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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 <[email protected]>
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#include <linux/mtd/concat.h>
38
39#include "mtdcore.h"
40
41struct backing_dev_info *mtd_bdi;
42
43#ifdef CONFIG_PM_SLEEP
44
45static int mtd_cls_suspend(struct device *dev)
46{
47 struct mtd_info *mtd = dev_get_drvdata(dev);
48
49 return mtd ? mtd_suspend(mtd) : 0;
50}
51
52static int mtd_cls_resume(struct device *dev)
53{
54 struct mtd_info *mtd = dev_get_drvdata(dev);
55
56 if (mtd)
57 mtd_resume(mtd);
58 return 0;
59}
60
61static SIMPLE_DEV_PM_OPS(mtd_cls_pm_ops, mtd_cls_suspend, mtd_cls_resume);
62#define MTD_CLS_PM_OPS (&mtd_cls_pm_ops)
63#else
64#define MTD_CLS_PM_OPS NULL
65#endif
66
67static struct class mtd_class = {
68 .name = "mtd",
69 .pm = MTD_CLS_PM_OPS,
70};
71
72static DEFINE_IDR(mtd_idr);
73
74/* These are exported solely for the purpose of mtd_blkdevs.c. You
75 should not use them for _anything_ else */
76DEFINE_MUTEX(mtd_table_mutex);
77EXPORT_SYMBOL_GPL(mtd_table_mutex);
78
79struct mtd_info *__mtd_next_device(int i)
80{
81 return idr_get_next(&mtd_idr, &i);
82}
83EXPORT_SYMBOL_GPL(__mtd_next_device);
84
85static LIST_HEAD(mtd_notifiers);
86
87
88#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
89
90/* REVISIT once MTD uses the driver model better, whoever allocates
91 * the mtd_info will probably want to use the release() hook...
92 */
93static void mtd_release(struct device *dev)
94{
95 struct mtd_info *mtd = dev_get_drvdata(dev);
96 dev_t index = MTD_DEVT(mtd->index);
97
98 idr_remove(&mtd_idr, mtd->index);
99 of_node_put(mtd_get_of_node(mtd));
100
101 if (mtd_is_partition(mtd))
102 release_mtd_partition(mtd);
103
104 /* remove /dev/mtdXro node */
105 device_destroy(&mtd_class, index + 1);
106}
107
108/*
109 * No-op device release used in add_mtd_device() error paths.
110 * Prevents mtd_release() from being called via device_release(),
111 * which would free the mtd_info that the caller still manages.
112 */
113static void mtd_dev_release_nop(struct device *dev)
114{
115}
116
117static void mtd_device_release(struct kref *kref)
118{
119 struct mtd_info *mtd = container_of(kref, struct mtd_info, refcnt);
120 bool is_partition = mtd_is_partition(mtd);
121
122 debugfs_remove_recursive(mtd->dbg.dfs_dir);
123
124 /* Try to remove the NVMEM provider */
125 nvmem_unregister(mtd->nvmem);
126
127 device_unregister(&mtd->dev);
128
129 /*
130 * Clear dev so mtd can be safely re-registered later if desired.
131 * Should not be done for partition,
132 * as it was already destroyed in device_unregister().
133 */
134 if (!is_partition)
135 memset(&mtd->dev, 0, sizeof(mtd->dev));
136
137 module_put(THIS_MODULE);
138}
139
140#define MTD_DEVICE_ATTR_RO(name) \
141static DEVICE_ATTR(name, 0444, mtd_##name##_show, NULL)
142
143#define MTD_DEVICE_ATTR_RW(name) \
144static DEVICE_ATTR(name, 0644, mtd_##name##_show, mtd_##name##_store)
145
146static ssize_t mtd_type_show(struct device *dev,
147 struct device_attribute *attr, char *buf)
148{
149 struct mtd_info *mtd = dev_get_drvdata(dev);
150 char *type;
151
152 switch (mtd->type) {
153 case MTD_ABSENT:
154 type = "absent";
155 break;
156 case MTD_RAM:
157 type = "ram";
158 break;
159 case MTD_ROM:
160 type = "rom";
161 break;
162 case MTD_NORFLASH:
163 type = "nor";
164 break;
165 case MTD_NANDFLASH:
166 type = "nand";
167 break;
168 case MTD_DATAFLASH:
169 type = "dataflash";
170 break;
171 case MTD_UBIVOLUME:
172 type = "ubi";
173 break;
174 case MTD_MLCNANDFLASH:
175 type = "mlc-nand";
176 break;
177 default:
178 type = "unknown";
179 }
180
181 return sysfs_emit(buf, "%s\n", type);
182}
183MTD_DEVICE_ATTR_RO(type);
184
185static ssize_t mtd_flags_show(struct device *dev,
186 struct device_attribute *attr, char *buf)
187{
188 struct mtd_info *mtd = dev_get_drvdata(dev);
189
190 return sysfs_emit(buf, "0x%lx\n", (unsigned long)mtd->flags);
191}
192MTD_DEVICE_ATTR_RO(flags);
193
194static ssize_t mtd_size_show(struct device *dev,
195 struct device_attribute *attr, char *buf)
196{
197 struct mtd_info *mtd = dev_get_drvdata(dev);
198
199 return sysfs_emit(buf, "%llu\n", (unsigned long long)mtd->size);
200}
201MTD_DEVICE_ATTR_RO(size);
202
203static ssize_t mtd_erasesize_show(struct device *dev,
204 struct device_attribute *attr, char *buf)
205{
206 struct mtd_info *mtd = dev_get_drvdata(dev);
207
208 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->erasesize);
209}
210MTD_DEVICE_ATTR_RO(erasesize);
211
212static ssize_t mtd_writesize_show(struct device *dev,
213 struct device_attribute *attr, char *buf)
214{
215 struct mtd_info *mtd = dev_get_drvdata(dev);
216
217 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->writesize);
218}
219MTD_DEVICE_ATTR_RO(writesize);
220
221static ssize_t mtd_subpagesize_show(struct device *dev,
222 struct device_attribute *attr, char *buf)
223{
224 struct mtd_info *mtd = dev_get_drvdata(dev);
225 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
226
227 return sysfs_emit(buf, "%u\n", subpagesize);
228}
229MTD_DEVICE_ATTR_RO(subpagesize);
230
231static ssize_t mtd_oobsize_show(struct device *dev,
232 struct device_attribute *attr, char *buf)
233{
234 struct mtd_info *mtd = dev_get_drvdata(dev);
235
236 return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->oobsize);
237}
238MTD_DEVICE_ATTR_RO(oobsize);
239
240static ssize_t mtd_oobavail_show(struct device *dev,
241 struct device_attribute *attr, char *buf)
242{
243 struct mtd_info *mtd = dev_get_drvdata(dev);
244
245 return sysfs_emit(buf, "%u\n", mtd->oobavail);
246}
247MTD_DEVICE_ATTR_RO(oobavail);
248
249static ssize_t mtd_numeraseregions_show(struct device *dev,
250 struct device_attribute *attr, char *buf)
251{
252 struct mtd_info *mtd = dev_get_drvdata(dev);
253
254 return sysfs_emit(buf, "%u\n", mtd->numeraseregions);
255}
256MTD_DEVICE_ATTR_RO(numeraseregions);
257
258static ssize_t mtd_name_show(struct device *dev,
259 struct device_attribute *attr, char *buf)
260{
261 struct mtd_info *mtd = dev_get_drvdata(dev);
262
263 return sysfs_emit(buf, "%s\n", mtd->name);
264}
265MTD_DEVICE_ATTR_RO(name);
266
267static ssize_t mtd_ecc_strength_show(struct device *dev,
268 struct device_attribute *attr, char *buf)
269{
270 struct mtd_info *mtd = dev_get_drvdata(dev);
271
272 return sysfs_emit(buf, "%u\n", mtd->ecc_strength);
273}
274MTD_DEVICE_ATTR_RO(ecc_strength);
275
276static ssize_t mtd_bitflip_threshold_show(struct device *dev,
277 struct device_attribute *attr,
278 char *buf)
279{
280 struct mtd_info *mtd = dev_get_drvdata(dev);
281
282 return sysfs_emit(buf, "%u\n", mtd->bitflip_threshold);
283}
284
285static ssize_t mtd_bitflip_threshold_store(struct device *dev,
286 struct device_attribute *attr,
287 const char *buf, size_t count)
288{
289 struct mtd_info *mtd = dev_get_drvdata(dev);
290 unsigned int bitflip_threshold;
291 int retval;
292
293 retval = kstrtouint(buf, 0, &bitflip_threshold);
294 if (retval)
295 return retval;
296
297 mtd->bitflip_threshold = bitflip_threshold;
298 return count;
299}
300MTD_DEVICE_ATTR_RW(bitflip_threshold);
301
302static ssize_t mtd_ecc_step_size_show(struct device *dev,
303 struct device_attribute *attr, char *buf)
304{
305 struct mtd_info *mtd = dev_get_drvdata(dev);
306
307 return sysfs_emit(buf, "%u\n", mtd->ecc_step_size);
308
309}
310MTD_DEVICE_ATTR_RO(ecc_step_size);
311
312static ssize_t mtd_corrected_bits_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->corrected);
319}
320MTD_DEVICE_ATTR_RO(corrected_bits); /* ecc stats corrected */
321
322static ssize_t mtd_ecc_failures_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->failed);
329}
330MTD_DEVICE_ATTR_RO(ecc_failures); /* ecc stats errors */
331
332static ssize_t mtd_bad_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->badblocks);
339}
340MTD_DEVICE_ATTR_RO(bad_blocks);
341
342static ssize_t mtd_bbt_blocks_show(struct device *dev,
343 struct device_attribute *attr, char *buf)
344{
345 struct mtd_info *mtd = dev_get_drvdata(dev);
346 struct mtd_ecc_stats *ecc_stats = &mtd->ecc_stats;
347
348 return sysfs_emit(buf, "%u\n", ecc_stats->bbtblocks);
349}
350MTD_DEVICE_ATTR_RO(bbt_blocks);
351
352static struct attribute *mtd_attrs[] = {
353 &dev_attr_type.attr,
354 &dev_attr_flags.attr,
355 &dev_attr_size.attr,
356 &dev_attr_erasesize.attr,
357 &dev_attr_writesize.attr,
358 &dev_attr_subpagesize.attr,
359 &dev_attr_oobsize.attr,
360 &dev_attr_oobavail.attr,
361 &dev_attr_numeraseregions.attr,
362 &dev_attr_name.attr,
363 &dev_attr_ecc_strength.attr,
364 &dev_attr_ecc_step_size.attr,
365 &dev_attr_corrected_bits.attr,
366 &dev_attr_ecc_failures.attr,
367 &dev_attr_bad_blocks.attr,
368 &dev_attr_bbt_blocks.attr,
369 &dev_attr_bitflip_threshold.attr,
370 NULL,
371};
372ATTRIBUTE_GROUPS(mtd);
373
374static const struct device_type mtd_devtype = {
375 .name = "mtd",
376 .groups = mtd_groups,
377 .release = mtd_release,
378};
379
380static bool mtd_expert_analysis_mode;
381
382#ifdef CONFIG_DEBUG_FS
383bool mtd_check_expert_analysis_mode(void)
384{
385 const char *mtd_expert_analysis_warning =
386 "Bad block checks have been entirely disabled.\n"
387 "This is only reserved for post-mortem forensics and debug purposes.\n"
388 "Never enable this mode if you do not know what you are doing!\n";
389
390 return WARN_ONCE(mtd_expert_analysis_mode, mtd_expert_analysis_warning);
391}
392EXPORT_SYMBOL_GPL(mtd_check_expert_analysis_mode);
393#endif
394
395static struct dentry *dfs_dir_mtd;
396
397static int mtd_ooblayout_show(struct seq_file *s, void *p,
398 int (*iter)(struct mtd_info *, int section,
399 struct mtd_oob_region *region))
400{
401 struct mtd_info *mtd = s->private;
402 int section;
403
404 for (section = 0;; section++) {
405 struct mtd_oob_region region;
406 int err;
407
408 err = iter(mtd, section, &region);
409 if (err) {
410 if (err == -ERANGE)
411 break;
412
413 return err;
414 }
415
416 seq_printf(s, "%-3d %4u %4u\n", section, region.offset,
417 region.length);
418 }
419
420 return 0;
421}
422
423static int mtd_ooblayout_ecc_show(struct seq_file *s, void *p)
424{
425 return mtd_ooblayout_show(s, p, mtd_ooblayout_ecc);
426}
427DEFINE_SHOW_ATTRIBUTE(mtd_ooblayout_ecc);
428
429static int mtd_ooblayout_free_show(struct seq_file *s, void *p)
430{
431 return mtd_ooblayout_show(s, p, mtd_ooblayout_free);
432}
433DEFINE_SHOW_ATTRIBUTE(mtd_ooblayout_free);
434
435static void mtd_debugfs_populate(struct mtd_info *mtd)
436{
437 struct device *dev = &mtd->dev;
438 struct mtd_oob_region region;
439
440 if (IS_ERR_OR_NULL(dfs_dir_mtd))
441 return;
442
443 mtd->dbg.dfs_dir = debugfs_create_dir(dev_name(dev), dfs_dir_mtd);
444 if (IS_ERR_OR_NULL(mtd->dbg.dfs_dir))
445 return;
446
447 /* Create ooblayout files only if at least one region is present. */
448 if (mtd_ooblayout_ecc(mtd, 0, &region) == 0)
449 debugfs_create_file("ooblayout_ecc", 0444, mtd->dbg.dfs_dir,
450 mtd, &mtd_ooblayout_ecc_fops);
451
452 if (mtd_ooblayout_free(mtd, 0, &region) == 0)
453 debugfs_create_file("ooblayout_free", 0444, mtd->dbg.dfs_dir,
454 mtd, &mtd_ooblayout_free_fops);
455}
456
457#ifndef CONFIG_MMU
458unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
459{
460 switch (mtd->type) {
461 case MTD_RAM:
462 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
463 NOMMU_MAP_READ | NOMMU_MAP_WRITE;
464 case MTD_ROM:
465 return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
466 NOMMU_MAP_READ;
467 default:
468 return NOMMU_MAP_COPY;
469 }
470}
471EXPORT_SYMBOL_GPL(mtd_mmap_capabilities);
472#endif
473
474static int mtd_reboot_notifier(struct notifier_block *n, unsigned long state,
475 void *cmd)
476{
477 struct mtd_info *mtd;
478
479 mtd = container_of(n, struct mtd_info, reboot_notifier);
480 mtd->_reboot(mtd);
481
482 return NOTIFY_DONE;
483}
484
485/**
486 * mtd_wunit_to_pairing_info - get pairing information of a wunit
487 * @mtd: pointer to new MTD device info structure
488 * @wunit: write unit we are interested in
489 * @info: returned pairing information
490 *
491 * Retrieve pairing information associated to the wunit.
492 * This is mainly useful when dealing with MLC/TLC NANDs where pages can be
493 * paired together, and where programming a page may influence the page it is
494 * paired with.
495 * The notion of page is replaced by the term wunit (write-unit) to stay
496 * consistent with the ->writesize field.
497 *
498 * The @wunit argument can be extracted from an absolute offset using
499 * mtd_offset_to_wunit(). @info is filled with the pairing information attached
500 * to @wunit.
501 *
502 * From the pairing info the MTD user can find all the wunits paired with
503 * @wunit using the following loop:
504 *
505 * for (i = 0; i < mtd_pairing_groups(mtd); i++) {
506 * info.pair = i;
507 * mtd_pairing_info_to_wunit(mtd, &info);
508 * ...
509 * }
510 */
511int mtd_wunit_to_pairing_info(struct mtd_info *mtd, int wunit,
512 struct mtd_pairing_info *info)
513{
514 struct mtd_info *master = mtd_get_master(mtd);
515 int npairs = mtd_wunit_per_eb(master) / mtd_pairing_groups(master);
516
517 if (wunit < 0 || wunit >= npairs)
518 return -EINVAL;
519
520 if (master->pairing && master->pairing->get_info)
521 return master->pairing->get_info(master, wunit, info);
522
523 info->group = 0;
524 info->pair = wunit;
525
526 return 0;
527}
528EXPORT_SYMBOL_GPL(mtd_wunit_to_pairing_info);
529
530/**
531 * mtd_pairing_info_to_wunit - get wunit from pairing information
532 * @mtd: pointer to new MTD device info structure
533 * @info: pairing information struct
534 *
535 * Returns a positive number representing the wunit associated to the info
536 * struct, or a negative error code.
537 *
538 * This is the reverse of mtd_wunit_to_pairing_info(), and can help one to
539 * iterate over all wunits of a given pair (see mtd_wunit_to_pairing_info()
540 * doc).
541 *
542 * It can also be used to only program the first page of each pair (i.e.
543 * page attached to group 0), which allows one to use an MLC NAND in
544 * software-emulated SLC mode:
545 *
546 * info.group = 0;
547 * npairs = mtd_wunit_per_eb(mtd) / mtd_pairing_groups(mtd);
548 * for (info.pair = 0; info.pair < npairs; info.pair++) {
549 * wunit = mtd_pairing_info_to_wunit(mtd, &info);
550 * mtd_write(mtd, mtd_wunit_to_offset(mtd, blkoffs, wunit),
551 * mtd->writesize, &retlen, buf + (i * mtd->writesize));
552 * }
553 */
554int mtd_pairing_info_to_wunit(struct mtd_info *mtd,
555 const struct mtd_pairing_info *info)
556{
557 struct mtd_info *master = mtd_get_master(mtd);
558 int ngroups = mtd_pairing_groups(master);
559 int npairs = mtd_wunit_per_eb(master) / ngroups;
560
561 if (!info || info->pair < 0 || info->pair >= npairs ||
562 info->group < 0 || info->group >= ngroups)
563 return -EINVAL;
564
565 if (master->pairing && master->pairing->get_wunit)
566 return mtd->pairing->get_wunit(master, info);
567
568 return info->pair;
569}
570EXPORT_SYMBOL_GPL(mtd_pairing_info_to_wunit);
571
572/**
573 * mtd_pairing_groups - get the number of pairing groups
574 * @mtd: pointer to new MTD device info structure
575 *
576 * Returns the number of pairing groups.
577 *
578 * This number is usually equal to the number of bits exposed by a single
579 * cell, and can be used in conjunction with mtd_pairing_info_to_wunit()
580 * to iterate over all pages of a given pair.
581 */
582int mtd_pairing_groups(struct mtd_info *mtd)
583{
584 struct mtd_info *master = mtd_get_master(mtd);
585
586 if (!master->pairing || !master->pairing->ngroups)
587 return 1;
588
589 return master->pairing->ngroups;
590}
591EXPORT_SYMBOL_GPL(mtd_pairing_groups);
592
593static int mtd_nvmem_reg_read(void *priv, unsigned int offset,
594 void *val, size_t bytes)
595{
596 struct mtd_info *mtd = priv;
597 size_t retlen;
598 int err;
599
600 err = mtd_read(mtd, offset, bytes, &retlen, val);
601 if (err && err != -EUCLEAN)
602 return err;
603
604 return retlen == bytes ? 0 : -EIO;
605}
606
607static int mtd_nvmem_add(struct mtd_info *mtd)
608{
609 struct device_node *node = mtd_get_of_node(mtd);
610 struct nvmem_config config = {};
611
612 config.id = NVMEM_DEVID_NONE;
613 config.dev = &mtd->dev;
614 config.name = dev_name(&mtd->dev);
615 config.owner = THIS_MODULE;
616 config.add_legacy_fixed_of_cells = of_device_is_compatible(node, "nvmem-cells");
617 config.reg_read = mtd_nvmem_reg_read;
618 config.size = mtd->size;
619 config.word_size = 1;
620 config.stride = 1;
621 config.read_only = true;
622 config.root_only = true;
623 config.ignore_wp = true;
624 config.priv = mtd;
625
626 mtd->nvmem = nvmem_register(&config);
627 if (IS_ERR(mtd->nvmem)) {
628 /* Just ignore if there is no NVMEM support in the kernel */
629 if (PTR_ERR(mtd->nvmem) == -EOPNOTSUPP)
630 mtd->nvmem = NULL;
631 else
632 return dev_err_probe(&mtd->dev, PTR_ERR(mtd->nvmem),
633 "Failed to register NVMEM device\n");
634 }
635
636 return 0;
637}
638
639static void mtd_check_of_node(struct mtd_info *mtd)
640{
641 struct device_node *partitions, *parent_dn, *mtd_dn = NULL;
642 const char *pname, *prefix = "partition-";
643 int plen, mtd_name_len, offset, prefix_len;
644
645 /* Check if MTD already has a device node */
646 if (mtd_get_of_node(mtd))
647 return;
648
649 if (!mtd_is_partition(mtd))
650 return;
651
652 parent_dn = of_node_get(mtd_get_of_node(mtd->parent));
653 if (!parent_dn)
654 return;
655
656 if (mtd_is_partition(mtd->parent))
657 partitions = of_node_get(parent_dn);
658 else
659 partitions = of_get_child_by_name(parent_dn, "partitions");
660 if (!partitions)
661 goto exit_parent;
662
663 prefix_len = strlen(prefix);
664 mtd_name_len = strlen(mtd->name);
665
666 /* Search if a partition is defined with the same name */
667 for_each_child_of_node(partitions, mtd_dn) {
668 /* Skip partition with no/wrong prefix */
669 if (!of_node_name_prefix(mtd_dn, prefix))
670 continue;
671
672 /* Label have priority. Check that first */
673 if (!of_property_read_string(mtd_dn, "label", &pname)) {
674 offset = 0;
675 } else {
676 pname = mtd_dn->name;
677 offset = prefix_len;
678 }
679
680 plen = strlen(pname) - offset;
681 if (plen == mtd_name_len &&
682 !strncmp(mtd->name, pname + offset, plen)) {
683 mtd_set_of_node(mtd, mtd_dn);
684 of_node_put(mtd_dn);
685 break;
686 }
687 }
688
689 of_node_put(partitions);
690exit_parent:
691 of_node_put(parent_dn);
692}
693
694/**
695 * add_mtd_device - register an MTD device
696 * @mtd: pointer to new MTD device info structure
697 *
698 * Add a device to the list of MTD devices present in the system, and
699 * notify each currently active MTD 'user' of its arrival. Returns
700 * zero on success or non-zero on failure.
701 */
702
703int add_mtd_device(struct mtd_info *mtd)
704{
705 struct device_node *np = mtd_get_of_node(mtd);
706 struct mtd_info *master = mtd_get_master(mtd);
707 struct mtd_notifier *not;
708 int i, error, ofidx;
709
710 /*
711 * May occur, for instance, on buggy drivers which call
712 * mtd_device_parse_register() multiple times on the same master MTD,
713 * especially with CONFIG_MTD_PARTITIONED_MASTER=y.
714 */
715 if (WARN_ONCE(mtd->dev.type, "MTD already registered\n"))
716 return -EEXIST;
717
718 BUG_ON(mtd->writesize == 0);
719
720 /*
721 * MTD drivers should implement ->_{write,read}() or
722 * ->_{write,read}_oob(), but not both.
723 */
724 if (WARN_ON((mtd->_write && mtd->_write_oob) ||
725 (mtd->_read && mtd->_read_oob)))
726 return -EINVAL;
727
728 if (WARN_ON((!mtd->erasesize || !master->_erase) &&
729 !(mtd->flags & MTD_NO_ERASE)))
730 return -EINVAL;
731
732 /*
733 * MTD_SLC_ON_MLC_EMULATION can only be set on partitions, when the
734 * master is an MLC NAND and has a proper pairing scheme defined.
735 * We also reject masters that implement ->_writev() for now, because
736 * NAND controller drivers don't implement this hook, and adding the
737 * SLC -> MLC address/length conversion to this path is useless if we
738 * don't have a user.
739 */
740 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION &&
741 (!mtd_is_partition(mtd) || master->type != MTD_MLCNANDFLASH ||
742 !master->pairing || master->_writev))
743 return -EINVAL;
744
745 mutex_lock(&mtd_table_mutex);
746
747 ofidx = -1;
748 if (np)
749 ofidx = of_alias_get_id(np, "mtd");
750 if (ofidx >= 0)
751 i = idr_alloc(&mtd_idr, mtd, ofidx, ofidx + 1, GFP_KERNEL);
752 else
753 i = idr_alloc(&mtd_idr, mtd, 0, 0, GFP_KERNEL);
754 if (i < 0) {
755 error = i;
756 goto fail_locked;
757 }
758
759 mtd->index = i;
760 kref_init(&mtd->refcnt);
761
762 /* default value if not set by driver */
763 if (mtd->bitflip_threshold == 0)
764 mtd->bitflip_threshold = mtd->ecc_strength;
765
766 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
767 int ngroups = mtd_pairing_groups(master);
768
769 mtd->erasesize /= ngroups;
770 mtd->size = (u64)mtd_div_by_eb(mtd->size, master) *
771 mtd->erasesize;
772 }
773
774 if (is_power_of_2(mtd->erasesize))
775 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
776 else
777 mtd->erasesize_shift = 0;
778
779 if (is_power_of_2(mtd->writesize))
780 mtd->writesize_shift = ffs(mtd->writesize) - 1;
781 else
782 mtd->writesize_shift = 0;
783
784 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
785 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
786
787 /* Some chips always power up locked. Unlock them now */
788 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
789 error = mtd_unlock(mtd, 0, mtd->size);
790 if (error && error != -EOPNOTSUPP)
791 printk(KERN_WARNING
792 "%s: unlock failed, writes may not work\n",
793 mtd->name);
794 /* Ignore unlock failures? */
795 error = 0;
796 }
797
798 /* Caller should have set dev.parent to match the
799 * physical device, if appropriate.
800 */
801 mtd->dev.type = &mtd_devtype;
802 mtd->dev.class = &mtd_class;
803 mtd->dev.devt = MTD_DEVT(i);
804 error = dev_set_name(&mtd->dev, "mtd%d", i);
805 if (error)
806 goto fail_devname;
807 dev_set_drvdata(&mtd->dev, mtd);
808 mtd_check_of_node(mtd);
809 of_node_get(mtd_get_of_node(mtd));
810 error = device_register(&mtd->dev);
811 if (error)
812 goto fail_added;
813
814 /* Add the nvmem provider */
815 error = mtd_nvmem_add(mtd);
816 if (error)
817 goto fail_nvmem_add;
818
819 mtd_debugfs_populate(mtd);
820
821 device_create(&mtd_class, mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
822 "mtd%dro", i);
823
824 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
825 /* No need to get a refcount on the module containing
826 the notifier, since we hold the mtd_table_mutex */
827 list_for_each_entry(not, &mtd_notifiers, list)
828 not->add(mtd);
829
830 mutex_unlock(&mtd_table_mutex);
831
832 if (of_property_read_bool(mtd_get_of_node(mtd), "linux,rootfs")) {
833 if (IS_BUILTIN(CONFIG_MTD)) {
834 pr_info("mtd: setting mtd%d (%s) as root device\n", mtd->index, mtd->name);
835 ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
836 } else {
837 pr_warn("mtd: can't set mtd%d (%s) as root device - mtd must be builtin\n",
838 mtd->index, mtd->name);
839 }
840 }
841
842 /* We _know_ we aren't being removed, because
843 our caller is still holding us here. So none
844 of this try_ nonsense, and no bitching about it
845 either. :) */
846 __module_get(THIS_MODULE);
847 return 0;
848
849fail_nvmem_add:
850 device_del(&mtd->dev);
851fail_added:
852 /*
853 * Clear type and set nop release to prevent mtd_release() ->
854 * release_mtd_partition() -> free_partition() from freeing mtd.
855 * The caller handles cleanup on failure.
856 */
857 mtd->dev.type = NULL;
858 mtd->dev.release = mtd_dev_release_nop;
859 put_device(&mtd->dev);
860 of_node_put(mtd_get_of_node(mtd));
861fail_devname:
862 idr_remove(&mtd_idr, i);
863fail_locked:
864 mutex_unlock(&mtd_table_mutex);
865 return error;
866}
867
868/**
869 * del_mtd_device - unregister an MTD device
870 * @mtd: pointer to MTD device info structure
871 *
872 * Remove a device from the list of MTD devices present in the system,
873 * and notify each currently active MTD 'user' of its departure.
874 * Returns zero on success or 1 on failure, which currently will happen
875 * if the requested device does not appear to be present in the list.
876 */
877
878int del_mtd_device(struct mtd_info *mtd)
879{
880 int ret;
881 struct mtd_notifier *not;
882
883 mutex_lock(&mtd_table_mutex);
884
885 if (idr_find(&mtd_idr, mtd->index) != mtd) {
886 ret = -ENODEV;
887 goto out_error;
888 }
889
890 /* No need to get a refcount on the module containing
891 the notifier, since we hold the mtd_table_mutex */
892 list_for_each_entry(not, &mtd_notifiers, list)
893 not->remove(mtd);
894
895 kref_put(&mtd->refcnt, mtd_device_release);
896 ret = 0;
897
898out_error:
899 mutex_unlock(&mtd_table_mutex);
900 return ret;
901}
902
903/*
904 * Set a few defaults based on the parent devices, if not provided by the
905 * driver
906 */
907static void mtd_set_dev_defaults(struct mtd_info *mtd)
908{
909 if (mtd->dev.parent) {
910 if (!mtd->owner && mtd->dev.parent->driver)
911 mtd->owner = mtd->dev.parent->driver->owner;
912 if (!mtd->name)
913 mtd->name = dev_name(mtd->dev.parent);
914 } else {
915 pr_debug("mtd device won't show a device symlink in sysfs\n");
916 }
917
918 INIT_LIST_HEAD(&mtd->partitions);
919 mutex_init(&mtd->master.partitions_lock);
920 mutex_init(&mtd->master.chrdev_lock);
921}
922
923static ssize_t mtd_otp_size(struct mtd_info *mtd, bool is_user)
924{
925 struct otp_info *info;
926 ssize_t size = 0;
927 unsigned int i;
928 size_t retlen;
929 int ret;
930
931 info = kmalloc(PAGE_SIZE, GFP_KERNEL);
932 if (!info)
933 return -ENOMEM;
934
935 if (is_user)
936 ret = mtd_get_user_prot_info(mtd, PAGE_SIZE, &retlen, info);
937 else
938 ret = mtd_get_fact_prot_info(mtd, PAGE_SIZE, &retlen, info);
939 if (ret)
940 goto err;
941
942 for (i = 0; i < retlen / sizeof(*info); i++)
943 size += info[i].length;
944
945 kfree(info);
946 return size;
947
948err:
949 kfree(info);
950
951 /* ENODATA means there is no OTP region. */
952 return ret == -ENODATA ? 0 : ret;
953}
954
955static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd,
956 const char *compatible,
957 int size,
958 nvmem_reg_read_t reg_read)
959{
960 struct nvmem_device *nvmem = NULL;
961 struct nvmem_config config = {};
962 struct device_node *np;
963
964 /* DT binding is optional */
965 np = of_get_compatible_child(mtd->dev.of_node, compatible);
966
967 /* OTP nvmem will be registered on the physical device */
968 config.dev = mtd->dev.parent;
969 config.name = compatible;
970 config.id = NVMEM_DEVID_AUTO;
971 config.owner = THIS_MODULE;
972 config.add_legacy_fixed_of_cells = !mtd_type_is_nand(mtd);
973 config.type = NVMEM_TYPE_OTP;
974 config.root_only = true;
975 config.ignore_wp = true;
976 config.reg_read = reg_read;
977 config.size = size;
978 config.of_node = np;
979 config.priv = mtd;
980
981 nvmem = nvmem_register(&config);
982 /* Just ignore if there is no NVMEM support in the kernel */
983 if (IS_ERR(nvmem) && PTR_ERR(nvmem) == -EOPNOTSUPP)
984 nvmem = NULL;
985
986 of_node_put(np);
987
988 return nvmem;
989}
990
991static int mtd_nvmem_user_otp_reg_read(void *priv, unsigned int offset,
992 void *val, size_t bytes)
993{
994 struct mtd_info *mtd = priv;
995 size_t retlen;
996 int ret;
997
998 ret = mtd_read_user_prot_reg(mtd, offset, bytes, &retlen, val);
999 if (ret)
1000 return ret;
1001
1002 return retlen == bytes ? 0 : -EIO;
1003}
1004
1005static int mtd_nvmem_fact_otp_reg_read(void *priv, unsigned int offset,
1006 void *val, size_t bytes)
1007{
1008 struct mtd_info *mtd = priv;
1009 size_t retlen;
1010 int ret;
1011
1012 ret = mtd_read_fact_prot_reg(mtd, offset, bytes, &retlen, val);
1013 if (ret)
1014 return ret;
1015
1016 return retlen == bytes ? 0 : -EIO;
1017}
1018
1019static int mtd_otp_nvmem_add(struct mtd_info *mtd)
1020{
1021 struct device *dev = mtd->dev.parent;
1022 struct nvmem_device *nvmem;
1023 ssize_t size;
1024 int err;
1025
1026 if (mtd->_get_user_prot_info && mtd->_read_user_prot_reg) {
1027 size = mtd_otp_size(mtd, true);
1028 if (size < 0) {
1029 err = size;
1030 goto err;
1031 }
1032
1033 if (size > 0) {
1034 nvmem = mtd_otp_nvmem_register(mtd, "user-otp", size,
1035 mtd_nvmem_user_otp_reg_read);
1036 if (IS_ERR(nvmem)) {
1037 err = PTR_ERR(nvmem);
1038 goto err;
1039 }
1040 mtd->otp_user_nvmem = nvmem;
1041 }
1042 }
1043
1044 if (mtd->_get_fact_prot_info && mtd->_read_fact_prot_reg) {
1045 size = mtd_otp_size(mtd, false);
1046 if (size < 0) {
1047 err = size;
1048 goto err;
1049 }
1050
1051 if (size > 0) {
1052 /*
1053 * The factory OTP contains thing such as a unique serial
1054 * number and is small, so let's read it out and put it
1055 * into the entropy pool.
1056 */
1057 void *otp;
1058
1059 otp = kmalloc(size, GFP_KERNEL);
1060 if (!otp) {
1061 err = -ENOMEM;
1062 goto err;
1063 }
1064 err = mtd_nvmem_fact_otp_reg_read(mtd, 0, otp, size);
1065 if (err < 0) {
1066 kfree(otp);
1067 goto err;
1068 }
1069 add_device_randomness(otp, err);
1070 kfree(otp);
1071
1072 nvmem = mtd_otp_nvmem_register(mtd, "factory-otp", size,
1073 mtd_nvmem_fact_otp_reg_read);
1074 if (IS_ERR(nvmem)) {
1075 err = PTR_ERR(nvmem);
1076 goto err;
1077 }
1078 mtd->otp_factory_nvmem = nvmem;
1079 }
1080 }
1081
1082 return 0;
1083
1084err:
1085 nvmem_unregister(mtd->otp_user_nvmem);
1086 mtd->otp_user_nvmem = NULL;
1087 /* Don't report error if OTP is not supported. */
1088 if (err == -EOPNOTSUPP)
1089 return 0;
1090 return dev_err_probe(dev, err, "Failed to register OTP NVMEM device\n");
1091}
1092
1093/**
1094 * mtd_device_parse_register - parse partitions and register an MTD device.
1095 *
1096 * @mtd: the MTD device to register
1097 * @types: the list of MTD partition probes to try, see
1098 * 'parse_mtd_partitions()' for more information
1099 * @parser_data: MTD partition parser-specific data
1100 * @parts: fallback partition information to register, if parsing fails;
1101 * only valid if %nr_parts > %0
1102 * @nr_parts: the number of partitions in parts, if zero then the full
1103 * MTD device is registered if no partition info is found
1104 *
1105 * This function aggregates MTD partitions parsing (done by
1106 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
1107 * basically follows the most common pattern found in many MTD drivers:
1108 *
1109 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
1110 * registered first.
1111 * * Then It tries to probe partitions on MTD device @mtd using parsers
1112 * specified in @types (if @types is %NULL, then the default list of parsers
1113 * is used, see 'parse_mtd_partitions()' for more information). If none are
1114 * found this functions tries to fallback to information specified in
1115 * @parts/@nr_parts.
1116 * * If no partitions were found this function just registers the MTD device
1117 * @mtd and exits.
1118 *
1119 * Returns zero in case of success and a negative error code in case of failure.
1120 */
1121int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
1122 struct mtd_part_parser_data *parser_data,
1123 const struct mtd_partition *parts,
1124 int nr_parts)
1125{
1126 int ret, err;
1127
1128 mtd_set_dev_defaults(mtd);
1129
1130 ret = mtd_otp_nvmem_add(mtd);
1131 if (ret)
1132 goto out;
1133
1134 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
1135 ret = add_mtd_device(mtd);
1136 if (ret)
1137 goto out;
1138 }
1139
1140 if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) {
1141 ret = mtd_virt_concat_node_create();
1142 if (ret < 0)
1143 goto out;
1144 }
1145
1146 /* Prefer parsed partitions over driver-provided fallback */
1147 ret = parse_mtd_partitions(mtd, types, parser_data);
1148 if (ret == -EPROBE_DEFER)
1149 goto out;
1150
1151 if (ret > 0)
1152 ret = 0;
1153 else if (nr_parts)
1154 ret = add_mtd_partitions(mtd, parts, nr_parts);
1155 else if (!device_is_registered(&mtd->dev))
1156 ret = add_mtd_device(mtd);
1157 else
1158 ret = 0;
1159
1160 if (ret)
1161 goto out;
1162
1163 if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) {
1164 ret = mtd_virt_concat_create_join();
1165 if (ret < 0)
1166 goto out;
1167 }
1168 /*
1169 * FIXME: some drivers unfortunately call this function more than once.
1170 * So we have to check if we've already assigned the reboot notifier.
1171 *
1172 * Generally, we can make multiple calls work for most cases, but it
1173 * does cause problems with parse_mtd_partitions() above (e.g.,
1174 * cmdlineparts will register partitions more than once).
1175 */
1176 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
1177 "MTD already registered\n");
1178 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
1179 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
1180 register_reboot_notifier(&mtd->reboot_notifier);
1181 }
1182
1183out:
1184 if (ret) {
1185 nvmem_unregister(mtd->otp_user_nvmem);
1186 nvmem_unregister(mtd->otp_factory_nvmem);
1187 }
1188
1189 if (ret && device_is_registered(&mtd->dev)) {
1190 err = del_mtd_device(mtd);
1191 if (err)
1192 pr_err("Error when deleting MTD device (%d)\n", err);
1193 }
1194
1195 return ret;
1196}
1197EXPORT_SYMBOL_GPL(mtd_device_parse_register);
1198
1199/**
1200 * mtd_device_unregister - unregister an existing MTD device.
1201 *
1202 * @master: the MTD device to unregister. This will unregister both the master
1203 * and any partitions if registered.
1204 */
1205int mtd_device_unregister(struct mtd_info *master)
1206{
1207 int err;
1208
1209 if (master->_reboot) {
1210 unregister_reboot_notifier(&master->reboot_notifier);
1211 memset(&master->reboot_notifier, 0, sizeof(master->reboot_notifier));
1212 }
1213
1214 nvmem_unregister(master->otp_user_nvmem);
1215 nvmem_unregister(master->otp_factory_nvmem);
1216
1217 if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) {
1218 err = mtd_virt_concat_destroy(master);
1219 if (err)
1220 return err;
1221 }
1222 err = del_mtd_partitions(master);
1223 if (err)
1224 return err;
1225
1226 if (!device_is_registered(&master->dev))
1227 return 0;
1228
1229 return del_mtd_device(master);
1230}
1231EXPORT_SYMBOL_GPL(mtd_device_unregister);
1232
1233/**
1234 * register_mtd_user - register a 'user' of MTD devices.
1235 * @new: pointer to notifier info structure
1236 *
1237 * Registers a pair of callbacks function to be called upon addition
1238 * or removal of MTD devices. Causes the 'add' callback to be immediately
1239 * invoked for each MTD device currently present in the system.
1240 */
1241void register_mtd_user (struct mtd_notifier *new)
1242{
1243 struct mtd_info *mtd;
1244
1245 mutex_lock(&mtd_table_mutex);
1246
1247 list_add(&new->list, &mtd_notifiers);
1248
1249 __module_get(THIS_MODULE);
1250
1251 mtd_for_each_device(mtd)
1252 new->add(mtd);
1253
1254 mutex_unlock(&mtd_table_mutex);
1255}
1256EXPORT_SYMBOL_GPL(register_mtd_user);
1257
1258/**
1259 * unregister_mtd_user - unregister a 'user' of MTD devices.
1260 * @old: pointer to notifier info structure
1261 *
1262 * Removes a callback function pair from the list of 'users' to be
1263 * notified upon addition or removal of MTD devices. Causes the
1264 * 'remove' callback to be immediately invoked for each MTD device
1265 * currently present in the system.
1266 */
1267int unregister_mtd_user (struct mtd_notifier *old)
1268{
1269 struct mtd_info *mtd;
1270
1271 mutex_lock(&mtd_table_mutex);
1272
1273 module_put(THIS_MODULE);
1274
1275 mtd_for_each_device(mtd)
1276 old->remove(mtd);
1277
1278 list_del(&old->list);
1279 mutex_unlock(&mtd_table_mutex);
1280 return 0;
1281}
1282EXPORT_SYMBOL_GPL(unregister_mtd_user);
1283
1284/**
1285 * get_mtd_device - obtain a validated handle for an MTD device
1286 * @mtd: last known address of the required MTD device
1287 * @num: internal device number of the required MTD device
1288 *
1289 * Given a number and NULL address, return the num'th entry in the device
1290 * table, if any. Given an address and num == -1, search the device table
1291 * for a device with that address and return if it's still present. Given
1292 * both, return the num'th driver only if its address matches. Return
1293 * error code if not.
1294 */
1295struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
1296{
1297 struct mtd_info *ret = NULL, *other;
1298 int err = -ENODEV;
1299
1300 mutex_lock(&mtd_table_mutex);
1301
1302 if (num == -1) {
1303 mtd_for_each_device(other) {
1304 if (other == mtd) {
1305 ret = mtd;
1306 break;
1307 }
1308 }
1309 } else if (num >= 0) {
1310 ret = idr_find(&mtd_idr, num);
1311 if (mtd && mtd != ret)
1312 ret = NULL;
1313 }
1314
1315 if (!ret) {
1316 ret = ERR_PTR(err);
1317 goto out;
1318 }
1319
1320 err = __get_mtd_device(ret);
1321 if (err)
1322 ret = ERR_PTR(err);
1323out:
1324 mutex_unlock(&mtd_table_mutex);
1325 return ret;
1326}
1327EXPORT_SYMBOL_GPL(get_mtd_device);
1328
1329
1330int __get_mtd_device(struct mtd_info *mtd)
1331{
1332 struct mtd_info *master = mtd_get_master(mtd);
1333 int err;
1334
1335 if (master->_get_device) {
1336 err = master->_get_device(master);
1337 if (err)
1338 return err;
1339 }
1340
1341 if (!try_module_get(master->owner)) {
1342 if (master->_put_device)
1343 master->_put_device(master);
1344 return -ENODEV;
1345 }
1346
1347 while (mtd) {
1348 if (mtd != master)
1349 kref_get(&mtd->refcnt);
1350 mtd = mtd->parent;
1351 }
1352
1353 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
1354 kref_get(&master->refcnt);
1355
1356 return 0;
1357}
1358EXPORT_SYMBOL_GPL(__get_mtd_device);
1359
1360/**
1361 * of_get_mtd_device_by_node - obtain an MTD device associated with a given node
1362 *
1363 * @np: device tree node
1364 */
1365struct mtd_info *of_get_mtd_device_by_node(struct device_node *np)
1366{
1367 struct mtd_info *mtd = NULL;
1368 struct mtd_info *tmp;
1369 int err;
1370
1371 mutex_lock(&mtd_table_mutex);
1372
1373 err = -EPROBE_DEFER;
1374 mtd_for_each_device(tmp) {
1375 if (mtd_get_of_node(tmp) == np) {
1376 mtd = tmp;
1377 err = __get_mtd_device(mtd);
1378 break;
1379 }
1380 }
1381
1382 mutex_unlock(&mtd_table_mutex);
1383
1384 return err ? ERR_PTR(err) : mtd;
1385}
1386EXPORT_SYMBOL_GPL(of_get_mtd_device_by_node);
1387
1388/**
1389 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1390 * device name
1391 * @name: MTD device name to open
1392 *
1393 * This function returns MTD device description structure in case of
1394 * success and an error code in case of failure.
1395 */
1396struct mtd_info *get_mtd_device_nm(const char *name)
1397{
1398 int err = -ENODEV;
1399 struct mtd_info *mtd = NULL, *other;
1400
1401 mutex_lock(&mtd_table_mutex);
1402
1403 mtd_for_each_device(other) {
1404 if (!strcmp(name, other->name)) {
1405 mtd = other;
1406 break;
1407 }
1408 }
1409
1410 if (!mtd)
1411 goto out_unlock;
1412
1413 err = __get_mtd_device(mtd);
1414 if (err)
1415 goto out_unlock;
1416
1417 mutex_unlock(&mtd_table_mutex);
1418 return mtd;
1419
1420out_unlock:
1421 mutex_unlock(&mtd_table_mutex);
1422 return ERR_PTR(err);
1423}
1424EXPORT_SYMBOL_GPL(get_mtd_device_nm);
1425
1426void put_mtd_device(struct mtd_info *mtd)
1427{
1428 mutex_lock(&mtd_table_mutex);
1429 __put_mtd_device(mtd);
1430 mutex_unlock(&mtd_table_mutex);
1431
1432}
1433EXPORT_SYMBOL_GPL(put_mtd_device);
1434
1435void __put_mtd_device(struct mtd_info *mtd)
1436{
1437 struct mtd_info *master = mtd_get_master(mtd);
1438
1439 while (mtd) {
1440 /* kref_put() can relese mtd, so keep a reference mtd->parent */
1441 struct mtd_info *parent = mtd->parent;
1442
1443 if (mtd != master)
1444 kref_put(&mtd->refcnt, mtd_device_release);
1445 mtd = parent;
1446 }
1447
1448 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
1449 kref_put(&master->refcnt, mtd_device_release);
1450
1451 module_put(master->owner);
1452
1453 /* must be the last as master can be freed in the _put_device */
1454 if (master->_put_device)
1455 master->_put_device(master);
1456}
1457EXPORT_SYMBOL_GPL(__put_mtd_device);
1458
1459/*
1460 * Erase is an synchronous operation. Device drivers are epected to return a
1461 * negative error code if the operation failed and update instr->fail_addr
1462 * to point the portion that was not properly erased.
1463 */
1464int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1465{
1466 struct mtd_info *master = mtd_get_master(mtd);
1467 u64 mst_ofs = mtd_get_master_ofs(mtd, 0);
1468 struct erase_info adjinstr;
1469 int ret;
1470
1471 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1472 adjinstr = *instr;
1473
1474 if (!mtd->erasesize || !master->_erase)
1475 return -ENOTSUPP;
1476
1477 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1478 return -EINVAL;
1479 if (!(mtd->flags & MTD_WRITEABLE))
1480 return -EROFS;
1481
1482 if (!instr->len)
1483 return 0;
1484
1485 ledtrig_mtd_activity();
1486
1487 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1488 adjinstr.addr = (loff_t)mtd_div_by_eb(instr->addr, mtd) *
1489 master->erasesize;
1490 adjinstr.len = ((u64)mtd_div_by_eb(instr->addr + instr->len, mtd) *
1491 master->erasesize) -
1492 adjinstr.addr;
1493 }
1494
1495 adjinstr.addr += mst_ofs;
1496
1497 ret = master->_erase(master, &adjinstr);
1498
1499 if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) {
1500 instr->fail_addr = adjinstr.fail_addr - mst_ofs;
1501 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1502 instr->fail_addr = mtd_div_by_eb(instr->fail_addr,
1503 master);
1504 instr->fail_addr *= mtd->erasesize;
1505 }
1506 }
1507
1508 return ret;
1509}
1510EXPORT_SYMBOL_GPL(mtd_erase);
1511ALLOW_ERROR_INJECTION(mtd_erase, ERRNO);
1512
1513/*
1514 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1515 */
1516int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1517 void **virt, resource_size_t *phys)
1518{
1519 struct mtd_info *master = mtd_get_master(mtd);
1520
1521 *retlen = 0;
1522 *virt = NULL;
1523 if (phys)
1524 *phys = 0;
1525 if (!master->_point)
1526 return -EOPNOTSUPP;
1527 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1528 return -EINVAL;
1529 if (!len)
1530 return 0;
1531
1532 from = mtd_get_master_ofs(mtd, from);
1533 return master->_point(master, from, len, retlen, virt, phys);
1534}
1535EXPORT_SYMBOL_GPL(mtd_point);
1536
1537/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1538int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1539{
1540 struct mtd_info *master = mtd_get_master(mtd);
1541
1542 if (!master->_unpoint)
1543 return -EOPNOTSUPP;
1544 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1545 return -EINVAL;
1546 if (!len)
1547 return 0;
1548 return master->_unpoint(master, mtd_get_master_ofs(mtd, from), len);
1549}
1550EXPORT_SYMBOL_GPL(mtd_unpoint);
1551
1552/*
1553 * Allow NOMMU mmap() to directly map the device (if not NULL)
1554 * - return the address to which the offset maps
1555 * - return -ENOSYS to indicate refusal to do the mapping
1556 */
1557unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1558 unsigned long offset, unsigned long flags)
1559{
1560 size_t retlen;
1561 void *virt;
1562 int ret;
1563
1564 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1565 if (ret)
1566 return ret;
1567 if (retlen != len) {
1568 mtd_unpoint(mtd, offset, retlen);
1569 return -ENOSYS;
1570 }
1571 return (unsigned long)virt;
1572}
1573EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1574
1575static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
1576 const struct mtd_ecc_stats *old_stats)
1577{
1578 struct mtd_ecc_stats diff;
1579
1580 if (master == mtd)
1581 return;
1582
1583 diff = master->ecc_stats;
1584 diff.failed -= old_stats->failed;
1585 diff.corrected -= old_stats->corrected;
1586
1587 while (mtd->parent) {
1588 mtd->ecc_stats.failed += diff.failed;
1589 mtd->ecc_stats.corrected += diff.corrected;
1590 mtd = mtd->parent;
1591 }
1592}
1593
1594int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1595 u_char *buf)
1596{
1597 struct mtd_oob_ops ops = {
1598 .len = len,
1599 .datbuf = buf,
1600 };
1601 int ret;
1602
1603 ret = mtd_read_oob(mtd, from, &ops);
1604 *retlen = ops.retlen;
1605
1606 WARN_ON_ONCE(*retlen != len && mtd_is_bitflip_or_eccerr(ret));
1607
1608 return ret;
1609}
1610EXPORT_SYMBOL_GPL(mtd_read);
1611ALLOW_ERROR_INJECTION(mtd_read, ERRNO);
1612
1613int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1614 const u_char *buf)
1615{
1616 struct mtd_oob_ops ops = {
1617 .len = len,
1618 .datbuf = (u8 *)buf,
1619 };
1620 int ret;
1621
1622 ret = mtd_write_oob(mtd, to, &ops);
1623 *retlen = ops.retlen;
1624
1625 return ret;
1626}
1627EXPORT_SYMBOL_GPL(mtd_write);
1628ALLOW_ERROR_INJECTION(mtd_write, ERRNO);
1629
1630/*
1631 * In blackbox flight recorder like scenarios we want to make successful writes
1632 * in interrupt context. panic_write() is only intended to be called when its
1633 * known the kernel is about to panic and we need the write to succeed. Since
1634 * the kernel is not going to be running for much longer, this function can
1635 * break locks and delay to ensure the write succeeds (but not sleep).
1636 */
1637int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1638 const u_char *buf)
1639{
1640 struct mtd_info *master = mtd_get_master(mtd);
1641
1642 *retlen = 0;
1643 if (!master->_panic_write)
1644 return -EOPNOTSUPP;
1645 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1646 return -EINVAL;
1647 if (!(mtd->flags & MTD_WRITEABLE))
1648 return -EROFS;
1649 if (!len)
1650 return 0;
1651 if (!master->oops_panic_write)
1652 master->oops_panic_write = true;
1653
1654 return master->_panic_write(master, mtd_get_master_ofs(mtd, to), len,
1655 retlen, buf);
1656}
1657EXPORT_SYMBOL_GPL(mtd_panic_write);
1658
1659static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1660 struct mtd_oob_ops *ops)
1661{
1662 /*
1663 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1664 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1665 * this case.
1666 */
1667 if (!ops->datbuf)
1668 ops->len = 0;
1669
1670 if (!ops->oobbuf)
1671 ops->ooblen = 0;
1672
1673 if (offs < 0 || offs + ops->len > mtd->size)
1674 return -EINVAL;
1675
1676 if (ops->ooblen) {
1677 size_t maxooblen;
1678
1679 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1680 return -EINVAL;
1681
1682 maxooblen = ((size_t)(mtd_div_by_ws(mtd->size, mtd) -
1683 mtd_div_by_ws(offs, mtd)) *
1684 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1685 if (ops->ooblen > maxooblen)
1686 return -EINVAL;
1687 }
1688
1689 return 0;
1690}
1691
1692static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from,
1693 struct mtd_oob_ops *ops)
1694{
1695 struct mtd_info *master = mtd_get_master(mtd);
1696 int ret;
1697
1698 from = mtd_get_master_ofs(mtd, from);
1699 if (master->_read_oob)
1700 ret = master->_read_oob(master, from, ops);
1701 else
1702 ret = master->_read(master, from, ops->len, &ops->retlen,
1703 ops->datbuf);
1704
1705 return ret;
1706}
1707
1708static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to,
1709 struct mtd_oob_ops *ops)
1710{
1711 struct mtd_info *master = mtd_get_master(mtd);
1712 int ret;
1713
1714 to = mtd_get_master_ofs(mtd, to);
1715 if (master->_write_oob)
1716 ret = master->_write_oob(master, to, ops);
1717 else
1718 ret = master->_write(master, to, ops->len, &ops->retlen,
1719 ops->datbuf);
1720
1721 return ret;
1722}
1723
1724static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read,
1725 struct mtd_oob_ops *ops)
1726{
1727 struct mtd_info *master = mtd_get_master(mtd);
1728 int ngroups = mtd_pairing_groups(master);
1729 int npairs = mtd_wunit_per_eb(master) / ngroups;
1730 struct mtd_oob_ops adjops = *ops;
1731 unsigned int wunit, oobavail;
1732 struct mtd_pairing_info info;
1733 int max_bitflips = 0;
1734 u32 ebofs, pageofs;
1735 loff_t base, pos;
1736
1737 ebofs = mtd_mod_by_eb(start, mtd);
1738 base = (loff_t)mtd_div_by_eb(start, mtd) * master->erasesize;
1739 info.group = 0;
1740 info.pair = mtd_div_by_ws(ebofs, mtd);
1741 pageofs = mtd_mod_by_ws(ebofs, mtd);
1742 oobavail = mtd_oobavail(mtd, ops);
1743
1744 while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) {
1745 int ret;
1746
1747 if (info.pair >= npairs) {
1748 info.pair = 0;
1749 base += master->erasesize;
1750 }
1751
1752 wunit = mtd_pairing_info_to_wunit(master, &info);
1753 pos = mtd_wunit_to_offset(mtd, base, wunit);
1754
1755 adjops.len = ops->len - ops->retlen;
1756 if (adjops.len > mtd->writesize - pageofs)
1757 adjops.len = mtd->writesize - pageofs;
1758
1759 adjops.ooblen = ops->ooblen - ops->oobretlen;
1760 if (adjops.ooblen > oobavail - adjops.ooboffs)
1761 adjops.ooblen = oobavail - adjops.ooboffs;
1762
1763 if (read) {
1764 ret = mtd_read_oob_std(mtd, pos + pageofs, &adjops);
1765 if (ret > 0)
1766 max_bitflips = max(max_bitflips, ret);
1767 } else {
1768 ret = mtd_write_oob_std(mtd, pos + pageofs, &adjops);
1769 }
1770
1771 if (ret < 0)
1772 return ret;
1773
1774 max_bitflips = max(max_bitflips, ret);
1775 ops->retlen += adjops.retlen;
1776 ops->oobretlen += adjops.oobretlen;
1777 adjops.datbuf += adjops.retlen;
1778 adjops.oobbuf += adjops.oobretlen;
1779 adjops.ooboffs = 0;
1780 pageofs = 0;
1781 info.pair++;
1782 }
1783
1784 return max_bitflips;
1785}
1786
1787int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1788{
1789 struct mtd_info *master = mtd_get_master(mtd);
1790 struct mtd_ecc_stats old_stats = master->ecc_stats;
1791 int ret_code;
1792
1793 ops->retlen = ops->oobretlen = 0;
1794
1795 ret_code = mtd_check_oob_ops(mtd, from, ops);
1796 if (ret_code)
1797 return ret_code;
1798
1799 ledtrig_mtd_activity();
1800
1801 /* Check the validity of a potential fallback on mtd->_read */
1802 if (!master->_read_oob && (!master->_read || ops->oobbuf))
1803 return -EOPNOTSUPP;
1804
1805 if (ops->stats)
1806 memset(ops->stats, 0, sizeof(*ops->stats));
1807
1808 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1809 ret_code = mtd_io_emulated_slc(mtd, from, true, ops);
1810 else
1811 ret_code = mtd_read_oob_std(mtd, from, ops);
1812
1813 mtd_update_ecc_stats(mtd, master, &old_stats);
1814
1815 /*
1816 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1817 * similar to mtd->_read(), returning a non-negative integer
1818 * representing max bitflips. In other cases, mtd->_read_oob() may
1819 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1820 */
1821 if (unlikely(ret_code < 0))
1822 return ret_code;
1823 if (mtd->ecc_strength == 0)
1824 return 0; /* device lacks ecc */
1825 if (ops->stats)
1826 ops->stats->max_bitflips = ret_code;
1827 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1828}
1829EXPORT_SYMBOL_GPL(mtd_read_oob);
1830
1831int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1832 struct mtd_oob_ops *ops)
1833{
1834 struct mtd_info *master = mtd_get_master(mtd);
1835 int ret;
1836
1837 ops->retlen = ops->oobretlen = 0;
1838
1839 if (!(mtd->flags & MTD_WRITEABLE))
1840 return -EROFS;
1841
1842 ret = mtd_check_oob_ops(mtd, to, ops);
1843 if (ret)
1844 return ret;
1845
1846 ledtrig_mtd_activity();
1847
1848 /* Check the validity of a potential fallback on mtd->_write */
1849 if (!master->_write_oob && (!master->_write || ops->oobbuf))
1850 return -EOPNOTSUPP;
1851
1852 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1853 return mtd_io_emulated_slc(mtd, to, false, ops);
1854
1855 return mtd_write_oob_std(mtd, to, ops);
1856}
1857EXPORT_SYMBOL_GPL(mtd_write_oob);
1858
1859/**
1860 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1861 * @mtd: MTD device structure
1862 * @section: ECC section. Depending on the layout you may have all the ECC
1863 * bytes stored in a single contiguous section, or one section
1864 * per ECC chunk (and sometime several sections for a single ECC
1865 * ECC chunk)
1866 * @oobecc: OOB region struct filled with the appropriate ECC position
1867 * information
1868 *
1869 * This function returns ECC section information in the OOB area. If you want
1870 * to get all the ECC bytes information, then you should call
1871 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1872 *
1873 * Returns zero on success, a negative error code otherwise.
1874 */
1875int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1876 struct mtd_oob_region *oobecc)
1877{
1878 struct mtd_info *master = mtd_get_master(mtd);
1879
1880 memset(oobecc, 0, sizeof(*oobecc));
1881
1882 if (!master || section < 0)
1883 return -EINVAL;
1884
1885 if (!master->ooblayout || !master->ooblayout->ecc)
1886 return -ENOTSUPP;
1887
1888 return master->ooblayout->ecc(master, section, oobecc);
1889}
1890EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1891
1892/**
1893 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1894 * section
1895 * @mtd: MTD device structure
1896 * @section: Free section you are interested in. Depending on the layout
1897 * you may have all the free bytes stored in a single contiguous
1898 * section, or one section per ECC chunk plus an extra section
1899 * for the remaining bytes (or other funky layout).
1900 * @oobfree: OOB region struct filled with the appropriate free position
1901 * information
1902 *
1903 * This function returns free bytes position in the OOB area. If you want
1904 * to get all the free bytes information, then you should call
1905 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1906 *
1907 * Returns zero on success, a negative error code otherwise.
1908 */
1909int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1910 struct mtd_oob_region *oobfree)
1911{
1912 struct mtd_info *master = mtd_get_master(mtd);
1913
1914 memset(oobfree, 0, sizeof(*oobfree));
1915
1916 if (!master || section < 0)
1917 return -EINVAL;
1918
1919 if (!master->ooblayout || !master->ooblayout->free)
1920 return -ENOTSUPP;
1921
1922 return master->ooblayout->free(master, section, oobfree);
1923}
1924EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1925
1926/**
1927 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1928 * @mtd: mtd info structure
1929 * @byte: the byte we are searching for
1930 * @sectionp: pointer where the section id will be stored
1931 * @oobregion: used to retrieve the ECC position
1932 * @iter: iterator function. Should be either mtd_ooblayout_free or
1933 * mtd_ooblayout_ecc depending on the region type you're searching for
1934 *
1935 * This function returns the section id and oobregion information of a
1936 * specific byte. For example, say you want to know where the 4th ECC byte is
1937 * stored, you'll use:
1938 *
1939 * mtd_ooblayout_find_region(mtd, 3, &section, &oobregion, mtd_ooblayout_ecc);
1940 *
1941 * Returns zero on success, a negative error code otherwise.
1942 */
1943static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1944 int *sectionp, struct mtd_oob_region *oobregion,
1945 int (*iter)(struct mtd_info *,
1946 int section,
1947 struct mtd_oob_region *oobregion))
1948{
1949 int pos = 0, ret, section = 0;
1950
1951 memset(oobregion, 0, sizeof(*oobregion));
1952
1953 while (1) {
1954 ret = iter(mtd, section, oobregion);
1955 if (ret)
1956 return ret;
1957
1958 if (pos + oobregion->length > byte)
1959 break;
1960
1961 pos += oobregion->length;
1962 section++;
1963 }
1964
1965 /*
1966 * Adjust region info to make it start at the beginning at the
1967 * 'start' ECC byte.
1968 */
1969 oobregion->offset += byte - pos;
1970 oobregion->length -= byte - pos;
1971 *sectionp = section;
1972
1973 return 0;
1974}
1975
1976/**
1977 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1978 * ECC byte
1979 * @mtd: mtd info structure
1980 * @eccbyte: the byte we are searching for
1981 * @section: pointer where the section id will be stored
1982 * @oobregion: OOB region information
1983 *
1984 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1985 * byte.
1986 *
1987 * Returns zero on success, a negative error code otherwise.
1988 */
1989int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1990 int *section,
1991 struct mtd_oob_region *oobregion)
1992{
1993 return mtd_ooblayout_find_region(mtd, eccbyte, section, oobregion,
1994 mtd_ooblayout_ecc);
1995}
1996EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1997
1998/**
1999 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
2000 * @mtd: mtd info structure
2001 * @buf: destination buffer to store OOB bytes
2002 * @oobbuf: OOB buffer
2003 * @start: first byte to retrieve
2004 * @nbytes: number of bytes to retrieve
2005 * @iter: section iterator
2006 *
2007 * Extract bytes attached to a specific category (ECC or free)
2008 * from the OOB buffer and copy them into buf.
2009 *
2010 * Returns zero on success, a negative error code otherwise.
2011 */
2012static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
2013 const u8 *oobbuf, int start, int nbytes,
2014 int (*iter)(struct mtd_info *,
2015 int section,
2016 struct mtd_oob_region *oobregion))
2017{
2018 struct mtd_oob_region oobregion;
2019 int section, ret;
2020
2021 ret = mtd_ooblayout_find_region(mtd, start, &section,
2022 &oobregion, iter);
2023
2024 while (!ret) {
2025 int cnt;
2026
2027 cnt = min_t(int, nbytes, oobregion.length);
2028 memcpy(buf, oobbuf + oobregion.offset, cnt);
2029 buf += cnt;
2030 nbytes -= cnt;
2031
2032 if (!nbytes)
2033 break;
2034
2035 ret = iter(mtd, ++section, &oobregion);
2036 }
2037
2038 return ret;
2039}
2040
2041/**
2042 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
2043 * @mtd: mtd info structure
2044 * @buf: source buffer to get OOB bytes from
2045 * @oobbuf: OOB buffer
2046 * @start: first OOB byte to set
2047 * @nbytes: number of OOB bytes to set
2048 * @iter: section iterator
2049 *
2050 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
2051 * is selected by passing the appropriate iterator.
2052 *
2053 * Returns zero on success, a negative error code otherwise.
2054 */
2055static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
2056 u8 *oobbuf, int start, int nbytes,
2057 int (*iter)(struct mtd_info *,
2058 int section,
2059 struct mtd_oob_region *oobregion))
2060{
2061 struct mtd_oob_region oobregion;
2062 int section, ret;
2063
2064 ret = mtd_ooblayout_find_region(mtd, start, &section,
2065 &oobregion, iter);
2066
2067 while (!ret) {
2068 int cnt;
2069
2070 cnt = min_t(int, nbytes, oobregion.length);
2071 memcpy(oobbuf + oobregion.offset, buf, cnt);
2072 buf += cnt;
2073 nbytes -= cnt;
2074
2075 if (!nbytes)
2076 break;
2077
2078 ret = iter(mtd, ++section, &oobregion);
2079 }
2080
2081 return ret;
2082}
2083
2084/**
2085 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
2086 * @mtd: mtd info structure
2087 * @iter: category iterator
2088 *
2089 * Count the number of bytes in a given category.
2090 *
2091 * Returns a positive value on success, a negative error code otherwise.
2092 */
2093static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
2094 int (*iter)(struct mtd_info *,
2095 int section,
2096 struct mtd_oob_region *oobregion))
2097{
2098 struct mtd_oob_region oobregion;
2099 int section = 0, ret, nbytes = 0;
2100
2101 while (1) {
2102 ret = iter(mtd, section++, &oobregion);
2103 if (ret) {
2104 if (ret == -ERANGE)
2105 ret = nbytes;
2106 break;
2107 }
2108
2109 nbytes += oobregion.length;
2110 }
2111
2112 return ret;
2113}
2114
2115/**
2116 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
2117 * @mtd: mtd info structure
2118 * @eccbuf: destination buffer to store ECC bytes
2119 * @oobbuf: OOB buffer
2120 * @start: first ECC byte to retrieve
2121 * @nbytes: number of ECC bytes to retrieve
2122 *
2123 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
2124 *
2125 * Returns zero on success, a negative error code otherwise.
2126 */
2127int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
2128 const u8 *oobbuf, int start, int nbytes)
2129{
2130 return mtd_ooblayout_get_bytes(mtd, eccbuf, oobbuf, start, nbytes,
2131 mtd_ooblayout_ecc);
2132}
2133EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
2134
2135/**
2136 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
2137 * @mtd: mtd info structure
2138 * @eccbuf: source buffer to get ECC bytes from
2139 * @oobbuf: OOB buffer
2140 * @start: first ECC byte to set
2141 * @nbytes: number of ECC bytes to set
2142 *
2143 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
2144 *
2145 * Returns zero on success, a negative error code otherwise.
2146 */
2147int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
2148 u8 *oobbuf, int start, int nbytes)
2149{
2150 return mtd_ooblayout_set_bytes(mtd, eccbuf, oobbuf, start, nbytes,
2151 mtd_ooblayout_ecc);
2152}
2153EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
2154
2155/**
2156 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
2157 * @mtd: mtd info structure
2158 * @databuf: destination buffer to store ECC bytes
2159 * @oobbuf: OOB buffer
2160 * @start: first ECC byte to retrieve
2161 * @nbytes: number of ECC bytes to retrieve
2162 *
2163 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
2164 *
2165 * Returns zero on success, a negative error code otherwise.
2166 */
2167int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
2168 const u8 *oobbuf, int start, int nbytes)
2169{
2170 return mtd_ooblayout_get_bytes(mtd, databuf, oobbuf, start, nbytes,
2171 mtd_ooblayout_free);
2172}
2173EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
2174
2175/**
2176 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
2177 * @mtd: mtd info structure
2178 * @databuf: source buffer to get data bytes from
2179 * @oobbuf: OOB buffer
2180 * @start: first ECC byte to set
2181 * @nbytes: number of ECC bytes to set
2182 *
2183 * Works like mtd_ooblayout_set_bytes(), except it acts on free bytes.
2184 *
2185 * Returns zero on success, a negative error code otherwise.
2186 */
2187int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
2188 u8 *oobbuf, int start, int nbytes)
2189{
2190 return mtd_ooblayout_set_bytes(mtd, databuf, oobbuf, start, nbytes,
2191 mtd_ooblayout_free);
2192}
2193EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
2194
2195/**
2196 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
2197 * @mtd: mtd info structure
2198 *
2199 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
2200 *
2201 * Returns zero on success, a negative error code otherwise.
2202 */
2203int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
2204{
2205 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_free);
2206}
2207EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
2208
2209/**
2210 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
2211 * @mtd: mtd info structure
2212 *
2213 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
2214 *
2215 * Returns zero on success, a negative error code otherwise.
2216 */
2217int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
2218{
2219 return mtd_ooblayout_count_bytes(mtd, mtd_ooblayout_ecc);
2220}
2221EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
2222
2223/*
2224 * Method to access the protection register area, present in some flash
2225 * devices. The user data is one time programmable but the factory data is read
2226 * only.
2227 */
2228int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
2229 struct otp_info *buf)
2230{
2231 struct mtd_info *master = mtd_get_master(mtd);
2232
2233 if (!master->_get_fact_prot_info)
2234 return -EOPNOTSUPP;
2235 if (!len)
2236 return 0;
2237 return master->_get_fact_prot_info(master, len, retlen, buf);
2238}
2239EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
2240
2241int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2242 size_t *retlen, u_char *buf)
2243{
2244 struct mtd_info *master = mtd_get_master(mtd);
2245
2246 *retlen = 0;
2247 if (!master->_read_fact_prot_reg)
2248 return -EOPNOTSUPP;
2249 if (!len)
2250 return 0;
2251 return master->_read_fact_prot_reg(master, from, len, retlen, buf);
2252}
2253EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
2254
2255int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
2256 struct otp_info *buf)
2257{
2258 struct mtd_info *master = mtd_get_master(mtd);
2259
2260 if (!master->_get_user_prot_info)
2261 return -EOPNOTSUPP;
2262 if (!len)
2263 return 0;
2264 return master->_get_user_prot_info(master, len, retlen, buf);
2265}
2266EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
2267
2268int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2269 size_t *retlen, u_char *buf)
2270{
2271 struct mtd_info *master = mtd_get_master(mtd);
2272
2273 *retlen = 0;
2274 if (!master->_read_user_prot_reg)
2275 return -EOPNOTSUPP;
2276 if (!len)
2277 return 0;
2278 return master->_read_user_prot_reg(master, from, len, retlen, buf);
2279}
2280EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
2281
2282int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
2283 size_t *retlen, const u_char *buf)
2284{
2285 struct mtd_info *master = mtd_get_master(mtd);
2286 int ret;
2287
2288 *retlen = 0;
2289 if (!master->_write_user_prot_reg)
2290 return -EOPNOTSUPP;
2291 if (!len)
2292 return 0;
2293 ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
2294 if (ret)
2295 return ret;
2296
2297 /*
2298 * If no data could be written at all, we are out of memory and
2299 * must return -ENOSPC.
2300 */
2301 return (*retlen) ? 0 : -ENOSPC;
2302}
2303EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
2304
2305int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2306{
2307 struct mtd_info *master = mtd_get_master(mtd);
2308
2309 if (!master->_lock_user_prot_reg)
2310 return -EOPNOTSUPP;
2311 if (!len)
2312 return 0;
2313 return master->_lock_user_prot_reg(master, from, len);
2314}
2315EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
2316
2317int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2318{
2319 struct mtd_info *master = mtd_get_master(mtd);
2320
2321 if (!master->_erase_user_prot_reg)
2322 return -EOPNOTSUPP;
2323 if (!len)
2324 return 0;
2325 return master->_erase_user_prot_reg(master, from, len);
2326}
2327EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg);
2328
2329/* Chip-supported device locking */
2330int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2331{
2332 struct mtd_info *master = mtd_get_master(mtd);
2333
2334 if (!master->_lock)
2335 return -EOPNOTSUPP;
2336 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2337 return -EINVAL;
2338 if (!len)
2339 return 0;
2340
2341 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2342 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2343 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2344 }
2345
2346 return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
2347}
2348EXPORT_SYMBOL_GPL(mtd_lock);
2349
2350int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2351{
2352 struct mtd_info *master = mtd_get_master(mtd);
2353
2354 if (!master->_unlock)
2355 return -EOPNOTSUPP;
2356 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2357 return -EINVAL;
2358 if (!len)
2359 return 0;
2360
2361 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2362 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2363 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2364 }
2365
2366 return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
2367}
2368EXPORT_SYMBOL_GPL(mtd_unlock);
2369
2370int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2371{
2372 struct mtd_info *master = mtd_get_master(mtd);
2373
2374 if (!master->_is_locked)
2375 return -EOPNOTSUPP;
2376 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2377 return -EINVAL;
2378 if (!len)
2379 return 0;
2380
2381 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2382 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2383 len = (u64)mtd_div_by_eb(len, mtd) * master->erasesize;
2384 }
2385
2386 return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
2387}
2388EXPORT_SYMBOL_GPL(mtd_is_locked);
2389
2390int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
2391{
2392 struct mtd_info *master = mtd_get_master(mtd);
2393
2394 if (ofs < 0 || ofs >= mtd->size)
2395 return -EINVAL;
2396 if (!master->_block_isreserved)
2397 return 0;
2398
2399 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2400 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2401
2402 return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
2403}
2404EXPORT_SYMBOL_GPL(mtd_block_isreserved);
2405
2406int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
2407{
2408 struct mtd_info *master = mtd_get_master(mtd);
2409
2410 if (ofs < 0 || ofs >= mtd->size)
2411 return -EINVAL;
2412 if (!master->_block_isbad)
2413 return 0;
2414
2415 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2416 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2417
2418 return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
2419}
2420EXPORT_SYMBOL_GPL(mtd_block_isbad);
2421
2422int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
2423{
2424 struct mtd_info *master = mtd_get_master(mtd);
2425 loff_t moffs;
2426 int ret;
2427
2428 if (!master->_block_markbad)
2429 return -EOPNOTSUPP;
2430 if (ofs < 0 || ofs >= mtd->size)
2431 return -EINVAL;
2432 if (!(mtd->flags & MTD_WRITEABLE))
2433 return -EROFS;
2434
2435 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2436 ofs = (loff_t)mtd_div_by_eb(ofs, mtd) * master->erasesize;
2437
2438 moffs = mtd_get_master_ofs(mtd, ofs);
2439
2440 if (master->_block_isbad) {
2441 ret = master->_block_isbad(master, moffs);
2442 if (ret > 0)
2443 return 0;
2444 }
2445
2446 ret = master->_block_markbad(master, moffs);
2447 if (ret)
2448 return ret;
2449
2450 while (mtd->parent) {
2451 mtd->ecc_stats.badblocks++;
2452 mtd = mtd->parent;
2453 }
2454
2455 return 0;
2456}
2457EXPORT_SYMBOL_GPL(mtd_block_markbad);
2458ALLOW_ERROR_INJECTION(mtd_block_markbad, ERRNO);
2459
2460/*
2461 * default_mtd_writev - the default writev method
2462 * @mtd: mtd device description object pointer
2463 * @vecs: the vectors to write
2464 * @count: count of vectors in @vecs
2465 * @to: the MTD device offset to write to
2466 * @retlen: on exit contains the count of bytes written to the MTD device.
2467 *
2468 * This function returns zero in case of success and a negative error code in
2469 * case of failure.
2470 */
2471static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2472 unsigned long count, loff_t to, size_t *retlen)
2473{
2474 unsigned long i;
2475 size_t totlen = 0, thislen;
2476 int ret = 0;
2477
2478 for (i = 0; i < count; i++) {
2479 if (!vecs[i].iov_len)
2480 continue;
2481 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
2482 vecs[i].iov_base);
2483 totlen += thislen;
2484 if (ret || thislen != vecs[i].iov_len)
2485 break;
2486 to += vecs[i].iov_len;
2487 }
2488 *retlen = totlen;
2489 return ret;
2490}
2491
2492/*
2493 * mtd_writev - the vector-based MTD write method
2494 * @mtd: mtd device description object pointer
2495 * @vecs: the vectors to write
2496 * @count: count of vectors in @vecs
2497 * @to: the MTD device offset to write to
2498 * @retlen: on exit contains the count of bytes written to the MTD device.
2499 *
2500 * This function returns zero in case of success and a negative error code in
2501 * case of failure.
2502 */
2503int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2504 unsigned long count, loff_t to, size_t *retlen)
2505{
2506 struct mtd_info *master = mtd_get_master(mtd);
2507
2508 *retlen = 0;
2509 if (!(mtd->flags & MTD_WRITEABLE))
2510 return -EROFS;
2511
2512 if (!master->_writev)
2513 return default_mtd_writev(mtd, vecs, count, to, retlen);
2514
2515 return master->_writev(master, vecs, count,
2516 mtd_get_master_ofs(mtd, to), retlen);
2517}
2518EXPORT_SYMBOL_GPL(mtd_writev);
2519
2520/**
2521 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
2522 * @mtd: mtd device description object pointer
2523 * @size: a pointer to the ideal or maximum size of the allocation, points
2524 * to the actual allocation size on success.
2525 *
2526 * This routine attempts to allocate a contiguous kernel buffer up to
2527 * the specified size, backing off the size of the request exponentially
2528 * until the request succeeds or until the allocation size falls below
2529 * the system page size. This attempts to make sure it does not adversely
2530 * impact system performance, so when allocating more than one page, we
2531 * ask the memory allocator to avoid re-trying, swapping, writing back
2532 * or performing I/O.
2533 *
2534 * Note, this function also makes sure that the allocated buffer is aligned to
2535 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
2536 *
2537 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
2538 * to handle smaller (i.e. degraded) buffer allocations under low- or
2539 * fragmented-memory situations where such reduced allocations, from a
2540 * requested ideal, are allowed.
2541 *
2542 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
2543 */
2544void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
2545{
2546 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
2547 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
2548 void *kbuf;
2549
2550 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
2551
2552 while (*size > min_alloc) {
2553 kbuf = kmalloc(*size, flags);
2554 if (kbuf)
2555 return kbuf;
2556
2557 *size >>= 1;
2558 *size = ALIGN(*size, mtd->writesize);
2559 }
2560
2561 /*
2562 * For the last resort allocation allow 'kmalloc()' to do all sorts of
2563 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
2564 */
2565 return kmalloc(*size, GFP_KERNEL);
2566}
2567EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
2568
2569#ifdef CONFIG_PROC_FS
2570
2571/*====================================================================*/
2572/* Support for /proc/mtd */
2573
2574static int mtd_proc_show(struct seq_file *m, void *v)
2575{
2576 struct mtd_info *mtd;
2577
2578 seq_puts(m, "dev: size erasesize name\n");
2579 mutex_lock(&mtd_table_mutex);
2580 mtd_for_each_device(mtd) {
2581 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
2582 mtd->index, (unsigned long long)mtd->size,
2583 mtd->erasesize, mtd->name);
2584 }
2585 mutex_unlock(&mtd_table_mutex);
2586 return 0;
2587}
2588#endif /* CONFIG_PROC_FS */
2589
2590/*====================================================================*/
2591/* Init code */
2592
2593static struct backing_dev_info * __init mtd_bdi_init(const char *name)
2594{
2595 struct backing_dev_info *bdi;
2596 int ret;
2597
2598 bdi = bdi_alloc(NUMA_NO_NODE);
2599 if (!bdi)
2600 return ERR_PTR(-ENOMEM);
2601 bdi->ra_pages = 0;
2602 bdi->io_pages = 0;
2603
2604 /*
2605 * We put '-0' suffix to the name to get the same name format as we
2606 * used to get. Since this is called only once, we get a unique name.
2607 */
2608 ret = bdi_register(bdi, "%.28s-0", name);
2609 if (ret)
2610 bdi_put(bdi);
2611
2612 return ret ? ERR_PTR(ret) : bdi;
2613}
2614
2615static struct proc_dir_entry *proc_mtd;
2616
2617static int __init init_mtd(void)
2618{
2619 int ret;
2620
2621 ret = class_register(&mtd_class);
2622 if (ret)
2623 goto err_reg;
2624
2625 mtd_bdi = mtd_bdi_init("mtd");
2626 if (IS_ERR(mtd_bdi)) {
2627 ret = PTR_ERR(mtd_bdi);
2628 goto err_bdi;
2629 }
2630
2631 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
2632
2633 ret = init_mtdchar();
2634 if (ret)
2635 goto out_procfs;
2636
2637 dfs_dir_mtd = debugfs_create_dir("mtd", NULL);
2638 debugfs_create_bool("expert_analysis_mode", 0600, dfs_dir_mtd,
2639 &mtd_expert_analysis_mode);
2640
2641 return 0;
2642
2643out_procfs:
2644 if (proc_mtd)
2645 remove_proc_entry("mtd", NULL);
2646 bdi_unregister(mtd_bdi);
2647 bdi_put(mtd_bdi);
2648err_bdi:
2649 class_unregister(&mtd_class);
2650err_reg:
2651 pr_err("Error registering mtd class or bdi: %d\n", ret);
2652 return ret;
2653}
2654
2655static void __exit cleanup_mtd(void)
2656{
2657 if (IS_REACHABLE(CONFIG_MTD_VIRT_CONCAT)) {
2658 mtd_virt_concat_destroy_joins();
2659 mtd_virt_concat_destroy_items();
2660 }
2661 debugfs_remove_recursive(dfs_dir_mtd);
2662 cleanup_mtdchar();
2663 if (proc_mtd)
2664 remove_proc_entry("mtd", NULL);
2665 class_unregister(&mtd_class);
2666 bdi_unregister(mtd_bdi);
2667 bdi_put(mtd_bdi);
2668 idr_destroy(&mtd_idr);
2669}
2670
2671module_init(init_mtd);
2672module_exit(cleanup_mtd);
2673
2674MODULE_LICENSE("GPL");
2675MODULE_AUTHOR("David Woodhouse <[email protected]>");
2676MODULE_DESCRIPTION("Core MTD registration and access routines");