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
  34 #include "mtdcore.h"
  35
  36 /* Our partition linked list */
  37 static LIST_HEAD(mtd_partitions);
  38 static DEFINE_MUTEX(mtd_partitions_mutex);
  39
  40 /* Our partition node structure */
  41 struct mtd_part {
  42         struct mtd_info mtd;
  43         struct mtd_info *master;
  44         uint64_t offset;
  45         struct list_head list;
  46 };
  47
  48 /*
  49  * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
  50  * the pointer to that structure with this macro.
  51  */
  52 #define PART(x)  ((struct mtd_part *)(x))
  53
  54
  55 /*
  56  * MTD methods which simply translate the effective address and pass through
  57  * to the _real_ device.
  58  */
  59
  60 static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
  61                 size_t *retlen, u_char *buf)
  62 {
  63         struct mtd_part *part = PART(mtd);
  64         struct mtd_ecc_stats stats;
  65         int res;
  66
  67         stats = part->master->ecc_stats;
  68         res = part->master->_read(part->master, from + part->offset, len,
  69                                   retlen, buf);
  70         if (unlikely(mtd_is_eccerr(res)))
  71                 mtd->ecc_stats.failed +=
  72                         part->master->ecc_stats.failed - stats.failed;
  73         else
  74                 mtd->ecc_stats.corrected +=
  75                         part->master->ecc_stats.corrected - stats.corrected;
  76         return res;
  77 }
  78
  79 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
  80                 size_t *retlen, void **virt, resource_size_t *phys)
  81 {
  82         struct mtd_part *part = PART(mtd);
  83
  84         return part->master->_point(part->master, from + part->offset, len,
  85                                     retlen, virt, phys);
  86 }
  87
  88 static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
  89 {
  90         struct mtd_part *part = PART(mtd);
  91
  92         return part->master->_unpoint(part->master, from + part->offset, len);
  93 }
  94
  95 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
  96                                             unsigned long len,
  97                                             unsigned long offset,
  98                                             unsigned long flags)
  99 {
 100         struct mtd_part *part = PART(mtd);
 101
 102         offset += part->offset;
 103         return part->master->_get_unmapped_area(part->master, len, offset,
 104                                                 flags);
 105 }
 106
 107 static int part_read_oob(struct mtd_info *mtd, loff_t from,
 108                 struct mtd_oob_ops *ops)
 109 {
 110         struct mtd_part *part = PART(mtd);
 111         int res;
 112
 113         if (from >= mtd->size)
 114                 return -EINVAL;
 115         if (ops->datbuf && from + ops->len > mtd->size)
 116                 return -EINVAL;
 117
 118         /*
 119          * If OOB is also requested, make sure that we do not read past the end
 120          * of this partition.
 121          */
 122         if (ops->oobbuf) {
 123                 size_t len, pages;
 124
 125                 if (ops->mode == MTD_OPS_AUTO_OOB)
 126                         len = mtd->oobavail;
 127                 else
 128                         len = mtd->oobsize;
 129                 pages = mtd_div_by_ws(mtd->size, mtd);
 130                 pages -= mtd_div_by_ws(from, mtd);
 131                 if (ops->ooboffs + ops->ooblen > pages * len)
 132                         return -EINVAL;
 133         }
 134
 135         res = part->master->_read_oob(part->master, from + part->offset, ops);
 136         if (unlikely(res)) {
 137                 if (mtd_is_bitflip(res))
 138                         mtd->ecc_stats.corrected++;
 139                 if (mtd_is_eccerr(res))
 140                         mtd->ecc_stats.failed++;
 141         }
 142         return res;
 143 }
 144
 145 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
 146                 size_t len, size_t *retlen, u_char *buf)
 147 {
 148         struct mtd_part *part = PART(mtd);
 149         return part->master->_read_user_prot_reg(part->master, from, len,
 150                                                  retlen, buf);
 151 }
 152
 153 static int part_get_user_prot_info(struct mtd_info *mtd, size_t len,
 154                                    size_t *retlen, struct otp_info *buf)
 155 {
 156         struct mtd_part *part = PART(mtd);
 157         return part->master->_get_user_prot_info(part->master, len, retlen,
 158                                                  buf);
 159 }
 160
 161 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
 162                 size_t len, size_t *retlen, u_char *buf)
 163 {
 164         struct mtd_part *part = PART(mtd);
 165         return part->master->_read_fact_prot_reg(part->master, from, len,
 166                                                  retlen, buf);
 167 }
 168
 169 static int part_get_fact_prot_info(struct mtd_info *mtd, size_t len,
 170                                    size_t *retlen, struct otp_info *buf)
 171 {
 172         struct mtd_part *part = PART(mtd);
 173         return part->master->_get_fact_prot_info(part->master, len, retlen,
 174                                                  buf);
 175 }
 176
 177 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
 178                 size_t *retlen, const u_char *buf)
 179 {
 180         struct mtd_part *part = PART(mtd);
 181         return part->master->_write(part->master, to + part->offset, len,
 182                                     retlen, buf);
 183 }
 184
 185 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
 186                 size_t *retlen, const u_char *buf)
 187 {
 188         struct mtd_part *part = PART(mtd);
 189         return part->master->_panic_write(part->master, to + part->offset, len,
 190                                           retlen, buf);
 191 }
 192
 193 static int part_write_oob(struct mtd_info *mtd, loff_t to,
 194                 struct mtd_oob_ops *ops)
 195 {
 196         struct mtd_part *part = PART(mtd);
 197
 198         if (to >= mtd->size)
 199                 return -EINVAL;
 200         if (ops->datbuf && to + ops->len > mtd->size)
 201                 return -EINVAL;
 202         return part->master->_write_oob(part->master, to + part->offset, ops);
 203 }
 204
 205 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
 206                 size_t len, size_t *retlen, u_char *buf)
 207 {
 208         struct mtd_part *part = PART(mtd);
 209         return part->master->_write_user_prot_reg(part->master, from, len,
 210                                                   retlen, buf);
 211 }
 212
 213 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
 214                 size_t len)
 215 {
 216         struct mtd_part *part = PART(mtd);
 217         return part->master->_lock_user_prot_reg(part->master, from, len);
 218 }
 219
 220 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
 221                 unsigned long count, loff_t to, size_t *retlen)
 222 {
 223         struct mtd_part *part = PART(mtd);
 224         return part->master->_writev(part->master, vecs, count,
 225                                      to + part->offset, retlen);
 226 }
 227
 228 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
 229 {
 230         struct mtd_part *part = PART(mtd);
 231         int ret;
 232
 233         instr->addr += part->offset;
 234         ret = part->master->_erase(part->master, instr);
 235         if (ret) {
 236                 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 237                         instr->fail_addr -= part->offset;
 238                 instr->addr -= part->offset;
 239         }
 240         return ret;
 241 }
 242
 243 void mtd_erase_callback(struct erase_info *instr)
 244 {
 245         if (instr->mtd->_erase == part_erase) {
 246                 struct mtd_part *part = PART(instr->mtd);
 247
 248                 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 249                         instr->fail_addr -= part->offset;
 250                 instr->addr -= part->offset;
 251         }
 252         if (instr->callback)
 253                 instr->callback(instr);
 254 }
 255 EXPORT_SYMBOL_GPL(mtd_erase_callback);
 256
 257 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 258 {
 259         struct mtd_part *part = PART(mtd);
 260         return part->master->_lock(part->master, ofs + part->offset, len);
 261 }
 262
 263 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 264 {
 265         struct mtd_part *part = PART(mtd);
 266         return part->master->_unlock(part->master, ofs + part->offset, len);
 267 }
 268
 269 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 270 {
 271         struct mtd_part *part = PART(mtd);
 272         return part->master->_is_locked(part->master, ofs + part->offset, len);
 273 }
 274
 275 static void part_sync(struct mtd_info *mtd)
 276 {
 277         struct mtd_part *part = PART(mtd);
 278         part->master->_sync(part->master);
 279 }
 280
 281 static int part_suspend(struct mtd_info *mtd)
 282 {
 283         struct mtd_part *part = PART(mtd);
 284         return part->master->_suspend(part->master);
 285 }
 286
 287 static void part_resume(struct mtd_info *mtd)
 288 {
 289         struct mtd_part *part = PART(mtd);
 290         part->master->_resume(part->master);
 291 }
 292
 293 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
 294 {
 295         struct mtd_part *part = PART(mtd);
 296         ofs += part->offset;
 297         return part->master->_block_isbad(part->master, ofs);
 298 }
 299
 300 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 301 {
 302         struct mtd_part *part = PART(mtd);
 303         int res;
 304
 305         ofs += part->offset;
 306         res = part->master->_block_markbad(part->master, ofs);
 307         if (!res)
 308                 mtd->ecc_stats.badblocks++;
 309         return res;
 310 }
 311
 312 static inline void free_partition(struct mtd_part *p)
 313 {
 314         kfree(p->mtd.name);
 315         kfree(p);
 316 }
 317
 318 /*
 319  * This function unregisters and destroy all slave MTD objects which are
 320  * attached to the given master MTD object.
 321  */
 322
 323 int del_mtd_partitions(struct mtd_info *master)
 324 {
 325         struct mtd_part *slave, *next;
 326         int ret, err = 0;
 327
 328         mutex_lock(&mtd_partitions_mutex);
 329         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 330                 if (slave->master == master) {
 331                         ret = del_mtd_device(&slave->mtd);
 332                         if (ret < 0) {
 333                                 err = ret;
 334                                 continue;
 335                         }
 336                         list_del(&slave->list);
 337                         free_partition(slave);
 338                 }
 339         mutex_unlock(&mtd_partitions_mutex);
 340
 341         return err;
 342 }
 343
 344 static struct mtd_part *allocate_partition(struct mtd_info *master,
 345                         const struct mtd_partition *part, int partno,
 346                         uint64_t cur_offset)
 347 {
 348         struct mtd_part *slave;
 349         char *name;
 350
 351         /* allocate the partition structure */
 352         slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 353         name = kstrdup(part->name, GFP_KERNEL);
 354         if (!name || !slave) {
 355                 printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
 356                        master->name);
 357                 kfree(name);
 358                 kfree(slave);
 359                 return ERR_PTR(-ENOMEM);
 360         }
 361
 362         /* set up the MTD object for this partition */
 363         slave->mtd.type = master->type;
 364         slave->mtd.flags = master->flags & ~part->mask_flags;
 365         slave->mtd.size = part->size;
 366         slave->mtd.writesize = master->writesize;
 367         slave->mtd.writebufsize = master->writebufsize;
 368         slave->mtd.oobsize = master->oobsize;
 369         slave->mtd.oobavail = master->oobavail;
 370         slave->mtd.subpage_sft = master->subpage_sft;
 371
 372         slave->mtd.name = name;
 373         slave->mtd.owner = master->owner;
 374         slave->mtd.backing_dev_info = master->backing_dev_info;
 375
 376         /* NOTE:  we don't arrange MTDs as a tree; it'd be error-prone
 377          * to have the same data be in two different partitions.
 378          */
 379         slave->mtd.dev.parent = master->dev.parent;
 380
 381         slave->mtd._read = part_read;
 382         slave->mtd._write = part_write;
 383
 384         if (master->_panic_write)
 385                 slave->mtd._panic_write = part_panic_write;
 386
 387         if (master->_point && master->_unpoint) {
 388                 slave->mtd._point = part_point;
 389                 slave->mtd._unpoint = part_unpoint;
 390         }
 391
 392         if (master->_get_unmapped_area)
 393                 slave->mtd._get_unmapped_area = part_get_unmapped_area;
 394         if (master->_read_oob)
 395                 slave->mtd._read_oob = part_read_oob;
 396         if (master->_write_oob)
 397                 slave->mtd._write_oob = part_write_oob;
 398         if (master->_read_user_prot_reg)
 399                 slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
 400         if (master->_read_fact_prot_reg)
 401                 slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
 402         if (master->_write_user_prot_reg)
 403                 slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
 404         if (master->_lock_user_prot_reg)
 405                 slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
 406         if (master->_get_user_prot_info)
 407                 slave->mtd._get_user_prot_info = part_get_user_prot_info;
 408         if (master->_get_fact_prot_info)
 409                 slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
 410         if (master->_sync)
 411                 slave->mtd._sync = part_sync;
 412         if (!partno && !master->dev.class && master->_suspend &&
 413             master->_resume) {
 414                         slave->mtd._suspend = part_suspend;
 415                         slave->mtd._resume = part_resume;
 416         }
 417         if (master->_writev)
 418                 slave->mtd._writev = part_writev;
 419         if (master->_lock)
 420                 slave->mtd._lock = part_lock;
 421         if (master->_unlock)
 422                 slave->mtd._unlock = part_unlock;
 423         if (master->_is_locked)
 424                 slave->mtd._is_locked = part_is_locked;
 425         if (master->_block_isbad)
 426                 slave->mtd._block_isbad = part_block_isbad;
 427         if (master->_block_markbad)
 428                 slave->mtd._block_markbad = part_block_markbad;
 429         slave->mtd._erase = part_erase;
 430         slave->master = master;
 431         slave->offset = part->offset;
 432
 433         if (slave->offset == MTDPART_OFS_APPEND)
 434                 slave->offset = cur_offset;
 435         if (slave->offset == MTDPART_OFS_NXTBLK) {
 436                 slave->offset = cur_offset;
 437                 if (mtd_mod_by_eb(cur_offset, master) != 0) {
 438                         /* Round up to next erasesize */
 439                         slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
 440                         printk(KERN_NOTICE "Moving partition %d: "
 441                                "0x%012llx -> 0x%012llx\n", partno,
 442                                (unsigned long long)cur_offset, (unsigned long long)slave->offset);
 443                 }
 444         }
 445         if (slave->offset == MTDPART_OFS_RETAIN) {
 446                 slave->offset = cur_offset;
 447                 if (master->size - slave->offset >= slave->mtd.size) {
 448                         slave->mtd.size = master->size - slave->offset
 449                                                         - slave->mtd.size;
 450                 } else {
 451                         printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
 452                                 part->name, master->size - slave->offset,
 453                                 slave->mtd.size);
 454                         /* register to preserve ordering */
 455                         goto out_register;
 456                 }
 457         }
 458         if (slave->mtd.size == MTDPART_SIZ_FULL)
 459                 slave->mtd.size = master->size - slave->offset;
 460
 461         printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
 462                 (unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
 463
 464         /* let's do some sanity checks */
 465         if (slave->offset >= master->size) {
 466                 /* let's register it anyway to preserve ordering */
 467                 slave->offset = 0;
 468                 slave->mtd.size = 0;
 469                 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
 470                         part->name);
 471                 goto out_register;
 472         }
 473         if (slave->offset + slave->mtd.size > master->size) {
 474                 slave->mtd.size = master->size - slave->offset;
 475                 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
 476                         part->name, master->name, (unsigned long long)slave->mtd.size);
 477         }
 478         if (master->numeraseregions > 1) {
 479                 /* Deal with variable erase size stuff */
 480                 int i, max = master->numeraseregions;
 481                 u64 end = slave->offset + slave->mtd.size;
 482                 struct mtd_erase_region_info *regions = master->eraseregions;
 483
 484                 /* Find the first erase regions which is part of this
 485                  * partition. */
 486                 for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
 487                         ;
 488                 /* The loop searched for the region _behind_ the first one */
 489                 if (i > 0)
 490                         i--;
 491
 492                 /* Pick biggest erasesize */
 493                 for (; i < max && regions[i].offset < end; i++) {
 494                         if (slave->mtd.erasesize < regions[i].erasesize) {
 495                                 slave->mtd.erasesize = regions[i].erasesize;
 496                         }
 497                 }
 498                 BUG_ON(slave->mtd.erasesize == 0);
 499         } else {
 500                 /* Single erase size */
 501                 slave->mtd.erasesize = master->erasesize;
 502         }
 503
 504         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 505             mtd_mod_by_eb(slave->offset, &slave->mtd)) {
 506                 /* Doesn't start on a boundary of major erase size */
 507                 /* FIXME: Let it be writable if it is on a boundary of
 508                  * _minor_ erase size though */
 509                 slave->mtd.flags &= ~MTD_WRITEABLE;
 510                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
 511                         part->name);
 512         }
 513         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 514             mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
 515                 slave->mtd.flags &= ~MTD_WRITEABLE;
 516                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
 517                         part->name);
 518         }
 519
 520         slave->mtd.ecclayout = master->ecclayout;
 521         slave->mtd.ecc_step_size = master->ecc_step_size;
 522         slave->mtd.ecc_strength = master->ecc_strength;
 523         slave->mtd.bitflip_threshold = master->bitflip_threshold;
 524
 525         if (master->_block_isbad) {
 526                 uint64_t offs = 0;
 527
 528                 while (offs < slave->mtd.size) {
 529                         if (mtd_block_isbad(master, offs + slave->offset))
 530                                 slave->mtd.ecc_stats.badblocks++;
 531                         offs += slave->mtd.erasesize;
 532                 }
 533         }
 534
 535 out_register:
 536         return slave;
 537 }
 538
 539 int mtd_add_partition(struct mtd_info *master, const char *name,
 540                       long long offset, long long length)
 541 {
 542         struct mtd_partition part;
 543         struct mtd_part *p, *new;
 544         uint64_t start, end;
 545         int ret = 0;
 546
 547         /* the direct offset is expected */
 548         if (offset == MTDPART_OFS_APPEND ||
 549             offset == MTDPART_OFS_NXTBLK)
 550                 return -EINVAL;
 551
 552         if (length == MTDPART_SIZ_FULL)
 553                 length = master->size - offset;
 554
 555         if (length <= 0)
 556                 return -EINVAL;
 557
 558         part.name = name;
 559         part.size = length;
 560         part.offset = offset;
 561         part.mask_flags = 0;
 562         part.ecclayout = NULL;
 563
 564         new = allocate_partition(master, &part, -1, offset);
 565         if (IS_ERR(new))
 566                 return PTR_ERR(new);
 567
 568         start = offset;
 569         end = offset + length;
 570
 571         mutex_lock(&mtd_partitions_mutex);
 572         list_for_each_entry(p, &mtd_partitions, list)
 573                 if (p->master == master) {
 574                         if ((start >= p->offset) &&
 575                             (start < (p->offset + p->mtd.size)))
 576                                 goto err_inv;
 577
 578                         if ((end >= p->offset) &&
 579                             (end < (p->offset + p->mtd.size)))
 580                                 goto err_inv;
 581                 }
 582
 583         list_add(&new->list, &mtd_partitions);
 584         mutex_unlock(&mtd_partitions_mutex);
 585
 586         add_mtd_device(&new->mtd);
 587
 588         return ret;
 589 err_inv:
 590         mutex_unlock(&mtd_partitions_mutex);
 591         free_partition(new);
 592         return -EINVAL;
 593 }
 594 EXPORT_SYMBOL_GPL(mtd_add_partition);
 595
 596 int mtd_del_partition(struct mtd_info *master, int partno)
 597 {
 598         struct mtd_part *slave, *next;
 599         int ret = -EINVAL;
 600
 601         mutex_lock(&mtd_partitions_mutex);
 602         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 603                 if ((slave->master == master) &&
 604                     (slave->mtd.index == partno)) {
 605                         ret = del_mtd_device(&slave->mtd);
 606                         if (ret < 0)
 607                                 break;
 608
 609                         list_del(&slave->list);
 610                         free_partition(slave);
 611                         break;
 612                 }
 613         mutex_unlock(&mtd_partitions_mutex);
 614
 615         return ret;
 616 }
 617 EXPORT_SYMBOL_GPL(mtd_del_partition);
 618
 619 /*
 620  * This function, given a master MTD object and a partition table, creates
 621  * and registers slave MTD objects which are bound to the master according to
 622  * the partition definitions.
 623  *
 624  * We don't register the master, or expect the caller to have done so,
 625  * for reasons of data integrity.
 626  */
 627
 628 int add_mtd_partitions(struct mtd_info *master,
 629                        const struct mtd_partition *parts,
 630                        int nbparts)
 631 {
 632         struct mtd_part *slave;
 633         uint64_t cur_offset = 0;
 634         int i;
 635
 636         printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 637
 638         for (i = 0; i < nbparts; i++) {
 639                 slave = allocate_partition(master, parts + i, i, cur_offset);
 640                 if (IS_ERR(slave))
 641                         return PTR_ERR(slave);
 642
 643                 mutex_lock(&mtd_partitions_mutex);
 644                 list_add(&slave->list, &mtd_partitions);
 645                 mutex_unlock(&mtd_partitions_mutex);
 646
 647                 add_mtd_device(&slave->mtd);
 648
 649                 cur_offset = slave->offset + slave->mtd.size;
 650         }
 651
 652         return 0;
 653 }
 654
 655 static DEFINE_SPINLOCK(part_parser_lock);
 656 static LIST_HEAD(part_parsers);
 657
 658 static struct mtd_part_parser *get_partition_parser(const char *name)
 659 {
 660         struct mtd_part_parser *p, *ret = NULL;
 661
 662         spin_lock(&part_parser_lock);
 663
 664         list_for_each_entry(p, &part_parsers, list)
 665                 if (!strcmp(p->name, name) && try_module_get(p->owner)) {
 666                         ret = p;
 667                         break;
 668                 }
 669
 670         spin_unlock(&part_parser_lock);
 671
 672         return ret;
 673 }
 674
 675 #define put_partition_parser(p) do { module_put((p)->owner); } while (0)
 676
 677 void register_mtd_parser(struct mtd_part_parser *p)
 678 {
 679         spin_lock(&part_parser_lock);
 680         list_add(&p->list, &part_parsers);
 681         spin_unlock(&part_parser_lock);
 682 }
 683 EXPORT_SYMBOL_GPL(register_mtd_parser);
 684
 685 void deregister_mtd_parser(struct mtd_part_parser *p)
 686 {
 687         spin_lock(&part_parser_lock);
 688         list_del(&p->list);
 689         spin_unlock(&part_parser_lock);
 690 }
 691 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
 692
 693 /*
 694  * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
 695  * are changing this array!
 696  */
 697 static const char * const default_mtd_part_types[] = {
 698         "cmdlinepart",
 699         "ofpart",
 700         NULL
 701 };
 702
 703 /**
 704  * parse_mtd_partitions - parse MTD partitions
 705  * @master: the master partition (describes whole MTD device)
 706  * @types: names of partition parsers to try or %NULL
 707  * @pparts: array of partitions found is returned here
 708  * @data: MTD partition parser-specific data
 709  *
 710  * This function tries to find partition on MTD device @master. It uses MTD
 711  * partition parsers, specified in @types. However, if @types is %NULL, then
 712  * the default list of parsers is used. The default list contains only the
 713  * "cmdlinepart" and "ofpart" parsers ATM.
 714  * Note: If there are more then one parser in @types, the kernel only takes the
 715  * partitions parsed out by the first parser.
 716  *
 717  * This function may return:
 718  * o a negative error code in case of failure
 719  * o zero if no partitions were found
 720  * o a positive number of found partitions, in which case on exit @pparts will
 721  *   point to an array containing this number of &struct mtd_info objects.
 722  */
 723 int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
 724                          struct mtd_partition **pparts,
 725                          struct mtd_part_parser_data *data)
 726 {
 727         struct mtd_part_parser *parser;
 728         int ret = 0;
 729
 730         if (!types)
 731                 types = default_mtd_part_types;
 732
 733         for ( ; ret <= 0 && *types; types++) {
 734                 parser = get_partition_parser(*types);
 735                 if (!parser && !request_module("%s", *types))
 736                         parser = get_partition_parser(*types);
 737                 if (!parser)
 738                         continue;
 739                 ret = (*parser->parse_fn)(master, pparts, data);
 740                 put_partition_parser(parser);
 741                 if (ret > 0) {
 742                         printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
 743                                ret, parser->name, master->name);
 744                         break;
 745                 }
 746         }
 747         return ret;
 748 }
 749
 750 int mtd_is_partition(const struct mtd_info *mtd)
 751 {
 752         struct mtd_part *part;
 753         int ispart = 0;
 754
 755         mutex_lock(&mtd_partitions_mutex);
 756         list_for_each_entry(part, &mtd_partitions, list)
 757                 if (&part->mtd == mtd) {
 758                         ispart = 1;
 759                         break;
 760                 }
 761         mutex_unlock(&mtd_partitions_mutex);
 762
 763         return ispart;
 764 }
 765 EXPORT_SYMBOL_GPL(mtd_is_partition);
 766
 767 /* Returns the size of the entire flash chip */
 768 uint64_t mtd_get_device_size(const struct mtd_info *mtd)
 769 {
 770         if (!mtd_is_partition(mtd))
 771                 return mtd->size;
 772
 773         return PART(mtd)->master->size;
 774 }
 775 EXPORT_SYMBOL_GPL(mtd_get_device_size);