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 = part->master->read(part->master, from + part->offset,
  74                                    len, retlen, buf);
  75         if (unlikely(res)) {
  76                 if (res == -EUCLEAN)
  77                         mtd->ecc_stats.corrected += part->master->ecc_stats.corrected - stats.corrected;
  78                 if (res == -EBADMSG)
  79                         mtd->ecc_stats.failed += part->master->ecc_stats.failed - stats.failed;
  80         }
  81         return res;
  82 }
  83
  84 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
  85                 size_t *retlen, void **virt, resource_size_t *phys)
  86 {
  87         struct mtd_part *part = PART(mtd);
  88         if (from >= mtd->size)
  89                 len = 0;
  90         else if (from + len > mtd->size)
  91                 len = mtd->size - from;
  92         return part->master->point (part->master, from + part->offset,
  93                                     len, retlen, virt, phys);
  94 }
  95
  96 static void part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
  97 {
  98         struct mtd_part *part = PART(mtd);
  99
 100         part->master->unpoint(part->master, from + part->offset, len);
 101 }
 102
 103 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
 104                                             unsigned long len,
 105                                             unsigned long offset,
 106                                             unsigned long flags)
 107 {
 108         struct mtd_part *part = PART(mtd);
 109
 110         offset += part->offset;
 111         return part->master->get_unmapped_area(part->master, len, offset,
 112                                                flags);
 113 }
 114
 115 static int part_read_oob(struct mtd_info *mtd, loff_t from,
 116                 struct mtd_oob_ops *ops)
 117 {
 118         struct mtd_part *part = PART(mtd);
 119         int res;
 120
 121         if (from >= mtd->size)
 122                 return -EINVAL;
 123         if (ops->datbuf && from + ops->len > mtd->size)
 124                 return -EINVAL;
 125
 126         /*
 127          * If OOB is also requested, make sure that we do not read past the end
 128          * of this partition.
 129          */
 130         if (ops->oobbuf) {
 131                 size_t len, pages;
 132
 133                 if (ops->mode == MTD_OOB_AUTO)
 134                         len = mtd->oobavail;
 135                 else
 136                         len = mtd->oobsize;
 137                 pages = mtd_div_by_ws(mtd->size, mtd);
 138                 pages -= mtd_div_by_ws(from, mtd);
 139                 if (ops->ooboffs + ops->ooblen > pages * len)
 140                         return -EINVAL;
 141         }
 142
 143         res = part->master->read_oob(part->master, from + part->offset, ops);
 144         if (unlikely(res)) {
 145                 if (res == -EUCLEAN)
 146                         mtd->ecc_stats.corrected++;
 147                 if (res == -EBADMSG)
 148                         mtd->ecc_stats.failed++;
 149         }
 150         return res;
 151 }
 152
 153 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
 154                 size_t len, size_t *retlen, u_char *buf)
 155 {
 156         struct mtd_part *part = PART(mtd);
 157         return part->master->read_user_prot_reg(part->master, from,
 158                                         len, retlen, buf);
 159 }
 160
 161 static int part_get_user_prot_info(struct mtd_info *mtd,
 162                 struct otp_info *buf, size_t len)
 163 {
 164         struct mtd_part *part = PART(mtd);
 165         return part->master->get_user_prot_info(part->master, buf, len);
 166 }
 167
 168 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
 169                 size_t len, size_t *retlen, u_char *buf)
 170 {
 171         struct mtd_part *part = PART(mtd);
 172         return part->master->read_fact_prot_reg(part->master, from,
 173                                         len, retlen, buf);
 174 }
 175
 176 static int part_get_fact_prot_info(struct mtd_info *mtd, struct otp_info *buf,
 177                 size_t len)
 178 {
 179         struct mtd_part *part = PART(mtd);
 180         return part->master->get_fact_prot_info(part->master, buf, len);
 181 }
 182
 183 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
 184                 size_t *retlen, const u_char *buf)
 185 {
 186         struct mtd_part *part = PART(mtd);
 187         if (!(mtd->flags & MTD_WRITEABLE))
 188                 return -EROFS;
 189         if (to >= mtd->size)
 190                 len = 0;
 191         else if (to + len > mtd->size)
 192                 len = mtd->size - to;
 193         return part->master->write(part->master, to + part->offset,
 194                                     len, retlen, buf);
 195 }
 196
 197 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
 198                 size_t *retlen, const u_char *buf)
 199 {
 200         struct mtd_part *part = PART(mtd);
 201         if (!(mtd->flags & MTD_WRITEABLE))
 202                 return -EROFS;
 203         if (to >= mtd->size)
 204                 len = 0;
 205         else if (to + len > mtd->size)
 206                 len = mtd->size - to;
 207         return part->master->panic_write(part->master, to + part->offset,
 208                                     len, retlen, buf);
 209 }
 210
 211 static int part_write_oob(struct mtd_info *mtd, loff_t to,
 212                 struct mtd_oob_ops *ops)
 213 {
 214         struct mtd_part *part = PART(mtd);
 215
 216         if (!(mtd->flags & MTD_WRITEABLE))
 217                 return -EROFS;
 218
 219         if (to >= mtd->size)
 220                 return -EINVAL;
 221         if (ops->datbuf && to + ops->len > mtd->size)
 222                 return -EINVAL;
 223         return part->master->write_oob(part->master, to + part->offset, ops);
 224 }
 225
 226 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
 227                 size_t len, size_t *retlen, u_char *buf)
 228 {
 229         struct mtd_part *part = PART(mtd);
 230         return part->master->write_user_prot_reg(part->master, from,
 231                                         len, retlen, buf);
 232 }
 233
 234 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
 235                 size_t len)
 236 {
 237         struct mtd_part *part = PART(mtd);
 238         return part->master->lock_user_prot_reg(part->master, from, len);
 239 }
 240
 241 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
 242                 unsigned long count, loff_t to, size_t *retlen)
 243 {
 244         struct mtd_part *part = PART(mtd);
 245         if (!(mtd->flags & MTD_WRITEABLE))
 246                 return -EROFS;
 247         return part->master->writev(part->master, vecs, count,
 248                                         to + part->offset, retlen);
 249 }
 250
 251 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
 252 {
 253         struct mtd_part *part = PART(mtd);
 254         int ret;
 255         if (!(mtd->flags & MTD_WRITEABLE))
 256                 return -EROFS;
 257         if (instr->addr >= mtd->size)
 258                 return -EINVAL;
 259         instr->addr += part->offset;
 260         ret = part->master->erase(part->master, instr);
 261         if (ret) {
 262                 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 263                         instr->fail_addr -= part->offset;
 264                 instr->addr -= part->offset;
 265         }
 266         return ret;
 267 }
 268
 269 void mtd_erase_callback(struct erase_info *instr)
 270 {
 271         if (instr->mtd->erase == part_erase) {
 272                 struct mtd_part *part = PART(instr->mtd);
 273
 274                 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 275                         instr->fail_addr -= part->offset;
 276                 instr->addr -= part->offset;
 277         }
 278         if (instr->callback)
 279                 instr->callback(instr);
 280 }
 281 EXPORT_SYMBOL_GPL(mtd_erase_callback);
 282
 283 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 284 {
 285         struct mtd_part *part = PART(mtd);
 286         if ((len + ofs) > mtd->size)
 287                 return -EINVAL;
 288         return part->master->lock(part->master, ofs + part->offset, len);
 289 }
 290
 291 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 292 {
 293         struct mtd_part *part = PART(mtd);
 294         if ((len + ofs) > mtd->size)
 295                 return -EINVAL;
 296         return part->master->unlock(part->master, ofs + part->offset, len);
 297 }
 298
 299 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 300 {
 301         struct mtd_part *part = PART(mtd);
 302         if ((len + ofs) > mtd->size)
 303                 return -EINVAL;
 304         return part->master->is_locked(part->master, ofs + part->offset, len);
 305 }
 306
 307 static void part_sync(struct mtd_info *mtd)
 308 {
 309         struct mtd_part *part = PART(mtd);
 310         part->master->sync(part->master);
 311 }
 312
 313 static int part_suspend(struct mtd_info *mtd)
 314 {
 315         struct mtd_part *part = PART(mtd);
 316         return part->master->suspend(part->master);
 317 }
 318
 319 static void part_resume(struct mtd_info *mtd)
 320 {
 321         struct mtd_part *part = PART(mtd);
 322         part->master->resume(part->master);
 323 }
 324
 325 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
 326 {
 327         struct mtd_part *part = PART(mtd);
 328         if (ofs >= mtd->size)
 329                 return -EINVAL;
 330         ofs += part->offset;
 331         return part->master->block_isbad(part->master, ofs);
 332 }
 333
 334 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 335 {
 336         struct mtd_part *part = PART(mtd);
 337         int res;
 338
 339         if (!(mtd->flags & MTD_WRITEABLE))
 340                 return -EROFS;
 341         if (ofs >= mtd->size)
 342                 return -EINVAL;
 343         ofs += part->offset;
 344         res = part->master->block_markbad(part->master, ofs);
 345         if (!res)
 346                 mtd->ecc_stats.badblocks++;
 347         return res;
 348 }
 349
 350 static inline void free_partition(struct mtd_part *p)
 351 {
 352         kfree(p->mtd.name);
 353         kfree(p);
 354 }
 355
 356 /*
 357  * This function unregisters and destroy all slave MTD objects which are
 358  * attached to the given master MTD object.
 359  */
 360
 361 int del_mtd_partitions(struct mtd_info *master)
 362 {
 363         struct mtd_part *slave, *next;
 364         int ret, err = 0;
 365
 366         mutex_lock(&mtd_partitions_mutex);
 367         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 368                 if (slave->master == master) {
 369                         ret = del_mtd_device(&slave->mtd);
 370                         if (ret < 0) {
 371                                 err = ret;
 372                                 continue;
 373                         }
 374                         list_del(&slave->list);
 375                         free_partition(slave);
 376                 }
 377         mutex_unlock(&mtd_partitions_mutex);
 378
 379         return err;
 380 }
 381
 382 static struct mtd_part *allocate_partition(struct mtd_info *master,
 383                         const struct mtd_partition *part, int partno,
 384                         uint64_t cur_offset)
 385 {
 386         struct mtd_part *slave;
 387         char *name;
 388
 389         /* allocate the partition structure */
 390         slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 391         name = kstrdup(part->name, GFP_KERNEL);
 392         if (!name || !slave) {
 393                 printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
 394                        master->name);
 395                 kfree(name);
 396                 kfree(slave);
 397                 return ERR_PTR(-ENOMEM);
 398         }
 399
 400         /* set up the MTD object for this partition */
 401         slave->mtd.type = master->type;
 402         slave->mtd.flags = master->flags & ~part->mask_flags;
 403         slave->mtd.size = part->size;
 404         slave->mtd.writesize = master->writesize;
 405         slave->mtd.writebufsize = master->writebufsize;
 406         slave->mtd.oobsize = master->oobsize;
 407         slave->mtd.oobavail = master->oobavail;
 408         slave->mtd.subpage_sft = master->subpage_sft;
 409
 410         slave->mtd.name = name;
 411         slave->mtd.owner = master->owner;
 412         slave->mtd.backing_dev_info = master->backing_dev_info;
 413
 414         /* NOTE:  we don't arrange MTDs as a tree; it'd be error-prone
 415          * to have the same data be in two different partitions.
 416          */
 417         slave->mtd.dev.parent = master->dev.parent;
 418
 419         slave->mtd.read = part_read;
 420         slave->mtd.write = part_write;
 421
 422         if (master->panic_write)
 423                 slave->mtd.panic_write = part_panic_write;
 424
 425         if (master->point && master->unpoint) {
 426                 slave->mtd.point = part_point;
 427                 slave->mtd.unpoint = part_unpoint;
 428         }
 429
 430         if (master->get_unmapped_area)
 431                 slave->mtd.get_unmapped_area = part_get_unmapped_area;
 432         if (master->read_oob)
 433                 slave->mtd.read_oob = part_read_oob;
 434         if (master->write_oob)
 435                 slave->mtd.write_oob = part_write_oob;
 436         if (master->read_user_prot_reg)
 437                 slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
 438         if (master->read_fact_prot_reg)
 439                 slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
 440         if (master->write_user_prot_reg)
 441                 slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
 442         if (master->lock_user_prot_reg)
 443                 slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
 444         if (master->get_user_prot_info)
 445                 slave->mtd.get_user_prot_info = part_get_user_prot_info;
 446         if (master->get_fact_prot_info)
 447                 slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
 448         if (master->sync)
 449                 slave->mtd.sync = part_sync;
 450         if (!partno && !master->dev.class && master->suspend && master->resume) {
 451                         slave->mtd.suspend = part_suspend;
 452                         slave->mtd.resume = part_resume;
 453         }
 454         if (master->writev)
 455                 slave->mtd.writev = part_writev;
 456         if (master->lock)
 457                 slave->mtd.lock = part_lock;
 458         if (master->unlock)
 459                 slave->mtd.unlock = part_unlock;
 460         if (master->is_locked)
 461                 slave->mtd.is_locked = part_is_locked;
 462         if (master->block_isbad)
 463                 slave->mtd.block_isbad = part_block_isbad;
 464         if (master->block_markbad)
 465                 slave->mtd.block_markbad = part_block_markbad;
 466         slave->mtd.erase = part_erase;
 467         slave->master = master;
 468         slave->offset = part->offset;
 469
 470         if (slave->offset == MTDPART_OFS_APPEND)
 471                 slave->offset = cur_offset;
 472         if (slave->offset == MTDPART_OFS_NXTBLK) {
 473                 slave->offset = cur_offset;
 474                 if (mtd_mod_by_eb(cur_offset, master) != 0) {
 475                         /* Round up to next erasesize */
 476                         slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
 477                         printk(KERN_NOTICE "Moving partition %d: "
 478                                "0x%012llx -> 0x%012llx\n", partno,
 479                                (unsigned long long)cur_offset, (unsigned long long)slave->offset);
 480                 }
 481         }
 482         if (slave->offset == MTDPART_OFS_RETAIN) {
 483                 slave->offset = cur_offset;
 484                 if (master->size - slave->offset >= slave->mtd.size) {
 485                         slave->mtd.size = master->size - slave->offset
 486                                                         - slave->mtd.size;
 487                 } else {
 488                         printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
 489                                 part->name, master->size - slave->offset,
 490                                 slave->mtd.size);
 491                         /* register to preserve ordering */
 492                         goto out_register;
 493                 }
 494         }
 495         if (slave->mtd.size == MTDPART_SIZ_FULL)
 496                 slave->mtd.size = master->size - slave->offset;
 497
 498         printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
 499                 (unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
 500
 501         /* let's do some sanity checks */
 502         if (slave->offset >= master->size) {
 503                 /* let's register it anyway to preserve ordering */
 504                 slave->offset = 0;
 505                 slave->mtd.size = 0;
 506                 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
 507                         part->name);
 508                 goto out_register;
 509         }
 510         if (slave->offset + slave->mtd.size > master->size) {
 511                 slave->mtd.size = master->size - slave->offset;
 512                 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
 513                         part->name, master->name, (unsigned long long)slave->mtd.size);
 514         }
 515         if (master->numeraseregions > 1) {
 516                 /* Deal with variable erase size stuff */
 517                 int i, max = master->numeraseregions;
 518                 u64 end = slave->offset + slave->mtd.size;
 519                 struct mtd_erase_region_info *regions = master->eraseregions;
 520
 521                 /* Find the first erase regions which is part of this
 522                  * partition. */
 523                 for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
 524                         ;
 525                 /* The loop searched for the region _behind_ the first one */
 526                 if (i > 0)
 527                         i--;
 528
 529                 /* Pick biggest erasesize */
 530                 for (; i < max && regions[i].offset < end; i++) {
 531                         if (slave->mtd.erasesize < regions[i].erasesize) {
 532                                 slave->mtd.erasesize = regions[i].erasesize;
 533                         }
 534                 }
 535                 BUG_ON(slave->mtd.erasesize == 0);
 536         } else {
 537                 /* Single erase size */
 538                 slave->mtd.erasesize = master->erasesize;
 539         }
 540
 541         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 542             mtd_mod_by_eb(slave->offset, &slave->mtd)) {
 543                 /* Doesn't start on a boundary of major erase size */
 544                 /* FIXME: Let it be writable if it is on a boundary of
 545                  * _minor_ erase size though */
 546                 slave->mtd.flags &= ~MTD_WRITEABLE;
 547                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
 548                         part->name);
 549         }
 550         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 551             mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
 552                 slave->mtd.flags &= ~MTD_WRITEABLE;
 553                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
 554                         part->name);
 555         }
 556
 557         slave->mtd.ecclayout = master->ecclayout;
 558         if (master->block_isbad) {
 559                 uint64_t offs = 0;
 560
 561                 while (offs < slave->mtd.size) {
 562                         if (master->block_isbad(master,
 563                                                 offs + slave->offset))
 564                                 slave->mtd.ecc_stats.badblocks++;
 565                         offs += slave->mtd.erasesize;
 566                 }
 567         }
 568
 569 out_register:
 570         return slave;
 571 }
 572
 573 int mtd_add_partition(struct mtd_info *master, char *name,
 574                       long long offset, long long length)
 575 {
 576         struct mtd_partition part;
 577         struct mtd_part *p, *new;
 578         uint64_t start, end;
 579         int ret = 0;
 580
 581         /* the direct offset is expected */
 582         if (offset == MTDPART_OFS_APPEND ||
 583             offset == MTDPART_OFS_NXTBLK)
 584                 return -EINVAL;
 585
 586         if (length == MTDPART_SIZ_FULL)
 587                 length = master->size - offset;
 588
 589         if (length <= 0)
 590                 return -EINVAL;
 591
 592         part.name = name;
 593         part.size = length;
 594         part.offset = offset;
 595         part.mask_flags = 0;
 596         part.ecclayout = NULL;
 597
 598         new = allocate_partition(master, &part, -1, offset);
 599         if (IS_ERR(new))
 600                 return PTR_ERR(new);
 601
 602         start = offset;
 603         end = offset + length;
 604
 605         mutex_lock(&mtd_partitions_mutex);
 606         list_for_each_entry(p, &mtd_partitions, list)
 607                 if (p->master == master) {
 608                         if ((start >= p->offset) &&
 609                             (start < (p->offset + p->mtd.size)))
 610                                 goto err_inv;
 611
 612                         if ((end >= p->offset) &&
 613                             (end < (p->offset + p->mtd.size)))
 614                                 goto err_inv;
 615                 }
 616
 617         list_add(&new->list, &mtd_partitions);
 618         mutex_unlock(&mtd_partitions_mutex);
 619
 620         add_mtd_device(&new->mtd);
 621
 622         return ret;
 623 err_inv:
 624         mutex_unlock(&mtd_partitions_mutex);
 625         free_partition(new);
 626         return -EINVAL;
 627 }
 628 EXPORT_SYMBOL_GPL(mtd_add_partition);
 629
 630 int mtd_del_partition(struct mtd_info *master, int partno)
 631 {
 632         struct mtd_part *slave, *next;
 633         int ret = -EINVAL;
 634
 635         mutex_lock(&mtd_partitions_mutex);
 636         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 637                 if ((slave->master == master) &&
 638                     (slave->mtd.index == partno)) {
 639                         ret = del_mtd_device(&slave->mtd);
 640                         if (ret < 0)
 641                                 break;
 642
 643                         list_del(&slave->list);
 644                         free_partition(slave);
 645                         break;
 646                 }
 647         mutex_unlock(&mtd_partitions_mutex);
 648
 649         return ret;
 650 }
 651 EXPORT_SYMBOL_GPL(mtd_del_partition);
 652
 653 /*
 654  * This function, given a master MTD object and a partition table, creates
 655  * and registers slave MTD objects which are bound to the master according to
 656  * the partition definitions.
 657  *
 658  * We don't register the master, or expect the caller to have done so,
 659  * for reasons of data integrity.
 660  */
 661
 662 int add_mtd_partitions(struct mtd_info *master,
 663                        const struct mtd_partition *parts,
 664                        int nbparts)
 665 {
 666         struct mtd_part *slave;
 667         uint64_t cur_offset = 0;
 668         int i;
 669
 670         printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 671
 672         for (i = 0; i < nbparts; i++) {
 673                 slave = allocate_partition(master, parts + i, i, cur_offset);
 674                 if (IS_ERR(slave))
 675                         return PTR_ERR(slave);
 676
 677                 mutex_lock(&mtd_partitions_mutex);
 678                 list_add(&slave->list, &mtd_partitions);
 679                 mutex_unlock(&mtd_partitions_mutex);
 680
 681                 add_mtd_device(&slave->mtd);
 682
 683                 cur_offset = slave->offset + slave->mtd.size;
 684         }
 685
 686         return 0;
 687 }
 688
 689 static DEFINE_SPINLOCK(part_parser_lock);
 690 static LIST_HEAD(part_parsers);
 691
 692 static struct mtd_part_parser *get_partition_parser(const char *name)
 693 {
 694         struct mtd_part_parser *p, *ret = NULL;
 695
 696         spin_lock(&part_parser_lock);
 697
 698         list_for_each_entry(p, &part_parsers, list)
 699                 if (!strcmp(p->name, name) && try_module_get(p->owner)) {
 700                         ret = p;
 701                         break;
 702                 }
 703
 704         spin_unlock(&part_parser_lock);
 705
 706         return ret;
 707 }
 708
 709 #define put_partition_parser(p) do { module_put((p)->owner); } while (0)
 710
 711 int register_mtd_parser(struct mtd_part_parser *p)
 712 {
 713         spin_lock(&part_parser_lock);
 714         list_add(&p->list, &part_parsers);
 715         spin_unlock(&part_parser_lock);
 716
 717         return 0;
 718 }
 719 EXPORT_SYMBOL_GPL(register_mtd_parser);
 720
 721 int deregister_mtd_parser(struct mtd_part_parser *p)
 722 {
 723         spin_lock(&part_parser_lock);
 724         list_del(&p->list);
 725         spin_unlock(&part_parser_lock);
 726         return 0;
 727 }
 728 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
 729
 730 /*
 731  * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
 732  * are changing this array!
 733  */
 734 static const char *default_mtd_part_types[] = {
 735         "cmdlinepart",
 736         "ofpart",
 737         NULL
 738 };
 739
 740 /**
 741  * parse_mtd_partitions - parse MTD partitions
 742  * @master: the master partition (describes whole MTD device)
 743  * @types: names of partition parsers to try or %NULL
 744  * @pparts: array of partitions found is returned here
 745  * @data: MTD partition parser-specific data
 746  *
 747  * This function tries to find partition on MTD device @master. It uses MTD
 748  * partition parsers, specified in @types. However, if @types is %NULL, then
 749  * the default list of parsers is used. The default list contains only the
 750  * "cmdlinepart" and "ofpart" parsers ATM.
 751  *
 752  * This function may return:
 753  * o a negative error code in case of failure
 754  * o zero if no partitions were found
 755  * o a positive number of found partitions, in which case on exit @pparts will
 756  *   point to an array containing this number of &struct mtd_info objects.
 757  */
 758 int parse_mtd_partitions(struct mtd_info *master, const char **types,
 759                          struct mtd_partition **pparts,
 760                          struct mtd_part_parser_data *data)
 761 {
 762         struct mtd_part_parser *parser;
 763         int ret = 0;
 764
 765         if (!types)
 766                 types = default_mtd_part_types;
 767
 768         for ( ; ret <= 0 && *types; types++) {
 769                 parser = get_partition_parser(*types);
 770                 if (!parser && !request_module("%s", *types))
 771                                 parser = get_partition_parser(*types);
 772                 if (!parser)
 773                         continue;
 774                 ret = (*parser->parse_fn)(master, pparts, data);
 775                 if (ret > 0) {
 776                         printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
 777                                ret, parser->name, master->name);
 778                 }
 779                 put_partition_parser(parser);
 780         }
 781         return ret;
 782 }
 783
 784 int mtd_is_partition(struct mtd_info *mtd)
 785 {
 786         struct mtd_part *part;
 787         int ispart = 0;
 788
 789         mutex_lock(&mtd_partitions_mutex);
 790         list_for_each_entry(part, &mtd_partitions, list)
 791                 if (&part->mtd == mtd) {
 792                         ispart = 1;
 793                         break;
 794                 }
 795         mutex_unlock(&mtd_partitions_mutex);
 796
 797         return ispart;
 798 }
 799 EXPORT_SYMBOL_GPL(mtd_is_partition);