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Merge tag 'io_uring-5.7-2020-05-22' of git://git.kernel.dk/linux-block
[thirdparty/linux.git] / drivers / mtd / mtdcore.c
CommitLineData
fd534e9b 1// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 2/*
1da177e4
LT
3 * Core registration and callback routines for MTD
4 * drivers and users.
5 *
a1452a37
DW
6 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
7 * Copyright © 2006 Red Hat UK Limited
1da177e4
LT
8 */
9
1da177e4
LT
10#include <linux/module.h>
11#include <linux/kernel.h>
1da177e4 12#include <linux/ptrace.h>
447d9bd8 13#include <linux/seq_file.h>
1da177e4
LT
14#include <linux/string.h>
15#include <linux/timer.h>
16#include <linux/major.h>
17#include <linux/fs.h>
7799308f 18#include <linux/err.h>
1da177e4
LT
19#include <linux/ioctl.h>
20#include <linux/init.h>
215a02fd 21#include <linux/of.h>
1da177e4 22#include <linux/proc_fs.h>
b520e412 23#include <linux/idr.h>
a33eb6b9 24#include <linux/backing-dev.h>
05d71b46 25#include <linux/gfp.h>
0d01ff25 26#include <linux/slab.h>
3efe41be 27#include <linux/reboot.h>
fea728c0 28#include <linux/leds.h>
e8e3edb9 29#include <linux/debugfs.h>
c4dfa25a 30#include <linux/nvmem-provider.h>
1da177e4
LT
31
32#include <linux/mtd/mtd.h>
f5671ab3 33#include <linux/mtd/partitions.h>
1da177e4 34
356d70f1 35#include "mtdcore.h"
660685d9 36
fa06052d 37struct backing_dev_info *mtd_bdi;
356d70f1 38
57b8045d
LPC
39#ifdef CONFIG_PM_SLEEP
40
41static 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
48static 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
57static 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
15bce40c
DW
62
63static struct class mtd_class = {
64 .name = "mtd",
65 .owner = THIS_MODULE,
57b8045d 66 .pm = MTD_CLS_PM_OPS,
15bce40c 67};
1f24b5a8 68
b520e412
BH
69static DEFINE_IDR(mtd_idr);
70
97894cda 71/* These are exported solely for the purpose of mtd_blkdevs.c. You
1da177e4 72 should not use them for _anything_ else */
48b19268 73DEFINE_MUTEX(mtd_table_mutex);
1da177e4 74EXPORT_SYMBOL_GPL(mtd_table_mutex);
b520e412
BH
75
76struct mtd_info *__mtd_next_device(int i)
77{
78 return idr_get_next(&mtd_idr, &i);
79}
80EXPORT_SYMBOL_GPL(__mtd_next_device);
1da177e4
LT
81
82static LIST_HEAD(mtd_notifiers);
83
1f24b5a8 84
1f24b5a8 85#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
1f24b5a8
DB
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 */
90static void mtd_release(struct device *dev)
91{
5e472128 92 struct mtd_info *mtd = dev_get_drvdata(dev);
d5de20a9 93 dev_t index = MTD_DEVT(mtd->index);
1f24b5a8 94
5e472128
BN
95 /* remove /dev/mtdXro node */
96 device_destroy(&mtd_class, index + 1);
15bce40c
DW
97}
98
1f24b5a8
DB
99static ssize_t mtd_type_show(struct device *dev,
100 struct device_attribute *attr, char *buf)
101{
d5de20a9 102 struct mtd_info *mtd = dev_get_drvdata(dev);
1f24b5a8
DB
103 char *type;
104
105 switch (mtd->type) {
106 case MTD_ABSENT:
107 type = "absent";
108 break;
109 case MTD_RAM:
110 type = "ram";
111 break;
112 case MTD_ROM:
113 type = "rom";
114 break;
115 case MTD_NORFLASH:
116 type = "nor";
117 break;
118 case MTD_NANDFLASH:
119 type = "nand";
120 break;
121 case MTD_DATAFLASH:
122 type = "dataflash";
123 break;
124 case MTD_UBIVOLUME:
125 type = "ubi";
126 break;
f4837246
HS
127 case MTD_MLCNANDFLASH:
128 type = "mlc-nand";
129 break;
1f24b5a8
DB
130 default:
131 type = "unknown";
132 }
133
134 return snprintf(buf, PAGE_SIZE, "%s\n", type);
135}
694bb7fc
KC
136static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
137
138static ssize_t mtd_flags_show(struct device *dev,
139 struct device_attribute *attr, char *buf)
140{
d5de20a9 141 struct mtd_info *mtd = dev_get_drvdata(dev);
694bb7fc
KC
142
143 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
694bb7fc
KC
144}
145static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
146
147static ssize_t mtd_size_show(struct device *dev,
148 struct device_attribute *attr, char *buf)
149{
d5de20a9 150 struct mtd_info *mtd = dev_get_drvdata(dev);
694bb7fc
KC
151
152 return snprintf(buf, PAGE_SIZE, "%llu\n",
153 (unsigned long long)mtd->size);
694bb7fc
KC
154}
155static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
156
157static ssize_t mtd_erasesize_show(struct device *dev,
158 struct device_attribute *attr, char *buf)
159{
d5de20a9 160 struct mtd_info *mtd = dev_get_drvdata(dev);
694bb7fc
KC
161
162 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
694bb7fc
KC
163}
164static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
165
166static ssize_t mtd_writesize_show(struct device *dev,
167 struct device_attribute *attr, char *buf)
168{
d5de20a9 169 struct mtd_info *mtd = dev_get_drvdata(dev);
694bb7fc
KC
170
171 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
694bb7fc
KC
172}
173static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
174
e7693548
AB
175static ssize_t mtd_subpagesize_show(struct device *dev,
176 struct device_attribute *attr, char *buf)
177{
d5de20a9 178 struct mtd_info *mtd = dev_get_drvdata(dev);
e7693548
AB
179 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
180
181 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
e7693548
AB
182}
183static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
184
694bb7fc
KC
185static ssize_t mtd_oobsize_show(struct device *dev,
186 struct device_attribute *attr, char *buf)
187{
d5de20a9 188 struct mtd_info *mtd = dev_get_drvdata(dev);
694bb7fc
KC
189
190 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
694bb7fc
KC
191}
192static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
193
7cc9aa66
XL
194static ssize_t mtd_oobavail_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, "%u\n", mtd->oobavail);
200}
201static DEVICE_ATTR(oobavail, S_IRUGO, mtd_oobavail_show, NULL);
202
694bb7fc
KC
203static ssize_t mtd_numeraseregions_show(struct device *dev,
204 struct device_attribute *attr, char *buf)
205{
d5de20a9 206 struct mtd_info *mtd = dev_get_drvdata(dev);
694bb7fc
KC
207
208 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
694bb7fc
KC
209}
210static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
211 NULL);
212
213static ssize_t mtd_name_show(struct device *dev,
214 struct device_attribute *attr, char *buf)
215{
d5de20a9 216 struct mtd_info *mtd = dev_get_drvdata(dev);
694bb7fc
KC
217
218 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
694bb7fc
KC
219}
220static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
1f24b5a8 221
a9b672e8
MD
222static ssize_t mtd_ecc_strength_show(struct device *dev,
223 struct device_attribute *attr, char *buf)
224{
225 struct mtd_info *mtd = dev_get_drvdata(dev);
226
227 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_strength);
228}
229static DEVICE_ATTR(ecc_strength, S_IRUGO, mtd_ecc_strength_show, NULL);
230
d062d4ed
MD
231static ssize_t mtd_bitflip_threshold_show(struct device *dev,
232 struct device_attribute *attr,
233 char *buf)
234{
235 struct mtd_info *mtd = dev_get_drvdata(dev);
236
237 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->bitflip_threshold);
238}
239
240static ssize_t mtd_bitflip_threshold_store(struct device *dev,
241 struct device_attribute *attr,
242 const char *buf, size_t count)
243{
244 struct mtd_info *mtd = dev_get_drvdata(dev);
245 unsigned int bitflip_threshold;
246 int retval;
247
248 retval = kstrtouint(buf, 0, &bitflip_threshold);
249 if (retval)
250 return retval;
251
252 mtd->bitflip_threshold = bitflip_threshold;
253 return count;
254}
255static DEVICE_ATTR(bitflip_threshold, S_IRUGO | S_IWUSR,
256 mtd_bitflip_threshold_show,
257 mtd_bitflip_threshold_store);
258
bf977e3f
HS
259static ssize_t mtd_ecc_step_size_show(struct device *dev,
260 struct device_attribute *attr, char *buf)
261{
262 struct mtd_info *mtd = dev_get_drvdata(dev);
263
264 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->ecc_step_size);
265
266}
267static DEVICE_ATTR(ecc_step_size, S_IRUGO, mtd_ecc_step_size_show, NULL);
268
990a3af0
EG
269static ssize_t mtd_ecc_stats_corrected_show(struct device *dev,
270 struct device_attribute *attr, char *buf)
271{
272 struct mtd_info *mtd = dev_get_drvdata(dev);
273 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
274
275 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->corrected);
276}
277static DEVICE_ATTR(corrected_bits, S_IRUGO,
278 mtd_ecc_stats_corrected_show, NULL);
279
280static ssize_t mtd_ecc_stats_errors_show(struct device *dev,
281 struct device_attribute *attr, char *buf)
282{
283 struct mtd_info *mtd = dev_get_drvdata(dev);
284 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
285
286 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->failed);
287}
288static DEVICE_ATTR(ecc_failures, S_IRUGO, mtd_ecc_stats_errors_show, NULL);
289
290static ssize_t mtd_badblocks_show(struct device *dev,
291 struct device_attribute *attr, char *buf)
292{
293 struct mtd_info *mtd = dev_get_drvdata(dev);
294 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
295
296 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->badblocks);
297}
298static DEVICE_ATTR(bad_blocks, S_IRUGO, mtd_badblocks_show, NULL);
299
300static ssize_t mtd_bbtblocks_show(struct device *dev,
301 struct device_attribute *attr, char *buf)
302{
303 struct mtd_info *mtd = dev_get_drvdata(dev);
304 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
305
306 return snprintf(buf, PAGE_SIZE, "%u\n", ecc_stats->bbtblocks);
307}
308static DEVICE_ATTR(bbt_blocks, S_IRUGO, mtd_bbtblocks_show, NULL);
309
1f24b5a8 310static struct attribute *mtd_attrs[] = {
694bb7fc
KC
311 &dev_attr_type.attr,
312 &dev_attr_flags.attr,
313 &dev_attr_size.attr,
314 &dev_attr_erasesize.attr,
315 &dev_attr_writesize.attr,
e7693548 316 &dev_attr_subpagesize.attr,
694bb7fc 317 &dev_attr_oobsize.attr,
7cc9aa66 318 &dev_attr_oobavail.attr,
694bb7fc
KC
319 &dev_attr_numeraseregions.attr,
320 &dev_attr_name.attr,
a9b672e8 321 &dev_attr_ecc_strength.attr,
bf977e3f 322 &dev_attr_ecc_step_size.attr,
990a3af0
EG
323 &dev_attr_corrected_bits.attr,
324 &dev_attr_ecc_failures.attr,
325 &dev_attr_bad_blocks.attr,
326 &dev_attr_bbt_blocks.attr,
d062d4ed 327 &dev_attr_bitflip_threshold.attr,
1f24b5a8
DB
328 NULL,
329};
54c738f6 330ATTRIBUTE_GROUPS(mtd);
1f24b5a8 331
75864b30 332static const struct device_type mtd_devtype = {
1f24b5a8
DB
333 .name = "mtd",
334 .groups = mtd_groups,
335 .release = mtd_release,
336};
337
1018c94b
ZL
338static int mtd_partid_show(struct seq_file *s, void *p)
339{
340 struct mtd_info *mtd = s->private;
341
342 seq_printf(s, "%s\n", mtd->dbg.partid);
343
344 return 0;
345}
346
347static int mtd_partid_debugfs_open(struct inode *inode, struct file *file)
348{
349 return single_open(file, mtd_partid_show, inode->i_private);
350}
351
352static const struct file_operations mtd_partid_debug_fops = {
353 .open = mtd_partid_debugfs_open,
354 .read = seq_read,
355 .llseek = seq_lseek,
356 .release = single_release,
357};
358
359static int mtd_partname_show(struct seq_file *s, void *p)
360{
361 struct mtd_info *mtd = s->private;
362
363 seq_printf(s, "%s\n", mtd->dbg.partname);
364
365 return 0;
366}
367
368static int mtd_partname_debugfs_open(struct inode *inode, struct file *file)
369{
370 return single_open(file, mtd_partname_show, inode->i_private);
371}
372
373static const struct file_operations mtd_partname_debug_fops = {
374 .open = mtd_partname_debugfs_open,
375 .read = seq_read,
376 .llseek = seq_lseek,
377 .release = single_release,
378};
379
380static struct dentry *dfs_dir_mtd;
381
382static void mtd_debugfs_populate(struct mtd_info *mtd)
383{
384 struct device *dev = &mtd->dev;
c2d73ba8 385 struct dentry *root;
1018c94b
ZL
386
387 if (IS_ERR_OR_NULL(dfs_dir_mtd))
388 return;
389
390 root = debugfs_create_dir(dev_name(dev), dfs_dir_mtd);
1018c94b
ZL
391 mtd->dbg.dfs_dir = root;
392
c2d73ba8
GKH
393 if (mtd->dbg.partid)
394 debugfs_create_file("partid", 0400, root, mtd,
395 &mtd_partid_debug_fops);
1018c94b 396
c2d73ba8
GKH
397 if (mtd->dbg.partname)
398 debugfs_create_file("partname", 0400, root, mtd,
399 &mtd_partname_debug_fops);
1018c94b
ZL
400}
401
b4caecd4
CH
402#ifndef CONFIG_MMU
403unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
404{
405 switch (mtd->type) {
406 case MTD_RAM:
407 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
408 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
409 case MTD_ROM:
410 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
411 NOMMU_MAP_READ;
412 default:
413 return NOMMU_MAP_COPY;
414 }
415}
706a4e5a 416EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
b4caecd4
CH
417#endif
418
3efe41be
BN
419static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
420 void *cmd)
421{
422 struct mtd_info *mtd;
423
424 mtd = container_of(n, struct mtd_info, reboot_notifier);
425 mtd->_reboot(mtd);
426
427 return NOTIFY_DONE;
428}
429
477b0229
BB
430/**
431 * mtd_wunit_to_pairing_info - get pairing information of a wunit
432 * @mtd: pointer to new MTD device info structure
433 * @wunit: write unit we are interested in
434 * @info: returned pairing information
435 *
436 * Retrieve pairing information associated to the wunit.
437 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
438 * paired together, and where programming a page may influence the page it is
439 * paired with.
440 * The notion of page is replaced by the term wunit (write-unit) to stay
441 * consistent with the ->writesize field.
442 *
443 * The @wunit argument can be extracted from an absolute offset using
444 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
445 * to @wunit.
446 *
447 * From the pairing info the MTD user can find all the wunits paired with
448 * @wunit using the following loop:
449 *
450 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
451 * info.pair = i;
452 * mtd_pairing_info_to_wunit(mtd, &info);
453 * ...
454 * }
455 */
456int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
457 struct mtd_pairing_info *info)
458{
46b5889c
MR
459 struct mtd_info *master = mtd_get_master(mtd);
460 int npairs = mtd_wunit_per_eb(master) / mtd_pairing_groups(master);
477b0229
BB
461
462 if (wunit < 0 || wunit >= npairs)
463 return -EINVAL;
464
46b5889c
MR
465 if (master->pairing && master->pairing->get_info)
466 return master->pairing->get_info(master, wunit, info);
477b0229
BB
467
468 info->group = 0;
469 info->pair = wunit;
470
471 return 0;
472}
473EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
474
475/**
c77a9312 476 * mtd_pairing_info_to_wunit - get wunit from pairing information
477b0229
BB
477 * @mtd: pointer to new MTD device info structure
478 * @info: pairing information struct
479 *
480 * Returns a positive number representing the wunit associated to the info
481 * struct, or a negative error code.
482 *
483 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
484 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
485 * doc).
486 *
487 * It can also be used to only program the first page of each pair (i.e.
488 * page attached to group 0), which allows one to use an MLC NAND in
489 * software-emulated SLC mode:
490 *
491 * info.group = 0;
492 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
493 * for (info.pair = 0; info.pair < npairs; info.pair++) {
494 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
495 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
496 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
497 * }
498 */
499int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
500 const struct mtd_pairing_info *info)
501{
46b5889c
MR
502 struct mtd_info *master = mtd_get_master(mtd);
503 int ngroups = mtd_pairing_groups(master);
504 int npairs = mtd_wunit_per_eb(master) / ngroups;
477b0229
BB
505
506 if (!info || info->pair < 0 || info->pair >= npairs ||
507 info->group < 0 || info->group >= ngroups)
508 return -EINVAL;
509
46b5889c
MR
510 if (master->pairing && master->pairing->get_wunit)
511 return mtd->pairing->get_wunit(master, info);
477b0229
BB
512
513 return info->pair;
514}
515EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
516
517/**
518 * mtd_pairing_groups - get the number of pairing groups
519 * @mtd: pointer to new MTD device info structure
520 *
521 * Returns the number of pairing groups.
522 *
523 * This number is usually equal to the number of bits exposed by a single
524 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
525 * to iterate over all pages of a given pair.
526 */
527int mtd_pairing_groups(struct mtd_info *mtd)
528{
46b5889c
MR
529 struct mtd_info *master = mtd_get_master(mtd);
530
531 if (!master->pairing || !master->pairing->ngroups)
477b0229
BB
532 return 1;
533
46b5889c 534 return master->pairing->ngroups;
477b0229
BB
535}
536EXPORT_SYMBOL_GPL(mtd_pairing_groups);
537
c4dfa25a
AB
538static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
539 void *val, size_t bytes)
540{
541 struct mtd_info *mtd = priv;
542 size_t retlen;
543 int err;
544
545 err = mtd_read(mtd, offset, bytes, &retlen, val);
546 if (err && err != -EUCLEAN)
547 return err;
548
549 return retlen == bytes ? 0 : -EIO;
550}
551
552static int mtd_nvmem_add(struct mtd_info *mtd)
553{
554 struct nvmem_config config = {};
555
6e952685 556 config.id = -1;
c4dfa25a 557 config.dev = &mtd->dev;
7b01b723 558 config.name = dev_name(&mtd->dev);
c4dfa25a
AB
559 config.owner = THIS_MODULE;
560 config.reg_read = mtd_nvmem_reg_read;
561 config.size = mtd->size;
562 config.word_size = 1;
563 config.stride = 1;
564 config.read_only = true;
565 config.root_only = true;
566 config.no_of_node = true;
567 config.priv = mtd;
568
569 mtd->nvmem = nvmem_register(&config);
570 if (IS_ERR(mtd->nvmem)) {
571 /* Just ignore if there is no NVMEM support in the kernel */
19e16fb4 572 if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP) {
c4dfa25a
AB
573 mtd->nvmem = NULL;
574 } else {
575 dev_err(&mtd->dev, "Failed to register NVMEM device\n");
576 return PTR_ERR(mtd->nvmem);
577 }
578 }
579
580 return 0;
581}
582
1da177e4
LT
583/**
584 * add_mtd_device - register an MTD device
585 * @mtd: pointer to new MTD device info structure
586 *
587 * Add a device to the list of MTD devices present in the system, and
588 * notify each currently active MTD 'user' of its arrival. Returns
57dd990c 589 * zero on success or non-zero on failure.
1da177e4
LT
590 */
591
592int add_mtd_device(struct mtd_info *mtd)
593{
46b5889c 594 struct mtd_info *master = mtd_get_master(mtd);
b520e412
BH
595 struct mtd_notifier *not;
596 int i, error;
1da177e4 597
be0dbff8
BN
598 /*
599 * May occur, for instance, on buggy drivers which call
600 * mtd_device_parse_register() multiple times on the same master MTD,
601 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
602 */
fa06052d 603 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
be0dbff8
BN
604 return -EEXIST;
605
783ed81f 606 BUG_ON(mtd->writesize == 0);
33f45c44 607
2431c4f5
BB
608 /*
609 * MTD drivers should implement ->_{write,read}() or
610 * ->_{write,read}_oob(), but not both.
611 */
612 if (WARN_ON((mtd->_write && mtd->_write_oob) ||
613 (mtd->_read && mtd->_read_oob)))
614 return -EINVAL;
615
46b5889c 616 if (WARN_ON((!mtd->erasesize || !master->_erase) &&
33f45c44
BB
617 !(mtd->flags & MTD_NO_ERASE)))
618 return -EINVAL;
619
48b19268 620 mutex_lock(&mtd_table_mutex);
1da177e4 621
589e9c4d 622 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
57dd990c
BN
623 if (i < 0) {
624 error = i;
b520e412 625 goto fail_locked;
57dd990c 626 }
1f24b5a8 627
b520e412
BH
628 mtd->index = i;
629 mtd->usecount = 0;
630
d062d4ed
MD
631 /* default value if not set by driver */
632 if (mtd->bitflip_threshold == 0)
633 mtd->bitflip_threshold = mtd->ecc_strength;
634
b520e412
BH
635 if (is_power_of_2(mtd->erasesize))
636 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
637 else
638 mtd->erasesize_shift = 0;
639
640 if (is_power_of_2(mtd->writesize))
641 mtd->writesize_shift = ffs(mtd->writesize) - 1;
642 else
643 mtd->writesize_shift = 0;
644
645 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
646 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
647
648 /* Some chips always power up locked. Unlock them now */
38134565
AB
649 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
650 error = mtd_unlock(mtd, 0, mtd->size);
651 if (error && error != -EOPNOTSUPP)
b520e412
BH
652 printk(KERN_WARNING
653 "%s: unlock failed, writes may not work\n",
654 mtd->name);
57dd990c
BN
655 /* Ignore unlock failures? */
656 error = 0;
b520e412
BH
657 }
658
659 /* Caller should have set dev.parent to match the
260e89a6 660 * physical device, if appropriate.
b520e412
BH
661 */
662 mtd->dev.type = &mtd_devtype;
663 mtd->dev.class = &mtd_class;
664 mtd->dev.devt = MTD_DEVT(i);
665 dev_set_name(&mtd->dev, "mtd%d", i);
666 dev_set_drvdata(&mtd->dev, mtd);
215a02fd 667 of_node_get(mtd_get_of_node(mtd));
57dd990c
BN
668 error = device_register(&mtd->dev);
669 if (error)
b520e412
BH
670 goto fail_added;
671
c4dfa25a
AB
672 /* Add the nvmem provider */
673 error = mtd_nvmem_add(mtd);
674 if (error)
675 goto fail_nvmem_add;
676
1018c94b 677 mtd_debugfs_populate(mtd);
e8e3edb9 678
5e472128
BN
679 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
680 "mtd%dro", i);
b520e412 681
289c0522 682 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
b520e412
BH
683 /* No need to get a refcount on the module containing
684 the notifier, since we hold the mtd_table_mutex */
685 list_for_each_entry(not, &mtd_notifiers, list)
686 not->add(mtd);
687
688 mutex_unlock(&mtd_table_mutex);
689 /* We _know_ we aren't being removed, because
690 our caller is still holding us here. So none
691 of this try_ nonsense, and no bitching about it
692 either. :) */
693 __module_get(THIS_MODULE);
694 return 0;
97894cda 695
c4dfa25a
AB
696fail_nvmem_add:
697 device_unregister(&mtd->dev);
b520e412 698fail_added:
215a02fd 699 of_node_put(mtd_get_of_node(mtd));
b520e412
BH
700 idr_remove(&mtd_idr, i);
701fail_locked:
48b19268 702 mutex_unlock(&mtd_table_mutex);
57dd990c 703 return error;
1da177e4
LT
704}
705
706/**
707 * del_mtd_device - unregister an MTD device
708 * @mtd: pointer to MTD device info structure
709 *
710 * Remove a device from the list of MTD devices present in the system,
711 * and notify each currently active MTD 'user' of its departure.
712 * Returns zero on success or 1 on failure, which currently will happen
713 * if the requested device does not appear to be present in the list.
714 */
715
eea72d5f 716int del_mtd_device(struct mtd_info *mtd)
1da177e4
LT
717{
718 int ret;
75c0b84d 719 struct mtd_notifier *not;
97894cda 720
48b19268 721 mutex_lock(&mtd_table_mutex);
1da177e4 722
e8e3edb9
MR
723 debugfs_remove_recursive(mtd->dbg.dfs_dir);
724
b520e412 725 if (idr_find(&mtd_idr, mtd->index) != mtd) {
1da177e4 726 ret = -ENODEV;
75c0b84d
ML
727 goto out_error;
728 }
729
730 /* No need to get a refcount on the module containing
731 the notifier, since we hold the mtd_table_mutex */
732 list_for_each_entry(not, &mtd_notifiers, list)
733 not->remove(mtd);
734
735 if (mtd->usecount) {
97894cda 736 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
1da177e4
LT
737 mtd->index, mtd->name, mtd->usecount);
738 ret = -EBUSY;
739 } else {
c4dfa25a
AB
740 /* Try to remove the NVMEM provider */
741 if (mtd->nvmem)
742 nvmem_unregister(mtd->nvmem);
743
694bb7fc
KC
744 device_unregister(&mtd->dev);
745
b520e412 746 idr_remove(&mtd_idr, mtd->index);
215a02fd 747 of_node_put(mtd_get_of_node(mtd));
1da177e4
LT
748
749 module_put(THIS_MODULE);
750 ret = 0;
751 }
752
75c0b84d 753out_error:
48b19268 754 mutex_unlock(&mtd_table_mutex);
1da177e4
LT
755 return ret;
756}
757
472b444e
BN
758/*
759 * Set a few defaults based on the parent devices, if not provided by the
760 * driver
761 */
762static void mtd_set_dev_defaults(struct mtd_info *mtd)
763{
764 if (mtd->dev.parent) {
765 if (!mtd->owner && mtd->dev.parent->driver)
766 mtd->owner = mtd->dev.parent->driver->owner;
767 if (!mtd->name)
768 mtd->name = dev_name(mtd->dev.parent);
769 } else {
770 pr_debug("mtd device won't show a device symlink in sysfs\n");
771 }
1186af45 772
46b5889c
MR
773 INIT_LIST_HEAD(&mtd->partitions);
774 mutex_init(&mtd->master.partitions_lock);
472b444e 775}
727dc612 776
1c4c215c
DB
777/**
778 * mtd_device_parse_register - parse partitions and register an MTD device.
779 *
780 * @mtd: the MTD device to register
781 * @types: the list of MTD partition probes to try, see
782 * 'parse_mtd_partitions()' for more information
c7975330 783 * @parser_data: MTD partition parser-specific data
1c4c215c
DB
784 * @parts: fallback partition information to register, if parsing fails;
785 * only valid if %nr_parts > %0
786 * @nr_parts: the number of partitions in parts, if zero then the full
787 * MTD device is registered if no partition info is found
788 *
789 * This function aggregates MTD partitions parsing (done by
790 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
791 * basically follows the most common pattern found in many MTD drivers:
792 *
55a999a0
RM
793 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
794 * registered first.
795 * * Then It tries to probe partitions on MTD device @mtd using parsers
1c4c215c
DB
796 * specified in @types (if @types is %NULL, then the default list of parsers
797 * is used, see 'parse_mtd_partitions()' for more information). If none are
798 * found this functions tries to fallback to information specified in
799 * @parts/@nr_parts.
1c4c215c
DB
800 * * If no partitions were found this function just registers the MTD device
801 * @mtd and exits.
802 *
803 * Returns zero in case of success and a negative error code in case of failure.
804 */
26a47346 805int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
c7975330 806 struct mtd_part_parser_data *parser_data,
1c4c215c
DB
807 const struct mtd_partition *parts,
808 int nr_parts)
809{
727dc612 810 int ret;
1c4c215c 811
472b444e
BN
812 mtd_set_dev_defaults(mtd);
813
2c77c57d
RM
814 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
815 ret = add_mtd_device(mtd);
816 if (ret)
817 return ret;
818 }
819
0dbe4ea7 820 /* Prefer parsed partitions over driver-provided fallback */
5ac67ce3
RM
821 ret = parse_mtd_partitions(mtd, types, parser_data);
822 if (ret > 0)
823 ret = 0;
824 else if (nr_parts)
0dbe4ea7
RM
825 ret = add_mtd_partitions(mtd, parts, nr_parts);
826 else if (!device_is_registered(&mtd->dev))
827 ret = add_mtd_device(mtd);
828 else
829 ret = 0;
830
3e00ed0e
BN
831 if (ret)
832 goto out;
1c4c215c 833
e1dd8641
NC
834 /*
835 * FIXME: some drivers unfortunately call this function more than once.
836 * So we have to check if we've already assigned the reboot notifier.
837 *
838 * Generally, we can make multiple calls work for most cases, but it
839 * does cause problems with parse_mtd_partitions() above (e.g.,
840 * cmdlineparts will register partitions more than once).
841 */
f8479dd6
BN
842 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
843 "MTD already registered\n");
e1dd8641 844 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
3efe41be
BN
845 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
846 register_reboot_notifier(&mtd->reboot_notifier);
847 }
848
3e00ed0e 849out:
2c77c57d
RM
850 if (ret && device_is_registered(&mtd->dev))
851 del_mtd_device(mtd);
852
727dc612 853 return ret;
1c4c215c
DB
854}
855EXPORT_SYMBOL_GPL(mtd_device_parse_register);
856
f5671ab3
JI
857/**
858 * mtd_device_unregister - unregister an existing MTD device.
859 *
860 * @master: the MTD device to unregister. This will unregister both the master
861 * and any partitions if registered.
862 */
863int mtd_device_unregister(struct mtd_info *master)
864{
865 int err;
866
3efe41be
BN
867 if (master->_reboot)
868 unregister_reboot_notifier(&master->reboot_notifier);
869
f5671ab3
JI
870 err = del_mtd_partitions(master);
871 if (err)
872 return err;
873
874 if (!device_is_registered(&master->dev))
875 return 0;
876
877 return del_mtd_device(master);
878}
879EXPORT_SYMBOL_GPL(mtd_device_unregister);
880
1da177e4
LT
881/**
882 * register_mtd_user - register a 'user' of MTD devices.
883 * @new: pointer to notifier info structure
884 *
885 * Registers a pair of callbacks function to be called upon addition
886 * or removal of MTD devices. Causes the 'add' callback to be immediately
887 * invoked for each MTD device currently present in the system.
888 */
1da177e4
LT
889void register_mtd_user (struct mtd_notifier *new)
890{
f1332ba2 891 struct mtd_info *mtd;
1da177e4 892
48b19268 893 mutex_lock(&mtd_table_mutex);
1da177e4
LT
894
895 list_add(&new->list, &mtd_notifiers);
896
d5ca5129 897 __module_get(THIS_MODULE);
97894cda 898
f1332ba2
BH
899 mtd_for_each_device(mtd)
900 new->add(mtd);
1da177e4 901
48b19268 902 mutex_unlock(&mtd_table_mutex);
1da177e4 903}
33c87b4a 904EXPORT_SYMBOL_GPL(register_mtd_user);
1da177e4
LT
905
906/**
49450795
AB
907 * unregister_mtd_user - unregister a 'user' of MTD devices.
908 * @old: pointer to notifier info structure
1da177e4
LT
909 *
910 * Removes a callback function pair from the list of 'users' to be
911 * notified upon addition or removal of MTD devices. Causes the
912 * 'remove' callback to be immediately invoked for each MTD device
913 * currently present in the system.
914 */
1da177e4
LT
915int unregister_mtd_user (struct mtd_notifier *old)
916{
f1332ba2 917 struct mtd_info *mtd;
1da177e4 918
48b19268 919 mutex_lock(&mtd_table_mutex);
1da177e4
LT
920
921 module_put(THIS_MODULE);
922
f1332ba2
BH
923 mtd_for_each_device(mtd)
924 old->remove(mtd);
97894cda 925
1da177e4 926 list_del(&old->list);
48b19268 927 mutex_unlock(&mtd_table_mutex);
1da177e4
LT
928 return 0;
929}
33c87b4a 930EXPORT_SYMBOL_GPL(unregister_mtd_user);
1da177e4
LT
931
932/**
933 * get_mtd_device - obtain a validated handle for an MTD device
934 * @mtd: last known address of the required MTD device
935 * @num: internal device number of the required MTD device
936 *
937 * Given a number and NULL address, return the num'th entry in the device
938 * table, if any. Given an address and num == -1, search the device table
939 * for a device with that address and return if it's still present. Given
9c74034f
AB
940 * both, return the num'th driver only if its address matches. Return
941 * error code if not.
1da177e4 942 */
1da177e4
LT
943struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
944{
f1332ba2
BH
945 struct mtd_info *ret = NULL, *other;
946 int err = -ENODEV;
1da177e4 947
48b19268 948 mutex_lock(&mtd_table_mutex);
1da177e4
LT
949
950 if (num == -1) {
f1332ba2
BH
951 mtd_for_each_device(other) {
952 if (other == mtd) {
953 ret = mtd;
954 break;
955 }
956 }
b520e412
BH
957 } else if (num >= 0) {
958 ret = idr_find(&mtd_idr, num);
1da177e4
LT
959 if (mtd && mtd != ret)
960 ret = NULL;
961 }
962
3bd45657
ML
963 if (!ret) {
964 ret = ERR_PTR(err);
965 goto out;
9fe912ce 966 }
1da177e4 967
3bd45657
ML
968 err = __get_mtd_device(ret);
969 if (err)
970 ret = ERR_PTR(err);
971out:
9c74034f
AB
972 mutex_unlock(&mtd_table_mutex);
973 return ret;
3bd45657 974}
33c87b4a 975EXPORT_SYMBOL_GPL(get_mtd_device);
1da177e4 976
3bd45657
ML
977
978int __get_mtd_device(struct mtd_info *mtd)
979{
46b5889c 980 struct mtd_info *master = mtd_get_master(mtd);
3bd45657
ML
981 int err;
982
46b5889c 983 if (!try_module_get(master->owner))
3bd45657
ML
984 return -ENODEV;
985
46b5889c
MR
986 if (master->_get_device) {
987 err = master->_get_device(mtd);
3bd45657
ML
988
989 if (err) {
46b5889c 990 module_put(master->owner);
3bd45657
ML
991 return err;
992 }
993 }
46b5889c
MR
994
995 while (mtd->parent) {
996 mtd->usecount++;
997 mtd = mtd->parent;
998 }
999
3bd45657 1000 return 0;
1da177e4 1001}
33c87b4a 1002EXPORT_SYMBOL_GPL(__get_mtd_device);
1da177e4 1003
7799308f
AB
1004/**
1005 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1006 * device name
1007 * @name: MTD device name to open
1008 *
1009 * This function returns MTD device description structure in case of
1010 * success and an error code in case of failure.
1011 */
7799308f
AB
1012struct mtd_info *get_mtd_device_nm(const char *name)
1013{
f1332ba2
BH
1014 int err = -ENODEV;
1015 struct mtd_info *mtd = NULL, *other;
7799308f
AB
1016
1017 mutex_lock(&mtd_table_mutex);
1018
f1332ba2
BH
1019 mtd_for_each_device(other) {
1020 if (!strcmp(name, other->name)) {
1021 mtd = other;
7799308f
AB
1022 break;
1023 }
1024 }
1025
9fe912ce 1026 if (!mtd)
7799308f
AB
1027 goto out_unlock;
1028
52534f2d
WG
1029 err = __get_mtd_device(mtd);
1030 if (err)
7799308f
AB
1031 goto out_unlock;
1032
9fe912ce
AB
1033 mutex_unlock(&mtd_table_mutex);
1034 return mtd;
7799308f
AB
1035
1036out_unlock:
1037 mutex_unlock(&mtd_table_mutex);
9fe912ce 1038 return ERR_PTR(err);
7799308f 1039}
33c87b4a 1040EXPORT_SYMBOL_GPL(get_mtd_device_nm);
7799308f 1041
1da177e4
LT
1042void put_mtd_device(struct mtd_info *mtd)
1043{
48b19268 1044 mutex_lock(&mtd_table_mutex);
3bd45657
ML
1045 __put_mtd_device(mtd);
1046 mutex_unlock(&mtd_table_mutex);
1047
1048}
33c87b4a 1049EXPORT_SYMBOL_GPL(put_mtd_device);
3bd45657
ML
1050
1051void __put_mtd_device(struct mtd_info *mtd)
1052{
46b5889c 1053 struct mtd_info *master = mtd_get_master(mtd);
3bd45657 1054
46b5889c
MR
1055 while (mtd->parent) {
1056 --mtd->usecount;
1057 BUG_ON(mtd->usecount < 0);
1058 mtd = mtd->parent;
1059 }
1060
1061 if (master->_put_device)
1062 master->_put_device(master);
1da177e4 1063
46b5889c 1064 module_put(master->owner);
1da177e4 1065}
33c87b4a 1066EXPORT_SYMBOL_GPL(__put_mtd_device);
1da177e4 1067
8273a0c9 1068/*
884cfd90
BB
1069 * Erase is an synchronous operation. Device drivers are epected to return a
1070 * negative error code if the operation failed and update instr->fail_addr
1071 * to point the portion that was not properly erased.
8273a0c9
AB
1072 */
1073int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1074{
46b5889c
MR
1075 struct mtd_info *master = mtd_get_master(mtd);
1076 u64 mst_ofs = mtd_get_master_ofs(mtd, 0);
1077 int ret;
1078
c585da9f
BB
1079 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1080
46b5889c 1081 if (!mtd->erasesize || !master->_erase)
e6e620f0
BB
1082 return -ENOTSUPP;
1083
0c2b4e21 1084 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
8273a0c9 1085 return -EINVAL;
664addc2
AB
1086 if (!(mtd->flags & MTD_WRITEABLE))
1087 return -EROFS;
e6e620f0 1088
e7bfb3fd 1089 if (!instr->len)
bcb1d238 1090 return 0;
e7bfb3fd 1091
fea728c0 1092 ledtrig_mtd_activity();
46b5889c
MR
1093
1094 instr->addr += mst_ofs;
1095 ret = master->_erase(master, instr);
1096 if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
1097 instr->fail_addr -= mst_ofs;
1098
1099 instr->addr -= mst_ofs;
1100 return ret;
8273a0c9
AB
1101}
1102EXPORT_SYMBOL_GPL(mtd_erase);
1103
1104/*
1105 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1106 */
1107int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1108 void **virt, resource_size_t *phys)
1109{
46b5889c
MR
1110 struct mtd_info *master = mtd_get_master(mtd);
1111
8273a0c9 1112 *retlen = 0;
0dd5235f
AB
1113 *virt = NULL;
1114 if (phys)
1115 *phys = 0;
46b5889c 1116 if (!master->_point)
8273a0c9 1117 return -EOPNOTSUPP;
0c2b4e21 1118 if (from < 0 || from >= mtd->size || len > mtd->size - from)
8273a0c9 1119 return -EINVAL;
bcb1d238
AB
1120 if (!len)
1121 return 0;
46b5889c
MR
1122
1123 from = mtd_get_master_ofs(mtd, from);
1124 return master->_point(master, from, len, retlen, virt, phys);
8273a0c9
AB
1125}
1126EXPORT_SYMBOL_GPL(mtd_point);
1127
1128/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1129int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1130{
46b5889c
MR
1131 struct mtd_info *master = mtd_get_master(mtd);
1132
1133 if (!master->_unpoint)
8273a0c9 1134 return -EOPNOTSUPP;
0c2b4e21 1135 if (from < 0 || from >= mtd->size || len > mtd->size - from)
8273a0c9 1136 return -EINVAL;
bcb1d238
AB
1137 if (!len)
1138 return 0;
46b5889c 1139 return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
8273a0c9
AB
1140}
1141EXPORT_SYMBOL_GPL(mtd_unpoint);
1142
1143/*
1144 * Allow NOMMU mmap() to directly map the device (if not NULL)
1145 * - return the address to which the offset maps
1146 * - return -ENOSYS to indicate refusal to do the mapping
1147 */
1148unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1149 unsigned long offset, unsigned long flags)
1150{
9eaa903c
NP
1151 size_t retlen;
1152 void *virt;
1153 int ret;
1154
1155 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1156 if (ret)
1157 return ret;
1158 if (retlen != len) {
1159 mtd_unpoint(mtd, offset, retlen);
1160 return -ENOSYS;
1161 }
1162 return (unsigned long)virt;
8273a0c9
AB
1163}
1164EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1165
46b5889c
MR
1166static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
1167 const struct mtd_ecc_stats *old_stats)
1168{
1169 struct mtd_ecc_stats diff;
1170
1171 if (master == mtd)
1172 return;
1173
1174 diff = master->ecc_stats;
1175 diff.failed -= old_stats->failed;
1176 diff.corrected -= old_stats->corrected;
1177
1178 while (mtd->parent) {
1179 mtd->ecc_stats.failed += diff.failed;
1180 mtd->ecc_stats.corrected += diff.corrected;
1181 mtd = mtd->parent;
1182 }
1183}
1184
8273a0c9
AB
1185int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1186 u_char *buf)
1187{
2431c4f5
BB
1188 struct mtd_oob_ops ops = {
1189 .len = len,
1190 .datbuf = buf,
1191 };
1192 int ret;
edbc4540 1193
2431c4f5
BB
1194 ret = mtd_read_oob(mtd, from, &ops);
1195 *retlen = ops.retlen;
24ff1292 1196
2431c4f5 1197 return ret;
8273a0c9
AB
1198}
1199EXPORT_SYMBOL_GPL(mtd_read);
1200
1201int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1202 const u_char *buf)
1203{
2431c4f5
BB
1204 struct mtd_oob_ops ops = {
1205 .len = len,
1206 .datbuf = (u8 *)buf,
1207 };
1208 int ret;
24ff1292 1209
2431c4f5
BB
1210 ret = mtd_write_oob(mtd, to, &ops);
1211 *retlen = ops.retlen;
24ff1292 1212
2431c4f5 1213 return ret;
8273a0c9
AB
1214}
1215EXPORT_SYMBOL_GPL(mtd_write);
1216
1217/*
1218 * In blackbox flight recorder like scenarios we want to make successful writes
1219 * in interrupt context. panic_write() is only intended to be called when its
1220 * known the kernel is about to panic and we need the write to succeed. Since
1221 * the kernel is not going to be running for much longer, this function can
1222 * break locks and delay to ensure the write succeeds (but not sleep).
1223 */
1224int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1225 const u_char *buf)
1226{
46b5889c
MR
1227 struct mtd_info *master = mtd_get_master(mtd);
1228
8273a0c9 1229 *retlen = 0;
46b5889c 1230 if (!master->_panic_write)
8273a0c9 1231 return -EOPNOTSUPP;
0c2b4e21 1232 if (to < 0 || to >= mtd->size || len > mtd->size - to)
8273a0c9 1233 return -EINVAL;
664addc2
AB
1234 if (!(mtd->flags & MTD_WRITEABLE))
1235 return -EROFS;
bcb1d238
AB
1236 if (!len)
1237 return 0;
9f897bfd
KD
1238 if (!mtd->oops_panic_write)
1239 mtd->oops_panic_write = true;
1240
46b5889c
MR
1241 return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
1242 retlen, buf);
8273a0c9
AB
1243}
1244EXPORT_SYMBOL_GPL(mtd_panic_write);
1245
5cdd929d
BB
1246static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1247 struct mtd_oob_ops *ops)
1248{
1249 /*
1250 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1251 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1252 * this case.
1253 */
1254 if (!ops->datbuf)
1255 ops->len = 0;
1256
1257 if (!ops->oobbuf)
1258 ops->ooblen = 0;
1259
d82c3682 1260 if (offs < 0 || offs + ops->len > mtd->size)
5cdd929d
BB
1261 return -EINVAL;
1262
1263 if (ops->ooblen) {
89f706db 1264 size_t maxooblen;
5cdd929d
BB
1265
1266 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1267 return -EINVAL;
1268
89f706db
MR
1269 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1270 mtd_div_by_ws(offs, mtd)) *
5cdd929d
BB
1271 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1272 if (ops->ooblen > maxooblen)
1273 return -EINVAL;
1274 }
1275
1276 return 0;
1277}
1278
d2d48480
BN
1279int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1280{
46b5889c
MR
1281 struct mtd_info *master = mtd_get_master(mtd);
1282 struct mtd_ecc_stats old_stats = master->ecc_stats;
e47f6858 1283 int ret_code;
46b5889c 1284
d2d48480 1285 ops->retlen = ops->oobretlen = 0;
fea728c0 1286
5cdd929d
BB
1287 ret_code = mtd_check_oob_ops(mtd, from, ops);
1288 if (ret_code)
1289 return ret_code;
1290
fea728c0 1291 ledtrig_mtd_activity();
89fd23ef
MR
1292
1293 /* Check the validity of a potential fallback on mtd->_read */
46b5889c 1294 if (!master->_read_oob && (!master->_read || ops->oobbuf))
89fd23ef
MR
1295 return -EOPNOTSUPP;
1296
46b5889c
MR
1297 from = mtd_get_master_ofs(mtd, from);
1298 if (master->_read_oob)
1299 ret_code = master->_read_oob(master, from, ops);
89fd23ef 1300 else
46b5889c
MR
1301 ret_code = master->_read(master, from, ops->len, &ops->retlen,
1302 ops->datbuf);
1303
1304 mtd_update_ecc_stats(mtd, master, &old_stats);
89fd23ef 1305
e47f6858
BN
1306 /*
1307 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1308 * similar to mtd->_read(), returning a non-negative integer
1309 * representing max bitflips. In other cases, mtd->_read_oob() may
1310 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1311 */
e47f6858
BN
1312 if (unlikely(ret_code < 0))
1313 return ret_code;
1314 if (mtd->ecc_strength == 0)
1315 return 0; /* device lacks ecc */
1316 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
d2d48480
BN
1317}
1318EXPORT_SYMBOL_GPL(mtd_read_oob);
1319
0c034fe3
EG
1320int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1321 struct mtd_oob_ops *ops)
1322{
46b5889c 1323 struct mtd_info *master = mtd_get_master(mtd);
5cdd929d
BB
1324 int ret;
1325
0c034fe3 1326 ops->retlen = ops->oobretlen = 0;
89fd23ef 1327
0c034fe3
EG
1328 if (!(mtd->flags & MTD_WRITEABLE))
1329 return -EROFS;
5cdd929d
BB
1330
1331 ret = mtd_check_oob_ops(mtd, to, ops);
1332 if (ret)
1333 return ret;
1334
fea728c0 1335 ledtrig_mtd_activity();
89fd23ef
MR
1336
1337 /* Check the validity of a potential fallback on mtd->_write */
46b5889c 1338 if (!master->_write_oob && (!master->_write || ops->oobbuf))
89fd23ef
MR
1339 return -EOPNOTSUPP;
1340
46b5889c
MR
1341 to = mtd_get_master_ofs(mtd, to);
1342
1343 if (master->_write_oob)
1344 return master->_write_oob(master, to, ops);
89fd23ef 1345 else
46b5889c
MR
1346 return master->_write(master, to, ops->len, &ops->retlen,
1347 ops->datbuf);
0c034fe3
EG
1348}
1349EXPORT_SYMBOL_GPL(mtd_write_oob);
1350
75eb2cec
BB
1351/**
1352 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1353 * @mtd: MTD device structure
1354 * @section: ECC section. Depending on the layout you may have all the ECC
1355 * bytes stored in a single contiguous section, or one section
1356 * per ECC chunk (and sometime several sections for a single ECC
1357 * ECC chunk)
1358 * @oobecc: OOB region struct filled with the appropriate ECC position
1359 * information
1360 *
7da0fffb 1361 * This function returns ECC section information in the OOB area. If you want
75eb2cec
BB
1362 * to get all the ECC bytes information, then you should call
1363 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1364 *
1365 * Returns zero on success, a negative error code otherwise.
1366 */
1367int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1368 struct mtd_oob_region *oobecc)
1369{
46b5889c
MR
1370 struct mtd_info *master = mtd_get_master(mtd);
1371
75eb2cec
BB
1372 memset(oobecc, 0, sizeof(*oobecc));
1373
46b5889c 1374 if (!master || section < 0)
75eb2cec
BB
1375 return -EINVAL;
1376
46b5889c 1377 if (!master->ooblayout || !master->ooblayout->ecc)
75eb2cec
BB
1378 return -ENOTSUPP;
1379
46b5889c 1380 return master->ooblayout->ecc(master, section, oobecc);
75eb2cec
BB
1381}
1382EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1383
1384/**
1385 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1386 * section
1387 * @mtd: MTD device structure
1388 * @section: Free section you are interested in. Depending on the layout
1389 * you may have all the free bytes stored in a single contiguous
1390 * section, or one section per ECC chunk plus an extra section
1391 * for the remaining bytes (or other funky layout).
1392 * @oobfree: OOB region struct filled with the appropriate free position
1393 * information
1394 *
7da0fffb 1395 * This function returns free bytes position in the OOB area. If you want
75eb2cec
BB
1396 * to get all the free bytes information, then you should call
1397 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1398 *
1399 * Returns zero on success, a negative error code otherwise.
1400 */
1401int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1402 struct mtd_oob_region *oobfree)
1403{
46b5889c
MR
1404 struct mtd_info *master = mtd_get_master(mtd);
1405
75eb2cec
BB
1406 memset(oobfree, 0, sizeof(*oobfree));
1407
46b5889c 1408 if (!master || section < 0)
75eb2cec
BB
1409 return -EINVAL;
1410
46b5889c 1411 if (!master->ooblayout || !master->ooblayout->free)
75eb2cec
BB
1412 return -ENOTSUPP;
1413
46b5889c 1414 return master->ooblayout->free(master, section, oobfree);
75eb2cec
BB
1415}
1416EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1417
1418/**
1419 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1420 * @mtd: mtd info structure
1421 * @byte: the byte we are searching for
1422 * @sectionp: pointer where the section id will be stored
1423 * @oobregion: used to retrieve the ECC position
1424 * @iter: iterator function. Should be either mtd_ooblayout_free or
1425 * mtd_ooblayout_ecc depending on the region type you're searching for
1426 *
7da0fffb 1427 * This function returns the section id and oobregion information of a
75eb2cec
BB
1428 * specific byte. For example, say you want to know where the 4th ECC byte is
1429 * stored, you'll use:
1430 *
1431 * mtd_ooblayout_find_region(mtd, 3, &section, &oobregion, mtd_ooblayout_ecc);
1432 *
1433 * Returns zero on success, a negative error code otherwise.
1434 */
1435static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1436 int *sectionp, struct mtd_oob_region *oobregion,
1437 int (*iter)(struct mtd_info *,
1438 int section,
1439 struct mtd_oob_region *oobregion))
1440{
1441 int pos = 0, ret, section = 0;
1442
1443 memset(oobregion, 0, sizeof(*oobregion));
1444
1445 while (1) {
1446 ret = iter(mtd, section, oobregion);
1447 if (ret)
1448 return ret;
1449
1450 if (pos + oobregion->length > byte)
1451 break;
1452
1453 pos += oobregion->length;
1454 section++;
1455 }
1456
1457 /*
1458 * Adjust region info to make it start at the beginning at the
1459 * 'start' ECC byte.
1460 */
1461 oobregion->offset += byte - pos;
1462 oobregion->length -= byte - pos;
1463 *sectionp = section;
1464
1465 return 0;
1466}
1467
1468/**
1469 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1470 * ECC byte
1471 * @mtd: mtd info structure
1472 * @eccbyte: the byte we are searching for
1473 * @sectionp: pointer where the section id will be stored
1474 * @oobregion: OOB region information
1475 *
1476 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1477 * byte.
1478 *
1479 * Returns zero on success, a negative error code otherwise.
1480 */
1481int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1482 int *section,
1483 struct mtd_oob_region *oobregion)
1484{
1485 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1486 mtd_ooblayout_ecc);
1487}
1488EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1489
1490/**
1491 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1492 * @mtd: mtd info structure
1493 * @buf: destination buffer to store OOB bytes
1494 * @oobbuf: OOB buffer
1495 * @start: first byte to retrieve
1496 * @nbytes: number of bytes to retrieve
1497 * @iter: section iterator
1498 *
1499 * Extract bytes attached to a specific category (ECC or free)
1500 * from the OOB buffer and copy them into buf.
1501 *
1502 * Returns zero on success, a negative error code otherwise.
1503 */
1504static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1505 const u8 *oobbuf, int start, int nbytes,
1506 int (*iter)(struct mtd_info *,
1507 int section,
1508 struct mtd_oob_region *oobregion))
1509{
8e8fd4d1
MY
1510 struct mtd_oob_region oobregion;
1511 int section, ret;
75eb2cec
BB
1512
1513 ret = mtd_ooblayout_find_region(mtd, start, &section,
1514 &oobregion, iter);
1515
1516 while (!ret) {
1517 int cnt;
1518
7c295ef9 1519 cnt = min_t(int, nbytes, oobregion.length);
75eb2cec
BB
1520 memcpy(buf, oobbuf + oobregion.offset, cnt);
1521 buf += cnt;
1522 nbytes -= cnt;
1523
1524 if (!nbytes)
1525 break;
1526
1527 ret = iter(mtd, ++section, &oobregion);
1528 }
1529
1530 return ret;
1531}
1532
1533/**
1534 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1535 * @mtd: mtd info structure
1536 * @buf: source buffer to get OOB bytes from
1537 * @oobbuf: OOB buffer
1538 * @start: first OOB byte to set
1539 * @nbytes: number of OOB bytes to set
1540 * @iter: section iterator
1541 *
1542 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1543 * is selected by passing the appropriate iterator.
1544 *
1545 * Returns zero on success, a negative error code otherwise.
1546 */
1547static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1548 u8 *oobbuf, int start, int nbytes,
1549 int (*iter)(struct mtd_info *,
1550 int section,
1551 struct mtd_oob_region *oobregion))
1552{
8e8fd4d1
MY
1553 struct mtd_oob_region oobregion;
1554 int section, ret;
75eb2cec
BB
1555
1556 ret = mtd_ooblayout_find_region(mtd, start, &section,
1557 &oobregion, iter);
1558
1559 while (!ret) {
1560 int cnt;
1561
7c295ef9 1562 cnt = min_t(int, nbytes, oobregion.length);
75eb2cec
BB
1563 memcpy(oobbuf + oobregion.offset, buf, cnt);
1564 buf += cnt;
1565 nbytes -= cnt;
1566
1567 if (!nbytes)
1568 break;
1569
1570 ret = iter(mtd, ++section, &oobregion);
1571 }
1572
1573 return ret;
1574}
1575
1576/**
1577 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1578 * @mtd: mtd info structure
1579 * @iter: category iterator
1580 *
1581 * Count the number of bytes in a given category.
1582 *
1583 * Returns a positive value on success, a negative error code otherwise.
1584 */
1585static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
1586 int (*iter)(struct mtd_info *,
1587 int section,
1588 struct mtd_oob_region *oobregion))
1589{
4d6aecfb 1590 struct mtd_oob_region oobregion;
75eb2cec
BB
1591 int section = 0, ret, nbytes = 0;
1592
1593 while (1) {
1594 ret = iter(mtd, section++, &oobregion);
1595 if (ret) {
1596 if (ret == -ERANGE)
1597 ret = nbytes;
1598 break;
1599 }
1600
1601 nbytes += oobregion.length;
1602 }
1603
1604 return ret;
1605}
1606
1607/**
1608 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
1609 * @mtd: mtd info structure
1610 * @eccbuf: destination buffer to store ECC bytes
1611 * @oobbuf: OOB buffer
1612 * @start: first ECC byte to retrieve
1613 * @nbytes: number of ECC bytes to retrieve
1614 *
1615 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1616 *
1617 * Returns zero on success, a negative error code otherwise.
1618 */
1619int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
1620 const u8 *oobbuf, int start, int nbytes)
1621{
1622 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1623 mtd_ooblayout_ecc);
1624}
1625EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
1626
1627/**
1628 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
1629 * @mtd: mtd info structure
1630 * @eccbuf: source buffer to get ECC bytes from
1631 * @oobbuf: OOB buffer
1632 * @start: first ECC byte to set
1633 * @nbytes: number of ECC bytes to set
1634 *
1635 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1636 *
1637 * Returns zero on success, a negative error code otherwise.
1638 */
1639int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
1640 u8 *oobbuf, int start, int nbytes)
1641{
1642 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
1643 mtd_ooblayout_ecc);
1644}
1645EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
1646
1647/**
1648 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
1649 * @mtd: mtd info structure
1650 * @databuf: destination buffer to store ECC bytes
1651 * @oobbuf: OOB buffer
1652 * @start: first ECC byte to retrieve
1653 * @nbytes: number of ECC bytes to retrieve
1654 *
1655 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1656 *
1657 * Returns zero on success, a negative error code otherwise.
1658 */
1659int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
1660 const u8 *oobbuf, int start, int nbytes)
1661{
1662 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
1663 mtd_ooblayout_free);
1664}
1665EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
1666
1667/**
c77a9312 1668 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
75eb2cec 1669 * @mtd: mtd info structure
c77a9312 1670 * @databuf: source buffer to get data bytes from
75eb2cec
BB
1671 * @oobbuf: OOB buffer
1672 * @start: first ECC byte to set
1673 * @nbytes: number of ECC bytes to set
1674 *
1675 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1676 *
1677 * Returns zero on success, a negative error code otherwise.
1678 */
1679int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
1680 u8 *oobbuf, int start, int nbytes)
1681{
1682 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
1683 mtd_ooblayout_free);
1684}
1685EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
1686
1687/**
1688 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1689 * @mtd: mtd info structure
1690 *
1691 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1692 *
1693 * Returns zero on success, a negative error code otherwise.
1694 */
1695int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
1696{
1697 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
1698}
1699EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
1700
1701/**
c77a9312 1702 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
75eb2cec
BB
1703 * @mtd: mtd info structure
1704 *
1705 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1706 *
1707 * Returns zero on success, a negative error code otherwise.
1708 */
1709int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
1710{
1711 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
1712}
1713EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
1714
de3cac93
AB
1715/*
1716 * Method to access the protection register area, present in some flash
1717 * devices. The user data is one time programmable but the factory data is read
1718 * only.
1719 */
4b78fc42
CR
1720int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1721 struct otp_info *buf)
de3cac93 1722{
46b5889c
MR
1723 struct mtd_info *master = mtd_get_master(mtd);
1724
1725 if (!master->_get_fact_prot_info)
de3cac93
AB
1726 return -EOPNOTSUPP;
1727 if (!len)
1728 return 0;
46b5889c 1729 return master->_get_fact_prot_info(master, len, retlen, buf);
de3cac93
AB
1730}
1731EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
1732
1733int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1734 size_t *retlen, u_char *buf)
1735{
46b5889c
MR
1736 struct mtd_info *master = mtd_get_master(mtd);
1737
de3cac93 1738 *retlen = 0;
46b5889c 1739 if (!master->_read_fact_prot_reg)
de3cac93
AB
1740 return -EOPNOTSUPP;
1741 if (!len)
1742 return 0;
46b5889c 1743 return master->_read_fact_prot_reg(master, from, len, retlen, buf);
de3cac93
AB
1744}
1745EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
1746
4b78fc42
CR
1747int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
1748 struct otp_info *buf)
de3cac93 1749{
46b5889c
MR
1750 struct mtd_info *master = mtd_get_master(mtd);
1751
1752 if (!master->_get_user_prot_info)
de3cac93
AB
1753 return -EOPNOTSUPP;
1754 if (!len)
1755 return 0;
46b5889c 1756 return master->_get_user_prot_info(master, len, retlen, buf);
de3cac93
AB
1757}
1758EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
1759
1760int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
1761 size_t *retlen, u_char *buf)
1762{
46b5889c
MR
1763 struct mtd_info *master = mtd_get_master(mtd);
1764
de3cac93 1765 *retlen = 0;
46b5889c 1766 if (!master->_read_user_prot_reg)
de3cac93
AB
1767 return -EOPNOTSUPP;
1768 if (!len)
1769 return 0;
46b5889c 1770 return master->_read_user_prot_reg(master, from, len, retlen, buf);
de3cac93
AB
1771}
1772EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
1773
1774int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
1775 size_t *retlen, u_char *buf)
1776{
46b5889c 1777 struct mtd_info *master = mtd_get_master(mtd);
9a78bc83
CR
1778 int ret;
1779
de3cac93 1780 *retlen = 0;
46b5889c 1781 if (!master->_write_user_prot_reg)
de3cac93
AB
1782 return -EOPNOTSUPP;
1783 if (!len)
1784 return 0;
46b5889c 1785 ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
9a78bc83
CR
1786 if (ret)
1787 return ret;
1788
1789 /*
1790 * If no data could be written at all, we are out of memory and
1791 * must return -ENOSPC.
1792 */
1793 return (*retlen) ? 0 : -ENOSPC;
de3cac93
AB
1794}
1795EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
1796
1797int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
1798{
46b5889c
MR
1799 struct mtd_info *master = mtd_get_master(mtd);
1800
1801 if (!master->_lock_user_prot_reg)
de3cac93
AB
1802 return -EOPNOTSUPP;
1803 if (!len)
1804 return 0;
46b5889c 1805 return master->_lock_user_prot_reg(master, from, len);
de3cac93
AB
1806}
1807EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
1808
8273a0c9
AB
1809/* Chip-supported device locking */
1810int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1811{
46b5889c
MR
1812 struct mtd_info *master = mtd_get_master(mtd);
1813
1814 if (!master->_lock)
8273a0c9 1815 return -EOPNOTSUPP;
0c2b4e21 1816 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
8273a0c9 1817 return -EINVAL;
bcb1d238
AB
1818 if (!len)
1819 return 0;
46b5889c 1820 return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
8273a0c9
AB
1821}
1822EXPORT_SYMBOL_GPL(mtd_lock);
1823
1824int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1825{
46b5889c
MR
1826 struct mtd_info *master = mtd_get_master(mtd);
1827
1828 if (!master->_unlock)
8273a0c9 1829 return -EOPNOTSUPP;
0c2b4e21 1830 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
8273a0c9 1831 return -EINVAL;
bcb1d238
AB
1832 if (!len)
1833 return 0;
46b5889c 1834 return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
8273a0c9
AB
1835}
1836EXPORT_SYMBOL_GPL(mtd_unlock);
1837
1838int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
1839{
46b5889c
MR
1840 struct mtd_info *master = mtd_get_master(mtd);
1841
1842 if (!master->_is_locked)
8273a0c9 1843 return -EOPNOTSUPP;
0c2b4e21 1844 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
8273a0c9 1845 return -EINVAL;
bcb1d238
AB
1846 if (!len)
1847 return 0;
46b5889c 1848 return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
8273a0c9
AB
1849}
1850EXPORT_SYMBOL_GPL(mtd_is_locked);
1851
8471bb73 1852int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
8273a0c9 1853{
46b5889c
MR
1854 struct mtd_info *master = mtd_get_master(mtd);
1855
0c2b4e21 1856 if (ofs < 0 || ofs >= mtd->size)
8471bb73 1857 return -EINVAL;
46b5889c 1858 if (!master->_block_isreserved)
8273a0c9 1859 return 0;
46b5889c 1860 return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
8471bb73
EG
1861}
1862EXPORT_SYMBOL_GPL(mtd_block_isreserved);
1863
1864int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
1865{
46b5889c
MR
1866 struct mtd_info *master = mtd_get_master(mtd);
1867
0c2b4e21 1868 if (ofs < 0 || ofs >= mtd->size)
8273a0c9 1869 return -EINVAL;
46b5889c 1870 if (!master->_block_isbad)
8471bb73 1871 return 0;
46b5889c 1872 return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
8273a0c9
AB
1873}
1874EXPORT_SYMBOL_GPL(mtd_block_isbad);
1875
1876int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
1877{
46b5889c
MR
1878 struct mtd_info *master = mtd_get_master(mtd);
1879 int ret;
1880
1881 if (!master->_block_markbad)
8273a0c9 1882 return -EOPNOTSUPP;
0c2b4e21 1883 if (ofs < 0 || ofs >= mtd->size)
8273a0c9 1884 return -EINVAL;
664addc2
AB
1885 if (!(mtd->flags & MTD_WRITEABLE))
1886 return -EROFS;
46b5889c
MR
1887
1888 ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
1889 if (ret)
1890 return ret;
1891
1892 while (mtd->parent) {
1893 mtd->ecc_stats.badblocks++;
1894 mtd = mtd->parent;
1895 }
1896
1897 return 0;
8273a0c9
AB
1898}
1899EXPORT_SYMBOL_GPL(mtd_block_markbad);
1900
52b02031
AB
1901/*
1902 * default_mtd_writev - the default writev method
1903 * @mtd: mtd device description object pointer
1904 * @vecs: the vectors to write
1905 * @count: count of vectors in @vecs
1906 * @to: the MTD device offset to write to
1907 * @retlen: on exit contains the count of bytes written to the MTD device.
1908 *
1909 * This function returns zero in case of success and a negative error code in
1910 * case of failure.
1da177e4 1911 */
1dbebd32
AB
1912static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1913 unsigned long count, loff_t to, size_t *retlen)
1da177e4
LT
1914{
1915 unsigned long i;
1916 size_t totlen = 0, thislen;
1917 int ret = 0;
1918
52b02031
AB
1919 for (i = 0; i < count; i++) {
1920 if (!vecs[i].iov_len)
1921 continue;
1922 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
1923 vecs[i].iov_base);
1924 totlen += thislen;
1925 if (ret || thislen != vecs[i].iov_len)
1926 break;
1927 to += vecs[i].iov_len;
1da177e4 1928 }
52b02031 1929 *retlen = totlen;
1da177e4
LT
1930 return ret;
1931}
1dbebd32
AB
1932
1933/*
1934 * mtd_writev - the vector-based MTD write method
1935 * @mtd: mtd device description object pointer
1936 * @vecs: the vectors to write
1937 * @count: count of vectors in @vecs
1938 * @to: the MTD device offset to write to
1939 * @retlen: on exit contains the count of bytes written to the MTD device.
1940 *
1941 * This function returns zero in case of success and a negative error code in
1942 * case of failure.
1943 */
1944int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
1945 unsigned long count, loff_t to, size_t *retlen)
1946{
46b5889c
MR
1947 struct mtd_info *master = mtd_get_master(mtd);
1948
1dbebd32 1949 *retlen = 0;
664addc2
AB
1950 if (!(mtd->flags & MTD_WRITEABLE))
1951 return -EROFS;
46b5889c
MR
1952
1953 if (!master->_writev)
1dbebd32 1954 return default_mtd_writev(mtd, vecs, count, to, retlen);
46b5889c
MR
1955
1956 return master->_writev(master, vecs, count,
1957 mtd_get_master_ofs(mtd, to), retlen);
1dbebd32
AB
1958}
1959EXPORT_SYMBOL_GPL(mtd_writev);
1da177e4 1960
33b53716
GE
1961/**
1962 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
52b02031
AB
1963 * @mtd: mtd device description object pointer
1964 * @size: a pointer to the ideal or maximum size of the allocation, points
33b53716
GE
1965 * to the actual allocation size on success.
1966 *
1967 * This routine attempts to allocate a contiguous kernel buffer up to
1968 * the specified size, backing off the size of the request exponentially
1969 * until the request succeeds or until the allocation size falls below
1970 * the system page size. This attempts to make sure it does not adversely
1971 * impact system performance, so when allocating more than one page, we
caf49191
LT
1972 * ask the memory allocator to avoid re-trying, swapping, writing back
1973 * or performing I/O.
33b53716
GE
1974 *
1975 * Note, this function also makes sure that the allocated buffer is aligned to
1976 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
1977 *
1978 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
1979 * to handle smaller (i.e. degraded) buffer allocations under low- or
1980 * fragmented-memory situations where such reduced allocations, from a
1981 * requested ideal, are allowed.
1982 *
1983 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1984 */
1985void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
1986{
d0164adc 1987 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
33b53716
GE
1988 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
1989 void *kbuf;
1990
1991 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
1992
1993 while (*size > min_alloc) {
1994 kbuf = kmalloc(*size, flags);
1995 if (kbuf)
1996 return kbuf;
1997
1998 *size >>= 1;
1999 *size = ALIGN(*size, mtd->writesize);
2000 }
2001
2002 /*
2003 * For the last resort allocation allow 'kmalloc()' to do all sorts of
2004 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
2005 */
2006 return kmalloc(*size, GFP_KERNEL);
2007}
33b53716 2008EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
1da177e4 2009
2d2dce0e
PM
2010#ifdef CONFIG_PROC_FS
2011
1da177e4
LT
2012/*====================================================================*/
2013/* Support for /proc/mtd */
2014
447d9bd8 2015static int mtd_proc_show(struct seq_file *m, void *v)
1da177e4 2016{
f1332ba2 2017 struct mtd_info *mtd;
1da177e4 2018
447d9bd8 2019 seq_puts(m, "dev: size erasesize name\n");
48b19268 2020 mutex_lock(&mtd_table_mutex);
f1332ba2 2021 mtd_for_each_device(mtd) {
447d9bd8
AD
2022 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
2023 mtd->index, (unsigned long long)mtd->size,
2024 mtd->erasesize, mtd->name);
d5ca5129 2025 }
48b19268 2026 mutex_unlock(&mtd_table_mutex);
d5ca5129 2027 return 0;
1da177e4 2028}
45b09076
KC
2029#endif /* CONFIG_PROC_FS */
2030
1da177e4
LT
2031/*====================================================================*/
2032/* Init code */
2033
445caaa2 2034static struct backing_dev_info * __init mtd_bdi_init(char *name)
0661b1ac 2035{
445caaa2 2036 struct backing_dev_info *bdi;
0661b1ac
JA
2037 int ret;
2038
fa06052d 2039 bdi = bdi_alloc(GFP_KERNEL);
445caaa2
SL
2040 if (!bdi)
2041 return ERR_PTR(-ENOMEM);
0661b1ac 2042
fa06052d
JK
2043 bdi->name = name;
2044 /*
2045 * We put '-0' suffix to the name to get the same name format as we
2046 * used to get. Since this is called only once, we get a unique name.
2047 */
7c4cc300 2048 ret = bdi_register(bdi, "%.28s-0", name);
0661b1ac 2049 if (ret)
fa06052d 2050 bdi_put(bdi);
0661b1ac 2051
445caaa2 2052 return ret ? ERR_PTR(ret) : bdi;
0661b1ac
JA
2053}
2054
93e56214
AB
2055static struct proc_dir_entry *proc_mtd;
2056
1da177e4
LT
2057static int __init init_mtd(void)
2058{
15bce40c 2059 int ret;
0661b1ac 2060
15bce40c 2061 ret = class_register(&mtd_class);
0661b1ac
JA
2062 if (ret)
2063 goto err_reg;
2064
445caaa2
SL
2065 mtd_bdi = mtd_bdi_init("mtd");
2066 if (IS_ERR(mtd_bdi)) {
2067 ret = PTR_ERR(mtd_bdi);
b4caecd4 2068 goto err_bdi;
445caaa2 2069 }
694bb7fc 2070
3f3942ac 2071 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
93e56214 2072
660685d9
AB
2073 ret = init_mtdchar();
2074 if (ret)
2075 goto out_procfs;
2076
e8e3edb9
MR
2077 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
2078
1da177e4 2079 return 0;
0661b1ac 2080
660685d9
AB
2081out_procfs:
2082 if (proc_mtd)
2083 remove_proc_entry("mtd", NULL);
fa06052d 2084 bdi_put(mtd_bdi);
b4caecd4 2085err_bdi:
0661b1ac
JA
2086 class_unregister(&mtd_class);
2087err_reg:
2088 pr_err("Error registering mtd class or bdi: %d\n", ret);
2089 return ret;
1da177e4
LT
2090}
2091
2092static void __exit cleanup_mtd(void)
2093{
e8e3edb9 2094 debugfs_remove_recursive(dfs_dir_mtd);
660685d9 2095 cleanup_mtdchar();
d5ca5129 2096 if (proc_mtd)
93e56214 2097 remove_proc_entry("mtd", NULL);
15bce40c 2098 class_unregister(&mtd_class);
fa06052d 2099 bdi_put(mtd_bdi);
35667b99 2100 idr_destroy(&mtd_idr);
1da177e4
LT
2101}
2102
2103module_init(init_mtd);
2104module_exit(cleanup_mtd);
2105
1da177e4
LT
2106MODULE_LICENSE("GPL");
2107MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2108MODULE_DESCRIPTION("Core MTD registration and access routines");