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
  69         if (from >= mtd->size)
  70                 len = 0;
  71         else if (from + len > mtd->size)
  72                 len = mtd->size - from;
  73         res = mtd_read(part->master, from + part->offset, len, retlen, buf);
  74         if (unlikely(res)) {
  75                 if (mtd_is_bitflip(res))
  76                         mtd->ecc_stats.corrected += part->master->ecc_stats.corrected - stats.corrected;
  77                 if (mtd_is_eccerr(res))
  78                         mtd->ecc_stats.failed += part->master->ecc_stats.failed - stats.failed;
  79         }
  80         return res;
  81 }
  82
  83 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
  84                 size_t *retlen, void **virt, resource_size_t *phys)
  85 {
  86         struct mtd_part *part = PART(mtd);
  87         if (from >= mtd->size)
  88                 len = 0;
  89         else if (from + len > mtd->size)
  90                 len = mtd->size - from;
  91         return mtd_point(part->master, from + part->offset, len, retlen,
  92                          virt, phys);
  93 }
  94
  95 static void part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
  96 {
  97         struct mtd_part *part = PART(mtd);
  98
  99         mtd_unpoint(part->master, from + part->offset, len);
 100 }
 101
 102 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
 103                                             unsigned long len,
 104                                             unsigned long offset,
 105                                             unsigned long flags)
 106 {
 107         struct mtd_part *part = PART(mtd);
 108
 109         offset += part->offset;
 110         return mtd_get_unmapped_area(part->master, len, offset, flags);
 111 }
 112
 113 static int part_read_oob(struct mtd_info *mtd, loff_t from,
 114                 struct mtd_oob_ops *ops)
 115 {
 116         struct mtd_part *part = PART(mtd);
 117         int res;
 118
 119         if (from >= mtd->size)
 120                 return -EINVAL;
 121         if (ops->datbuf && from + ops->len > mtd->size)
 122                 return -EINVAL;
 123
 124         /*
 125          * If OOB is also requested, make sure that we do not read past the end
 126          * of this partition.
 127          */
 128         if (ops->oobbuf) {
 129                 size_t len, pages;
 130
 131                 if (ops->mode == MTD_OPS_AUTO_OOB)
 132                         len = mtd->oobavail;
 133                 else
 134                         len = mtd->oobsize;
 135                 pages = mtd_div_by_ws(mtd->size, mtd);
 136                 pages -= mtd_div_by_ws(from, mtd);
 137                 if (ops->ooboffs + ops->ooblen > pages * len)
 138                         return -EINVAL;
 139         }
 140
 141         res = mtd_read_oob(part->master, from + part->offset, ops);
 142         if (unlikely(res)) {
 143                 if (mtd_is_bitflip(res))
 144                         mtd->ecc_stats.corrected++;
 145                 if (mtd_is_eccerr(res))
 146                         mtd->ecc_stats.failed++;
 147         }
 148         return res;
 149 }
 150
 151 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
 152                 size_t len, size_t *retlen, u_char *buf)
 153 {
 154         struct mtd_part *part = PART(mtd);
 155         return mtd_read_user_prot_reg(part->master, from, len, retlen, buf);
 156 }
 157
 158 static int part_get_user_prot_info(struct mtd_info *mtd,
 159                 struct otp_info *buf, size_t len)
 160 {
 161         struct mtd_part *part = PART(mtd);
 162         return mtd_get_user_prot_info(part->master, buf, len);
 163 }
 164
 165 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
 166                 size_t len, size_t *retlen, u_char *buf)
 167 {
 168         struct mtd_part *part = PART(mtd);
 169         return mtd_read_fact_prot_reg(part->master, from, len, retlen, buf);
 170 }
 171
 172 static int part_get_fact_prot_info(struct mtd_info *mtd, struct otp_info *buf,
 173                 size_t len)
 174 {
 175         struct mtd_part *part = PART(mtd);
 176         return mtd_get_fact_prot_info(part->master, buf, len);
 177 }
 178
 179 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
 180                 size_t *retlen, const u_char *buf)
 181 {
 182         struct mtd_part *part = PART(mtd);
 183         if (!(mtd->flags & MTD_WRITEABLE))
 184                 return -EROFS;
 185         if (to >= mtd->size)
 186                 len = 0;
 187         else if (to + len > mtd->size)
 188                 len = mtd->size - to;
 189         return mtd_write(part->master, to + part->offset, len, retlen, buf);
 190 }
 191
 192 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
 193                 size_t *retlen, const u_char *buf)
 194 {
 195         struct mtd_part *part = PART(mtd);
 196         if (!(mtd->flags & MTD_WRITEABLE))
 197                 return -EROFS;
 198         if (to >= mtd->size)
 199                 len = 0;
 200         else if (to + len > mtd->size)
 201                 len = mtd->size - to;
 202         return mtd_panic_write(part->master, to + part->offset, len, retlen,
 203                                buf);
 204 }
 205
 206 static int part_write_oob(struct mtd_info *mtd, loff_t to,
 207                 struct mtd_oob_ops *ops)
 208 {
 209         struct mtd_part *part = PART(mtd);
 210
 211         if (!(mtd->flags & MTD_WRITEABLE))
 212                 return -EROFS;
 213
 214         if (to >= mtd->size)
 215                 return -EINVAL;
 216         if (ops->datbuf && to + ops->len > mtd->size)
 217                 return -EINVAL;
 218         return mtd_write_oob(part->master, to + part->offset, ops);
 219 }
 220
 221 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
 222                 size_t len, size_t *retlen, u_char *buf)
 223 {
 224         struct mtd_part *part = PART(mtd);
 225         return mtd_write_user_prot_reg(part->master, from, len, retlen, buf);
 226 }
 227
 228 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
 229                 size_t len)
 230 {
 231         struct mtd_part *part = PART(mtd);
 232         return mtd_lock_user_prot_reg(part->master, from, len);
 233 }
 234
 235 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
 236                 unsigned long count, loff_t to, size_t *retlen)
 237 {
 238         struct mtd_part *part = PART(mtd);
 239         if (!(mtd->flags & MTD_WRITEABLE))
 240                 return -EROFS;
 241         return mtd_writev(part->master, vecs, count, to + part->offset,
 242                           retlen);
 243 }
 244
 245 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
 246 {
 247         struct mtd_part *part = PART(mtd);
 248         int ret;
 249         if (!(mtd->flags & MTD_WRITEABLE))
 250                 return -EROFS;
 251         if (instr->addr >= mtd->size)
 252                 return -EINVAL;
 253         instr->addr += part->offset;
 254         ret = mtd_erase(part->master, instr);
 255         if (ret) {
 256                 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 257                         instr->fail_addr -= part->offset;
 258                 instr->addr -= part->offset;
 259         }
 260         return ret;
 261 }
 262
 263 void mtd_erase_callback(struct erase_info *instr)
 264 {
 265         if (instr->mtd->erase == part_erase) {
 266                 struct mtd_part *part = PART(instr->mtd);
 267
 268                 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 269                         instr->fail_addr -= part->offset;
 270                 instr->addr -= part->offset;
 271         }
 272         if (instr->callback)
 273                 instr->callback(instr);
 274 }
 275 EXPORT_SYMBOL_GPL(mtd_erase_callback);
 276
 277 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 278 {
 279         struct mtd_part *part = PART(mtd);
 280         if ((len + ofs) > mtd->size)
 281                 return -EINVAL;
 282         return mtd_lock(part->master, ofs + part->offset, len);
 283 }
 284
 285 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 286 {
 287         struct mtd_part *part = PART(mtd);
 288         if ((len + ofs) > mtd->size)
 289                 return -EINVAL;
 290         return mtd_unlock(part->master, ofs + part->offset, len);
 291 }
 292
 293 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 294 {
 295         struct mtd_part *part = PART(mtd);
 296         if ((len + ofs) > mtd->size)
 297                 return -EINVAL;
 298         return mtd_is_locked(part->master, ofs + part->offset, len);
 299 }
 300
 301 static void part_sync(struct mtd_info *mtd)
 302 {
 303         struct mtd_part *part = PART(mtd);
 304         mtd_sync(part->master);
 305 }
 306
 307 static int part_suspend(struct mtd_info *mtd)
 308 {
 309         struct mtd_part *part = PART(mtd);
 310         return mtd_suspend(part->master);
 311 }
 312
 313 static void part_resume(struct mtd_info *mtd)
 314 {
 315         struct mtd_part *part = PART(mtd);
 316         mtd_resume(part->master);
 317 }
 318
 319 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
 320 {
 321         struct mtd_part *part = PART(mtd);
 322         if (ofs >= mtd->size)
 323                 return -EINVAL;
 324         ofs += part->offset;
 325         return mtd_block_isbad(part->master, ofs);
 326 }
 327
 328 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 329 {
 330         struct mtd_part *part = PART(mtd);
 331         int res;
 332
 333         if (!(mtd->flags & MTD_WRITEABLE))
 334                 return -EROFS;
 335         if (ofs >= mtd->size)
 336                 return -EINVAL;
 337         ofs += part->offset;
 338         res = mtd_block_markbad(part->master, ofs);
 339         if (!res)
 340                 mtd->ecc_stats.badblocks++;
 341         return res;
 342 }
 343
 344 static inline void free_partition(struct mtd_part *p)
 345 {
 346         kfree(p->mtd.name);
 347         kfree(p);
 348 }
 349
 350 /*
 351  * This function unregisters and destroy all slave MTD objects which are
 352  * attached to the given master MTD object.
 353  */
 354
 355 int del_mtd_partitions(struct mtd_info *master)
 356 {
 357         struct mtd_part *slave, *next;
 358         int ret, err = 0;
 359
 360         mutex_lock(&mtd_partitions_mutex);
 361         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 362                 if (slave->master == master) {
 363                         ret = del_mtd_device(&slave->mtd);
 364                         if (ret < 0) {
 365                                 err = ret;
 366                                 continue;
 367                         }
 368                         list_del(&slave->list);
 369                         free_partition(slave);
 370                 }
 371         mutex_unlock(&mtd_partitions_mutex);
 372
 373         return err;
 374 }
 375
 376 static struct mtd_part *allocate_partition(struct mtd_info *master,
 377                         const struct mtd_partition *part, int partno,
 378                         uint64_t cur_offset)
 379 {
 380         struct mtd_part *slave;
 381         char *name;
 382
 383         /* allocate the partition structure */
 384         slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 385         name = kstrdup(part->name, GFP_KERNEL);
 386         if (!name || !slave) {
 387                 printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
 388                        master->name);
 389                 kfree(name);
 390                 kfree(slave);
 391                 return ERR_PTR(-ENOMEM);
 392         }
 393
 394         /* set up the MTD object for this partition */
 395         slave->mtd.type = master->type;
 396         slave->mtd.flags = master->flags & ~part->mask_flags;
 397         slave->mtd.size = part->size;
 398         slave->mtd.writesize = master->writesize;
 399         slave->mtd.writebufsize = master->writebufsize;
 400         slave->mtd.oobsize = master->oobsize;
 401         slave->mtd.oobavail = master->oobavail;
 402         slave->mtd.subpage_sft = master->subpage_sft;
 403
 404         slave->mtd.name = name;
 405         slave->mtd.owner = master->owner;
 406         slave->mtd.backing_dev_info = master->backing_dev_info;
 407
 408         /* NOTE:  we don't arrange MTDs as a tree; it'd be error-prone
 409          * to have the same data be in two different partitions.
 410          */
 411         slave->mtd.dev.parent = master->dev.parent;
 412
 413         slave->mtd.read = part_read;
 414         slave->mtd.write = part_write;
 415
 416         if (master->panic_write)
 417                 slave->mtd.panic_write = part_panic_write;
 418
 419         if (master->point && master->unpoint) {
 420                 slave->mtd.point = part_point;
 421                 slave->mtd.unpoint = part_unpoint;
 422         }
 423
 424         if (master->get_unmapped_area)
 425                 slave->mtd.get_unmapped_area = part_get_unmapped_area;
 426         if (master->read_oob)
 427                 slave->mtd.read_oob = part_read_oob;
 428         if (master->write_oob)
 429                 slave->mtd.write_oob = part_write_oob;
 430         if (master->read_user_prot_reg)
 431                 slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
 432         if (master->read_fact_prot_reg)
 433                 slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
 434         if (master->write_user_prot_reg)
 435                 slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
 436         if (master->lock_user_prot_reg)
 437                 slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
 438         if (master->get_user_prot_info)
 439                 slave->mtd.get_user_prot_info = part_get_user_prot_info;
 440         if (master->get_fact_prot_info)
 441                 slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
 442         if (master->sync)
 443                 slave->mtd.sync = part_sync;
 444         if (!partno && !master->dev.class && master->suspend && master->resume) {
 445                         slave->mtd.suspend = part_suspend;
 446                         slave->mtd.resume = part_resume;
 447         }
 448         if (master->writev)
 449                 slave->mtd.writev = part_writev;
 450         if (master->lock)
 451                 slave->mtd.lock = part_lock;
 452         if (master->unlock)
 453                 slave->mtd.unlock = part_unlock;
 454         if (master->is_locked)
 455                 slave->mtd.is_locked = part_is_locked;
 456         if (master->block_isbad)
 457                 slave->mtd.block_isbad = part_block_isbad;
 458         if (master->block_markbad)
 459                 slave->mtd.block_markbad = part_block_markbad;
 460         slave->mtd.erase = part_erase;
 461         slave->master = master;
 462         slave->offset = part->offset;
 463
 464         if (slave->offset == MTDPART_OFS_APPEND)
 465                 slave->offset = cur_offset;
 466         if (slave->offset == MTDPART_OFS_NXTBLK) {
 467                 slave->offset = cur_offset;
 468                 if (mtd_mod_by_eb(cur_offset, master) != 0) {
 469                         /* Round up to next erasesize */
 470                         slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
 471                         printk(KERN_NOTICE "Moving partition %d: "
 472                                "0x%012llx -> 0x%012llx\n", partno,
 473                                (unsigned long long)cur_offset, (unsigned long long)slave->offset);
 474                 }
 475         }
 476         if (slave->offset == MTDPART_OFS_RETAIN) {
 477                 slave->offset = cur_offset;
 478                 if (master->size - slave->offset >= slave->mtd.size) {
 479                         slave->mtd.size = master->size - slave->offset
 480                                                         - slave->mtd.size;
 481                 } else {
 482                         printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
 483                                 part->name, master->size - slave->offset,
 484                                 slave->mtd.size);
 485                         /* register to preserve ordering */
 486                         goto out_register;
 487                 }
 488         }
 489         if (slave->mtd.size == MTDPART_SIZ_FULL)
 490                 slave->mtd.size = master->size - slave->offset;
 491
 492         printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
 493                 (unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
 494
 495         /* let's do some sanity checks */
 496         if (slave->offset >= master->size) {
 497                 /* let's register it anyway to preserve ordering */
 498                 slave->offset = 0;
 499                 slave->mtd.size = 0;
 500                 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
 501                         part->name);
 502                 goto out_register;
 503         }
 504         if (slave->offset + slave->mtd.size > master->size) {
 505                 slave->mtd.size = master->size - slave->offset;
 506                 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
 507                         part->name, master->name, (unsigned long long)slave->mtd.size);
 508         }
 509         if (master->numeraseregions > 1) {
 510                 /* Deal with variable erase size stuff */
 511                 int i, max = master->numeraseregions;
 512                 u64 end = slave->offset + slave->mtd.size;
 513                 struct mtd_erase_region_info *regions = master->eraseregions;
 514
 515                 /* Find the first erase regions which is part of this
 516                  * partition. */
 517                 for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
 518                         ;
 519                 /* The loop searched for the region _behind_ the first one */
 520                 if (i > 0)
 521                         i--;
 522
 523                 /* Pick biggest erasesize */
 524                 for (; i < max && regions[i].offset < end; i++) {
 525                         if (slave->mtd.erasesize < regions[i].erasesize) {
 526                                 slave->mtd.erasesize = regions[i].erasesize;
 527                         }
 528                 }
 529                 BUG_ON(slave->mtd.erasesize == 0);
 530         } else {
 531                 /* Single erase size */
 532                 slave->mtd.erasesize = master->erasesize;
 533         }
 534
 535         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 536             mtd_mod_by_eb(slave->offset, &slave->mtd)) {
 537                 /* Doesn't start on a boundary of major erase size */
 538                 /* FIXME: Let it be writable if it is on a boundary of
 539                  * _minor_ erase size though */
 540                 slave->mtd.flags &= ~MTD_WRITEABLE;
 541                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
 542                         part->name);
 543         }
 544         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 545             mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
 546                 slave->mtd.flags &= ~MTD_WRITEABLE;
 547                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
 548                         part->name);
 549         }
 550
 551         slave->mtd.ecclayout = master->ecclayout;
 552         if (master->block_isbad) {
 553                 uint64_t offs = 0;
 554
 555                 while (offs < slave->mtd.size) {
 556                         if (mtd_block_isbad(master, offs + slave->offset))
 557                                 slave->mtd.ecc_stats.badblocks++;
 558                         offs += slave->mtd.erasesize;
 559                 }
 560         }
 561
 562 out_register:
 563         return slave;
 564 }
 565
 566 int mtd_add_partition(struct mtd_info *master, char *name,
 567                       long long offset, long long length)
 568 {
 569         struct mtd_partition part;
 570         struct mtd_part *p, *new;
 571         uint64_t start, end;
 572         int ret = 0;
 573
 574         /* the direct offset is expected */
 575         if (offset == MTDPART_OFS_APPEND ||
 576             offset == MTDPART_OFS_NXTBLK)
 577                 return -EINVAL;
 578
 579         if (length == MTDPART_SIZ_FULL)
 580                 length = master->size - offset;
 581
 582         if (length <= 0)
 583                 return -EINVAL;
 584
 585         part.name = name;
 586         part.size = length;
 587         part.offset = offset;
 588         part.mask_flags = 0;
 589         part.ecclayout = NULL;
 590
 591         new = allocate_partition(master, &part, -1, offset);
 592         if (IS_ERR(new))
 593                 return PTR_ERR(new);
 594
 595         start = offset;
 596         end = offset + length;
 597
 598         mutex_lock(&mtd_partitions_mutex);
 599         list_for_each_entry(p, &mtd_partitions, list)
 600                 if (p->master == master) {
 601                         if ((start >= p->offset) &&
 602                             (start < (p->offset + p->mtd.size)))
 603                                 goto err_inv;
 604
 605                         if ((end >= p->offset) &&
 606                             (end < (p->offset + p->mtd.size)))
 607                                 goto err_inv;
 608                 }
 609
 610         list_add(&new->list, &mtd_partitions);
 611         mutex_unlock(&mtd_partitions_mutex);
 612
 613         add_mtd_device(&new->mtd);
 614
 615         return ret;
 616 err_inv:
 617         mutex_unlock(&mtd_partitions_mutex);
 618         free_partition(new);
 619         return -EINVAL;
 620 }
 621 EXPORT_SYMBOL_GPL(mtd_add_partition);
 622
 623 int mtd_del_partition(struct mtd_info *master, int partno)
 624 {
 625         struct mtd_part *slave, *next;
 626         int ret = -EINVAL;
 627
 628         mutex_lock(&mtd_partitions_mutex);
 629         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 630                 if ((slave->master == master) &&
 631                     (slave->mtd.index == partno)) {
 632                         ret = del_mtd_device(&slave->mtd);
 633                         if (ret < 0)
 634                                 break;
 635
 636                         list_del(&slave->list);
 637                         free_partition(slave);
 638                         break;
 639                 }
 640         mutex_unlock(&mtd_partitions_mutex);
 641
 642         return ret;
 643 }
 644 EXPORT_SYMBOL_GPL(mtd_del_partition);
 645
 646 /*
 647  * This function, given a master MTD object and a partition table, creates
 648  * and registers slave MTD objects which are bound to the master according to
 649  * the partition definitions.
 650  *
 651  * We don't register the master, or expect the caller to have done so,
 652  * for reasons of data integrity.
 653  */
 654
 655 int add_mtd_partitions(struct mtd_info *master,
 656                        const struct mtd_partition *parts,
 657                        int nbparts)
 658 {
 659         struct mtd_part *slave;
 660         uint64_t cur_offset = 0;
 661         int i;
 662
 663         printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 664
 665         for (i = 0; i < nbparts; i++) {
 666                 slave = allocate_partition(master, parts + i, i, cur_offset);
 667                 if (IS_ERR(slave))
 668                         return PTR_ERR(slave);
 669
 670                 mutex_lock(&mtd_partitions_mutex);
 671                 list_add(&slave->list, &mtd_partitions);
 672                 mutex_unlock(&mtd_partitions_mutex);
 673
 674                 add_mtd_device(&slave->mtd);
 675
 676                 cur_offset = slave->offset + slave->mtd.size;
 677         }
 678
 679         return 0;
 680 }
 681
 682 static DEFINE_SPINLOCK(part_parser_lock);
 683 static LIST_HEAD(part_parsers);
 684
 685 static struct mtd_part_parser *get_partition_parser(const char *name)
 686 {
 687         struct mtd_part_parser *p, *ret = NULL;
 688
 689         spin_lock(&part_parser_lock);
 690
 691         list_for_each_entry(p, &part_parsers, list)
 692                 if (!strcmp(p->name, name) && try_module_get(p->owner)) {
 693                         ret = p;
 694                         break;
 695                 }
 696
 697         spin_unlock(&part_parser_lock);
 698
 699         return ret;
 700 }
 701
 702 #define put_partition_parser(p) do { module_put((p)->owner); } while (0)
 703
 704 int register_mtd_parser(struct mtd_part_parser *p)
 705 {
 706         spin_lock(&part_parser_lock);
 707         list_add(&p->list, &part_parsers);
 708         spin_unlock(&part_parser_lock);
 709
 710         return 0;
 711 }
 712 EXPORT_SYMBOL_GPL(register_mtd_parser);
 713
 714 int deregister_mtd_parser(struct mtd_part_parser *p)
 715 {
 716         spin_lock(&part_parser_lock);
 717         list_del(&p->list);
 718         spin_unlock(&part_parser_lock);
 719         return 0;
 720 }
 721 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
 722
 723 /*
 724  * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
 725  * are changing this array!
 726  */
 727 static const char *default_mtd_part_types[] = {
 728         "cmdlinepart",
 729         "ofpart",
 730         NULL
 731 };
 732
 733 /**
 734  * parse_mtd_partitions - parse MTD partitions
 735  * @master: the master partition (describes whole MTD device)
 736  * @types: names of partition parsers to try or %NULL
 737  * @pparts: array of partitions found is returned here
 738  * @data: MTD partition parser-specific data
 739  *
 740  * This function tries to find partition on MTD device @master. It uses MTD
 741  * partition parsers, specified in @types. However, if @types is %NULL, then
 742  * the default list of parsers is used. The default list contains only the
 743  * "cmdlinepart" and "ofpart" parsers ATM.
 744  *
 745  * This function may return:
 746  * o a negative error code in case of failure
 747  * o zero if no partitions were found
 748  * o a positive number of found partitions, in which case on exit @pparts will
 749  *   point to an array containing this number of &struct mtd_info objects.
 750  */
 751 int parse_mtd_partitions(struct mtd_info *master, const char **types,
 752                          struct mtd_partition **pparts,
 753                          struct mtd_part_parser_data *data)
 754 {
 755         struct mtd_part_parser *parser;
 756         int ret = 0;
 757
 758         if (!types)
 759                 types = default_mtd_part_types;
 760
 761         for ( ; ret <= 0 && *types; types++) {
 762                 parser = get_partition_parser(*types);
 763                 if (!parser && !request_module("%s", *types))
 764                                 parser = get_partition_parser(*types);
 765                 if (!parser)
 766                         continue;
 767                 ret = (*parser->parse_fn)(master, pparts, data);
 768                 if (ret > 0) {
 769                         printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
 770                                ret, parser->name, master->name);
 771                 }
 772                 put_partition_parser(parser);
 773         }
 774         return ret;
 775 }
 776
 777 int mtd_is_partition(struct mtd_info *mtd)
 778 {
 779         struct mtd_part *part;
 780         int ispart = 0;
 781
 782         mutex_lock(&mtd_partitions_mutex);
 783         list_for_each_entry(part, &mtd_partitions, list)
 784                 if (&part->mtd == mtd) {
 785                         ispart = 1;
 786                         break;
 787                 }
 788         mutex_unlock(&mtd_partitions_mutex);
 789
 790         return ispart;
 791 }
 792 EXPORT_SYMBOL_GPL(mtd_is_partition);