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Merge tag 'mm-hotfixes-stable-2025-07-11-16-16' of git://git.kernel.org/pub/scm/linux...
[linux-block.git] / drivers / mtd / mtdcore.c
... / ...
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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Core registration and callback routines for MTD
4 * drivers and users.
5 *
6 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
7 * Copyright © 2006 Red Hat UK Limited
8 */
9
10#include <linux/module.h>
11#include <linux/kernel.h>
12#include <linux/ptrace.h>
13#include <linux/seq_file.h>
14#include <linux/string.h>
15#include <linux/timer.h>
16#include <linux/major.h>
17#include <linux/fs.h>
18#include <linux/err.h>
19#include <linux/ioctl.h>
20#include <linux/init.h>
21#include <linux/of.h>
22#include <linux/proc_fs.h>
23#include <linux/idr.h>
24#include <linux/backing-dev.h>
25#include <linux/gfp.h>
26#include <linux/random.h>
27#include <linux/slab.h>
28#include <linux/reboot.h>
29#include <linux/leds.h>
30#include <linux/debugfs.h>
31#include <linux/nvmem-provider.h>
32#include <linux/root_dev.h>
33#include <linux/error-injection.h>
34
35#include <linux/mtd/mtd.h>
36#include <linux/mtd/partitions.h>
37
38#include "mtdcore.h"
39
40struct backing_dev_info *mtd_bdi;
41
42#ifdef CONFIG_PM_SLEEP
43
44static int mtd_cls_suspend(struct device *dev)
45{
46 struct mtd_info *mtd = dev_get_drvdata(dev);
47
48 return mtd ? mtd_suspend(mtd) : 0;
49}
50
51static int mtd_cls_resume(struct device *dev)
52{
53 struct mtd_info *mtd = dev_get_drvdata(dev);
54
55 if (mtd)
56 mtd_resume(mtd);
57 return 0;
58}
59
60static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
61#define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
62#else
63#define MTD_CLS_PM_OPS NULL
64#endif
65
66static struct class mtd_class = {
67 .name = "mtd",
68 .pm = MTD_CLS_PM_OPS,
69};
70
71static DEFINE_IDR(mtd_idr);
72
73/* These are exported solely for the purpose of mtd_blkdevs.c. You
74 should not use them for _anything_ else */
75DEFINE_MUTEX(mtd_table_mutex);
76EXPORT_SYMBOL_GPL(mtd_table_mutex);
77
78struct mtd_info *__mtd_next_device(int i)
79{
80 return idr_get_next(&mtd_idr, &i);
81}
82EXPORT_SYMBOL_GPL(__mtd_next_device);
83
84static LIST_HEAD(mtd_notifiers);
85
86
87#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
88
89/* REVISIT once MTD uses the driver model better, whoever allocates
90 * the mtd_info will probably want to use the release() hook...
91 */
92static void mtd_release(struct device *dev)
93{
94 struct mtd_info *mtd = dev_get_drvdata(dev);
95 dev_t index = MTD_DEVT(mtd->index);
96
97 idr_remove(&mtd_idr, mtd->index);
98 of_node_put(mtd_get_of_node(mtd));
99
100 if (mtd_is_partition(mtd))
101 release_mtd_partition(mtd);
102
103 /* remove /dev/mtdXro node */
104 device_destroy(&mtd_class, index + 1);
105}
106
107static void mtd_device_release(struct kref *kref)
108{
109 struct mtd_info *mtd = container_of(kref, struct mtd_info, refcnt);
110 bool is_partition = mtd_is_partition(mtd);
111
112 debugfs_remove_recursive(mtd->dbg.dfs_dir);
113
114 /* Try to remove the NVMEM provider */
115 nvmem_unregister(mtd->nvmem);
116
117 device_unregister(&mtd->dev);
118
119 /*
120 * Clear dev so mtd can be safely re-registered later if desired.
121 * Should not be done for partition,
122 * as it was already destroyed in device_unregister().
123 */
124 if (!is_partition)
125 memset(&mtd->dev, 0, sizeof(mtd->dev));
126
127 module_put(THIS_MODULE);
128}
129
130#define MTD_DEVICE_ATTR_RO(name) \
131static DEVICE_ATTR(name, 0444, mtd_##name##_show, NULL)
132
133#define MTD_DEVICE_ATTR_RW(name) \
134static DEVICE_ATTR(name, 0644, mtd_##name##_show, mtd_##name##_store)
135
136static ssize_t mtd_type_show(struct device *dev,
137 struct device_attribute *attr, char *buf)
138{
139 struct mtd_info *mtd = dev_get_drvdata(dev);
140 char *type;
141
142 switch (mtd->type) {
143 case MTD_ABSENT:
144 type = "absent";
145 break;
146 case MTD_RAM:
147 type = "ram";
148 break;
149 case MTD_ROM:
150 type = "rom";
151 break;
152 case MTD_NORFLASH:
153 type = "nor";
154 break;
155 case MTD_NANDFLASH:
156 type = "nand";
157 break;
158 case MTD_DATAFLASH:
159 type = "dataflash";
160 break;
161 case MTD_UBIVOLUME:
162 type = "ubi";
163 break;
164 case MTD_MLCNANDFLASH:
165 type = "mlc-nand";
166 break;
167 default:
168 type = "unknown";
169 }
170
171 return sysfs_emit(buf, "%s\n", type);
172}
173MTD_DEVICE_ATTR_RO(type);
174
175static ssize_t mtd_flags_show(struct device *dev,
176 struct device_attribute *attr, char *buf)
177{
178 struct mtd_info *mtd = dev_get_drvdata(dev);
179
180 return sysfs_emit(buf, "0x%lx\n", (unsigned long)mtd->flags);
181}
182MTD_DEVICE_ATTR_RO(flags);
183
184static ssize_t mtd_size_show(struct device *dev,
185 struct device_attribute *attr, char *buf)
186{
187 struct mtd_info *mtd = dev_get_drvdata(dev);
188
189 return sysfs_emit(buf, "%llu\n", (unsigned long long)mtd->size);
190}
191MTD_DEVICE_ATTR_RO(size);
192
193static ssize_t mtd_erasesize_show(struct device *dev,
194 struct device_attribute *attr, char *buf)
195{
196 struct mtd_info *mtd = dev_get_drvdata(dev);
197
198 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->erasesize);
199}
200MTD_DEVICE_ATTR_RO(erasesize);
201
202static ssize_t mtd_writesize_show(struct device *dev,
203 struct device_attribute *attr, char *buf)
204{
205 struct mtd_info *mtd = dev_get_drvdata(dev);
206
207 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->writesize);
208}
209MTD_DEVICE_ATTR_RO(writesize);
210
211static ssize_t mtd_subpagesize_show(struct device *dev,
212 struct device_attribute *attr, char *buf)
213{
214 struct mtd_info *mtd = dev_get_drvdata(dev);
215 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
216
217 return sysfs_emit(buf, "%u\n", subpagesize);
218}
219MTD_DEVICE_ATTR_RO(subpagesize);
220
221static ssize_t mtd_oobsize_show(struct device *dev,
222 struct device_attribute *attr, char *buf)
223{
224 struct mtd_info *mtd = dev_get_drvdata(dev);
225
226 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->oobsize);
227}
228MTD_DEVICE_ATTR_RO(oobsize);
229
230static ssize_t mtd_oobavail_show(struct device *dev,
231 struct device_attribute *attr, char *buf)
232{
233 struct mtd_info *mtd = dev_get_drvdata(dev);
234
235 return sysfs_emit(buf, "%u\n", mtd->oobavail);
236}
237MTD_DEVICE_ATTR_RO(oobavail);
238
239static ssize_t mtd_numeraseregions_show(struct device *dev,
240 struct device_attribute *attr, char *buf)
241{
242 struct mtd_info *mtd = dev_get_drvdata(dev);
243
244 return sysfs_emit(buf, "%u\n", mtd->numeraseregions);
245}
246MTD_DEVICE_ATTR_RO(numeraseregions);
247
248static ssize_t mtd_name_show(struct device *dev,
249 struct device_attribute *attr, char *buf)
250{
251 struct mtd_info *mtd = dev_get_drvdata(dev);
252
253 return sysfs_emit(buf, "%s\n", mtd->name);
254}
255MTD_DEVICE_ATTR_RO(name);
256
257static ssize_t mtd_ecc_strength_show(struct device *dev,
258 struct device_attribute *attr, char *buf)
259{
260 struct mtd_info *mtd = dev_get_drvdata(dev);
261
262 return sysfs_emit(buf, "%u\n", mtd->ecc_strength);
263}
264MTD_DEVICE_ATTR_RO(ecc_strength);
265
266static ssize_t mtd_bitflip_threshold_show(struct device *dev,
267 struct device_attribute *attr,
268 char *buf)
269{
270 struct mtd_info *mtd = dev_get_drvdata(dev);
271
272 return sysfs_emit(buf, "%u\n", mtd->bitflip_threshold);
273}
274
275static ssize_t mtd_bitflip_threshold_store(struct device *dev,
276 struct device_attribute *attr,
277 const char *buf, size_t count)
278{
279 struct mtd_info *mtd = dev_get_drvdata(dev);
280 unsigned int bitflip_threshold;
281 int retval;
282
283 retval = kstrtouint(buf, 0, &bitflip_threshold);
284 if (retval)
285 return retval;
286
287 mtd->bitflip_threshold = bitflip_threshold;
288 return count;
289}
290MTD_DEVICE_ATTR_RW(bitflip_threshold);
291
292static ssize_t mtd_ecc_step_size_show(struct device *dev,
293 struct device_attribute *attr, char *buf)
294{
295 struct mtd_info *mtd = dev_get_drvdata(dev);
296
297 return sysfs_emit(buf, "%u\n", mtd->ecc_step_size);
298
299}
300MTD_DEVICE_ATTR_RO(ecc_step_size);
301
302static ssize_t mtd_corrected_bits_show(struct device *dev,
303 struct device_attribute *attr, char *buf)
304{
305 struct mtd_info *mtd = dev_get_drvdata(dev);
306 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
307
308 return sysfs_emit(buf, "%u\n", ecc_stats->corrected);
309}
310MTD_DEVICE_ATTR_RO(corrected_bits); /* ecc stats corrected */
311
312static ssize_t mtd_ecc_failures_show(struct device *dev,
313 struct device_attribute *attr, char *buf)
314{
315 struct mtd_info *mtd = dev_get_drvdata(dev);
316 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
317
318 return sysfs_emit(buf, "%u\n", ecc_stats->failed);
319}
320MTD_DEVICE_ATTR_RO(ecc_failures); /* ecc stats errors */
321
322static ssize_t mtd_bad_blocks_show(struct device *dev,
323 struct device_attribute *attr, char *buf)
324{
325 struct mtd_info *mtd = dev_get_drvdata(dev);
326 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
327
328 return sysfs_emit(buf, "%u\n", ecc_stats->badblocks);
329}
330MTD_DEVICE_ATTR_RO(bad_blocks);
331
332static ssize_t mtd_bbt_blocks_show(struct device *dev,
333 struct device_attribute *attr, char *buf)
334{
335 struct mtd_info *mtd = dev_get_drvdata(dev);
336 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
337
338 return sysfs_emit(buf, "%u\n", ecc_stats->bbtblocks);
339}
340MTD_DEVICE_ATTR_RO(bbt_blocks);
341
342static struct attribute *mtd_attrs[] = {
343 &dev_attr_type.attr,
344 &dev_attr_flags.attr,
345 &dev_attr_size.attr,
346 &dev_attr_erasesize.attr,
347 &dev_attr_writesize.attr,
348 &dev_attr_subpagesize.attr,
349 &dev_attr_oobsize.attr,
350 &dev_attr_oobavail.attr,
351 &dev_attr_numeraseregions.attr,
352 &dev_attr_name.attr,
353 &dev_attr_ecc_strength.attr,
354 &dev_attr_ecc_step_size.attr,
355 &dev_attr_corrected_bits.attr,
356 &dev_attr_ecc_failures.attr,
357 &dev_attr_bad_blocks.attr,
358 &dev_attr_bbt_blocks.attr,
359 &dev_attr_bitflip_threshold.attr,
360 NULL,
361};
362ATTRIBUTE_GROUPS(mtd);
363
364static const struct device_type mtd_devtype = {
365 .name = "mtd",
366 .groups = mtd_groups,
367 .release = mtd_release,
368};
369
370static bool mtd_expert_analysis_mode;
371
372#ifdef CONFIG_DEBUG_FS
373bool mtd_check_expert_analysis_mode(void)
374{
375 const char *mtd_expert_analysis_warning =
376 "Bad block checks have been entirely disabled.\n"
377 "This is only reserved for post-mortem forensics and debug purposes.\n"
378 "Never enable this mode if you do not know what you are doing!\n";
379
380 return WARN_ONCE(mtd_expert_analysis_mode, mtd_expert_analysis_warning);
381}
382EXPORT_SYMBOL_GPL(mtd_check_expert_analysis_mode);
383#endif
384
385static struct dentry *dfs_dir_mtd;
386
387static void mtd_debugfs_populate(struct mtd_info *mtd)
388{
389 struct device *dev = &mtd->dev;
390
391 if (IS_ERR_OR_NULL(dfs_dir_mtd))
392 return;
393
394 mtd->dbg.dfs_dir = debugfs_create_dir(dev_name(dev), dfs_dir_mtd);
395}
396
397#ifndef CONFIG_MMU
398unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
399{
400 switch (mtd->type) {
401 case MTD_RAM:
402 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
403 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
404 case MTD_ROM:
405 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
406 NOMMU_MAP_READ;
407 default:
408 return NOMMU_MAP_COPY;
409 }
410}
411EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
412#endif
413
414static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
415 void *cmd)
416{
417 struct mtd_info *mtd;
418
419 mtd = container_of(n, struct mtd_info, reboot_notifier);
420 mtd->_reboot(mtd);
421
422 return NOTIFY_DONE;
423}
424
425/**
426 * mtd_wunit_to_pairing_info - get pairing information of a wunit
427 * @mtd: pointer to new MTD device info structure
428 * @wunit: write unit we are interested in
429 * @info: returned pairing information
430 *
431 * Retrieve pairing information associated to the wunit.
432 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
433 * paired together, and where programming a page may influence the page it is
434 * paired with.
435 * The notion of page is replaced by the term wunit (write-unit) to stay
436 * consistent with the ->writesize field.
437 *
438 * The @wunit argument can be extracted from an absolute offset using
439 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
440 * to @wunit.
441 *
442 * From the pairing info the MTD user can find all the wunits paired with
443 * @wunit using the following loop:
444 *
445 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
446 * info.pair = i;
447 * mtd_pairing_info_to_wunit(mtd, &info);
448 * ...
449 * }
450 */
451int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
452 struct mtd_pairing_info *info)
453{
454 struct mtd_info *master = mtd_get_master(mtd);
455 int npairs = mtd_wunit_per_eb(master) / mtd_pairing_groups(master);
456
457 if (wunit < 0 || wunit >= npairs)
458 return -EINVAL;
459
460 if (master->pairing && master->pairing->get_info)
461 return master->pairing->get_info(master, wunit, info);
462
463 info->group = 0;
464 info->pair = wunit;
465
466 return 0;
467}
468EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
469
470/**
471 * mtd_pairing_info_to_wunit - get wunit from pairing information
472 * @mtd: pointer to new MTD device info structure
473 * @info: pairing information struct
474 *
475 * Returns a positive number representing the wunit associated to the info
476 * struct, or a negative error code.
477 *
478 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
479 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
480 * doc).
481 *
482 * It can also be used to only program the first page of each pair (i.e.
483 * page attached to group 0), which allows one to use an MLC NAND in
484 * software-emulated SLC mode:
485 *
486 * info.group = 0;
487 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
488 * for (info.pair = 0; info.pair < npairs; info.pair++) {
489 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
490 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
491 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
492 * }
493 */
494int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
495 const struct mtd_pairing_info *info)
496{
497 struct mtd_info *master = mtd_get_master(mtd);
498 int ngroups = mtd_pairing_groups(master);
499 int npairs = mtd_wunit_per_eb(master) / ngroups;
500
501 if (!info || info->pair < 0 || info->pair >= npairs ||
502 info->group < 0 || info->group >= ngroups)
503 return -EINVAL;
504
505 if (master->pairing && master->pairing->get_wunit)
506 return mtd->pairing->get_wunit(master, info);
507
508 return info->pair;
509}
510EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
511
512/**
513 * mtd_pairing_groups - get the number of pairing groups
514 * @mtd: pointer to new MTD device info structure
515 *
516 * Returns the number of pairing groups.
517 *
518 * This number is usually equal to the number of bits exposed by a single
519 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
520 * to iterate over all pages of a given pair.
521 */
522int mtd_pairing_groups(struct mtd_info *mtd)
523{
524 struct mtd_info *master = mtd_get_master(mtd);
525
526 if (!master->pairing || !master->pairing->ngroups)
527 return 1;
528
529 return master->pairing->ngroups;
530}
531EXPORT_SYMBOL_GPL(mtd_pairing_groups);
532
533static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
534 void *val, size_t bytes)
535{
536 struct mtd_info *mtd = priv;
537 size_t retlen;
538 int err;
539
540 err = mtd_read(mtd, offset, bytes, &retlen, val);
541 if (err && err != -EUCLEAN)
542 return err;
543
544 return retlen == bytes ? 0 : -EIO;
545}
546
547static int mtd_nvmem_add(struct mtd_info *mtd)
548{
549 struct device_node *node = mtd_get_of_node(mtd);
550 struct nvmem_config config = {};
551
552 config.id = NVMEM_DEVID_NONE;
553 config.dev = &mtd->dev;
554 config.name = dev_name(&mtd->dev);
555 config.owner = THIS_MODULE;
556 config.add_legacy_fixed_of_cells = of_device_is_compatible(node, "nvmem-cells");
557 config.reg_read = mtd_nvmem_reg_read;
558 config.size = mtd->size;
559 config.word_size = 1;
560 config.stride = 1;
561 config.read_only = true;
562 config.root_only = true;
563 config.ignore_wp = true;
564 config.priv = mtd;
565
566 mtd->nvmem = nvmem_register(&config);
567 if (IS_ERR(mtd->nvmem)) {
568 /* Just ignore if there is no NVMEM support in the kernel */
569 if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP)
570 mtd->nvmem = NULL;
571 else
572 return dev_err_probe(&mtd->dev, PTR_ERR(mtd->nvmem),
573 "Failed to register NVMEM device\n");
574 }
575
576 return 0;
577}
578
579static void mtd_check_of_node(struct mtd_info *mtd)
580{
581 struct device_node *partitions, *parent_dn, *mtd_dn = NULL;
582 const char *pname, *prefix = "partition-";
583 int plen, mtd_name_len, offset, prefix_len;
584
585 /* Check if MTD already has a device node */
586 if (mtd_get_of_node(mtd))
587 return;
588
589 if (!mtd_is_partition(mtd))
590 return;
591
592 parent_dn = of_node_get(mtd_get_of_node(mtd->parent));
593 if (!parent_dn)
594 return;
595
596 if (mtd_is_partition(mtd->parent))
597 partitions = of_node_get(parent_dn);
598 else
599 partitions = of_get_child_by_name(parent_dn, "partitions");
600 if (!partitions)
601 goto exit_parent;
602
603 prefix_len = strlen(prefix);
604 mtd_name_len = strlen(mtd->name);
605
606 /* Search if a partition is defined with the same name */
607 for_each_child_of_node(partitions, mtd_dn) {
608 /* Skip partition with no/wrong prefix */
609 if (!of_node_name_prefix(mtd_dn, prefix))
610 continue;
611
612 /* Label have priority. Check that first */
613 if (!of_property_read_string(mtd_dn, "label", &pname)) {
614 offset = 0;
615 } else {
616 pname = mtd_dn->name;
617 offset = prefix_len;
618 }
619
620 plen = strlen(pname) - offset;
621 if (plen == mtd_name_len &&
622 !strncmp(mtd->name, pname + offset, plen)) {
623 mtd_set_of_node(mtd, mtd_dn);
624 of_node_put(mtd_dn);
625 break;
626 }
627 }
628
629 of_node_put(partitions);
630exit_parent:
631 of_node_put(parent_dn);
632}
633
634/**
635 * add_mtd_device - register an MTD device
636 * @mtd: pointer to new MTD device info structure
637 *
638 * Add a device to the list of MTD devices present in the system, and
639 * notify each currently active MTD 'user' of its arrival. Returns
640 * zero on success or non-zero on failure.
641 */
642
643int add_mtd_device(struct mtd_info *mtd)
644{
645 struct device_node *np = mtd_get_of_node(mtd);
646 struct mtd_info *master = mtd_get_master(mtd);
647 struct mtd_notifier *not;
648 int i, error, ofidx;
649
650 /*
651 * May occur, for instance, on buggy drivers which call
652 * mtd_device_parse_register() multiple times on the same master MTD,
653 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
654 */
655 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
656 return -EEXIST;
657
658 BUG_ON(mtd->writesize == 0);
659
660 /*
661 * MTD drivers should implement ->_{write,read}() or
662 * ->_{write,read}_oob(), but not both.
663 */
664 if (WARN_ON((mtd->_write && mtd->_write_oob) ||
665 (mtd->_read && mtd->_read_oob)))
666 return -EINVAL;
667
668 if (WARN_ON((!mtd->erasesize || !master->_erase) &&
669 !(mtd->flags & MTD_NO_ERASE)))
670 return -EINVAL;
671
672 /*
673 * MTD_SLC_ON_MLC_EMULATION can only be set on partitions, when the
674 * master is an MLC NAND and has a proper pairing scheme defined.
675 * We also reject masters that implement ->_writev() for now, because
676 * NAND controller drivers don't implement this hook, and adding the
677 * SLC -> MLC address/length conversion to this path is useless if we
678 * don't have a user.
679 */
680 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION &&
681 (!mtd_is_partition(mtd) || master->type != MTD_MLCNANDFLASH ||
682 !master->pairing || master->_writev))
683 return -EINVAL;
684
685 mutex_lock(&mtd_table_mutex);
686
687 ofidx = -1;
688 if (np)
689 ofidx = of_alias_get_id(np, "mtd");
690 if (ofidx >= 0)
691 i = idr_alloc(&mtd_idr, mtd, ofidx, ofidx + 1, GFP_KERNEL);
692 else
693 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
694 if (i < 0) {
695 error = i;
696 goto fail_locked;
697 }
698
699 mtd->index = i;
700 kref_init(&mtd->refcnt);
701
702 /* default value if not set by driver */
703 if (mtd->bitflip_threshold == 0)
704 mtd->bitflip_threshold = mtd->ecc_strength;
705
706 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
707 int ngroups = mtd_pairing_groups(master);
708
709 mtd->erasesize /= ngroups;
710 mtd->size = (u64)mtd_div_by_eb(mtd->size, master) *
711 mtd->erasesize;
712 }
713
714 if (is_power_of_2(mtd->erasesize))
715 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
716 else
717 mtd->erasesize_shift = 0;
718
719 if (is_power_of_2(mtd->writesize))
720 mtd->writesize_shift = ffs(mtd->writesize) - 1;
721 else
722 mtd->writesize_shift = 0;
723
724 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
725 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
726
727 /* Some chips always power up locked. Unlock them now */
728 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
729 error = mtd_unlock(mtd, 0, mtd->size);
730 if (error && error != -EOPNOTSUPP)
731 printk(KERN_WARNING
732 "%s: unlock failed, writes may not work\n",
733 mtd->name);
734 /* Ignore unlock failures? */
735 error = 0;
736 }
737
738 /* Caller should have set dev.parent to match the
739 * physical device, if appropriate.
740 */
741 mtd->dev.type = &mtd_devtype;
742 mtd->dev.class = &mtd_class;
743 mtd->dev.devt = MTD_DEVT(i);
744 error = dev_set_name(&mtd->dev, "mtd%d", i);
745 if (error)
746 goto fail_devname;
747 dev_set_drvdata(&mtd->dev, mtd);
748 mtd_check_of_node(mtd);
749 of_node_get(mtd_get_of_node(mtd));
750 error = device_register(&mtd->dev);
751 if (error) {
752 put_device(&mtd->dev);
753 goto fail_added;
754 }
755
756 /* Add the nvmem provider */
757 error = mtd_nvmem_add(mtd);
758 if (error)
759 goto fail_nvmem_add;
760
761 mtd_debugfs_populate(mtd);
762
763 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
764 "mtd%dro", i);
765
766 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
767 /* No need to get a refcount on the module containing
768 the notifier, since we hold the mtd_table_mutex */
769 list_for_each_entry(not, &mtd_notifiers, list)
770 not->add(mtd);
771
772 mutex_unlock(&mtd_table_mutex);
773
774 if (of_property_read_bool(mtd_get_of_node(mtd), "linux,rootfs")) {
775 if (IS_BUILTIN(CONFIG_MTD)) {
776 pr_info("mtd: setting mtd%d (%s) as root device\n", mtd->index, mtd->name);
777 ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
778 } else {
779 pr_warn("mtd: can't set mtd%d (%s) as root device - mtd must be builtin\n",
780 mtd->index, mtd->name);
781 }
782 }
783
784 /* We _know_ we aren't being removed, because
785 our caller is still holding us here. So none
786 of this try_ nonsense, and no bitching about it
787 either. :) */
788 __module_get(THIS_MODULE);
789 return 0;
790
791fail_nvmem_add:
792 device_unregister(&mtd->dev);
793fail_added:
794 of_node_put(mtd_get_of_node(mtd));
795fail_devname:
796 idr_remove(&mtd_idr, i);
797fail_locked:
798 mutex_unlock(&mtd_table_mutex);
799 return error;
800}
801
802/**
803 * del_mtd_device - unregister an MTD device
804 * @mtd: pointer to MTD device info structure
805 *
806 * Remove a device from the list of MTD devices present in the system,
807 * and notify each currently active MTD 'user' of its departure.
808 * Returns zero on success or 1 on failure, which currently will happen
809 * if the requested device does not appear to be present in the list.
810 */
811
812int del_mtd_device(struct mtd_info *mtd)
813{
814 int ret;
815 struct mtd_notifier *not;
816
817 mutex_lock(&mtd_table_mutex);
818
819 if (idr_find(&mtd_idr, mtd->index) != mtd) {
820 ret = -ENODEV;
821 goto out_error;
822 }
823
824 /* No need to get a refcount on the module containing
825 the notifier, since we hold the mtd_table_mutex */
826 list_for_each_entry(not, &mtd_notifiers, list)
827 not->remove(mtd);
828
829 kref_put(&mtd->refcnt, mtd_device_release);
830 ret = 0;
831
832out_error:
833 mutex_unlock(&mtd_table_mutex);
834 return ret;
835}
836
837/*
838 * Set a few defaults based on the parent devices, if not provided by the
839 * driver
840 */
841static void mtd_set_dev_defaults(struct mtd_info *mtd)
842{
843 if (mtd->dev.parent) {
844 if (!mtd->owner && mtd->dev.parent->driver)
845 mtd->owner = mtd->dev.parent->driver->owner;
846 if (!mtd->name)
847 mtd->name = dev_name(mtd->dev.parent);
848 } else {
849 pr_debug("mtd device won't show a device symlink in sysfs\n");
850 }
851
852 INIT_LIST_HEAD(&mtd->partitions);
853 mutex_init(&mtd->master.partitions_lock);
854 mutex_init(&mtd->master.chrdev_lock);
855}
856
857static ssize_t mtd_otp_size(struct mtd_info *mtd, bool is_user)
858{
859 struct otp_info *info;
860 ssize_t size = 0;
861 unsigned int i;
862 size_t retlen;
863 int ret;
864
865 info = kmalloc(PAGE_SIZE, GFP_KERNEL);
866 if (!info)
867 return -ENOMEM;
868
869 if (is_user)
870 ret = mtd_get_user_prot_info(mtd, PAGE_SIZE, &retlen, info);
871 else
872 ret = mtd_get_fact_prot_info(mtd, PAGE_SIZE, &retlen, info);
873 if (ret)
874 goto err;
875
876 for (i = 0; i < retlen / sizeof(*info); i++)
877 size += info[i].length;
878
879 kfree(info);
880 return size;
881
882err:
883 kfree(info);
884
885 /* ENODATA means there is no OTP region. */
886 return ret == -ENODATA ? 0 : ret;
887}
888
889static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd,
890 const char *compatible,
891 int size,
892 nvmem_reg_read_t reg_read)
893{
894 struct nvmem_device *nvmem = NULL;
895 struct nvmem_config config = {};
896 struct device_node *np;
897
898 /* DT binding is optional */
899 np = of_get_compatible_child(mtd->dev.of_node, compatible);
900
901 /* OTP nvmem will be registered on the physical device */
902 config.dev = mtd->dev.parent;
903 config.name = compatible;
904 config.id = NVMEM_DEVID_AUTO;
905 config.owner = THIS_MODULE;
906 config.add_legacy_fixed_of_cells = !mtd_type_is_nand(mtd);
907 config.type = NVMEM_TYPE_OTP;
908 config.root_only = true;
909 config.ignore_wp = true;
910 config.reg_read = reg_read;
911 config.size = size;
912 config.of_node = np;
913 config.priv = mtd;
914
915 nvmem = nvmem_register(&config);
916 /* Just ignore if there is no NVMEM support in the kernel */
917 if (IS_ERR(nvmem) && PTR_ERR(nvmem) == -EOPNOTSUPP)
918 nvmem = NULL;
919
920 of_node_put(np);
921
922 return nvmem;
923}
924
925static int mtd_nvmem_user_otp_reg_read(void *priv, unsigned int offset,
926 void *val, size_t bytes)
927{
928 struct mtd_info *mtd = priv;
929 size_t retlen;
930 int ret;
931
932 ret = mtd_read_user_prot_reg(mtd, offset, bytes, &retlen, val);
933 if (ret)
934 return ret;
935
936 return retlen == bytes ? 0 : -EIO;
937}
938
939static int mtd_nvmem_fact_otp_reg_read(void *priv, unsigned int offset,
940 void *val, size_t bytes)
941{
942 struct mtd_info *mtd = priv;
943 size_t retlen;
944 int ret;
945
946 ret = mtd_read_fact_prot_reg(mtd, offset, bytes, &retlen, val);
947 if (ret)
948 return ret;
949
950 return retlen == bytes ? 0 : -EIO;
951}
952
953static int mtd_otp_nvmem_add(struct mtd_info *mtd)
954{
955 struct device *dev = mtd->dev.parent;
956 struct nvmem_device *nvmem;
957 ssize_t size;
958 int err;
959
960 if (mtd->_get_user_prot_info && mtd->_read_user_prot_reg) {
961 size = mtd_otp_size(mtd, true);
962 if (size < 0) {
963 err = size;
964 goto err;
965 }
966
967 if (size > 0) {
968 nvmem = mtd_otp_nvmem_register(mtd, "user-otp", size,
969 mtd_nvmem_user_otp_reg_read);
970 if (IS_ERR(nvmem)) {
971 err = PTR_ERR(nvmem);
972 goto err;
973 }
974 mtd->otp_user_nvmem = nvmem;
975 }
976 }
977
978 if (mtd->_get_fact_prot_info && mtd->_read_fact_prot_reg) {
979 size = mtd_otp_size(mtd, false);
980 if (size < 0) {
981 err = size;
982 goto err;
983 }
984
985 if (size > 0) {
986 /*
987 * The factory OTP contains thing such as a unique serial
988 * number and is small, so let's read it out and put it
989 * into the entropy pool.
990 */
991 void *otp;
992
993 otp = kmalloc(size, GFP_KERNEL);
994 if (!otp) {
995 err = -ENOMEM;
996 goto err;
997 }
998 err = mtd_nvmem_fact_otp_reg_read(mtd, 0, otp, size);
999 if (err < 0) {
1000 kfree(otp);
1001 goto err;
1002 }
1003 add_device_randomness(otp, err);
1004 kfree(otp);
1005
1006 nvmem = mtd_otp_nvmem_register(mtd, "factory-otp", size,
1007 mtd_nvmem_fact_otp_reg_read);
1008 if (IS_ERR(nvmem)) {
1009 err = PTR_ERR(nvmem);
1010 goto err;
1011 }
1012 mtd->otp_factory_nvmem = nvmem;
1013 }
1014 }
1015
1016 return 0;
1017
1018err:
1019 nvmem_unregister(mtd->otp_user_nvmem);
1020 /* Don't report error if OTP is not supported. */
1021 if (err == -EOPNOTSUPP)
1022 return 0;
1023 return dev_err_probe(dev, err, "Failed to register OTP NVMEM device\n");
1024}
1025
1026/**
1027 * mtd_device_parse_register - parse partitions and register an MTD device.
1028 *
1029 * @mtd: the MTD device to register
1030 * @types: the list of MTD partition probes to try, see
1031 * 'parse_mtd_partitions()' for more information
1032 * @parser_data: MTD partition parser-specific data
1033 * @parts: fallback partition information to register, if parsing fails;
1034 * only valid if %nr_parts > %0
1035 * @nr_parts: the number of partitions in parts, if zero then the full
1036 * MTD device is registered if no partition info is found
1037 *
1038 * This function aggregates MTD partitions parsing (done by
1039 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
1040 * basically follows the most common pattern found in many MTD drivers:
1041 *
1042 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
1043 * registered first.
1044 * * Then It tries to probe partitions on MTD device @mtd using parsers
1045 * specified in @types (if @types is %NULL, then the default list of parsers
1046 * is used, see 'parse_mtd_partitions()' for more information). If none are
1047 * found this functions tries to fallback to information specified in
1048 * @parts/@nr_parts.
1049 * * If no partitions were found this function just registers the MTD device
1050 * @mtd and exits.
1051 *
1052 * Returns zero in case of success and a negative error code in case of failure.
1053 */
1054int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
1055 struct mtd_part_parser_data *parser_data,
1056 const struct mtd_partition *parts,
1057 int nr_parts)
1058{
1059 int ret, err;
1060
1061 mtd_set_dev_defaults(mtd);
1062
1063 ret = mtd_otp_nvmem_add(mtd);
1064 if (ret)
1065 goto out;
1066
1067 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
1068 ret = add_mtd_device(mtd);
1069 if (ret)
1070 goto out;
1071 }
1072
1073 /* Prefer parsed partitions over driver-provided fallback */
1074 ret = parse_mtd_partitions(mtd, types, parser_data);
1075 if (ret == -EPROBE_DEFER)
1076 goto out;
1077
1078 if (ret > 0)
1079 ret = 0;
1080 else if (nr_parts)
1081 ret = add_mtd_partitions(mtd, parts, nr_parts);
1082 else if (!device_is_registered(&mtd->dev))
1083 ret = add_mtd_device(mtd);
1084 else
1085 ret = 0;
1086
1087 if (ret)
1088 goto out;
1089
1090 /*
1091 * FIXME: some drivers unfortunately call this function more than once.
1092 * So we have to check if we've already assigned the reboot notifier.
1093 *
1094 * Generally, we can make multiple calls work for most cases, but it
1095 * does cause problems with parse_mtd_partitions() above (e.g.,
1096 * cmdlineparts will register partitions more than once).
1097 */
1098 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
1099 "MTD already registered\n");
1100 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
1101 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
1102 register_reboot_notifier(&mtd->reboot_notifier);
1103 }
1104
1105out:
1106 if (ret) {
1107 nvmem_unregister(mtd->otp_user_nvmem);
1108 nvmem_unregister(mtd->otp_factory_nvmem);
1109 }
1110
1111 if (ret && device_is_registered(&mtd->dev)) {
1112 err = del_mtd_device(mtd);
1113 if (err)
1114 pr_err("Error when deleting MTD device (%d)\n", err);
1115 }
1116
1117 return ret;
1118}
1119EXPORT_SYMBOL_GPL(mtd_device_parse_register);
1120
1121/**
1122 * mtd_device_unregister - unregister an existing MTD device.
1123 *
1124 * @master: the MTD device to unregister. This will unregister both the master
1125 * and any partitions if registered.
1126 */
1127int mtd_device_unregister(struct mtd_info *master)
1128{
1129 int err;
1130
1131 if (master->_reboot) {
1132 unregister_reboot_notifier(&master->reboot_notifier);
1133 memset(&master->reboot_notifier, 0, sizeof(master->reboot_notifier));
1134 }
1135
1136 nvmem_unregister(master->otp_user_nvmem);
1137 nvmem_unregister(master->otp_factory_nvmem);
1138
1139 err = del_mtd_partitions(master);
1140 if (err)
1141 return err;
1142
1143 if (!device_is_registered(&master->dev))
1144 return 0;
1145
1146 return del_mtd_device(master);
1147}
1148EXPORT_SYMBOL_GPL(mtd_device_unregister);
1149
1150/**
1151 * register_mtd_user - register a 'user' of MTD devices.
1152 * @new: pointer to notifier info structure
1153 *
1154 * Registers a pair of callbacks function to be called upon addition
1155 * or removal of MTD devices. Causes the 'add' callback to be immediately
1156 * invoked for each MTD device currently present in the system.
1157 */
1158void register_mtd_user (struct mtd_notifier *new)
1159{
1160 struct mtd_info *mtd;
1161
1162 mutex_lock(&mtd_table_mutex);
1163
1164 list_add(&new->list, &mtd_notifiers);
1165
1166 __module_get(THIS_MODULE);
1167
1168 mtd_for_each_device(mtd)
1169 new->add(mtd);
1170
1171 mutex_unlock(&mtd_table_mutex);
1172}
1173EXPORT_SYMBOL_GPL(register_mtd_user);
1174
1175/**
1176 * unregister_mtd_user - unregister a 'user' of MTD devices.
1177 * @old: pointer to notifier info structure
1178 *
1179 * Removes a callback function pair from the list of 'users' to be
1180 * notified upon addition or removal of MTD devices. Causes the
1181 * 'remove' callback to be immediately invoked for each MTD device
1182 * currently present in the system.
1183 */
1184int unregister_mtd_user (struct mtd_notifier *old)
1185{
1186 struct mtd_info *mtd;
1187
1188 mutex_lock(&mtd_table_mutex);
1189
1190 module_put(THIS_MODULE);
1191
1192 mtd_for_each_device(mtd)
1193 old->remove(mtd);
1194
1195 list_del(&old->list);
1196 mutex_unlock(&mtd_table_mutex);
1197 return 0;
1198}
1199EXPORT_SYMBOL_GPL(unregister_mtd_user);
1200
1201/**
1202 * get_mtd_device - obtain a validated handle for an MTD device
1203 * @mtd: last known address of the required MTD device
1204 * @num: internal device number of the required MTD device
1205 *
1206 * Given a number and NULL address, return the num'th entry in the device
1207 * table, if any. Given an address and num == -1, search the device table
1208 * for a device with that address and return if it's still present. Given
1209 * both, return the num'th driver only if its address matches. Return
1210 * error code if not.
1211 */
1212struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
1213{
1214 struct mtd_info *ret = NULL, *other;
1215 int err = -ENODEV;
1216
1217 mutex_lock(&mtd_table_mutex);
1218
1219 if (num == -1) {
1220 mtd_for_each_device(other) {
1221 if (other == mtd) {
1222 ret = mtd;
1223 break;
1224 }
1225 }
1226 } else if (num >= 0) {
1227 ret = idr_find(&mtd_idr, num);
1228 if (mtd && mtd != ret)
1229 ret = NULL;
1230 }
1231
1232 if (!ret) {
1233 ret = ERR_PTR(err);
1234 goto out;
1235 }
1236
1237 err = __get_mtd_device(ret);
1238 if (err)
1239 ret = ERR_PTR(err);
1240out:
1241 mutex_unlock(&mtd_table_mutex);
1242 return ret;
1243}
1244EXPORT_SYMBOL_GPL(get_mtd_device);
1245
1246
1247int __get_mtd_device(struct mtd_info *mtd)
1248{
1249 struct mtd_info *master = mtd_get_master(mtd);
1250 int err;
1251
1252 if (master->_get_device) {
1253 err = master->_get_device(mtd);
1254 if (err)
1255 return err;
1256 }
1257
1258 if (!try_module_get(master->owner)) {
1259 if (master->_put_device)
1260 master->_put_device(master);
1261 return -ENODEV;
1262 }
1263
1264 while (mtd) {
1265 if (mtd != master)
1266 kref_get(&mtd->refcnt);
1267 mtd = mtd->parent;
1268 }
1269
1270 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
1271 kref_get(&master->refcnt);
1272
1273 return 0;
1274}
1275EXPORT_SYMBOL_GPL(__get_mtd_device);
1276
1277/**
1278 * of_get_mtd_device_by_node - obtain an MTD device associated with a given node
1279 *
1280 * @np: device tree node
1281 */
1282struct mtd_info *of_get_mtd_device_by_node(struct device_node *np)
1283{
1284 struct mtd_info *mtd = NULL;
1285 struct mtd_info *tmp;
1286 int err;
1287
1288 mutex_lock(&mtd_table_mutex);
1289
1290 err = -EPROBE_DEFER;
1291 mtd_for_each_device(tmp) {
1292 if (mtd_get_of_node(tmp) == np) {
1293 mtd = tmp;
1294 err = __get_mtd_device(mtd);
1295 break;
1296 }
1297 }
1298
1299 mutex_unlock(&mtd_table_mutex);
1300
1301 return err ? ERR_PTR(err) : mtd;
1302}
1303EXPORT_SYMBOL_GPL(of_get_mtd_device_by_node);
1304
1305/**
1306 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1307 * device name
1308 * @name: MTD device name to open
1309 *
1310 * This function returns MTD device description structure in case of
1311 * success and an error code in case of failure.
1312 */
1313struct mtd_info *get_mtd_device_nm(const char *name)
1314{
1315 int err = -ENODEV;
1316 struct mtd_info *mtd = NULL, *other;
1317
1318 mutex_lock(&mtd_table_mutex);
1319
1320 mtd_for_each_device(other) {
1321 if (!strcmp(name, other->name)) {
1322 mtd = other;
1323 break;
1324 }
1325 }
1326
1327 if (!mtd)
1328 goto out_unlock;
1329
1330 err = __get_mtd_device(mtd);
1331 if (err)
1332 goto out_unlock;
1333
1334 mutex_unlock(&mtd_table_mutex);
1335 return mtd;
1336
1337out_unlock:
1338 mutex_unlock(&mtd_table_mutex);
1339 return ERR_PTR(err);
1340}
1341EXPORT_SYMBOL_GPL(get_mtd_device_nm);
1342
1343void put_mtd_device(struct mtd_info *mtd)
1344{
1345 mutex_lock(&mtd_table_mutex);
1346 __put_mtd_device(mtd);
1347 mutex_unlock(&mtd_table_mutex);
1348
1349}
1350EXPORT_SYMBOL_GPL(put_mtd_device);
1351
1352void __put_mtd_device(struct mtd_info *mtd)
1353{
1354 struct mtd_info *master = mtd_get_master(mtd);
1355
1356 while (mtd) {
1357 /* kref_put() can relese mtd, so keep a reference mtd->parent */
1358 struct mtd_info *parent = mtd->parent;
1359
1360 if (mtd != master)
1361 kref_put(&mtd->refcnt, mtd_device_release);
1362 mtd = parent;
1363 }
1364
1365 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
1366 kref_put(&master->refcnt, mtd_device_release);
1367
1368 module_put(master->owner);
1369
1370 /* must be the last as master can be freed in the _put_device */
1371 if (master->_put_device)
1372 master->_put_device(master);
1373}
1374EXPORT_SYMBOL_GPL(__put_mtd_device);
1375
1376/*
1377 * Erase is an synchronous operation. Device drivers are epected to return a
1378 * negative error code if the operation failed and update instr->fail_addr
1379 * to point the portion that was not properly erased.
1380 */
1381int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1382{
1383 struct mtd_info *master = mtd_get_master(mtd);
1384 u64 mst_ofs = mtd_get_master_ofs(mtd, 0);
1385 struct erase_info adjinstr;
1386 int ret;
1387
1388 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1389 adjinstr = *instr;
1390
1391 if (!mtd->erasesize || !master->_erase)
1392 return -ENOTSUPP;
1393
1394 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1395 return -EINVAL;
1396 if (!(mtd->flags & MTD_WRITEABLE))
1397 return -EROFS;
1398
1399 if (!instr->len)
1400 return 0;
1401
1402 ledtrig_mtd_activity();
1403
1404 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1405 adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) *
1406 master->erasesize;
1407 adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) *
1408 master->erasesize) -
1409 adjinstr.addr;
1410 }
1411
1412 adjinstr.addr += mst_ofs;
1413
1414 ret = master->_erase(master, &adjinstr);
1415
1416 if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) {
1417 instr->fail_addr = adjinstr.fail_addr - mst_ofs;
1418 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1419 instr->fail_addr = mtd_div_by_eb(instr->fail_addr,
1420 master);
1421 instr->fail_addr *= mtd->erasesize;
1422 }
1423 }
1424
1425 return ret;
1426}
1427EXPORT_SYMBOL_GPL(mtd_erase);
1428ALLOW_ERROR_INJECTION(mtd_erase, ERRNO);
1429
1430/*
1431 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1432 */
1433int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1434 void **virt, resource_size_t *phys)
1435{
1436 struct mtd_info *master = mtd_get_master(mtd);
1437
1438 *retlen = 0;
1439 *virt = NULL;
1440 if (phys)
1441 *phys = 0;
1442 if (!master->_point)
1443 return -EOPNOTSUPP;
1444 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1445 return -EINVAL;
1446 if (!len)
1447 return 0;
1448
1449 from = mtd_get_master_ofs(mtd, from);
1450 return master->_point(master, from, len, retlen, virt, phys);
1451}
1452EXPORT_SYMBOL_GPL(mtd_point);
1453
1454/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1455int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1456{
1457 struct mtd_info *master = mtd_get_master(mtd);
1458
1459 if (!master->_unpoint)
1460 return -EOPNOTSUPP;
1461 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1462 return -EINVAL;
1463 if (!len)
1464 return 0;
1465 return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
1466}
1467EXPORT_SYMBOL_GPL(mtd_unpoint);
1468
1469/*
1470 * Allow NOMMU mmap() to directly map the device (if not NULL)
1471 * - return the address to which the offset maps
1472 * - return -ENOSYS to indicate refusal to do the mapping
1473 */
1474unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1475 unsigned long offset, unsigned long flags)
1476{
1477 size_t retlen;
1478 void *virt;
1479 int ret;
1480
1481 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1482 if (ret)
1483 return ret;
1484 if (retlen != len) {
1485 mtd_unpoint(mtd, offset, retlen);
1486 return -ENOSYS;
1487 }
1488 return (unsigned long)virt;
1489}
1490EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1491
1492static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
1493 const struct mtd_ecc_stats *old_stats)
1494{
1495 struct mtd_ecc_stats diff;
1496
1497 if (master == mtd)
1498 return;
1499
1500 diff = master->ecc_stats;
1501 diff.failed -= old_stats->failed;
1502 diff.corrected -= old_stats->corrected;
1503
1504 while (mtd->parent) {
1505 mtd->ecc_stats.failed += diff.failed;
1506 mtd->ecc_stats.corrected += diff.corrected;
1507 mtd = mtd->parent;
1508 }
1509}
1510
1511int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1512 u_char *buf)
1513{
1514 struct mtd_oob_ops ops = {
1515 .len = len,
1516 .datbuf = buf,
1517 };
1518 int ret;
1519
1520 ret = mtd_read_oob(mtd, from, &ops);
1521 *retlen = ops.retlen;
1522
1523 WARN_ON_ONCE(*retlen != len && mtd_is_bitflip_or_eccerr(ret));
1524
1525 return ret;
1526}
1527EXPORT_SYMBOL_GPL(mtd_read);
1528ALLOW_ERROR_INJECTION(mtd_read, ERRNO);
1529
1530int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1531 const u_char *buf)
1532{
1533 struct mtd_oob_ops ops = {
1534 .len = len,
1535 .datbuf = (u8 *)buf,
1536 };
1537 int ret;
1538
1539 ret = mtd_write_oob(mtd, to, &ops);
1540 *retlen = ops.retlen;
1541
1542 return ret;
1543}
1544EXPORT_SYMBOL_GPL(mtd_write);
1545ALLOW_ERROR_INJECTION(mtd_write, ERRNO);
1546
1547/*
1548 * In blackbox flight recorder like scenarios we want to make successful writes
1549 * in interrupt context. panic_write() is only intended to be called when its
1550 * known the kernel is about to panic and we need the write to succeed. Since
1551 * the kernel is not going to be running for much longer, this function can
1552 * break locks and delay to ensure the write succeeds (but not sleep).
1553 */
1554int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1555 const u_char *buf)
1556{
1557 struct mtd_info *master = mtd_get_master(mtd);
1558
1559 *retlen = 0;
1560 if (!master->_panic_write)
1561 return -EOPNOTSUPP;
1562 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1563 return -EINVAL;
1564 if (!(mtd->flags & MTD_WRITEABLE))
1565 return -EROFS;
1566 if (!len)
1567 return 0;
1568 if (!master->oops_panic_write)
1569 master->oops_panic_write = true;
1570
1571 return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
1572 retlen, buf);
1573}
1574EXPORT_SYMBOL_GPL(mtd_panic_write);
1575
1576static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1577 struct mtd_oob_ops *ops)
1578{
1579 /*
1580 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1581 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1582 * this case.
1583 */
1584 if (!ops->datbuf)
1585 ops->len = 0;
1586
1587 if (!ops->oobbuf)
1588 ops->ooblen = 0;
1589
1590 if (offs < 0 || offs + ops->len > mtd->size)
1591 return -EINVAL;
1592
1593 if (ops->ooblen) {
1594 size_t maxooblen;
1595
1596 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1597 return -EINVAL;
1598
1599 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1600 mtd_div_by_ws(offs, mtd)) *
1601 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1602 if (ops->ooblen > maxooblen)
1603 return -EINVAL;
1604 }
1605
1606 return 0;
1607}
1608
1609static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from,
1610 struct mtd_oob_ops *ops)
1611{
1612 struct mtd_info *master = mtd_get_master(mtd);
1613 int ret;
1614
1615 from = mtd_get_master_ofs(mtd, from);
1616 if (master->_read_oob)
1617 ret = master->_read_oob(master, from, ops);
1618 else
1619 ret = master->_read(master, from, ops->len, &ops->retlen,
1620 ops->datbuf);
1621
1622 return ret;
1623}
1624
1625static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to,
1626 struct mtd_oob_ops *ops)
1627{
1628 struct mtd_info *master = mtd_get_master(mtd);
1629 int ret;
1630
1631 to = mtd_get_master_ofs(mtd, to);
1632 if (master->_write_oob)
1633 ret = master->_write_oob(master, to, ops);
1634 else
1635 ret = master->_write(master, to, ops->len, &ops->retlen,
1636 ops->datbuf);
1637
1638 return ret;
1639}
1640
1641static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read,
1642 struct mtd_oob_ops *ops)
1643{
1644 struct mtd_info *master = mtd_get_master(mtd);
1645 int ngroups = mtd_pairing_groups(master);
1646 int npairs = mtd_wunit_per_eb(master) / ngroups;
1647 struct mtd_oob_ops adjops = *ops;
1648 unsigned int wunit, oobavail;
1649 struct mtd_pairing_info info;
1650 int max_bitflips = 0;
1651 u32 ebofs, pageofs;
1652 loff_t base, pos;
1653
1654 ebofs = mtd_mod_by_eb(start, mtd);
1655 base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize;
1656 info.group = 0;
1657 info.pair = mtd_div_by_ws(ebofs, mtd);
1658 pageofs = mtd_mod_by_ws(ebofs, mtd);
1659 oobavail = mtd_oobavail(mtd, ops);
1660
1661 while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) {
1662 int ret;
1663
1664 if (info.pair >= npairs) {
1665 info.pair = 0;
1666 base += master->erasesize;
1667 }
1668
1669 wunit = mtd_pairing_info_to_wunit(master, &info);
1670 pos = mtd_wunit_to_offset(mtd, base, wunit);
1671
1672 adjops.len = ops->len - ops->retlen;
1673 if (adjops.len > mtd->writesize - pageofs)
1674 adjops.len = mtd->writesize - pageofs;
1675
1676 adjops.ooblen = ops->ooblen - ops->oobretlen;
1677 if (adjops.ooblen > oobavail - adjops.ooboffs)
1678 adjops.ooblen = oobavail - adjops.ooboffs;
1679
1680 if (read) {
1681 ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops);
1682 if (ret > 0)
1683 max_bitflips = max(max_bitflips, ret);
1684 } else {
1685 ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops);
1686 }
1687
1688 if (ret < 0)
1689 return ret;
1690
1691 max_bitflips = max(max_bitflips, ret);
1692 ops->retlen += adjops.retlen;
1693 ops->oobretlen += adjops.oobretlen;
1694 adjops.datbuf += adjops.retlen;
1695 adjops.oobbuf += adjops.oobretlen;
1696 adjops.ooboffs = 0;
1697 pageofs = 0;
1698 info.pair++;
1699 }
1700
1701 return max_bitflips;
1702}
1703
1704int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1705{
1706 struct mtd_info *master = mtd_get_master(mtd);
1707 struct mtd_ecc_stats old_stats = master->ecc_stats;
1708 int ret_code;
1709
1710 ops->retlen = ops->oobretlen = 0;
1711
1712 ret_code = mtd_check_oob_ops(mtd, from, ops);
1713 if (ret_code)
1714 return ret_code;
1715
1716 ledtrig_mtd_activity();
1717
1718 /* Check the validity of a potential fallback on mtd->_read */
1719 if (!master->_read_oob && (!master->_read || ops->oobbuf))
1720 return -EOPNOTSUPP;
1721
1722 if (ops->stats)
1723 memset(ops->stats, 0, sizeof(*ops->stats));
1724
1725 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1726 ret_code = mtd_io_emulated_slc(mtd, from, true, ops);
1727 else
1728 ret_code = mtd_read_oob_std(mtd, from, ops);
1729
1730 mtd_update_ecc_stats(mtd, master, &old_stats);
1731
1732 /*
1733 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1734 * similar to mtd->_read(), returning a non-negative integer
1735 * representing max bitflips. In other cases, mtd->_read_oob() may
1736 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1737 */
1738 if (unlikely(ret_code < 0))
1739 return ret_code;
1740 if (mtd->ecc_strength == 0)
1741 return 0; /* device lacks ecc */
1742 if (ops->stats)
1743 ops->stats->max_bitflips = ret_code;
1744 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1745}
1746EXPORT_SYMBOL_GPL(mtd_read_oob);
1747
1748int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1749 struct mtd_oob_ops *ops)
1750{
1751 struct mtd_info *master = mtd_get_master(mtd);
1752 int ret;
1753
1754 ops->retlen = ops->oobretlen = 0;
1755
1756 if (!(mtd->flags & MTD_WRITEABLE))
1757 return -EROFS;
1758
1759 ret = mtd_check_oob_ops(mtd, to, ops);
1760 if (ret)
1761 return ret;
1762
1763 ledtrig_mtd_activity();
1764
1765 /* Check the validity of a potential fallback on mtd->_write */
1766 if (!master->_write_oob && (!master->_write || ops->oobbuf))
1767 return -EOPNOTSUPP;
1768
1769 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1770 return mtd_io_emulated_slc(mtd, to, false, ops);
1771
1772 return mtd_write_oob_std(mtd, to, ops);
1773}
1774EXPORT_SYMBOL_GPL(mtd_write_oob);
1775
1776/**
1777 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1778 * @mtd: MTD device structure
1779 * @section: ECC section. Depending on the layout you may have all the ECC
1780 * bytes stored in a single contiguous section, or one section
1781 * per ECC chunk (and sometime several sections for a single ECC
1782 * ECC chunk)
1783 * @oobecc: OOB region struct filled with the appropriate ECC position
1784 * information
1785 *
1786 * This function returns ECC section information in the OOB area. If you want
1787 * to get all the ECC bytes information, then you should call
1788 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1789 *
1790 * Returns zero on success, a negative error code otherwise.
1791 */
1792int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1793 struct mtd_oob_region *oobecc)
1794{
1795 struct mtd_info *master = mtd_get_master(mtd);
1796
1797 memset(oobecc, 0, sizeof(*oobecc));
1798
1799 if (!master || section < 0)
1800 return -EINVAL;
1801
1802 if (!master->ooblayout || !master->ooblayout->ecc)
1803 return -ENOTSUPP;
1804
1805 return master->ooblayout->ecc(master, section, oobecc);
1806}
1807EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1808
1809/**
1810 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1811 * section
1812 * @mtd: MTD device structure
1813 * @section: Free section you are interested in. Depending on the layout
1814 * you may have all the free bytes stored in a single contiguous
1815 * section, or one section per ECC chunk plus an extra section
1816 * for the remaining bytes (or other funky layout).
1817 * @oobfree: OOB region struct filled with the appropriate free position
1818 * information
1819 *
1820 * This function returns free bytes position in the OOB area. If you want
1821 * to get all the free bytes information, then you should call
1822 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1823 *
1824 * Returns zero on success, a negative error code otherwise.
1825 */
1826int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1827 struct mtd_oob_region *oobfree)
1828{
1829 struct mtd_info *master = mtd_get_master(mtd);
1830
1831 memset(oobfree, 0, sizeof(*oobfree));
1832
1833 if (!master || section < 0)
1834 return -EINVAL;
1835
1836 if (!master->ooblayout || !master->ooblayout->free)
1837 return -ENOTSUPP;
1838
1839 return master->ooblayout->free(master, section, oobfree);
1840}
1841EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1842
1843/**
1844 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1845 * @mtd: mtd info structure
1846 * @byte: the byte we are searching for
1847 * @sectionp: pointer where the section id will be stored
1848 * @oobregion: used to retrieve the ECC position
1849 * @iter: iterator function. Should be either mtd_ooblayout_free or
1850 * mtd_ooblayout_ecc depending on the region type you're searching for
1851 *
1852 * This function returns the section id and oobregion information of a
1853 * specific byte. For example, say you want to know where the 4th ECC byte is
1854 * stored, you'll use:
1855 *
1856 * mtd_ooblayout_find_region(mtd, 3, &section, &oobregion, mtd_ooblayout_ecc);
1857 *
1858 * Returns zero on success, a negative error code otherwise.
1859 */
1860static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1861 int *sectionp, struct mtd_oob_region *oobregion,
1862 int (*iter)(struct mtd_info *,
1863 int section,
1864 struct mtd_oob_region *oobregion))
1865{
1866 int pos = 0, ret, section = 0;
1867
1868 memset(oobregion, 0, sizeof(*oobregion));
1869
1870 while (1) {
1871 ret = iter(mtd, section, oobregion);
1872 if (ret)
1873 return ret;
1874
1875 if (pos + oobregion->length > byte)
1876 break;
1877
1878 pos += oobregion->length;
1879 section++;
1880 }
1881
1882 /*
1883 * Adjust region info to make it start at the beginning at the
1884 * 'start' ECC byte.
1885 */
1886 oobregion->offset += byte - pos;
1887 oobregion->length -= byte - pos;
1888 *sectionp = section;
1889
1890 return 0;
1891}
1892
1893/**
1894 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1895 * ECC byte
1896 * @mtd: mtd info structure
1897 * @eccbyte: the byte we are searching for
1898 * @section: pointer where the section id will be stored
1899 * @oobregion: OOB region information
1900 *
1901 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1902 * byte.
1903 *
1904 * Returns zero on success, a negative error code otherwise.
1905 */
1906int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1907 int *section,
1908 struct mtd_oob_region *oobregion)
1909{
1910 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1911 mtd_ooblayout_ecc);
1912}
1913EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1914
1915/**
1916 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1917 * @mtd: mtd info structure
1918 * @buf: destination buffer to store OOB bytes
1919 * @oobbuf: OOB buffer
1920 * @start: first byte to retrieve
1921 * @nbytes: number of bytes to retrieve
1922 * @iter: section iterator
1923 *
1924 * Extract bytes attached to a specific category (ECC or free)
1925 * from the OOB buffer and copy them into buf.
1926 *
1927 * Returns zero on success, a negative error code otherwise.
1928 */
1929static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1930 const u8 *oobbuf, int start, int nbytes,
1931 int (*iter)(struct mtd_info *,
1932 int section,
1933 struct mtd_oob_region *oobregion))
1934{
1935 struct mtd_oob_region oobregion;
1936 int section, ret;
1937
1938 ret = mtd_ooblayout_find_region(mtd, start, &section,
1939 &oobregion, iter);
1940
1941 while (!ret) {
1942 int cnt;
1943
1944 cnt = min_t(int, nbytes, oobregion.length);
1945 memcpy(buf, oobbuf + oobregion.offset, cnt);
1946 buf += cnt;
1947 nbytes -= cnt;
1948
1949 if (!nbytes)
1950 break;
1951
1952 ret = iter(mtd, ++section, &oobregion);
1953 }
1954
1955 return ret;
1956}
1957
1958/**
1959 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1960 * @mtd: mtd info structure
1961 * @buf: source buffer to get OOB bytes from
1962 * @oobbuf: OOB buffer
1963 * @start: first OOB byte to set
1964 * @nbytes: number of OOB bytes to set
1965 * @iter: section iterator
1966 *
1967 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1968 * is selected by passing the appropriate iterator.
1969 *
1970 * Returns zero on success, a negative error code otherwise.
1971 */
1972static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1973 u8 *oobbuf, int start, int nbytes,
1974 int (*iter)(struct mtd_info *,
1975 int section,
1976 struct mtd_oob_region *oobregion))
1977{
1978 struct mtd_oob_region oobregion;
1979 int section, ret;
1980
1981 ret = mtd_ooblayout_find_region(mtd, start, &section,
1982 &oobregion, iter);
1983
1984 while (!ret) {
1985 int cnt;
1986
1987 cnt = min_t(int, nbytes, oobregion.length);
1988 memcpy(oobbuf + oobregion.offset, buf, cnt);
1989 buf += cnt;
1990 nbytes -= cnt;
1991
1992 if (!nbytes)
1993 break;
1994
1995 ret = iter(mtd, ++section, &oobregion);
1996 }
1997
1998 return ret;
1999}
2000
2001/**
2002 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
2003 * @mtd: mtd info structure
2004 * @iter: category iterator
2005 *
2006 * Count the number of bytes in a given category.
2007 *
2008 * Returns a positive value on success, a negative error code otherwise.
2009 */
2010static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
2011 int (*iter)(struct mtd_info *,
2012 int section,
2013 struct mtd_oob_region *oobregion))
2014{
2015 struct mtd_oob_region oobregion;
2016 int section = 0, ret, nbytes = 0;
2017
2018 while (1) {
2019 ret = iter(mtd, section++, &oobregion);
2020 if (ret) {
2021 if (ret == -ERANGE)
2022 ret = nbytes;
2023 break;
2024 }
2025
2026 nbytes += oobregion.length;
2027 }
2028
2029 return ret;
2030}
2031
2032/**
2033 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
2034 * @mtd: mtd info structure
2035 * @eccbuf: destination buffer to store ECC bytes
2036 * @oobbuf: OOB buffer
2037 * @start: first ECC byte to retrieve
2038 * @nbytes: number of ECC bytes to retrieve
2039 *
2040 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
2041 *
2042 * Returns zero on success, a negative error code otherwise.
2043 */
2044int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
2045 const u8 *oobbuf, int start, int nbytes)
2046{
2047 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
2048 mtd_ooblayout_ecc);
2049}
2050EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
2051
2052/**
2053 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
2054 * @mtd: mtd info structure
2055 * @eccbuf: source buffer to get ECC bytes from
2056 * @oobbuf: OOB buffer
2057 * @start: first ECC byte to set
2058 * @nbytes: number of ECC bytes to set
2059 *
2060 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
2061 *
2062 * Returns zero on success, a negative error code otherwise.
2063 */
2064int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
2065 u8 *oobbuf, int start, int nbytes)
2066{
2067 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
2068 mtd_ooblayout_ecc);
2069}
2070EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
2071
2072/**
2073 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
2074 * @mtd: mtd info structure
2075 * @databuf: destination buffer to store ECC bytes
2076 * @oobbuf: OOB buffer
2077 * @start: first ECC byte to retrieve
2078 * @nbytes: number of ECC bytes to retrieve
2079 *
2080 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
2081 *
2082 * Returns zero on success, a negative error code otherwise.
2083 */
2084int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
2085 const u8 *oobbuf, int start, int nbytes)
2086{
2087 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
2088 mtd_ooblayout_free);
2089}
2090EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
2091
2092/**
2093 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
2094 * @mtd: mtd info structure
2095 * @databuf: source buffer to get data bytes from
2096 * @oobbuf: OOB buffer
2097 * @start: first ECC byte to set
2098 * @nbytes: number of ECC bytes to set
2099 *
2100 * Works like mtd_ooblayout_set_bytes(), except it acts on free bytes.
2101 *
2102 * Returns zero on success, a negative error code otherwise.
2103 */
2104int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
2105 u8 *oobbuf, int start, int nbytes)
2106{
2107 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
2108 mtd_ooblayout_free);
2109}
2110EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
2111
2112/**
2113 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
2114 * @mtd: mtd info structure
2115 *
2116 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
2117 *
2118 * Returns zero on success, a negative error code otherwise.
2119 */
2120int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
2121{
2122 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
2123}
2124EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
2125
2126/**
2127 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
2128 * @mtd: mtd info structure
2129 *
2130 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
2131 *
2132 * Returns zero on success, a negative error code otherwise.
2133 */
2134int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
2135{
2136 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
2137}
2138EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
2139
2140/*
2141 * Method to access the protection register area, present in some flash
2142 * devices. The user data is one time programmable but the factory data is read
2143 * only.
2144 */
2145int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
2146 struct otp_info *buf)
2147{
2148 struct mtd_info *master = mtd_get_master(mtd);
2149
2150 if (!master->_get_fact_prot_info)
2151 return -EOPNOTSUPP;
2152 if (!len)
2153 return 0;
2154 return master->_get_fact_prot_info(master, len, retlen, buf);
2155}
2156EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
2157
2158int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2159 size_t *retlen, u_char *buf)
2160{
2161 struct mtd_info *master = mtd_get_master(mtd);
2162
2163 *retlen = 0;
2164 if (!master->_read_fact_prot_reg)
2165 return -EOPNOTSUPP;
2166 if (!len)
2167 return 0;
2168 return master->_read_fact_prot_reg(master, from, len, retlen, buf);
2169}
2170EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
2171
2172int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
2173 struct otp_info *buf)
2174{
2175 struct mtd_info *master = mtd_get_master(mtd);
2176
2177 if (!master->_get_user_prot_info)
2178 return -EOPNOTSUPP;
2179 if (!len)
2180 return 0;
2181 return master->_get_user_prot_info(master, len, retlen, buf);
2182}
2183EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
2184
2185int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2186 size_t *retlen, u_char *buf)
2187{
2188 struct mtd_info *master = mtd_get_master(mtd);
2189
2190 *retlen = 0;
2191 if (!master->_read_user_prot_reg)
2192 return -EOPNOTSUPP;
2193 if (!len)
2194 return 0;
2195 return master->_read_user_prot_reg(master, from, len, retlen, buf);
2196}
2197EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
2198
2199int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
2200 size_t *retlen, const u_char *buf)
2201{
2202 struct mtd_info *master = mtd_get_master(mtd);
2203 int ret;
2204
2205 *retlen = 0;
2206 if (!master->_write_user_prot_reg)
2207 return -EOPNOTSUPP;
2208 if (!len)
2209 return 0;
2210 ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
2211 if (ret)
2212 return ret;
2213
2214 /*
2215 * If no data could be written at all, we are out of memory and
2216 * must return -ENOSPC.
2217 */
2218 return (*retlen) ? 0 : -ENOSPC;
2219}
2220EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
2221
2222int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2223{
2224 struct mtd_info *master = mtd_get_master(mtd);
2225
2226 if (!master->_lock_user_prot_reg)
2227 return -EOPNOTSUPP;
2228 if (!len)
2229 return 0;
2230 return master->_lock_user_prot_reg(master, from, len);
2231}
2232EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
2233
2234int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2235{
2236 struct mtd_info *master = mtd_get_master(mtd);
2237
2238 if (!master->_erase_user_prot_reg)
2239 return -EOPNOTSUPP;
2240 if (!len)
2241 return 0;
2242 return master->_erase_user_prot_reg(master, from, len);
2243}
2244EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg);
2245
2246/* Chip-supported device locking */
2247int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2248{
2249 struct mtd_info *master = mtd_get_master(mtd);
2250
2251 if (!master->_lock)
2252 return -EOPNOTSUPP;
2253 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2254 return -EINVAL;
2255 if (!len)
2256 return 0;
2257
2258 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2259 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2260 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2261 }
2262
2263 return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
2264}
2265EXPORT_SYMBOL_GPL(mtd_lock);
2266
2267int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2268{
2269 struct mtd_info *master = mtd_get_master(mtd);
2270
2271 if (!master->_unlock)
2272 return -EOPNOTSUPP;
2273 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2274 return -EINVAL;
2275 if (!len)
2276 return 0;
2277
2278 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2279 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2280 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2281 }
2282
2283 return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
2284}
2285EXPORT_SYMBOL_GPL(mtd_unlock);
2286
2287int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2288{
2289 struct mtd_info *master = mtd_get_master(mtd);
2290
2291 if (!master->_is_locked)
2292 return -EOPNOTSUPP;
2293 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2294 return -EINVAL;
2295 if (!len)
2296 return 0;
2297
2298 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2299 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2300 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2301 }
2302
2303 return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
2304}
2305EXPORT_SYMBOL_GPL(mtd_is_locked);
2306
2307int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
2308{
2309 struct mtd_info *master = mtd_get_master(mtd);
2310
2311 if (ofs < 0 || ofs >= mtd->size)
2312 return -EINVAL;
2313 if (!master->_block_isreserved)
2314 return 0;
2315
2316 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2317 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2318
2319 return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
2320}
2321EXPORT_SYMBOL_GPL(mtd_block_isreserved);
2322
2323int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
2324{
2325 struct mtd_info *master = mtd_get_master(mtd);
2326
2327 if (ofs < 0 || ofs >= mtd->size)
2328 return -EINVAL;
2329 if (!master->_block_isbad)
2330 return 0;
2331
2332 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2333 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2334
2335 return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
2336}
2337EXPORT_SYMBOL_GPL(mtd_block_isbad);
2338
2339int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
2340{
2341 struct mtd_info *master = mtd_get_master(mtd);
2342 int ret;
2343
2344 if (!master->_block_markbad)
2345 return -EOPNOTSUPP;
2346 if (ofs < 0 || ofs >= mtd->size)
2347 return -EINVAL;
2348 if (!(mtd->flags & MTD_WRITEABLE))
2349 return -EROFS;
2350
2351 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2352 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2353
2354 ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
2355 if (ret)
2356 return ret;
2357
2358 while (mtd->parent) {
2359 mtd->ecc_stats.badblocks++;
2360 mtd = mtd->parent;
2361 }
2362
2363 return 0;
2364}
2365EXPORT_SYMBOL_GPL(mtd_block_markbad);
2366ALLOW_ERROR_INJECTION(mtd_block_markbad, ERRNO);
2367
2368/*
2369 * default_mtd_writev - the default writev method
2370 * @mtd: mtd device description object pointer
2371 * @vecs: the vectors to write
2372 * @count: count of vectors in @vecs
2373 * @to: the MTD device offset to write to
2374 * @retlen: on exit contains the count of bytes written to the MTD device.
2375 *
2376 * This function returns zero in case of success and a negative error code in
2377 * case of failure.
2378 */
2379static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2380 unsigned long count, loff_t to, size_t *retlen)
2381{
2382 unsigned long i;
2383 size_t totlen = 0, thislen;
2384 int ret = 0;
2385
2386 for (i = 0; i < count; i++) {
2387 if (!vecs[i].iov_len)
2388 continue;
2389 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
2390 vecs[i].iov_base);
2391 totlen += thislen;
2392 if (ret || thislen != vecs[i].iov_len)
2393 break;
2394 to += vecs[i].iov_len;
2395 }
2396 *retlen = totlen;
2397 return ret;
2398}
2399
2400/*
2401 * mtd_writev - the vector-based MTD write method
2402 * @mtd: mtd device description object pointer
2403 * @vecs: the vectors to write
2404 * @count: count of vectors in @vecs
2405 * @to: the MTD device offset to write to
2406 * @retlen: on exit contains the count of bytes written to the MTD device.
2407 *
2408 * This function returns zero in case of success and a negative error code in
2409 * case of failure.
2410 */
2411int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2412 unsigned long count, loff_t to, size_t *retlen)
2413{
2414 struct mtd_info *master = mtd_get_master(mtd);
2415
2416 *retlen = 0;
2417 if (!(mtd->flags & MTD_WRITEABLE))
2418 return -EROFS;
2419
2420 if (!master->_writev)
2421 return default_mtd_writev(mtd, vecs, count, to, retlen);
2422
2423 return master->_writev(master, vecs, count,
2424 mtd_get_master_ofs(mtd, to), retlen);
2425}
2426EXPORT_SYMBOL_GPL(mtd_writev);
2427
2428/**
2429 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
2430 * @mtd: mtd device description object pointer
2431 * @size: a pointer to the ideal or maximum size of the allocation, points
2432 * to the actual allocation size on success.
2433 *
2434 * This routine attempts to allocate a contiguous kernel buffer up to
2435 * the specified size, backing off the size of the request exponentially
2436 * until the request succeeds or until the allocation size falls below
2437 * the system page size. This attempts to make sure it does not adversely
2438 * impact system performance, so when allocating more than one page, we
2439 * ask the memory allocator to avoid re-trying, swapping, writing back
2440 * or performing I/O.
2441 *
2442 * Note, this function also makes sure that the allocated buffer is aligned to
2443 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
2444 *
2445 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
2446 * to handle smaller (i.e. degraded) buffer allocations under low- or
2447 * fragmented-memory situations where such reduced allocations, from a
2448 * requested ideal, are allowed.
2449 *
2450 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
2451 */
2452void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
2453{
2454 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
2455 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
2456 void *kbuf;
2457
2458 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
2459
2460 while (*size > min_alloc) {
2461 kbuf = kmalloc(*size, flags);
2462 if (kbuf)
2463 return kbuf;
2464
2465 *size >>= 1;
2466 *size = ALIGN(*size, mtd->writesize);
2467 }
2468
2469 /*
2470 * For the last resort allocation allow 'kmalloc()' to do all sorts of
2471 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
2472 */
2473 return kmalloc(*size, GFP_KERNEL);
2474}
2475EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
2476
2477#ifdef CONFIG_PROC_FS
2478
2479/*====================================================================*/
2480/* Support for /proc/mtd */
2481
2482static int mtd_proc_show(struct seq_file *m, void *v)
2483{
2484 struct mtd_info *mtd;
2485
2486 seq_puts(m, "dev: size erasesize name\n");
2487 mutex_lock(&mtd_table_mutex);
2488 mtd_for_each_device(mtd) {
2489 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
2490 mtd->index, (unsigned long long)mtd->size,
2491 mtd->erasesize, mtd->name);
2492 }
2493 mutex_unlock(&mtd_table_mutex);
2494 return 0;
2495}
2496#endif /* CONFIG_PROC_FS */
2497
2498/*====================================================================*/
2499/* Init code */
2500
2501static struct backing_dev_info * __init mtd_bdi_init(const char *name)
2502{
2503 struct backing_dev_info *bdi;
2504 int ret;
2505
2506 bdi = bdi_alloc(NUMA_NO_NODE);
2507 if (!bdi)
2508 return ERR_PTR(-ENOMEM);
2509 bdi->ra_pages = 0;
2510 bdi->io_pages = 0;
2511
2512 /*
2513 * We put '-0' suffix to the name to get the same name format as we
2514 * used to get. Since this is called only once, we get a unique name.
2515 */
2516 ret = bdi_register(bdi, "%.28s-0", name);
2517 if (ret)
2518 bdi_put(bdi);
2519
2520 return ret ? ERR_PTR(ret) : bdi;
2521}
2522
2523static struct proc_dir_entry *proc_mtd;
2524
2525static int __init init_mtd(void)
2526{
2527 int ret;
2528
2529 ret = class_register(&mtd_class);
2530 if (ret)
2531 goto err_reg;
2532
2533 mtd_bdi = mtd_bdi_init("mtd");
2534 if (IS_ERR(mtd_bdi)) {
2535 ret = PTR_ERR(mtd_bdi);
2536 goto err_bdi;
2537 }
2538
2539 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
2540
2541 ret = init_mtdchar();
2542 if (ret)
2543 goto out_procfs;
2544
2545 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
2546 debugfs_create_bool("expert_analysis_mode", 0600, dfs_dir_mtd,
2547 &mtd_expert_analysis_mode);
2548
2549 return 0;
2550
2551out_procfs:
2552 if (proc_mtd)
2553 remove_proc_entry("mtd", NULL);
2554 bdi_unregister(mtd_bdi);
2555 bdi_put(mtd_bdi);
2556err_bdi:
2557 class_unregister(&mtd_class);
2558err_reg:
2559 pr_err("Error registering mtd class or bdi: %d\n", ret);
2560 return ret;
2561}
2562
2563static void __exit cleanup_mtd(void)
2564{
2565 debugfs_remove_recursive(dfs_dir_mtd);
2566 cleanup_mtdchar();
2567 if (proc_mtd)
2568 remove_proc_entry("mtd", NULL);
2569 class_unregister(&mtd_class);
2570 bdi_unregister(mtd_bdi);
2571 bdi_put(mtd_bdi);
2572 idr_destroy(&mtd_idr);
2573}
2574
2575module_init(init_mtd);
2576module_exit(cleanup_mtd);
2577
2578MODULE_LICENSE("GPL");
2579MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2580MODULE_DESCRIPTION("Core MTD registration and access routines");
Linux 6.x block layer and io_uring tree(s)