xref: /openbmc/linux/drivers/mtd/mtdchar.c (revision 7a010c3c)
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  */
34 struct mtd_file_info {
35 	struct mtd_info *mtd;
36 	enum mtd_file_modes mode;
37 };
38 
39 static 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 
45 static 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 
84 out1:
85 	put_mtd_device(mtd);
86 	return ret;
87 } /* mtdchar_open */
88 
89 /*====================================================================*/
90 
91 static 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 
127 static 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 
217 static 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 
310 static 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 
340 static 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 
382 static 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  */
443 static 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 
491 static 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 
541 static 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 
576 static int mtdchar_write_ioctl(struct mtd_info *mtd,
577 		struct mtd_write_req __user *argp)
578 {
579 	struct mtd_info *master = mtd_get_master(mtd);
580 	struct mtd_write_req req;
581 	struct mtd_oob_ops ops = {};
582 	const void __user *usr_data, *usr_oob;
583 	int ret;
584 
585 	if (copy_from_user(&req, argp, sizeof(req)))
586 		return -EFAULT;
587 
588 	usr_data = (const void __user *)(uintptr_t)req.usr_data;
589 	usr_oob = (const void __user *)(uintptr_t)req.usr_oob;
590 
591 	if (!master->_write_oob)
592 		return -EOPNOTSUPP;
593 	ops.mode = req.mode;
594 	ops.len = (size_t)req.len;
595 	ops.ooblen = (size_t)req.ooblen;
596 	ops.ooboffs = 0;
597 
598 	if (usr_data) {
599 		ops.datbuf = memdup_user(usr_data, ops.len);
600 		if (IS_ERR(ops.datbuf))
601 			return PTR_ERR(ops.datbuf);
602 	} else {
603 		ops.datbuf = NULL;
604 	}
605 
606 	if (usr_oob) {
607 		ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
608 		if (IS_ERR(ops.oobbuf)) {
609 			kfree(ops.datbuf);
610 			return PTR_ERR(ops.oobbuf);
611 		}
612 	} else {
613 		ops.oobbuf = NULL;
614 	}
615 
616 	ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
617 
618 	kfree(ops.datbuf);
619 	kfree(ops.oobbuf);
620 
621 	return ret;
622 }
623 
624 static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
625 {
626 	struct mtd_file_info *mfi = file->private_data;
627 	struct mtd_info *mtd = mfi->mtd;
628 	struct mtd_info *master = mtd_get_master(mtd);
629 	void __user *argp = (void __user *)arg;
630 	int ret = 0;
631 	struct mtd_info_user info;
632 
633 	pr_debug("MTD_ioctl\n");
634 
635 	/*
636 	 * Check the file mode to require "dangerous" commands to have write
637 	 * permissions.
638 	 */
639 	switch (cmd) {
640 	/* "safe" commands */
641 	case MEMGETREGIONCOUNT:
642 	case MEMGETREGIONINFO:
643 	case MEMGETINFO:
644 	case MEMREADOOB:
645 	case MEMREADOOB64:
646 	case MEMISLOCKED:
647 	case MEMGETOOBSEL:
648 	case MEMGETBADBLOCK:
649 	case OTPSELECT:
650 	case OTPGETREGIONCOUNT:
651 	case OTPGETREGIONINFO:
652 	case ECCGETLAYOUT:
653 	case ECCGETSTATS:
654 	case MTDFILEMODE:
655 	case BLKPG:
656 	case BLKRRPART:
657 		break;
658 
659 	/* "dangerous" commands */
660 	case MEMERASE:
661 	case MEMERASE64:
662 	case MEMLOCK:
663 	case MEMUNLOCK:
664 	case MEMSETBADBLOCK:
665 	case MEMWRITEOOB:
666 	case MEMWRITEOOB64:
667 	case MEMWRITE:
668 	case OTPLOCK:
669 	case OTPERASE:
670 		if (!(file->f_mode & FMODE_WRITE))
671 			return -EPERM;
672 		break;
673 
674 	default:
675 		return -ENOTTY;
676 	}
677 
678 	switch (cmd) {
679 	case MEMGETREGIONCOUNT:
680 		if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
681 			return -EFAULT;
682 		break;
683 
684 	case MEMGETREGIONINFO:
685 	{
686 		uint32_t ur_idx;
687 		struct mtd_erase_region_info *kr;
688 		struct region_info_user __user *ur = argp;
689 
690 		if (get_user(ur_idx, &(ur->regionindex)))
691 			return -EFAULT;
692 
693 		if (ur_idx >= mtd->numeraseregions)
694 			return -EINVAL;
695 
696 		kr = &(mtd->eraseregions[ur_idx]);
697 
698 		if (put_user(kr->offset, &(ur->offset))
699 		    || put_user(kr->erasesize, &(ur->erasesize))
700 		    || put_user(kr->numblocks, &(ur->numblocks)))
701 			return -EFAULT;
702 
703 		break;
704 	}
705 
706 	case MEMGETINFO:
707 		memset(&info, 0, sizeof(info));
708 		info.type	= mtd->type;
709 		info.flags	= mtd->flags;
710 		info.size	= mtd->size;
711 		info.erasesize	= mtd->erasesize;
712 		info.writesize	= mtd->writesize;
713 		info.oobsize	= mtd->oobsize;
714 		/* The below field is obsolete */
715 		info.padding	= 0;
716 		if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
717 			return -EFAULT;
718 		break;
719 
720 	case MEMERASE:
721 	case MEMERASE64:
722 	{
723 		struct erase_info *erase;
724 
725 		erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
726 		if (!erase)
727 			ret = -ENOMEM;
728 		else {
729 			if (cmd == MEMERASE64) {
730 				struct erase_info_user64 einfo64;
731 
732 				if (copy_from_user(&einfo64, argp,
733 					    sizeof(struct erase_info_user64))) {
734 					kfree(erase);
735 					return -EFAULT;
736 				}
737 				erase->addr = einfo64.start;
738 				erase->len = einfo64.length;
739 			} else {
740 				struct erase_info_user einfo32;
741 
742 				if (copy_from_user(&einfo32, argp,
743 					    sizeof(struct erase_info_user))) {
744 					kfree(erase);
745 					return -EFAULT;
746 				}
747 				erase->addr = einfo32.start;
748 				erase->len = einfo32.length;
749 			}
750 
751 			ret = mtd_erase(mtd, erase);
752 			kfree(erase);
753 		}
754 		break;
755 	}
756 
757 	case MEMWRITEOOB:
758 	{
759 		struct mtd_oob_buf buf;
760 		struct mtd_oob_buf __user *buf_user = argp;
761 
762 		/* NOTE: writes return length to buf_user->length */
763 		if (copy_from_user(&buf, argp, sizeof(buf)))
764 			ret = -EFAULT;
765 		else
766 			ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
767 				buf.ptr, &buf_user->length);
768 		break;
769 	}
770 
771 	case MEMREADOOB:
772 	{
773 		struct mtd_oob_buf buf;
774 		struct mtd_oob_buf __user *buf_user = argp;
775 
776 		/* NOTE: writes return length to buf_user->start */
777 		if (copy_from_user(&buf, argp, sizeof(buf)))
778 			ret = -EFAULT;
779 		else
780 			ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
781 				buf.ptr, &buf_user->start);
782 		break;
783 	}
784 
785 	case MEMWRITEOOB64:
786 	{
787 		struct mtd_oob_buf64 buf;
788 		struct mtd_oob_buf64 __user *buf_user = argp;
789 
790 		if (copy_from_user(&buf, argp, sizeof(buf)))
791 			ret = -EFAULT;
792 		else
793 			ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
794 				(void __user *)(uintptr_t)buf.usr_ptr,
795 				&buf_user->length);
796 		break;
797 	}
798 
799 	case MEMREADOOB64:
800 	{
801 		struct mtd_oob_buf64 buf;
802 		struct mtd_oob_buf64 __user *buf_user = argp;
803 
804 		if (copy_from_user(&buf, argp, sizeof(buf)))
805 			ret = -EFAULT;
806 		else
807 			ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
808 				(void __user *)(uintptr_t)buf.usr_ptr,
809 				&buf_user->length);
810 		break;
811 	}
812 
813 	case MEMWRITE:
814 	{
815 		ret = mtdchar_write_ioctl(mtd,
816 		      (struct mtd_write_req __user *)arg);
817 		break;
818 	}
819 
820 	case MEMLOCK:
821 	{
822 		struct erase_info_user einfo;
823 
824 		if (copy_from_user(&einfo, argp, sizeof(einfo)))
825 			return -EFAULT;
826 
827 		ret = mtd_lock(mtd, einfo.start, einfo.length);
828 		break;
829 	}
830 
831 	case MEMUNLOCK:
832 	{
833 		struct erase_info_user einfo;
834 
835 		if (copy_from_user(&einfo, argp, sizeof(einfo)))
836 			return -EFAULT;
837 
838 		ret = mtd_unlock(mtd, einfo.start, einfo.length);
839 		break;
840 	}
841 
842 	case MEMISLOCKED:
843 	{
844 		struct erase_info_user einfo;
845 
846 		if (copy_from_user(&einfo, argp, sizeof(einfo)))
847 			return -EFAULT;
848 
849 		ret = mtd_is_locked(mtd, einfo.start, einfo.length);
850 		break;
851 	}
852 
853 	/* Legacy interface */
854 	case MEMGETOOBSEL:
855 	{
856 		struct nand_oobinfo oi;
857 
858 		if (!master->ooblayout)
859 			return -EOPNOTSUPP;
860 
861 		ret = get_oobinfo(mtd, &oi);
862 		if (ret)
863 			return ret;
864 
865 		if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
866 			return -EFAULT;
867 		break;
868 	}
869 
870 	case MEMGETBADBLOCK:
871 	{
872 		loff_t offs;
873 
874 		if (copy_from_user(&offs, argp, sizeof(loff_t)))
875 			return -EFAULT;
876 		return mtd_block_isbad(mtd, offs);
877 	}
878 
879 	case MEMSETBADBLOCK:
880 	{
881 		loff_t offs;
882 
883 		if (copy_from_user(&offs, argp, sizeof(loff_t)))
884 			return -EFAULT;
885 		return mtd_block_markbad(mtd, offs);
886 	}
887 
888 	case OTPSELECT:
889 	{
890 		int mode;
891 		if (copy_from_user(&mode, argp, sizeof(int)))
892 			return -EFAULT;
893 
894 		mfi->mode = MTD_FILE_MODE_NORMAL;
895 
896 		ret = otp_select_filemode(mfi, mode);
897 
898 		file->f_pos = 0;
899 		break;
900 	}
901 
902 	case OTPGETREGIONCOUNT:
903 	case OTPGETREGIONINFO:
904 	{
905 		struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
906 		size_t retlen;
907 		if (!buf)
908 			return -ENOMEM;
909 		switch (mfi->mode) {
910 		case MTD_FILE_MODE_OTP_FACTORY:
911 			ret = mtd_get_fact_prot_info(mtd, 4096, &retlen, buf);
912 			break;
913 		case MTD_FILE_MODE_OTP_USER:
914 			ret = mtd_get_user_prot_info(mtd, 4096, &retlen, buf);
915 			break;
916 		default:
917 			ret = -EINVAL;
918 			break;
919 		}
920 		if (!ret) {
921 			if (cmd == OTPGETREGIONCOUNT) {
922 				int nbr = retlen / sizeof(struct otp_info);
923 				ret = copy_to_user(argp, &nbr, sizeof(int));
924 			} else
925 				ret = copy_to_user(argp, buf, retlen);
926 			if (ret)
927 				ret = -EFAULT;
928 		}
929 		kfree(buf);
930 		break;
931 	}
932 
933 	case OTPLOCK:
934 	case OTPERASE:
935 	{
936 		struct otp_info oinfo;
937 
938 		if (mfi->mode != MTD_FILE_MODE_OTP_USER)
939 			return -EINVAL;
940 		if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
941 			return -EFAULT;
942 		if (cmd == OTPLOCK)
943 			ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
944 		else
945 			ret = mtd_erase_user_prot_reg(mtd, oinfo.start, oinfo.length);
946 		break;
947 	}
948 
949 	/* This ioctl is being deprecated - it truncates the ECC layout */
950 	case ECCGETLAYOUT:
951 	{
952 		struct nand_ecclayout_user *usrlay;
953 
954 		if (!master->ooblayout)
955 			return -EOPNOTSUPP;
956 
957 		usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
958 		if (!usrlay)
959 			return -ENOMEM;
960 
961 		shrink_ecclayout(mtd, usrlay);
962 
963 		if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
964 			ret = -EFAULT;
965 		kfree(usrlay);
966 		break;
967 	}
968 
969 	case ECCGETSTATS:
970 	{
971 		if (copy_to_user(argp, &mtd->ecc_stats,
972 				 sizeof(struct mtd_ecc_stats)))
973 			return -EFAULT;
974 		break;
975 	}
976 
977 	case MTDFILEMODE:
978 	{
979 		mfi->mode = 0;
980 
981 		switch(arg) {
982 		case MTD_FILE_MODE_OTP_FACTORY:
983 		case MTD_FILE_MODE_OTP_USER:
984 			ret = otp_select_filemode(mfi, arg);
985 			break;
986 
987 		case MTD_FILE_MODE_RAW:
988 			if (!mtd_has_oob(mtd))
989 				return -EOPNOTSUPP;
990 			mfi->mode = arg;
991 			break;
992 
993 		case MTD_FILE_MODE_NORMAL:
994 			break;
995 		default:
996 			ret = -EINVAL;
997 		}
998 		file->f_pos = 0;
999 		break;
1000 	}
1001 
1002 	case BLKPG:
1003 	{
1004 		struct blkpg_ioctl_arg __user *blk_arg = argp;
1005 		struct blkpg_ioctl_arg a;
1006 
1007 		if (copy_from_user(&a, blk_arg, sizeof(a)))
1008 			ret = -EFAULT;
1009 		else
1010 			ret = mtdchar_blkpg_ioctl(mtd, &a);
1011 		break;
1012 	}
1013 
1014 	case BLKRRPART:
1015 	{
1016 		/* No reread partition feature. Just return ok */
1017 		ret = 0;
1018 		break;
1019 	}
1020 	}
1021 
1022 	return ret;
1023 } /* memory_ioctl */
1024 
1025 static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1026 {
1027 	struct mtd_file_info *mfi = file->private_data;
1028 	struct mtd_info *mtd = mfi->mtd;
1029 	struct mtd_info *master = mtd_get_master(mtd);
1030 	int ret;
1031 
1032 	mutex_lock(&master->master.chrdev_lock);
1033 	ret = mtdchar_ioctl(file, cmd, arg);
1034 	mutex_unlock(&master->master.chrdev_lock);
1035 
1036 	return ret;
1037 }
1038 
1039 #ifdef CONFIG_COMPAT
1040 
1041 struct mtd_oob_buf32 {
1042 	u_int32_t start;
1043 	u_int32_t length;
1044 	compat_caddr_t ptr;	/* unsigned char* */
1045 };
1046 
1047 #define MEMWRITEOOB32		_IOWR('M', 3, struct mtd_oob_buf32)
1048 #define MEMREADOOB32		_IOWR('M', 4, struct mtd_oob_buf32)
1049 
1050 static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1051 	unsigned long arg)
1052 {
1053 	struct mtd_file_info *mfi = file->private_data;
1054 	struct mtd_info *mtd = mfi->mtd;
1055 	struct mtd_info *master = mtd_get_master(mtd);
1056 	void __user *argp = compat_ptr(arg);
1057 	int ret = 0;
1058 
1059 	mutex_lock(&master->master.chrdev_lock);
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(&master->master.chrdev_lock);
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
1135 static 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 
1160 static 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  */
1171 static 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 
1195 static 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 
1213 int __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 
1228 void __exit cleanup_mtdchar(void)
1229 {
1230 	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1231 }
1232 
1233 MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1234