xref: /openbmc/linux/drivers/mtd/mtdchar.c (revision 39b6f3aa)
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/mtd/mtd.h>
36 #include <linux/mtd/partitions.h>
37 #include <linux/mtd/map.h>
38 
39 #include <asm/uaccess.h>
40 
41 #include "mtdcore.h"
42 
43 static DEFINE_MUTEX(mtd_mutex);
44 
45 /*
46  * Data structure to hold the pointer to the mtd device as well
47  * as mode information of various use cases.
48  */
49 struct mtd_file_info {
50 	struct mtd_info *mtd;
51 	struct inode *ino;
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 	struct mtd_info *mtd = mfi->mtd;
59 
60 	switch (orig) {
61 	case SEEK_SET:
62 		break;
63 	case SEEK_CUR:
64 		offset += file->f_pos;
65 		break;
66 	case SEEK_END:
67 		offset += mtd->size;
68 		break;
69 	default:
70 		return -EINVAL;
71 	}
72 
73 	if (offset >= 0 && offset <= mtd->size)
74 		return file->f_pos = offset;
75 
76 	return -EINVAL;
77 }
78 
79 static int count;
80 static struct vfsmount *mnt;
81 static struct file_system_type mtd_inodefs_type;
82 
83 static int mtdchar_open(struct inode *inode, struct file *file)
84 {
85 	int minor = iminor(inode);
86 	int devnum = minor >> 1;
87 	int ret = 0;
88 	struct mtd_info *mtd;
89 	struct mtd_file_info *mfi;
90 	struct inode *mtd_ino;
91 
92 	pr_debug("MTD_open\n");
93 
94 	/* You can't open the RO devices RW */
95 	if ((file->f_mode & FMODE_WRITE) && (minor & 1))
96 		return -EACCES;
97 
98 	ret = simple_pin_fs(&mtd_inodefs_type, &mnt, &count);
99 	if (ret)
100 		return ret;
101 
102 	mutex_lock(&mtd_mutex);
103 	mtd = get_mtd_device(NULL, devnum);
104 
105 	if (IS_ERR(mtd)) {
106 		ret = PTR_ERR(mtd);
107 		goto out;
108 	}
109 
110 	if (mtd->type == MTD_ABSENT) {
111 		ret = -ENODEV;
112 		goto out1;
113 	}
114 
115 	mtd_ino = iget_locked(mnt->mnt_sb, devnum);
116 	if (!mtd_ino) {
117 		ret = -ENOMEM;
118 		goto out1;
119 	}
120 	if (mtd_ino->i_state & I_NEW) {
121 		mtd_ino->i_private = mtd;
122 		mtd_ino->i_mode = S_IFCHR;
123 		mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
124 		unlock_new_inode(mtd_ino);
125 	}
126 	file->f_mapping = mtd_ino->i_mapping;
127 
128 	/* You can't open it RW if it's not a writeable device */
129 	if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
130 		ret = -EACCES;
131 		goto out2;
132 	}
133 
134 	mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
135 	if (!mfi) {
136 		ret = -ENOMEM;
137 		goto out2;
138 	}
139 	mfi->ino = mtd_ino;
140 	mfi->mtd = mtd;
141 	file->private_data = mfi;
142 	mutex_unlock(&mtd_mutex);
143 	return 0;
144 
145 out2:
146 	iput(mtd_ino);
147 out1:
148 	put_mtd_device(mtd);
149 out:
150 	mutex_unlock(&mtd_mutex);
151 	simple_release_fs(&mnt, &count);
152 	return ret;
153 } /* mtdchar_open */
154 
155 /*====================================================================*/
156 
157 static int mtdchar_close(struct inode *inode, struct file *file)
158 {
159 	struct mtd_file_info *mfi = file->private_data;
160 	struct mtd_info *mtd = mfi->mtd;
161 
162 	pr_debug("MTD_close\n");
163 
164 	/* Only sync if opened RW */
165 	if ((file->f_mode & FMODE_WRITE))
166 		mtd_sync(mtd);
167 
168 	iput(mfi->ino);
169 
170 	put_mtd_device(mtd);
171 	file->private_data = NULL;
172 	kfree(mfi);
173 	simple_release_fs(&mnt, &count);
174 
175 	return 0;
176 } /* mtdchar_close */
177 
178 /* Back in June 2001, dwmw2 wrote:
179  *
180  *   FIXME: This _really_ needs to die. In 2.5, we should lock the
181  *   userspace buffer down and use it directly with readv/writev.
182  *
183  * The implementation below, using mtd_kmalloc_up_to, mitigates
184  * allocation failures when the system is under low-memory situations
185  * or if memory is highly fragmented at the cost of reducing the
186  * performance of the requested transfer due to a smaller buffer size.
187  *
188  * A more complex but more memory-efficient implementation based on
189  * get_user_pages and iovecs to cover extents of those pages is a
190  * longer-term goal, as intimated by dwmw2 above. However, for the
191  * write case, this requires yet more complex head and tail transfer
192  * handling when those head and tail offsets and sizes are such that
193  * alignment requirements are not met in the NAND subdriver.
194  */
195 
196 static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
197 			loff_t *ppos)
198 {
199 	struct mtd_file_info *mfi = file->private_data;
200 	struct mtd_info *mtd = mfi->mtd;
201 	size_t retlen;
202 	size_t total_retlen=0;
203 	int ret=0;
204 	int len;
205 	size_t size = count;
206 	char *kbuf;
207 
208 	pr_debug("MTD_read\n");
209 
210 	if (*ppos + count > mtd->size)
211 		count = mtd->size - *ppos;
212 
213 	if (!count)
214 		return 0;
215 
216 	kbuf = mtd_kmalloc_up_to(mtd, &size);
217 	if (!kbuf)
218 		return -ENOMEM;
219 
220 	while (count) {
221 		len = min_t(size_t, count, size);
222 
223 		switch (mfi->mode) {
224 		case MTD_FILE_MODE_OTP_FACTORY:
225 			ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
226 						     &retlen, kbuf);
227 			break;
228 		case MTD_FILE_MODE_OTP_USER:
229 			ret = mtd_read_user_prot_reg(mtd, *ppos, len,
230 						     &retlen, kbuf);
231 			break;
232 		case MTD_FILE_MODE_RAW:
233 		{
234 			struct mtd_oob_ops ops;
235 
236 			ops.mode = MTD_OPS_RAW;
237 			ops.datbuf = kbuf;
238 			ops.oobbuf = NULL;
239 			ops.len = len;
240 
241 			ret = mtd_read_oob(mtd, *ppos, &ops);
242 			retlen = ops.retlen;
243 			break;
244 		}
245 		default:
246 			ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
247 		}
248 		/* Nand returns -EBADMSG on ECC errors, but it returns
249 		 * the data. For our userspace tools it is important
250 		 * to dump areas with ECC errors!
251 		 * For kernel internal usage it also might return -EUCLEAN
252 		 * to signal the caller that a bitflip has occurred and has
253 		 * been corrected by the ECC algorithm.
254 		 * Userspace software which accesses NAND this way
255 		 * must be aware of the fact that it deals with NAND
256 		 */
257 		if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
258 			*ppos += retlen;
259 			if (copy_to_user(buf, kbuf, retlen)) {
260 				kfree(kbuf);
261 				return -EFAULT;
262 			}
263 			else
264 				total_retlen += retlen;
265 
266 			count -= retlen;
267 			buf += retlen;
268 			if (retlen == 0)
269 				count = 0;
270 		}
271 		else {
272 			kfree(kbuf);
273 			return ret;
274 		}
275 
276 	}
277 
278 	kfree(kbuf);
279 	return total_retlen;
280 } /* mtdchar_read */
281 
282 static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
283 			loff_t *ppos)
284 {
285 	struct mtd_file_info *mfi = file->private_data;
286 	struct mtd_info *mtd = mfi->mtd;
287 	size_t size = count;
288 	char *kbuf;
289 	size_t retlen;
290 	size_t total_retlen=0;
291 	int ret=0;
292 	int len;
293 
294 	pr_debug("MTD_write\n");
295 
296 	if (*ppos == mtd->size)
297 		return -ENOSPC;
298 
299 	if (*ppos + count > mtd->size)
300 		count = mtd->size - *ppos;
301 
302 	if (!count)
303 		return 0;
304 
305 	kbuf = mtd_kmalloc_up_to(mtd, &size);
306 	if (!kbuf)
307 		return -ENOMEM;
308 
309 	while (count) {
310 		len = min_t(size_t, count, size);
311 
312 		if (copy_from_user(kbuf, buf, len)) {
313 			kfree(kbuf);
314 			return -EFAULT;
315 		}
316 
317 		switch (mfi->mode) {
318 		case MTD_FILE_MODE_OTP_FACTORY:
319 			ret = -EROFS;
320 			break;
321 		case MTD_FILE_MODE_OTP_USER:
322 			ret = mtd_write_user_prot_reg(mtd, *ppos, len,
323 						      &retlen, kbuf);
324 			break;
325 
326 		case MTD_FILE_MODE_RAW:
327 		{
328 			struct mtd_oob_ops ops;
329 
330 			ops.mode = MTD_OPS_RAW;
331 			ops.datbuf = kbuf;
332 			ops.oobbuf = NULL;
333 			ops.ooboffs = 0;
334 			ops.len = len;
335 
336 			ret = mtd_write_oob(mtd, *ppos, &ops);
337 			retlen = ops.retlen;
338 			break;
339 		}
340 
341 		default:
342 			ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
343 		}
344 		if (!ret) {
345 			*ppos += retlen;
346 			total_retlen += retlen;
347 			count -= retlen;
348 			buf += retlen;
349 		}
350 		else {
351 			kfree(kbuf);
352 			return ret;
353 		}
354 	}
355 
356 	kfree(kbuf);
357 	return total_retlen;
358 } /* mtdchar_write */
359 
360 /*======================================================================
361 
362     IOCTL calls for getting device parameters.
363 
364 ======================================================================*/
365 static void mtdchar_erase_callback (struct erase_info *instr)
366 {
367 	wake_up((wait_queue_head_t *)instr->priv);
368 }
369 
370 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
371 {
372 	struct mtd_info *mtd = mfi->mtd;
373 	size_t retlen;
374 
375 	switch (mode) {
376 	case MTD_OTP_FACTORY:
377 		if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
378 				-EOPNOTSUPP)
379 			return -EOPNOTSUPP;
380 
381 		mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
382 		break;
383 	case MTD_OTP_USER:
384 		if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
385 				-EOPNOTSUPP)
386 			return -EOPNOTSUPP;
387 
388 		mfi->mode = MTD_FILE_MODE_OTP_USER;
389 		break;
390 	case MTD_OTP_OFF:
391 		mfi->mode = MTD_FILE_MODE_NORMAL;
392 		break;
393 	default:
394 		return -EINVAL;
395 	}
396 
397 	return 0;
398 }
399 
400 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
401 	uint64_t start, uint32_t length, void __user *ptr,
402 	uint32_t __user *retp)
403 {
404 	struct mtd_file_info *mfi = file->private_data;
405 	struct mtd_oob_ops ops;
406 	uint32_t retlen;
407 	int ret = 0;
408 
409 	if (!(file->f_mode & FMODE_WRITE))
410 		return -EPERM;
411 
412 	if (length > 4096)
413 		return -EINVAL;
414 
415 	if (!mtd->_write_oob)
416 		ret = -EOPNOTSUPP;
417 	else
418 		ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
419 
420 	if (ret)
421 		return ret;
422 
423 	ops.ooblen = length;
424 	ops.ooboffs = start & (mtd->writesize - 1);
425 	ops.datbuf = NULL;
426 	ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
427 		MTD_OPS_PLACE_OOB;
428 
429 	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
430 		return -EINVAL;
431 
432 	ops.oobbuf = memdup_user(ptr, length);
433 	if (IS_ERR(ops.oobbuf))
434 		return PTR_ERR(ops.oobbuf);
435 
436 	start &= ~((uint64_t)mtd->writesize - 1);
437 	ret = mtd_write_oob(mtd, start, &ops);
438 
439 	if (ops.oobretlen > 0xFFFFFFFFU)
440 		ret = -EOVERFLOW;
441 	retlen = ops.oobretlen;
442 	if (copy_to_user(retp, &retlen, sizeof(length)))
443 		ret = -EFAULT;
444 
445 	kfree(ops.oobbuf);
446 	return ret;
447 }
448 
449 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
450 	uint64_t start, uint32_t length, void __user *ptr,
451 	uint32_t __user *retp)
452 {
453 	struct mtd_file_info *mfi = file->private_data;
454 	struct mtd_oob_ops ops;
455 	int ret = 0;
456 
457 	if (length > 4096)
458 		return -EINVAL;
459 
460 	if (!access_ok(VERIFY_WRITE, ptr, length))
461 		return -EFAULT;
462 
463 	ops.ooblen = length;
464 	ops.ooboffs = start & (mtd->writesize - 1);
465 	ops.datbuf = NULL;
466 	ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
467 		MTD_OPS_PLACE_OOB;
468 
469 	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
470 		return -EINVAL;
471 
472 	ops.oobbuf = kmalloc(length, GFP_KERNEL);
473 	if (!ops.oobbuf)
474 		return -ENOMEM;
475 
476 	start &= ~((uint64_t)mtd->writesize - 1);
477 	ret = mtd_read_oob(mtd, start, &ops);
478 
479 	if (put_user(ops.oobretlen, retp))
480 		ret = -EFAULT;
481 	else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
482 					    ops.oobretlen))
483 		ret = -EFAULT;
484 
485 	kfree(ops.oobbuf);
486 
487 	/*
488 	 * NAND returns -EBADMSG on ECC errors, but it returns the OOB
489 	 * data. For our userspace tools it is important to dump areas
490 	 * with ECC errors!
491 	 * For kernel internal usage it also might return -EUCLEAN
492 	 * to signal the caller that a bitflip has occured and has
493 	 * been corrected by the ECC algorithm.
494 	 *
495 	 * Note: currently the standard NAND function, nand_read_oob_std,
496 	 * does not calculate ECC for the OOB area, so do not rely on
497 	 * this behavior unless you have replaced it with your own.
498 	 */
499 	if (mtd_is_bitflip_or_eccerr(ret))
500 		return 0;
501 
502 	return ret;
503 }
504 
505 /*
506  * Copies (and truncates, if necessary) data from the larger struct,
507  * nand_ecclayout, to the smaller, deprecated layout struct,
508  * nand_ecclayout_user. This is necessary only to support the deprecated
509  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
510  * nand_ecclayout flexibly (i.e. the struct may change size in new
511  * releases without requiring major rewrites).
512  */
513 static int shrink_ecclayout(const struct nand_ecclayout *from,
514 		struct nand_ecclayout_user *to)
515 {
516 	int i;
517 
518 	if (!from || !to)
519 		return -EINVAL;
520 
521 	memset(to, 0, sizeof(*to));
522 
523 	to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
524 	for (i = 0; i < to->eccbytes; i++)
525 		to->eccpos[i] = from->eccpos[i];
526 
527 	for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
528 		if (from->oobfree[i].length == 0 &&
529 				from->oobfree[i].offset == 0)
530 			break;
531 		to->oobavail += from->oobfree[i].length;
532 		to->oobfree[i] = from->oobfree[i];
533 	}
534 
535 	return 0;
536 }
537 
538 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
539 			   struct blkpg_ioctl_arg __user *arg)
540 {
541 	struct blkpg_ioctl_arg a;
542 	struct blkpg_partition p;
543 
544 	if (!capable(CAP_SYS_ADMIN))
545 		return -EPERM;
546 
547 	if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
548 		return -EFAULT;
549 
550 	if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
551 		return -EFAULT;
552 
553 	switch (a.op) {
554 	case BLKPG_ADD_PARTITION:
555 
556 		/* Only master mtd device must be used to add partitions */
557 		if (mtd_is_partition(mtd))
558 			return -EINVAL;
559 
560 		return mtd_add_partition(mtd, p.devname, p.start, p.length);
561 
562 	case BLKPG_DEL_PARTITION:
563 
564 		if (p.pno < 0)
565 			return -EINVAL;
566 
567 		return mtd_del_partition(mtd, p.pno);
568 
569 	default:
570 		return -EINVAL;
571 	}
572 }
573 
574 static int mtdchar_write_ioctl(struct mtd_info *mtd,
575 		struct mtd_write_req __user *argp)
576 {
577 	struct mtd_write_req req;
578 	struct mtd_oob_ops ops;
579 	void __user *usr_data, *usr_oob;
580 	int ret;
581 
582 	if (copy_from_user(&req, argp, sizeof(req)) ||
583 			!access_ok(VERIFY_READ, req.usr_data, req.len) ||
584 			!access_ok(VERIFY_READ, req.usr_oob, req.ooblen))
585 		return -EFAULT;
586 	if (!mtd->_write_oob)
587 		return -EOPNOTSUPP;
588 
589 	ops.mode = req.mode;
590 	ops.len = (size_t)req.len;
591 	ops.ooblen = (size_t)req.ooblen;
592 	ops.ooboffs = 0;
593 
594 	usr_data = (void __user *)(uintptr_t)req.usr_data;
595 	usr_oob = (void __user *)(uintptr_t)req.usr_oob;
596 
597 	if (req.usr_data) {
598 		ops.datbuf = memdup_user(usr_data, ops.len);
599 		if (IS_ERR(ops.datbuf))
600 			return PTR_ERR(ops.datbuf);
601 	} else {
602 		ops.datbuf = NULL;
603 	}
604 
605 	if (req.usr_oob) {
606 		ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
607 		if (IS_ERR(ops.oobbuf)) {
608 			kfree(ops.datbuf);
609 			return PTR_ERR(ops.oobbuf);
610 		}
611 	} else {
612 		ops.oobbuf = NULL;
613 	}
614 
615 	ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
616 
617 	kfree(ops.datbuf);
618 	kfree(ops.oobbuf);
619 
620 	return ret;
621 }
622 
623 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
624 {
625 	struct mtd_file_info *mfi = file->private_data;
626 	struct mtd_info *mtd = mfi->mtd;
627 	void __user *argp = (void __user *)arg;
628 	int ret = 0;
629 	u_long size;
630 	struct mtd_info_user info;
631 
632 	pr_debug("MTD_ioctl\n");
633 
634 	size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
635 	if (cmd & IOC_IN) {
636 		if (!access_ok(VERIFY_READ, argp, size))
637 			return -EFAULT;
638 	}
639 	if (cmd & IOC_OUT) {
640 		if (!access_ok(VERIFY_WRITE, argp, size))
641 			return -EFAULT;
642 	}
643 
644 	switch (cmd) {
645 	case MEMGETREGIONCOUNT:
646 		if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
647 			return -EFAULT;
648 		break;
649 
650 	case MEMGETREGIONINFO:
651 	{
652 		uint32_t ur_idx;
653 		struct mtd_erase_region_info *kr;
654 		struct region_info_user __user *ur = argp;
655 
656 		if (get_user(ur_idx, &(ur->regionindex)))
657 			return -EFAULT;
658 
659 		if (ur_idx >= mtd->numeraseregions)
660 			return -EINVAL;
661 
662 		kr = &(mtd->eraseregions[ur_idx]);
663 
664 		if (put_user(kr->offset, &(ur->offset))
665 		    || put_user(kr->erasesize, &(ur->erasesize))
666 		    || put_user(kr->numblocks, &(ur->numblocks)))
667 			return -EFAULT;
668 
669 		break;
670 	}
671 
672 	case MEMGETINFO:
673 		memset(&info, 0, sizeof(info));
674 		info.type	= mtd->type;
675 		info.flags	= mtd->flags;
676 		info.size	= mtd->size;
677 		info.erasesize	= mtd->erasesize;
678 		info.writesize	= mtd->writesize;
679 		info.oobsize	= mtd->oobsize;
680 		/* The below field is obsolete */
681 		info.padding	= 0;
682 		if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
683 			return -EFAULT;
684 		break;
685 
686 	case MEMERASE:
687 	case MEMERASE64:
688 	{
689 		struct erase_info *erase;
690 
691 		if(!(file->f_mode & FMODE_WRITE))
692 			return -EPERM;
693 
694 		erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
695 		if (!erase)
696 			ret = -ENOMEM;
697 		else {
698 			wait_queue_head_t waitq;
699 			DECLARE_WAITQUEUE(wait, current);
700 
701 			init_waitqueue_head(&waitq);
702 
703 			if (cmd == MEMERASE64) {
704 				struct erase_info_user64 einfo64;
705 
706 				if (copy_from_user(&einfo64, argp,
707 					    sizeof(struct erase_info_user64))) {
708 					kfree(erase);
709 					return -EFAULT;
710 				}
711 				erase->addr = einfo64.start;
712 				erase->len = einfo64.length;
713 			} else {
714 				struct erase_info_user einfo32;
715 
716 				if (copy_from_user(&einfo32, argp,
717 					    sizeof(struct erase_info_user))) {
718 					kfree(erase);
719 					return -EFAULT;
720 				}
721 				erase->addr = einfo32.start;
722 				erase->len = einfo32.length;
723 			}
724 			erase->mtd = mtd;
725 			erase->callback = mtdchar_erase_callback;
726 			erase->priv = (unsigned long)&waitq;
727 
728 			/*
729 			  FIXME: Allow INTERRUPTIBLE. Which means
730 			  not having the wait_queue head on the stack.
731 
732 			  If the wq_head is on the stack, and we
733 			  leave because we got interrupted, then the
734 			  wq_head is no longer there when the
735 			  callback routine tries to wake us up.
736 			*/
737 			ret = mtd_erase(mtd, erase);
738 			if (!ret) {
739 				set_current_state(TASK_UNINTERRUPTIBLE);
740 				add_wait_queue(&waitq, &wait);
741 				if (erase->state != MTD_ERASE_DONE &&
742 				    erase->state != MTD_ERASE_FAILED)
743 					schedule();
744 				remove_wait_queue(&waitq, &wait);
745 				set_current_state(TASK_RUNNING);
746 
747 				ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
748 			}
749 			kfree(erase);
750 		}
751 		break;
752 	}
753 
754 	case MEMWRITEOOB:
755 	{
756 		struct mtd_oob_buf buf;
757 		struct mtd_oob_buf __user *buf_user = argp;
758 
759 		/* NOTE: writes return length to buf_user->length */
760 		if (copy_from_user(&buf, argp, sizeof(buf)))
761 			ret = -EFAULT;
762 		else
763 			ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
764 				buf.ptr, &buf_user->length);
765 		break;
766 	}
767 
768 	case MEMREADOOB:
769 	{
770 		struct mtd_oob_buf buf;
771 		struct mtd_oob_buf __user *buf_user = argp;
772 
773 		/* NOTE: writes return length to buf_user->start */
774 		if (copy_from_user(&buf, argp, sizeof(buf)))
775 			ret = -EFAULT;
776 		else
777 			ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
778 				buf.ptr, &buf_user->start);
779 		break;
780 	}
781 
782 	case MEMWRITEOOB64:
783 	{
784 		struct mtd_oob_buf64 buf;
785 		struct mtd_oob_buf64 __user *buf_user = argp;
786 
787 		if (copy_from_user(&buf, argp, sizeof(buf)))
788 			ret = -EFAULT;
789 		else
790 			ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
791 				(void __user *)(uintptr_t)buf.usr_ptr,
792 				&buf_user->length);
793 		break;
794 	}
795 
796 	case MEMREADOOB64:
797 	{
798 		struct mtd_oob_buf64 buf;
799 		struct mtd_oob_buf64 __user *buf_user = argp;
800 
801 		if (copy_from_user(&buf, argp, sizeof(buf)))
802 			ret = -EFAULT;
803 		else
804 			ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
805 				(void __user *)(uintptr_t)buf.usr_ptr,
806 				&buf_user->length);
807 		break;
808 	}
809 
810 	case MEMWRITE:
811 	{
812 		ret = mtdchar_write_ioctl(mtd,
813 		      (struct mtd_write_req __user *)arg);
814 		break;
815 	}
816 
817 	case MEMLOCK:
818 	{
819 		struct erase_info_user einfo;
820 
821 		if (copy_from_user(&einfo, argp, sizeof(einfo)))
822 			return -EFAULT;
823 
824 		ret = mtd_lock(mtd, einfo.start, einfo.length);
825 		break;
826 	}
827 
828 	case MEMUNLOCK:
829 	{
830 		struct erase_info_user einfo;
831 
832 		if (copy_from_user(&einfo, argp, sizeof(einfo)))
833 			return -EFAULT;
834 
835 		ret = mtd_unlock(mtd, einfo.start, einfo.length);
836 		break;
837 	}
838 
839 	case MEMISLOCKED:
840 	{
841 		struct erase_info_user einfo;
842 
843 		if (copy_from_user(&einfo, argp, sizeof(einfo)))
844 			return -EFAULT;
845 
846 		ret = mtd_is_locked(mtd, einfo.start, einfo.length);
847 		break;
848 	}
849 
850 	/* Legacy interface */
851 	case MEMGETOOBSEL:
852 	{
853 		struct nand_oobinfo oi;
854 
855 		if (!mtd->ecclayout)
856 			return -EOPNOTSUPP;
857 		if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
858 			return -EINVAL;
859 
860 		oi.useecc = MTD_NANDECC_AUTOPLACE;
861 		memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
862 		memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
863 		       sizeof(oi.oobfree));
864 		oi.eccbytes = mtd->ecclayout->eccbytes;
865 
866 		if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
867 			return -EFAULT;
868 		break;
869 	}
870 
871 	case MEMGETBADBLOCK:
872 	{
873 		loff_t offs;
874 
875 		if (copy_from_user(&offs, argp, sizeof(loff_t)))
876 			return -EFAULT;
877 		return mtd_block_isbad(mtd, offs);
878 		break;
879 	}
880 
881 	case MEMSETBADBLOCK:
882 	{
883 		loff_t offs;
884 
885 		if (copy_from_user(&offs, argp, sizeof(loff_t)))
886 			return -EFAULT;
887 		return mtd_block_markbad(mtd, offs);
888 		break;
889 	}
890 
891 	case OTPSELECT:
892 	{
893 		int mode;
894 		if (copy_from_user(&mode, argp, sizeof(int)))
895 			return -EFAULT;
896 
897 		mfi->mode = MTD_FILE_MODE_NORMAL;
898 
899 		ret = otp_select_filemode(mfi, mode);
900 
901 		file->f_pos = 0;
902 		break;
903 	}
904 
905 	case OTPGETREGIONCOUNT:
906 	case OTPGETREGIONINFO:
907 	{
908 		struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
909 		if (!buf)
910 			return -ENOMEM;
911 		switch (mfi->mode) {
912 		case MTD_FILE_MODE_OTP_FACTORY:
913 			ret = mtd_get_fact_prot_info(mtd, buf, 4096);
914 			break;
915 		case MTD_FILE_MODE_OTP_USER:
916 			ret = mtd_get_user_prot_info(mtd, buf, 4096);
917 			break;
918 		default:
919 			ret = -EINVAL;
920 			break;
921 		}
922 		if (ret >= 0) {
923 			if (cmd == OTPGETREGIONCOUNT) {
924 				int nbr = ret / sizeof(struct otp_info);
925 				ret = copy_to_user(argp, &nbr, sizeof(int));
926 			} else
927 				ret = copy_to_user(argp, buf, ret);
928 			if (ret)
929 				ret = -EFAULT;
930 		}
931 		kfree(buf);
932 		break;
933 	}
934 
935 	case OTPLOCK:
936 	{
937 		struct otp_info oinfo;
938 
939 		if (mfi->mode != MTD_FILE_MODE_OTP_USER)
940 			return -EINVAL;
941 		if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
942 			return -EFAULT;
943 		ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
944 		break;
945 	}
946 
947 	/* This ioctl is being deprecated - it truncates the ECC layout */
948 	case ECCGETLAYOUT:
949 	{
950 		struct nand_ecclayout_user *usrlay;
951 
952 		if (!mtd->ecclayout)
953 			return -EOPNOTSUPP;
954 
955 		usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
956 		if (!usrlay)
957 			return -ENOMEM;
958 
959 		shrink_ecclayout(mtd->ecclayout, usrlay);
960 
961 		if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
962 			ret = -EFAULT;
963 		kfree(usrlay);
964 		break;
965 	}
966 
967 	case ECCGETSTATS:
968 	{
969 		if (copy_to_user(argp, &mtd->ecc_stats,
970 				 sizeof(struct mtd_ecc_stats)))
971 			return -EFAULT;
972 		break;
973 	}
974 
975 	case MTDFILEMODE:
976 	{
977 		mfi->mode = 0;
978 
979 		switch(arg) {
980 		case MTD_FILE_MODE_OTP_FACTORY:
981 		case MTD_FILE_MODE_OTP_USER:
982 			ret = otp_select_filemode(mfi, arg);
983 			break;
984 
985 		case MTD_FILE_MODE_RAW:
986 			if (!mtd_has_oob(mtd))
987 				return -EOPNOTSUPP;
988 			mfi->mode = arg;
989 
990 		case MTD_FILE_MODE_NORMAL:
991 			break;
992 		default:
993 			ret = -EINVAL;
994 		}
995 		file->f_pos = 0;
996 		break;
997 	}
998 
999 	case BLKPG:
1000 	{
1001 		ret = mtdchar_blkpg_ioctl(mtd,
1002 		      (struct blkpg_ioctl_arg __user *)arg);
1003 		break;
1004 	}
1005 
1006 	case BLKRRPART:
1007 	{
1008 		/* No reread partition feature. Just return ok */
1009 		ret = 0;
1010 		break;
1011 	}
1012 
1013 	default:
1014 		ret = -ENOTTY;
1015 	}
1016 
1017 	return ret;
1018 } /* memory_ioctl */
1019 
1020 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1021 {
1022 	int ret;
1023 
1024 	mutex_lock(&mtd_mutex);
1025 	ret = mtdchar_ioctl(file, cmd, arg);
1026 	mutex_unlock(&mtd_mutex);
1027 
1028 	return ret;
1029 }
1030 
1031 #ifdef CONFIG_COMPAT
1032 
1033 struct mtd_oob_buf32 {
1034 	u_int32_t start;
1035 	u_int32_t length;
1036 	compat_caddr_t ptr;	/* unsigned char* */
1037 };
1038 
1039 #define MEMWRITEOOB32		_IOWR('M', 3, struct mtd_oob_buf32)
1040 #define MEMREADOOB32		_IOWR('M', 4, struct mtd_oob_buf32)
1041 
1042 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1043 	unsigned long arg)
1044 {
1045 	struct mtd_file_info *mfi = file->private_data;
1046 	struct mtd_info *mtd = mfi->mtd;
1047 	void __user *argp = compat_ptr(arg);
1048 	int ret = 0;
1049 
1050 	mutex_lock(&mtd_mutex);
1051 
1052 	switch (cmd) {
1053 	case MEMWRITEOOB32:
1054 	{
1055 		struct mtd_oob_buf32 buf;
1056 		struct mtd_oob_buf32 __user *buf_user = argp;
1057 
1058 		if (copy_from_user(&buf, argp, sizeof(buf)))
1059 			ret = -EFAULT;
1060 		else
1061 			ret = mtdchar_writeoob(file, mtd, buf.start,
1062 				buf.length, compat_ptr(buf.ptr),
1063 				&buf_user->length);
1064 		break;
1065 	}
1066 
1067 	case MEMREADOOB32:
1068 	{
1069 		struct mtd_oob_buf32 buf;
1070 		struct mtd_oob_buf32 __user *buf_user = argp;
1071 
1072 		/* NOTE: writes return length to buf->start */
1073 		if (copy_from_user(&buf, argp, sizeof(buf)))
1074 			ret = -EFAULT;
1075 		else
1076 			ret = mtdchar_readoob(file, mtd, buf.start,
1077 				buf.length, compat_ptr(buf.ptr),
1078 				&buf_user->start);
1079 		break;
1080 	}
1081 	default:
1082 		ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1083 	}
1084 
1085 	mutex_unlock(&mtd_mutex);
1086 
1087 	return ret;
1088 }
1089 
1090 #endif /* CONFIG_COMPAT */
1091 
1092 /*
1093  * try to determine where a shared mapping can be made
1094  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1095  *   mappings)
1096  */
1097 #ifndef CONFIG_MMU
1098 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1099 					   unsigned long addr,
1100 					   unsigned long len,
1101 					   unsigned long pgoff,
1102 					   unsigned long flags)
1103 {
1104 	struct mtd_file_info *mfi = file->private_data;
1105 	struct mtd_info *mtd = mfi->mtd;
1106 	unsigned long offset;
1107 	int ret;
1108 
1109 	if (addr != 0)
1110 		return (unsigned long) -EINVAL;
1111 
1112 	if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1113 		return (unsigned long) -EINVAL;
1114 
1115 	offset = pgoff << PAGE_SHIFT;
1116 	if (offset > mtd->size - len)
1117 		return (unsigned long) -EINVAL;
1118 
1119 	ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1120 	return ret == -EOPNOTSUPP ? -ENOSYS : ret;
1121 }
1122 #endif
1123 
1124 /*
1125  * set up a mapping for shared memory segments
1126  */
1127 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1128 {
1129 #ifdef CONFIG_MMU
1130 	struct mtd_file_info *mfi = file->private_data;
1131 	struct mtd_info *mtd = mfi->mtd;
1132 	struct map_info *map = mtd->priv;
1133 
1134         /* This is broken because it assumes the MTD device is map-based
1135 	   and that mtd->priv is a valid struct map_info.  It should be
1136 	   replaced with something that uses the mtd_get_unmapped_area()
1137 	   operation properly. */
1138 	if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1139 #ifdef pgprot_noncached
1140 		if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1141 			vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1142 #endif
1143 		return vm_iomap_memory(vma, map->phys, map->size);
1144 	}
1145 	return -ENOSYS;
1146 #else
1147 	return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1148 #endif
1149 }
1150 
1151 static const struct file_operations mtd_fops = {
1152 	.owner		= THIS_MODULE,
1153 	.llseek		= mtdchar_lseek,
1154 	.read		= mtdchar_read,
1155 	.write		= mtdchar_write,
1156 	.unlocked_ioctl	= mtdchar_unlocked_ioctl,
1157 #ifdef CONFIG_COMPAT
1158 	.compat_ioctl	= mtdchar_compat_ioctl,
1159 #endif
1160 	.open		= mtdchar_open,
1161 	.release	= mtdchar_close,
1162 	.mmap		= mtdchar_mmap,
1163 #ifndef CONFIG_MMU
1164 	.get_unmapped_area = mtdchar_get_unmapped_area,
1165 #endif
1166 };
1167 
1168 static const struct super_operations mtd_ops = {
1169 	.drop_inode = generic_delete_inode,
1170 	.statfs = simple_statfs,
1171 };
1172 
1173 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1174 				int flags, const char *dev_name, void *data)
1175 {
1176 	return mount_pseudo(fs_type, "mtd_inode:", &mtd_ops, NULL, MTD_INODE_FS_MAGIC);
1177 }
1178 
1179 static struct file_system_type mtd_inodefs_type = {
1180        .name = "mtd_inodefs",
1181        .mount = mtd_inodefs_mount,
1182        .kill_sb = kill_anon_super,
1183 };
1184 MODULE_ALIAS_FS("mtd_inodefs");
1185 
1186 int __init init_mtdchar(void)
1187 {
1188 	int ret;
1189 
1190 	ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1191 				   "mtd", &mtd_fops);
1192 	if (ret < 0) {
1193 		pr_err("Can't allocate major number %d for MTD\n",
1194 		       MTD_CHAR_MAJOR);
1195 		return ret;
1196 	}
1197 
1198 	ret = register_filesystem(&mtd_inodefs_type);
1199 	if (ret) {
1200 		pr_err("Can't register mtd_inodefs filesystem, error %d\n",
1201 		       ret);
1202 		goto err_unregister_chdev;
1203 	}
1204 
1205 	return ret;
1206 
1207 err_unregister_chdev:
1208 	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1209 	return ret;
1210 }
1211 
1212 void __exit cleanup_mtdchar(void)
1213 {
1214 	unregister_filesystem(&mtd_inodefs_type);
1215 	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1216 }
1217 
1218 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1219