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#include <linux/kconfig.h>
  34
  35#include "mtdcore.h"
  36
  37/* Our partition linked list */
  38static LIST_HEAD(mtd_partitions);
  39static DEFINE_MUTEX(mtd_partitions_mutex);
  40
  41/* Our partition node structure */
  42struct 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
  61static 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
  80static 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
  89static 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
  96static 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
 108static 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
 146static 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
 154static 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
 162static 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
 170static 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
 178static 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
 186static 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
 194static 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
 206static 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
 214static 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
 221static 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
 229static 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
 244void 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}
 256EXPORT_SYMBOL_GPL(mtd_erase_callback);
 257
 258static 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
 264static 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
 270static 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
 276static void part_sync(struct mtd_info *mtd)
 277{
 278        struct mtd_part *part = PART(mtd);
 279        part->master->_sync(part->master);
 280}
 281
 282static int part_suspend(struct mtd_info *mtd)
 283{
 284        struct mtd_part *part = PART(mtd);
 285        return part->master->_suspend(part->master);
 286}
 287
 288static void part_resume(struct mtd_info *mtd)
 289{
 290        struct mtd_part *part = PART(mtd);
 291        part->master->_resume(part->master);
 292}
 293
 294static 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
 301static 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
 308static 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
 320static 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
 331int 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
 352static 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
 553out_register:
 554        return slave;
 555}
 556
 557static 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
 565static DEVICE_ATTR(offset, S_IRUGO, mtd_partition_offset_show, NULL);
 566
 567static const struct attribute *mtd_partition_attrs[] = {
 568        &dev_attr_offset.attr,
 569        NULL
 570};
 571
 572static 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
 581int 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}
 619EXPORT_SYMBOL_GPL(mtd_add_partition);
 620
 621int 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}
 644EXPORT_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
 655int 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
 683static DEFINE_SPINLOCK(part_parser_lock);
 684static LIST_HEAD(part_parsers);
 685
 686static 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
 705void 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}
 711EXPORT_SYMBOL_GPL(register_mtd_parser);
 712
 713void 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}
 719EXPORT_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 */
 725static 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 */
 751int 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
 778int 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}
 793EXPORT_SYMBOL_GPL(mtd_is_partition);
 794
 795/* Returns the size of the entire flash chip */
 796uint64_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}
 803EXPORT_SYMBOL_GPL(mtd_get_device_size);
 804