drivers/mtd/mtdpart.c

   1 /*
   2  * Simple MTD partitioning layer
   3  *
   4  * Copyright © 2000 Nicolas Pitre <nico@fluxnic.net>
   5  * Copyright © 2002 Thomas Gleixner <gleixner@linutronix.de>
   6  * Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  21  *
  22  */
  23
  24 #include <linux/module.h>
  25 #include <linux/types.h>
  26 #include <linux/kernel.h>
  27 #include <linux/slab.h>
  28 #include <linux/list.h>
  29 #include <linux/kmod.h>
  30 #include <linux/mtd/mtd.h>
  31 #include <linux/mtd/partitions.h>
  32 #include <linux/err.h>
  33 #include <linux/of.h>
  34
  35 #include "mtdcore.h"
  36
  37 /* Our partition linked list */
  38 static LIST_HEAD(mtd_partitions);
  39 static DEFINE_MUTEX(mtd_partitions_mutex);
  40
  41 /**
  42  * struct mtd_part - our partition node structure
  43  *
  44  * @mtd: struct holding partition details
  45  * @parent: parent mtd - flash device or another partition
  46  * @offset: partition offset relative to the *flash device*
  47  */
  48 struct mtd_part {
  49         struct mtd_info mtd;
  50         struct mtd_info *parent;
  51         uint64_t offset;
  52         struct list_head list;
  53 };
  54
  55 /*
  56  * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
  57  * the pointer to that structure.
  58  */
  59 static inline struct mtd_part *mtd_to_part(const struct mtd_info *mtd)
  60 {
  61         return container_of(mtd, struct mtd_part, mtd);
  62 }
  63
  64
  65 /*
  66  * MTD methods which simply translate the effective address and pass through
  67  * to the _real_ device.
  68  */
  69
  70 static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
  71                 size_t *retlen, u_char *buf)
  72 {
  73         struct mtd_part *part = mtd_to_part(mtd);
  74         struct mtd_ecc_stats stats;
  75         int res;
  76
  77         stats = part->parent->ecc_stats;
  78         res = part->parent->_read(part->parent, from + part->offset, len,
  79                                   retlen, buf);
  80         if (unlikely(mtd_is_eccerr(res)))
  81                 mtd->ecc_stats.failed +=
  82                         part->parent->ecc_stats.failed - stats.failed;
  83         else
  84                 mtd->ecc_stats.corrected +=
  85                         part->parent->ecc_stats.corrected - stats.corrected;
  86         return res;
  87 }
  88
  89 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
  90                 size_t *retlen, void **virt, resource_size_t *phys)
  91 {
  92         struct mtd_part *part = mtd_to_part(mtd);
  93
  94         return part->parent->_point(part->parent, from + part->offset, len,
  95                                     retlen, virt, phys);
  96 }
  97
  98 static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
  99 {
 100         struct mtd_part *part = mtd_to_part(mtd);
 101
 102         return part->parent->_unpoint(part->parent, from + part->offset, len);
 103 }
 104
 105 static int part_read_oob(struct mtd_info *mtd, loff_t from,
 106                 struct mtd_oob_ops *ops)
 107 {
 108         struct mtd_part *part = mtd_to_part(mtd);
 109         struct mtd_ecc_stats stats;
 110         int res;
 111
 112         stats = part->parent->ecc_stats;
 113         res = part->parent->_read_oob(part->parent, from + part->offset, ops);
 114         if (unlikely(mtd_is_eccerr(res)))
 115                 mtd->ecc_stats.failed +=
 116                         part->parent->ecc_stats.failed - stats.failed;
 117         else
 118                 mtd->ecc_stats.corrected +=
 119                         part->parent->ecc_stats.corrected - stats.corrected;
 120         return res;
 121 }
 122
 123 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
 124                 size_t len, size_t *retlen, u_char *buf)
 125 {
 126         struct mtd_part *part = mtd_to_part(mtd);
 127         return part->parent->_read_user_prot_reg(part->parent, from, len,
 128                                                  retlen, buf);
 129 }
 130
 131 static int part_get_user_prot_info(struct mtd_info *mtd, size_t len,
 132                                    size_t *retlen, struct otp_info *buf)
 133 {
 134         struct mtd_part *part = mtd_to_part(mtd);
 135         return part->parent->_get_user_prot_info(part->parent, len, retlen,
 136                                                  buf);
 137 }
 138
 139 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
 140                 size_t len, size_t *retlen, u_char *buf)
 141 {
 142         struct mtd_part *part = mtd_to_part(mtd);
 143         return part->parent->_read_fact_prot_reg(part->parent, from, len,
 144                                                  retlen, buf);
 145 }
 146
 147 static int part_get_fact_prot_info(struct mtd_info *mtd, size_t len,
 148                                    size_t *retlen, struct otp_info *buf)
 149 {
 150         struct mtd_part *part = mtd_to_part(mtd);
 151         return part->parent->_get_fact_prot_info(part->parent, len, retlen,
 152                                                  buf);
 153 }
 154
 155 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
 156                 size_t *retlen, const u_char *buf)
 157 {
 158         struct mtd_part *part = mtd_to_part(mtd);
 159         return part->parent->_write(part->parent, to + part->offset, len,
 160                                     retlen, buf);
 161 }
 162
 163 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
 164                 size_t *retlen, const u_char *buf)
 165 {
 166         struct mtd_part *part = mtd_to_part(mtd);
 167         return part->parent->_panic_write(part->parent, to + part->offset, len,
 168                                           retlen, buf);
 169 }
 170
 171 static int part_write_oob(struct mtd_info *mtd, loff_t to,
 172                 struct mtd_oob_ops *ops)
 173 {
 174         struct mtd_part *part = mtd_to_part(mtd);
 175
 176         return part->parent->_write_oob(part->parent, to + part->offset, ops);
 177 }
 178
 179 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
 180                 size_t len, size_t *retlen, u_char *buf)
 181 {
 182         struct mtd_part *part = mtd_to_part(mtd);
 183         return part->parent->_write_user_prot_reg(part->parent, from, len,
 184                                                   retlen, buf);
 185 }
 186
 187 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
 188                 size_t len)
 189 {
 190         struct mtd_part *part = mtd_to_part(mtd);
 191         return part->parent->_lock_user_prot_reg(part->parent, from, len);
 192 }
 193
 194 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
 195                 unsigned long count, loff_t to, size_t *retlen)
 196 {
 197         struct mtd_part *part = mtd_to_part(mtd);
 198         return part->parent->_writev(part->parent, vecs, count,
 199                                      to + part->offset, retlen);
 200 }
 201
 202 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
 203 {
 204         struct mtd_part *part = mtd_to_part(mtd);
 205         int ret;
 206
 207         instr->addr += part->offset;
 208         ret = part->parent->_erase(part->parent, instr);
 209         if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 210                 instr->fail_addr -= part->offset;
 211         instr->addr -= part->offset;
 212
 213         return ret;
 214 }
 215
 216 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 217 {
 218         struct mtd_part *part = mtd_to_part(mtd);
 219         return part->parent->_lock(part->parent, ofs + part->offset, len);
 220 }
 221
 222 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 223 {
 224         struct mtd_part *part = mtd_to_part(mtd);
 225         return part->parent->_unlock(part->parent, ofs + part->offset, len);
 226 }
 227
 228 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 229 {
 230         struct mtd_part *part = mtd_to_part(mtd);
 231         return part->parent->_is_locked(part->parent, ofs + part->offset, len);
 232 }
 233
 234 static void part_sync(struct mtd_info *mtd)
 235 {
 236         struct mtd_part *part = mtd_to_part(mtd);
 237         part->parent->_sync(part->parent);
 238 }
 239
 240 static int part_suspend(struct mtd_info *mtd)
 241 {
 242         struct mtd_part *part = mtd_to_part(mtd);
 243         return part->parent->_suspend(part->parent);
 244 }
 245
 246 static void part_resume(struct mtd_info *mtd)
 247 {
 248         struct mtd_part *part = mtd_to_part(mtd);
 249         part->parent->_resume(part->parent);
 250 }
 251
 252 static int part_block_isreserved(struct mtd_info *mtd, loff_t ofs)
 253 {
 254         struct mtd_part *part = mtd_to_part(mtd);
 255         ofs += part->offset;
 256         return part->parent->_block_isreserved(part->parent, ofs);
 257 }
 258
 259 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
 260 {
 261         struct mtd_part *part = mtd_to_part(mtd);
 262         ofs += part->offset;
 263         return part->parent->_block_isbad(part->parent, ofs);
 264 }
 265
 266 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 267 {
 268         struct mtd_part *part = mtd_to_part(mtd);
 269         int res;
 270
 271         ofs += part->offset;
 272         res = part->parent->_block_markbad(part->parent, ofs);
 273         if (!res)
 274                 mtd->ecc_stats.badblocks++;
 275         return res;
 276 }
 277
 278 static int part_get_device(struct mtd_info *mtd)
 279 {
 280         struct mtd_part *part = mtd_to_part(mtd);
 281         return part->parent->_get_device(part->parent);
 282 }
 283
 284 static void part_put_device(struct mtd_info *mtd)
 285 {
 286         struct mtd_part *part = mtd_to_part(mtd);
 287         part->parent->_put_device(part->parent);
 288 }
 289
 290 static int part_ooblayout_ecc(struct mtd_info *mtd, int section,
 291                               struct mtd_oob_region *oobregion)
 292 {
 293         struct mtd_part *part = mtd_to_part(mtd);
 294
 295         return mtd_ooblayout_ecc(part->parent, section, oobregion);
 296 }
 297
 298 static int part_ooblayout_free(struct mtd_info *mtd, int section,
 299                                struct mtd_oob_region *oobregion)
 300 {
 301         struct mtd_part *part = mtd_to_part(mtd);
 302
 303         return mtd_ooblayout_free(part->parent, section, oobregion);
 304 }
 305
 306 static const struct mtd_ooblayout_ops part_ooblayout_ops = {
 307         .ecc = part_ooblayout_ecc,
 308         .free = part_ooblayout_free,
 309 };
 310
 311 static int part_max_bad_blocks(struct mtd_info *mtd, loff_t ofs, size_t len)
 312 {
 313         struct mtd_part *part = mtd_to_part(mtd);
 314
 315         return part->parent->_max_bad_blocks(part->parent,
 316                                              ofs + part->offset, len);
 317 }
 318
 319 static inline void free_partition(struct mtd_part *p)
 320 {
 321         kfree(p->mtd.name);
 322         kfree(p);
 323 }
 324
 325 static struct mtd_part *allocate_partition(struct mtd_info *parent,
 326                         const struct mtd_partition *part, int partno,
 327                         uint64_t cur_offset)
 328 {
 329         int wr_alignment = (parent->flags & MTD_NO_ERASE) ? parent->writesize :
 330                                                             parent->erasesize;
 331         struct mtd_part *slave;
 332         u32 remainder;
 333         char *name;
 334         u64 tmp;
 335
 336         /* allocate the partition structure */
 337         slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 338         name = kstrdup(part->name, GFP_KERNEL);
 339         if (!name || !slave) {
 340                 printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
 341                        parent->name);
 342                 kfree(name);
 343                 kfree(slave);
 344                 return ERR_PTR(-ENOMEM);
 345         }
 346
 347         /* set up the MTD object for this partition */
 348         slave->mtd.type = parent->type;
 349         slave->mtd.flags = parent->flags & ~part->mask_flags;
 350         slave->mtd.size = part->size;
 351         slave->mtd.writesize = parent->writesize;
 352         slave->mtd.writebufsize = parent->writebufsize;
 353         slave->mtd.oobsize = parent->oobsize;
 354         slave->mtd.oobavail = parent->oobavail;
 355         slave->mtd.subpage_sft = parent->subpage_sft;
 356         slave->mtd.pairing = parent->pairing;
 357
 358         slave->mtd.name = name;
 359         slave->mtd.owner = parent->owner;
 360
 361         /* NOTE: Historically, we didn't arrange MTDs as a tree out of
 362          * concern for showing the same data in multiple partitions.
 363          * However, it is very useful to have the master node present,
 364          * so the MTD_PARTITIONED_MASTER option allows that. The master
 365          * will have device nodes etc only if this is set, so make the
 366          * parent conditional on that option. Note, this is a way to
 367          * distinguish between the master and the partition in sysfs.
 368          */
 369         slave->mtd.dev.parent = IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER) || mtd_is_partition(parent) ?
 370                                 &parent->dev :
 371                                 parent->dev.parent;
 372         slave->mtd.dev.of_node = part->of_node;
 373
 374         if (parent->_read)
 375                 slave->mtd._read = part_read;
 376         if (parent->_write)
 377                 slave->mtd._write = part_write;
 378
 379         if (parent->_panic_write)
 380                 slave->mtd._panic_write = part_panic_write;
 381
 382         if (parent->_point && parent->_unpoint) {
 383                 slave->mtd._point = part_point;
 384                 slave->mtd._unpoint = part_unpoint;
 385         }
 386
 387         if (parent->_read_oob)
 388                 slave->mtd._read_oob = part_read_oob;
 389         if (parent->_write_oob)
 390                 slave->mtd._write_oob = part_write_oob;
 391         if (parent->_read_user_prot_reg)
 392                 slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
 393         if (parent->_read_fact_prot_reg)
 394                 slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
 395         if (parent->_write_user_prot_reg)
 396                 slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
 397         if (parent->_lock_user_prot_reg)
 398                 slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
 399         if (parent->_get_user_prot_info)
 400                 slave->mtd._get_user_prot_info = part_get_user_prot_info;
 401         if (parent->_get_fact_prot_info)
 402                 slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
 403         if (parent->_sync)
 404                 slave->mtd._sync = part_sync;
 405         if (!partno && !parent->dev.class && parent->_suspend &&
 406             parent->_resume) {
 407                 slave->mtd._suspend = part_suspend;
 408                 slave->mtd._resume = part_resume;
 409         }
 410         if (parent->_writev)
 411                 slave->mtd._writev = part_writev;
 412         if (parent->_lock)
 413                 slave->mtd._lock = part_lock;
 414         if (parent->_unlock)
 415                 slave->mtd._unlock = part_unlock;
 416         if (parent->_is_locked)
 417                 slave->mtd._is_locked = part_is_locked;
 418         if (parent->_block_isreserved)
 419                 slave->mtd._block_isreserved = part_block_isreserved;
 420         if (parent->_block_isbad)
 421                 slave->mtd._block_isbad = part_block_isbad;
 422         if (parent->_block_markbad)
 423                 slave->mtd._block_markbad = part_block_markbad;
 424         if (parent->_max_bad_blocks)
 425                 slave->mtd._max_bad_blocks = part_max_bad_blocks;
 426
 427         if (parent->_get_device)
 428                 slave->mtd._get_device = part_get_device;
 429         if (parent->_put_device)
 430                 slave->mtd._put_device = part_put_device;
 431
 432         slave->mtd._erase = part_erase;
 433         slave->parent = parent;
 434         slave->offset = part->offset;
 435
 436         if (slave->offset == MTDPART_OFS_APPEND)
 437                 slave->offset = cur_offset;
 438         if (slave->offset == MTDPART_OFS_NXTBLK) {
 439                 tmp = cur_offset;
 440                 slave->offset = cur_offset;
 441                 remainder = do_div(tmp, wr_alignment);
 442                 if (remainder) {
 443                         slave->offset += wr_alignment - remainder;
 444                         printk(KERN_NOTICE "Moving partition %d: "
 445                                "0x%012llx -> 0x%012llx\n", partno,
 446                                (unsigned long long)cur_offset, (unsigned long long)slave->offset);
 447                 }
 448         }
 449         if (slave->offset == MTDPART_OFS_RETAIN) {
 450                 slave->offset = cur_offset;
 451                 if (parent->size - slave->offset >= slave->mtd.size) {
 452                         slave->mtd.size = parent->size - slave->offset
 453                                                         - slave->mtd.size;
 454                 } else {
 455                         printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
 456                                 part->name, parent->size - slave->offset,
 457                                 slave->mtd.size);
 458                         /* register to preserve ordering */
 459                         goto out_register;
 460                 }
 461         }
 462         if (slave->mtd.size == MTDPART_SIZ_FULL)
 463                 slave->mtd.size = parent->size - slave->offset;
 464
 465         printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
 466                 (unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
 467
 468         /* let's do some sanity checks */
 469         if (slave->offset >= parent->size) {
 470                 /* let's register it anyway to preserve ordering */
 471                 slave->offset = 0;
 472                 slave->mtd.size = 0;
 473                 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
 474                         part->name);
 475                 goto out_register;
 476         }
 477         if (slave->offset + slave->mtd.size > parent->size) {
 478                 slave->mtd.size = parent->size - slave->offset;
 479                 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
 480                         part->name, parent->name, (unsigned long long)slave->mtd.size);
 481         }
 482         if (parent->numeraseregions > 1) {
 483                 /* Deal with variable erase size stuff */
 484                 int i, max = parent->numeraseregions;
 485                 u64 end = slave->offset + slave->mtd.size;
 486                 struct mtd_erase_region_info *regions = parent->eraseregions;
 487
 488                 /* Find the first erase regions which is part of this
 489                  * partition. */
 490                 for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
 491                         ;
 492                 /* The loop searched for the region _behind_ the first one */
 493                 if (i > 0)
 494                         i--;
 495
 496                 /* Pick biggest erasesize */
 497                 for (; i < max && regions[i].offset < end; i++) {
 498                         if (slave->mtd.erasesize < regions[i].erasesize) {
 499                                 slave->mtd.erasesize = regions[i].erasesize;
 500                         }
 501                 }
 502                 BUG_ON(slave->mtd.erasesize == 0);
 503         } else {
 504                 /* Single erase size */
 505                 slave->mtd.erasesize = parent->erasesize;
 506         }
 507
 508         /*
 509          * Slave erasesize might differ from the master one if the master
 510          * exposes several regions with different erasesize. Adjust
 511          * wr_alignment accordingly.
 512          */
 513         if (!(slave->mtd.flags & MTD_NO_ERASE))
 514                 wr_alignment = slave->mtd.erasesize;
 515
 516         tmp = slave->offset;
 517         remainder = do_div(tmp, wr_alignment);
 518         if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
 519                 /* Doesn't start on a boundary of major erase size */
 520                 /* FIXME: Let it be writable if it is on a boundary of
 521                  * _minor_ erase size though */
 522                 slave->mtd.flags &= ~MTD_WRITEABLE;
 523                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n",
 524                         part->name);
 525         }
 526
 527         tmp = slave->mtd.size;
 528         remainder = do_div(tmp, wr_alignment);
 529         if ((slave->mtd.flags & MTD_WRITEABLE) && remainder) {
 530                 slave->mtd.flags &= ~MTD_WRITEABLE;
 531                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n",
 532                         part->name);
 533         }
 534
 535         mtd_set_ooblayout(&slave->mtd, &part_ooblayout_ops);
 536         slave->mtd.ecc_step_size = parent->ecc_step_size;
 537         slave->mtd.ecc_strength = parent->ecc_strength;
 538         slave->mtd.bitflip_threshold = parent->bitflip_threshold;
 539
 540         if (parent->_block_isbad) {
 541                 uint64_t offs = 0;
 542
 543                 while (offs < slave->mtd.size) {
 544                         if (mtd_block_isreserved(parent, offs + slave->offset))
 545                                 slave->mtd.ecc_stats.bbtblocks++;
 546                         else if (mtd_block_isbad(parent, offs + slave->offset))
 547                                 slave->mtd.ecc_stats.badblocks++;
 548                         offs += slave->mtd.erasesize;
 549                 }
 550         }
 551
 552 out_register:
 553         return slave;
 554 }
 555
 556 static ssize_t mtd_partition_offset_show(struct device *dev,
 557                 struct device_attribute *attr, char *buf)
 558 {
 559         struct mtd_info *mtd = dev_get_drvdata(dev);
 560         struct mtd_part *part = mtd_to_part(mtd);
 561         return snprintf(buf, PAGE_SIZE, "%lld\n", part->offset);
 562 }
 563
 564 static DEVICE_ATTR(offset, S_IRUGO, mtd_partition_offset_show, NULL);
 565
 566 static const struct attribute *mtd_partition_attrs[] = {
 567         &dev_attr_offset.attr,
 568         NULL
 569 };
 570
 571 static int mtd_add_partition_attrs(struct mtd_part *new)
 572 {
 573         int ret = sysfs_create_files(&new->mtd.dev.kobj, mtd_partition_attrs);
 574         if (ret)
 575                 printk(KERN_WARNING
 576                        "mtd: failed to create partition attrs, err=%d\n", ret);
 577         return ret;
 578 }
 579
 580 int mtd_add_partition(struct mtd_info *parent, const char *name,
 581                       long long offset, long long length)
 582 {
 583         struct mtd_partition part;
 584         struct mtd_part *new;
 585         int ret = 0;
 586
 587         /* the direct offset is expected */
 588         if (offset == MTDPART_OFS_APPEND ||
 589             offset == MTDPART_OFS_NXTBLK)
 590                 return -EINVAL;
 591
 592         if (length == MTDPART_SIZ_FULL)
 593                 length = parent->size - offset;
 594
 595         if (length <= 0)
 596                 return -EINVAL;
 597
 598         memset(&part, 0, sizeof(part));
 599         part.name = name;
 600         part.size = length;
 601         part.offset = offset;
 602
 603         new = allocate_partition(parent, &part, -1, offset);
 604         if (IS_ERR(new))
 605                 return PTR_ERR(new);
 606
 607         mutex_lock(&mtd_partitions_mutex);
 608         list_add(&new->list, &mtd_partitions);
 609         mutex_unlock(&mtd_partitions_mutex);
 610
 611         add_mtd_device(&new->mtd);
 612
 613         mtd_add_partition_attrs(new);
 614
 615         return ret;
 616 }
 617 EXPORT_SYMBOL_GPL(mtd_add_partition);
 618
 619 /**
 620  * __mtd_del_partition - delete MTD partition
 621  *
 622  * @priv: internal MTD struct for partition to be deleted
 623  *
 624  * This function must be called with the partitions mutex locked.
 625  */
 626 static int __mtd_del_partition(struct mtd_part *priv)
 627 {
 628         struct mtd_part *child, *next;
 629         int err;
 630
 631         list_for_each_entry_safe(child, next, &mtd_partitions, list) {
 632                 if (child->parent == &priv->mtd) {
 633                         err = __mtd_del_partition(child);
 634                         if (err)
 635                                 return err;
 636                 }
 637         }
 638
 639         sysfs_remove_files(&priv->mtd.dev.kobj, mtd_partition_attrs);
 640
 641         err = del_mtd_device(&priv->mtd);
 642         if (err)
 643                 return err;
 644
 645         list_del(&priv->list);
 646         free_partition(priv);
 647
 648         return 0;
 649 }
 650
 651 /*
 652  * This function unregisters and destroy all slave MTD objects which are
 653  * attached to the given MTD object.
 654  */
 655 int del_mtd_partitions(struct mtd_info *mtd)
 656 {
 657         struct mtd_part *slave, *next;
 658         int ret, err = 0;
 659
 660         mutex_lock(&mtd_partitions_mutex);
 661         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 662                 if (slave->parent == mtd) {
 663                         ret = __mtd_del_partition(slave);
 664                         if (ret < 0)
 665                                 err = ret;
 666                 }
 667         mutex_unlock(&mtd_partitions_mutex);
 668
 669         return err;
 670 }
 671
 672 int mtd_del_partition(struct mtd_info *mtd, int partno)
 673 {
 674         struct mtd_part *slave, *next;
 675         int ret = -EINVAL;
 676
 677         mutex_lock(&mtd_partitions_mutex);
 678         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 679                 if ((slave->parent == mtd) &&
 680                     (slave->mtd.index == partno)) {
 681                         ret = __mtd_del_partition(slave);
 682                         break;
 683                 }
 684         mutex_unlock(&mtd_partitions_mutex);
 685
 686         return ret;
 687 }
 688 EXPORT_SYMBOL_GPL(mtd_del_partition);
 689
 690 /*
 691  * This function, given a master MTD object and a partition table, creates
 692  * and registers slave MTD objects which are bound to the master according to
 693  * the partition definitions.
 694  *
 695  * For historical reasons, this function's caller only registers the master
 696  * if the MTD_PARTITIONED_MASTER config option is set.
 697  */
 698
 699 int add_mtd_partitions(struct mtd_info *master,
 700                        const struct mtd_partition *parts,
 701                        int nbparts)
 702 {
 703         struct mtd_part *slave;
 704         uint64_t cur_offset = 0;
 705         int i;
 706
 707         printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 708
 709         for (i = 0; i < nbparts; i++) {
 710                 slave = allocate_partition(master, parts + i, i, cur_offset);
 711                 if (IS_ERR(slave)) {
 712                         del_mtd_partitions(master);
 713                         return PTR_ERR(slave);
 714                 }
 715
 716                 mutex_lock(&mtd_partitions_mutex);
 717                 list_add(&slave->list, &mtd_partitions);
 718                 mutex_unlock(&mtd_partitions_mutex);
 719
 720                 add_mtd_device(&slave->mtd);
 721                 mtd_add_partition_attrs(slave);
 722                 /* Look for subpartitions */
 723                 parse_mtd_partitions(&slave->mtd, parts[i].types, NULL);
 724
 725                 cur_offset = slave->offset + slave->mtd.size;
 726         }
 727
 728         return 0;
 729 }
 730
 731 static DEFINE_SPINLOCK(part_parser_lock);
 732 static LIST_HEAD(part_parsers);
 733
 734 static struct mtd_part_parser *mtd_part_parser_get(const char *name)
 735 {
 736         struct mtd_part_parser *p, *ret = NULL;
 737
 738         spin_lock(&part_parser_lock);
 739
 740         list_for_each_entry(p, &part_parsers, list)
 741                 if (!strcmp(p->name, name) && try_module_get(p->owner)) {
 742                         ret = p;
 743                         break;
 744                 }
 745
 746         spin_unlock(&part_parser_lock);
 747
 748         return ret;
 749 }
 750
 751 static inline void mtd_part_parser_put(const struct mtd_part_parser *p)
 752 {
 753         module_put(p->owner);
 754 }
 755
 756 /*
 757  * Many partition parsers just expected the core to kfree() all their data in
 758  * one chunk. Do that by default.
 759  */
 760 static void mtd_part_parser_cleanup_default(const struct mtd_partition *pparts,
 761                                             int nr_parts)
 762 {
 763         kfree(pparts);
 764 }
 765
 766 int __register_mtd_parser(struct mtd_part_parser *p, struct module *owner)
 767 {
 768         p->owner = owner;
 769
 770         if (!p->cleanup)
 771                 p->cleanup = &mtd_part_parser_cleanup_default;
 772
 773         spin_lock(&part_parser_lock);
 774         list_add(&p->list, &part_parsers);
 775         spin_unlock(&part_parser_lock);
 776
 777         return 0;
 778 }
 779 EXPORT_SYMBOL_GPL(__register_mtd_parser);
 780
 781 void deregister_mtd_parser(struct mtd_part_parser *p)
 782 {
 783         spin_lock(&part_parser_lock);
 784         list_del(&p->list);
 785         spin_unlock(&part_parser_lock);
 786 }
 787 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
 788
 789 /*
 790  * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
 791  * are changing this array!
 792  */
 793 static const char * const default_mtd_part_types[] = {
 794         "cmdlinepart",
 795         "ofpart",
 796         NULL
 797 };
 798
 799 /* Check DT only when looking for subpartitions. */
 800 static const char * const default_subpartition_types[] = {
 801         "ofpart",
 802         NULL
 803 };
 804
 805 static int mtd_part_do_parse(struct mtd_part_parser *parser,
 806                              struct mtd_info *master,
 807                              struct mtd_partitions *pparts,
 808                              struct mtd_part_parser_data *data)
 809 {
 810         int ret;
 811
 812         ret = (*parser->parse_fn)(master, &pparts->parts, data);
 813         pr_debug("%s: parser %s: %i\n", master->name, parser->name, ret);
 814         if (ret <= 0)
 815                 return ret;
 816
 817         pr_notice("%d %s partitions found on MTD device %s\n", ret,
 818                   parser->name, master->name);
 819
 820         pparts->nr_parts = ret;
 821         pparts->parser = parser;
 822
 823         return ret;
 824 }
 825
 826 /**
 827  * mtd_part_get_compatible_parser - find MTD parser by a compatible string
 828  *
 829  * @compat: compatible string describing partitions in a device tree
 830  *
 831  * MTD parsers can specify supported partitions by providing a table of
 832  * compatibility strings. This function finds a parser that advertises support
 833  * for a passed value of "compatible".
 834  */
 835 static struct mtd_part_parser *mtd_part_get_compatible_parser(const char *compat)
 836 {
 837         struct mtd_part_parser *p, *ret = NULL;
 838
 839         spin_lock(&part_parser_lock);
 840
 841         list_for_each_entry(p, &part_parsers, list) {
 842                 const struct of_device_id *matches;
 843
 844                 matches = p->of_match_table;
 845                 if (!matches)
 846                         continue;
 847
 848                 for (; matches->compatible[0]; matches++) {
 849                         if (!strcmp(matches->compatible, compat) &&
 850                             try_module_get(p->owner)) {
 851                                 ret = p;
 852                                 break;
 853                         }
 854                 }
 855
 856                 if (ret)
 857                         break;
 858         }
 859
 860         spin_unlock(&part_parser_lock);
 861
 862         return ret;
 863 }
 864
 865 static int mtd_part_of_parse(struct mtd_info *master,
 866                              struct mtd_partitions *pparts)
 867 {
 868         struct mtd_part_parser *parser;
 869         struct device_node *np;
 870         struct property *prop;
 871         const char *compat;
 872         const char *fixed = "fixed-partitions";
 873         int ret, err = 0;
 874
 875         np = mtd_get_of_node(master);
 876         if (!mtd_is_partition(master))
 877                 np = of_get_child_by_name(np, "partitions");
 878         of_property_for_each_string(np, "compatible", prop, compat) {
 879                 parser = mtd_part_get_compatible_parser(compat);
 880                 if (!parser)
 881                         continue;
 882                 ret = mtd_part_do_parse(parser, master, pparts, NULL);
 883                 if (ret > 0) {
 884                         of_node_put(np);
 885                         return ret;
 886                 }
 887                 mtd_part_parser_put(parser);
 888                 if (ret < 0 && !err)
 889                         err = ret;
 890         }
 891         of_node_put(np);
 892
 893         /*
 894          * For backward compatibility we have to try the "fixed-partitions"
 895          * parser. It supports old DT format with partitions specified as a
 896          * direct subnodes of a flash device DT node without any compatibility
 897          * specified we could match.
 898          */
 899         parser = mtd_part_parser_get(fixed);
 900         if (!parser && !request_module("%s", fixed))
 901                 parser = mtd_part_parser_get(fixed);
 902         if (parser) {
 903                 ret = mtd_part_do_parse(parser, master, pparts, NULL);
 904                 if (ret > 0)
 905                         return ret;
 906                 mtd_part_parser_put(parser);
 907                 if (ret < 0 && !err)
 908                         err = ret;
 909         }
 910
 911         return err;
 912 }
 913
 914 /**
 915  * parse_mtd_partitions - parse and register MTD partitions
 916  *
 917  * @master: the master partition (describes whole MTD device)
 918  * @types: names of partition parsers to try or %NULL
 919  * @data: MTD partition parser-specific data
 920  *
 921  * This function tries to find & register partitions on MTD device @master. It
 922  * uses MTD partition parsers, specified in @types. However, if @types is %NULL,
 923  * then the default list of parsers is used. The default list contains only the
 924  * "cmdlinepart" and "ofpart" parsers ATM.
 925  * Note: If there are more then one parser in @types, the kernel only takes the
 926  * partitions parsed out by the first parser.
 927  *
 928  * This function may return:
 929  * o a negative error code in case of failure
 930  * o number of found partitions otherwise
 931  */
 932 int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
 933                          struct mtd_part_parser_data *data)
 934 {
 935         struct mtd_partitions pparts = { };
 936         struct mtd_part_parser *parser;
 937         int ret, err = 0;
 938
 939         if (!types)
 940                 types = mtd_is_partition(master) ? default_subpartition_types :
 941                         default_mtd_part_types;
 942
 943         for ( ; *types; types++) {
 944                 /*
 945                  * ofpart is a special type that means OF partitioning info
 946                  * should be used. It requires a bit different logic so it is
 947                  * handled in a separated function.
 948                  */
 949                 if (!strcmp(*types, "ofpart")) {
 950                         ret = mtd_part_of_parse(master, &pparts);
 951                 } else {
 952                         pr_debug("%s: parsing partitions %s\n", master->name,
 953                                  *types);
 954                         parser = mtd_part_parser_get(*types);
 955                         if (!parser && !request_module("%s", *types))
 956                                 parser = mtd_part_parser_get(*types);
 957                         pr_debug("%s: got parser %s\n", master->name,
 958                                 parser ? parser->name : NULL);
 959                         if (!parser)
 960                                 continue;
 961                         ret = mtd_part_do_parse(parser, master, &pparts, data);
 962                         if (ret <= 0)
 963                                 mtd_part_parser_put(parser);
 964                 }
 965                 /* Found partitions! */
 966                 if (ret > 0) {
 967                         err = add_mtd_partitions(master, pparts.parts,
 968                                                  pparts.nr_parts);
 969                         mtd_part_parser_cleanup(&pparts);
 970                         return err ? err : pparts.nr_parts;
 971                 }
 972                 /*
 973                  * Stash the first error we see; only report it if no parser
 974                  * succeeds
 975                  */
 976                 if (ret < 0 && !err)
 977                         err = ret;
 978         }
 979         return err;
 980 }
 981
 982 void mtd_part_parser_cleanup(struct mtd_partitions *parts)
 983 {
 984         const struct mtd_part_parser *parser;
 985
 986         if (!parts)
 987                 return;
 988
 989         parser = parts->parser;
 990         if (parser) {
 991                 if (parser->cleanup)
 992                         parser->cleanup(parts->parts, parts->nr_parts);
 993
 994                 mtd_part_parser_put(parser);
 995         }
 996 }
 997
 998 int mtd_is_partition(const struct mtd_info *mtd)
 999 {
1000         struct mtd_part *part;
1001         int ispart = 0;
1002
1003         mutex_lock(&mtd_partitions_mutex);
1004         list_for_each_entry(part, &mtd_partitions, list)
1005                 if (&part->mtd == mtd) {
1006                         ispart = 1;
1007                         break;
1008                 }
1009         mutex_unlock(&mtd_partitions_mutex);
1010
1011         return ispart;
1012 }
1013 EXPORT_SYMBOL_GPL(mtd_is_partition);
1014
1015 /* Returns the size of the entire flash chip */
1016 uint64_t mtd_get_device_size(const struct mtd_info *mtd)
1017 {
1018         if (!mtd_is_partition(mtd))
1019                 return mtd->size;
1020
1021         return mtd_get_device_size(mtd_to_part(mtd)->parent);
1022 }
1023 EXPORT_SYMBOL_GPL(mtd_get_device_size);