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 with this macro.
  52  */
  53 #define PART(x)  ((struct mtd_part *)(x))
  54
  55
  56 /*
  57  * MTD methods which simply translate the effective address and pass through
  58  * to the _real_ device.
  59  */
  60
  61 static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
  62                 size_t *retlen, u_char *buf)
  63 {
  64         struct mtd_part *part = PART(mtd);
  65         struct mtd_ecc_stats stats;
  66         int res;
  67
  68         stats = part->master->ecc_stats;
  69         res = part->master->_read(part->master, from + part->offset, len,
  70                                   retlen, buf);
  71         if (unlikely(mtd_is_eccerr(res)))
  72                 mtd->ecc_stats.failed +=
  73                         part->master->ecc_stats.failed - stats.failed;
  74         else
  75                 mtd->ecc_stats.corrected +=
  76                         part->master->ecc_stats.corrected - stats.corrected;
  77         return res;
  78 }
  79
  80 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
  81                 size_t *retlen, void **virt, resource_size_t *phys)
  82 {
  83         struct mtd_part *part = PART(mtd);
  84
  85         return part->master->_point(part->master, from + part->offset, len,
  86                                     retlen, virt, phys);
  87 }
  88
  89 static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
  90 {
  91         struct mtd_part *part = PART(mtd);
  92
  93         return part->master->_unpoint(part->master, from + part->offset, len);
  94 }
  95
  96 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
  97                                             unsigned long len,
  98                                             unsigned long offset,
  99                                             unsigned long flags)
 100 {
 101         struct mtd_part *part = PART(mtd);
 102
 103         offset += part->offset;
 104         return part->master->_get_unmapped_area(part->master, len, offset,
 105                                                 flags);
 106 }
 107
 108 static int part_read_oob(struct mtd_info *mtd, loff_t from,
 109                 struct mtd_oob_ops *ops)
 110 {
 111         struct mtd_part *part = PART(mtd);
 112         int res;
 113
 114         if (from >= mtd->size)
 115                 return -EINVAL;
 116         if (ops->datbuf && from + ops->len > mtd->size)
 117                 return -EINVAL;
 118
 119         /*
 120          * If OOB is also requested, make sure that we do not read past the end
 121          * of this partition.
 122          */
 123         if (ops->oobbuf) {
 124                 size_t len, pages;
 125
 126                 if (ops->mode == MTD_OPS_AUTO_OOB)
 127                         len = mtd->oobavail;
 128                 else
 129                         len = mtd->oobsize;
 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 = 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 = 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 = 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 = 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 = 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 = 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 = 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 = 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 = 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 = 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 = 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 = 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 = 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 = 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 = 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 = 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 = 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 = 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 = 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 = 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 = 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 inline void free_partition(struct mtd_part *p)
 321 {
 322         kfree(p->mtd.name);
 323         kfree(p);
 324 }
 325
 326 /*
 327  * This function unregisters and destroy all slave MTD objects which are
 328  * attached to the given master MTD object.
 329  */
 330
 331 int del_mtd_partitions(struct mtd_info *master)
 332 {
 333         struct mtd_part *slave, *next;
 334         int ret, err = 0;
 335
 336         mutex_lock(&mtd_partitions_mutex);
 337         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 338                 if (slave->master == master) {
 339                         ret = del_mtd_device(&slave->mtd);
 340                         if (ret < 0) {
 341                                 err = ret;
 342                                 continue;
 343                         }
 344                         list_del(&slave->list);
 345                         free_partition(slave);
 346                 }
 347         mutex_unlock(&mtd_partitions_mutex);
 348
 349         return err;
 350 }
 351
 352 static struct mtd_part *allocate_partition(struct mtd_info *master,
 353                         const struct mtd_partition *part, int partno,
 354                         uint64_t cur_offset)
 355 {
 356         struct mtd_part *slave;
 357         char *name;
 358
 359         /* allocate the partition structure */
 360         slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 361         name = kstrdup(part->name, GFP_KERNEL);
 362         if (!name || !slave) {
 363                 printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
 364                        master->name);
 365                 kfree(name);
 366                 kfree(slave);
 367                 return ERR_PTR(-ENOMEM);
 368         }
 369
 370         /* set up the MTD object for this partition */
 371         slave->mtd.type = master->type;
 372         slave->mtd.flags = master->flags & ~part->mask_flags;
 373         slave->mtd.size = part->size;
 374         slave->mtd.writesize = master->writesize;
 375         slave->mtd.writebufsize = master->writebufsize;
 376         slave->mtd.oobsize = master->oobsize;
 377         slave->mtd.oobavail = master->oobavail;
 378         slave->mtd.subpage_sft = master->subpage_sft;
 379
 380         slave->mtd.name = name;
 381         slave->mtd.owner = master->owner;
 382
 383         /* NOTE: Historically, we didn't arrange MTDs as a tree out of
 384          * concern for showing the same data in multiple partitions.
 385          * However, it is very useful to have the master node present,
 386          * so the MTD_PARTITIONED_MASTER option allows that. The master
 387          * will have device nodes etc only if this is set, so make the
 388          * parent conditional on that option. Note, this is a way to
 389          * distinguish between the master and the partition in sysfs.
 390          */
 391         slave->mtd.dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) ?
 392                                 &master->dev :
 393                                 master->dev.parent;
 394
 395         slave->mtd._read = part_read;
 396         slave->mtd._write = part_write;
 397
 398         if (master->_panic_write)
 399                 slave->mtd._panic_write = part_panic_write;
 400
 401         if (master->_point && master->_unpoint) {
 402                 slave->mtd._point = part_point;
 403                 slave->mtd._unpoint = part_unpoint;
 404         }
 405
 406         if (master->_get_unmapped_area)
 407                 slave->mtd._get_unmapped_area = part_get_unmapped_area;
 408         if (master->_read_oob)
 409                 slave->mtd._read_oob = part_read_oob;
 410         if (master->_write_oob)
 411                 slave->mtd._write_oob = part_write_oob;
 412         if (master->_read_user_prot_reg)
 413                 slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
 414         if (master->_read_fact_prot_reg)
 415                 slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
 416         if (master->_write_user_prot_reg)
 417                 slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
 418         if (master->_lock_user_prot_reg)
 419                 slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
 420         if (master->_get_user_prot_info)
 421                 slave->mtd._get_user_prot_info = part_get_user_prot_info;
 422         if (master->_get_fact_prot_info)
 423                 slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
 424         if (master->_sync)
 425                 slave->mtd._sync = part_sync;
 426         if (!partno && !master->dev.class && master->_suspend &&
 427             master->_resume) {
 428                         slave->mtd._suspend = part_suspend;
 429                         slave->mtd._resume = part_resume;
 430         }
 431         if (master->_writev)
 432                 slave->mtd._writev = part_writev;
 433         if (master->_lock)
 434                 slave->mtd._lock = part_lock;
 435         if (master->_unlock)
 436                 slave->mtd._unlock = part_unlock;
 437         if (master->_is_locked)
 438                 slave->mtd._is_locked = part_is_locked;
 439         if (master->_block_isreserved)
 440                 slave->mtd._block_isreserved = part_block_isreserved;
 441         if (master->_block_isbad)
 442                 slave->mtd._block_isbad = part_block_isbad;
 443         if (master->_block_markbad)
 444                 slave->mtd._block_markbad = part_block_markbad;
 445         slave->mtd._erase = part_erase;
 446         slave->master = master;
 447         slave->offset = part->offset;
 448
 449         if (slave->offset == MTDPART_OFS_APPEND)
 450                 slave->offset = cur_offset;
 451         if (slave->offset == MTDPART_OFS_NXTBLK) {
 452                 slave->offset = cur_offset;
 453                 if (mtd_mod_by_eb(cur_offset, master) != 0) {
 454                         /* Round up to next erasesize */
 455                         slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
 456                         printk(KERN_NOTICE "Moving partition %d: "
 457                                "0x%012llx -> 0x%012llx\n", partno,
 458                                (unsigned long long)cur_offset, (unsigned long long)slave->offset);
 459                 }
 460         }
 461         if (slave->offset == MTDPART_OFS_RETAIN) {
 462                 slave->offset = cur_offset;
 463                 if (master->size - slave->offset >= slave->mtd.size) {
 464                         slave->mtd.size = master->size - slave->offset
 465                                                         - slave->mtd.size;
 466                 } else {
 467                         printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
 468                                 part->name, master->size - slave->offset,
 469                                 slave->mtd.size);
 470                         /* register to preserve ordering */
 471                         goto out_register;
 472                 }
 473         }
 474         if (slave->mtd.size == MTDPART_SIZ_FULL)
 475                 slave->mtd.size = master->size - slave->offset;
 476
 477         printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
 478                 (unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
 479
 480         /* let's do some sanity checks */
 481         if (slave->offset >= master->size) {
 482                 /* let's register it anyway to preserve ordering */
 483                 slave->offset = 0;
 484                 slave->mtd.size = 0;
 485                 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
 486                         part->name);
 487                 goto out_register;
 488         }
 489         if (slave->offset + slave->mtd.size > master->size) {
 490                 slave->mtd.size = master->size - slave->offset;
 491                 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
 492                         part->name, master->name, (unsigned long long)slave->mtd.size);
 493         }
 494         if (master->numeraseregions > 1) {
 495                 /* Deal with variable erase size stuff */
 496                 int i, max = master->numeraseregions;
 497                 u64 end = slave->offset + slave->mtd.size;
 498                 struct mtd_erase_region_info *regions = master->eraseregions;
 499
 500                 /* Find the first erase regions which is part of this
 501                  * partition. */
 502                 for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
 503                         ;
 504                 /* The loop searched for the region _behind_ the first one */
 505                 if (i > 0)
 506                         i--;
 507
 508                 /* Pick biggest erasesize */
 509                 for (; i < max && regions[i].offset < end; i++) {
 510                         if (slave->mtd.erasesize < regions[i].erasesize) {
 511                                 slave->mtd.erasesize = regions[i].erasesize;
 512                         }
 513                 }
 514                 BUG_ON(slave->mtd.erasesize == 0);
 515         } else {
 516                 /* Single erase size */
 517                 slave->mtd.erasesize = master->erasesize;
 518         }
 519
 520         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 521             mtd_mod_by_eb(slave->offset, &slave->mtd)) {
 522                 /* Doesn't start on a boundary of major erase size */
 523                 /* FIXME: Let it be writable if it is on a boundary of
 524                  * _minor_ erase size though */
 525                 slave->mtd.flags &= ~MTD_WRITEABLE;
 526                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
 527                         part->name);
 528         }
 529         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 530             mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
 531                 slave->mtd.flags &= ~MTD_WRITEABLE;
 532                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
 533                         part->name);
 534         }
 535
 536         slave->mtd.ecclayout = master->ecclayout;
 537         slave->mtd.ecc_step_size = master->ecc_step_size;
 538         slave->mtd.ecc_strength = master->ecc_strength;
 539         slave->mtd.bitflip_threshold = master->bitflip_threshold;
 540
 541         if (master->_block_isbad) {
 542                 uint64_t offs = 0;
 543
 544                 while (offs < slave->mtd.size) {
 545                         if (mtd_block_isreserved(master, offs + slave->offset))
 546                                 slave->mtd.ecc_stats.bbtblocks++;
 547                         else if (mtd_block_isbad(master, offs + slave->offset))
 548                                 slave->mtd.ecc_stats.badblocks++;
 549                         offs += slave->mtd.erasesize;
 550                 }
 551         }
 552
 553 out_register:
 554         return slave;
 555 }
 556
 557 static ssize_t mtd_partition_offset_show(struct device *dev,
 558                 struct device_attribute *attr, char *buf)
 559 {
 560         struct mtd_info *mtd = dev_get_drvdata(dev);
 561         struct mtd_part *part = PART(mtd);
 562         return snprintf(buf, PAGE_SIZE, "%lld\n", part->offset);
 563 }
 564
 565 static DEVICE_ATTR(offset, S_IRUGO, mtd_partition_offset_show, NULL);
 566
 567 static const struct attribute *mtd_partition_attrs[] = {
 568         &dev_attr_offset.attr,
 569         NULL
 570 };
 571
 572 static int mtd_add_partition_attrs(struct mtd_part *new)
 573 {
 574         int ret = sysfs_create_files(&new->mtd.dev.kobj, mtd_partition_attrs);
 575         if (ret)
 576                 printk(KERN_WARNING
 577                        "mtd: failed to create partition attrs, err=%d\n", ret);
 578         return ret;
 579 }
 580
 581 int mtd_add_partition(struct mtd_info *master, const char *name,
 582                       long long offset, long long length)
 583 {
 584         struct mtd_partition part;
 585         struct mtd_part *new;
 586         int ret = 0;
 587
 588         /* the direct offset is expected */
 589         if (offset == MTDPART_OFS_APPEND ||
 590             offset == MTDPART_OFS_NXTBLK)
 591                 return -EINVAL;
 592
 593         if (length == MTDPART_SIZ_FULL)
 594                 length = master->size - offset;
 595
 596         if (length <= 0)
 597                 return -EINVAL;
 598
 599         part.name = name;
 600         part.size = length;
 601         part.offset = offset;
 602         part.mask_flags = 0;
 603         part.ecclayout = NULL;
 604
 605         new = allocate_partition(master, &part, -1, offset);
 606         if (IS_ERR(new))
 607                 return PTR_ERR(new);
 608
 609         mutex_lock(&mtd_partitions_mutex);
 610         list_add(&new->list, &mtd_partitions);
 611         mutex_unlock(&mtd_partitions_mutex);
 612
 613         add_mtd_device(&new->mtd);
 614
 615         mtd_add_partition_attrs(new);
 616
 617         return ret;
 618 }
 619 EXPORT_SYMBOL_GPL(mtd_add_partition);
 620
 621 int mtd_del_partition(struct mtd_info *master, int partno)
 622 {
 623         struct mtd_part *slave, *next;
 624         int ret = -EINVAL;
 625
 626         mutex_lock(&mtd_partitions_mutex);
 627         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 628                 if ((slave->master == master) &&
 629                     (slave->mtd.index == partno)) {
 630                         sysfs_remove_files(&slave->mtd.dev.kobj,
 631                                            mtd_partition_attrs);
 632                         ret = del_mtd_device(&slave->mtd);
 633                         if (ret < 0)
 634                                 break;
 635
 636                         list_del(&slave->list);
 637                         free_partition(slave);
 638                         break;
 639                 }
 640         mutex_unlock(&mtd_partitions_mutex);
 641
 642         return ret;
 643 }
 644 EXPORT_SYMBOL_GPL(mtd_del_partition);
 645
 646 /*
 647  * This function, given a master MTD object and a partition table, creates
 648  * and registers slave MTD objects which are bound to the master according to
 649  * the partition definitions.
 650  *
 651  * For historical reasons, this function's caller only registers the master
 652  * if the MTD_PARTITIONED_MASTER config option is set.
 653  */
 654
 655 int add_mtd_partitions(struct mtd_info *master,
 656                        const struct mtd_partition *parts,
 657                        int nbparts)
 658 {
 659         struct mtd_part *slave;
 660         uint64_t cur_offset = 0;
 661         int i;
 662
 663         printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 664
 665         for (i = 0; i < nbparts; i++) {
 666                 slave = allocate_partition(master, parts + i, i, cur_offset);
 667                 if (IS_ERR(slave))
 668                         return PTR_ERR(slave);
 669
 670                 mutex_lock(&mtd_partitions_mutex);
 671                 list_add(&slave->list, &mtd_partitions);
 672                 mutex_unlock(&mtd_partitions_mutex);
 673
 674                 add_mtd_device(&slave->mtd);
 675                 mtd_add_partition_attrs(slave);
 676
 677                 cur_offset = slave->offset + slave->mtd.size;
 678         }
 679
 680         return 0;
 681 }
 682
 683 static DEFINE_SPINLOCK(part_parser_lock);
 684 static LIST_HEAD(part_parsers);
 685
 686 static struct mtd_part_parser *get_partition_parser(const char *name)
 687 {
 688         struct mtd_part_parser *p, *ret = NULL;
 689
 690         spin_lock(&part_parser_lock);
 691
 692         list_for_each_entry(p, &part_parsers, list)
 693                 if (!strcmp(p->name, name) && try_module_get(p->owner)) {
 694                         ret = p;
 695                         break;
 696                 }
 697
 698         spin_unlock(&part_parser_lock);
 699
 700         return ret;
 701 }
 702
 703 #define put_partition_parser(p) do { module_put((p)->owner); } while (0)
 704
 705 void register_mtd_parser(struct mtd_part_parser *p)
 706 {
 707         spin_lock(&part_parser_lock);
 708         list_add(&p->list, &part_parsers);
 709         spin_unlock(&part_parser_lock);
 710 }
 711 EXPORT_SYMBOL_GPL(register_mtd_parser);
 712
 713 void deregister_mtd_parser(struct mtd_part_parser *p)
 714 {
 715         spin_lock(&part_parser_lock);
 716         list_del(&p->list);
 717         spin_unlock(&part_parser_lock);
 718 }
 719 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
 720
 721 /*
 722  * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
 723  * are changing this array!
 724  */
 725 static const char * const default_mtd_part_types[] = {
 726         "cmdlinepart",
 727         "ofpart",
 728         NULL
 729 };
 730
 731 /**
 732  * parse_mtd_partitions - parse MTD partitions
 733  * @master: the master partition (describes whole MTD device)
 734  * @types: names of partition parsers to try or %NULL
 735  * @pparts: array of partitions found is returned here
 736  * @data: MTD partition parser-specific data
 737  *
 738  * This function tries to find partition on MTD device @master. It uses MTD
 739  * partition parsers, specified in @types. However, if @types is %NULL, then
 740  * the default list of parsers is used. The default list contains only the
 741  * "cmdlinepart" and "ofpart" parsers ATM.
 742  * Note: If there are more then one parser in @types, the kernel only takes the
 743  * partitions parsed out by the first parser.
 744  *
 745  * This function may return:
 746  * o a negative error code in case of failure
 747  * o zero if no partitions were found
 748  * o a positive number of found partitions, in which case on exit @pparts will
 749  *   point to an array containing this number of &struct mtd_info objects.
 750  */
 751 int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
 752                          struct mtd_partition **pparts,
 753                          struct mtd_part_parser_data *data)
 754 {
 755         struct mtd_part_parser *parser;
 756         int ret = 0;
 757
 758         if (!types)
 759                 types = default_mtd_part_types;
 760
 761         for ( ; ret <= 0 && *types; types++) {
 762                 parser = get_partition_parser(*types);
 763                 if (!parser && !request_module("%s", *types))
 764                         parser = get_partition_parser(*types);
 765                 if (!parser)
 766                         continue;
 767                 ret = (*parser->parse_fn)(master, pparts, data);
 768                 put_partition_parser(parser);
 769                 if (ret > 0) {
 770                         printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
 771                                ret, parser->name, master->name);
 772                         break;
 773                 }
 774         }
 775         return ret;
 776 }
 777
 778 int mtd_is_partition(const struct mtd_info *mtd)
 779 {
 780         struct mtd_part *part;
 781         int ispart = 0;
 782
 783         mutex_lock(&mtd_partitions_mutex);
 784         list_for_each_entry(part, &mtd_partitions, list)
 785                 if (&part->mtd == mtd) {
 786                         ispart = 1;
 787                         break;
 788                 }
 789         mutex_unlock(&mtd_partitions_mutex);
 790
 791         return ispart;
 792 }
 793 EXPORT_SYMBOL_GPL(mtd_is_partition);
 794
 795 /* Returns the size of the entire flash chip */
 796 uint64_t mtd_get_device_size(const struct mtd_info *mtd)
 797 {
 798         if (!mtd_is_partition(mtd))
 799                 return mtd->size;
 800
 801         return PART(mtd)->master->size;
 802 }
 803 EXPORT_SYMBOL_GPL(mtd_get_device_size);