xref: /openbmc/linux/drivers/mtd/mtdchar.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1135 				int flags, const char *dev_name, void *data)
1136 {
1137 	return mount_pseudo(fs_type, "mtd_inode:", NULL, MTD_INODE_FS_MAGIC);
1138 }
1139 
1140 static struct file_system_type mtd_inodefs_type = {
1141        .name = "mtd_inodefs",
1142        .mount = mtd_inodefs_mount,
1143        .kill_sb = kill_anon_super,
1144 };
1145 
1146 static void mtdchar_notify_add(struct mtd_info *mtd)
1147 {
1148 }
1149 
1150 static void mtdchar_notify_remove(struct mtd_info *mtd)
1151 {
1152 	struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1153 
1154 	if (mtd_ino) {
1155 		/* Destroy the inode if it exists */
1156 		mtd_ino->i_nlink = 0;
1157 		iput(mtd_ino);
1158 	}
1159 }
1160 
1161 static struct mtd_notifier mtdchar_notifier = {
1162 	.add = mtdchar_notify_add,
1163 	.remove = mtdchar_notify_remove,
1164 };
1165 
1166 static int __init init_mtdchar(void)
1167 {
1168 	int ret;
1169 
1170 	ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1171 				   "mtd", &mtd_fops);
1172 	if (ret < 0) {
1173 		pr_notice("Can't allocate major number %d for "
1174 				"Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1175 		return ret;
1176 	}
1177 
1178 	ret = register_filesystem(&mtd_inodefs_type);
1179 	if (ret) {
1180 		pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1181 		goto err_unregister_chdev;
1182 	}
1183 
1184 	mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1185 	if (IS_ERR(mtd_inode_mnt)) {
1186 		ret = PTR_ERR(mtd_inode_mnt);
1187 		pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1188 		goto err_unregister_filesystem;
1189 	}
1190 	register_mtd_user(&mtdchar_notifier);
1191 
1192 	return ret;
1193 
1194 err_unregister_filesystem:
1195 	unregister_filesystem(&mtd_inodefs_type);
1196 err_unregister_chdev:
1197 	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1198 	return ret;
1199 }
1200 
1201 static void __exit cleanup_mtdchar(void)
1202 {
1203 	unregister_mtd_user(&mtdchar_notifier);
1204 	mntput(mtd_inode_mnt);
1205 	unregister_filesystem(&mtd_inodefs_type);
1206 	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1207 }
1208 
1209 module_init(init_mtdchar);
1210 module_exit(cleanup_mtdchar);
1211 
1212 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1213 
1214 MODULE_LICENSE("GPL");
1215 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1216 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1217 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1218