 
172 	if ((err = _fdt_splice_struct(fdt, (*prop)->data, FDT_TAGALIGN(oldlen),
173 				      FDT_TAGALIGN(len))))
174 		return err;
175 
176 	(*prop)->len = cpu_to_fdt32(len);
177 	return 0;
178 }
179 
180 static int _fdt_add_property(void *fdt, int nodeoffset, const char *name,
181 			     int len, struct fdt_property **prop)
182 {
183 	int proplen;
184 	int nextoffset;
185 	int namestroff;
186 	int err;
187 
188 	if ((nextoffset = _fdt_check_node_offset(fdt, nodeoffset)) < 0)
189 		return nextoffset;
190 
191 	namestroff = _fdt_find_add_string(fdt, name);
192 	if (namestroff < 0)
193 		return namestroff;
194 
195 	*prop = _fdt_offset_ptr_w(fdt, nextoffset);
196 	proplen = sizeof(**prop) + FDT_TAGALIGN(len);
197 
198 	err = _fdt_splice_struct(fdt, *prop, 0, proplen);
199 	if (err)
200 		return err;
201 
202 	(*prop)->tag = cpu_to_fdt32(FDT_PROP);
203 	(*prop)->nameoff = cpu_to_fdt32(namestroff);
204 	(*prop)->len = cpu_to_fdt32(len);
205 	return 0;
206 }
207 
208 int fdt_set_name(void *fdt, int nodeoffset, const char *name)
209 {
210 	char *namep;
211 	int oldlen, newlen;
212 	int err;
213 
214 	FDT_RW_CHECK_HEADER(fdt);
215 
216 	namep = (char *)(uintptr_t)fdt_get_name(fdt, nodeoffset, &oldlen);
217 	if (!namep)
218 		return oldlen;
219 
220 	newlen = strlen(name);
221 
222 	err = _fdt_splice_struct(fdt, namep, FDT_TAGALIGN(oldlen+1),
223 				 FDT_TAGALIGN(newlen+1));
224 	if (err)
225 		return err;
226 
227 	memcpy(namep, name, newlen+1);
228 	return 0;
229 }
230 
231 int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name,
232 			    int len, void **prop_data)
233 {
234 	struct fdt_property *prop;
235 	int err;
236 
237 	FDT_RW_CHECK_HEADER(fdt);
238 
239 	err = _fdt_resize_property(fdt, nodeoffset, name, len, &prop);
240 	if (err == -FDT_ERR_NOTFOUND)
241 		err = _fdt_add_property(fdt, nodeoffset, name, len, &prop);
242 	if (err)
243 		return err;
244 
245 	*prop_data = prop->data;
246 	return 0;
247 }
248 
249 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
250 		const void *val, int len)
251 {
252 	void *prop_data;
253 	int err;
254 
255 	err = fdt_setprop_placeholder(fdt, nodeoffset, name, len, &prop_data);
256 	if (err)
257 		return err;
258 
259 	if (len)
260 		memcpy(prop_data, val, len);
261 	return 0;
262 }
263 
264 int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
265 		   const void *val, int len)
266 {
267 	struct fdt_property *prop;
268 	int err, oldlen, newlen;
269 
270 	FDT_RW_CHECK_HEADER(fdt);
271 
272 	prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
273 	if (prop) {
274 		newlen = len + oldlen;
275 		err = _fdt_splice_struct(fdt, prop->data,
276 					 FDT_TAGALIGN(oldlen),
277 					 FDT_TAGALIGN(newlen));
278 		if (err)
279 			return err;
280 		prop->len = cpu_to_fdt32(newlen);
281 		memcpy(prop->data + oldlen, val, len);
282 	} else {
283 		err = _fdt_add_property(fdt, nodeoffset, name, len, &prop);
284 		if (err)
285 			return err;
286 		memcpy(prop->data, val, len);
287 	}
288 	return 0;
289 }
290 
291 int fdt_delprop(void *fdt, int nodeoffset, const char *name)
292 {
293 	struct fdt_property *prop;
294 	int len, proplen;
295 
296 	FDT_RW_CHECK_HEADER(fdt);
297 
298 	prop = fdt_get_property_w(fdt, nodeoffset, name, &len);
299 	if (!prop)
300 		return len;
301 
302 	proplen = sizeof(*prop) + FDT_TAGALIGN(len);
303 	return _fdt_splice_struct(fdt, prop, proplen, 0);
304 }
305 
306 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
307 			    const char *name, int namelen)
308 {
309 	struct fdt_node_header *nh;
310 	int offset, nextoffset;
311 	int nodelen;
312 	int err;
313 	uint32_t tag;
314 	fdt32_t *endtag;
315 
316 	FDT_RW_CHECK_HEADER(fdt);
317 
318 	offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
319 	if (offset >= 0)
320 		return -FDT_ERR_EXISTS;
321 	else if (offset != -FDT_ERR_NOTFOUND)
322 		return offset;
323 
324 	/* Try to place the new node after the parent's properties */
325 	fdt_next_tag(fdt, parentoffset, &nextoffset); /* skip the BEGIN_NODE */
326 	do {
327 		offset = nextoffset;
328 		tag = fdt_next_tag(fdt, offset, &nextoffset);
329 	} while ((tag == FDT_PROP) || (tag == FDT_NOP));
330 
331 	nh = _fdt_offset_ptr_w(fdt, offset);
332 	nodelen = sizeof(*nh) + FDT_TAGALIGN(namelen+1) + FDT_TAGSIZE;
333 
334 	err = _fdt_splice_struct(fdt, nh, 0, nodelen);
335 	if (err)
336 		return err;
337 
338 	nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
339 	memset(nh->name, 0, FDT_TAGALIGN(namelen+1));
340 	memcpy(nh->name, name, namelen);
341 	endtag = (fdt32_t *)((char *)nh + nodelen - FDT_TAGSIZE);
342 	*endtag = cpu_to_fdt32(FDT_END_NODE);
343 
344 	return offset;
345 }
346 
347 int fdt_add_subnode(void *fdt, int parentoffset, const char *name)
348 {
349 	return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name));
350 }
351 
352 int fdt_del_node(void *fdt, int nodeoffset)
353 {
354 	int endoffset;
355 
356 	FDT_RW_CHECK_HEADER(fdt);
357 
358 	endoffset = _fdt_node_end_offset(fdt, nodeoffset);
359 	if (endoffset < 0)
360 		return endoffset;
361 
362 	return _fdt_splice_struct(fdt, _fdt_offset_ptr_w(fdt, nodeoffset),
363 				  endoffset - nodeoffset, 0);
364 }
365 
366 static void _fdt_packblocks(const char *old, char *new,
367 			    int mem_rsv_size, int struct_size)
368 {
369 	int mem_rsv_off, struct_off, strings_off;
370 
371 	mem_rsv_off = FDT_ALIGN(sizeof(struct fdt_header), 8);
372 	struct_off = mem_rsv_off + mem_rsv_size;
373 	strings_off = struct_off + struct_size;
374 
375 	memmove(new + mem_rsv_off, old + fdt_off_mem_rsvmap(old), mem_rsv_size);
376 	fdt_set_off_mem_rsvmap(new, mem_rsv_off);
377 
378 	memmove(new + struct_off, old + fdt_off_dt_struct(old), struct_size);
379 	fdt_set_off_dt_struct(new, struct_off);
380 	fdt_set_size_dt_struct(new, struct_size);
381 
382 	memmove(new + strings_off, old + fdt_off_dt_strings(old),
383 		fdt_size_dt_strings(old));
384 	fdt_set_off_dt_strings(new, strings_off);
385 	fdt_set_size_dt_strings(new, fdt_size_dt_strings(old));
386 }
387 
388 int fdt_open_into(const void *fdt, void *buf, int bufsize)
389 {
390 	int err;
391 	int mem_rsv_size, struct_size;
392 	int newsize;
393 	const char *fdtstart = fdt;
394 	const char *fdtend = fdtstart + fdt_totalsize(fdt);
395 	char *tmp;
396 
397 	FDT_CHECK_HEADER(fdt);
398 
399 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
400 		* sizeof(struct fdt_reserve_entry);
401 
402 	if (fdt_version(fdt) >= 17) {
403 		struct_size = fdt_size_dt_struct(fdt);
404 	} else {
405 		struct_size = 0;
406 		while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END)
407 			;
408 		if (struct_size < 0)
409 			return struct_size;
410 	}
411 
412 	if (!_fdt_blocks_misordered(fdt, mem_rsv_size, struct_size)) {
413 		/* no further work necessary */
414 		err = fdt_move(fdt, buf, bufsize);
415 		if (err)
416 			return err;
417 		fdt_set_version(buf, 17);
418 		fdt_set_size_dt_struct(buf, struct_size);
419 		fdt_set_totalsize(buf, bufsize);
420 		return 0;
421 	}
422 
423 	/* Need to reorder */
424 	newsize = FDT_ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size
425 		+ struct_size + fdt_size_dt_strings(fdt);
426 
427 	if (bufsize < newsize)
428 		return -FDT_ERR_NOSPACE;
429 
430 	/* First attempt to build converted tree at beginning of buffer */
431 	tmp = buf;
432 	/* But if that overlaps with the old tree... */
433 	if (((tmp + newsize) > fdtstart) && (tmp < fdtend)) {
434 		/* Try right after the old tree instead */
435 		tmp = (char *)(uintptr_t)fdtend;
436 		if ((tmp + newsize) > ((char *)buf + bufsize))
437 			return -FDT_ERR_NOSPACE;
438 	}
439 
440 	_fdt_packblocks(fdt, tmp, mem_rsv_size, struct_size);
441 	memmove(buf, tmp, newsize);
442 
443 	fdt_set_magic(buf, FDT_MAGIC);
444 	fdt_set_totalsize(buf, bufsize);
445 	fdt_set_version(buf, 17);
446 	fdt_set_last_comp_version(buf, 16);
447 	fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt));
448 
449 	return 0;
450 }
451 
452 int fdt_pack(void *fdt)
453 {
454 	int mem_rsv_size;
455 
456 	FDT_RW_CHECK_HEADER(fdt);
457 
458 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
459 		* sizeof(struct fdt_reserve_entry);
460 	_fdt_packblocks(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt));
461 	fdt_set_totalsize(fdt, _fdt_data_size(fdt));
462 
463 	return 0;
464 }
465 
466 int fdt_remove_unused_strings(const void *old, void *new)
467 {
468 	const struct fdt_property *old_prop;
469 	struct fdt_property *new_prop;
470 	int size = fdt_totalsize(old);
471 	int next_offset, offset;
472 	const char *str;
473 	int ret;
474 	int tag = FDT_PROP;
475 
476 	/* Make a copy and remove the strings */
477 	memcpy(new, old, size);
478 	fdt_set_size_dt_strings(new, 0);
479 
480 	/* Add every property name back into the new string table */
481 	for (offset = 0; tag != FDT_END; offset = next_offset) {
482 		tag = fdt_next_tag(old, offset, &next_offset);
483 		if (tag != FDT_PROP)
484 			continue;
485 		old_prop = fdt_get_property_by_offset(old, offset, NULL);
486 		new_prop = (struct fdt_property *)(unsigned long)
487 			fdt_get_property_by_offset(new, offset, NULL);
488 		str = fdt_string(old, fdt32_to_cpu(old_prop->nameoff));
489 		ret = _fdt_find_add_string(new, str);
490 		if (ret < 0)
491 			return ret;
492 		new_prop->nameoff = cpu_to_fdt32(ret);
493 	}
494 
495 	return 0;
496 }
497