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
30/*
31 * Data structure to hold the pointer to the mtd device as well
32 * as mode information of various use cases.
33 */
34struct mtd_file_info {
35	struct mtd_info *mtd;
36	enum mtd_file_modes mode;
37};
38
39static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig)
40{
41	struct mtd_file_info *mfi = file->private_data;
42	return fixed_size_llseek(file, offset, orig, mfi->mtd->size);
43}
44
45static int mtdchar_open(struct inode *inode, struct file *file)
46{
47	int minor = iminor(inode);
48	int devnum = minor >> 1;
49	int ret = 0;
50	struct mtd_info *mtd;
51	struct mtd_file_info *mfi;
52
53	pr_debug("MTD_open\n");
54
55	/* You can't open the RO devices RW */
56	if ((file->f_mode & FMODE_WRITE) && (minor & 1))
57		return -EACCES;
58
59	mtd = get_mtd_device(NULL, devnum);
60
61	if (IS_ERR(mtd))
62		return PTR_ERR(mtd);
63
64	if (mtd->type == MTD_ABSENT) {
65		ret = -ENODEV;
66		goto out1;
67	}
68
69	/* You can't open it RW if it's not a writeable device */
70	if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
71		ret = -EACCES;
72		goto out1;
73	}
74
75	mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
76	if (!mfi) {
77		ret = -ENOMEM;
78		goto out1;
79	}
80	mfi->mtd = mtd;
81	file->private_data = mfi;
82	return 0;
83
84out1:
85	put_mtd_device(mtd);
86	return ret;
87} /* mtdchar_open */
88
89/*====================================================================*/
90
91static int mtdchar_close(struct inode *inode, struct file *file)
92{
93	struct mtd_file_info *mfi = file->private_data;
94	struct mtd_info *mtd = mfi->mtd;
95
96	pr_debug("MTD_close\n");
97
98	/* Only sync if opened RW */
99	if ((file->f_mode & FMODE_WRITE))
100		mtd_sync(mtd);
101
102	put_mtd_device(mtd);
103	file->private_data = NULL;
104	kfree(mfi);
105
106	return 0;
107} /* mtdchar_close */
108
109/* Back in June 2001, dwmw2 wrote:
110 *
111 *   FIXME: This _really_ needs to die. In 2.5, we should lock the
112 *   userspace buffer down and use it directly with readv/writev.
113 *
114 * The implementation below, using mtd_kmalloc_up_to, mitigates
115 * allocation failures when the system is under low-memory situations
116 * or if memory is highly fragmented at the cost of reducing the
117 * performance of the requested transfer due to a smaller buffer size.
118 *
119 * A more complex but more memory-efficient implementation based on
120 * get_user_pages and iovecs to cover extents of those pages is a
121 * longer-term goal, as intimated by dwmw2 above. However, for the
122 * write case, this requires yet more complex head and tail transfer
123 * handling when those head and tail offsets and sizes are such that
124 * alignment requirements are not met in the NAND subdriver.
125 */
126
127static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
128			loff_t *ppos)
129{
130	struct mtd_file_info *mfi = file->private_data;
131	struct mtd_info *mtd = mfi->mtd;
132	size_t retlen;
133	size_t total_retlen=0;
134	int ret=0;
135	int len;
136	size_t size = count;
137	char *kbuf;
138
139	pr_debug("MTD_read\n");
140
141	if (*ppos + count > mtd->size) {
142		if (*ppos < mtd->size)
143			count = mtd->size - *ppos;
144		else
145			count = 0;
146	}
147
148	if (!count)
149		return 0;
150
151	kbuf = mtd_kmalloc_up_to(mtd, &size);
152	if (!kbuf)
153		return -ENOMEM;
154
155	while (count) {
156		len = min_t(size_t, count, size);
157
158		switch (mfi->mode) {
159		case MTD_FILE_MODE_OTP_FACTORY:
160			ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
161						     &retlen, kbuf);
162			break;
163		case MTD_FILE_MODE_OTP_USER:
164			ret = mtd_read_user_prot_reg(mtd, *ppos, len,
165						     &retlen, kbuf);
166			break;
167		case MTD_FILE_MODE_RAW:
168		{
169			struct mtd_oob_ops ops = {};
170
171			ops.mode = MTD_OPS_RAW;
172			ops.datbuf = kbuf;
173			ops.oobbuf = NULL;
174			ops.len = len;
175
176			ret = mtd_read_oob(mtd, *ppos, &ops);
177			retlen = ops.retlen;
178			break;
179		}
180		default:
181			ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
182		}
183		/* Nand returns -EBADMSG on ECC errors, but it returns
184		 * the data. For our userspace tools it is important
185		 * to dump areas with ECC errors!
186		 * For kernel internal usage it also might return -EUCLEAN
187		 * to signal the caller that a bitflip has occurred and has
188		 * been corrected by the ECC algorithm.
189		 * Userspace software which accesses NAND this way
190		 * must be aware of the fact that it deals with NAND
191		 */
192		if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
193			*ppos += retlen;
194			if (copy_to_user(buf, kbuf, retlen)) {
195				kfree(kbuf);
196				return -EFAULT;
197			}
198			else
199				total_retlen += retlen;
200
201			count -= retlen;
202			buf += retlen;
203			if (retlen == 0)
204				count = 0;
205		}
206		else {
207			kfree(kbuf);
208			return ret;
209		}
210
211	}
212
213	kfree(kbuf);
214	return total_retlen;
215} /* mtdchar_read */
216
217static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
218			loff_t *ppos)
219{
220	struct mtd_file_info *mfi = file->private_data;
221	struct mtd_info *mtd = mfi->mtd;
222	size_t size = count;
223	char *kbuf;
224	size_t retlen;
225	size_t total_retlen=0;
226	int ret=0;
227	int len;
228
229	pr_debug("MTD_write\n");
230
231	if (*ppos >= mtd->size)
232		return -ENOSPC;
233
234	if (*ppos + count > mtd->size)
235		count = mtd->size - *ppos;
236
237	if (!count)
238		return 0;
239
240	kbuf = mtd_kmalloc_up_to(mtd, &size);
241	if (!kbuf)
242		return -ENOMEM;
243
244	while (count) {
245		len = min_t(size_t, count, size);
246
247		if (copy_from_user(kbuf, buf, len)) {
248			kfree(kbuf);
249			return -EFAULT;
250		}
251
252		switch (mfi->mode) {
253		case MTD_FILE_MODE_OTP_FACTORY:
254			ret = -EROFS;
255			break;
256		case MTD_FILE_MODE_OTP_USER:
257			ret = mtd_write_user_prot_reg(mtd, *ppos, len,
258						      &retlen, kbuf);
259			break;
260
261		case MTD_FILE_MODE_RAW:
262		{
263			struct mtd_oob_ops ops = {};
264
265			ops.mode = MTD_OPS_RAW;
266			ops.datbuf = kbuf;
267			ops.oobbuf = NULL;
268			ops.ooboffs = 0;
269			ops.len = len;
270
271			ret = mtd_write_oob(mtd, *ppos, &ops);
272			retlen = ops.retlen;
273			break;
274		}
275
276		default:
277			ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
278		}
279
280		/*
281		 * Return -ENOSPC only if no data could be written at all.
282		 * Otherwise just return the number of bytes that actually
283		 * have been written.
284		 */
285		if ((ret == -ENOSPC) && (total_retlen))
286			break;
287
288		if (!ret) {
289			*ppos += retlen;
290			total_retlen += retlen;
291			count -= retlen;
292			buf += retlen;
293		}
294		else {
295			kfree(kbuf);
296			return ret;
297		}
298	}
299
300	kfree(kbuf);
301	return total_retlen;
302} /* mtdchar_write */
303
304/*======================================================================
305
306    IOCTL calls for getting device parameters.
307
308======================================================================*/
309
310static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
311{
312	struct mtd_info *mtd = mfi->mtd;
313	size_t retlen;
314
315	switch (mode) {
316	case MTD_OTP_FACTORY:
317		if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
318				-EOPNOTSUPP)
319			return -EOPNOTSUPP;
320
321		mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
322		break;
323	case MTD_OTP_USER:
324		if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
325				-EOPNOTSUPP)
326			return -EOPNOTSUPP;
327
328		mfi->mode = MTD_FILE_MODE_OTP_USER;
329		break;
330	case MTD_OTP_OFF:
331		mfi->mode = MTD_FILE_MODE_NORMAL;
332		break;
333	default:
334		return -EINVAL;
335	}
336
337	return 0;
338}
339
340static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
341	uint64_t start, uint32_t length, void __user *ptr,
342	uint32_t __user *retp)
343{
344	struct mtd_info *master  = mtd_get_master(mtd);
345	struct mtd_file_info *mfi = file->private_data;
346	struct mtd_oob_ops ops = {};
347	uint32_t retlen;
348	int ret = 0;
349
350	if (length > 4096)
351		return -EINVAL;
352
353	if (!master->_write_oob)
354		return -EOPNOTSUPP;
355
356	ops.ooblen = length;
357	ops.ooboffs = start & (mtd->writesize - 1);
358	ops.datbuf = NULL;
359	ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
360		MTD_OPS_PLACE_OOB;
361
362	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
363		return -EINVAL;
364
365	ops.oobbuf = memdup_user(ptr, length);
366	if (IS_ERR(ops.oobbuf))
367		return PTR_ERR(ops.oobbuf);
368
369	start &= ~((uint64_t)mtd->writesize - 1);
370	ret = mtd_write_oob(mtd, start, &ops);
371
372	if (ops.oobretlen > 0xFFFFFFFFU)
373		ret = -EOVERFLOW;
374	retlen = ops.oobretlen;
375	if (copy_to_user(retp, &retlen, sizeof(length)))
376		ret = -EFAULT;
377
378	kfree(ops.oobbuf);
379	return ret;
380}
381
382static int mtdchar_readoob(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	int ret = 0;
389
390	if (length > 4096)
391		return -EINVAL;
392
393	ops.ooblen = length;
394	ops.ooboffs = start & (mtd->writesize - 1);
395	ops.datbuf = NULL;
396	ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
397		MTD_OPS_PLACE_OOB;
398
399	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
400		return -EINVAL;
401
402	ops.oobbuf = kmalloc(length, GFP_KERNEL);
403	if (!ops.oobbuf)
404		return -ENOMEM;
405
406	start &= ~((uint64_t)mtd->writesize - 1);
407	ret = mtd_read_oob(mtd, start, &ops);
408
409	if (put_user(ops.oobretlen, retp))
410		ret = -EFAULT;
411	else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
412					    ops.oobretlen))
413		ret = -EFAULT;
414
415	kfree(ops.oobbuf);
416
417	/*
418	 * NAND returns -EBADMSG on ECC errors, but it returns the OOB
419	 * data. For our userspace tools it is important to dump areas
420	 * with ECC errors!
421	 * For kernel internal usage it also might return -EUCLEAN
422	 * to signal the caller that a bitflip has occurred and has
423	 * been corrected by the ECC algorithm.
424	 *
425	 * Note: currently the standard NAND function, nand_read_oob_std,
426	 * does not calculate ECC for the OOB area, so do not rely on
427	 * this behavior unless you have replaced it with your own.
428	 */
429	if (mtd_is_bitflip_or_eccerr(ret))
430		return 0;
431
432	return ret;
433}
434
435/*
436 * Copies (and truncates, if necessary) OOB layout information to the
437 * deprecated layout struct, nand_ecclayout_user. This is necessary only to
438 * support the deprecated API ioctl ECCGETLAYOUT while allowing all new
439 * functionality to use mtd_ooblayout_ops flexibly (i.e. mtd_ooblayout_ops
440 * can describe any kind of OOB layout with almost zero overhead from a
441 * memory usage point of view).
442 */
443static int shrink_ecclayout(struct mtd_info *mtd,
444			    struct nand_ecclayout_user *to)
445{
446	struct mtd_oob_region oobregion;
447	int i, section = 0, ret;
448
449	if (!mtd || !to)
450		return -EINVAL;
451
452	memset(to, 0, sizeof(*to));
453
454	to->eccbytes = 0;
455	for (i = 0; i < MTD_MAX_ECCPOS_ENTRIES;) {
456		u32 eccpos;
457
458		ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
459		if (ret < 0) {
460			if (ret != -ERANGE)
461				return ret;
462
463			break;
464		}
465
466		eccpos = oobregion.offset;
467		for (; i < MTD_MAX_ECCPOS_ENTRIES &&
468		       eccpos < oobregion.offset + oobregion.length; i++) {
469			to->eccpos[i] = eccpos++;
470			to->eccbytes++;
471		}
472	}
473
474	for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
475		ret = mtd_ooblayout_free(mtd, i, &oobregion);
476		if (ret < 0) {
477			if (ret != -ERANGE)
478				return ret;
479
480			break;
481		}
482
483		to->oobfree[i].offset = oobregion.offset;
484		to->oobfree[i].length = oobregion.length;
485		to->oobavail += to->oobfree[i].length;
486	}
487
488	return 0;
489}
490
491static int get_oobinfo(struct mtd_info *mtd, struct nand_oobinfo *to)
492{
493	struct mtd_oob_region oobregion;
494	int i, section = 0, ret;
495
496	if (!mtd || !to)
497		return -EINVAL;
498
499	memset(to, 0, sizeof(*to));
500
501	to->eccbytes = 0;
502	for (i = 0; i < ARRAY_SIZE(to->eccpos);) {
503		u32 eccpos;
504
505		ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
506		if (ret < 0) {
507			if (ret != -ERANGE)
508				return ret;
509
510			break;
511		}
512
513		if (oobregion.length + i > ARRAY_SIZE(to->eccpos))
514			return -EINVAL;
515
516		eccpos = oobregion.offset;
517		for (; eccpos < oobregion.offset + oobregion.length; i++) {
518			to->eccpos[i] = eccpos++;
519			to->eccbytes++;
520		}
521	}
522
523	for (i = 0; i < 8; i++) {
524		ret = mtd_ooblayout_free(mtd, i, &oobregion);
525		if (ret < 0) {
526			if (ret != -ERANGE)
527				return ret;
528
529			break;
530		}
531
532		to->oobfree[i][0] = oobregion.offset;
533		to->oobfree[i][1] = oobregion.length;
534	}
535
536	to->useecc = MTD_NANDECC_AUTOPLACE;
537
538	return 0;
539}
540
541static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
542			       struct blkpg_ioctl_arg *arg)
543{
544	struct blkpg_partition p;
545
546	if (!capable(CAP_SYS_ADMIN))
547		return -EPERM;
548
549	if (copy_from_user(&p, arg->data, sizeof(p)))
550		return -EFAULT;
551
552	switch (arg->op) {
553	case BLKPG_ADD_PARTITION:
554
555		/* Only master mtd device must be used to add partitions */
556		if (mtd_is_partition(mtd))
557			return -EINVAL;
558
559		/* Sanitize user input */
560		p.devname[BLKPG_DEVNAMELTH - 1] = '\0';
561
562		return mtd_add_partition(mtd, p.devname, p.start, p.length);
563
564	case BLKPG_DEL_PARTITION:
565
566		if (p.pno < 0)
567			return -EINVAL;
568
569		return mtd_del_partition(mtd, p.pno);
570
571	default:
572		return -EINVAL;
573	}
574}
575
576static void adjust_oob_length(struct mtd_info *mtd, uint64_t start,
577			      struct mtd_oob_ops *ops)
578{
579	uint32_t start_page, end_page;
580	u32 oob_per_page;
581
582	if (ops->len == 0 || ops->ooblen == 0)
583		return;
584
585	start_page = mtd_div_by_ws(start, mtd);
586	end_page = mtd_div_by_ws(start + ops->len - 1, mtd);
587	oob_per_page = mtd_oobavail(mtd, ops);
588
589	ops->ooblen = min_t(size_t, ops->ooblen,
590			    (end_page - start_page + 1) * oob_per_page);
591}
592
593static noinline_for_stack int
594mtdchar_write_ioctl(struct mtd_info *mtd, struct mtd_write_req __user *argp)
595{
596	struct mtd_info *master = mtd_get_master(mtd);
597	struct mtd_write_req req;
598	const void __user *usr_data, *usr_oob;
599	uint8_t *datbuf = NULL, *oobbuf = NULL;
600	size_t datbuf_len, oobbuf_len;
601	int ret = 0;
602
603	if (copy_from_user(&req, argp, sizeof(req)))
604		return -EFAULT;
605
606	usr_data = (const void __user *)(uintptr_t)req.usr_data;
607	usr_oob = (const void __user *)(uintptr_t)req.usr_oob;
608
609	if (!master->_write_oob)
610		return -EOPNOTSUPP;
611
612	if (!usr_data)
613		req.len = 0;
614
615	if (!usr_oob)
616		req.ooblen = 0;
617
618	req.len &= 0xffffffff;
619	req.ooblen &= 0xffffffff;
620
621	if (req.start + req.len > mtd->size)
622		return -EINVAL;
623
624	datbuf_len = min_t(size_t, req.len, mtd->erasesize);
625	if (datbuf_len > 0) {
626		datbuf = kvmalloc(datbuf_len, GFP_KERNEL);
627		if (!datbuf)
628			return -ENOMEM;
629	}
630
631	oobbuf_len = min_t(size_t, req.ooblen, mtd->erasesize);
632	if (oobbuf_len > 0) {
633		oobbuf = kvmalloc(oobbuf_len, GFP_KERNEL);
634		if (!oobbuf) {
635			kvfree(datbuf);
636			return -ENOMEM;
637		}
638	}
639
640	while (req.len > 0 || (!usr_data && req.ooblen > 0)) {
641		struct mtd_oob_ops ops = {
642			.mode = req.mode,
643			.len = min_t(size_t, req.len, datbuf_len),
644			.ooblen = min_t(size_t, req.ooblen, oobbuf_len),
645			.datbuf = datbuf,
646			.oobbuf = oobbuf,
647		};
648
649		/*
650		 * Shorten non-page-aligned, eraseblock-sized writes so that
651		 * the write ends on an eraseblock boundary.  This is necessary
652		 * for adjust_oob_length() to properly handle non-page-aligned
653		 * writes.
654		 */
655		if (ops.len == mtd->erasesize)
656			ops.len -= mtd_mod_by_ws(req.start + ops.len, mtd);
657
658		/*
659		 * For writes which are not OOB-only, adjust the amount of OOB
660		 * data written according to the number of data pages written.
661		 * This is necessary to prevent OOB data from being skipped
662		 * over in data+OOB writes requiring multiple mtd_write_oob()
663		 * calls to be completed.
664		 */
665		adjust_oob_length(mtd, req.start, &ops);
666
667		if (copy_from_user(datbuf, usr_data, ops.len) ||
668		    copy_from_user(oobbuf, usr_oob, ops.ooblen)) {
669			ret = -EFAULT;
670			break;
671		}
672
673		ret = mtd_write_oob(mtd, req.start, &ops);
674		if (ret)
675			break;
676
677		req.start += ops.retlen;
678		req.len -= ops.retlen;
679		usr_data += ops.retlen;
680
681		req.ooblen -= ops.oobretlen;
682		usr_oob += ops.oobretlen;
683	}
684
685	kvfree(datbuf);
686	kvfree(oobbuf);
687
688	return ret;
689}
690
691static noinline_for_stack int
692mtdchar_read_ioctl(struct mtd_info *mtd, struct mtd_read_req __user *argp)
693{
694	struct mtd_info *master = mtd_get_master(mtd);
695	struct mtd_read_req req;
696	void __user *usr_data, *usr_oob;
697	uint8_t *datbuf = NULL, *oobbuf = NULL;
698	size_t datbuf_len, oobbuf_len;
699	size_t orig_len, orig_ooblen;
700	int ret = 0;
701
702	if (copy_from_user(&req, argp, sizeof(req)))
703		return -EFAULT;
704
705	orig_len = req.len;
706	orig_ooblen = req.ooblen;
707
708	usr_data = (void __user *)(uintptr_t)req.usr_data;
709	usr_oob = (void __user *)(uintptr_t)req.usr_oob;
710
711	if (!master->_read_oob)
712		return -EOPNOTSUPP;
713
714	if (!usr_data)
715		req.len = 0;
716
717	if (!usr_oob)
718		req.ooblen = 0;
719
720	req.ecc_stats.uncorrectable_errors = 0;
721	req.ecc_stats.corrected_bitflips = 0;
722	req.ecc_stats.max_bitflips = 0;
723
724	req.len &= 0xffffffff;
725	req.ooblen &= 0xffffffff;
726
727	if (req.start + req.len > mtd->size) {
728		ret = -EINVAL;
729		goto out;
730	}
731
732	datbuf_len = min_t(size_t, req.len, mtd->erasesize);
733	if (datbuf_len > 0) {
734		datbuf = kvmalloc(datbuf_len, GFP_KERNEL);
735		if (!datbuf) {
736			ret = -ENOMEM;
737			goto out;
738		}
739	}
740
741	oobbuf_len = min_t(size_t, req.ooblen, mtd->erasesize);
742	if (oobbuf_len > 0) {
743		oobbuf = kvmalloc(oobbuf_len, GFP_KERNEL);
744		if (!oobbuf) {
745			ret = -ENOMEM;
746			goto out;
747		}
748	}
749
750	while (req.len > 0 || (!usr_data && req.ooblen > 0)) {
751		struct mtd_req_stats stats;
752		struct mtd_oob_ops ops = {
753			.mode = req.mode,
754			.len = min_t(size_t, req.len, datbuf_len),
755			.ooblen = min_t(size_t, req.ooblen, oobbuf_len),
756			.datbuf = datbuf,
757			.oobbuf = oobbuf,
758			.stats = &stats,
759		};
760
761		/*
762		 * Shorten non-page-aligned, eraseblock-sized reads so that the
763		 * read ends on an eraseblock boundary.  This is necessary in
764		 * order to prevent OOB data for some pages from being
765		 * duplicated in the output of non-page-aligned reads requiring
766		 * multiple mtd_read_oob() calls to be completed.
767		 */
768		if (ops.len == mtd->erasesize)
769			ops.len -= mtd_mod_by_ws(req.start + ops.len, mtd);
770
771		ret = mtd_read_oob(mtd, (loff_t)req.start, &ops);
772
773		req.ecc_stats.uncorrectable_errors +=
774			stats.uncorrectable_errors;
775		req.ecc_stats.corrected_bitflips += stats.corrected_bitflips;
776		req.ecc_stats.max_bitflips =
777			max(req.ecc_stats.max_bitflips, stats.max_bitflips);
778
779		if (ret && !mtd_is_bitflip_or_eccerr(ret))
780			break;
781
782		if (copy_to_user(usr_data, ops.datbuf, ops.retlen) ||
783		    copy_to_user(usr_oob, ops.oobbuf, ops.oobretlen)) {
784			ret = -EFAULT;
785			break;
786		}
787
788		req.start += ops.retlen;
789		req.len -= ops.retlen;
790		usr_data += ops.retlen;
791
792		req.ooblen -= ops.oobretlen;
793		usr_oob += ops.oobretlen;
794	}
795
796	/*
797	 * As multiple iterations of the above loop (and therefore multiple
798	 * mtd_read_oob() calls) may be necessary to complete the read request,
799	 * adjust the final return code to ensure it accounts for all detected
800	 * ECC errors.
801	 */
802	if (!ret || mtd_is_bitflip(ret)) {
803		if (req.ecc_stats.uncorrectable_errors > 0)
804			ret = -EBADMSG;
805		else if (req.ecc_stats.corrected_bitflips > 0)
806			ret = -EUCLEAN;
807	}
808
809out:
810	req.len = orig_len - req.len;
811	req.ooblen = orig_ooblen - req.ooblen;
812
813	if (copy_to_user(argp, &req, sizeof(req)))
814		ret = -EFAULT;
815
816	kvfree(datbuf);
817	kvfree(oobbuf);
818
819	return ret;
820}
821
822static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
823{
824	struct mtd_file_info *mfi = file->private_data;
825	struct mtd_info *mtd = mfi->mtd;
826	struct mtd_info *master = mtd_get_master(mtd);
827	void __user *argp = (void __user *)arg;
828	int ret = 0;
829	struct mtd_info_user info;
830
831	pr_debug("MTD_ioctl\n");
832
833	/*
834	 * Check the file mode to require "dangerous" commands to have write
835	 * permissions.
836	 */
837	switch (cmd) {
838	/* "safe" commands */
839	case MEMGETREGIONCOUNT:
840	case MEMGETREGIONINFO:
841	case MEMGETINFO:
842	case MEMREADOOB:
843	case MEMREADOOB64:
844	case MEMREAD:
845	case MEMISLOCKED:
846	case MEMGETOOBSEL:
847	case MEMGETBADBLOCK:
848	case OTPSELECT:
849	case OTPGETREGIONCOUNT:
850	case OTPGETREGIONINFO:
851	case ECCGETLAYOUT:
852	case ECCGETSTATS:
853	case MTDFILEMODE:
854	case BLKPG:
855	case BLKRRPART:
856		break;
857
858	/* "dangerous" commands */
859	case MEMERASE:
860	case MEMERASE64:
861	case MEMLOCK:
862	case MEMUNLOCK:
863	case MEMSETBADBLOCK:
864	case MEMWRITEOOB:
865	case MEMWRITEOOB64:
866	case MEMWRITE:
867	case OTPLOCK:
868	case OTPERASE:
869		if (!(file->f_mode & FMODE_WRITE))
870			return -EPERM;
871		break;
872
873	default:
874		return -ENOTTY;
875	}
876
877	switch (cmd) {
878	case MEMGETREGIONCOUNT:
879		if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
880			return -EFAULT;
881		break;
882
883	case MEMGETREGIONINFO:
884	{
885		uint32_t ur_idx;
886		struct mtd_erase_region_info *kr;
887		struct region_info_user __user *ur = argp;
888
889		if (get_user(ur_idx, &(ur->regionindex)))
890			return -EFAULT;
891
892		if (ur_idx >= mtd->numeraseregions)
893			return -EINVAL;
894
895		kr = &(mtd->eraseregions[ur_idx]);
896
897		if (put_user(kr->offset, &(ur->offset))
898		    || put_user(kr->erasesize, &(ur->erasesize))
899		    || put_user(kr->numblocks, &(ur->numblocks)))
900			return -EFAULT;
901
902		break;
903	}
904
905	case MEMGETINFO:
906		memset(&info, 0, sizeof(info));
907		info.type	= mtd->type;
908		info.flags	= mtd->flags;
909		info.size	= mtd->size;
910		info.erasesize	= mtd->erasesize;
911		info.writesize	= mtd->writesize;
912		info.oobsize	= mtd->oobsize;
913		/* The below field is obsolete */
914		info.padding	= 0;
915		if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
916			return -EFAULT;
917		break;
918
919	case MEMERASE:
920	case MEMERASE64:
921	{
922		struct erase_info *erase;
923
924		erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
925		if (!erase)
926			ret = -ENOMEM;
927		else {
928			if (cmd == MEMERASE64) {
929				struct erase_info_user64 einfo64;
930
931				if (copy_from_user(&einfo64, argp,
932					    sizeof(struct erase_info_user64))) {
933					kfree(erase);
934					return -EFAULT;
935				}
936				erase->addr = einfo64.start;
937				erase->len = einfo64.length;
938			} else {
939				struct erase_info_user einfo32;
940
941				if (copy_from_user(&einfo32, argp,
942					    sizeof(struct erase_info_user))) {
943					kfree(erase);
944					return -EFAULT;
945				}
946				erase->addr = einfo32.start;
947				erase->len = einfo32.length;
948			}
949
950			ret = mtd_erase(mtd, erase);
951			kfree(erase);
952		}
953		break;
954	}
955
956	case MEMWRITEOOB:
957	{
958		struct mtd_oob_buf buf;
959		struct mtd_oob_buf __user *buf_user = argp;
960
961		/* NOTE: writes return length to buf_user->length */
962		if (copy_from_user(&buf, argp, sizeof(buf)))
963			ret = -EFAULT;
964		else
965			ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
966				buf.ptr, &buf_user->length);
967		break;
968	}
969
970	case MEMREADOOB:
971	{
972		struct mtd_oob_buf buf;
973		struct mtd_oob_buf __user *buf_user = argp;
974
975		/* NOTE: writes return length to buf_user->start */
976		if (copy_from_user(&buf, argp, sizeof(buf)))
977			ret = -EFAULT;
978		else
979			ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
980				buf.ptr, &buf_user->start);
981		break;
982	}
983
984	case MEMWRITEOOB64:
985	{
986		struct mtd_oob_buf64 buf;
987		struct mtd_oob_buf64 __user *buf_user = argp;
988
989		if (copy_from_user(&buf, argp, sizeof(buf)))
990			ret = -EFAULT;
991		else
992			ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
993				(void __user *)(uintptr_t)buf.usr_ptr,
994				&buf_user->length);
995		break;
996	}
997
998	case MEMREADOOB64:
999	{
1000		struct mtd_oob_buf64 buf;
1001		struct mtd_oob_buf64 __user *buf_user = argp;
1002
1003		if (copy_from_user(&buf, argp, sizeof(buf)))
1004			ret = -EFAULT;
1005		else
1006			ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
1007				(void __user *)(uintptr_t)buf.usr_ptr,
1008				&buf_user->length);
1009		break;
1010	}
1011
1012	case MEMWRITE:
1013	{
1014		ret = mtdchar_write_ioctl(mtd,
1015		      (struct mtd_write_req __user *)arg);
1016		break;
1017	}
1018
1019	case MEMREAD:
1020	{
1021		ret = mtdchar_read_ioctl(mtd,
1022		      (struct mtd_read_req __user *)arg);
1023		break;
1024	}
1025
1026	case MEMLOCK:
1027	{
1028		struct erase_info_user einfo;
1029
1030		if (copy_from_user(&einfo, argp, sizeof(einfo)))
1031			return -EFAULT;
1032
1033		ret = mtd_lock(mtd, einfo.start, einfo.length);
1034		break;
1035	}
1036
1037	case MEMUNLOCK:
1038	{
1039		struct erase_info_user einfo;
1040
1041		if (copy_from_user(&einfo, argp, sizeof(einfo)))
1042			return -EFAULT;
1043
1044		ret = mtd_unlock(mtd, einfo.start, einfo.length);
1045		break;
1046	}
1047
1048	case MEMISLOCKED:
1049	{
1050		struct erase_info_user einfo;
1051
1052		if (copy_from_user(&einfo, argp, sizeof(einfo)))
1053			return -EFAULT;
1054
1055		ret = mtd_is_locked(mtd, einfo.start, einfo.length);
1056		break;
1057	}
1058
1059	/* Legacy interface */
1060	case MEMGETOOBSEL:
1061	{
1062		struct nand_oobinfo oi;
1063
1064		if (!master->ooblayout)
1065			return -EOPNOTSUPP;
1066
1067		ret = get_oobinfo(mtd, &oi);
1068		if (ret)
1069			return ret;
1070
1071		if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
1072			return -EFAULT;
1073		break;
1074	}
1075
1076	case MEMGETBADBLOCK:
1077	{
1078		loff_t offs;
1079
1080		if (copy_from_user(&offs, argp, sizeof(loff_t)))
1081			return -EFAULT;
1082		return mtd_block_isbad(mtd, offs);
1083	}
1084
1085	case MEMSETBADBLOCK:
1086	{
1087		loff_t offs;
1088
1089		if (copy_from_user(&offs, argp, sizeof(loff_t)))
1090			return -EFAULT;
1091		return mtd_block_markbad(mtd, offs);
1092	}
1093
1094	case OTPSELECT:
1095	{
1096		int mode;
1097		if (copy_from_user(&mode, argp, sizeof(int)))
1098			return -EFAULT;
1099
1100		mfi->mode = MTD_FILE_MODE_NORMAL;
1101
1102		ret = otp_select_filemode(mfi, mode);
1103
1104		file->f_pos = 0;
1105		break;
1106	}
1107
1108	case OTPGETREGIONCOUNT:
1109	case OTPGETREGIONINFO:
1110	{
1111		struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
1112		size_t retlen;
1113		if (!buf)
1114			return -ENOMEM;
1115		switch (mfi->mode) {
1116		case MTD_FILE_MODE_OTP_FACTORY:
1117			ret = mtd_get_fact_prot_info(mtd, 4096, &retlen, buf);
1118			break;
1119		case MTD_FILE_MODE_OTP_USER:
1120			ret = mtd_get_user_prot_info(mtd, 4096, &retlen, buf);
1121			break;
1122		default:
1123			ret = -EINVAL;
1124			break;
1125		}
1126		if (!ret) {
1127			if (cmd == OTPGETREGIONCOUNT) {
1128				int nbr = retlen / sizeof(struct otp_info);
1129				ret = copy_to_user(argp, &nbr, sizeof(int));
1130			} else
1131				ret = copy_to_user(argp, buf, retlen);
1132			if (ret)
1133				ret = -EFAULT;
1134		}
1135		kfree(buf);
1136		break;
1137	}
1138
1139	case OTPLOCK:
1140	case OTPERASE:
1141	{
1142		struct otp_info oinfo;
1143
1144		if (mfi->mode != MTD_FILE_MODE_OTP_USER)
1145			return -EINVAL;
1146		if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
1147			return -EFAULT;
1148		if (cmd == OTPLOCK)
1149			ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
1150		else
1151			ret = mtd_erase_user_prot_reg(mtd, oinfo.start, oinfo.length);
1152		break;
1153	}
1154
1155	/* This ioctl is being deprecated - it truncates the ECC layout */
1156	case ECCGETLAYOUT:
1157	{
1158		struct nand_ecclayout_user *usrlay;
1159
1160		if (!master->ooblayout)
1161			return -EOPNOTSUPP;
1162
1163		usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
1164		if (!usrlay)
1165			return -ENOMEM;
1166
1167		shrink_ecclayout(mtd, usrlay);
1168
1169		if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
1170			ret = -EFAULT;
1171		kfree(usrlay);
1172		break;
1173	}
1174
1175	case ECCGETSTATS:
1176	{
1177		if (copy_to_user(argp, &mtd->ecc_stats,
1178				 sizeof(struct mtd_ecc_stats)))
1179			return -EFAULT;
1180		break;
1181	}
1182
1183	case MTDFILEMODE:
1184	{
1185		mfi->mode = 0;
1186
1187		switch(arg) {
1188		case MTD_FILE_MODE_OTP_FACTORY:
1189		case MTD_FILE_MODE_OTP_USER:
1190			ret = otp_select_filemode(mfi, arg);
1191			break;
1192
1193		case MTD_FILE_MODE_RAW:
1194			if (!mtd_has_oob(mtd))
1195				return -EOPNOTSUPP;
1196			mfi->mode = arg;
1197			break;
1198
1199		case MTD_FILE_MODE_NORMAL:
1200			break;
1201		default:
1202			ret = -EINVAL;
1203		}
1204		file->f_pos = 0;
1205		break;
1206	}
1207
1208	case BLKPG:
1209	{
1210		struct blkpg_ioctl_arg __user *blk_arg = argp;
1211		struct blkpg_ioctl_arg a;
1212
1213		if (copy_from_user(&a, blk_arg, sizeof(a)))
1214			ret = -EFAULT;
1215		else
1216			ret = mtdchar_blkpg_ioctl(mtd, &a);
1217		break;
1218	}
1219
1220	case BLKRRPART:
1221	{
1222		/* No reread partition feature. Just return ok */
1223		ret = 0;
1224		break;
1225	}
1226	}
1227
1228	return ret;
1229} /* memory_ioctl */
1230
1231static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1232{
1233	struct mtd_file_info *mfi = file->private_data;
1234	struct mtd_info *mtd = mfi->mtd;
1235	struct mtd_info *master = mtd_get_master(mtd);
1236	int ret;
1237
1238	mutex_lock(&master->master.chrdev_lock);
1239	ret = mtdchar_ioctl(file, cmd, arg);
1240	mutex_unlock(&master->master.chrdev_lock);
1241
1242	return ret;
1243}
1244
1245#ifdef CONFIG_COMPAT
1246
1247struct mtd_oob_buf32 {
1248	u_int32_t start;
1249	u_int32_t length;
1250	compat_caddr_t ptr;	/* unsigned char* */
1251};
1252
1253#define MEMWRITEOOB32		_IOWR('M', 3, struct mtd_oob_buf32)
1254#define MEMREADOOB32		_IOWR('M', 4, struct mtd_oob_buf32)
1255
1256static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1257	unsigned long arg)
1258{
1259	struct mtd_file_info *mfi = file->private_data;
1260	struct mtd_info *mtd = mfi->mtd;
1261	struct mtd_info *master = mtd_get_master(mtd);
1262	void __user *argp = compat_ptr(arg);
1263	int ret = 0;
1264
1265	mutex_lock(&master->master.chrdev_lock);
1266
1267	switch (cmd) {
1268	case MEMWRITEOOB32:
1269	{
1270		struct mtd_oob_buf32 buf;
1271		struct mtd_oob_buf32 __user *buf_user = argp;
1272
1273		if (!(file->f_mode & FMODE_WRITE)) {
1274			ret = -EPERM;
1275			break;
1276		}
1277
1278		if (copy_from_user(&buf, argp, sizeof(buf)))
1279			ret = -EFAULT;
1280		else
1281			ret = mtdchar_writeoob(file, mtd, buf.start,
1282				buf.length, compat_ptr(buf.ptr),
1283				&buf_user->length);
1284		break;
1285	}
1286
1287	case MEMREADOOB32:
1288	{
1289		struct mtd_oob_buf32 buf;
1290		struct mtd_oob_buf32 __user *buf_user = argp;
1291
1292		/* NOTE: writes return length to buf->start */
1293		if (copy_from_user(&buf, argp, sizeof(buf)))
1294			ret = -EFAULT;
1295		else
1296			ret = mtdchar_readoob(file, mtd, buf.start,
1297				buf.length, compat_ptr(buf.ptr),
1298				&buf_user->start);
1299		break;
1300	}
1301
1302	case BLKPG:
1303	{
1304		/* Convert from blkpg_compat_ioctl_arg to blkpg_ioctl_arg */
1305		struct blkpg_compat_ioctl_arg __user *uarg = argp;
1306		struct blkpg_compat_ioctl_arg compat_arg;
1307		struct blkpg_ioctl_arg a;
1308
1309		if (copy_from_user(&compat_arg, uarg, sizeof(compat_arg))) {
1310			ret = -EFAULT;
1311			break;
1312		}
1313
1314		memset(&a, 0, sizeof(a));
1315		a.op = compat_arg.op;
1316		a.flags = compat_arg.flags;
1317		a.datalen = compat_arg.datalen;
1318		a.data = compat_ptr(compat_arg.data);
1319
1320		ret = mtdchar_blkpg_ioctl(mtd, &a);
1321		break;
1322	}
1323
1324	default:
1325		ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1326	}
1327
1328	mutex_unlock(&master->master.chrdev_lock);
1329
1330	return ret;
1331}
1332
1333#endif /* CONFIG_COMPAT */
1334
1335/*
1336 * try to determine where a shared mapping can be made
1337 * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1338 *   mappings)
1339 */
1340#ifndef CONFIG_MMU
1341static unsigned long mtdchar_get_unmapped_area(struct file *file,
1342					   unsigned long addr,
1343					   unsigned long len,
1344					   unsigned long pgoff,
1345					   unsigned long flags)
1346{
1347	struct mtd_file_info *mfi = file->private_data;
1348	struct mtd_info *mtd = mfi->mtd;
1349	unsigned long offset;
1350	int ret;
1351
1352	if (addr != 0)
1353		return (unsigned long) -EINVAL;
1354
1355	if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1356		return (unsigned long) -EINVAL;
1357
1358	offset = pgoff << PAGE_SHIFT;
1359	if (offset > mtd->size - len)
1360		return (unsigned long) -EINVAL;
1361
1362	ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1363	return ret == -EOPNOTSUPP ? -ENODEV : ret;
1364}
1365
1366static unsigned mtdchar_mmap_capabilities(struct file *file)
1367{
1368	struct mtd_file_info *mfi = file->private_data;
1369
1370	return mtd_mmap_capabilities(mfi->mtd);
1371}
1372#endif
1373
1374/*
1375 * set up a mapping for shared memory segments
1376 */
1377static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1378{
1379#ifdef CONFIG_MMU
1380	struct mtd_file_info *mfi = file->private_data;
1381	struct mtd_info *mtd = mfi->mtd;
1382	struct map_info *map = mtd->priv;
1383
1384        /* This is broken because it assumes the MTD device is map-based
1385	   and that mtd->priv is a valid struct map_info.  It should be
1386	   replaced with something that uses the mtd_get_unmapped_area()
1387	   operation properly. */
1388	if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1389#ifdef pgprot_noncached
1390		if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1391			vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1392#endif
1393		return vm_iomap_memory(vma, map->phys, map->size);
1394	}
1395	return -ENODEV;
1396#else
1397	return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
1398#endif
1399}
1400
1401static const struct file_operations mtd_fops = {
1402	.owner		= THIS_MODULE,
1403	.llseek		= mtdchar_lseek,
1404	.read		= mtdchar_read,
1405	.write		= mtdchar_write,
1406	.unlocked_ioctl	= mtdchar_unlocked_ioctl,
1407#ifdef CONFIG_COMPAT
1408	.compat_ioctl	= mtdchar_compat_ioctl,
1409#endif
1410	.open		= mtdchar_open,
1411	.release	= mtdchar_close,
1412	.mmap		= mtdchar_mmap,
1413#ifndef CONFIG_MMU
1414	.get_unmapped_area = mtdchar_get_unmapped_area,
1415	.mmap_capabilities = mtdchar_mmap_capabilities,
1416#endif
1417};
1418
1419int __init init_mtdchar(void)
1420{
1421	int ret;
1422
1423	ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1424				   "mtd", &mtd_fops);
1425	if (ret < 0) {
1426		pr_err("Can't allocate major number %d for MTD\n",
1427		       MTD_CHAR_MAJOR);
1428		return ret;
1429	}
1430
1431	return ret;
1432}
1433
1434void __exit cleanup_mtdchar(void)
1435{
1436	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1437}
1438
1439MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1440