xref: /linux/drivers/mtd/mtdchar.c (revision 93df8a1ed6231727c5db94a80b1a6bd5ee67cec3)
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/magic.h>
35 #include <linux/major.h>
36 #include <linux/mtd/mtd.h>
37 #include <linux/mtd/partitions.h>
38 #include <linux/mtd/map.h>
39 
40 #include <asm/uaccess.h>
41 
42 #include "mtdcore.h"
43 
44 static DEFINE_MUTEX(mtd_mutex);
45 
46 /*
47  * Data structure to hold the pointer to the mtd device as well
48  * as mode information of various use cases.
49  */
50 struct mtd_file_info {
51 	struct mtd_info *mtd;
52 	enum mtd_file_modes mode;
53 };
54 
55 static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig)
56 {
57 	struct mtd_file_info *mfi = file->private_data;
58 	return fixed_size_llseek(file, offset, orig, mfi->mtd->size);
59 }
60 
61 static int mtdchar_open(struct inode *inode, struct file *file)
62 {
63 	int minor = iminor(inode);
64 	int devnum = minor >> 1;
65 	int ret = 0;
66 	struct mtd_info *mtd;
67 	struct mtd_file_info *mfi;
68 
69 	pr_debug("MTD_open\n");
70 
71 	/* You can't open the RO devices RW */
72 	if ((file->f_mode & FMODE_WRITE) && (minor & 1))
73 		return -EACCES;
74 
75 	mutex_lock(&mtd_mutex);
76 	mtd = get_mtd_device(NULL, devnum);
77 
78 	if (IS_ERR(mtd)) {
79 		ret = PTR_ERR(mtd);
80 		goto out;
81 	}
82 
83 	if (mtd->type == MTD_ABSENT) {
84 		ret = -ENODEV;
85 		goto out1;
86 	}
87 
88 	/* You can't open it RW if it's not a writeable device */
89 	if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
90 		ret = -EACCES;
91 		goto out1;
92 	}
93 
94 	mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
95 	if (!mfi) {
96 		ret = -ENOMEM;
97 		goto out1;
98 	}
99 	mfi->mtd = mtd;
100 	file->private_data = mfi;
101 	mutex_unlock(&mtd_mutex);
102 	return 0;
103 
104 out1:
105 	put_mtd_device(mtd);
106 out:
107 	mutex_unlock(&mtd_mutex);
108 	return ret;
109 } /* mtdchar_open */
110 
111 /*====================================================================*/
112 
113 static int mtdchar_close(struct inode *inode, struct file *file)
114 {
115 	struct mtd_file_info *mfi = file->private_data;
116 	struct mtd_info *mtd = mfi->mtd;
117 
118 	pr_debug("MTD_close\n");
119 
120 	/* Only sync if opened RW */
121 	if ((file->f_mode & FMODE_WRITE))
122 		mtd_sync(mtd);
123 
124 	put_mtd_device(mtd);
125 	file->private_data = NULL;
126 	kfree(mfi);
127 
128 	return 0;
129 } /* mtdchar_close */
130 
131 /* Back in June 2001, dwmw2 wrote:
132  *
133  *   FIXME: This _really_ needs to die. In 2.5, we should lock the
134  *   userspace buffer down and use it directly with readv/writev.
135  *
136  * The implementation below, using mtd_kmalloc_up_to, mitigates
137  * allocation failures when the system is under low-memory situations
138  * or if memory is highly fragmented at the cost of reducing the
139  * performance of the requested transfer due to a smaller buffer size.
140  *
141  * A more complex but more memory-efficient implementation based on
142  * get_user_pages and iovecs to cover extents of those pages is a
143  * longer-term goal, as intimated by dwmw2 above. However, for the
144  * write case, this requires yet more complex head and tail transfer
145  * handling when those head and tail offsets and sizes are such that
146  * alignment requirements are not met in the NAND subdriver.
147  */
148 
149 static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
150 			loff_t *ppos)
151 {
152 	struct mtd_file_info *mfi = file->private_data;
153 	struct mtd_info *mtd = mfi->mtd;
154 	size_t retlen;
155 	size_t total_retlen=0;
156 	int ret=0;
157 	int len;
158 	size_t size = count;
159 	char *kbuf;
160 
161 	pr_debug("MTD_read\n");
162 
163 	if (*ppos + count > mtd->size)
164 		count = mtd->size - *ppos;
165 
166 	if (!count)
167 		return 0;
168 
169 	kbuf = mtd_kmalloc_up_to(mtd, &size);
170 	if (!kbuf)
171 		return -ENOMEM;
172 
173 	while (count) {
174 		len = min_t(size_t, count, size);
175 
176 		switch (mfi->mode) {
177 		case MTD_FILE_MODE_OTP_FACTORY:
178 			ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
179 						     &retlen, kbuf);
180 			break;
181 		case MTD_FILE_MODE_OTP_USER:
182 			ret = mtd_read_user_prot_reg(mtd, *ppos, len,
183 						     &retlen, kbuf);
184 			break;
185 		case MTD_FILE_MODE_RAW:
186 		{
187 			struct mtd_oob_ops ops;
188 
189 			ops.mode = MTD_OPS_RAW;
190 			ops.datbuf = kbuf;
191 			ops.oobbuf = NULL;
192 			ops.len = len;
193 
194 			ret = mtd_read_oob(mtd, *ppos, &ops);
195 			retlen = ops.retlen;
196 			break;
197 		}
198 		default:
199 			ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
200 		}
201 		/* Nand returns -EBADMSG on ECC errors, but it returns
202 		 * the data. For our userspace tools it is important
203 		 * to dump areas with ECC errors!
204 		 * For kernel internal usage it also might return -EUCLEAN
205 		 * to signal the caller that a bitflip has occurred and has
206 		 * been corrected by the ECC algorithm.
207 		 * Userspace software which accesses NAND this way
208 		 * must be aware of the fact that it deals with NAND
209 		 */
210 		if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
211 			*ppos += retlen;
212 			if (copy_to_user(buf, kbuf, retlen)) {
213 				kfree(kbuf);
214 				return -EFAULT;
215 			}
216 			else
217 				total_retlen += retlen;
218 
219 			count -= retlen;
220 			buf += retlen;
221 			if (retlen == 0)
222 				count = 0;
223 		}
224 		else {
225 			kfree(kbuf);
226 			return ret;
227 		}
228 
229 	}
230 
231 	kfree(kbuf);
232 	return total_retlen;
233 } /* mtdchar_read */
234 
235 static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
236 			loff_t *ppos)
237 {
238 	struct mtd_file_info *mfi = file->private_data;
239 	struct mtd_info *mtd = mfi->mtd;
240 	size_t size = count;
241 	char *kbuf;
242 	size_t retlen;
243 	size_t total_retlen=0;
244 	int ret=0;
245 	int len;
246 
247 	pr_debug("MTD_write\n");
248 
249 	if (*ppos == mtd->size)
250 		return -ENOSPC;
251 
252 	if (*ppos + count > mtd->size)
253 		count = mtd->size - *ppos;
254 
255 	if (!count)
256 		return 0;
257 
258 	kbuf = mtd_kmalloc_up_to(mtd, &size);
259 	if (!kbuf)
260 		return -ENOMEM;
261 
262 	while (count) {
263 		len = min_t(size_t, count, size);
264 
265 		if (copy_from_user(kbuf, buf, len)) {
266 			kfree(kbuf);
267 			return -EFAULT;
268 		}
269 
270 		switch (mfi->mode) {
271 		case MTD_FILE_MODE_OTP_FACTORY:
272 			ret = -EROFS;
273 			break;
274 		case MTD_FILE_MODE_OTP_USER:
275 			ret = mtd_write_user_prot_reg(mtd, *ppos, len,
276 						      &retlen, kbuf);
277 			break;
278 
279 		case MTD_FILE_MODE_RAW:
280 		{
281 			struct mtd_oob_ops ops;
282 
283 			ops.mode = MTD_OPS_RAW;
284 			ops.datbuf = kbuf;
285 			ops.oobbuf = NULL;
286 			ops.ooboffs = 0;
287 			ops.len = len;
288 
289 			ret = mtd_write_oob(mtd, *ppos, &ops);
290 			retlen = ops.retlen;
291 			break;
292 		}
293 
294 		default:
295 			ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
296 		}
297 
298 		/*
299 		 * Return -ENOSPC only if no data could be written at all.
300 		 * Otherwise just return the number of bytes that actually
301 		 * have been written.
302 		 */
303 		if ((ret == -ENOSPC) && (total_retlen))
304 			break;
305 
306 		if (!ret) {
307 			*ppos += retlen;
308 			total_retlen += retlen;
309 			count -= retlen;
310 			buf += retlen;
311 		}
312 		else {
313 			kfree(kbuf);
314 			return ret;
315 		}
316 	}
317 
318 	kfree(kbuf);
319 	return total_retlen;
320 } /* mtdchar_write */
321 
322 /*======================================================================
323 
324     IOCTL calls for getting device parameters.
325 
326 ======================================================================*/
327 static void mtdchar_erase_callback (struct erase_info *instr)
328 {
329 	wake_up((wait_queue_head_t *)instr->priv);
330 }
331 
332 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
333 {
334 	struct mtd_info *mtd = mfi->mtd;
335 	size_t retlen;
336 
337 	switch (mode) {
338 	case MTD_OTP_FACTORY:
339 		if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
340 				-EOPNOTSUPP)
341 			return -EOPNOTSUPP;
342 
343 		mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
344 		break;
345 	case MTD_OTP_USER:
346 		if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
347 				-EOPNOTSUPP)
348 			return -EOPNOTSUPP;
349 
350 		mfi->mode = MTD_FILE_MODE_OTP_USER;
351 		break;
352 	case MTD_OTP_OFF:
353 		mfi->mode = MTD_FILE_MODE_NORMAL;
354 		break;
355 	default:
356 		return -EINVAL;
357 	}
358 
359 	return 0;
360 }
361 
362 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
363 	uint64_t start, uint32_t length, void __user *ptr,
364 	uint32_t __user *retp)
365 {
366 	struct mtd_file_info *mfi = file->private_data;
367 	struct mtd_oob_ops ops;
368 	uint32_t retlen;
369 	int ret = 0;
370 
371 	if (!(file->f_mode & FMODE_WRITE))
372 		return -EPERM;
373 
374 	if (length > 4096)
375 		return -EINVAL;
376 
377 	if (!mtd->_write_oob)
378 		ret = -EOPNOTSUPP;
379 	else
380 		ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
381 
382 	if (ret)
383 		return ret;
384 
385 	ops.ooblen = length;
386 	ops.ooboffs = start & (mtd->writesize - 1);
387 	ops.datbuf = NULL;
388 	ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
389 		MTD_OPS_PLACE_OOB;
390 
391 	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
392 		return -EINVAL;
393 
394 	ops.oobbuf = memdup_user(ptr, length);
395 	if (IS_ERR(ops.oobbuf))
396 		return PTR_ERR(ops.oobbuf);
397 
398 	start &= ~((uint64_t)mtd->writesize - 1);
399 	ret = mtd_write_oob(mtd, start, &ops);
400 
401 	if (ops.oobretlen > 0xFFFFFFFFU)
402 		ret = -EOVERFLOW;
403 	retlen = ops.oobretlen;
404 	if (copy_to_user(retp, &retlen, sizeof(length)))
405 		ret = -EFAULT;
406 
407 	kfree(ops.oobbuf);
408 	return ret;
409 }
410 
411 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
412 	uint64_t start, uint32_t length, void __user *ptr,
413 	uint32_t __user *retp)
414 {
415 	struct mtd_file_info *mfi = file->private_data;
416 	struct mtd_oob_ops ops;
417 	int ret = 0;
418 
419 	if (length > 4096)
420 		return -EINVAL;
421 
422 	if (!access_ok(VERIFY_WRITE, ptr, length))
423 		return -EFAULT;
424 
425 	ops.ooblen = length;
426 	ops.ooboffs = start & (mtd->writesize - 1);
427 	ops.datbuf = NULL;
428 	ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
429 		MTD_OPS_PLACE_OOB;
430 
431 	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
432 		return -EINVAL;
433 
434 	ops.oobbuf = kmalloc(length, GFP_KERNEL);
435 	if (!ops.oobbuf)
436 		return -ENOMEM;
437 
438 	start &= ~((uint64_t)mtd->writesize - 1);
439 	ret = mtd_read_oob(mtd, start, &ops);
440 
441 	if (put_user(ops.oobretlen, retp))
442 		ret = -EFAULT;
443 	else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
444 					    ops.oobretlen))
445 		ret = -EFAULT;
446 
447 	kfree(ops.oobbuf);
448 
449 	/*
450 	 * NAND returns -EBADMSG on ECC errors, but it returns the OOB
451 	 * data. For our userspace tools it is important to dump areas
452 	 * with ECC errors!
453 	 * For kernel internal usage it also might return -EUCLEAN
454 	 * to signal the caller that a bitflip has occured and has
455 	 * been corrected by the ECC algorithm.
456 	 *
457 	 * Note: currently the standard NAND function, nand_read_oob_std,
458 	 * does not calculate ECC for the OOB area, so do not rely on
459 	 * this behavior unless you have replaced it with your own.
460 	 */
461 	if (mtd_is_bitflip_or_eccerr(ret))
462 		return 0;
463 
464 	return ret;
465 }
466 
467 /*
468  * Copies (and truncates, if necessary) data from the larger struct,
469  * nand_ecclayout, to the smaller, deprecated layout struct,
470  * nand_ecclayout_user. This is necessary only to support the deprecated
471  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
472  * nand_ecclayout flexibly (i.e. the struct may change size in new
473  * releases without requiring major rewrites).
474  */
475 static int shrink_ecclayout(const struct nand_ecclayout *from,
476 		struct nand_ecclayout_user *to)
477 {
478 	int i;
479 
480 	if (!from || !to)
481 		return -EINVAL;
482 
483 	memset(to, 0, sizeof(*to));
484 
485 	to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
486 	for (i = 0; i < to->eccbytes; i++)
487 		to->eccpos[i] = from->eccpos[i];
488 
489 	for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
490 		if (from->oobfree[i].length == 0 &&
491 				from->oobfree[i].offset == 0)
492 			break;
493 		to->oobavail += from->oobfree[i].length;
494 		to->oobfree[i] = from->oobfree[i];
495 	}
496 
497 	return 0;
498 }
499 
500 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
501 			   struct blkpg_ioctl_arg __user *arg)
502 {
503 	struct blkpg_ioctl_arg a;
504 	struct blkpg_partition p;
505 
506 	if (!capable(CAP_SYS_ADMIN))
507 		return -EPERM;
508 
509 	if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
510 		return -EFAULT;
511 
512 	if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
513 		return -EFAULT;
514 
515 	switch (a.op) {
516 	case BLKPG_ADD_PARTITION:
517 
518 		/* Only master mtd device must be used to add partitions */
519 		if (mtd_is_partition(mtd))
520 			return -EINVAL;
521 
522 		/* Sanitize user input */
523 		p.devname[BLKPG_DEVNAMELTH - 1] = '\0';
524 
525 		return mtd_add_partition(mtd, p.devname, p.start, p.length);
526 
527 	case BLKPG_DEL_PARTITION:
528 
529 		if (p.pno < 0)
530 			return -EINVAL;
531 
532 		return mtd_del_partition(mtd, p.pno);
533 
534 	default:
535 		return -EINVAL;
536 	}
537 }
538 
539 static int mtdchar_write_ioctl(struct mtd_info *mtd,
540 		struct mtd_write_req __user *argp)
541 {
542 	struct mtd_write_req req;
543 	struct mtd_oob_ops ops;
544 	const void __user *usr_data, *usr_oob;
545 	int ret;
546 
547 	if (copy_from_user(&req, argp, sizeof(req)))
548 		return -EFAULT;
549 
550 	usr_data = (const void __user *)(uintptr_t)req.usr_data;
551 	usr_oob = (const void __user *)(uintptr_t)req.usr_oob;
552 	if (!access_ok(VERIFY_READ, usr_data, req.len) ||
553 	    !access_ok(VERIFY_READ, usr_oob, req.ooblen))
554 		return -EFAULT;
555 
556 	if (!mtd->_write_oob)
557 		return -EOPNOTSUPP;
558 
559 	ops.mode = req.mode;
560 	ops.len = (size_t)req.len;
561 	ops.ooblen = (size_t)req.ooblen;
562 	ops.ooboffs = 0;
563 
564 	if (usr_data) {
565 		ops.datbuf = memdup_user(usr_data, ops.len);
566 		if (IS_ERR(ops.datbuf))
567 			return PTR_ERR(ops.datbuf);
568 	} else {
569 		ops.datbuf = NULL;
570 	}
571 
572 	if (usr_oob) {
573 		ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
574 		if (IS_ERR(ops.oobbuf)) {
575 			kfree(ops.datbuf);
576 			return PTR_ERR(ops.oobbuf);
577 		}
578 	} else {
579 		ops.oobbuf = NULL;
580 	}
581 
582 	ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
583 
584 	kfree(ops.datbuf);
585 	kfree(ops.oobbuf);
586 
587 	return ret;
588 }
589 
590 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
591 {
592 	struct mtd_file_info *mfi = file->private_data;
593 	struct mtd_info *mtd = mfi->mtd;
594 	void __user *argp = (void __user *)arg;
595 	int ret = 0;
596 	u_long size;
597 	struct mtd_info_user info;
598 
599 	pr_debug("MTD_ioctl\n");
600 
601 	size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
602 	if (cmd & IOC_IN) {
603 		if (!access_ok(VERIFY_READ, argp, size))
604 			return -EFAULT;
605 	}
606 	if (cmd & IOC_OUT) {
607 		if (!access_ok(VERIFY_WRITE, argp, size))
608 			return -EFAULT;
609 	}
610 
611 	switch (cmd) {
612 	case MEMGETREGIONCOUNT:
613 		if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
614 			return -EFAULT;
615 		break;
616 
617 	case MEMGETREGIONINFO:
618 	{
619 		uint32_t ur_idx;
620 		struct mtd_erase_region_info *kr;
621 		struct region_info_user __user *ur = argp;
622 
623 		if (get_user(ur_idx, &(ur->regionindex)))
624 			return -EFAULT;
625 
626 		if (ur_idx >= mtd->numeraseregions)
627 			return -EINVAL;
628 
629 		kr = &(mtd->eraseregions[ur_idx]);
630 
631 		if (put_user(kr->offset, &(ur->offset))
632 		    || put_user(kr->erasesize, &(ur->erasesize))
633 		    || put_user(kr->numblocks, &(ur->numblocks)))
634 			return -EFAULT;
635 
636 		break;
637 	}
638 
639 	case MEMGETINFO:
640 		memset(&info, 0, sizeof(info));
641 		info.type	= mtd->type;
642 		info.flags	= mtd->flags;
643 		info.size	= mtd->size;
644 		info.erasesize	= mtd->erasesize;
645 		info.writesize	= mtd->writesize;
646 		info.oobsize	= mtd->oobsize;
647 		/* The below field is obsolete */
648 		info.padding	= 0;
649 		if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
650 			return -EFAULT;
651 		break;
652 
653 	case MEMERASE:
654 	case MEMERASE64:
655 	{
656 		struct erase_info *erase;
657 
658 		if(!(file->f_mode & FMODE_WRITE))
659 			return -EPERM;
660 
661 		erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
662 		if (!erase)
663 			ret = -ENOMEM;
664 		else {
665 			wait_queue_head_t waitq;
666 			DECLARE_WAITQUEUE(wait, current);
667 
668 			init_waitqueue_head(&waitq);
669 
670 			if (cmd == MEMERASE64) {
671 				struct erase_info_user64 einfo64;
672 
673 				if (copy_from_user(&einfo64, argp,
674 					    sizeof(struct erase_info_user64))) {
675 					kfree(erase);
676 					return -EFAULT;
677 				}
678 				erase->addr = einfo64.start;
679 				erase->len = einfo64.length;
680 			} else {
681 				struct erase_info_user einfo32;
682 
683 				if (copy_from_user(&einfo32, argp,
684 					    sizeof(struct erase_info_user))) {
685 					kfree(erase);
686 					return -EFAULT;
687 				}
688 				erase->addr = einfo32.start;
689 				erase->len = einfo32.length;
690 			}
691 			erase->mtd = mtd;
692 			erase->callback = mtdchar_erase_callback;
693 			erase->priv = (unsigned long)&waitq;
694 
695 			/*
696 			  FIXME: Allow INTERRUPTIBLE. Which means
697 			  not having the wait_queue head on the stack.
698 
699 			  If the wq_head is on the stack, and we
700 			  leave because we got interrupted, then the
701 			  wq_head is no longer there when the
702 			  callback routine tries to wake us up.
703 			*/
704 			ret = mtd_erase(mtd, erase);
705 			if (!ret) {
706 				set_current_state(TASK_UNINTERRUPTIBLE);
707 				add_wait_queue(&waitq, &wait);
708 				if (erase->state != MTD_ERASE_DONE &&
709 				    erase->state != MTD_ERASE_FAILED)
710 					schedule();
711 				remove_wait_queue(&waitq, &wait);
712 				set_current_state(TASK_RUNNING);
713 
714 				ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
715 			}
716 			kfree(erase);
717 		}
718 		break;
719 	}
720 
721 	case MEMWRITEOOB:
722 	{
723 		struct mtd_oob_buf buf;
724 		struct mtd_oob_buf __user *buf_user = argp;
725 
726 		/* NOTE: writes return length to buf_user->length */
727 		if (copy_from_user(&buf, argp, sizeof(buf)))
728 			ret = -EFAULT;
729 		else
730 			ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
731 				buf.ptr, &buf_user->length);
732 		break;
733 	}
734 
735 	case MEMREADOOB:
736 	{
737 		struct mtd_oob_buf buf;
738 		struct mtd_oob_buf __user *buf_user = argp;
739 
740 		/* NOTE: writes return length to buf_user->start */
741 		if (copy_from_user(&buf, argp, sizeof(buf)))
742 			ret = -EFAULT;
743 		else
744 			ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
745 				buf.ptr, &buf_user->start);
746 		break;
747 	}
748 
749 	case MEMWRITEOOB64:
750 	{
751 		struct mtd_oob_buf64 buf;
752 		struct mtd_oob_buf64 __user *buf_user = argp;
753 
754 		if (copy_from_user(&buf, argp, sizeof(buf)))
755 			ret = -EFAULT;
756 		else
757 			ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
758 				(void __user *)(uintptr_t)buf.usr_ptr,
759 				&buf_user->length);
760 		break;
761 	}
762 
763 	case MEMREADOOB64:
764 	{
765 		struct mtd_oob_buf64 buf;
766 		struct mtd_oob_buf64 __user *buf_user = argp;
767 
768 		if (copy_from_user(&buf, argp, sizeof(buf)))
769 			ret = -EFAULT;
770 		else
771 			ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
772 				(void __user *)(uintptr_t)buf.usr_ptr,
773 				&buf_user->length);
774 		break;
775 	}
776 
777 	case MEMWRITE:
778 	{
779 		ret = mtdchar_write_ioctl(mtd,
780 		      (struct mtd_write_req __user *)arg);
781 		break;
782 	}
783 
784 	case MEMLOCK:
785 	{
786 		struct erase_info_user einfo;
787 
788 		if (copy_from_user(&einfo, argp, sizeof(einfo)))
789 			return -EFAULT;
790 
791 		ret = mtd_lock(mtd, einfo.start, einfo.length);
792 		break;
793 	}
794 
795 	case MEMUNLOCK:
796 	{
797 		struct erase_info_user einfo;
798 
799 		if (copy_from_user(&einfo, argp, sizeof(einfo)))
800 			return -EFAULT;
801 
802 		ret = mtd_unlock(mtd, einfo.start, einfo.length);
803 		break;
804 	}
805 
806 	case MEMISLOCKED:
807 	{
808 		struct erase_info_user einfo;
809 
810 		if (copy_from_user(&einfo, argp, sizeof(einfo)))
811 			return -EFAULT;
812 
813 		ret = mtd_is_locked(mtd, einfo.start, einfo.length);
814 		break;
815 	}
816 
817 	/* Legacy interface */
818 	case MEMGETOOBSEL:
819 	{
820 		struct nand_oobinfo oi;
821 
822 		if (!mtd->ecclayout)
823 			return -EOPNOTSUPP;
824 		if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
825 			return -EINVAL;
826 
827 		oi.useecc = MTD_NANDECC_AUTOPLACE;
828 		memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
829 		memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
830 		       sizeof(oi.oobfree));
831 		oi.eccbytes = mtd->ecclayout->eccbytes;
832 
833 		if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
834 			return -EFAULT;
835 		break;
836 	}
837 
838 	case MEMGETBADBLOCK:
839 	{
840 		loff_t offs;
841 
842 		if (copy_from_user(&offs, argp, sizeof(loff_t)))
843 			return -EFAULT;
844 		return mtd_block_isbad(mtd, offs);
845 		break;
846 	}
847 
848 	case MEMSETBADBLOCK:
849 	{
850 		loff_t offs;
851 
852 		if (copy_from_user(&offs, argp, sizeof(loff_t)))
853 			return -EFAULT;
854 		return mtd_block_markbad(mtd, offs);
855 		break;
856 	}
857 
858 	case OTPSELECT:
859 	{
860 		int mode;
861 		if (copy_from_user(&mode, argp, sizeof(int)))
862 			return -EFAULT;
863 
864 		mfi->mode = MTD_FILE_MODE_NORMAL;
865 
866 		ret = otp_select_filemode(mfi, mode);
867 
868 		file->f_pos = 0;
869 		break;
870 	}
871 
872 	case OTPGETREGIONCOUNT:
873 	case OTPGETREGIONINFO:
874 	{
875 		struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
876 		size_t retlen;
877 		if (!buf)
878 			return -ENOMEM;
879 		switch (mfi->mode) {
880 		case MTD_FILE_MODE_OTP_FACTORY:
881 			ret = mtd_get_fact_prot_info(mtd, 4096, &retlen, buf);
882 			break;
883 		case MTD_FILE_MODE_OTP_USER:
884 			ret = mtd_get_user_prot_info(mtd, 4096, &retlen, buf);
885 			break;
886 		default:
887 			ret = -EINVAL;
888 			break;
889 		}
890 		if (!ret) {
891 			if (cmd == OTPGETREGIONCOUNT) {
892 				int nbr = retlen / sizeof(struct otp_info);
893 				ret = copy_to_user(argp, &nbr, sizeof(int));
894 			} else
895 				ret = copy_to_user(argp, buf, retlen);
896 			if (ret)
897 				ret = -EFAULT;
898 		}
899 		kfree(buf);
900 		break;
901 	}
902 
903 	case OTPLOCK:
904 	{
905 		struct otp_info oinfo;
906 
907 		if (mfi->mode != MTD_FILE_MODE_OTP_USER)
908 			return -EINVAL;
909 		if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
910 			return -EFAULT;
911 		ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
912 		break;
913 	}
914 
915 	/* This ioctl is being deprecated - it truncates the ECC layout */
916 	case ECCGETLAYOUT:
917 	{
918 		struct nand_ecclayout_user *usrlay;
919 
920 		if (!mtd->ecclayout)
921 			return -EOPNOTSUPP;
922 
923 		usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
924 		if (!usrlay)
925 			return -ENOMEM;
926 
927 		shrink_ecclayout(mtd->ecclayout, usrlay);
928 
929 		if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
930 			ret = -EFAULT;
931 		kfree(usrlay);
932 		break;
933 	}
934 
935 	case ECCGETSTATS:
936 	{
937 		if (copy_to_user(argp, &mtd->ecc_stats,
938 				 sizeof(struct mtd_ecc_stats)))
939 			return -EFAULT;
940 		break;
941 	}
942 
943 	case MTDFILEMODE:
944 	{
945 		mfi->mode = 0;
946 
947 		switch(arg) {
948 		case MTD_FILE_MODE_OTP_FACTORY:
949 		case MTD_FILE_MODE_OTP_USER:
950 			ret = otp_select_filemode(mfi, arg);
951 			break;
952 
953 		case MTD_FILE_MODE_RAW:
954 			if (!mtd_has_oob(mtd))
955 				return -EOPNOTSUPP;
956 			mfi->mode = arg;
957 
958 		case MTD_FILE_MODE_NORMAL:
959 			break;
960 		default:
961 			ret = -EINVAL;
962 		}
963 		file->f_pos = 0;
964 		break;
965 	}
966 
967 	case BLKPG:
968 	{
969 		ret = mtdchar_blkpg_ioctl(mtd,
970 		      (struct blkpg_ioctl_arg __user *)arg);
971 		break;
972 	}
973 
974 	case BLKRRPART:
975 	{
976 		/* No reread partition feature. Just return ok */
977 		ret = 0;
978 		break;
979 	}
980 
981 	default:
982 		ret = -ENOTTY;
983 	}
984 
985 	return ret;
986 } /* memory_ioctl */
987 
988 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
989 {
990 	int ret;
991 
992 	mutex_lock(&mtd_mutex);
993 	ret = mtdchar_ioctl(file, cmd, arg);
994 	mutex_unlock(&mtd_mutex);
995 
996 	return ret;
997 }
998 
999 #ifdef CONFIG_COMPAT
1000 
1001 struct mtd_oob_buf32 {
1002 	u_int32_t start;
1003 	u_int32_t length;
1004 	compat_caddr_t ptr;	/* unsigned char* */
1005 };
1006 
1007 #define MEMWRITEOOB32		_IOWR('M', 3, struct mtd_oob_buf32)
1008 #define MEMREADOOB32		_IOWR('M', 4, struct mtd_oob_buf32)
1009 
1010 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1011 	unsigned long arg)
1012 {
1013 	struct mtd_file_info *mfi = file->private_data;
1014 	struct mtd_info *mtd = mfi->mtd;
1015 	void __user *argp = compat_ptr(arg);
1016 	int ret = 0;
1017 
1018 	mutex_lock(&mtd_mutex);
1019 
1020 	switch (cmd) {
1021 	case MEMWRITEOOB32:
1022 	{
1023 		struct mtd_oob_buf32 buf;
1024 		struct mtd_oob_buf32 __user *buf_user = argp;
1025 
1026 		if (copy_from_user(&buf, argp, sizeof(buf)))
1027 			ret = -EFAULT;
1028 		else
1029 			ret = mtdchar_writeoob(file, mtd, buf.start,
1030 				buf.length, compat_ptr(buf.ptr),
1031 				&buf_user->length);
1032 		break;
1033 	}
1034 
1035 	case MEMREADOOB32:
1036 	{
1037 		struct mtd_oob_buf32 buf;
1038 		struct mtd_oob_buf32 __user *buf_user = argp;
1039 
1040 		/* NOTE: writes return length to buf->start */
1041 		if (copy_from_user(&buf, argp, sizeof(buf)))
1042 			ret = -EFAULT;
1043 		else
1044 			ret = mtdchar_readoob(file, mtd, buf.start,
1045 				buf.length, compat_ptr(buf.ptr),
1046 				&buf_user->start);
1047 		break;
1048 	}
1049 	default:
1050 		ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1051 	}
1052 
1053 	mutex_unlock(&mtd_mutex);
1054 
1055 	return ret;
1056 }
1057 
1058 #endif /* CONFIG_COMPAT */
1059 
1060 /*
1061  * try to determine where a shared mapping can be made
1062  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1063  *   mappings)
1064  */
1065 #ifndef CONFIG_MMU
1066 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1067 					   unsigned long addr,
1068 					   unsigned long len,
1069 					   unsigned long pgoff,
1070 					   unsigned long flags)
1071 {
1072 	struct mtd_file_info *mfi = file->private_data;
1073 	struct mtd_info *mtd = mfi->mtd;
1074 	unsigned long offset;
1075 	int ret;
1076 
1077 	if (addr != 0)
1078 		return (unsigned long) -EINVAL;
1079 
1080 	if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1081 		return (unsigned long) -EINVAL;
1082 
1083 	offset = pgoff << PAGE_SHIFT;
1084 	if (offset > mtd->size - len)
1085 		return (unsigned long) -EINVAL;
1086 
1087 	ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1088 	return ret == -EOPNOTSUPP ? -ENODEV : ret;
1089 }
1090 
1091 static unsigned mtdchar_mmap_capabilities(struct file *file)
1092 {
1093 	struct mtd_file_info *mfi = file->private_data;
1094 
1095 	return mtd_mmap_capabilities(mfi->mtd);
1096 }
1097 #endif
1098 
1099 /*
1100  * set up a mapping for shared memory segments
1101  */
1102 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1103 {
1104 #ifdef CONFIG_MMU
1105 	struct mtd_file_info *mfi = file->private_data;
1106 	struct mtd_info *mtd = mfi->mtd;
1107 	struct map_info *map = mtd->priv;
1108 
1109         /* This is broken because it assumes the MTD device is map-based
1110 	   and that mtd->priv is a valid struct map_info.  It should be
1111 	   replaced with something that uses the mtd_get_unmapped_area()
1112 	   operation properly. */
1113 	if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1114 #ifdef pgprot_noncached
1115 		if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1116 			vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1117 #endif
1118 		return vm_iomap_memory(vma, map->phys, map->size);
1119 	}
1120 	return -ENODEV;
1121 #else
1122 	return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
1123 #endif
1124 }
1125 
1126 static const struct file_operations mtd_fops = {
1127 	.owner		= THIS_MODULE,
1128 	.llseek		= mtdchar_lseek,
1129 	.read		= mtdchar_read,
1130 	.write		= mtdchar_write,
1131 	.unlocked_ioctl	= mtdchar_unlocked_ioctl,
1132 #ifdef CONFIG_COMPAT
1133 	.compat_ioctl	= mtdchar_compat_ioctl,
1134 #endif
1135 	.open		= mtdchar_open,
1136 	.release	= mtdchar_close,
1137 	.mmap		= mtdchar_mmap,
1138 #ifndef CONFIG_MMU
1139 	.get_unmapped_area = mtdchar_get_unmapped_area,
1140 	.mmap_capabilities = mtdchar_mmap_capabilities,
1141 #endif
1142 };
1143 
1144 int __init init_mtdchar(void)
1145 {
1146 	int ret;
1147 
1148 	ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1149 				   "mtd", &mtd_fops);
1150 	if (ret < 0) {
1151 		pr_err("Can't allocate major number %d for MTD\n",
1152 		       MTD_CHAR_MAJOR);
1153 		return ret;
1154 	}
1155 
1156 	return ret;
1157 }
1158 
1159 void __exit cleanup_mtdchar(void)
1160 {
1161 	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1162 }
1163 
1164 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1165