3eff1e562ad3c96ca168432b829d8dca5f36abea
[~shefty/rdma-dev.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 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
170    userspace buffer down and use it directly with readv/writev.
171 */
172 #define MAX_KMALLOC_SIZE 0x20000
173
174 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
175 {
176         struct mtd_file_info *mfi = file->private_data;
177         struct mtd_info *mtd = mfi->mtd;
178         size_t retlen=0;
179         size_t total_retlen=0;
180         int ret=0;
181         int len;
182         char *kbuf;
183
184         DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
185
186         if (*ppos + count > mtd->size)
187                 count = mtd->size - *ppos;
188
189         if (!count)
190                 return 0;
191
192         /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
193            and pass them directly to the MTD functions */
194
195         if (count > MAX_KMALLOC_SIZE)
196                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
197         else
198                 kbuf=kmalloc(count, GFP_KERNEL);
199
200         if (!kbuf)
201                 return -ENOMEM;
202
203         while (count) {
204
205                 if (count > MAX_KMALLOC_SIZE)
206                         len = MAX_KMALLOC_SIZE;
207                 else
208                         len = count;
209
210                 switch (mfi->mode) {
211                 case MTD_MODE_OTP_FACTORY:
212                         ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
213                         break;
214                 case MTD_MODE_OTP_USER:
215                         ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
216                         break;
217                 case MTD_MODE_RAW:
218                 {
219                         struct mtd_oob_ops ops;
220
221                         ops.mode = MTD_OOB_RAW;
222                         ops.datbuf = kbuf;
223                         ops.oobbuf = NULL;
224                         ops.len = len;
225
226                         ret = mtd->read_oob(mtd, *ppos, &ops);
227                         retlen = ops.retlen;
228                         break;
229                 }
230                 default:
231                         ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
232                 }
233                 /* Nand returns -EBADMSG on ecc errors, but it returns
234                  * the data. For our userspace tools it is important
235                  * to dump areas with ecc errors !
236                  * For kernel internal usage it also might return -EUCLEAN
237                  * to signal the caller that a bitflip has occured and has
238                  * been corrected by the ECC algorithm.
239                  * Userspace software which accesses NAND this way
240                  * must be aware of the fact that it deals with NAND
241                  */
242                 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
243                         *ppos += retlen;
244                         if (copy_to_user(buf, kbuf, retlen)) {
245                                 kfree(kbuf);
246                                 return -EFAULT;
247                         }
248                         else
249                                 total_retlen += retlen;
250
251                         count -= retlen;
252                         buf += retlen;
253                         if (retlen == 0)
254                                 count = 0;
255                 }
256                 else {
257                         kfree(kbuf);
258                         return ret;
259                 }
260
261         }
262
263         kfree(kbuf);
264         return total_retlen;
265 } /* mtd_read */
266
267 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
268 {
269         struct mtd_file_info *mfi = file->private_data;
270         struct mtd_info *mtd = mfi->mtd;
271         char *kbuf;
272         size_t retlen;
273         size_t total_retlen=0;
274         int ret=0;
275         int len;
276
277         DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
278
279         if (*ppos == mtd->size)
280                 return -ENOSPC;
281
282         if (*ppos + count > mtd->size)
283                 count = mtd->size - *ppos;
284
285         if (!count)
286                 return 0;
287
288         if (count > MAX_KMALLOC_SIZE)
289                 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
290         else
291                 kbuf=kmalloc(count, GFP_KERNEL);
292
293         if (!kbuf)
294                 return -ENOMEM;
295
296         while (count) {
297
298                 if (count > MAX_KMALLOC_SIZE)
299                         len = MAX_KMALLOC_SIZE;
300                 else
301                         len = count;
302
303                 if (copy_from_user(kbuf, buf, len)) {
304                         kfree(kbuf);
305                         return -EFAULT;
306                 }
307
308                 switch (mfi->mode) {
309                 case MTD_MODE_OTP_FACTORY:
310                         ret = -EROFS;
311                         break;
312                 case MTD_MODE_OTP_USER:
313                         if (!mtd->write_user_prot_reg) {
314                                 ret = -EOPNOTSUPP;
315                                 break;
316                         }
317                         ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
318                         break;
319
320                 case MTD_MODE_RAW:
321                 {
322                         struct mtd_oob_ops ops;
323
324                         ops.mode = MTD_OOB_RAW;
325                         ops.datbuf = kbuf;
326                         ops.oobbuf = NULL;
327                         ops.len = len;
328
329                         ret = mtd->write_oob(mtd, *ppos, &ops);
330                         retlen = ops.retlen;
331                         break;
332                 }
333
334                 default:
335                         ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
336                 }
337                 if (!ret) {
338                         *ppos += retlen;
339                         total_retlen += retlen;
340                         count -= retlen;
341                         buf += retlen;
342                 }
343                 else {
344                         kfree(kbuf);
345                         return ret;
346                 }
347         }
348
349         kfree(kbuf);
350         return total_retlen;
351 } /* mtd_write */
352
353 /*======================================================================
354
355     IOCTL calls for getting device parameters.
356
357 ======================================================================*/
358 static void mtdchar_erase_callback (struct erase_info *instr)
359 {
360         wake_up((wait_queue_head_t *)instr->priv);
361 }
362
363 #ifdef CONFIG_HAVE_MTD_OTP
364 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
365 {
366         struct mtd_info *mtd = mfi->mtd;
367         int ret = 0;
368
369         switch (mode) {
370         case MTD_OTP_FACTORY:
371                 if (!mtd->read_fact_prot_reg)
372                         ret = -EOPNOTSUPP;
373                 else
374                         mfi->mode = MTD_MODE_OTP_FACTORY;
375                 break;
376         case MTD_OTP_USER:
377                 if (!mtd->read_fact_prot_reg)
378                         ret = -EOPNOTSUPP;
379                 else
380                         mfi->mode = MTD_MODE_OTP_USER;
381                 break;
382         default:
383                 ret = -EINVAL;
384         case MTD_OTP_OFF:
385                 break;
386         }
387         return ret;
388 }
389 #else
390 # define otp_select_filemode(f,m)       -EOPNOTSUPP
391 #endif
392
393 static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
394         uint64_t start, uint32_t length, void __user *ptr,
395         uint32_t __user *retp)
396 {
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->oobsize - 1);
417         ops.datbuf = NULL;
418         ops.mode = MTD_OOB_PLACE;
419
420         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
421                 return -EINVAL;
422
423         ops.oobbuf = memdup_user(ptr, length);
424         if (IS_ERR(ops.oobbuf))
425                 return PTR_ERR(ops.oobbuf);
426
427         start &= ~((uint64_t)mtd->oobsize - 1);
428         ret = mtd->write_oob(mtd, start, &ops);
429
430         if (ops.oobretlen > 0xFFFFFFFFU)
431                 ret = -EOVERFLOW;
432         retlen = ops.oobretlen;
433         if (copy_to_user(retp, &retlen, sizeof(length)))
434                 ret = -EFAULT;
435
436         kfree(ops.oobbuf);
437         return ret;
438 }
439
440 static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
441         uint32_t length, void __user *ptr, uint32_t __user *retp)
442 {
443         struct mtd_oob_ops ops;
444         int ret = 0;
445
446         if (length > 4096)
447                 return -EINVAL;
448
449         if (!mtd->read_oob)
450                 ret = -EOPNOTSUPP;
451         else
452                 ret = access_ok(VERIFY_WRITE, ptr,
453                                 length) ? 0 : -EFAULT;
454         if (ret)
455                 return ret;
456
457         ops.ooblen = length;
458         ops.ooboffs = start & (mtd->oobsize - 1);
459         ops.datbuf = NULL;
460         ops.mode = MTD_OOB_PLACE;
461
462         if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
463                 return -EINVAL;
464
465         ops.oobbuf = kmalloc(length, GFP_KERNEL);
466         if (!ops.oobbuf)
467                 return -ENOMEM;
468
469         start &= ~((uint64_t)mtd->oobsize - 1);
470         ret = mtd->read_oob(mtd, start, &ops);
471
472         if (put_user(ops.oobretlen, retp))
473                 ret = -EFAULT;
474         else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
475                                             ops.oobretlen))
476                 ret = -EFAULT;
477
478         kfree(ops.oobbuf);
479         return ret;
480 }
481
482 /*
483  * Copies (and truncates, if necessary) data from the larger struct,
484  * nand_ecclayout, to the smaller, deprecated layout struct,
485  * nand_ecclayout_user. This is necessary only to suppport the deprecated
486  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
487  * nand_ecclayout flexibly (i.e. the struct may change size in new
488  * releases without requiring major rewrites).
489  */
490 static int shrink_ecclayout(const struct nand_ecclayout *from,
491                 struct nand_ecclayout_user *to)
492 {
493         int i;
494
495         if (!from || !to)
496                 return -EINVAL;
497
498         memset(to, 0, sizeof(*to));
499
500         to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
501         for (i = 0; i < to->eccbytes; i++)
502                 to->eccpos[i] = from->eccpos[i];
503
504         for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
505                 if (from->oobfree[i].length == 0 &&
506                                 from->oobfree[i].offset == 0)
507                         break;
508                 to->oobavail += from->oobfree[i].length;
509                 to->oobfree[i] = from->oobfree[i];
510         }
511
512         return 0;
513 }
514
515 #ifdef CONFIG_MTD_PARTITIONS
516 static int mtd_blkpg_ioctl(struct mtd_info *mtd,
517                            struct blkpg_ioctl_arg __user *arg)
518 {
519         struct blkpg_ioctl_arg a;
520         struct blkpg_partition p;
521
522         if (!capable(CAP_SYS_ADMIN))
523                 return -EPERM;
524
525         /* Only master mtd device must be used to control partitions */
526         if (!mtd_is_master(mtd))
527                 return -EINVAL;
528
529         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
530                 return -EFAULT;
531
532         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
533                 return -EFAULT;
534
535         switch (a.op) {
536         case BLKPG_ADD_PARTITION:
537
538                 return mtd_add_partition(mtd, p.devname, p.start, p.length);
539
540         case BLKPG_DEL_PARTITION:
541
542                 if (p.pno < 0)
543                         return -EINVAL;
544
545                 return mtd_del_partition(mtd, p.pno);
546
547         default:
548                 return -EINVAL;
549         }
550 }
551 #endif
552
553
554 static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
555 {
556         struct mtd_file_info *mfi = file->private_data;
557         struct mtd_info *mtd = mfi->mtd;
558         void __user *argp = (void __user *)arg;
559         int ret = 0;
560         u_long size;
561         struct mtd_info_user info;
562
563         DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
564
565         size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
566         if (cmd & IOC_IN) {
567                 if (!access_ok(VERIFY_READ, argp, size))
568                         return -EFAULT;
569         }
570         if (cmd & IOC_OUT) {
571                 if (!access_ok(VERIFY_WRITE, argp, size))
572                         return -EFAULT;
573         }
574
575         switch (cmd) {
576         case MEMGETREGIONCOUNT:
577                 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
578                         return -EFAULT;
579                 break;
580
581         case MEMGETREGIONINFO:
582         {
583                 uint32_t ur_idx;
584                 struct mtd_erase_region_info *kr;
585                 struct region_info_user __user *ur = argp;
586
587                 if (get_user(ur_idx, &(ur->regionindex)))
588                         return -EFAULT;
589
590                 if (ur_idx >= mtd->numeraseregions)
591                         return -EINVAL;
592
593                 kr = &(mtd->eraseregions[ur_idx]);
594
595                 if (put_user(kr->offset, &(ur->offset))
596                     || put_user(kr->erasesize, &(ur->erasesize))
597                     || put_user(kr->numblocks, &(ur->numblocks)))
598                         return -EFAULT;
599
600                 break;
601         }
602
603         case MEMGETINFO:
604                 info.type       = mtd->type;
605                 info.flags      = mtd->flags;
606                 info.size       = mtd->size;
607                 info.erasesize  = mtd->erasesize;
608                 info.writesize  = mtd->writesize;
609                 info.oobsize    = mtd->oobsize;
610                 /* The below fields are obsolete */
611                 info.ecctype    = -1;
612                 info.eccsize    = 0;
613                 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
614                         return -EFAULT;
615                 break;
616
617         case MEMERASE:
618         case MEMERASE64:
619         {
620                 struct erase_info *erase;
621
622                 if(!(file->f_mode & FMODE_WRITE))
623                         return -EPERM;
624
625                 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
626                 if (!erase)
627                         ret = -ENOMEM;
628                 else {
629                         wait_queue_head_t waitq;
630                         DECLARE_WAITQUEUE(wait, current);
631
632                         init_waitqueue_head(&waitq);
633
634                         if (cmd == MEMERASE64) {
635                                 struct erase_info_user64 einfo64;
636
637                                 if (copy_from_user(&einfo64, argp,
638                                             sizeof(struct erase_info_user64))) {
639                                         kfree(erase);
640                                         return -EFAULT;
641                                 }
642                                 erase->addr = einfo64.start;
643                                 erase->len = einfo64.length;
644                         } else {
645                                 struct erase_info_user einfo32;
646
647                                 if (copy_from_user(&einfo32, argp,
648                                             sizeof(struct erase_info_user))) {
649                                         kfree(erase);
650                                         return -EFAULT;
651                                 }
652                                 erase->addr = einfo32.start;
653                                 erase->len = einfo32.length;
654                         }
655                         erase->mtd = mtd;
656                         erase->callback = mtdchar_erase_callback;
657                         erase->priv = (unsigned long)&waitq;
658
659                         /*
660                           FIXME: Allow INTERRUPTIBLE. Which means
661                           not having the wait_queue head on the stack.
662
663                           If the wq_head is on the stack, and we
664                           leave because we got interrupted, then the
665                           wq_head is no longer there when the
666                           callback routine tries to wake us up.
667                         */
668                         ret = mtd->erase(mtd, erase);
669                         if (!ret) {
670                                 set_current_state(TASK_UNINTERRUPTIBLE);
671                                 add_wait_queue(&waitq, &wait);
672                                 if (erase->state != MTD_ERASE_DONE &&
673                                     erase->state != MTD_ERASE_FAILED)
674                                         schedule();
675                                 remove_wait_queue(&waitq, &wait);
676                                 set_current_state(TASK_RUNNING);
677
678                                 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
679                         }
680                         kfree(erase);
681                 }
682                 break;
683         }
684
685         case MEMWRITEOOB:
686         {
687                 struct mtd_oob_buf buf;
688                 struct mtd_oob_buf __user *buf_user = argp;
689
690                 /* NOTE: writes return length to buf_user->length */
691                 if (copy_from_user(&buf, argp, sizeof(buf)))
692                         ret = -EFAULT;
693                 else
694                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
695                                 buf.ptr, &buf_user->length);
696                 break;
697         }
698
699         case MEMREADOOB:
700         {
701                 struct mtd_oob_buf buf;
702                 struct mtd_oob_buf __user *buf_user = argp;
703
704                 /* NOTE: writes return length to buf_user->start */
705                 if (copy_from_user(&buf, argp, sizeof(buf)))
706                         ret = -EFAULT;
707                 else
708                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
709                                 buf.ptr, &buf_user->start);
710                 break;
711         }
712
713         case MEMWRITEOOB64:
714         {
715                 struct mtd_oob_buf64 buf;
716                 struct mtd_oob_buf64 __user *buf_user = argp;
717
718                 if (copy_from_user(&buf, argp, sizeof(buf)))
719                         ret = -EFAULT;
720                 else
721                         ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
722                                 (void __user *)(uintptr_t)buf.usr_ptr,
723                                 &buf_user->length);
724                 break;
725         }
726
727         case MEMREADOOB64:
728         {
729                 struct mtd_oob_buf64 buf;
730                 struct mtd_oob_buf64 __user *buf_user = argp;
731
732                 if (copy_from_user(&buf, argp, sizeof(buf)))
733                         ret = -EFAULT;
734                 else
735                         ret = mtd_do_readoob(mtd, buf.start, buf.length,
736                                 (void __user *)(uintptr_t)buf.usr_ptr,
737                                 &buf_user->length);
738                 break;
739         }
740
741         case MEMLOCK:
742         {
743                 struct erase_info_user einfo;
744
745                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
746                         return -EFAULT;
747
748                 if (!mtd->lock)
749                         ret = -EOPNOTSUPP;
750                 else
751                         ret = mtd->lock(mtd, einfo.start, einfo.length);
752                 break;
753         }
754
755         case MEMUNLOCK:
756         {
757                 struct erase_info_user einfo;
758
759                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
760                         return -EFAULT;
761
762                 if (!mtd->unlock)
763                         ret = -EOPNOTSUPP;
764                 else
765                         ret = mtd->unlock(mtd, einfo.start, einfo.length);
766                 break;
767         }
768
769         case MEMISLOCKED:
770         {
771                 struct erase_info_user einfo;
772
773                 if (copy_from_user(&einfo, argp, sizeof(einfo)))
774                         return -EFAULT;
775
776                 if (!mtd->is_locked)
777                         ret = -EOPNOTSUPP;
778                 else
779                         ret = mtd->is_locked(mtd, einfo.start, einfo.length);
780                 break;
781         }
782
783         /* Legacy interface */
784         case MEMGETOOBSEL:
785         {
786                 struct nand_oobinfo oi;
787
788                 if (!mtd->ecclayout)
789                         return -EOPNOTSUPP;
790                 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
791                         return -EINVAL;
792
793                 oi.useecc = MTD_NANDECC_AUTOPLACE;
794                 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
795                 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
796                        sizeof(oi.oobfree));
797                 oi.eccbytes = mtd->ecclayout->eccbytes;
798
799                 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
800                         return -EFAULT;
801                 break;
802         }
803
804         case MEMGETBADBLOCK:
805         {
806                 loff_t offs;
807
808                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
809                         return -EFAULT;
810                 if (!mtd->block_isbad)
811                         ret = -EOPNOTSUPP;
812                 else
813                         return mtd->block_isbad(mtd, offs);
814                 break;
815         }
816
817         case MEMSETBADBLOCK:
818         {
819                 loff_t offs;
820
821                 if (copy_from_user(&offs, argp, sizeof(loff_t)))
822                         return -EFAULT;
823                 if (!mtd->block_markbad)
824                         ret = -EOPNOTSUPP;
825                 else
826                         return mtd->block_markbad(mtd, offs);
827                 break;
828         }
829
830 #ifdef CONFIG_HAVE_MTD_OTP
831         case OTPSELECT:
832         {
833                 int mode;
834                 if (copy_from_user(&mode, argp, sizeof(int)))
835                         return -EFAULT;
836
837                 mfi->mode = MTD_MODE_NORMAL;
838
839                 ret = otp_select_filemode(mfi, mode);
840
841                 file->f_pos = 0;
842                 break;
843         }
844
845         case OTPGETREGIONCOUNT:
846         case OTPGETREGIONINFO:
847         {
848                 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
849                 if (!buf)
850                         return -ENOMEM;
851                 ret = -EOPNOTSUPP;
852                 switch (mfi->mode) {
853                 case MTD_MODE_OTP_FACTORY:
854                         if (mtd->get_fact_prot_info)
855                                 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
856                         break;
857                 case MTD_MODE_OTP_USER:
858                         if (mtd->get_user_prot_info)
859                                 ret = mtd->get_user_prot_info(mtd, buf, 4096);
860                         break;
861                 default:
862                         break;
863                 }
864                 if (ret >= 0) {
865                         if (cmd == OTPGETREGIONCOUNT) {
866                                 int nbr = ret / sizeof(struct otp_info);
867                                 ret = copy_to_user(argp, &nbr, sizeof(int));
868                         } else
869                                 ret = copy_to_user(argp, buf, ret);
870                         if (ret)
871                                 ret = -EFAULT;
872                 }
873                 kfree(buf);
874                 break;
875         }
876
877         case OTPLOCK:
878         {
879                 struct otp_info oinfo;
880
881                 if (mfi->mode != MTD_MODE_OTP_USER)
882                         return -EINVAL;
883                 if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
884                         return -EFAULT;
885                 if (!mtd->lock_user_prot_reg)
886                         return -EOPNOTSUPP;
887                 ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
888                 break;
889         }
890 #endif
891
892         /* This ioctl is being deprecated - it truncates the ecc layout */
893         case ECCGETLAYOUT:
894         {
895                 struct nand_ecclayout_user *usrlay;
896
897                 if (!mtd->ecclayout)
898                         return -EOPNOTSUPP;
899
900                 usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
901                 if (!usrlay)
902                         return -ENOMEM;
903
904                 shrink_ecclayout(mtd->ecclayout, usrlay);
905
906                 if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
907                         ret = -EFAULT;
908                 kfree(usrlay);
909                 break;
910         }
911
912         case ECCGETSTATS:
913         {
914                 if (copy_to_user(argp, &mtd->ecc_stats,
915                                  sizeof(struct mtd_ecc_stats)))
916                         return -EFAULT;
917                 break;
918         }
919
920         case MTDFILEMODE:
921         {
922                 mfi->mode = 0;
923
924                 switch(arg) {
925                 case MTD_MODE_OTP_FACTORY:
926                 case MTD_MODE_OTP_USER:
927                         ret = otp_select_filemode(mfi, arg);
928                         break;
929
930                 case MTD_MODE_RAW:
931                         if (!mtd->read_oob || !mtd->write_oob)
932                                 return -EOPNOTSUPP;
933                         mfi->mode = arg;
934
935                 case MTD_MODE_NORMAL:
936                         break;
937                 default:
938                         ret = -EINVAL;
939                 }
940                 file->f_pos = 0;
941                 break;
942         }
943
944 #ifdef CONFIG_MTD_PARTITIONS
945         case BLKPG:
946         {
947                 ret = mtd_blkpg_ioctl(mtd,
948                       (struct blkpg_ioctl_arg __user *)arg);
949                 break;
950         }
951
952         case BLKRRPART:
953         {
954                 /* No reread partition feature. Just return ok */
955                 ret = 0;
956                 break;
957         }
958 #endif
959
960         default:
961                 ret = -ENOTTY;
962         }
963
964         return ret;
965 } /* memory_ioctl */
966
967 static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
968 {
969         int ret;
970
971         mutex_lock(&mtd_mutex);
972         ret = mtd_ioctl(file, cmd, arg);
973         mutex_unlock(&mtd_mutex);
974
975         return ret;
976 }
977
978 #ifdef CONFIG_COMPAT
979
980 struct mtd_oob_buf32 {
981         u_int32_t start;
982         u_int32_t length;
983         compat_caddr_t ptr;     /* unsigned char* */
984 };
985
986 #define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
987 #define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
988
989 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
990         unsigned long arg)
991 {
992         struct mtd_file_info *mfi = file->private_data;
993         struct mtd_info *mtd = mfi->mtd;
994         void __user *argp = compat_ptr(arg);
995         int ret = 0;
996
997         mutex_lock(&mtd_mutex);
998
999         switch (cmd) {
1000         case MEMWRITEOOB32:
1001         {
1002                 struct mtd_oob_buf32 buf;
1003                 struct mtd_oob_buf32 __user *buf_user = argp;
1004
1005                 if (copy_from_user(&buf, argp, sizeof(buf)))
1006                         ret = -EFAULT;
1007                 else
1008                         ret = mtd_do_writeoob(file, mtd, buf.start,
1009                                 buf.length, compat_ptr(buf.ptr),
1010                                 &buf_user->length);
1011                 break;
1012         }
1013
1014         case MEMREADOOB32:
1015         {
1016                 struct mtd_oob_buf32 buf;
1017                 struct mtd_oob_buf32 __user *buf_user = argp;
1018
1019                 /* NOTE: writes return length to buf->start */
1020                 if (copy_from_user(&buf, argp, sizeof(buf)))
1021                         ret = -EFAULT;
1022                 else
1023                         ret = mtd_do_readoob(mtd, buf.start,
1024                                 buf.length, compat_ptr(buf.ptr),
1025                                 &buf_user->start);
1026                 break;
1027         }
1028         default:
1029                 ret = mtd_ioctl(file, cmd, (unsigned long)argp);
1030         }
1031
1032         mutex_unlock(&mtd_mutex);
1033
1034         return ret;
1035 }
1036
1037 #endif /* CONFIG_COMPAT */
1038
1039 /*
1040  * try to determine where a shared mapping can be made
1041  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1042  *   mappings)
1043  */
1044 #ifndef CONFIG_MMU
1045 static unsigned long mtd_get_unmapped_area(struct file *file,
1046                                            unsigned long addr,
1047                                            unsigned long len,
1048                                            unsigned long pgoff,
1049                                            unsigned long flags)
1050 {
1051         struct mtd_file_info *mfi = file->private_data;
1052         struct mtd_info *mtd = mfi->mtd;
1053
1054         if (mtd->get_unmapped_area) {
1055                 unsigned long offset;
1056
1057                 if (addr != 0)
1058                         return (unsigned long) -EINVAL;
1059
1060                 if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1061                         return (unsigned long) -EINVAL;
1062
1063                 offset = pgoff << PAGE_SHIFT;
1064                 if (offset > mtd->size - len)
1065                         return (unsigned long) -EINVAL;
1066
1067                 return mtd->get_unmapped_area(mtd, len, offset, flags);
1068         }
1069
1070         /* can't map directly */
1071         return (unsigned long) -ENOSYS;
1072 }
1073 #endif
1074
1075 /*
1076  * set up a mapping for shared memory segments
1077  */
1078 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
1079 {
1080 #ifdef CONFIG_MMU
1081         struct mtd_file_info *mfi = file->private_data;
1082         struct mtd_info *mtd = mfi->mtd;
1083         struct map_info *map = mtd->priv;
1084         unsigned long start;
1085         unsigned long off;
1086         u32 len;
1087
1088         if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
1089                 off = vma->vm_pgoff << PAGE_SHIFT;
1090                 start = map->phys;
1091                 len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
1092                 start &= PAGE_MASK;
1093                 if ((vma->vm_end - vma->vm_start + off) > len)
1094                         return -EINVAL;
1095
1096                 off += start;
1097                 vma->vm_pgoff = off >> PAGE_SHIFT;
1098                 vma->vm_flags |= VM_IO | VM_RESERVED;
1099
1100 #ifdef pgprot_noncached
1101                 if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1102                         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1103 #endif
1104                 if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1105                                        vma->vm_end - vma->vm_start,
1106                                        vma->vm_page_prot))
1107                         return -EAGAIN;
1108
1109                 return 0;
1110         }
1111         return -ENOSYS;
1112 #else
1113         return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1114 #endif
1115 }
1116
1117 static const struct file_operations mtd_fops = {
1118         .owner          = THIS_MODULE,
1119         .llseek         = mtd_lseek,
1120         .read           = mtd_read,
1121         .write          = mtd_write,
1122         .unlocked_ioctl = mtd_unlocked_ioctl,
1123 #ifdef CONFIG_COMPAT
1124         .compat_ioctl   = mtd_compat_ioctl,
1125 #endif
1126         .open           = mtd_open,
1127         .release        = mtd_close,
1128         .mmap           = mtd_mmap,
1129 #ifndef CONFIG_MMU
1130         .get_unmapped_area = mtd_get_unmapped_area,
1131 #endif
1132 };
1133
1134 static int mtd_inodefs_get_sb(struct file_system_type *fs_type, int flags,
1135                                const char *dev_name, void *data,
1136                                struct vfsmount *mnt)
1137 {
1138         return get_sb_pseudo(fs_type, "mtd_inode:", NULL, MTD_INODE_FS_MAGIC,
1139                              mnt);
1140 }
1141
1142 static struct file_system_type mtd_inodefs_type = {
1143        .name = "mtd_inodefs",
1144        .get_sb = mtd_inodefs_get_sb,
1145        .kill_sb = kill_anon_super,
1146 };
1147
1148 static void mtdchar_notify_add(struct mtd_info *mtd)
1149 {
1150 }
1151
1152 static void mtdchar_notify_remove(struct mtd_info *mtd)
1153 {
1154         struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1155
1156         if (mtd_ino) {
1157                 /* Destroy the inode if it exists */
1158                 mtd_ino->i_nlink = 0;
1159                 iput(mtd_ino);
1160         }
1161 }
1162
1163 static struct mtd_notifier mtdchar_notifier = {
1164         .add = mtdchar_notify_add,
1165         .remove = mtdchar_notify_remove,
1166 };
1167
1168 static int __init init_mtdchar(void)
1169 {
1170         int ret;
1171
1172         ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1173                                    "mtd", &mtd_fops);
1174         if (ret < 0) {
1175                 pr_notice("Can't allocate major number %d for "
1176                                 "Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1177                 return ret;
1178         }
1179
1180         ret = register_filesystem(&mtd_inodefs_type);
1181         if (ret) {
1182                 pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1183                 goto err_unregister_chdev;
1184         }
1185
1186         mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1187         if (IS_ERR(mtd_inode_mnt)) {
1188                 ret = PTR_ERR(mtd_inode_mnt);
1189                 pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1190                 goto err_unregister_filesystem;
1191         }
1192         register_mtd_user(&mtdchar_notifier);
1193
1194         return ret;
1195
1196 err_unregister_filesystem:
1197         unregister_filesystem(&mtd_inodefs_type);
1198 err_unregister_chdev:
1199         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1200         return ret;
1201 }
1202
1203 static void __exit cleanup_mtdchar(void)
1204 {
1205         unregister_mtd_user(&mtdchar_notifier);
1206         mntput(mtd_inode_mnt);
1207         unregister_filesystem(&mtd_inodefs_type);
1208         __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1209 }
1210
1211 module_init(init_mtdchar);
1212 module_exit(cleanup_mtdchar);
1213
1214 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1215
1216 MODULE_LICENSE("GPL");
1217 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1218 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1219 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);