xref: /kernel/linux/linux-5.10/drivers/mtd/mtdchar.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
4 */
5
6#include <linux/device.h>
7#include <linux/fs.h>
8#include <linux/mm.h>
9#include <linux/err.h>
10#include <linux/init.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/sched.h>
15#include <linux/mutex.h>
16#include <linux/backing-dev.h>
17#include <linux/compat.h>
18#include <linux/mount.h>
19#include <linux/blkpg.h>
20#include <linux/magic.h>
21#include <linux/major.h>
22#include <linux/mtd/mtd.h>
23#include <linux/mtd/partitions.h>
24#include <linux/mtd/map.h>
25
26#include <linux/uaccess.h>
27
28#include "mtdcore.h"
29
30static DEFINE_MUTEX(mtd_mutex);
31
32/*
33 * Data structure to hold the pointer to the mtd device as well
34 * as mode information of various use cases.
35 */
36struct mtd_file_info {
37	struct mtd_info *mtd;
38	enum mtd_file_modes mode;
39};
40
41static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig)
42{
43	struct mtd_file_info *mfi = file->private_data;
44	return fixed_size_llseek(file, offset, orig, mfi->mtd->size);
45}
46
47static int mtdchar_open(struct inode *inode, struct file *file)
48{
49	int minor = iminor(inode);
50	int devnum = minor >> 1;
51	int ret = 0;
52	struct mtd_info *mtd;
53	struct mtd_file_info *mfi;
54
55	pr_debug("MTD_open\n");
56
57	/* You can't open the RO devices RW */
58	if ((file->f_mode & FMODE_WRITE) && (minor & 1))
59		return -EACCES;
60
61	mutex_lock(&mtd_mutex);
62	mtd = get_mtd_device(NULL, devnum);
63
64	if (IS_ERR(mtd)) {
65		ret = PTR_ERR(mtd);
66		goto out;
67	}
68
69	if (mtd->type == MTD_ABSENT) {
70		ret = -ENODEV;
71		goto out1;
72	}
73
74	/* You can't open it RW if it's not a writeable device */
75	if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
76		ret = -EACCES;
77		goto out1;
78	}
79
80	mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
81	if (!mfi) {
82		ret = -ENOMEM;
83		goto out1;
84	}
85	mfi->mtd = mtd;
86	file->private_data = mfi;
87	mutex_unlock(&mtd_mutex);
88	return 0;
89
90out1:
91	put_mtd_device(mtd);
92out:
93	mutex_unlock(&mtd_mutex);
94	return ret;
95} /* mtdchar_open */
96
97/*====================================================================*/
98
99static int mtdchar_close(struct inode *inode, struct file *file)
100{
101	struct mtd_file_info *mfi = file->private_data;
102	struct mtd_info *mtd = mfi->mtd;
103
104	pr_debug("MTD_close\n");
105
106	/* Only sync if opened RW */
107	if ((file->f_mode & FMODE_WRITE))
108		mtd_sync(mtd);
109
110	put_mtd_device(mtd);
111	file->private_data = NULL;
112	kfree(mfi);
113
114	return 0;
115} /* mtdchar_close */
116
117/* Back in June 2001, dwmw2 wrote:
118 *
119 *   FIXME: This _really_ needs to die. In 2.5, we should lock the
120 *   userspace buffer down and use it directly with readv/writev.
121 *
122 * The implementation below, using mtd_kmalloc_up_to, mitigates
123 * allocation failures when the system is under low-memory situations
124 * or if memory is highly fragmented at the cost of reducing the
125 * performance of the requested transfer due to a smaller buffer size.
126 *
127 * A more complex but more memory-efficient implementation based on
128 * get_user_pages and iovecs to cover extents of those pages is a
129 * longer-term goal, as intimated by dwmw2 above. However, for the
130 * write case, this requires yet more complex head and tail transfer
131 * handling when those head and tail offsets and sizes are such that
132 * alignment requirements are not met in the NAND subdriver.
133 */
134
135static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
136			loff_t *ppos)
137{
138	struct mtd_file_info *mfi = file->private_data;
139	struct mtd_info *mtd = mfi->mtd;
140	size_t retlen;
141	size_t total_retlen=0;
142	int ret=0;
143	int len;
144	size_t size = count;
145	char *kbuf;
146
147	pr_debug("MTD_read\n");
148
149	if (*ppos + count > mtd->size) {
150		if (*ppos < mtd->size)
151			count = mtd->size - *ppos;
152		else
153			count = 0;
154	}
155
156	if (!count)
157		return 0;
158
159	kbuf = mtd_kmalloc_up_to(mtd, &size);
160	if (!kbuf)
161		return -ENOMEM;
162
163	while (count) {
164		len = min_t(size_t, count, size);
165
166		switch (mfi->mode) {
167		case MTD_FILE_MODE_OTP_FACTORY:
168			ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
169						     &retlen, kbuf);
170			break;
171		case MTD_FILE_MODE_OTP_USER:
172			ret = mtd_read_user_prot_reg(mtd, *ppos, len,
173						     &retlen, kbuf);
174			break;
175		case MTD_FILE_MODE_RAW:
176		{
177			struct mtd_oob_ops ops = {};
178
179			ops.mode = MTD_OPS_RAW;
180			ops.datbuf = kbuf;
181			ops.oobbuf = NULL;
182			ops.len = len;
183
184			ret = mtd_read_oob(mtd, *ppos, &ops);
185			retlen = ops.retlen;
186			break;
187		}
188		default:
189			ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
190		}
191		/* Nand returns -EBADMSG on ECC errors, but it returns
192		 * the data. For our userspace tools it is important
193		 * to dump areas with ECC errors!
194		 * For kernel internal usage it also might return -EUCLEAN
195		 * to signal the caller that a bitflip has occurred and has
196		 * been corrected by the ECC algorithm.
197		 * Userspace software which accesses NAND this way
198		 * must be aware of the fact that it deals with NAND
199		 */
200		if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
201			*ppos += retlen;
202			if (copy_to_user(buf, kbuf, retlen)) {
203				kfree(kbuf);
204				return -EFAULT;
205			}
206			else
207				total_retlen += retlen;
208
209			count -= retlen;
210			buf += retlen;
211			if (retlen == 0)
212				count = 0;
213		}
214		else {
215			kfree(kbuf);
216			return ret;
217		}
218
219	}
220
221	kfree(kbuf);
222	return total_retlen;
223} /* mtdchar_read */
224
225static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
226			loff_t *ppos)
227{
228	struct mtd_file_info *mfi = file->private_data;
229	struct mtd_info *mtd = mfi->mtd;
230	size_t size = count;
231	char *kbuf;
232	size_t retlen;
233	size_t total_retlen=0;
234	int ret=0;
235	int len;
236
237	pr_debug("MTD_write\n");
238
239	if (*ppos >= mtd->size)
240		return -ENOSPC;
241
242	if (*ppos + count > mtd->size)
243		count = mtd->size - *ppos;
244
245	if (!count)
246		return 0;
247
248	kbuf = mtd_kmalloc_up_to(mtd, &size);
249	if (!kbuf)
250		return -ENOMEM;
251
252	while (count) {
253		len = min_t(size_t, count, size);
254
255		if (copy_from_user(kbuf, buf, len)) {
256			kfree(kbuf);
257			return -EFAULT;
258		}
259
260		switch (mfi->mode) {
261		case MTD_FILE_MODE_OTP_FACTORY:
262			ret = -EROFS;
263			break;
264		case MTD_FILE_MODE_OTP_USER:
265			ret = mtd_write_user_prot_reg(mtd, *ppos, len,
266						      &retlen, kbuf);
267			break;
268
269		case MTD_FILE_MODE_RAW:
270		{
271			struct mtd_oob_ops ops = {};
272
273			ops.mode = MTD_OPS_RAW;
274			ops.datbuf = kbuf;
275			ops.oobbuf = NULL;
276			ops.ooboffs = 0;
277			ops.len = len;
278
279			ret = mtd_write_oob(mtd, *ppos, &ops);
280			retlen = ops.retlen;
281			break;
282		}
283
284		default:
285			ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
286		}
287
288		/*
289		 * Return -ENOSPC only if no data could be written at all.
290		 * Otherwise just return the number of bytes that actually
291		 * have been written.
292		 */
293		if ((ret == -ENOSPC) && (total_retlen))
294			break;
295
296		if (!ret) {
297			*ppos += retlen;
298			total_retlen += retlen;
299			count -= retlen;
300			buf += retlen;
301		}
302		else {
303			kfree(kbuf);
304			return ret;
305		}
306	}
307
308	kfree(kbuf);
309	return total_retlen;
310} /* mtdchar_write */
311
312/*======================================================================
313
314    IOCTL calls for getting device parameters.
315
316======================================================================*/
317
318static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
319{
320	struct mtd_info *mtd = mfi->mtd;
321	size_t retlen;
322
323	switch (mode) {
324	case MTD_OTP_FACTORY:
325		if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
326				-EOPNOTSUPP)
327			return -EOPNOTSUPP;
328
329		mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
330		break;
331	case MTD_OTP_USER:
332		if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
333				-EOPNOTSUPP)
334			return -EOPNOTSUPP;
335
336		mfi->mode = MTD_FILE_MODE_OTP_USER;
337		break;
338	case MTD_OTP_OFF:
339		mfi->mode = MTD_FILE_MODE_NORMAL;
340		break;
341	default:
342		return -EINVAL;
343	}
344
345	return 0;
346}
347
348static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
349	uint64_t start, uint32_t length, void __user *ptr,
350	uint32_t __user *retp)
351{
352	struct mtd_info *master  = mtd_get_master(mtd);
353	struct mtd_file_info *mfi = file->private_data;
354	struct mtd_oob_ops ops = {};
355	uint32_t retlen;
356	int ret = 0;
357
358	if (length > 4096)
359		return -EINVAL;
360
361	if (!master->_write_oob)
362		return -EOPNOTSUPP;
363
364	ops.ooblen = length;
365	ops.ooboffs = start & (mtd->writesize - 1);
366	ops.datbuf = NULL;
367	ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
368		MTD_OPS_PLACE_OOB;
369
370	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
371		return -EINVAL;
372
373	ops.oobbuf = memdup_user(ptr, length);
374	if (IS_ERR(ops.oobbuf))
375		return PTR_ERR(ops.oobbuf);
376
377	start &= ~((uint64_t)mtd->writesize - 1);
378	ret = mtd_write_oob(mtd, start, &ops);
379
380	if (ops.oobretlen > 0xFFFFFFFFU)
381		ret = -EOVERFLOW;
382	retlen = ops.oobretlen;
383	if (copy_to_user(retp, &retlen, sizeof(length)))
384		ret = -EFAULT;
385
386	kfree(ops.oobbuf);
387	return ret;
388}
389
390static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
391	uint64_t start, uint32_t length, void __user *ptr,
392	uint32_t __user *retp)
393{
394	struct mtd_file_info *mfi = file->private_data;
395	struct mtd_oob_ops ops = {};
396	int ret = 0;
397
398	if (length > 4096)
399		return -EINVAL;
400
401	ops.ooblen = length;
402	ops.ooboffs = start & (mtd->writesize - 1);
403	ops.datbuf = NULL;
404	ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
405		MTD_OPS_PLACE_OOB;
406
407	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
408		return -EINVAL;
409
410	ops.oobbuf = kmalloc(length, GFP_KERNEL);
411	if (!ops.oobbuf)
412		return -ENOMEM;
413
414	start &= ~((uint64_t)mtd->writesize - 1);
415	ret = mtd_read_oob(mtd, start, &ops);
416
417	if (put_user(ops.oobretlen, retp))
418		ret = -EFAULT;
419	else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
420					    ops.oobretlen))
421		ret = -EFAULT;
422
423	kfree(ops.oobbuf);
424
425	/*
426	 * NAND returns -EBADMSG on ECC errors, but it returns the OOB
427	 * data. For our userspace tools it is important to dump areas
428	 * with ECC errors!
429	 * For kernel internal usage it also might return -EUCLEAN
430	 * to signal the caller that a bitflip has occurred and has
431	 * been corrected by the ECC algorithm.
432	 *
433	 * Note: currently the standard NAND function, nand_read_oob_std,
434	 * does not calculate ECC for the OOB area, so do not rely on
435	 * this behavior unless you have replaced it with your own.
436	 */
437	if (mtd_is_bitflip_or_eccerr(ret))
438		return 0;
439
440	return ret;
441}
442
443/*
444 * Copies (and truncates, if necessary) OOB layout information to the
445 * deprecated layout struct, nand_ecclayout_user. This is necessary only to
446 * support the deprecated API ioctl ECCGETLAYOUT while allowing all new
447 * functionality to use mtd_ooblayout_ops flexibly (i.e. mtd_ooblayout_ops
448 * can describe any kind of OOB layout with almost zero overhead from a
449 * memory usage point of view).
450 */
451static int shrink_ecclayout(struct mtd_info *mtd,
452			    struct nand_ecclayout_user *to)
453{
454	struct mtd_oob_region oobregion;
455	int i, section = 0, ret;
456
457	if (!mtd || !to)
458		return -EINVAL;
459
460	memset(to, 0, sizeof(*to));
461
462	to->eccbytes = 0;
463	for (i = 0; i < MTD_MAX_ECCPOS_ENTRIES;) {
464		u32 eccpos;
465
466		ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
467		if (ret < 0) {
468			if (ret != -ERANGE)
469				return ret;
470
471			break;
472		}
473
474		eccpos = oobregion.offset;
475		for (; i < MTD_MAX_ECCPOS_ENTRIES &&
476		       eccpos < oobregion.offset + oobregion.length; i++) {
477			to->eccpos[i] = eccpos++;
478			to->eccbytes++;
479		}
480	}
481
482	for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
483		ret = mtd_ooblayout_free(mtd, i, &oobregion);
484		if (ret < 0) {
485			if (ret != -ERANGE)
486				return ret;
487
488			break;
489		}
490
491		to->oobfree[i].offset = oobregion.offset;
492		to->oobfree[i].length = oobregion.length;
493		to->oobavail += to->oobfree[i].length;
494	}
495
496	return 0;
497}
498
499static int get_oobinfo(struct mtd_info *mtd, struct nand_oobinfo *to)
500{
501	struct mtd_oob_region oobregion;
502	int i, section = 0, ret;
503
504	if (!mtd || !to)
505		return -EINVAL;
506
507	memset(to, 0, sizeof(*to));
508
509	to->eccbytes = 0;
510	for (i = 0; i < ARRAY_SIZE(to->eccpos);) {
511		u32 eccpos;
512
513		ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
514		if (ret < 0) {
515			if (ret != -ERANGE)
516				return ret;
517
518			break;
519		}
520
521		if (oobregion.length + i > ARRAY_SIZE(to->eccpos))
522			return -EINVAL;
523
524		eccpos = oobregion.offset;
525		for (; eccpos < oobregion.offset + oobregion.length; i++) {
526			to->eccpos[i] = eccpos++;
527			to->eccbytes++;
528		}
529	}
530
531	for (i = 0; i < 8; i++) {
532		ret = mtd_ooblayout_free(mtd, i, &oobregion);
533		if (ret < 0) {
534			if (ret != -ERANGE)
535				return ret;
536
537			break;
538		}
539
540		to->oobfree[i][0] = oobregion.offset;
541		to->oobfree[i][1] = oobregion.length;
542	}
543
544	to->useecc = MTD_NANDECC_AUTOPLACE;
545
546	return 0;
547}
548
549static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
550			       struct blkpg_ioctl_arg *arg)
551{
552	struct blkpg_partition p;
553
554	if (!capable(CAP_SYS_ADMIN))
555		return -EPERM;
556
557	if (copy_from_user(&p, arg->data, sizeof(p)))
558		return -EFAULT;
559
560	switch (arg->op) {
561	case BLKPG_ADD_PARTITION:
562
563		/* Only master mtd device must be used to add partitions */
564		if (mtd_is_partition(mtd))
565			return -EINVAL;
566
567		/* Sanitize user input */
568		p.devname[BLKPG_DEVNAMELTH - 1] = '\0';
569
570		return mtd_add_partition(mtd, p.devname, p.start, p.length);
571
572	case BLKPG_DEL_PARTITION:
573
574		if (p.pno < 0)
575			return -EINVAL;
576
577		return mtd_del_partition(mtd, p.pno);
578
579	default:
580		return -EINVAL;
581	}
582}
583
584static int mtdchar_write_ioctl(struct mtd_info *mtd,
585		struct mtd_write_req __user *argp)
586{
587	struct mtd_info *master = mtd_get_master(mtd);
588	struct mtd_write_req req;
589	struct mtd_oob_ops ops = {};
590	const void __user *usr_data, *usr_oob;
591	int ret;
592
593	if (copy_from_user(&req, argp, sizeof(req)))
594		return -EFAULT;
595
596	usr_data = (const void __user *)(uintptr_t)req.usr_data;
597	usr_oob = (const void __user *)(uintptr_t)req.usr_oob;
598
599	if (!master->_write_oob)
600		return -EOPNOTSUPP;
601	ops.mode = req.mode;
602	ops.len = (size_t)req.len;
603	ops.ooblen = (size_t)req.ooblen;
604	ops.ooboffs = 0;
605
606	if (usr_data) {
607		ops.datbuf = memdup_user(usr_data, ops.len);
608		if (IS_ERR(ops.datbuf))
609			return PTR_ERR(ops.datbuf);
610	} else {
611		ops.datbuf = NULL;
612	}
613
614	if (usr_oob) {
615		ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
616		if (IS_ERR(ops.oobbuf)) {
617			kfree(ops.datbuf);
618			return PTR_ERR(ops.oobbuf);
619		}
620	} else {
621		ops.oobbuf = NULL;
622	}
623
624	ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
625
626	kfree(ops.datbuf);
627	kfree(ops.oobbuf);
628
629	return ret;
630}
631
632static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
633{
634	struct mtd_file_info *mfi = file->private_data;
635	struct mtd_info *mtd = mfi->mtd;
636	struct mtd_info *master = mtd_get_master(mtd);
637	void __user *argp = (void __user *)arg;
638	int ret = 0;
639	struct mtd_info_user info;
640
641	pr_debug("MTD_ioctl\n");
642
643	/*
644	 * Check the file mode to require "dangerous" commands to have write
645	 * permissions.
646	 */
647	switch (cmd) {
648	/* "safe" commands */
649	case MEMGETREGIONCOUNT:
650	case MEMGETREGIONINFO:
651	case MEMGETINFO:
652	case MEMREADOOB:
653	case MEMREADOOB64:
654	case MEMISLOCKED:
655	case MEMGETOOBSEL:
656	case MEMGETBADBLOCK:
657	case OTPSELECT:
658	case OTPGETREGIONCOUNT:
659	case OTPGETREGIONINFO:
660	case ECCGETLAYOUT:
661	case ECCGETSTATS:
662	case MTDFILEMODE:
663	case BLKPG:
664	case BLKRRPART:
665		break;
666
667	/* "dangerous" commands */
668	case MEMERASE:
669	case MEMERASE64:
670	case MEMLOCK:
671	case MEMUNLOCK:
672	case MEMSETBADBLOCK:
673	case MEMWRITEOOB:
674	case MEMWRITEOOB64:
675	case MEMWRITE:
676	case OTPLOCK:
677		if (!(file->f_mode & FMODE_WRITE))
678			return -EPERM;
679		break;
680
681	default:
682		return -ENOTTY;
683	}
684
685	switch (cmd) {
686	case MEMGETREGIONCOUNT:
687		if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
688			return -EFAULT;
689		break;
690
691	case MEMGETREGIONINFO:
692	{
693		uint32_t ur_idx;
694		struct mtd_erase_region_info *kr;
695		struct region_info_user __user *ur = argp;
696
697		if (get_user(ur_idx, &(ur->regionindex)))
698			return -EFAULT;
699
700		if (ur_idx >= mtd->numeraseregions)
701			return -EINVAL;
702
703		kr = &(mtd->eraseregions[ur_idx]);
704
705		if (put_user(kr->offset, &(ur->offset))
706		    || put_user(kr->erasesize, &(ur->erasesize))
707		    || put_user(kr->numblocks, &(ur->numblocks)))
708			return -EFAULT;
709
710		break;
711	}
712
713	case MEMGETINFO:
714		memset(&info, 0, sizeof(info));
715		info.type	= mtd->type;
716		info.flags	= mtd->flags;
717		info.size	= mtd->size;
718		info.erasesize	= mtd->erasesize;
719		info.writesize	= mtd->writesize;
720		info.oobsize	= mtd->oobsize;
721		/* The below field is obsolete */
722		info.padding	= 0;
723		if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
724			return -EFAULT;
725		break;
726
727	case MEMERASE:
728	case MEMERASE64:
729	{
730		struct erase_info *erase;
731
732		erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
733		if (!erase)
734			ret = -ENOMEM;
735		else {
736			if (cmd == MEMERASE64) {
737				struct erase_info_user64 einfo64;
738
739				if (copy_from_user(&einfo64, argp,
740					    sizeof(struct erase_info_user64))) {
741					kfree(erase);
742					return -EFAULT;
743				}
744				erase->addr = einfo64.start;
745				erase->len = einfo64.length;
746			} else {
747				struct erase_info_user einfo32;
748
749				if (copy_from_user(&einfo32, argp,
750					    sizeof(struct erase_info_user))) {
751					kfree(erase);
752					return -EFAULT;
753				}
754				erase->addr = einfo32.start;
755				erase->len = einfo32.length;
756			}
757
758			ret = mtd_erase(mtd, erase);
759			kfree(erase);
760		}
761		break;
762	}
763
764	case MEMWRITEOOB:
765	{
766		struct mtd_oob_buf buf;
767		struct mtd_oob_buf __user *buf_user = argp;
768
769		/* NOTE: writes return length to buf_user->length */
770		if (copy_from_user(&buf, argp, sizeof(buf)))
771			ret = -EFAULT;
772		else
773			ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
774				buf.ptr, &buf_user->length);
775		break;
776	}
777
778	case MEMREADOOB:
779	{
780		struct mtd_oob_buf buf;
781		struct mtd_oob_buf __user *buf_user = argp;
782
783		/* NOTE: writes return length to buf_user->start */
784		if (copy_from_user(&buf, argp, sizeof(buf)))
785			ret = -EFAULT;
786		else
787			ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
788				buf.ptr, &buf_user->start);
789		break;
790	}
791
792	case MEMWRITEOOB64:
793	{
794		struct mtd_oob_buf64 buf;
795		struct mtd_oob_buf64 __user *buf_user = argp;
796
797		if (copy_from_user(&buf, argp, sizeof(buf)))
798			ret = -EFAULT;
799		else
800			ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
801				(void __user *)(uintptr_t)buf.usr_ptr,
802				&buf_user->length);
803		break;
804	}
805
806	case MEMREADOOB64:
807	{
808		struct mtd_oob_buf64 buf;
809		struct mtd_oob_buf64 __user *buf_user = argp;
810
811		if (copy_from_user(&buf, argp, sizeof(buf)))
812			ret = -EFAULT;
813		else
814			ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
815				(void __user *)(uintptr_t)buf.usr_ptr,
816				&buf_user->length);
817		break;
818	}
819
820	case MEMWRITE:
821	{
822		ret = mtdchar_write_ioctl(mtd,
823		      (struct mtd_write_req __user *)arg);
824		break;
825	}
826
827	case MEMLOCK:
828	{
829		struct erase_info_user einfo;
830
831		if (copy_from_user(&einfo, argp, sizeof(einfo)))
832			return -EFAULT;
833
834		ret = mtd_lock(mtd, einfo.start, einfo.length);
835		break;
836	}
837
838	case MEMUNLOCK:
839	{
840		struct erase_info_user einfo;
841
842		if (copy_from_user(&einfo, argp, sizeof(einfo)))
843			return -EFAULT;
844
845		ret = mtd_unlock(mtd, einfo.start, einfo.length);
846		break;
847	}
848
849	case MEMISLOCKED:
850	{
851		struct erase_info_user einfo;
852
853		if (copy_from_user(&einfo, argp, sizeof(einfo)))
854			return -EFAULT;
855
856		ret = mtd_is_locked(mtd, einfo.start, einfo.length);
857		break;
858	}
859
860	/* Legacy interface */
861	case MEMGETOOBSEL:
862	{
863		struct nand_oobinfo oi;
864
865		if (!master->ooblayout)
866			return -EOPNOTSUPP;
867
868		ret = get_oobinfo(mtd, &oi);
869		if (ret)
870			return ret;
871
872		if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
873			return -EFAULT;
874		break;
875	}
876
877	case MEMGETBADBLOCK:
878	{
879		loff_t offs;
880
881		if (copy_from_user(&offs, argp, sizeof(loff_t)))
882			return -EFAULT;
883		return mtd_block_isbad(mtd, offs);
884		break;
885	}
886
887	case MEMSETBADBLOCK:
888	{
889		loff_t offs;
890
891		if (copy_from_user(&offs, argp, sizeof(loff_t)))
892			return -EFAULT;
893		return mtd_block_markbad(mtd, offs);
894		break;
895	}
896
897	case OTPSELECT:
898	{
899		int mode;
900		if (copy_from_user(&mode, argp, sizeof(int)))
901			return -EFAULT;
902
903		mfi->mode = MTD_FILE_MODE_NORMAL;
904
905		ret = otp_select_filemode(mfi, mode);
906
907		file->f_pos = 0;
908		break;
909	}
910
911	case OTPGETREGIONCOUNT:
912	case OTPGETREGIONINFO:
913	{
914		struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
915		size_t retlen;
916		if (!buf)
917			return -ENOMEM;
918		switch (mfi->mode) {
919		case MTD_FILE_MODE_OTP_FACTORY:
920			ret = mtd_get_fact_prot_info(mtd, 4096, &retlen, buf);
921			break;
922		case MTD_FILE_MODE_OTP_USER:
923			ret = mtd_get_user_prot_info(mtd, 4096, &retlen, buf);
924			break;
925		default:
926			ret = -EINVAL;
927			break;
928		}
929		if (!ret) {
930			if (cmd == OTPGETREGIONCOUNT) {
931				int nbr = retlen / sizeof(struct otp_info);
932				ret = copy_to_user(argp, &nbr, sizeof(int));
933			} else
934				ret = copy_to_user(argp, buf, retlen);
935			if (ret)
936				ret = -EFAULT;
937		}
938		kfree(buf);
939		break;
940	}
941
942	case OTPLOCK:
943	{
944		struct otp_info oinfo;
945
946		if (mfi->mode != MTD_FILE_MODE_OTP_USER)
947			return -EINVAL;
948		if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
949			return -EFAULT;
950		ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
951		break;
952	}
953
954	/* This ioctl is being deprecated - it truncates the ECC layout */
955	case ECCGETLAYOUT:
956	{
957		struct nand_ecclayout_user *usrlay;
958
959		if (!master->ooblayout)
960			return -EOPNOTSUPP;
961
962		usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
963		if (!usrlay)
964			return -ENOMEM;
965
966		shrink_ecclayout(mtd, usrlay);
967
968		if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
969			ret = -EFAULT;
970		kfree(usrlay);
971		break;
972	}
973
974	case ECCGETSTATS:
975	{
976		if (copy_to_user(argp, &mtd->ecc_stats,
977				 sizeof(struct mtd_ecc_stats)))
978			return -EFAULT;
979		break;
980	}
981
982	case MTDFILEMODE:
983	{
984		mfi->mode = 0;
985
986		switch(arg) {
987		case MTD_FILE_MODE_OTP_FACTORY:
988		case MTD_FILE_MODE_OTP_USER:
989			ret = otp_select_filemode(mfi, arg);
990			break;
991
992		case MTD_FILE_MODE_RAW:
993			if (!mtd_has_oob(mtd))
994				return -EOPNOTSUPP;
995			mfi->mode = arg;
996
997		case MTD_FILE_MODE_NORMAL:
998			break;
999		default:
1000			ret = -EINVAL;
1001		}
1002		file->f_pos = 0;
1003		break;
1004	}
1005
1006	case BLKPG:
1007	{
1008		struct blkpg_ioctl_arg __user *blk_arg = argp;
1009		struct blkpg_ioctl_arg a;
1010
1011		if (copy_from_user(&a, blk_arg, sizeof(a)))
1012			ret = -EFAULT;
1013		else
1014			ret = mtdchar_blkpg_ioctl(mtd, &a);
1015		break;
1016	}
1017
1018	case BLKRRPART:
1019	{
1020		/* No reread partition feature. Just return ok */
1021		ret = 0;
1022		break;
1023	}
1024	}
1025
1026	return ret;
1027} /* memory_ioctl */
1028
1029static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1030{
1031	int ret;
1032
1033	mutex_lock(&mtd_mutex);
1034	ret = mtdchar_ioctl(file, cmd, arg);
1035	mutex_unlock(&mtd_mutex);
1036
1037	return ret;
1038}
1039
1040#ifdef CONFIG_COMPAT
1041
1042struct mtd_oob_buf32 {
1043	u_int32_t start;
1044	u_int32_t length;
1045	compat_caddr_t ptr;	/* unsigned char* */
1046};
1047
1048#define MEMWRITEOOB32		_IOWR('M', 3, struct mtd_oob_buf32)
1049#define MEMREADOOB32		_IOWR('M', 4, struct mtd_oob_buf32)
1050
1051static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1052	unsigned long arg)
1053{
1054	struct mtd_file_info *mfi = file->private_data;
1055	struct mtd_info *mtd = mfi->mtd;
1056	void __user *argp = compat_ptr(arg);
1057	int ret = 0;
1058
1059	mutex_lock(&mtd_mutex);
1060
1061	switch (cmd) {
1062	case MEMWRITEOOB32:
1063	{
1064		struct mtd_oob_buf32 buf;
1065		struct mtd_oob_buf32 __user *buf_user = argp;
1066
1067		if (!(file->f_mode & FMODE_WRITE)) {
1068			ret = -EPERM;
1069			break;
1070		}
1071
1072		if (copy_from_user(&buf, argp, sizeof(buf)))
1073			ret = -EFAULT;
1074		else
1075			ret = mtdchar_writeoob(file, mtd, buf.start,
1076				buf.length, compat_ptr(buf.ptr),
1077				&buf_user->length);
1078		break;
1079	}
1080
1081	case MEMREADOOB32:
1082	{
1083		struct mtd_oob_buf32 buf;
1084		struct mtd_oob_buf32 __user *buf_user = argp;
1085
1086		/* NOTE: writes return length to buf->start */
1087		if (copy_from_user(&buf, argp, sizeof(buf)))
1088			ret = -EFAULT;
1089		else
1090			ret = mtdchar_readoob(file, mtd, buf.start,
1091				buf.length, compat_ptr(buf.ptr),
1092				&buf_user->start);
1093		break;
1094	}
1095
1096	case BLKPG:
1097	{
1098		/* Convert from blkpg_compat_ioctl_arg to blkpg_ioctl_arg */
1099		struct blkpg_compat_ioctl_arg __user *uarg = argp;
1100		struct blkpg_compat_ioctl_arg compat_arg;
1101		struct blkpg_ioctl_arg a;
1102
1103		if (copy_from_user(&compat_arg, uarg, sizeof(compat_arg))) {
1104			ret = -EFAULT;
1105			break;
1106		}
1107
1108		memset(&a, 0, sizeof(a));
1109		a.op = compat_arg.op;
1110		a.flags = compat_arg.flags;
1111		a.datalen = compat_arg.datalen;
1112		a.data = compat_ptr(compat_arg.data);
1113
1114		ret = mtdchar_blkpg_ioctl(mtd, &a);
1115		break;
1116	}
1117
1118	default:
1119		ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1120	}
1121
1122	mutex_unlock(&mtd_mutex);
1123
1124	return ret;
1125}
1126
1127#endif /* CONFIG_COMPAT */
1128
1129/*
1130 * try to determine where a shared mapping can be made
1131 * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1132 *   mappings)
1133 */
1134#ifndef CONFIG_MMU
1135static unsigned long mtdchar_get_unmapped_area(struct file *file,
1136					   unsigned long addr,
1137					   unsigned long len,
1138					   unsigned long pgoff,
1139					   unsigned long flags)
1140{
1141	struct mtd_file_info *mfi = file->private_data;
1142	struct mtd_info *mtd = mfi->mtd;
1143	unsigned long offset;
1144	int ret;
1145
1146	if (addr != 0)
1147		return (unsigned long) -EINVAL;
1148
1149	if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1150		return (unsigned long) -EINVAL;
1151
1152	offset = pgoff << PAGE_SHIFT;
1153	if (offset > mtd->size - len)
1154		return (unsigned long) -EINVAL;
1155
1156	ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1157	return ret == -EOPNOTSUPP ? -ENODEV : ret;
1158}
1159
1160static unsigned mtdchar_mmap_capabilities(struct file *file)
1161{
1162	struct mtd_file_info *mfi = file->private_data;
1163
1164	return mtd_mmap_capabilities(mfi->mtd);
1165}
1166#endif
1167
1168/*
1169 * set up a mapping for shared memory segments
1170 */
1171static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1172{
1173#ifdef CONFIG_MMU
1174	struct mtd_file_info *mfi = file->private_data;
1175	struct mtd_info *mtd = mfi->mtd;
1176	struct map_info *map = mtd->priv;
1177
1178        /* This is broken because it assumes the MTD device is map-based
1179	   and that mtd->priv is a valid struct map_info.  It should be
1180	   replaced with something that uses the mtd_get_unmapped_area()
1181	   operation properly. */
1182	if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1183#ifdef pgprot_noncached
1184		if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1185			vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1186#endif
1187		return vm_iomap_memory(vma, map->phys, map->size);
1188	}
1189	return -ENODEV;
1190#else
1191	return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
1192#endif
1193}
1194
1195static const struct file_operations mtd_fops = {
1196	.owner		= THIS_MODULE,
1197	.llseek		= mtdchar_lseek,
1198	.read		= mtdchar_read,
1199	.write		= mtdchar_write,
1200	.unlocked_ioctl	= mtdchar_unlocked_ioctl,
1201#ifdef CONFIG_COMPAT
1202	.compat_ioctl	= mtdchar_compat_ioctl,
1203#endif
1204	.open		= mtdchar_open,
1205	.release	= mtdchar_close,
1206	.mmap		= mtdchar_mmap,
1207#ifndef CONFIG_MMU
1208	.get_unmapped_area = mtdchar_get_unmapped_area,
1209	.mmap_capabilities = mtdchar_mmap_capabilities,
1210#endif
1211};
1212
1213int __init init_mtdchar(void)
1214{
1215	int ret;
1216
1217	ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1218				   "mtd", &mtd_fops);
1219	if (ret < 0) {
1220		pr_err("Can't allocate major number %d for MTD\n",
1221		       MTD_CHAR_MAJOR);
1222		return ret;
1223	}
1224
1225	return ret;
1226}
1227
1228void __exit cleanup_mtdchar(void)
1229{
1230	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1231}
1232
1233MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1234