drivers/mtd/mtdpart.c

   1 /*
   2  * Simple MTD partitioning layer
   3  *
   4  * Copyright © 2000 Nicolas Pitre <nico@fluxnic.net>
   5  * Copyright © 2002 Thomas Gleixner <gleixner@linutronix.de>
   6  * Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program 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 License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  21  *
  22  */
  23
  24 #include <linux/module.h>
  25 #include <linux/types.h>
  26 #include <linux/kernel.h>
  27 #include <linux/slab.h>
  28 #include <linux/list.h>
  29 #include <linux/kmod.h>
  30 #include <linux/mtd/mtd.h>
  31 #include <linux/mtd/partitions.h>
  32 #include <linux/err.h>
  33 #include <linux/of.h>
  34
  35 #include "mtdcore.h"
  36
  37 /* Our partition linked list */
  38 static LIST_HEAD(mtd_partitions);
  39 static DEFINE_MUTEX(mtd_partitions_mutex);
  40
  41 /**
  42  * struct mtd_part - our partition node structure
  43  *
  44  * @mtd: struct holding partition details
  45  * @parent: parent mtd - flash device or another partition
  46  * @offset: partition offset relative to the *flash device*
  47  */
  48 struct mtd_part {
  49         struct mtd_info mtd;
  50         struct mtd_info *parent;
  51         uint64_t offset;
  52         struct list_head list;
  53 };
  54
  55 /*
  56  * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
  57  * the pointer to that structure.
  58  */
  59 static inline struct mtd_part *mtd_to_part(const struct mtd_info *mtd)
  60 {
  61         return container_of(mtd, struct mtd_part, mtd);
  62 }
  63
  64 static u64 part_absolute_offset(struct mtd_info *mtd)
  65 {
  66         struct mtd_part *part = mtd_to_part(mtd);
  67
  68         if (!mtd_is_partition(mtd))
  69                 return 0;
  70
  71         return part_absolute_offset(part->parent) + part->offset;
  72 }
  73
  74 /*
  75  * MTD methods which simply translate the effective address and pass through
  76  * to the _real_ device.
  77  */
  78
  79 static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
  80                 size_t *retlen, u_char *buf)
  81 {
  82         struct mtd_part *part = mtd_to_part(mtd);
  83         struct mtd_ecc_stats stats;
  84         int res;
  85
  86         stats = part->parent->ecc_stats;
  87         res = part->parent->_read(part->parent, from + part->offset, len,
  88                                   retlen, buf);
  89         if (unlikely(mtd_is_eccerr(res)))
  90                 mtd->ecc_stats.failed +=
  91                         part->parent->ecc_stats.failed - stats.failed;
  92         else
  93                 mtd->ecc_stats.corrected +=
  94                         part->parent->ecc_stats.corrected - stats.corrected;
  95         return res;
  96 }
  97
  98 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
  99                 size_t *retlen, void **virt, resource_size_t *phys)
 100 {
 101         struct mtd_part *part = mtd_to_part(mtd);
 102
 103         return part->parent->_point(part->parent, from + part->offset, len,
 104                                     retlen, virt, phys);
 105 }
 106
 107 static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
 108 {
 109         struct mtd_part *part = mtd_to_part(mtd);
 110
 111         return part->parent->_unpoint(part->parent, from + part->offset, len);
 112 }
 113
 114 static int part_read_oob(struct mtd_info *mtd, loff_t from,
 115                 struct mtd_oob_ops *ops)
 116 {
 117         struct mtd_part *part = mtd_to_part(mtd);
 118         struct mtd_ecc_stats stats;
 119         int res;
 120
 121         stats = part->parent->ecc_stats;
 122         res = part->parent->_read_oob(part->parent, from + part->offset, ops);
 123         if (unlikely(mtd_is_eccerr(res)))
 124                 mtd->ecc_stats.failed +=
 125                         part->parent->ecc_stats.failed - stats.failed;
 126         else
 127                 mtd->ecc_stats.corrected +=
 128                         part->parent->ecc_stats.corrected - stats.corrected;
 129         return res;
 130 }
 131
 132 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
 133                 size_t len, size_t *retlen, u_char *buf)
 134 {
 135         struct mtd_part *part = mtd_to_part(mtd);
 136         return part->parent->_read_user_prot_reg(part->parent, from, len,
 137                                                  retlen, buf);
 138 }
 139
 140 static int part_get_user_prot_info(struct mtd_info *mtd, size_t len,
 141                                    size_t *retlen, struct otp_info *buf)
 142 {
 143         struct mtd_part *part = mtd_to_part(mtd);
 144         return part->parent->_get_user_prot_info(part->parent, len, retlen,
 145                                                  buf);
 146 }
 147
 148 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
 149                 size_t len, size_t *retlen, u_char *buf)
 150 {
 151         struct mtd_part *part = mtd_to_part(mtd);
 152         return part->parent->_read_fact_prot_reg(part->parent, from, len,
 153                                                  retlen, buf);
 154 }
 155
 156 static int part_get_fact_prot_info(struct mtd_info *mtd, size_t len,
 157                                    size_t *retlen, struct otp_info *buf)
 158 {
 159         struct mtd_part *part = mtd_to_part(mtd);
 160         return part->parent->_get_fact_prot_info(part->parent, len, retlen,
 161                                                  buf);
 162 }
 163
 164 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
 165                 size_t *retlen, const u_char *buf)
 166 {
 167         struct mtd_part *part = mtd_to_part(mtd);
 168         return part->parent->_write(part->parent, to + part->offset, len,
 169                                     retlen, buf);
 170 }
 171
 172 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
 173                 size_t *retlen, const u_char *buf)
 174 {
 175         struct mtd_part *part = mtd_to_part(mtd);
 176         return part->parent->_panic_write(part->parent, to + part->offset, len,
 177                                           retlen, buf);
 178 }
 179
 180 static int part_write_oob(struct mtd_info *mtd, loff_t to,
 181                 struct mtd_oob_ops *ops)
 182 {
 183         struct mtd_part *part = mtd_to_part(mtd);
 184
 185         return part->parent->_write_oob(part->parent, to + part->offset, ops);
 186 }
 187
 188 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
 189                 size_t len, size_t *retlen, u_char *buf)
 190 {
 191         struct mtd_part *part = mtd_to_part(mtd);
 192         return part->parent->_write_user_prot_reg(part->parent, from, len,
 193                                                   retlen, buf);
 194 }
 195
 196 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
 197                 size_t len)
 198 {
 199         struct mtd_part *part = mtd_to_part(mtd);
 200         return part->parent->_lock_user_prot_reg(part->parent, from, len);
 201 }
 202
 203 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
 204                 unsigned long count, loff_t to, size_t *retlen)
 205 {
 206         struct mtd_part *part = mtd_to_part(mtd);
 207         return part->parent->_writev(part->parent, vecs, count,
 208                                      to + part->offset, retlen);
 209 }
 210
 211 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
 212 {
 213         struct mtd_part *part = mtd_to_part(mtd);
 214         int ret;
 215
 216         instr->addr += part->offset;
 217         ret = part->parent->_erase(part->parent, instr);
 218         if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 219                 instr->fail_addr -= part->offset;
 220         instr->addr -= part->offset;
 221
 222         return ret;
 223 }
 224
 225 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 226 {
 227         struct mtd_part *part = mtd_to_part(mtd);
 228         return part->parent->_lock(part->parent, ofs + part->offset, len);
 229 }
 230
 231 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 232 {
 233         struct mtd_part *part = mtd_to_part(mtd);
 234         return part->parent->_unlock(part->parent, ofs + part->offset, len);
 235 }
 236
 237 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 238 {
 239         struct mtd_part *part = mtd_to_part(mtd);
 240         return part->parent->_is_locked(part->parent, ofs + part->offset, len);
 241 }
 242
 243 static void part_sync(struct mtd_info *mtd)
 244 {
 245         struct mtd_part *part = mtd_to_part(mtd);
 246         part->parent->_sync(part->parent);
 247 }
 248
 249 static int part_suspend(struct mtd_info *mtd)
 250 {
 251         struct mtd_part *part = mtd_to_part(mtd);
 252         return part->parent->_suspend(part->parent);
 253 }
 254
 255 static void part_resume(struct mtd_info *mtd)
 256 {
 257         struct mtd_part *part = mtd_to_part(mtd);
 258         part->parent->_resume(part->parent);
 259 }
 260
 261 static int part_block_isreserved(struct mtd_info *mtd, loff_t ofs)
 262 {
 263         struct mtd_part *part = mtd_to_part(mtd);
 264         ofs += part->offset;
 265         return part->parent->_block_isreserved(part->parent, ofs);
 266 }
 267
 268 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
 269 {
 270         struct mtd_part *part = mtd_to_part(mtd);
 271         ofs += part->offset;
 272         return part->parent->_block_isbad(part->parent, ofs);
 273 }
 274
 275 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 276 {
 277         struct mtd_part *part = mtd_to_part(mtd);
 278         int res;
 279
 280         ofs += part->offset;
 281         res = part->parent->_block_markbad(part->parent, ofs);
 282         if (!res)
 283                 mtd->ecc_stats.badblocks++;
 284         return res;
 285 }
 286
 287 static int part_get_device(struct mtd_info *mtd)
 288 {
 289         struct mtd_part *part = mtd_to_part(mtd);
 290         return part->parent->_get_device(part->parent);
 291 }
 292
 293 static void part_put_device(struct mtd_info *mtd)
 294 {
 295         struct mtd_part *part = mtd_to_part(mtd);
 296         part->parent->_put_device(part->parent);
 297 }
 298
 299 static int part_ooblayout_ecc(struct mtd_info *mtd, int section,
 300                               struct mtd_oob_region *oobregion)
 301 {
 302         struct mtd_part *part = mtd_to_part(mtd);
 303
 304         return mtd_ooblayout_ecc(part->parent, section, oobregion);
 305 }
 306
 307 static int part_ooblayout_free(struct mtd_info *mtd, int section,
 308                                struct mtd_oob_region *oobregion)
 309 {
 310         struct mtd_part *part = mtd_to_part(mtd);
 311
 312         return mtd_ooblayout_free(part->parent, section, oobregion);
 313 }
 314
 315 static const struct mtd_ooblayout_ops part_ooblayout_ops = {
 316         .ecc = part_ooblayout_ecc,
 317         .free = part_ooblayout_free,
 318 };
 319
 320 static int part_max_bad_blocks(struct mtd_info *mtd, loff_t ofs, size_t len)
 321 {
 322         struct mtd_part *part = mtd_to_part(mtd);
 323
 324         return part->parent->_max_bad_blocks(part->parent,
 325                                              ofs + part->offset, len);
 326 }
 327
 328 static inline void free_partition(struct mtd_part *p)
 329 {
 330         kfree(p->mtd.name);
 331         kfree(p);
 332 }
 333
 334 static struct mtd_part *allocate_partition(struct mtd_info *parent,
 335                         const struct mtd_partition *part, int partno,
 336                         uint64_t cur_offset)
 337 {
 338         int wr_alignment = (parent->flags & MTD_NO_ERASE) ? parent->writesize :
 339                                                             parent->erasesize;
 340         struct mtd_part *slave;
 341         u32 remainder;
 342         char *name;
 343         u64 tmp;
 344
 345         /* allocate the partition structure */
 346         slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 347         name = kstrdup(part->name, GFP_KERNEL);
 348         if (!name || !slave) {
 349                 printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
 350                        parent->name);
 351                 kfree(name);
 352                 kfree(slave);
 353                 return ERR_PTR(-ENOMEM);
 354         }
 355
 356         /* set up the MTD object for this partition */
 357         slave->mtd.type = parent->type;
 358         slave->mtd.flags = parent->orig_flags & ~part->mask_flags;
 359         slave->mtd.orig_flags = slave->mtd.flags;
 360         slave->mtd.size = part->size;
 361         slave->mtd.writesize = parent->writesize;
 362         slave->mtd.writebufsize = parent->writebufsize;
 363         slave->mtd.oobsize = parent->oobsize;
 364         slave->mtd.oobavail = parent->oobavail;
 365         slave->mtd.subpage_sft = parent->subpage_sft;
 366         slave->mtd.pairing = parent->pairing;
 367
 368         slave->mtd.name = name;
 369         slave->mtd.owner = parent->owner;
 370
 371         /* NOTE: Historically, we didn't arrange MTDs as a tree out of
 372          * concern for showing the same data in multiple partitions.
 373          * However, it is very useful to have the master node present,
 374          * so the MTD_PARTITIONED_MASTER option allows that. The master
 375          * will have device nodes etc only if this is set, so make the
 376          * parent conditional on that option. Note, this is a way to
 377          * distinguish between the master and the partition in sysfs.
 378          */
 379         slave->mtd.dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) || mtd_is_partition(parent) ?
 380                                 &parent->dev :
 381                                 parent->dev.parent;
 382         slave->mtd.dev.of_node = part->of_node;
 383
 384         if (parent->_read)
 385                 slave->mtd._read = part_read;
 386         if (parent->_write)
 387                 slave->mtd._write = part_write;
 388
 389         if (parent->_panic_write)
 390                 slave->mtd._panic_write = part_panic_write;
 391
 392         if (parent->_point && parent->_unpoint) {
 393                 slave->mtd._point = part_point;
 394                 slave->mtd._unpoint = part_unpoint;
 395         }
 396
 397         if (parent->_read_oob)
 398                 slave->mtd._read_oob = part_read_oob;
 399         if (parent->_write_oob)
 400                 slave->mtd._write_oob = part_write_oob;
 401         if (parent->_read_user_prot_reg)
 402                 slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
 403         if (parent->_read_fact_prot_reg)
 404                 slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
 405         if (parent->_write_user_prot_reg)
 406                 slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
 407         if (parent->_lock_user_prot_reg)
 408                 slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
 409         if (parent->_get_user_prot_info)
 410                 slave->mtd._get_user_prot_info = part_get_user_prot_info;
 411         if (parent->_get_fact_prot_info)
 412                 slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
 413         if (parent->_sync)
 414                 slave->mtd._sync = part_sync;
 415         if (!partno && !parent->dev.class && parent->_suspend &&
 416             parent->_resume) {
 417                 slave->mtd._suspend = part_suspend;
 418                 slave->mtd._resume = part_resume;
 419         }
 420         if (parent->_writev)
 421                 slave->mtd._writev = part_writev;
 422         if (parent->_lock)
 423                 slave->mtd._lock = part_lock;
 424         if (parent->_unlock)
 425                 slave->mtd._unlock = part_unlock;
 426         if (parent->_is_locked)
 427                 slave->mtd._is_locked = part_is_locked;
 428         if (parent->_block_isreserved)
 429                 slave->mtd._block_isreserved = part_block_isreserved;
 430         if (parent->_block_isbad)
 431                 slave->mtd._block_isbad = part_block_isbad;
 432         if (parent->_block_markbad)
 433                 slave->mtd._block_markbad = part_block_markbad;
 434         if (parent->_max_bad_blocks)
 435                 slave->mtd._max_bad_blocks = part_max_bad_blocks;
 436
 437         if (parent->_get_device)
 438                 slave->mtd._get_device = part_get_device;
 439         if (parent->_put_device)
 440                 slave->mtd._put_device = part_put_device;
 441
 442         slave->mtd._erase = part_erase;
 443         slave->parent = parent;
 444         slave->offset = part->offset;
 445
 446         if (slave->offset == MTDPART_OFS_APPEND)
 447                 slave->offset = cur_offset;
 448         if (slave->offset == MTDPART_OFS_NXTBLK) {
 449                 tmp = cur_offset;
 450                 slave->offset = cur_offset;
 451                 remainder = do_div(tmp, wr_alignment);
 452                 if (remainder) {
 453                         slave->offset += wr_alignment - remainder;
 454                         printk(KERN_NOTICE "Moving partition %d: "
 455                                "0x%012llx -> 0x%012llx\n", partno,
 456                                (unsigned long long)cur_offset, (unsigned long long)slave->offset);
 457                 }
 458         }
 459         if (slave->offset == MTDPART_OFS_RETAIN) {
 460                 slave->offset = cur_offset;
 461                 if (parent->size - slave->offset >= slave->mtd.size) {
 462                         slave->mtd.size = parent->size - slave->offset
 463                                                         - slave->mtd.size;
 464                 } else {
 465                         printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
 466                                 part->name, parent->size - slave->offset,
 467                                 slave->mtd.size);
 468                         /* register to preserve ordering */
 469                         goto out_register;
 470                 }
 471         }
 472         if (slave->mtd.size == MTDPART_SIZ_FULL)
 473                 slave->mtd.size = parent->size - slave->offset;
 474
 475         printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
 476                 (unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
 477
 478         /* let's do some sanity checks */
 479         if (slave->offset >= parent->size) {
 480                 /* let's register it anyway to preserve ordering */
 481                 slave->offset = 0;
 482                 slave->mtd.size = 0;
 483
 484                 /* Initialize ->erasesize to make add_mtd_device() happy. */
 485                 slave->mtd.erasesize = parent->erasesize;
 486
 487                 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
 488                         part->name);
 489                 goto out_register;
 490         }
 491         if (slave->offset + slave->mtd.size > parent->size) {
 492                 slave->mtd.size = parent->size - slave->offset;
 493                 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
 494                         part->name, parent->name, (unsigned long long)slave->mtd.size);
 495         }
 496         if (parent->numeraseregions > 1) {
 497                 /* Deal with variable erase size stuff */
 498                 int i, max = parent->numeraseregions;
 499                 u64 end = slave->offset + slave->mtd.size;
 500                 struct mtd_erase_region_info *regions = parent->eraseregions;
 501
 502                 /* Find the first erase regions which is part of this
 503                  * partition. */
 504                 for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
 505                         ;
 506                 /* The loop searched for the region _behind_ the first one */
 507                 if (i > 0)
 508                         i--;
 509
 510                 /* Pick biggest erasesize */
 511                 for (; i < max && regions[i].offset < end; i++) {
 512                         if (slave->mtd.erasesize < regions[i].erasesize) {
 513                                 slave->mtd.erasesize = regions[i].erasesize;
 514                         }
 515                 }
 516                 BUG_ON(slave->mtd.erasesize == 0);
 517         } else {
 518                 /* Single erase size */
 519                 slave->mtd.erasesize = parent->erasesize;
 520         }
 521
 522         /*
 523          * Slave erasesize might differ from the master one if the master
 524          * exposes several regions with different erasesize. Adjust
 525          * wr_alignment accordingly.
 526          */
 527         if (!(slave->mtd.flags & MTD_NO_ERASE))
 528                 wr_alignment = slave->mtd.erasesize;
 529
 530         tmp = part_absolute_offset(parent) + slave->offset;
 531         remainder = do_div(tmp, wr_alignment);
 532         if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
 533                 /* Doesn't start on a boundary of major erase size */
 534                 /* FIXME: Let it be writable if it is on a boundary of
 535                  * _minor_ erase size though */
 536                 slave->mtd.flags &= ~MTD_WRITEABLE;
 537                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n",
 538                         part->name);
 539         }
 540
 541         tmp = part_absolute_offset(parent) + slave->mtd.size;
 542         remainder = do_div(tmp, wr_alignment);
 543         if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
 544                 slave->mtd.flags &= ~MTD_WRITEABLE;
 545                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n",
 546                         part->name);
 547         }
 548
 549         mtd_set_ooblayout(&slave->mtd, &part_ooblayout_ops);
 550         slave->mtd.ecc_step_size = parent->ecc_step_size;
 551         slave->mtd.ecc_strength = parent->ecc_strength;
 552         slave->mtd.bitflip_threshold = parent->bitflip_threshold;
 553
 554         if (parent->_block_isbad) {
 555                 uint64_t offs = 0;
 556
 557                 while (offs < slave->mtd.size) {
 558                         if (mtd_block_isreserved(parent, offs + slave->offset))
 559                                 slave->mtd.ecc_stats.bbtblocks++;
 560                         else if (mtd_block_isbad(parent, offs + slave->offset))
 561                                 slave->mtd.ecc_stats.badblocks++;
 562                         offs += slave->mtd.erasesize;
 563                 }
 564         }
 565
 566 out_register:
 567         return slave;
 568 }
 569
 570 static ssize_t mtd_partition_offset_show(struct device *dev,
 571                 struct device_attribute *attr, char *buf)
 572 {
 573         struct mtd_info *mtd = dev_get_drvdata(dev);
 574         struct mtd_part *part = mtd_to_part(mtd);
 575         return snprintf(buf, PAGE_SIZE, "%lld\n", part->offset);
 576 }
 577
 578 static DEVICE_ATTR(offset, S_IRUGO, mtd_partition_offset_show, NULL);
 579
 580 static const struct attribute *mtd_partition_attrs[] = {
 581         &dev_attr_offset.attr,
 582         NULL
 583 };
 584
 585 static int mtd_add_partition_attrs(struct mtd_part *new)
 586 {
 587         int ret = sysfs_create_files(&new->mtd.dev.kobj, mtd_partition_attrs);
 588         if (ret)
 589                 printk(KERN_WARNING
 590                        "mtd: failed to create partition attrs, err=%d\n", ret);
 591         return ret;
 592 }
 593
 594 int mtd_add_partition(struct mtd_info *parent, const char *name,
 595                       long long offset, long long length)
 596 {
 597         struct mtd_partition part;
 598         struct mtd_part *new;
 599         int ret = 0;
 600
 601         /* the direct offset is expected */
 602         if (offset == MTDPART_OFS_APPEND ||
 603             offset == MTDPART_OFS_NXTBLK)
 604                 return -EINVAL;
 605
 606         if (length == MTDPART_SIZ_FULL)
 607                 length = parent->size - offset;
 608
 609         if (length <= 0)
 610                 return -EINVAL;
 611
 612         memset(&part, 0, sizeof(part));
 613         part.name = name;
 614         part.size = length;
 615         part.offset = offset;
 616
 617         new = allocate_partition(parent, &part, -1, offset);
 618         if (IS_ERR(new))
 619                 return PTR_ERR(new);
 620
 621         mutex_lock(&mtd_partitions_mutex);
 622         list_add(&new->list, &mtd_partitions);
 623         mutex_unlock(&mtd_partitions_mutex);
 624
 625         ret = add_mtd_device(&new->mtd);
 626         if (ret)
 627                 goto err_remove_part;
 628
 629         mtd_add_partition_attrs(new);
 630
 631         return 0;
 632
 633 err_remove_part:
 634         mutex_lock(&mtd_partitions_mutex);
 635         list_del(&new->list);
 636         mutex_unlock(&mtd_partitions_mutex);
 637
 638         free_partition(new);
 639
 640         return ret;
 641 }
 642 EXPORT_SYMBOL_GPL(mtd_add_partition);
 643
 644 /**
 645  * __mtd_del_partition - delete MTD partition
 646  *
 647  * @priv: internal MTD struct for partition to be deleted
 648  *
 649  * This function must be called with the partitions mutex locked.
 650  */
 651 static int __mtd_del_partition(struct mtd_part *priv)
 652 {
 653         struct mtd_part *child, *next;
 654         int err;
 655
 656         list_for_each_entry_safe(child, next, &mtd_partitions, list) {
 657                 if (child->parent == &priv->mtd) {
 658                         err = __mtd_del_partition(child);
 659                         if (err)
 660                                 return err;
 661                 }
 662         }
 663
 664         sysfs_remove_files(&priv->mtd.dev.kobj, mtd_partition_attrs);
 665
 666         err = del_mtd_device(&priv->mtd);
 667         if (err)
 668                 return err;
 669
 670         list_del(&priv->list);
 671         free_partition(priv);
 672
 673         return 0;
 674 }
 675
 676 /*
 677  * This function unregisters and destroy all slave MTD objects which are
 678  * attached to the given MTD object.
 679  */
 680 int del_mtd_partitions(struct mtd_info *mtd)
 681 {
 682         struct mtd_part *slave, *next;
 683         int ret, err = 0;
 684
 685         mutex_lock(&mtd_partitions_mutex);
 686         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 687                 if (slave->parent == mtd) {
 688                         ret = __mtd_del_partition(slave);
 689                         if (ret < 0)
 690                                 err = ret;
 691                 }
 692         mutex_unlock(&mtd_partitions_mutex);
 693
 694         return err;
 695 }
 696
 697 int mtd_del_partition(struct mtd_info *mtd, int partno)
 698 {
 699         struct mtd_part *slave, *next;
 700         int ret = -EINVAL;
 701
 702         mutex_lock(&mtd_partitions_mutex);
 703         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 704                 if ((slave->parent == mtd) &&
 705                     (slave->mtd.index == partno)) {
 706                         ret = __mtd_del_partition(slave);
 707                         break;
 708                 }
 709         mutex_unlock(&mtd_partitions_mutex);
 710
 711         return ret;
 712 }
 713 EXPORT_SYMBOL_GPL(mtd_del_partition);
 714
 715 /*
 716  * This function, given a master MTD object and a partition table, creates
 717  * and registers slave MTD objects which are bound to the master according to
 718  * the partition definitions.
 719  *
 720  * For historical reasons, this function's caller only registers the master
 721  * if the MTD_PARTITIONED_MASTER config option is set.
 722  */
 723
 724 int add_mtd_partitions(struct mtd_info *master,
 725                        const struct mtd_partition *parts,
 726                        int nbparts)
 727 {
 728         struct mtd_part *slave;
 729         uint64_t cur_offset = 0;
 730         int i, ret;
 731
 732         printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 733
 734         for (i = 0; i < nbparts; i++) {
 735                 slave = allocate_partition(master, parts + i, i, cur_offset);
 736                 if (IS_ERR(slave)) {
 737                         ret = PTR_ERR(slave);
 738                         goto err_del_partitions;
 739                 }
 740
 741                 mutex_lock(&mtd_partitions_mutex);
 742                 list_add(&slave->list, &mtd_partitions);
 743                 mutex_unlock(&mtd_partitions_mutex);
 744
 745                 ret = add_mtd_device(&slave->mtd);
 746                 if (ret) {
 747                         mutex_lock(&mtd_partitions_mutex);
 748                         list_del(&slave->list);
 749                         mutex_unlock(&mtd_partitions_mutex);
 750
 751                         free_partition(slave);
 752                         goto err_del_partitions;
 753                 }
 754
 755                 mtd_add_partition_attrs(slave);
 756                 /* Look for subpartitions */
 757                 parse_mtd_partitions(&slave->mtd, parts[i].types, NULL);
 758
 759                 cur_offset = slave->offset + slave->mtd.size;
 760         }
 761
 762         return 0;
 763
 764 err_del_partitions:
 765         del_mtd_partitions(master);
 766
 767         return ret;
 768 }
 769
 770 static DEFINE_SPINLOCK(part_parser_lock);
 771 static LIST_HEAD(part_parsers);
 772
 773 static struct mtd_part_parser *mtd_part_parser_get(const char *name)
 774 {
 775         struct mtd_part_parser *p, *ret = NULL;
 776
 777         spin_lock(&part_parser_lock);
 778
 779         list_for_each_entry(p, &part_parsers, list)
 780                 if (!strcmp(p->name, name) && try_module_get(p->owner)) {
 781                         ret = p;
 782                         break;
 783                 }
 784
 785         spin_unlock(&part_parser_lock);
 786
 787         return ret;
 788 }
 789
 790 static inline void mtd_part_parser_put(const struct mtd_part_parser *p)
 791 {
 792         module_put(p->owner);
 793 }
 794
 795 /*
 796  * Many partition parsers just expected the core to kfree() all their data in
 797  * one chunk. Do that by default.
 798  */
 799 static void mtd_part_parser_cleanup_default(const struct mtd_partition *pparts,
 800                                             int nr_parts)
 801 {
 802         kfree(pparts);
 803 }
 804
 805 int __register_mtd_parser(struct mtd_part_parser *p, struct module *owner)
 806 {
 807         p->owner = owner;
 808
 809         if (!p->cleanup)
 810                 p->cleanup = &mtd_part_parser_cleanup_default;
 811
 812         spin_lock(&part_parser_lock);
 813         list_add(&p->list, &part_parsers);
 814         spin_unlock(&part_parser_lock);
 815
 816         return 0;
 817 }
 818 EXPORT_SYMBOL_GPL(__register_mtd_parser);
 819
 820 void deregister_mtd_parser(struct mtd_part_parser *p)
 821 {
 822         spin_lock(&part_parser_lock);
 823         list_del(&p->list);
 824         spin_unlock(&part_parser_lock);
 825 }
 826 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
 827
 828 /*
 829  * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
 830  * are changing this array!
 831  */
 832 static const char * const default_mtd_part_types[] = {
 833         "cmdlinepart",
 834         "ofpart",
 835         NULL
 836 };
 837
 838 /* Check DT only when looking for subpartitions. */
 839 static const char * const default_subpartition_types[] = {
 840         "ofpart",
 841         NULL
 842 };
 843
 844 static int mtd_part_do_parse(struct mtd_part_parser *parser,
 845                              struct mtd_info *master,
 846                              struct mtd_partitions *pparts,
 847                              struct mtd_part_parser_data *data)
 848 {
 849         int ret;
 850
 851         ret = (*parser->parse_fn)(master, &pparts->parts, data);
 852         pr_debug("%s: parser %s: %i\n", master->name, parser->name, ret);
 853         if (ret <= 0)
 854                 return ret;
 855
 856         pr_notice("%d %s partitions found on MTD device %s\n", ret,
 857                   parser->name, master->name);
 858
 859         pparts->nr_parts = ret;
 860         pparts->parser = parser;
 861
 862         return ret;
 863 }
 864
 865 /**
 866  * mtd_part_get_compatible_parser - find MTD parser by a compatible string
 867  *
 868  * @compat: compatible string describing partitions in a device tree
 869  *
 870  * MTD parsers can specify supported partitions by providing a table of
 871  * compatibility strings. This function finds a parser that advertises support
 872  * for a passed value of "compatible".
 873  */
 874 static struct mtd_part_parser *mtd_part_get_compatible_parser(const char *compat)
 875 {
 876         struct mtd_part_parser *p, *ret = NULL;
 877
 878         spin_lock(&part_parser_lock);
 879
 880         list_for_each_entry(p, &part_parsers, list) {
 881                 const struct of_device_id *matches;
 882
 883                 matches = p->of_match_table;
 884                 if (!matches)
 885                         continue;
 886
 887                 for (; matches->compatible[0]; matches++) {
 888                         if (!strcmp(matches->compatible, compat) &&
 889                             try_module_get(p->owner)) {
 890                                 ret = p;
 891                                 break;
 892                         }
 893                 }
 894
 895                 if (ret)
 896                         break;
 897         }
 898
 899         spin_unlock(&part_parser_lock);
 900
 901         return ret;
 902 }
 903
 904 static int mtd_part_of_parse(struct mtd_info *master,
 905                              struct mtd_partitions *pparts)
 906 {
 907         struct mtd_part_parser *parser;
 908         struct device_node *np;
 909         struct property *prop;
 910         const char *compat;
 911         const char *fixed = "fixed-partitions";
 912         int ret, err = 0;
 913
 914         np = mtd_get_of_node(master);
 915         if (mtd_is_partition(master))
 916                 of_node_get(np);
 917         else
 918                 np = of_get_child_by_name(np, "partitions");
 919
 920         of_property_for_each_string(np, "compatible", prop, compat) {
 921                 parser = mtd_part_get_compatible_parser(compat);
 922                 if (!parser)
 923                         continue;
 924                 ret = mtd_part_do_parse(parser, master, pparts, NULL);
 925                 if (ret > 0) {
 926                         of_node_put(np);
 927                         return ret;
 928                 }
 929                 mtd_part_parser_put(parser);
 930                 if (ret < 0 && !err)
 931                         err = ret;
 932         }
 933         of_node_put(np);
 934
 935         /*
 936          * For backward compatibility we have to try the "fixed-partitions"
 937          * parser. It supports old DT format with partitions specified as a
 938          * direct subnodes of a flash device DT node without any compatibility
 939          * specified we could match.
 940          */
 941         parser = mtd_part_parser_get(fixed);
 942         if (!parser && !request_module("%s", fixed))
 943                 parser = mtd_part_parser_get(fixed);
 944         if (parser) {
 945                 ret = mtd_part_do_parse(parser, master, pparts, NULL);
 946                 if (ret > 0)
 947                         return ret;
 948                 mtd_part_parser_put(parser);
 949                 if (ret < 0 && !err)
 950                         err = ret;
 951         }
 952
 953         return err;
 954 }
 955
 956 /**
 957  * parse_mtd_partitions - parse and register MTD partitions
 958  *
 959  * @master: the master partition (describes whole MTD device)
 960  * @types: names of partition parsers to try or %NULL
 961  * @data: MTD partition parser-specific data
 962  *
 963  * This function tries to find & register partitions on MTD device @master. It
 964  * uses MTD partition parsers, specified in @types. However, if @types is %NULL,
 965  * then the default list of parsers is used. The default list contains only the
 966  * "cmdlinepart" and "ofpart" parsers ATM.
 967  * Note: If there are more then one parser in @types, the kernel only takes the
 968  * partitions parsed out by the first parser.
 969  *
 970  * This function may return:
 971  * o a negative error code in case of failure
 972  * o number of found partitions otherwise
 973  */
 974 int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
 975                          struct mtd_part_parser_data *data)
 976 {
 977         struct mtd_partitions pparts = { };
 978         struct mtd_part_parser *parser;
 979         int ret, err = 0;
 980
 981         if (!types)
 982                 types = mtd_is_partition(master) ? default_subpartition_types :
 983                         default_mtd_part_types;
 984
 985         for ( ; *types; types++) {
 986                 /*
 987                  * ofpart is a special type that means OF partitioning info
 988                  * should be used. It requires a bit different logic so it is
 989                  * handled in a separated function.
 990                  */
 991                 if (!strcmp(*types, "ofpart")) {
 992                         ret = mtd_part_of_parse(master, &pparts);
 993                 } else {
 994                         pr_debug("%s: parsing partitions %s\n", master->name,
 995                                  *types);
 996                         parser = mtd_part_parser_get(*types);
 997                         if (!parser && !request_module("%s", *types))
 998                                 parser = mtd_part_parser_get(*types);
 999                         pr_debug("%s: got parser %s\n", master->name,
1000                                 parser ? parser->name : NULL);
1001                         if (!parser)
1002                                 continue;
1003                         ret = mtd_part_do_parse(parser, master, &pparts, data);
1004                         if (ret <= 0)
1005                                 mtd_part_parser_put(parser);
1006                 }
1007                 /* Found partitions! */
1008                 if (ret > 0) {
1009                         err = add_mtd_partitions(master, pparts.parts,
1010                                                  pparts.nr_parts);
1011                         mtd_part_parser_cleanup(&pparts);
1012                         return err ? err : pparts.nr_parts;
1013                 }
1014                 /*
1015                  * Stash the first error we see; only report it if no parser
1016                  * succeeds
1017                  */
1018                 if (ret < 0 && !err)
1019                         err = ret;
1020         }
1021         return err;
1022 }
1023
1024 void mtd_part_parser_cleanup(struct mtd_partitions *parts)
1025 {
1026         const struct mtd_part_parser *parser;
1027
1028         if (!parts)
1029                 return;
1030
1031         parser = parts->parser;
1032         if (parser) {
1033                 if (parser->cleanup)
1034                         parser->cleanup(parts->parts, parts->nr_parts);
1035
1036                 mtd_part_parser_put(parser);
1037         }
1038 }
1039
1040 int mtd_is_partition(const struct mtd_info *mtd)
1041 {
1042         struct mtd_part *part;
1043         int ispart = 0;
1044
1045         mutex_lock(&mtd_partitions_mutex);
1046         list_for_each_entry(part, &mtd_partitions, list)
1047                 if (&part->mtd == mtd) {
1048                         ispart = 1;
1049                         break;
1050                 }
1051         mutex_unlock(&mtd_partitions_mutex);
1052
1053         return ispart;
1054 }
1055 EXPORT_SYMBOL_GPL(mtd_is_partition);
1056
1057 /* Returns the size of the entire flash chip */
1058 uint64_t mtd_get_device_size(const struct mtd_info *mtd)
1059 {
1060         if (!mtd_is_partition(mtd))
1061                 return mtd->size;
1062
1063         return mtd_get_device_size(mtd_to_part(mtd)->parent);
1064 }
1065 EXPORT_SYMBOL_GPL(mtd_get_device_size);