drivers/mtd/mtdpart.c

   1 /*
   2  * Simple MTD partitioning layer
   3  *
   4  * (C) 2000 Nicolas Pitre <nico@cam.org>
   5  *
   6  * This code is GPL
   7  *
   8  * $Id: mtdpart.c,v 1.32 2002/10/21 13:40:05 jocke Exp $
   9  *
  10  *      02-21-2002      Thomas Gleixner <gleixner@autronix.de>
  11  *                      added support for read_oob, write_oob
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/types.h>
  16 #include <linux/kernel.h>
  17 #include <linux/slab.h>
  18 #include <linux/list.h>
  19
  20 #include <linux/mtd/mtd.h>
  21 #include <linux/mtd/partitions.h>
  22
  23
  24 /* Our partition linked list */
  25 static LIST_HEAD(mtd_partitions);
  26
  27 /* Our partition node structure */
  28 struct mtd_part {
  29         struct mtd_info mtd;
  30         struct mtd_info *master;
  31         u_int32_t offset;
  32         int index;
  33         struct list_head list;
  34         int registered;
  35 };
  36
  37 /*
  38  * Given a pointer to the MTD object in the mtd_part structure, we can retrieve
  39  * the pointer to that structure with this macro.
  40  */
  41 #define PART(x)  ((struct mtd_part *)(x))
  42
  43
  44 /*
  45  * MTD methods which simply translate the effective address and pass through
  46  * to the _real_ device.
  47  */
  48
  49 static int part_read (struct mtd_info *mtd, loff_t from, size_t len,
  50                         size_t *retlen, u_char *buf)
  51 {
  52         struct mtd_part *part = PART(mtd);
  53         if (from >= mtd->size)
  54                 len = 0;
  55         else if (from + len > mtd->size)
  56                 len = mtd->size - from;
  57         return part->master->read (part->master, from + part->offset,
  58                                         len, retlen, buf);
  59 }
  60
  61 static int part_point (struct mtd_info *mtd, loff_t from, size_t len,
  62                         size_t *retlen, u_char **buf)
  63 {
  64         struct mtd_part *part = PART(mtd);
  65         if (from >= mtd->size)
  66                 len = 0;
  67         else if (from + len > mtd->size)
  68                 len = mtd->size - from;
  69         return part->master->point (part->master, from + part->offset,
  70                                     len, retlen, buf);
  71 }
  72 static void part_unpoint (struct mtd_info *mtd, u_char *addr, loff_t from, size_t len)
  73 {
  74         struct mtd_part *part = PART(mtd);
  75
  76         part->master->unpoint (part->master, addr, from + part->offset, len);
  77 }
  78
  79
  80 static int part_read_ecc (struct mtd_info *mtd, loff_t from, size_t len,
  81                         size_t *retlen, u_char *buf, u_char *eccbuf, int oobsel)
  82 {
  83         struct mtd_part *part = PART(mtd);
  84         if (from >= mtd->size)
  85                 len = 0;
  86         else if (from + len > mtd->size)
  87                 len = mtd->size - from;
  88         return part->master->read_ecc (part->master, from + part->offset,
  89                                         len, retlen, buf, eccbuf, oobsel);
  90 }
  91
  92 static int part_read_oob (struct mtd_info *mtd, loff_t from, size_t len,
  93                         size_t *retlen, u_char *buf)
  94 {
  95         struct mtd_part *part = PART(mtd);
  96         if (from >= mtd->size)
  97                 len = 0;
  98         else if (from + len > mtd->size)
  99                 len = mtd->size - from;
 100         return part->master->read_oob (part->master, from + part->offset,
 101                                         len, retlen, buf);
 102 }
 103
 104 static int part_read_user_prot_reg (struct mtd_info *mtd, loff_t from, size_t len,
 105                         size_t *retlen, u_char *buf)
 106 {
 107         struct mtd_part *part = PART(mtd);
 108         return part->master->read_user_prot_reg (part->master, from,
 109                                         len, retlen, buf);
 110 }
 111
 112 static int part_read_fact_prot_reg (struct mtd_info *mtd, loff_t from, size_t len,
 113                         size_t *retlen, u_char *buf)
 114 {
 115         struct mtd_part *part = PART(mtd);
 116         return part->master->read_user_prot_reg (part->master, from,
 117                                         len, retlen, buf);
 118 }
 119
 120 static int part_write (struct mtd_info *mtd, loff_t to, size_t len,
 121                         size_t *retlen, const u_char *buf)
 122 {
 123         struct mtd_part *part = PART(mtd);
 124         if (!(mtd->flags & MTD_WRITEABLE))
 125                 return -EROFS;
 126         if (to >= mtd->size)
 127                 len = 0;
 128         else if (to + len > mtd->size)
 129                 len = mtd->size - to;
 130         return part->master->write (part->master, to + part->offset,
 131                                         len, retlen, buf);
 132 }
 133
 134 static int part_write_ecc (struct mtd_info *mtd, loff_t to, size_t len,
 135                         size_t *retlen, const u_char *buf,
 136                          u_char *eccbuf, int oobsel)
 137 {
 138         struct mtd_part *part = PART(mtd);
 139         if (!(mtd->flags & MTD_WRITEABLE))
 140                 return -EROFS;
 141         if (to >= mtd->size)
 142                 len = 0;
 143         else if (to + len > mtd->size)
 144                 len = mtd->size - to;
 145         return part->master->write_ecc (part->master, to + part->offset,
 146                                         len, retlen, buf, eccbuf, oobsel);
 147 }
 148
 149 static int part_write_oob (struct mtd_info *mtd, loff_t to, size_t len,
 150                         size_t *retlen, const u_char *buf)
 151 {
 152         struct mtd_part *part = PART(mtd);
 153         if (!(mtd->flags & MTD_WRITEABLE))
 154                 return -EROFS;
 155         if (to >= mtd->size)
 156                 len = 0;
 157         else if (to + len > mtd->size)
 158                 len = mtd->size - to;
 159         return part->master->write_oob (part->master, to + part->offset,
 160                                         len, retlen, buf);
 161 }
 162
 163 static int part_write_user_prot_reg (struct mtd_info *mtd, loff_t from, size_t len,
 164                         size_t *retlen, u_char *buf)
 165 {
 166         struct mtd_part *part = PART(mtd);
 167         return part->master->write_user_prot_reg (part->master, from,
 168                                         len, retlen, buf);
 169 }
 170
 171 static int part_writev (struct mtd_info *mtd,  const struct iovec *vecs,
 172                          unsigned long count, loff_t to, size_t *retlen)
 173 {
 174         struct mtd_part *part = PART(mtd);
 175         if (!(mtd->flags & MTD_WRITEABLE))
 176                 return -EROFS;
 177         return part->master->writev (part->master, vecs, count,
 178                                         to + part->offset, retlen);
 179 }
 180
 181 static int part_readv (struct mtd_info *mtd,  struct iovec *vecs,
 182                          unsigned long count, loff_t from, size_t *retlen)
 183 {
 184         struct mtd_part *part = PART(mtd);
 185         return part->master->readv (part->master, vecs, count,
 186                                         from + part->offset, retlen);
 187 }
 188
 189 static int part_writev_ecc (struct mtd_info *mtd,  const struct iovec *vecs,
 190                          unsigned long count, loff_t to, size_t *retlen,
 191                          u_char *eccbuf, int oobsel)
 192 {
 193         struct mtd_part *part = PART(mtd);
 194         if (!(mtd->flags & MTD_WRITEABLE))
 195                 return -EROFS;
 196         return part->master->writev_ecc (part->master, vecs, count,
 197                                         to + part->offset, retlen,
 198                                         eccbuf, oobsel);
 199 }
 200
 201 static int part_readv_ecc (struct mtd_info *mtd,  struct iovec *vecs,
 202                          unsigned long count, loff_t from, size_t *retlen,
 203                          u_char *eccbuf, int oobsel)
 204 {
 205         struct mtd_part *part = PART(mtd);
 206         return part->master->readv_ecc (part->master, vecs, count,
 207                                         from + part->offset, retlen,
 208                                         eccbuf, oobsel);
 209 }
 210
 211 static int part_erase (struct mtd_info *mtd, struct erase_info *instr)
 212 {
 213         struct mtd_part *part = PART(mtd);
 214         if (!(mtd->flags & MTD_WRITEABLE))
 215                 return -EROFS;
 216         if (instr->addr >= mtd->size)
 217                 return -EINVAL;
 218         instr->addr += part->offset;
 219         return part->master->erase(part->master, instr);
 220 }
 221
 222 static int part_lock (struct mtd_info *mtd, loff_t ofs, size_t len)
 223 {
 224         struct mtd_part *part = PART(mtd);
 225         if ((len + ofs) > mtd->size)
 226                 return -EINVAL;
 227         return part->master->lock(part->master, ofs + part->offset, len);
 228 }
 229
 230 static int part_unlock (struct mtd_info *mtd, loff_t ofs, size_t len)
 231 {
 232         struct mtd_part *part = PART(mtd);
 233         if ((len + ofs) > mtd->size)
 234                 return -EINVAL;
 235         return part->master->unlock(part->master, ofs + part->offset, len);
 236 }
 237
 238 static void part_sync(struct mtd_info *mtd)
 239 {
 240         struct mtd_part *part = PART(mtd);
 241         part->master->sync(part->master);
 242 }
 243
 244 static int part_suspend(struct mtd_info *mtd)
 245 {
 246         struct mtd_part *part = PART(mtd);
 247         return part->master->suspend(part->master);
 248 }
 249
 250 static void part_resume(struct mtd_info *mtd)
 251 {
 252         struct mtd_part *part = PART(mtd);
 253         part->master->resume(part->master);
 254 }
 255
 256 /*
 257  * This function unregisters and destroy all slave MTD objects which are
 258  * attached to the given master MTD object.
 259  */
 260
 261 int del_mtd_partitions(struct mtd_info *master)
 262 {
 263         struct list_head *node;
 264         struct mtd_part *slave;
 265
 266         for (node = mtd_partitions.next;
 267              node != &mtd_partitions;
 268              node = node->next) {
 269                 slave = list_entry(node, struct mtd_part, list);
 270                 if (slave->master == master) {
 271                         struct list_head *prev = node->prev;
 272                         __list_del(prev, node->next);
 273                         if(slave->registered)
 274                                 del_mtd_device(&slave->mtd);
 275                         kfree(slave);
 276                         node = prev;
 277                 }
 278         }
 279
 280         return 0;
 281 }
 282
 283 /*
 284  * This function, given a master MTD object and a partition table, creates
 285  * and registers slave MTD objects which are bound to the master according to
 286  * the partition definitions.
 287  * (Q: should we register the master MTD object as well?)
 288  */
 289
 290 int add_mtd_partitions(struct mtd_info *master,
 291                        struct mtd_partition *parts,
 292                        int nbparts)
 293 {
 294         struct mtd_part *slave;
 295         u_int32_t cur_offset = 0;
 296         int i;
 297
 298         printk (KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 299
 300         for (i = 0; i < nbparts; i++) {
 301
 302                 /* allocate the partition structure */
 303                 slave = kmalloc (sizeof(*slave), GFP_KERNEL);
 304                 if (!slave) {
 305                         printk ("memory allocation error while creating partitions for \"%s\"\n",
 306                                 master->name);
 307                         del_mtd_partitions(master);
 308                         return -ENOMEM;
 309                 }
 310                 memset(slave, 0, sizeof(*slave));
 311                 list_add(&slave->list, &mtd_partitions);
 312
 313                 /* set up the MTD object for this partition */
 314                 slave->mtd.type = master->type;
 315                 slave->mtd.flags = master->flags & ~parts[i].mask_flags;
 316                 slave->mtd.size = parts[i].size;
 317                 slave->mtd.oobblock = master->oobblock;
 318                 slave->mtd.oobsize = master->oobsize;
 319                 slave->mtd.ecctype = master->ecctype;
 320                 slave->mtd.eccsize = master->eccsize;
 321
 322                 slave->mtd.name = parts[i].name;
 323                 slave->mtd.bank_size = master->bank_size;
 324                 slave->mtd.module = master->module;
 325
 326                 slave->mtd.read = part_read;
 327                 slave->mtd.write = part_write;
 328
 329                 if(master->point && master->unpoint){
 330                         slave->mtd.point = part_point;
 331                         slave->mtd.unpoint = part_unpoint;
 332                 }
 333
 334                 if (master->read_ecc)
 335                         slave->mtd.read_ecc = part_read_ecc;
 336                 if (master->write_ecc)
 337                         slave->mtd.write_ecc = part_write_ecc;
 338                 if (master->read_oob)
 339                         slave->mtd.read_oob = part_read_oob;
 340                 if (master->write_oob)
 341                         slave->mtd.write_oob = part_write_oob;
 342                 if(master->read_user_prot_reg)
 343                         slave->mtd.read_user_prot_reg = part_read_user_prot_reg;
 344                 if(master->read_fact_prot_reg)
 345                         slave->mtd.read_fact_prot_reg = part_read_fact_prot_reg;
 346                 if(master->write_user_prot_reg)
 347                         slave->mtd.write_user_prot_reg = part_write_user_prot_reg;
 348                 if (master->sync)
 349                         slave->mtd.sync = part_sync;
 350                 if (!i && master->suspend && master->resume) {
 351                                 slave->mtd.suspend = part_suspend;
 352                                 slave->mtd.resume = part_resume;
 353                 }
 354                 if (master->writev)
 355                         slave->mtd.writev = part_writev;
 356                 if (master->readv)
 357                         slave->mtd.readv = part_readv;
 358                 if (master->writev_ecc)
 359                         slave->mtd.writev_ecc = part_writev_ecc;
 360                 if (master->readv_ecc)
 361                         slave->mtd.readv_ecc = part_readv_ecc;
 362                 if (master->lock)
 363                         slave->mtd.lock = part_lock;
 364                 if (master->unlock)
 365                         slave->mtd.unlock = part_unlock;
 366                 slave->mtd.erase = part_erase;
 367                 slave->master = master;
 368                 slave->offset = parts[i].offset;
 369                 slave->index = i;
 370
 371                 if (slave->offset == MTDPART_OFS_APPEND)
 372                         slave->offset = cur_offset;
 373                 if (slave->offset == MTDPART_OFS_NXTBLK) {
 374                         u_int32_t emask = master->erasesize-1;
 375                         slave->offset = (cur_offset + emask) & ~emask;
 376                         if (slave->offset != cur_offset) {
 377                                 printk(KERN_NOTICE "Moving partition %d: "
 378                                        "0x%08x -> 0x%08x\n", i,
 379                                        cur_offset, slave->offset);
 380                         }
 381                 }
 382                 if (slave->mtd.size == MTDPART_SIZ_FULL)
 383                         slave->mtd.size = master->size - slave->offset;
 384                 cur_offset = slave->offset + slave->mtd.size;
 385
 386                 printk (KERN_NOTICE "0x%08x-0x%08x : \"%s\"\n", slave->offset,
 387                         slave->offset + slave->mtd.size, slave->mtd.name);
 388
 389                 /* let's do some sanity checks */
 390                 if (slave->offset >= master->size) {
 391                                 /* let's register it anyway to preserve ordering */
 392                         slave->offset = 0;
 393                         slave->mtd.size = 0;
 394                         printk ("mtd: partition \"%s\" is out of reach -- disabled\n",
 395                                 parts[i].name);
 396                 }
 397                 if (slave->offset + slave->mtd.size > master->size) {
 398                         slave->mtd.size = master->size - slave->offset;
 399                         printk ("mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#x\n",
 400                                 parts[i].name, master->name, slave->mtd.size);
 401                 }
 402                 if (master->numeraseregions>1) {
 403                         /* Deal with variable erase size stuff */
 404                         int i;
 405                         struct mtd_erase_region_info *regions = master->eraseregions;
 406
 407                         /* Find the first erase regions which is part of this partition. */
 408                         for (i=0; i < master->numeraseregions && slave->offset >= regions[i].offset; i++)
 409                                 ;
 410
 411                         for (i--; i < master->numeraseregions && slave->offset + slave->mtd.size > regions[i].offset; i++) {
 412                                 if (slave->mtd.erasesize < regions[i].erasesize) {
 413                                         slave->mtd.erasesize = regions[i].erasesize;
 414                                 }
 415                         }
 416                 } else {
 417                         /* Single erase size */
 418                         slave->mtd.erasesize = master->erasesize;
 419                 }
 420
 421                 if ((slave->mtd.flags & MTD_WRITEABLE) &&
 422                     (slave->offset % slave->mtd.erasesize)) {
 423                         /* Doesn't start on a boundary of major erase size */
 424                         /* FIXME: Let it be writable if it is on a boundary of _minor_ erase size though */
 425                         slave->mtd.flags &= ~MTD_WRITEABLE;
 426                         printk ("mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
 427                                 parts[i].name);
 428                 }
 429                 if ((slave->mtd.flags & MTD_WRITEABLE) &&
 430                     (slave->mtd.size % slave->mtd.erasesize)) {
 431                         slave->mtd.flags &= ~MTD_WRITEABLE;
 432                         printk ("mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
 433                                 parts[i].name);
 434                 }
 435
 436                 if(parts[i].mtdp)
 437                 {       /* store the object pointer (caller may or may not register it */
 438                         *parts[i].mtdp = &slave->mtd;
 439                         slave->registered = 0;
 440                 }
 441                 else
 442                 {
 443                         /* register our partition */
 444                         add_mtd_device(&slave->mtd);
 445                         slave->registered = 1;
 446                 }
 447         }
 448
 449         return 0;
 450 }
 451
 452 EXPORT_SYMBOL(add_mtd_partitions);
 453 EXPORT_SYMBOL(del_mtd_partitions);
 454
 455
 456 MODULE_LICENSE("GPL");
 457 MODULE_AUTHOR("Nicolas Pitre <nico@cam.org>");
 458 MODULE_DESCRIPTION("Generic support for partitioning of MTD devices");
 459