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, nextid: &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, id: mtd->index);
98 of_node_put(node: 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(cls: &mtd_class, devt: 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(dentry: mtd->dbg.dfs_dir);
113
114 /* Try to remove the NVMEM provider */
115 nvmem_unregister(nvmem: mtd->nvmem);
116
117 device_unregister(dev: &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, fmt: "%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, fmt: "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, fmt: "%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, fmt: "%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, fmt: "%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, fmt: "%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, fmt: "%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, fmt: "%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, fmt: "%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, fmt: "%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, fmt: "%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, fmt: "%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(s: buf, base: 0, res: &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, fmt: "%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, fmt: "%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, fmt: "%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, fmt: "%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, fmt: "%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(ptr: dfs_dir_mtd))
392 return;
393
394 mtd->dbg.dfs_dir = debugfs_create_dir(name: dev_name(dev), parent: 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(mtd: master) / mtd_pairing_groups(mtd: 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(mtd: master);
499 int npairs = mtd_wunit_per_eb(mtd: 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, from: offset, len: bytes, retlen: &retlen, buf: 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(dev: &mtd->dev);
555 config.owner = THIS_MODULE;
556 config.add_legacy_fixed_of_cells = of_device_is_compatible(device: 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(cfg: &config);
567 if (IS_ERR(ptr: mtd->nvmem)) {
568 /* Just ignore if there is no NVMEM support in the kernel */
569 if (PTR_ERR(ptr: mtd->nvmem) == -EOPNOTSUPP)
570 mtd->nvmem = NULL;
571 else
572 return dev_err_probe(dev: &mtd->dev, err: PTR_ERR(ptr: mtd->nvmem),
573 fmt: "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(node: mtd_get_of_node(mtd: mtd->parent));
593 if (!parent_dn)
594 return;
595
596 if (mtd_is_partition(mtd: mtd->parent))
597 partitions = of_node_get(node: parent_dn);
598 else
599 partitions = of_get_child_by_name(node: parent_dn, name: "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(np: mtd_dn, prefix))
610 continue;
611
612 /* Label have priority. Check that first */
613 if (!of_property_read_string(np: mtd_dn, propname: "label", out_string: &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, np: mtd_dn);
624 of_node_put(node: mtd_dn);
625 break;
626 }
627 }
628
629 of_node_put(node: partitions);
630exit_parent:
631 of_node_put(node: 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, stem: "mtd");
690 if (ofidx >= 0)
691 i = idr_alloc(&mtd_idr, ptr: mtd, start: ofidx, end: ofidx + 1, GFP_KERNEL);
692 else
693 i = idr_alloc(&mtd_idr, ptr: mtd, start: 0, end: 0, GFP_KERNEL);
694 if (i < 0) {
695 error = i;
696 goto fail_locked;
697 }
698
699 mtd->index = i;
700 kref_init(kref: &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(sz: mtd->size, mtd: master) *
711 mtd->erasesize;
712 }
713
714 if (is_power_of_2(n: mtd->erasesize))
715 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
716 else
717 mtd->erasesize_shift = 0;
718
719 if (is_power_of_2(n: 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, ofs: 0, len: 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 dev_set_name(dev: &mtd->dev, name: "mtd%d", i);
745 dev_set_drvdata(dev: &mtd->dev, data: mtd);
746 mtd_check_of_node(mtd);
747 of_node_get(node: mtd_get_of_node(mtd));
748 error = device_register(dev: &mtd->dev);
749 if (error) {
750 put_device(dev: &mtd->dev);
751 goto fail_added;
752 }
753
754 /* Add the nvmem provider */
755 error = mtd_nvmem_add(mtd);
756 if (error)
757 goto fail_nvmem_add;
758
759 mtd_debugfs_populate(mtd);
760
761 device_create(cls: &mtd_class, parent: mtd->dev.parent, MTD_DEVT(i) + 1, NULL,
762 fmt: "mtd%dro", i);
763
764 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
765 /* No need to get a refcount on the module containing
766 the notifier, since we hold the mtd_table_mutex */
767 list_for_each_entry(not, &mtd_notifiers, list)
768 not->add(mtd);
769
770 mutex_unlock(lock: &mtd_table_mutex);
771
772 if (of_property_read_bool(np: mtd_get_of_node(mtd), propname: "linux,rootfs")) {
773 if (IS_BUILTIN(CONFIG_MTD)) {
774 pr_info("mtd: setting mtd%d (%s) as root device\n", mtd->index, mtd->name);
775 ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
776 } else {
777 pr_warn("mtd: can't set mtd%d (%s) as root device - mtd must be builtin\n",
778 mtd->index, mtd->name);
779 }
780 }
781
782 /* We _know_ we aren't being removed, because
783 our caller is still holding us here. So none
784 of this try_ nonsense, and no bitching about it
785 either. :) */
786 __module_get(THIS_MODULE);
787 return 0;
788
789fail_nvmem_add:
790 device_unregister(dev: &mtd->dev);
791fail_added:
792 of_node_put(node: mtd_get_of_node(mtd));
793 idr_remove(&mtd_idr, id: i);
794fail_locked:
795 mutex_unlock(lock: &mtd_table_mutex);
796 return error;
797}
798
799/**
800 * del_mtd_device - unregister an MTD device
801 * @mtd: pointer to MTD device info structure
802 *
803 * Remove a device from the list of MTD devices present in the system,
804 * and notify each currently active MTD 'user' of its departure.
805 * Returns zero on success or 1 on failure, which currently will happen
806 * if the requested device does not appear to be present in the list.
807 */
808
809int del_mtd_device(struct mtd_info *mtd)
810{
811 int ret;
812 struct mtd_notifier *not;
813
814 mutex_lock(&mtd_table_mutex);
815
816 if (idr_find(&mtd_idr, id: mtd->index) != mtd) {
817 ret = -ENODEV;
818 goto out_error;
819 }
820
821 /* No need to get a refcount on the module containing
822 the notifier, since we hold the mtd_table_mutex */
823 list_for_each_entry(not, &mtd_notifiers, list)
824 not->remove(mtd);
825
826 kref_put(kref: &mtd->refcnt, release: mtd_device_release);
827 ret = 0;
828
829out_error:
830 mutex_unlock(lock: &mtd_table_mutex);
831 return ret;
832}
833
834/*
835 * Set a few defaults based on the parent devices, if not provided by the
836 * driver
837 */
838static void mtd_set_dev_defaults(struct mtd_info *mtd)
839{
840 if (mtd->dev.parent) {
841 if (!mtd->owner && mtd->dev.parent->driver)
842 mtd->owner = mtd->dev.parent->driver->owner;
843 if (!mtd->name)
844 mtd->name = dev_name(dev: mtd->dev.parent);
845 } else {
846 pr_debug("mtd device won't show a device symlink in sysfs\n");
847 }
848
849 INIT_LIST_HEAD(list: &mtd->partitions);
850 mutex_init(&mtd->master.partitions_lock);
851 mutex_init(&mtd->master.chrdev_lock);
852}
853
854static ssize_t mtd_otp_size(struct mtd_info *mtd, bool is_user)
855{
856 struct otp_info *info;
857 ssize_t size = 0;
858 unsigned int i;
859 size_t retlen;
860 int ret;
861
862 info = kmalloc(PAGE_SIZE, GFP_KERNEL);
863 if (!info)
864 return -ENOMEM;
865
866 if (is_user)
867 ret = mtd_get_user_prot_info(mtd, PAGE_SIZE, retlen: &retlen, buf: info);
868 else
869 ret = mtd_get_fact_prot_info(mtd, PAGE_SIZE, retlen: &retlen, buf: info);
870 if (ret)
871 goto err;
872
873 for (i = 0; i < retlen / sizeof(*info); i++)
874 size += info[i].length;
875
876 kfree(objp: info);
877 return size;
878
879err:
880 kfree(objp: info);
881
882 /* ENODATA means there is no OTP region. */
883 return ret == -ENODATA ? 0 : ret;
884}
885
886static struct nvmem_device *mtd_otp_nvmem_register(struct mtd_info *mtd,
887 const char *compatible,
888 int size,
889 nvmem_reg_read_t reg_read)
890{
891 struct nvmem_device *nvmem = NULL;
892 struct nvmem_config config = {};
893 struct device_node *np;
894
895 /* DT binding is optional */
896 np = of_get_compatible_child(parent: mtd->dev.of_node, compatible);
897
898 /* OTP nvmem will be registered on the physical device */
899 config.dev = mtd->dev.parent;
900 config.name = compatible;
901 config.id = NVMEM_DEVID_AUTO;
902 config.owner = THIS_MODULE;
903 config.add_legacy_fixed_of_cells = true;
904 config.type = NVMEM_TYPE_OTP;
905 config.root_only = true;
906 config.ignore_wp = true;
907 config.reg_read = reg_read;
908 config.size = size;
909 config.of_node = np;
910 config.priv = mtd;
911
912 nvmem = nvmem_register(cfg: &config);
913 /* Just ignore if there is no NVMEM support in the kernel */
914 if (IS_ERR(ptr: nvmem) && PTR_ERR(ptr: nvmem) == -EOPNOTSUPP)
915 nvmem = NULL;
916
917 of_node_put(node: np);
918
919 return nvmem;
920}
921
922static int mtd_nvmem_user_otp_reg_read(void *priv, unsigned int offset,
923 void *val, size_t bytes)
924{
925 struct mtd_info *mtd = priv;
926 size_t retlen;
927 int ret;
928
929 ret = mtd_read_user_prot_reg(mtd, from: offset, len: bytes, retlen: &retlen, buf: val);
930 if (ret)
931 return ret;
932
933 return retlen == bytes ? 0 : -EIO;
934}
935
936static int mtd_nvmem_fact_otp_reg_read(void *priv, unsigned int offset,
937 void *val, size_t bytes)
938{
939 struct mtd_info *mtd = priv;
940 size_t retlen;
941 int ret;
942
943 ret = mtd_read_fact_prot_reg(mtd, from: offset, len: bytes, retlen: &retlen, buf: val);
944 if (ret)
945 return ret;
946
947 return retlen == bytes ? 0 : -EIO;
948}
949
950static int mtd_otp_nvmem_add(struct mtd_info *mtd)
951{
952 struct device *dev = mtd->dev.parent;
953 struct nvmem_device *nvmem;
954 ssize_t size;
955 int err;
956
957 if (mtd->_get_user_prot_info && mtd->_read_user_prot_reg) {
958 size = mtd_otp_size(mtd, is_user: true);
959 if (size < 0)
960 return size;
961
962 if (size > 0) {
963 nvmem = mtd_otp_nvmem_register(mtd, compatible: "user-otp", size,
964 reg_read: mtd_nvmem_user_otp_reg_read);
965 if (IS_ERR(ptr: nvmem)) {
966 err = PTR_ERR(ptr: nvmem);
967 goto err;
968 }
969 mtd->otp_user_nvmem = nvmem;
970 }
971 }
972
973 if (mtd->_get_fact_prot_info && mtd->_read_fact_prot_reg) {
974 size = mtd_otp_size(mtd, is_user: false);
975 if (size < 0) {
976 err = size;
977 goto err;
978 }
979
980 if (size > 0) {
981 /*
982 * The factory OTP contains thing such as a unique serial
983 * number and is small, so let's read it out and put it
984 * into the entropy pool.
985 */
986 void *otp;
987
988 otp = kmalloc(size, GFP_KERNEL);
989 if (!otp) {
990 err = -ENOMEM;
991 goto err;
992 }
993 err = mtd_nvmem_fact_otp_reg_read(priv: mtd, offset: 0, val: otp, bytes: size);
994 if (err < 0) {
995 kfree(objp: otp);
996 goto err;
997 }
998 add_device_randomness(buf: otp, len: err);
999 kfree(objp: otp);
1000
1001 nvmem = mtd_otp_nvmem_register(mtd, compatible: "factory-otp", size,
1002 reg_read: mtd_nvmem_fact_otp_reg_read);
1003 if (IS_ERR(ptr: nvmem)) {
1004 err = PTR_ERR(ptr: nvmem);
1005 goto err;
1006 }
1007 mtd->otp_factory_nvmem = nvmem;
1008 }
1009 }
1010
1011 return 0;
1012
1013err:
1014 nvmem_unregister(nvmem: mtd->otp_user_nvmem);
1015 return dev_err_probe(dev, err, fmt: "Failed to register OTP NVMEM device\n");
1016}
1017
1018/**
1019 * mtd_device_parse_register - parse partitions and register an MTD device.
1020 *
1021 * @mtd: the MTD device to register
1022 * @types: the list of MTD partition probes to try, see
1023 * 'parse_mtd_partitions()' for more information
1024 * @parser_data: MTD partition parser-specific data
1025 * @parts: fallback partition information to register, if parsing fails;
1026 * only valid if %nr_parts > %0
1027 * @nr_parts: the number of partitions in parts, if zero then the full
1028 * MTD device is registered if no partition info is found
1029 *
1030 * This function aggregates MTD partitions parsing (done by
1031 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
1032 * basically follows the most common pattern found in many MTD drivers:
1033 *
1034 * * If the MTD_PARTITIONED_MASTER option is set, then the device as a whole is
1035 * registered first.
1036 * * Then It tries to probe partitions on MTD device @mtd using parsers
1037 * specified in @types (if @types is %NULL, then the default list of parsers
1038 * is used, see 'parse_mtd_partitions()' for more information). If none are
1039 * found this functions tries to fallback to information specified in
1040 * @parts/@nr_parts.
1041 * * If no partitions were found this function just registers the MTD device
1042 * @mtd and exits.
1043 *
1044 * Returns zero in case of success and a negative error code in case of failure.
1045 */
1046int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
1047 struct mtd_part_parser_data *parser_data,
1048 const struct mtd_partition *parts,
1049 int nr_parts)
1050{
1051 int ret;
1052
1053 mtd_set_dev_defaults(mtd);
1054
1055 ret = mtd_otp_nvmem_add(mtd);
1056 if (ret)
1057 goto out;
1058
1059 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER)) {
1060 ret = add_mtd_device(mtd);
1061 if (ret)
1062 goto out;
1063 }
1064
1065 /* Prefer parsed partitions over driver-provided fallback */
1066 ret = parse_mtd_partitions(master: mtd, types, data: parser_data);
1067 if (ret == -EPROBE_DEFER)
1068 goto out;
1069
1070 if (ret > 0)
1071 ret = 0;
1072 else if (nr_parts)
1073 ret = add_mtd_partitions(mtd, parts, nr_parts);
1074 else if (!device_is_registered(dev: &mtd->dev))
1075 ret = add_mtd_device(mtd);
1076 else
1077 ret = 0;
1078
1079 if (ret)
1080 goto out;
1081
1082 /*
1083 * FIXME: some drivers unfortunately call this function more than once.
1084 * So we have to check if we've already assigned the reboot notifier.
1085 *
1086 * Generally, we can make multiple calls work for most cases, but it
1087 * does cause problems with parse_mtd_partitions() above (e.g.,
1088 * cmdlineparts will register partitions more than once).
1089 */
1090 WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call,
1091 "MTD already registered\n");
1092 if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
1093 mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
1094 register_reboot_notifier(&mtd->reboot_notifier);
1095 }
1096
1097out:
1098 if (ret) {
1099 nvmem_unregister(nvmem: mtd->otp_user_nvmem);
1100 nvmem_unregister(nvmem: mtd->otp_factory_nvmem);
1101 }
1102
1103 if (ret && device_is_registered(dev: &mtd->dev))
1104 del_mtd_device(mtd);
1105
1106 return ret;
1107}
1108EXPORT_SYMBOL_GPL(mtd_device_parse_register);
1109
1110/**
1111 * mtd_device_unregister - unregister an existing MTD device.
1112 *
1113 * @master: the MTD device to unregister. This will unregister both the master
1114 * and any partitions if registered.
1115 */
1116int mtd_device_unregister(struct mtd_info *master)
1117{
1118 int err;
1119
1120 if (master->_reboot) {
1121 unregister_reboot_notifier(&master->reboot_notifier);
1122 memset(&master->reboot_notifier, 0, sizeof(master->reboot_notifier));
1123 }
1124
1125 nvmem_unregister(nvmem: master->otp_user_nvmem);
1126 nvmem_unregister(nvmem: master->otp_factory_nvmem);
1127
1128 err = del_mtd_partitions(master);
1129 if (err)
1130 return err;
1131
1132 if (!device_is_registered(dev: &master->dev))
1133 return 0;
1134
1135 return del_mtd_device(mtd: master);
1136}
1137EXPORT_SYMBOL_GPL(mtd_device_unregister);
1138
1139/**
1140 * register_mtd_user - register a 'user' of MTD devices.
1141 * @new: pointer to notifier info structure
1142 *
1143 * Registers a pair of callbacks function to be called upon addition
1144 * or removal of MTD devices. Causes the 'add' callback to be immediately
1145 * invoked for each MTD device currently present in the system.
1146 */
1147void register_mtd_user (struct mtd_notifier *new)
1148{
1149 struct mtd_info *mtd;
1150
1151 mutex_lock(&mtd_table_mutex);
1152
1153 list_add(new: &new->list, head: &mtd_notifiers);
1154
1155 __module_get(THIS_MODULE);
1156
1157 mtd_for_each_device(mtd)
1158 new->add(mtd);
1159
1160 mutex_unlock(lock: &mtd_table_mutex);
1161}
1162EXPORT_SYMBOL_GPL(register_mtd_user);
1163
1164/**
1165 * unregister_mtd_user - unregister a 'user' of MTD devices.
1166 * @old: pointer to notifier info structure
1167 *
1168 * Removes a callback function pair from the list of 'users' to be
1169 * notified upon addition or removal of MTD devices. Causes the
1170 * 'remove' callback to be immediately invoked for each MTD device
1171 * currently present in the system.
1172 */
1173int unregister_mtd_user (struct mtd_notifier *old)
1174{
1175 struct mtd_info *mtd;
1176
1177 mutex_lock(&mtd_table_mutex);
1178
1179 module_put(THIS_MODULE);
1180
1181 mtd_for_each_device(mtd)
1182 old->remove(mtd);
1183
1184 list_del(entry: &old->list);
1185 mutex_unlock(lock: &mtd_table_mutex);
1186 return 0;
1187}
1188EXPORT_SYMBOL_GPL(unregister_mtd_user);
1189
1190/**
1191 * get_mtd_device - obtain a validated handle for an MTD device
1192 * @mtd: last known address of the required MTD device
1193 * @num: internal device number of the required MTD device
1194 *
1195 * Given a number and NULL address, return the num'th entry in the device
1196 * table, if any. Given an address and num == -1, search the device table
1197 * for a device with that address and return if it's still present. Given
1198 * both, return the num'th driver only if its address matches. Return
1199 * error code if not.
1200 */
1201struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
1202{
1203 struct mtd_info *ret = NULL, *other;
1204 int err = -ENODEV;
1205
1206 mutex_lock(&mtd_table_mutex);
1207
1208 if (num == -1) {
1209 mtd_for_each_device(other) {
1210 if (other == mtd) {
1211 ret = mtd;
1212 break;
1213 }
1214 }
1215 } else if (num >= 0) {
1216 ret = idr_find(&mtd_idr, id: num);
1217 if (mtd && mtd != ret)
1218 ret = NULL;
1219 }
1220
1221 if (!ret) {
1222 ret = ERR_PTR(error: err);
1223 goto out;
1224 }
1225
1226 err = __get_mtd_device(mtd: ret);
1227 if (err)
1228 ret = ERR_PTR(error: err);
1229out:
1230 mutex_unlock(lock: &mtd_table_mutex);
1231 return ret;
1232}
1233EXPORT_SYMBOL_GPL(get_mtd_device);
1234
1235
1236int __get_mtd_device(struct mtd_info *mtd)
1237{
1238 struct mtd_info *master = mtd_get_master(mtd);
1239 int err;
1240
1241 if (master->_get_device) {
1242 err = master->_get_device(mtd);
1243 if (err)
1244 return err;
1245 }
1246
1247 if (!try_module_get(module: master->owner)) {
1248 if (master->_put_device)
1249 master->_put_device(master);
1250 return -ENODEV;
1251 }
1252
1253 while (mtd) {
1254 if (mtd != master)
1255 kref_get(kref: &mtd->refcnt);
1256 mtd = mtd->parent;
1257 }
1258
1259 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
1260 kref_get(kref: &master->refcnt);
1261
1262 return 0;
1263}
1264EXPORT_SYMBOL_GPL(__get_mtd_device);
1265
1266/**
1267 * of_get_mtd_device_by_node - obtain an MTD device associated with a given node
1268 *
1269 * @np: device tree node
1270 */
1271struct mtd_info *of_get_mtd_device_by_node(struct device_node *np)
1272{
1273 struct mtd_info *mtd = NULL;
1274 struct mtd_info *tmp;
1275 int err;
1276
1277 mutex_lock(&mtd_table_mutex);
1278
1279 err = -EPROBE_DEFER;
1280 mtd_for_each_device(tmp) {
1281 if (mtd_get_of_node(mtd: tmp) == np) {
1282 mtd = tmp;
1283 err = __get_mtd_device(mtd);
1284 break;
1285 }
1286 }
1287
1288 mutex_unlock(lock: &mtd_table_mutex);
1289
1290 return err ? ERR_PTR(error: err) : mtd;
1291}
1292EXPORT_SYMBOL_GPL(of_get_mtd_device_by_node);
1293
1294/**
1295 * get_mtd_device_nm - obtain a validated handle for an MTD device by
1296 * device name
1297 * @name: MTD device name to open
1298 *
1299 * This function returns MTD device description structure in case of
1300 * success and an error code in case of failure.
1301 */
1302struct mtd_info *get_mtd_device_nm(const char *name)
1303{
1304 int err = -ENODEV;
1305 struct mtd_info *mtd = NULL, *other;
1306
1307 mutex_lock(&mtd_table_mutex);
1308
1309 mtd_for_each_device(other) {
1310 if (!strcmp(name, other->name)) {
1311 mtd = other;
1312 break;
1313 }
1314 }
1315
1316 if (!mtd)
1317 goto out_unlock;
1318
1319 err = __get_mtd_device(mtd);
1320 if (err)
1321 goto out_unlock;
1322
1323 mutex_unlock(lock: &mtd_table_mutex);
1324 return mtd;
1325
1326out_unlock:
1327 mutex_unlock(lock: &mtd_table_mutex);
1328 return ERR_PTR(error: err);
1329}
1330EXPORT_SYMBOL_GPL(get_mtd_device_nm);
1331
1332void put_mtd_device(struct mtd_info *mtd)
1333{
1334 mutex_lock(&mtd_table_mutex);
1335 __put_mtd_device(mtd);
1336 mutex_unlock(lock: &mtd_table_mutex);
1337
1338}
1339EXPORT_SYMBOL_GPL(put_mtd_device);
1340
1341void __put_mtd_device(struct mtd_info *mtd)
1342{
1343 struct mtd_info *master = mtd_get_master(mtd);
1344
1345 while (mtd) {
1346 /* kref_put() can relese mtd, so keep a reference mtd->parent */
1347 struct mtd_info *parent = mtd->parent;
1348
1349 if (mtd != master)
1350 kref_put(kref: &mtd->refcnt, release: mtd_device_release);
1351 mtd = parent;
1352 }
1353
1354 if (IS_ENABLED(CONFIG_MTD_PARTITIONED_MASTER))
1355 kref_put(kref: &master->refcnt, release: mtd_device_release);
1356
1357 module_put(module: master->owner);
1358
1359 /* must be the last as master can be freed in the _put_device */
1360 if (master->_put_device)
1361 master->_put_device(master);
1362}
1363EXPORT_SYMBOL_GPL(__put_mtd_device);
1364
1365/*
1366 * Erase is an synchronous operation. Device drivers are epected to return a
1367 * negative error code if the operation failed and update instr->fail_addr
1368 * to point the portion that was not properly erased.
1369 */
1370int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
1371{
1372 struct mtd_info *master = mtd_get_master(mtd);
1373 u64 mst_ofs = mtd_get_master_ofs(mtd, ofs: 0);
1374 struct erase_info adjinstr;
1375 int ret;
1376
1377 instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
1378 adjinstr = *instr;
1379
1380 if (!mtd->erasesize || !master->_erase)
1381 return -ENOTSUPP;
1382
1383 if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
1384 return -EINVAL;
1385 if (!(mtd->flags & MTD_WRITEABLE))
1386 return -EROFS;
1387
1388 if (!instr->len)
1389 return 0;
1390
1391 ledtrig_mtd_activity();
1392
1393 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1394 adjinstr.addr = (loff_t)mtd_div_by_eb(sz: instr->addr, mtd) *
1395 master->erasesize;
1396 adjinstr.len = ((u64)mtd_div_by_eb(sz: instr->addr + instr->len, mtd) *
1397 master->erasesize) -
1398 adjinstr.addr;
1399 }
1400
1401 adjinstr.addr += mst_ofs;
1402
1403 ret = master->_erase(master, &adjinstr);
1404
1405 if (adjinstr.fail_addr != MTD_FAIL_ADDR_UNKNOWN) {
1406 instr->fail_addr = adjinstr.fail_addr - mst_ofs;
1407 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
1408 instr->fail_addr = mtd_div_by_eb(sz: instr->fail_addr,
1409 mtd: master);
1410 instr->fail_addr *= mtd->erasesize;
1411 }
1412 }
1413
1414 return ret;
1415}
1416EXPORT_SYMBOL_GPL(mtd_erase);
1417ALLOW_ERROR_INJECTION(mtd_erase, ERRNO);
1418
1419/*
1420 * This stuff for eXecute-In-Place. phys is optional and may be set to NULL.
1421 */
1422int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1423 void **virt, resource_size_t *phys)
1424{
1425 struct mtd_info *master = mtd_get_master(mtd);
1426
1427 *retlen = 0;
1428 *virt = NULL;
1429 if (phys)
1430 *phys = 0;
1431 if (!master->_point)
1432 return -EOPNOTSUPP;
1433 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1434 return -EINVAL;
1435 if (!len)
1436 return 0;
1437
1438 from = mtd_get_master_ofs(mtd, ofs: from);
1439 return master->_point(master, from, len, retlen, virt, phys);
1440}
1441EXPORT_SYMBOL_GPL(mtd_point);
1442
1443/* We probably shouldn't allow XIP if the unpoint isn't a NULL */
1444int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1445{
1446 struct mtd_info *master = mtd_get_master(mtd);
1447
1448 if (!master->_unpoint)
1449 return -EOPNOTSUPP;
1450 if (from < 0 || from >= mtd->size || len > mtd->size - from)
1451 return -EINVAL;
1452 if (!len)
1453 return 0;
1454 return master->_unpoint(master, mtd_get_master_ofs(mtd, ofs: from), len);
1455}
1456EXPORT_SYMBOL_GPL(mtd_unpoint);
1457
1458/*
1459 * Allow NOMMU mmap() to directly map the device (if not NULL)
1460 * - return the address to which the offset maps
1461 * - return -ENOSYS to indicate refusal to do the mapping
1462 */
1463unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
1464 unsigned long offset, unsigned long flags)
1465{
1466 size_t retlen;
1467 void *virt;
1468 int ret;
1469
1470 ret = mtd_point(mtd, offset, len, &retlen, &virt, NULL);
1471 if (ret)
1472 return ret;
1473 if (retlen != len) {
1474 mtd_unpoint(mtd, offset, retlen);
1475 return -ENOSYS;
1476 }
1477 return (unsigned long)virt;
1478}
1479EXPORT_SYMBOL_GPL(mtd_get_unmapped_area);
1480
1481static void mtd_update_ecc_stats(struct mtd_info *mtd, struct mtd_info *master,
1482 const struct mtd_ecc_stats *old_stats)
1483{
1484 struct mtd_ecc_stats diff;
1485
1486 if (master == mtd)
1487 return;
1488
1489 diff = master->ecc_stats;
1490 diff.failed -= old_stats->failed;
1491 diff.corrected -= old_stats->corrected;
1492
1493 while (mtd->parent) {
1494 mtd->ecc_stats.failed += diff.failed;
1495 mtd->ecc_stats.corrected += diff.corrected;
1496 mtd = mtd->parent;
1497 }
1498}
1499
1500int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
1501 u_char *buf)
1502{
1503 struct mtd_oob_ops ops = {
1504 .len = len,
1505 .datbuf = buf,
1506 };
1507 int ret;
1508
1509 ret = mtd_read_oob(mtd, from, ops: &ops);
1510 *retlen = ops.retlen;
1511
1512 WARN_ON_ONCE(*retlen != len && mtd_is_bitflip_or_eccerr(ret));
1513
1514 return ret;
1515}
1516EXPORT_SYMBOL_GPL(mtd_read);
1517ALLOW_ERROR_INJECTION(mtd_read, ERRNO);
1518
1519int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1520 const u_char *buf)
1521{
1522 struct mtd_oob_ops ops = {
1523 .len = len,
1524 .datbuf = (u8 *)buf,
1525 };
1526 int ret;
1527
1528 ret = mtd_write_oob(mtd, to, ops: &ops);
1529 *retlen = ops.retlen;
1530
1531 return ret;
1532}
1533EXPORT_SYMBOL_GPL(mtd_write);
1534ALLOW_ERROR_INJECTION(mtd_write, ERRNO);
1535
1536/*
1537 * In blackbox flight recorder like scenarios we want to make successful writes
1538 * in interrupt context. panic_write() is only intended to be called when its
1539 * known the kernel is about to panic and we need the write to succeed. Since
1540 * the kernel is not going to be running for much longer, this function can
1541 * break locks and delay to ensure the write succeeds (but not sleep).
1542 */
1543int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
1544 const u_char *buf)
1545{
1546 struct mtd_info *master = mtd_get_master(mtd);
1547
1548 *retlen = 0;
1549 if (!master->_panic_write)
1550 return -EOPNOTSUPP;
1551 if (to < 0 || to >= mtd->size || len > mtd->size - to)
1552 return -EINVAL;
1553 if (!(mtd->flags & MTD_WRITEABLE))
1554 return -EROFS;
1555 if (!len)
1556 return 0;
1557 if (!master->oops_panic_write)
1558 master->oops_panic_write = true;
1559
1560 return master->_panic_write(master, mtd_get_master_ofs(mtd, ofs: to), len,
1561 retlen, buf);
1562}
1563EXPORT_SYMBOL_GPL(mtd_panic_write);
1564
1565static int mtd_check_oob_ops(struct mtd_info *mtd, loff_t offs,
1566 struct mtd_oob_ops *ops)
1567{
1568 /*
1569 * Some users are setting ->datbuf or ->oobbuf to NULL, but are leaving
1570 * ->len or ->ooblen uninitialized. Force ->len and ->ooblen to 0 in
1571 * this case.
1572 */
1573 if (!ops->datbuf)
1574 ops->len = 0;
1575
1576 if (!ops->oobbuf)
1577 ops->ooblen = 0;
1578
1579 if (offs < 0 || offs + ops->len > mtd->size)
1580 return -EINVAL;
1581
1582 if (ops->ooblen) {
1583 size_t maxooblen;
1584
1585 if (ops->ooboffs >= mtd_oobavail(mtd, ops))
1586 return -EINVAL;
1587
1588 maxooblen = ((size_t)(mtd_div_by_ws(sz: mtd->size, mtd) -
1589 mtd_div_by_ws(sz: offs, mtd)) *
1590 mtd_oobavail(mtd, ops)) - ops->ooboffs;
1591 if (ops->ooblen > maxooblen)
1592 return -EINVAL;
1593 }
1594
1595 return 0;
1596}
1597
1598static int mtd_read_oob_std(struct mtd_info *mtd, loff_t from,
1599 struct mtd_oob_ops *ops)
1600{
1601 struct mtd_info *master = mtd_get_master(mtd);
1602 int ret;
1603
1604 from = mtd_get_master_ofs(mtd, ofs: from);
1605 if (master->_read_oob)
1606 ret = master->_read_oob(master, from, ops);
1607 else
1608 ret = master->_read(master, from, ops->len, &ops->retlen,
1609 ops->datbuf);
1610
1611 return ret;
1612}
1613
1614static int mtd_write_oob_std(struct mtd_info *mtd, loff_t to,
1615 struct mtd_oob_ops *ops)
1616{
1617 struct mtd_info *master = mtd_get_master(mtd);
1618 int ret;
1619
1620 to = mtd_get_master_ofs(mtd, ofs: to);
1621 if (master->_write_oob)
1622 ret = master->_write_oob(master, to, ops);
1623 else
1624 ret = master->_write(master, to, ops->len, &ops->retlen,
1625 ops->datbuf);
1626
1627 return ret;
1628}
1629
1630static int mtd_io_emulated_slc(struct mtd_info *mtd, loff_t start, bool read,
1631 struct mtd_oob_ops *ops)
1632{
1633 struct mtd_info *master = mtd_get_master(mtd);
1634 int ngroups = mtd_pairing_groups(master);
1635 int npairs = mtd_wunit_per_eb(mtd: master) / ngroups;
1636 struct mtd_oob_ops adjops = *ops;
1637 unsigned int wunit, oobavail;
1638 struct mtd_pairing_info info;
1639 int max_bitflips = 0;
1640 u32 ebofs, pageofs;
1641 loff_t base, pos;
1642
1643 ebofs = mtd_mod_by_eb(sz: start, mtd);
1644 base = (loff_t)mtd_div_by_eb(sz: start, mtd) * master->erasesize;
1645 info.group = 0;
1646 info.pair = mtd_div_by_ws(sz: ebofs, mtd);
1647 pageofs = mtd_mod_by_ws(sz: ebofs, mtd);
1648 oobavail = mtd_oobavail(mtd, ops);
1649
1650 while (ops->retlen < ops->len || ops->oobretlen < ops->ooblen) {
1651 int ret;
1652
1653 if (info.pair >= npairs) {
1654 info.pair = 0;
1655 base += master->erasesize;
1656 }
1657
1658 wunit = mtd_pairing_info_to_wunit(master, &info);
1659 pos = mtd_wunit_to_offset(mtd, base, wunit);
1660
1661 adjops.len = ops->len - ops->retlen;
1662 if (adjops.len > mtd->writesize - pageofs)
1663 adjops.len = mtd->writesize - pageofs;
1664
1665 adjops.ooblen = ops->ooblen - ops->oobretlen;
1666 if (adjops.ooblen > oobavail - adjops.ooboffs)
1667 adjops.ooblen = oobavail - adjops.ooboffs;
1668
1669 if (read) {
1670 ret = mtd_read_oob_std(mtd, from: pos + pageofs, ops: &adjops);
1671 if (ret > 0)
1672 max_bitflips = max(max_bitflips, ret);
1673 } else {
1674 ret = mtd_write_oob_std(mtd, to: pos + pageofs, ops: &adjops);
1675 }
1676
1677 if (ret < 0)
1678 return ret;
1679
1680 max_bitflips = max(max_bitflips, ret);
1681 ops->retlen += adjops.retlen;
1682 ops->oobretlen += adjops.oobretlen;
1683 adjops.datbuf += adjops.retlen;
1684 adjops.oobbuf += adjops.oobretlen;
1685 adjops.ooboffs = 0;
1686 pageofs = 0;
1687 info.pair++;
1688 }
1689
1690 return max_bitflips;
1691}
1692
1693int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops)
1694{
1695 struct mtd_info *master = mtd_get_master(mtd);
1696 struct mtd_ecc_stats old_stats = master->ecc_stats;
1697 int ret_code;
1698
1699 ops->retlen = ops->oobretlen = 0;
1700
1701 ret_code = mtd_check_oob_ops(mtd, offs: from, ops);
1702 if (ret_code)
1703 return ret_code;
1704
1705 ledtrig_mtd_activity();
1706
1707 /* Check the validity of a potential fallback on mtd->_read */
1708 if (!master->_read_oob && (!master->_read || ops->oobbuf))
1709 return -EOPNOTSUPP;
1710
1711 if (ops->stats)
1712 memset(ops->stats, 0, sizeof(*ops->stats));
1713
1714 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1715 ret_code = mtd_io_emulated_slc(mtd, start: from, read: true, ops);
1716 else
1717 ret_code = mtd_read_oob_std(mtd, from, ops);
1718
1719 mtd_update_ecc_stats(mtd, master, old_stats: &old_stats);
1720
1721 /*
1722 * In cases where ops->datbuf != NULL, mtd->_read_oob() has semantics
1723 * similar to mtd->_read(), returning a non-negative integer
1724 * representing max bitflips. In other cases, mtd->_read_oob() may
1725 * return -EUCLEAN. In all cases, perform similar logic to mtd_read().
1726 */
1727 if (unlikely(ret_code < 0))
1728 return ret_code;
1729 if (mtd->ecc_strength == 0)
1730 return 0; /* device lacks ecc */
1731 if (ops->stats)
1732 ops->stats->max_bitflips = ret_code;
1733 return ret_code >= mtd->bitflip_threshold ? -EUCLEAN : 0;
1734}
1735EXPORT_SYMBOL_GPL(mtd_read_oob);
1736
1737int mtd_write_oob(struct mtd_info *mtd, loff_t to,
1738 struct mtd_oob_ops *ops)
1739{
1740 struct mtd_info *master = mtd_get_master(mtd);
1741 int ret;
1742
1743 ops->retlen = ops->oobretlen = 0;
1744
1745 if (!(mtd->flags & MTD_WRITEABLE))
1746 return -EROFS;
1747
1748 ret = mtd_check_oob_ops(mtd, offs: to, ops);
1749 if (ret)
1750 return ret;
1751
1752 ledtrig_mtd_activity();
1753
1754 /* Check the validity of a potential fallback on mtd->_write */
1755 if (!master->_write_oob && (!master->_write || ops->oobbuf))
1756 return -EOPNOTSUPP;
1757
1758 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
1759 return mtd_io_emulated_slc(mtd, start: to, read: false, ops);
1760
1761 return mtd_write_oob_std(mtd, to, ops);
1762}
1763EXPORT_SYMBOL_GPL(mtd_write_oob);
1764
1765/**
1766 * mtd_ooblayout_ecc - Get the OOB region definition of a specific ECC section
1767 * @mtd: MTD device structure
1768 * @section: ECC section. Depending on the layout you may have all the ECC
1769 * bytes stored in a single contiguous section, or one section
1770 * per ECC chunk (and sometime several sections for a single ECC
1771 * ECC chunk)
1772 * @oobecc: OOB region struct filled with the appropriate ECC position
1773 * information
1774 *
1775 * This function returns ECC section information in the OOB area. If you want
1776 * to get all the ECC bytes information, then you should call
1777 * mtd_ooblayout_ecc(mtd, section++, oobecc) until it returns -ERANGE.
1778 *
1779 * Returns zero on success, a negative error code otherwise.
1780 */
1781int mtd_ooblayout_ecc(struct mtd_info *mtd, int section,
1782 struct mtd_oob_region *oobecc)
1783{
1784 struct mtd_info *master = mtd_get_master(mtd);
1785
1786 memset(oobecc, 0, sizeof(*oobecc));
1787
1788 if (!master || section < 0)
1789 return -EINVAL;
1790
1791 if (!master->ooblayout || !master->ooblayout->ecc)
1792 return -ENOTSUPP;
1793
1794 return master->ooblayout->ecc(master, section, oobecc);
1795}
1796EXPORT_SYMBOL_GPL(mtd_ooblayout_ecc);
1797
1798/**
1799 * mtd_ooblayout_free - Get the OOB region definition of a specific free
1800 * section
1801 * @mtd: MTD device structure
1802 * @section: Free section you are interested in. Depending on the layout
1803 * you may have all the free bytes stored in a single contiguous
1804 * section, or one section per ECC chunk plus an extra section
1805 * for the remaining bytes (or other funky layout).
1806 * @oobfree: OOB region struct filled with the appropriate free position
1807 * information
1808 *
1809 * This function returns free bytes position in the OOB area. If you want
1810 * to get all the free bytes information, then you should call
1811 * mtd_ooblayout_free(mtd, section++, oobfree) until it returns -ERANGE.
1812 *
1813 * Returns zero on success, a negative error code otherwise.
1814 */
1815int mtd_ooblayout_free(struct mtd_info *mtd, int section,
1816 struct mtd_oob_region *oobfree)
1817{
1818 struct mtd_info *master = mtd_get_master(mtd);
1819
1820 memset(oobfree, 0, sizeof(*oobfree));
1821
1822 if (!master || section < 0)
1823 return -EINVAL;
1824
1825 if (!master->ooblayout || !master->ooblayout->free)
1826 return -ENOTSUPP;
1827
1828 return master->ooblayout->free(master, section, oobfree);
1829}
1830EXPORT_SYMBOL_GPL(mtd_ooblayout_free);
1831
1832/**
1833 * mtd_ooblayout_find_region - Find the region attached to a specific byte
1834 * @mtd: mtd info structure
1835 * @byte: the byte we are searching for
1836 * @sectionp: pointer where the section id will be stored
1837 * @oobregion: used to retrieve the ECC position
1838 * @iter: iterator function. Should be either mtd_ooblayout_free or
1839 * mtd_ooblayout_ecc depending on the region type you're searching for
1840 *
1841 * This function returns the section id and oobregion information of a
1842 * specific byte. For example, say you want to know where the 4th ECC byte is
1843 * stored, you'll use:
1844 *
1845 * mtd_ooblayout_find_region(mtd, 3, &section, &oobregion, mtd_ooblayout_ecc);
1846 *
1847 * Returns zero on success, a negative error code otherwise.
1848 */
1849static int mtd_ooblayout_find_region(struct mtd_info *mtd, int byte,
1850 int *sectionp, struct mtd_oob_region *oobregion,
1851 int (*iter)(struct mtd_info *,
1852 int section,
1853 struct mtd_oob_region *oobregion))
1854{
1855 int pos = 0, ret, section = 0;
1856
1857 memset(oobregion, 0, sizeof(*oobregion));
1858
1859 while (1) {
1860 ret = iter(mtd, section, oobregion);
1861 if (ret)
1862 return ret;
1863
1864 if (pos + oobregion->length > byte)
1865 break;
1866
1867 pos += oobregion->length;
1868 section++;
1869 }
1870
1871 /*
1872 * Adjust region info to make it start at the beginning at the
1873 * 'start' ECC byte.
1874 */
1875 oobregion->offset += byte - pos;
1876 oobregion->length -= byte - pos;
1877 *sectionp = section;
1878
1879 return 0;
1880}
1881
1882/**
1883 * mtd_ooblayout_find_eccregion - Find the ECC region attached to a specific
1884 * ECC byte
1885 * @mtd: mtd info structure
1886 * @eccbyte: the byte we are searching for
1887 * @section: pointer where the section id will be stored
1888 * @oobregion: OOB region information
1889 *
1890 * Works like mtd_ooblayout_find_region() except it searches for a specific ECC
1891 * byte.
1892 *
1893 * Returns zero on success, a negative error code otherwise.
1894 */
1895int mtd_ooblayout_find_eccregion(struct mtd_info *mtd, int eccbyte,
1896 int *section,
1897 struct mtd_oob_region *oobregion)
1898{
1899 return mtd_ooblayout_find_region(mtd, byte: eccbyte, sectionp: section, oobregion,
1900 iter: mtd_ooblayout_ecc);
1901}
1902EXPORT_SYMBOL_GPL(mtd_ooblayout_find_eccregion);
1903
1904/**
1905 * mtd_ooblayout_get_bytes - Extract OOB bytes from the oob buffer
1906 * @mtd: mtd info structure
1907 * @buf: destination buffer to store OOB bytes
1908 * @oobbuf: OOB buffer
1909 * @start: first byte to retrieve
1910 * @nbytes: number of bytes to retrieve
1911 * @iter: section iterator
1912 *
1913 * Extract bytes attached to a specific category (ECC or free)
1914 * from the OOB buffer and copy them into buf.
1915 *
1916 * Returns zero on success, a negative error code otherwise.
1917 */
1918static int mtd_ooblayout_get_bytes(struct mtd_info *mtd, u8 *buf,
1919 const u8 *oobbuf, int start, int nbytes,
1920 int (*iter)(struct mtd_info *,
1921 int section,
1922 struct mtd_oob_region *oobregion))
1923{
1924 struct mtd_oob_region oobregion;
1925 int section, ret;
1926
1927 ret = mtd_ooblayout_find_region(mtd, byte: start, sectionp: &section,
1928 oobregion: &oobregion, iter);
1929
1930 while (!ret) {
1931 int cnt;
1932
1933 cnt = min_t(int, nbytes, oobregion.length);
1934 memcpy(buf, oobbuf + oobregion.offset, cnt);
1935 buf += cnt;
1936 nbytes -= cnt;
1937
1938 if (!nbytes)
1939 break;
1940
1941 ret = iter(mtd, ++section, &oobregion);
1942 }
1943
1944 return ret;
1945}
1946
1947/**
1948 * mtd_ooblayout_set_bytes - put OOB bytes into the oob buffer
1949 * @mtd: mtd info structure
1950 * @buf: source buffer to get OOB bytes from
1951 * @oobbuf: OOB buffer
1952 * @start: first OOB byte to set
1953 * @nbytes: number of OOB bytes to set
1954 * @iter: section iterator
1955 *
1956 * Fill the OOB buffer with data provided in buf. The category (ECC or free)
1957 * is selected by passing the appropriate iterator.
1958 *
1959 * Returns zero on success, a negative error code otherwise.
1960 */
1961static int mtd_ooblayout_set_bytes(struct mtd_info *mtd, const u8 *buf,
1962 u8 *oobbuf, int start, int nbytes,
1963 int (*iter)(struct mtd_info *,
1964 int section,
1965 struct mtd_oob_region *oobregion))
1966{
1967 struct mtd_oob_region oobregion;
1968 int section, ret;
1969
1970 ret = mtd_ooblayout_find_region(mtd, byte: start, sectionp: &section,
1971 oobregion: &oobregion, iter);
1972
1973 while (!ret) {
1974 int cnt;
1975
1976 cnt = min_t(int, nbytes, oobregion.length);
1977 memcpy(oobbuf + oobregion.offset, buf, cnt);
1978 buf += cnt;
1979 nbytes -= cnt;
1980
1981 if (!nbytes)
1982 break;
1983
1984 ret = iter(mtd, ++section, &oobregion);
1985 }
1986
1987 return ret;
1988}
1989
1990/**
1991 * mtd_ooblayout_count_bytes - count the number of bytes in a OOB category
1992 * @mtd: mtd info structure
1993 * @iter: category iterator
1994 *
1995 * Count the number of bytes in a given category.
1996 *
1997 * Returns a positive value on success, a negative error code otherwise.
1998 */
1999static int mtd_ooblayout_count_bytes(struct mtd_info *mtd,
2000 int (*iter)(struct mtd_info *,
2001 int section,
2002 struct mtd_oob_region *oobregion))
2003{
2004 struct mtd_oob_region oobregion;
2005 int section = 0, ret, nbytes = 0;
2006
2007 while (1) {
2008 ret = iter(mtd, section++, &oobregion);
2009 if (ret) {
2010 if (ret == -ERANGE)
2011 ret = nbytes;
2012 break;
2013 }
2014
2015 nbytes += oobregion.length;
2016 }
2017
2018 return ret;
2019}
2020
2021/**
2022 * mtd_ooblayout_get_eccbytes - extract ECC bytes from the oob buffer
2023 * @mtd: mtd info structure
2024 * @eccbuf: destination buffer to store ECC bytes
2025 * @oobbuf: OOB buffer
2026 * @start: first ECC byte to retrieve
2027 * @nbytes: number of ECC bytes to retrieve
2028 *
2029 * Works like mtd_ooblayout_get_bytes(), except it acts on ECC bytes.
2030 *
2031 * Returns zero on success, a negative error code otherwise.
2032 */
2033int mtd_ooblayout_get_eccbytes(struct mtd_info *mtd, u8 *eccbuf,
2034 const u8 *oobbuf, int start, int nbytes)
2035{
2036 return mtd_ooblayout_get_bytes(mtd, buf: eccbuf, oobbuf, start, nbytes,
2037 iter: mtd_ooblayout_ecc);
2038}
2039EXPORT_SYMBOL_GPL(mtd_ooblayout_get_eccbytes);
2040
2041/**
2042 * mtd_ooblayout_set_eccbytes - set ECC bytes into the oob buffer
2043 * @mtd: mtd info structure
2044 * @eccbuf: source buffer to get ECC bytes from
2045 * @oobbuf: OOB buffer
2046 * @start: first ECC byte to set
2047 * @nbytes: number of ECC bytes to set
2048 *
2049 * Works like mtd_ooblayout_set_bytes(), except it acts on ECC bytes.
2050 *
2051 * Returns zero on success, a negative error code otherwise.
2052 */
2053int mtd_ooblayout_set_eccbytes(struct mtd_info *mtd, const u8 *eccbuf,
2054 u8 *oobbuf, int start, int nbytes)
2055{
2056 return mtd_ooblayout_set_bytes(mtd, buf: eccbuf, oobbuf, start, nbytes,
2057 iter: mtd_ooblayout_ecc);
2058}
2059EXPORT_SYMBOL_GPL(mtd_ooblayout_set_eccbytes);
2060
2061/**
2062 * mtd_ooblayout_get_databytes - extract data bytes from the oob buffer
2063 * @mtd: mtd info structure
2064 * @databuf: destination buffer to store ECC bytes
2065 * @oobbuf: OOB buffer
2066 * @start: first ECC byte to retrieve
2067 * @nbytes: number of ECC bytes to retrieve
2068 *
2069 * Works like mtd_ooblayout_get_bytes(), except it acts on free bytes.
2070 *
2071 * Returns zero on success, a negative error code otherwise.
2072 */
2073int mtd_ooblayout_get_databytes(struct mtd_info *mtd, u8 *databuf,
2074 const u8 *oobbuf, int start, int nbytes)
2075{
2076 return mtd_ooblayout_get_bytes(mtd, buf: databuf, oobbuf, start, nbytes,
2077 iter: mtd_ooblayout_free);
2078}
2079EXPORT_SYMBOL_GPL(mtd_ooblayout_get_databytes);
2080
2081/**
2082 * mtd_ooblayout_set_databytes - set data bytes into the oob buffer
2083 * @mtd: mtd info structure
2084 * @databuf: source buffer to get data bytes from
2085 * @oobbuf: OOB buffer
2086 * @start: first ECC byte to set
2087 * @nbytes: number of ECC bytes to set
2088 *
2089 * Works like mtd_ooblayout_set_bytes(), except it acts on free bytes.
2090 *
2091 * Returns zero on success, a negative error code otherwise.
2092 */
2093int mtd_ooblayout_set_databytes(struct mtd_info *mtd, const u8 *databuf,
2094 u8 *oobbuf, int start, int nbytes)
2095{
2096 return mtd_ooblayout_set_bytes(mtd, buf: databuf, oobbuf, start, nbytes,
2097 iter: mtd_ooblayout_free);
2098}
2099EXPORT_SYMBOL_GPL(mtd_ooblayout_set_databytes);
2100
2101/**
2102 * mtd_ooblayout_count_freebytes - count the number of free bytes in OOB
2103 * @mtd: mtd info structure
2104 *
2105 * Works like mtd_ooblayout_count_bytes(), except it count free bytes.
2106 *
2107 * Returns zero on success, a negative error code otherwise.
2108 */
2109int mtd_ooblayout_count_freebytes(struct mtd_info *mtd)
2110{
2111 return mtd_ooblayout_count_bytes(mtd, iter: mtd_ooblayout_free);
2112}
2113EXPORT_SYMBOL_GPL(mtd_ooblayout_count_freebytes);
2114
2115/**
2116 * mtd_ooblayout_count_eccbytes - count the number of ECC bytes in OOB
2117 * @mtd: mtd info structure
2118 *
2119 * Works like mtd_ooblayout_count_bytes(), except it count ECC bytes.
2120 *
2121 * Returns zero on success, a negative error code otherwise.
2122 */
2123int mtd_ooblayout_count_eccbytes(struct mtd_info *mtd)
2124{
2125 return mtd_ooblayout_count_bytes(mtd, iter: mtd_ooblayout_ecc);
2126}
2127EXPORT_SYMBOL_GPL(mtd_ooblayout_count_eccbytes);
2128
2129/*
2130 * Method to access the protection register area, present in some flash
2131 * devices. The user data is one time programmable but the factory data is read
2132 * only.
2133 */
2134int mtd_get_fact_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
2135 struct otp_info *buf)
2136{
2137 struct mtd_info *master = mtd_get_master(mtd);
2138
2139 if (!master->_get_fact_prot_info)
2140 return -EOPNOTSUPP;
2141 if (!len)
2142 return 0;
2143 return master->_get_fact_prot_info(master, len, retlen, buf);
2144}
2145EXPORT_SYMBOL_GPL(mtd_get_fact_prot_info);
2146
2147int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2148 size_t *retlen, u_char *buf)
2149{
2150 struct mtd_info *master = mtd_get_master(mtd);
2151
2152 *retlen = 0;
2153 if (!master->_read_fact_prot_reg)
2154 return -EOPNOTSUPP;
2155 if (!len)
2156 return 0;
2157 return master->_read_fact_prot_reg(master, from, len, retlen, buf);
2158}
2159EXPORT_SYMBOL_GPL(mtd_read_fact_prot_reg);
2160
2161int mtd_get_user_prot_info(struct mtd_info *mtd, size_t len, size_t *retlen,
2162 struct otp_info *buf)
2163{
2164 struct mtd_info *master = mtd_get_master(mtd);
2165
2166 if (!master->_get_user_prot_info)
2167 return -EOPNOTSUPP;
2168 if (!len)
2169 return 0;
2170 return master->_get_user_prot_info(master, len, retlen, buf);
2171}
2172EXPORT_SYMBOL_GPL(mtd_get_user_prot_info);
2173
2174int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
2175 size_t *retlen, u_char *buf)
2176{
2177 struct mtd_info *master = mtd_get_master(mtd);
2178
2179 *retlen = 0;
2180 if (!master->_read_user_prot_reg)
2181 return -EOPNOTSUPP;
2182 if (!len)
2183 return 0;
2184 return master->_read_user_prot_reg(master, from, len, retlen, buf);
2185}
2186EXPORT_SYMBOL_GPL(mtd_read_user_prot_reg);
2187
2188int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
2189 size_t *retlen, const u_char *buf)
2190{
2191 struct mtd_info *master = mtd_get_master(mtd);
2192 int ret;
2193
2194 *retlen = 0;
2195 if (!master->_write_user_prot_reg)
2196 return -EOPNOTSUPP;
2197 if (!len)
2198 return 0;
2199 ret = master->_write_user_prot_reg(master, to, len, retlen, buf);
2200 if (ret)
2201 return ret;
2202
2203 /*
2204 * If no data could be written at all, we are out of memory and
2205 * must return -ENOSPC.
2206 */
2207 return (*retlen) ? 0 : -ENOSPC;
2208}
2209EXPORT_SYMBOL_GPL(mtd_write_user_prot_reg);
2210
2211int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2212{
2213 struct mtd_info *master = mtd_get_master(mtd);
2214
2215 if (!master->_lock_user_prot_reg)
2216 return -EOPNOTSUPP;
2217 if (!len)
2218 return 0;
2219 return master->_lock_user_prot_reg(master, from, len);
2220}
2221EXPORT_SYMBOL_GPL(mtd_lock_user_prot_reg);
2222
2223int mtd_erase_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len)
2224{
2225 struct mtd_info *master = mtd_get_master(mtd);
2226
2227 if (!master->_erase_user_prot_reg)
2228 return -EOPNOTSUPP;
2229 if (!len)
2230 return 0;
2231 return master->_erase_user_prot_reg(master, from, len);
2232}
2233EXPORT_SYMBOL_GPL(mtd_erase_user_prot_reg);
2234
2235/* Chip-supported device locking */
2236int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2237{
2238 struct mtd_info *master = mtd_get_master(mtd);
2239
2240 if (!master->_lock)
2241 return -EOPNOTSUPP;
2242 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2243 return -EINVAL;
2244 if (!len)
2245 return 0;
2246
2247 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2248 ofs = (loff_t)mtd_div_by_eb(sz: ofs, mtd) * master->erasesize;
2249 len = (u64)mtd_div_by_eb(sz: len, mtd) * master->erasesize;
2250 }
2251
2252 return master->_lock(master, mtd_get_master_ofs(mtd, ofs), len);
2253}
2254EXPORT_SYMBOL_GPL(mtd_lock);
2255
2256int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2257{
2258 struct mtd_info *master = mtd_get_master(mtd);
2259
2260 if (!master->_unlock)
2261 return -EOPNOTSUPP;
2262 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2263 return -EINVAL;
2264 if (!len)
2265 return 0;
2266
2267 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2268 ofs = (loff_t)mtd_div_by_eb(sz: ofs, mtd) * master->erasesize;
2269 len = (u64)mtd_div_by_eb(sz: len, mtd) * master->erasesize;
2270 }
2271
2272 return master->_unlock(master, mtd_get_master_ofs(mtd, ofs), len);
2273}
2274EXPORT_SYMBOL_GPL(mtd_unlock);
2275
2276int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
2277{
2278 struct mtd_info *master = mtd_get_master(mtd);
2279
2280 if (!master->_is_locked)
2281 return -EOPNOTSUPP;
2282 if (ofs < 0 || ofs >= mtd->size || len > mtd->size - ofs)
2283 return -EINVAL;
2284 if (!len)
2285 return 0;
2286
2287 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION) {
2288 ofs = (loff_t)mtd_div_by_eb(sz: ofs, mtd) * master->erasesize;
2289 len = (u64)mtd_div_by_eb(sz: len, mtd) * master->erasesize;
2290 }
2291
2292 return master->_is_locked(master, mtd_get_master_ofs(mtd, ofs), len);
2293}
2294EXPORT_SYMBOL_GPL(mtd_is_locked);
2295
2296int mtd_block_isreserved(struct mtd_info *mtd, loff_t ofs)
2297{
2298 struct mtd_info *master = mtd_get_master(mtd);
2299
2300 if (ofs < 0 || ofs >= mtd->size)
2301 return -EINVAL;
2302 if (!master->_block_isreserved)
2303 return 0;
2304
2305 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2306 ofs = (loff_t)mtd_div_by_eb(sz: ofs, mtd) * master->erasesize;
2307
2308 return master->_block_isreserved(master, mtd_get_master_ofs(mtd, ofs));
2309}
2310EXPORT_SYMBOL_GPL(mtd_block_isreserved);
2311
2312int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
2313{
2314 struct mtd_info *master = mtd_get_master(mtd);
2315
2316 if (ofs < 0 || ofs >= mtd->size)
2317 return -EINVAL;
2318 if (!master->_block_isbad)
2319 return 0;
2320
2321 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2322 ofs = (loff_t)mtd_div_by_eb(sz: ofs, mtd) * master->erasesize;
2323
2324 return master->_block_isbad(master, mtd_get_master_ofs(mtd, ofs));
2325}
2326EXPORT_SYMBOL_GPL(mtd_block_isbad);
2327
2328int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs)
2329{
2330 struct mtd_info *master = mtd_get_master(mtd);
2331 int ret;
2332
2333 if (!master->_block_markbad)
2334 return -EOPNOTSUPP;
2335 if (ofs < 0 || ofs >= mtd->size)
2336 return -EINVAL;
2337 if (!(mtd->flags & MTD_WRITEABLE))
2338 return -EROFS;
2339
2340 if (mtd->flags & MTD_SLC_ON_MLC_EMULATION)
2341 ofs = (loff_t)mtd_div_by_eb(sz: ofs, mtd) * master->erasesize;
2342
2343 ret = master->_block_markbad(master, mtd_get_master_ofs(mtd, ofs));
2344 if (ret)
2345 return ret;
2346
2347 while (mtd->parent) {
2348 mtd->ecc_stats.badblocks++;
2349 mtd = mtd->parent;
2350 }
2351
2352 return 0;
2353}
2354EXPORT_SYMBOL_GPL(mtd_block_markbad);
2355ALLOW_ERROR_INJECTION(mtd_block_markbad, ERRNO);
2356
2357/*
2358 * default_mtd_writev - the default writev method
2359 * @mtd: mtd device description object pointer
2360 * @vecs: the vectors to write
2361 * @count: count of vectors in @vecs
2362 * @to: the MTD device offset to write to
2363 * @retlen: on exit contains the count of bytes written to the MTD device.
2364 *
2365 * This function returns zero in case of success and a negative error code in
2366 * case of failure.
2367 */
2368static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2369 unsigned long count, loff_t to, size_t *retlen)
2370{
2371 unsigned long i;
2372 size_t totlen = 0, thislen;
2373 int ret = 0;
2374
2375 for (i = 0; i < count; i++) {
2376 if (!vecs[i].iov_len)
2377 continue;
2378 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
2379 vecs[i].iov_base);
2380 totlen += thislen;
2381 if (ret || thislen != vecs[i].iov_len)
2382 break;
2383 to += vecs[i].iov_len;
2384 }
2385 *retlen = totlen;
2386 return ret;
2387}
2388
2389/*
2390 * mtd_writev - the vector-based MTD write method
2391 * @mtd: mtd device description object pointer
2392 * @vecs: the vectors to write
2393 * @count: count of vectors in @vecs
2394 * @to: the MTD device offset to write to
2395 * @retlen: on exit contains the count of bytes written to the MTD device.
2396 *
2397 * This function returns zero in case of success and a negative error code in
2398 * case of failure.
2399 */
2400int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
2401 unsigned long count, loff_t to, size_t *retlen)
2402{
2403 struct mtd_info *master = mtd_get_master(mtd);
2404
2405 *retlen = 0;
2406 if (!(mtd->flags & MTD_WRITEABLE))
2407 return -EROFS;
2408
2409 if (!master->_writev)
2410 return default_mtd_writev(mtd, vecs, count, to, retlen);
2411
2412 return master->_writev(master, vecs, count,
2413 mtd_get_master_ofs(mtd, ofs: to), retlen);
2414}
2415EXPORT_SYMBOL_GPL(mtd_writev);
2416
2417/**
2418 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
2419 * @mtd: mtd device description object pointer
2420 * @size: a pointer to the ideal or maximum size of the allocation, points
2421 * to the actual allocation size on success.
2422 *
2423 * This routine attempts to allocate a contiguous kernel buffer up to
2424 * the specified size, backing off the size of the request exponentially
2425 * until the request succeeds or until the allocation size falls below
2426 * the system page size. This attempts to make sure it does not adversely
2427 * impact system performance, so when allocating more than one page, we
2428 * ask the memory allocator to avoid re-trying, swapping, writing back
2429 * or performing I/O.
2430 *
2431 * Note, this function also makes sure that the allocated buffer is aligned to
2432 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
2433 *
2434 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
2435 * to handle smaller (i.e. degraded) buffer allocations under low- or
2436 * fragmented-memory situations where such reduced allocations, from a
2437 * requested ideal, are allowed.
2438 *
2439 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
2440 */
2441void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
2442{
2443 gfp_t flags = __GFP_NOWARN | __GFP_DIRECT_RECLAIM | __GFP_NORETRY;
2444 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
2445 void *kbuf;
2446
2447 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
2448
2449 while (*size > min_alloc) {
2450 kbuf = kmalloc(size: *size, flags);
2451 if (kbuf)
2452 return kbuf;
2453
2454 *size >>= 1;
2455 *size = ALIGN(*size, mtd->writesize);
2456 }
2457
2458 /*
2459 * For the last resort allocation allow 'kmalloc()' to do all sorts of
2460 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
2461 */
2462 return kmalloc(size: *size, GFP_KERNEL);
2463}
2464EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
2465
2466#ifdef CONFIG_PROC_FS
2467
2468/*====================================================================*/
2469/* Support for /proc/mtd */
2470
2471static int mtd_proc_show(struct seq_file *m, void *v)
2472{
2473 struct mtd_info *mtd;
2474
2475 seq_puts(m, s: "dev: size erasesize name\n");
2476 mutex_lock(&mtd_table_mutex);
2477 mtd_for_each_device(mtd) {
2478 seq_printf(m, fmt: "mtd%d: %8.8llx %8.8x \"%s\"\n",
2479 mtd->index, (unsigned long long)mtd->size,
2480 mtd->erasesize, mtd->name);
2481 }
2482 mutex_unlock(lock: &mtd_table_mutex);
2483 return 0;
2484}
2485#endif /* CONFIG_PROC_FS */
2486
2487/*====================================================================*/
2488/* Init code */
2489
2490static struct backing_dev_info * __init mtd_bdi_init(const char *name)
2491{
2492 struct backing_dev_info *bdi;
2493 int ret;
2494
2495 bdi = bdi_alloc(NUMA_NO_NODE);
2496 if (!bdi)
2497 return ERR_PTR(error: -ENOMEM);
2498 bdi->ra_pages = 0;
2499 bdi->io_pages = 0;
2500
2501 /*
2502 * We put '-0' suffix to the name to get the same name format as we
2503 * used to get. Since this is called only once, we get a unique name.
2504 */
2505 ret = bdi_register(bdi, fmt: "%.28s-0", name);
2506 if (ret)
2507 bdi_put(bdi);
2508
2509 return ret ? ERR_PTR(error: ret) : bdi;
2510}
2511
2512static struct proc_dir_entry *proc_mtd;
2513
2514static int __init init_mtd(void)
2515{
2516 int ret;
2517
2518 ret = class_register(class: &mtd_class);
2519 if (ret)
2520 goto err_reg;
2521
2522 mtd_bdi = mtd_bdi_init(name: "mtd");
2523 if (IS_ERR(ptr: mtd_bdi)) {
2524 ret = PTR_ERR(ptr: mtd_bdi);
2525 goto err_bdi;
2526 }
2527
2528 proc_mtd = proc_create_single("mtd", 0, NULL, mtd_proc_show);
2529
2530 ret = init_mtdchar();
2531 if (ret)
2532 goto out_procfs;
2533
2534 dfs_dir_mtd = debugfs_create_dir(name: "mtd", NULL);
2535 debugfs_create_bool(name: "expert_analysis_mode", mode: 0600, parent: dfs_dir_mtd,
2536 value: &mtd_expert_analysis_mode);
2537
2538 return 0;
2539
2540out_procfs:
2541 if (proc_mtd)
2542 remove_proc_entry("mtd", NULL);
2543 bdi_unregister(bdi: mtd_bdi);
2544 bdi_put(bdi: mtd_bdi);
2545err_bdi:
2546 class_unregister(class: &mtd_class);
2547err_reg:
2548 pr_err("Error registering mtd class or bdi: %d\n", ret);
2549 return ret;
2550}
2551
2552static void __exit cleanup_mtd(void)
2553{
2554 debugfs_remove_recursive(dentry: dfs_dir_mtd);
2555 cleanup_mtdchar();
2556 if (proc_mtd)
2557 remove_proc_entry("mtd", NULL);
2558 class_unregister(class: &mtd_class);
2559 bdi_unregister(bdi: mtd_bdi);
2560 bdi_put(bdi: mtd_bdi);
2561 idr_destroy(&mtd_idr);
2562}
2563
2564module_init(init_mtd);
2565module_exit(cleanup_mtd);
2566
2567MODULE_LICENSE("GPL");
2568MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
2569MODULE_DESCRIPTION("Core MTD registration and access routines");
2570

source code of linux/drivers/mtd/mtdcore.c