1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Core registration and callback routines for MTD
6 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
7 * Copyright © 2006 Red Hat UK Limited
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>
18 #include <linux/err.h>
19 #include <linux/ioctl.h>
20 #include <linux/init.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>
32 #include <linux/mtd/mtd.h>
33 #include <linux/mtd/partitions.h>
37 struct backing_dev_info
*mtd_bdi
;
39 #ifdef CONFIG_PM_SLEEP
41 static int mtd_cls_suspend(struct device
*dev
)
43 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
45 return mtd
? mtd_suspend(mtd
) : 0;
48 static int mtd_cls_resume(struct device
*dev
)
50 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
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)
60 #define MTD_CLS_PM_OPS NULL
63 static struct class mtd_class
= {
69 static DEFINE_IDR(mtd_idr
);
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
);
76 struct mtd_info
*__mtd_next_device(int i
)
78 return idr_get_next(&mtd_idr
, &i
);
80 EXPORT_SYMBOL_GPL(__mtd_next_device
);
82 static LIST_HEAD(mtd_notifiers
);
85 #define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
87 /* REVISIT once MTD uses the driver model better, whoever allocates
88 * the mtd_info will probably want to use the release() hook...
90 static void mtd_release(struct device
*dev
)
92 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
93 dev_t index
= MTD_DEVT(mtd
->index
);
95 /* remove /dev/mtdXro node */
96 device_destroy(&mtd_class
, index
+ 1);
99 static ssize_t
mtd_type_show(struct device
*dev
,
100 struct device_attribute
*attr
, char *buf
)
102 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
127 case MTD_MLCNANDFLASH
:
134 return snprintf(buf
, PAGE_SIZE
, "%s\n", type
);
136 static DEVICE_ATTR(type
, S_IRUGO
, mtd_type_show
, NULL
);
138 static ssize_t
mtd_flags_show(struct device
*dev
,
139 struct device_attribute
*attr
, char *buf
)
141 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
143 return snprintf(buf
, PAGE_SIZE
, "0x%lx\n", (unsigned long)mtd
->flags
);
145 static DEVICE_ATTR(flags
, S_IRUGO
, mtd_flags_show
, NULL
);
147 static ssize_t
mtd_size_show(struct device
*dev
,
148 struct device_attribute
*attr
, char *buf
)
150 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
152 return snprintf(buf
, PAGE_SIZE
, "%llu\n",
153 (unsigned long long)mtd
->size
);
155 static DEVICE_ATTR(size
, S_IRUGO
, mtd_size_show
, NULL
);
157 static ssize_t
mtd_erasesize_show(struct device
*dev
,
158 struct device_attribute
*attr
, char *buf
)
160 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
162 return snprintf(buf
, PAGE_SIZE
, "%lu\n", (unsigned long)mtd
->erasesize
);
164 static DEVICE_ATTR(erasesize
, S_IRUGO
, mtd_erasesize_show
, NULL
);
166 static ssize_t
mtd_writesize_show(struct device
*dev
,
167 struct device_attribute
*attr
, char *buf
)
169 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
171 return snprintf(buf
, PAGE_SIZE
, "%lu\n", (unsigned long)mtd
->writesize
);
173 static DEVICE_ATTR(writesize
, S_IRUGO
, mtd_writesize_show
, NULL
);
175 static ssize_t
mtd_subpagesize_show(struct device
*dev
,
176 struct device_attribute
*attr
, char *buf
)
178 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
179 unsigned int subpagesize
= mtd
->writesize
>> mtd
->subpage_sft
;
181 return snprintf(buf
, PAGE_SIZE
, "%u\n", subpagesize
);
183 static DEVICE_ATTR(subpagesize
, S_IRUGO
, mtd_subpagesize_show
, NULL
);
185 static ssize_t
mtd_oobsize_show(struct device
*dev
,
186 struct device_attribute
*attr
, char *buf
)
188 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
190 return snprintf(buf
, PAGE_SIZE
, "%lu\n", (unsigned long)mtd
->oobsize
);
192 static DEVICE_ATTR(oobsize
, S_IRUGO
, mtd_oobsize_show
, NULL
);
194 static ssize_t
mtd_oobavail_show(struct device
*dev
,
195 struct device_attribute
*attr
, char *buf
)
197 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
199 return snprintf(buf
, PAGE_SIZE
, "%u\n", mtd
->oobavail
);
201 static DEVICE_ATTR(oobavail
, S_IRUGO
, mtd_oobavail_show
, NULL
);
203 static ssize_t
mtd_numeraseregions_show(struct device
*dev
,
204 struct device_attribute
*attr
, char *buf
)
206 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
208 return snprintf(buf
, PAGE_SIZE
, "%u\n", mtd
->numeraseregions
);
210 static DEVICE_ATTR(numeraseregions
, S_IRUGO
, mtd_numeraseregions_show
,
213 static ssize_t
mtd_name_show(struct device
*dev
,
214 struct device_attribute
*attr
, char *buf
)
216 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
218 return snprintf(buf
, PAGE_SIZE
, "%s\n", mtd
->name
);
220 static DEVICE_ATTR(name
, S_IRUGO
, mtd_name_show
, NULL
);
222 static ssize_t
mtd_ecc_strength_show(struct device
*dev
,
223 struct device_attribute
*attr
, char *buf
)
225 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
227 return snprintf(buf
, PAGE_SIZE
, "%u\n", mtd
->ecc_strength
);
229 static DEVICE_ATTR(ecc_strength
, S_IRUGO
, mtd_ecc_strength_show
, NULL
);
231 static ssize_t
mtd_bitflip_threshold_show(struct device
*dev
,
232 struct device_attribute
*attr
,
235 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
237 return snprintf(buf
, PAGE_SIZE
, "%u\n", mtd
->bitflip_threshold
);
240 static ssize_t
mtd_bitflip_threshold_store(struct device
*dev
,
241 struct device_attribute
*attr
,
242 const char *buf
, size_t count
)
244 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
245 unsigned int bitflip_threshold
;
248 retval
= kstrtouint(buf
, 0, &bitflip_threshold
);
252 mtd
->bitflip_threshold
= bitflip_threshold
;
255 static DEVICE_ATTR(bitflip_threshold
, S_IRUGO
| S_IWUSR
,
256 mtd_bitflip_threshold_show
,
257 mtd_bitflip_threshold_store
);
259 static ssize_t
mtd_ecc_step_size_show(struct device
*dev
,
260 struct device_attribute
*attr
, char *buf
)
262 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
264 return snprintf(buf
, PAGE_SIZE
, "%u\n", mtd
->ecc_step_size
);
267 static DEVICE_ATTR(ecc_step_size
, S_IRUGO
, mtd_ecc_step_size_show
, NULL
);
269 static ssize_t
mtd_ecc_stats_corrected_show(struct device
*dev
,
270 struct device_attribute
*attr
, char *buf
)
272 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
273 struct mtd_ecc_stats
*ecc_stats
= &mtd
->ecc_stats
;
275 return snprintf(buf
, PAGE_SIZE
, "%u\n", ecc_stats
->corrected
);
277 static DEVICE_ATTR(corrected_bits
, S_IRUGO
,
278 mtd_ecc_stats_corrected_show
, NULL
);
280 static ssize_t
mtd_ecc_stats_errors_show(struct device
*dev
,
281 struct device_attribute
*attr
, char *buf
)
283 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
284 struct mtd_ecc_stats
*ecc_stats
= &mtd
->ecc_stats
;
286 return snprintf(buf
, PAGE_SIZE
, "%u\n", ecc_stats
->failed
);
288 static DEVICE_ATTR(ecc_failures
, S_IRUGO
, mtd_ecc_stats_errors_show
, NULL
);
290 static ssize_t
mtd_badblocks_show(struct device
*dev
,
291 struct device_attribute
*attr
, char *buf
)
293 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
294 struct mtd_ecc_stats
*ecc_stats
= &mtd
->ecc_stats
;
296 return snprintf(buf
, PAGE_SIZE
, "%u\n", ecc_stats
->badblocks
);
298 static DEVICE_ATTR(bad_blocks
, S_IRUGO
, mtd_badblocks_show
, NULL
);
300 static ssize_t
mtd_bbtblocks_show(struct device
*dev
,
301 struct device_attribute
*attr
, char *buf
)
303 struct mtd_info
*mtd
= dev_get_drvdata(dev
);
304 struct mtd_ecc_stats
*ecc_stats
= &mtd
->ecc_stats
;
306 return snprintf(buf
, PAGE_SIZE
, "%u\n", ecc_stats
->bbtblocks
);
308 static DEVICE_ATTR(bbt_blocks
, S_IRUGO
, mtd_bbtblocks_show
, NULL
);
310 static struct attribute
*mtd_attrs
[] = {
312 &dev_attr_flags
.attr
,
314 &dev_attr_erasesize
.attr
,
315 &dev_attr_writesize
.attr
,
316 &dev_attr_subpagesize
.attr
,
317 &dev_attr_oobsize
.attr
,
318 &dev_attr_oobavail
.attr
,
319 &dev_attr_numeraseregions
.attr
,
321 &dev_attr_ecc_strength
.attr
,
322 &dev_attr_ecc_step_size
.attr
,
323 &dev_attr_corrected_bits
.attr
,
324 &dev_attr_ecc_failures
.attr
,
325 &dev_attr_bad_blocks
.attr
,
326 &dev_attr_bbt_blocks
.attr
,
327 &dev_attr_bitflip_threshold
.attr
,
330 ATTRIBUTE_GROUPS(mtd
);
332 static const struct device_type mtd_devtype
= {
334 .groups
= mtd_groups
,
335 .release
= mtd_release
,
338 static int mtd_partid_show(struct seq_file
*s
, void *p
)
340 struct mtd_info
*mtd
= s
->private;
342 seq_printf(s
, "%s\n", mtd
->dbg
.partid
);
347 static int mtd_partid_debugfs_open(struct inode
*inode
, struct file
*file
)
349 return single_open(file
, mtd_partid_show
, inode
->i_private
);
352 static const struct file_operations mtd_partid_debug_fops
= {
353 .open
= mtd_partid_debugfs_open
,
356 .release
= single_release
,
359 static int mtd_partname_show(struct seq_file
*s
, void *p
)
361 struct mtd_info
*mtd
= s
->private;
363 seq_printf(s
, "%s\n", mtd
->dbg
.partname
);
368 static int mtd_partname_debugfs_open(struct inode
*inode
, struct file
*file
)
370 return single_open(file
, mtd_partname_show
, inode
->i_private
);
373 static const struct file_operations mtd_partname_debug_fops
= {
374 .open
= mtd_partname_debugfs_open
,
377 .release
= single_release
,
380 static struct dentry
*dfs_dir_mtd
;
382 static void mtd_debugfs_populate(struct mtd_info
*mtd
)
384 struct device
*dev
= &mtd
->dev
;
387 if (IS_ERR_OR_NULL(dfs_dir_mtd
))
390 root
= debugfs_create_dir(dev_name(dev
), dfs_dir_mtd
);
391 mtd
->dbg
.dfs_dir
= root
;
394 debugfs_create_file("partid", 0400, root
, mtd
,
395 &mtd_partid_debug_fops
);
397 if (mtd
->dbg
.partname
)
398 debugfs_create_file("partname", 0400, root
, mtd
,
399 &mtd_partname_debug_fops
);
403 unsigned mtd_mmap_capabilities(struct mtd_info
*mtd
)
407 return NOMMU_MAP_COPY
| NOMMU_MAP_DIRECT
| NOMMU_MAP_EXEC
|
408 NOMMU_MAP_READ
| NOMMU_MAP_WRITE
;
410 return NOMMU_MAP_COPY
| NOMMU_MAP_DIRECT
| NOMMU_MAP_EXEC
|
413 return NOMMU_MAP_COPY
;
416 EXPORT_SYMBOL_GPL(mtd_mmap_capabilities
);
419 static int mtd_reboot_notifier(struct notifier_block
*n
, unsigned long state
,
422 struct mtd_info
*mtd
;
424 mtd
= container_of(n
, struct mtd_info
, reboot_notifier
);
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
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
440 * The notion of page is replaced by the term wunit (write-unit) to stay
441 * consistent with the ->writesize field.
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
447 * From the pairing info the MTD user can find all the wunits paired with
448 * @wunit using the following loop:
450 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
452 * mtd_pairing_info_to_wunit(mtd, &info);
456 int mtd_wunit_to_pairing_info(struct mtd_info
*mtd
, int wunit
,
457 struct mtd_pairing_info
*info
)
459 struct mtd_info
*master
= mtd_get_master(mtd
);
460 int npairs
= mtd_wunit_per_eb(master
) / mtd_pairing_groups(master
);
462 if (wunit
< 0 || wunit
>= npairs
)
465 if (master
->pairing
&& master
->pairing
->get_info
)
466 return master
->pairing
->get_info(master
, wunit
, info
);
473 EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info
);
476 * mtd_pairing_info_to_wunit - get wunit from pairing information
477 * @mtd: pointer to new MTD device info structure
478 * @info: pairing information struct
480 * Returns a positive number representing the wunit associated to the info
481 * struct, or a negative error code.
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()
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:
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));
499 int mtd_pairing_info_to_wunit(struct mtd_info
*mtd
,
500 const struct mtd_pairing_info
*info
)
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
;
506 if (!info
|| info
->pair
< 0 || info
->pair
>= npairs
||
507 info
->group
< 0 || info
->group
>= ngroups
)
510 if (master
->pairing
&& master
->pairing
->get_wunit
)
511 return mtd
->pairing
->get_wunit(master
, info
);
515 EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit
);
518 * mtd_pairing_groups - get the number of pairing groups
519 * @mtd: pointer to new MTD device info structure
521 * Returns the number of pairing groups.
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.
527 int mtd_pairing_groups(struct mtd_info
*mtd
)
529 struct mtd_info
*master
= mtd_get_master(mtd
);
531 if (!master
->pairing
|| !master
->pairing
->ngroups
)
534 return master
->pairing
->ngroups
;
536 EXPORT_SYMBOL_GPL(mtd_pairing_groups
);
538 static int mtd_nvmem_reg_read(void *priv
, unsigned int offset
,
539 void *val
, size_t bytes
)
541 struct mtd_info
*mtd
= priv
;
545 err
= mtd_read(mtd
, offset
, bytes
, &retlen
, val
);
546 if (err
&& err
!= -EUCLEAN
)
549 return retlen
== bytes
? 0 : -EIO
;
552 static int mtd_nvmem_add(struct mtd_info
*mtd
)
554 struct nvmem_config config
= {};
557 config
.dev
= &mtd
->dev
;
558 config
.name
= dev_name(&mtd
->dev
);
559 config
.owner
= THIS_MODULE
;
560 config
.reg_read
= mtd_nvmem_reg_read
;
561 config
.size
= mtd
->size
;
562 config
.word_size
= 1;
564 config
.read_only
= true;
565 config
.root_only
= true;
566 config
.no_of_node
= true;
569 mtd
->nvmem
= nvmem_register(&config
);
570 if (IS_ERR(mtd
->nvmem
)) {
571 /* Just ignore if there is no NVMEM support in the kernel */
572 if (PTR_ERR(mtd
->nvmem
) == -EOPNOTSUPP
) {
575 dev_err(&mtd
->dev
, "Failed to register NVMEM device\n");
576 return PTR_ERR(mtd
->nvmem
);
584 * add_mtd_device - register an MTD device
585 * @mtd: pointer to new MTD device info structure
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
589 * zero on success or non-zero on failure.
592 int add_mtd_device(struct mtd_info
*mtd
)
594 struct mtd_info
*master
= mtd_get_master(mtd
);
595 struct mtd_notifier
*not;
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.
603 if (WARN_ONCE(mtd
->dev
.type
, "MTD already registered\n"))
606 BUG_ON(mtd
->writesize
== 0);
609 * MTD drivers should implement ->_{write,read}() or
610 * ->_{write,read}_oob(), but not both.
612 if (WARN_ON((mtd
->_write
&& mtd
->_write_oob
) ||
613 (mtd
->_read
&& mtd
->_read_oob
)))
616 if (WARN_ON((!mtd
->erasesize
|| !master
->_erase
) &&
617 !(mtd
->flags
& MTD_NO_ERASE
)))
620 mutex_lock(&mtd_table_mutex
);
622 i
= idr_alloc(&mtd_idr
, mtd
, 0, 0, GFP_KERNEL
);
631 /* default value if not set by driver */
632 if (mtd
->bitflip_threshold
== 0)
633 mtd
->bitflip_threshold
= mtd
->ecc_strength
;
635 if (is_power_of_2(mtd
->erasesize
))
636 mtd
->erasesize_shift
= ffs(mtd
->erasesize
) - 1;
638 mtd
->erasesize_shift
= 0;
640 if (is_power_of_2(mtd
->writesize
))
641 mtd
->writesize_shift
= ffs(mtd
->writesize
) - 1;
643 mtd
->writesize_shift
= 0;
645 mtd
->erasesize_mask
= (1 << mtd
->erasesize_shift
) - 1;
646 mtd
->writesize_mask
= (1 << mtd
->writesize_shift
) - 1;
648 /* Some chips always power up locked. Unlock them now */
649 if ((mtd
->flags
& MTD_WRITEABLE
) && (mtd
->flags
& MTD_POWERUP_LOCK
)) {
650 error
= mtd_unlock(mtd
, 0, mtd
->size
);
651 if (error
&& error
!= -EOPNOTSUPP
)
653 "%s: unlock failed, writes may not work\n",
655 /* Ignore unlock failures? */
659 /* Caller should have set dev.parent to match the
660 * physical device, if appropriate.
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
);
667 of_node_get(mtd_get_of_node(mtd
));
668 error
= device_register(&mtd
->dev
);
672 /* Add the nvmem provider */
673 error
= mtd_nvmem_add(mtd
);
677 mtd_debugfs_populate(mtd
);
679 device_create(&mtd_class
, mtd
->dev
.parent
, MTD_DEVT(i
) + 1, NULL
,
682 pr_debug("mtd: Giving out device %d to %s\n", i
, mtd
->name
);
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
)
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
693 __module_get(THIS_MODULE
);
697 device_unregister(&mtd
->dev
);
699 of_node_put(mtd_get_of_node(mtd
));
700 idr_remove(&mtd_idr
, i
);
702 mutex_unlock(&mtd_table_mutex
);
707 * del_mtd_device - unregister an MTD device
708 * @mtd: pointer to MTD device info structure
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.
716 int del_mtd_device(struct mtd_info
*mtd
)
719 struct mtd_notifier
*not;
721 mutex_lock(&mtd_table_mutex
);
723 debugfs_remove_recursive(mtd
->dbg
.dfs_dir
);
725 if (idr_find(&mtd_idr
, mtd
->index
) != mtd
) {
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
)
736 printk(KERN_NOTICE
"Removing MTD device #%d (%s) with use count %d\n",
737 mtd
->index
, mtd
->name
, mtd
->usecount
);
740 /* Try to remove the NVMEM provider */
742 nvmem_unregister(mtd
->nvmem
);
744 device_unregister(&mtd
->dev
);
746 idr_remove(&mtd_idr
, mtd
->index
);
747 of_node_put(mtd_get_of_node(mtd
));
749 module_put(THIS_MODULE
);
754 mutex_unlock(&mtd_table_mutex
);
759 * Set a few defaults based on the parent devices, if not provided by the
762 static void mtd_set_dev_defaults(struct mtd_info
*mtd
)
764 if (mtd
->dev
.parent
) {
765 if (!mtd
->owner
&& mtd
->dev
.parent
->driver
)
766 mtd
->owner
= mtd
->dev
.parent
->driver
->owner
;
768 mtd
->name
= dev_name(mtd
->dev
.parent
);
770 pr_debug("mtd device won't show a device symlink in sysfs\n");
773 INIT_LIST_HEAD(&mtd
->partitions
);
774 mutex_init(&mtd
->master
.partitions_lock
);
778 * mtd_device_parse_register - parse partitions and register an MTD device.
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
783 * @parser_data: MTD partition parser-specific data
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
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:
793 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
795 * * Then It tries to probe partitions on MTD device @mtd using parsers
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
800 * * If no partitions were found this function just registers the MTD device
803 * Returns zero in case of success and a negative error code in case of failure.
805 int mtd_device_parse_register(struct mtd_info
*mtd
, const char * const *types
,
806 struct mtd_part_parser_data
*parser_data
,
807 const struct mtd_partition
*parts
,
812 mtd_set_dev_defaults(mtd
);
814 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER
)) {
815 ret
= add_mtd_device(mtd
);
820 /* Prefer parsed partitions over driver-provided fallback */
821 ret
= parse_mtd_partitions(mtd
, types
, parser_data
);
825 ret
= add_mtd_partitions(mtd
, parts
, nr_parts
);
826 else if (!device_is_registered(&mtd
->dev
))
827 ret
= add_mtd_device(mtd
);
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.
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).
842 WARN_ONCE(mtd
->_reboot
&& mtd
->reboot_notifier
.notifier_call
,
843 "MTD already registered\n");
844 if (mtd
->_reboot
&& !mtd
->reboot_notifier
.notifier_call
) {
845 mtd
->reboot_notifier
.notifier_call
= mtd_reboot_notifier
;
846 register_reboot_notifier(&mtd
->reboot_notifier
);
850 if (ret
&& device_is_registered(&mtd
->dev
))
855 EXPORT_SYMBOL_GPL(mtd_device_parse_register
);
858 * mtd_device_unregister - unregister an existing MTD device.
860 * @master: the MTD device to unregister. This will unregister both the master
861 * and any partitions if registered.
863 int mtd_device_unregister(struct mtd_info
*master
)
868 unregister_reboot_notifier(&master
->reboot_notifier
);
870 err
= del_mtd_partitions(master
);
874 if (!device_is_registered(&master
->dev
))
877 return del_mtd_device(master
);
879 EXPORT_SYMBOL_GPL(mtd_device_unregister
);
882 * register_mtd_user - register a 'user' of MTD devices.
883 * @new: pointer to notifier info structure
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.
889 void register_mtd_user (struct mtd_notifier
*new)
891 struct mtd_info
*mtd
;
893 mutex_lock(&mtd_table_mutex
);
895 list_add(&new->list
, &mtd_notifiers
);
897 __module_get(THIS_MODULE
);
899 mtd_for_each_device(mtd
)
902 mutex_unlock(&mtd_table_mutex
);
904 EXPORT_SYMBOL_GPL(register_mtd_user
);
907 * unregister_mtd_user - unregister a 'user' of MTD devices.
908 * @old: pointer to notifier info structure
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.
915 int unregister_mtd_user (struct mtd_notifier
*old
)
917 struct mtd_info
*mtd
;
919 mutex_lock(&mtd_table_mutex
);
921 module_put(THIS_MODULE
);
923 mtd_for_each_device(mtd
)
926 list_del(&old
->list
);
927 mutex_unlock(&mtd_table_mutex
);
930 EXPORT_SYMBOL_GPL(unregister_mtd_user
);
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
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
940 * both, return the num'th driver only if its address matches. Return
943 struct mtd_info
*get_mtd_device(struct mtd_info
*mtd
, int num
)
945 struct mtd_info
*ret
= NULL
, *other
;
948 mutex_lock(&mtd_table_mutex
);
951 mtd_for_each_device(other
) {
957 } else if (num
>= 0) {
958 ret
= idr_find(&mtd_idr
, num
);
959 if (mtd
&& mtd
!= ret
)
968 err
= __get_mtd_device(ret
);
972 mutex_unlock(&mtd_table_mutex
);
975 EXPORT_SYMBOL_GPL(get_mtd_device
);
978 int __get_mtd_device(struct mtd_info
*mtd
)
980 struct mtd_info
*master
= mtd_get_master(mtd
);
983 if (!try_module_get(master
->owner
))
986 if (master
->_get_device
) {
987 err
= master
->_get_device(mtd
);
990 module_put(master
->owner
);
995 while (mtd
->parent
) {
1002 EXPORT_SYMBOL_GPL(__get_mtd_device
);
1005 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1007 * @name: MTD device name to open
1009 * This function returns MTD device description structure in case of
1010 * success and an error code in case of failure.
1012 struct mtd_info
*get_mtd_device_nm(const char *name
)
1015 struct mtd_info
*mtd
= NULL
, *other
;
1017 mutex_lock(&mtd_table_mutex
);
1019 mtd_for_each_device(other
) {
1020 if (!strcmp(name
, other
->name
)) {
1029 err
= __get_mtd_device(mtd
);
1033 mutex_unlock(&mtd_table_mutex
);
1037 mutex_unlock(&mtd_table_mutex
);
1038 return ERR_PTR(err
);
1040 EXPORT_SYMBOL_GPL(get_mtd_device_nm
);
1042 void put_mtd_device(struct mtd_info
*mtd
)
1044 mutex_lock(&mtd_table_mutex
);
1045 __put_mtd_device(mtd
);
1046 mutex_unlock(&mtd_table_mutex
);
1049 EXPORT_SYMBOL_GPL(put_mtd_device
);
1051 void __put_mtd_device(struct mtd_info
*mtd
)
1053 struct mtd_info
*master
= mtd_get_master(mtd
);
1055 while (mtd
->parent
) {
1057 BUG_ON(mtd
->usecount
< 0);
1061 if (master
->_put_device
)
1062 master
->_put_device(master
);
1064 module_put(master
->owner
);
1066 EXPORT_SYMBOL_GPL(__put_mtd_device
);
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.
1073 int mtd_erase(struct mtd_info
*mtd
, struct erase_info
*instr
)
1075 struct mtd_info
*master
= mtd_get_master(mtd
);
1076 u64 mst_ofs
= mtd_get_master_ofs(mtd
, 0);
1079 instr
->fail_addr
= MTD_FAIL_ADDR_UNKNOWN
;
1081 if (!mtd
->erasesize
|| !master
->_erase
)
1084 if (instr
->addr
>= mtd
->size
|| instr
->len
> mtd
->size
- instr
->addr
)
1086 if (!(mtd
->flags
& MTD_WRITEABLE
))
1092 ledtrig_mtd_activity();
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
;
1099 instr
->addr
-= mst_ofs
;
1102 EXPORT_SYMBOL_GPL(mtd_erase
);
1105 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1107 int mtd_point(struct mtd_info
*mtd
, loff_t from
, size_t len
, size_t *retlen
,
1108 void **virt
, resource_size_t
*phys
)
1110 struct mtd_info
*master
= mtd_get_master(mtd
);
1116 if (!master
->_point
)
1118 if (from
< 0 || from
>= mtd
->size
|| len
> mtd
->size
- from
)
1123 from
= mtd_get_master_ofs(mtd
, from
);
1124 return master
->_point(master
, from
, len
, retlen
, virt
, phys
);
1126 EXPORT_SYMBOL_GPL(mtd_point
);
1128 /* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1129 int mtd_unpoint(struct mtd_info
*mtd
, loff_t from
, size_t len
)
1131 struct mtd_info
*master
= mtd_get_master(mtd
);
1133 if (!master
->_unpoint
)
1135 if (from
< 0 || from
>= mtd
->size
|| len
> mtd
->size
- from
)
1139 return master
->_unpoint(master
, mtd_get_master_ofs(mtd
, from
), len
);
1141 EXPORT_SYMBOL_GPL(mtd_unpoint
);
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
1148 unsigned long mtd_get_unmapped_area(struct mtd_info
*mtd
, unsigned long len
,
1149 unsigned long offset
, unsigned long flags
)
1155 ret
= mtd_point(mtd
, offset
, len
, &retlen
, &virt
, NULL
);
1158 if (retlen
!= len
) {
1159 mtd_unpoint(mtd
, offset
, retlen
);
1162 return (unsigned long)virt
;
1164 EXPORT_SYMBOL_GPL(mtd_get_unmapped_area
);
1166 static void mtd_update_ecc_stats(struct mtd_info
*mtd
, struct mtd_info
*master
,
1167 const struct mtd_ecc_stats
*old_stats
)
1169 struct mtd_ecc_stats diff
;
1174 diff
= master
->ecc_stats
;
1175 diff
.failed
-= old_stats
->failed
;
1176 diff
.corrected
-= old_stats
->corrected
;
1178 while (mtd
->parent
) {
1179 mtd
->ecc_stats
.failed
+= diff
.failed
;
1180 mtd
->ecc_stats
.corrected
+= diff
.corrected
;
1185 int mtd_read(struct mtd_info
*mtd
, loff_t from
, size_t len
, size_t *retlen
,
1188 struct mtd_oob_ops ops
= {
1194 ret
= mtd_read_oob(mtd
, from
, &ops
);
1195 *retlen
= ops
.retlen
;
1199 EXPORT_SYMBOL_GPL(mtd_read
);
1201 int mtd_write(struct mtd_info
*mtd
, loff_t to
, size_t len
, size_t *retlen
,
1204 struct mtd_oob_ops ops
= {
1206 .datbuf
= (u8
*)buf
,
1210 ret
= mtd_write_oob(mtd
, to
, &ops
);
1211 *retlen
= ops
.retlen
;
1215 EXPORT_SYMBOL_GPL(mtd_write
);
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).
1224 int mtd_panic_write(struct mtd_info
*mtd
, loff_t to
, size_t len
, size_t *retlen
,
1227 struct mtd_info
*master
= mtd_get_master(mtd
);
1230 if (!master
->_panic_write
)
1232 if (to
< 0 || to
>= mtd
->size
|| len
> mtd
->size
- to
)
1234 if (!(mtd
->flags
& MTD_WRITEABLE
))
1238 if (!mtd
->oops_panic_write
)
1239 mtd
->oops_panic_write
= true;
1241 return master
->_panic_write(master
, mtd_get_master_ofs(mtd
, to
), len
,
1244 EXPORT_SYMBOL_GPL(mtd_panic_write
);
1246 static int mtd_check_oob_ops(struct mtd_info
*mtd
, loff_t offs
,
1247 struct mtd_oob_ops
*ops
)
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
1260 if (offs
< 0 || offs
+ ops
->len
> mtd
->size
)
1266 if (ops
->ooboffs
>= mtd_oobavail(mtd
, ops
))
1269 maxooblen
= ((size_t)(mtd_div_by_ws(mtd
->size
, mtd
) -
1270 mtd_div_by_ws(offs
, mtd
)) *
1271 mtd_oobavail(mtd
, ops
)) - ops
->ooboffs
;
1272 if (ops
->ooblen
> maxooblen
)
1279 int mtd_read_oob(struct mtd_info
*mtd
, loff_t from
, struct mtd_oob_ops
*ops
)
1281 struct mtd_info
*master
= mtd_get_master(mtd
);
1282 struct mtd_ecc_stats old_stats
= master
->ecc_stats
;
1285 ops
->retlen
= ops
->oobretlen
= 0;
1287 ret_code
= mtd_check_oob_ops(mtd
, from
, ops
);
1291 ledtrig_mtd_activity();
1293 /* Check the validity of a potential fallback on mtd->_read */
1294 if (!master
->_read_oob
&& (!master
->_read
|| ops
->oobbuf
))
1297 from
= mtd_get_master_ofs(mtd
, from
);
1298 if (master
->_read_oob
)
1299 ret_code
= master
->_read_oob(master
, from
, ops
);
1301 ret_code
= master
->_read(master
, from
, ops
->len
, &ops
->retlen
,
1304 mtd_update_ecc_stats(mtd
, master
, &old_stats
);
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().
1312 if (unlikely(ret_code
< 0))
1314 if (mtd
->ecc_strength
== 0)
1315 return 0; /* device lacks ecc */
1316 return ret_code
>= mtd
->bitflip_threshold
? -EUCLEAN
: 0;
1318 EXPORT_SYMBOL_GPL(mtd_read_oob
);
1320 int mtd_write_oob(struct mtd_info
*mtd
, loff_t to
,
1321 struct mtd_oob_ops
*ops
)
1323 struct mtd_info
*master
= mtd_get_master(mtd
);
1326 ops
->retlen
= ops
->oobretlen
= 0;
1328 if (!(mtd
->flags
& MTD_WRITEABLE
))
1331 ret
= mtd_check_oob_ops(mtd
, to
, ops
);
1335 ledtrig_mtd_activity();
1337 /* Check the validity of a potential fallback on mtd->_write */
1338 if (!master
->_write_oob
&& (!master
->_write
|| ops
->oobbuf
))
1341 to
= mtd_get_master_ofs(mtd
, to
);
1343 if (master
->_write_oob
)
1344 return master
->_write_oob(master
, to
, ops
);
1346 return master
->_write(master
, to
, ops
->len
, &ops
->retlen
,
1349 EXPORT_SYMBOL_GPL(mtd_write_oob
);
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
1358 * @oobecc: OOB region struct filled with the appropriate ECC position
1361 * This function returns ECC section information in the OOB area. If you want
1362 * to get all the ECC bytes information, then you should call
1363 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1365 * Returns zero on success, a negative error code otherwise.
1367 int mtd_ooblayout_ecc(struct mtd_info
*mtd
, int section
,
1368 struct mtd_oob_region
*oobecc
)
1370 struct mtd_info
*master
= mtd_get_master(mtd
);
1372 memset(oobecc
, 0, sizeof(*oobecc
));
1374 if (!master
|| section
< 0)
1377 if (!master
->ooblayout
|| !master
->ooblayout
->ecc
)
1380 return master
->ooblayout
->ecc(master
, section
, oobecc
);
1382 EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc
);
1385 * mtd_ooblayout_free - Get the OOB region definition of a specific free
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
1395 * This function returns free bytes position in the OOB area. If you want
1396 * to get all the free bytes information, then you should call
1397 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1399 * Returns zero on success, a negative error code otherwise.
1401 int mtd_ooblayout_free(struct mtd_info
*mtd
, int section
,
1402 struct mtd_oob_region
*oobfree
)
1404 struct mtd_info
*master
= mtd_get_master(mtd
);
1406 memset(oobfree
, 0, sizeof(*oobfree
));
1408 if (!master
|| section
< 0)
1411 if (!master
->ooblayout
|| !master
->ooblayout
->free
)
1414 return master
->ooblayout
->free(master
, section
, oobfree
);
1416 EXPORT_SYMBOL_GPL(mtd_ooblayout_free
);
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
1427 * This function returns the section id and oobregion information of a
1428 * specific byte. For example, say you want to know where the 4th ECC byte is
1429 * stored, you'll use:
1431 * mtd_ooblayout_find_region(mtd, 3, §ion, &oobregion, mtd_ooblayout_ecc);
1433 * Returns zero on success, a negative error code otherwise.
1435 static 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
*,
1439 struct mtd_oob_region
*oobregion
))
1441 int pos
= 0, ret
, section
= 0;
1443 memset(oobregion
, 0, sizeof(*oobregion
));
1446 ret
= iter(mtd
, section
, oobregion
);
1450 if (pos
+ oobregion
->length
> byte
)
1453 pos
+= oobregion
->length
;
1458 * Adjust region info to make it start at the beginning at the
1461 oobregion
->offset
+= byte
- pos
;
1462 oobregion
->length
-= byte
- pos
;
1463 *sectionp
= section
;
1469 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
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
1476 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1479 * Returns zero on success, a negative error code otherwise.
1481 int mtd_ooblayout_find_eccregion(struct mtd_info
*mtd
, int eccbyte
,
1483 struct mtd_oob_region
*oobregion
)
1485 return mtd_ooblayout_find_region(mtd
, eccbyte
, section
, oobregion
,
1488 EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion
);
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
1499 * Extract bytes attached to a specific category (ECC or free)
1500 * from the OOB buffer and copy them into buf.
1502 * Returns zero on success, a negative error code otherwise.
1504 static 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
*,
1508 struct mtd_oob_region
*oobregion
))
1510 struct mtd_oob_region oobregion
;
1513 ret
= mtd_ooblayout_find_region(mtd
, start
, §ion
,
1519 cnt
= min_t(int, nbytes
, oobregion
.length
);
1520 memcpy(buf
, oobbuf
+ oobregion
.offset
, cnt
);
1527 ret
= iter(mtd
, ++section
, &oobregion
);
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
1542 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1543 * is selected by passing the appropriate iterator.
1545 * Returns zero on success, a negative error code otherwise.
1547 static 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
*,
1551 struct mtd_oob_region
*oobregion
))
1553 struct mtd_oob_region oobregion
;
1556 ret
= mtd_ooblayout_find_region(mtd
, start
, §ion
,
1562 cnt
= min_t(int, nbytes
, oobregion
.length
);
1563 memcpy(oobbuf
+ oobregion
.offset
, buf
, cnt
);
1570 ret
= iter(mtd
, ++section
, &oobregion
);
1577 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1578 * @mtd: mtd info structure
1579 * @iter: category iterator
1581 * Count the number of bytes in a given category.
1583 * Returns a positive value on success, a negative error code otherwise.
1585 static int mtd_ooblayout_count_bytes(struct mtd_info
*mtd
,
1586 int (*iter
)(struct mtd_info
*,
1588 struct mtd_oob_region
*oobregion
))
1590 struct mtd_oob_region oobregion
;
1591 int section
= 0, ret
, nbytes
= 0;
1594 ret
= iter(mtd
, section
++, &oobregion
);
1601 nbytes
+= oobregion
.length
;
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
1615 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
1617 * Returns zero on success, a negative error code otherwise.
1619 int mtd_ooblayout_get_eccbytes(struct mtd_info
*mtd
, u8
*eccbuf
,
1620 const u8
*oobbuf
, int start
, int nbytes
)
1622 return mtd_ooblayout_get_bytes(mtd
, eccbuf
, oobbuf
, start
, nbytes
,
1625 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes
);
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
1635 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
1637 * Returns zero on success, a negative error code otherwise.
1639 int mtd_ooblayout_set_eccbytes(struct mtd_info
*mtd
, const u8
*eccbuf
,
1640 u8
*oobbuf
, int start
, int nbytes
)
1642 return mtd_ooblayout_set_bytes(mtd
, eccbuf
, oobbuf
, start
, nbytes
,
1645 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes
);
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
1655 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1657 * Returns zero on success, a negative error code otherwise.
1659 int mtd_ooblayout_get_databytes(struct mtd_info
*mtd
, u8
*databuf
,
1660 const u8
*oobbuf
, int start
, int nbytes
)
1662 return mtd_ooblayout_get_bytes(mtd
, databuf
, oobbuf
, start
, nbytes
,
1663 mtd_ooblayout_free
);
1665 EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes
);
1668 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
1669 * @mtd: mtd info structure
1670 * @databuf: source buffer to get data bytes from
1671 * @oobbuf: OOB buffer
1672 * @start: first ECC byte to set
1673 * @nbytes: number of ECC bytes to set
1675 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
1677 * Returns zero on success, a negative error code otherwise.
1679 int mtd_ooblayout_set_databytes(struct mtd_info
*mtd
, const u8
*databuf
,
1680 u8
*oobbuf
, int start
, int nbytes
)
1682 return mtd_ooblayout_set_bytes(mtd
, databuf
, oobbuf
, start
, nbytes
,
1683 mtd_ooblayout_free
);
1685 EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes
);
1688 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
1689 * @mtd: mtd info structure
1691 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
1693 * Returns zero on success, a negative error code otherwise.
1695 int mtd_ooblayout_count_freebytes(struct mtd_info
*mtd
)
1697 return mtd_ooblayout_count_bytes(mtd
, mtd_ooblayout_free
);
1699 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes
);
1702 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
1703 * @mtd: mtd info structure
1705 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
1707 * Returns zero on success, a negative error code otherwise.
1709 int mtd_ooblayout_count_eccbytes(struct mtd_info
*mtd
)
1711 return mtd_ooblayout_count_bytes(mtd
, mtd_ooblayout_ecc
);
1713 EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes
);
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
1720 int mtd_get_fact_prot_info(struct mtd_info
*mtd
, size_t len
, size_t *retlen
,
1721 struct otp_info
*buf
)
1723 struct mtd_info
*master
= mtd_get_master(mtd
);
1725 if (!master
->_get_fact_prot_info
)
1729 return master
->_get_fact_prot_info(master
, len
, retlen
, buf
);
1731 EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info
);
1733 int mtd_read_fact_prot_reg(struct mtd_info
*mtd
, loff_t from
, size_t len
,
1734 size_t *retlen
, u_char
*buf
)
1736 struct mtd_info
*master
= mtd_get_master(mtd
);
1739 if (!master
->_read_fact_prot_reg
)
1743 return master
->_read_fact_prot_reg(master
, from
, len
, retlen
, buf
);
1745 EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg
);
1747 int mtd_get_user_prot_info(struct mtd_info
*mtd
, size_t len
, size_t *retlen
,
1748 struct otp_info
*buf
)
1750 struct mtd_info
*master
= mtd_get_master(mtd
);
1752 if (!master
->_get_user_prot_info
)
1756 return master
->_get_user_prot_info(master
, len
, retlen
, buf
);
1758 EXPORT_SYMBOL_GPL(mtd_get_user_prot_info
);
1760 int mtd_read_user_prot_reg(struct mtd_info
*mtd
, loff_t from
, size_t len
,
1761 size_t *retlen
, u_char
*buf
)
1763 struct mtd_info
*master
= mtd_get_master(mtd
);
1766 if (!master
->_read_user_prot_reg
)
1770 return master
->_read_user_prot_reg(master
, from
, len
, retlen
, buf
);
1772 EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg
);
1774 int mtd_write_user_prot_reg(struct mtd_info
*mtd
, loff_t to
, size_t len
,
1775 size_t *retlen
, u_char
*buf
)
1777 struct mtd_info
*master
= mtd_get_master(mtd
);
1781 if (!master
->_write_user_prot_reg
)
1785 ret
= master
->_write_user_prot_reg(master
, to
, len
, retlen
, buf
);
1790 * If no data could be written at all, we are out of memory and
1791 * must return -ENOSPC.
1793 return (*retlen
) ? 0 : -ENOSPC
;
1795 EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg
);
1797 int mtd_lock_user_prot_reg(struct mtd_info
*mtd
, loff_t from
, size_t len
)
1799 struct mtd_info
*master
= mtd_get_master(mtd
);
1801 if (!master
->_lock_user_prot_reg
)
1805 return master
->_lock_user_prot_reg(master
, from
, len
);
1807 EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg
);
1809 /* Chip-supported device locking */
1810 int mtd_lock(struct mtd_info
*mtd
, loff_t ofs
, uint64_t len
)
1812 struct mtd_info
*master
= mtd_get_master(mtd
);
1816 if (ofs
< 0 || ofs
>= mtd
->size
|| len
> mtd
->size
- ofs
)
1820 return master
->_lock(master
, mtd_get_master_ofs(mtd
, ofs
), len
);
1822 EXPORT_SYMBOL_GPL(mtd_lock
);
1824 int mtd_unlock(struct mtd_info
*mtd
, loff_t ofs
, uint64_t len
)
1826 struct mtd_info
*master
= mtd_get_master(mtd
);
1828 if (!master
->_unlock
)
1830 if (ofs
< 0 || ofs
>= mtd
->size
|| len
> mtd
->size
- ofs
)
1834 return master
->_unlock(master
, mtd_get_master_ofs(mtd
, ofs
), len
);
1836 EXPORT_SYMBOL_GPL(mtd_unlock
);
1838 int mtd_is_locked(struct mtd_info
*mtd
, loff_t ofs
, uint64_t len
)
1840 struct mtd_info
*master
= mtd_get_master(mtd
);
1842 if (!master
->_is_locked
)
1844 if (ofs
< 0 || ofs
>= mtd
->size
|| len
> mtd
->size
- ofs
)
1848 return master
->_is_locked(master
, mtd_get_master_ofs(mtd
, ofs
), len
);
1850 EXPORT_SYMBOL_GPL(mtd_is_locked
);
1852 int mtd_block_isreserved(struct mtd_info
*mtd
, loff_t ofs
)
1854 struct mtd_info
*master
= mtd_get_master(mtd
);
1856 if (ofs
< 0 || ofs
>= mtd
->size
)
1858 if (!master
->_block_isreserved
)
1860 return master
->_block_isreserved(master
, mtd_get_master_ofs(mtd
, ofs
));
1862 EXPORT_SYMBOL_GPL(mtd_block_isreserved
);
1864 int mtd_block_isbad(struct mtd_info
*mtd
, loff_t ofs
)
1866 struct mtd_info
*master
= mtd_get_master(mtd
);
1868 if (ofs
< 0 || ofs
>= mtd
->size
)
1870 if (!master
->_block_isbad
)
1872 return master
->_block_isbad(master
, mtd_get_master_ofs(mtd
, ofs
));
1874 EXPORT_SYMBOL_GPL(mtd_block_isbad
);
1876 int mtd_block_markbad(struct mtd_info
*mtd
, loff_t ofs
)
1878 struct mtd_info
*master
= mtd_get_master(mtd
);
1881 if (!master
->_block_markbad
)
1883 if (ofs
< 0 || ofs
>= mtd
->size
)
1885 if (!(mtd
->flags
& MTD_WRITEABLE
))
1888 ret
= master
->_block_markbad(master
, mtd_get_master_ofs(mtd
, ofs
));
1892 while (mtd
->parent
) {
1893 mtd
->ecc_stats
.badblocks
++;
1899 EXPORT_SYMBOL_GPL(mtd_block_markbad
);
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.
1909 * This function returns zero in case of success and a negative error code in
1912 static int default_mtd_writev(struct mtd_info
*mtd
, const struct kvec
*vecs
,
1913 unsigned long count
, loff_t to
, size_t *retlen
)
1916 size_t totlen
= 0, thislen
;
1919 for (i
= 0; i
< count
; i
++) {
1920 if (!vecs
[i
].iov_len
)
1922 ret
= mtd_write(mtd
, to
, vecs
[i
].iov_len
, &thislen
,
1925 if (ret
|| thislen
!= vecs
[i
].iov_len
)
1927 to
+= vecs
[i
].iov_len
;
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.
1941 * This function returns zero in case of success and a negative error code in
1944 int mtd_writev(struct mtd_info
*mtd
, const struct kvec
*vecs
,
1945 unsigned long count
, loff_t to
, size_t *retlen
)
1947 struct mtd_info
*master
= mtd_get_master(mtd
);
1950 if (!(mtd
->flags
& MTD_WRITEABLE
))
1953 if (!master
->_writev
)
1954 return default_mtd_writev(mtd
, vecs
, count
, to
, retlen
);
1956 return master
->_writev(master
, vecs
, count
,
1957 mtd_get_master_ofs(mtd
, to
), retlen
);
1959 EXPORT_SYMBOL_GPL(mtd_writev
);
1962 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
1963 * @mtd: mtd device description object pointer
1964 * @size: a pointer to the ideal or maximum size of the allocation, points
1965 * to the actual allocation size on success.
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
1972 * ask the memory allocator to avoid re-trying, swapping, writing back
1973 * or performing I/O.
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.
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.
1983 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
1985 void *mtd_kmalloc_up_to(const struct mtd_info
*mtd
, size_t *size
)
1987 gfp_t flags
= __GFP_NOWARN
| __GFP_DIRECT_RECLAIM
| __GFP_NORETRY
;
1988 size_t min_alloc
= max_t(size_t, mtd
->writesize
, PAGE_SIZE
);
1991 *size
= min_t(size_t, *size
, KMALLOC_MAX_SIZE
);
1993 while (*size
> min_alloc
) {
1994 kbuf
= kmalloc(*size
, flags
);
1999 *size
= ALIGN(*size
, mtd
->writesize
);
2003 * For the last resort allocation allow 'kmalloc()' to do all sorts of
2004 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
2006 return kmalloc(*size
, GFP_KERNEL
);
2008 EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to
);
2010 #ifdef CONFIG_PROC_FS
2012 /*====================================================================*/
2013 /* Support for /proc/mtd */
2015 static int mtd_proc_show(struct seq_file
*m
, void *v
)
2017 struct mtd_info
*mtd
;
2019 seq_puts(m
, "dev: size erasesize name\n");
2020 mutex_lock(&mtd_table_mutex
);
2021 mtd_for_each_device(mtd
) {
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
);
2026 mutex_unlock(&mtd_table_mutex
);
2029 #endif /* CONFIG_PROC_FS */
2031 /*====================================================================*/
2034 static struct backing_dev_info
* __init
mtd_bdi_init(char *name
)
2036 struct backing_dev_info
*bdi
;
2039 bdi
= bdi_alloc(NUMA_NO_NODE
);
2041 return ERR_PTR(-ENOMEM
);
2044 * We put '-0' suffix to the name to get the same name format as we
2045 * used to get. Since this is called only once, we get a unique name.
2047 ret
= bdi_register(bdi
, "%.28s-0", name
);
2051 return ret
? ERR_PTR(ret
) : bdi
;
2054 static struct proc_dir_entry
*proc_mtd
;
2056 static int __init
init_mtd(void)
2060 ret
= class_register(&mtd_class
);
2064 mtd_bdi
= mtd_bdi_init("mtd");
2065 if (IS_ERR(mtd_bdi
)) {
2066 ret
= PTR_ERR(mtd_bdi
);
2070 proc_mtd
= proc_create_single("mtd", 0, NULL
, mtd_proc_show
);
2072 ret
= init_mtdchar();
2076 dfs_dir_mtd
= debugfs_create_dir("mtd", NULL
);
2082 remove_proc_entry("mtd", NULL
);
2085 class_unregister(&mtd_class
);
2087 pr_err("Error registering mtd class or bdi: %d\n", ret
);
2091 static void __exit
cleanup_mtd(void)
2093 debugfs_remove_recursive(dfs_dir_mtd
);
2096 remove_proc_entry("mtd", NULL
);
2097 class_unregister(&mtd_class
);
2099 idr_destroy(&mtd_idr
);
2102 module_init(init_mtd
);
2103 module_exit(cleanup_mtd
);
2105 MODULE_LICENSE("GPL");
2106 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2107 MODULE_DESCRIPTION("Core MTD registration and access routines");