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v5.4
   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_file_info *mfi = file->private_data;
 353	struct mtd_oob_ops ops;
 354	uint32_t retlen;
 355	int ret = 0;
 356
 357	if (!(file->f_mode & FMODE_WRITE))
 358		return -EPERM;
 359
 360	if (length > 4096)
 361		return -EINVAL;
 362
 363	if (!mtd->_write_oob)
 364		return -EOPNOTSUPP;
 365
 366	ops.ooblen = length;
 367	ops.ooboffs = start & (mtd->writesize - 1);
 368	ops.datbuf = NULL;
 369	ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 370		MTD_OPS_PLACE_OOB;
 371
 372	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 373		return -EINVAL;
 374
 375	ops.oobbuf = memdup_user(ptr, length);
 376	if (IS_ERR(ops.oobbuf))
 377		return PTR_ERR(ops.oobbuf);
 378
 379	start &= ~((uint64_t)mtd->writesize - 1);
 380	ret = mtd_write_oob(mtd, start, &ops);
 381
 382	if (ops.oobretlen > 0xFFFFFFFFU)
 383		ret = -EOVERFLOW;
 384	retlen = ops.oobretlen;
 385	if (copy_to_user(retp, &retlen, sizeof(length)))
 386		ret = -EFAULT;
 387
 388	kfree(ops.oobbuf);
 389	return ret;
 390}
 391
 392static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
 393	uint64_t start, uint32_t length, void __user *ptr,
 394	uint32_t __user *retp)
 395{
 396	struct mtd_file_info *mfi = file->private_data;
 397	struct mtd_oob_ops ops;
 398	int ret = 0;
 399
 400	if (length > 4096)
 401		return -EINVAL;
 402
 403	ops.ooblen = length;
 404	ops.ooboffs = start & (mtd->writesize - 1);
 405	ops.datbuf = NULL;
 406	ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 407		MTD_OPS_PLACE_OOB;
 408
 409	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 410		return -EINVAL;
 411
 412	ops.oobbuf = kmalloc(length, GFP_KERNEL);
 413	if (!ops.oobbuf)
 414		return -ENOMEM;
 415
 416	start &= ~((uint64_t)mtd->writesize - 1);
 417	ret = mtd_read_oob(mtd, start, &ops);
 418
 419	if (put_user(ops.oobretlen, retp))
 420		ret = -EFAULT;
 421	else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 422					    ops.oobretlen))
 423		ret = -EFAULT;
 424
 425	kfree(ops.oobbuf);
 426
 427	/*
 428	 * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 429	 * data. For our userspace tools it is important to dump areas
 430	 * with ECC errors!
 431	 * For kernel internal usage it also might return -EUCLEAN
 432	 * to signal the caller that a bitflip has occurred and has
 433	 * been corrected by the ECC algorithm.
 434	 *
 435	 * Note: currently the standard NAND function, nand_read_oob_std,
 436	 * does not calculate ECC for the OOB area, so do not rely on
 437	 * this behavior unless you have replaced it with your own.
 438	 */
 439	if (mtd_is_bitflip_or_eccerr(ret))
 440		return 0;
 441
 442	return ret;
 443}
 444
 445/*
 446 * Copies (and truncates, if necessary) OOB layout information to the
 447 * deprecated layout struct, nand_ecclayout_user. This is necessary only to
 448 * support the deprecated API ioctl ECCGETLAYOUT while allowing all new
 449 * functionality to use mtd_ooblayout_ops flexibly (i.e. mtd_ooblayout_ops
 450 * can describe any kind of OOB layout with almost zero overhead from a
 451 * memory usage point of view).
 452 */
 453static int shrink_ecclayout(struct mtd_info *mtd,
 454			    struct nand_ecclayout_user *to)
 455{
 456	struct mtd_oob_region oobregion;
 457	int i, section = 0, ret;
 458
 459	if (!mtd || !to)
 460		return -EINVAL;
 461
 462	memset(to, 0, sizeof(*to));
 463
 464	to->eccbytes = 0;
 465	for (i = 0; i < MTD_MAX_ECCPOS_ENTRIES;) {
 466		u32 eccpos;
 467
 468		ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
 469		if (ret < 0) {
 470			if (ret != -ERANGE)
 471				return ret;
 472
 473			break;
 474		}
 475
 476		eccpos = oobregion.offset;
 477		for (; i < MTD_MAX_ECCPOS_ENTRIES &&
 478		       eccpos < oobregion.offset + oobregion.length; i++) {
 479			to->eccpos[i] = eccpos++;
 480			to->eccbytes++;
 481		}
 482	}
 483
 484	for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 485		ret = mtd_ooblayout_free(mtd, i, &oobregion);
 486		if (ret < 0) {
 487			if (ret != -ERANGE)
 488				return ret;
 489
 490			break;
 491		}
 492
 493		to->oobfree[i].offset = oobregion.offset;
 494		to->oobfree[i].length = oobregion.length;
 495		to->oobavail += to->oobfree[i].length;
 496	}
 497
 498	return 0;
 499}
 500
 501static int get_oobinfo(struct mtd_info *mtd, struct nand_oobinfo *to)
 502{
 503	struct mtd_oob_region oobregion;
 504	int i, section = 0, ret;
 505
 506	if (!mtd || !to)
 507		return -EINVAL;
 508
 509	memset(to, 0, sizeof(*to));
 510
 511	to->eccbytes = 0;
 512	for (i = 0; i < ARRAY_SIZE(to->eccpos);) {
 513		u32 eccpos;
 514
 515		ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
 516		if (ret < 0) {
 517			if (ret != -ERANGE)
 518				return ret;
 519
 520			break;
 521		}
 522
 523		if (oobregion.length + i > ARRAY_SIZE(to->eccpos))
 524			return -EINVAL;
 525
 526		eccpos = oobregion.offset;
 527		for (; eccpos < oobregion.offset + oobregion.length; i++) {
 528			to->eccpos[i] = eccpos++;
 529			to->eccbytes++;
 530		}
 531	}
 532
 533	for (i = 0; i < 8; i++) {
 534		ret = mtd_ooblayout_free(mtd, i, &oobregion);
 535		if (ret < 0) {
 536			if (ret != -ERANGE)
 537				return ret;
 538
 539			break;
 540		}
 541
 542		to->oobfree[i][0] = oobregion.offset;
 543		to->oobfree[i][1] = oobregion.length;
 544	}
 545
 546	to->useecc = MTD_NANDECC_AUTOPLACE;
 547
 548	return 0;
 549}
 550
 551static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
 552			       struct blkpg_ioctl_arg *arg)
 553{
 554	struct blkpg_partition p;
 555
 556	if (!capable(CAP_SYS_ADMIN))
 557		return -EPERM;
 558
 559	if (copy_from_user(&p, arg->data, sizeof(p)))
 560		return -EFAULT;
 561
 562	switch (arg->op) {
 563	case BLKPG_ADD_PARTITION:
 564
 565		/* Only master mtd device must be used to add partitions */
 566		if (mtd_is_partition(mtd))
 567			return -EINVAL;
 568
 569		/* Sanitize user input */
 570		p.devname[BLKPG_DEVNAMELTH - 1] = '\0';
 571
 572		return mtd_add_partition(mtd, p.devname, p.start, p.length);
 573
 574	case BLKPG_DEL_PARTITION:
 575
 576		if (p.pno < 0)
 577			return -EINVAL;
 578
 579		return mtd_del_partition(mtd, p.pno);
 580
 581	default:
 582		return -EINVAL;
 583	}
 584}
 585
 586static int mtdchar_write_ioctl(struct mtd_info *mtd,
 587		struct mtd_write_req __user *argp)
 588{
 589	struct mtd_write_req req;
 590	struct mtd_oob_ops ops;
 591	const void __user *usr_data, *usr_oob;
 592	int ret;
 593
 594	if (copy_from_user(&req, argp, sizeof(req)))
 595		return -EFAULT;
 596
 597	usr_data = (const void __user *)(uintptr_t)req.usr_data;
 598	usr_oob = (const void __user *)(uintptr_t)req.usr_oob;
 599
 600	if (!mtd->_write_oob)
 601		return -EOPNOTSUPP;
 602
 603	ops.mode = req.mode;
 604	ops.len = (size_t)req.len;
 605	ops.ooblen = (size_t)req.ooblen;
 606	ops.ooboffs = 0;
 607
 608	if (usr_data) {
 609		ops.datbuf = memdup_user(usr_data, ops.len);
 610		if (IS_ERR(ops.datbuf))
 611			return PTR_ERR(ops.datbuf);
 612	} else {
 613		ops.datbuf = NULL;
 614	}
 615
 616	if (usr_oob) {
 617		ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 618		if (IS_ERR(ops.oobbuf)) {
 619			kfree(ops.datbuf);
 620			return PTR_ERR(ops.oobbuf);
 621		}
 622	} else {
 623		ops.oobbuf = NULL;
 624	}
 625
 626	ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
 627
 628	kfree(ops.datbuf);
 629	kfree(ops.oobbuf);
 630
 631	return ret;
 632}
 633
 634static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 635{
 636	struct mtd_file_info *mfi = file->private_data;
 637	struct mtd_info *mtd = mfi->mtd;
 638	void __user *argp = (void __user *)arg;
 639	int ret = 0;
 640	struct mtd_info_user info;
 641
 642	pr_debug("MTD_ioctl\n");
 643
 644	switch (cmd) {
 645	case MEMGETREGIONCOUNT:
 646		if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 647			return -EFAULT;
 648		break;
 649
 650	case MEMGETREGIONINFO:
 651	{
 652		uint32_t ur_idx;
 653		struct mtd_erase_region_info *kr;
 654		struct region_info_user __user *ur = argp;
 655
 656		if (get_user(ur_idx, &(ur->regionindex)))
 657			return -EFAULT;
 658
 659		if (ur_idx >= mtd->numeraseregions)
 660			return -EINVAL;
 661
 662		kr = &(mtd->eraseregions[ur_idx]);
 663
 664		if (put_user(kr->offset, &(ur->offset))
 665		    || put_user(kr->erasesize, &(ur->erasesize))
 666		    || put_user(kr->numblocks, &(ur->numblocks)))
 667			return -EFAULT;
 668
 669		break;
 670	}
 671
 672	case MEMGETINFO:
 673		memset(&info, 0, sizeof(info));
 674		info.type	= mtd->type;
 675		info.flags	= mtd->flags;
 676		info.size	= mtd->size;
 677		info.erasesize	= mtd->erasesize;
 678		info.writesize	= mtd->writesize;
 679		info.oobsize	= mtd->oobsize;
 680		/* The below field is obsolete */
 681		info.padding	= 0;
 682		if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 683			return -EFAULT;
 684		break;
 685
 686	case MEMERASE:
 687	case MEMERASE64:
 688	{
 689		struct erase_info *erase;
 690
 691		if(!(file->f_mode & FMODE_WRITE))
 692			return -EPERM;
 693
 694		erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 695		if (!erase)
 696			ret = -ENOMEM;
 697		else {
 698			if (cmd == MEMERASE64) {
 699				struct erase_info_user64 einfo64;
 700
 701				if (copy_from_user(&einfo64, argp,
 702					    sizeof(struct erase_info_user64))) {
 703					kfree(erase);
 704					return -EFAULT;
 705				}
 706				erase->addr = einfo64.start;
 707				erase->len = einfo64.length;
 708			} else {
 709				struct erase_info_user einfo32;
 710
 711				if (copy_from_user(&einfo32, argp,
 712					    sizeof(struct erase_info_user))) {
 713					kfree(erase);
 714					return -EFAULT;
 715				}
 716				erase->addr = einfo32.start;
 717				erase->len = einfo32.length;
 718			}
 719
 720			ret = mtd_erase(mtd, erase);
 721			kfree(erase);
 722		}
 723		break;
 724	}
 725
 726	case MEMWRITEOOB:
 727	{
 728		struct mtd_oob_buf buf;
 729		struct mtd_oob_buf __user *buf_user = argp;
 730
 731		/* NOTE: writes return length to buf_user->length */
 732		if (copy_from_user(&buf, argp, sizeof(buf)))
 733			ret = -EFAULT;
 734		else
 735			ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 736				buf.ptr, &buf_user->length);
 737		break;
 738	}
 739
 740	case MEMREADOOB:
 741	{
 742		struct mtd_oob_buf buf;
 743		struct mtd_oob_buf __user *buf_user = argp;
 744
 745		/* NOTE: writes return length to buf_user->start */
 746		if (copy_from_user(&buf, argp, sizeof(buf)))
 747			ret = -EFAULT;
 748		else
 749			ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 750				buf.ptr, &buf_user->start);
 751		break;
 752	}
 753
 754	case MEMWRITEOOB64:
 755	{
 756		struct mtd_oob_buf64 buf;
 757		struct mtd_oob_buf64 __user *buf_user = argp;
 758
 759		if (copy_from_user(&buf, argp, sizeof(buf)))
 760			ret = -EFAULT;
 761		else
 762			ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 763				(void __user *)(uintptr_t)buf.usr_ptr,
 764				&buf_user->length);
 765		break;
 766	}
 767
 768	case MEMREADOOB64:
 769	{
 770		struct mtd_oob_buf64 buf;
 771		struct mtd_oob_buf64 __user *buf_user = argp;
 772
 773		if (copy_from_user(&buf, argp, sizeof(buf)))
 774			ret = -EFAULT;
 775		else
 776			ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 777				(void __user *)(uintptr_t)buf.usr_ptr,
 778				&buf_user->length);
 779		break;
 780	}
 781
 782	case MEMWRITE:
 783	{
 784		ret = mtdchar_write_ioctl(mtd,
 785		      (struct mtd_write_req __user *)arg);
 786		break;
 787	}
 788
 789	case MEMLOCK:
 790	{
 791		struct erase_info_user einfo;
 792
 793		if (copy_from_user(&einfo, argp, sizeof(einfo)))
 794			return -EFAULT;
 795
 796		ret = mtd_lock(mtd, einfo.start, einfo.length);
 797		break;
 798	}
 799
 800	case MEMUNLOCK:
 801	{
 802		struct erase_info_user einfo;
 803
 804		if (copy_from_user(&einfo, argp, sizeof(einfo)))
 805			return -EFAULT;
 806
 807		ret = mtd_unlock(mtd, einfo.start, einfo.length);
 808		break;
 809	}
 810
 811	case MEMISLOCKED:
 812	{
 813		struct erase_info_user einfo;
 814
 815		if (copy_from_user(&einfo, argp, sizeof(einfo)))
 816			return -EFAULT;
 817
 818		ret = mtd_is_locked(mtd, einfo.start, einfo.length);
 819		break;
 820	}
 821
 822	/* Legacy interface */
 823	case MEMGETOOBSEL:
 824	{
 825		struct nand_oobinfo oi;
 826
 827		if (!mtd->ooblayout)
 828			return -EOPNOTSUPP;
 829
 830		ret = get_oobinfo(mtd, &oi);
 831		if (ret)
 832			return ret;
 833
 834		if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 835			return -EFAULT;
 836		break;
 837	}
 838
 839	case MEMGETBADBLOCK:
 840	{
 841		loff_t offs;
 842
 843		if (copy_from_user(&offs, argp, sizeof(loff_t)))
 844			return -EFAULT;
 845		return mtd_block_isbad(mtd, offs);
 846		break;
 847	}
 848
 849	case MEMSETBADBLOCK:
 850	{
 851		loff_t offs;
 852
 853		if (copy_from_user(&offs, argp, sizeof(loff_t)))
 854			return -EFAULT;
 855		return mtd_block_markbad(mtd, offs);
 856		break;
 857	}
 858
 859	case OTPSELECT:
 860	{
 861		int mode;
 862		if (copy_from_user(&mode, argp, sizeof(int)))
 863			return -EFAULT;
 864
 865		mfi->mode = MTD_FILE_MODE_NORMAL;
 866
 867		ret = otp_select_filemode(mfi, mode);
 868
 869		file->f_pos = 0;
 870		break;
 871	}
 872
 873	case OTPGETREGIONCOUNT:
 874	case OTPGETREGIONINFO:
 875	{
 876		struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 877		size_t retlen;
 878		if (!buf)
 879			return -ENOMEM;
 880		switch (mfi->mode) {
 881		case MTD_FILE_MODE_OTP_FACTORY:
 882			ret = mtd_get_fact_prot_info(mtd, 4096, &retlen, buf);
 883			break;
 884		case MTD_FILE_MODE_OTP_USER:
 885			ret = mtd_get_user_prot_info(mtd, 4096, &retlen, buf);
 886			break;
 887		default:
 888			ret = -EINVAL;
 889			break;
 890		}
 891		if (!ret) {
 892			if (cmd == OTPGETREGIONCOUNT) {
 893				int nbr = retlen / sizeof(struct otp_info);
 894				ret = copy_to_user(argp, &nbr, sizeof(int));
 895			} else
 896				ret = copy_to_user(argp, buf, retlen);
 897			if (ret)
 898				ret = -EFAULT;
 899		}
 900		kfree(buf);
 901		break;
 902	}
 903
 904	case OTPLOCK:
 905	{
 906		struct otp_info oinfo;
 907
 908		if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 909			return -EINVAL;
 910		if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 911			return -EFAULT;
 912		ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 913		break;
 914	}
 915
 916	/* This ioctl is being deprecated - it truncates the ECC layout */
 917	case ECCGETLAYOUT:
 918	{
 919		struct nand_ecclayout_user *usrlay;
 920
 921		if (!mtd->ooblayout)
 922			return -EOPNOTSUPP;
 923
 924		usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 925		if (!usrlay)
 926			return -ENOMEM;
 927
 928		shrink_ecclayout(mtd, usrlay);
 929
 930		if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 931			ret = -EFAULT;
 932		kfree(usrlay);
 933		break;
 934	}
 935
 936	case ECCGETSTATS:
 937	{
 938		if (copy_to_user(argp, &mtd->ecc_stats,
 939				 sizeof(struct mtd_ecc_stats)))
 940			return -EFAULT;
 941		break;
 942	}
 943
 944	case MTDFILEMODE:
 945	{
 946		mfi->mode = 0;
 947
 948		switch(arg) {
 949		case MTD_FILE_MODE_OTP_FACTORY:
 950		case MTD_FILE_MODE_OTP_USER:
 951			ret = otp_select_filemode(mfi, arg);
 952			break;
 953
 954		case MTD_FILE_MODE_RAW:
 955			if (!mtd_has_oob(mtd))
 956				return -EOPNOTSUPP;
 957			mfi->mode = arg;
 958
 959		case MTD_FILE_MODE_NORMAL:
 960			break;
 961		default:
 962			ret = -EINVAL;
 963		}
 964		file->f_pos = 0;
 965		break;
 966	}
 967
 968	case BLKPG:
 969	{
 970		struct blkpg_ioctl_arg __user *blk_arg = argp;
 971		struct blkpg_ioctl_arg a;
 972
 973		if (copy_from_user(&a, blk_arg, sizeof(a)))
 974			ret = -EFAULT;
 975		else
 976			ret = mtdchar_blkpg_ioctl(mtd, &a);
 977		break;
 978	}
 979
 980	case BLKRRPART:
 981	{
 982		/* No reread partition feature. Just return ok */
 983		ret = 0;
 984		break;
 985	}
 986
 987	default:
 988		ret = -ENOTTY;
 989	}
 990
 991	return ret;
 992} /* memory_ioctl */
 993
 994static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
 995{
 996	int ret;
 997
 998	mutex_lock(&mtd_mutex);
 999	ret = mtdchar_ioctl(file, cmd, arg);
1000	mutex_unlock(&mtd_mutex);
1001
1002	return ret;
1003}
1004
1005#ifdef CONFIG_COMPAT
1006
1007struct mtd_oob_buf32 {
1008	u_int32_t start;
1009	u_int32_t length;
1010	compat_caddr_t ptr;	/* unsigned char* */
1011};
1012
1013#define MEMWRITEOOB32		_IOWR('M', 3, struct mtd_oob_buf32)
1014#define MEMREADOOB32		_IOWR('M', 4, struct mtd_oob_buf32)
1015
1016static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1017	unsigned long arg)
1018{
1019	struct mtd_file_info *mfi = file->private_data;
1020	struct mtd_info *mtd = mfi->mtd;
1021	void __user *argp = compat_ptr(arg);
1022	int ret = 0;
1023
1024	mutex_lock(&mtd_mutex);
1025
1026	switch (cmd) {
1027	case MEMWRITEOOB32:
1028	{
1029		struct mtd_oob_buf32 buf;
1030		struct mtd_oob_buf32 __user *buf_user = argp;
1031
1032		if (copy_from_user(&buf, argp, sizeof(buf)))
1033			ret = -EFAULT;
1034		else
1035			ret = mtdchar_writeoob(file, mtd, buf.start,
1036				buf.length, compat_ptr(buf.ptr),
1037				&buf_user->length);
1038		break;
1039	}
1040
1041	case MEMREADOOB32:
1042	{
1043		struct mtd_oob_buf32 buf;
1044		struct mtd_oob_buf32 __user *buf_user = argp;
1045
1046		/* NOTE: writes return length to buf->start */
1047		if (copy_from_user(&buf, argp, sizeof(buf)))
1048			ret = -EFAULT;
1049		else
1050			ret = mtdchar_readoob(file, mtd, buf.start,
1051				buf.length, compat_ptr(buf.ptr),
1052				&buf_user->start);
1053		break;
1054	}
1055
1056	case BLKPG:
1057	{
1058		/* Convert from blkpg_compat_ioctl_arg to blkpg_ioctl_arg */
1059		struct blkpg_compat_ioctl_arg __user *uarg = argp;
1060		struct blkpg_compat_ioctl_arg compat_arg;
1061		struct blkpg_ioctl_arg a;
1062
1063		if (copy_from_user(&compat_arg, uarg, sizeof(compat_arg))) {
1064			ret = -EFAULT;
1065			break;
1066		}
1067
1068		memset(&a, 0, sizeof(a));
1069		a.op = compat_arg.op;
1070		a.flags = compat_arg.flags;
1071		a.datalen = compat_arg.datalen;
1072		a.data = compat_ptr(compat_arg.data);
1073
1074		ret = mtdchar_blkpg_ioctl(mtd, &a);
1075		break;
1076	}
1077
1078	default:
1079		ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1080	}
1081
1082	mutex_unlock(&mtd_mutex);
1083
1084	return ret;
1085}
1086
1087#endif /* CONFIG_COMPAT */
1088
1089/*
1090 * try to determine where a shared mapping can be made
1091 * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1092 *   mappings)
1093 */
1094#ifndef CONFIG_MMU
1095static unsigned long mtdchar_get_unmapped_area(struct file *file,
1096					   unsigned long addr,
1097					   unsigned long len,
1098					   unsigned long pgoff,
1099					   unsigned long flags)
1100{
1101	struct mtd_file_info *mfi = file->private_data;
1102	struct mtd_info *mtd = mfi->mtd;
1103	unsigned long offset;
1104	int ret;
1105
1106	if (addr != 0)
1107		return (unsigned long) -EINVAL;
1108
1109	if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1110		return (unsigned long) -EINVAL;
1111
1112	offset = pgoff << PAGE_SHIFT;
1113	if (offset > mtd->size - len)
1114		return (unsigned long) -EINVAL;
1115
1116	ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1117	return ret == -EOPNOTSUPP ? -ENODEV : ret;
1118}
1119
1120static unsigned mtdchar_mmap_capabilities(struct file *file)
1121{
1122	struct mtd_file_info *mfi = file->private_data;
1123
1124	return mtd_mmap_capabilities(mfi->mtd);
1125}
1126#endif
1127
1128/*
1129 * set up a mapping for shared memory segments
1130 */
1131static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1132{
1133#ifdef CONFIG_MMU
1134	struct mtd_file_info *mfi = file->private_data;
1135	struct mtd_info *mtd = mfi->mtd;
1136	struct map_info *map = mtd->priv;
1137
1138        /* This is broken because it assumes the MTD device is map-based
1139	   and that mtd->priv is a valid struct map_info.  It should be
1140	   replaced with something that uses the mtd_get_unmapped_area()
1141	   operation properly. */
1142	if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1143#ifdef pgprot_noncached
1144		if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1145			vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1146#endif
1147		return vm_iomap_memory(vma, map->phys, map->size);
1148	}
1149	return -ENODEV;
1150#else
1151	return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
1152#endif
1153}
1154
1155static const struct file_operations mtd_fops = {
1156	.owner		= THIS_MODULE,
1157	.llseek		= mtdchar_lseek,
1158	.read		= mtdchar_read,
1159	.write		= mtdchar_write,
1160	.unlocked_ioctl	= mtdchar_unlocked_ioctl,
1161#ifdef CONFIG_COMPAT
1162	.compat_ioctl	= mtdchar_compat_ioctl,
1163#endif
1164	.open		= mtdchar_open,
1165	.release	= mtdchar_close,
1166	.mmap		= mtdchar_mmap,
1167#ifndef CONFIG_MMU
1168	.get_unmapped_area = mtdchar_get_unmapped_area,
1169	.mmap_capabilities = mtdchar_mmap_capabilities,
1170#endif
1171};
1172
1173int __init init_mtdchar(void)
1174{
1175	int ret;
1176
1177	ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1178				   "mtd", &mtd_fops);
1179	if (ret < 0) {
1180		pr_err("Can't allocate major number %d for MTD\n",
1181		       MTD_CHAR_MAJOR);
1182		return ret;
1183	}
1184
1185	return ret;
1186}
1187
1188void __exit cleanup_mtdchar(void)
1189{
1190	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1191}
1192
1193MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
v4.17
 
   1/*
   2 * Copyright © 1999-2010 David Woodhouse <dwmw2@infradead.org>
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License as published by
   6 * the Free Software Foundation; either version 2 of the License, or
   7 * (at your option) any later version.
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write to the Free Software
  16 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17 *
  18 */
  19
  20#include <linux/device.h>
  21#include <linux/fs.h>
  22#include <linux/mm.h>
  23#include <linux/err.h>
  24#include <linux/init.h>
  25#include <linux/kernel.h>
  26#include <linux/module.h>
  27#include <linux/slab.h>
  28#include <linux/sched.h>
  29#include <linux/mutex.h>
  30#include <linux/backing-dev.h>
  31#include <linux/compat.h>
  32#include <linux/mount.h>
  33#include <linux/blkpg.h>
  34#include <linux/magic.h>
  35#include <linux/major.h>
  36#include <linux/mtd/mtd.h>
  37#include <linux/mtd/partitions.h>
  38#include <linux/mtd/map.h>
  39
  40#include <linux/uaccess.h>
  41
  42#include "mtdcore.h"
  43
  44static DEFINE_MUTEX(mtd_mutex);
  45
  46/*
  47 * Data structure to hold the pointer to the mtd device as well
  48 * as mode information of various use cases.
  49 */
  50struct mtd_file_info {
  51	struct mtd_info *mtd;
  52	enum mtd_file_modes mode;
  53};
  54
  55static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig)
  56{
  57	struct mtd_file_info *mfi = file->private_data;
  58	return fixed_size_llseek(file, offset, orig, mfi->mtd->size);
  59}
  60
  61static int mtdchar_open(struct inode *inode, struct file *file)
  62{
  63	int minor = iminor(inode);
  64	int devnum = minor >> 1;
  65	int ret = 0;
  66	struct mtd_info *mtd;
  67	struct mtd_file_info *mfi;
  68
  69	pr_debug("MTD_open\n");
  70
  71	/* You can't open the RO devices RW */
  72	if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  73		return -EACCES;
  74
  75	mutex_lock(&mtd_mutex);
  76	mtd = get_mtd_device(NULL, devnum);
  77
  78	if (IS_ERR(mtd)) {
  79		ret = PTR_ERR(mtd);
  80		goto out;
  81	}
  82
  83	if (mtd->type == MTD_ABSENT) {
  84		ret = -ENODEV;
  85		goto out1;
  86	}
  87
  88	/* You can't open it RW if it's not a writeable device */
  89	if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
  90		ret = -EACCES;
  91		goto out1;
  92	}
  93
  94	mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
  95	if (!mfi) {
  96		ret = -ENOMEM;
  97		goto out1;
  98	}
  99	mfi->mtd = mtd;
 100	file->private_data = mfi;
 101	mutex_unlock(&mtd_mutex);
 102	return 0;
 103
 104out1:
 105	put_mtd_device(mtd);
 106out:
 107	mutex_unlock(&mtd_mutex);
 108	return ret;
 109} /* mtdchar_open */
 110
 111/*====================================================================*/
 112
 113static int mtdchar_close(struct inode *inode, struct file *file)
 114{
 115	struct mtd_file_info *mfi = file->private_data;
 116	struct mtd_info *mtd = mfi->mtd;
 117
 118	pr_debug("MTD_close\n");
 119
 120	/* Only sync if opened RW */
 121	if ((file->f_mode & FMODE_WRITE))
 122		mtd_sync(mtd);
 123
 124	put_mtd_device(mtd);
 125	file->private_data = NULL;
 126	kfree(mfi);
 127
 128	return 0;
 129} /* mtdchar_close */
 130
 131/* Back in June 2001, dwmw2 wrote:
 132 *
 133 *   FIXME: This _really_ needs to die. In 2.5, we should lock the
 134 *   userspace buffer down and use it directly with readv/writev.
 135 *
 136 * The implementation below, using mtd_kmalloc_up_to, mitigates
 137 * allocation failures when the system is under low-memory situations
 138 * or if memory is highly fragmented at the cost of reducing the
 139 * performance of the requested transfer due to a smaller buffer size.
 140 *
 141 * A more complex but more memory-efficient implementation based on
 142 * get_user_pages and iovecs to cover extents of those pages is a
 143 * longer-term goal, as intimated by dwmw2 above. However, for the
 144 * write case, this requires yet more complex head and tail transfer
 145 * handling when those head and tail offsets and sizes are such that
 146 * alignment requirements are not met in the NAND subdriver.
 147 */
 148
 149static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
 150			loff_t *ppos)
 151{
 152	struct mtd_file_info *mfi = file->private_data;
 153	struct mtd_info *mtd = mfi->mtd;
 154	size_t retlen;
 155	size_t total_retlen=0;
 156	int ret=0;
 157	int len;
 158	size_t size = count;
 159	char *kbuf;
 160
 161	pr_debug("MTD_read\n");
 162
 163	if (*ppos + count > mtd->size)
 164		count = mtd->size - *ppos;
 
 
 
 
 165
 166	if (!count)
 167		return 0;
 168
 169	kbuf = mtd_kmalloc_up_to(mtd, &size);
 170	if (!kbuf)
 171		return -ENOMEM;
 172
 173	while (count) {
 174		len = min_t(size_t, count, size);
 175
 176		switch (mfi->mode) {
 177		case MTD_FILE_MODE_OTP_FACTORY:
 178			ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
 179						     &retlen, kbuf);
 180			break;
 181		case MTD_FILE_MODE_OTP_USER:
 182			ret = mtd_read_user_prot_reg(mtd, *ppos, len,
 183						     &retlen, kbuf);
 184			break;
 185		case MTD_FILE_MODE_RAW:
 186		{
 187			struct mtd_oob_ops ops;
 188
 189			ops.mode = MTD_OPS_RAW;
 190			ops.datbuf = kbuf;
 191			ops.oobbuf = NULL;
 192			ops.len = len;
 193
 194			ret = mtd_read_oob(mtd, *ppos, &ops);
 195			retlen = ops.retlen;
 196			break;
 197		}
 198		default:
 199			ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
 200		}
 201		/* Nand returns -EBADMSG on ECC errors, but it returns
 202		 * the data. For our userspace tools it is important
 203		 * to dump areas with ECC errors!
 204		 * For kernel internal usage it also might return -EUCLEAN
 205		 * to signal the caller that a bitflip has occurred and has
 206		 * been corrected by the ECC algorithm.
 207		 * Userspace software which accesses NAND this way
 208		 * must be aware of the fact that it deals with NAND
 209		 */
 210		if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
 211			*ppos += retlen;
 212			if (copy_to_user(buf, kbuf, retlen)) {
 213				kfree(kbuf);
 214				return -EFAULT;
 215			}
 216			else
 217				total_retlen += retlen;
 218
 219			count -= retlen;
 220			buf += retlen;
 221			if (retlen == 0)
 222				count = 0;
 223		}
 224		else {
 225			kfree(kbuf);
 226			return ret;
 227		}
 228
 229	}
 230
 231	kfree(kbuf);
 232	return total_retlen;
 233} /* mtdchar_read */
 234
 235static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
 236			loff_t *ppos)
 237{
 238	struct mtd_file_info *mfi = file->private_data;
 239	struct mtd_info *mtd = mfi->mtd;
 240	size_t size = count;
 241	char *kbuf;
 242	size_t retlen;
 243	size_t total_retlen=0;
 244	int ret=0;
 245	int len;
 246
 247	pr_debug("MTD_write\n");
 248
 249	if (*ppos == mtd->size)
 250		return -ENOSPC;
 251
 252	if (*ppos + count > mtd->size)
 253		count = mtd->size - *ppos;
 254
 255	if (!count)
 256		return 0;
 257
 258	kbuf = mtd_kmalloc_up_to(mtd, &size);
 259	if (!kbuf)
 260		return -ENOMEM;
 261
 262	while (count) {
 263		len = min_t(size_t, count, size);
 264
 265		if (copy_from_user(kbuf, buf, len)) {
 266			kfree(kbuf);
 267			return -EFAULT;
 268		}
 269
 270		switch (mfi->mode) {
 271		case MTD_FILE_MODE_OTP_FACTORY:
 272			ret = -EROFS;
 273			break;
 274		case MTD_FILE_MODE_OTP_USER:
 275			ret = mtd_write_user_prot_reg(mtd, *ppos, len,
 276						      &retlen, kbuf);
 277			break;
 278
 279		case MTD_FILE_MODE_RAW:
 280		{
 281			struct mtd_oob_ops ops;
 282
 283			ops.mode = MTD_OPS_RAW;
 284			ops.datbuf = kbuf;
 285			ops.oobbuf = NULL;
 286			ops.ooboffs = 0;
 287			ops.len = len;
 288
 289			ret = mtd_write_oob(mtd, *ppos, &ops);
 290			retlen = ops.retlen;
 291			break;
 292		}
 293
 294		default:
 295			ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
 296		}
 297
 298		/*
 299		 * Return -ENOSPC only if no data could be written at all.
 300		 * Otherwise just return the number of bytes that actually
 301		 * have been written.
 302		 */
 303		if ((ret == -ENOSPC) && (total_retlen))
 304			break;
 305
 306		if (!ret) {
 307			*ppos += retlen;
 308			total_retlen += retlen;
 309			count -= retlen;
 310			buf += retlen;
 311		}
 312		else {
 313			kfree(kbuf);
 314			return ret;
 315		}
 316	}
 317
 318	kfree(kbuf);
 319	return total_retlen;
 320} /* mtdchar_write */
 321
 322/*======================================================================
 323
 324    IOCTL calls for getting device parameters.
 325
 326======================================================================*/
 327
 328static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 329{
 330	struct mtd_info *mtd = mfi->mtd;
 331	size_t retlen;
 332
 333	switch (mode) {
 334	case MTD_OTP_FACTORY:
 335		if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 336				-EOPNOTSUPP)
 337			return -EOPNOTSUPP;
 338
 339		mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
 340		break;
 341	case MTD_OTP_USER:
 342		if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 343				-EOPNOTSUPP)
 344			return -EOPNOTSUPP;
 345
 346		mfi->mode = MTD_FILE_MODE_OTP_USER;
 347		break;
 348	case MTD_OTP_OFF:
 349		mfi->mode = MTD_FILE_MODE_NORMAL;
 350		break;
 351	default:
 352		return -EINVAL;
 353	}
 354
 355	return 0;
 356}
 357
 358static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
 359	uint64_t start, uint32_t length, void __user *ptr,
 360	uint32_t __user *retp)
 361{
 362	struct mtd_file_info *mfi = file->private_data;
 363	struct mtd_oob_ops ops;
 364	uint32_t retlen;
 365	int ret = 0;
 366
 367	if (!(file->f_mode & FMODE_WRITE))
 368		return -EPERM;
 369
 370	if (length > 4096)
 371		return -EINVAL;
 372
 373	if (!mtd->_write_oob)
 374		return -EOPNOTSUPP;
 375
 376	ops.ooblen = length;
 377	ops.ooboffs = start & (mtd->writesize - 1);
 378	ops.datbuf = NULL;
 379	ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 380		MTD_OPS_PLACE_OOB;
 381
 382	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 383		return -EINVAL;
 384
 385	ops.oobbuf = memdup_user(ptr, length);
 386	if (IS_ERR(ops.oobbuf))
 387		return PTR_ERR(ops.oobbuf);
 388
 389	start &= ~((uint64_t)mtd->writesize - 1);
 390	ret = mtd_write_oob(mtd, start, &ops);
 391
 392	if (ops.oobretlen > 0xFFFFFFFFU)
 393		ret = -EOVERFLOW;
 394	retlen = ops.oobretlen;
 395	if (copy_to_user(retp, &retlen, sizeof(length)))
 396		ret = -EFAULT;
 397
 398	kfree(ops.oobbuf);
 399	return ret;
 400}
 401
 402static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
 403	uint64_t start, uint32_t length, void __user *ptr,
 404	uint32_t __user *retp)
 405{
 406	struct mtd_file_info *mfi = file->private_data;
 407	struct mtd_oob_ops ops;
 408	int ret = 0;
 409
 410	if (length > 4096)
 411		return -EINVAL;
 412
 413	ops.ooblen = length;
 414	ops.ooboffs = start & (mtd->writesize - 1);
 415	ops.datbuf = NULL;
 416	ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 417		MTD_OPS_PLACE_OOB;
 418
 419	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 420		return -EINVAL;
 421
 422	ops.oobbuf = kmalloc(length, GFP_KERNEL);
 423	if (!ops.oobbuf)
 424		return -ENOMEM;
 425
 426	start &= ~((uint64_t)mtd->writesize - 1);
 427	ret = mtd_read_oob(mtd, start, &ops);
 428
 429	if (put_user(ops.oobretlen, retp))
 430		ret = -EFAULT;
 431	else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 432					    ops.oobretlen))
 433		ret = -EFAULT;
 434
 435	kfree(ops.oobbuf);
 436
 437	/*
 438	 * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 439	 * data. For our userspace tools it is important to dump areas
 440	 * with ECC errors!
 441	 * For kernel internal usage it also might return -EUCLEAN
 442	 * to signal the caller that a bitflip has occurred and has
 443	 * been corrected by the ECC algorithm.
 444	 *
 445	 * Note: currently the standard NAND function, nand_read_oob_std,
 446	 * does not calculate ECC for the OOB area, so do not rely on
 447	 * this behavior unless you have replaced it with your own.
 448	 */
 449	if (mtd_is_bitflip_or_eccerr(ret))
 450		return 0;
 451
 452	return ret;
 453}
 454
 455/*
 456 * Copies (and truncates, if necessary) OOB layout information to the
 457 * deprecated layout struct, nand_ecclayout_user. This is necessary only to
 458 * support the deprecated API ioctl ECCGETLAYOUT while allowing all new
 459 * functionality to use mtd_ooblayout_ops flexibly (i.e. mtd_ooblayout_ops
 460 * can describe any kind of OOB layout with almost zero overhead from a
 461 * memory usage point of view).
 462 */
 463static int shrink_ecclayout(struct mtd_info *mtd,
 464			    struct nand_ecclayout_user *to)
 465{
 466	struct mtd_oob_region oobregion;
 467	int i, section = 0, ret;
 468
 469	if (!mtd || !to)
 470		return -EINVAL;
 471
 472	memset(to, 0, sizeof(*to));
 473
 474	to->eccbytes = 0;
 475	for (i = 0; i < MTD_MAX_ECCPOS_ENTRIES;) {
 476		u32 eccpos;
 477
 478		ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
 479		if (ret < 0) {
 480			if (ret != -ERANGE)
 481				return ret;
 482
 483			break;
 484		}
 485
 486		eccpos = oobregion.offset;
 487		for (; i < MTD_MAX_ECCPOS_ENTRIES &&
 488		       eccpos < oobregion.offset + oobregion.length; i++) {
 489			to->eccpos[i] = eccpos++;
 490			to->eccbytes++;
 491		}
 492	}
 493
 494	for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 495		ret = mtd_ooblayout_free(mtd, i, &oobregion);
 496		if (ret < 0) {
 497			if (ret != -ERANGE)
 498				return ret;
 499
 500			break;
 501		}
 502
 503		to->oobfree[i].offset = oobregion.offset;
 504		to->oobfree[i].length = oobregion.length;
 505		to->oobavail += to->oobfree[i].length;
 506	}
 507
 508	return 0;
 509}
 510
 511static int get_oobinfo(struct mtd_info *mtd, struct nand_oobinfo *to)
 512{
 513	struct mtd_oob_region oobregion;
 514	int i, section = 0, ret;
 515
 516	if (!mtd || !to)
 517		return -EINVAL;
 518
 519	memset(to, 0, sizeof(*to));
 520
 521	to->eccbytes = 0;
 522	for (i = 0; i < ARRAY_SIZE(to->eccpos);) {
 523		u32 eccpos;
 524
 525		ret = mtd_ooblayout_ecc(mtd, section++, &oobregion);
 526		if (ret < 0) {
 527			if (ret != -ERANGE)
 528				return ret;
 529
 530			break;
 531		}
 532
 533		if (oobregion.length + i > ARRAY_SIZE(to->eccpos))
 534			return -EINVAL;
 535
 536		eccpos = oobregion.offset;
 537		for (; eccpos < oobregion.offset + oobregion.length; i++) {
 538			to->eccpos[i] = eccpos++;
 539			to->eccbytes++;
 540		}
 541	}
 542
 543	for (i = 0; i < 8; i++) {
 544		ret = mtd_ooblayout_free(mtd, i, &oobregion);
 545		if (ret < 0) {
 546			if (ret != -ERANGE)
 547				return ret;
 548
 549			break;
 550		}
 551
 552		to->oobfree[i][0] = oobregion.offset;
 553		to->oobfree[i][1] = oobregion.length;
 554	}
 555
 556	to->useecc = MTD_NANDECC_AUTOPLACE;
 557
 558	return 0;
 559}
 560
 561static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
 562			       struct blkpg_ioctl_arg *arg)
 563{
 564	struct blkpg_partition p;
 565
 566	if (!capable(CAP_SYS_ADMIN))
 567		return -EPERM;
 568
 569	if (copy_from_user(&p, arg->data, sizeof(p)))
 570		return -EFAULT;
 571
 572	switch (arg->op) {
 573	case BLKPG_ADD_PARTITION:
 574
 575		/* Only master mtd device must be used to add partitions */
 576		if (mtd_is_partition(mtd))
 577			return -EINVAL;
 578
 579		/* Sanitize user input */
 580		p.devname[BLKPG_DEVNAMELTH - 1] = '\0';
 581
 582		return mtd_add_partition(mtd, p.devname, p.start, p.length);
 583
 584	case BLKPG_DEL_PARTITION:
 585
 586		if (p.pno < 0)
 587			return -EINVAL;
 588
 589		return mtd_del_partition(mtd, p.pno);
 590
 591	default:
 592		return -EINVAL;
 593	}
 594}
 595
 596static int mtdchar_write_ioctl(struct mtd_info *mtd,
 597		struct mtd_write_req __user *argp)
 598{
 599	struct mtd_write_req req;
 600	struct mtd_oob_ops ops;
 601	const void __user *usr_data, *usr_oob;
 602	int ret;
 603
 604	if (copy_from_user(&req, argp, sizeof(req)))
 605		return -EFAULT;
 606
 607	usr_data = (const void __user *)(uintptr_t)req.usr_data;
 608	usr_oob = (const void __user *)(uintptr_t)req.usr_oob;
 609
 610	if (!mtd->_write_oob)
 611		return -EOPNOTSUPP;
 612
 613	ops.mode = req.mode;
 614	ops.len = (size_t)req.len;
 615	ops.ooblen = (size_t)req.ooblen;
 616	ops.ooboffs = 0;
 617
 618	if (usr_data) {
 619		ops.datbuf = memdup_user(usr_data, ops.len);
 620		if (IS_ERR(ops.datbuf))
 621			return PTR_ERR(ops.datbuf);
 622	} else {
 623		ops.datbuf = NULL;
 624	}
 625
 626	if (usr_oob) {
 627		ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 628		if (IS_ERR(ops.oobbuf)) {
 629			kfree(ops.datbuf);
 630			return PTR_ERR(ops.oobbuf);
 631		}
 632	} else {
 633		ops.oobbuf = NULL;
 634	}
 635
 636	ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
 637
 638	kfree(ops.datbuf);
 639	kfree(ops.oobbuf);
 640
 641	return ret;
 642}
 643
 644static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 645{
 646	struct mtd_file_info *mfi = file->private_data;
 647	struct mtd_info *mtd = mfi->mtd;
 648	void __user *argp = (void __user *)arg;
 649	int ret = 0;
 650	struct mtd_info_user info;
 651
 652	pr_debug("MTD_ioctl\n");
 653
 654	switch (cmd) {
 655	case MEMGETREGIONCOUNT:
 656		if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 657			return -EFAULT;
 658		break;
 659
 660	case MEMGETREGIONINFO:
 661	{
 662		uint32_t ur_idx;
 663		struct mtd_erase_region_info *kr;
 664		struct region_info_user __user *ur = argp;
 665
 666		if (get_user(ur_idx, &(ur->regionindex)))
 667			return -EFAULT;
 668
 669		if (ur_idx >= mtd->numeraseregions)
 670			return -EINVAL;
 671
 672		kr = &(mtd->eraseregions[ur_idx]);
 673
 674		if (put_user(kr->offset, &(ur->offset))
 675		    || put_user(kr->erasesize, &(ur->erasesize))
 676		    || put_user(kr->numblocks, &(ur->numblocks)))
 677			return -EFAULT;
 678
 679		break;
 680	}
 681
 682	case MEMGETINFO:
 683		memset(&info, 0, sizeof(info));
 684		info.type	= mtd->type;
 685		info.flags	= mtd->flags;
 686		info.size	= mtd->size;
 687		info.erasesize	= mtd->erasesize;
 688		info.writesize	= mtd->writesize;
 689		info.oobsize	= mtd->oobsize;
 690		/* The below field is obsolete */
 691		info.padding	= 0;
 692		if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 693			return -EFAULT;
 694		break;
 695
 696	case MEMERASE:
 697	case MEMERASE64:
 698	{
 699		struct erase_info *erase;
 700
 701		if(!(file->f_mode & FMODE_WRITE))
 702			return -EPERM;
 703
 704		erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 705		if (!erase)
 706			ret = -ENOMEM;
 707		else {
 708			if (cmd == MEMERASE64) {
 709				struct erase_info_user64 einfo64;
 710
 711				if (copy_from_user(&einfo64, argp,
 712					    sizeof(struct erase_info_user64))) {
 713					kfree(erase);
 714					return -EFAULT;
 715				}
 716				erase->addr = einfo64.start;
 717				erase->len = einfo64.length;
 718			} else {
 719				struct erase_info_user einfo32;
 720
 721				if (copy_from_user(&einfo32, argp,
 722					    sizeof(struct erase_info_user))) {
 723					kfree(erase);
 724					return -EFAULT;
 725				}
 726				erase->addr = einfo32.start;
 727				erase->len = einfo32.length;
 728			}
 729
 730			ret = mtd_erase(mtd, erase);
 731			kfree(erase);
 732		}
 733		break;
 734	}
 735
 736	case MEMWRITEOOB:
 737	{
 738		struct mtd_oob_buf buf;
 739		struct mtd_oob_buf __user *buf_user = argp;
 740
 741		/* NOTE: writes return length to buf_user->length */
 742		if (copy_from_user(&buf, argp, sizeof(buf)))
 743			ret = -EFAULT;
 744		else
 745			ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 746				buf.ptr, &buf_user->length);
 747		break;
 748	}
 749
 750	case MEMREADOOB:
 751	{
 752		struct mtd_oob_buf buf;
 753		struct mtd_oob_buf __user *buf_user = argp;
 754
 755		/* NOTE: writes return length to buf_user->start */
 756		if (copy_from_user(&buf, argp, sizeof(buf)))
 757			ret = -EFAULT;
 758		else
 759			ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 760				buf.ptr, &buf_user->start);
 761		break;
 762	}
 763
 764	case MEMWRITEOOB64:
 765	{
 766		struct mtd_oob_buf64 buf;
 767		struct mtd_oob_buf64 __user *buf_user = argp;
 768
 769		if (copy_from_user(&buf, argp, sizeof(buf)))
 770			ret = -EFAULT;
 771		else
 772			ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 773				(void __user *)(uintptr_t)buf.usr_ptr,
 774				&buf_user->length);
 775		break;
 776	}
 777
 778	case MEMREADOOB64:
 779	{
 780		struct mtd_oob_buf64 buf;
 781		struct mtd_oob_buf64 __user *buf_user = argp;
 782
 783		if (copy_from_user(&buf, argp, sizeof(buf)))
 784			ret = -EFAULT;
 785		else
 786			ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 787				(void __user *)(uintptr_t)buf.usr_ptr,
 788				&buf_user->length);
 789		break;
 790	}
 791
 792	case MEMWRITE:
 793	{
 794		ret = mtdchar_write_ioctl(mtd,
 795		      (struct mtd_write_req __user *)arg);
 796		break;
 797	}
 798
 799	case MEMLOCK:
 800	{
 801		struct erase_info_user einfo;
 802
 803		if (copy_from_user(&einfo, argp, sizeof(einfo)))
 804			return -EFAULT;
 805
 806		ret = mtd_lock(mtd, einfo.start, einfo.length);
 807		break;
 808	}
 809
 810	case MEMUNLOCK:
 811	{
 812		struct erase_info_user einfo;
 813
 814		if (copy_from_user(&einfo, argp, sizeof(einfo)))
 815			return -EFAULT;
 816
 817		ret = mtd_unlock(mtd, einfo.start, einfo.length);
 818		break;
 819	}
 820
 821	case MEMISLOCKED:
 822	{
 823		struct erase_info_user einfo;
 824
 825		if (copy_from_user(&einfo, argp, sizeof(einfo)))
 826			return -EFAULT;
 827
 828		ret = mtd_is_locked(mtd, einfo.start, einfo.length);
 829		break;
 830	}
 831
 832	/* Legacy interface */
 833	case MEMGETOOBSEL:
 834	{
 835		struct nand_oobinfo oi;
 836
 837		if (!mtd->ooblayout)
 838			return -EOPNOTSUPP;
 839
 840		ret = get_oobinfo(mtd, &oi);
 841		if (ret)
 842			return ret;
 843
 844		if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 845			return -EFAULT;
 846		break;
 847	}
 848
 849	case MEMGETBADBLOCK:
 850	{
 851		loff_t offs;
 852
 853		if (copy_from_user(&offs, argp, sizeof(loff_t)))
 854			return -EFAULT;
 855		return mtd_block_isbad(mtd, offs);
 856		break;
 857	}
 858
 859	case MEMSETBADBLOCK:
 860	{
 861		loff_t offs;
 862
 863		if (copy_from_user(&offs, argp, sizeof(loff_t)))
 864			return -EFAULT;
 865		return mtd_block_markbad(mtd, offs);
 866		break;
 867	}
 868
 869	case OTPSELECT:
 870	{
 871		int mode;
 872		if (copy_from_user(&mode, argp, sizeof(int)))
 873			return -EFAULT;
 874
 875		mfi->mode = MTD_FILE_MODE_NORMAL;
 876
 877		ret = otp_select_filemode(mfi, mode);
 878
 879		file->f_pos = 0;
 880		break;
 881	}
 882
 883	case OTPGETREGIONCOUNT:
 884	case OTPGETREGIONINFO:
 885	{
 886		struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 887		size_t retlen;
 888		if (!buf)
 889			return -ENOMEM;
 890		switch (mfi->mode) {
 891		case MTD_FILE_MODE_OTP_FACTORY:
 892			ret = mtd_get_fact_prot_info(mtd, 4096, &retlen, buf);
 893			break;
 894		case MTD_FILE_MODE_OTP_USER:
 895			ret = mtd_get_user_prot_info(mtd, 4096, &retlen, buf);
 896			break;
 897		default:
 898			ret = -EINVAL;
 899			break;
 900		}
 901		if (!ret) {
 902			if (cmd == OTPGETREGIONCOUNT) {
 903				int nbr = retlen / sizeof(struct otp_info);
 904				ret = copy_to_user(argp, &nbr, sizeof(int));
 905			} else
 906				ret = copy_to_user(argp, buf, retlen);
 907			if (ret)
 908				ret = -EFAULT;
 909		}
 910		kfree(buf);
 911		break;
 912	}
 913
 914	case OTPLOCK:
 915	{
 916		struct otp_info oinfo;
 917
 918		if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 919			return -EINVAL;
 920		if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 921			return -EFAULT;
 922		ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 923		break;
 924	}
 925
 926	/* This ioctl is being deprecated - it truncates the ECC layout */
 927	case ECCGETLAYOUT:
 928	{
 929		struct nand_ecclayout_user *usrlay;
 930
 931		if (!mtd->ooblayout)
 932			return -EOPNOTSUPP;
 933
 934		usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 935		if (!usrlay)
 936			return -ENOMEM;
 937
 938		shrink_ecclayout(mtd, usrlay);
 939
 940		if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 941			ret = -EFAULT;
 942		kfree(usrlay);
 943		break;
 944	}
 945
 946	case ECCGETSTATS:
 947	{
 948		if (copy_to_user(argp, &mtd->ecc_stats,
 949				 sizeof(struct mtd_ecc_stats)))
 950			return -EFAULT;
 951		break;
 952	}
 953
 954	case MTDFILEMODE:
 955	{
 956		mfi->mode = 0;
 957
 958		switch(arg) {
 959		case MTD_FILE_MODE_OTP_FACTORY:
 960		case MTD_FILE_MODE_OTP_USER:
 961			ret = otp_select_filemode(mfi, arg);
 962			break;
 963
 964		case MTD_FILE_MODE_RAW:
 965			if (!mtd_has_oob(mtd))
 966				return -EOPNOTSUPP;
 967			mfi->mode = arg;
 968
 969		case MTD_FILE_MODE_NORMAL:
 970			break;
 971		default:
 972			ret = -EINVAL;
 973		}
 974		file->f_pos = 0;
 975		break;
 976	}
 977
 978	case BLKPG:
 979	{
 980		struct blkpg_ioctl_arg __user *blk_arg = argp;
 981		struct blkpg_ioctl_arg a;
 982
 983		if (copy_from_user(&a, blk_arg, sizeof(a)))
 984			ret = -EFAULT;
 985		else
 986			ret = mtdchar_blkpg_ioctl(mtd, &a);
 987		break;
 988	}
 989
 990	case BLKRRPART:
 991	{
 992		/* No reread partition feature. Just return ok */
 993		ret = 0;
 994		break;
 995	}
 996
 997	default:
 998		ret = -ENOTTY;
 999	}
1000
1001	return ret;
1002} /* memory_ioctl */
1003
1004static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1005{
1006	int ret;
1007
1008	mutex_lock(&mtd_mutex);
1009	ret = mtdchar_ioctl(file, cmd, arg);
1010	mutex_unlock(&mtd_mutex);
1011
1012	return ret;
1013}
1014
1015#ifdef CONFIG_COMPAT
1016
1017struct mtd_oob_buf32 {
1018	u_int32_t start;
1019	u_int32_t length;
1020	compat_caddr_t ptr;	/* unsigned char* */
1021};
1022
1023#define MEMWRITEOOB32		_IOWR('M', 3, struct mtd_oob_buf32)
1024#define MEMREADOOB32		_IOWR('M', 4, struct mtd_oob_buf32)
1025
1026static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1027	unsigned long arg)
1028{
1029	struct mtd_file_info *mfi = file->private_data;
1030	struct mtd_info *mtd = mfi->mtd;
1031	void __user *argp = compat_ptr(arg);
1032	int ret = 0;
1033
1034	mutex_lock(&mtd_mutex);
1035
1036	switch (cmd) {
1037	case MEMWRITEOOB32:
1038	{
1039		struct mtd_oob_buf32 buf;
1040		struct mtd_oob_buf32 __user *buf_user = argp;
1041
1042		if (copy_from_user(&buf, argp, sizeof(buf)))
1043			ret = -EFAULT;
1044		else
1045			ret = mtdchar_writeoob(file, mtd, buf.start,
1046				buf.length, compat_ptr(buf.ptr),
1047				&buf_user->length);
1048		break;
1049	}
1050
1051	case MEMREADOOB32:
1052	{
1053		struct mtd_oob_buf32 buf;
1054		struct mtd_oob_buf32 __user *buf_user = argp;
1055
1056		/* NOTE: writes return length to buf->start */
1057		if (copy_from_user(&buf, argp, sizeof(buf)))
1058			ret = -EFAULT;
1059		else
1060			ret = mtdchar_readoob(file, mtd, buf.start,
1061				buf.length, compat_ptr(buf.ptr),
1062				&buf_user->start);
1063		break;
1064	}
1065
1066	case BLKPG:
1067	{
1068		/* Convert from blkpg_compat_ioctl_arg to blkpg_ioctl_arg */
1069		struct blkpg_compat_ioctl_arg __user *uarg = argp;
1070		struct blkpg_compat_ioctl_arg compat_arg;
1071		struct blkpg_ioctl_arg a;
1072
1073		if (copy_from_user(&compat_arg, uarg, sizeof(compat_arg))) {
1074			ret = -EFAULT;
1075			break;
1076		}
1077
1078		memset(&a, 0, sizeof(a));
1079		a.op = compat_arg.op;
1080		a.flags = compat_arg.flags;
1081		a.datalen = compat_arg.datalen;
1082		a.data = compat_ptr(compat_arg.data);
1083
1084		ret = mtdchar_blkpg_ioctl(mtd, &a);
1085		break;
1086	}
1087
1088	default:
1089		ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1090	}
1091
1092	mutex_unlock(&mtd_mutex);
1093
1094	return ret;
1095}
1096
1097#endif /* CONFIG_COMPAT */
1098
1099/*
1100 * try to determine where a shared mapping can be made
1101 * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1102 *   mappings)
1103 */
1104#ifndef CONFIG_MMU
1105static unsigned long mtdchar_get_unmapped_area(struct file *file,
1106					   unsigned long addr,
1107					   unsigned long len,
1108					   unsigned long pgoff,
1109					   unsigned long flags)
1110{
1111	struct mtd_file_info *mfi = file->private_data;
1112	struct mtd_info *mtd = mfi->mtd;
1113	unsigned long offset;
1114	int ret;
1115
1116	if (addr != 0)
1117		return (unsigned long) -EINVAL;
1118
1119	if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1120		return (unsigned long) -EINVAL;
1121
1122	offset = pgoff << PAGE_SHIFT;
1123	if (offset > mtd->size - len)
1124		return (unsigned long) -EINVAL;
1125
1126	ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1127	return ret == -EOPNOTSUPP ? -ENODEV : ret;
1128}
1129
1130static unsigned mtdchar_mmap_capabilities(struct file *file)
1131{
1132	struct mtd_file_info *mfi = file->private_data;
1133
1134	return mtd_mmap_capabilities(mfi->mtd);
1135}
1136#endif
1137
1138/*
1139 * set up a mapping for shared memory segments
1140 */
1141static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1142{
1143#ifdef CONFIG_MMU
1144	struct mtd_file_info *mfi = file->private_data;
1145	struct mtd_info *mtd = mfi->mtd;
1146	struct map_info *map = mtd->priv;
1147
1148        /* This is broken because it assumes the MTD device is map-based
1149	   and that mtd->priv is a valid struct map_info.  It should be
1150	   replaced with something that uses the mtd_get_unmapped_area()
1151	   operation properly. */
1152	if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1153#ifdef pgprot_noncached
1154		if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1155			vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1156#endif
1157		return vm_iomap_memory(vma, map->phys, map->size);
1158	}
1159	return -ENODEV;
1160#else
1161	return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
1162#endif
1163}
1164
1165static const struct file_operations mtd_fops = {
1166	.owner		= THIS_MODULE,
1167	.llseek		= mtdchar_lseek,
1168	.read		= mtdchar_read,
1169	.write		= mtdchar_write,
1170	.unlocked_ioctl	= mtdchar_unlocked_ioctl,
1171#ifdef CONFIG_COMPAT
1172	.compat_ioctl	= mtdchar_compat_ioctl,
1173#endif
1174	.open		= mtdchar_open,
1175	.release	= mtdchar_close,
1176	.mmap		= mtdchar_mmap,
1177#ifndef CONFIG_MMU
1178	.get_unmapped_area = mtdchar_get_unmapped_area,
1179	.mmap_capabilities = mtdchar_mmap_capabilities,
1180#endif
1181};
1182
1183int __init init_mtdchar(void)
1184{
1185	int ret;
1186
1187	ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1188				   "mtd", &mtd_fops);
1189	if (ret < 0) {
1190		pr_err("Can't allocate major number %d for MTD\n",
1191		       MTD_CHAR_MAJOR);
1192		return ret;
1193	}
1194
1195	return ret;
1196}
1197
1198void __exit cleanup_mtdchar(void)
1199{
1200	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1201}
1202
1203MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);