xref: /openbmc/linux/drivers/mtd/mtdchar.c (revision e23feb16)
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 	return fixed_size_llseek(file, offset, orig, mfi->mtd->size);
59 }
60 
61 static int count;
62 static struct vfsmount *mnt;
63 static struct file_system_type mtd_inodefs_type;
64 
65 static int mtdchar_open(struct inode *inode, struct file *file)
66 {
67 	int minor = iminor(inode);
68 	int devnum = minor >> 1;
69 	int ret = 0;
70 	struct mtd_info *mtd;
71 	struct mtd_file_info *mfi;
72 	struct inode *mtd_ino;
73 
74 	pr_debug("MTD_open\n");
75 
76 	/* You can't open the RO devices RW */
77 	if ((file->f_mode & FMODE_WRITE) && (minor & 1))
78 		return -EACCES;
79 
80 	ret = simple_pin_fs(&mtd_inodefs_type, &mnt, &count);
81 	if (ret)
82 		return ret;
83 
84 	mutex_lock(&mtd_mutex);
85 	mtd = get_mtd_device(NULL, devnum);
86 
87 	if (IS_ERR(mtd)) {
88 		ret = PTR_ERR(mtd);
89 		goto out;
90 	}
91 
92 	if (mtd->type == MTD_ABSENT) {
93 		ret = -ENODEV;
94 		goto out1;
95 	}
96 
97 	mtd_ino = iget_locked(mnt->mnt_sb, devnum);
98 	if (!mtd_ino) {
99 		ret = -ENOMEM;
100 		goto out1;
101 	}
102 	if (mtd_ino->i_state & I_NEW) {
103 		mtd_ino->i_private = mtd;
104 		mtd_ino->i_mode = S_IFCHR;
105 		mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
106 		unlock_new_inode(mtd_ino);
107 	}
108 	file->f_mapping = mtd_ino->i_mapping;
109 
110 	/* You can't open it RW if it's not a writeable device */
111 	if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
112 		ret = -EACCES;
113 		goto out2;
114 	}
115 
116 	mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
117 	if (!mfi) {
118 		ret = -ENOMEM;
119 		goto out2;
120 	}
121 	mfi->ino = mtd_ino;
122 	mfi->mtd = mtd;
123 	file->private_data = mfi;
124 	mutex_unlock(&mtd_mutex);
125 	return 0;
126 
127 out2:
128 	iput(mtd_ino);
129 out1:
130 	put_mtd_device(mtd);
131 out:
132 	mutex_unlock(&mtd_mutex);
133 	simple_release_fs(&mnt, &count);
134 	return ret;
135 } /* mtdchar_open */
136 
137 /*====================================================================*/
138 
139 static int mtdchar_close(struct inode *inode, struct file *file)
140 {
141 	struct mtd_file_info *mfi = file->private_data;
142 	struct mtd_info *mtd = mfi->mtd;
143 
144 	pr_debug("MTD_close\n");
145 
146 	/* Only sync if opened RW */
147 	if ((file->f_mode & FMODE_WRITE))
148 		mtd_sync(mtd);
149 
150 	iput(mfi->ino);
151 
152 	put_mtd_device(mtd);
153 	file->private_data = NULL;
154 	kfree(mfi);
155 	simple_release_fs(&mnt, &count);
156 
157 	return 0;
158 } /* mtdchar_close */
159 
160 /* Back in June 2001, dwmw2 wrote:
161  *
162  *   FIXME: This _really_ needs to die. In 2.5, we should lock the
163  *   userspace buffer down and use it directly with readv/writev.
164  *
165  * The implementation below, using mtd_kmalloc_up_to, mitigates
166  * allocation failures when the system is under low-memory situations
167  * or if memory is highly fragmented at the cost of reducing the
168  * performance of the requested transfer due to a smaller buffer size.
169  *
170  * A more complex but more memory-efficient implementation based on
171  * get_user_pages and iovecs to cover extents of those pages is a
172  * longer-term goal, as intimated by dwmw2 above. However, for the
173  * write case, this requires yet more complex head and tail transfer
174  * handling when those head and tail offsets and sizes are such that
175  * alignment requirements are not met in the NAND subdriver.
176  */
177 
178 static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
179 			loff_t *ppos)
180 {
181 	struct mtd_file_info *mfi = file->private_data;
182 	struct mtd_info *mtd = mfi->mtd;
183 	size_t retlen;
184 	size_t total_retlen=0;
185 	int ret=0;
186 	int len;
187 	size_t size = count;
188 	char *kbuf;
189 
190 	pr_debug("MTD_read\n");
191 
192 	if (*ppos + count > mtd->size)
193 		count = mtd->size - *ppos;
194 
195 	if (!count)
196 		return 0;
197 
198 	kbuf = mtd_kmalloc_up_to(mtd, &size);
199 	if (!kbuf)
200 		return -ENOMEM;
201 
202 	while (count) {
203 		len = min_t(size_t, count, size);
204 
205 		switch (mfi->mode) {
206 		case MTD_FILE_MODE_OTP_FACTORY:
207 			ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
208 						     &retlen, kbuf);
209 			break;
210 		case MTD_FILE_MODE_OTP_USER:
211 			ret = mtd_read_user_prot_reg(mtd, *ppos, len,
212 						     &retlen, kbuf);
213 			break;
214 		case MTD_FILE_MODE_RAW:
215 		{
216 			struct mtd_oob_ops ops;
217 
218 			ops.mode = MTD_OPS_RAW;
219 			ops.datbuf = kbuf;
220 			ops.oobbuf = NULL;
221 			ops.len = len;
222 
223 			ret = mtd_read_oob(mtd, *ppos, &ops);
224 			retlen = ops.retlen;
225 			break;
226 		}
227 		default:
228 			ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
229 		}
230 		/* Nand returns -EBADMSG on ECC errors, but it returns
231 		 * the data. For our userspace tools it is important
232 		 * to dump areas with ECC errors!
233 		 * For kernel internal usage it also might return -EUCLEAN
234 		 * to signal the caller that a bitflip has occurred and has
235 		 * been corrected by the ECC algorithm.
236 		 * Userspace software which accesses NAND this way
237 		 * must be aware of the fact that it deals with NAND
238 		 */
239 		if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
240 			*ppos += retlen;
241 			if (copy_to_user(buf, kbuf, retlen)) {
242 				kfree(kbuf);
243 				return -EFAULT;
244 			}
245 			else
246 				total_retlen += retlen;
247 
248 			count -= retlen;
249 			buf += retlen;
250 			if (retlen == 0)
251 				count = 0;
252 		}
253 		else {
254 			kfree(kbuf);
255 			return ret;
256 		}
257 
258 	}
259 
260 	kfree(kbuf);
261 	return total_retlen;
262 } /* mtdchar_read */
263 
264 static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
265 			loff_t *ppos)
266 {
267 	struct mtd_file_info *mfi = file->private_data;
268 	struct mtd_info *mtd = mfi->mtd;
269 	size_t size = count;
270 	char *kbuf;
271 	size_t retlen;
272 	size_t total_retlen=0;
273 	int ret=0;
274 	int len;
275 
276 	pr_debug("MTD_write\n");
277 
278 	if (*ppos == mtd->size)
279 		return -ENOSPC;
280 
281 	if (*ppos + count > mtd->size)
282 		count = mtd->size - *ppos;
283 
284 	if (!count)
285 		return 0;
286 
287 	kbuf = mtd_kmalloc_up_to(mtd, &size);
288 	if (!kbuf)
289 		return -ENOMEM;
290 
291 	while (count) {
292 		len = min_t(size_t, count, size);
293 
294 		if (copy_from_user(kbuf, buf, len)) {
295 			kfree(kbuf);
296 			return -EFAULT;
297 		}
298 
299 		switch (mfi->mode) {
300 		case MTD_FILE_MODE_OTP_FACTORY:
301 			ret = -EROFS;
302 			break;
303 		case MTD_FILE_MODE_OTP_USER:
304 			ret = mtd_write_user_prot_reg(mtd, *ppos, len,
305 						      &retlen, kbuf);
306 			break;
307 
308 		case MTD_FILE_MODE_RAW:
309 		{
310 			struct mtd_oob_ops ops;
311 
312 			ops.mode = MTD_OPS_RAW;
313 			ops.datbuf = kbuf;
314 			ops.oobbuf = NULL;
315 			ops.ooboffs = 0;
316 			ops.len = len;
317 
318 			ret = mtd_write_oob(mtd, *ppos, &ops);
319 			retlen = ops.retlen;
320 			break;
321 		}
322 
323 		default:
324 			ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
325 		}
326 		if (!ret) {
327 			*ppos += retlen;
328 			total_retlen += retlen;
329 			count -= retlen;
330 			buf += retlen;
331 		}
332 		else {
333 			kfree(kbuf);
334 			return ret;
335 		}
336 	}
337 
338 	kfree(kbuf);
339 	return total_retlen;
340 } /* mtdchar_write */
341 
342 /*======================================================================
343 
344     IOCTL calls for getting device parameters.
345 
346 ======================================================================*/
347 static void mtdchar_erase_callback (struct erase_info *instr)
348 {
349 	wake_up((wait_queue_head_t *)instr->priv);
350 }
351 
352 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
353 {
354 	struct mtd_info *mtd = mfi->mtd;
355 	size_t retlen;
356 
357 	switch (mode) {
358 	case MTD_OTP_FACTORY:
359 		if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
360 				-EOPNOTSUPP)
361 			return -EOPNOTSUPP;
362 
363 		mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
364 		break;
365 	case MTD_OTP_USER:
366 		if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
367 				-EOPNOTSUPP)
368 			return -EOPNOTSUPP;
369 
370 		mfi->mode = MTD_FILE_MODE_OTP_USER;
371 		break;
372 	case MTD_OTP_OFF:
373 		mfi->mode = MTD_FILE_MODE_NORMAL;
374 		break;
375 	default:
376 		return -EINVAL;
377 	}
378 
379 	return 0;
380 }
381 
382 static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
383 	uint64_t start, uint32_t length, void __user *ptr,
384 	uint32_t __user *retp)
385 {
386 	struct mtd_file_info *mfi = file->private_data;
387 	struct mtd_oob_ops ops;
388 	uint32_t retlen;
389 	int ret = 0;
390 
391 	if (!(file->f_mode & FMODE_WRITE))
392 		return -EPERM;
393 
394 	if (length > 4096)
395 		return -EINVAL;
396 
397 	if (!mtd->_write_oob)
398 		ret = -EOPNOTSUPP;
399 	else
400 		ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
401 
402 	if (ret)
403 		return ret;
404 
405 	ops.ooblen = length;
406 	ops.ooboffs = start & (mtd->writesize - 1);
407 	ops.datbuf = NULL;
408 	ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
409 		MTD_OPS_PLACE_OOB;
410 
411 	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
412 		return -EINVAL;
413 
414 	ops.oobbuf = memdup_user(ptr, length);
415 	if (IS_ERR(ops.oobbuf))
416 		return PTR_ERR(ops.oobbuf);
417 
418 	start &= ~((uint64_t)mtd->writesize - 1);
419 	ret = mtd_write_oob(mtd, start, &ops);
420 
421 	if (ops.oobretlen > 0xFFFFFFFFU)
422 		ret = -EOVERFLOW;
423 	retlen = ops.oobretlen;
424 	if (copy_to_user(retp, &retlen, sizeof(length)))
425 		ret = -EFAULT;
426 
427 	kfree(ops.oobbuf);
428 	return ret;
429 }
430 
431 static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
432 	uint64_t start, uint32_t length, void __user *ptr,
433 	uint32_t __user *retp)
434 {
435 	struct mtd_file_info *mfi = file->private_data;
436 	struct mtd_oob_ops ops;
437 	int ret = 0;
438 
439 	if (length > 4096)
440 		return -EINVAL;
441 
442 	if (!access_ok(VERIFY_WRITE, ptr, length))
443 		return -EFAULT;
444 
445 	ops.ooblen = length;
446 	ops.ooboffs = start & (mtd->writesize - 1);
447 	ops.datbuf = NULL;
448 	ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
449 		MTD_OPS_PLACE_OOB;
450 
451 	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
452 		return -EINVAL;
453 
454 	ops.oobbuf = kmalloc(length, GFP_KERNEL);
455 	if (!ops.oobbuf)
456 		return -ENOMEM;
457 
458 	start &= ~((uint64_t)mtd->writesize - 1);
459 	ret = mtd_read_oob(mtd, start, &ops);
460 
461 	if (put_user(ops.oobretlen, retp))
462 		ret = -EFAULT;
463 	else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
464 					    ops.oobretlen))
465 		ret = -EFAULT;
466 
467 	kfree(ops.oobbuf);
468 
469 	/*
470 	 * NAND returns -EBADMSG on ECC errors, but it returns the OOB
471 	 * data. For our userspace tools it is important to dump areas
472 	 * with ECC errors!
473 	 * For kernel internal usage it also might return -EUCLEAN
474 	 * to signal the caller that a bitflip has occured and has
475 	 * been corrected by the ECC algorithm.
476 	 *
477 	 * Note: currently the standard NAND function, nand_read_oob_std,
478 	 * does not calculate ECC for the OOB area, so do not rely on
479 	 * this behavior unless you have replaced it with your own.
480 	 */
481 	if (mtd_is_bitflip_or_eccerr(ret))
482 		return 0;
483 
484 	return ret;
485 }
486 
487 /*
488  * Copies (and truncates, if necessary) data from the larger struct,
489  * nand_ecclayout, to the smaller, deprecated layout struct,
490  * nand_ecclayout_user. This is necessary only to support the deprecated
491  * API ioctl ECCGETLAYOUT while allowing all new functionality to use
492  * nand_ecclayout flexibly (i.e. the struct may change size in new
493  * releases without requiring major rewrites).
494  */
495 static int shrink_ecclayout(const struct nand_ecclayout *from,
496 		struct nand_ecclayout_user *to)
497 {
498 	int i;
499 
500 	if (!from || !to)
501 		return -EINVAL;
502 
503 	memset(to, 0, sizeof(*to));
504 
505 	to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
506 	for (i = 0; i < to->eccbytes; i++)
507 		to->eccpos[i] = from->eccpos[i];
508 
509 	for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
510 		if (from->oobfree[i].length == 0 &&
511 				from->oobfree[i].offset == 0)
512 			break;
513 		to->oobavail += from->oobfree[i].length;
514 		to->oobfree[i] = from->oobfree[i];
515 	}
516 
517 	return 0;
518 }
519 
520 static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
521 			   struct blkpg_ioctl_arg __user *arg)
522 {
523 	struct blkpg_ioctl_arg a;
524 	struct blkpg_partition p;
525 
526 	if (!capable(CAP_SYS_ADMIN))
527 		return -EPERM;
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 		/* Only master mtd device must be used to add partitions */
539 		if (mtd_is_partition(mtd))
540 			return -EINVAL;
541 
542 		return mtd_add_partition(mtd, p.devname, p.start, p.length);
543 
544 	case BLKPG_DEL_PARTITION:
545 
546 		if (p.pno < 0)
547 			return -EINVAL;
548 
549 		return mtd_del_partition(mtd, p.pno);
550 
551 	default:
552 		return -EINVAL;
553 	}
554 }
555 
556 static int mtdchar_write_ioctl(struct mtd_info *mtd,
557 		struct mtd_write_req __user *argp)
558 {
559 	struct mtd_write_req req;
560 	struct mtd_oob_ops ops;
561 	void __user *usr_data, *usr_oob;
562 	int ret;
563 
564 	if (copy_from_user(&req, argp, sizeof(req)) ||
565 			!access_ok(VERIFY_READ, req.usr_data, req.len) ||
566 			!access_ok(VERIFY_READ, req.usr_oob, req.ooblen))
567 		return -EFAULT;
568 	if (!mtd->_write_oob)
569 		return -EOPNOTSUPP;
570 
571 	ops.mode = req.mode;
572 	ops.len = (size_t)req.len;
573 	ops.ooblen = (size_t)req.ooblen;
574 	ops.ooboffs = 0;
575 
576 	usr_data = (void __user *)(uintptr_t)req.usr_data;
577 	usr_oob = (void __user *)(uintptr_t)req.usr_oob;
578 
579 	if (req.usr_data) {
580 		ops.datbuf = memdup_user(usr_data, ops.len);
581 		if (IS_ERR(ops.datbuf))
582 			return PTR_ERR(ops.datbuf);
583 	} else {
584 		ops.datbuf = NULL;
585 	}
586 
587 	if (req.usr_oob) {
588 		ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
589 		if (IS_ERR(ops.oobbuf)) {
590 			kfree(ops.datbuf);
591 			return PTR_ERR(ops.oobbuf);
592 		}
593 	} else {
594 		ops.oobbuf = NULL;
595 	}
596 
597 	ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
598 
599 	kfree(ops.datbuf);
600 	kfree(ops.oobbuf);
601 
602 	return ret;
603 }
604 
605 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
606 {
607 	struct mtd_file_info *mfi = file->private_data;
608 	struct mtd_info *mtd = mfi->mtd;
609 	void __user *argp = (void __user *)arg;
610 	int ret = 0;
611 	u_long size;
612 	struct mtd_info_user info;
613 
614 	pr_debug("MTD_ioctl\n");
615 
616 	size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
617 	if (cmd & IOC_IN) {
618 		if (!access_ok(VERIFY_READ, argp, size))
619 			return -EFAULT;
620 	}
621 	if (cmd & IOC_OUT) {
622 		if (!access_ok(VERIFY_WRITE, argp, size))
623 			return -EFAULT;
624 	}
625 
626 	switch (cmd) {
627 	case MEMGETREGIONCOUNT:
628 		if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
629 			return -EFAULT;
630 		break;
631 
632 	case MEMGETREGIONINFO:
633 	{
634 		uint32_t ur_idx;
635 		struct mtd_erase_region_info *kr;
636 		struct region_info_user __user *ur = argp;
637 
638 		if (get_user(ur_idx, &(ur->regionindex)))
639 			return -EFAULT;
640 
641 		if (ur_idx >= mtd->numeraseregions)
642 			return -EINVAL;
643 
644 		kr = &(mtd->eraseregions[ur_idx]);
645 
646 		if (put_user(kr->offset, &(ur->offset))
647 		    || put_user(kr->erasesize, &(ur->erasesize))
648 		    || put_user(kr->numblocks, &(ur->numblocks)))
649 			return -EFAULT;
650 
651 		break;
652 	}
653 
654 	case MEMGETINFO:
655 		memset(&info, 0, sizeof(info));
656 		info.type	= mtd->type;
657 		info.flags	= mtd->flags;
658 		info.size	= mtd->size;
659 		info.erasesize	= mtd->erasesize;
660 		info.writesize	= mtd->writesize;
661 		info.oobsize	= mtd->oobsize;
662 		/* The below field is obsolete */
663 		info.padding	= 0;
664 		if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
665 			return -EFAULT;
666 		break;
667 
668 	case MEMERASE:
669 	case MEMERASE64:
670 	{
671 		struct erase_info *erase;
672 
673 		if(!(file->f_mode & FMODE_WRITE))
674 			return -EPERM;
675 
676 		erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
677 		if (!erase)
678 			ret = -ENOMEM;
679 		else {
680 			wait_queue_head_t waitq;
681 			DECLARE_WAITQUEUE(wait, current);
682 
683 			init_waitqueue_head(&waitq);
684 
685 			if (cmd == MEMERASE64) {
686 				struct erase_info_user64 einfo64;
687 
688 				if (copy_from_user(&einfo64, argp,
689 					    sizeof(struct erase_info_user64))) {
690 					kfree(erase);
691 					return -EFAULT;
692 				}
693 				erase->addr = einfo64.start;
694 				erase->len = einfo64.length;
695 			} else {
696 				struct erase_info_user einfo32;
697 
698 				if (copy_from_user(&einfo32, argp,
699 					    sizeof(struct erase_info_user))) {
700 					kfree(erase);
701 					return -EFAULT;
702 				}
703 				erase->addr = einfo32.start;
704 				erase->len = einfo32.length;
705 			}
706 			erase->mtd = mtd;
707 			erase->callback = mtdchar_erase_callback;
708 			erase->priv = (unsigned long)&waitq;
709 
710 			/*
711 			  FIXME: Allow INTERRUPTIBLE. Which means
712 			  not having the wait_queue head on the stack.
713 
714 			  If the wq_head is on the stack, and we
715 			  leave because we got interrupted, then the
716 			  wq_head is no longer there when the
717 			  callback routine tries to wake us up.
718 			*/
719 			ret = mtd_erase(mtd, erase);
720 			if (!ret) {
721 				set_current_state(TASK_UNINTERRUPTIBLE);
722 				add_wait_queue(&waitq, &wait);
723 				if (erase->state != MTD_ERASE_DONE &&
724 				    erase->state != MTD_ERASE_FAILED)
725 					schedule();
726 				remove_wait_queue(&waitq, &wait);
727 				set_current_state(TASK_RUNNING);
728 
729 				ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
730 			}
731 			kfree(erase);
732 		}
733 		break;
734 	}
735 
736 	case MEMWRITEOOB:
737 	{
738 		struct mtd_oob_buf buf;
739 		struct mtd_oob_buf __user *buf_user = argp;
740 
741 		/* NOTE: writes return length to buf_user->length */
742 		if (copy_from_user(&buf, argp, sizeof(buf)))
743 			ret = -EFAULT;
744 		else
745 			ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
746 				buf.ptr, &buf_user->length);
747 		break;
748 	}
749 
750 	case MEMREADOOB:
751 	{
752 		struct mtd_oob_buf buf;
753 		struct mtd_oob_buf __user *buf_user = argp;
754 
755 		/* NOTE: writes return length to buf_user->start */
756 		if (copy_from_user(&buf, argp, sizeof(buf)))
757 			ret = -EFAULT;
758 		else
759 			ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
760 				buf.ptr, &buf_user->start);
761 		break;
762 	}
763 
764 	case MEMWRITEOOB64:
765 	{
766 		struct mtd_oob_buf64 buf;
767 		struct mtd_oob_buf64 __user *buf_user = argp;
768 
769 		if (copy_from_user(&buf, argp, sizeof(buf)))
770 			ret = -EFAULT;
771 		else
772 			ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
773 				(void __user *)(uintptr_t)buf.usr_ptr,
774 				&buf_user->length);
775 		break;
776 	}
777 
778 	case MEMREADOOB64:
779 	{
780 		struct mtd_oob_buf64 buf;
781 		struct mtd_oob_buf64 __user *buf_user = argp;
782 
783 		if (copy_from_user(&buf, argp, sizeof(buf)))
784 			ret = -EFAULT;
785 		else
786 			ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
787 				(void __user *)(uintptr_t)buf.usr_ptr,
788 				&buf_user->length);
789 		break;
790 	}
791 
792 	case MEMWRITE:
793 	{
794 		ret = mtdchar_write_ioctl(mtd,
795 		      (struct mtd_write_req __user *)arg);
796 		break;
797 	}
798 
799 	case MEMLOCK:
800 	{
801 		struct erase_info_user einfo;
802 
803 		if (copy_from_user(&einfo, argp, sizeof(einfo)))
804 			return -EFAULT;
805 
806 		ret = mtd_lock(mtd, einfo.start, einfo.length);
807 		break;
808 	}
809 
810 	case MEMUNLOCK:
811 	{
812 		struct erase_info_user einfo;
813 
814 		if (copy_from_user(&einfo, argp, sizeof(einfo)))
815 			return -EFAULT;
816 
817 		ret = mtd_unlock(mtd, einfo.start, einfo.length);
818 		break;
819 	}
820 
821 	case MEMISLOCKED:
822 	{
823 		struct erase_info_user einfo;
824 
825 		if (copy_from_user(&einfo, argp, sizeof(einfo)))
826 			return -EFAULT;
827 
828 		ret = mtd_is_locked(mtd, einfo.start, einfo.length);
829 		break;
830 	}
831 
832 	/* Legacy interface */
833 	case MEMGETOOBSEL:
834 	{
835 		struct nand_oobinfo oi;
836 
837 		if (!mtd->ecclayout)
838 			return -EOPNOTSUPP;
839 		if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
840 			return -EINVAL;
841 
842 		oi.useecc = MTD_NANDECC_AUTOPLACE;
843 		memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
844 		memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
845 		       sizeof(oi.oobfree));
846 		oi.eccbytes = mtd->ecclayout->eccbytes;
847 
848 		if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
849 			return -EFAULT;
850 		break;
851 	}
852 
853 	case MEMGETBADBLOCK:
854 	{
855 		loff_t offs;
856 
857 		if (copy_from_user(&offs, argp, sizeof(loff_t)))
858 			return -EFAULT;
859 		return mtd_block_isbad(mtd, offs);
860 		break;
861 	}
862 
863 	case MEMSETBADBLOCK:
864 	{
865 		loff_t offs;
866 
867 		if (copy_from_user(&offs, argp, sizeof(loff_t)))
868 			return -EFAULT;
869 		return mtd_block_markbad(mtd, offs);
870 		break;
871 	}
872 
873 	case OTPSELECT:
874 	{
875 		int mode;
876 		if (copy_from_user(&mode, argp, sizeof(int)))
877 			return -EFAULT;
878 
879 		mfi->mode = MTD_FILE_MODE_NORMAL;
880 
881 		ret = otp_select_filemode(mfi, mode);
882 
883 		file->f_pos = 0;
884 		break;
885 	}
886 
887 	case OTPGETREGIONCOUNT:
888 	case OTPGETREGIONINFO:
889 	{
890 		struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
891 		if (!buf)
892 			return -ENOMEM;
893 		switch (mfi->mode) {
894 		case MTD_FILE_MODE_OTP_FACTORY:
895 			ret = mtd_get_fact_prot_info(mtd, buf, 4096);
896 			break;
897 		case MTD_FILE_MODE_OTP_USER:
898 			ret = mtd_get_user_prot_info(mtd, buf, 4096);
899 			break;
900 		default:
901 			ret = -EINVAL;
902 			break;
903 		}
904 		if (ret >= 0) {
905 			if (cmd == OTPGETREGIONCOUNT) {
906 				int nbr = ret / sizeof(struct otp_info);
907 				ret = copy_to_user(argp, &nbr, sizeof(int));
908 			} else
909 				ret = copy_to_user(argp, buf, ret);
910 			if (ret)
911 				ret = -EFAULT;
912 		}
913 		kfree(buf);
914 		break;
915 	}
916 
917 	case OTPLOCK:
918 	{
919 		struct otp_info oinfo;
920 
921 		if (mfi->mode != MTD_FILE_MODE_OTP_USER)
922 			return -EINVAL;
923 		if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
924 			return -EFAULT;
925 		ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
926 		break;
927 	}
928 
929 	/* This ioctl is being deprecated - it truncates the ECC layout */
930 	case ECCGETLAYOUT:
931 	{
932 		struct nand_ecclayout_user *usrlay;
933 
934 		if (!mtd->ecclayout)
935 			return -EOPNOTSUPP;
936 
937 		usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
938 		if (!usrlay)
939 			return -ENOMEM;
940 
941 		shrink_ecclayout(mtd->ecclayout, usrlay);
942 
943 		if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
944 			ret = -EFAULT;
945 		kfree(usrlay);
946 		break;
947 	}
948 
949 	case ECCGETSTATS:
950 	{
951 		if (copy_to_user(argp, &mtd->ecc_stats,
952 				 sizeof(struct mtd_ecc_stats)))
953 			return -EFAULT;
954 		break;
955 	}
956 
957 	case MTDFILEMODE:
958 	{
959 		mfi->mode = 0;
960 
961 		switch(arg) {
962 		case MTD_FILE_MODE_OTP_FACTORY:
963 		case MTD_FILE_MODE_OTP_USER:
964 			ret = otp_select_filemode(mfi, arg);
965 			break;
966 
967 		case MTD_FILE_MODE_RAW:
968 			if (!mtd_has_oob(mtd))
969 				return -EOPNOTSUPP;
970 			mfi->mode = arg;
971 
972 		case MTD_FILE_MODE_NORMAL:
973 			break;
974 		default:
975 			ret = -EINVAL;
976 		}
977 		file->f_pos = 0;
978 		break;
979 	}
980 
981 	case BLKPG:
982 	{
983 		ret = mtdchar_blkpg_ioctl(mtd,
984 		      (struct blkpg_ioctl_arg __user *)arg);
985 		break;
986 	}
987 
988 	case BLKRRPART:
989 	{
990 		/* No reread partition feature. Just return ok */
991 		ret = 0;
992 		break;
993 	}
994 
995 	default:
996 		ret = -ENOTTY;
997 	}
998 
999 	return ret;
1000 } /* memory_ioctl */
1001 
1002 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1003 {
1004 	int ret;
1005 
1006 	mutex_lock(&mtd_mutex);
1007 	ret = mtdchar_ioctl(file, cmd, arg);
1008 	mutex_unlock(&mtd_mutex);
1009 
1010 	return ret;
1011 }
1012 
1013 #ifdef CONFIG_COMPAT
1014 
1015 struct mtd_oob_buf32 {
1016 	u_int32_t start;
1017 	u_int32_t length;
1018 	compat_caddr_t ptr;	/* unsigned char* */
1019 };
1020 
1021 #define MEMWRITEOOB32		_IOWR('M', 3, struct mtd_oob_buf32)
1022 #define MEMREADOOB32		_IOWR('M', 4, struct mtd_oob_buf32)
1023 
1024 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1025 	unsigned long arg)
1026 {
1027 	struct mtd_file_info *mfi = file->private_data;
1028 	struct mtd_info *mtd = mfi->mtd;
1029 	void __user *argp = compat_ptr(arg);
1030 	int ret = 0;
1031 
1032 	mutex_lock(&mtd_mutex);
1033 
1034 	switch (cmd) {
1035 	case MEMWRITEOOB32:
1036 	{
1037 		struct mtd_oob_buf32 buf;
1038 		struct mtd_oob_buf32 __user *buf_user = argp;
1039 
1040 		if (copy_from_user(&buf, argp, sizeof(buf)))
1041 			ret = -EFAULT;
1042 		else
1043 			ret = mtdchar_writeoob(file, mtd, buf.start,
1044 				buf.length, compat_ptr(buf.ptr),
1045 				&buf_user->length);
1046 		break;
1047 	}
1048 
1049 	case MEMREADOOB32:
1050 	{
1051 		struct mtd_oob_buf32 buf;
1052 		struct mtd_oob_buf32 __user *buf_user = argp;
1053 
1054 		/* NOTE: writes return length to buf->start */
1055 		if (copy_from_user(&buf, argp, sizeof(buf)))
1056 			ret = -EFAULT;
1057 		else
1058 			ret = mtdchar_readoob(file, mtd, buf.start,
1059 				buf.length, compat_ptr(buf.ptr),
1060 				&buf_user->start);
1061 		break;
1062 	}
1063 	default:
1064 		ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1065 	}
1066 
1067 	mutex_unlock(&mtd_mutex);
1068 
1069 	return ret;
1070 }
1071 
1072 #endif /* CONFIG_COMPAT */
1073 
1074 /*
1075  * try to determine where a shared mapping can be made
1076  * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1077  *   mappings)
1078  */
1079 #ifndef CONFIG_MMU
1080 static unsigned long mtdchar_get_unmapped_area(struct file *file,
1081 					   unsigned long addr,
1082 					   unsigned long len,
1083 					   unsigned long pgoff,
1084 					   unsigned long flags)
1085 {
1086 	struct mtd_file_info *mfi = file->private_data;
1087 	struct mtd_info *mtd = mfi->mtd;
1088 	unsigned long offset;
1089 	int ret;
1090 
1091 	if (addr != 0)
1092 		return (unsigned long) -EINVAL;
1093 
1094 	if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1095 		return (unsigned long) -EINVAL;
1096 
1097 	offset = pgoff << PAGE_SHIFT;
1098 	if (offset > mtd->size - len)
1099 		return (unsigned long) -EINVAL;
1100 
1101 	ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1102 	return ret == -EOPNOTSUPP ? -ENOSYS : ret;
1103 }
1104 #endif
1105 
1106 /*
1107  * set up a mapping for shared memory segments
1108  */
1109 static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1110 {
1111 #ifdef CONFIG_MMU
1112 	struct mtd_file_info *mfi = file->private_data;
1113 	struct mtd_info *mtd = mfi->mtd;
1114 	struct map_info *map = mtd->priv;
1115 
1116         /* This is broken because it assumes the MTD device is map-based
1117 	   and that mtd->priv is a valid struct map_info.  It should be
1118 	   replaced with something that uses the mtd_get_unmapped_area()
1119 	   operation properly. */
1120 	if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1121 #ifdef pgprot_noncached
1122 		if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1123 			vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1124 #endif
1125 		return vm_iomap_memory(vma, map->phys, map->size);
1126 	}
1127 	return -ENOSYS;
1128 #else
1129 	return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1130 #endif
1131 }
1132 
1133 static const struct file_operations mtd_fops = {
1134 	.owner		= THIS_MODULE,
1135 	.llseek		= mtdchar_lseek,
1136 	.read		= mtdchar_read,
1137 	.write		= mtdchar_write,
1138 	.unlocked_ioctl	= mtdchar_unlocked_ioctl,
1139 #ifdef CONFIG_COMPAT
1140 	.compat_ioctl	= mtdchar_compat_ioctl,
1141 #endif
1142 	.open		= mtdchar_open,
1143 	.release	= mtdchar_close,
1144 	.mmap		= mtdchar_mmap,
1145 #ifndef CONFIG_MMU
1146 	.get_unmapped_area = mtdchar_get_unmapped_area,
1147 #endif
1148 };
1149 
1150 static const struct super_operations mtd_ops = {
1151 	.drop_inode = generic_delete_inode,
1152 	.statfs = simple_statfs,
1153 };
1154 
1155 static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1156 				int flags, const char *dev_name, void *data)
1157 {
1158 	return mount_pseudo(fs_type, "mtd_inode:", &mtd_ops, NULL, MTD_INODE_FS_MAGIC);
1159 }
1160 
1161 static struct file_system_type mtd_inodefs_type = {
1162        .name = "mtd_inodefs",
1163        .mount = mtd_inodefs_mount,
1164        .kill_sb = kill_anon_super,
1165 };
1166 MODULE_ALIAS_FS("mtd_inodefs");
1167 
1168 int __init init_mtdchar(void)
1169 {
1170 	int ret;
1171 
1172 	ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1173 				   "mtd", &mtd_fops);
1174 	if (ret < 0) {
1175 		pr_err("Can't allocate major number %d for MTD\n",
1176 		       MTD_CHAR_MAJOR);
1177 		return ret;
1178 	}
1179 
1180 	ret = register_filesystem(&mtd_inodefs_type);
1181 	if (ret) {
1182 		pr_err("Can't register mtd_inodefs filesystem, error %d\n",
1183 		       ret);
1184 		goto err_unregister_chdev;
1185 	}
1186 
1187 	return ret;
1188 
1189 err_unregister_chdev:
1190 	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1191 	return ret;
1192 }
1193 
1194 void __exit cleanup_mtdchar(void)
1195 {
1196 	unregister_filesystem(&mtd_inodefs_type);
1197 	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1198 }
1199 
1200 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1201