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
  34 #include "mtdcore.h"
  35
  36 #define DYNAMIC_CHANGE_MTD_WRITEABLE
  37 #ifdef DYNAMIC_CHANGE_MTD_WRITEABLE //wschen 2011-01-05
  38 #include <linux/proc_fs.h>
  39 #include <asm/uaccess.h>
  40 static struct mtd_info *my_mtd = NULL;
  41 int mtd_writeable_proc_write(struct file *file, const char *buffer, unsigned long count, void *data);
  42
  43 struct mtd_change {
  44     uint64_t size;
  45     uint64_t offset;
  46 };
  47 int mtd_change_proc_write(struct file *file, const char *buffer, unsigned long count, void *data);
  48 #endif
  49
  50
  51 /* Our partition linked list */
  52 static LIST_HEAD(mtd_partitions);
  53 static DEFINE_MUTEX(mtd_partitions_mutex);
  54
  55 /* Our partition node structure */
  56 struct mtd_part {
  57         struct mtd_info mtd;
  58         struct mtd_info *master;
  59         uint64_t offset;
  60         struct list_head list;
  61 };
  62
  63 /*
  64  * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
  65  * the pointer to that structure with this macro.
  66  */
  67 #define PART(x)  ((struct mtd_part *)(x))
  68
  69
  70 /*
  71  * MTD methods which simply translate the effective address and pass through
  72  * to the _real_ device.
  73  */
  74
  75 static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
  76                 size_t *retlen, u_char *buf)
  77 {
  78         struct mtd_part *part = PART(mtd);
  79         struct mtd_ecc_stats stats;
  80         int res;
  81
  82         stats = part->master->ecc_stats;
  83         res = part->master->_read(part->master, from + part->offset, len,
  84                                   retlen, buf);
  85         if (unlikely(mtd_is_eccerr(res)))
  86                 mtd->ecc_stats.failed +=
  87                         part->master->ecc_stats.failed - stats.failed;
  88         else
  89                 mtd->ecc_stats.corrected +=
  90                         part->master->ecc_stats.corrected - stats.corrected;
  91         return res;
  92 }
  93
  94 static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
  95                 size_t *retlen, void **virt, resource_size_t *phys)
  96 {
  97         struct mtd_part *part = PART(mtd);
  98
  99         return part->master->_point(part->master, from + part->offset, len,
 100                                     retlen, virt, phys);
 101 }
 102
 103 static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
 104 {
 105         struct mtd_part *part = PART(mtd);
 106
 107         return part->master->_unpoint(part->master, from + part->offset, len);
 108 }
 109
 110 static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
 111                                             unsigned long len,
 112                                             unsigned long offset,
 113                                             unsigned long flags)
 114 {
 115         struct mtd_part *part = PART(mtd);
 116
 117         offset += part->offset;
 118         return part->master->_get_unmapped_area(part->master, len, offset,
 119                                                 flags);
 120 }
 121
 122 static int part_read_oob(struct mtd_info *mtd, loff_t from,
 123                 struct mtd_oob_ops *ops)
 124 {
 125         struct mtd_part *part = PART(mtd);
 126         int res;
 127
 128         if (from >= mtd->size)
 129                 return -EINVAL;
 130         if (ops->datbuf && from + ops->len > mtd->size)
 131                 return -EINVAL;
 132
 133         /*
 134          * If OOB is also requested, make sure that we do not read past the end
 135          * of this partition.
 136          */
 137         if (ops->oobbuf) {
 138                 size_t len, pages;
 139
 140                 if (ops->mode == MTD_OPS_AUTO_OOB)
 141                         len = mtd->oobavail;
 142                 else
 143                         len = mtd->oobsize;
 144                 pages = mtd_div_by_ws(mtd->size, mtd);
 145                 pages -= mtd_div_by_ws(from, mtd);
 146                 if (ops->ooboffs + ops->ooblen > pages * len)
 147                         return -EINVAL;
 148         }
 149
 150         res = part->master->_read_oob(part->master, from + part->offset, ops);
 151         if (unlikely(res)) {
 152                 if (mtd_is_bitflip(res))
 153                         mtd->ecc_stats.corrected++;
 154                 if (mtd_is_eccerr(res))
 155                         mtd->ecc_stats.failed++;
 156         }
 157         return res;
 158 }
 159
 160 static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
 161                 size_t len, size_t *retlen, u_char *buf)
 162 {
 163         struct mtd_part *part = PART(mtd);
 164         return part->master->_read_user_prot_reg(part->master, from, len,
 165                                                  retlen, buf);
 166 }
 167
 168 static int part_get_user_prot_info(struct mtd_info *mtd,
 169                 struct otp_info *buf, size_t len)
 170 {
 171         struct mtd_part *part = PART(mtd);
 172         return part->master->_get_user_prot_info(part->master, buf, len);
 173 }
 174
 175 static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
 176                 size_t len, size_t *retlen, u_char *buf)
 177 {
 178         struct mtd_part *part = PART(mtd);
 179         return part->master->_read_fact_prot_reg(part->master, from, len,
 180                                                  retlen, buf);
 181 }
 182
 183 static int part_get_fact_prot_info(struct mtd_info *mtd, struct otp_info *buf,
 184                 size_t len)
 185 {
 186         struct mtd_part *part = PART(mtd);
 187         return part->master->_get_fact_prot_info(part->master, buf, len);
 188 }
 189
 190 static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
 191                 size_t *retlen, const u_char *buf)
 192 {
 193         struct mtd_part *part = PART(mtd);
 194         return part->master->_write(part->master, to + part->offset, len,
 195                                     retlen, buf);
 196 }
 197
 198 static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
 199                 size_t *retlen, const u_char *buf)
 200 {
 201         struct mtd_part *part = PART(mtd);
 202         return part->master->_panic_write(part->master, to + part->offset, len,
 203                                           retlen, buf);
 204 }
 205
 206 static int part_write_oob(struct mtd_info *mtd, loff_t to,
 207                 struct mtd_oob_ops *ops)
 208 {
 209         struct mtd_part *part = PART(mtd);
 210
 211         if (to >= mtd->size)
 212                 return -EINVAL;
 213         if (ops->datbuf && to + ops->len > mtd->size)
 214                 return -EINVAL;
 215         return part->master->_write_oob(part->master, to + part->offset, ops);
 216 }
 217
 218 static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
 219                 size_t len, size_t *retlen, u_char *buf)
 220 {
 221         struct mtd_part *part = PART(mtd);
 222         return part->master->_write_user_prot_reg(part->master, from, len,
 223                                                   retlen, buf);
 224 }
 225
 226 static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
 227                 size_t len)
 228 {
 229         struct mtd_part *part = PART(mtd);
 230         return part->master->_lock_user_prot_reg(part->master, from, len);
 231 }
 232
 233 static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
 234                 unsigned long count, loff_t to, size_t *retlen)
 235 {
 236         struct mtd_part *part = PART(mtd);
 237         return part->master->_writev(part->master, vecs, count,
 238                                      to + part->offset, retlen);
 239 }
 240
 241 static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
 242 {
 243         struct mtd_part *part = PART(mtd);
 244         int ret;
 245
 246         instr->addr += part->offset;
 247         ret = part->master->_erase(part->master, instr);
 248         if (ret) {
 249                 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 250                         instr->fail_addr -= part->offset;
 251                 instr->addr -= part->offset;
 252         }
 253         return ret;
 254 }
 255
 256 void mtd_erase_callback(struct erase_info *instr)
 257 {
 258         if (instr->mtd->_erase == part_erase) {
 259                 struct mtd_part *part = PART(instr->mtd);
 260
 261                 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
 262                         instr->fail_addr -= part->offset;
 263                 instr->addr -= part->offset;
 264         }
 265         if (instr->callback)
 266                 instr->callback(instr);
 267 }
 268 EXPORT_SYMBOL_GPL(mtd_erase_callback);
 269
 270 static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 271 {
 272         struct mtd_part *part = PART(mtd);
 273         return part->master->_lock(part->master, ofs + part->offset, len);
 274 }
 275
 276 static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 277 {
 278         struct mtd_part *part = PART(mtd);
 279         return part->master->_unlock(part->master, ofs + part->offset, len);
 280 }
 281
 282 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
 283 {
 284         struct mtd_part *part = PART(mtd);
 285         return part->master->_is_locked(part->master, ofs + part->offset, len);
 286 }
 287
 288 static void part_sync(struct mtd_info *mtd)
 289 {
 290         struct mtd_part *part = PART(mtd);
 291         part->master->_sync(part->master);
 292 }
 293
 294 static int part_suspend(struct mtd_info *mtd)
 295 {
 296         struct mtd_part *part = PART(mtd);
 297         return part->master->_suspend(part->master);
 298 }
 299
 300 static void part_resume(struct mtd_info *mtd)
 301 {
 302         struct mtd_part *part = PART(mtd);
 303         part->master->_resume(part->master);
 304 }
 305
 306 static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
 307 {
 308         struct mtd_part *part = PART(mtd);
 309         ofs += part->offset;
 310         return part->master->_block_isbad(part->master, ofs);
 311 }
 312
 313 static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 314 {
 315         struct mtd_part *part = PART(mtd);
 316         int res;
 317
 318         ofs += part->offset;
 319         res = part->master->_block_markbad(part->master, ofs);
 320         if (!res)
 321                 mtd->ecc_stats.badblocks++;
 322         return res;
 323 }
 324
 325 static inline void free_partition(struct mtd_part *p)
 326 {
 327         kfree(p->mtd.name);
 328         kfree(p);
 329 }
 330
 331 /*
 332  * This function unregisters and destroy all slave MTD objects which are
 333  * attached to the given master MTD object.
 334  */
 335
 336 int del_mtd_partitions(struct mtd_info *master)
 337 {
 338         struct mtd_part *slave, *next;
 339         int ret, err = 0;
 340
 341         mutex_lock(&mtd_partitions_mutex);
 342         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 343                 if (slave->master == master) {
 344 #ifdef DYNAMIC_CHANGE_MTD_WRITEABLE //wschen 2011-01-05
 345                         my_mtd = NULL;
 346 #endif
 347
 348                         ret = del_mtd_device(&slave->mtd);
 349                         if (ret < 0) {
 350                                 err = ret;
 351                                 continue;
 352                         }
 353                         list_del(&slave->list);
 354                         free_partition(slave);
 355                 }
 356         mutex_unlock(&mtd_partitions_mutex);
 357
 358         return err;
 359 }
 360
 361 static struct mtd_part *allocate_partition(struct mtd_info *master,
 362                         const struct mtd_partition *part, int partno,
 363                         uint64_t cur_offset)
 364 {
 365         struct mtd_part *slave;
 366         char *name;
 367
 368         /* allocate the partition structure */
 369         slave = kzalloc(sizeof(*slave), GFP_KERNEL);
 370         name = kstrdup(part->name, GFP_KERNEL);
 371         if (!name || !slave) {
 372                 printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
 373                        master->name);
 374                 kfree(name);
 375                 kfree(slave);
 376                 return ERR_PTR(-ENOMEM);
 377         }
 378
 379         /* set up the MTD object for this partition */
 380         slave->mtd.type = master->type;
 381         slave->mtd.flags = master->flags & ~part->mask_flags;
 382         slave->mtd.size = part->size;
 383         slave->mtd.writesize = master->writesize;
 384         slave->mtd.writebufsize = master->writebufsize;
 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 = 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         if (master->_panic_write)
 402                 slave->mtd._panic_write = part_panic_write;
 403
 404         if (master->_point && master->_unpoint) {
 405                 slave->mtd._point = part_point;
 406                 slave->mtd._unpoint = part_unpoint;
 407         }
 408
 409         if (master->_get_unmapped_area)
 410                 slave->mtd._get_unmapped_area = part_get_unmapped_area;
 411         if (master->_read_oob)
 412                 slave->mtd._read_oob = part_read_oob;
 413         if (master->_write_oob)
 414                 slave->mtd._write_oob = part_write_oob;
 415         if (master->_read_user_prot_reg)
 416                 slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
 417         if (master->_read_fact_prot_reg)
 418                 slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
 419         if (master->_write_user_prot_reg)
 420                 slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
 421         if (master->_lock_user_prot_reg)
 422                 slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
 423         if (master->_get_user_prot_info)
 424                 slave->mtd._get_user_prot_info = part_get_user_prot_info;
 425         if (master->_get_fact_prot_info)
 426                 slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
 427         if (master->_sync)
 428                 slave->mtd._sync = part_sync;
 429         if (!partno && !master->dev.class && master->_suspend &&
 430             master->_resume) {
 431                         slave->mtd._suspend = part_suspend;
 432                         slave->mtd._resume = part_resume;
 433         }
 434         if (master->_writev)
 435                 slave->mtd._writev = part_writev;
 436         if (master->_lock)
 437                 slave->mtd._lock = part_lock;
 438         if (master->_unlock)
 439                 slave->mtd._unlock = part_unlock;
 440         if (master->_is_locked)
 441                 slave->mtd._is_locked = part_is_locked;
 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->offset == MTDPART_OFS_RETAIN) {
 463                 slave->offset = cur_offset;
 464                 if (master->size - slave->offset >= slave->mtd.size) {
 465                         slave->mtd.size = master->size - slave->offset
 466                                                         - slave->mtd.size;
 467                 } else {
 468                         printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
 469                                 part->name, master->size - slave->offset,
 470                                 slave->mtd.size);
 471                         /* register to preserve ordering */
 472                         goto out_register;
 473                 }
 474         }
 475         if (slave->mtd.size == MTDPART_SIZ_FULL)
 476                 slave->mtd.size = master->size - slave->offset;
 477
 478         printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
 479                 (unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
 480
 481         /* let's do some sanity checks */
 482         if (slave->offset >= master->size) {
 483                 /* let's register it anyway to preserve ordering */
 484                 slave->offset = 0;
 485                 slave->mtd.size = 0;
 486                 printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
 487                         part->name);
 488                 goto out_register;
 489         }
 490         if (slave->offset + slave->mtd.size > master->size) {
 491                 slave->mtd.size = master->size - slave->offset;
 492                 printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
 493                         part->name, master->name, (unsigned long long)slave->mtd.size);
 494         }
 495         if (master->numeraseregions > 1) {
 496                 /* Deal with variable erase size stuff */
 497                 int i, max = master->numeraseregions;
 498                 u64 end = slave->offset + slave->mtd.size;
 499                 struct mtd_erase_region_info *regions = master->eraseregions;
 500
 501                 /* Find the first erase regions which is part of this
 502                  * partition. */
 503                 for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
 504                         ;
 505                 /* The loop searched for the region _behind_ the first one */
 506                 if (i > 0)
 507                         i--;
 508
 509                 /* Pick biggest erasesize */
 510                 for (; i < max && regions[i].offset < end; i++) {
 511                         if (slave->mtd.erasesize < regions[i].erasesize) {
 512                                 slave->mtd.erasesize = regions[i].erasesize;
 513                         }
 514                 }
 515                 BUG_ON(slave->mtd.erasesize == 0);
 516         } else {
 517                 /* Single erase size */
 518                 slave->mtd.erasesize = master->erasesize;
 519         }
 520
 521         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 522             mtd_mod_by_eb(slave->offset, &slave->mtd)) {
 523                 /* Doesn't start on a boundary of major erase size */
 524                 /* FIXME: Let it be writable if it is on a boundary of
 525                  * _minor_ erase size though */
 526                 slave->mtd.flags &= ~MTD_WRITEABLE;
 527                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
 528                         part->name);
 529         }
 530         if ((slave->mtd.flags & MTD_WRITEABLE) &&
 531             mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
 532                 slave->mtd.flags &= ~MTD_WRITEABLE;
 533                 printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
 534                         part->name);
 535         }
 536
 537         slave->mtd.ecclayout = master->ecclayout;
 538         slave->mtd.ecc_strength = master->ecc_strength;
 539         slave->mtd.bitflip_threshold = master->bitflip_threshold;
 540
 541         if (master->_block_isbad) {
 542                 uint64_t offs = 0;
 543
 544                 while (offs < slave->mtd.size) {
 545                         if (mtd_block_isbad(master, offs + slave->offset))
 546                                 slave->mtd.ecc_stats.badblocks++;
 547                         offs += slave->mtd.erasesize;
 548                 }
 549         }
 550
 551 out_register:
 552         return slave;
 553 }
 554
 555 int mtd_add_partition(struct mtd_info *master, char *name,
 556                       long long offset, long long length)
 557 {
 558         struct mtd_partition part;
 559         struct mtd_part *p, *new;
 560         uint64_t start, end;
 561         int ret = 0;
 562
 563         /* the direct offset is expected */
 564         if (offset == MTDPART_OFS_APPEND ||
 565             offset == MTDPART_OFS_NXTBLK)
 566                 return -EINVAL;
 567
 568         if (length == MTDPART_SIZ_FULL)
 569                 length = master->size - offset;
 570
 571         if (length <= 0)
 572                 return -EINVAL;
 573
 574         part.name = name;
 575         part.size = length;
 576         part.offset = offset;
 577         part.mask_flags = 0;
 578         part.ecclayout = NULL;
 579
 580         new = allocate_partition(master, &part, -1, offset);
 581         if (IS_ERR(new))
 582                 return PTR_ERR(new);
 583
 584         start = offset;
 585         end = offset + length;
 586
 587         mutex_lock(&mtd_partitions_mutex);
 588         list_for_each_entry(p, &mtd_partitions, list)
 589                 if (p->master == master) {
 590                         if ((start >= p->offset) &&
 591                             (start < (p->offset + p->mtd.size)))
 592                                 goto err_inv;
 593
 594                         if ((end >= p->offset) &&
 595                             (end < (p->offset + p->mtd.size)))
 596                                 goto err_inv;
 597                 }
 598
 599         list_add(&new->list, &mtd_partitions);
 600         mutex_unlock(&mtd_partitions_mutex);
 601
 602         add_mtd_device(&new->mtd);
 603
 604         return ret;
 605 err_inv:
 606         mutex_unlock(&mtd_partitions_mutex);
 607         free_partition(new);
 608         return -EINVAL;
 609 }
 610 EXPORT_SYMBOL_GPL(mtd_add_partition);
 611
 612 int mtd_del_partition(struct mtd_info *master, int partno)
 613 {
 614         struct mtd_part *slave, *next;
 615         int ret = -EINVAL;
 616
 617         mutex_lock(&mtd_partitions_mutex);
 618         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 619                 if ((slave->master == master) &&
 620                     (slave->mtd.index == partno)) {
 621                         ret = del_mtd_device(&slave->mtd);
 622                         if (ret < 0)
 623                                 break;
 624
 625                         list_del(&slave->list);
 626                         free_partition(slave);
 627                         break;
 628                 }
 629         mutex_unlock(&mtd_partitions_mutex);
 630
 631         return ret;
 632 }
 633 EXPORT_SYMBOL_GPL(mtd_del_partition);
 634
 635 /*
 636  * This function, given a master MTD object and a partition table, creates
 637  * and registers slave MTD objects which are bound to the master according to
 638  * the partition definitions.
 639  *
 640  * We don't register the master, or expect the caller to have done so,
 641  * for reasons of data integrity.
 642  */
 643
 644 int add_mtd_partitions(struct mtd_info *master,
 645                        const struct mtd_partition *parts,
 646                        int nbparts)
 647 {
 648         struct mtd_part *slave;
 649         uint64_t cur_offset = 0;
 650         int i;
 651
 652         printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 653
 654         for (i = 0; i < nbparts; i++) {
 655                 slave = allocate_partition(master, parts + i, i, cur_offset);
 656                 if (IS_ERR(slave)) {
 657                         del_mtd_partitions(master);
 658                         return PTR_ERR(slave);
 659                 }
 660
 661                 mutex_lock(&mtd_partitions_mutex);
 662                 list_add(&slave->list, &mtd_partitions);
 663                 mutex_unlock(&mtd_partitions_mutex);
 664
 665                 add_mtd_device(&slave->mtd);
 666
 667                 cur_offset = slave->offset + slave->mtd.size;
 668         }
 669 #ifdef DYNAMIC_CHANGE_MTD_WRITEABLE //wschen 2011-01-05
 670         my_mtd = master;
 671 #endif
 672         return 0;
 673 }
 674
 675 static DEFINE_SPINLOCK(part_parser_lock);
 676 static LIST_HEAD(part_parsers);
 677
 678 static struct mtd_part_parser *get_partition_parser(const char *name)
 679 {
 680         struct mtd_part_parser *p, *ret = NULL;
 681
 682         spin_lock(&part_parser_lock);
 683
 684         list_for_each_entry(p, &part_parsers, list)
 685                 if (!strcmp(p->name, name) && try_module_get(p->owner)) {
 686                         ret = p;
 687                         break;
 688                 }
 689
 690         spin_unlock(&part_parser_lock);
 691
 692         return ret;
 693 }
 694
 695 #define put_partition_parser(p) do { module_put((p)->owner); } while (0)
 696
 697 int register_mtd_parser(struct mtd_part_parser *p)
 698 {
 699         spin_lock(&part_parser_lock);
 700         list_add(&p->list, &part_parsers);
 701         spin_unlock(&part_parser_lock);
 702
 703         return 0;
 704 }
 705 EXPORT_SYMBOL_GPL(register_mtd_parser);
 706
 707 int deregister_mtd_parser(struct mtd_part_parser *p)
 708 {
 709         spin_lock(&part_parser_lock);
 710         list_del(&p->list);
 711         spin_unlock(&part_parser_lock);
 712         return 0;
 713 }
 714 EXPORT_SYMBOL_GPL(deregister_mtd_parser);
 715
 716 /*
 717  * Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
 718  * are changing this array!
 719  */
 720 static const char * const default_mtd_part_types[] = {
 721         "cmdlinepart",
 722         "ofpart",
 723         NULL
 724 };
 725
 726 /**
 727  * parse_mtd_partitions - parse MTD partitions
 728  * @master: the master partition (describes whole MTD device)
 729  * @types: names of partition parsers to try or %NULL
 730  * @pparts: array of partitions found is returned here
 731  * @data: MTD partition parser-specific data
 732  *
 733  * This function tries to find partition on MTD device @master. It uses MTD
 734  * partition parsers, specified in @types. However, if @types is %NULL, then
 735  * the default list of parsers is used. The default list contains only the
 736  * "cmdlinepart" and "ofpart" parsers ATM.
 737  * Note: If there are more then one parser in @types, the kernel only takes the
 738  * partitions parsed out by the first parser.
 739  *
 740  * This function may return:
 741  * o a negative error code in case of failure
 742  * o zero if no partitions were found
 743  * o a positive number of found partitions, in which case on exit @pparts will
 744  *   point to an array containing this number of &struct mtd_info objects.
 745  */
 746 int parse_mtd_partitions(struct mtd_info *master, const char *const *types,
 747                          struct mtd_partition **pparts,
 748                          struct mtd_part_parser_data *data)
 749 {
 750         struct mtd_part_parser *parser;
 751         int ret = 0;
 752
 753         if (!types)
 754                 types = default_mtd_part_types;
 755
 756         for ( ; ret <= 0 && *types; types++) {
 757                 parser = get_partition_parser(*types);
 758                 if (!parser && !request_module("%s", *types))
 759                         parser = get_partition_parser(*types);
 760                 if (!parser)
 761                         continue;
 762                 ret = (*parser->parse_fn)(master, pparts, data);
 763                 put_partition_parser(parser);
 764                 if (ret > 0) {
 765                         printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
 766                                ret, parser->name, master->name);
 767                         break;
 768                 }
 769         }
 770         return ret;
 771 }
 772
 773 int mtd_is_partition(const struct mtd_info *mtd)
 774 {
 775         struct mtd_part *part;
 776         int ispart = 0;
 777
 778         mutex_lock(&mtd_partitions_mutex);
 779         list_for_each_entry(part, &mtd_partitions, list)
 780                 if (&part->mtd == mtd) {
 781                         ispart = 1;
 782                         break;
 783                 }
 784         mutex_unlock(&mtd_partitions_mutex);
 785
 786         return ispart;
 787 }
 788 EXPORT_SYMBOL_GPL(mtd_is_partition);
 789
 790 #ifdef CONFIG_MTK_MTD_NAND
 791 u64 mtd_partition_start_address(struct mtd_info *mtd)
 792 {
 793         struct mtd_part *part = PART(mtd);
 794         return part->offset;
 795 }
 796 EXPORT_SYMBOL_GPL(mtd_partition_start_address);
 797 #endif
 798
 799 /* Returns the size of the entire flash chip */
 800 uint64_t mtd_get_device_size(const struct mtd_info *mtd)
 801 {
 802         if (!mtd_is_partition(mtd))
 803                 return mtd->size;
 804
 805         return PART(mtd)->master->size;
 806 }
 807 EXPORT_SYMBOL_GPL(mtd_get_device_size);
 808
 809 #ifdef DYNAMIC_CHANGE_MTD_WRITEABLE //wschen 2011-01-05
 810 int mtd_writeable_proc_write(struct file *file, const char *buffer, unsigned long count, void *data)
 811 {
 812     char buf[3];
 813
 814     if (count != 3) {
 815         return -EFAULT;
 816     }
 817
 818     if (copy_from_user(buf, buffer, 3)) {
 819         return -EFAULT;
 820     }
 821
 822     if ((buf[0] != 0) || (buf[1] != 0) || (buf[2] != 0)) {
 823         return -EFAULT;
 824     }
 825
 826     if (my_mtd) {
 827
 828         struct mtd_part *slave, *next;
 829
 830         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 831             if (slave->master == my_mtd) {
 832                 slave->mtd.flags |= MTD_WRITEABLE;
 833             }
 834     }
 835
 836     return count;
 837 }
 838
 839 #define MTD_CHANGE_NUM 4
 840 int mtd_change_proc_write(struct file *file, const char *buffer, unsigned long count, void *data)
 841 {
 842     struct mtd_change mtd_change[MTD_CHANGE_NUM];
 843     int write_3 = 0;
 844
 845     if (count == (sizeof(struct mtd_change) * (MTD_CHANGE_NUM - 1))) {
 846         write_3 = 1;
 847     } else if (count != (sizeof(struct mtd_change) * MTD_CHANGE_NUM)) {
 848         return -EFAULT;
 849     }
 850
 851     if (copy_from_user(mtd_change, buffer, count)) {
 852         return -EFAULT;
 853     }
 854
 855     if (my_mtd) {
 856         struct mtd_part *slave, *next;
 857
 858         list_for_each_entry_safe(slave, next, &mtd_partitions, list)
 859             if (slave->master == my_mtd) {
 860                 if (write_3 == 1) {
 861                     if (strncmp(slave->mtd.name, "system", strlen(slave->mtd.name)) == 0) {
 862                         slave->mtd.size = mtd_change[0].size;
 863                         slave->offset = mtd_change[0].offset;
 864                     } else if (strncmp(slave->mtd.name, "cache", strlen(slave->mtd.name)) == 0) {
 865                         slave->mtd.size = mtd_change[1].size;
 866                         slave->offset = mtd_change[1].offset;
 867                     } else if (strncmp(slave->mtd.name, "userdata", strlen(slave->mtd.name)) == 0) {
 868                         slave->mtd.size = mtd_change[2].size;
 869                         slave->offset = mtd_change[2].offset;
 870                     }
 871                 } else {
 872                     //4 arguments
 873                     if (strncmp(slave->mtd.name, "expdb", strlen(slave->mtd.name)) == 0) {
 874                         slave->mtd.size = mtd_change[0].size;
 875                         slave->offset = mtd_change[0].offset;
 876                     } else if (strncmp(slave->mtd.name, "system", strlen(slave->mtd.name)) == 0) {
 877                         slave->mtd.size = mtd_change[1].size;
 878                         slave->offset = mtd_change[1].offset;
 879                     } else if (strncmp(slave->mtd.name, "cache", strlen(slave->mtd.name)) == 0) {
 880                         slave->mtd.size = mtd_change[2].size;
 881                         slave->offset = mtd_change[2].offset;
 882                     } else if (strncmp(slave->mtd.name, "userdata", strlen(slave->mtd.name)) == 0) {
 883                         slave->mtd.size = mtd_change[3].size;
 884                         slave->offset = mtd_change[3].offset;
 885                     }
 886                 }
 887             }
 888     }
 889
 890     return count;
 891 }
 892 #endif