| 1 | /* |
| 2 | * Core registration and callback routines for MTD |
| 3 | * drivers and users. |
| 4 | * |
| 5 | * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org> |
| 6 | * Copyright © 2006 Red Hat UK Limited |
| 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/kernel.h> |
| 26 | #include <linux/ptrace.h> |
| 27 | #include <linux/seq_file.h> |
| 28 | #include <linux/string.h> |
| 29 | #include <linux/timer.h> |
| 30 | #include <linux/major.h> |
| 31 | #include <linux/fs.h> |
| 32 | #include <linux/err.h> |
| 33 | #include <linux/ioctl.h> |
| 34 | #include <linux/init.h> |
| 35 | #include <linux/proc_fs.h> |
| 36 | #include <linux/idr.h> |
| 37 | #include <linux/backing-dev.h> |
| 38 | #include <linux/gfp.h> |
| 39 | |
| 40 | #include <linux/mtd/mtd.h> |
| 41 | #include <linux/mtd/partitions.h> |
| 42 | |
| 43 | #include "mtdcore.h" |
| 44 | /* |
| 45 | * backing device capabilities for non-mappable devices (such as NAND flash) |
| 46 | * - permits private mappings, copies are taken of the data |
| 47 | */ |
| 48 | static struct backing_dev_info mtd_bdi_unmappable = { |
| 49 | .capabilities = BDI_CAP_MAP_COPY, |
| 50 | }; |
| 51 | |
| 52 | /* |
| 53 | * backing device capabilities for R/O mappable devices (such as ROM) |
| 54 | * - permits private mappings, copies are taken of the data |
| 55 | * - permits non-writable shared mappings |
| 56 | */ |
| 57 | static struct backing_dev_info mtd_bdi_ro_mappable = { |
| 58 | .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT | |
| 59 | BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP), |
| 60 | }; |
| 61 | |
| 62 | /* |
| 63 | * backing device capabilities for writable mappable devices (such as RAM) |
| 64 | * - permits private mappings, copies are taken of the data |
| 65 | * - permits non-writable shared mappings |
| 66 | */ |
| 67 | static struct backing_dev_info mtd_bdi_rw_mappable = { |
| 68 | .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT | |
| 69 | BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP | |
| 70 | BDI_CAP_WRITE_MAP), |
| 71 | }; |
| 72 | |
| 73 | static int mtd_cls_suspend(struct device *dev, pm_message_t state); |
| 74 | static int mtd_cls_resume(struct device *dev); |
| 75 | |
| 76 | static struct class mtd_class = { |
| 77 | .name = "mtd", |
| 78 | .owner = THIS_MODULE, |
| 79 | .suspend = mtd_cls_suspend, |
| 80 | .resume = mtd_cls_resume, |
| 81 | }; |
| 82 | |
| 83 | static DEFINE_IDR(mtd_idr); |
| 84 | |
| 85 | /* These are exported solely for the purpose of mtd_blkdevs.c. You |
| 86 | should not use them for _anything_ else */ |
| 87 | DEFINE_MUTEX(mtd_table_mutex); |
| 88 | EXPORT_SYMBOL_GPL(mtd_table_mutex); |
| 89 | |
| 90 | struct mtd_info *__mtd_next_device(int i) |
| 91 | { |
| 92 | return idr_get_next(&mtd_idr, &i); |
| 93 | } |
| 94 | EXPORT_SYMBOL_GPL(__mtd_next_device); |
| 95 | |
| 96 | static LIST_HEAD(mtd_notifiers); |
| 97 | |
| 98 | |
| 99 | #if defined(CONFIG_MTD_CHAR) || defined(CONFIG_MTD_CHAR_MODULE) |
| 100 | #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2) |
| 101 | #else |
| 102 | #define MTD_DEVT(index) 0 |
| 103 | #endif |
| 104 | |
| 105 | /* REVISIT once MTD uses the driver model better, whoever allocates |
| 106 | * the mtd_info will probably want to use the release() hook... |
| 107 | */ |
| 108 | static void mtd_release(struct device *dev) |
| 109 | { |
| 110 | struct mtd_info *mtd = dev_get_drvdata(dev); |
| 111 | dev_t index = MTD_DEVT(mtd->index); |
| 112 | |
| 113 | /* remove /dev/mtdXro node if needed */ |
| 114 | if (index) |
| 115 | device_destroy(&mtd_class, index + 1); |
| 116 | } |
| 117 | |
| 118 | static int mtd_cls_suspend(struct device *dev, pm_message_t state) |
| 119 | { |
| 120 | struct mtd_info *mtd = dev_get_drvdata(dev); |
| 121 | |
| 122 | if (mtd && mtd->suspend) |
| 123 | return mtd_suspend(mtd); |
| 124 | else |
| 125 | return 0; |
| 126 | } |
| 127 | |
| 128 | static int mtd_cls_resume(struct device *dev) |
| 129 | { |
| 130 | struct mtd_info *mtd = dev_get_drvdata(dev); |
| 131 | |
| 132 | if (mtd && mtd->resume) |
| 133 | mtd_resume(mtd); |
| 134 | return 0; |
| 135 | } |
| 136 | |
| 137 | static ssize_t mtd_type_show(struct device *dev, |
| 138 | struct device_attribute *attr, char *buf) |
| 139 | { |
| 140 | struct mtd_info *mtd = dev_get_drvdata(dev); |
| 141 | char *type; |
| 142 | |
| 143 | switch (mtd->type) { |
| 144 | case MTD_ABSENT: |
| 145 | type = "absent"; |
| 146 | break; |
| 147 | case MTD_RAM: |
| 148 | type = "ram"; |
| 149 | break; |
| 150 | case MTD_ROM: |
| 151 | type = "rom"; |
| 152 | break; |
| 153 | case MTD_NORFLASH: |
| 154 | type = "nor"; |
| 155 | break; |
| 156 | case MTD_NANDFLASH: |
| 157 | type = "nand"; |
| 158 | break; |
| 159 | case MTD_DATAFLASH: |
| 160 | type = "dataflash"; |
| 161 | break; |
| 162 | case MTD_UBIVOLUME: |
| 163 | type = "ubi"; |
| 164 | break; |
| 165 | default: |
| 166 | type = "unknown"; |
| 167 | } |
| 168 | |
| 169 | return snprintf(buf, PAGE_SIZE, "%s\n", type); |
| 170 | } |
| 171 | static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL); |
| 172 | |
| 173 | static ssize_t mtd_flags_show(struct device *dev, |
| 174 | struct device_attribute *attr, char *buf) |
| 175 | { |
| 176 | struct mtd_info *mtd = dev_get_drvdata(dev); |
| 177 | |
| 178 | return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags); |
| 179 | |
| 180 | } |
| 181 | static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL); |
| 182 | |
| 183 | static ssize_t mtd_size_show(struct device *dev, |
| 184 | struct device_attribute *attr, char *buf) |
| 185 | { |
| 186 | struct mtd_info *mtd = dev_get_drvdata(dev); |
| 187 | |
| 188 | return snprintf(buf, PAGE_SIZE, "%llu\n", |
| 189 | (unsigned long long)mtd->size); |
| 190 | |
| 191 | } |
| 192 | static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL); |
| 193 | |
| 194 | static ssize_t mtd_erasesize_show(struct device *dev, |
| 195 | struct device_attribute *attr, char *buf) |
| 196 | { |
| 197 | struct mtd_info *mtd = dev_get_drvdata(dev); |
| 198 | |
| 199 | return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize); |
| 200 | |
| 201 | } |
| 202 | static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL); |
| 203 | |
| 204 | static ssize_t mtd_writesize_show(struct device *dev, |
| 205 | struct device_attribute *attr, char *buf) |
| 206 | { |
| 207 | struct mtd_info *mtd = dev_get_drvdata(dev); |
| 208 | |
| 209 | return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize); |
| 210 | |
| 211 | } |
| 212 | static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL); |
| 213 | |
| 214 | static ssize_t mtd_subpagesize_show(struct device *dev, |
| 215 | struct device_attribute *attr, char *buf) |
| 216 | { |
| 217 | struct mtd_info *mtd = dev_get_drvdata(dev); |
| 218 | unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft; |
| 219 | |
| 220 | return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize); |
| 221 | |
| 222 | } |
| 223 | static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL); |
| 224 | |
| 225 | static ssize_t mtd_oobsize_show(struct device *dev, |
| 226 | struct device_attribute *attr, char *buf) |
| 227 | { |
| 228 | struct mtd_info *mtd = dev_get_drvdata(dev); |
| 229 | |
| 230 | return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize); |
| 231 | |
| 232 | } |
| 233 | static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL); |
| 234 | |
| 235 | static ssize_t mtd_numeraseregions_show(struct device *dev, |
| 236 | struct device_attribute *attr, char *buf) |
| 237 | { |
| 238 | struct mtd_info *mtd = dev_get_drvdata(dev); |
| 239 | |
| 240 | return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions); |
| 241 | |
| 242 | } |
| 243 | static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show, |
| 244 | NULL); |
| 245 | |
| 246 | static ssize_t mtd_name_show(struct device *dev, |
| 247 | struct device_attribute *attr, char *buf) |
| 248 | { |
| 249 | struct mtd_info *mtd = dev_get_drvdata(dev); |
| 250 | |
| 251 | return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name); |
| 252 | |
| 253 | } |
| 254 | static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL); |
| 255 | |
| 256 | static struct attribute *mtd_attrs[] = { |
| 257 | &dev_attr_type.attr, |
| 258 | &dev_attr_flags.attr, |
| 259 | &dev_attr_size.attr, |
| 260 | &dev_attr_erasesize.attr, |
| 261 | &dev_attr_writesize.attr, |
| 262 | &dev_attr_subpagesize.attr, |
| 263 | &dev_attr_oobsize.attr, |
| 264 | &dev_attr_numeraseregions.attr, |
| 265 | &dev_attr_name.attr, |
| 266 | NULL, |
| 267 | }; |
| 268 | |
| 269 | static struct attribute_group mtd_group = { |
| 270 | .attrs = mtd_attrs, |
| 271 | }; |
| 272 | |
| 273 | static const struct attribute_group *mtd_groups[] = { |
| 274 | &mtd_group, |
| 275 | NULL, |
| 276 | }; |
| 277 | |
| 278 | static struct device_type mtd_devtype = { |
| 279 | .name = "mtd", |
| 280 | .groups = mtd_groups, |
| 281 | .release = mtd_release, |
| 282 | }; |
| 283 | |
| 284 | /** |
| 285 | * add_mtd_device - register an MTD device |
| 286 | * @mtd: pointer to new MTD device info structure |
| 287 | * |
| 288 | * Add a device to the list of MTD devices present in the system, and |
| 289 | * notify each currently active MTD 'user' of its arrival. Returns |
| 290 | * zero on success or 1 on failure, which currently will only happen |
| 291 | * if there is insufficient memory or a sysfs error. |
| 292 | */ |
| 293 | |
| 294 | int add_mtd_device(struct mtd_info *mtd) |
| 295 | { |
| 296 | struct mtd_notifier *not; |
| 297 | int i, error; |
| 298 | |
| 299 | if (!mtd->backing_dev_info) { |
| 300 | switch (mtd->type) { |
| 301 | case MTD_RAM: |
| 302 | mtd->backing_dev_info = &mtd_bdi_rw_mappable; |
| 303 | break; |
| 304 | case MTD_ROM: |
| 305 | mtd->backing_dev_info = &mtd_bdi_ro_mappable; |
| 306 | break; |
| 307 | default: |
| 308 | mtd->backing_dev_info = &mtd_bdi_unmappable; |
| 309 | break; |
| 310 | } |
| 311 | } |
| 312 | |
| 313 | BUG_ON(mtd->writesize == 0); |
| 314 | mutex_lock(&mtd_table_mutex); |
| 315 | |
| 316 | do { |
| 317 | if (!idr_pre_get(&mtd_idr, GFP_KERNEL)) |
| 318 | goto fail_locked; |
| 319 | error = idr_get_new(&mtd_idr, mtd, &i); |
| 320 | } while (error == -EAGAIN); |
| 321 | |
| 322 | if (error) |
| 323 | goto fail_locked; |
| 324 | |
| 325 | mtd->index = i; |
| 326 | mtd->usecount = 0; |
| 327 | |
| 328 | if (is_power_of_2(mtd->erasesize)) |
| 329 | mtd->erasesize_shift = ffs(mtd->erasesize) - 1; |
| 330 | else |
| 331 | mtd->erasesize_shift = 0; |
| 332 | |
| 333 | if (is_power_of_2(mtd->writesize)) |
| 334 | mtd->writesize_shift = ffs(mtd->writesize) - 1; |
| 335 | else |
| 336 | mtd->writesize_shift = 0; |
| 337 | |
| 338 | mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1; |
| 339 | mtd->writesize_mask = (1 << mtd->writesize_shift) - 1; |
| 340 | |
| 341 | /* Some chips always power up locked. Unlock them now */ |
| 342 | if ((mtd->flags & MTD_WRITEABLE) |
| 343 | && (mtd->flags & MTD_POWERUP_LOCK) && mtd->unlock) { |
| 344 | if (mtd_unlock(mtd, 0, mtd->size)) |
| 345 | printk(KERN_WARNING |
| 346 | "%s: unlock failed, writes may not work\n", |
| 347 | mtd->name); |
| 348 | } |
| 349 | |
| 350 | /* Caller should have set dev.parent to match the |
| 351 | * physical device. |
| 352 | */ |
| 353 | mtd->dev.type = &mtd_devtype; |
| 354 | mtd->dev.class = &mtd_class; |
| 355 | mtd->dev.devt = MTD_DEVT(i); |
| 356 | dev_set_name(&mtd->dev, "mtd%d", i); |
| 357 | dev_set_drvdata(&mtd->dev, mtd); |
| 358 | if (device_register(&mtd->dev) != 0) |
| 359 | goto fail_added; |
| 360 | |
| 361 | if (MTD_DEVT(i)) |
| 362 | device_create(&mtd_class, mtd->dev.parent, |
| 363 | MTD_DEVT(i) + 1, |
| 364 | NULL, "mtd%dro", i); |
| 365 | |
| 366 | pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name); |
| 367 | /* No need to get a refcount on the module containing |
| 368 | the notifier, since we hold the mtd_table_mutex */ |
| 369 | list_for_each_entry(not, &mtd_notifiers, list) |
| 370 | not->add(mtd); |
| 371 | |
| 372 | mutex_unlock(&mtd_table_mutex); |
| 373 | /* We _know_ we aren't being removed, because |
| 374 | our caller is still holding us here. So none |
| 375 | of this try_ nonsense, and no bitching about it |
| 376 | either. :) */ |
| 377 | __module_get(THIS_MODULE); |
| 378 | return 0; |
| 379 | |
| 380 | fail_added: |
| 381 | idr_remove(&mtd_idr, i); |
| 382 | fail_locked: |
| 383 | mutex_unlock(&mtd_table_mutex); |
| 384 | return 1; |
| 385 | } |
| 386 | |
| 387 | /** |
| 388 | * del_mtd_device - unregister an MTD device |
| 389 | * @mtd: pointer to MTD device info structure |
| 390 | * |
| 391 | * Remove a device from the list of MTD devices present in the system, |
| 392 | * and notify each currently active MTD 'user' of its departure. |
| 393 | * Returns zero on success or 1 on failure, which currently will happen |
| 394 | * if the requested device does not appear to be present in the list. |
| 395 | */ |
| 396 | |
| 397 | int del_mtd_device(struct mtd_info *mtd) |
| 398 | { |
| 399 | int ret; |
| 400 | struct mtd_notifier *not; |
| 401 | |
| 402 | mutex_lock(&mtd_table_mutex); |
| 403 | |
| 404 | if (idr_find(&mtd_idr, mtd->index) != mtd) { |
| 405 | ret = -ENODEV; |
| 406 | goto out_error; |
| 407 | } |
| 408 | |
| 409 | /* No need to get a refcount on the module containing |
| 410 | the notifier, since we hold the mtd_table_mutex */ |
| 411 | list_for_each_entry(not, &mtd_notifiers, list) |
| 412 | not->remove(mtd); |
| 413 | |
| 414 | if (mtd->usecount) { |
| 415 | printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n", |
| 416 | mtd->index, mtd->name, mtd->usecount); |
| 417 | ret = -EBUSY; |
| 418 | } else { |
| 419 | device_unregister(&mtd->dev); |
| 420 | |
| 421 | idr_remove(&mtd_idr, mtd->index); |
| 422 | |
| 423 | module_put(THIS_MODULE); |
| 424 | ret = 0; |
| 425 | } |
| 426 | |
| 427 | out_error: |
| 428 | mutex_unlock(&mtd_table_mutex); |
| 429 | return ret; |
| 430 | } |
| 431 | |
| 432 | /** |
| 433 | * mtd_device_parse_register - parse partitions and register an MTD device. |
| 434 | * |
| 435 | * @mtd: the MTD device to register |
| 436 | * @types: the list of MTD partition probes to try, see |
| 437 | * 'parse_mtd_partitions()' for more information |
| 438 | * @parser_data: MTD partition parser-specific data |
| 439 | * @parts: fallback partition information to register, if parsing fails; |
| 440 | * only valid if %nr_parts > %0 |
| 441 | * @nr_parts: the number of partitions in parts, if zero then the full |
| 442 | * MTD device is registered if no partition info is found |
| 443 | * |
| 444 | * This function aggregates MTD partitions parsing (done by |
| 445 | * 'parse_mtd_partitions()') and MTD device and partitions registering. It |
| 446 | * basically follows the most common pattern found in many MTD drivers: |
| 447 | * |
| 448 | * * It first tries to probe partitions on MTD device @mtd using parsers |
| 449 | * specified in @types (if @types is %NULL, then the default list of parsers |
| 450 | * is used, see 'parse_mtd_partitions()' for more information). If none are |
| 451 | * found this functions tries to fallback to information specified in |
| 452 | * @parts/@nr_parts. |
| 453 | * * If any partitioning info was found, this function registers the found |
| 454 | * partitions. |
| 455 | * * If no partitions were found this function just registers the MTD device |
| 456 | * @mtd and exits. |
| 457 | * |
| 458 | * Returns zero in case of success and a negative error code in case of failure. |
| 459 | */ |
| 460 | int mtd_device_parse_register(struct mtd_info *mtd, const char **types, |
| 461 | struct mtd_part_parser_data *parser_data, |
| 462 | const struct mtd_partition *parts, |
| 463 | int nr_parts) |
| 464 | { |
| 465 | int err; |
| 466 | struct mtd_partition *real_parts; |
| 467 | |
| 468 | err = parse_mtd_partitions(mtd, types, &real_parts, parser_data); |
| 469 | if (err <= 0 && nr_parts && parts) { |
| 470 | real_parts = kmemdup(parts, sizeof(*parts) * nr_parts, |
| 471 | GFP_KERNEL); |
| 472 | if (!real_parts) |
| 473 | err = -ENOMEM; |
| 474 | else |
| 475 | err = nr_parts; |
| 476 | } |
| 477 | |
| 478 | if (err > 0) { |
| 479 | err = add_mtd_partitions(mtd, real_parts, err); |
| 480 | kfree(real_parts); |
| 481 | } else if (err == 0) { |
| 482 | err = add_mtd_device(mtd); |
| 483 | if (err == 1) |
| 484 | err = -ENODEV; |
| 485 | } |
| 486 | |
| 487 | return err; |
| 488 | } |
| 489 | EXPORT_SYMBOL_GPL(mtd_device_parse_register); |
| 490 | |
| 491 | /** |
| 492 | * mtd_device_unregister - unregister an existing MTD device. |
| 493 | * |
| 494 | * @master: the MTD device to unregister. This will unregister both the master |
| 495 | * and any partitions if registered. |
| 496 | */ |
| 497 | int mtd_device_unregister(struct mtd_info *master) |
| 498 | { |
| 499 | int err; |
| 500 | |
| 501 | err = del_mtd_partitions(master); |
| 502 | if (err) |
| 503 | return err; |
| 504 | |
| 505 | if (!device_is_registered(&master->dev)) |
| 506 | return 0; |
| 507 | |
| 508 | return del_mtd_device(master); |
| 509 | } |
| 510 | EXPORT_SYMBOL_GPL(mtd_device_unregister); |
| 511 | |
| 512 | /** |
| 513 | * register_mtd_user - register a 'user' of MTD devices. |
| 514 | * @new: pointer to notifier info structure |
| 515 | * |
| 516 | * Registers a pair of callbacks function to be called upon addition |
| 517 | * or removal of MTD devices. Causes the 'add' callback to be immediately |
| 518 | * invoked for each MTD device currently present in the system. |
| 519 | */ |
| 520 | |
| 521 | void register_mtd_user (struct mtd_notifier *new) |
| 522 | { |
| 523 | struct mtd_info *mtd; |
| 524 | |
| 525 | mutex_lock(&mtd_table_mutex); |
| 526 | |
| 527 | list_add(&new->list, &mtd_notifiers); |
| 528 | |
| 529 | __module_get(THIS_MODULE); |
| 530 | |
| 531 | mtd_for_each_device(mtd) |
| 532 | new->add(mtd); |
| 533 | |
| 534 | mutex_unlock(&mtd_table_mutex); |
| 535 | } |
| 536 | |
| 537 | /** |
| 538 | * unregister_mtd_user - unregister a 'user' of MTD devices. |
| 539 | * @old: pointer to notifier info structure |
| 540 | * |
| 541 | * Removes a callback function pair from the list of 'users' to be |
| 542 | * notified upon addition or removal of MTD devices. Causes the |
| 543 | * 'remove' callback to be immediately invoked for each MTD device |
| 544 | * currently present in the system. |
| 545 | */ |
| 546 | |
| 547 | int unregister_mtd_user (struct mtd_notifier *old) |
| 548 | { |
| 549 | struct mtd_info *mtd; |
| 550 | |
| 551 | mutex_lock(&mtd_table_mutex); |
| 552 | |
| 553 | module_put(THIS_MODULE); |
| 554 | |
| 555 | mtd_for_each_device(mtd) |
| 556 | old->remove(mtd); |
| 557 | |
| 558 | list_del(&old->list); |
| 559 | mutex_unlock(&mtd_table_mutex); |
| 560 | return 0; |
| 561 | } |
| 562 | |
| 563 | |
| 564 | /** |
| 565 | * get_mtd_device - obtain a validated handle for an MTD device |
| 566 | * @mtd: last known address of the required MTD device |
| 567 | * @num: internal device number of the required MTD device |
| 568 | * |
| 569 | * Given a number and NULL address, return the num'th entry in the device |
| 570 | * table, if any. Given an address and num == -1, search the device table |
| 571 | * for a device with that address and return if it's still present. Given |
| 572 | * both, return the num'th driver only if its address matches. Return |
| 573 | * error code if not. |
| 574 | */ |
| 575 | |
| 576 | struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num) |
| 577 | { |
| 578 | struct mtd_info *ret = NULL, *other; |
| 579 | int err = -ENODEV; |
| 580 | |
| 581 | mutex_lock(&mtd_table_mutex); |
| 582 | |
| 583 | if (num == -1) { |
| 584 | mtd_for_each_device(other) { |
| 585 | if (other == mtd) { |
| 586 | ret = mtd; |
| 587 | break; |
| 588 | } |
| 589 | } |
| 590 | } else if (num >= 0) { |
| 591 | ret = idr_find(&mtd_idr, num); |
| 592 | if (mtd && mtd != ret) |
| 593 | ret = NULL; |
| 594 | } |
| 595 | |
| 596 | if (!ret) { |
| 597 | ret = ERR_PTR(err); |
| 598 | goto out; |
| 599 | } |
| 600 | |
| 601 | err = __get_mtd_device(ret); |
| 602 | if (err) |
| 603 | ret = ERR_PTR(err); |
| 604 | out: |
| 605 | mutex_unlock(&mtd_table_mutex); |
| 606 | return ret; |
| 607 | } |
| 608 | |
| 609 | |
| 610 | int __get_mtd_device(struct mtd_info *mtd) |
| 611 | { |
| 612 | int err; |
| 613 | |
| 614 | if (!try_module_get(mtd->owner)) |
| 615 | return -ENODEV; |
| 616 | |
| 617 | if (mtd->get_device) { |
| 618 | err = mtd->get_device(mtd); |
| 619 | |
| 620 | if (err) { |
| 621 | module_put(mtd->owner); |
| 622 | return err; |
| 623 | } |
| 624 | } |
| 625 | mtd->usecount++; |
| 626 | return 0; |
| 627 | } |
| 628 | |
| 629 | /** |
| 630 | * get_mtd_device_nm - obtain a validated handle for an MTD device by |
| 631 | * device name |
| 632 | * @name: MTD device name to open |
| 633 | * |
| 634 | * This function returns MTD device description structure in case of |
| 635 | * success and an error code in case of failure. |
| 636 | */ |
| 637 | |
| 638 | struct mtd_info *get_mtd_device_nm(const char *name) |
| 639 | { |
| 640 | int err = -ENODEV; |
| 641 | struct mtd_info *mtd = NULL, *other; |
| 642 | |
| 643 | mutex_lock(&mtd_table_mutex); |
| 644 | |
| 645 | mtd_for_each_device(other) { |
| 646 | if (!strcmp(name, other->name)) { |
| 647 | mtd = other; |
| 648 | break; |
| 649 | } |
| 650 | } |
| 651 | |
| 652 | if (!mtd) |
| 653 | goto out_unlock; |
| 654 | |
| 655 | err = __get_mtd_device(mtd); |
| 656 | if (err) |
| 657 | goto out_unlock; |
| 658 | |
| 659 | mutex_unlock(&mtd_table_mutex); |
| 660 | return mtd; |
| 661 | |
| 662 | out_unlock: |
| 663 | mutex_unlock(&mtd_table_mutex); |
| 664 | return ERR_PTR(err); |
| 665 | } |
| 666 | |
| 667 | void put_mtd_device(struct mtd_info *mtd) |
| 668 | { |
| 669 | mutex_lock(&mtd_table_mutex); |
| 670 | __put_mtd_device(mtd); |
| 671 | mutex_unlock(&mtd_table_mutex); |
| 672 | |
| 673 | } |
| 674 | |
| 675 | void __put_mtd_device(struct mtd_info *mtd) |
| 676 | { |
| 677 | --mtd->usecount; |
| 678 | BUG_ON(mtd->usecount < 0); |
| 679 | |
| 680 | if (mtd->put_device) |
| 681 | mtd->put_device(mtd); |
| 682 | |
| 683 | module_put(mtd->owner); |
| 684 | } |
| 685 | |
| 686 | /* default_mtd_writev - default mtd writev method for MTD devices that |
| 687 | * don't implement their own |
| 688 | */ |
| 689 | |
| 690 | int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs, |
| 691 | unsigned long count, loff_t to, size_t *retlen) |
| 692 | { |
| 693 | unsigned long i; |
| 694 | size_t totlen = 0, thislen; |
| 695 | int ret = 0; |
| 696 | |
| 697 | if(!mtd->write) { |
| 698 | ret = -EROFS; |
| 699 | } else { |
| 700 | for (i=0; i<count; i++) { |
| 701 | if (!vecs[i].iov_len) |
| 702 | continue; |
| 703 | ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen, |
| 704 | vecs[i].iov_base); |
| 705 | totlen += thislen; |
| 706 | if (ret || thislen != vecs[i].iov_len) |
| 707 | break; |
| 708 | to += vecs[i].iov_len; |
| 709 | } |
| 710 | } |
| 711 | if (retlen) |
| 712 | *retlen = totlen; |
| 713 | return ret; |
| 714 | } |
| 715 | |
| 716 | /** |
| 717 | * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size |
| 718 | * @size: A pointer to the ideal or maximum size of the allocation. Points |
| 719 | * to the actual allocation size on success. |
| 720 | * |
| 721 | * This routine attempts to allocate a contiguous kernel buffer up to |
| 722 | * the specified size, backing off the size of the request exponentially |
| 723 | * until the request succeeds or until the allocation size falls below |
| 724 | * the system page size. This attempts to make sure it does not adversely |
| 725 | * impact system performance, so when allocating more than one page, we |
| 726 | * ask the memory allocator to avoid re-trying, swapping, writing back |
| 727 | * or performing I/O. |
| 728 | * |
| 729 | * Note, this function also makes sure that the allocated buffer is aligned to |
| 730 | * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value. |
| 731 | * |
| 732 | * This is called, for example by mtd_{read,write} and jffs2_scan_medium, |
| 733 | * to handle smaller (i.e. degraded) buffer allocations under low- or |
| 734 | * fragmented-memory situations where such reduced allocations, from a |
| 735 | * requested ideal, are allowed. |
| 736 | * |
| 737 | * Returns a pointer to the allocated buffer on success; otherwise, NULL. |
| 738 | */ |
| 739 | void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size) |
| 740 | { |
| 741 | gfp_t flags = __GFP_NOWARN | __GFP_WAIT | |
| 742 | __GFP_NORETRY | __GFP_NO_KSWAPD; |
| 743 | size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE); |
| 744 | void *kbuf; |
| 745 | |
| 746 | *size = min_t(size_t, *size, KMALLOC_MAX_SIZE); |
| 747 | |
| 748 | while (*size > min_alloc) { |
| 749 | kbuf = kmalloc(*size, flags); |
| 750 | if (kbuf) |
| 751 | return kbuf; |
| 752 | |
| 753 | *size >>= 1; |
| 754 | *size = ALIGN(*size, mtd->writesize); |
| 755 | } |
| 756 | |
| 757 | /* |
| 758 | * For the last resort allocation allow 'kmalloc()' to do all sorts of |
| 759 | * things (write-back, dropping caches, etc) by using GFP_KERNEL. |
| 760 | */ |
| 761 | return kmalloc(*size, GFP_KERNEL); |
| 762 | } |
| 763 | |
| 764 | EXPORT_SYMBOL_GPL(get_mtd_device); |
| 765 | EXPORT_SYMBOL_GPL(get_mtd_device_nm); |
| 766 | EXPORT_SYMBOL_GPL(__get_mtd_device); |
| 767 | EXPORT_SYMBOL_GPL(put_mtd_device); |
| 768 | EXPORT_SYMBOL_GPL(__put_mtd_device); |
| 769 | EXPORT_SYMBOL_GPL(register_mtd_user); |
| 770 | EXPORT_SYMBOL_GPL(unregister_mtd_user); |
| 771 | EXPORT_SYMBOL_GPL(default_mtd_writev); |
| 772 | EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to); |
| 773 | |
| 774 | #ifdef CONFIG_PROC_FS |
| 775 | |
| 776 | /*====================================================================*/ |
| 777 | /* Support for /proc/mtd */ |
| 778 | |
| 779 | static struct proc_dir_entry *proc_mtd; |
| 780 | |
| 781 | static int mtd_proc_show(struct seq_file *m, void *v) |
| 782 | { |
| 783 | struct mtd_info *mtd; |
| 784 | |
| 785 | seq_puts(m, "dev: size erasesize name\n"); |
| 786 | mutex_lock(&mtd_table_mutex); |
| 787 | mtd_for_each_device(mtd) { |
| 788 | seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n", |
| 789 | mtd->index, (unsigned long long)mtd->size, |
| 790 | mtd->erasesize, mtd->name); |
| 791 | } |
| 792 | mutex_unlock(&mtd_table_mutex); |
| 793 | return 0; |
| 794 | } |
| 795 | |
| 796 | static int mtd_proc_open(struct inode *inode, struct file *file) |
| 797 | { |
| 798 | return single_open(file, mtd_proc_show, NULL); |
| 799 | } |
| 800 | |
| 801 | static const struct file_operations mtd_proc_ops = { |
| 802 | .open = mtd_proc_open, |
| 803 | .read = seq_read, |
| 804 | .llseek = seq_lseek, |
| 805 | .release = single_release, |
| 806 | }; |
| 807 | #endif /* CONFIG_PROC_FS */ |
| 808 | |
| 809 | /*====================================================================*/ |
| 810 | /* Init code */ |
| 811 | |
| 812 | static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name) |
| 813 | { |
| 814 | int ret; |
| 815 | |
| 816 | ret = bdi_init(bdi); |
| 817 | if (!ret) |
| 818 | ret = bdi_register(bdi, NULL, name); |
| 819 | |
| 820 | if (ret) |
| 821 | bdi_destroy(bdi); |
| 822 | |
| 823 | return ret; |
| 824 | } |
| 825 | |
| 826 | static int __init init_mtd(void) |
| 827 | { |
| 828 | int ret; |
| 829 | |
| 830 | ret = class_register(&mtd_class); |
| 831 | if (ret) |
| 832 | goto err_reg; |
| 833 | |
| 834 | ret = mtd_bdi_init(&mtd_bdi_unmappable, "mtd-unmap"); |
| 835 | if (ret) |
| 836 | goto err_bdi1; |
| 837 | |
| 838 | ret = mtd_bdi_init(&mtd_bdi_ro_mappable, "mtd-romap"); |
| 839 | if (ret) |
| 840 | goto err_bdi2; |
| 841 | |
| 842 | ret = mtd_bdi_init(&mtd_bdi_rw_mappable, "mtd-rwmap"); |
| 843 | if (ret) |
| 844 | goto err_bdi3; |
| 845 | |
| 846 | #ifdef CONFIG_PROC_FS |
| 847 | proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops); |
| 848 | #endif /* CONFIG_PROC_FS */ |
| 849 | return 0; |
| 850 | |
| 851 | err_bdi3: |
| 852 | bdi_destroy(&mtd_bdi_ro_mappable); |
| 853 | err_bdi2: |
| 854 | bdi_destroy(&mtd_bdi_unmappable); |
| 855 | err_bdi1: |
| 856 | class_unregister(&mtd_class); |
| 857 | err_reg: |
| 858 | pr_err("Error registering mtd class or bdi: %d\n", ret); |
| 859 | return ret; |
| 860 | } |
| 861 | |
| 862 | static void __exit cleanup_mtd(void) |
| 863 | { |
| 864 | #ifdef CONFIG_PROC_FS |
| 865 | if (proc_mtd) |
| 866 | remove_proc_entry( "mtd", NULL); |
| 867 | #endif /* CONFIG_PROC_FS */ |
| 868 | class_unregister(&mtd_class); |
| 869 | bdi_destroy(&mtd_bdi_unmappable); |
| 870 | bdi_destroy(&mtd_bdi_ro_mappable); |
| 871 | bdi_destroy(&mtd_bdi_rw_mappable); |
| 872 | } |
| 873 | |
| 874 | module_init(init_mtd); |
| 875 | module_exit(cleanup_mtd); |
| 876 | |
| 877 | MODULE_LICENSE("GPL"); |
| 878 | MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>"); |
| 879 | MODULE_DESCRIPTION("Core MTD registration and access routines"); |