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 MEMLOCK:
 655	case MEMUNLOCK:
 656	case MEMISLOCKED:
 657	case MEMGETOOBSEL:
 658	case MEMGETBADBLOCK:
 659	case MEMSETBADBLOCK:
 660	case OTPSELECT:
 661	case OTPGETREGIONCOUNT:
 662	case OTPGETREGIONINFO:
 663	case OTPLOCK:
 664	case ECCGETLAYOUT:
 665	case ECCGETSTATS:
 666	case MTDFILEMODE:
 667	case BLKPG:
 668	case BLKRRPART:
 669		break;
 670
 671	/* "dangerous" commands */
 672	case MEMERASE:
 673	case MEMERASE64:
 674	case MEMWRITEOOB:
 675	case MEMWRITEOOB64:
 676	case MEMWRITE:
 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);