drivers/mtd/mtdpart.c

   1 /*
   2  * Simple MTD partitioning layer
   3  *
   4  * Copyright © 2000 Nicolas Pitre <nico@fluxnic.net>
   5  * Copyright © 2002 Thomas Gleixner <gleixner@linutronix.de>
   6  * Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  21  *
  22  */
  23
  24 #include <linux/module.h>
  25 #include <linux/types.h>
  26 #include <linux/kernel.h>
  27 #include <linux/slab.h>
  28 #include <linux/list.h>
  29 #include <linux/kmod.h>
  30 #include <linux/mtd/mtd.h>
  31 #include <linux/mtd/partitions.h>
  32 #include <linux/err.h>
  33
  34 #include "mtdcore.h"
  35
  36 /* Our partition linked list */
  37 static LIST_HEAD(mtd_partitions);
  38 static DEFINE_MUTEX(mtd_partitions_mutex);
  39
  40 /* Our partition node structure */
  41 struct mtd_part {
  42         struct mtd_info mtd;
  43         struct mtd_info *master;
  44         uint64_t offset;
  45         struct list_head list;
  46 };
  47
  48 /*
  49  * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
  50  * the pointer to that structure with this macro.
  51  */
  52 #define PART(x)  ((struct mtd_part *)(x))
  53
  54
  55 /*
  56  * MTD methods which simply translate the effective address and pass through
  57  * to the _real_ device.
  58  */
  59
  60 static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
  61                 size_t *retlen, u_char *buf)
  62 {
  63         struct mtd_part *part = PART(mtd);
  64         struct mtd_ecc_stats stats;
  65         int res;
  66
  67         stats = part->master->ecc_stats;
  68         res = part->master->_read(part->master, from + part->offset, len,
  69                                   retlen, buf);
  70         if (unlikely(mtd_is_eccerr(res)))
  71                 mtd->ecc_stats.failed +=
  72                         part->master->ecc_stats.failed - stats.failed;
  73         else
  74                 mtd->ecc_stats.corrected +=
  75                         part->master->ecc_stats.corrected - stats.corrected;
  76         return res;
  77 }
  78
  79 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
  80                 size_t *retlen, void **virt, resource_size_t *phys)
  81 {
  82         struct mtd_part *part = PART(mtd);
  83
  84         return part->master->_point(part->master, from + part->offset, len,
  85                                     retlen, virt, phys);
  86 }
  87
  88 static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
  89 {
  90         struct mtd_part *part = PART(mtd);
  91
  92         return part->master->_unpoint(part->master, from + part->offset, len);
  93 }
  94
  95 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
  96                                             unsigned long len,
  97                                             unsigned long offset,
  98                                             unsigned long flags)
  99 {
 100         struct mtd_part *part = PART(mtd);
 101
 102         offset += part->offset;
 103         return part->master->_get_unmapped_area(part->master, len, offset,
 104                                                 flags);
 105 }
 106
 107 static int part_read_oob(struct mtd_info *mtd, loff_t from,
 108                 struct mtd_oob_ops *ops)
 109 {
 110         struct mtd_part *part = PART(mtd);
 111         int res;
 112
 113         if (from >= mtd->size)
 114                 return -EINVAL;
 115         if (ops->datbuf && from + ops->len > mtd->size)
 116                 return -EINVAL;
 117
 118         /*
 119          * If OOB is also requested, make sure that we do not read past the end
 120          * of this partition.
 121          */
 122         if (ops->oobbuf) {
 123                 size_t len, pages;
 124
 125                 if (ops->mode == MTD_OPS_AUTO_OOB)
 126                         len = mtd->oobavail;
 127                 else
 128                         len = mtd->oobsize;
 129                 pages = mtd_div_by_ws(mtd->size, mtd);
 130                 pages -= mtd_div_by_ws(from, mtd);
 131                 if (ops->ooboffs + ops->ooblen > pages * len)
 132                         return -EINVAL;
 133         }
 134
 135         res = part->master->_read_oob(part->master, from + part->offset, ops);
 136         if (unlikely(res)) {
 137                 if (mtd_is_bitflip(res))
 138                         mtd->ecc_stats.corrected++;
 139                 if (mtd_is_eccerr(res))
 140                         mtd->ecc_stats.failed++;
 141         }
 142         return res;
 143 }
 144
 145 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
 146                 size_t len, size_t *retlen, u_char *buf)
 147 {
 148         struct mtd_part *part = PART(mtd);
 149         return part->master->_read_user_prot_reg(part->master, from, len,
 150                                                  retlen, buf);
 151 }
 152
 153 static int part_get_user_prot_info(struct mtd_info *mtd, size_t len,
 154                                    size_t *retlen, struct otp_info *buf)
 155 {
 156         struct mtd_part *part = PART(mtd);
 157         return part->master->_get_user_prot_info(part->master, len, retlen,
 158                                                  buf);
 159 }
 160
 161 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
 162                 size_t len, size_t *retlen, u_char *buf)
 163 {
 164         struct mtd_part *part = PART(mtd);
 165         return part->master->_read_fact_prot_reg(part->master, from, len,
 166                                                  retlen, buf);
 167 }
 168
 169 static int part_get_fact_prot_info(struct mtd_info *mtd, size_t len,
 170                                    size_t *retlen, struct otp_info *buf)
 171 {
 172         struct mtd_part *part = PART(mtd);
 173         return part->master->_get_fact_prot_info(part->master, len, retlen,
 174                                                  buf);
 175 }
 176
 177 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
 178                 size_t *retlen, const u_char *buf)
 179 {
 180         struct mtd_part *part = PART(mtd);
 181         return part->master->_write(part->master, to + part->offset, len,
 182                                     retlen, buf);
 183 }
 184
 185 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
 186                 size_t *retlen, const u_char *buf)
 187 {
 188         struct mtd_part *part = PART(mtd);
 189         return part->master->_panic_write(part->master, to + part->offset, len,
 190                                           retlen, buf);
 191 }
 192
 193 static int part_write_oob(struct mtd_info *mtd, loff_t to,
 194                 struct mtd_oob_ops *ops)
 195 {
 196         struct mtd_part *part = PART(mtd);
 197
 198         if (to >= mtd->size)
 199                 return -EINVAL;
 200         if (ops->datbuf && to + ops->len > mtd->size)
 201                 return -EINVAL;
 202         return part->master->_write_oob(part->master, to + part->offset, ops);
 203 }
 204
 205 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
 206                 size_t len, size_t *retlen, u_char *buf)
 207 {
 208         struct mtd_part *part = PART(mtd);
 209         return part->master->_write_user_prot_reg(part->master, from, len,
 210                                                   retlen, buf);
 211 }
 212
 213 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
 214                 size_t len)
 215 {
 216         struct mtd_part *part = PART(mtd);
 217         return part->master->_lock_user_prot_reg(part->master, from, len);
 218 }
 219
 220 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
 221                 unsigned long count, loff_t to, size_t *retlen)
 222 {
 223         struct mtd_part *part = PART(mtd);
 224         return part->master->_writev(part->master, vecs, count,
 225                                      to + part->offset, retlen);
 226 }
 227
 228 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
 229 {
 230         struct mtd_part *part = PART(mtd);
 231         int ret;
 232
 233         instr->addr += part->offset;
 234         ret = part->master->_erase(part->master, instr);
 235         if (ret) {
 236                 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 237                         instr->fail_addr -= part->offset;
 238                 instr->addr -= part->offset;
 239         }
 240         return ret;
 241 }
 242
 243 void mtd_erase_callback(struct erase_info *instr)
 244 {
 245         if (instr->mtd->_erase == part_erase) {
 246                 struct mtd_part *part = PART(instr->mtd);
 247
 248                 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 249                         instr->fail_addr -= part->offset;
 250                 instr->addr -= part->offset;
 251         }
 252         if (instr->callback)
 253                 instr->callback(instr);
 254 }
 255 EXPORT_SYMBOL_GPL(mtd_erase_callback);
 256
 257 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 258 {
 259         struct mtd_part *part = PART(mtd);
 260         return part->master->_lock(part->master, ofs + part->offset, len);
 261 }
 262
 263 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 264 {
 265         struct mtd_part *part = PART(mtd);
 266         return part->master->_unlock(part->master, ofs + part->offset, len);
 267 }
 268
 269 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 270 {
 271         struct mtd_part *part = PART(mtd);
 272         return part->master->_is_locked(part->master, ofs + part->offset, len);
 273 }
 274
 275 static void part_sync(struct mtd_info *mtd)
 276 {
 277         struct mtd_part *part = PART(mtd);
 278         part->master->_sync(part->master);
 279 }
 280
 281 static int part_suspend(struct mtd_info *mtd)
 282 {
 283         struct mtd_part *part = PART(mtd);
 284         return part->master->_suspend(part->master);
 285 }
 286
 287 static void part_resume(struct mtd_info *mtd)
 288 {
 289         struct mtd_part *part = PART(mtd);
 290         part->master->_resume(part->master);
 291 }
 292
 293 static int part_block_isreserved(struct mtd_info *mtd, loff_t ofs)
 294 {
 295         struct mtd_part *part = PART(mtd);
 296         ofs += part->offset;
 297         return part->master->_block_isreserved(part->master, ofs);
 298 }
 299
 300 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
 301 {
 302         struct mtd_part *part = PART(mtd);
 303         ofs += part->offset;
 304         return part->master->_block_isbad(part->master, ofs);
 305 }
 306
 307 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 308 {
 309         struct mtd_part *part = PART(mtd);
 310         int res;
 311
 312         ofs += part->offset;
 313         res = part->master->_block_markbad(part->master, ofs);
 314         if (!res)
 315                 mtd->ecc_stats.badblocks++;
 316         return res;
 317 }
 318
 319 static inline void free_partition(struct mtd_part *p)
 320 {
 321         kfree(p->mtd.name);
 322         kfree(p);
 323 }
 324
 325 /*
 326  * This function unregisters and destroy all slave MTD objects which are
 327  * attached to the given master MTD object.
 328  */
 329
 330 int del_mtd_partitions(struct mtd_info *master)
 331 {
 332         struct mtd_part *slave, *next;
 333         int ret, err = 0;
 334
 335         mutex_lock(&mtd_partitions_mutex);
 336         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 337                 if (slave->master == master) {
 338                         ret = del_mtd_device(&slave->mtd);
 339                         if (ret < 0) {
 340                                 err = ret;
 341                                 continue;
 342                         }
 343                         list_del(&slave->list);
 344                         free_partition(slave);
 345                 }
 346         mutex_unlock(&mtd_partitions_mutex);
 347
 348         return err;
 349 }
 350
 351 static struct mtd_part *allocate_partition(struct mtd_info *master,
 352                         const struct mtd_partition *part, int partno,
 353                         uint64_t cur_offset)
 354 {
 355         struct mtd_part *slave;
 356         char *name;
 357
 358         /* allocate the partition structure */
 359         slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 360         name = kstrdup(part->name, GFP_KERNEL);
 361         if (!name || !slave) {
 362                 printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
 363                        master->name);
 364                 kfree(name);
 365                 kfree(slave);
 366                 return ERR_PTR(-ENOMEM);
 367         }
 368
 369         /* set up the MTD object for this partition */
 370         slave->mtd.type = master->type;
 371         slave->mtd.flags = master->flags & ~part->mask_flags;
 372         slave->mtd.size = part->size;
 373         slave->mtd.writesize = master->writesize;
 374         slave->mtd.writebufsize = master->writebufsize;
 375         slave->mtd.oobsize = master->oobsize;
 376         slave->mtd.oobavail = master->oobavail;
 377         slave->mtd.subpage_sft = master->subpage_sft;
 378
 379         slave->mtd.name = name;
 380         slave->mtd.owner = master->owner;
 381         slave->mtd.backing_dev_info = master->backing_dev_info;
 382
 383         /* NOTE:  we don't arrange MTDs as a tree; it'd be error-prone
 384          * to have the same data be in two different partitions.
 385          */
 386         slave->mtd.dev.parent = master->dev.parent;
 387
 388         slave->mtd._read = part_read;
 389         slave->mtd._write = part_write;
 390
 391         if (master->_panic_write)
 392                 slave->mtd._panic_write = part_panic_write;
 393
 394         if (master->_point && master->_unpoint) {
 395                 slave->mtd._point = part_point;
 396                 slave->mtd._unpoint = part_unpoint;
 397         }
 398
 399         if (master->_get_unmapped_area)
 400                 slave->mtd._get_unmapped_area = part_get_unmapped_area;
 401         if (master->_read_oob)
 402                 slave->mtd._read_oob = part_read_oob;
 403         if (master->_write_oob)
 404                 slave->mtd._write_oob = part_write_oob;
 405         if (master->_read_user_prot_reg)
 406                 slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
 407         if (master->_read_fact_prot_reg)
 408                 slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
 409         if (master->_write_user_prot_reg)
 410                 slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
 411         if (master->_lock_user_prot_reg)
 412                 slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
 413         if (master->_get_user_prot_info)
 414                 slave->mtd._get_user_prot_info = part_get_user_prot_info;
 415         if (master->_get_fact_prot_info)
 416                 slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
 417         if (master->_sync)
 418                 slave->mtd._sync = part_sync;
 419         if (!partno && !master->dev.class && master->_suspend &&
 420             master->_resume) {
 421                         slave->mtd._suspend = part_suspend;
 422                         slave->mtd._resume = part_resume;
 423         }
 424         if (master->_writev)
 425                 slave->mtd._writev = part_writev;
 426         if (master->_lock)
 427                 slave->mtd._lock = part_lock;
 428         if (master->_unlock)
 429                 slave->mtd._unlock = part_unlock;
 430         if (master->_is_locked)
 431                 slave->mtd._is_locked = part_is_locked;
 432         if (master->_block_isreserved)
 433                 slave->mtd._block_isreserved = part_block_isreserved;
 434         if (master->_block_isbad)
 435                 slave->mtd._block_isbad = part_block_isbad;
 436         if (master->_block_markbad)
 437                 slave->mtd._block_markbad = part_block_markbad;
 438         slave->mtd._erase = part_erase;
 439         slave->master = master;
 440         slave->offset = part->offset;
 441
 442         if (slave->offset == MTDPART_OFS_APPEND)
 443                 slave->offset = cur_offset;
 444         if (slave->offset == MTDPART_OFS_NXTBLK) {
 445                 slave->offset = cur_offset;
 446                 if (mtd_mod_by_eb(cur_offset, master) != 0) {
 447                         /* Round up to next erasesize */
 448                         slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
 449                         printk(KERN_NOTICE "Moving partition %d: "
 450                                "0x%012llx -> 0x%012llx\n", partno,
 451                                (unsigned long long)cur_offset, (unsigned long long)slave->offset);
 452                 }
 453         }
 454         if (slave->offset == MTDPART_OFS_RETAIN) {
 455                 slave->offset = cur_offset;
 456                 if (master->size - slave->offset >= slave->mtd.size) {
 457                         slave->mtd.size = master->size - slave->offset
 458                                                         - slave->mtd.size;
 459                 } else {
 460                         printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
 461                                 part->name, master->size - slave->offset,
 462                                 slave->mtd.size);
 463                         /* register to preserve ordering */
 464                         goto out_register;
 465                 }
 466         }
 467         if (slave->mtd.size == MTDPART_SIZ_FULL)
 468                 slave->mtd.size = master->size - slave->offset;
 469
 470         printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
 471                 (unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
 472
 473         /* let's do some sanity checks */
 474         if (slave->offset >= master->size) {
 475                 /* let's register it anyway to preserve ordering */
 476                 slave->offset = 0;
 477                 slave->mtd.size = 0;
 478                 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
 479                         part->name);
 480                 goto out_register;
 481         }
 482         if (slave->offset + slave->mtd.size > master->size) {
 483                 slave->mtd.size = master->size - slave->offset;
 484                 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
 485                         part->name, master->name, (unsigned long long)slave->mtd.size);
 486         }
 487         if (master->numeraseregions > 1) {
 488                 /* Deal with variable erase size stuff */
 489                 int i, max = master->numeraseregions;
 490                 u64 end = slave->offset + slave->mtd.size;
 491                 struct mtd_erase_region_info *regions = master->eraseregions;
 492
 493                 /* Find the first erase regions which is part of this
 494                  * partition. */
 495                 for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
 496                         ;
 497                 /* The loop searched for the region _behind_ the first one */
 498                 if (i > 0)
 499                         i--;
 500
 501                 /* Pick biggest erasesize */
 502                 for (; i < max && regions[i].offset < end; i++) {
 503                         if (slave->mtd.erasesize < regions[i].erasesize) {
 504                                 slave->mtd.erasesize = regions[i].erasesize;
 505                         }
 506                 }
 507                 BUG_ON(slave->mtd.erasesize == 0);
 508         } else {
 509                 /* Single erase size */
 510                 slave->mtd.erasesize = master->erasesize;
 511         }
 512
 513         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 514             mtd_mod_by_eb(slave->offset, &slave->mtd)) {
 515                 /* Doesn't start on a boundary of major erase size */
 516                 /* FIXME: Let it be writable if it is on a boundary of
 517                  * _minor_ erase size though */
 518                 slave->mtd.flags &= ~MTD_WRITEABLE;
 519                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
 520                         part->name);
 521         }
 522         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 523             mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
 524                 slave->mtd.flags &= ~MTD_WRITEABLE;
 525                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
 526                         part->name);
 527         }
 528
 529         slave->mtd.ecclayout = master->ecclayout;
 530         slave->mtd.ecc_step_size = master->ecc_step_size;
 531         slave->mtd.ecc_strength = master->ecc_strength;
 532         slave->mtd.bitflip_threshold = master->bitflip_threshold;
 533
 534         if (master->_block_isbad) {
 535                 uint64_t offs = 0;
 536
 537                 while (offs < slave->mtd.size) {
 538                         if (mtd_block_isbad(master, offs + slave->offset))
 539                                 slave->mtd.ecc_stats.badblocks++;
 540                         offs += slave->mtd.erasesize;
 541                 }
 542         }
 543
 544 out_register:
 545         return slave;
 546 }
 547
 548 int mtd_add_partition(struct mtd_info *master, const char *name,
 549                       long long offset, long long length)
 550 {
 551         struct mtd_partition part;
 552         struct mtd_part *p, *new;
 553         uint64_t start, end;
 554         int ret = 0;
 555
 556         /* the direct offset is expected */
 557         if (offset == MTDPART_OFS_APPEND ||
 558             offset == MTDPART_OFS_NXTBLK)
 559                 return -EINVAL;
 560
 561         if (length == MTDPART_SIZ_FULL)
 562                 length = master->size - offset;
 563
 564         if (length <= 0)
 565                 return -EINVAL;
 566
 567         part.name = name;
 568         part.size = length;
 569         part.offset = offset;
 570         part.mask_flags = 0;
 571         part.ecclayout = NULL;
 572
 573         new = allocate_partition(master, &part, -1, offset);
 574         if (IS_ERR(new))
 575                 return PTR_ERR(new);
 576
 577         start = offset;
 578         end = offset + length;
 579
 580         mutex_lock(&mtd_partitions_mutex);
 581         list_for_each_entry(p, &mtd_partitions, list)
 582                 if (p->master == master) {
 583                         if ((start >= p->offset) &&
 584                             (start < (p->offset + p->mtd.size)))
 585                                 goto err_inv;
 586
 587                         if ((end >= p->offset) &&
 588                             (end < (p->offset + p->mtd.size)))
 589                                 goto err_inv;
 590                 }
 591
 592         list_add(&new->list, &mtd_partitions);
 593         mutex_unlock(&mtd_partitions_mutex);
 594
 595         add_mtd_device(&new->mtd);
 596
 597         return ret;
 598 err_inv:
 599         mutex_unlock(&mtd_partitions_mutex);
 600         free_partition(new);
 601         return -EINVAL;
 602 }
 603 EXPORT_SYMBOL_GPL(mtd_add_partition);
 604
 605 int mtd_del_partition(struct mtd_info *master, int partno)
 606 {
 607         struct mtd_part *slave, *next;
 608         int ret = -EINVAL;
 609
 610         mutex_lock(&mtd_partitions_mutex);
 611         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 612                 if ((slave->master == master) &&
 613                     (slave->mtd.index == partno)) {
 614                         ret = del_mtd_device(&slave->mtd);
 615                         if (ret < 0)
 616                                 break;
 617
 618                         list_del(&slave->list);
 619                         free_partition(slave);
 620                         break;
 621                 }
 622         mutex_unlock(&mtd_partitions_mutex);
 623
 624         return ret;
 625 }
 626 EXPORT_SYMBOL_GPL(mtd_del_partition);
 627
 628 /*
 629  * This function, given a master MTD object and a partition table, creates
 630  * and registers slave MTD objects which are bound to the master according to
 631  * the partition definitions.
 632  *
 633  * We don't register the master, or expect the caller to have done so,
 634  * for reasons of data integrity.
 635  */
 636
 637 int add_mtd_partitions(struct mtd_info *master,
 638                        const struct mtd_partition *parts,
 639                        int nbparts)
 640 {
 641         struct mtd_part *slave;
 642         uint64_t cur_offset = 0;
 643         int i;
 644
 645         printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 646
 647         for (i = 0; i < nbparts; i++) {
 648                 slave = allocate_partition(master, parts + i, i, cur_offset);
 649                 if (IS_ERR(slave))
 650                         return PTR_ERR(slave);
 651
 652                 mutex_lock(&mtd_partitions_mutex);
 653                 list_add(&slave->list, &mtd_partitions);
 654                 mutex_unlock(&mtd_partitions_mutex);
 655
 656                 add_mtd_device(&slave->mtd);
 657
 658                 cur_offset = slave->offset + slave->mtd.size;
 659         }
 660
 661         return 0;
 662 }
 663
 664 static DEFINE_SPINLOCK(part_parser_lock);
 665 static LIST_HEAD(part_parsers);
 666
 667 static struct mtd_part_parser *get_partition_parser(const char *name)
 668 {
 669         struct mtd_part_parser *p, *ret = NULL;
 670
 671         spin_lock(&part_parser_lock);
 672
 673         list_for_each_entry(p, &part_parsers, list)
 674                 if (!strcmp(p->name, name) && try_module_get(p->owner)) {
 675                         ret = p;
 676                         break;
 677                 }
 678
 679         spin_unlock(&part_parser_lock);
 680
 681         return ret;
 682 }
 683
 684 #define put_partition_parser(p) do { module_put((p)->owner); } while (0)
 685
 686 void register_mtd_parser(struct mtd_part_parser *p)
 687 {
 688         spin_lock(&part_parser_lock);
 689         list_add(&p->list, &part_parsers);
 690         spin_unlock(&part_parser_lock);
 691 }
 692 EXPORT_SYMBOL_GPL(register_mtd_parser);
 693
 694 void deregister_mtd_parser(struct mtd_part_parser *p)
 695 {
 696         spin_lock(&part_parser_lock);
 697         list_del(&p->list);
 698         spin_unlock(&part_parser_lock);
 699 }
 700 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
 701
 702 /*
 703  * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
 704  * are changing this array!
 705  */
 706 static const char * const default_mtd_part_types[] = {
 707         "cmdlinepart",
 708         "ofpart",
 709         NULL
 710 };
 711
 712 /**
 713  * parse_mtd_partitions - parse MTD partitions
 714  * @master: the master partition (describes whole MTD device)
 715  * @types: names of partition parsers to try or %NULL
 716  * @pparts: array of partitions found is returned here
 717  * @data: MTD partition parser-specific data
 718  *
 719  * This function tries to find partition on MTD device @master. It uses MTD
 720  * partition parsers, specified in @types. However, if @types is %NULL, then
 721  * the default list of parsers is used. The default list contains only the
 722  * "cmdlinepart" and "ofpart" parsers ATM.
 723  * Note: If there are more then one parser in @types, the kernel only takes the
 724  * partitions parsed out by the first parser.
 725  *
 726  * This function may return:
 727  * o a negative error code in case of failure
 728  * o zero if no partitions were found
 729  * o a positive number of found partitions, in which case on exit @pparts will
 730  *   point to an array containing this number of &struct mtd_info objects.
 731  */
 732 int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
 733                          struct mtd_partition **pparts,
 734                          struct mtd_part_parser_data *data)
 735 {
 736         struct mtd_part_parser *parser;
 737         int ret = 0;
 738
 739         if (!types)
 740                 types = default_mtd_part_types;
 741
 742         for ( ; ret <= 0 && *types; types++) {
 743                 parser = get_partition_parser(*types);
 744                 if (!parser && !request_module("%s", *types))
 745                         parser = get_partition_parser(*types);
 746                 if (!parser)
 747                         continue;
 748                 ret = (*parser->parse_fn)(master, pparts, data);
 749                 put_partition_parser(parser);
 750                 if (ret > 0) {
 751                         printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
 752                                ret, parser->name, master->name);
 753                         break;
 754                 }
 755         }
 756         return ret;
 757 }
 758
 759 int mtd_is_partition(const struct mtd_info *mtd)
 760 {
 761         struct mtd_part *part;
 762         int ispart = 0;
 763
 764         mutex_lock(&mtd_partitions_mutex);
 765         list_for_each_entry(part, &mtd_partitions, list)
 766                 if (&part->mtd == mtd) {
 767                         ispart = 1;
 768                         break;
 769                 }
 770         mutex_unlock(&mtd_partitions_mutex);
 771
 772         return ispart;
 773 }
 774 EXPORT_SYMBOL_GPL(mtd_is_partition);
 775
 776 /* Returns the size of the entire flash chip */
 777 uint64_t mtd_get_device_size(const struct mtd_info *mtd)
 778 {
 779         if (!mtd_is_partition(mtd))
 780                 return mtd->size;
 781
 782         return PART(mtd)->master->size;
 783 }
 784 EXPORT_SYMBOL_GPL(mtd_get_device_size);