xref: /linux/drivers/mtd/mtdchar.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
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/smp_lock.h>
30 #include <linux/backing-dev.h>
31 #include <linux/compat.h>
32 #include <linux/mount.h>
33 
34 #include <linux/mtd/mtd.h>
35 #include <linux/mtd/map.h>
36 
37 #include <asm/uaccess.h>
38 
39 #define MTD_INODE_FS_MAGIC 0x11307854
40 static struct vfsmount *mtd_inode_mnt __read_mostly;
41 
42 /*
43  * Data structure to hold the pointer to the mtd device as well
44  * as mode information ofr various use cases.
45  */
46 struct mtd_file_info {
47 	struct mtd_info *mtd;
48 	struct inode *ino;
49 	enum mtd_file_modes mode;
50 };
51 
52 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
53 {
54 	struct mtd_file_info *mfi = file->private_data;
55 	struct mtd_info *mtd = mfi->mtd;
56 
57 	switch (orig) {
58 	case SEEK_SET:
59 		break;
60 	case SEEK_CUR:
61 		offset += file->f_pos;
62 		break;
63 	case SEEK_END:
64 		offset += mtd->size;
65 		break;
66 	default:
67 		return -EINVAL;
68 	}
69 
70 	if (offset >= 0 && offset <= mtd->size)
71 		return file->f_pos = offset;
72 
73 	return -EINVAL;
74 }
75 
76 
77 
78 static int mtd_open(struct inode *inode, struct file *file)
79 {
80 	int minor = iminor(inode);
81 	int devnum = minor >> 1;
82 	int ret = 0;
83 	struct mtd_info *mtd;
84 	struct mtd_file_info *mfi;
85 	struct inode *mtd_ino;
86 
87 	DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
88 
89 	/* You can't open the RO devices RW */
90 	if ((file->f_mode & FMODE_WRITE) && (minor & 1))
91 		return -EACCES;
92 
93 	lock_kernel();
94 	mtd = get_mtd_device(NULL, devnum);
95 
96 	if (IS_ERR(mtd)) {
97 		ret = PTR_ERR(mtd);
98 		goto out;
99 	}
100 
101 	if (mtd->type == MTD_ABSENT) {
102 		put_mtd_device(mtd);
103 		ret = -ENODEV;
104 		goto out;
105 	}
106 
107 	mtd_ino = iget_locked(mtd_inode_mnt->mnt_sb, devnum);
108 	if (!mtd_ino) {
109 		put_mtd_device(mtd);
110 		ret = -ENOMEM;
111 		goto out;
112 	}
113 	if (mtd_ino->i_state & I_NEW) {
114 		mtd_ino->i_private = mtd;
115 		mtd_ino->i_mode = S_IFCHR;
116 		mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
117 		unlock_new_inode(mtd_ino);
118 	}
119 	file->f_mapping = mtd_ino->i_mapping;
120 
121 	/* You can't open it RW if it's not a writeable device */
122 	if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
123 		iput(mtd_ino);
124 		put_mtd_device(mtd);
125 		ret = -EACCES;
126 		goto out;
127 	}
128 
129 	mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
130 	if (!mfi) {
131 		iput(mtd_ino);
132 		put_mtd_device(mtd);
133 		ret = -ENOMEM;
134 		goto out;
135 	}
136 	mfi->ino = mtd_ino;
137 	mfi->mtd = mtd;
138 	file->private_data = mfi;
139 
140 out:
141 	unlock_kernel();
142 	return ret;
143 } /* mtd_open */
144 
145 /*====================================================================*/
146 
147 static int mtd_close(struct inode *inode, struct file *file)
148 {
149 	struct mtd_file_info *mfi = file->private_data;
150 	struct mtd_info *mtd = mfi->mtd;
151 
152 	DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
153 
154 	/* Only sync if opened RW */
155 	if ((file->f_mode & FMODE_WRITE) && mtd->sync)
156 		mtd->sync(mtd);
157 
158 	iput(mfi->ino);
159 
160 	put_mtd_device(mtd);
161 	file->private_data = NULL;
162 	kfree(mfi);
163 
164 	return 0;
165 } /* mtd_close */
166 
167 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
168    userspace buffer down and use it directly with readv/writev.
169 */
170 #define MAX_KMALLOC_SIZE 0x20000
171 
172 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
173 {
174 	struct mtd_file_info *mfi = file->private_data;
175 	struct mtd_info *mtd = mfi->mtd;
176 	size_t retlen=0;
177 	size_t total_retlen=0;
178 	int ret=0;
179 	int len;
180 	char *kbuf;
181 
182 	DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
183 
184 	if (*ppos + count > mtd->size)
185 		count = mtd->size - *ppos;
186 
187 	if (!count)
188 		return 0;
189 
190 	/* FIXME: Use kiovec in 2.5 to lock down the user's buffers
191 	   and pass them directly to the MTD functions */
192 
193 	if (count > MAX_KMALLOC_SIZE)
194 		kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
195 	else
196 		kbuf=kmalloc(count, GFP_KERNEL);
197 
198 	if (!kbuf)
199 		return -ENOMEM;
200 
201 	while (count) {
202 
203 		if (count > MAX_KMALLOC_SIZE)
204 			len = MAX_KMALLOC_SIZE;
205 		else
206 			len = count;
207 
208 		switch (mfi->mode) {
209 		case MTD_MODE_OTP_FACTORY:
210 			ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
211 			break;
212 		case MTD_MODE_OTP_USER:
213 			ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
214 			break;
215 		case MTD_MODE_RAW:
216 		{
217 			struct mtd_oob_ops ops;
218 
219 			ops.mode = MTD_OOB_RAW;
220 			ops.datbuf = kbuf;
221 			ops.oobbuf = NULL;
222 			ops.len = len;
223 
224 			ret = mtd->read_oob(mtd, *ppos, &ops);
225 			retlen = ops.retlen;
226 			break;
227 		}
228 		default:
229 			ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
230 		}
231 		/* Nand returns -EBADMSG on ecc errors, but it returns
232 		 * the data. For our userspace tools it is important
233 		 * to dump areas with ecc errors !
234 		 * For kernel internal usage it also might return -EUCLEAN
235 		 * to signal the caller that a bitflip has occured and has
236 		 * been corrected by the ECC algorithm.
237 		 * Userspace software which accesses NAND this way
238 		 * must be aware of the fact that it deals with NAND
239 		 */
240 		if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
241 			*ppos += retlen;
242 			if (copy_to_user(buf, kbuf, retlen)) {
243 				kfree(kbuf);
244 				return -EFAULT;
245 			}
246 			else
247 				total_retlen += retlen;
248 
249 			count -= retlen;
250 			buf += retlen;
251 			if (retlen == 0)
252 				count = 0;
253 		}
254 		else {
255 			kfree(kbuf);
256 			return ret;
257 		}
258 
259 	}
260 
261 	kfree(kbuf);
262 	return total_retlen;
263 } /* mtd_read */
264 
265 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
266 {
267 	struct mtd_file_info *mfi = file->private_data;
268 	struct mtd_info *mtd = mfi->mtd;
269 	char *kbuf;
270 	size_t retlen;
271 	size_t total_retlen=0;
272 	int ret=0;
273 	int len;
274 
275 	DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
276 
277 	if (*ppos == mtd->size)
278 		return -ENOSPC;
279 
280 	if (*ppos + count > mtd->size)
281 		count = mtd->size - *ppos;
282 
283 	if (!count)
284 		return 0;
285 
286 	if (count > MAX_KMALLOC_SIZE)
287 		kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
288 	else
289 		kbuf=kmalloc(count, GFP_KERNEL);
290 
291 	if (!kbuf)
292 		return -ENOMEM;
293 
294 	while (count) {
295 
296 		if (count > MAX_KMALLOC_SIZE)
297 			len = MAX_KMALLOC_SIZE;
298 		else
299 			len = count;
300 
301 		if (copy_from_user(kbuf, buf, len)) {
302 			kfree(kbuf);
303 			return -EFAULT;
304 		}
305 
306 		switch (mfi->mode) {
307 		case MTD_MODE_OTP_FACTORY:
308 			ret = -EROFS;
309 			break;
310 		case MTD_MODE_OTP_USER:
311 			if (!mtd->write_user_prot_reg) {
312 				ret = -EOPNOTSUPP;
313 				break;
314 			}
315 			ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
316 			break;
317 
318 		case MTD_MODE_RAW:
319 		{
320 			struct mtd_oob_ops ops;
321 
322 			ops.mode = MTD_OOB_RAW;
323 			ops.datbuf = kbuf;
324 			ops.oobbuf = NULL;
325 			ops.len = len;
326 
327 			ret = mtd->write_oob(mtd, *ppos, &ops);
328 			retlen = ops.retlen;
329 			break;
330 		}
331 
332 		default:
333 			ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
334 		}
335 		if (!ret) {
336 			*ppos += retlen;
337 			total_retlen += retlen;
338 			count -= retlen;
339 			buf += retlen;
340 		}
341 		else {
342 			kfree(kbuf);
343 			return ret;
344 		}
345 	}
346 
347 	kfree(kbuf);
348 	return total_retlen;
349 } /* mtd_write */
350 
351 /*======================================================================
352 
353     IOCTL calls for getting device parameters.
354 
355 ======================================================================*/
356 static void mtdchar_erase_callback (struct erase_info *instr)
357 {
358 	wake_up((wait_queue_head_t *)instr->priv);
359 }
360 
361 #ifdef CONFIG_HAVE_MTD_OTP
362 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
363 {
364 	struct mtd_info *mtd = mfi->mtd;
365 	int ret = 0;
366 
367 	switch (mode) {
368 	case MTD_OTP_FACTORY:
369 		if (!mtd->read_fact_prot_reg)
370 			ret = -EOPNOTSUPP;
371 		else
372 			mfi->mode = MTD_MODE_OTP_FACTORY;
373 		break;
374 	case MTD_OTP_USER:
375 		if (!mtd->read_fact_prot_reg)
376 			ret = -EOPNOTSUPP;
377 		else
378 			mfi->mode = MTD_MODE_OTP_USER;
379 		break;
380 	default:
381 		ret = -EINVAL;
382 	case MTD_OTP_OFF:
383 		break;
384 	}
385 	return ret;
386 }
387 #else
388 # define otp_select_filemode(f,m)	-EOPNOTSUPP
389 #endif
390 
391 static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
392 	uint64_t start, uint32_t length, void __user *ptr,
393 	uint32_t __user *retp)
394 {
395 	struct mtd_oob_ops ops;
396 	uint32_t retlen;
397 	int ret = 0;
398 
399 	if (!(file->f_mode & FMODE_WRITE))
400 		return -EPERM;
401 
402 	if (length > 4096)
403 		return -EINVAL;
404 
405 	if (!mtd->write_oob)
406 		ret = -EOPNOTSUPP;
407 	else
408 		ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
409 
410 	if (ret)
411 		return ret;
412 
413 	ops.ooblen = length;
414 	ops.ooboffs = start & (mtd->oobsize - 1);
415 	ops.datbuf = NULL;
416 	ops.mode = MTD_OOB_PLACE;
417 
418 	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
419 		return -EINVAL;
420 
421 	ops.oobbuf = memdup_user(ptr, length);
422 	if (IS_ERR(ops.oobbuf))
423 		return PTR_ERR(ops.oobbuf);
424 
425 	start &= ~((uint64_t)mtd->oobsize - 1);
426 	ret = mtd->write_oob(mtd, start, &ops);
427 
428 	if (ops.oobretlen > 0xFFFFFFFFU)
429 		ret = -EOVERFLOW;
430 	retlen = ops.oobretlen;
431 	if (copy_to_user(retp, &retlen, sizeof(length)))
432 		ret = -EFAULT;
433 
434 	kfree(ops.oobbuf);
435 	return ret;
436 }
437 
438 static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
439 	uint32_t length, void __user *ptr, uint32_t __user *retp)
440 {
441 	struct mtd_oob_ops ops;
442 	int ret = 0;
443 
444 	if (length > 4096)
445 		return -EINVAL;
446 
447 	if (!mtd->read_oob)
448 		ret = -EOPNOTSUPP;
449 	else
450 		ret = access_ok(VERIFY_WRITE, ptr,
451 				length) ? 0 : -EFAULT;
452 	if (ret)
453 		return ret;
454 
455 	ops.ooblen = length;
456 	ops.ooboffs = start & (mtd->oobsize - 1);
457 	ops.datbuf = NULL;
458 	ops.mode = MTD_OOB_PLACE;
459 
460 	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
461 		return -EINVAL;
462 
463 	ops.oobbuf = kmalloc(length, GFP_KERNEL);
464 	if (!ops.oobbuf)
465 		return -ENOMEM;
466 
467 	start &= ~((uint64_t)mtd->oobsize - 1);
468 	ret = mtd->read_oob(mtd, start, &ops);
469 
470 	if (put_user(ops.oobretlen, retp))
471 		ret = -EFAULT;
472 	else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
473 					    ops.oobretlen))
474 		ret = -EFAULT;
475 
476 	kfree(ops.oobbuf);
477 	return ret;
478 }
479 
480 static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
481 {
482 	struct mtd_file_info *mfi = file->private_data;
483 	struct mtd_info *mtd = mfi->mtd;
484 	void __user *argp = (void __user *)arg;
485 	int ret = 0;
486 	u_long size;
487 	struct mtd_info_user info;
488 
489 	DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
490 
491 	size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
492 	if (cmd & IOC_IN) {
493 		if (!access_ok(VERIFY_READ, argp, size))
494 			return -EFAULT;
495 	}
496 	if (cmd & IOC_OUT) {
497 		if (!access_ok(VERIFY_WRITE, argp, size))
498 			return -EFAULT;
499 	}
500 
501 	switch (cmd) {
502 	case MEMGETREGIONCOUNT:
503 		if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
504 			return -EFAULT;
505 		break;
506 
507 	case MEMGETREGIONINFO:
508 	{
509 		uint32_t ur_idx;
510 		struct mtd_erase_region_info *kr;
511 		struct region_info_user __user *ur = argp;
512 
513 		if (get_user(ur_idx, &(ur->regionindex)))
514 			return -EFAULT;
515 
516 		kr = &(mtd->eraseregions[ur_idx]);
517 
518 		if (put_user(kr->offset, &(ur->offset))
519 		    || put_user(kr->erasesize, &(ur->erasesize))
520 		    || put_user(kr->numblocks, &(ur->numblocks)))
521 			return -EFAULT;
522 
523 		break;
524 	}
525 
526 	case MEMGETINFO:
527 		info.type	= mtd->type;
528 		info.flags	= mtd->flags;
529 		info.size	= mtd->size;
530 		info.erasesize	= mtd->erasesize;
531 		info.writesize	= mtd->writesize;
532 		info.oobsize	= mtd->oobsize;
533 		/* The below fields are obsolete */
534 		info.ecctype	= -1;
535 		info.eccsize	= 0;
536 		if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
537 			return -EFAULT;
538 		break;
539 
540 	case MEMERASE:
541 	case MEMERASE64:
542 	{
543 		struct erase_info *erase;
544 
545 		if(!(file->f_mode & FMODE_WRITE))
546 			return -EPERM;
547 
548 		erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
549 		if (!erase)
550 			ret = -ENOMEM;
551 		else {
552 			wait_queue_head_t waitq;
553 			DECLARE_WAITQUEUE(wait, current);
554 
555 			init_waitqueue_head(&waitq);
556 
557 			if (cmd == MEMERASE64) {
558 				struct erase_info_user64 einfo64;
559 
560 				if (copy_from_user(&einfo64, argp,
561 					    sizeof(struct erase_info_user64))) {
562 					kfree(erase);
563 					return -EFAULT;
564 				}
565 				erase->addr = einfo64.start;
566 				erase->len = einfo64.length;
567 			} else {
568 				struct erase_info_user einfo32;
569 
570 				if (copy_from_user(&einfo32, argp,
571 					    sizeof(struct erase_info_user))) {
572 					kfree(erase);
573 					return -EFAULT;
574 				}
575 				erase->addr = einfo32.start;
576 				erase->len = einfo32.length;
577 			}
578 			erase->mtd = mtd;
579 			erase->callback = mtdchar_erase_callback;
580 			erase->priv = (unsigned long)&waitq;
581 
582 			/*
583 			  FIXME: Allow INTERRUPTIBLE. Which means
584 			  not having the wait_queue head on the stack.
585 
586 			  If the wq_head is on the stack, and we
587 			  leave because we got interrupted, then the
588 			  wq_head is no longer there when the
589 			  callback routine tries to wake us up.
590 			*/
591 			ret = mtd->erase(mtd, erase);
592 			if (!ret) {
593 				set_current_state(TASK_UNINTERRUPTIBLE);
594 				add_wait_queue(&waitq, &wait);
595 				if (erase->state != MTD_ERASE_DONE &&
596 				    erase->state != MTD_ERASE_FAILED)
597 					schedule();
598 				remove_wait_queue(&waitq, &wait);
599 				set_current_state(TASK_RUNNING);
600 
601 				ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
602 			}
603 			kfree(erase);
604 		}
605 		break;
606 	}
607 
608 	case MEMWRITEOOB:
609 	{
610 		struct mtd_oob_buf buf;
611 		struct mtd_oob_buf __user *buf_user = argp;
612 
613 		/* NOTE: writes return length to buf_user->length */
614 		if (copy_from_user(&buf, argp, sizeof(buf)))
615 			ret = -EFAULT;
616 		else
617 			ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
618 				buf.ptr, &buf_user->length);
619 		break;
620 	}
621 
622 	case MEMREADOOB:
623 	{
624 		struct mtd_oob_buf buf;
625 		struct mtd_oob_buf __user *buf_user = argp;
626 
627 		/* NOTE: writes return length to buf_user->start */
628 		if (copy_from_user(&buf, argp, sizeof(buf)))
629 			ret = -EFAULT;
630 		else
631 			ret = mtd_do_readoob(mtd, buf.start, buf.length,
632 				buf.ptr, &buf_user->start);
633 		break;
634 	}
635 
636 	case MEMWRITEOOB64:
637 	{
638 		struct mtd_oob_buf64 buf;
639 		struct mtd_oob_buf64 __user *buf_user = argp;
640 
641 		if (copy_from_user(&buf, argp, sizeof(buf)))
642 			ret = -EFAULT;
643 		else
644 			ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
645 				(void __user *)(uintptr_t)buf.usr_ptr,
646 				&buf_user->length);
647 		break;
648 	}
649 
650 	case MEMREADOOB64:
651 	{
652 		struct mtd_oob_buf64 buf;
653 		struct mtd_oob_buf64 __user *buf_user = argp;
654 
655 		if (copy_from_user(&buf, argp, sizeof(buf)))
656 			ret = -EFAULT;
657 		else
658 			ret = mtd_do_readoob(mtd, buf.start, buf.length,
659 				(void __user *)(uintptr_t)buf.usr_ptr,
660 				&buf_user->length);
661 		break;
662 	}
663 
664 	case MEMLOCK:
665 	{
666 		struct erase_info_user einfo;
667 
668 		if (copy_from_user(&einfo, argp, sizeof(einfo)))
669 			return -EFAULT;
670 
671 		if (!mtd->lock)
672 			ret = -EOPNOTSUPP;
673 		else
674 			ret = mtd->lock(mtd, einfo.start, einfo.length);
675 		break;
676 	}
677 
678 	case MEMUNLOCK:
679 	{
680 		struct erase_info_user einfo;
681 
682 		if (copy_from_user(&einfo, argp, sizeof(einfo)))
683 			return -EFAULT;
684 
685 		if (!mtd->unlock)
686 			ret = -EOPNOTSUPP;
687 		else
688 			ret = mtd->unlock(mtd, einfo.start, einfo.length);
689 		break;
690 	}
691 
692 	case MEMISLOCKED:
693 	{
694 		struct erase_info_user einfo;
695 
696 		if (copy_from_user(&einfo, argp, sizeof(einfo)))
697 			return -EFAULT;
698 
699 		if (!mtd->is_locked)
700 			ret = -EOPNOTSUPP;
701 		else
702 			ret = mtd->is_locked(mtd, einfo.start, einfo.length);
703 		break;
704 	}
705 
706 	/* Legacy interface */
707 	case MEMGETOOBSEL:
708 	{
709 		struct nand_oobinfo oi;
710 
711 		if (!mtd->ecclayout)
712 			return -EOPNOTSUPP;
713 		if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
714 			return -EINVAL;
715 
716 		oi.useecc = MTD_NANDECC_AUTOPLACE;
717 		memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
718 		memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
719 		       sizeof(oi.oobfree));
720 		oi.eccbytes = mtd->ecclayout->eccbytes;
721 
722 		if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
723 			return -EFAULT;
724 		break;
725 	}
726 
727 	case MEMGETBADBLOCK:
728 	{
729 		loff_t offs;
730 
731 		if (copy_from_user(&offs, argp, sizeof(loff_t)))
732 			return -EFAULT;
733 		if (!mtd->block_isbad)
734 			ret = -EOPNOTSUPP;
735 		else
736 			return mtd->block_isbad(mtd, offs);
737 		break;
738 	}
739 
740 	case MEMSETBADBLOCK:
741 	{
742 		loff_t offs;
743 
744 		if (copy_from_user(&offs, argp, sizeof(loff_t)))
745 			return -EFAULT;
746 		if (!mtd->block_markbad)
747 			ret = -EOPNOTSUPP;
748 		else
749 			return mtd->block_markbad(mtd, offs);
750 		break;
751 	}
752 
753 #ifdef CONFIG_HAVE_MTD_OTP
754 	case OTPSELECT:
755 	{
756 		int mode;
757 		if (copy_from_user(&mode, argp, sizeof(int)))
758 			return -EFAULT;
759 
760 		mfi->mode = MTD_MODE_NORMAL;
761 
762 		ret = otp_select_filemode(mfi, mode);
763 
764 		file->f_pos = 0;
765 		break;
766 	}
767 
768 	case OTPGETREGIONCOUNT:
769 	case OTPGETREGIONINFO:
770 	{
771 		struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
772 		if (!buf)
773 			return -ENOMEM;
774 		ret = -EOPNOTSUPP;
775 		switch (mfi->mode) {
776 		case MTD_MODE_OTP_FACTORY:
777 			if (mtd->get_fact_prot_info)
778 				ret = mtd->get_fact_prot_info(mtd, buf, 4096);
779 			break;
780 		case MTD_MODE_OTP_USER:
781 			if (mtd->get_user_prot_info)
782 				ret = mtd->get_user_prot_info(mtd, buf, 4096);
783 			break;
784 		default:
785 			break;
786 		}
787 		if (ret >= 0) {
788 			if (cmd == OTPGETREGIONCOUNT) {
789 				int nbr = ret / sizeof(struct otp_info);
790 				ret = copy_to_user(argp, &nbr, sizeof(int));
791 			} else
792 				ret = copy_to_user(argp, buf, ret);
793 			if (ret)
794 				ret = -EFAULT;
795 		}
796 		kfree(buf);
797 		break;
798 	}
799 
800 	case OTPLOCK:
801 	{
802 		struct otp_info oinfo;
803 
804 		if (mfi->mode != MTD_MODE_OTP_USER)
805 			return -EINVAL;
806 		if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
807 			return -EFAULT;
808 		if (!mtd->lock_user_prot_reg)
809 			return -EOPNOTSUPP;
810 		ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
811 		break;
812 	}
813 #endif
814 
815 	case ECCGETLAYOUT:
816 	{
817 		if (!mtd->ecclayout)
818 			return -EOPNOTSUPP;
819 
820 		if (copy_to_user(argp, mtd->ecclayout,
821 				 sizeof(struct nand_ecclayout)))
822 			return -EFAULT;
823 		break;
824 	}
825 
826 	case ECCGETSTATS:
827 	{
828 		if (copy_to_user(argp, &mtd->ecc_stats,
829 				 sizeof(struct mtd_ecc_stats)))
830 			return -EFAULT;
831 		break;
832 	}
833 
834 	case MTDFILEMODE:
835 	{
836 		mfi->mode = 0;
837 
838 		switch(arg) {
839 		case MTD_MODE_OTP_FACTORY:
840 		case MTD_MODE_OTP_USER:
841 			ret = otp_select_filemode(mfi, arg);
842 			break;
843 
844 		case MTD_MODE_RAW:
845 			if (!mtd->read_oob || !mtd->write_oob)
846 				return -EOPNOTSUPP;
847 			mfi->mode = arg;
848 
849 		case MTD_MODE_NORMAL:
850 			break;
851 		default:
852 			ret = -EINVAL;
853 		}
854 		file->f_pos = 0;
855 		break;
856 	}
857 
858 	default:
859 		ret = -ENOTTY;
860 	}
861 
862 	return ret;
863 } /* memory_ioctl */
864 
865 static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
866 {
867 	int ret;
868 
869 	lock_kernel();
870 	ret = mtd_ioctl(file, cmd, arg);
871 	unlock_kernel();
872 
873 	return ret;
874 }
875 
876 #ifdef CONFIG_COMPAT
877 
878 struct mtd_oob_buf32 {
879 	u_int32_t start;
880 	u_int32_t length;
881 	compat_caddr_t ptr;	/* unsigned char* */
882 };
883 
884 #define MEMWRITEOOB32		_IOWR('M', 3, struct mtd_oob_buf32)
885 #define MEMREADOOB32		_IOWR('M', 4, struct mtd_oob_buf32)
886 
887 static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
888 	unsigned long arg)
889 {
890 	struct mtd_file_info *mfi = file->private_data;
891 	struct mtd_info *mtd = mfi->mtd;
892 	void __user *argp = compat_ptr(arg);
893 	int ret = 0;
894 
895 	lock_kernel();
896 
897 	switch (cmd) {
898 	case MEMWRITEOOB32:
899 	{
900 		struct mtd_oob_buf32 buf;
901 		struct mtd_oob_buf32 __user *buf_user = argp;
902 
903 		if (copy_from_user(&buf, argp, sizeof(buf)))
904 			ret = -EFAULT;
905 		else
906 			ret = mtd_do_writeoob(file, mtd, buf.start,
907 				buf.length, compat_ptr(buf.ptr),
908 				&buf_user->length);
909 		break;
910 	}
911 
912 	case MEMREADOOB32:
913 	{
914 		struct mtd_oob_buf32 buf;
915 		struct mtd_oob_buf32 __user *buf_user = argp;
916 
917 		/* NOTE: writes return length to buf->start */
918 		if (copy_from_user(&buf, argp, sizeof(buf)))
919 			ret = -EFAULT;
920 		else
921 			ret = mtd_do_readoob(mtd, buf.start,
922 				buf.length, compat_ptr(buf.ptr),
923 				&buf_user->start);
924 		break;
925 	}
926 	default:
927 		ret = mtd_ioctl(file, cmd, (unsigned long)argp);
928 	}
929 
930 	unlock_kernel();
931 
932 	return ret;
933 }
934 
935 #endif /* CONFIG_COMPAT */
936 
937 /*
938  * try to determine where a shared mapping can be made
939  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
940  *   mappings)
941  */
942 #ifndef CONFIG_MMU
943 static unsigned long mtd_get_unmapped_area(struct file *file,
944 					   unsigned long addr,
945 					   unsigned long len,
946 					   unsigned long pgoff,
947 					   unsigned long flags)
948 {
949 	struct mtd_file_info *mfi = file->private_data;
950 	struct mtd_info *mtd = mfi->mtd;
951 
952 	if (mtd->get_unmapped_area) {
953 		unsigned long offset;
954 
955 		if (addr != 0)
956 			return (unsigned long) -EINVAL;
957 
958 		if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
959 			return (unsigned long) -EINVAL;
960 
961 		offset = pgoff << PAGE_SHIFT;
962 		if (offset > mtd->size - len)
963 			return (unsigned long) -EINVAL;
964 
965 		return mtd->get_unmapped_area(mtd, len, offset, flags);
966 	}
967 
968 	/* can't map directly */
969 	return (unsigned long) -ENOSYS;
970 }
971 #endif
972 
973 /*
974  * set up a mapping for shared memory segments
975  */
976 static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
977 {
978 #ifdef CONFIG_MMU
979 	struct mtd_file_info *mfi = file->private_data;
980 	struct mtd_info *mtd = mfi->mtd;
981 	struct map_info *map = mtd->priv;
982 	unsigned long start;
983 	unsigned long off;
984 	u32 len;
985 
986 	if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
987 		off = vma->vm_pgoff << PAGE_SHIFT;
988 		start = map->phys;
989 		len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
990 		start &= PAGE_MASK;
991 		if ((vma->vm_end - vma->vm_start + off) > len)
992 			return -EINVAL;
993 
994 		off += start;
995 		vma->vm_pgoff = off >> PAGE_SHIFT;
996 		vma->vm_flags |= VM_IO | VM_RESERVED;
997 
998 #ifdef pgprot_noncached
999 		if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1000 			vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1001 #endif
1002 		if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1003 				       vma->vm_end - vma->vm_start,
1004 				       vma->vm_page_prot))
1005 			return -EAGAIN;
1006 
1007 		return 0;
1008 	}
1009 	return -ENOSYS;
1010 #else
1011 	return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1012 #endif
1013 }
1014 
1015 static const struct file_operations mtd_fops = {
1016 	.owner		= THIS_MODULE,
1017 	.llseek		= mtd_lseek,
1018 	.read		= mtd_read,
1019 	.write		= mtd_write,
1020 	.unlocked_ioctl	= mtd_unlocked_ioctl,
1021 #ifdef CONFIG_COMPAT
1022 	.compat_ioctl	= mtd_compat_ioctl,
1023 #endif
1024 	.open		= mtd_open,
1025 	.release	= mtd_close,
1026 	.mmap		= mtd_mmap,
1027 #ifndef CONFIG_MMU
1028 	.get_unmapped_area = mtd_get_unmapped_area,
1029 #endif
1030 };
1031 
1032 static int mtd_inodefs_get_sb(struct file_system_type *fs_type, int flags,
1033                                const char *dev_name, void *data,
1034                                struct vfsmount *mnt)
1035 {
1036         return get_sb_pseudo(fs_type, "mtd_inode:", NULL, MTD_INODE_FS_MAGIC,
1037                              mnt);
1038 }
1039 
1040 static struct file_system_type mtd_inodefs_type = {
1041        .name = "mtd_inodefs",
1042        .get_sb = mtd_inodefs_get_sb,
1043        .kill_sb = kill_anon_super,
1044 };
1045 
1046 static void mtdchar_notify_add(struct mtd_info *mtd)
1047 {
1048 }
1049 
1050 static void mtdchar_notify_remove(struct mtd_info *mtd)
1051 {
1052 	struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1053 
1054 	if (mtd_ino) {
1055 		/* Destroy the inode if it exists */
1056 		mtd_ino->i_nlink = 0;
1057 		iput(mtd_ino);
1058 	}
1059 }
1060 
1061 static struct mtd_notifier mtdchar_notifier = {
1062 	.add = mtdchar_notify_add,
1063 	.remove = mtdchar_notify_remove,
1064 };
1065 
1066 static int __init init_mtdchar(void)
1067 {
1068 	int ret;
1069 
1070 	ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1071 				   "mtd", &mtd_fops);
1072 	if (ret < 0) {
1073 		pr_notice("Can't allocate major number %d for "
1074 				"Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1075 		return ret;
1076 	}
1077 
1078 	ret = register_filesystem(&mtd_inodefs_type);
1079 	if (ret) {
1080 		pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1081 		goto err_unregister_chdev;
1082 	}
1083 
1084 	mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1085 	if (IS_ERR(mtd_inode_mnt)) {
1086 		ret = PTR_ERR(mtd_inode_mnt);
1087 		pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1088 		goto err_unregister_filesystem;
1089 	}
1090 	register_mtd_user(&mtdchar_notifier);
1091 
1092 	return ret;
1093 
1094 err_unregister_filesystem:
1095 	unregister_filesystem(&mtd_inodefs_type);
1096 err_unregister_chdev:
1097 	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1098 	return ret;
1099 }
1100 
1101 static void __exit cleanup_mtdchar(void)
1102 {
1103 	unregister_mtd_user(&mtdchar_notifier);
1104 	mntput(mtd_inode_mnt);
1105 	unregister_filesystem(&mtd_inodefs_type);
1106 	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1107 }
1108 
1109 module_init(init_mtdchar);
1110 module_exit(cleanup_mtdchar);
1111 
1112 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1113 
1114 MODULE_LICENSE("GPL");
1115 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1116 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1117 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1118