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