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 = part->master->read(part->master, from + part->offset,
  74                                   len, retlen, buf);
  75        if (unlikely(res)) {
  76                if (mtd_is_bitflip(res))
  77                        mtd->ecc_stats.corrected += part->master->ecc_stats.corrected - stats.corrected;
  78                if (mtd_is_eccerr(res))
  79                        mtd->ecc_stats.failed += part->master->ecc_stats.failed - stats.failed;
  80        }
  81        return res;
  82}
  83
  84static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
  85                size_t *retlen, void **virt, resource_size_t *phys)
  86{
  87        struct mtd_part *part = PART(mtd);
  88        if (from >= mtd->size)
  89                len = 0;
  90        else if (from + len > mtd->size)
  91                len = mtd->size - from;
  92        return part->master->point (part->master, from + part->offset,
  93                                    len, retlen, virt, phys);
  94}
  95
  96static void part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
  97{
  98        struct mtd_part *part = PART(mtd);
  99
 100        part->master->unpoint(part->master, from + part->offset, len);
 101}
 102
 103static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
 104                                            unsigned long len,
 105                                            unsigned long offset,
 106                                            unsigned long flags)
 107{
 108        struct mtd_part *part = PART(mtd);
 109
 110        offset += part->offset;
 111        return part->master->get_unmapped_area(part->master, len, offset,
 112                                               flags);
 113}
 114
 115static int part_read_oob(struct mtd_info *mtd, loff_t from,
 116                struct mtd_oob_ops *ops)
 117{
 118        struct mtd_part *part = PART(mtd);
 119        int res;
 120
 121        if (from >= mtd->size)
 122                return -EINVAL;
 123        if (ops->datbuf && from + ops->len > mtd->size)
 124                return -EINVAL;
 125
 126        /*
 127         * If OOB is also requested, make sure that we do not read past the end
 128         * of this partition.
 129         */
 130        if (ops->oobbuf) {
 131                size_t len, pages;
 132
 133                if (ops->mode == MTD_OPS_AUTO_OOB)
 134                        len = mtd->oobavail;
 135                else
 136                        len = mtd->oobsize;
 137                pages = mtd_div_by_ws(mtd->size, mtd);
 138                pages -= mtd_div_by_ws(from, mtd);
 139                if (ops->ooboffs + ops->ooblen > pages * len)
 140                        return -EINVAL;
 141        }
 142
 143        res = part->master->read_oob(part->master, from + part->offset, ops);
 144        if (unlikely(res)) {
 145                if (mtd_is_bitflip(res))
 146                        mtd->ecc_stats.corrected++;
 147                if (mtd_is_eccerr(res))
 148                        mtd->ecc_stats.failed++;
 149        }
 150        return res;
 151}
 152
 153static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
 154                size_t len, size_t *retlen, u_char *buf)
 155{
 156        struct mtd_part *part = PART(mtd);
 157        return part->master->read_user_prot_reg(part->master, from,
 158                                        len, retlen, buf);
 159}
 160
 161static int part_get_user_prot_info(struct mtd_info *mtd,
 162                struct otp_info *buf, size_t len)
 163{
 164        struct mtd_part *part = PART(mtd);
 165        return part->master->get_user_prot_info(part->master, buf, len);
 166}
 167
 168static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
 169                size_t len, size_t *retlen, u_char *buf)
 170{
 171        struct mtd_part *part = PART(mtd);
 172        return part->master->read_fact_prot_reg(part->master, from,
 173                                        len, retlen, buf);
 174}
 175
 176static int part_get_fact_prot_info(struct mtd_info *mtd, struct otp_info *buf,
 177                size_t len)
 178{
 179        struct mtd_part *part = PART(mtd);
 180        return part->master->get_fact_prot_info(part->master, buf, len);
 181}
 182
 183static int part_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        if (!(mtd->flags & MTD_WRITEABLE))
 188                return -EROFS;
 189        if (to >= mtd->size)
 190                len = 0;
 191        else if (to + len > mtd->size)
 192                len = mtd->size - to;
 193        return part->master->write(part->master, to + part->offset,
 194                                    len, retlen, buf);
 195}
 196
 197static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
 198                size_t *retlen, const u_char *buf)
 199{
 200        struct mtd_part *part = PART(mtd);
 201        if (!(mtd->flags & MTD_WRITEABLE))
 202                return -EROFS;
 203        if (to >= mtd->size)
 204                len = 0;
 205        else if (to + len > mtd->size)
 206                len = mtd->size - to;
 207        return part->master->panic_write(part->master, to + part->offset,
 208                                    len, retlen, buf);
 209}
 210
 211static int part_write_oob(struct mtd_info *mtd, loff_t to,
 212                struct mtd_oob_ops *ops)
 213{
 214        struct mtd_part *part = PART(mtd);
 215
 216        if (!(mtd->flags & MTD_WRITEABLE))
 217                return -EROFS;
 218
 219        if (to >= mtd->size)
 220                return -EINVAL;
 221        if (ops->datbuf && to + ops->len > mtd->size)
 222                return -EINVAL;
 223        return part->master->write_oob(part->master, to + part->offset, ops);
 224}
 225
 226static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
 227                size_t len, size_t *retlen, u_char *buf)
 228{
 229        struct mtd_part *part = PART(mtd);
 230        return part->master->write_user_prot_reg(part->master, from,
 231                                        len, retlen, buf);
 232}
 233
 234static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
 235                size_t len)
 236{
 237        struct mtd_part *part = PART(mtd);
 238        return part->master->lock_user_prot_reg(part->master, from, len);
 239}
 240
 241static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
 242                unsigned long count, loff_t to, size_t *retlen)
 243{
 244        struct mtd_part *part = PART(mtd);
 245        if (!(mtd->flags & MTD_WRITEABLE))
 246                return -EROFS;
 247        return part->master->writev(part->master, vecs, count,
 248                                        to + part->offset, retlen);
 249}
 250
 251static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
 252{
 253        struct mtd_part *part = PART(mtd);
 254        int ret;
 255        if (!(mtd->flags & MTD_WRITEABLE))
 256                return -EROFS;
 257        if (instr->addr >= mtd->size)
 258                return -EINVAL;
 259        instr->addr += part->offset;
 260        ret = part->master->erase(part->master, instr);
 261        if (ret) {
 262                if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 263                        instr->fail_addr -= part->offset;
 264                instr->addr -= part->offset;
 265        }
 266        return ret;
 267}
 268
 269void mtd_erase_callback(struct erase_info *instr)
 270{
 271        if (instr->mtd->erase == part_erase) {
 272                struct mtd_part *part = PART(instr->mtd);
 273
 274                if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 275                        instr->fail_addr -= part->offset;
 276                instr->addr -= part->offset;
 277        }
 278        if (instr->callback)
 279                instr->callback(instr);
 280}
 281EXPORT_SYMBOL_GPL(mtd_erase_callback);
 282
 283static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 284{
 285        struct mtd_part *part = PART(mtd);
 286        if ((len + ofs) > mtd->size)
 287                return -EINVAL;
 288        return part->master->lock(part->master, ofs + part->offset, len);
 289}
 290
 291static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 292{
 293        struct mtd_part *part = PART(mtd);
 294        if ((len + ofs) > mtd->size)
 295                return -EINVAL;
 296        return part->master->unlock(part->master, ofs + part->offset, len);
 297}
 298
 299static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 300{
 301        struct mtd_part *part = PART(mtd);
 302        if ((len + ofs) > mtd->size)
 303                return -EINVAL;
 304        return part->master->is_locked(part->master, ofs + part->offset, len);
 305}
 306
 307static void part_sync(struct mtd_info *mtd)
 308{
 309        struct mtd_part *part = PART(mtd);
 310        part->master->sync(part->master);
 311}
 312
 313static int part_suspend(struct mtd_info *mtd)
 314{
 315        struct mtd_part *part = PART(mtd);
 316        return part->master->suspend(part->master);
 317}
 318
 319static void part_resume(struct mtd_info *mtd)
 320{
 321        struct mtd_part *part = PART(mtd);
 322        part->master->resume(part->master);
 323}
 324
 325static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
 326{
 327        struct mtd_part *part = PART(mtd);
 328        if (ofs >= mtd->size)
 329                return -EINVAL;
 330        ofs += part->offset;
 331        return part->master->block_isbad(part->master, ofs);
 332}
 333
 334static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 335{
 336        struct mtd_part *part = PART(mtd);
 337        int res;
 338
 339        if (!(mtd->flags & MTD_WRITEABLE))
 340                return -EROFS;
 341        if (ofs >= mtd->size)
 342                return -EINVAL;
 343        ofs += part->offset;
 344        res = part->master->block_markbad(part->master, ofs);
 345        if (!res)
 346                mtd->ecc_stats.badblocks++;
 347        return res;
 348}
 349
 350static inline void free_partition(struct mtd_part *p)
 351{
 352        kfree(p->mtd.name);
 353        kfree(p);
 354}
 355
 356/*
 357 * This function unregisters and destroy all slave MTD objects which are
 358 * attached to the given master MTD object.
 359 */
 360
 361int del_mtd_partitions(struct mtd_info *master)
 362{
 363        struct mtd_part *slave, *next;
 364        int ret, err = 0;
 365
 366        mutex_lock(&mtd_partitions_mutex);
 367        list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 368                if (slave->master == master) {
 369                        ret = del_mtd_device(&slave->mtd);
 370                        if (ret < 0) {
 371                                err = ret;
 372                                continue;
 373                        }
 374                        list_del(&slave->list);
 375                        free_partition(slave);
 376                }
 377        mutex_unlock(&mtd_partitions_mutex);
 378
 379        return err;
 380}
 381
 382static struct mtd_part *allocate_partition(struct mtd_info *master,
 383                        const struct mtd_partition *part, int partno,
 384                        uint64_t cur_offset)
 385{
 386        struct mtd_part *slave;
 387        char *name;
 388
 389        /* allocate the partition structure */
 390        slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 391        name = kstrdup(part->name, GFP_KERNEL);
 392        if (!name || !slave) {
 393                printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
 394                       master->name);
 395                kfree(name);
 396                kfree(slave);
 397                return ERR_PTR(-ENOMEM);
 398        }
 399
 400        /* set up the MTD object for this partition */
 401        slave->mtd.type = master->type;
 402        slave->mtd.flags = master->flags & ~part->mask_flags;
 403        slave->mtd.size = part->size;
 404        slave->mtd.writesize = master->writesize;
 405        slave->mtd.writebufsize = master->writebufsize;
 406        slave->mtd.oobsize = master->oobsize;
 407        slave->mtd.oobavail = master->oobavail;
 408        slave->mtd.subpage_sft = master->subpage_sft;
 409
 410        slave->mtd.name = name;
 411        slave->mtd.owner = master->owner;
 412        slave->mtd.backing_dev_info = master->backing_dev_info;
 413
 414        /* NOTE:  we don't arrange MTDs as a tree; it'd be error-prone
 415         * to have the same data be in two different partitions.
 416         */
 417        slave->mtd.dev.parent = master->dev.parent;
 418
 419        slave->mtd.read = part_read;
 420        slave->mtd.write = part_write;
 421
 422        if (master->panic_write)
 423                slave->mtd.panic_write = part_panic_write;
 424
 425        if (master->point && master->unpoint) {
 426                slave->mtd.point = part_point;
 427                slave->mtd.unpoint = part_unpoint;
 428        }
 429
 430        if (master->get_unmapped_area)
 431                slave->mtd.get_unmapped_area = part_get_unmapped_area;
 432        if (master->read_oob)
 433                slave->mtd.read_oob = part_read_oob;
 434        if (master->write_oob)
 435                slave->mtd.write_oob = part_write_oob;
 436        if (master->read_user_prot_reg)
 437                slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
 438        if (master->read_fact_prot_reg)
 439                slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
 440        if (master->write_user_prot_reg)
 441                slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
 442        if (master->lock_user_prot_reg)
 443                slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
 444        if (master->get_user_prot_info)
 445                slave->mtd.get_user_prot_info = part_get_user_prot_info;
 446        if (master->get_fact_prot_info)
 447                slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
 448        if (master->sync)
 449                slave->mtd.sync = part_sync;
 450        if (!partno && !master->dev.class && master->suspend && master->resume) {
 451                        slave->mtd.suspend = part_suspend;
 452                        slave->mtd.resume = part_resume;
 453        }
 454        if (master->writev)
 455                slave->mtd.writev = part_writev;
 456        if (master->lock)
 457                slave->mtd.lock = part_lock;
 458        if (master->unlock)
 459                slave->mtd.unlock = part_unlock;
 460        if (master->is_locked)
 461                slave->mtd.is_locked = part_is_locked;
 462        if (master->block_isbad)
 463                slave->mtd.block_isbad = part_block_isbad;
 464        if (master->block_markbad)
 465                slave->mtd.block_markbad = part_block_markbad;
 466        slave->mtd.erase = part_erase;
 467        slave->master = master;
 468        slave->offset = part->offset;
 469
 470        if (slave->offset == MTDPART_OFS_APPEND)
 471                slave->offset = cur_offset;
 472        if (slave->offset == MTDPART_OFS_NXTBLK) {
 473                slave->offset = cur_offset;
 474                if (mtd_mod_by_eb(cur_offset, master) != 0) {
 475                        /* Round up to next erasesize */
 476                        slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
 477                        printk(KERN_NOTICE "Moving partition %d: "
 478                               "0x%012llx -> 0x%012llx\n", partno,
 479                               (unsigned long long)cur_offset, (unsigned long long)slave->offset);
 480                }
 481        }
 482        if (slave->offset == MTDPART_OFS_RETAIN) {
 483                slave->offset = cur_offset;
 484                if (master->size - slave->offset >= slave->mtd.size) {
 485                        slave->mtd.size = master->size - slave->offset
 486                                                        - slave->mtd.size;
 487                } else {
 488                        printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
 489                                part->name, master->size - slave->offset,
 490                                slave->mtd.size);
 491                        /* register to preserve ordering */
 492                        goto out_register;
 493                }
 494        }
 495        if (slave->mtd.size == MTDPART_SIZ_FULL)
 496                slave->mtd.size = master->size - slave->offset;
 497
 498        printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
 499                (unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
 500
 501        /* let's do some sanity checks */
 502        if (slave->offset >= master->size) {
 503                /* let's register it anyway to preserve ordering */
 504                slave->offset = 0;
 505                slave->mtd.size = 0;
 506                printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
 507                        part->name);
 508                goto out_register;
 509        }
 510        if (slave->offset + slave->mtd.size > master->size) {
 511                slave->mtd.size = master->size - slave->offset;
 512                printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
 513                        part->name, master->name, (unsigned long long)slave->mtd.size);
 514        }
 515        if (master->numeraseregions > 1) {
 516                /* Deal with variable erase size stuff */
 517                int i, max = master->numeraseregions;
 518                u64 end = slave->offset + slave->mtd.size;
 519                struct mtd_erase_region_info *regions = master->eraseregions;
 520
 521                /* Find the first erase regions which is part of this
 522                 * partition. */
 523                for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
 524                        ;
 525                /* The loop searched for the region _behind_ the first one */
 526                if (i > 0)
 527                        i--;
 528
 529                /* Pick biggest erasesize */
 530                for (; i < max && regions[i].offset < end; i++) {
 531                        if (slave->mtd.erasesize < regions[i].erasesize) {
 532                                slave->mtd.erasesize = regions[i].erasesize;
 533                        }
 534                }
 535                BUG_ON(slave->mtd.erasesize == 0);
 536        } else {
 537                /* Single erase size */
 538                slave->mtd.erasesize = master->erasesize;
 539        }
 540
 541        if ((slave->mtd.flags & MTD_WRITEABLE) &&
 542            mtd_mod_by_eb(slave->offset, &slave->mtd)) {
 543                /* Doesn't start on a boundary of major erase size */
 544                /* FIXME: Let it be writable if it is on a boundary of
 545                 * _minor_ erase size though */
 546                slave->mtd.flags &= ~MTD_WRITEABLE;
 547                printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
 548                        part->name);
 549        }
 550        if ((slave->mtd.flags & MTD_WRITEABLE) &&
 551            mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
 552                slave->mtd.flags &= ~MTD_WRITEABLE;
 553                printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
 554                        part->name);
 555        }
 556
 557        slave->mtd.ecclayout = master->ecclayout;
 558        if (master->block_isbad) {
 559                uint64_t offs = 0;
 560
 561                while (offs < slave->mtd.size) {
 562                        if (master->block_isbad(master,
 563                                                offs + slave->offset))
 564                                slave->mtd.ecc_stats.badblocks++;
 565                        offs += slave->mtd.erasesize;
 566                }
 567        }
 568
 569out_register:
 570        return slave;
 571}
 572
 573int mtd_add_partition(struct mtd_info *master, char *name,
 574                      long long offset, long long length)
 575{
 576        struct mtd_partition part;
 577        struct mtd_part *p, *new;
 578        uint64_t start, end;
 579        int ret = 0;
 580
 581        /* the direct offset is expected */
 582        if (offset == MTDPART_OFS_APPEND ||
 583            offset == MTDPART_OFS_NXTBLK)
 584                return -EINVAL;
 585
 586        if (length == MTDPART_SIZ_FULL)
 587                length = master->size - offset;
 588
 589        if (length <= 0)
 590                return -EINVAL;
 591
 592        part.name = name;
 593        part.size = length;
 594        part.offset = offset;
 595        part.mask_flags = 0;
 596        part.ecclayout = NULL;
 597
 598        new = allocate_partition(master, &part, -1, offset);
 599        if (IS_ERR(new))
 600                return PTR_ERR(new);
 601
 602        start = offset;
 603        end = offset + length;
 604
 605        mutex_lock(&mtd_partitions_mutex);
 606        list_for_each_entry(p, &mtd_partitions, list)
 607                if (p->master == master) {
 608                        if ((start >= p->offset) &&
 609                            (start < (p->offset + p->mtd.size)))
 610                                goto err_inv;
 611
 612                        if ((end >= p->offset) &&
 613                            (end < (p->offset + p->mtd.size)))
 614                                goto err_inv;
 615                }
 616
 617        list_add(&new->list, &mtd_partitions);
 618        mutex_unlock(&mtd_partitions_mutex);
 619
 620        add_mtd_device(&new->mtd);
 621
 622        return ret;
 623err_inv:
 624        mutex_unlock(&mtd_partitions_mutex);
 625        free_partition(new);
 626        return -EINVAL;
 627}
 628EXPORT_SYMBOL_GPL(mtd_add_partition);
 629
 630int mtd_del_partition(struct mtd_info *master, int partno)
 631{
 632        struct mtd_part *slave, *next;
 633        int ret = -EINVAL;
 634
 635        mutex_lock(&mtd_partitions_mutex);
 636        list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 637                if ((slave->master == master) &&
 638                    (slave->mtd.index == partno)) {
 639                        ret = del_mtd_device(&slave->mtd);
 640                        if (ret < 0)
 641                                break;
 642
 643                        list_del(&slave->list);
 644                        free_partition(slave);
 645                        break;
 646                }
 647        mutex_unlock(&mtd_partitions_mutex);
 648
 649        return ret;
 650}
 651EXPORT_SYMBOL_GPL(mtd_del_partition);
 652
 653/*
 654 * This function, given a master MTD object and a partition table, creates
 655 * and registers slave MTD objects which are bound to the master according to
 656 * the partition definitions.
 657 *
 658 * We don't register the master, or expect the caller to have done so,
 659 * for reasons of data integrity.
 660 */
 661
 662int add_mtd_partitions(struct mtd_info *master,
 663                       const struct mtd_partition *parts,
 664                       int nbparts)
 665{
 666        struct mtd_part *slave;
 667        uint64_t cur_offset = 0;
 668        int i;
 669
 670        printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 671
 672        for (i = 0; i < nbparts; i++) {
 673                slave = allocate_partition(master, parts + i, i, cur_offset);
 674                if (IS_ERR(slave))
 675                        return PTR_ERR(slave);
 676
 677                mutex_lock(&mtd_partitions_mutex);
 678                list_add(&slave->list, &mtd_partitions);
 679                mutex_unlock(&mtd_partitions_mutex);
 680
 681                add_mtd_device(&slave->mtd);
 682
 683                cur_offset = slave->offset + slave->mtd.size;
 684        }
 685
 686        return 0;
 687}
 688
 689static DEFINE_SPINLOCK(part_parser_lock);
 690static LIST_HEAD(part_parsers);
 691
 692static struct mtd_part_parser *get_partition_parser(const char *name)
 693{
 694        struct mtd_part_parser *p, *ret = NULL;
 695
 696        spin_lock(&part_parser_lock);
 697
 698        list_for_each_entry(p, &part_parsers, list)
 699                if (!strcmp(p->name, name) && try_module_get(p->owner)) {
 700                        ret = p;
 701                        break;
 702                }
 703
 704        spin_unlock(&part_parser_lock);
 705
 706        return ret;
 707}
 708
 709#define put_partition_parser(p) do { module_put((p)->owner); } while (0)
 710
 711int register_mtd_parser(struct mtd_part_parser *p)
 712{
 713        spin_lock(&part_parser_lock);
 714        list_add(&p->list, &part_parsers);
 715        spin_unlock(&part_parser_lock);
 716
 717        return 0;
 718}
 719EXPORT_SYMBOL_GPL(register_mtd_parser);
 720
 721int deregister_mtd_parser(struct mtd_part_parser *p)
 722{
 723        spin_lock(&part_parser_lock);
 724        list_del(&p->list);
 725        spin_unlock(&part_parser_lock);
 726        return 0;
 727}
 728EXPORT_SYMBOL_GPL(deregister_mtd_parser);
 729
 730/*
 731 * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
 732 * are changing this array!
 733 */
 734static const char *default_mtd_part_types[] = {
 735        "cmdlinepart",
 736        "ofpart",
 737        NULL
 738};
 739
 740/**
 741 * parse_mtd_partitions - parse MTD partitions
 742 * @master: the master partition (describes whole MTD device)
 743 * @types: names of partition parsers to try or %NULL
 744 * @pparts: array of partitions found is returned here
 745 * @data: MTD partition parser-specific data
 746 *
 747 * This function tries to find partition on MTD device @master. It uses MTD
 748 * partition parsers, specified in @types. However, if @types is %NULL, then
 749 * the default list of parsers is used. The default list contains only the
 750 * "cmdlinepart" and "ofpart" parsers ATM.
 751 *
 752 * This function may return:
 753 * o a negative error code in case of failure
 754 * o zero if no partitions were found
 755 * o a positive number of found partitions, in which case on exit @pparts will
 756 *   point to an array containing this number of &struct mtd_info objects.
 757 */
 758int parse_mtd_partitions(struct mtd_info *master, const char **types,
 759                         struct mtd_partition **pparts,
 760                         struct mtd_part_parser_data *data)
 761{
 762        struct mtd_part_parser *parser;
 763        int ret = 0;
 764
 765        if (!types)
 766                types = default_mtd_part_types;
 767
 768        for ( ; ret <= 0 && *types; types++) {
 769                parser = get_partition_parser(*types);
 770                if (!parser && !request_module("%s", *types))
 771                                parser = get_partition_parser(*types);
 772                if (!parser)
 773                        continue;
 774                ret = (*parser->parse_fn)(master, pparts, data);
 775                if (ret > 0) {
 776                        printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
 777                               ret, parser->name, master->name);
 778                }
 779                put_partition_parser(parser);
 780        }
 781        return ret;
 782}
 783
 784int mtd_is_partition(struct mtd_info *mtd)
 785{
 786        struct mtd_part *part;
 787        int ispart = 0;
 788
 789        mutex_lock(&mtd_partitions_mutex);
 790        list_for_each_entry(part, &mtd_partitions, list)
 791                if (&part->mtd == mtd) {
 792                        ispart = 1;
 793                        break;
 794                }
 795        mutex_unlock(&mtd_partitions_mutex);
 796
 797        return ispart;
 798}
 799EXPORT_SYMBOL_GPL(mtd_is_partition);
 800
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