drivers/mtd/mtdpart.c

   1 /*
   2  * Simple MTD partitioning layer
   3  *
   4  * (C) 2000 Nicolas Pitre <nico@fluxnic.net>
   5  *
   6  * This code is GPL
   7  *
   8  *      02-21-2002      Thomas Gleixner <gleixner@autronix.de>
   9  *                      added support for read_oob, write_oob
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/types.h>
  14 #include <linux/kernel.h>
  15 #include <linux/slab.h>
  16 #include <linux/list.h>
  17 #include <linux/kmod.h>
  18 #include <linux/mtd/mtd.h>
  19 #include <linux/mtd/partitions.h>
  20 #include <linux/mtd/compatmac.h>
  21
  22 /* Our partition linked list */
  23 static LIST_HEAD(mtd_partitions);
  24
  25 /* Our partition node structure */
  26 struct mtd_part {
  27         struct mtd_info mtd;
  28         struct mtd_info *master;
  29         struct memory_accessor macc;
  30         uint64_t offset;
  31         struct list_head list;
  32 };
  33
  34 /*
  35  * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
  36  * the pointer to that structure with this macro.
  37  */
  38 #define PART(x)  ((struct mtd_part *)(x))
  39
  40
  41 /*
  42  * MTD methods which simply translate the effective address and pass through
  43  * to the _real_ device.
  44  */
  45
  46 static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
  47                 size_t *retlen, u_char *buf)
  48 {
  49         struct mtd_part *part = PART(mtd);
  50         struct mtd_ecc_stats stats;
  51         int res;
  52
  53         stats = part->master->ecc_stats;
  54
  55         if (from >= mtd->size)
  56                 len = 0;
  57         else if (from + len > mtd->size)
  58                 len = mtd->size - from;
  59         res = part->master->read(part->master, from + part->offset,
  60                                    len, retlen, buf);
  61         if (unlikely(res)) {
  62                 if (res == -EUCLEAN)
  63                         mtd->ecc_stats.corrected += part->master->ecc_stats.corrected - stats.corrected;
  64                 if (res == -EBADMSG)
  65                         mtd->ecc_stats.failed += part->master->ecc_stats.failed - stats.failed;
  66         }
  67         return res;
  68 }
  69
  70 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
  71                 size_t *retlen, void **virt, resource_size_t *phys)
  72 {
  73         struct mtd_part *part = PART(mtd);
  74         if (from >= mtd->size)
  75                 len = 0;
  76         else if (from + len > mtd->size)
  77                 len = mtd->size - from;
  78         return part->master->point (part->master, from + part->offset,
  79                                     len, retlen, virt, phys);
  80 }
  81
  82 static void part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
  83 {
  84         struct mtd_part *part = PART(mtd);
  85
  86         part->master->unpoint(part->master, from + part->offset, len);
  87 }
  88
  89 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
  90                                             unsigned long len,
  91                                             unsigned long offset,
  92                                             unsigned long flags)
  93 {
  94         struct mtd_part *part = PART(mtd);
  95
  96         offset += part->offset;
  97         return part->master->get_unmapped_area(part->master, len, offset,
  98                                                flags);
  99 }
 100
 101 static int part_read_oob(struct mtd_info *mtd, loff_t from,
 102                 struct mtd_oob_ops *ops)
 103 {
 104         struct mtd_part *part = PART(mtd);
 105         int res;
 106
 107         if (from >= mtd->size)
 108                 return -EINVAL;
 109         if (ops->datbuf && from + ops->len > mtd->size)
 110                 return -EINVAL;
 111         res = part->master->read_oob(part->master, from + part->offset, ops);
 112
 113         if (unlikely(res)) {
 114                 if (res == -EUCLEAN)
 115                         mtd->ecc_stats.corrected++;
 116                 if (res == -EBADMSG)
 117                         mtd->ecc_stats.failed++;
 118         }
 119         return res;
 120 }
 121
 122 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
 123                 size_t len, size_t *retlen, u_char *buf)
 124 {
 125         struct mtd_part *part = PART(mtd);
 126         return part->master->read_user_prot_reg(part->master, from,
 127                                         len, retlen, buf);
 128 }
 129
 130 static int part_get_user_prot_info(struct mtd_info *mtd,
 131                 struct otp_info *buf, size_t len)
 132 {
 133         struct mtd_part *part = PART(mtd);
 134         return part->master->get_user_prot_info(part->master, buf, len);
 135 }
 136
 137 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
 138                 size_t len, size_t *retlen, u_char *buf)
 139 {
 140         struct mtd_part *part = PART(mtd);
 141         return part->master->read_fact_prot_reg(part->master, from,
 142                                         len, retlen, buf);
 143 }
 144
 145 static int part_get_fact_prot_info(struct mtd_info *mtd, struct otp_info *buf,
 146                 size_t len)
 147 {
 148         struct mtd_part *part = PART(mtd);
 149         return part->master->get_fact_prot_info(part->master, buf, len);
 150 }
 151
 152 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
 153                 size_t *retlen, const u_char *buf)
 154 {
 155         struct mtd_part *part = PART(mtd);
 156         if (!(mtd->flags & MTD_WRITEABLE))
 157                 return -EROFS;
 158         if (to >= mtd->size)
 159                 len = 0;
 160         else if (to + len > mtd->size)
 161                 len = mtd->size - to;
 162         return part->master->write(part->master, to + part->offset,
 163                                     len, retlen, buf);
 164 }
 165
 166 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
 167                 size_t *retlen, const u_char *buf)
 168 {
 169         struct mtd_part *part = PART(mtd);
 170         if (!(mtd->flags & MTD_WRITEABLE))
 171                 return -EROFS;
 172         if (to >= mtd->size)
 173                 len = 0;
 174         else if (to + len > mtd->size)
 175                 len = mtd->size - to;
 176         return part->master->panic_write(part->master, to + part->offset,
 177                                     len, retlen, buf);
 178 }
 179
 180 static int part_write_oob(struct mtd_info *mtd, loff_t to,
 181                 struct mtd_oob_ops *ops)
 182 {
 183         struct mtd_part *part = PART(mtd);
 184
 185         if (!(mtd->flags & MTD_WRITEABLE))
 186                 return -EROFS;
 187
 188         if (to >= mtd->size)
 189                 return -EINVAL;
 190         if (ops->datbuf && to + ops->len > mtd->size)
 191                 return -EINVAL;
 192         return part->master->write_oob(part->master, to + part->offset, ops);
 193 }
 194
 195 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
 196                 size_t len, size_t *retlen, u_char *buf)
 197 {
 198         struct mtd_part *part = PART(mtd);
 199         return part->master->write_user_prot_reg(part->master, from,
 200                                         len, retlen, buf);
 201 }
 202
 203 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
 204                 size_t len)
 205 {
 206         struct mtd_part *part = PART(mtd);
 207         return part->master->lock_user_prot_reg(part->master, from, len);
 208 }
 209
 210 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
 211                 unsigned long count, loff_t to, size_t *retlen)
 212 {
 213         struct mtd_part *part = PART(mtd);
 214         if (!(mtd->flags & MTD_WRITEABLE))
 215                 return -EROFS;
 216         return part->master->writev(part->master, vecs, count,
 217                                         to + part->offset, retlen);
 218 }
 219
 220 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
 221 {
 222         struct mtd_part *part = PART(mtd);
 223         int ret;
 224         if (!(mtd->flags & MTD_WRITEABLE))
 225                 return -EROFS;
 226         if (instr->addr >= mtd->size)
 227                 return -EINVAL;
 228         instr->addr += part->offset;
 229         ret = part->master->erase(part->master, instr);
 230         if (ret) {
 231                 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 232                         instr->fail_addr -= part->offset;
 233                 instr->addr -= part->offset;
 234         }
 235         return ret;
 236 }
 237
 238 void mtd_erase_callback(struct erase_info *instr)
 239 {
 240         if (instr->mtd->erase == part_erase) {
 241                 struct mtd_part *part = PART(instr->mtd);
 242
 243                 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 244                         instr->fail_addr -= part->offset;
 245                 instr->addr -= part->offset;
 246         }
 247         if (instr->callback)
 248                 instr->callback(instr);
 249 }
 250 EXPORT_SYMBOL_GPL(mtd_erase_callback);
 251
 252 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 253 {
 254         struct mtd_part *part = PART(mtd);
 255         if ((len + ofs) > mtd->size)
 256                 return -EINVAL;
 257         return part->master->lock(part->master, ofs + part->offset, len);
 258 }
 259
 260 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 261 {
 262         struct mtd_part *part = PART(mtd);
 263         if ((len + ofs) > mtd->size)
 264                 return -EINVAL;
 265         return part->master->unlock(part->master, ofs + part->offset, len);
 266 }
 267
 268 static void part_sync(struct mtd_info *mtd)
 269 {
 270         struct mtd_part *part = PART(mtd);
 271         part->master->sync(part->master);
 272 }
 273
 274 static int part_suspend(struct mtd_info *mtd)
 275 {
 276         struct mtd_part *part = PART(mtd);
 277         return part->master->suspend(part->master);
 278 }
 279
 280 static void part_resume(struct mtd_info *mtd)
 281 {
 282         struct mtd_part *part = PART(mtd);
 283         part->master->resume(part->master);
 284 }
 285
 286 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
 287 {
 288         struct mtd_part *part = PART(mtd);
 289         if (ofs >= mtd->size)
 290                 return -EINVAL;
 291         ofs += part->offset;
 292         return part->master->block_isbad(part->master, ofs);
 293 }
 294
 295 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 296 {
 297         struct mtd_part *part = PART(mtd);
 298         int res;
 299
 300         if (!(mtd->flags & MTD_WRITEABLE))
 301                 return -EROFS;
 302         if (ofs >= mtd->size)
 303                 return -EINVAL;
 304         ofs += part->offset;
 305         res = part->master->block_markbad(part->master, ofs);
 306         if (!res)
 307                 mtd->ecc_stats.badblocks++;
 308         return res;
 309 }
 310
 311 /*
 312  * This function unregisters and destroy all slave MTD objects which are
 313  * attached to the given master MTD object.
 314  */
 315
 316 int del_mtd_partitions(struct mtd_info *master)
 317 {
 318         struct mtd_part *slave, *next;
 319
 320         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 321                 if (slave->master == master) {
 322                         list_del(&slave->list);
 323                         del_mtd_device(&slave->mtd);
 324                         kfree(slave);
 325                 }
 326
 327         return 0;
 328 }
 329 EXPORT_SYMBOL(del_mtd_partitions);
 330
 331 /*
 332  * This lets other kernel code access the flash data. For example, it
 333  * might hold a board's Ethernet address, or board-specific calibration
 334  * data generated on the manufacturing floor.
 335  */
 336 static ssize_t mtd_macc_read(struct memory_accessor *macc, char *buf,
 337                         off_t offset, size_t count)
 338 {
 339         struct mtd_part *part = container_of(macc, struct mtd_part, macc);
 340         ssize_t ret = -EIO;
 341         size_t retlen;
 342
 343         if (part_read((struct mtd_info *)part, offset, count,
 344                         &retlen, buf) == 0)
 345                 ret = retlen;
 346
 347         return ret;
 348 }
 349
 350 static ssize_t mtd_macc_write(struct memory_accessor *macc, const char *buf,
 351                         off_t offset, size_t count)
 352 {
 353         struct mtd_part *part = container_of(macc, struct mtd_part, macc);
 354         ssize_t ret = -EIO;
 355         size_t retlen;
 356
 357         if (part_write((struct mtd_info *)part, offset, count,
 358                         &retlen, buf) == 0)
 359                 ret = retlen;
 360
 361         return ret;
 362 }
 363
 364 static struct mtd_part *add_one_partition(struct mtd_info *master,
 365                 const struct mtd_partition *part, int partno,
 366                 uint64_t cur_offset)
 367 {
 368         struct mtd_part *slave;
 369
 370         /* allocate the partition structure */
 371         slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 372         if (!slave) {
 373                 printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
 374                         master->name);
 375                 del_mtd_partitions(master);
 376                 return NULL;
 377         }
 378         list_add(&slave->list, &mtd_partitions);
 379
 380         /* set up the MTD object for this partition */
 381         slave->mtd.type = master->type;
 382         slave->mtd.flags = master->flags & ~part->mask_flags;
 383         slave->mtd.size = part->size;
 384         slave->mtd.writesize = master->writesize;
 385         slave->mtd.oobsize = master->oobsize;
 386         slave->mtd.oobavail = master->oobavail;
 387         slave->mtd.subpage_sft = master->subpage_sft;
 388
 389         slave->mtd.name = part->name;
 390         slave->mtd.owner = master->owner;
 391         slave->mtd.backing_dev_info = master->backing_dev_info;
 392
 393         /* NOTE:  we don't arrange MTDs as a tree; it'd be error-prone
 394          * to have the same data be in two different partitions.
 395          */
 396         slave->mtd.dev.parent = master->dev.parent;
 397
 398         slave->mtd.read = part_read;
 399         slave->mtd.write = part_write;
 400
 401         slave->macc.read = mtd_macc_read;
 402         slave->macc.write = mtd_macc_write;
 403
 404         if (master->panic_write)
 405                 slave->mtd.panic_write = part_panic_write;
 406
 407         if (master->point && master->unpoint) {
 408                 slave->mtd.point = part_point;
 409                 slave->mtd.unpoint = part_unpoint;
 410         }
 411
 412         if (master->get_unmapped_area)
 413                 slave->mtd.get_unmapped_area = part_get_unmapped_area;
 414         if (master->read_oob)
 415                 slave->mtd.read_oob = part_read_oob;
 416         if (master->write_oob)
 417                 slave->mtd.write_oob = part_write_oob;
 418         if (master->read_user_prot_reg)
 419                 slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
 420         if (master->read_fact_prot_reg)
 421                 slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
 422         if (master->write_user_prot_reg)
 423                 slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
 424         if (master->lock_user_prot_reg)
 425                 slave->mtd.lock_user_prot_reg = part_lock_user_prot_reg;
 426         if (master->get_user_prot_info)
 427                 slave->mtd.get_user_prot_info = part_get_user_prot_info;
 428         if (master->get_fact_prot_info)
 429                 slave->mtd.get_fact_prot_info = part_get_fact_prot_info;
 430         if (master->sync)
 431                 slave->mtd.sync = part_sync;
 432         if (!partno && !master->dev.class && master->suspend && master->resume) {
 433                         slave->mtd.suspend = part_suspend;
 434                         slave->mtd.resume = part_resume;
 435         }
 436         if (master->writev)
 437                 slave->mtd.writev = part_writev;
 438         if (master->lock)
 439                 slave->mtd.lock = part_lock;
 440         if (master->unlock)
 441                 slave->mtd.unlock = part_unlock;
 442         if (master->block_isbad)
 443                 slave->mtd.block_isbad = part_block_isbad;
 444         if (master->block_markbad)
 445                 slave->mtd.block_markbad = part_block_markbad;
 446         slave->mtd.erase = part_erase;
 447         slave->master = master;
 448         slave->offset = part->offset;
 449
 450         if (slave->offset == MTDPART_OFS_APPEND)
 451                 slave->offset = cur_offset;
 452         if (slave->offset == MTDPART_OFS_NXTBLK) {
 453                 slave->offset = cur_offset;
 454                 if (mtd_mod_by_eb(cur_offset, master) != 0) {
 455                         /* Round up to next erasesize */
 456                         slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
 457                         printk(KERN_NOTICE "Moving partition %d: "
 458                                "0x%012llx -> 0x%012llx\n", partno,
 459                                (unsigned long long)cur_offset, (unsigned long long)slave->offset);
 460                 }
 461         }
 462         if (slave->mtd.size == MTDPART_SIZ_FULL)
 463                 slave->mtd.size = master->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         if (part->setup)
 469                 part->setup(&slave->macc, (void *)part->context);
 470
 471         /* let's do some sanity checks */
 472         if (slave->offset >= master->size) {
 473                 /* let's register it anyway to preserve ordering */
 474                 slave->offset = 0;
 475                 slave->mtd.size = 0;
 476                 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
 477                         part->name);
 478                 goto out_register;
 479         }
 480         if (slave->offset + slave->mtd.size > master->size) {
 481                 slave->mtd.size = master->size - slave->offset;
 482                 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
 483                         part->name, master->name, (unsigned long long)slave->mtd.size);
 484         }
 485         if (master->numeraseregions > 1) {
 486                 /* Deal with variable erase size stuff */
 487                 int i, max = master->numeraseregions;
 488                 u64 end = slave->offset + slave->mtd.size;
 489                 struct mtd_erase_region_info *regions = master->eraseregions;
 490
 491                 /* Find the first erase regions which is part of this
 492                  * partition. */
 493                 for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
 494                         ;
 495                 /* The loop searched for the region _behind_ the first one */
 496                 if (i > 0)
 497                         i--;
 498
 499                 /* Pick biggest erasesize */
 500                 for (; i < max && regions[i].offset < end; i++) {
 501                         if (slave->mtd.erasesize < regions[i].erasesize) {
 502                                 slave->mtd.erasesize = regions[i].erasesize;
 503                         }
 504                 }
 505                 BUG_ON(slave->mtd.erasesize == 0);
 506         } else {
 507                 /* Single erase size */
 508                 slave->mtd.erasesize = master->erasesize;
 509         }
 510
 511         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 512             mtd_mod_by_eb(slave->offset, &slave->mtd)) {
 513                 /* Doesn't start on a boundary of major erase size */
 514                 /* FIXME: Let it be writable if it is on a boundary of
 515                  * _minor_ erase size though */
 516                 slave->mtd.flags &= ~MTD_WRITEABLE;
 517                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
 518                         part->name);
 519         }
 520         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 521             mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
 522                 slave->mtd.flags &= ~MTD_WRITEABLE;
 523                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
 524                         part->name);
 525         }
 526
 527         slave->mtd.ecclayout = master->ecclayout;
 528         if (master->block_isbad) {
 529                 uint64_t offs = 0;
 530
 531                 while (offs < slave->mtd.size) {
 532                         if (master->block_isbad(master,
 533                                                 offs + slave->offset))
 534                                 slave->mtd.ecc_stats.badblocks++;
 535                         offs += slave->mtd.erasesize;
 536                 }
 537         }
 538
 539 out_register:
 540         /* register our partition */
 541         add_mtd_device(&slave->mtd);
 542
 543         return slave;
 544 }
 545
 546 /*
 547  * This function, given a master MTD object and a partition table, creates
 548  * and registers slave MTD objects which are bound to the master according to
 549  * the partition definitions.
 550  *
 551  * We don't register the master, or expect the caller to have done so,
 552  * for reasons of data integrity.
 553  */
 554
 555 int add_mtd_partitions(struct mtd_info *master,
 556                        const struct mtd_partition *parts,
 557                        int nbparts)
 558 {
 559         struct mtd_part *slave;
 560         uint64_t cur_offset = 0;
 561         int i;
 562
 563         printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 564
 565         for (i = 0; i < nbparts; i++) {
 566                 slave = add_one_partition(master, parts + i, i, cur_offset);
 567                 if (!slave)
 568                         return -ENOMEM;
 569                 cur_offset = slave->offset + slave->mtd.size;
 570         }
 571
 572         return 0;
 573 }
 574 EXPORT_SYMBOL(add_mtd_partitions);
 575
 576 static DEFINE_SPINLOCK(part_parser_lock);
 577 static LIST_HEAD(part_parsers);
 578
 579 static struct mtd_part_parser *get_partition_parser(const char *name)
 580 {
 581         struct mtd_part_parser *p, *ret = NULL;
 582
 583         spin_lock(&part_parser_lock);
 584
 585         list_for_each_entry(p, &part_parsers, list)
 586                 if (!strcmp(p->name, name) && try_module_get(p->owner)) {
 587                         ret = p;
 588                         break;
 589                 }
 590
 591         spin_unlock(&part_parser_lock);
 592
 593         return ret;
 594 }
 595
 596 int register_mtd_parser(struct mtd_part_parser *p)
 597 {
 598         spin_lock(&part_parser_lock);
 599         list_add(&p->list, &part_parsers);
 600         spin_unlock(&part_parser_lock);
 601
 602         return 0;
 603 }
 604 EXPORT_SYMBOL_GPL(register_mtd_parser);
 605
 606 int deregister_mtd_parser(struct mtd_part_parser *p)
 607 {
 608         spin_lock(&part_parser_lock);
 609         list_del(&p->list);
 610         spin_unlock(&part_parser_lock);
 611         return 0;
 612 }
 613 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
 614
 615 int parse_mtd_partitions(struct mtd_info *master, const char **types,
 616                          struct mtd_partition **pparts, unsigned long origin)
 617 {
 618         struct mtd_part_parser *parser;
 619         int ret = 0;
 620
 621         for ( ; ret <= 0 && *types; types++) {
 622                 parser = get_partition_parser(*types);
 623                 if (!parser && !request_module("%s", *types))
 624                                 parser = get_partition_parser(*types);
 625                 if (!parser) {
 626                         printk(KERN_NOTICE "%s partition parsing not available\n",
 627                                *types);
 628                         continue;
 629                 }
 630                 ret = (*parser->parse_fn)(master, pparts, origin);
 631                 if (ret > 0) {
 632                         printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
 633                                ret, parser->name, master->name);
 634                 }
 635                 put_partition_parser(parser);
 636         }
 637         return ret;
 638 }
 639 EXPORT_SYMBOL_GPL(parse_mtd_partitions);