media: soc_camera: tegra: fix one building warning
[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 ofr 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 mtd_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 mtd_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         DEBUG(MTD_DEBUG_LEVEL0, "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 } /* mtd_open */
146
147 /*====================================================================*/
148
149 static int mtd_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         DEBUG(MTD_DEBUG_LEVEL0, "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 } /* mtd_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 mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
188 {
189         struct mtd_file_info *mfi = file->private_data;
190         struct mtd_info *mtd = mfi->mtd;
191         size_t retlen=0;
192         size_t total_retlen=0;
193         int ret=0;
194         int len;
195         size_t size = count;
196         char *kbuf;
197
198         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
199
200         if (*ppos + count > mtd->size)
201                 count = mtd->size - *ppos;
202
203         if (!count)
204                 return 0;
205
206         kbuf = mtd_kmalloc_up_to(mtd, &size);
207         if (!kbuf)
208                 return -ENOMEM;
209
210         while (count) {
211                 len = min_t(size_t, count, size);
212
213                 switch (mfi->mode) {
214                 case MTD_MODE_OTP_FACTORY:
215                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
216                         break;
217                 case MTD_MODE_OTP_USER:
218                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
219                         break;
220                 case MTD_MODE_RAW:
221                 {
222                         struct mtd_oob_ops ops;
223
224                         ops.mode = MTD_OOB_RAW;
225                         ops.datbuf = kbuf;
226                         ops.oobbuf = NULL;
227                         ops.len = len;
228
229                         ret = mtd->read_oob(mtd, *ppos, &ops);
230                         retlen = ops.retlen;
231                         break;
232                 }
233                 default:
234                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
235                 }
236                 /* Nand returns -EBADMSG on ecc errors, but it returns
237                  * the data. For our userspace tools it is important
238                  * to dump areas with ecc errors !
239                  * For kernel internal usage it also might return -EUCLEAN
240                  * to signal the caller that a bitflip has occurred and has
241                  * been corrected by the ECC algorithm.
242                  * Userspace software which accesses NAND this way
243                  * must be aware of the fact that it deals with NAND
244                  */
245                 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
246                         *ppos += retlen;
247                         if (copy_to_user(buf, kbuf, retlen)) {
248                                 kfree(kbuf);
249                                 return -EFAULT;
250                         }
251                         else
252                                 total_retlen += retlen;
253
254                         count -= retlen;
255                         buf += retlen;
256                         if (retlen == 0)
257                                 count = 0;
258                 }
259                 else {
260                         kfree(kbuf);
261                         return ret;
262                 }
263
264         }
265
266         kfree(kbuf);
267         return total_retlen;
268 } /* mtd_read */
269
270 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
271 {
272         struct mtd_file_info *mfi = file->private_data;
273         struct mtd_info *mtd = mfi->mtd;
274         size_t size = count;
275         char *kbuf;
276         size_t retlen;
277         size_t total_retlen=0;
278         int ret=0;
279         int len;
280
281         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
282
283         if (*ppos == mtd->size)
284                 return -ENOSPC;
285
286         if (*ppos + count > mtd->size)
287                 count = mtd->size - *ppos;
288
289         if (!count)
290                 return 0;
291
292         kbuf = mtd_kmalloc_up_to(mtd, &size);
293         if (!kbuf)
294                 return -ENOMEM;
295
296         while (count) {
297                 len = min_t(size_t, count, size);
298
299                 if (copy_from_user(kbuf, buf, len)) {
300                         kfree(kbuf);
301                         return -EFAULT;
302                 }
303
304                 switch (mfi->mode) {
305                 case MTD_MODE_OTP_FACTORY:
306                         ret = -EROFS;
307                         break;
308                 case MTD_MODE_OTP_USER:
309                         if (!mtd->write_user_prot_reg) {
310                                 ret = -EOPNOTSUPP;
311                                 break;
312                         }
313                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
314                         break;
315
316                 case MTD_MODE_RAW:
317                 {
318                         struct mtd_oob_ops ops;
319
320                         ops.mode = MTD_OOB_RAW;
321                         ops.datbuf = kbuf;
322                         ops.oobbuf = NULL;
323                         ops.ooboffs = 0;
324                         ops.len = len;
325
326                         ret = mtd->write_oob(mtd, *ppos, &ops);
327                         retlen = ops.retlen;
328                         break;
329                 }
330
331                 default:
332                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
333                 }
334                 if (!ret) {
335                         *ppos += retlen;
336                         total_retlen += retlen;
337                         count -= retlen;
338                         buf += retlen;
339                 }
340                 else {
341                         kfree(kbuf);
342                         return ret;
343                 }
344         }
345
346         kfree(kbuf);
347         return total_retlen;
348 } /* mtd_write */
349
350 /*======================================================================
351
352     IOCTL calls for getting device parameters.
353
354 ======================================================================*/
355 static void mtdchar_erase_callback (struct erase_info *instr)
356 {
357         wake_up((wait_queue_head_t *)instr->priv);
358 }
359
360 #ifdef CONFIG_HAVE_MTD_OTP
361 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
362 {
363         struct mtd_info *mtd = mfi->mtd;
364         int ret = 0;
365
366         switch (mode) {
367         case MTD_OTP_FACTORY:
368                 if (!mtd->read_fact_prot_reg)
369                         ret = -EOPNOTSUPP;
370                 else
371                         mfi->mode = MTD_MODE_OTP_FACTORY;
372                 break;
373         case MTD_OTP_USER:
374                 if (!mtd->read_fact_prot_reg)
375                         ret = -EOPNOTSUPP;
376                 else
377                         mfi->mode = MTD_MODE_OTP_USER;
378                 break;
379         default:
380                 ret = -EINVAL;
381         case MTD_OTP_OFF:
382                 break;
383         }
384         return ret;
385 }
386 #else
387 # define otp_select_filemode(f,m)       -EOPNOTSUPP
388 #endif
389
390 static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
391         uint64_t start, uint32_t length, void __user *ptr,
392         uint32_t __user *retp)
393 {
394         struct mtd_oob_ops ops;
395         uint32_t retlen;
396         int ret = 0;
397
398         if (!(file->f_mode & FMODE_WRITE))
399                 return -EPERM;
400
401         if (length > 4096)
402                 return -EINVAL;
403
404         if (!mtd->write_oob)
405                 ret = -EOPNOTSUPP;
406         else
407                 ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
408
409         if (ret)
410                 return ret;
411
412         ops.ooblen = length;
413         ops.ooboffs = start & (mtd->oobsize - 1);
414         ops.datbuf = NULL;
415         ops.mode = MTD_OOB_PLACE;
416
417         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
418                 return -EINVAL;
419
420         ops.oobbuf = memdup_user(ptr, length);
421         if (IS_ERR(ops.oobbuf))
422                 return PTR_ERR(ops.oobbuf);
423
424         start &= ~((uint64_t)mtd->oobsize - 1);
425         ret = mtd->write_oob(mtd, start, &ops);
426
427         if (ops.oobretlen > 0xFFFFFFFFU)
428                 ret = -EOVERFLOW;
429         retlen = ops.oobretlen;
430         if (copy_to_user(retp, &retlen, sizeof(length)))
431                 ret = -EFAULT;
432
433         kfree(ops.oobbuf);
434         return ret;
435 }
436
437 static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
438         uint32_t length, void __user *ptr, uint32_t __user *retp)
439 {
440         struct mtd_oob_ops ops;
441         int ret = 0;
442
443         if (length > 4096)
444                 return -EINVAL;
445
446         if (!mtd->read_oob)
447                 ret = -EOPNOTSUPP;
448         else
449                 ret = access_ok(VERIFY_WRITE, ptr,
450                                 length) ? 0 : -EFAULT;
451         if (ret)
452                 return ret;
453
454         ops.ooblen = length;
455         ops.ooboffs = start & (mtd->oobsize - 1);
456         ops.datbuf = NULL;
457         ops.mode = MTD_OOB_PLACE;
458
459         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
460                 return -EINVAL;
461
462         ops.oobbuf = kmalloc(length, GFP_KERNEL);
463         if (!ops.oobbuf)
464                 return -ENOMEM;
465
466         start &= ~((uint64_t)mtd->oobsize - 1);
467         ret = mtd->read_oob(mtd, start, &ops);
468
469         if (put_user(ops.oobretlen, retp))
470                 ret = -EFAULT;
471         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
472                                             ops.oobretlen))
473                 ret = -EFAULT;
474
475         kfree(ops.oobbuf);
476         return ret;
477 }
478
479 /*
480  * Copies (and truncates, if necessary) data from the larger struct,
481  * nand_ecclayout, to the smaller, deprecated layout struct,
482  * nand_ecclayout_user. This is necessary only to suppport the deprecated
483  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
484  * nand_ecclayout flexibly (i.e. the struct may change size in new
485  * releases without requiring major rewrites).
486  */
487 static int shrink_ecclayout(const struct nand_ecclayout *from,
488                 struct nand_ecclayout_user *to)
489 {
490         int i;
491
492         if (!from || !to)
493                 return -EINVAL;
494
495         memset(to, 0, sizeof(*to));
496
497         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
498         for (i = 0; i < to->eccbytes; i++)
499                 to->eccpos[i] = from->eccpos[i];
500
501         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
502                 if (from->oobfree[i].length == 0 &&
503                                 from->oobfree[i].offset == 0)
504                         break;
505                 to->oobavail += from->oobfree[i].length;
506                 to->oobfree[i] = from->oobfree[i];
507         }
508
509         return 0;
510 }
511
512 static int mtd_blkpg_ioctl(struct mtd_info *mtd,
513                            struct blkpg_ioctl_arg __user *arg)
514 {
515         struct blkpg_ioctl_arg a;
516         struct blkpg_partition p;
517
518         if (!capable(CAP_SYS_ADMIN))
519                 return -EPERM;
520
521         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
522                 return -EFAULT;
523
524         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
525                 return -EFAULT;
526
527         switch (a.op) {
528         case BLKPG_ADD_PARTITION:
529
530                 /* Only master mtd device must be used to add partitions */
531                 if (mtd_is_partition(mtd))
532                         return -EINVAL;
533
534                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
535
536         case BLKPG_DEL_PARTITION:
537
538                 if (p.pno < 0)
539                         return -EINVAL;
540
541                 return mtd_del_partition(mtd, p.pno);
542
543         default:
544                 return -EINVAL;
545         }
546 }
547
548 static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
549 {
550         struct mtd_file_info *mfi = file->private_data;
551         struct mtd_info *mtd = mfi->mtd;
552         void __user *argp = (void __user *)arg;
553         int ret = 0;
554         u_long size;
555         struct mtd_info_user info;
556
557         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
558
559         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
560         if (cmd & IOC_IN) {
561                 if (!access_ok(VERIFY_READ, argp, size))
562                         return -EFAULT;
563         }
564         if (cmd & IOC_OUT) {
565                 if (!access_ok(VERIFY_WRITE, argp, size))
566                         return -EFAULT;
567         }
568
569         switch (cmd) {
570         case MEMGETREGIONCOUNT:
571                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
572                         return -EFAULT;
573                 break;
574
575         case MEMGETREGIONINFO:
576         {
577                 uint32_t ur_idx;
578                 struct mtd_erase_region_info *kr;
579                 struct region_info_user __user *ur = argp;
580
581                 if (get_user(ur_idx, &(ur->regionindex)))
582                         return -EFAULT;
583
584                 if (ur_idx >= mtd->numeraseregions)
585                         return -EINVAL;
586
587                 kr = &(mtd->eraseregions[ur_idx]);
588
589                 if (put_user(kr->offset, &(ur->offset))
590                     || put_user(kr->erasesize, &(ur->erasesize))
591                     || put_user(kr->numblocks, &(ur->numblocks)))
592                         return -EFAULT;
593
594                 break;
595         }
596
597         case MEMGETINFO:
598                 memset(&info, 0, sizeof(info));
599                 info.type       = mtd->type;
600                 info.flags      = mtd->flags;
601                 info.size       = mtd->size;
602                 info.erasesize  = mtd->erasesize;
603                 info.writesize  = mtd->writesize;
604                 info.oobsize    = mtd->oobsize;
605                 /* The below fields are obsolete */
606                 info.ecctype    = -1;
607                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
608                         return -EFAULT;
609                 break;
610
611         case MEMERASE:
612         case MEMERASE64:
613         {
614                 struct erase_info *erase;
615
616                 if(!(file->f_mode & FMODE_WRITE))
617                         return -EPERM;
618
619                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
620                 if (!erase)
621                         ret = -ENOMEM;
622                 else {
623                         wait_queue_head_t waitq;
624                         DECLARE_WAITQUEUE(wait, current);
625
626                         init_waitqueue_head(&waitq);
627
628                         if (cmd == MEMERASE64) {
629                                 struct erase_info_user64 einfo64;
630
631                                 if (copy_from_user(&einfo64, argp,
632                                             sizeof(struct erase_info_user64))) {
633                                         kfree(erase);
634                                         return -EFAULT;
635                                 }
636                                 erase->addr = einfo64.start;
637                                 erase->len = einfo64.length;
638                         } else {
639                                 struct erase_info_user einfo32;
640
641                                 if (copy_from_user(&einfo32, argp,
642                                             sizeof(struct erase_info_user))) {
643                                         kfree(erase);
644                                         return -EFAULT;
645                                 }
646                                 erase->addr = einfo32.start;
647                                 erase->len = einfo32.length;
648                         }
649                         erase->mtd = mtd;
650                         erase->callback = mtdchar_erase_callback;
651                         erase->priv = (unsigned long)&waitq;
652
653                         /*
654                           FIXME: Allow INTERRUPTIBLE. Which means
655                           not having the wait_queue head on the stack.
656
657                           If the wq_head is on the stack, and we
658                           leave because we got interrupted, then the
659                           wq_head is no longer there when the
660                           callback routine tries to wake us up.
661                         */
662                         ret = mtd->erase(mtd, erase);
663                         if (!ret) {
664                                 set_current_state(TASK_UNINTERRUPTIBLE);
665                                 add_wait_queue(&waitq, &wait);
666                                 if (erase->state != MTD_ERASE_DONE &&
667                                     erase->state != MTD_ERASE_FAILED)
668                                         schedule();
669                                 remove_wait_queue(&waitq, &wait);
670                                 set_current_state(TASK_RUNNING);
671
672                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
673                         }
674                         kfree(erase);
675                 }
676                 break;
677         }
678
679         case MEMWRITEOOB:
680         {
681                 struct mtd_oob_buf buf;
682                 struct mtd_oob_buf __user *buf_user = argp;
683
684                 /* NOTE: writes return length to buf_user->length */
685                 if (copy_from_user(&buf, argp, sizeof(buf)))
686                         ret = -EFAULT;
687                 else
688                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
689                                 buf.ptr, &buf_user->length);
690                 break;
691         }
692
693         case MEMREADOOB:
694         {
695                 struct mtd_oob_buf buf;
696                 struct mtd_oob_buf __user *buf_user = argp;
697
698                 /* NOTE: writes return length to buf_user->start */
699                 if (copy_from_user(&buf, argp, sizeof(buf)))
700                         ret = -EFAULT;
701                 else
702                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
703                                 buf.ptr, &buf_user->start);
704                 break;
705         }
706
707         case MEMWRITEOOB64:
708         {
709                 struct mtd_oob_buf64 buf;
710                 struct mtd_oob_buf64 __user *buf_user = argp;
711
712                 if (copy_from_user(&buf, argp, sizeof(buf)))
713                         ret = -EFAULT;
714                 else
715                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
716                                 (void __user *)(uintptr_t)buf.usr_ptr,
717                                 &buf_user->length);
718                 break;
719         }
720
721         case MEMREADOOB64:
722         {
723                 struct mtd_oob_buf64 buf;
724                 struct mtd_oob_buf64 __user *buf_user = argp;
725
726                 if (copy_from_user(&buf, argp, sizeof(buf)))
727                         ret = -EFAULT;
728                 else
729                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
730                                 (void __user *)(uintptr_t)buf.usr_ptr,
731                                 &buf_user->length);
732                 break;
733         }
734
735         case MEMLOCK:
736         {
737                 struct erase_info_user einfo;
738
739                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
740                         return -EFAULT;
741
742                 if (!mtd->lock)
743                         ret = -EOPNOTSUPP;
744                 else
745                         ret = mtd->lock(mtd, einfo.start, einfo.length);
746                 break;
747         }
748
749         case MEMUNLOCK:
750         {
751                 struct erase_info_user einfo;
752
753                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
754                         return -EFAULT;
755
756                 if (!mtd->unlock)
757                         ret = -EOPNOTSUPP;
758                 else
759                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
760                 break;
761         }
762
763         case MEMISLOCKED:
764         {
765                 struct erase_info_user einfo;
766
767                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
768                         return -EFAULT;
769
770                 if (!mtd->is_locked)
771                         ret = -EOPNOTSUPP;
772                 else
773                         ret = mtd->is_locked(mtd, einfo.start, einfo.length);
774                 break;
775         }
776
777         /* Legacy interface */
778         case MEMGETOOBSEL:
779         {
780                 struct nand_oobinfo oi;
781
782                 if (!mtd->ecclayout)
783                         return -EOPNOTSUPP;
784                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
785                         return -EINVAL;
786
787                 oi.useecc = MTD_NANDECC_AUTOPLACE;
788                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
789                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
790                        sizeof(oi.oobfree));
791                 oi.eccbytes = mtd->ecclayout->eccbytes;
792
793                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
794                         return -EFAULT;
795                 break;
796         }
797
798         case MEMGETBADBLOCK:
799         {
800                 loff_t offs;
801
802                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
803                         return -EFAULT;
804                 if (!mtd->block_isbad)
805                         ret = -EOPNOTSUPP;
806                 else
807                         return mtd->block_isbad(mtd, offs);
808                 break;
809         }
810
811         case MEMSETBADBLOCK:
812         {
813                 loff_t offs;
814
815                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
816                         return -EFAULT;
817                 if (!mtd->block_markbad)
818                         ret = -EOPNOTSUPP;
819                 else
820                         return mtd->block_markbad(mtd, offs);
821                 break;
822         }
823
824 #ifdef CONFIG_HAVE_MTD_OTP
825         case OTPSELECT:
826         {
827                 int mode;
828                 if (copy_from_user(&mode, argp, sizeof(int)))
829                         return -EFAULT;
830
831                 mfi->mode = MTD_MODE_NORMAL;
832
833                 ret = otp_select_filemode(mfi, mode);
834
835                 file->f_pos = 0;
836                 break;
837         }
838
839         case OTPGETREGIONCOUNT:
840         case OTPGETREGIONINFO:
841         {
842                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
843                 if (!buf)
844                         return -ENOMEM;
845                 ret = -EOPNOTSUPP;
846                 switch (mfi->mode) {
847                 case MTD_MODE_OTP_FACTORY:
848                         if (mtd->get_fact_prot_info)
849                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
850                         break;
851                 case MTD_MODE_OTP_USER:
852                         if (mtd->get_user_prot_info)
853                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
854                         break;
855                 default:
856                         break;
857                 }
858                 if (ret >= 0) {
859                         if (cmd == OTPGETREGIONCOUNT) {
860                                 int nbr = ret / sizeof(struct otp_info);
861                                 ret = copy_to_user(argp, &nbr, sizeof(int));
862                         } else
863                                 ret = copy_to_user(argp, buf, ret);
864                         if (ret)
865                                 ret = -EFAULT;
866                 }
867                 kfree(buf);
868                 break;
869         }
870
871         case OTPLOCK:
872         {
873                 struct otp_info oinfo;
874
875                 if (mfi->mode != MTD_MODE_OTP_USER)
876                         return -EINVAL;
877                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
878                         return -EFAULT;
879                 if (!mtd->lock_user_prot_reg)
880                         return -EOPNOTSUPP;
881                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
882                 break;
883         }
884 #endif
885
886         /* This ioctl is being deprecated - it truncates the ecc layout */
887         case ECCGETLAYOUT:
888         {
889                 struct nand_ecclayout_user *usrlay;
890
891                 if (!mtd->ecclayout)
892                         return -EOPNOTSUPP;
893
894                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
895                 if (!usrlay)
896                         return -ENOMEM;
897
898                 shrink_ecclayout(mtd->ecclayout, usrlay);
899
900                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
901                         ret = -EFAULT;
902                 kfree(usrlay);
903                 break;
904         }
905
906         case ECCGETSTATS:
907         {
908                 if (copy_to_user(argp, &mtd->ecc_stats,
909                                  sizeof(struct mtd_ecc_stats)))
910                         return -EFAULT;
911                 break;
912         }
913
914         case MTDFILEMODE:
915         {
916                 mfi->mode = 0;
917
918                 switch(arg) {
919                 case MTD_MODE_OTP_FACTORY:
920                 case MTD_MODE_OTP_USER:
921                         ret = otp_select_filemode(mfi, arg);
922                         break;
923
924                 case MTD_MODE_RAW:
925                         if (!mtd->read_oob || !mtd->write_oob)
926                                 return -EOPNOTSUPP;
927                         mfi->mode = arg;
928
929                 case MTD_MODE_NORMAL:
930                         break;
931                 default:
932                         ret = -EINVAL;
933                 }
934                 file->f_pos = 0;
935                 break;
936         }
937
938         case BLKPG:
939         {
940                 ret = mtd_blkpg_ioctl(mtd,
941                       (struct blkpg_ioctl_arg __user *)arg);
942                 break;
943         }
944
945         case BLKRRPART:
946         {
947                 /* No reread partition feature. Just return ok */
948                 ret = 0;
949                 break;
950         }
951
952         default:
953                 ret = -ENOTTY;
954         }
955
956         return ret;
957 } /* memory_ioctl */
958
959 static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
960 {
961         int ret;
962
963         mutex_lock(&mtd_mutex);
964         ret = mtd_ioctl(file, cmd, arg);
965         mutex_unlock(&mtd_mutex);
966
967         return ret;
968 }
969
970 #ifdef CONFIG_COMPAT
971
972 struct mtd_oob_buf32 {
973         u_int32_t start;
974         u_int32_t length;
975         compat_caddr_t ptr;     /* unsigned char* */
976 };
977
978 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
979 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
980
981 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
982         unsigned long arg)
983 {
984         struct mtd_file_info *mfi = file->private_data;
985         struct mtd_info *mtd = mfi->mtd;
986         void __user *argp = compat_ptr(arg);
987         int ret = 0;
988
989         mutex_lock(&mtd_mutex);
990
991         switch (cmd) {
992         case MEMWRITEOOB32:
993         {
994                 struct mtd_oob_buf32 buf;
995                 struct mtd_oob_buf32 __user *buf_user = argp;
996
997                 if (copy_from_user(&buf, argp, sizeof(buf)))
998                         ret = -EFAULT;
999                 else
1000                         ret = mtd_do_writeoob(file, mtd, buf.start,
1001                                 buf.length, compat_ptr(buf.ptr),
1002                                 &buf_user->length);
1003                 break;
1004         }
1005
1006         case MEMREADOOB32:
1007         {
1008                 struct mtd_oob_buf32 buf;
1009                 struct mtd_oob_buf32 __user *buf_user = argp;
1010
1011                 /* NOTE: writes return length to buf->start */
1012                 if (copy_from_user(&buf, argp, sizeof(buf)))
1013                         ret = -EFAULT;
1014                 else
1015                         ret = mtd_do_readoob(mtd, buf.start,
1016                                 buf.length, compat_ptr(buf.ptr),
1017                                 &buf_user->start);
1018                 break;
1019         }
1020         default:
1021                 ret = mtd_ioctl(file, cmd, (unsigned long)argp);
1022         }
1023
1024         mutex_unlock(&mtd_mutex);
1025
1026         return ret;
1027 }
1028
1029 #endif /* CONFIG_COMPAT */
1030
1031 /*
1032  * try to determine where a shared mapping can be made
1033  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1034  *   mappings)
1035  */
1036 #ifndef CONFIG_MMU
1037 static unsigned long mtd_get_unmapped_area(struct file *file,
1038                                            unsigned long addr,
1039                                            unsigned long len,
1040                                            unsigned long pgoff,
1041                                            unsigned long flags)
1042 {
1043         struct mtd_file_info *mfi = file->private_data;
1044         struct mtd_info *mtd = mfi->mtd;
1045
1046         if (mtd->get_unmapped_area) {
1047                 unsigned long offset;
1048
1049                 if (addr != 0)
1050                         return (unsigned long) -EINVAL;
1051
1052                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1053                         return (unsigned long) -EINVAL;
1054
1055                 offset = pgoff << PAGE_SHIFT;
1056                 if (offset > mtd->size - len)
1057                         return (unsigned long) -EINVAL;
1058
1059                 return mtd->get_unmapped_area(mtd, len, offset, flags);
1060         }
1061
1062         /* can't map directly */
1063         return (unsigned long) -ENOSYS;
1064 }
1065 #endif
1066
1067 /*
1068  * set up a mapping for shared memory segments
1069  */
1070 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
1071 {
1072 #ifdef CONFIG_MMU
1073         struct mtd_file_info *mfi = file->private_data;
1074         struct mtd_info *mtd = mfi->mtd;
1075         struct map_info *map = mtd->priv;
1076         unsigned long start;
1077         unsigned long off;
1078         u32 len;
1079
1080         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
1081                 off = vma->vm_pgoff << PAGE_SHIFT;
1082                 start = map->phys;
1083                 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
1084                 start &= PAGE_MASK;
1085                 if ((vma->vm_end - vma->vm_start + off) > len)
1086                         return -EINVAL;
1087
1088                 off += start;
1089                 vma->vm_pgoff = off >> PAGE_SHIFT;
1090                 vma->vm_flags |= VM_IO | VM_RESERVED;
1091
1092 #ifdef pgprot_noncached
1093                 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1094                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1095 #endif
1096                 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1097                                        vma->vm_end - vma->vm_start,
1098                                        vma->vm_page_prot))
1099                         return -EAGAIN;
1100
1101                 return 0;
1102         }
1103         return -ENOSYS;
1104 #else
1105         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1106 #endif
1107 }
1108
1109 static const struct file_operations mtd_fops = {
1110         .owner          = THIS_MODULE,
1111         .llseek         = mtd_lseek,
1112         .read           = mtd_read,
1113         .write          = mtd_write,
1114         .unlocked_ioctl = mtd_unlocked_ioctl,
1115 #ifdef CONFIG_COMPAT
1116         .compat_ioctl   = mtd_compat_ioctl,
1117 #endif
1118         .open           = mtd_open,
1119         .release        = mtd_close,
1120         .mmap           = mtd_mmap,
1121 #ifndef CONFIG_MMU
1122         .get_unmapped_area = mtd_get_unmapped_area,
1123 #endif
1124 };
1125
1126 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1127                                 int flags, const char *dev_name, void *data)
1128 {
1129         return mount_pseudo(fs_type, "mtd_inode:", NULL, NULL, MTD_INODE_FS_MAGIC);
1130 }
1131
1132 static struct file_system_type mtd_inodefs_type = {
1133        .name = "mtd_inodefs",
1134        .mount = mtd_inodefs_mount,
1135        .kill_sb = kill_anon_super,
1136 };
1137
1138 static void mtdchar_notify_add(struct mtd_info *mtd)
1139 {
1140 }
1141
1142 static void mtdchar_notify_remove(struct mtd_info *mtd)
1143 {
1144         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1145
1146         if (mtd_ino) {
1147                 /* Destroy the inode if it exists */
1148                 mtd_ino->i_nlink = 0;
1149                 iput(mtd_ino);
1150         }
1151 }
1152
1153 static struct mtd_notifier mtdchar_notifier = {
1154         .add = mtdchar_notify_add,
1155         .remove = mtdchar_notify_remove,
1156 };
1157
1158 static int __init init_mtdchar(void)
1159 {
1160         int ret;
1161
1162         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1163                                    "mtd", &mtd_fops);
1164         if (ret < 0) {
1165                 pr_notice("Can't allocate major number %d for "
1166                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1167                 return ret;
1168         }
1169
1170         ret = register_filesystem(&mtd_inodefs_type);
1171         if (ret) {
1172                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1173                 goto err_unregister_chdev;
1174         }
1175
1176         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1177         if (IS_ERR(mtd_inode_mnt)) {
1178                 ret = PTR_ERR(mtd_inode_mnt);
1179                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1180                 goto err_unregister_filesystem;
1181         }
1182         register_mtd_user(&mtdchar_notifier);
1183
1184         return ret;
1185
1186 err_unregister_filesystem:
1187         unregister_filesystem(&mtd_inodefs_type);
1188 err_unregister_chdev:
1189         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1190         return ret;
1191 }
1192
1193 static void __exit cleanup_mtdchar(void)
1194 {
1195         unregister_mtd_user(&mtdchar_notifier);
1196         kern_unmount(mtd_inode_mnt);
1197         unregister_filesystem(&mtd_inodefs_type);
1198         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1199 }
1200
1201 module_init(init_mtdchar);
1202 module_exit(cleanup_mtdchar);
1203
1204 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1205
1206 MODULE_LICENSE("GPL");
1207 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1208 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1209 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);