xref: /openbmc/u-boot/lib/libfdt/fdt_rw.c (revision f20562e4)
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 	int err;
152 
153 	FDT_RW_CHECK_HEADER(fdt);
154 
155 	if (n >= fdt_num_mem_rsv(fdt))
156 		return -FDT_ERR_NOTFOUND;
157 
158 	err = _fdt_splice_mem_rsv(fdt, re, 1, 0);
159 	if (err)
160 		return err;
161 	return 0;
162 }
163 
164 static int _fdt_resize_property(void *fdt, int nodeoffset, const char *name,
165 				int len, struct fdt_property **prop)
166 {
167 	int oldlen;
168 	int err;
169 
170 	*prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
171 	if (! (*prop))
172 		return oldlen;
173 
174 	if ((err = _fdt_splice_struct(fdt, (*prop)->data, FDT_TAGALIGN(oldlen),
175 				      FDT_TAGALIGN(len))))
176 		return err;
177 
178 	(*prop)->len = cpu_to_fdt32(len);
179 	return 0;
180 }
181 
182 static int _fdt_add_property(void *fdt, int nodeoffset, const char *name,
183 			     int len, struct fdt_property **prop)
184 {
185 	int proplen;
186 	int nextoffset;
187 	int namestroff;
188 	int err;
189 
190 	if ((nextoffset = _fdt_check_node_offset(fdt, nodeoffset)) < 0)
191 		return nextoffset;
192 
193 	namestroff = _fdt_find_add_string(fdt, name);
194 	if (namestroff < 0)
195 		return namestroff;
196 
197 	*prop = _fdt_offset_ptr_w(fdt, nextoffset);
198 	proplen = sizeof(**prop) + FDT_TAGALIGN(len);
199 
200 	err = _fdt_splice_struct(fdt, *prop, 0, proplen);
201 	if (err)
202 		return err;
203 
204 	(*prop)->tag = cpu_to_fdt32(FDT_PROP);
205 	(*prop)->nameoff = cpu_to_fdt32(namestroff);
206 	(*prop)->len = cpu_to_fdt32(len);
207 	return 0;
208 }
209 
210 int fdt_set_name(void *fdt, int nodeoffset, const char *name)
211 {
212 	char *namep;
213 	int oldlen, newlen;
214 	int err;
215 
216 	FDT_RW_CHECK_HEADER(fdt);
217 
218 	namep = (char *)(uintptr_t)fdt_get_name(fdt, nodeoffset, &oldlen);
219 	if (!namep)
220 		return oldlen;
221 
222 	newlen = strlen(name);
223 
224 	err = _fdt_splice_struct(fdt, namep, FDT_TAGALIGN(oldlen+1),
225 				 FDT_TAGALIGN(newlen+1));
226 	if (err)
227 		return err;
228 
229 	memcpy(namep, name, newlen+1);
230 	return 0;
231 }
232 
233 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
234 		const void *val, int len)
235 {
236 	struct fdt_property *prop;
237 	int err;
238 
239 	FDT_RW_CHECK_HEADER(fdt);
240 
241 	err = _fdt_resize_property(fdt, nodeoffset, name, len, &prop);
242 	if (err == -FDT_ERR_NOTFOUND)
243 		err = _fdt_add_property(fdt, nodeoffset, name, len, &prop);
244 	if (err)
245 		return err;
246 
247 	memcpy(prop->data, val, len);
248 	return 0;
249 }
250 
251 int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
252 		   const void *val, int len)
253 {
254 	struct fdt_property *prop;
255 	int err, oldlen, newlen;
256 
257 	FDT_RW_CHECK_HEADER(fdt);
258 
259 	prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
260 	if (prop) {
261 		newlen = len + oldlen;
262 		err = _fdt_splice_struct(fdt, prop->data,
263 					 FDT_TAGALIGN(oldlen),
264 					 FDT_TAGALIGN(newlen));
265 		if (err)
266 			return err;
267 		prop->len = cpu_to_fdt32(newlen);
268 		memcpy(prop->data + oldlen, val, len);
269 	} else {
270 		err = _fdt_add_property(fdt, nodeoffset, name, len, &prop);
271 		if (err)
272 			return err;
273 		memcpy(prop->data, val, len);
274 	}
275 	return 0;
276 }
277 
278 int fdt_delprop(void *fdt, int nodeoffset, const char *name)
279 {
280 	struct fdt_property *prop;
281 	int len, proplen;
282 
283 	FDT_RW_CHECK_HEADER(fdt);
284 
285 	prop = fdt_get_property_w(fdt, nodeoffset, name, &len);
286 	if (! prop)
287 		return len;
288 
289 	proplen = sizeof(*prop) + FDT_TAGALIGN(len);
290 	return _fdt_splice_struct(fdt, prop, proplen, 0);
291 }
292 
293 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
294 			    const char *name, int namelen)
295 {
296 	struct fdt_node_header *nh;
297 	int offset, nextoffset;
298 	int nodelen;
299 	int err;
300 	uint32_t tag;
301 	fdt32_t *endtag;
302 
303 	FDT_RW_CHECK_HEADER(fdt);
304 
305 	offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
306 	if (offset >= 0)
307 		return -FDT_ERR_EXISTS;
308 	else if (offset != -FDT_ERR_NOTFOUND)
309 		return offset;
310 
311 	/* Try to place the new node after the parent's properties */
312 	fdt_next_tag(fdt, parentoffset, &nextoffset); /* skip the BEGIN_NODE */
313 	do {
314 		offset = nextoffset;
315 		tag = fdt_next_tag(fdt, offset, &nextoffset);
316 	} while ((tag == FDT_PROP) || (tag == FDT_NOP));
317 
318 	nh = _fdt_offset_ptr_w(fdt, offset);
319 	nodelen = sizeof(*nh) + FDT_TAGALIGN(namelen+1) + FDT_TAGSIZE;
320 
321 	err = _fdt_splice_struct(fdt, nh, 0, nodelen);
322 	if (err)
323 		return err;
324 
325 	nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
326 	memset(nh->name, 0, FDT_TAGALIGN(namelen+1));
327 	memcpy(nh->name, name, namelen);
328 	endtag = (fdt32_t *)((char *)nh + nodelen - FDT_TAGSIZE);
329 	*endtag = cpu_to_fdt32(FDT_END_NODE);
330 
331 	return offset;
332 }
333 
334 int fdt_add_subnode(void *fdt, int parentoffset, const char *name)
335 {
336 	return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name));
337 }
338 
339 int fdt_del_node(void *fdt, int nodeoffset)
340 {
341 	int endoffset;
342 
343 	FDT_RW_CHECK_HEADER(fdt);
344 
345 	endoffset = _fdt_node_end_offset(fdt, nodeoffset);
346 	if (endoffset < 0)
347 		return endoffset;
348 
349 	return _fdt_splice_struct(fdt, _fdt_offset_ptr_w(fdt, nodeoffset),
350 				  endoffset - nodeoffset, 0);
351 }
352 
353 static void _fdt_packblocks(const char *old, char *new,
354 			    int mem_rsv_size, int struct_size)
355 {
356 	int mem_rsv_off, struct_off, strings_off;
357 
358 	mem_rsv_off = FDT_ALIGN(sizeof(struct fdt_header), 8);
359 	struct_off = mem_rsv_off + mem_rsv_size;
360 	strings_off = struct_off + struct_size;
361 
362 	memmove(new + mem_rsv_off, old + fdt_off_mem_rsvmap(old), mem_rsv_size);
363 	fdt_set_off_mem_rsvmap(new, mem_rsv_off);
364 
365 	memmove(new + struct_off, old + fdt_off_dt_struct(old), struct_size);
366 	fdt_set_off_dt_struct(new, struct_off);
367 	fdt_set_size_dt_struct(new, struct_size);
368 
369 	memmove(new + strings_off, old + fdt_off_dt_strings(old),
370 		fdt_size_dt_strings(old));
371 	fdt_set_off_dt_strings(new, strings_off);
372 	fdt_set_size_dt_strings(new, fdt_size_dt_strings(old));
373 }
374 
375 int fdt_open_into(const void *fdt, void *buf, int bufsize)
376 {
377 	int err;
378 	int mem_rsv_size, struct_size;
379 	int newsize;
380 	const char *fdtstart = fdt;
381 	const char *fdtend = fdtstart + fdt_totalsize(fdt);
382 	char *tmp;
383 
384 	FDT_CHECK_HEADER(fdt);
385 
386 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
387 		* sizeof(struct fdt_reserve_entry);
388 
389 	if (fdt_version(fdt) >= 17) {
390 		struct_size = fdt_size_dt_struct(fdt);
391 	} else {
392 		struct_size = 0;
393 		while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END)
394 			;
395 		if (struct_size < 0)
396 			return struct_size;
397 	}
398 
399 	if (!_fdt_blocks_misordered(fdt, mem_rsv_size, struct_size)) {
400 		/* no further work necessary */
401 		err = fdt_move(fdt, buf, bufsize);
402 		if (err)
403 			return err;
404 		fdt_set_version(buf, 17);
405 		fdt_set_size_dt_struct(buf, struct_size);
406 		fdt_set_totalsize(buf, bufsize);
407 		return 0;
408 	}
409 
410 	/* Need to reorder */
411 	newsize = FDT_ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size
412 		+ struct_size + fdt_size_dt_strings(fdt);
413 
414 	if (bufsize < newsize)
415 		return -FDT_ERR_NOSPACE;
416 
417 	/* First attempt to build converted tree at beginning of buffer */
418 	tmp = buf;
419 	/* But if that overlaps with the old tree... */
420 	if (((tmp + newsize) > fdtstart) && (tmp < fdtend)) {
421 		/* Try right after the old tree instead */
422 		tmp = (char *)(uintptr_t)fdtend;
423 		if ((tmp + newsize) > ((char *)buf + bufsize))
424 			return -FDT_ERR_NOSPACE;
425 	}
426 
427 	_fdt_packblocks(fdt, tmp, mem_rsv_size, struct_size);
428 	memmove(buf, tmp, newsize);
429 
430 	fdt_set_magic(buf, FDT_MAGIC);
431 	fdt_set_totalsize(buf, bufsize);
432 	fdt_set_version(buf, 17);
433 	fdt_set_last_comp_version(buf, 16);
434 	fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt));
435 
436 	return 0;
437 }
438 
439 int fdt_pack(void *fdt)
440 {
441 	int mem_rsv_size;
442 
443 	FDT_RW_CHECK_HEADER(fdt);
444 
445 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
446 		* sizeof(struct fdt_reserve_entry);
447 	_fdt_packblocks(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt));
448 	fdt_set_totalsize(fdt, _fdt_data_size(fdt));
449 
450 	return 0;
451 }
452 
453 int fdt_remove_unused_strings(const void *old, void *new)
454 {
455 	const struct fdt_property *old_prop;
456 	struct fdt_property *new_prop;
457 	int size = fdt_totalsize(old);
458 	int next_offset, offset;
459 	const char *str;
460 	int ret;
461 	int tag = FDT_PROP;
462 
463 	/* Make a copy and remove the strings */
464 	memcpy(new, old, size);
465 	fdt_set_size_dt_strings(new, 0);
466 
467 	/* Add every property name back into the new string table */
468 	for (offset = 0; tag != FDT_END; offset = next_offset) {
469 		tag = fdt_next_tag(old, offset, &next_offset);
470 		if (tag != FDT_PROP)
471 			continue;
472 		old_prop = fdt_get_property_by_offset(old, offset, NULL);
473 		new_prop = (struct fdt_property *)(unsigned long)
474 			fdt_get_property_by_offset(new, offset, NULL);
475 		str = fdt_string(old, fdt32_to_cpu(old_prop->nameoff));
476 		ret = _fdt_find_add_string(new, str);
477 		if (ret < 0)
478 			return ret;
479 		new_prop->nameoff = cpu_to_fdt32(ret);
480 	}
481 
482 	return 0;
483 }
484