mtd: introduce mtd_get_unmapped_area interface
[linux-2.6.git] / drivers / mtd / mtdchar.c
1 /*
2  * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  *
18  */
19
20 #include <linux/device.h>
21 #include <linux/fs.h>
22 #include <linux/mm.h>
23 #include <linux/err.h>
24 #include <linux/init.h>
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/slab.h>
28 #include <linux/sched.h>
29 #include <linux/mutex.h>
30 #include <linux/backing-dev.h>
31 #include <linux/compat.h>
32 #include <linux/mount.h>
33 #include <linux/blkpg.h>
34 #include <linux/mtd/mtd.h>
35 #include <linux/mtd/partitions.h>
36 #include <linux/mtd/map.h>
37
38 #include <asm/uaccess.h>
39
40 #define MTD_INODE_FS_MAGIC 0x11307854
41 static DEFINE_MUTEX(mtd_mutex);
42 static struct vfsmount *mtd_inode_mnt __read_mostly;
43
44 /*
45  * Data structure to hold the pointer to the mtd device as well
46  * as mode information of various use cases.
47  */
48 struct mtd_file_info {
49         struct mtd_info *mtd;
50         struct inode *ino;
51         enum mtd_file_modes mode;
52 };
53
54 static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig)
55 {
56         struct mtd_file_info *mfi = file->private_data;
57         struct mtd_info *mtd = mfi->mtd;
58
59         switch (orig) {
60         case SEEK_SET:
61                 break;
62         case SEEK_CUR:
63                 offset += file->f_pos;
64                 break;
65         case SEEK_END:
66                 offset += mtd->size;
67                 break;
68         default:
69                 return -EINVAL;
70         }
71
72         if (offset >= 0 && offset <= mtd->size)
73                 return file->f_pos = offset;
74
75         return -EINVAL;
76 }
77
78
79
80 static int mtdchar_open(struct inode *inode, struct file *file)
81 {
82         int minor = iminor(inode);
83         int devnum = minor >> 1;
84         int ret = 0;
85         struct mtd_info *mtd;
86         struct mtd_file_info *mfi;
87         struct inode *mtd_ino;
88
89         pr_debug("MTD_open\n");
90
91         /* You can't open the RO devices RW */
92         if ((file->f_mode & FMODE_WRITE) && (minor & 1))
93                 return -EACCES;
94
95         mutex_lock(&mtd_mutex);
96         mtd = get_mtd_device(NULL, devnum);
97
98         if (IS_ERR(mtd)) {
99                 ret = PTR_ERR(mtd);
100                 goto out;
101         }
102
103         if (mtd->type == MTD_ABSENT) {
104                 put_mtd_device(mtd);
105                 ret = -ENODEV;
106                 goto out;
107         }
108
109         mtd_ino = iget_locked(mtd_inode_mnt->mnt_sb, devnum);
110         if (!mtd_ino) {
111                 put_mtd_device(mtd);
112                 ret = -ENOMEM;
113                 goto out;
114         }
115         if (mtd_ino->i_state & I_NEW) {
116                 mtd_ino->i_private = mtd;
117                 mtd_ino->i_mode = S_IFCHR;
118                 mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
119                 unlock_new_inode(mtd_ino);
120         }
121         file->f_mapping = mtd_ino->i_mapping;
122
123         /* You can't open it RW if it's not a writeable device */
124         if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
125                 iput(mtd_ino);
126                 put_mtd_device(mtd);
127                 ret = -EACCES;
128                 goto out;
129         }
130
131         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
132         if (!mfi) {
133                 iput(mtd_ino);
134                 put_mtd_device(mtd);
135                 ret = -ENOMEM;
136                 goto out;
137         }
138         mfi->ino = mtd_ino;
139         mfi->mtd = mtd;
140         file->private_data = mfi;
141
142 out:
143         mutex_unlock(&mtd_mutex);
144         return ret;
145 } /* mtdchar_open */
146
147 /*====================================================================*/
148
149 static int mtdchar_close(struct inode *inode, struct file *file)
150 {
151         struct mtd_file_info *mfi = file->private_data;
152         struct mtd_info *mtd = mfi->mtd;
153
154         pr_debug("MTD_close\n");
155
156         /* Only sync if opened RW */
157         if ((file->f_mode & FMODE_WRITE) && mtd->sync)
158                 mtd->sync(mtd);
159
160         iput(mfi->ino);
161
162         put_mtd_device(mtd);
163         file->private_data = NULL;
164         kfree(mfi);
165
166         return 0;
167 } /* mtdchar_close */
168
169 /* Back in June 2001, dwmw2 wrote:
170  *
171  *   FIXME: This _really_ needs to die. In 2.5, we should lock the
172  *   userspace buffer down and use it directly with readv/writev.
173  *
174  * The implementation below, using mtd_kmalloc_up_to, mitigates
175  * allocation failures when the system is under low-memory situations
176  * or if memory is highly fragmented at the cost of reducing the
177  * performance of the requested transfer due to a smaller buffer size.
178  *
179  * A more complex but more memory-efficient implementation based on
180  * get_user_pages and iovecs to cover extents of those pages is a
181  * longer-term goal, as intimated by dwmw2 above. However, for the
182  * write case, this requires yet more complex head and tail transfer
183  * handling when those head and tail offsets and sizes are such that
184  * alignment requirements are not met in the NAND subdriver.
185  */
186
187 static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
188                         loff_t *ppos)
189 {
190         struct mtd_file_info *mfi = file->private_data;
191         struct mtd_info *mtd = mfi->mtd;
192         size_t retlen=0;
193         size_t total_retlen=0;
194         int ret=0;
195         int len;
196         size_t size = count;
197         char *kbuf;
198
199         pr_debug("MTD_read\n");
200
201         if (*ppos + count > mtd->size)
202                 count = mtd->size - *ppos;
203
204         if (!count)
205                 return 0;
206
207         kbuf = mtd_kmalloc_up_to(mtd, &size);
208         if (!kbuf)
209                 return -ENOMEM;
210
211         while (count) {
212                 len = min_t(size_t, count, size);
213
214                 switch (mfi->mode) {
215                 case MTD_FILE_MODE_OTP_FACTORY:
216                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
217                         break;
218                 case MTD_FILE_MODE_OTP_USER:
219                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
220                         break;
221                 case MTD_FILE_MODE_RAW:
222                 {
223                         struct mtd_oob_ops ops;
224
225                         ops.mode = MTD_OPS_RAW;
226                         ops.datbuf = kbuf;
227                         ops.oobbuf = NULL;
228                         ops.len = len;
229
230                         ret = mtd->read_oob(mtd, *ppos, &ops);
231                         retlen = ops.retlen;
232                         break;
233                 }
234                 default:
235                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
236                 }
237                 /* Nand returns -EBADMSG on ECC errors, but it returns
238                  * the data. For our userspace tools it is important
239                  * to dump areas with ECC errors!
240                  * For kernel internal usage it also might return -EUCLEAN
241                  * to signal the caller that a bitflip has occurred and has
242                  * been corrected by the ECC algorithm.
243                  * Userspace software which accesses NAND this way
244                  * must be aware of the fact that it deals with NAND
245                  */
246                 if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
247                         *ppos += retlen;
248                         if (copy_to_user(buf, kbuf, retlen)) {
249                                 kfree(kbuf);
250                                 return -EFAULT;
251                         }
252                         else
253                                 total_retlen += retlen;
254
255                         count -= retlen;
256                         buf += retlen;
257                         if (retlen == 0)
258                                 count = 0;
259                 }
260                 else {
261                         kfree(kbuf);
262                         return ret;
263                 }
264
265         }
266
267         kfree(kbuf);
268         return total_retlen;
269 } /* mtdchar_read */
270
271 static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
272                         loff_t *ppos)
273 {
274         struct mtd_file_info *mfi = file->private_data;
275         struct mtd_info *mtd = mfi->mtd;
276         size_t size = count;
277         char *kbuf;
278         size_t retlen;
279         size_t total_retlen=0;
280         int ret=0;
281         int len;
282
283         pr_debug("MTD_write\n");
284
285         if (*ppos == mtd->size)
286                 return -ENOSPC;
287
288         if (*ppos + count > mtd->size)
289                 count = mtd->size - *ppos;
290
291         if (!count)
292                 return 0;
293
294         kbuf = mtd_kmalloc_up_to(mtd, &size);
295         if (!kbuf)
296                 return -ENOMEM;
297
298         while (count) {
299                 len = min_t(size_t, count, size);
300
301                 if (copy_from_user(kbuf, buf, len)) {
302                         kfree(kbuf);
303                         return -EFAULT;
304                 }
305
306                 switch (mfi->mode) {
307                 case MTD_FILE_MODE_OTP_FACTORY:
308                         ret = -EROFS;
309                         break;
310                 case MTD_FILE_MODE_OTP_USER:
311                         if (!mtd->write_user_prot_reg) {
312                                 ret = -EOPNOTSUPP;
313                                 break;
314                         }
315                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
316                         break;
317
318                 case MTD_FILE_MODE_RAW:
319                 {
320                         struct mtd_oob_ops ops;
321
322                         ops.mode = MTD_OPS_RAW;
323                         ops.datbuf = kbuf;
324                         ops.oobbuf = NULL;
325                         ops.ooboffs = 0;
326                         ops.len = len;
327
328                         ret = mtd->write_oob(mtd, *ppos, &ops);
329                         retlen = ops.retlen;
330                         break;
331                 }
332
333                 default:
334                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
335                 }
336                 if (!ret) {
337                         *ppos += retlen;
338                         total_retlen += retlen;
339                         count -= retlen;
340                         buf += retlen;
341                 }
342                 else {
343                         kfree(kbuf);
344                         return ret;
345                 }
346         }
347
348         kfree(kbuf);
349         return total_retlen;
350 } /* mtdchar_write */
351
352 /*======================================================================
353
354     IOCTL calls for getting device parameters.
355
356 ======================================================================*/
357 static void mtdchar_erase_callback (struct erase_info *instr)
358 {
359         wake_up((wait_queue_head_t *)instr->priv);
360 }
361
362 #ifdef CONFIG_HAVE_MTD_OTP
363 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
364 {
365         struct mtd_info *mtd = mfi->mtd;
366         int ret = 0;
367
368         switch (mode) {
369         case MTD_OTP_FACTORY:
370                 if (!mtd->read_fact_prot_reg)
371                         ret = -EOPNOTSUPP;
372                 else
373                         mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
374                 break;
375         case MTD_OTP_USER:
376                 if (!mtd->read_fact_prot_reg)
377                         ret = -EOPNOTSUPP;
378                 else
379                         mfi->mode = MTD_FILE_MODE_OTP_USER;
380                 break;
381         default:
382                 ret = -EINVAL;
383         case MTD_OTP_OFF:
384                 break;
385         }
386         return ret;
387 }
388 #else
389 # define otp_select_filemode(f,m)       -EOPNOTSUPP
390 #endif
391
392 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
393         uint64_t start, uint32_t length, void __user *ptr,
394         uint32_t __user *retp)
395 {
396         struct mtd_file_info *mfi = file->private_data;
397         struct mtd_oob_ops ops;
398         uint32_t retlen;
399         int ret = 0;
400
401         if (!(file->f_mode & FMODE_WRITE))
402                 return -EPERM;
403
404         if (length > 4096)
405                 return -EINVAL;
406
407         if (!mtd->write_oob)
408                 ret = -EOPNOTSUPP;
409         else
410                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
411
412         if (ret)
413                 return ret;
414
415         ops.ooblen = length;
416         ops.ooboffs = start & (mtd->writesize - 1);
417         ops.datbuf = NULL;
418         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
419                 MTD_OPS_PLACE_OOB;
420
421         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
422                 return -EINVAL;
423
424         ops.oobbuf = memdup_user(ptr, length);
425         if (IS_ERR(ops.oobbuf))
426                 return PTR_ERR(ops.oobbuf);
427
428         start &= ~((uint64_t)mtd->writesize - 1);
429         ret = mtd->write_oob(mtd, start, &ops);
430
431         if (ops.oobretlen > 0xFFFFFFFFU)
432                 ret = -EOVERFLOW;
433         retlen = ops.oobretlen;
434         if (copy_to_user(retp, &retlen, sizeof(length)))
435                 ret = -EFAULT;
436
437         kfree(ops.oobbuf);
438         return ret;
439 }
440
441 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
442         uint64_t start, uint32_t length, void __user *ptr,
443         uint32_t __user *retp)
444 {
445         struct mtd_file_info *mfi = file->private_data;
446         struct mtd_oob_ops ops;
447         int ret = 0;
448
449         if (length > 4096)
450                 return -EINVAL;
451
452         if (!mtd->read_oob)
453                 ret = -EOPNOTSUPP;
454         else
455                 ret = access_ok(VERIFY_WRITE, ptr,
456                                 length) ? 0 : -EFAULT;
457         if (ret)
458                 return ret;
459
460         ops.ooblen = length;
461         ops.ooboffs = start & (mtd->writesize - 1);
462         ops.datbuf = NULL;
463         ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
464                 MTD_OPS_PLACE_OOB;
465
466         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
467                 return -EINVAL;
468
469         ops.oobbuf = kmalloc(length, GFP_KERNEL);
470         if (!ops.oobbuf)
471                 return -ENOMEM;
472
473         start &= ~((uint64_t)mtd->writesize - 1);
474         ret = mtd->read_oob(mtd, start, &ops);
475
476         if (put_user(ops.oobretlen, retp))
477                 ret = -EFAULT;
478         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
479                                             ops.oobretlen))
480                 ret = -EFAULT;
481
482         kfree(ops.oobbuf);
483
484         /*
485          * NAND returns -EBADMSG on ECC errors, but it returns the OOB
486          * data. For our userspace tools it is important to dump areas
487          * with ECC errors!
488          * For kernel internal usage it also might return -EUCLEAN
489          * to signal the caller that a bitflip has occured and has
490          * been corrected by the ECC algorithm.
491          *
492          * Note: currently the standard NAND function, nand_read_oob_std,
493          * does not calculate ECC for the OOB area, so do not rely on
494          * this behavior unless you have replaced it with your own.
495          */
496         if (mtd_is_bitflip_or_eccerr(ret))
497                 return 0;
498
499         return ret;
500 }
501
502 /*
503  * Copies (and truncates, if necessary) data from the larger struct,
504  * nand_ecclayout, to the smaller, deprecated layout struct,
505  * nand_ecclayout_user. This is necessary only to support the deprecated
506  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
507  * nand_ecclayout flexibly (i.e. the struct may change size in new
508  * releases without requiring major rewrites).
509  */
510 static int shrink_ecclayout(const struct nand_ecclayout *from,
511                 struct nand_ecclayout_user *to)
512 {
513         int i;
514
515         if (!from || !to)
516                 return -EINVAL;
517
518         memset(to, 0, sizeof(*to));
519
520         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
521         for (i = 0; i < to->eccbytes; i++)
522                 to->eccpos[i] = from->eccpos[i];
523
524         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
525                 if (from->oobfree[i].length == 0 &&
526                                 from->oobfree[i].offset == 0)
527                         break;
528                 to->oobavail += from->oobfree[i].length;
529                 to->oobfree[i] = from->oobfree[i];
530         }
531
532         return 0;
533 }
534
535 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
536                            struct blkpg_ioctl_arg __user *arg)
537 {
538         struct blkpg_ioctl_arg a;
539         struct blkpg_partition p;
540
541         if (!capable(CAP_SYS_ADMIN))
542                 return -EPERM;
543
544         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
545                 return -EFAULT;
546
547         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
548                 return -EFAULT;
549
550         switch (a.op) {
551         case BLKPG_ADD_PARTITION:
552
553                 /* Only master mtd device must be used to add partitions */
554                 if (mtd_is_partition(mtd))
555                         return -EINVAL;
556
557                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
558
559         case BLKPG_DEL_PARTITION:
560
561                 if (p.pno < 0)
562                         return -EINVAL;
563
564                 return mtd_del_partition(mtd, p.pno);
565
566         default:
567                 return -EINVAL;
568         }
569 }
570
571 static int mtdchar_write_ioctl(struct mtd_info *mtd,
572                 struct mtd_write_req __user *argp)
573 {
574         struct mtd_write_req req;
575         struct mtd_oob_ops ops;
576         void __user *usr_data, *usr_oob;
577         int ret;
578
579         if (copy_from_user(&req, argp, sizeof(req)) ||
580                         !access_ok(VERIFY_READ, req.usr_data, req.len) ||
581                         !access_ok(VERIFY_READ, req.usr_oob, req.ooblen))
582                 return -EFAULT;
583         if (!mtd->write_oob)
584                 return -EOPNOTSUPP;
585
586         ops.mode = req.mode;
587         ops.len = (size_t)req.len;
588         ops.ooblen = (size_t)req.ooblen;
589         ops.ooboffs = 0;
590
591         usr_data = (void __user *)(uintptr_t)req.usr_data;
592         usr_oob = (void __user *)(uintptr_t)req.usr_oob;
593
594         if (req.usr_data) {
595                 ops.datbuf = memdup_user(usr_data, ops.len);
596                 if (IS_ERR(ops.datbuf))
597                         return PTR_ERR(ops.datbuf);
598         } else {
599                 ops.datbuf = NULL;
600         }
601
602         if (req.usr_oob) {
603                 ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
604                 if (IS_ERR(ops.oobbuf)) {
605                         kfree(ops.datbuf);
606                         return PTR_ERR(ops.oobbuf);
607                 }
608         } else {
609                 ops.oobbuf = NULL;
610         }
611
612         ret = mtd->write_oob(mtd, (loff_t)req.start, &ops);
613
614         kfree(ops.datbuf);
615         kfree(ops.oobbuf);
616
617         return ret;
618 }
619
620 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
621 {
622         struct mtd_file_info *mfi = file->private_data;
623         struct mtd_info *mtd = mfi->mtd;
624         void __user *argp = (void __user *)arg;
625         int ret = 0;
626         u_long size;
627         struct mtd_info_user info;
628
629         pr_debug("MTD_ioctl\n");
630
631         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
632         if (cmd & IOC_IN) {
633                 if (!access_ok(VERIFY_READ, argp, size))
634                         return -EFAULT;
635         }
636         if (cmd & IOC_OUT) {
637                 if (!access_ok(VERIFY_WRITE, argp, size))
638                         return -EFAULT;
639         }
640
641         switch (cmd) {
642         case MEMGETREGIONCOUNT:
643                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
644                         return -EFAULT;
645                 break;
646
647         case MEMGETREGIONINFO:
648         {
649                 uint32_t ur_idx;
650                 struct mtd_erase_region_info *kr;
651                 struct region_info_user __user *ur = argp;
652
653                 if (get_user(ur_idx, &(ur->regionindex)))
654                         return -EFAULT;
655
656                 if (ur_idx >= mtd->numeraseregions)
657                         return -EINVAL;
658
659                 kr = &(mtd->eraseregions[ur_idx]);
660
661                 if (put_user(kr->offset, &(ur->offset))
662                     || put_user(kr->erasesize, &(ur->erasesize))
663                     || put_user(kr->numblocks, &(ur->numblocks)))
664                         return -EFAULT;
665
666                 break;
667         }
668
669         case MEMGETINFO:
670                 memset(&info, 0, sizeof(info));
671                 info.type       = mtd->type;
672                 info.flags      = mtd->flags;
673                 info.size       = mtd->size;
674                 info.erasesize  = mtd->erasesize;
675                 info.writesize  = mtd->writesize;
676                 info.oobsize    = mtd->oobsize;
677                 /* The below field is obsolete */
678                 info.padding    = 0;
679                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
680                         return -EFAULT;
681                 break;
682
683         case MEMERASE:
684         case MEMERASE64:
685         {
686                 struct erase_info *erase;
687
688                 if(!(file->f_mode & FMODE_WRITE))
689                         return -EPERM;
690
691                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
692                 if (!erase)
693                         ret = -ENOMEM;
694                 else {
695                         wait_queue_head_t waitq;
696                         DECLARE_WAITQUEUE(wait, current);
697
698                         init_waitqueue_head(&waitq);
699
700                         if (cmd == MEMERASE64) {
701                                 struct erase_info_user64 einfo64;
702
703                                 if (copy_from_user(&einfo64, argp,
704                                             sizeof(struct erase_info_user64))) {
705                                         kfree(erase);
706                                         return -EFAULT;
707                                 }
708                                 erase->addr = einfo64.start;
709                                 erase->len = einfo64.length;
710                         } else {
711                                 struct erase_info_user einfo32;
712
713                                 if (copy_from_user(&einfo32, argp,
714                                             sizeof(struct erase_info_user))) {
715                                         kfree(erase);
716                                         return -EFAULT;
717                                 }
718                                 erase->addr = einfo32.start;
719                                 erase->len = einfo32.length;
720                         }
721                         erase->mtd = mtd;
722                         erase->callback = mtdchar_erase_callback;
723                         erase->priv = (unsigned long)&waitq;
724
725                         /*
726                           FIXME: Allow INTERRUPTIBLE. Which means
727                           not having the wait_queue head on the stack.
728
729                           If the wq_head is on the stack, and we
730                           leave because we got interrupted, then the
731                           wq_head is no longer there when the
732                           callback routine tries to wake us up.
733                         */
734                         ret = mtd_erase(mtd, erase);
735                         if (!ret) {
736                                 set_current_state(TASK_UNINTERRUPTIBLE);
737                                 add_wait_queue(&waitq, &wait);
738                                 if (erase->state != MTD_ERASE_DONE &&
739                                     erase->state != MTD_ERASE_FAILED)
740                                         schedule();
741                                 remove_wait_queue(&waitq, &wait);
742                                 set_current_state(TASK_RUNNING);
743
744                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
745                         }
746                         kfree(erase);
747                 }
748                 break;
749         }
750
751         case MEMWRITEOOB:
752         {
753                 struct mtd_oob_buf buf;
754                 struct mtd_oob_buf __user *buf_user = argp;
755
756                 /* NOTE: writes return length to buf_user->length */
757                 if (copy_from_user(&buf, argp, sizeof(buf)))
758                         ret = -EFAULT;
759                 else
760                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
761                                 buf.ptr, &buf_user->length);
762                 break;
763         }
764
765         case MEMREADOOB:
766         {
767                 struct mtd_oob_buf buf;
768                 struct mtd_oob_buf __user *buf_user = argp;
769
770                 /* NOTE: writes return length to buf_user->start */
771                 if (copy_from_user(&buf, argp, sizeof(buf)))
772                         ret = -EFAULT;
773                 else
774                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
775                                 buf.ptr, &buf_user->start);
776                 break;
777         }
778
779         case MEMWRITEOOB64:
780         {
781                 struct mtd_oob_buf64 buf;
782                 struct mtd_oob_buf64 __user *buf_user = argp;
783
784                 if (copy_from_user(&buf, argp, sizeof(buf)))
785                         ret = -EFAULT;
786                 else
787                         ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
788                                 (void __user *)(uintptr_t)buf.usr_ptr,
789                                 &buf_user->length);
790                 break;
791         }
792
793         case MEMREADOOB64:
794         {
795                 struct mtd_oob_buf64 buf;
796                 struct mtd_oob_buf64 __user *buf_user = argp;
797
798                 if (copy_from_user(&buf, argp, sizeof(buf)))
799                         ret = -EFAULT;
800                 else
801                         ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
802                                 (void __user *)(uintptr_t)buf.usr_ptr,
803                                 &buf_user->length);
804                 break;
805         }
806
807         case MEMWRITE:
808         {
809                 ret = mtdchar_write_ioctl(mtd,
810                       (struct mtd_write_req __user *)arg);
811                 break;
812         }
813
814         case MEMLOCK:
815         {
816                 struct erase_info_user einfo;
817
818                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
819                         return -EFAULT;
820
821                 if (!mtd->lock)
822                         ret = -EOPNOTSUPP;
823                 else
824                         ret = mtd->lock(mtd, einfo.start, einfo.length);
825                 break;
826         }
827
828         case MEMUNLOCK:
829         {
830                 struct erase_info_user einfo;
831
832                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
833                         return -EFAULT;
834
835                 if (!mtd->unlock)
836                         ret = -EOPNOTSUPP;
837                 else
838                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
839                 break;
840         }
841
842         case MEMISLOCKED:
843         {
844                 struct erase_info_user einfo;
845
846                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
847                         return -EFAULT;
848
849                 if (!mtd->is_locked)
850                         ret = -EOPNOTSUPP;
851                 else
852                         ret = mtd->is_locked(mtd, einfo.start, einfo.length);
853                 break;
854         }
855
856         /* Legacy interface */
857         case MEMGETOOBSEL:
858         {
859                 struct nand_oobinfo oi;
860
861                 if (!mtd->ecclayout)
862                         return -EOPNOTSUPP;
863                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
864                         return -EINVAL;
865
866                 oi.useecc = MTD_NANDECC_AUTOPLACE;
867                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
868                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
869                        sizeof(oi.oobfree));
870                 oi.eccbytes = mtd->ecclayout->eccbytes;
871
872                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
873                         return -EFAULT;
874                 break;
875         }
876
877         case MEMGETBADBLOCK:
878         {
879                 loff_t offs;
880
881                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
882                         return -EFAULT;
883                 if (!mtd->block_isbad)
884                         ret = -EOPNOTSUPP;
885                 else
886                         return mtd->block_isbad(mtd, offs);
887                 break;
888         }
889
890         case MEMSETBADBLOCK:
891         {
892                 loff_t offs;
893
894                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
895                         return -EFAULT;
896                 if (!mtd->block_markbad)
897                         ret = -EOPNOTSUPP;
898                 else
899                         return mtd->block_markbad(mtd, offs);
900                 break;
901         }
902
903 #ifdef CONFIG_HAVE_MTD_OTP
904         case OTPSELECT:
905         {
906                 int mode;
907                 if (copy_from_user(&mode, argp, sizeof(int)))
908                         return -EFAULT;
909
910                 mfi->mode = MTD_FILE_MODE_NORMAL;
911
912                 ret = otp_select_filemode(mfi, mode);
913
914                 file->f_pos = 0;
915                 break;
916         }
917
918         case OTPGETREGIONCOUNT:
919         case OTPGETREGIONINFO:
920         {
921                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
922                 if (!buf)
923                         return -ENOMEM;
924                 ret = -EOPNOTSUPP;
925                 switch (mfi->mode) {
926                 case MTD_FILE_MODE_OTP_FACTORY:
927                         if (mtd->get_fact_prot_info)
928                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
929                         break;
930                 case MTD_FILE_MODE_OTP_USER:
931                         if (mtd->get_user_prot_info)
932                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
933                         break;
934                 default:
935                         break;
936                 }
937                 if (ret >= 0) {
938                         if (cmd == OTPGETREGIONCOUNT) {
939                                 int nbr = ret / sizeof(struct otp_info);
940                                 ret = copy_to_user(argp, &nbr, sizeof(int));
941                         } else
942                                 ret = copy_to_user(argp, buf, ret);
943                         if (ret)
944                                 ret = -EFAULT;
945                 }
946                 kfree(buf);
947                 break;
948         }
949
950         case OTPLOCK:
951         {
952                 struct otp_info oinfo;
953
954                 if (mfi->mode != MTD_FILE_MODE_OTP_USER)
955                         return -EINVAL;
956                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
957                         return -EFAULT;
958                 if (!mtd->lock_user_prot_reg)
959                         return -EOPNOTSUPP;
960                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
961                 break;
962         }
963 #endif
964
965         /* This ioctl is being deprecated - it truncates the ECC layout */
966         case ECCGETLAYOUT:
967         {
968                 struct nand_ecclayout_user *usrlay;
969
970                 if (!mtd->ecclayout)
971                         return -EOPNOTSUPP;
972
973                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
974                 if (!usrlay)
975                         return -ENOMEM;
976
977                 shrink_ecclayout(mtd->ecclayout, usrlay);
978
979                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
980                         ret = -EFAULT;
981                 kfree(usrlay);
982                 break;
983         }
984
985         case ECCGETSTATS:
986         {
987                 if (copy_to_user(argp, &mtd->ecc_stats,
988                                  sizeof(struct mtd_ecc_stats)))
989                         return -EFAULT;
990                 break;
991         }
992
993         case MTDFILEMODE:
994         {
995                 mfi->mode = 0;
996
997                 switch(arg) {
998                 case MTD_FILE_MODE_OTP_FACTORY:
999                 case MTD_FILE_MODE_OTP_USER:
1000                         ret = otp_select_filemode(mfi, arg);
1001                         break;
1002
1003                 case MTD_FILE_MODE_RAW:
1004                         if (!mtd->read_oob || !mtd->write_oob)
1005                                 return -EOPNOTSUPP;
1006                         mfi->mode = arg;
1007
1008                 case MTD_FILE_MODE_NORMAL:
1009                         break;
1010                 default:
1011                         ret = -EINVAL;
1012                 }
1013                 file->f_pos = 0;
1014                 break;
1015         }
1016
1017         case BLKPG:
1018         {
1019                 ret = mtdchar_blkpg_ioctl(mtd,
1020                       (struct blkpg_ioctl_arg __user *)arg);
1021                 break;
1022         }
1023
1024         case BLKRRPART:
1025         {
1026                 /* No reread partition feature. Just return ok */
1027                 ret = 0;
1028                 break;
1029         }
1030
1031         default:
1032                 ret = -ENOTTY;
1033         }
1034
1035         return ret;
1036 } /* memory_ioctl */
1037
1038 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1039 {
1040         int ret;
1041
1042         mutex_lock(&mtd_mutex);
1043         ret = mtdchar_ioctl(file, cmd, arg);
1044         mutex_unlock(&mtd_mutex);
1045
1046         return ret;
1047 }
1048
1049 #ifdef CONFIG_COMPAT
1050
1051 struct mtd_oob_buf32 {
1052         u_int32_t start;
1053         u_int32_t length;
1054         compat_caddr_t ptr;     /* unsigned char* */
1055 };
1056
1057 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1058 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1059
1060 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1061         unsigned long arg)
1062 {
1063         struct mtd_file_info *mfi = file->private_data;
1064         struct mtd_info *mtd = mfi->mtd;
1065         void __user *argp = compat_ptr(arg);
1066         int ret = 0;
1067
1068         mutex_lock(&mtd_mutex);
1069
1070         switch (cmd) {
1071         case MEMWRITEOOB32:
1072         {
1073                 struct mtd_oob_buf32 buf;
1074                 struct mtd_oob_buf32 __user *buf_user = argp;
1075
1076                 if (copy_from_user(&buf, argp, sizeof(buf)))
1077                         ret = -EFAULT;
1078                 else
1079                         ret = mtdchar_writeoob(file, mtd, buf.start,
1080                                 buf.length, compat_ptr(buf.ptr),
1081                                 &buf_user->length);
1082                 break;
1083         }
1084
1085         case MEMREADOOB32:
1086         {
1087                 struct mtd_oob_buf32 buf;
1088                 struct mtd_oob_buf32 __user *buf_user = argp;
1089
1090                 /* NOTE: writes return length to buf->start */
1091                 if (copy_from_user(&buf, argp, sizeof(buf)))
1092                         ret = -EFAULT;
1093                 else
1094                         ret = mtdchar_readoob(file, mtd, buf.start,
1095                                 buf.length, compat_ptr(buf.ptr),
1096                                 &buf_user->start);
1097                 break;
1098         }
1099         default:
1100                 ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1101         }
1102
1103         mutex_unlock(&mtd_mutex);
1104
1105         return ret;
1106 }
1107
1108 #endif /* CONFIG_COMPAT */
1109
1110 /*
1111  * try to determine where a shared mapping can be made
1112  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1113  *   mappings)
1114  */
1115 #ifndef CONFIG_MMU
1116 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1117                                            unsigned long addr,
1118                                            unsigned long len,
1119                                            unsigned long pgoff,
1120                                            unsigned long flags)
1121 {
1122         struct mtd_file_info *mfi = file->private_data;
1123         struct mtd_info *mtd = mfi->mtd;
1124
1125         if (mtd->get_unmapped_area) {
1126                 unsigned long offset;
1127
1128                 if (addr != 0)
1129                         return (unsigned long) -EINVAL;
1130
1131                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1132                         return (unsigned long) -EINVAL;
1133
1134                 offset = pgoff << PAGE_SHIFT;
1135                 if (offset > mtd->size - len)
1136                         return (unsigned long) -EINVAL;
1137
1138                 return mtd_get_unmapped_area(mtd, len, offset, flags);
1139         }
1140
1141         /* can't map directly */
1142         return (unsigned long) -ENOSYS;
1143 }
1144 #endif
1145
1146 /*
1147  * set up a mapping for shared memory segments
1148  */
1149 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1150 {
1151 #ifdef CONFIG_MMU
1152         struct mtd_file_info *mfi = file->private_data;
1153         struct mtd_info *mtd = mfi->mtd;
1154         struct map_info *map = mtd->priv;
1155         unsigned long start;
1156         unsigned long off;
1157         u32 len;
1158
1159         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
1160                 off = vma->vm_pgoff << PAGE_SHIFT;
1161                 start = map->phys;
1162                 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
1163                 start &= PAGE_MASK;
1164                 if ((vma->vm_end - vma->vm_start + off) > len)
1165                         return -EINVAL;
1166
1167                 off += start;
1168                 vma->vm_pgoff = off >> PAGE_SHIFT;
1169                 vma->vm_flags |= VM_IO | VM_RESERVED;
1170
1171 #ifdef pgprot_noncached
1172                 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1173                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1174 #endif
1175                 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1176                                        vma->vm_end - vma->vm_start,
1177                                        vma->vm_page_prot))
1178                         return -EAGAIN;
1179
1180                 return 0;
1181         }
1182         return -ENOSYS;
1183 #else
1184         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1185 #endif
1186 }
1187
1188 static const struct file_operations mtd_fops = {
1189         .owner          = THIS_MODULE,
1190         .llseek         = mtdchar_lseek,
1191         .read           = mtdchar_read,
1192         .write          = mtdchar_write,
1193         .unlocked_ioctl = mtdchar_unlocked_ioctl,
1194 #ifdef CONFIG_COMPAT
1195         .compat_ioctl   = mtdchar_compat_ioctl,
1196 #endif
1197         .open           = mtdchar_open,
1198         .release        = mtdchar_close,
1199         .mmap           = mtdchar_mmap,
1200 #ifndef CONFIG_MMU
1201         .get_unmapped_area = mtdchar_get_unmapped_area,
1202 #endif
1203 };
1204
1205 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1206                                 int flags, const char *dev_name, void *data)
1207 {
1208         return mount_pseudo(fs_type, "mtd_inode:", NULL, NULL, MTD_INODE_FS_MAGIC);
1209 }
1210
1211 static struct file_system_type mtd_inodefs_type = {
1212        .name = "mtd_inodefs",
1213        .mount = mtd_inodefs_mount,
1214        .kill_sb = kill_anon_super,
1215 };
1216
1217 static void mtdchar_notify_add(struct mtd_info *mtd)
1218 {
1219 }
1220
1221 static void mtdchar_notify_remove(struct mtd_info *mtd)
1222 {
1223         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1224
1225         if (mtd_ino) {
1226                 /* Destroy the inode if it exists */
1227                 clear_nlink(mtd_ino);
1228                 iput(mtd_ino);
1229         }
1230 }
1231
1232 static struct mtd_notifier mtdchar_notifier = {
1233         .add = mtdchar_notify_add,
1234         .remove = mtdchar_notify_remove,
1235 };
1236
1237 static int __init init_mtdchar(void)
1238 {
1239         int ret;
1240
1241         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1242                                    "mtd", &mtd_fops);
1243         if (ret < 0) {
1244                 pr_notice("Can't allocate major number %d for "
1245                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1246                 return ret;
1247         }
1248
1249         ret = register_filesystem(&mtd_inodefs_type);
1250         if (ret) {
1251                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1252                 goto err_unregister_chdev;
1253         }
1254
1255         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1256         if (IS_ERR(mtd_inode_mnt)) {
1257                 ret = PTR_ERR(mtd_inode_mnt);
1258                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1259                 goto err_unregister_filesystem;
1260         }
1261         register_mtd_user(&mtdchar_notifier);
1262
1263         return ret;
1264
1265 err_unregister_filesystem:
1266         unregister_filesystem(&mtd_inodefs_type);
1267 err_unregister_chdev:
1268         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1269         return ret;
1270 }
1271
1272 static void __exit cleanup_mtdchar(void)
1273 {
1274         unregister_mtd_user(&mtdchar_notifier);
1275         kern_unmount(mtd_inode_mnt);
1276         unregister_filesystem(&mtd_inodefs_type);
1277         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1278 }
1279
1280 module_init(init_mtdchar);
1281 module_exit(cleanup_mtdchar);
1282
1283 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1284
1285 MODULE_LICENSE("GPL");
1286 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1287 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1288 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);