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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * Core registration and callback routines for MTD
3 * drivers and users.
4 *
David Woodhousea1452a32010-08-08 20:58:20 +01005 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
6 * Copyright © 2006 Red Hat UK Limited
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070022 */
23
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/module.h>
25#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/ptrace.h>
Alexey Dobriyan447d9bd2011-05-13 23:34:19 +030027#include <linux/seq_file.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/string.h>
29#include <linux/timer.h>
30#include <linux/major.h>
31#include <linux/fs.h>
Artem Bityutskiy77993082006-10-11 14:52:44 +030032#include <linux/err.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include <linux/ioctl.h>
34#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include <linux/proc_fs.h>
Ben Hutchingsb520e412010-01-29 20:59:42 +000036#include <linux/idr.h>
Jörn Engela33eb6b2010-04-27 09:40:52 +020037#include <linux/backing-dev.h>
Tejun Heo05d71b462010-03-30 02:52:39 +090038#include <linux/gfp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40#include <linux/mtd/mtd.h>
Jamie Ilesf5671ab2011-05-23 17:15:46 +010041#include <linux/mtd/partitions.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
Ben Dooks356d70f2007-05-28 20:28:34 +010043#include "mtdcore.h"
Jörn Engela33eb6b2010-04-27 09:40:52 +020044/*
45 * backing device capabilities for non-mappable devices (such as NAND flash)
46 * - permits private mappings, copies are taken of the data
47 */
H Hartley Sweetenca91fac2011-01-11 18:37:25 -060048static struct backing_dev_info mtd_bdi_unmappable = {
Jörn Engela33eb6b2010-04-27 09:40:52 +020049 .capabilities = BDI_CAP_MAP_COPY,
50};
51
52/*
53 * backing device capabilities for R/O mappable devices (such as ROM)
54 * - permits private mappings, copies are taken of the data
55 * - permits non-writable shared mappings
56 */
H Hartley Sweetenca91fac2011-01-11 18:37:25 -060057static struct backing_dev_info mtd_bdi_ro_mappable = {
Jörn Engela33eb6b2010-04-27 09:40:52 +020058 .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
59 BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP),
60};
61
62/*
63 * backing device capabilities for writable mappable devices (such as RAM)
64 * - permits private mappings, copies are taken of the data
65 * - permits non-writable shared mappings
66 */
H Hartley Sweetenca91fac2011-01-11 18:37:25 -060067static struct backing_dev_info mtd_bdi_rw_mappable = {
Jörn Engela33eb6b2010-04-27 09:40:52 +020068 .capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
69 BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP |
70 BDI_CAP_WRITE_MAP),
71};
Ben Dooks356d70f2007-05-28 20:28:34 +010072
David Woodhouse15bce402009-04-05 07:40:58 -070073static int mtd_cls_suspend(struct device *dev, pm_message_t state);
74static int mtd_cls_resume(struct device *dev);
David Brownell1f24b5a2009-03-26 00:42:41 -070075
David Woodhouse15bce402009-04-05 07:40:58 -070076static struct class mtd_class = {
77 .name = "mtd",
78 .owner = THIS_MODULE,
79 .suspend = mtd_cls_suspend,
80 .resume = mtd_cls_resume,
81};
David Brownell1f24b5a2009-03-26 00:42:41 -070082
Ben Hutchingsb520e412010-01-29 20:59:42 +000083static DEFINE_IDR(mtd_idr);
84
Thomas Gleixner97894cd2005-11-07 11:15:26 +000085/* These are exported solely for the purpose of mtd_blkdevs.c. You
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 should not use them for _anything_ else */
Ingo Molnar48b19262006-03-31 02:29:41 -080087DEFINE_MUTEX(mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088EXPORT_SYMBOL_GPL(mtd_table_mutex);
Ben Hutchingsb520e412010-01-29 20:59:42 +000089
90struct mtd_info *__mtd_next_device(int i)
91{
92 return idr_get_next(&mtd_idr, &i);
93}
94EXPORT_SYMBOL_GPL(__mtd_next_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
96static LIST_HEAD(mtd_notifiers);
97
David Brownell1f24b5a2009-03-26 00:42:41 -070098
99#if defined(CONFIG_MTD_CHAR) || defined(CONFIG_MTD_CHAR_MODULE)
100#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
101#else
102#define MTD_DEVT(index) 0
103#endif
104
105/* REVISIT once MTD uses the driver model better, whoever allocates
106 * the mtd_info will probably want to use the release() hook...
107 */
108static void mtd_release(struct device *dev)
109{
Artem Bityutskiyd5de20a2011-12-29 18:00:29 +0200110 struct mtd_info *mtd = dev_get_drvdata(dev);
111 dev_t index = MTD_DEVT(mtd->index);
David Brownell1f24b5a2009-03-26 00:42:41 -0700112
113 /* remove /dev/mtdXro node if needed */
Denis V. Lunev2fdb1142009-04-12 08:14:46 +0100114 if (index)
David Woodhouse15bce402009-04-05 07:40:58 -0700115 device_destroy(&mtd_class, index + 1);
116}
117
118static int mtd_cls_suspend(struct device *dev, pm_message_t state)
119{
Artem Bityutskiyd5de20a2011-12-29 18:00:29 +0200120 struct mtd_info *mtd = dev_get_drvdata(dev);
Saeed Bishara6afc4fd2009-07-28 04:56:43 -0700121
Artem Bityutskiy1a308712012-01-16 11:07:16 +0200122 return mtd ? mtd_suspend(mtd) : 0;
David Woodhouse15bce402009-04-05 07:40:58 -0700123}
124
125static int mtd_cls_resume(struct device *dev)
126{
Artem Bityutskiyd5de20a2011-12-29 18:00:29 +0200127 struct mtd_info *mtd = dev_get_drvdata(dev);
Artem Bityutskiy33c87b42011-12-30 16:11:14 +0200128
Saeed Bishara6afc4fd2009-07-28 04:56:43 -0700129 if (mtd && mtd->resume)
Artem Bityutskiyead995f2011-12-23 19:31:25 +0200130 mtd_resume(mtd);
David Woodhouse15bce402009-04-05 07:40:58 -0700131 return 0;
David Brownell1f24b5a2009-03-26 00:42:41 -0700132}
133
134static ssize_t mtd_type_show(struct device *dev,
135 struct device_attribute *attr, char *buf)
136{
Artem Bityutskiyd5de20a2011-12-29 18:00:29 +0200137 struct mtd_info *mtd = dev_get_drvdata(dev);
David Brownell1f24b5a2009-03-26 00:42:41 -0700138 char *type;
139
140 switch (mtd->type) {
141 case MTD_ABSENT:
142 type = "absent";
143 break;
144 case MTD_RAM:
145 type = "ram";
146 break;
147 case MTD_ROM:
148 type = "rom";
149 break;
150 case MTD_NORFLASH:
151 type = "nor";
152 break;
153 case MTD_NANDFLASH:
154 type = "nand";
155 break;
156 case MTD_DATAFLASH:
157 type = "dataflash";
158 break;
159 case MTD_UBIVOLUME:
160 type = "ubi";
161 break;
162 default:
163 type = "unknown";
164 }
165
166 return snprintf(buf, PAGE_SIZE, "%s\n", type);
167}
Kevin Cernekee694bb7f2009-04-03 13:00:45 -0700168static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);
169
170static ssize_t mtd_flags_show(struct device *dev,
171 struct device_attribute *attr, char *buf)
172{
Artem Bityutskiyd5de20a2011-12-29 18:00:29 +0200173 struct mtd_info *mtd = dev_get_drvdata(dev);
Kevin Cernekee694bb7f2009-04-03 13:00:45 -0700174
175 return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);
176
177}
178static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);
179
180static ssize_t mtd_size_show(struct device *dev,
181 struct device_attribute *attr, char *buf)
182{
Artem Bityutskiyd5de20a2011-12-29 18:00:29 +0200183 struct mtd_info *mtd = dev_get_drvdata(dev);
Kevin Cernekee694bb7f2009-04-03 13:00:45 -0700184
185 return snprintf(buf, PAGE_SIZE, "%llu\n",
186 (unsigned long long)mtd->size);
187
188}
189static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);
190
191static ssize_t mtd_erasesize_show(struct device *dev,
192 struct device_attribute *attr, char *buf)
193{
Artem Bityutskiyd5de20a2011-12-29 18:00:29 +0200194 struct mtd_info *mtd = dev_get_drvdata(dev);
Kevin Cernekee694bb7f2009-04-03 13:00:45 -0700195
196 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);
197
198}
199static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);
200
201static ssize_t mtd_writesize_show(struct device *dev,
202 struct device_attribute *attr, char *buf)
203{
Artem Bityutskiyd5de20a2011-12-29 18:00:29 +0200204 struct mtd_info *mtd = dev_get_drvdata(dev);
Kevin Cernekee694bb7f2009-04-03 13:00:45 -0700205
206 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);
207
208}
209static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);
210
Artem Bityutskiye7693542009-04-18 12:29:42 +0300211static ssize_t mtd_subpagesize_show(struct device *dev,
212 struct device_attribute *attr, char *buf)
213{
Artem Bityutskiyd5de20a2011-12-29 18:00:29 +0200214 struct mtd_info *mtd = dev_get_drvdata(dev);
Artem Bityutskiye7693542009-04-18 12:29:42 +0300215 unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;
216
217 return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);
218
219}
220static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);
221
Kevin Cernekee694bb7f2009-04-03 13:00:45 -0700222static ssize_t mtd_oobsize_show(struct device *dev,
223 struct device_attribute *attr, char *buf)
224{
Artem Bityutskiyd5de20a2011-12-29 18:00:29 +0200225 struct mtd_info *mtd = dev_get_drvdata(dev);
Kevin Cernekee694bb7f2009-04-03 13:00:45 -0700226
227 return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);
228
229}
230static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);
231
232static ssize_t mtd_numeraseregions_show(struct device *dev,
233 struct device_attribute *attr, char *buf)
234{
Artem Bityutskiyd5de20a2011-12-29 18:00:29 +0200235 struct mtd_info *mtd = dev_get_drvdata(dev);
Kevin Cernekee694bb7f2009-04-03 13:00:45 -0700236
237 return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);
238
239}
240static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
241 NULL);
242
243static ssize_t mtd_name_show(struct device *dev,
244 struct device_attribute *attr, char *buf)
245{
Artem Bityutskiyd5de20a2011-12-29 18:00:29 +0200246 struct mtd_info *mtd = dev_get_drvdata(dev);
Kevin Cernekee694bb7f2009-04-03 13:00:45 -0700247
248 return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);
249
250}
251static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);
David Brownell1f24b5a2009-03-26 00:42:41 -0700252
253static struct attribute *mtd_attrs[] = {
Kevin Cernekee694bb7f2009-04-03 13:00:45 -0700254 &dev_attr_type.attr,
255 &dev_attr_flags.attr,
256 &dev_attr_size.attr,
257 &dev_attr_erasesize.attr,
258 &dev_attr_writesize.attr,
Artem Bityutskiye7693542009-04-18 12:29:42 +0300259 &dev_attr_subpagesize.attr,
Kevin Cernekee694bb7f2009-04-03 13:00:45 -0700260 &dev_attr_oobsize.attr,
261 &dev_attr_numeraseregions.attr,
262 &dev_attr_name.attr,
David Brownell1f24b5a2009-03-26 00:42:41 -0700263 NULL,
264};
265
H Hartley Sweetenfca91082009-08-06 16:05:32 -0700266static struct attribute_group mtd_group = {
David Brownell1f24b5a2009-03-26 00:42:41 -0700267 .attrs = mtd_attrs,
268};
269
David Woodhouse6469f542009-09-20 05:55:36 -0700270static const struct attribute_group *mtd_groups[] = {
David Brownell1f24b5a2009-03-26 00:42:41 -0700271 &mtd_group,
272 NULL,
273};
274
275static struct device_type mtd_devtype = {
276 .name = "mtd",
277 .groups = mtd_groups,
278 .release = mtd_release,
279};
280
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281/**
282 * add_mtd_device - register an MTD device
283 * @mtd: pointer to new MTD device info structure
284 *
285 * Add a device to the list of MTD devices present in the system, and
286 * notify each currently active MTD 'user' of its arrival. Returns
287 * zero on success or 1 on failure, which currently will only happen
Ben Hutchingsb520e412010-01-29 20:59:42 +0000288 * if there is insufficient memory or a sysfs error.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 */
290
291int add_mtd_device(struct mtd_info *mtd)
292{
Ben Hutchingsb520e412010-01-29 20:59:42 +0000293 struct mtd_notifier *not;
294 int i, error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295
David Howells402d3262009-02-12 10:40:00 +0000296 if (!mtd->backing_dev_info) {
297 switch (mtd->type) {
298 case MTD_RAM:
299 mtd->backing_dev_info = &mtd_bdi_rw_mappable;
300 break;
301 case MTD_ROM:
302 mtd->backing_dev_info = &mtd_bdi_ro_mappable;
303 break;
304 default:
305 mtd->backing_dev_info = &mtd_bdi_unmappable;
306 break;
307 }
308 }
309
Artem B. Bityutskiy783ed812006-06-14 19:53:44 +0400310 BUG_ON(mtd->writesize == 0);
Ingo Molnar48b19262006-03-31 02:29:41 -0800311 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312
Ben Hutchingsb520e412010-01-29 20:59:42 +0000313 do {
314 if (!idr_pre_get(&mtd_idr, GFP_KERNEL))
315 goto fail_locked;
316 error = idr_get_new(&mtd_idr, mtd, &i);
317 } while (error == -EAGAIN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318
Ben Hutchingsb520e412010-01-29 20:59:42 +0000319 if (error)
320 goto fail_locked;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321
Ben Hutchingsb520e412010-01-29 20:59:42 +0000322 mtd->index = i;
323 mtd->usecount = 0;
Adrian Hunter69423d92008-12-10 13:37:21 +0000324
Ben Hutchingsb520e412010-01-29 20:59:42 +0000325 if (is_power_of_2(mtd->erasesize))
326 mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
327 else
328 mtd->erasesize_shift = 0;
Adrian Hunter69423d92008-12-10 13:37:21 +0000329
Ben Hutchingsb520e412010-01-29 20:59:42 +0000330 if (is_power_of_2(mtd->writesize))
331 mtd->writesize_shift = ffs(mtd->writesize) - 1;
332 else
333 mtd->writesize_shift = 0;
Adrian Hunter69423d92008-12-10 13:37:21 +0000334
Ben Hutchingsb520e412010-01-29 20:59:42 +0000335 mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
336 mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;
Håvard Skinnemoen187ef152006-09-22 10:07:08 +0100337
Ben Hutchingsb520e412010-01-29 20:59:42 +0000338 /* Some chips always power up locked. Unlock them now */
Artem Bityutskiy38134562011-12-30 17:00:35 +0200339 if ((mtd->flags & MTD_WRITEABLE) && (mtd->flags & MTD_POWERUP_LOCK)) {
340 error = mtd_unlock(mtd, 0, mtd->size);
341 if (error && error != -EOPNOTSUPP)
Ben Hutchingsb520e412010-01-29 20:59:42 +0000342 printk(KERN_WARNING
343 "%s: unlock failed, writes may not work\n",
344 mtd->name);
345 }
David Brownell1f24b5a2009-03-26 00:42:41 -0700346
Ben Hutchingsb520e412010-01-29 20:59:42 +0000347 /* Caller should have set dev.parent to match the
348 * physical device.
349 */
350 mtd->dev.type = &mtd_devtype;
351 mtd->dev.class = &mtd_class;
352 mtd->dev.devt = MTD_DEVT(i);
353 dev_set_name(&mtd->dev, "mtd%d", i);
354 dev_set_drvdata(&mtd->dev, mtd);
355 if (device_register(&mtd->dev) != 0)
356 goto fail_added;
David Brownell1f24b5a2009-03-26 00:42:41 -0700357
Ben Hutchingsb520e412010-01-29 20:59:42 +0000358 if (MTD_DEVT(i))
359 device_create(&mtd_class, mtd->dev.parent,
360 MTD_DEVT(i) + 1,
361 NULL, "mtd%dro", i);
Thomas Gleixner97894cd2005-11-07 11:15:26 +0000362
Brian Norris289c0522011-07-19 10:06:09 -0700363 pr_debug("mtd: Giving out device %d to %s\n", i, mtd->name);
Ben Hutchingsb520e412010-01-29 20:59:42 +0000364 /* No need to get a refcount on the module containing
365 the notifier, since we hold the mtd_table_mutex */
366 list_for_each_entry(not, &mtd_notifiers, list)
367 not->add(mtd);
Thomas Gleixner97894cd2005-11-07 11:15:26 +0000368
Ingo Molnar48b19262006-03-31 02:29:41 -0800369 mutex_unlock(&mtd_table_mutex);
Ben Hutchingsb520e412010-01-29 20:59:42 +0000370 /* We _know_ we aren't being removed, because
371 our caller is still holding us here. So none
372 of this try_ nonsense, and no bitching about it
373 either. :) */
374 __module_get(THIS_MODULE);
375 return 0;
376
377fail_added:
378 idr_remove(&mtd_idr, i);
379fail_locked:
380 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 return 1;
382}
383
384/**
385 * del_mtd_device - unregister an MTD device
386 * @mtd: pointer to MTD device info structure
387 *
388 * Remove a device from the list of MTD devices present in the system,
389 * and notify each currently active MTD 'user' of its departure.
390 * Returns zero on success or 1 on failure, which currently will happen
391 * if the requested device does not appear to be present in the list.
392 */
393
Jamie Ileseea72d52011-05-23 10:23:42 +0100394int del_mtd_device(struct mtd_info *mtd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395{
396 int ret;
Maxim Levitsky75c0b842010-02-22 20:39:32 +0200397 struct mtd_notifier *not;
Thomas Gleixner97894cd2005-11-07 11:15:26 +0000398
Ingo Molnar48b19262006-03-31 02:29:41 -0800399 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400
Ben Hutchingsb520e412010-01-29 20:59:42 +0000401 if (idr_find(&mtd_idr, mtd->index) != mtd) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 ret = -ENODEV;
Maxim Levitsky75c0b842010-02-22 20:39:32 +0200403 goto out_error;
404 }
405
406 /* No need to get a refcount on the module containing
407 the notifier, since we hold the mtd_table_mutex */
408 list_for_each_entry(not, &mtd_notifiers, list)
409 not->remove(mtd);
410
411 if (mtd->usecount) {
Thomas Gleixner97894cd2005-11-07 11:15:26 +0000412 printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 mtd->index, mtd->name, mtd->usecount);
414 ret = -EBUSY;
415 } else {
Kevin Cernekee694bb7f2009-04-03 13:00:45 -0700416 device_unregister(&mtd->dev);
417
Ben Hutchingsb520e412010-01-29 20:59:42 +0000418 idr_remove(&mtd_idr, mtd->index);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419
420 module_put(THIS_MODULE);
421 ret = 0;
422 }
423
Maxim Levitsky75c0b842010-02-22 20:39:32 +0200424out_error:
Ingo Molnar48b19262006-03-31 02:29:41 -0800425 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 return ret;
427}
428
429/**
Dmitry Eremin-Solenikov1c4c2152011-03-25 22:26:25 +0300430 * mtd_device_parse_register - parse partitions and register an MTD device.
431 *
432 * @mtd: the MTD device to register
433 * @types: the list of MTD partition probes to try, see
434 * 'parse_mtd_partitions()' for more information
Dmitry Eremin-Solenikovc7975332011-06-10 18:18:28 +0400435 * @parser_data: MTD partition parser-specific data
Dmitry Eremin-Solenikov1c4c2152011-03-25 22:26:25 +0300436 * @parts: fallback partition information to register, if parsing fails;
437 * only valid if %nr_parts > %0
438 * @nr_parts: the number of partitions in parts, if zero then the full
439 * MTD device is registered if no partition info is found
440 *
441 * This function aggregates MTD partitions parsing (done by
442 * 'parse_mtd_partitions()') and MTD device and partitions registering. It
443 * basically follows the most common pattern found in many MTD drivers:
444 *
445 * * It first tries to probe partitions on MTD device @mtd using parsers
446 * specified in @types (if @types is %NULL, then the default list of parsers
447 * is used, see 'parse_mtd_partitions()' for more information). If none are
448 * found this functions tries to fallback to information specified in
449 * @parts/@nr_parts.
Brian Norris92394b5c2011-07-20 09:53:42 -0700450 * * If any partitioning info was found, this function registers the found
Dmitry Eremin-Solenikov1c4c2152011-03-25 22:26:25 +0300451 * partitions.
452 * * If no partitions were found this function just registers the MTD device
453 * @mtd and exits.
454 *
455 * Returns zero in case of success and a negative error code in case of failure.
456 */
457int mtd_device_parse_register(struct mtd_info *mtd, const char **types,
Dmitry Eremin-Solenikovc7975332011-06-10 18:18:28 +0400458 struct mtd_part_parser_data *parser_data,
Dmitry Eremin-Solenikov1c4c2152011-03-25 22:26:25 +0300459 const struct mtd_partition *parts,
460 int nr_parts)
461{
462 int err;
463 struct mtd_partition *real_parts;
464
Dmitry Eremin-Solenikovc7975332011-06-10 18:18:28 +0400465 err = parse_mtd_partitions(mtd, types, &real_parts, parser_data);
Jason Liu4d523b602011-08-24 19:26:28 +0800466 if (err <= 0 && nr_parts && parts) {
Dmitry Eremin-Solenikov1c4c2152011-03-25 22:26:25 +0300467 real_parts = kmemdup(parts, sizeof(*parts) * nr_parts,
468 GFP_KERNEL);
Jason Liu4d523b602011-08-24 19:26:28 +0800469 if (!real_parts)
Dmitry Eremin-Solenikov1c4c2152011-03-25 22:26:25 +0300470 err = -ENOMEM;
Jason Liu4d523b602011-08-24 19:26:28 +0800471 else
472 err = nr_parts;
Dmitry Eremin-Solenikov1c4c2152011-03-25 22:26:25 +0300473 }
474
475 if (err > 0) {
476 err = add_mtd_partitions(mtd, real_parts, err);
477 kfree(real_parts);
478 } else if (err == 0) {
479 err = add_mtd_device(mtd);
480 if (err == 1)
481 err = -ENODEV;
482 }
483
484 return err;
485}
486EXPORT_SYMBOL_GPL(mtd_device_parse_register);
487
488/**
Jamie Ilesf5671ab2011-05-23 17:15:46 +0100489 * mtd_device_unregister - unregister an existing MTD device.
490 *
491 * @master: the MTD device to unregister. This will unregister both the master
492 * and any partitions if registered.
493 */
494int mtd_device_unregister(struct mtd_info *master)
495{
496 int err;
497
498 err = del_mtd_partitions(master);
499 if (err)
500 return err;
501
502 if (!device_is_registered(&master->dev))
503 return 0;
504
505 return del_mtd_device(master);
506}
507EXPORT_SYMBOL_GPL(mtd_device_unregister);
508
509/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 * register_mtd_user - register a 'user' of MTD devices.
511 * @new: pointer to notifier info structure
512 *
513 * Registers a pair of callbacks function to be called upon addition
514 * or removal of MTD devices. Causes the 'add' callback to be immediately
515 * invoked for each MTD device currently present in the system.
516 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517void register_mtd_user (struct mtd_notifier *new)
518{
Ben Hutchingsf1332ba2010-01-29 20:57:11 +0000519 struct mtd_info *mtd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520
Ingo Molnar48b19262006-03-31 02:29:41 -0800521 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522
523 list_add(&new->list, &mtd_notifiers);
524
Wanlong Gaod5ca5122011-05-20 21:14:30 +0800525 __module_get(THIS_MODULE);
Thomas Gleixner97894cd2005-11-07 11:15:26 +0000526
Ben Hutchingsf1332ba2010-01-29 20:57:11 +0000527 mtd_for_each_device(mtd)
528 new->add(mtd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529
Ingo Molnar48b19262006-03-31 02:29:41 -0800530 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531}
Artem Bityutskiy33c87b42011-12-30 16:11:14 +0200532EXPORT_SYMBOL_GPL(register_mtd_user);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533
534/**
Artem B. Bityuckiy49450792005-02-18 14:34:54 +0000535 * unregister_mtd_user - unregister a 'user' of MTD devices.
536 * @old: pointer to notifier info structure
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 *
538 * Removes a callback function pair from the list of 'users' to be
539 * notified upon addition or removal of MTD devices. Causes the
540 * 'remove' callback to be immediately invoked for each MTD device
541 * currently present in the system.
542 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543int unregister_mtd_user (struct mtd_notifier *old)
544{
Ben Hutchingsf1332ba2010-01-29 20:57:11 +0000545 struct mtd_info *mtd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546
Ingo Molnar48b19262006-03-31 02:29:41 -0800547 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548
549 module_put(THIS_MODULE);
550
Ben Hutchingsf1332ba2010-01-29 20:57:11 +0000551 mtd_for_each_device(mtd)
552 old->remove(mtd);
Thomas Gleixner97894cd2005-11-07 11:15:26 +0000553
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 list_del(&old->list);
Ingo Molnar48b19262006-03-31 02:29:41 -0800555 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 return 0;
557}
Artem Bityutskiy33c87b42011-12-30 16:11:14 +0200558EXPORT_SYMBOL_GPL(unregister_mtd_user);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559
560/**
561 * get_mtd_device - obtain a validated handle for an MTD device
562 * @mtd: last known address of the required MTD device
563 * @num: internal device number of the required MTD device
564 *
565 * Given a number and NULL address, return the num'th entry in the device
566 * table, if any. Given an address and num == -1, search the device table
567 * for a device with that address and return if it's still present. Given
Artem Bityutskiy9c740342006-10-11 14:52:47 +0300568 * both, return the num'th driver only if its address matches. Return
569 * error code if not.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
572{
Ben Hutchingsf1332ba2010-01-29 20:57:11 +0000573 struct mtd_info *ret = NULL, *other;
574 int err = -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575
Ingo Molnar48b19262006-03-31 02:29:41 -0800576 mutex_lock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577
578 if (num == -1) {
Ben Hutchingsf1332ba2010-01-29 20:57:11 +0000579 mtd_for_each_device(other) {
580 if (other == mtd) {
581 ret = mtd;
582 break;
583 }
584 }
Ben Hutchingsb520e412010-01-29 20:59:42 +0000585 } else if (num >= 0) {
586 ret = idr_find(&mtd_idr, num);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 if (mtd && mtd != ret)
588 ret = NULL;
589 }
590
Maxim Levitsky3bd45652010-02-22 20:39:28 +0200591 if (!ret) {
592 ret = ERR_PTR(err);
593 goto out;
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300594 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595
Maxim Levitsky3bd45652010-02-22 20:39:28 +0200596 err = __get_mtd_device(ret);
597 if (err)
598 ret = ERR_PTR(err);
599out:
Ingo Molnar48b19262006-03-31 02:29:41 -0800600 mutex_unlock(&mtd_table_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 return ret;
Maxim Levitsky3bd45652010-02-22 20:39:28 +0200602}
Artem Bityutskiy33c87b42011-12-30 16:11:14 +0200603EXPORT_SYMBOL_GPL(get_mtd_device);
Artem Bityutskiy9c740342006-10-11 14:52:47 +0300604
Maxim Levitsky3bd45652010-02-22 20:39:28 +0200605
606int __get_mtd_device(struct mtd_info *mtd)
607{
608 int err;
609
610 if (!try_module_get(mtd->owner))
611 return -ENODEV;
612
613 if (mtd->get_device) {
Maxim Levitsky3bd45652010-02-22 20:39:28 +0200614 err = mtd->get_device(mtd);
615
616 if (err) {
617 module_put(mtd->owner);
618 return err;
619 }
620 }
621 mtd->usecount++;
622 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623}
Artem Bityutskiy33c87b42011-12-30 16:11:14 +0200624EXPORT_SYMBOL_GPL(__get_mtd_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625
Artem Bityutskiy77993082006-10-11 14:52:44 +0300626/**
627 * get_mtd_device_nm - obtain a validated handle for an MTD device by
628 * device name
629 * @name: MTD device name to open
630 *
631 * This function returns MTD device description structure in case of
632 * success and an error code in case of failure.
633 */
Artem Bityutskiy77993082006-10-11 14:52:44 +0300634struct mtd_info *get_mtd_device_nm(const char *name)
635{
Ben Hutchingsf1332ba2010-01-29 20:57:11 +0000636 int err = -ENODEV;
637 struct mtd_info *mtd = NULL, *other;
Artem Bityutskiy77993082006-10-11 14:52:44 +0300638
639 mutex_lock(&mtd_table_mutex);
640
Ben Hutchingsf1332ba2010-01-29 20:57:11 +0000641 mtd_for_each_device(other) {
642 if (!strcmp(name, other->name)) {
643 mtd = other;
Artem Bityutskiy77993082006-10-11 14:52:44 +0300644 break;
645 }
646 }
647
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300648 if (!mtd)
Artem Bityutskiy77993082006-10-11 14:52:44 +0300649 goto out_unlock;
650
Wanlong Gao52534f22011-05-17 22:36:18 +0800651 err = __get_mtd_device(mtd);
652 if (err)
Artem Bityutskiy77993082006-10-11 14:52:44 +0300653 goto out_unlock;
654
Artem Bityutskiy77993082006-10-11 14:52:44 +0300655 mutex_unlock(&mtd_table_mutex);
656 return mtd;
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300657
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300658out_unlock:
659 mutex_unlock(&mtd_table_mutex);
660 return ERR_PTR(err);
Artem Bityutskiy77993082006-10-11 14:52:44 +0300661}
Artem Bityutskiy33c87b42011-12-30 16:11:14 +0200662EXPORT_SYMBOL_GPL(get_mtd_device_nm);
Artem Bityutskiy77993082006-10-11 14:52:44 +0300663
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664void put_mtd_device(struct mtd_info *mtd)
665{
Ingo Molnar48b19262006-03-31 02:29:41 -0800666 mutex_lock(&mtd_table_mutex);
Maxim Levitsky3bd45652010-02-22 20:39:28 +0200667 __put_mtd_device(mtd);
668 mutex_unlock(&mtd_table_mutex);
669
670}
Artem Bityutskiy33c87b42011-12-30 16:11:14 +0200671EXPORT_SYMBOL_GPL(put_mtd_device);
Maxim Levitsky3bd45652010-02-22 20:39:28 +0200672
673void __put_mtd_device(struct mtd_info *mtd)
674{
675 --mtd->usecount;
676 BUG_ON(mtd->usecount < 0);
677
Artem Bityutskiy9fe912c2006-10-11 14:52:45 +0300678 if (mtd->put_device)
679 mtd->put_device(mtd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680
681 module_put(mtd->owner);
682}
Artem Bityutskiy33c87b42011-12-30 16:11:14 +0200683EXPORT_SYMBOL_GPL(__put_mtd_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684
Artem Bityutskiy52b02032011-12-30 15:57:25 +0200685/*
686 * default_mtd_writev - the default writev method
687 * @mtd: mtd device description object pointer
688 * @vecs: the vectors to write
689 * @count: count of vectors in @vecs
690 * @to: the MTD device offset to write to
691 * @retlen: on exit contains the count of bytes written to the MTD device.
692 *
693 * This function returns zero in case of success and a negative error code in
694 * case of failure.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 */
Artem Bityutskiy1dbebd32011-12-30 16:23:41 +0200696static int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
697 unsigned long count, loff_t to, size_t *retlen)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698{
699 unsigned long i;
700 size_t totlen = 0, thislen;
701 int ret = 0;
702
Artem Bityutskiy52b02032011-12-30 15:57:25 +0200703 for (i = 0; i < count; i++) {
704 if (!vecs[i].iov_len)
705 continue;
706 ret = mtd_write(mtd, to, vecs[i].iov_len, &thislen,
707 vecs[i].iov_base);
708 totlen += thislen;
709 if (ret || thislen != vecs[i].iov_len)
710 break;
711 to += vecs[i].iov_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 }
Artem Bityutskiy52b02032011-12-30 15:57:25 +0200713 *retlen = totlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 return ret;
715}
Artem Bityutskiy1dbebd32011-12-30 16:23:41 +0200716
717/*
718 * mtd_writev - the vector-based MTD write method
719 * @mtd: mtd device description object pointer
720 * @vecs: the vectors to write
721 * @count: count of vectors in @vecs
722 * @to: the MTD device offset to write to
723 * @retlen: on exit contains the count of bytes written to the MTD device.
724 *
725 * This function returns zero in case of success and a negative error code in
726 * case of failure.
727 */
728int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
729 unsigned long count, loff_t to, size_t *retlen)
730{
731 *retlen = 0;
732 if (!mtd->writev)
733 return default_mtd_writev(mtd, vecs, count, to, retlen);
734 return mtd->writev(mtd, vecs, count, to, retlen);
735}
736EXPORT_SYMBOL_GPL(mtd_writev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737
Grant Erickson33b53712011-04-08 08:51:32 -0700738/**
739 * mtd_kmalloc_up_to - allocate a contiguous buffer up to the specified size
Artem Bityutskiy52b02032011-12-30 15:57:25 +0200740 * @mtd: mtd device description object pointer
741 * @size: a pointer to the ideal or maximum size of the allocation, points
Grant Erickson33b53712011-04-08 08:51:32 -0700742 * to the actual allocation size on success.
743 *
744 * This routine attempts to allocate a contiguous kernel buffer up to
745 * the specified size, backing off the size of the request exponentially
746 * until the request succeeds or until the allocation size falls below
747 * the system page size. This attempts to make sure it does not adversely
748 * impact system performance, so when allocating more than one page, we
749 * ask the memory allocator to avoid re-trying, swapping, writing back
750 * or performing I/O.
751 *
752 * Note, this function also makes sure that the allocated buffer is aligned to
753 * the MTD device's min. I/O unit, i.e. the "mtd->writesize" value.
754 *
755 * This is called, for example by mtd_{read,write} and jffs2_scan_medium,
756 * to handle smaller (i.e. degraded) buffer allocations under low- or
757 * fragmented-memory situations where such reduced allocations, from a
758 * requested ideal, are allowed.
759 *
760 * Returns a pointer to the allocated buffer on success; otherwise, NULL.
761 */
762void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size)
763{
764 gfp_t flags = __GFP_NOWARN | __GFP_WAIT |
765 __GFP_NORETRY | __GFP_NO_KSWAPD;
766 size_t min_alloc = max_t(size_t, mtd->writesize, PAGE_SIZE);
767 void *kbuf;
768
769 *size = min_t(size_t, *size, KMALLOC_MAX_SIZE);
770
771 while (*size > min_alloc) {
772 kbuf = kmalloc(*size, flags);
773 if (kbuf)
774 return kbuf;
775
776 *size >>= 1;
777 *size = ALIGN(*size, mtd->writesize);
778 }
779
780 /*
781 * For the last resort allocation allow 'kmalloc()' to do all sorts of
782 * things (write-back, dropping caches, etc) by using GFP_KERNEL.
783 */
784 return kmalloc(*size, GFP_KERNEL);
785}
Grant Erickson33b53712011-04-08 08:51:32 -0700786EXPORT_SYMBOL_GPL(mtd_kmalloc_up_to);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787
Pavel Machek2d2dce02006-03-31 02:29:49 -0800788#ifdef CONFIG_PROC_FS
789
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790/*====================================================================*/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791/* Support for /proc/mtd */
792
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793static struct proc_dir_entry *proc_mtd;
794
Alexey Dobriyan447d9bd2011-05-13 23:34:19 +0300795static int mtd_proc_show(struct seq_file *m, void *v)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796{
Ben Hutchingsf1332ba2010-01-29 20:57:11 +0000797 struct mtd_info *mtd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798
Alexey Dobriyan447d9bd2011-05-13 23:34:19 +0300799 seq_puts(m, "dev: size erasesize name\n");
Ingo Molnar48b19262006-03-31 02:29:41 -0800800 mutex_lock(&mtd_table_mutex);
Ben Hutchingsf1332ba2010-01-29 20:57:11 +0000801 mtd_for_each_device(mtd) {
Alexey Dobriyan447d9bd2011-05-13 23:34:19 +0300802 seq_printf(m, "mtd%d: %8.8llx %8.8x \"%s\"\n",
803 mtd->index, (unsigned long long)mtd->size,
804 mtd->erasesize, mtd->name);
Wanlong Gaod5ca5122011-05-20 21:14:30 +0800805 }
Ingo Molnar48b19262006-03-31 02:29:41 -0800806 mutex_unlock(&mtd_table_mutex);
Wanlong Gaod5ca5122011-05-20 21:14:30 +0800807 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808}
809
Alexey Dobriyan447d9bd2011-05-13 23:34:19 +0300810static int mtd_proc_open(struct inode *inode, struct file *file)
811{
812 return single_open(file, mtd_proc_show, NULL);
813}
814
815static const struct file_operations mtd_proc_ops = {
816 .open = mtd_proc_open,
817 .read = seq_read,
818 .llseek = seq_lseek,
819 .release = single_release,
820};
Kevin Cernekee45b09072009-04-04 11:03:04 -0700821#endif /* CONFIG_PROC_FS */
822
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823/*====================================================================*/
824/* Init code */
825
Jens Axboe0661b1a2010-04-27 09:49:47 +0200826static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
827{
828 int ret;
829
830 ret = bdi_init(bdi);
831 if (!ret)
832 ret = bdi_register(bdi, NULL, name);
833
834 if (ret)
835 bdi_destroy(bdi);
836
837 return ret;
838}
839
Linus Torvalds1da177e2005-04-16 15:20:36 -0700840static int __init init_mtd(void)
841{
David Woodhouse15bce402009-04-05 07:40:58 -0700842 int ret;
Kevin Cernekee694bb7f2009-04-03 13:00:45 -0700843
Jens Axboe0661b1a2010-04-27 09:49:47 +0200844 ret = class_register(&mtd_class);
845 if (ret)
846 goto err_reg;
847
848 ret = mtd_bdi_init(&mtd_bdi_unmappable, "mtd-unmap");
849 if (ret)
850 goto err_bdi1;
851
852 ret = mtd_bdi_init(&mtd_bdi_ro_mappable, "mtd-romap");
853 if (ret)
854 goto err_bdi2;
855
856 ret = mtd_bdi_init(&mtd_bdi_rw_mappable, "mtd-rwmap");
857 if (ret)
858 goto err_bdi3;
859
Kevin Cernekee45b09072009-04-04 11:03:04 -0700860#ifdef CONFIG_PROC_FS
Alexey Dobriyan447d9bd2011-05-13 23:34:19 +0300861 proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
Kevin Cernekee45b09072009-04-04 11:03:04 -0700862#endif /* CONFIG_PROC_FS */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863 return 0;
Jens Axboe0661b1a2010-04-27 09:49:47 +0200864
865err_bdi3:
866 bdi_destroy(&mtd_bdi_ro_mappable);
867err_bdi2:
868 bdi_destroy(&mtd_bdi_unmappable);
869err_bdi1:
870 class_unregister(&mtd_class);
871err_reg:
872 pr_err("Error registering mtd class or bdi: %d\n", ret);
873 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874}
875
876static void __exit cleanup_mtd(void)
877{
Kevin Cernekee45b09072009-04-04 11:03:04 -0700878#ifdef CONFIG_PROC_FS
Wanlong Gaod5ca5122011-05-20 21:14:30 +0800879 if (proc_mtd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 remove_proc_entry( "mtd", NULL);
Kevin Cernekee45b09072009-04-04 11:03:04 -0700881#endif /* CONFIG_PROC_FS */
David Woodhouse15bce402009-04-05 07:40:58 -0700882 class_unregister(&mtd_class);
Jens Axboe0661b1a2010-04-27 09:49:47 +0200883 bdi_destroy(&mtd_bdi_unmappable);
884 bdi_destroy(&mtd_bdi_ro_mappable);
885 bdi_destroy(&mtd_bdi_rw_mappable);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886}
887
888module_init(init_mtd);
889module_exit(cleanup_mtd);
890
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891MODULE_LICENSE("GPL");
892MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
893MODULE_DESCRIPTION("Core MTD registration and access routines");