/drivers/mtd/mtdchar.c

   1/*
   2 * Copyright Š 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/mtd/mtd.h>
  35#include <linux/mtd/partitions.h>
  36#include <linux/mtd/map.h>
  37
  38#include <asm/uaccess.h>
  39
  40#define MTD_INODE_FS_MAGIC 0x11307854
  41static DEFINE_MUTEX(mtd_mutex);
  42static struct vfsmount *mtd_inode_mnt __read_mostly;
  43
  44/*
  45 * Data structure to hold the pointer to the mtd device as well
  46 * as mode information ofr various use cases.
  47 */
  48struct mtd_file_info {
  49	struct mtd_info *mtd;
  50	struct inode *ino;
  51	enum mtd_file_modes mode;
  52};
  53
  54static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
  55{
  56	struct mtd_file_info *mfi = file->private_data;
  57	struct mtd_info *mtd = mfi->mtd;
  58
  59	switch (orig) {
  60	case SEEK_SET:
  61		break;
  62	case SEEK_CUR:
  63		offset += file->f_pos;
  64		break;
  65	case SEEK_END:
  66		offset += mtd->size;
  67		break;
  68	default:
  69		return -EINVAL;
  70	}
  71
  72	if (offset >= 0 && offset <= mtd->size)
  73		return file->f_pos = offset;
  74
  75	return -EINVAL;
  76}
  77
  78
  79
  80static int mtd_open(struct inode *inode, struct file *file)
  81{
  82	int minor = iminor(inode);
  83	int devnum = minor >> 1;
  84	int ret = 0;
  85	struct mtd_info *mtd;
  86	struct mtd_file_info *mfi;
  87	struct inode *mtd_ino;
  88
  89	DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
  90
  91	/* You can't open the RO devices RW */
  92	if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  93		return -EACCES;
  94
  95	mutex_lock(&mtd_mutex);
  96	mtd = get_mtd_device(NULL, devnum);
  97
  98	if (IS_ERR(mtd)) {
  99		ret = PTR_ERR(mtd);
 100		goto out;
 101	}
 102
 103	if (mtd->type == MTD_ABSENT) {
 104		put_mtd_device(mtd);
 105		ret = -ENODEV;
 106		goto out;
 107	}
 108
 109	mtd_ino = iget_locked(mtd_inode_mnt->mnt_sb, devnum);
 110	if (!mtd_ino) {
 111		put_mtd_device(mtd);
 112		ret = -ENOMEM;
 113		goto out;
 114	}
 115	if (mtd_ino->i_state & I_NEW) {
 116		mtd_ino->i_private = mtd;
 117		mtd_ino->i_mode = S_IFCHR;
 118		mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
 119		unlock_new_inode(mtd_ino);
 120	}
 121	file->f_mapping = mtd_ino->i_mapping;
 122
 123	/* You can't open it RW if it's not a writeable device */
 124	if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
 125		iput(mtd_ino);
 126		put_mtd_device(mtd);
 127		ret = -EACCES;
 128		goto out;
 129	}
 130
 131	mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
 132	if (!mfi) {
 133		iput(mtd_ino);
 134		put_mtd_device(mtd);
 135		ret = -ENOMEM;
 136		goto out;
 137	}
 138	mfi->ino = mtd_ino;
 139	mfi->mtd = mtd;
 140	file->private_data = mfi;
 141
 142out:
 143	mutex_unlock(&mtd_mutex);
 144	return ret;
 145} /* mtd_open */
 146
 147/*====================================================================*/
 148
 149static int mtd_close(struct inode *inode, struct file *file)
 150{
 151	struct mtd_file_info *mfi = file->private_data;
 152	struct mtd_info *mtd = mfi->mtd;
 153
 154	DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
 155
 156	/* Only sync if opened RW */
 157	if ((file->f_mode & FMODE_WRITE) && mtd->sync)
 158		mtd->sync(mtd);
 159
 160	iput(mfi->ino);
 161
 162	put_mtd_device(mtd);
 163	file->private_data = NULL;
 164	kfree(mfi);
 165
 166	return 0;
 167} /* mtd_close */
 168
 169/* Back in June 2001, dwmw2 wrote:
 170 *
 171 *   FIXME: This _really_ needs to die. In 2.5, we should lock the
 172 *   userspace buffer down and use it directly with readv/writev.
 173 *
 174 * The implementation below, using mtd_kmalloc_up_to, mitigates
 175 * allocation failures when the system is under low-memory situations
 176 * or if memory is highly fragmented at the cost of reducing the
 177 * performance of the requested transfer due to a smaller buffer size.
 178 *
 179 * A more complex but more memory-efficient implementation based on
 180 * get_user_pages and iovecs to cover extents of those pages is a
 181 * longer-term goal, as intimated by dwmw2 above. However, for the
 182 * write case, this requires yet more complex head and tail transfer
 183 * handling when those head and tail offsets and sizes are such that
 184 * alignment requirements are not met in the NAND subdriver.
 185 */
 186
 187static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
 188{
 189	struct mtd_file_info *mfi = file->private_data;
 190	struct mtd_info *mtd = mfi->mtd;
 191	size_t retlen=0;
 192	size_t total_retlen=0;
 193	int ret=0;
 194	int len;
 195	size_t size = count;
 196	char *kbuf;
 197
 198	DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
 199
 200	if (*ppos + count > mtd->size)
 201		count = mtd->size - *ppos;
 202
 203	if (!count)
 204		return 0;
 205
 206	kbuf = mtd_kmalloc_up_to(mtd, &size);
 207	if (!kbuf)
 208		return -ENOMEM;
 209
 210	while (count) {
 211		len = min_t(size_t, count, size);
 212
 213		switch (mfi->mode) {
 214		case MTD_MODE_OTP_FACTORY:
 215			ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 216			break;
 217		case MTD_MODE_OTP_USER:
 218			ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 219			break;
 220		case MTD_MODE_RAW:
 221		{
 222			struct mtd_oob_ops ops;
 223
 224			ops.mode = MTD_OOB_RAW;
 225			ops.datbuf = kbuf;
 226			ops.oobbuf = NULL;
 227			ops.len = len;
 228
 229			ret = mtd->read_oob(mtd, *ppos, &ops);
 230			retlen = ops.retlen;
 231			break;
 232		}
 233		default:
 234			ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
 235		}
 236		/* Nand returns -EBADMSG on ecc errors, but it returns
 237		 * the data. For our userspace tools it is important
 238		 * to dump areas with ecc errors !
 239		 * For kernel internal usage it also might return -EUCLEAN
 240		 * to signal the caller that a bitflip has occurred and has
 241		 * been corrected by the ECC algorithm.
 242		 * Userspace software which accesses NAND this way
 243		 * must be aware of the fact that it deals with NAND
 244		 */
 245		if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
 246			*ppos += retlen;
 247			if (copy_to_user(buf, kbuf, retlen)) {
 248				kfree(kbuf);
 249				return -EFAULT;
 250			}
 251			else
 252				total_retlen += retlen;
 253
 254			count -= retlen;
 255			buf += retlen;
 256			if (retlen == 0)
 257				count = 0;
 258		}
 259		else {
 260			kfree(kbuf);
 261			return ret;
 262		}
 263
 264	}
 265
 266	kfree(kbuf);
 267	return total_retlen;
 268} /* mtd_read */
 269
 270static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
 271{
 272	struct mtd_file_info *mfi = file->private_data;
 273	struct mtd_info *mtd = mfi->mtd;
 274	size_t size = count;
 275	char *kbuf;
 276	size_t retlen;
 277	size_t total_retlen=0;
 278	int ret=0;
 279	int len;
 280
 281	DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
 282
 283	if (*ppos == mtd->size)
 284		return -ENOSPC;
 285
 286	if (*ppos + count > mtd->size)
 287		count = mtd->size - *ppos;
 288
 289	if (!count)
 290		return 0;
 291
 292	kbuf = mtd_kmalloc_up_to(mtd, &size);
 293	if (!kbuf)
 294		return -ENOMEM;
 295
 296	while (count) {
 297		len = min_t(size_t, count, size);
 298
 299		if (copy_from_user(kbuf, buf, len)) {
 300			kfree(kbuf);
 301			return -EFAULT;
 302		}
 303
 304		switch (mfi->mode) {
 305		case MTD_MODE_OTP_FACTORY:
 306			ret = -EROFS;
 307			break;
 308		case MTD_MODE_OTP_USER:
 309			if (!mtd->write_user_prot_reg) {
 310				ret = -EOPNOTSUPP;
 311				break;
 312			}
 313			ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
 314			break;
 315
 316		case MTD_MODE_RAW:
 317		{
 318			struct mtd_oob_ops ops;
 319
 320			ops.mode = MTD_OOB_RAW;
 321			ops.datbuf = kbuf;
 322			ops.oobbuf = NULL;
 323			ops.ooboffs = 0;
 324			ops.len = len;
 325
 326			ret = mtd->write_oob(mtd, *ppos, &ops);
 327			retlen = ops.retlen;
 328			break;
 329		}
 330
 331		default:
 332			ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
 333		}
 334		if (!ret) {
 335			*ppos += retlen;
 336			total_retlen += retlen;
 337			count -= retlen;
 338			buf += retlen;
 339		}
 340		else {
 341			kfree(kbuf);
 342			return ret;
 343		}
 344	}
 345
 346	kfree(kbuf);
 347	return total_retlen;
 348} /* mtd_write */
 349
 350/*======================================================================
 351
 352    IOCTL calls for getting device parameters.
 353
 354======================================================================*/
 355static void mtdchar_erase_callback (struct erase_info *instr)
 356{
 357	wake_up((wait_queue_head_t *)instr->priv);
 358}
 359
 360#ifdef CONFIG_HAVE_MTD_OTP
 361static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 362{
 363	struct mtd_info *mtd = mfi->mtd;
 364	int ret = 0;
 365
 366	switch (mode) {
 367	case MTD_OTP_FACTORY:
 368		if (!mtd->read_fact_prot_reg)
 369			ret = -EOPNOTSUPP;
 370		else
 371			mfi->mode = MTD_MODE_OTP_FACTORY;
 372		break;
 373	case MTD_OTP_USER:
 374		if (!mtd->read_fact_prot_reg)
 375			ret = -EOPNOTSUPP;
 376		else
 377			mfi->mode = MTD_MODE_OTP_USER;
 378		break;
 379	default:
 380		ret = -EINVAL;
 381	case MTD_OTP_OFF:
 382		break;
 383	}
 384	return ret;
 385}
 386#else
 387# define otp_select_filemode(f,m)	-EOPNOTSUPP
 388#endif
 389
 390static int mtd_do_writeoob(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_oob_ops ops;
 395	uint32_t retlen;
 396	int ret = 0;
 397
 398	if (!(file->f_mode & FMODE_WRITE))
 399		return -EPERM;
 400
 401	if (length > 4096)
 402		return -EINVAL;
 403
 404	if (!mtd->write_oob)
 405		ret = -EOPNOTSUPP;
 406	else
 407		ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 408
 409	if (ret)
 410		return ret;
 411
 412	ops.ooblen = length;
 413	ops.ooboffs = start & (mtd->oobsize - 1);
 414	ops.datbuf = NULL;
 415	ops.mode = MTD_OOB_PLACE;
 416
 417	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 418		return -EINVAL;
 419
 420	ops.oobbuf = memdup_user(ptr, length);
 421	if (IS_ERR(ops.oobbuf))
 422		return PTR_ERR(ops.oobbuf);
 423
 424	start &= ~((uint64_t)mtd->oobsize - 1);
 425	ret = mtd->write_oob(mtd, start, &ops);
 426
 427	if (ops.oobretlen > 0xFFFFFFFFU)
 428		ret = -EOVERFLOW;
 429	retlen = ops.oobretlen;
 430	if (copy_to_user(retp, &retlen, sizeof(length)))
 431		ret = -EFAULT;
 432
 433	kfree(ops.oobbuf);
 434	return ret;
 435}
 436
 437static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
 438	uint32_t length, void __user *ptr, uint32_t __user *retp)
 439{
 440	struct mtd_oob_ops ops;
 441	int ret = 0;
 442
 443	if (length > 4096)
 444		return -EINVAL;
 445
 446	if (!mtd->read_oob)
 447		ret = -EOPNOTSUPP;
 448	else
 449		ret = access_ok(VERIFY_WRITE, ptr,
 450				length) ? 0 : -EFAULT;
 451	if (ret)
 452		return ret;
 453
 454	ops.ooblen = length;
 455	ops.ooboffs = start & (mtd->oobsize - 1);
 456	ops.datbuf = NULL;
 457	ops.mode = MTD_OOB_PLACE;
 458
 459	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 460		return -EINVAL;
 461
 462	ops.oobbuf = kmalloc(length, GFP_KERNEL);
 463	if (!ops.oobbuf)
 464		return -ENOMEM;
 465
 466	start &= ~((uint64_t)mtd->oobsize - 1);
 467	ret = mtd->read_oob(mtd, start, &ops);
 468
 469	if (put_user(ops.oobretlen, retp))
 470		ret = -EFAULT;
 471	else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 472					    ops.oobretlen))
 473		ret = -EFAULT;
 474
 475	kfree(ops.oobbuf);
 476	return ret;
 477}
 478
 479/*
 480 * Copies (and truncates, if necessary) data from the larger struct,
 481 * nand_ecclayout, to the smaller, deprecated layout struct,
 482 * nand_ecclayout_user. This is necessary only to suppport the deprecated
 483 * API ioctl ECCGETLAYOUT while allowing all new functionality to use
 484 * nand_ecclayout flexibly (i.e. the struct may change size in new
 485 * releases without requiring major rewrites).
 486 */
 487static int shrink_ecclayout(const struct nand_ecclayout *from,
 488		struct nand_ecclayout_user *to)
 489{
 490	int i;
 491
 492	if (!from || !to)
 493		return -EINVAL;
 494
 495	memset(to, 0, sizeof(*to));
 496
 497	to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
 498	for (i = 0; i < to->eccbytes; i++)
 499		to->eccpos[i] = from->eccpos[i];
 500
 501	for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 502		if (from->oobfree[i].length == 0 &&
 503				from->oobfree[i].offset == 0)
 504			break;
 505		to->oobavail += from->oobfree[i].length;
 506		to->oobfree[i] = from->oobfree[i];
 507	}
 508
 509	return 0;
 510}
 511
 512static int mtd_blkpg_ioctl(struct mtd_info *mtd,
 513			   struct blkpg_ioctl_arg __user *arg)
 514{
 515	struct blkpg_ioctl_arg a;
 516	struct blkpg_partition p;
 517
 518	if (!capable(CAP_SYS_ADMIN))
 519		return -EPERM;
 520
 521	if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
 522		return -EFAULT;
 523
 524	if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
 525		return -EFAULT;
 526
 527	switch (a.op) {
 528	case BLKPG_ADD_PARTITION:
 529
 530		/* Only master mtd device must be used to add partitions */
 531		if (mtd_is_partition(mtd))
 532			return -EINVAL;
 533
 534		return mtd_add_partition(mtd, p.devname, p.start, p.length);
 535
 536	case BLKPG_DEL_PARTITION:
 537
 538		if (p.pno < 0)
 539			return -EINVAL;
 540
 541		return mtd_del_partition(mtd, p.pno);
 542
 543	default:
 544		return -EINVAL;
 545	}
 546}
 547
 548static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
 549{
 550	struct mtd_file_info *mfi = file->private_data;
 551	struct mtd_info *mtd = mfi->mtd;
 552	void __user *argp = (void __user *)arg;
 553	int ret = 0;
 554	u_long size;
 555	struct mtd_info_user info;
 556
 557	DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
 558
 559	size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 560	if (cmd & IOC_IN) {
 561		if (!access_ok(VERIFY_READ, argp, size))
 562			return -EFAULT;
 563	}
 564	if (cmd & IOC_OUT) {
 565		if (!access_ok(VERIFY_WRITE, argp, size))
 566			return -EFAULT;
 567	}
 568
 569	switch (cmd) {
 570	case MEMGETREGIONCOUNT:
 571		if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 572			return -EFAULT;
 573		break;
 574
 575	case MEMGETREGIONINFO:
 576	{
 577		uint32_t ur_idx;
 578		struct mtd_erase_region_info *kr;
 579		struct region_info_user __user *ur = argp;
 580
 581		if (get_user(ur_idx, &(ur->regionindex)))
 582			return -EFAULT;
 583
 584		if (ur_idx >= mtd->numeraseregions)
 585			return -EINVAL;
 586
 587		kr = &(mtd->eraseregions[ur_idx]);
 588
 589		if (put_user(kr->offset, &(ur->offset))
 590		    || put_user(kr->erasesize, &(ur->erasesize))
 591		    || put_user(kr->numblocks, &(ur->numblocks)))
 592			return -EFAULT;
 593
 594		break;
 595	}
 596
 597	case MEMGETINFO:
 598		memset(&info, 0, sizeof(info));
 599		info.type	= mtd->type;
 600		info.flags	= mtd->flags;
 601		info.size	= mtd->size;
 602		info.erasesize	= mtd->erasesize;
 603		info.writesize	= mtd->writesize;
 604		info.oobsize	= mtd->oobsize;
 605		/* The below fields are obsolete */
 606		info.ecctype	= -1;
 607		if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 608			return -EFAULT;
 609		break;
 610
 611	case MEMERASE:
 612	case MEMERASE64:
 613	{
 614		struct erase_info *erase;
 615
 616		if(!(file->f_mode & FMODE_WRITE))
 617			return -EPERM;
 618
 619		erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 620		if (!erase)
 621			ret = -ENOMEM;
 622		else {
 623			wait_queue_head_t waitq;
 624			DECLARE_WAITQUEUE(wait, current);
 625
 626			init_waitqueue_head(&waitq);
 627
 628			if (cmd == MEMERASE64) {
 629				struct erase_info_user64 einfo64;
 630
 631				if (copy_from_user(&einfo64, argp,
 632					    sizeof(struct erase_info_user64))) {
 633					kfree(erase);
 634					return -EFAULT;
 635				}
 636				erase->addr = einfo64.start;
 637				erase->len = einfo64.length;
 638			} else {
 639				struct erase_info_user einfo32;
 640
 641				if (copy_from_user(&einfo32, argp,
 642					    sizeof(struct erase_info_user))) {
 643					kfree(erase);
 644					return -EFAULT;
 645				}
 646				erase->addr = einfo32.start;
 647				erase->len = einfo32.length;
 648			}
 649			erase->mtd = mtd;
 650			erase->callback = mtdchar_erase_callback;
 651			erase->priv = (unsigned long)&waitq;
 652
 653			/*
 654			  FIXME: Allow INTERRUPTIBLE. Which means
 655			  not having the wait_queue head on the stack.
 656
 657			  If the wq_head is on the stack, and we
 658			  leave because we got interrupted, then the
 659			  wq_head is no longer there when the
 660			  callback routine tries to wake us up.
 661			*/
 662			ret = mtd->erase(mtd, erase);
 663			if (!ret) {
 664				set_current_state(TASK_UNINTERRUPTIBLE);
 665				add_wait_queue(&waitq, &wait);
 666				if (erase->state != MTD_ERASE_DONE &&
 667				    erase->state != MTD_ERASE_FAILED)
 668					schedule();
 669				remove_wait_queue(&waitq, &wait);
 670				set_current_state(TASK_RUNNING);
 671
 672				ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 673			}
 674			kfree(erase);
 675		}
 676		break;
 677	}
 678
 679	case MEMWRITEOOB:
 680	{
 681		struct mtd_oob_buf buf;
 682		struct mtd_oob_buf __user *buf_user = argp;
 683
 684		/* NOTE: writes return length to buf_user->length */
 685		if (copy_from_user(&buf, argp, sizeof(buf)))
 686			ret = -EFAULT;
 687		else
 688			ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 689				buf.ptr, &buf_user->length);
 690		break;
 691	}
 692
 693	case MEMREADOOB:
 694	{
 695		struct mtd_oob_buf buf;
 696		struct mtd_oob_buf __user *buf_user = argp;
 697
 698		/* NOTE: writes return length to buf_user->start */
 699		if (copy_from_user(&buf, argp, sizeof(buf)))
 700			ret = -EFAULT;
 701		else
 702			ret = mtd_do_readoob(mtd, buf.start, buf.length,
 703				buf.ptr, &buf_user->start);
 704		break;
 705	}
 706
 707	case MEMWRITEOOB64:
 708	{
 709		struct mtd_oob_buf64 buf;
 710		struct mtd_oob_buf64 __user *buf_user = argp;
 711
 712		if (copy_from_user(&buf, argp, sizeof(buf)))
 713			ret = -EFAULT;
 714		else
 715			ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
 716				(void __user *)(uintptr_t)buf.usr_ptr,
 717				&buf_user->length);
 718		break;
 719	}
 720
 721	case MEMREADOOB64:
 722	{
 723		struct mtd_oob_buf64 buf;
 724		struct mtd_oob_buf64 __user *buf_user = argp;
 725
 726		if (copy_from_user(&buf, argp, sizeof(buf)))
 727			ret = -EFAULT;
 728		else
 729			ret = mtd_do_readoob(mtd, buf.start, buf.length,
 730				(void __user *)(uintptr_t)buf.usr_ptr,
 731				&buf_user->length);
 732		break;
 733	}
 734
 735	case MEMLOCK:
 736	{
 737		struct erase_info_user einfo;
 738
 739		if (copy_from_user(&einfo, argp, sizeof(einfo)))
 740			return -EFAULT;
 741
 742		if (!mtd->lock)
 743			ret = -EOPNOTSUPP;
 744		else
 745			ret = mtd->lock(mtd, einfo.start, einfo.length);
 746		break;
 747	}
 748
 749	case MEMUNLOCK:
 750	{
 751		struct erase_info_user einfo;
 752
 753		if (copy_from_user(&einfo, argp, sizeof(einfo)))
 754			return -EFAULT;
 755
 756		if (!mtd->unlock)
 757			ret = -EOPNOTSUPP;
 758		else
 759			ret = mtd->unlock(mtd, einfo.start, einfo.length);
 760		break;
 761	}
 762
 763	case MEMISLOCKED:
 764	{
 765		struct erase_info_user einfo;
 766
 767		if (copy_from_user(&einfo, argp, sizeof(einfo)))
 768			return -EFAULT;
 769
 770		if (!mtd->is_locked)
 771			ret = -EOPNOTSUPP;
 772		else
 773			ret = mtd->is_locked(mtd, einfo.start, einfo.length);
 774		break;
 775	}
 776
 777	/* Legacy interface */
 778	case MEMGETOOBSEL:
 779	{
 780		struct nand_oobinfo oi;
 781
 782		if (!mtd->ecclayout)
 783			return -EOPNOTSUPP;
 784		if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 785			return -EINVAL;
 786
 787		oi.useecc = MTD_NANDECC_AUTOPLACE;
 788		memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 789		memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 790		       sizeof(oi.oobfree));
 791		oi.eccbytes = mtd->ecclayout->eccbytes;
 792
 793		if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 794			return -EFAULT;
 795		break;
 796	}
 797
 798	case MEMGETBADBLOCK:
 799	{
 800		loff_t offs;
 801
 802		if (copy_from_user(&offs, argp, sizeof(loff_t)))
 803			return -EFAULT;
 804		if (!mtd->block_isbad)
 805			ret = -EOPNOTSUPP;
 806		else
 807			return mtd->block_isbad(mtd, offs);
 808		break;
 809	}
 810
 811	case MEMSETBADBLOCK:
 812	{
 813		loff_t offs;
 814
 815		if (copy_from_user(&offs, argp, sizeof(loff_t)))
 816			return -EFAULT;
 817		if (!mtd->block_markbad)
 818			ret = -EOPNOTSUPP;
 819		else
 820			return mtd->block_markbad(mtd, offs);
 821		break;
 822	}
 823
 824#ifdef CONFIG_HAVE_MTD_OTP
 825	case OTPSELECT:
 826	{
 827		int mode;
 828		if (copy_from_user(&mode, argp, sizeof(int)))
 829			return -EFAULT;
 830
 831		mfi->mode = MTD_MODE_NORMAL;
 832
 833		ret = otp_select_filemode(mfi, mode);
 834
 835		file->f_pos = 0;
 836		break;
 837	}
 838
 839	case OTPGETREGIONCOUNT:
 840	case OTPGETREGIONINFO:
 841	{
 842		struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 843		if (!buf)
 844			return -ENOMEM;
 845		ret = -EOPNOTSUPP;
 846		switch (mfi->mode) {
 847		case MTD_MODE_OTP_FACTORY:
 848			if (mtd->get_fact_prot_info)
 849				ret = mtd->get_fact_prot_info(mtd, buf, 4096);
 850			break;
 851		case MTD_MODE_OTP_USER:
 852			if (mtd->get_user_prot_info)
 853				ret = mtd->get_user_prot_info(mtd, buf, 4096);
 854			break;
 855		default:
 856			break;
 857		}
 858		if (ret >= 0) {
 859			if (cmd == OTPGETREGIONCOUNT) {
 860				int nbr = ret / sizeof(struct otp_info);
 861				ret = copy_to_user(argp, &nbr, sizeof(int));
 862			} else
 863				ret = copy_to_user(argp, buf, ret);
 864			if (ret)
 865				ret = -EFAULT;
 866		}
 867		kfree(buf);
 868		break;
 869	}
 870
 871	case OTPLOCK:
 872	{
 873		struct otp_info oinfo;
 874
 875		if (mfi->mode != MTD_MODE_OTP_USER)
 876			return -EINVAL;
 877		if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 878			return -EFAULT;
 879		if (!mtd->lock_user_prot_reg)
 880			return -EOPNOTSUPP;
 881		ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 882		break;
 883	}
 884#endif
 885
 886	/* This ioctl is being deprecated - it truncates the ecc layout */
 887	case ECCGETLAYOUT:
 888	{
 889		struct nand_ecclayout_user *usrlay;
 890
 891		if (!mtd->ecclayout)
 892			return -EOPNOTSUPP;
 893
 894		usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 895		if (!usrlay)
 896			return -ENOMEM;
 897
 898		shrink_ecclayout(mtd->ecclayout, usrlay);
 899
 900		if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 901			ret = -EFAULT;
 902		kfree(usrlay);
 903		break;
 904	}
 905
 906	case ECCGETSTATS:
 907	{
 908		if (copy_to_user(argp, &mtd->ecc_stats,
 909				 sizeof(struct mtd_ecc_stats)))
 910			return -EFAULT;
 911		break;
 912	}
 913
 914	case MTDFILEMODE:
 915	{
 916		mfi->mode = 0;
 917
 918		switch(arg) {
 919		case MTD_MODE_OTP_FACTORY:
 920		case MTD_MODE_OTP_USER:
 921			ret = otp_select_filemode(mfi, arg);
 922			break;
 923
 924		case MTD_MODE_RAW:
 925			if (!mtd->read_oob || !mtd->write_oob)
 926				return -EOPNOTSUPP;
 927			mfi->mode = arg;
 928
 929		case MTD_MODE_NORMAL:
 930			break;
 931		default:
 932			ret = -EINVAL;
 933		}
 934		file->f_pos = 0;
 935		break;
 936	}
 937
 938	case BLKPG:
 939	{
 940		ret = mtd_blkpg_ioctl(mtd,
 941		      (struct blkpg_ioctl_arg __user *)arg);
 942		break;
 943	}
 944
 945	case BLKRRPART:
 946	{
 947		/* No reread partition feature. Just return ok */
 948		ret = 0;
 949		break;
 950	}
 951
 952	default:
 953		ret = -ENOTTY;
 954	}
 955
 956	return ret;
 957} /* memory_ioctl */
 958
 959static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
 960{
 961	int ret;
 962
 963	mutex_lock(&mtd_mutex);
 964	ret = mtd_ioctl(file, cmd, arg);
 965	mutex_unlock(&mtd_mutex);
 966
 967	return ret;
 968}
 969
 970#ifdef CONFIG_COMPAT
 971
 972struct mtd_oob_buf32 {
 973	u_int32_t start;
 974	u_int32_t length;
 975	compat_caddr_t ptr;	/* unsigned char* */
 976};
 977
 978#define MEMWRITEOOB32		_IOWR('M', 3, struct mtd_oob_buf32)
 979#define MEMREADOOB32		_IOWR('M', 4, struct mtd_oob_buf32)
 980
 981static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
 982	unsigned long arg)
 983{
 984	struct mtd_file_info *mfi = file->private_data;
 985	struct mtd_info *mtd = mfi->mtd;
 986	void __user *argp = compat_ptr(arg);
 987	int ret = 0;
 988
 989	mutex_lock(&mtd_mutex);
 990
 991	switch (cmd) {
 992	case MEMWRITEOOB32:
 993	{
 994		struct mtd_oob_buf32 buf;
 995		struct mtd_oob_buf32 __user *buf_user = argp;
 996
 997		if (copy_from_user(&buf, argp, sizeof(buf)))
 998			ret = -EFAULT;
 999		else
1000			ret = mtd_do_writeoob(file, mtd, buf.start,
1001				buf.length, compat_ptr(buf.ptr),
1002				&buf_user->length);
1003		break;
1004	}
1005
1006	case MEMREADOOB32:
1007	{
1008		struct mtd_oob_buf32 buf;
1009		struct mtd_oob_buf32 __user *buf_user = argp;
1010
1011		/* NOTE: writes return length to buf->start */
1012		if (copy_from_user(&buf, argp, sizeof(buf)))
1013			ret = -EFAULT;
1014		else
1015			ret = mtd_do_readoob(mtd, buf.start,
1016				buf.length, compat_ptr(buf.ptr),
1017				&buf_user->start);
1018		break;
1019	}
1020	default:
1021		ret = mtd_ioctl(file, cmd, (unsigned long)argp);
1022	}
1023
1024	mutex_unlock(&mtd_mutex);
1025
1026	return ret;
1027}
1028
1029#endif /* CONFIG_COMPAT */
1030
1031/*
1032 * try to determine where a shared mapping can be made
1033 * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1034 *   mappings)
1035 */
1036#ifndef CONFIG_MMU
1037static unsigned long mtd_get_unmapped_area(struct file *file,
1038					   unsigned long addr,
1039					   unsigned long len,
1040					   unsigned long pgoff,
1041					   unsigned long flags)
1042{
1043	struct mtd_file_info *mfi = file->private_data;
1044	struct mtd_info *mtd = mfi->mtd;
1045
1046	if (mtd->get_unmapped_area) {
1047		unsigned long offset;
1048
1049		if (addr != 0)
1050			return (unsigned long) -EINVAL;
1051
1052		if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1053			return (unsigned long) -EINVAL;
1054
1055		offset = pgoff << PAGE_SHIFT;
1056		if (offset > mtd->size - len)
1057			return (unsigned long) -EINVAL;
1058
1059		return mtd->get_unmapped_area(mtd, len, offset, flags);
1060	}
1061
1062	/* can't map directly */
1063	return (unsigned long) -ENOSYS;
1064}
1065#endif
1066
1067/*
1068 * set up a mapping for shared memory segments
1069 */
1070static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
1071{
1072#ifdef CONFIG_MMU
1073	struct mtd_file_info *mfi = file->private_data;
1074	struct mtd_info *mtd = mfi->mtd;
1075	struct map_info *map = mtd->priv;
1076	unsigned long start;
1077	unsigned long off;
1078	u32 len;
1079
1080	if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
1081		off = vma->vm_pgoff << PAGE_SHIFT;
1082		start = map->phys;
1083		len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
1084		start &= PAGE_MASK;
1085		if ((vma->vm_end - vma->vm_start + off) > len)
1086			return -EINVAL;
1087
1088		off += start;
1089		vma->vm_pgoff = off >> PAGE_SHIFT;
1090		vma->vm_flags |= VM_IO | VM_RESERVED;
1091
1092#ifdef pgprot_noncached
1093		if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
1094			vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1095#endif
1096		if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
1097				       vma->vm_end - vma->vm_start,
1098				       vma->vm_page_prot))
1099			return -EAGAIN;
1100
1101		return 0;
1102	}
1103	return -ENOSYS;
1104#else
1105	return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1106#endif
1107}
1108
1109static const struct file_operations mtd_fops = {
1110	.owner		= THIS_MODULE,
1111	.llseek		= mtd_lseek,
1112	.read		= mtd_read,
1113	.write		= mtd_write,
1114	.unlocked_ioctl	= mtd_unlocked_ioctl,
1115#ifdef CONFIG_COMPAT
1116	.compat_ioctl	= mtd_compat_ioctl,
1117#endif
1118	.open		= mtd_open,
1119	.release	= mtd_close,
1120	.mmap		= mtd_mmap,
1121#ifndef CONFIG_MMU
1122	.get_unmapped_area = mtd_get_unmapped_area,
1123#endif
1124};
1125
1126static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1127				int flags, const char *dev_name, void *data)
1128{
1129	return mount_pseudo(fs_type, "mtd_inode:", NULL, NULL, MTD_INODE_FS_MAGIC);
1130}
1131
1132static struct file_system_type mtd_inodefs_type = {
1133       .name = "mtd_inodefs",
1134       .mount = mtd_inodefs_mount,
1135       .kill_sb = kill_anon_super,
1136};
1137
1138static void mtdchar_notify_add(struct mtd_info *mtd)
1139{
1140}
1141
1142static void mtdchar_notify_remove(struct mtd_info *mtd)
1143{
1144	struct inode *mtd_ino = ilookup(mtd_inode_mnt->mnt_sb, mtd->index);
1145
1146	if (mtd_ino) {
1147		/* Destroy the inode if it exists */
1148		mtd_ino->i_nlink = 0;
1149		iput(mtd_ino);
1150	}
1151}
1152
1153static struct mtd_notifier mtdchar_notifier = {
1154	.add = mtdchar_notify_add,
1155	.remove = mtdchar_notify_remove,
1156};
1157
1158static int __init init_mtdchar(void)
1159{
1160	int ret;
1161
1162	ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1163				   "mtd", &mtd_fops);
1164	if (ret < 0) {
1165		pr_notice("Can't allocate major number %d for "
1166				"Memory Technology Devices.\n", MTD_CHAR_MAJOR);
1167		return ret;
1168	}
1169
1170	ret = register_filesystem(&mtd_inodefs_type);
1171	if (ret) {
1172		pr_notice("Can't register mtd_inodefs filesystem: %d\n", ret);
1173		goto err_unregister_chdev;
1174	}
1175
1176	mtd_inode_mnt = kern_mount(&mtd_inodefs_type);
1177	if (IS_ERR(mtd_inode_mnt)) {
1178		ret = PTR_ERR(mtd_inode_mnt);
1179		pr_notice("Error mounting mtd_inodefs filesystem: %d\n", ret);
1180		goto err_unregister_filesystem;
1181	}
1182	register_mtd_user(&mtdchar_notifier);
1183
1184	return ret;
1185
1186err_unregister_filesystem:
1187	unregister_filesystem(&mtd_inodefs_type);
1188err_unregister_chdev:
1189	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1190	return ret;
1191}
1192
1193static void __exit cleanup_mtdchar(void)
1194{
1195	unregister_mtd_user(&mtdchar_notifier);
1196	mntput(mtd_inode_mnt);
1197	unregister_filesystem(&mtd_inodefs_type);
1198	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1199}
1200
1201module_init(init_mtdchar);
1202module_exit(cleanup_mtdchar);
1203
1204MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1205
1206MODULE_LICENSE("GPL");
1207MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
1208MODULE_DESCRIPTION("Direct character-device access to MTD devices");
1209MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);