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 = mtd_read(part->master, from + part->offset, len, retlen, buf);
  69         if (unlikely(res)) {
  70                 if (mtd_is_bitflip(res))
  71                         mtd->ecc_stats.corrected += part->master->ecc_stats.corrected - stats.corrected;
  72                 if (mtd_is_eccerr(res))
  73                         mtd->ecc_stats.failed += part->master->ecc_stats.failed - stats.failed;
  74         }
  75         return res;
  76 }
  77
  78 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
  79                 size_t *retlen, void **virt, resource_size_t *phys)
  80 {
  81         struct mtd_part *part = PART(mtd);
  82
  83         return mtd_point(part->master, from + part->offset, len, retlen,
  84                          virt, phys);
  85 }
  86
  87 static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
  88 {
  89         struct mtd_part *part = PART(mtd);
  90
  91         return mtd_unpoint(part->master, from + part->offset, len);
  92 }
  93
  94 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
  95                                             unsigned long len,
  96                                             unsigned long offset,
  97                                             unsigned long flags)
  98 {
  99         struct mtd_part *part = PART(mtd);
 100
 101         offset += part->offset;
 102         return mtd_get_unmapped_area(part->master, len, offset, flags);
 103 }
 104
 105 static int part_read_oob(struct mtd_info *mtd, loff_t from,
 106                 struct mtd_oob_ops *ops)
 107 {
 108         struct mtd_part *part = PART(mtd);
 109         int res;
 110
 111         if (from >= mtd->size)
 112                 return -EINVAL;
 113         if (ops->datbuf && from + ops->len > mtd->size)
 114                 return -EINVAL;
 115
 116         /*
 117          * If OOB is also requested, make sure that we do not read past the end
 118          * of this partition.
 119          */
 120         if (ops->oobbuf) {
 121                 size_t len, pages;
 122
 123                 if (ops->mode == MTD_OPS_AUTO_OOB)
 124                         len = mtd->oobavail;
 125                 else
 126                         len = mtd->oobsize;
 127                 pages = mtd_div_by_ws(mtd->size, mtd);
 128                 pages -= mtd_div_by_ws(from, mtd);
 129                 if (ops->ooboffs + ops->ooblen > pages * len)
 130                         return -EINVAL;
 131         }
 132
 133         res = mtd_read_oob(part->master, from + part->offset, ops);
 134         if (unlikely(res)) {
 135                 if (mtd_is_bitflip(res))
 136                         mtd->ecc_stats.corrected++;
 137                 if (mtd_is_eccerr(res))
 138                         mtd->ecc_stats.failed++;
 139         }
 140         return res;
 141 }
 142
 143 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
 144                 size_t len, size_t *retlen, u_char *buf)
 145 {
 146         struct mtd_part *part = PART(mtd);
 147         return mtd_read_user_prot_reg(part->master, from, len, retlen, buf);
 148 }
 149
 150 static int part_get_user_prot_info(struct mtd_info *mtd,
 151                 struct otp_info *buf, size_t len)
 152 {
 153         struct mtd_part *part = PART(mtd);
 154         return mtd_get_user_prot_info(part->master, buf, len);
 155 }
 156
 157 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
 158                 size_t len, size_t *retlen, u_char *buf)
 159 {
 160         struct mtd_part *part = PART(mtd);
 161         return mtd_read_fact_prot_reg(part->master, from, len, retlen, buf);
 162 }
 163
 164 static int part_get_fact_prot_info(struct mtd_info *mtd, struct otp_info *buf,
 165                 size_t len)
 166 {
 167         struct mtd_part *part = PART(mtd);
 168         return mtd_get_fact_prot_info(part->master, buf, len);
 169 }
 170
 171 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
 172                 size_t *retlen, const u_char *buf)
 173 {
 174         struct mtd_part *part = PART(mtd);
 175         if (!(mtd->flags & MTD_WRITEABLE))
 176                 return -EROFS;
 177         return mtd_write(part->master, to + part->offset, len, retlen, buf);
 178 }
 179
 180 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
 181                 size_t *retlen, const u_char *buf)
 182 {
 183         struct mtd_part *part = PART(mtd);
 184         if (!(mtd->flags & MTD_WRITEABLE))
 185                 return -EROFS;
 186         return mtd_panic_write(part->master, to + part->offset, len, retlen,
 187                                buf);
 188 }
 189
 190 static int part_write_oob(struct mtd_info *mtd, loff_t to,
 191                 struct mtd_oob_ops *ops)
 192 {
 193         struct mtd_part *part = PART(mtd);
 194
 195         if (!(mtd->flags & MTD_WRITEABLE))
 196                 return -EROFS;
 197
 198         if (to >= mtd->size)
 199                 return -EINVAL;
 200         if (ops->datbuf && to + ops->len > mtd->size)
 201                 return -EINVAL;
 202         return mtd_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 mtd_write_user_prot_reg(part->master, from, len, retlen, buf);
 210 }
 211
 212 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
 213                 size_t len)
 214 {
 215         struct mtd_part *part = PART(mtd);
 216         return mtd_lock_user_prot_reg(part->master, from, len);
 217 }
 218
 219 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
 220                 unsigned long count, loff_t to, size_t *retlen)
 221 {
 222         struct mtd_part *part = PART(mtd);
 223         if (!(mtd->flags & MTD_WRITEABLE))
 224                 return -EROFS;
 225         return mtd_writev(part->master, vecs, count, to + part->offset,
 226                           retlen);
 227 }
 228
 229 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
 230 {
 231         struct mtd_part *part = PART(mtd);
 232         int ret;
 233         if (!(mtd->flags & MTD_WRITEABLE))
 234                 return -EROFS;
 235         instr->addr += part->offset;
 236         ret = mtd_erase(part->master, instr);
 237         if (ret) {
 238                 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 239                         instr->fail_addr -= part->offset;
 240                 instr->addr -= part->offset;
 241         }
 242         return ret;
 243 }
 244
 245 void mtd_erase_callback(struct erase_info *instr)
 246 {
 247         if (instr->mtd->_erase == part_erase) {
 248                 struct mtd_part *part = PART(instr->mtd);
 249
 250                 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 251                         instr->fail_addr -= part->offset;
 252                 instr->addr -= part->offset;
 253         }
 254         if (instr->callback)
 255                 instr->callback(instr);
 256 }
 257 EXPORT_SYMBOL_GPL(mtd_erase_callback);
 258
 259 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 260 {
 261         struct mtd_part *part = PART(mtd);
 262         return mtd_lock(part->master, ofs + part->offset, len);
 263 }
 264
 265 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 266 {
 267         struct mtd_part *part = PART(mtd);
 268         return mtd_unlock(part->master, ofs + part->offset, len);
 269 }
 270
 271 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 272 {
 273         struct mtd_part *part = PART(mtd);
 274         return mtd_is_locked(part->master, ofs + part->offset, len);
 275 }
 276
 277 static void part_sync(struct mtd_info *mtd)
 278 {
 279         struct mtd_part *part = PART(mtd);
 280         mtd_sync(part->master);
 281 }
 282
 283 static int part_suspend(struct mtd_info *mtd)
 284 {
 285         struct mtd_part *part = PART(mtd);
 286         return mtd_suspend(part->master);
 287 }
 288
 289 static void part_resume(struct mtd_info *mtd)
 290 {
 291         struct mtd_part *part = PART(mtd);
 292         mtd_resume(part->master);
 293 }
 294
 295 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
 296 {
 297         struct mtd_part *part = PART(mtd);
 298         ofs += part->offset;
 299         return mtd_block_isbad(part->master, ofs);
 300 }
 301
 302 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 303 {
 304         struct mtd_part *part = PART(mtd);
 305         int res;
 306
 307         if (!(mtd->flags & MTD_WRITEABLE))
 308                 return -EROFS;
 309         ofs += part->offset;
 310         res = mtd_block_markbad(part->master, ofs);
 311         if (!res)
 312                 mtd->ecc_stats.badblocks++;
 313         return res;
 314 }
 315
 316 static inline void free_partition(struct mtd_part *p)
 317 {
 318         kfree(p->mtd.name);
 319         kfree(p);
 320 }
 321
 322 /*
 323  * This function unregisters and destroy all slave MTD objects which are
 324  * attached to the given master MTD object.
 325  */
 326
 327 int del_mtd_partitions(struct mtd_info *master)
 328 {
 329         struct mtd_part *slave, *next;
 330         int ret, err = 0;
 331
 332         mutex_lock(&mtd_partitions_mutex);
 333         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 334                 if (slave->master == master) {
 335                         ret = del_mtd_device(&slave->mtd);
 336                         if (ret < 0) {
 337                                 err = ret;
 338                                 continue;
 339                         }
 340                         list_del(&slave->list);
 341                         free_partition(slave);
 342                 }
 343         mutex_unlock(&mtd_partitions_mutex);
 344
 345         return err;
 346 }
 347
 348 static struct mtd_part *allocate_partition(struct mtd_info *master,
 349                         const struct mtd_partition *part, int partno,
 350                         uint64_t cur_offset)
 351 {
 352         struct mtd_part *slave;
 353         char *name;
 354
 355         /* allocate the partition structure */
 356         slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 357         name = kstrdup(part->name, GFP_KERNEL);
 358         if (!name || !slave) {
 359                 printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
 360                        master->name);
 361                 kfree(name);
 362                 kfree(slave);
 363                 return ERR_PTR(-ENOMEM);
 364         }
 365
 366         /* set up the MTD object for this partition */
 367         slave->mtd.type = master->type;
 368         slave->mtd.flags = master->flags & ~part->mask_flags;
 369         slave->mtd.size = part->size;
 370         slave->mtd.writesize = master->writesize;
 371         slave->mtd.writebufsize = master->writebufsize;
 372         slave->mtd.oobsize = master->oobsize;
 373         slave->mtd.oobavail = master->oobavail;
 374         slave->mtd.subpage_sft = master->subpage_sft;
 375
 376         slave->mtd.name = name;
 377         slave->mtd.owner = master->owner;
 378         slave->mtd.backing_dev_info = master->backing_dev_info;
 379
 380         /* NOTE:  we don't arrange MTDs as a tree; it'd be error-prone
 381          * to have the same data be in two different partitions.
 382          */
 383         slave->mtd.dev.parent = master->dev.parent;
 384
 385         slave->mtd._read = part_read;
 386         slave->mtd._write = part_write;
 387
 388         if (master->_panic_write)
 389                 slave->mtd._panic_write = part_panic_write;
 390
 391         if (master->_point && master->_unpoint) {
 392                 slave->mtd._point = part_point;
 393                 slave->mtd._unpoint = part_unpoint;
 394         }
 395
 396         if (master->_get_unmapped_area)
 397                 slave->mtd._get_unmapped_area = part_get_unmapped_area;
 398         if (master->_read_oob)
 399                 slave->mtd._read_oob = part_read_oob;
 400         if (master->_write_oob)
 401                 slave->mtd._write_oob = part_write_oob;
 402         if (master->_read_user_prot_reg)
 403                 slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
 404         if (master->_read_fact_prot_reg)
 405                 slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
 406         if (master->_write_user_prot_reg)
 407                 slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
 408         if (master->_lock_user_prot_reg)
 409                 slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
 410         if (master->_get_user_prot_info)
 411                 slave->mtd._get_user_prot_info = part_get_user_prot_info;
 412         if (master->_get_fact_prot_info)
 413                 slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
 414         if (master->_sync)
 415                 slave->mtd._sync = part_sync;
 416         if (!partno && !master->dev.class && master->_suspend &&
 417             master->_resume) {
 418                         slave->mtd._suspend = part_suspend;
 419                         slave->mtd._resume = part_resume;
 420         }
 421         if (master->_writev)
 422                 slave->mtd._writev = part_writev;
 423         if (master->_lock)
 424                 slave->mtd._lock = part_lock;
 425         if (master->_unlock)
 426                 slave->mtd._unlock = part_unlock;
 427         if (master->_is_locked)
 428                 slave->mtd._is_locked = part_is_locked;
 429         if (master->_block_isbad)
 430                 slave->mtd._block_isbad = part_block_isbad;
 431         if (master->_block_markbad)
 432                 slave->mtd._block_markbad = part_block_markbad;
 433         slave->mtd._erase = part_erase;
 434         slave->master = master;
 435         slave->offset = part->offset;
 436
 437         if (slave->offset == MTDPART_OFS_APPEND)
 438                 slave->offset = cur_offset;
 439         if (slave->offset == MTDPART_OFS_NXTBLK) {
 440                 slave->offset = cur_offset;
 441                 if (mtd_mod_by_eb(cur_offset, master) != 0) {
 442                         /* Round up to next erasesize */
 443                         slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
 444                         printk(KERN_NOTICE "Moving partition %d: "
 445                                "0x%012llx -> 0x%012llx\n", partno,
 446                                (unsigned long long)cur_offset, (unsigned long long)slave->offset);
 447                 }
 448         }
 449         if (slave->offset == MTDPART_OFS_RETAIN) {
 450                 slave->offset = cur_offset;
 451                 if (master->size - slave->offset >= slave->mtd.size) {
 452                         slave->mtd.size = master->size - slave->offset
 453                                                         - slave->mtd.size;
 454                 } else {
 455                         printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
 456                                 part->name, master->size - slave->offset,
 457                                 slave->mtd.size);
 458                         /* register to preserve ordering */
 459                         goto out_register;
 460                 }
 461         }
 462         if (slave->mtd.size == MTDPART_SIZ_FULL)
 463                 slave->mtd.size = master->size - slave->offset;
 464
 465         printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
 466                 (unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
 467
 468         /* let's do some sanity checks */
 469         if (slave->offset >= master->size) {
 470                 /* let's register it anyway to preserve ordering */
 471                 slave->offset = 0;
 472                 slave->mtd.size = 0;
 473                 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
 474                         part->name);
 475                 goto out_register;
 476         }
 477         if (slave->offset + slave->mtd.size > master->size) {
 478                 slave->mtd.size = master->size - slave->offset;
 479                 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
 480                         part->name, master->name, (unsigned long long)slave->mtd.size);
 481         }
 482         if (master->numeraseregions > 1) {
 483                 /* Deal with variable erase size stuff */
 484                 int i, max = master->numeraseregions;
 485                 u64 end = slave->offset + slave->mtd.size;
 486                 struct mtd_erase_region_info *regions = master->eraseregions;
 487
 488                 /* Find the first erase regions which is part of this
 489                  * partition. */
 490                 for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
 491                         ;
 492                 /* The loop searched for the region _behind_ the first one */
 493                 if (i > 0)
 494                         i--;
 495
 496                 /* Pick biggest erasesize */
 497                 for (; i < max && regions[i].offset < end; i++) {
 498                         if (slave->mtd.erasesize < regions[i].erasesize) {
 499                                 slave->mtd.erasesize = regions[i].erasesize;
 500                         }
 501                 }
 502                 BUG_ON(slave->mtd.erasesize == 0);
 503         } else {
 504                 /* Single erase size */
 505                 slave->mtd.erasesize = master->erasesize;
 506         }
 507
 508         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 509             mtd_mod_by_eb(slave->offset, &slave->mtd)) {
 510                 /* Doesn't start on a boundary of major erase size */
 511                 /* FIXME: Let it be writable if it is on a boundary of
 512                  * _minor_ erase size though */
 513                 slave->mtd.flags &= ~MTD_WRITEABLE;
 514                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
 515                         part->name);
 516         }
 517         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 518             mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
 519                 slave->mtd.flags &= ~MTD_WRITEABLE;
 520                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
 521                         part->name);
 522         }
 523
 524         slave->mtd.ecclayout = master->ecclayout;
 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, 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 int 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         return 0;
 684 }
 685 EXPORT_SYMBOL_GPL(register_mtd_parser);
 686
 687 int deregister_mtd_parser(struct mtd_part_parser *p)
 688 {
 689         spin_lock(&part_parser_lock);
 690         list_del(&p->list);
 691         spin_unlock(&part_parser_lock);
 692         return 0;
 693 }
 694 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
 695
 696 /*
 697  * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
 698  * are changing this array!
 699  */
 700 static const char *default_mtd_part_types[] = {
 701         "cmdlinepart",
 702         "ofpart",
 703         NULL
 704 };
 705
 706 /**
 707  * parse_mtd_partitions - parse MTD partitions
 708  * @master: the master partition (describes whole MTD device)
 709  * @types: names of partition parsers to try or %NULL
 710  * @pparts: array of partitions found is returned here
 711  * @data: MTD partition parser-specific data
 712  *
 713  * This function tries to find partition on MTD device @master. It uses MTD
 714  * partition parsers, specified in @types. However, if @types is %NULL, then
 715  * the default list of parsers is used. The default list contains only the
 716  * "cmdlinepart" and "ofpart" parsers ATM.
 717  *
 718  * This function may return:
 719  * o a negative error code in case of failure
 720  * o zero if no partitions were found
 721  * o a positive number of found partitions, in which case on exit @pparts will
 722  *   point to an array containing this number of &struct mtd_info objects.
 723  */
 724 int parse_mtd_partitions(struct mtd_info *master, const char **types,
 725                          struct mtd_partition **pparts,
 726                          struct mtd_part_parser_data *data)
 727 {
 728         struct mtd_part_parser *parser;
 729         int ret = 0;
 730
 731         if (!types)
 732                 types = default_mtd_part_types;
 733
 734         for ( ; ret <= 0 && *types; types++) {
 735                 parser = get_partition_parser(*types);
 736                 if (!parser && !request_module("%s", *types))
 737                         parser = get_partition_parser(*types);
 738                 if (!parser)
 739                         continue;
 740                 ret = (*parser->parse_fn)(master, pparts, data);
 741                 if (ret > 0) {
 742                         printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
 743                                ret, parser->name, master->name);
 744                 }
 745                 put_partition_parser(parser);
 746         }
 747         return ret;
 748 }
 749
 750 int mtd_is_partition(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);