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