1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Core registration and callback routines for MTD
4 * drivers and users.
5 *
6 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
7 * Copyright © 2006 Red Hat UK Limited
8 */
9
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/ptrace.h>
13 #include <linux/seq_file.h>
14 #include <linux/string.h>
15 #include <linux/timer.h>
16 #include <linux/major.h>
17 #include <linux/fs.h>
18 #include <linux/err.h>
19 #include <linux/ioctl.h>
20 #include <linux/init.h>
21 #include <linux/of.h>
22 #include <linux/proc_fs.h>
23 #include <linux/idr.h>
24 #include <linux/backing-dev.h>
25 #include <linux/gfp.h>
26 #include <linux/slab.h>
27 #include <linux/reboot.h>
28 #include <linux/leds.h>
29 #include <linux/debugfs.h>
30 #include <linux/nvmem-provider.h>
31
32 #include <linux/mtd/mtd.h>
33 #include <linux/mtd/partitions.h>
34
35 #include "mtdcore.h"
36
37 struct backing_dev_info *mtd_bdi;
38
39 #ifdef CONFIG_PM_SLEEP
40
mtd_cls_suspend(struct device * dev)41 static int mtd_cls_suspend(struct device *dev)
42 {
43 struct mtd_info *mtd = dev_get_drvdata(dev);
44
45 return mtd ? mtd_suspend(mtd) : 0;
46 }
47
mtd_cls_resume(struct device * dev)48 static int mtd_cls_resume(struct device *dev)
49 {
50 struct mtd_info *mtd = dev_get_drvdata(dev);
51
52 if (mtd)
53 mtd_resume(mtd);
54 return 0;
55 }
56
57 static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
58 #define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
59 #else
60 #define MTD_CLS_PM_OPS NULL
61 #endif
62
63 static struct class mtd_class = {
64 .name = "mtd",
65 .owner = THIS_MODULE,
66 .pm = MTD_CLS_PM_OPS,
67 };
68
69 static DEFINE_IDR(mtd_idr);
70
71 /* These are exported solely for the purpose of mtd_blkdevs.c. You
72 should not use them for _anything_ else */
73 DEFINE_MUTEX(mtd_table_mutex);
74 EXPORT_SYMBOL_GPL(mtd_table_mutex);
75
__mtd_next_device(int i)76 struct mtd_info *__mtd_next_device(int i)
77 {
78 return idr_get_next(&mtd_idr, &i);
79 }
80 EXPORT_SYMBOL_GPL(__mtd_next_device);
81
82 static LIST_HEAD(mtd_notifiers);
83
84
85 #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
86
87 /* REVISIT once MTD uses the driver model better, whoever allocates
88 * the mtd_info will probably want to use the release() hook...
89 */
mtd_release(struct device * dev)90 static void mtd_release(struct device *dev)
91 {
92 struct mtd_info *mtd = dev_get_drvdata(dev);
93 dev_t index = MTD_DEVT(mtd->index);
94
95 /* remove /dev/mtdXro node */
96 device_destroy(&mtd_class, index + 1);
97 }
98
99 #define MTD_DEVICE_ATTR_RO(name) \
100 static DEVICE_ATTR(name, 0444, mtd_##name##_show, NULL)
101
102 #define MTD_DEVICE_ATTR_RW(name) \
103 static DEVICE_ATTR(name, 0644, mtd_##name##_show, mtd_##name##_store)
104
mtd_type_show(struct device * dev,struct device_attribute * attr,char * buf)105 static ssize_t mtd_type_show(struct device *dev,
106 struct device_attribute *attr, char *buf)
107 {
108 struct mtd_info *mtd = dev_get_drvdata(dev);
109 char *type;
110
111 switch (mtd->type) {
112 case MTD_ABSENT:
113 type = "absent";
114 break;
115 case MTD_RAM:
116 type = "ram";
117 break;
118 case MTD_ROM:
119 type = "rom";
120 break;
121 case MTD_NORFLASH:
122 type = "nor";
123 break;
124 case MTD_NANDFLASH:
125 type = "nand";
126 break;
127 case MTD_DATAFLASH:
128 type = "dataflash";
129 break;
130 case MTD_UBIVOLUME:
131 type = "ubi";
132 break;
133 case MTD_MLCNANDFLASH:
134 type = "mlc-nand";
135 break;
136 default:
137 type = "unknown";
138 }
139
140 return sysfs_emit(buf, "%s\n", type);
141 }
142 MTD_DEVICE_ATTR_RO(type);
143
mtd_flags_show(struct device * dev,struct device_attribute * attr,char * buf)144 static ssize_t mtd_flags_show(struct device *dev,
145 struct device_attribute *attr, char *buf)
146 {
147 struct mtd_info *mtd = dev_get_drvdata(dev);
148
149 return sysfs_emit(buf, "0x%lx\n", (unsigned long)mtd->flags);
150 }
151 MTD_DEVICE_ATTR_RO(flags);
152
mtd_size_show(struct device * dev,struct device_attribute * attr,char * buf)153 static ssize_t mtd_size_show(struct device *dev,
154 struct device_attribute *attr, char *buf)
155 {
156 struct mtd_info *mtd = dev_get_drvdata(dev);
157
158 return sysfs_emit(buf, "%llu\n", (unsigned long long)mtd->size);
159 }
160 MTD_DEVICE_ATTR_RO(size);
161
mtd_erasesize_show(struct device * dev,struct device_attribute * attr,char * buf)162 static ssize_t mtd_erasesize_show(struct device *dev,
163 struct device_attribute *attr, char *buf)
164 {
165 struct mtd_info *mtd = dev_get_drvdata(dev);
166
167 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->erasesize);
168 }
169 MTD_DEVICE_ATTR_RO(erasesize);
170
mtd_writesize_show(struct device * dev,struct device_attribute * attr,char * buf)171 static ssize_t mtd_writesize_show(struct device *dev,
172 struct device_attribute *attr, char *buf)
173 {
174 struct mtd_info *mtd = dev_get_drvdata(dev);
175
176 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->writesize);
177 }
178 MTD_DEVICE_ATTR_RO(writesize);
179
mtd_subpagesize_show(struct device * dev,struct device_attribute * attr,char * buf)180 static ssize_t mtd_subpagesize_show(struct device *dev,
181 struct device_attribute *attr, char *buf)
182 {
183 struct mtd_info *mtd = dev_get_drvdata(dev);
184 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
185
186 return sysfs_emit(buf, "%u\n", subpagesize);
187 }
188 MTD_DEVICE_ATTR_RO(subpagesize);
189
mtd_oobsize_show(struct device * dev,struct device_attribute * attr,char * buf)190 static ssize_t mtd_oobsize_show(struct device *dev,
191 struct device_attribute *attr, char *buf)
192 {
193 struct mtd_info *mtd = dev_get_drvdata(dev);
194
195 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->oobsize);
196 }
197 MTD_DEVICE_ATTR_RO(oobsize);
198
mtd_oobavail_show(struct device * dev,struct device_attribute * attr,char * buf)199 static ssize_t mtd_oobavail_show(struct device *dev,
200 struct device_attribute *attr, char *buf)
201 {
202 struct mtd_info *mtd = dev_get_drvdata(dev);
203
204 return sysfs_emit(buf, "%u\n", mtd->oobavail);
205 }
206 MTD_DEVICE_ATTR_RO(oobavail);
207
mtd_numeraseregions_show(struct device * dev,struct device_attribute * attr,char * buf)208 static ssize_t mtd_numeraseregions_show(struct device *dev,
209 struct device_attribute *attr, char *buf)
210 {
211 struct mtd_info *mtd = dev_get_drvdata(dev);
212
213 return sysfs_emit(buf, "%u\n", mtd->numeraseregions);
214 }
215 MTD_DEVICE_ATTR_RO(numeraseregions);
216
mtd_name_show(struct device * dev,struct device_attribute * attr,char * buf)217 static ssize_t mtd_name_show(struct device *dev,
218 struct device_attribute *attr, char *buf)
219 {
220 struct mtd_info *mtd = dev_get_drvdata(dev);
221
222 return sysfs_emit(buf, "%s\n", mtd->name);
223 }
224 MTD_DEVICE_ATTR_RO(name);
225
mtd_ecc_strength_show(struct device * dev,struct device_attribute * attr,char * buf)226 static ssize_t mtd_ecc_strength_show(struct device *dev,
227 struct device_attribute *attr, char *buf)
228 {
229 struct mtd_info *mtd = dev_get_drvdata(dev);
230
231 return sysfs_emit(buf, "%u\n", mtd->ecc_strength);
232 }
233 MTD_DEVICE_ATTR_RO(ecc_strength);
234
mtd_bitflip_threshold_show(struct device * dev,struct device_attribute * attr,char * buf)235 static ssize_t mtd_bitflip_threshold_show(struct device *dev,
236 struct device_attribute *attr,
237 char *buf)
238 {
239 struct mtd_info *mtd = dev_get_drvdata(dev);
240
241 return sysfs_emit(buf, "%u\n", mtd->bitflip_threshold);
242 }
243
mtd_bitflip_threshold_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)244 static ssize_t mtd_bitflip_threshold_store(struct device *dev,
245 struct device_attribute *attr,
246 const char *buf, size_t count)
247 {
248 struct mtd_info *mtd = dev_get_drvdata(dev);
249 unsigned int bitflip_threshold;
250 int retval;
251
252 retval = kstrtouint(buf, 0, &bitflip_threshold);
253 if (retval)
254 return retval;
255
256 mtd->bitflip_threshold = bitflip_threshold;
257 return count;
258 }
259 MTD_DEVICE_ATTR_RW(bitflip_threshold);
260
mtd_ecc_step_size_show(struct device * dev,struct device_attribute * attr,char * buf)261 static ssize_t mtd_ecc_step_size_show(struct device *dev,
262 struct device_attribute *attr, char *buf)
263 {
264 struct mtd_info *mtd = dev_get_drvdata(dev);
265
266 return sysfs_emit(buf, "%u\n", mtd->ecc_step_size);
267
268 }
269 MTD_DEVICE_ATTR_RO(ecc_step_size);
270
mtd_corrected_bits_show(struct device * dev,struct device_attribute * attr,char * buf)271 static ssize_t mtd_corrected_bits_show(struct device *dev,
272 struct device_attribute *attr, char *buf)
273 {
274 struct mtd_info *mtd = dev_get_drvdata(dev);
275 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
276
277 return sysfs_emit(buf, "%u\n", ecc_stats->corrected);
278 }
279 MTD_DEVICE_ATTR_RO(corrected_bits); /* ecc stats corrected */
280
mtd_ecc_failures_show(struct device * dev,struct device_attribute * attr,char * buf)281 static ssize_t mtd_ecc_failures_show(struct device *dev,
282 struct device_attribute *attr, char *buf)
283 {
284 struct mtd_info *mtd = dev_get_drvdata(dev);
285 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
286
287 return sysfs_emit(buf, "%u\n", ecc_stats->failed);
288 }
289 MTD_DEVICE_ATTR_RO(ecc_failures); /* ecc stats errors */
290
mtd_bad_blocks_show(struct device * dev,struct device_attribute * attr,char * buf)291 static ssize_t mtd_bad_blocks_show(struct device *dev,
292 struct device_attribute *attr, char *buf)
293 {
294 struct mtd_info *mtd = dev_get_drvdata(dev);
295 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
296
297 return sysfs_emit(buf, "%u\n", ecc_stats->badblocks);
298 }
299 MTD_DEVICE_ATTR_RO(bad_blocks);
300
mtd_bbt_blocks_show(struct device * dev,struct device_attribute * attr,char * buf)301 static ssize_t mtd_bbt_blocks_show(struct device *dev,
302 struct device_attribute *attr, char *buf)
303 {
304 struct mtd_info *mtd = dev_get_drvdata(dev);
305 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
306
307 return sysfs_emit(buf, "%u\n", ecc_stats->bbtblocks);
308 }
309 MTD_DEVICE_ATTR_RO(bbt_blocks);
310
311 static struct attribute *mtd_attrs[] = {
312 &dev_attr_type.attr,
313 &dev_attr_flags.attr,
314 &dev_attr_size.attr,
315 &dev_attr_erasesize.attr,
316 &dev_attr_writesize.attr,
317 &dev_attr_subpagesize.attr,
318 &dev_attr_oobsize.attr,
319 &dev_attr_oobavail.attr,
320 &dev_attr_numeraseregions.attr,
321 &dev_attr_name.attr,
322 &dev_attr_ecc_strength.attr,
323 &dev_attr_ecc_step_size.attr,
324 &dev_attr_corrected_bits.attr,
325 &dev_attr_ecc_failures.attr,
326 &dev_attr_bad_blocks.attr,
327 &dev_attr_bbt_blocks.attr,
328 &dev_attr_bitflip_threshold.attr,
329 NULL,
330 };
331 ATTRIBUTE_GROUPS(mtd);
332
333 static const struct device_type mtd_devtype = {
334 .name = "mtd",
335 .groups = mtd_groups,
336 .release = mtd_release,
337 };
338
339 static bool mtd_expert_analysis_mode;
340
341 #ifdef CONFIG_DEBUG_FS
mtd_check_expert_analysis_mode(void)342 bool mtd_check_expert_analysis_mode(void)
343 {
344 const char *mtd_expert_analysis_warning =
345 "Bad block checks have been entirely disabled.\n"
346 "This is only reserved for post-mortem forensics and debug purposes.\n"
347 "Never enable this mode if you do not know what you are doing!\n";
348
349 return WARN_ONCE(mtd_expert_analysis_mode, mtd_expert_analysis_warning);
350 }
351 EXPORT_SYMBOL_GPL(mtd_check_expert_analysis_mode);
352 #endif
353
354 static struct dentry *dfs_dir_mtd;
355
mtd_debugfs_populate(struct mtd_info * mtd)356 static void mtd_debugfs_populate(struct mtd_info *mtd)
357 {
358 struct device *dev = &mtd->dev;
359
360 if (IS_ERR_OR_NULL(dfs_dir_mtd))
361 return;
362
363 mtd->dbg.dfs_dir = debugfs_create_dir(dev_name(dev), dfs_dir_mtd);
364 }
365
366 #ifndef CONFIG_MMU
mtd_mmap_capabilities(struct mtd_info * mtd)367 unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
368 {
369 switch (mtd->type) {
370 case MTD_RAM:
371 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
372 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
373 case MTD_ROM:
374 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
375 NOMMU_MAP_READ;
376 default:
377 return NOMMU_MAP_COPY;
378 }
379 }
380 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
381 #endif
382
mtd_reboot_notifier(struct notifier_block * n,unsigned long state,void * cmd)383 static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
384 void *cmd)
385 {
386 struct mtd_info *mtd;
387
388 mtd = container_of(n, struct mtd_info, reboot_notifier);
389 mtd->_reboot(mtd);
390
391 return NOTIFY_DONE;
392 }
393
394 /**
395 * mtd_wunit_to_pairing_info - get pairing information of a wunit
396 * @mtd: pointer to new MTD device info structure
397 * @wunit: write unit we are interested in
398 * @info: returned pairing information
399 *
400 * Retrieve pairing information associated to the wunit.
401 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
402 * paired together, and where programming a page may influence the page it is
403 * paired with.
404 * The notion of page is replaced by the term wunit (write-unit) to stay
405 * consistent with the ->writesize field.
406 *
407 * The @wunit argument can be extracted from an absolute offset using
408 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
409 * to @wunit.
410 *
411 * From the pairing info the MTD user can find all the wunits paired with
412 * @wunit using the following loop:
413 *
414 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
415 * info.pair = i;
416 * mtd_pairing_info_to_wunit(mtd, &info);
417 * ...
418 * }
419 */
mtd_wunit_to_pairing_info(struct mtd_info * mtd,int wunit,struct mtd_pairing_info * info)420 int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
421 struct mtd_pairing_info *info)
422 {
423 struct mtd_info *master = mtd_get_master(mtd);
424 int npairs = mtd_wunit_per_eb(master) / mtd_pairing_groups(master);
425
426 if (wunit < 0 || wunit >= npairs)
427 return -EINVAL;
428
429 if (master->pairing && master->pairing->get_info)
430 return master->pairing->get_info(master, wunit, info);
431
432 info->group = 0;
433 info->pair = wunit;
434
435 return 0;
436 }
437 EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
438
439 /**
440 * mtd_pairing_info_to_wunit - get wunit from pairing information
441 * @mtd: pointer to new MTD device info structure
442 * @info: pairing information struct
443 *
444 * Returns a positive number representing the wunit associated to the info
445 * struct, or a negative error code.
446 *
447 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
448 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
449 * doc).
450 *
451 * It can also be used to only program the first page of each pair (i.e.
452 * page attached to group 0), which allows one to use an MLC NAND in
453 * software-emulated SLC mode:
454 *
455 * info.group = 0;
456 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
457 * for (info.pair = 0; info.pair < npairs; info.pair++) {
458 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
459 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
460 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
461 * }
462 */
mtd_pairing_info_to_wunit(struct mtd_info * mtd,const struct mtd_pairing_info * info)463 int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
464 const struct mtd_pairing_info *info)
465 {
466 struct mtd_info *master = mtd_get_master(mtd);
467 int ngroups = mtd_pairing_groups(master);
468 int npairs = mtd_wunit_per_eb(master) / ngroups;
469
470 if (!info || info->pair < 0 || info->pair >= npairs ||
471 info->group < 0 || info->group >= ngroups)
472 return -EINVAL;
473
474 if (master->pairing && master->pairing->get_wunit)
475 return mtd->pairing->get_wunit(master, info);
476
477 return info->pair;
478 }
479 EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
480
481 /**
482 * mtd_pairing_groups - get the number of pairing groups
483 * @mtd: pointer to new MTD device info structure
484 *
485 * Returns the number of pairing groups.
486 *
487 * This number is usually equal to the number of bits exposed by a single
488 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
489 * to iterate over all pages of a given pair.
490 */
mtd_pairing_groups(struct mtd_info * mtd)491 int mtd_pairing_groups(struct mtd_info *mtd)
492 {
493 struct mtd_info *master = mtd_get_master(mtd);
494
495 if (!master->pairing || !master->pairing->ngroups)
496 return 1;
497
498 return master->pairing->ngroups;
499 }
500 EXPORT_SYMBOL_GPL(mtd_pairing_groups);
501
mtd_nvmem_reg_read(void * priv,unsigned int offset,void * val,size_t bytes)502 static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
503 void *val, size_t bytes)
504 {
505 struct mtd_info *mtd = priv;
506 size_t retlen;
507 int err;
508
509 err = mtd_read(mtd, offset, bytes, &retlen, val);
510 if (err && err != -EUCLEAN)
511 return err;
512
513 return retlen == bytes ? 0 : -EIO;
514 }
515
mtd_nvmem_add(struct mtd_info * mtd)516 static int mtd_nvmem_add(struct mtd_info *mtd)
517 {
518 struct device_node *node = mtd_get_of_node(mtd);
519 struct nvmem_config config = {};
520
521 config.id = -1;
522 config.dev = &mtd->dev;
523 config.name = dev_name(&mtd->dev);
524 config.owner = THIS_MODULE;
525 config.reg_read = mtd_nvmem_reg_read;
526 config.size = mtd->size;
527 config.word_size = 1;
528 config.stride = 1;
529 config.read_only = true;
530 config.root_only = true;
531 config.ignore_wp = true;
532 config.no_of_node = !of_device_is_compatible(node, "nvmem-cells");
533 config.priv = mtd;
534
535 mtd->nvmem = nvmem_register(&config);
536 if (IS_ERR(mtd->nvmem)) {
537 /* Just ignore if there is no NVMEM support in the kernel */
538 if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP) {
539 mtd->nvmem = NULL;
540 } else {
541 dev_err(&mtd->dev, "Failed to register NVMEM device\n");
542 return PTR_ERR(mtd->nvmem);
543 }
544 }
545
546 return 0;
547 }
548
mtd_check_of_node(struct mtd_info * mtd)549 static void mtd_check_of_node(struct mtd_info *mtd)
550 {
551 struct device_node *partitions, *parent_dn, *mtd_dn = NULL;
552 const char *pname, *prefix = "partition-";
553 int plen, mtd_name_len, offset, prefix_len;
554 struct mtd_info *parent;
555 bool found = false;
556
557 /* Check if MTD already has a device node */
558 if (dev_of_node(&mtd->dev))
559 return;
560
561 /* Check if a partitions node exist */
562 if (!mtd_is_partition(mtd))
563 return;
564 parent = mtd->parent;
565 parent_dn = of_node_get(dev_of_node(&parent->dev));
566 if (!parent_dn)
567 return;
568
569 partitions = of_get_child_by_name(parent_dn, "partitions");
570 if (!partitions)
571 goto exit_parent;
572
573 prefix_len = strlen(prefix);
574 mtd_name_len = strlen(mtd->name);
575
576 /* Search if a partition is defined with the same name */
577 for_each_child_of_node(partitions, mtd_dn) {
578 offset = 0;
579
580 /* Skip partition with no/wrong prefix */
581 if (!of_node_name_prefix(mtd_dn, "partition-"))
582 continue;
583
584 /* Label have priority. Check that first */
585 if (of_property_read_string(mtd_dn, "label", &pname)) {
586 of_property_read_string(mtd_dn, "name", &pname);
587 offset = prefix_len;
588 }
589
590 plen = strlen(pname) - offset;
591 if (plen == mtd_name_len &&
592 !strncmp(mtd->name, pname + offset, plen)) {
593 found = true;
594 break;
595 }
596 }
597
598 if (!found)
599 goto exit_partitions;
600
601 /* Set of_node only for nvmem */
602 if (of_device_is_compatible(mtd_dn, "nvmem-cells"))
603 mtd_set_of_node(mtd, mtd_dn);
604
605 exit_partitions:
606 of_node_put(partitions);
607 exit_parent:
608 of_node_put(parent_dn);
609 }
610
611 /**
612 * add_mtd_device - register an MTD device
613 * @mtd: pointer to new MTD device info structure
614 *
615 * Add a device to the list of MTD devices present in the system, and
616 * notify each currently active MTD 'user' of its arrival. Returns
617 * zero on success or non-zero on failure.
618 */
619
add_mtd_device(struct mtd_info * mtd)620 int add_mtd_device(struct mtd_info *mtd)
621 {
622 struct device_node *np = mtd_get_of_node(mtd);
623 struct mtd_info *master = mtd_get_master(mtd);
624 struct mtd_notifier *not;
625 int i, error, ofidx;
626
627 /*
628 * May occur, for instance, on buggy drivers which call
629 * mtd_device_parse_register() multiple times on the same master MTD,
630 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
631 */
632 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
633 return -EEXIST;
634
635 BUG_ON(mtd->writesize == 0);
636
637 /*
638 * MTD drivers should implement ->_{write,read}() or
639 * ->_{write,read}_oob(), but not both.
640 */
641 if (WARN_ON((mtd->_write && mtd->_write_oob) ||
642 (mtd->_read && mtd->_read_oob)))
643 return -EINVAL;
644
645 if (WARN_ON((!mtd->erasesize || !master->_erase) &&
646 !(mtd->flags & MTD_NO_ERASE)))
647 return -EINVAL;
648
649 /*
650 * MTD_SLC_ON_MLC_EMULATION can only be set on partitions, when the
651 * master is an MLC NAND and has a proper pairing scheme defined.
652 * We also reject masters that implement ->_writev() for now, because
653 * NAND controller drivers don't implement this hook, and adding the
654 * SLC -> MLC address/length conversion to this path is useless if we
655 * don't have a user.
656 */
657 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION &&
658 (!mtd_is_partition(mtd) || master->type != MTD_MLCNANDFLASH ||
659 !master->pairing || master->_writev))
660 return -EINVAL;
661
662 mutex_lock(&mtd_table_mutex);
663
664 ofidx = -1;
665 if (np)
666 ofidx = of_alias_get_id(np, "mtd");
667 if (ofidx >= 0)
668 i = idr_alloc(&mtd_idr, mtd, ofidx, ofidx + 1, GFP_KERNEL);
669 else
670 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
671 if (i < 0) {
672 error = i;
673 goto fail_locked;
674 }
675
676 mtd->index = i;
677 mtd->usecount = 0;
678
679 /* default value if not set by driver */
680 if (mtd->bitflip_threshold == 0)
681 mtd->bitflip_threshold = mtd->ecc_strength;
682
683 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
684 int ngroups = mtd_pairing_groups(master);
685
686 mtd->erasesize /= ngroups;
687 mtd->size = (u64)mtd_div_by_eb(mtd->size, master) *
688 mtd->erasesize;
689 }
690
691 if (is_power_of_2(mtd->erasesize))
692 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
693 else
694 mtd->erasesize_shift = 0;
695
696 if (is_power_of_2(mtd->writesize))
697 mtd->writesize_shift = ffs(mtd->writesize) - 1;
698 else
699 mtd->writesize_shift = 0;
700
701 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
702 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
703
704 /* Some chips always power up locked. Unlock them now */
705 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
706 error = mtd_unlock(mtd, 0, mtd->size);
707 if (error && error != -EOPNOTSUPP)
708 printk(KERN_WARNING
709 "%s: unlock failed, writes may not work\n",
710 mtd->name);
711 /* Ignore unlock failures? */
712 error = 0;
713 }
714
715 /* Caller should have set dev.parent to match the
716 * physical device, if appropriate.
717 */
718 mtd->dev.type = &mtd_devtype;
719 mtd->dev.class = &mtd_class;
720 mtd->dev.devt = MTD_DEVT(i);
721 dev_set_name(&mtd->dev, "mtd%d", i);
722 dev_set_drvdata(&mtd->dev, mtd);
723 mtd_check_of_node(mtd);
724 of_node_get(mtd_get_of_node(mtd));
725 error = device_register(&mtd->dev);
726 if (error) {
727 put_device(&mtd->dev);
728 goto fail_added;
729 }
730
731 /* Add the nvmem provider */
732 error = mtd_nvmem_add(mtd);
733 if (error)
734 goto fail_nvmem_add;
735
736 mtd_debugfs_populate(mtd);
737
738 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
739 "mtd%dro", i);
740
741 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
742 /* No need to get a refcount on the module containing
743 the notifier, since we hold the mtd_table_mutex */
744 list_for_each_entry(not, &mtd_notifiers, list)
745 not->add(mtd);
746
747 mutex_unlock(&mtd_table_mutex);
748 /* We _know_ we aren't being removed, because
749 our caller is still holding us here. So none
750 of this try_ nonsense, and no bitching about it
751 either. :) */
752 __module_get(THIS_MODULE);
753 return 0;
754
755 fail_nvmem_add:
756 device_unregister(&mtd->dev);
757 fail_added:
758 of_node_put(mtd_get_of_node(mtd));
759 idr_remove(&mtd_idr, i);
760 fail_locked:
761 mutex_unlock(&mtd_table_mutex);
762 return error;
763 }
764
765 /**
766 * del_mtd_device - unregister an MTD device
767 * @mtd: pointer to MTD device info structure
768 *
769 * Remove a device from the list of MTD devices present in the system,
770 * and notify each currently active MTD 'user' of its departure.
771 * Returns zero on success or 1 on failure, which currently will happen
772 * if the requested device does not appear to be present in the list.
773 */
774
del_mtd_device(struct mtd_info * mtd)775 int del_mtd_device(struct mtd_info *mtd)
776 {
777 int ret;
778 struct mtd_notifier *not;
779 struct device_node *mtd_of_node;
780
781 mutex_lock(&mtd_table_mutex);
782
783 if (idr_find(&mtd_idr, mtd->index) != mtd) {
784 ret = -ENODEV;
785 goto out_error;
786 }
787
788 /* No need to get a refcount on the module containing
789 the notifier, since we hold the mtd_table_mutex */
790 list_for_each_entry(not, &mtd_notifiers, list)
791 not->remove(mtd);
792
793 if (mtd->usecount) {
794 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
795 mtd->index, mtd->name, mtd->usecount);
796 ret = -EBUSY;
797 } else {
798 mtd_of_node = mtd_get_of_node(mtd);
799 debugfs_remove_recursive(mtd->dbg.dfs_dir);
800
801 /* Try to remove the NVMEM provider */
802 nvmem_unregister(mtd->nvmem);
803
804 device_unregister(&mtd->dev);
805
806 /* Clear dev so mtd can be safely re-registered later if desired */
807 memset(&mtd->dev, 0, sizeof(mtd->dev));
808
809 idr_remove(&mtd_idr, mtd->index);
810 of_node_put(mtd_of_node);
811
812 module_put(THIS_MODULE);
813 ret = 0;
814 }
815
816 out_error:
817 mutex_unlock(&mtd_table_mutex);
818 return ret;
819 }
820
821 /*
822 * Set a few defaults based on the parent devices, if not provided by the
823 * driver
824 */
mtd_set_dev_defaults(struct mtd_info * mtd)825 static void mtd_set_dev_defaults(struct mtd_info *mtd)
826 {
827 if (mtd->dev.parent) {
828 if (!mtd->owner && mtd->dev.parent->driver)
829 mtd->owner = mtd->dev.parent->driver->owner;
830 if (!mtd->name)
831 mtd->name = dev_name(mtd->dev.parent);
832 } else {
833 pr_debug("mtd device won't show a device symlink in sysfs\n");
834 }
835
836 INIT_LIST_HEAD(&mtd->partitions);
837 mutex_init(&mtd->master.partitions_lock);
838 mutex_init(&mtd->master.chrdev_lock);
839 }
840
mtd_otp_size(struct mtd_info * mtd,bool is_user)841 static ssize_t mtd_otp_size(struct mtd_info *mtd, bool is_user)
842 {
843 struct otp_info *info;
844 ssize_t size = 0;
845 unsigned int i;
846 size_t retlen;
847 int ret;
848
849 info = kmalloc(PAGE_SIZE, GFP_KERNEL);
850 if (!info)
851 return -ENOMEM;
852
853 if (is_user)
854 ret = mtd_get_user_prot_info(mtd, PAGE_SIZE, &retlen, info);
855 else
856 ret = mtd_get_fact_prot_info(mtd, PAGE_SIZE, &retlen, info);
857 if (ret)
858 goto err;
859
860 for (i = 0; i < retlen / sizeof(*info); i++)
861 size += info[i].length;
862
863 kfree(info);
864 return size;
865
866 err:
867 kfree(info);
868
869 /* ENODATA means there is no OTP region. */
870 return ret == -ENODATA ? 0 : ret;
871 }
872
mtd_otp_nvmem_register(struct mtd_info * mtd,const char * compatible,int size,nvmem_reg_read_t reg_read)873 static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd,
874 const char *compatible,
875 int size,
876 nvmem_reg_read_t reg_read)
877 {
878 struct nvmem_device *nvmem = NULL;
879 struct nvmem_config config = {};
880 struct device_node *np;
881
882 /* DT binding is optional */
883 np = of_get_compatible_child(mtd->dev.of_node, compatible);
884
885 /* OTP nvmem will be registered on the physical device */
886 config.dev = mtd->dev.parent;
887 config.name = kasprintf(GFP_KERNEL, "%s-%s", dev_name(&mtd->dev), compatible);
888 config.id = NVMEM_DEVID_NONE;
889 config.owner = THIS_MODULE;
890 config.type = NVMEM_TYPE_OTP;
891 config.root_only = true;
892 config.ignore_wp = true;
893 config.reg_read = reg_read;
894 config.size = size;
895 config.of_node = np;
896 config.priv = mtd;
897
898 nvmem = nvmem_register(&config);
899 /* Just ignore if there is no NVMEM support in the kernel */
900 if (IS_ERR(nvmem) && PTR_ERR(nvmem) == -EOPNOTSUPP)
901 nvmem = NULL;
902
903 of_node_put(np);
904 kfree(config.name);
905
906 return nvmem;
907 }
908
mtd_nvmem_user_otp_reg_read(void * priv,unsigned int offset,void * val,size_t bytes)909 static int mtd_nvmem_user_otp_reg_read(void *priv, unsigned int offset,
910 void *val, size_t bytes)
911 {
912 struct mtd_info *mtd = priv;
913 size_t retlen;
914 int ret;
915
916 ret = mtd_read_user_prot_reg(mtd, offset, bytes, &retlen, val);
917 if (ret)
918 return ret;
919
920 return retlen == bytes ? 0 : -EIO;
921 }
922
mtd_nvmem_fact_otp_reg_read(void * priv,unsigned int offset,void * val,size_t bytes)923 static int mtd_nvmem_fact_otp_reg_read(void *priv, unsigned int offset,
924 void *val, size_t bytes)
925 {
926 struct mtd_info *mtd = priv;
927 size_t retlen;
928 int ret;
929
930 ret = mtd_read_fact_prot_reg(mtd, offset, bytes, &retlen, val);
931 if (ret)
932 return ret;
933
934 return retlen == bytes ? 0 : -EIO;
935 }
936
mtd_otp_nvmem_add(struct mtd_info * mtd)937 static int mtd_otp_nvmem_add(struct mtd_info *mtd)
938 {
939 struct nvmem_device *nvmem;
940 ssize_t size;
941 int err;
942
943 if (mtd->_get_user_prot_info && mtd->_read_user_prot_reg) {
944 size = mtd_otp_size(mtd, true);
945 if (size < 0)
946 return size;
947
948 if (size > 0) {
949 nvmem = mtd_otp_nvmem_register(mtd, "user-otp", size,
950 mtd_nvmem_user_otp_reg_read);
951 if (IS_ERR(nvmem)) {
952 dev_err(&mtd->dev, "Failed to register OTP NVMEM device\n");
953 return PTR_ERR(nvmem);
954 }
955 mtd->otp_user_nvmem = nvmem;
956 }
957 }
958
959 if (mtd->_get_fact_prot_info && mtd->_read_fact_prot_reg) {
960 size = mtd_otp_size(mtd, false);
961 if (size < 0) {
962 err = size;
963 goto err;
964 }
965
966 if (size > 0) {
967 nvmem = mtd_otp_nvmem_register(mtd, "factory-otp", size,
968 mtd_nvmem_fact_otp_reg_read);
969 if (IS_ERR(nvmem)) {
970 dev_err(&mtd->dev, "Failed to register OTP NVMEM device\n");
971 err = PTR_ERR(nvmem);
972 goto err;
973 }
974 mtd->otp_factory_nvmem = nvmem;
975 }
976 }
977
978 return 0;
979
980 err:
981 nvmem_unregister(mtd->otp_user_nvmem);
982 return err;
983 }
984
985 /**
986 * mtd_device_parse_register - parse partitions and register an MTD device.
987 *
988 * @mtd: the MTD device to register
989 * @types: the list of MTD partition probes to try, see
990 * 'parse_mtd_partitions()' for more information
991 * @parser_data: MTD partition parser-specific data
992 * @parts: fallback partition information to register, if parsing fails;
993 * only valid if %nr_parts > %0
994 * @nr_parts: the number of partitions in parts, if zero then the full
995 * MTD device is registered if no partition info is found
996 *
997 * This function aggregates MTD partitions parsing (done by
998 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
999 * basically follows the most common pattern found in many MTD drivers:
1000 *
1001 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
1002 * registered first.
1003 * * Then It tries to probe partitions on MTD device @mtd using parsers
1004 * specified in @types (if @types is %NULL, then the default list of parsers
1005 * is used, see 'parse_mtd_partitions()' for more information). If none are
1006 * found this functions tries to fallback to information specified in
1007 * @parts/@nr_parts.
1008 * * If no partitions were found this function just registers the MTD device
1009 * @mtd and exits.
1010 *
1011 * Returns zero in case of success and a negative error code in case of failure.
1012 */
mtd_device_parse_register(struct mtd_info * mtd,const char * const * types,struct mtd_part_parser_data * parser_data,const struct mtd_partition * parts,int nr_parts)1013 int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
1014 struct mtd_part_parser_data *parser_data,
1015 const struct mtd_partition *parts,
1016 int nr_parts)
1017 {
1018 int ret;
1019
1020 mtd_set_dev_defaults(mtd);
1021
1022 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
1023 ret = add_mtd_device(mtd);
1024 if (ret)
1025 return ret;
1026 }
1027
1028 /* Prefer parsed partitions over driver-provided fallback */
1029 ret = parse_mtd_partitions(mtd, types, parser_data);
1030 if (ret == -EPROBE_DEFER)
1031 goto out;
1032
1033 if (ret > 0)
1034 ret = 0;
1035 else if (nr_parts)
1036 ret = add_mtd_partitions(mtd, parts, nr_parts);
1037 else if (!device_is_registered(&mtd->dev))
1038 ret = add_mtd_device(mtd);
1039 else
1040 ret = 0;
1041
1042 if (ret)
1043 goto out;
1044
1045 /*
1046 * FIXME: some drivers unfortunately call this function more than once.
1047 * So we have to check if we've already assigned the reboot notifier.
1048 *
1049 * Generally, we can make multiple calls work for most cases, but it
1050 * does cause problems with parse_mtd_partitions() above (e.g.,
1051 * cmdlineparts will register partitions more than once).
1052 */
1053 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
1054 "MTD already registered\n");
1055 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
1056 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
1057 register_reboot_notifier(&mtd->reboot_notifier);
1058 }
1059
1060 ret = mtd_otp_nvmem_add(mtd);
1061
1062 out:
1063 if (ret && device_is_registered(&mtd->dev))
1064 del_mtd_device(mtd);
1065
1066 return ret;
1067 }
1068 EXPORT_SYMBOL_GPL(mtd_device_parse_register);
1069
1070 /**
1071 * mtd_device_unregister - unregister an existing MTD device.
1072 *
1073 * @master: the MTD device to unregister. This will unregister both the master
1074 * and any partitions if registered.
1075 */
mtd_device_unregister(struct mtd_info * master)1076 int mtd_device_unregister(struct mtd_info *master)
1077 {
1078 int err;
1079
1080 if (master->_reboot) {
1081 unregister_reboot_notifier(&master->reboot_notifier);
1082 memset(&master->reboot_notifier, 0, sizeof(master->reboot_notifier));
1083 }
1084
1085 nvmem_unregister(master->otp_user_nvmem);
1086 nvmem_unregister(master->otp_factory_nvmem);
1087
1088 err = del_mtd_partitions(master);
1089 if (err)
1090 return err;
1091
1092 if (!device_is_registered(&master->dev))
1093 return 0;
1094
1095 return del_mtd_device(master);
1096 }
1097 EXPORT_SYMBOL_GPL(mtd_device_unregister);
1098
1099 /**
1100 * register_mtd_user - register a 'user' of MTD devices.
1101 * @new: pointer to notifier info structure
1102 *
1103 * Registers a pair of callbacks function to be called upon addition
1104 * or removal of MTD devices. Causes the 'add' callback to be immediately
1105 * invoked for each MTD device currently present in the system.
1106 */
register_mtd_user(struct mtd_notifier * new)1107 void register_mtd_user (struct mtd_notifier *new)
1108 {
1109 struct mtd_info *mtd;
1110
1111 mutex_lock(&mtd_table_mutex);
1112
1113 list_add(&new->list, &mtd_notifiers);
1114
1115 __module_get(THIS_MODULE);
1116
1117 mtd_for_each_device(mtd)
1118 new->add(mtd);
1119
1120 mutex_unlock(&mtd_table_mutex);
1121 }
1122 EXPORT_SYMBOL_GPL(register_mtd_user);
1123
1124 /**
1125 * unregister_mtd_user - unregister a 'user' of MTD devices.
1126 * @old: pointer to notifier info structure
1127 *
1128 * Removes a callback function pair from the list of 'users' to be
1129 * notified upon addition or removal of MTD devices. Causes the
1130 * 'remove' callback to be immediately invoked for each MTD device
1131 * currently present in the system.
1132 */
unregister_mtd_user(struct mtd_notifier * old)1133 int unregister_mtd_user (struct mtd_notifier *old)
1134 {
1135 struct mtd_info *mtd;
1136
1137 mutex_lock(&mtd_table_mutex);
1138
1139 module_put(THIS_MODULE);
1140
1141 mtd_for_each_device(mtd)
1142 old->remove(mtd);
1143
1144 list_del(&old->list);
1145 mutex_unlock(&mtd_table_mutex);
1146 return 0;
1147 }
1148 EXPORT_SYMBOL_GPL(unregister_mtd_user);
1149
1150 /**
1151 * get_mtd_device - obtain a validated handle for an MTD device
1152 * @mtd: last known address of the required MTD device
1153 * @num: internal device number of the required MTD device
1154 *
1155 * Given a number and NULL address, return the num'th entry in the device
1156 * table, if any. Given an address and num == -1, search the device table
1157 * for a device with that address and return if it's still present. Given
1158 * both, return the num'th driver only if its address matches. Return
1159 * error code if not.
1160 */
get_mtd_device(struct mtd_info * mtd,int num)1161 struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
1162 {
1163 struct mtd_info *ret = NULL, *other;
1164 int err = -ENODEV;
1165
1166 mutex_lock(&mtd_table_mutex);
1167
1168 if (num == -1) {
1169 mtd_for_each_device(other) {
1170 if (other == mtd) {
1171 ret = mtd;
1172 break;
1173 }
1174 }
1175 } else if (num >= 0) {
1176 ret = idr_find(&mtd_idr, num);
1177 if (mtd && mtd != ret)
1178 ret = NULL;
1179 }
1180
1181 if (!ret) {
1182 ret = ERR_PTR(err);
1183 goto out;
1184 }
1185
1186 err = __get_mtd_device(ret);
1187 if (err)
1188 ret = ERR_PTR(err);
1189 out:
1190 mutex_unlock(&mtd_table_mutex);
1191 return ret;
1192 }
1193 EXPORT_SYMBOL_GPL(get_mtd_device);
1194
1195
__get_mtd_device(struct mtd_info * mtd)1196 int __get_mtd_device(struct mtd_info *mtd)
1197 {
1198 struct mtd_info *master = mtd_get_master(mtd);
1199 int err;
1200
1201 if (!try_module_get(master->owner))
1202 return -ENODEV;
1203
1204 if (master->_get_device) {
1205 err = master->_get_device(mtd);
1206
1207 if (err) {
1208 module_put(master->owner);
1209 return err;
1210 }
1211 }
1212
1213 master->usecount++;
1214
1215 while (mtd->parent) {
1216 mtd->usecount++;
1217 mtd = mtd->parent;
1218 }
1219
1220 return 0;
1221 }
1222 EXPORT_SYMBOL_GPL(__get_mtd_device);
1223
1224 /**
1225 * of_get_mtd_device_by_node - obtain an MTD device associated with a given node
1226 *
1227 * @np: device tree node
1228 */
of_get_mtd_device_by_node(struct device_node * np)1229 struct mtd_info *of_get_mtd_device_by_node(struct device_node *np)
1230 {
1231 struct mtd_info *mtd = NULL;
1232 struct mtd_info *tmp;
1233 int err;
1234
1235 mutex_lock(&mtd_table_mutex);
1236
1237 err = -EPROBE_DEFER;
1238 mtd_for_each_device(tmp) {
1239 if (mtd_get_of_node(tmp) == np) {
1240 mtd = tmp;
1241 err = __get_mtd_device(mtd);
1242 break;
1243 }
1244 }
1245
1246 mutex_unlock(&mtd_table_mutex);
1247
1248 return err ? ERR_PTR(err) : mtd;
1249 }
1250 EXPORT_SYMBOL_GPL(of_get_mtd_device_by_node);
1251
1252 /**
1253 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1254 * device name
1255 * @name: MTD device name to open
1256 *
1257 * This function returns MTD device description structure in case of
1258 * success and an error code in case of failure.
1259 */
get_mtd_device_nm(const char * name)1260 struct mtd_info *get_mtd_device_nm(const char *name)
1261 {
1262 int err = -ENODEV;
1263 struct mtd_info *mtd = NULL, *other;
1264
1265 mutex_lock(&mtd_table_mutex);
1266
1267 mtd_for_each_device(other) {
1268 if (!strcmp(name, other->name)) {
1269 mtd = other;
1270 break;
1271 }
1272 }
1273
1274 if (!mtd)
1275 goto out_unlock;
1276
1277 err = __get_mtd_device(mtd);
1278 if (err)
1279 goto out_unlock;
1280
1281 mutex_unlock(&mtd_table_mutex);
1282 return mtd;
1283
1284 out_unlock:
1285 mutex_unlock(&mtd_table_mutex);
1286 return ERR_PTR(err);
1287 }
1288 EXPORT_SYMBOL_GPL(get_mtd_device_nm);
1289
put_mtd_device(struct mtd_info * mtd)1290 void put_mtd_device(struct mtd_info *mtd)
1291 {
1292 mutex_lock(&mtd_table_mutex);
1293 __put_mtd_device(mtd);
1294 mutex_unlock(&mtd_table_mutex);
1295
1296 }
1297 EXPORT_SYMBOL_GPL(put_mtd_device);
1298
__put_mtd_device(struct mtd_info * mtd)1299 void __put_mtd_device(struct mtd_info *mtd)
1300 {
1301 struct mtd_info *master = mtd_get_master(mtd);
1302
1303 while (mtd->parent) {
1304 --mtd->usecount;
1305 BUG_ON(mtd->usecount < 0);
1306 mtd = mtd->parent;
1307 }
1308
1309 master->usecount--;
1310
1311 if (master->_put_device)
1312 master->_put_device(master);
1313
1314 module_put(master->owner);
1315 }
1316 EXPORT_SYMBOL_GPL(__put_mtd_device);
1317
1318 /*
1319 * Erase is an synchronous operation. Device drivers are epected to return a
1320 * negative error code if the operation failed and update instr->fail_addr
1321 * to point the portion that was not properly erased.
1322 */
mtd_erase(struct mtd_info * mtd,struct erase_info * instr)1323 int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1324 {
1325 struct mtd_info *master = mtd_get_master(mtd);
1326 u64 mst_ofs = mtd_get_master_ofs(mtd, 0);
1327 struct erase_info adjinstr;
1328 int ret;
1329
1330 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1331 adjinstr = *instr;
1332
1333 if (!mtd->erasesize || !master->_erase)
1334 return -ENOTSUPP;
1335
1336 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1337 return -EINVAL;
1338 if (!(mtd->flags & MTD_WRITEABLE))
1339 return -EROFS;
1340
1341 if (!instr->len)
1342 return 0;
1343
1344 ledtrig_mtd_activity();
1345
1346 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1347 adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) *
1348 master->erasesize;
1349 adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) *
1350 master->erasesize) -
1351 adjinstr.addr;
1352 }
1353
1354 adjinstr.addr += mst_ofs;
1355
1356 ret = master->_erase(master, &adjinstr);
1357
1358 if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) {
1359 instr->fail_addr = adjinstr.fail_addr - mst_ofs;
1360 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1361 instr->fail_addr = mtd_div_by_eb(instr->fail_addr,
1362 master);
1363 instr->fail_addr *= mtd->erasesize;
1364 }
1365 }
1366
1367 return ret;
1368 }
1369 EXPORT_SYMBOL_GPL(mtd_erase);
1370
1371 /*
1372 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1373 */
mtd_point(struct mtd_info * mtd,loff_t from,size_t len,size_t * retlen,void ** virt,resource_size_t * phys)1374 int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1375 void **virt, resource_size_t *phys)
1376 {
1377 struct mtd_info *master = mtd_get_master(mtd);
1378
1379 *retlen = 0;
1380 *virt = NULL;
1381 if (phys)
1382 *phys = 0;
1383 if (!master->_point)
1384 return -EOPNOTSUPP;
1385 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1386 return -EINVAL;
1387 if (!len)
1388 return 0;
1389
1390 from = mtd_get_master_ofs(mtd, from);
1391 return master->_point(master, from, len, retlen, virt, phys);
1392 }
1393 EXPORT_SYMBOL_GPL(mtd_point);
1394
1395 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
mtd_unpoint(struct mtd_info * mtd,loff_t from,size_t len)1396 int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1397 {
1398 struct mtd_info *master = mtd_get_master(mtd);
1399
1400 if (!master->_unpoint)
1401 return -EOPNOTSUPP;
1402 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1403 return -EINVAL;
1404 if (!len)
1405 return 0;
1406 return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
1407 }
1408 EXPORT_SYMBOL_GPL(mtd_unpoint);
1409
1410 /*
1411 * Allow NOMMU mmap() to directly map the device (if not NULL)
1412 * - return the address to which the offset maps
1413 * - return -ENOSYS to indicate refusal to do the mapping
1414 */
mtd_get_unmapped_area(struct mtd_info * mtd,unsigned long len,unsigned long offset,unsigned long flags)1415 unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1416 unsigned long offset, unsigned long flags)
1417 {
1418 size_t retlen;
1419 void *virt;
1420 int ret;
1421
1422 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1423 if (ret)
1424 return ret;
1425 if (retlen != len) {
1426 mtd_unpoint(mtd, offset, retlen);
1427 return -ENOSYS;
1428 }
1429 return (unsigned long)virt;
1430 }
1431 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1432
mtd_update_ecc_stats(struct mtd_info * mtd,struct mtd_info * master,const struct mtd_ecc_stats * old_stats)1433 static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
1434 const struct mtd_ecc_stats *old_stats)
1435 {
1436 struct mtd_ecc_stats diff;
1437
1438 if (master == mtd)
1439 return;
1440
1441 diff = master->ecc_stats;
1442 diff.failed -= old_stats->failed;
1443 diff.corrected -= old_stats->corrected;
1444
1445 while (mtd->parent) {
1446 mtd->ecc_stats.failed += diff.failed;
1447 mtd->ecc_stats.corrected += diff.corrected;
1448 mtd = mtd->parent;
1449 }
1450 }
1451
mtd_read(struct mtd_info * mtd,loff_t from,size_t len,size_t * retlen,u_char * buf)1452 int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1453 u_char *buf)
1454 {
1455 struct mtd_oob_ops ops = {
1456 .len = len,
1457 .datbuf = buf,
1458 };
1459 int ret;
1460
1461 ret = mtd_read_oob(mtd, from, &ops);
1462 *retlen = ops.retlen;
1463
1464 return ret;
1465 }
1466 EXPORT_SYMBOL_GPL(mtd_read);
1467
mtd_write(struct mtd_info * mtd,loff_t to,size_t len,size_t * retlen,const u_char * buf)1468 int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1469 const u_char *buf)
1470 {
1471 struct mtd_oob_ops ops = {
1472 .len = len,
1473 .datbuf = (u8 *)buf,
1474 };
1475 int ret;
1476
1477 ret = mtd_write_oob(mtd, to, &ops);
1478 *retlen = ops.retlen;
1479
1480 return ret;
1481 }
1482 EXPORT_SYMBOL_GPL(mtd_write);
1483
1484 /*
1485 * In blackbox flight recorder like scenarios we want to make successful writes
1486 * in interrupt context. panic_write() is only intended to be called when its
1487 * known the kernel is about to panic and we need the write to succeed. Since
1488 * the kernel is not going to be running for much longer, this function can
1489 * break locks and delay to ensure the write succeeds (but not sleep).
1490 */
mtd_panic_write(struct mtd_info * mtd,loff_t to,size_t len,size_t * retlen,const u_char * buf)1491 int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1492 const u_char *buf)
1493 {
1494 struct mtd_info *master = mtd_get_master(mtd);
1495
1496 *retlen = 0;
1497 if (!master->_panic_write)
1498 return -EOPNOTSUPP;
1499 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1500 return -EINVAL;
1501 if (!(mtd->flags & MTD_WRITEABLE))
1502 return -EROFS;
1503 if (!len)
1504 return 0;
1505 if (!master->oops_panic_write)
1506 master->oops_panic_write = true;
1507
1508 return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
1509 retlen, buf);
1510 }
1511 EXPORT_SYMBOL_GPL(mtd_panic_write);
1512
mtd_check_oob_ops(struct mtd_info * mtd,loff_t offs,struct mtd_oob_ops * ops)1513 static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1514 struct mtd_oob_ops *ops)
1515 {
1516 /*
1517 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1518 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1519 * this case.
1520 */
1521 if (!ops->datbuf)
1522 ops->len = 0;
1523
1524 if (!ops->oobbuf)
1525 ops->ooblen = 0;
1526
1527 if (offs < 0 || offs + ops->len > mtd->size)
1528 return -EINVAL;
1529
1530 if (ops->ooblen) {
1531 size_t maxooblen;
1532
1533 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1534 return -EINVAL;
1535
1536 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1537 mtd_div_by_ws(offs, mtd)) *
1538 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1539 if (ops->ooblen > maxooblen)
1540 return -EINVAL;
1541 }
1542
1543 return 0;
1544 }
1545
mtd_read_oob_std(struct mtd_info * mtd,loff_t from,struct mtd_oob_ops * ops)1546 static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from,
1547 struct mtd_oob_ops *ops)
1548 {
1549 struct mtd_info *master = mtd_get_master(mtd);
1550 int ret;
1551
1552 from = mtd_get_master_ofs(mtd, from);
1553 if (master->_read_oob)
1554 ret = master->_read_oob(master, from, ops);
1555 else
1556 ret = master->_read(master, from, ops->len, &ops->retlen,
1557 ops->datbuf);
1558
1559 return ret;
1560 }
1561
mtd_write_oob_std(struct mtd_info * mtd,loff_t to,struct mtd_oob_ops * ops)1562 static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to,
1563 struct mtd_oob_ops *ops)
1564 {
1565 struct mtd_info *master = mtd_get_master(mtd);
1566 int ret;
1567
1568 to = mtd_get_master_ofs(mtd, to);
1569 if (master->_write_oob)
1570 ret = master->_write_oob(master, to, ops);
1571 else
1572 ret = master->_write(master, to, ops->len, &ops->retlen,
1573 ops->datbuf);
1574
1575 return ret;
1576 }
1577
mtd_io_emulated_slc(struct mtd_info * mtd,loff_t start,bool read,struct mtd_oob_ops * ops)1578 static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read,
1579 struct mtd_oob_ops *ops)
1580 {
1581 struct mtd_info *master = mtd_get_master(mtd);
1582 int ngroups = mtd_pairing_groups(master);
1583 int npairs = mtd_wunit_per_eb(master) / ngroups;
1584 struct mtd_oob_ops adjops = *ops;
1585 unsigned int wunit, oobavail;
1586 struct mtd_pairing_info info;
1587 int max_bitflips = 0;
1588 u32 ebofs, pageofs;
1589 loff_t base, pos;
1590
1591 ebofs = mtd_mod_by_eb(start, mtd);
1592 base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize;
1593 info.group = 0;
1594 info.pair = mtd_div_by_ws(ebofs, mtd);
1595 pageofs = mtd_mod_by_ws(ebofs, mtd);
1596 oobavail = mtd_oobavail(mtd, ops);
1597
1598 while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) {
1599 int ret;
1600
1601 if (info.pair >= npairs) {
1602 info.pair = 0;
1603 base += master->erasesize;
1604 }
1605
1606 wunit = mtd_pairing_info_to_wunit(master, &info);
1607 pos = mtd_wunit_to_offset(mtd, base, wunit);
1608
1609 adjops.len = ops->len - ops->retlen;
1610 if (adjops.len > mtd->writesize - pageofs)
1611 adjops.len = mtd->writesize - pageofs;
1612
1613 adjops.ooblen = ops->ooblen - ops->oobretlen;
1614 if (adjops.ooblen > oobavail - adjops.ooboffs)
1615 adjops.ooblen = oobavail - adjops.ooboffs;
1616
1617 if (read) {
1618 ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops);
1619 if (ret > 0)
1620 max_bitflips = max(max_bitflips, ret);
1621 } else {
1622 ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops);
1623 }
1624
1625 if (ret < 0)
1626 return ret;
1627
1628 max_bitflips = max(max_bitflips, ret);
1629 ops->retlen += adjops.retlen;
1630 ops->oobretlen += adjops.oobretlen;
1631 adjops.datbuf += adjops.retlen;
1632 adjops.oobbuf += adjops.oobretlen;
1633 adjops.ooboffs = 0;
1634 pageofs = 0;
1635 info.pair++;
1636 }
1637
1638 return max_bitflips;
1639 }
1640
mtd_read_oob(struct mtd_info * mtd,loff_t from,struct mtd_oob_ops * ops)1641 int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1642 {
1643 struct mtd_info *master = mtd_get_master(mtd);
1644 struct mtd_ecc_stats old_stats = master->ecc_stats;
1645 int ret_code;
1646
1647 ops->retlen = ops->oobretlen = 0;
1648
1649 ret_code = mtd_check_oob_ops(mtd, from, ops);
1650 if (ret_code)
1651 return ret_code;
1652
1653 ledtrig_mtd_activity();
1654
1655 /* Check the validity of a potential fallback on mtd->_read */
1656 if (!master->_read_oob && (!master->_read || ops->oobbuf))
1657 return -EOPNOTSUPP;
1658
1659 if (ops->stats)
1660 memset(ops->stats, 0, sizeof(*ops->stats));
1661
1662 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1663 ret_code = mtd_io_emulated_slc(mtd, from, true, ops);
1664 else
1665 ret_code = mtd_read_oob_std(mtd, from, ops);
1666
1667 mtd_update_ecc_stats(mtd, master, &old_stats);
1668
1669 /*
1670 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1671 * similar to mtd->_read(), returning a non-negative integer
1672 * representing max bitflips. In other cases, mtd->_read_oob() may
1673 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1674 */
1675 if (unlikely(ret_code < 0))
1676 return ret_code;
1677 if (mtd->ecc_strength == 0)
1678 return 0; /* device lacks ecc */
1679 if (ops->stats)
1680 ops->stats->max_bitflips = ret_code;
1681 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1682 }
1683 EXPORT_SYMBOL_GPL(mtd_read_oob);
1684
mtd_write_oob(struct mtd_info * mtd,loff_t to,struct mtd_oob_ops * ops)1685 int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1686 struct mtd_oob_ops *ops)
1687 {
1688 struct mtd_info *master = mtd_get_master(mtd);
1689 int ret;
1690
1691 ops->retlen = ops->oobretlen = 0;
1692
1693 if (!(mtd->flags & MTD_WRITEABLE))
1694 return -EROFS;
1695
1696 ret = mtd_check_oob_ops(mtd, to, ops);
1697 if (ret)
1698 return ret;
1699
1700 ledtrig_mtd_activity();
1701
1702 /* Check the validity of a potential fallback on mtd->_write */
1703 if (!master->_write_oob && (!master->_write || ops->oobbuf))
1704 return -EOPNOTSUPP;
1705
1706 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1707 return mtd_io_emulated_slc(mtd, to, false, ops);
1708
1709 return mtd_write_oob_std(mtd, to, ops);
1710 }
1711 EXPORT_SYMBOL_GPL(mtd_write_oob);
1712
1713 /**
1714 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1715 * @mtd: MTD device structure
1716 * @section: ECC section. Depending on the layout you may have all the ECC
1717 * bytes stored in a single contiguous section, or one section
1718 * per ECC chunk (and sometime several sections for a single ECC
1719 * ECC chunk)
1720 * @oobecc: OOB region struct filled with the appropriate ECC position
1721 * information
1722 *
1723 * This function returns ECC section information in the OOB area. If you want
1724 * to get all the ECC bytes information, then you should call
1725 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1726 *
1727 * Returns zero on success, a negative error code otherwise.
1728 */
mtd_ooblayout_ecc(struct mtd_info * mtd,int section,struct mtd_oob_region * oobecc)1729 int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1730 struct mtd_oob_region *oobecc)
1731 {
1732 struct mtd_info *master = mtd_get_master(mtd);
1733
1734 memset(oobecc, 0, sizeof(*oobecc));
1735
1736 if (!master || section < 0)
1737 return -EINVAL;
1738
1739 if (!master->ooblayout || !master->ooblayout->ecc)
1740 return -ENOTSUPP;
1741
1742 return master->ooblayout->ecc(master, section, oobecc);
1743 }
1744 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1745
1746 /**
1747 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1748 * section
1749 * @mtd: MTD device structure
1750 * @section: Free section you are interested in. Depending on the layout
1751 * you may have all the free bytes stored in a single contiguous
1752 * section, or one section per ECC chunk plus an extra section
1753 * for the remaining bytes (or other funky layout).
1754 * @oobfree: OOB region struct filled with the appropriate free position
1755 * information
1756 *
1757 * This function returns free bytes position in the OOB area. If you want
1758 * to get all the free bytes information, then you should call
1759 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1760 *
1761 * Returns zero on success, a negative error code otherwise.
1762 */
mtd_ooblayout_free(struct mtd_info * mtd,int section,struct mtd_oob_region * oobfree)1763 int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1764 struct mtd_oob_region *oobfree)
1765 {
1766 struct mtd_info *master = mtd_get_master(mtd);
1767
1768 memset(oobfree, 0, sizeof(*oobfree));
1769
1770 if (!master || section < 0)
1771 return -EINVAL;
1772
1773 if (!master->ooblayout || !master->ooblayout->free)
1774 return -ENOTSUPP;
1775
1776 return master->ooblayout->free(master, section, oobfree);
1777 }
1778 EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1779
1780 /**
1781 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1782 * @mtd: mtd info structure
1783 * @byte: the byte we are searching for
1784 * @sectionp: pointer where the section id will be stored
1785 * @oobregion: used to retrieve the ECC position
1786 * @iter: iterator function. Should be either mtd_ooblayout_free or
1787 * mtd_ooblayout_ecc depending on the region type you're searching for
1788 *
1789 * This function returns the section id and oobregion information of a
1790 * specific byte. For example, say you want to know where the 4th ECC byte is
1791 * stored, you'll use:
1792 *
1793 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1794 *
1795 * Returns zero on success, a negative error code otherwise.
1796 */
mtd_ooblayout_find_region(struct mtd_info * mtd,int byte,int * sectionp,struct mtd_oob_region * oobregion,int (* iter)(struct mtd_info *,int section,struct mtd_oob_region * oobregion))1797 static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1798 int *sectionp, struct mtd_oob_region *oobregion,
1799 int (*iter)(struct mtd_info *,
1800 int section,
1801 struct mtd_oob_region *oobregion))
1802 {
1803 int pos = 0, ret, section = 0;
1804
1805 memset(oobregion, 0, sizeof(*oobregion));
1806
1807 while (1) {
1808 ret = iter(mtd, section, oobregion);
1809 if (ret)
1810 return ret;
1811
1812 if (pos + oobregion->length > byte)
1813 break;
1814
1815 pos += oobregion->length;
1816 section++;
1817 }
1818
1819 /*
1820 * Adjust region info to make it start at the beginning at the
1821 * 'start' ECC byte.
1822 */
1823 oobregion->offset += byte - pos;
1824 oobregion->length -= byte - pos;
1825 *sectionp = section;
1826
1827 return 0;
1828 }
1829
1830 /**
1831 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1832 * ECC byte
1833 * @mtd: mtd info structure
1834 * @eccbyte: the byte we are searching for
1835 * @section: pointer where the section id will be stored
1836 * @oobregion: OOB region information
1837 *
1838 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1839 * byte.
1840 *
1841 * Returns zero on success, a negative error code otherwise.
1842 */
mtd_ooblayout_find_eccregion(struct mtd_info * mtd,int eccbyte,int * section,struct mtd_oob_region * oobregion)1843 int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1844 int *section,
1845 struct mtd_oob_region *oobregion)
1846 {
1847 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1848 mtd_ooblayout_ecc);
1849 }
1850 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1851
1852 /**
1853 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1854 * @mtd: mtd info structure
1855 * @buf: destination buffer to store OOB bytes
1856 * @oobbuf: OOB buffer
1857 * @start: first byte to retrieve
1858 * @nbytes: number of bytes to retrieve
1859 * @iter: section iterator
1860 *
1861 * Extract bytes attached to a specific category (ECC or free)
1862 * from the OOB buffer and copy them into buf.
1863 *
1864 * Returns zero on success, a negative error code otherwise.
1865 */
mtd_ooblayout_get_bytes(struct mtd_info * mtd,u8 * buf,const u8 * oobbuf,int start,int nbytes,int (* iter)(struct mtd_info *,int section,struct mtd_oob_region * oobregion))1866 static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1867 const u8 *oobbuf, int start, int nbytes,
1868 int (*iter)(struct mtd_info *,
1869 int section,
1870 struct mtd_oob_region *oobregion))
1871 {
1872 struct mtd_oob_region oobregion;
1873 int section, ret;
1874
1875 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1876 &oobregion, iter);
1877
1878 while (!ret) {
1879 int cnt;
1880
1881 cnt = min_t(int, nbytes, oobregion.length);
1882 memcpy(buf, oobbuf + oobregion.offset, cnt);
1883 buf += cnt;
1884 nbytes -= cnt;
1885
1886 if (!nbytes)
1887 break;
1888
1889 ret = iter(mtd, ++section, &oobregion);
1890 }
1891
1892 return ret;
1893 }
1894
1895 /**
1896 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1897 * @mtd: mtd info structure
1898 * @buf: source buffer to get OOB bytes from
1899 * @oobbuf: OOB buffer
1900 * @start: first OOB byte to set
1901 * @nbytes: number of OOB bytes to set
1902 * @iter: section iterator
1903 *
1904 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1905 * is selected by passing the appropriate iterator.
1906 *
1907 * Returns zero on success, a negative error code otherwise.
1908 */
mtd_ooblayout_set_bytes(struct mtd_info * mtd,const u8 * buf,u8 * oobbuf,int start,int nbytes,int (* iter)(struct mtd_info *,int section,struct mtd_oob_region * oobregion))1909 static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1910 u8 *oobbuf, int start, int nbytes,
1911 int (*iter)(struct mtd_info *,
1912 int section,
1913 struct mtd_oob_region *oobregion))
1914 {
1915 struct mtd_oob_region oobregion;
1916 int section, ret;
1917
1918 ret = mtd_ooblayout_find_region(mtd, start, §ion,
1919 &oobregion, iter);
1920
1921 while (!ret) {
1922 int cnt;
1923
1924 cnt = min_t(int, nbytes, oobregion.length);
1925 memcpy(oobbuf + oobregion.offset, buf, cnt);
1926 buf += cnt;
1927 nbytes -= cnt;
1928
1929 if (!nbytes)
1930 break;
1931
1932 ret = iter(mtd, ++section, &oobregion);
1933 }
1934
1935 return ret;
1936 }
1937
1938 /**
1939 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1940 * @mtd: mtd info structure
1941 * @iter: category iterator
1942 *
1943 * Count the number of bytes in a given category.
1944 *
1945 * Returns a positive value on success, a negative error code otherwise.
1946 */
mtd_ooblayout_count_bytes(struct mtd_info * mtd,int (* iter)(struct mtd_info *,int section,struct mtd_oob_region * oobregion))1947 static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1948 int (*iter)(struct mtd_info *,
1949 int section,
1950 struct mtd_oob_region *oobregion))
1951 {
1952 struct mtd_oob_region oobregion;
1953 int section = 0, ret, nbytes = 0;
1954
1955 while (1) {
1956 ret = iter(mtd, section++, &oobregion);
1957 if (ret) {
1958 if (ret == -ERANGE)
1959 ret = nbytes;
1960 break;
1961 }
1962
1963 nbytes += oobregion.length;
1964 }
1965
1966 return ret;
1967 }
1968
1969 /**
1970 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1971 * @mtd: mtd info structure
1972 * @eccbuf: destination buffer to store ECC bytes
1973 * @oobbuf: OOB buffer
1974 * @start: first ECC byte to retrieve
1975 * @nbytes: number of ECC bytes to retrieve
1976 *
1977 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1978 *
1979 * Returns zero on success, a negative error code otherwise.
1980 */
mtd_ooblayout_get_eccbytes(struct mtd_info * mtd,u8 * eccbuf,const u8 * oobbuf,int start,int nbytes)1981 int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1982 const u8 *oobbuf, int start, int nbytes)
1983 {
1984 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1985 mtd_ooblayout_ecc);
1986 }
1987 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1988
1989 /**
1990 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1991 * @mtd: mtd info structure
1992 * @eccbuf: source buffer to get ECC bytes from
1993 * @oobbuf: OOB buffer
1994 * @start: first ECC byte to set
1995 * @nbytes: number of ECC bytes to set
1996 *
1997 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1998 *
1999 * Returns zero on success, a negative error code otherwise.
2000 */
mtd_ooblayout_set_eccbytes(struct mtd_info * mtd,const u8 * eccbuf,u8 * oobbuf,int start,int nbytes)2001 int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
2002 u8 *oobbuf, int start, int nbytes)
2003 {
2004 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
2005 mtd_ooblayout_ecc);
2006 }
2007 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
2008
2009 /**
2010 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
2011 * @mtd: mtd info structure
2012 * @databuf: destination buffer to store ECC bytes
2013 * @oobbuf: OOB buffer
2014 * @start: first ECC byte to retrieve
2015 * @nbytes: number of ECC bytes to retrieve
2016 *
2017 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
2018 *
2019 * Returns zero on success, a negative error code otherwise.
2020 */
mtd_ooblayout_get_databytes(struct mtd_info * mtd,u8 * databuf,const u8 * oobbuf,int start,int nbytes)2021 int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
2022 const u8 *oobbuf, int start, int nbytes)
2023 {
2024 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
2025 mtd_ooblayout_free);
2026 }
2027 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
2028
2029 /**
2030 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
2031 * @mtd: mtd info structure
2032 * @databuf: source buffer to get data bytes from
2033 * @oobbuf: OOB buffer
2034 * @start: first ECC byte to set
2035 * @nbytes: number of ECC bytes to set
2036 *
2037 * Works like mtd_ooblayout_set_bytes(), except it acts on free bytes.
2038 *
2039 * Returns zero on success, a negative error code otherwise.
2040 */
mtd_ooblayout_set_databytes(struct mtd_info * mtd,const u8 * databuf,u8 * oobbuf,int start,int nbytes)2041 int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
2042 u8 *oobbuf, int start, int nbytes)
2043 {
2044 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
2045 mtd_ooblayout_free);
2046 }
2047 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
2048
2049 /**
2050 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
2051 * @mtd: mtd info structure
2052 *
2053 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
2054 *
2055 * Returns zero on success, a negative error code otherwise.
2056 */
mtd_ooblayout_count_freebytes(struct mtd_info * mtd)2057 int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
2058 {
2059 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
2060 }
2061 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
2062
2063 /**
2064 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
2065 * @mtd: mtd info structure
2066 *
2067 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
2068 *
2069 * Returns zero on success, a negative error code otherwise.
2070 */
mtd_ooblayout_count_eccbytes(struct mtd_info * mtd)2071 int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
2072 {
2073 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
2074 }
2075 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
2076
2077 /*
2078 * Method to access the protection register area, present in some flash
2079 * devices. The user data is one time programmable but the factory data is read
2080 * only.
2081 */
mtd_get_fact_prot_info(struct mtd_info * mtd,size_t len,size_t * retlen,struct otp_info * buf)2082 int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
2083 struct otp_info *buf)
2084 {
2085 struct mtd_info *master = mtd_get_master(mtd);
2086
2087 if (!master->_get_fact_prot_info)
2088 return -EOPNOTSUPP;
2089 if (!len)
2090 return 0;
2091 return master->_get_fact_prot_info(master, len, retlen, buf);
2092 }
2093 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
2094
mtd_read_fact_prot_reg(struct mtd_info * mtd,loff_t from,size_t len,size_t * retlen,u_char * buf)2095 int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2096 size_t *retlen, u_char *buf)
2097 {
2098 struct mtd_info *master = mtd_get_master(mtd);
2099
2100 *retlen = 0;
2101 if (!master->_read_fact_prot_reg)
2102 return -EOPNOTSUPP;
2103 if (!len)
2104 return 0;
2105 return master->_read_fact_prot_reg(master, from, len, retlen, buf);
2106 }
2107 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
2108
mtd_get_user_prot_info(struct mtd_info * mtd,size_t len,size_t * retlen,struct otp_info * buf)2109 int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
2110 struct otp_info *buf)
2111 {
2112 struct mtd_info *master = mtd_get_master(mtd);
2113
2114 if (!master->_get_user_prot_info)
2115 return -EOPNOTSUPP;
2116 if (!len)
2117 return 0;
2118 return master->_get_user_prot_info(master, len, retlen, buf);
2119 }
2120 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
2121
mtd_read_user_prot_reg(struct mtd_info * mtd,loff_t from,size_t len,size_t * retlen,u_char * buf)2122 int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2123 size_t *retlen, u_char *buf)
2124 {
2125 struct mtd_info *master = mtd_get_master(mtd);
2126
2127 *retlen = 0;
2128 if (!master->_read_user_prot_reg)
2129 return -EOPNOTSUPP;
2130 if (!len)
2131 return 0;
2132 return master->_read_user_prot_reg(master, from, len, retlen, buf);
2133 }
2134 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
2135
mtd_write_user_prot_reg(struct mtd_info * mtd,loff_t to,size_t len,size_t * retlen,const u_char * buf)2136 int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
2137 size_t *retlen, const u_char *buf)
2138 {
2139 struct mtd_info *master = mtd_get_master(mtd);
2140 int ret;
2141
2142 *retlen = 0;
2143 if (!master->_write_user_prot_reg)
2144 return -EOPNOTSUPP;
2145 if (!len)
2146 return 0;
2147 ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
2148 if (ret)
2149 return ret;
2150
2151 /*
2152 * If no data could be written at all, we are out of memory and
2153 * must return -ENOSPC.
2154 */
2155 return (*retlen) ? 0 : -ENOSPC;
2156 }
2157 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
2158
mtd_lock_user_prot_reg(struct mtd_info * mtd,loff_t from,size_t len)2159 int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2160 {
2161 struct mtd_info *master = mtd_get_master(mtd);
2162
2163 if (!master->_lock_user_prot_reg)
2164 return -EOPNOTSUPP;
2165 if (!len)
2166 return 0;
2167 return master->_lock_user_prot_reg(master, from, len);
2168 }
2169 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
2170
mtd_erase_user_prot_reg(struct mtd_info * mtd,loff_t from,size_t len)2171 int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2172 {
2173 struct mtd_info *master = mtd_get_master(mtd);
2174
2175 if (!master->_erase_user_prot_reg)
2176 return -EOPNOTSUPP;
2177 if (!len)
2178 return 0;
2179 return master->_erase_user_prot_reg(master, from, len);
2180 }
2181 EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg);
2182
2183 /* Chip-supported device locking */
mtd_lock(struct mtd_info * mtd,loff_t ofs,uint64_t len)2184 int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2185 {
2186 struct mtd_info *master = mtd_get_master(mtd);
2187
2188 if (!master->_lock)
2189 return -EOPNOTSUPP;
2190 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2191 return -EINVAL;
2192 if (!len)
2193 return 0;
2194
2195 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2196 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2197 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2198 }
2199
2200 return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
2201 }
2202 EXPORT_SYMBOL_GPL(mtd_lock);
2203
mtd_unlock(struct mtd_info * mtd,loff_t ofs,uint64_t len)2204 int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2205 {
2206 struct mtd_info *master = mtd_get_master(mtd);
2207
2208 if (!master->_unlock)
2209 return -EOPNOTSUPP;
2210 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2211 return -EINVAL;
2212 if (!len)
2213 return 0;
2214
2215 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2216 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2217 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2218 }
2219
2220 return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
2221 }
2222 EXPORT_SYMBOL_GPL(mtd_unlock);
2223
mtd_is_locked(struct mtd_info * mtd,loff_t ofs,uint64_t len)2224 int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2225 {
2226 struct mtd_info *master = mtd_get_master(mtd);
2227
2228 if (!master->_is_locked)
2229 return -EOPNOTSUPP;
2230 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2231 return -EINVAL;
2232 if (!len)
2233 return 0;
2234
2235 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2236 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2237 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2238 }
2239
2240 return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
2241 }
2242 EXPORT_SYMBOL_GPL(mtd_is_locked);
2243
mtd_block_isreserved(struct mtd_info * mtd,loff_t ofs)2244 int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
2245 {
2246 struct mtd_info *master = mtd_get_master(mtd);
2247
2248 if (ofs < 0 || ofs >= mtd->size)
2249 return -EINVAL;
2250 if (!master->_block_isreserved)
2251 return 0;
2252
2253 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2254 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2255
2256 return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
2257 }
2258 EXPORT_SYMBOL_GPL(mtd_block_isreserved);
2259
mtd_block_isbad(struct mtd_info * mtd,loff_t ofs)2260 int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
2261 {
2262 struct mtd_info *master = mtd_get_master(mtd);
2263
2264 if (ofs < 0 || ofs >= mtd->size)
2265 return -EINVAL;
2266 if (!master->_block_isbad)
2267 return 0;
2268
2269 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2270 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2271
2272 return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
2273 }
2274 EXPORT_SYMBOL_GPL(mtd_block_isbad);
2275
mtd_block_markbad(struct mtd_info * mtd,loff_t ofs)2276 int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
2277 {
2278 struct mtd_info *master = mtd_get_master(mtd);
2279 int ret;
2280
2281 if (!master->_block_markbad)
2282 return -EOPNOTSUPP;
2283 if (ofs < 0 || ofs >= mtd->size)
2284 return -EINVAL;
2285 if (!(mtd->flags & MTD_WRITEABLE))
2286 return -EROFS;
2287
2288 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2289 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2290
2291 ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
2292 if (ret)
2293 return ret;
2294
2295 while (mtd->parent) {
2296 mtd->ecc_stats.badblocks++;
2297 mtd = mtd->parent;
2298 }
2299
2300 return 0;
2301 }
2302 EXPORT_SYMBOL_GPL(mtd_block_markbad);
2303
2304 /*
2305 * default_mtd_writev - the default writev method
2306 * @mtd: mtd device description object pointer
2307 * @vecs: the vectors to write
2308 * @count: count of vectors in @vecs
2309 * @to: the MTD device offset to write to
2310 * @retlen: on exit contains the count of bytes written to the MTD device.
2311 *
2312 * This function returns zero in case of success and a negative error code in
2313 * case of failure.
2314 */
default_mtd_writev(struct mtd_info * mtd,const struct kvec * vecs,unsigned long count,loff_t to,size_t * retlen)2315 static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2316 unsigned long count, loff_t to, size_t *retlen)
2317 {
2318 unsigned long i;
2319 size_t totlen = 0, thislen;
2320 int ret = 0;
2321
2322 for (i = 0; i < count; i++) {
2323 if (!vecs[i].iov_len)
2324 continue;
2325 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
2326 vecs[i].iov_base);
2327 totlen += thislen;
2328 if (ret || thislen != vecs[i].iov_len)
2329 break;
2330 to += vecs[i].iov_len;
2331 }
2332 *retlen = totlen;
2333 return ret;
2334 }
2335
2336 /*
2337 * mtd_writev - the vector-based MTD write method
2338 * @mtd: mtd device description object pointer
2339 * @vecs: the vectors to write
2340 * @count: count of vectors in @vecs
2341 * @to: the MTD device offset to write to
2342 * @retlen: on exit contains the count of bytes written to the MTD device.
2343 *
2344 * This function returns zero in case of success and a negative error code in
2345 * case of failure.
2346 */
mtd_writev(struct mtd_info * mtd,const struct kvec * vecs,unsigned long count,loff_t to,size_t * retlen)2347 int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2348 unsigned long count, loff_t to, size_t *retlen)
2349 {
2350 struct mtd_info *master = mtd_get_master(mtd);
2351
2352 *retlen = 0;
2353 if (!(mtd->flags & MTD_WRITEABLE))
2354 return -EROFS;
2355
2356 if (!master->_writev)
2357 return default_mtd_writev(mtd, vecs, count, to, retlen);
2358
2359 return master->_writev(master, vecs, count,
2360 mtd_get_master_ofs(mtd, to), retlen);
2361 }
2362 EXPORT_SYMBOL_GPL(mtd_writev);
2363
2364 /**
2365 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
2366 * @mtd: mtd device description object pointer
2367 * @size: a pointer to the ideal or maximum size of the allocation, points
2368 * to the actual allocation size on success.
2369 *
2370 * This routine attempts to allocate a contiguous kernel buffer up to
2371 * the specified size, backing off the size of the request exponentially
2372 * until the request succeeds or until the allocation size falls below
2373 * the system page size. This attempts to make sure it does not adversely
2374 * impact system performance, so when allocating more than one page, we
2375 * ask the memory allocator to avoid re-trying, swapping, writing back
2376 * or performing I/O.
2377 *
2378 * Note, this function also makes sure that the allocated buffer is aligned to
2379 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
2380 *
2381 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
2382 * to handle smaller (i.e. degraded) buffer allocations under low- or
2383 * fragmented-memory situations where such reduced allocations, from a
2384 * requested ideal, are allowed.
2385 *
2386 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
2387 */
mtd_kmalloc_up_to(const struct mtd_info * mtd,size_t * size)2388 void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
2389 {
2390 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
2391 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
2392 void *kbuf;
2393
2394 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
2395
2396 while (*size > min_alloc) {
2397 kbuf = kmalloc(*size, flags);
2398 if (kbuf)
2399 return kbuf;
2400
2401 *size >>= 1;
2402 *size = ALIGN(*size, mtd->writesize);
2403 }
2404
2405 /*
2406 * For the last resort allocation allow 'kmalloc()' to do all sorts of
2407 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
2408 */
2409 return kmalloc(*size, GFP_KERNEL);
2410 }
2411 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
2412
2413 #ifdef CONFIG_PROC_FS
2414
2415 /*====================================================================*/
2416 /* Support for /proc/mtd */
2417
mtd_proc_show(struct seq_file * m,void * v)2418 static int mtd_proc_show(struct seq_file *m, void *v)
2419 {
2420 struct mtd_info *mtd;
2421
2422 seq_puts(m, "dev: size erasesize name\n");
2423 mutex_lock(&mtd_table_mutex);
2424 mtd_for_each_device(mtd) {
2425 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
2426 mtd->index, (unsigned long long)mtd->size,
2427 mtd->erasesize, mtd->name);
2428 }
2429 mutex_unlock(&mtd_table_mutex);
2430 return 0;
2431 }
2432 #endif /* CONFIG_PROC_FS */
2433
2434 /*====================================================================*/
2435 /* Init code */
2436
mtd_bdi_init(const char * name)2437 static struct backing_dev_info * __init mtd_bdi_init(const char *name)
2438 {
2439 struct backing_dev_info *bdi;
2440 int ret;
2441
2442 bdi = bdi_alloc(NUMA_NO_NODE);
2443 if (!bdi)
2444 return ERR_PTR(-ENOMEM);
2445 bdi->ra_pages = 0;
2446 bdi->io_pages = 0;
2447
2448 /*
2449 * We put '-0' suffix to the name to get the same name format as we
2450 * used to get. Since this is called only once, we get a unique name.
2451 */
2452 ret = bdi_register(bdi, "%.28s-0", name);
2453 if (ret)
2454 bdi_put(bdi);
2455
2456 return ret ? ERR_PTR(ret) : bdi;
2457 }
2458
2459 static struct proc_dir_entry *proc_mtd;
2460
init_mtd(void)2461 static int __init init_mtd(void)
2462 {
2463 int ret;
2464
2465 ret = class_register(&mtd_class);
2466 if (ret)
2467 goto err_reg;
2468
2469 mtd_bdi = mtd_bdi_init("mtd");
2470 if (IS_ERR(mtd_bdi)) {
2471 ret = PTR_ERR(mtd_bdi);
2472 goto err_bdi;
2473 }
2474
2475 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
2476
2477 ret = init_mtdchar();
2478 if (ret)
2479 goto out_procfs;
2480
2481 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
2482 debugfs_create_bool("expert_analysis_mode", 0600, dfs_dir_mtd,
2483 &mtd_expert_analysis_mode);
2484
2485 return 0;
2486
2487 out_procfs:
2488 if (proc_mtd)
2489 remove_proc_entry("mtd", NULL);
2490 bdi_unregister(mtd_bdi);
2491 bdi_put(mtd_bdi);
2492 err_bdi:
2493 class_unregister(&mtd_class);
2494 err_reg:
2495 pr_err("Error registering mtd class or bdi: %d\n", ret);
2496 return ret;
2497 }
2498
cleanup_mtd(void)2499 static void __exit cleanup_mtd(void)
2500 {
2501 debugfs_remove_recursive(dfs_dir_mtd);
2502 cleanup_mtdchar();
2503 if (proc_mtd)
2504 remove_proc_entry("mtd", NULL);
2505 class_unregister(&mtd_class);
2506 bdi_unregister(mtd_bdi);
2507 bdi_put(mtd_bdi);
2508 idr_destroy(&mtd_idr);
2509 }
2510
2511 module_init(init_mtd);
2512 module_exit(cleanup_mtd);
2513
2514 MODULE_LICENSE("GPL");
2515 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2516 MODULE_DESCRIPTION("Core MTD registration and access routines");
2517