linux/drivers/mtd/mtdchar.c
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   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/mtd/mtd.h>
  36#include <linux/mtd/partitions.h>
  37#include <linux/mtd/map.h>
  38
  39#include <asm/uaccess.h>
  40
  41#include "mtdcore.h"
  42
  43static DEFINE_MUTEX(mtd_mutex);
  44
  45/*
  46 * Data structure to hold the pointer to the mtd device as well
  47 * as mode information of various use cases.
  48 */
  49struct mtd_file_info {
  50        struct mtd_info *mtd;
  51        struct inode *ino;
  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        struct mtd_info *mtd = mfi->mtd;
  59
  60        switch (orig) {
  61        case SEEK_SET:
  62                break;
  63        case SEEK_CUR:
  64                offset += file->f_pos;
  65                break;
  66        case SEEK_END:
  67                offset += mtd->size;
  68                break;
  69        default:
  70                return -EINVAL;
  71        }
  72
  73        if (offset >= 0 && offset <= mtd->size)
  74                return file->f_pos = offset;
  75
  76        return -EINVAL;
  77}
  78
  79static int count;
  80static struct vfsmount *mnt;
  81static struct file_system_type mtd_inodefs_type;
  82
  83static int mtdchar_open(struct inode *inode, struct file *file)
  84{
  85        int minor = iminor(inode);
  86        int devnum = minor >> 1;
  87        int ret = 0;
  88        struct mtd_info *mtd;
  89        struct mtd_file_info *mfi;
  90        struct inode *mtd_ino;
  91
  92        pr_debug("MTD_open\n");
  93
  94        /* You can't open the RO devices RW */
  95        if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  96                return -EACCES;
  97
  98        ret = simple_pin_fs(&mtd_inodefs_type, &mnt, &count);
  99        if (ret)
 100                return ret;
 101
 102        mutex_lock(&mtd_mutex);
 103        mtd = get_mtd_device(NULL, devnum);
 104
 105        if (IS_ERR(mtd)) {
 106                ret = PTR_ERR(mtd);
 107                goto out;
 108        }
 109
 110        if (mtd->type == MTD_ABSENT) {
 111                ret = -ENODEV;
 112                goto out1;
 113        }
 114
 115        mtd_ino = iget_locked(mnt->mnt_sb, devnum);
 116        if (!mtd_ino) {
 117                ret = -ENOMEM;
 118                goto out1;
 119        }
 120        if (mtd_ino->i_state & I_NEW) {
 121                mtd_ino->i_private = mtd;
 122                mtd_ino->i_mode = S_IFCHR;
 123                mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
 124                unlock_new_inode(mtd_ino);
 125        }
 126        file->f_mapping = mtd_ino->i_mapping;
 127
 128        /* You can't open it RW if it's not a writeable device */
 129        if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
 130                ret = -EACCES;
 131                goto out2;
 132        }
 133
 134        mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
 135        if (!mfi) {
 136                ret = -ENOMEM;
 137                goto out2;
 138        }
 139        mfi->ino = mtd_ino;
 140        mfi->mtd = mtd;
 141        file->private_data = mfi;
 142        mutex_unlock(&mtd_mutex);
 143        return 0;
 144
 145out2:
 146        iput(mtd_ino);
 147out1:
 148        put_mtd_device(mtd);
 149out:
 150        mutex_unlock(&mtd_mutex);
 151        simple_release_fs(&mnt, &count);
 152        return ret;
 153} /* mtdchar_open */
 154
 155/*====================================================================*/
 156
 157static int mtdchar_close(struct inode *inode, struct file *file)
 158{
 159        struct mtd_file_info *mfi = file->private_data;
 160        struct mtd_info *mtd = mfi->mtd;
 161
 162        pr_debug("MTD_close\n");
 163
 164        /* Only sync if opened RW */
 165        if ((file->f_mode & FMODE_WRITE))
 166                mtd_sync(mtd);
 167
 168        iput(mfi->ino);
 169
 170        put_mtd_device(mtd);
 171        file->private_data = NULL;
 172        kfree(mfi);
 173        simple_release_fs(&mnt, &count);
 174
 175        return 0;
 176} /* mtdchar_close */
 177
 178/* Back in June 2001, dwmw2 wrote:
 179 *
 180 *   FIXME: This _really_ needs to die. In 2.5, we should lock the
 181 *   userspace buffer down and use it directly with readv/writev.
 182 *
 183 * The implementation below, using mtd_kmalloc_up_to, mitigates
 184 * allocation failures when the system is under low-memory situations
 185 * or if memory is highly fragmented at the cost of reducing the
 186 * performance of the requested transfer due to a smaller buffer size.
 187 *
 188 * A more complex but more memory-efficient implementation based on
 189 * get_user_pages and iovecs to cover extents of those pages is a
 190 * longer-term goal, as intimated by dwmw2 above. However, for the
 191 * write case, this requires yet more complex head and tail transfer
 192 * handling when those head and tail offsets and sizes are such that
 193 * alignment requirements are not met in the NAND subdriver.
 194 */
 195
 196static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
 197                        loff_t *ppos)
 198{
 199        struct mtd_file_info *mfi = file->private_data;
 200        struct mtd_info *mtd = mfi->mtd;
 201        size_t retlen;
 202        size_t total_retlen=0;
 203        int ret=0;
 204        int len;
 205        size_t size = count;
 206        char *kbuf;
 207
 208        pr_debug("MTD_read\n");
 209
 210        if (*ppos + count > mtd->size)
 211                count = mtd->size - *ppos;
 212
 213        if (!count)
 214                return 0;
 215
 216        kbuf = mtd_kmalloc_up_to(mtd, &size);
 217        if (!kbuf)
 218                return -ENOMEM;
 219
 220        while (count) {
 221                len = min_t(size_t, count, size);
 222
 223                switch (mfi->mode) {
 224                case MTD_FILE_MODE_OTP_FACTORY:
 225                        ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
 226                                                     &retlen, kbuf);
 227                        break;
 228                case MTD_FILE_MODE_OTP_USER:
 229                        ret = mtd_read_user_prot_reg(mtd, *ppos, len,
 230                                                     &retlen, kbuf);
 231                        break;
 232                case MTD_FILE_MODE_RAW:
 233                {
 234                        struct mtd_oob_ops ops;
 235
 236                        ops.mode = MTD_OPS_RAW;
 237                        ops.datbuf = kbuf;
 238                        ops.oobbuf = NULL;
 239                        ops.len = len;
 240
 241                        ret = mtd_read_oob(mtd, *ppos, &ops);
 242                        retlen = ops.retlen;
 243                        break;
 244                }
 245                default:
 246                        ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
 247                }
 248                /* Nand returns -EBADMSG on ECC errors, but it returns
 249                 * the data. For our userspace tools it is important
 250                 * to dump areas with ECC errors!
 251                 * For kernel internal usage it also might return -EUCLEAN
 252                 * to signal the caller that a bitflip has occurred and has
 253                 * been corrected by the ECC algorithm.
 254                 * Userspace software which accesses NAND this way
 255                 * must be aware of the fact that it deals with NAND
 256                 */
 257                if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
 258                        *ppos += retlen;
 259                        if (copy_to_user(buf, kbuf, retlen)) {
 260                                kfree(kbuf);
 261                                return -EFAULT;
 262                        }
 263                        else
 264                                total_retlen += retlen;
 265
 266                        count -= retlen;
 267                        buf += retlen;
 268                        if (retlen == 0)
 269                                count = 0;
 270                }
 271                else {
 272                        kfree(kbuf);
 273                        return ret;
 274                }
 275
 276        }
 277
 278        kfree(kbuf);
 279        return total_retlen;
 280} /* mtdchar_read */
 281
 282static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
 283                        loff_t *ppos)
 284{
 285        struct mtd_file_info *mfi = file->private_data;
 286        struct mtd_info *mtd = mfi->mtd;
 287        size_t size = count;
 288        char *kbuf;
 289        size_t retlen;
 290        size_t total_retlen=0;
 291        int ret=0;
 292        int len;
 293
 294        pr_debug("MTD_write\n");
 295
 296        if (*ppos == mtd->size)
 297                return -ENOSPC;
 298
 299        if (*ppos + count > mtd->size)
 300                count = mtd->size - *ppos;
 301
 302        if (!count)
 303                return 0;
 304
 305        kbuf = mtd_kmalloc_up_to(mtd, &size);
 306        if (!kbuf)
 307                return -ENOMEM;
 308
 309        while (count) {
 310                len = min_t(size_t, count, size);
 311
 312                if (copy_from_user(kbuf, buf, len)) {
 313                        kfree(kbuf);
 314                        return -EFAULT;
 315                }
 316
 317                switch (mfi->mode) {
 318                case MTD_FILE_MODE_OTP_FACTORY:
 319                        ret = -EROFS;
 320                        break;
 321                case MTD_FILE_MODE_OTP_USER:
 322                        ret = mtd_write_user_prot_reg(mtd, *ppos, len,
 323                                                      &retlen, kbuf);
 324                        break;
 325
 326                case MTD_FILE_MODE_RAW:
 327                {
 328                        struct mtd_oob_ops ops;
 329
 330                        ops.mode = MTD_OPS_RAW;
 331                        ops.datbuf = kbuf;
 332                        ops.oobbuf = NULL;
 333                        ops.ooboffs = 0;
 334                        ops.len = len;
 335
 336                        ret = mtd_write_oob(mtd, *ppos, &ops);
 337                        retlen = ops.retlen;
 338                        break;
 339                }
 340
 341                default:
 342                        ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
 343                }
 344                if (!ret) {
 345                        *ppos += retlen;
 346                        total_retlen += retlen;
 347                        count -= retlen;
 348                        buf += retlen;
 349                }
 350                else {
 351                        kfree(kbuf);
 352                        return ret;
 353                }
 354        }
 355
 356        kfree(kbuf);
 357        return total_retlen;
 358} /* mtdchar_write */
 359
 360/*======================================================================
 361
 362    IOCTL calls for getting device parameters.
 363
 364======================================================================*/
 365static void mtdchar_erase_callback (struct erase_info *instr)
 366{
 367        wake_up((wait_queue_head_t *)instr->priv);
 368}
 369
 370static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 371{
 372        struct mtd_info *mtd = mfi->mtd;
 373        size_t retlen;
 374
 375        switch (mode) {
 376        case MTD_OTP_FACTORY:
 377                if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 378                                -EOPNOTSUPP)
 379                        return -EOPNOTSUPP;
 380
 381                mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
 382                break;
 383        case MTD_OTP_USER:
 384                if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 385                                -EOPNOTSUPP)
 386                        return -EOPNOTSUPP;
 387
 388                mfi->mode = MTD_FILE_MODE_OTP_USER;
 389                break;
 390        case MTD_OTP_OFF:
 391                mfi->mode = MTD_FILE_MODE_NORMAL;
 392                break;
 393        default:
 394                return -EINVAL;
 395        }
 396
 397        return 0;
 398}
 399
 400static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
 401        uint64_t start, uint32_t length, void __user *ptr,
 402        uint32_t __user *retp)
 403{
 404        struct mtd_file_info *mfi = file->private_data;
 405        struct mtd_oob_ops ops;
 406        uint32_t retlen;
 407        int ret = 0;
 408
 409        if (!(file->f_mode & FMODE_WRITE))
 410                return -EPERM;
 411
 412        if (length > 4096)
 413                return -EINVAL;
 414
 415        if (!mtd->_write_oob)
 416                ret = -EOPNOTSUPP;
 417        else
 418                ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 419
 420        if (ret)
 421                return ret;
 422
 423        ops.ooblen = length;
 424        ops.ooboffs = start & (mtd->writesize - 1);
 425        ops.datbuf = NULL;
 426        ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 427                MTD_OPS_PLACE_OOB;
 428
 429        if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 430                return -EINVAL;
 431
 432        ops.oobbuf = memdup_user(ptr, length);
 433        if (IS_ERR(ops.oobbuf))
 434                return PTR_ERR(ops.oobbuf);
 435
 436        start &= ~((uint64_t)mtd->writesize - 1);
 437        ret = mtd_write_oob(mtd, start, &ops);
 438
 439        if (ops.oobretlen > 0xFFFFFFFFU)
 440                ret = -EOVERFLOW;
 441        retlen = ops.oobretlen;
 442        if (copy_to_user(retp, &retlen, sizeof(length)))
 443                ret = -EFAULT;
 444
 445        kfree(ops.oobbuf);
 446        return ret;
 447}
 448
 449static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
 450        uint64_t start, uint32_t length, void __user *ptr,
 451        uint32_t __user *retp)
 452{
 453        struct mtd_file_info *mfi = file->private_data;
 454        struct mtd_oob_ops ops;
 455        int ret = 0;
 456
 457        if (length > 4096)
 458                return -EINVAL;
 459
 460        if (!access_ok(VERIFY_WRITE, ptr, length))
 461                return -EFAULT;
 462
 463        ops.ooblen = length;
 464        ops.ooboffs = start & (mtd->writesize - 1);
 465        ops.datbuf = NULL;
 466        ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 467                MTD_OPS_PLACE_OOB;
 468
 469        if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 470                return -EINVAL;
 471
 472        ops.oobbuf = kmalloc(length, GFP_KERNEL);
 473        if (!ops.oobbuf)
 474                return -ENOMEM;
 475
 476        start &= ~((uint64_t)mtd->writesize - 1);
 477        ret = mtd_read_oob(mtd, start, &ops);
 478
 479        if (put_user(ops.oobretlen, retp))
 480                ret = -EFAULT;
 481        else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 482                                            ops.oobretlen))
 483                ret = -EFAULT;
 484
 485        kfree(ops.oobbuf);
 486
 487        /*
 488         * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 489         * data. For our userspace tools it is important to dump areas
 490         * with ECC errors!
 491         * For kernel internal usage it also might return -EUCLEAN
 492         * to signal the caller that a bitflip has occured and has
 493         * been corrected by the ECC algorithm.
 494         *
 495         * Note: currently the standard NAND function, nand_read_oob_std,
 496         * does not calculate ECC for the OOB area, so do not rely on
 497         * this behavior unless you have replaced it with your own.
 498         */
 499        if (mtd_is_bitflip_or_eccerr(ret))
 500                return 0;
 501
 502        return ret;
 503}
 504
 505/*
 506 * Copies (and truncates, if necessary) data from the larger struct,
 507 * nand_ecclayout, to the smaller, deprecated layout struct,
 508 * nand_ecclayout_user. This is necessary only to support the deprecated
 509 * API ioctl ECCGETLAYOUT while allowing all new functionality to use
 510 * nand_ecclayout flexibly (i.e. the struct may change size in new
 511 * releases without requiring major rewrites).
 512 */
 513static int shrink_ecclayout(const struct nand_ecclayout *from,
 514                struct nand_ecclayout_user *to)
 515{
 516        int i;
 517
 518        if (!from || !to)
 519                return -EINVAL;
 520
 521        memset(to, 0, sizeof(*to));
 522
 523        to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
 524        for (i = 0; i < to->eccbytes; i++)
 525                to->eccpos[i] = from->eccpos[i];
 526
 527        for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 528                if (from->oobfree[i].length == 0 &&
 529                                from->oobfree[i].offset == 0)
 530                        break;
 531                to->oobavail += from->oobfree[i].length;
 532                to->oobfree[i] = from->oobfree[i];
 533        }
 534
 535        return 0;
 536}
 537
 538static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
 539                           struct blkpg_ioctl_arg __user *arg)
 540{
 541        struct blkpg_ioctl_arg a;
 542        struct blkpg_partition p;
 543
 544        if (!capable(CAP_SYS_ADMIN))
 545                return -EPERM;
 546
 547        if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
 548                return -EFAULT;
 549
 550        if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
 551                return -EFAULT;
 552
 553        switch (a.op) {
 554        case BLKPG_ADD_PARTITION:
 555
 556                /* Only master mtd device must be used to add partitions */
 557                if (mtd_is_partition(mtd))
 558                        return -EINVAL;
 559
 560                return mtd_add_partition(mtd, p.devname, p.start, p.length);
 561
 562        case BLKPG_DEL_PARTITION:
 563
 564                if (p.pno < 0)
 565                        return -EINVAL;
 566
 567                return mtd_del_partition(mtd, p.pno);
 568
 569        default:
 570                return -EINVAL;
 571        }
 572}
 573
 574static int mtdchar_write_ioctl(struct mtd_info *mtd,
 575                struct mtd_write_req __user *argp)
 576{
 577        struct mtd_write_req req;
 578        struct mtd_oob_ops ops;
 579        void __user *usr_data, *usr_oob;
 580        int ret;
 581
 582        if (copy_from_user(&req, argp, sizeof(req)) ||
 583                        !access_ok(VERIFY_READ, req.usr_data, req.len) ||
 584                        !access_ok(VERIFY_READ, req.usr_oob, req.ooblen))
 585                return -EFAULT;
 586        if (!mtd->_write_oob)
 587                return -EOPNOTSUPP;
 588
 589        ops.mode = req.mode;
 590        ops.len = (size_t)req.len;
 591        ops.ooblen = (size_t)req.ooblen;
 592        ops.ooboffs = 0;
 593
 594        usr_data = (void __user *)(uintptr_t)req.usr_data;
 595        usr_oob = (void __user *)(uintptr_t)req.usr_oob;
 596
 597        if (req.usr_data) {
 598                ops.datbuf = memdup_user(usr_data, ops.len);
 599                if (IS_ERR(ops.datbuf))
 600                        return PTR_ERR(ops.datbuf);
 601        } else {
 602                ops.datbuf = NULL;
 603        }
 604
 605        if (req.usr_oob) {
 606                ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 607                if (IS_ERR(ops.oobbuf)) {
 608                        kfree(ops.datbuf);
 609                        return PTR_ERR(ops.oobbuf);
 610                }
 611        } else {
 612                ops.oobbuf = NULL;
 613        }
 614
 615        ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
 616
 617        kfree(ops.datbuf);
 618        kfree(ops.oobbuf);
 619
 620        return ret;
 621}
 622
 623static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 624{
 625        struct mtd_file_info *mfi = file->private_data;
 626        struct mtd_info *mtd = mfi->mtd;
 627        void __user *argp = (void __user *)arg;
 628        int ret = 0;
 629        u_long size;
 630        struct mtd_info_user info;
 631
 632        pr_debug("MTD_ioctl\n");
 633
 634        size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 635        if (cmd & IOC_IN) {
 636                if (!access_ok(VERIFY_READ, argp, size))
 637                        return -EFAULT;
 638        }
 639        if (cmd & IOC_OUT) {
 640                if (!access_ok(VERIFY_WRITE, argp, size))
 641                        return -EFAULT;
 642        }
 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                        wait_queue_head_t waitq;
 699                        DECLARE_WAITQUEUE(wait, current);
 700
 701                        init_waitqueue_head(&waitq);
 702
 703                        if (cmd == MEMERASE64) {
 704                                struct erase_info_user64 einfo64;
 705
 706                                if (copy_from_user(&einfo64, argp,
 707                                            sizeof(struct erase_info_user64))) {
 708                                        kfree(erase);
 709                                        return -EFAULT;
 710                                }
 711                                erase->addr = einfo64.start;
 712                                erase->len = einfo64.length;
 713                        } else {
 714                                struct erase_info_user einfo32;
 715
 716                                if (copy_from_user(&einfo32, argp,
 717                                            sizeof(struct erase_info_user))) {
 718                                        kfree(erase);
 719                                        return -EFAULT;
 720                                }
 721                                erase->addr = einfo32.start;
 722                                erase->len = einfo32.length;
 723                        }
 724                        erase->mtd = mtd;
 725                        erase->callback = mtdchar_erase_callback;
 726                        erase->priv = (unsigned long)&waitq;
 727
 728                        /*
 729                          FIXME: Allow INTERRUPTIBLE. Which means
 730                          not having the wait_queue head on the stack.
 731
 732                          If the wq_head is on the stack, and we
 733                          leave because we got interrupted, then the
 734                          wq_head is no longer there when the
 735                          callback routine tries to wake us up.
 736                        */
 737                        ret = mtd_erase(mtd, erase);
 738                        if (!ret) {
 739                                set_current_state(TASK_UNINTERRUPTIBLE);
 740                                add_wait_queue(&waitq, &wait);
 741                                if (erase->state != MTD_ERASE_DONE &&
 742                                    erase->state != MTD_ERASE_FAILED)
 743                                        schedule();
 744                                remove_wait_queue(&waitq, &wait);
 745                                set_current_state(TASK_RUNNING);
 746
 747                                ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 748                        }
 749                        kfree(erase);
 750                }
 751                break;
 752        }
 753
 754        case MEMWRITEOOB:
 755        {
 756                struct mtd_oob_buf buf;
 757                struct mtd_oob_buf __user *buf_user = argp;
 758
 759                /* NOTE: writes return length to buf_user->length */
 760                if (copy_from_user(&buf, argp, sizeof(buf)))
 761                        ret = -EFAULT;
 762                else
 763                        ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 764                                buf.ptr, &buf_user->length);
 765                break;
 766        }
 767
 768        case MEMREADOOB:
 769        {
 770                struct mtd_oob_buf buf;
 771                struct mtd_oob_buf __user *buf_user = argp;
 772
 773                /* NOTE: writes return length to buf_user->start */
 774                if (copy_from_user(&buf, argp, sizeof(buf)))
 775                        ret = -EFAULT;
 776                else
 777                        ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 778                                buf.ptr, &buf_user->start);
 779                break;
 780        }
 781
 782        case MEMWRITEOOB64:
 783        {
 784                struct mtd_oob_buf64 buf;
 785                struct mtd_oob_buf64 __user *buf_user = argp;
 786
 787                if (copy_from_user(&buf, argp, sizeof(buf)))
 788                        ret = -EFAULT;
 789                else
 790                        ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 791                                (void __user *)(uintptr_t)buf.usr_ptr,
 792                                &buf_user->length);
 793                break;
 794        }
 795
 796        case MEMREADOOB64:
 797        {
 798                struct mtd_oob_buf64 buf;
 799                struct mtd_oob_buf64 __user *buf_user = argp;
 800
 801                if (copy_from_user(&buf, argp, sizeof(buf)))
 802                        ret = -EFAULT;
 803                else
 804                        ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 805                                (void __user *)(uintptr_t)buf.usr_ptr,
 806                                &buf_user->length);
 807                break;
 808        }
 809
 810        case MEMWRITE:
 811        {
 812                ret = mtdchar_write_ioctl(mtd,
 813                      (struct mtd_write_req __user *)arg);
 814                break;
 815        }
 816
 817        case MEMLOCK:
 818        {
 819                struct erase_info_user einfo;
 820
 821                if (copy_from_user(&einfo, argp, sizeof(einfo)))
 822                        return -EFAULT;
 823
 824                ret = mtd_lock(mtd, einfo.start, einfo.length);
 825                break;
 826        }
 827
 828        case MEMUNLOCK:
 829        {
 830                struct erase_info_user einfo;
 831
 832                if (copy_from_user(&einfo, argp, sizeof(einfo)))
 833                        return -EFAULT;
 834
 835                ret = mtd_unlock(mtd, einfo.start, einfo.length);
 836                break;
 837        }
 838
 839        case MEMISLOCKED:
 840        {
 841                struct erase_info_user einfo;
 842
 843                if (copy_from_user(&einfo, argp, sizeof(einfo)))
 844                        return -EFAULT;
 845
 846                ret = mtd_is_locked(mtd, einfo.start, einfo.length);
 847                break;
 848        }
 849
 850        /* Legacy interface */
 851        case MEMGETOOBSEL:
 852        {
 853                struct nand_oobinfo oi;
 854
 855                if (!mtd->ecclayout)
 856                        return -EOPNOTSUPP;
 857                if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 858                        return -EINVAL;
 859
 860                oi.useecc = MTD_NANDECC_AUTOPLACE;
 861                memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 862                memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 863                       sizeof(oi.oobfree));
 864                oi.eccbytes = mtd->ecclayout->eccbytes;
 865
 866                if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 867                        return -EFAULT;
 868                break;
 869        }
 870
 871        case MEMGETBADBLOCK:
 872        {
 873                loff_t offs;
 874
 875                if (copy_from_user(&offs, argp, sizeof(loff_t)))
 876                        return -EFAULT;
 877                return mtd_block_isbad(mtd, offs);
 878                break;
 879        }
 880
 881        case MEMSETBADBLOCK:
 882        {
 883                loff_t offs;
 884
 885                if (copy_from_user(&offs, argp, sizeof(loff_t)))
 886                        return -EFAULT;
 887                return mtd_block_markbad(mtd, offs);
 888                break;
 889        }
 890
 891        case OTPSELECT:
 892        {
 893                int mode;
 894                if (copy_from_user(&mode, argp, sizeof(int)))
 895                        return -EFAULT;
 896
 897                mfi->mode = MTD_FILE_MODE_NORMAL;
 898
 899                ret = otp_select_filemode(mfi, mode);
 900
 901                file->f_pos = 0;
 902                break;
 903        }
 904
 905        case OTPGETREGIONCOUNT:
 906        case OTPGETREGIONINFO:
 907        {
 908                struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 909                if (!buf)
 910                        return -ENOMEM;
 911                switch (mfi->mode) {
 912                case MTD_FILE_MODE_OTP_FACTORY:
 913                        ret = mtd_get_fact_prot_info(mtd, buf, 4096);
 914                        break;
 915                case MTD_FILE_MODE_OTP_USER:
 916                        ret = mtd_get_user_prot_info(mtd, buf, 4096);
 917                        break;
 918                default:
 919                        ret = -EINVAL;
 920                        break;
 921                }
 922                if (ret >= 0) {
 923                        if (cmd == OTPGETREGIONCOUNT) {
 924                                int nbr = ret / sizeof(struct otp_info);
 925                                ret = copy_to_user(argp, &nbr, sizeof(int));
 926                        } else
 927                                ret = copy_to_user(argp, buf, ret);
 928                        if (ret)
 929                                ret = -EFAULT;
 930                }
 931                kfree(buf);
 932                break;
 933        }
 934
 935        case OTPLOCK:
 936        {
 937                struct otp_info oinfo;
 938
 939                if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 940                        return -EINVAL;
 941                if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 942                        return -EFAULT;
 943                ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 944                break;
 945        }
 946
 947        /* This ioctl is being deprecated - it truncates the ECC layout */
 948        case ECCGETLAYOUT:
 949        {
 950                struct nand_ecclayout_user *usrlay;
 951
 952                if (!mtd->ecclayout)
 953                        return -EOPNOTSUPP;
 954
 955                usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 956                if (!usrlay)
 957                        return -ENOMEM;
 958
 959                shrink_ecclayout(mtd->ecclayout, usrlay);
 960
 961                if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 962                        ret = -EFAULT;
 963                kfree(usrlay);
 964                break;
 965        }
 966
 967        case ECCGETSTATS:
 968        {
 969                if (copy_to_user(argp, &mtd->ecc_stats,
 970                                 sizeof(struct mtd_ecc_stats)))
 971                        return -EFAULT;
 972                break;
 973        }
 974
 975        case MTDFILEMODE:
 976        {
 977                mfi->mode = 0;
 978
 979                switch(arg) {
 980                case MTD_FILE_MODE_OTP_FACTORY:
 981                case MTD_FILE_MODE_OTP_USER:
 982                        ret = otp_select_filemode(mfi, arg);
 983                        break;
 984
 985                case MTD_FILE_MODE_RAW:
 986                        if (!mtd_has_oob(mtd))
 987                                return -EOPNOTSUPP;
 988                        mfi->mode = arg;
 989
 990                case MTD_FILE_MODE_NORMAL:
 991                        break;
 992                default:
 993                        ret = -EINVAL;
 994                }
 995                file->f_pos = 0;
 996                break;
 997        }
 998
 999        case BLKPG:
1000        {
1001                ret = mtdchar_blkpg_ioctl(mtd,
1002                      (struct blkpg_ioctl_arg __user *)arg);
1003                break;
1004        }
1005
1006        case BLKRRPART:
1007        {
1008                /* No reread partition feature. Just return ok */
1009                ret = 0;
1010                break;
1011        }
1012
1013        default:
1014                ret = -ENOTTY;
1015        }
1016
1017        return ret;
1018} /* memory_ioctl */
1019
1020static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1021{
1022        int ret;
1023
1024        mutex_lock(&mtd_mutex);
1025        ret = mtdchar_ioctl(file, cmd, arg);
1026        mutex_unlock(&mtd_mutex);
1027
1028        return ret;
1029}
1030
1031#ifdef CONFIG_COMPAT
1032
1033struct mtd_oob_buf32 {
1034        u_int32_t start;
1035        u_int32_t length;
1036        compat_caddr_t ptr;     /* unsigned char* */
1037};
1038
1039#define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1040#define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1041
1042static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1043        unsigned long arg)
1044{
1045        struct mtd_file_info *mfi = file->private_data;
1046        struct mtd_info *mtd = mfi->mtd;
1047        void __user *argp = compat_ptr(arg);
1048        int ret = 0;
1049
1050        mutex_lock(&mtd_mutex);
1051
1052        switch (cmd) {
1053        case MEMWRITEOOB32:
1054        {
1055                struct mtd_oob_buf32 buf;
1056                struct mtd_oob_buf32 __user *buf_user = argp;
1057
1058                if (copy_from_user(&buf, argp, sizeof(buf)))
1059                        ret = -EFAULT;
1060                else
1061                        ret = mtdchar_writeoob(file, mtd, buf.start,
1062                                buf.length, compat_ptr(buf.ptr),
1063                                &buf_user->length);
1064                break;
1065        }
1066
1067        case MEMREADOOB32:
1068        {
1069                struct mtd_oob_buf32 buf;
1070                struct mtd_oob_buf32 __user *buf_user = argp;
1071
1072                /* NOTE: writes return length to buf->start */
1073                if (copy_from_user(&buf, argp, sizeof(buf)))
1074                        ret = -EFAULT;
1075                else
1076                        ret = mtdchar_readoob(file, mtd, buf.start,
1077                                buf.length, compat_ptr(buf.ptr),
1078                                &buf_user->start);
1079                break;
1080        }
1081        default:
1082                ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1083        }
1084
1085        mutex_unlock(&mtd_mutex);
1086
1087        return ret;
1088}
1089
1090#endif /* CONFIG_COMPAT */
1091
1092/*
1093 * try to determine where a shared mapping can be made
1094 * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1095 *   mappings)
1096 */
1097#ifndef CONFIG_MMU
1098static unsigned long mtdchar_get_unmapped_area(struct file *file,
1099                                           unsigned long addr,
1100                                           unsigned long len,
1101                                           unsigned long pgoff,
1102                                           unsigned long flags)
1103{
1104        struct mtd_file_info *mfi = file->private_data;
1105        struct mtd_info *mtd = mfi->mtd;
1106        unsigned long offset;
1107        int ret;
1108
1109        if (addr != 0)
1110                return (unsigned long) -EINVAL;
1111
1112        if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1113                return (unsigned long) -EINVAL;
1114
1115        offset = pgoff << PAGE_SHIFT;
1116        if (offset > mtd->size - len)
1117                return (unsigned long) -EINVAL;
1118
1119        ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1120        return ret == -EOPNOTSUPP ? -ENOSYS : ret;
1121}
1122#endif
1123
1124/*
1125 * set up a mapping for shared memory segments
1126 */
1127static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1128{
1129#ifdef CONFIG_MMU
1130        struct mtd_file_info *mfi = file->private_data;
1131        struct mtd_info *mtd = mfi->mtd;
1132        struct map_info *map = mtd->priv;
1133
1134        /* This is broken because it assumes the MTD device is map-based
1135           and that mtd->priv is a valid struct map_info.  It should be
1136           replaced with something that uses the mtd_get_unmapped_area()
1137           operation properly. */
1138        if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1139#ifdef pgprot_noncached
1140                if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1141                        vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1142#endif
1143                return vm_iomap_memory(vma, map->phys, map->size);
1144        }
1145        return -ENOSYS;
1146#else
1147        return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
1148#endif
1149}
1150
1151static const struct file_operations mtd_fops = {
1152        .owner          = THIS_MODULE,
1153        .llseek         = mtdchar_lseek,
1154        .read           = mtdchar_read,
1155        .write          = mtdchar_write,
1156        .unlocked_ioctl = mtdchar_unlocked_ioctl,
1157#ifdef CONFIG_COMPAT
1158        .compat_ioctl   = mtdchar_compat_ioctl,
1159#endif
1160        .open           = mtdchar_open,
1161        .release        = mtdchar_close,
1162        .mmap           = mtdchar_mmap,
1163#ifndef CONFIG_MMU
1164        .get_unmapped_area = mtdchar_get_unmapped_area,
1165#endif
1166};
1167
1168static const struct super_operations mtd_ops = {
1169        .drop_inode = generic_delete_inode,
1170        .statfs = simple_statfs,
1171};
1172
1173static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1174                                int flags, const char *dev_name, void *data)
1175{
1176        return mount_pseudo(fs_type, "mtd_inode:", &mtd_ops, NULL, MTD_INODE_FS_MAGIC);
1177}
1178
1179static struct file_system_type mtd_inodefs_type = {
1180       .name = "mtd_inodefs",
1181       .mount = mtd_inodefs_mount,
1182       .kill_sb = kill_anon_super,
1183};
1184MODULE_ALIAS_FS("mtd_inodefs");
1185
1186int __init init_mtdchar(void)
1187{
1188        int ret;
1189
1190        ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1191                                   "mtd", &mtd_fops);
1192        if (ret < 0) {
1193                pr_err("Can't allocate major number %d for MTD\n",
1194                       MTD_CHAR_MAJOR);
1195                return ret;
1196        }
1197
1198        ret = register_filesystem(&mtd_inodefs_type);
1199        if (ret) {
1200                pr_err("Can't register mtd_inodefs filesystem, error %d\n",
1201                       ret);
1202                goto err_unregister_chdev;
1203        }
1204
1205        return ret;
1206
1207err_unregister_chdev:
1208        __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1209        return ret;
1210}
1211
1212void __exit cleanup_mtdchar(void)
1213{
1214        unregister_filesystem(&mtd_inodefs_type);
1215        __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1216}
1217
1218MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1219
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