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
  69        if (from >= mtd->size)
  70                len = 0;
  71        else if (from + len > mtd->size)
  72                len = mtd->size - from;
  73        res = mtd_read(part->master, from + part->offset, len, retlen, buf);
  74        if (unlikely(res)) {
  75                if (mtd_is_bitflip(res))
  76                        mtd->ecc_stats.corrected += part->master->ecc_stats.corrected - stats.corrected;
  77                if (mtd_is_eccerr(res))
  78                        mtd->ecc_stats.failed += part->master->ecc_stats.failed - stats.failed;
  79        }
  80        return res;
  81}
  82
  83static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
  84                size_t *retlen, void **virt, resource_size_t *phys)
  85{
  86        struct mtd_part *part = PART(mtd);
  87        if (from >= mtd->size)
  88                len = 0;
  89        else if (from + len > mtd->size)
  90                len = mtd->size - from;
  91        return mtd_point(part->master, from + part->offset, len, retlen,
  92                         virt, phys);
  93}
  94
  95static void part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
  96{
  97        struct mtd_part *part = PART(mtd);
  98
  99        mtd_unpoint(part->master, from + part->offset, len);
 100}
 101
 102static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
 103                                            unsigned long len,
 104                                            unsigned long offset,
 105                                            unsigned long flags)
 106{
 107        struct mtd_part *part = PART(mtd);
 108
 109        offset += part->offset;
 110        return mtd_get_unmapped_area(part->master, len, offset, flags);
 111}
 112
 113static int part_read_oob(struct mtd_info *mtd, loff_t from,
 114                struct mtd_oob_ops *ops)
 115{
 116        struct mtd_part *part = PART(mtd);
 117        int res;
 118
 119        if (from >= mtd->size)
 120                return -EINVAL;
 121        if (ops->datbuf && from + ops->len > mtd->size)
 122                return -EINVAL;
 123
 124        /*
 125         * If OOB is also requested, make sure that we do not read past the end
 126         * of this partition.
 127         */
 128        if (ops->oobbuf) {
 129                size_t len, pages;
 130
 131                if (ops->mode == MTD_OPS_AUTO_OOB)
 132                        len = mtd->oobavail;
 133                else
 134                        len = mtd->oobsize;
 135                pages = mtd_div_by_ws(mtd->size, mtd);
 136                pages -= mtd_div_by_ws(from, mtd);
 137                if (ops->ooboffs + ops->ooblen > pages * len)
 138                        return -EINVAL;
 139        }
 140
 141        res = mtd_read_oob(part->master, from + part->offset, ops);
 142        if (unlikely(res)) {
 143                if (mtd_is_bitflip(res))
 144                        mtd->ecc_stats.corrected++;
 145                if (mtd_is_eccerr(res))
 146                        mtd->ecc_stats.failed++;
 147        }
 148        return res;
 149}
 150
 151static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
 152                size_t len, size_t *retlen, u_char *buf)
 153{
 154        struct mtd_part *part = PART(mtd);
 155        return mtd_read_user_prot_reg(part->master, from, len, retlen, buf);
 156}
 157
 158static int part_get_user_prot_info(struct mtd_info *mtd,
 159                struct otp_info *buf, size_t len)
 160{
 161        struct mtd_part *part = PART(mtd);
 162        return mtd_get_user_prot_info(part->master, buf, len);
 163}
 164
 165static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
 166                size_t len, size_t *retlen, u_char *buf)
 167{
 168        struct mtd_part *part = PART(mtd);
 169        return mtd_read_fact_prot_reg(part->master, from, len, retlen, buf);
 170}
 171
 172static int part_get_fact_prot_info(struct mtd_info *mtd, struct otp_info *buf,
 173                size_t len)
 174{
 175        struct mtd_part *part = PART(mtd);
 176        return mtd_get_fact_prot_info(part->master, buf, len);
 177}
 178
 179static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
 180                size_t *retlen, const u_char *buf)
 181{
 182        struct mtd_part *part = PART(mtd);
 183        if (!(mtd->flags & MTD_WRITEABLE))
 184                return -EROFS;
 185        if (to >= mtd->size)
 186                len = 0;
 187        else if (to + len > mtd->size)
 188                len = mtd->size - to;
 189        return mtd_write(part->master, to + part->offset, len, retlen, buf);
 190}
 191
 192static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
 193                size_t *retlen, const u_char *buf)
 194{
 195        struct mtd_part *part = PART(mtd);
 196        if (!(mtd->flags & MTD_WRITEABLE))
 197                return -EROFS;
 198        if (to >= mtd->size)
 199                len = 0;
 200        else if (to + len > mtd->size)
 201                len = mtd->size - to;
 202        return mtd_panic_write(part->master, to + part->offset, len, retlen,
 203                               buf);
 204}
 205
 206static int part_write_oob(struct mtd_info *mtd, loff_t to,
 207                struct mtd_oob_ops *ops)
 208{
 209        struct mtd_part *part = PART(mtd);
 210
 211        if (!(mtd->flags & MTD_WRITEABLE))
 212                return -EROFS;
 213
 214        if (to >= mtd->size)
 215                return -EINVAL;
 216        if (ops->datbuf && to + ops->len > mtd->size)
 217                return -EINVAL;
 218        return mtd_write_oob(part->master, to + part->offset, ops);
 219}
 220
 221static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
 222                size_t len, size_t *retlen, u_char *buf)
 223{
 224        struct mtd_part *part = PART(mtd);
 225        return mtd_write_user_prot_reg(part->master, from, len, retlen, buf);
 226}
 227
 228static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
 229                size_t len)
 230{
 231        struct mtd_part *part = PART(mtd);
 232        return mtd_lock_user_prot_reg(part->master, from, len);
 233}
 234
 235static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
 236                unsigned long count, loff_t to, size_t *retlen)
 237{
 238        struct mtd_part *part = PART(mtd);
 239        if (!(mtd->flags & MTD_WRITEABLE))
 240                return -EROFS;
 241        return mtd_writev(part->master, vecs, count, to + part->offset,
 242                          retlen);
 243}
 244
 245static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
 246{
 247        struct mtd_part *part = PART(mtd);
 248        int ret;
 249        if (!(mtd->flags & MTD_WRITEABLE))
 250                return -EROFS;
 251        if (instr->addr >= mtd->size)
 252                return -EINVAL;
 253        instr->addr += part->offset;
 254        ret = mtd_erase(part->master, instr);
 255        if (ret) {
 256                if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 257                        instr->fail_addr -= part->offset;
 258                instr->addr -= part->offset;
 259        }
 260        return ret;
 261}
 262
 263void mtd_erase_callback(struct erase_info *instr)
 264{
 265        if (instr->mtd->erase == part_erase) {
 266                struct mtd_part *part = PART(instr->mtd);
 267
 268                if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 269                        instr->fail_addr -= part->offset;
 270                instr->addr -= part->offset;
 271        }
 272        if (instr->callback)
 273                instr->callback(instr);
 274}
 275EXPORT_SYMBOL_GPL(mtd_erase_callback);
 276
 277static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 278{
 279        struct mtd_part *part = PART(mtd);
 280        if ((len + ofs) > mtd->size)
 281                return -EINVAL;
 282        return mtd_lock(part->master, ofs + part->offset, len);
 283}
 284
 285static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 286{
 287        struct mtd_part *part = PART(mtd);
 288        if ((len + ofs) > mtd->size)
 289                return -EINVAL;
 290        return mtd_unlock(part->master, ofs + part->offset, len);
 291}
 292
 293static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 294{
 295        struct mtd_part *part = PART(mtd);
 296        if ((len + ofs) > mtd->size)
 297                return -EINVAL;
 298        return mtd_is_locked(part->master, ofs + part->offset, len);
 299}
 300
 301static void part_sync(struct mtd_info *mtd)
 302{
 303        struct mtd_part *part = PART(mtd);
 304        mtd_sync(part->master);
 305}
 306
 307static int part_suspend(struct mtd_info *mtd)
 308{
 309        struct mtd_part *part = PART(mtd);
 310        return mtd_suspend(part->master);
 311}
 312
 313static void part_resume(struct mtd_info *mtd)
 314{
 315        struct mtd_part *part = PART(mtd);
 316        mtd_resume(part->master);
 317}
 318
 319static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
 320{
 321        struct mtd_part *part = PART(mtd);
 322        if (ofs >= mtd->size)
 323                return -EINVAL;
 324        ofs += part->offset;
 325        return mtd_block_isbad(part->master, ofs);
 326}
 327
 328static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 329{
 330        struct mtd_part *part = PART(mtd);
 331        int res;
 332
 333        if (!(mtd->flags & MTD_WRITEABLE))
 334                return -EROFS;
 335        if (ofs >= mtd->size)
 336                return -EINVAL;
 337        ofs += part->offset;
 338        res = mtd_block_markbad(part->master, ofs);
 339        if (!res)
 340                mtd->ecc_stats.badblocks++;
 341        return res;
 342}
 343
 344static inline void free_partition(struct mtd_part *p)
 345{
 346        kfree(p->mtd.name);
 347        kfree(p);
 348}
 349
 350/*
 351 * This function unregisters and destroy all slave MTD objects which are
 352 * attached to the given master MTD object.
 353 */
 354
 355int del_mtd_partitions(struct mtd_info *master)
 356{
 357        struct mtd_part *slave, *next;
 358        int ret, err = 0;
 359
 360        mutex_lock(&mtd_partitions_mutex);
 361        list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 362                if (slave->master == master) {
 363                        ret = del_mtd_device(&slave->mtd);
 364                        if (ret < 0) {
 365                                err = ret;
 366                                continue;
 367                        }
 368                        list_del(&slave->list);
 369                        free_partition(slave);
 370                }
 371        mutex_unlock(&mtd_partitions_mutex);
 372
 373        return err;
 374}
 375
 376static struct mtd_part *allocate_partition(struct mtd_info *master,
 377                        const struct mtd_partition *part, int partno,
 378                        uint64_t cur_offset)
 379{
 380        struct mtd_part *slave;
 381        char *name;
 382
 383        /* allocate the partition structure */
 384        slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 385        name = kstrdup(part->name, GFP_KERNEL);
 386        if (!name || !slave) {
 387                printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
 388                       master->name);
 389                kfree(name);
 390                kfree(slave);
 391                return ERR_PTR(-ENOMEM);
 392        }
 393
 394        /* set up the MTD object for this partition */
 395        slave->mtd.type = master->type;
 396        slave->mtd.flags = master->flags & ~part->mask_flags;
 397        slave->mtd.size = part->size;
 398        slave->mtd.writesize = master->writesize;
 399        slave->mtd.writebufsize = master->writebufsize;
 400        slave->mtd.oobsize = master->oobsize;
 401        slave->mtd.oobavail = master->oobavail;
 402        slave->mtd.subpage_sft = master->subpage_sft;
 403
 404        slave->mtd.name = name;
 405        slave->mtd.owner = master->owner;
 406        slave->mtd.backing_dev_info = master->backing_dev_info;
 407
 408        /* NOTE:  we don't arrange MTDs as a tree; it'd be error-prone
 409         * to have the same data be in two different partitions.
 410         */
 411        slave->mtd.dev.parent = master->dev.parent;
 412
 413        slave->mtd.read = part_read;
 414        slave->mtd.write = part_write;
 415
 416        if (master->panic_write)
 417                slave->mtd.panic_write = part_panic_write;
 418
 419        if (master->point && master->unpoint) {
 420                slave->mtd.point = part_point;
 421                slave->mtd.unpoint = part_unpoint;
 422        }
 423
 424        if (master->get_unmapped_area)
 425                slave->mtd.get_unmapped_area = part_get_unmapped_area;
 426        if (master->read_oob)
 427                slave->mtd.read_oob = part_read_oob;
 428        if (master->write_oob)
 429                slave->mtd.write_oob = part_write_oob;
 430        if (master->read_user_prot_reg)
 431                slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
 432        if (master->read_fact_prot_reg)
 433                slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
 434        if (master->write_user_prot_reg)
 435                slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
 436        if (master->lock_user_prot_reg)
 437                slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
 438        if (master->get_user_prot_info)
 439                slave->mtd.get_user_prot_info = part_get_user_prot_info;
 440        if (master->get_fact_prot_info)
 441                slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
 442        if (master->sync)
 443                slave->mtd.sync = part_sync;
 444        if (!partno && !master->dev.class && master->suspend && master->resume) {
 445                        slave->mtd.suspend = part_suspend;
 446                        slave->mtd.resume = part_resume;
 447        }
 448        if (master->writev)
 449                slave->mtd.writev = part_writev;
 450        if (master->lock)
 451                slave->mtd.lock = part_lock;
 452        if (master->unlock)
 453                slave->mtd.unlock = part_unlock;
 454        if (master->is_locked)
 455                slave->mtd.is_locked = part_is_locked;
 456        if (master->block_isbad)
 457                slave->mtd.block_isbad = part_block_isbad;
 458        if (master->block_markbad)
 459                slave->mtd.block_markbad = part_block_markbad;
 460        slave->mtd.erase = part_erase;
 461        slave->master = master;
 462        slave->offset = part->offset;
 463
 464        if (slave->offset == MTDPART_OFS_APPEND)
 465                slave->offset = cur_offset;
 466        if (slave->offset == MTDPART_OFS_NXTBLK) {
 467                slave->offset = cur_offset;
 468                if (mtd_mod_by_eb(cur_offset, master) != 0) {
 469                        /* Round up to next erasesize */
 470                        slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
 471                        printk(KERN_NOTICE "Moving partition %d: "
 472                               "0x%012llx -> 0x%012llx\n", partno,
 473                               (unsigned long long)cur_offset, (unsigned long long)slave->offset);
 474                }
 475        }
 476        if (slave->offset == MTDPART_OFS_RETAIN) {
 477                slave->offset = cur_offset;
 478                if (master->size - slave->offset >= slave->mtd.size) {
 479                        slave->mtd.size = master->size - slave->offset
 480                                                        - slave->mtd.size;
 481                } else {
 482                        printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
 483                                part->name, master->size - slave->offset,
 484                                slave->mtd.size);
 485                        /* register to preserve ordering */
 486                        goto out_register;
 487                }
 488        }
 489        if (slave->mtd.size == MTDPART_SIZ_FULL)
 490                slave->mtd.size = master->size - slave->offset;
 491
 492        printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
 493                (unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
 494
 495        /* let's do some sanity checks */
 496        if (slave->offset >= master->size) {
 497                /* let's register it anyway to preserve ordering */
 498                slave->offset = 0;
 499                slave->mtd.size = 0;
 500                printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
 501                        part->name);
 502                goto out_register;
 503        }
 504        if (slave->offset + slave->mtd.size > master->size) {
 505                slave->mtd.size = master->size - slave->offset;
 506                printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
 507                        part->name, master->name, (unsigned long long)slave->mtd.size);
 508        }
 509        if (master->numeraseregions > 1) {
 510                /* Deal with variable erase size stuff */
 511                int i, max = master->numeraseregions;
 512                u64 end = slave->offset + slave->mtd.size;
 513                struct mtd_erase_region_info *regions = master->eraseregions;
 514
 515                /* Find the first erase regions which is part of this
 516                 * partition. */
 517                for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
 518                        ;
 519                /* The loop searched for the region _behind_ the first one */
 520                if (i > 0)
 521                        i--;
 522
 523                /* Pick biggest erasesize */
 524                for (; i < max && regions[i].offset < end; i++) {
 525                        if (slave->mtd.erasesize < regions[i].erasesize) {
 526                                slave->mtd.erasesize = regions[i].erasesize;
 527                        }
 528                }
 529                BUG_ON(slave->mtd.erasesize == 0);
 530        } else {
 531                /* Single erase size */
 532                slave->mtd.erasesize = master->erasesize;
 533        }
 534
 535        if ((slave->mtd.flags & MTD_WRITEABLE) &&
 536            mtd_mod_by_eb(slave->offset, &slave->mtd)) {
 537                /* Doesn't start on a boundary of major erase size */
 538                /* FIXME: Let it be writable if it is on a boundary of
 539                 * _minor_ erase size though */
 540                slave->mtd.flags &= ~MTD_WRITEABLE;
 541                printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
 542                        part->name);
 543        }
 544        if ((slave->mtd.flags & MTD_WRITEABLE) &&
 545            mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
 546                slave->mtd.flags &= ~MTD_WRITEABLE;
 547                printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
 548                        part->name);
 549        }
 550
 551        slave->mtd.ecclayout = master->ecclayout;
 552        if (master->block_isbad) {
 553                uint64_t offs = 0;
 554
 555                while (offs < slave->mtd.size) {
 556                        if (mtd_block_isbad(master, offs + slave->offset))
 557                                slave->mtd.ecc_stats.badblocks++;
 558                        offs += slave->mtd.erasesize;
 559                }
 560        }
 561
 562out_register:
 563        return slave;
 564}
 565
 566int mtd_add_partition(struct mtd_info *master, char *name,
 567                      long long offset, long long length)
 568{
 569        struct mtd_partition part;
 570        struct mtd_part *p, *new;
 571        uint64_t start, end;
 572        int ret = 0;
 573
 574        /* the direct offset is expected */
 575        if (offset == MTDPART_OFS_APPEND ||
 576            offset == MTDPART_OFS_NXTBLK)
 577                return -EINVAL;
 578
 579        if (length == MTDPART_SIZ_FULL)
 580                length = master->size - offset;
 581
 582        if (length <= 0)
 583                return -EINVAL;
 584
 585        part.name = name;
 586        part.size = length;
 587        part.offset = offset;
 588        part.mask_flags = 0;
 589        part.ecclayout = NULL;
 590
 591        new = allocate_partition(master, &part, -1, offset);
 592        if (IS_ERR(new))
 593                return PTR_ERR(new);
 594
 595        start = offset;
 596        end = offset + length;
 597
 598        mutex_lock(&mtd_partitions_mutex);
 599        list_for_each_entry(p, &mtd_partitions, list)
 600                if (p->master == master) {
 601                        if ((start >= p->offset) &&
 602                            (start < (p->offset + p->mtd.size)))
 603                                goto err_inv;
 604
 605                        if ((end >= p->offset) &&
 606                            (end < (p->offset + p->mtd.size)))
 607                                goto err_inv;
 608                }
 609
 610        list_add(&new->list, &mtd_partitions);
 611        mutex_unlock(&mtd_partitions_mutex);
 612
 613        add_mtd_device(&new->mtd);
 614
 615        return ret;
 616err_inv:
 617        mutex_unlock(&mtd_partitions_mutex);
 618        free_partition(new);
 619        return -EINVAL;
 620}
 621EXPORT_SYMBOL_GPL(mtd_add_partition);
 622
 623int mtd_del_partition(struct mtd_info *master, int partno)
 624{
 625        struct mtd_part *slave, *next;
 626        int ret = -EINVAL;
 627
 628        mutex_lock(&mtd_partitions_mutex);
 629        list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 630                if ((slave->master == master) &&
 631                    (slave->mtd.index == partno)) {
 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 * We don't register the master, or expect the caller to have done so,
 652 * for reasons of data integrity.
 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
 676                cur_offset = slave->offset + slave->mtd.size;
 677        }
 678
 679        return 0;
 680}
 681
 682static DEFINE_SPINLOCK(part_parser_lock);
 683static LIST_HEAD(part_parsers);
 684
 685static struct mtd_part_parser *get_partition_parser(const char *name)
 686{
 687        struct mtd_part_parser *p, *ret = NULL;
 688
 689        spin_lock(&part_parser_lock);
 690
 691        list_for_each_entry(p, &part_parsers, list)
 692                if (!strcmp(p->name, name) && try_module_get(p->owner)) {
 693                        ret = p;
 694                        break;
 695                }
 696
 697        spin_unlock(&part_parser_lock);
 698
 699        return ret;
 700}
 701
 702#define put_partition_parser(p) do { module_put((p)->owner); } while (0)
 703
 704int register_mtd_parser(struct mtd_part_parser *p)
 705{
 706        spin_lock(&part_parser_lock);
 707        list_add(&p->list, &part_parsers);
 708        spin_unlock(&part_parser_lock);
 709
 710        return 0;
 711}
 712EXPORT_SYMBOL_GPL(register_mtd_parser);
 713
 714int deregister_mtd_parser(struct mtd_part_parser *p)
 715{
 716        spin_lock(&part_parser_lock);
 717        list_del(&p->list);
 718        spin_unlock(&part_parser_lock);
 719        return 0;
 720}
 721EXPORT_SYMBOL_GPL(deregister_mtd_parser);
 722
 723/*
 724 * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
 725 * are changing this array!
 726 */
 727static const char *default_mtd_part_types[] = {
 728        "cmdlinepart",
 729        "ofpart",
 730        NULL
 731};
 732
 733/**
 734 * parse_mtd_partitions - parse MTD partitions
 735 * @master: the master partition (describes whole MTD device)
 736 * @types: names of partition parsers to try or %NULL
 737 * @pparts: array of partitions found is returned here
 738 * @data: MTD partition parser-specific data
 739 *
 740 * This function tries to find partition on MTD device @master. It uses MTD
 741 * partition parsers, specified in @types. However, if @types is %NULL, then
 742 * the default list of parsers is used. The default list contains only the
 743 * "cmdlinepart" and "ofpart" parsers ATM.
 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 **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                if (ret > 0) {
 769                        printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
 770                               ret, parser->name, master->name);
 771                }
 772                put_partition_parser(parser);
 773        }
 774        return ret;
 775}
 776
 777int mtd_is_partition(struct mtd_info *mtd)
 778{
 779        struct mtd_part *part;
 780        int ispart = 0;
 781
 782        mutex_lock(&mtd_partitions_mutex);
 783        list_for_each_entry(part, &mtd_partitions, list)
 784                if (&part->mtd == mtd) {
 785                        ispart = 1;
 786                        break;
 787                }
 788        mutex_unlock(&mtd_partitions_mutex);
 789
 790        return ispart;
 791}
 792EXPORT_SYMBOL_GPL(mtd_is_partition);
 793
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