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 #include <linux/kconfig.h>
  34
  35 #include "mtdcore.h"
  36
  37 /* Our partition linked list */
  38 static LIST_HEAD(mtd_partitions);
  39 static DEFINE_MUTEX(mtd_partitions_mutex);
  40
  41 /* Our partition node structure */
  42 struct mtd_part {
  43         struct mtd_info mtd;
  44         struct mtd_info *master;
  45         uint64_t offset;
  46         struct list_head list;
  47 };
  48
  49 /*
  50  * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
  51  * the pointer to that structure.
  52  */
  53 static inline struct mtd_part *mtd_to_part(const struct mtd_info *mtd)
  54 {
  55         return container_of(mtd, struct mtd_part, mtd);
  56 }
  57
  58
  59 /*
  60  * MTD methods which simply translate the effective address and pass through
  61  * to the _real_ device.
  62  */
  63
  64 static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
  65                 size_t *retlen, u_char *buf)
  66 {
  67         struct mtd_part *part = mtd_to_part(mtd);
  68         struct mtd_ecc_stats stats;
  69         int res;
  70
  71         stats = part->master->ecc_stats;
  72         res = part->master->_read(part->master, from + part->offset, len,
  73                                   retlen, buf);
  74         if (unlikely(mtd_is_eccerr(res)))
  75                 mtd->ecc_stats.failed +=
  76                         part->master->ecc_stats.failed - stats.failed;
  77         else
  78                 mtd->ecc_stats.corrected +=
  79                         part->master->ecc_stats.corrected - stats.corrected;
  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 = mtd_to_part(mtd);
  87
  88         return part->master->_point(part->master, from + part->offset, len,
  89                                     retlen, virt, phys);
  90 }
  91
  92 static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
  93 {
  94         struct mtd_part *part = mtd_to_part(mtd);
  95
  96         return part->master->_unpoint(part->master, from + part->offset, len);
  97 }
  98
  99 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
 100                                             unsigned long len,
 101                                             unsigned long offset,
 102                                             unsigned long flags)
 103 {
 104         struct mtd_part *part = mtd_to_part(mtd);
 105
 106         offset += part->offset;
 107         return part->master->_get_unmapped_area(part->master, len, offset,
 108                                                 flags);
 109 }
 110
 111 static int part_read_oob(struct mtd_info *mtd, loff_t from,
 112                 struct mtd_oob_ops *ops)
 113 {
 114         struct mtd_part *part = mtd_to_part(mtd);
 115         int res;
 116
 117         if (from >= mtd->size)
 118                 return -EINVAL;
 119         if (ops->datbuf && from + ops->len > mtd->size)
 120                 return -EINVAL;
 121
 122         /*
 123          * If OOB is also requested, make sure that we do not read past the end
 124          * of this partition.
 125          */
 126         if (ops->oobbuf) {
 127                 size_t len, pages;
 128
 129                 len = mtd_oobavail(mtd, ops);
 130                 pages = mtd_div_by_ws(mtd->size, mtd);
 131                 pages -= mtd_div_by_ws(from, mtd);
 132                 if (ops->ooboffs + ops->ooblen > pages * len)
 133                         return -EINVAL;
 134         }
 135
 136         res = part->master->_read_oob(part->master, from + part->offset, ops);
 137         if (unlikely(res)) {
 138                 if (mtd_is_bitflip(res))
 139                         mtd->ecc_stats.corrected++;
 140                 if (mtd_is_eccerr(res))
 141                         mtd->ecc_stats.failed++;
 142         }
 143         return res;
 144 }
 145
 146 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
 147                 size_t len, size_t *retlen, u_char *buf)
 148 {
 149         struct mtd_part *part = mtd_to_part(mtd);
 150         return part->master->_read_user_prot_reg(part->master, from, len,
 151                                                  retlen, buf);
 152 }
 153
 154 static int part_get_user_prot_info(struct mtd_info *mtd, size_t len,
 155                                    size_t *retlen, struct otp_info *buf)
 156 {
 157         struct mtd_part *part = mtd_to_part(mtd);
 158         return part->master->_get_user_prot_info(part->master, len, retlen,
 159                                                  buf);
 160 }
 161
 162 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
 163                 size_t len, size_t *retlen, u_char *buf)
 164 {
 165         struct mtd_part *part = mtd_to_part(mtd);
 166         return part->master->_read_fact_prot_reg(part->master, from, len,
 167                                                  retlen, buf);
 168 }
 169
 170 static int part_get_fact_prot_info(struct mtd_info *mtd, size_t len,
 171                                    size_t *retlen, struct otp_info *buf)
 172 {
 173         struct mtd_part *part = mtd_to_part(mtd);
 174         return part->master->_get_fact_prot_info(part->master, len, retlen,
 175                                                  buf);
 176 }
 177
 178 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
 179                 size_t *retlen, const u_char *buf)
 180 {
 181         struct mtd_part *part = mtd_to_part(mtd);
 182         return part->master->_write(part->master, to + part->offset, len,
 183                                     retlen, buf);
 184 }
 185
 186 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
 187                 size_t *retlen, const u_char *buf)
 188 {
 189         struct mtd_part *part = mtd_to_part(mtd);
 190         return part->master->_panic_write(part->master, to + part->offset, len,
 191                                           retlen, buf);
 192 }
 193
 194 static int part_write_oob(struct mtd_info *mtd, loff_t to,
 195                 struct mtd_oob_ops *ops)
 196 {
 197         struct mtd_part *part = mtd_to_part(mtd);
 198
 199         if (to >= mtd->size)
 200                 return -EINVAL;
 201         if (ops->datbuf && to + ops->len > mtd->size)
 202                 return -EINVAL;
 203         return part->master->_write_oob(part->master, to + part->offset, ops);
 204 }
 205
 206 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
 207                 size_t len, size_t *retlen, u_char *buf)
 208 {
 209         struct mtd_part *part = mtd_to_part(mtd);
 210         return part->master->_write_user_prot_reg(part->master, from, len,
 211                                                   retlen, buf);
 212 }
 213
 214 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
 215                 size_t len)
 216 {
 217         struct mtd_part *part = mtd_to_part(mtd);
 218         return part->master->_lock_user_prot_reg(part->master, from, len);
 219 }
 220
 221 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
 222                 unsigned long count, loff_t to, size_t *retlen)
 223 {
 224         struct mtd_part *part = mtd_to_part(mtd);
 225         return part->master->_writev(part->master, vecs, count,
 226                                      to + part->offset, retlen);
 227 }
 228
 229 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
 230 {
 231         struct mtd_part *part = mtd_to_part(mtd);
 232         int ret;
 233
 234         instr->addr += part->offset;
 235         ret = part->master->_erase(part->master, instr);
 236         if (ret) {
 237                 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 238                         instr->fail_addr -= part->offset;
 239                 instr->addr -= part->offset;
 240         }
 241         return ret;
 242 }
 243
 244 void mtd_erase_callback(struct erase_info *instr)
 245 {
 246         if (instr->mtd->_erase == part_erase) {
 247                 struct mtd_part *part = mtd_to_part(instr->mtd);
 248
 249                 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 250                         instr->fail_addr -= part->offset;
 251                 instr->addr -= part->offset;
 252         }
 253         if (instr->callback)
 254                 instr->callback(instr);
 255 }
 256 EXPORT_SYMBOL_GPL(mtd_erase_callback);
 257
 258 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 259 {
 260         struct mtd_part *part = mtd_to_part(mtd);
 261         return part->master->_lock(part->master, ofs + part->offset, len);
 262 }
 263
 264 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 265 {
 266         struct mtd_part *part = mtd_to_part(mtd);
 267         return part->master->_unlock(part->master, ofs + part->offset, len);
 268 }
 269
 270 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 271 {
 272         struct mtd_part *part = mtd_to_part(mtd);
 273         return part->master->_is_locked(part->master, ofs + part->offset, len);
 274 }
 275
 276 static void part_sync(struct mtd_info *mtd)
 277 {
 278         struct mtd_part *part = mtd_to_part(mtd);
 279         part->master->_sync(part->master);
 280 }
 281
 282 static int part_suspend(struct mtd_info *mtd)
 283 {
 284         struct mtd_part *part = mtd_to_part(mtd);
 285         return part->master->_suspend(part->master);
 286 }
 287
 288 static void part_resume(struct mtd_info *mtd)
 289 {
 290         struct mtd_part *part = mtd_to_part(mtd);
 291         part->master->_resume(part->master);
 292 }
 293
 294 static int part_block_isreserved(struct mtd_info *mtd, loff_t ofs)
 295 {
 296         struct mtd_part *part = mtd_to_part(mtd);
 297         ofs += part->offset;
 298         return part->master->_block_isreserved(part->master, ofs);
 299 }
 300
 301 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
 302 {
 303         struct mtd_part *part = mtd_to_part(mtd);
 304         ofs += part->offset;
 305         return part->master->_block_isbad(part->master, ofs);
 306 }
 307
 308 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 309 {
 310         struct mtd_part *part = mtd_to_part(mtd);
 311         int res;
 312
 313         ofs += part->offset;
 314         res = part->master->_block_markbad(part->master, ofs);
 315         if (!res)
 316                 mtd->ecc_stats.badblocks++;
 317         return res;
 318 }
 319
 320 static int part_ooblayout_ecc(struct mtd_info *mtd, int section,
 321                               struct mtd_oob_region *oobregion)
 322 {
 323         struct mtd_part *part = mtd_to_part(mtd);
 324
 325         return mtd_ooblayout_ecc(part->master, section, oobregion);
 326 }
 327
 328 static int part_ooblayout_free(struct mtd_info *mtd, int section,
 329                                struct mtd_oob_region *oobregion)
 330 {
 331         struct mtd_part *part = mtd_to_part(mtd);
 332
 333         return mtd_ooblayout_free(part->master, section, oobregion);
 334 }
 335
 336 static const struct mtd_ooblayout_ops part_ooblayout_ops = {
 337         .ecc = part_ooblayout_ecc,
 338         .free = part_ooblayout_free,
 339 };
 340
 341 static inline void free_partition(struct mtd_part *p)
 342 {
 343         kfree(p->mtd.name);
 344         kfree(p);
 345 }
 346
 347 /*
 348  * This function unregisters and destroy all slave MTD objects which are
 349  * attached to the given master MTD object.
 350  */
 351
 352 int del_mtd_partitions(struct mtd_info *master)
 353 {
 354         struct mtd_part *slave, *next;
 355         int ret, err = 0;
 356
 357         mutex_lock(&mtd_partitions_mutex);
 358         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 359                 if (slave->master == master) {
 360                         ret = del_mtd_device(&slave->mtd);
 361                         if (ret < 0) {
 362                                 err = ret;
 363                                 continue;
 364                         }
 365                         list_del(&slave->list);
 366                         free_partition(slave);
 367                 }
 368         mutex_unlock(&mtd_partitions_mutex);
 369
 370         return err;
 371 }
 372
 373 static struct mtd_part *allocate_partition(struct mtd_info *master,
 374                         const struct mtd_partition *part, int partno,
 375                         uint64_t cur_offset)
 376 {
 377         struct mtd_part *slave;
 378         char *name;
 379
 380         /* allocate the partition structure */
 381         slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 382         name = kstrdup(part->name, GFP_KERNEL);
 383         if (!name || !slave) {
 384                 printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
 385                        master->name);
 386                 kfree(name);
 387                 kfree(slave);
 388                 return ERR_PTR(-ENOMEM);
 389         }
 390
 391         /* set up the MTD object for this partition */
 392         slave->mtd.type = master->type;
 393         slave->mtd.flags = master->flags & ~part->mask_flags;
 394         slave->mtd.size = part->size;
 395         slave->mtd.writesize = master->writesize;
 396         slave->mtd.writebufsize = master->writebufsize;
 397         slave->mtd.oobsize = master->oobsize;
 398         slave->mtd.oobavail = master->oobavail;
 399         slave->mtd.subpage_sft = master->subpage_sft;
 400         slave->mtd.pairing = master->pairing;
 401
 402         slave->mtd.name = name;
 403         slave->mtd.owner = master->owner;
 404
 405         /* NOTE: Historically, we didn't arrange MTDs as a tree out of
 406          * concern for showing the same data in multiple partitions.
 407          * However, it is very useful to have the master node present,
 408          * so the MTD_PARTITIONED_MASTER option allows that. The master
 409          * will have device nodes etc only if this is set, so make the
 410          * parent conditional on that option. Note, this is a way to
 411          * distinguish between the master and the partition in sysfs.
 412          */
 413         slave->mtd.dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) ?
 414                                 &master->dev :
 415                                 master->dev.parent;
 416
 417         slave->mtd._read = part_read;
 418         slave->mtd._write = part_write;
 419
 420         if (master->_panic_write)
 421                 slave->mtd._panic_write = part_panic_write;
 422
 423         if (master->_point && master->_unpoint) {
 424                 slave->mtd._point = part_point;
 425                 slave->mtd._unpoint = part_unpoint;
 426         }
 427
 428         if (master->_get_unmapped_area)
 429                 slave->mtd._get_unmapped_area = part_get_unmapped_area;
 430         if (master->_read_oob)
 431                 slave->mtd._read_oob = part_read_oob;
 432         if (master->_write_oob)
 433                 slave->mtd._write_oob = part_write_oob;
 434         if (master->_read_user_prot_reg)
 435                 slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
 436         if (master->_read_fact_prot_reg)
 437                 slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
 438         if (master->_write_user_prot_reg)
 439                 slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
 440         if (master->_lock_user_prot_reg)
 441                 slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
 442         if (master->_get_user_prot_info)
 443                 slave->mtd._get_user_prot_info = part_get_user_prot_info;
 444         if (master->_get_fact_prot_info)
 445                 slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
 446         if (master->_sync)
 447                 slave->mtd._sync = part_sync;
 448         if (!partno && !master->dev.class && master->_suspend &&
 449             master->_resume) {
 450                         slave->mtd._suspend = part_suspend;
 451                         slave->mtd._resume = part_resume;
 452         }
 453         if (master->_writev)
 454                 slave->mtd._writev = part_writev;
 455         if (master->_lock)
 456                 slave->mtd._lock = part_lock;
 457         if (master->_unlock)
 458                 slave->mtd._unlock = part_unlock;
 459         if (master->_is_locked)
 460                 slave->mtd._is_locked = part_is_locked;
 461         if (master->_block_isreserved)
 462                 slave->mtd._block_isreserved = part_block_isreserved;
 463         if (master->_block_isbad)
 464                 slave->mtd._block_isbad = part_block_isbad;
 465         if (master->_block_markbad)
 466                 slave->mtd._block_markbad = part_block_markbad;
 467         slave->mtd._erase = part_erase;
 468         slave->master = master;
 469         slave->offset = part->offset;
 470
 471         if (slave->offset == MTDPART_OFS_APPEND)
 472                 slave->offset = cur_offset;
 473         if (slave->offset == MTDPART_OFS_NXTBLK) {
 474                 slave->offset = cur_offset;
 475                 if (mtd_mod_by_eb(cur_offset, master) != 0) {
 476                         /* Round up to next erasesize */
 477                         slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
 478                         printk(KERN_NOTICE "Moving partition %d: "
 479                                "0x%012llx -> 0x%012llx\n", partno,
 480                                (unsigned long long)cur_offset, (unsigned long long)slave->offset);
 481                 }
 482         }
 483         if (slave->offset == MTDPART_OFS_RETAIN) {
 484                 slave->offset = cur_offset;
 485                 if (master->size - slave->offset >= slave->mtd.size) {
 486                         slave->mtd.size = master->size - slave->offset
 487                                                         - slave->mtd.size;
 488                 } else {
 489                         printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
 490                                 part->name, master->size - slave->offset,
 491                                 slave->mtd.size);
 492                         /* register to preserve ordering */
 493                         goto out_register;
 494                 }
 495         }
 496         if (slave->mtd.size == MTDPART_SIZ_FULL)
 497                 slave->mtd.size = master->size - slave->offset;
 498
 499         printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
 500                 (unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
 501
 502         /* let's do some sanity checks */
 503         if (slave->offset >= master->size) {
 504                 /* let's register it anyway to preserve ordering */
 505                 slave->offset = 0;
 506                 slave->mtd.size = 0;
 507                 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
 508                         part->name);
 509                 goto out_register;
 510         }
 511         if (slave->offset + slave->mtd.size > master->size) {
 512                 slave->mtd.size = master->size - slave->offset;
 513                 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
 514                         part->name, master->name, (unsigned long long)slave->mtd.size);
 515         }
 516         if (master->numeraseregions > 1) {
 517                 /* Deal with variable erase size stuff */
 518                 int i, max = master->numeraseregions;
 519                 u64 end = slave->offset + slave->mtd.size;
 520                 struct mtd_erase_region_info *regions = master->eraseregions;
 521
 522                 /* Find the first erase regions which is part of this
 523                  * partition. */
 524                 for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
 525                         ;
 526                 /* The loop searched for the region _behind_ the first one */
 527                 if (i > 0)
 528                         i--;
 529
 530                 /* Pick biggest erasesize */
 531                 for (; i < max && regions[i].offset < end; i++) {
 532                         if (slave->mtd.erasesize < regions[i].erasesize) {
 533                                 slave->mtd.erasesize = regions[i].erasesize;
 534                         }
 535                 }
 536                 BUG_ON(slave->mtd.erasesize == 0);
 537         } else {
 538                 /* Single erase size */
 539                 slave->mtd.erasesize = master->erasesize;
 540         }
 541
 542         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 543             mtd_mod_by_eb(slave->offset, &slave->mtd)) {
 544                 /* Doesn't start on a boundary of major erase size */
 545                 /* FIXME: Let it be writable if it is on a boundary of
 546                  * _minor_ erase size though */
 547                 slave->mtd.flags &= ~MTD_WRITEABLE;
 548                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
 549                         part->name);
 550         }
 551         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 552             mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
 553                 slave->mtd.flags &= ~MTD_WRITEABLE;
 554                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
 555                         part->name);
 556         }
 557
 558         mtd_set_ooblayout(&slave->mtd, &part_ooblayout_ops);
 559         slave->mtd.ecc_step_size = master->ecc_step_size;
 560         slave->mtd.ecc_strength = master->ecc_strength;
 561         slave->mtd.bitflip_threshold = master->bitflip_threshold;
 562
 563         if (master->_block_isbad) {
 564                 uint64_t offs = 0;
 565
 566                 while (offs < slave->mtd.size) {
 567                         if (mtd_block_isreserved(master, offs + slave->offset))
 568                                 slave->mtd.ecc_stats.bbtblocks++;
 569                         else if (mtd_block_isbad(master, offs + slave->offset))
 570                                 slave->mtd.ecc_stats.badblocks++;
 571                         offs += slave->mtd.erasesize;
 572                 }
 573         }
 574
 575 out_register:
 576         return slave;
 577 }
 578
 579 static ssize_t mtd_partition_offset_show(struct device *dev,
 580                 struct device_attribute *attr, char *buf)
 581 {
 582         struct mtd_info *mtd = dev_get_drvdata(dev);
 583         struct mtd_part *part = mtd_to_part(mtd);
 584         return snprintf(buf, PAGE_SIZE, "%lld\n", part->offset);
 585 }
 586
 587 static DEVICE_ATTR(offset, S_IRUGO, mtd_partition_offset_show, NULL);
 588
 589 static const struct attribute *mtd_partition_attrs[] = {
 590         &dev_attr_offset.attr,
 591         NULL
 592 };
 593
 594 static int mtd_add_partition_attrs(struct mtd_part *new)
 595 {
 596         int ret = sysfs_create_files(&new->mtd.dev.kobj, mtd_partition_attrs);
 597         if (ret)
 598                 printk(KERN_WARNING
 599                        "mtd: failed to create partition attrs, err=%d\n", ret);
 600         return ret;
 601 }
 602
 603 int mtd_add_partition(struct mtd_info *master, const char *name,
 604                       long long offset, long long length)
 605 {
 606         struct mtd_partition part;
 607         struct mtd_part *new;
 608         int ret = 0;
 609
 610         /* the direct offset is expected */
 611         if (offset == MTDPART_OFS_APPEND ||
 612             offset == MTDPART_OFS_NXTBLK)
 613                 return -EINVAL;
 614
 615         if (length == MTDPART_SIZ_FULL)
 616                 length = master->size - offset;
 617
 618         if (length <= 0)
 619                 return -EINVAL;
 620
 621         memset(&part, 0, sizeof(part));
 622         part.name = name;
 623         part.size = length;
 624         part.offset = offset;
 625
 626         new = allocate_partition(master, &part, -1, offset);
 627         if (IS_ERR(new))
 628                 return PTR_ERR(new);
 629
 630         mutex_lock(&mtd_partitions_mutex);
 631         list_add(&new->list, &mtd_partitions);
 632         mutex_unlock(&mtd_partitions_mutex);
 633
 634         add_mtd_device(&new->mtd);
 635
 636         mtd_add_partition_attrs(new);
 637
 638         return ret;
 639 }
 640 EXPORT_SYMBOL_GPL(mtd_add_partition);
 641
 642 int mtd_del_partition(struct mtd_info *master, int partno)
 643 {
 644         struct mtd_part *slave, *next;
 645         int ret = -EINVAL;
 646
 647         mutex_lock(&mtd_partitions_mutex);
 648         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 649                 if ((slave->master == master) &&
 650                     (slave->mtd.index == partno)) {
 651                         sysfs_remove_files(&slave->mtd.dev.kobj,
 652                                            mtd_partition_attrs);
 653                         ret = del_mtd_device(&slave->mtd);
 654                         if (ret < 0)
 655                                 break;
 656
 657                         list_del(&slave->list);
 658                         free_partition(slave);
 659                         break;
 660                 }
 661         mutex_unlock(&mtd_partitions_mutex);
 662
 663         return ret;
 664 }
 665 EXPORT_SYMBOL_GPL(mtd_del_partition);
 666
 667 /*
 668  * This function, given a master MTD object and a partition table, creates
 669  * and registers slave MTD objects which are bound to the master according to
 670  * the partition definitions.
 671  *
 672  * For historical reasons, this function's caller only registers the master
 673  * if the MTD_PARTITIONED_MASTER config option is set.
 674  */
 675
 676 int add_mtd_partitions(struct mtd_info *master,
 677                        const struct mtd_partition *parts,
 678                        int nbparts)
 679 {
 680         struct mtd_part *slave;
 681         uint64_t cur_offset = 0;
 682         int i;
 683
 684         printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 685
 686         for (i = 0; i < nbparts; i++) {
 687                 slave = allocate_partition(master, parts + i, i, cur_offset);
 688                 if (IS_ERR(slave)) {
 689                         del_mtd_partitions(master);
 690                         return PTR_ERR(slave);
 691                 }
 692
 693                 mutex_lock(&mtd_partitions_mutex);
 694                 list_add(&slave->list, &mtd_partitions);
 695                 mutex_unlock(&mtd_partitions_mutex);
 696
 697                 add_mtd_device(&slave->mtd);
 698                 mtd_add_partition_attrs(slave);
 699
 700                 cur_offset = slave->offset + slave->mtd.size;
 701         }
 702
 703         return 0;
 704 }
 705
 706 static DEFINE_SPINLOCK(part_parser_lock);
 707 static LIST_HEAD(part_parsers);
 708
 709 static struct mtd_part_parser *mtd_part_parser_get(const char *name)
 710 {
 711         struct mtd_part_parser *p, *ret = NULL;
 712
 713         spin_lock(&part_parser_lock);
 714
 715         list_for_each_entry(p, &part_parsers, list)
 716                 if (!strcmp(p->name, name) && try_module_get(p->owner)) {
 717                         ret = p;
 718                         break;
 719                 }
 720
 721         spin_unlock(&part_parser_lock);
 722
 723         return ret;
 724 }
 725
 726 static inline void mtd_part_parser_put(const struct mtd_part_parser *p)
 727 {
 728         module_put(p->owner);
 729 }
 730
 731 /*
 732  * Many partition parsers just expected the core to kfree() all their data in
 733  * one chunk. Do that by default.
 734  */
 735 static void mtd_part_parser_cleanup_default(const struct mtd_partition *pparts,
 736                                             int nr_parts)
 737 {
 738         kfree(pparts);
 739 }
 740
 741 int __register_mtd_parser(struct mtd_part_parser *p, struct module *owner)
 742 {
 743         p->owner = owner;
 744
 745         if (!p->cleanup)
 746                 p->cleanup = &mtd_part_parser_cleanup_default;
 747
 748         spin_lock(&part_parser_lock);
 749         list_add(&p->list, &part_parsers);
 750         spin_unlock(&part_parser_lock);
 751
 752         return 0;
 753 }
 754 EXPORT_SYMBOL_GPL(__register_mtd_parser);
 755
 756 void deregister_mtd_parser(struct mtd_part_parser *p)
 757 {
 758         spin_lock(&part_parser_lock);
 759         list_del(&p->list);
 760         spin_unlock(&part_parser_lock);
 761 }
 762 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
 763
 764 /*
 765  * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
 766  * are changing this array!
 767  */
 768 static const char * const default_mtd_part_types[] = {
 769         "cmdlinepart",
 770         "ofpart",
 771         NULL
 772 };
 773
 774 /**
 775  * parse_mtd_partitions - parse MTD partitions
 776  * @master: the master partition (describes whole MTD device)
 777  * @types: names of partition parsers to try or %NULL
 778  * @pparts: info about partitions found is returned here
 779  * @data: MTD partition parser-specific data
 780  *
 781  * This function tries to find partition on MTD device @master. It uses MTD
 782  * partition parsers, specified in @types. However, if @types is %NULL, then
 783  * the default list of parsers is used. The default list contains only the
 784  * "cmdlinepart" and "ofpart" parsers ATM.
 785  * Note: If there are more then one parser in @types, the kernel only takes the
 786  * partitions parsed out by the first parser.
 787  *
 788  * This function may return:
 789  * o a negative error code in case of failure
 790  * o zero otherwise, and @pparts will describe the partitions, number of
 791  *   partitions, and the parser which parsed them. Caller must release
 792  *   resources with mtd_part_parser_cleanup() when finished with the returned
 793  *   data.
 794  */
 795 int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
 796                          struct mtd_partitions *pparts,
 797                          struct mtd_part_parser_data *data)
 798 {
 799         struct mtd_part_parser *parser;
 800         int ret, err = 0;
 801
 802         if (!types)
 803                 types = default_mtd_part_types;
 804
 805         for ( ; *types; types++) {
 806                 pr_debug("%s: parsing partitions %s\n", master->name, *types);
 807                 parser = mtd_part_parser_get(*types);
 808                 if (!parser && !request_module("%s", *types))
 809                         parser = mtd_part_parser_get(*types);
 810                 pr_debug("%s: got parser %s\n", master->name,
 811                          parser ? parser->name : NULL);
 812                 if (!parser)
 813                         continue;
 814                 ret = (*parser->parse_fn)(master, &pparts->parts, data);
 815                 pr_debug("%s: parser %s: %i\n",
 816                          master->name, parser->name, ret);
 817                 if (ret > 0) {
 818                         printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
 819                                ret, parser->name, master->name);
 820                         pparts->nr_parts = ret;
 821                         pparts->parser = parser;
 822                         return 0;
 823                 }
 824                 mtd_part_parser_put(parser);
 825                 /*
 826                  * Stash the first error we see; only report it if no parser
 827                  * succeeds
 828                  */
 829                 if (ret < 0 && !err)
 830                         err = ret;
 831         }
 832         return err;
 833 }
 834
 835 void mtd_part_parser_cleanup(struct mtd_partitions *parts)
 836 {
 837         const struct mtd_part_parser *parser;
 838
 839         if (!parts)
 840                 return;
 841
 842         parser = parts->parser;
 843         if (parser) {
 844                 if (parser->cleanup)
 845                         parser->cleanup(parts->parts, parts->nr_parts);
 846
 847                 mtd_part_parser_put(parser);
 848         }
 849 }
 850
 851 int mtd_is_partition(const struct mtd_info *mtd)
 852 {
 853         struct mtd_part *part;
 854         int ispart = 0;
 855
 856         mutex_lock(&mtd_partitions_mutex);
 857         list_for_each_entry(part, &mtd_partitions, list)
 858                 if (&part->mtd == mtd) {
 859                         ispart = 1;
 860                         break;
 861                 }
 862         mutex_unlock(&mtd_partitions_mutex);
 863
 864         return ispart;
 865 }
 866 EXPORT_SYMBOL_GPL(mtd_is_partition);
 867
 868 /* Returns the size of the entire flash chip */
 869 uint64_t mtd_get_device_size(const struct mtd_info *mtd)
 870 {
 871         if (!mtd_is_partition(mtd))
 872                 return mtd->size;
 873
 874         return mtd_to_part(mtd)->master->size;
 875 }
 876 EXPORT_SYMBOL_GPL(mtd_get_device_size);