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