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      1 /*
      2  * libfdt - Flat Device Tree manipulation
      3  * Copyright (C) 2006 David Gibson, IBM Corporation.
      4  *
      5  * libfdt is dual licensed: you can use it either under the terms of
      6  * the GPL, or the BSD license, at your option.
      7  *
      8  *  a) This library is free software; you can redistribute it and/or
      9  *     modify it under the terms of the GNU General Public License as
     10  *     published by the Free Software Foundation; either version 2 of the
     11  *     License, or (at your option) any later version.
     12  *
     13  *     This library is distributed in the hope that it will be useful,
     14  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
     15  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     16  *     GNU General Public License for more details.
     17  *
     18  *     You should have received a copy of the GNU General Public
     19  *     License along with this library; if not, write to the Free
     20  *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
     21  *     MA 02110-1301 USA
     22  *
     23  * Alternatively,
     24  *
     25  *  b) Redistribution and use in source and binary forms, with or
     26  *     without modification, are permitted provided that the following
     27  *     conditions are met:
     28  *
     29  *     1. Redistributions of source code must retain the above
     30  *        copyright notice, this list of conditions and the following
     31  *        disclaimer.
     32  *     2. Redistributions in binary form must reproduce the above
     33  *        copyright notice, this list of conditions and the following
     34  *        disclaimer in the documentation and/or other materials
     35  *        provided with the distribution.
     36  *
     37  *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
     38  *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
     39  *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     40  *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     41  *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
     42  *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     43  *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     44  *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     45  *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     46  *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     47  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     48  *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
     49  *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     50  */
     51 #include "libfdt_env.h"
     52 
     53 #include <fdt.h>
     54 #include <libfdt.h>
     55 
     56 #include "libfdt_internal.h"
     57 
     58 static int _fdt_blocks_misordered(const void *fdt,
     59 			      int mem_rsv_size, int struct_size)
     60 {
     61 	return (fdt_off_mem_rsvmap(fdt) < FDT_ALIGN(sizeof(struct fdt_header), 8))
     62 		|| (fdt_off_dt_struct(fdt) <
     63 		    (fdt_off_mem_rsvmap(fdt) + mem_rsv_size))
     64 		|| (fdt_off_dt_strings(fdt) <
     65 		    (fdt_off_dt_struct(fdt) + struct_size))
     66 		|| (fdt_totalsize(fdt) <
     67 		    (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt)));
     68 }
     69 
     70 static int _fdt_rw_check_header(void *fdt)
     71 {
     72 	FDT_CHECK_HEADER(fdt);
     73 
     74 	if (fdt_version(fdt) < 17)
     75 		return -FDT_ERR_BADVERSION;
     76 	if (_fdt_blocks_misordered(fdt, sizeof(struct fdt_reserve_entry),
     77 				   fdt_size_dt_struct(fdt)))
     78 		return -FDT_ERR_BADLAYOUT;
     79 	if (fdt_version(fdt) > 17)
     80 		fdt_set_version(fdt, 17);
     81 
     82 	return 0;
     83 }
     84 
     85 #define FDT_RW_CHECK_HEADER(fdt) \
     86 	{ \
     87 		int err; \
     88 		if ((err = _fdt_rw_check_header(fdt)) != 0) \
     89 			return err; \
     90 	}
     91 
     92 static inline int _fdt_data_size(void *fdt)
     93 {
     94 	return fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt);
     95 }
     96 
     97 static int _fdt_splice(void *fdt, void *splicepoint, int oldlen, int newlen)
     98 {
     99 	char *p = splicepoint;
    100 	char *end = (char *)fdt + _fdt_data_size(fdt);
    101 
    102 	if (((p + oldlen) < p) || ((p + oldlen) > end))
    103 		return -FDT_ERR_BADOFFSET;
    104 	if ((end - oldlen + newlen) > ((char *)fdt + fdt_totalsize(fdt)))
    105 		return -FDT_ERR_NOSPACE;
    106 	memmove(p + newlen, p + oldlen, end - p - oldlen);
    107 	return 0;
    108 }
    109 
    110 static int _fdt_splice_mem_rsv(void *fdt, struct fdt_reserve_entry *p,
    111 			       int oldn, int newn)
    112 {
    113 	int delta = (newn - oldn) * sizeof(*p);
    114 	int err;
    115 	err = _fdt_splice(fdt, p, oldn * sizeof(*p), newn * sizeof(*p));
    116 	if (err)
    117 		return err;
    118 	fdt_set_off_dt_struct(fdt, fdt_off_dt_struct(fdt) + delta);
    119 	fdt_set_off_dt_strings(fdt, fdt_off_dt_strings(fdt) + delta);
    120 	return 0;
    121 }
    122 
    123 static int _fdt_splice_struct(void *fdt, void *p,
    124 			      int oldlen, int newlen)
    125 {
    126 	int delta = newlen - oldlen;
    127 	int err;
    128 
    129 	err = _fdt_splice(fdt, p, oldlen, newlen);
    130 	if (err)
    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 	err = _fdt_splice(fdt, p, 0, newlen);
    145 	if (err)
    146 		return err;
    147 
    148 	fdt_set_size_dt_strings(fdt, fdt_size_dt_strings(fdt) + newlen);
    149 	return 0;
    150 }
    151 
    152 static int _fdt_find_add_string(void *fdt, const char *s)
    153 {
    154 	char *strtab = (char *)fdt + fdt_off_dt_strings(fdt);
    155 	const char *p;
    156 	char *new;
    157 	int len = strlen(s) + 1;
    158 	int err;
    159 
    160 	p = _fdt_find_string(strtab, fdt_size_dt_strings(fdt), s);
    161 	if (p)
    162 		/* found it */
    163 		return (p - strtab);
    164 
    165 	new = strtab + fdt_size_dt_strings(fdt);
    166 	err = _fdt_splice_string(fdt, len);
    167 	if (err)
    168 		return err;
    169 
    170 	memcpy(new, s, len);
    171 	return (new - strtab);
    172 }
    173 
    174 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size)
    175 {
    176 	struct fdt_reserve_entry *re;
    177 	int err;
    178 
    179 	FDT_RW_CHECK_HEADER(fdt);
    180 
    181 	re = _fdt_mem_rsv_w(fdt, fdt_num_mem_rsv(fdt));
    182 	err = _fdt_splice_mem_rsv(fdt, re, 0, 1);
    183 	if (err)
    184 		return err;
    185 
    186 	re->address = cpu_to_fdt64(address);
    187 	re->size = cpu_to_fdt64(size);
    188 	return 0;
    189 }
    190 
    191 int fdt_del_mem_rsv(void *fdt, int n)
    192 {
    193 	struct fdt_reserve_entry *re = _fdt_mem_rsv_w(fdt, n);
    194 	int err;
    195 
    196 	FDT_RW_CHECK_HEADER(fdt);
    197 
    198 	if (n >= fdt_num_mem_rsv(fdt))
    199 		return -FDT_ERR_NOTFOUND;
    200 
    201 	err = _fdt_splice_mem_rsv(fdt, re, 1, 0);
    202 	if (err)
    203 		return err;
    204 	return 0;
    205 }
    206 
    207 static int _fdt_resize_property(void *fdt, int nodeoffset, const char *name,
    208 				int len, struct fdt_property **prop)
    209 {
    210 	int oldlen;
    211 	int err;
    212 
    213 	*prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
    214 	if (! (*prop))
    215 		return oldlen;
    216 
    217 	err = _fdt_splice_struct(fdt, (*prop)->data, FDT_TAGALIGN(oldlen),
    218 	              FDT_TAGALIGN(len));
    219 	if (err)
    220 		return err;
    221 
    222 	(*prop)->len = cpu_to_fdt32(len);
    223 	return 0;
    224 }
    225 
    226 static int _fdt_add_property(void *fdt, int nodeoffset, const char *name,
    227 			     int len, struct fdt_property **prop)
    228 {
    229 	int proplen;
    230 	int nextoffset;
    231 	int namestroff;
    232 	int err;
    233 
    234 	if ((nextoffset = _fdt_check_node_offset(fdt, nodeoffset)) < 0)
    235 		return nextoffset;
    236 
    237 	namestroff = _fdt_find_add_string(fdt, name);
    238 	if (namestroff < 0)
    239 		return namestroff;
    240 
    241 	*prop = _fdt_offset_ptr_w(fdt, nextoffset);
    242 	proplen = sizeof(**prop) + FDT_TAGALIGN(len);
    243 
    244 	err = _fdt_splice_struct(fdt, *prop, 0, proplen);
    245 	if (err)
    246 		return err;
    247 
    248 	(*prop)->tag = cpu_to_fdt32(FDT_PROP);
    249 	(*prop)->nameoff = cpu_to_fdt32(namestroff);
    250 	(*prop)->len = cpu_to_fdt32(len);
    251 	return 0;
    252 }
    253 
    254 int fdt_set_name(void *fdt, int nodeoffset, const char *name)
    255 {
    256 	char *namep;
    257 	int oldlen, newlen;
    258 	int err;
    259 
    260 	FDT_RW_CHECK_HEADER(fdt);
    261 
    262 	namep = (char *)(uintptr_t)fdt_get_name(fdt, nodeoffset, &oldlen);
    263 	if (!namep)
    264 		return oldlen;
    265 
    266 	newlen = strlen(name);
    267 
    268 	err = _fdt_splice_struct(fdt, namep, FDT_TAGALIGN(oldlen+1),
    269 				 FDT_TAGALIGN(newlen+1));
    270 	if (err)
    271 		return err;
    272 
    273 	memcpy(namep, name, newlen+1);
    274 	return 0;
    275 }
    276 
    277 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
    278 		const void *val, int len)
    279 {
    280 	struct fdt_property *prop;
    281 	int err;
    282 
    283 	FDT_RW_CHECK_HEADER(fdt);
    284 
    285 	err = _fdt_resize_property(fdt, nodeoffset, name, len, &prop);
    286 	if (err == -FDT_ERR_NOTFOUND)
    287 		err = _fdt_add_property(fdt, nodeoffset, name, len, &prop);
    288 	if (err)
    289 		return err;
    290 
    291 	memcpy(prop->data, val, len);
    292 	return 0;
    293 }
    294 
    295 int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
    296 		   const void *val, int len)
    297 {
    298 	struct fdt_property *prop;
    299 	int err, oldlen, newlen;
    300 
    301 	FDT_RW_CHECK_HEADER(fdt);
    302 
    303 	prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
    304 	if (prop) {
    305 		newlen = len + oldlen;
    306 		err = _fdt_splice_struct(fdt, prop->data,
    307 					 FDT_TAGALIGN(oldlen),
    308 					 FDT_TAGALIGN(newlen));
    309 		if (err)
    310 			return err;
    311 		prop->len = cpu_to_fdt32(newlen);
    312 		memcpy(prop->data + oldlen, val, len);
    313 	} else {
    314 		err = _fdt_add_property(fdt, nodeoffset, name, len, &prop);
    315 		if (err)
    316 			return err;
    317 		memcpy(prop->data, val, len);
    318 	}
    319 	return 0;
    320 }
    321 
    322 int fdt_delprop(void *fdt, int nodeoffset, const char *name)
    323 {
    324 	struct fdt_property *prop;
    325 	int len, proplen;
    326 
    327 	FDT_RW_CHECK_HEADER(fdt);
    328 
    329 	prop = fdt_get_property_w(fdt, nodeoffset, name, &len);
    330 	if (! prop)
    331 		return len;
    332 
    333 	proplen = sizeof(*prop) + FDT_TAGALIGN(len);
    334 	return _fdt_splice_struct(fdt, prop, proplen, 0);
    335 }
    336 
    337 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
    338 			    const char *name, int namelen)
    339 {
    340 	struct fdt_node_header *nh;
    341 	int offset, nextoffset;
    342 	int nodelen;
    343 	int err;
    344 	uint32_t tag;
    345 	fdt32_t *endtag;
    346 
    347 	FDT_RW_CHECK_HEADER(fdt);
    348 
    349 	offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
    350 	if (offset >= 0)
    351 		return -FDT_ERR_EXISTS;
    352 	else if (offset != -FDT_ERR_NOTFOUND)
    353 		return offset;
    354 
    355 	/* Try to place the new node after the parent's properties */
    356 	fdt_next_tag(fdt, parentoffset, &nextoffset); /* skip the BEGIN_NODE */
    357 	do {
    358 		offset = nextoffset;
    359 		tag = fdt_next_tag(fdt, offset, &nextoffset);
    360 	} while ((tag == FDT_PROP) || (tag == FDT_NOP));
    361 
    362 	nh = _fdt_offset_ptr_w(fdt, offset);
    363 	nodelen = sizeof(*nh) + FDT_TAGALIGN(namelen+1) + FDT_TAGSIZE;
    364 
    365 	err = _fdt_splice_struct(fdt, nh, 0, nodelen);
    366 	if (err)
    367 		return err;
    368 
    369 	nh->tag = cpu_to_fdt32(FDT_BEGIN_NODE);
    370 	memset(nh->name, 0, FDT_TAGALIGN(namelen+1));
    371 	memcpy(nh->name, name, namelen);
    372 	endtag = (fdt32_t *)((char *)nh + nodelen - FDT_TAGSIZE);
    373 	*endtag = cpu_to_fdt32(FDT_END_NODE);
    374 
    375 	return offset;
    376 }
    377 
    378 int fdt_add_subnode(void *fdt, int parentoffset, const char *name)
    379 {
    380 	return fdt_add_subnode_namelen(fdt, parentoffset, name, strlen(name));
    381 }
    382 
    383 int fdt_del_node(void *fdt, int nodeoffset)
    384 {
    385 	int endoffset;
    386 
    387 	FDT_RW_CHECK_HEADER(fdt);
    388 
    389 	endoffset = _fdt_node_end_offset(fdt, nodeoffset);
    390 	if (endoffset < 0)
    391 		return endoffset;
    392 
    393 	return _fdt_splice_struct(fdt, _fdt_offset_ptr_w(fdt, nodeoffset),
    394 				  endoffset - nodeoffset, 0);
    395 }
    396 
    397 static void _fdt_packblocks(const char *old, char *new,
    398 			    int mem_rsv_size, int struct_size)
    399 {
    400 	int mem_rsv_off, struct_off, strings_off;
    401 
    402 	mem_rsv_off = FDT_ALIGN(sizeof(struct fdt_header), 8);
    403 	struct_off = mem_rsv_off + mem_rsv_size;
    404 	strings_off = struct_off + struct_size;
    405 
    406 	memmove(new + mem_rsv_off, old + fdt_off_mem_rsvmap(old), mem_rsv_size);
    407 	fdt_set_off_mem_rsvmap(new, mem_rsv_off);
    408 
    409 	memmove(new + struct_off, old + fdt_off_dt_struct(old), struct_size);
    410 	fdt_set_off_dt_struct(new, struct_off);
    411 	fdt_set_size_dt_struct(new, struct_size);
    412 
    413 	memmove(new + strings_off, old + fdt_off_dt_strings(old),
    414 		fdt_size_dt_strings(old));
    415 	fdt_set_off_dt_strings(new, strings_off);
    416 	fdt_set_size_dt_strings(new, fdt_size_dt_strings(old));
    417 }
    418 
    419 int fdt_open_into(const void *fdt, void *buf, int bufsize)
    420 {
    421 	int err;
    422 	int mem_rsv_size, struct_size;
    423 	int newsize;
    424 	const char *fdtstart = fdt;
    425 	const char *fdtend = fdtstart + fdt_totalsize(fdt);
    426 	char *tmp;
    427 
    428 	FDT_CHECK_HEADER(fdt);
    429 
    430 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
    431 		* sizeof(struct fdt_reserve_entry);
    432 
    433 	if (fdt_version(fdt) >= 17) {
    434 		struct_size = fdt_size_dt_struct(fdt);
    435 	} else {
    436 		struct_size = 0;
    437 		while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END)
    438 			;
    439 		if (struct_size < 0)
    440 			return struct_size;
    441 	}
    442 
    443 	if (!_fdt_blocks_misordered(fdt, mem_rsv_size, struct_size)) {
    444 		/* no further work necessary */
    445 		err = fdt_move(fdt, buf, bufsize);
    446 		if (err)
    447 			return err;
    448 		fdt_set_version(buf, 17);
    449 		fdt_set_size_dt_struct(buf, struct_size);
    450 		fdt_set_totalsize(buf, bufsize);
    451 		return 0;
    452 	}
    453 
    454 	/* Need to reorder */
    455 	newsize = FDT_ALIGN(sizeof(struct fdt_header), 8) + mem_rsv_size
    456 		+ struct_size + fdt_size_dt_strings(fdt);
    457 
    458 	if (bufsize < newsize)
    459 		return -FDT_ERR_NOSPACE;
    460 
    461 	/* First attempt to build converted tree at beginning of buffer */
    462 	tmp = buf;
    463 	/* But if that overlaps with the old tree... */
    464 	if (((tmp + newsize) > fdtstart) && (tmp < fdtend)) {
    465 		/* Try right after the old tree instead */
    466 		tmp = (char *)(uintptr_t)fdtend;
    467 		if ((tmp + newsize) > ((char *)buf + bufsize))
    468 			return -FDT_ERR_NOSPACE;
    469 	}
    470 
    471 	_fdt_packblocks(fdt, tmp, mem_rsv_size, struct_size);
    472 	memmove(buf, tmp, newsize);
    473 
    474 	fdt_set_magic(buf, FDT_MAGIC);
    475 	fdt_set_totalsize(buf, bufsize);
    476 	fdt_set_version(buf, 17);
    477 	fdt_set_last_comp_version(buf, 16);
    478 	fdt_set_boot_cpuid_phys(buf, fdt_boot_cpuid_phys(fdt));
    479 
    480 	return 0;
    481 }
    482 
    483 int fdt_pack(void *fdt)
    484 {
    485 	int mem_rsv_size;
    486 
    487 	FDT_RW_CHECK_HEADER(fdt);
    488 
    489 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
    490 		* sizeof(struct fdt_reserve_entry);
    491 	_fdt_packblocks(fdt, fdt, mem_rsv_size, fdt_size_dt_struct(fdt));
    492 	fdt_set_totalsize(fdt, _fdt_data_size(fdt));
    493 
    494 	return 0;
    495 }
    496