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/major.h>
  36#include <linux/mtd/mtd.h>
  37#include <linux/mtd/partitions.h>
  38#include <linux/mtd/map.h>
  39
  40#include <asm/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        struct inode *ino;
  53        enum mtd_file_modes mode;
  54};
  55
  56static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig)
  57{
  58        struct mtd_file_info *mfi = file->private_data;
  59        return fixed_size_llseek(file, offset, orig, mfi->mtd->size);
  60}
  61
  62static int count;
  63static struct vfsmount *mnt;
  64static struct file_system_type mtd_inodefs_type;
  65
  66static int mtdchar_open(struct inode *inode, struct file *file)
  67{
  68        int minor = iminor(inode);
  69        int devnum = minor >> 1;
  70        int ret = 0;
  71        struct mtd_info *mtd;
  72        struct mtd_file_info *mfi;
  73        struct inode *mtd_ino;
  74
  75        pr_debug("MTD_open\n");
  76
  77        /* You can't open the RO devices RW */
  78        if ((file->f_mode & FMODE_WRITE) && (minor & 1))
  79                return -EACCES;
  80
  81        ret = simple_pin_fs(&mtd_inodefs_type, &mnt, &count);
  82        if (ret)
  83                return ret;
  84
  85        mutex_lock(&mtd_mutex);
  86        mtd = get_mtd_device(NULL, devnum);
  87
  88        if (IS_ERR(mtd)) {
  89                ret = PTR_ERR(mtd);
  90                goto out;
  91        }
  92
  93        if (mtd->type == MTD_ABSENT) {
  94                ret = -ENODEV;
  95                goto out1;
  96        }
  97
  98        mtd_ino = iget_locked(mnt->mnt_sb, devnum);
  99        if (!mtd_ino) {
 100                ret = -ENOMEM;
 101                goto out1;
 102        }
 103        if (mtd_ino->i_state & I_NEW) {
 104                mtd_ino->i_private = mtd;
 105                mtd_ino->i_mode = S_IFCHR;
 106                mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
 107                unlock_new_inode(mtd_ino);
 108        }
 109        file->f_mapping = mtd_ino->i_mapping;
 110
 111        /* You can't open it RW if it's not a writeable device */
 112        if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
 113                ret = -EACCES;
 114                goto out2;
 115        }
 116
 117        mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
 118        if (!mfi) {
 119                ret = -ENOMEM;
 120                goto out2;
 121        }
 122        mfi->ino = mtd_ino;
 123        mfi->mtd = mtd;
 124        file->private_data = mfi;
 125        mutex_unlock(&mtd_mutex);
 126        return 0;
 127
 128out2:
 129        iput(mtd_ino);
 130out1:
 131        put_mtd_device(mtd);
 132out:
 133        mutex_unlock(&mtd_mutex);
 134        simple_release_fs(&mnt, &count);
 135        return ret;
 136} /* mtdchar_open */
 137
 138/*====================================================================*/
 139
 140static int mtdchar_close(struct inode *inode, struct file *file)
 141{
 142        struct mtd_file_info *mfi = file->private_data;
 143        struct mtd_info *mtd = mfi->mtd;
 144
 145        pr_debug("MTD_close\n");
 146
 147        /* Only sync if opened RW */
 148        if ((file->f_mode & FMODE_WRITE))
 149                mtd_sync(mtd);
 150
 151        iput(mfi->ino);
 152
 153        put_mtd_device(mtd);
 154        file->private_data = NULL;
 155        kfree(mfi);
 156        simple_release_fs(&mnt, &count);
 157
 158        return 0;
 159} /* mtdchar_close */
 160
 161/* Back in June 2001, dwmw2 wrote:
 162 *
 163 *   FIXME: This _really_ needs to die. In 2.5, we should lock the
 164 *   userspace buffer down and use it directly with readv/writev.
 165 *
 166 * The implementation below, using mtd_kmalloc_up_to, mitigates
 167 * allocation failures when the system is under low-memory situations
 168 * or if memory is highly fragmented at the cost of reducing the
 169 * performance of the requested transfer due to a smaller buffer size.
 170 *
 171 * A more complex but more memory-efficient implementation based on
 172 * get_user_pages and iovecs to cover extents of those pages is a
 173 * longer-term goal, as intimated by dwmw2 above. However, for the
 174 * write case, this requires yet more complex head and tail transfer
 175 * handling when those head and tail offsets and sizes are such that
 176 * alignment requirements are not met in the NAND subdriver.
 177 */
 178
 179static ssize_t mtdchar_read(struct file *file, char __user *buf, size_t count,
 180                        loff_t *ppos)
 181{
 182        struct mtd_file_info *mfi = file->private_data;
 183        struct mtd_info *mtd = mfi->mtd;
 184        size_t retlen;
 185        size_t total_retlen=0;
 186        int ret=0;
 187        int len;
 188        size_t size = count;
 189        char *kbuf;
 190
 191        pr_debug("MTD_read\n");
 192
 193        if (*ppos + count > mtd->size)
 194                count = mtd->size - *ppos;
 195
 196        if (!count)
 197                return 0;
 198
 199        kbuf = mtd_kmalloc_up_to(mtd, &size);
 200        if (!kbuf)
 201                return -ENOMEM;
 202
 203        while (count) {
 204                len = min_t(size_t, count, size);
 205
 206                switch (mfi->mode) {
 207                case MTD_FILE_MODE_OTP_FACTORY:
 208                        ret = mtd_read_fact_prot_reg(mtd, *ppos, len,
 209                                                     &retlen, kbuf);
 210                        break;
 211                case MTD_FILE_MODE_OTP_USER:
 212                        ret = mtd_read_user_prot_reg(mtd, *ppos, len,
 213                                                     &retlen, kbuf);
 214                        break;
 215                case MTD_FILE_MODE_RAW:
 216                {
 217                        struct mtd_oob_ops ops;
 218
 219                        ops.mode = MTD_OPS_RAW;
 220                        ops.datbuf = kbuf;
 221                        ops.oobbuf = NULL;
 222                        ops.len = len;
 223
 224                        ret = mtd_read_oob(mtd, *ppos, &ops);
 225                        retlen = ops.retlen;
 226                        break;
 227                }
 228                default:
 229                        ret = mtd_read(mtd, *ppos, len, &retlen, kbuf);
 230                }
 231                /* Nand returns -EBADMSG on ECC errors, but it returns
 232                 * the data. For our userspace tools it is important
 233                 * to dump areas with ECC errors!
 234                 * For kernel internal usage it also might return -EUCLEAN
 235                 * to signal the caller that a bitflip has occurred and has
 236                 * been corrected by the ECC algorithm.
 237                 * Userspace software which accesses NAND this way
 238                 * must be aware of the fact that it deals with NAND
 239                 */
 240                if (!ret || mtd_is_bitflip_or_eccerr(ret)) {
 241                        *ppos += retlen;
 242                        if (copy_to_user(buf, kbuf, retlen)) {
 243                                kfree(kbuf);
 244                                return -EFAULT;
 245                        }
 246                        else
 247                                total_retlen += retlen;
 248
 249                        count -= retlen;
 250                        buf += retlen;
 251                        if (retlen == 0)
 252                                count = 0;
 253                }
 254                else {
 255                        kfree(kbuf);
 256                        return ret;
 257                }
 258
 259        }
 260
 261        kfree(kbuf);
 262        return total_retlen;
 263} /* mtdchar_read */
 264
 265static ssize_t mtdchar_write(struct file *file, const char __user *buf, size_t count,
 266                        loff_t *ppos)
 267{
 268        struct mtd_file_info *mfi = file->private_data;
 269        struct mtd_info *mtd = mfi->mtd;
 270        size_t size = count;
 271        char *kbuf;
 272        size_t retlen;
 273        size_t total_retlen=0;
 274        int ret=0;
 275        int len;
 276
 277        pr_debug("MTD_write\n");
 278
 279        if (*ppos == mtd->size)
 280                return -ENOSPC;
 281
 282        if (*ppos + count > mtd->size)
 283                count = mtd->size - *ppos;
 284
 285        if (!count)
 286                return 0;
 287
 288        kbuf = mtd_kmalloc_up_to(mtd, &size);
 289        if (!kbuf)
 290                return -ENOMEM;
 291
 292        while (count) {
 293                len = min_t(size_t, count, size);
 294
 295                if (copy_from_user(kbuf, buf, len)) {
 296                        kfree(kbuf);
 297                        return -EFAULT;
 298                }
 299
 300                switch (mfi->mode) {
 301                case MTD_FILE_MODE_OTP_FACTORY:
 302                        ret = -EROFS;
 303                        break;
 304                case MTD_FILE_MODE_OTP_USER:
 305                        ret = mtd_write_user_prot_reg(mtd, *ppos, len,
 306                                                      &retlen, kbuf);
 307                        break;
 308
 309                case MTD_FILE_MODE_RAW:
 310                {
 311                        struct mtd_oob_ops ops;
 312
 313                        ops.mode = MTD_OPS_RAW;
 314                        ops.datbuf = kbuf;
 315                        ops.oobbuf = NULL;
 316                        ops.ooboffs = 0;
 317                        ops.len = len;
 318
 319                        ret = mtd_write_oob(mtd, *ppos, &ops);
 320                        retlen = ops.retlen;
 321                        break;
 322                }
 323
 324                default:
 325                        ret = mtd_write(mtd, *ppos, len, &retlen, kbuf);
 326                }
 327                if (!ret) {
 328                        *ppos += retlen;
 329                        total_retlen += retlen;
 330                        count -= retlen;
 331                        buf += retlen;
 332                }
 333                else {
 334                        kfree(kbuf);
 335                        return ret;
 336                }
 337        }
 338
 339        kfree(kbuf);
 340        return total_retlen;
 341} /* mtdchar_write */
 342
 343/*======================================================================
 344
 345    IOCTL calls for getting device parameters.
 346
 347======================================================================*/
 348static void mtdchar_erase_callback (struct erase_info *instr)
 349{
 350        wake_up((wait_queue_head_t *)instr->priv);
 351}
 352
 353static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
 354{
 355        struct mtd_info *mtd = mfi->mtd;
 356        size_t retlen;
 357
 358        switch (mode) {
 359        case MTD_OTP_FACTORY:
 360                if (mtd_read_fact_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 361                                -EOPNOTSUPP)
 362                        return -EOPNOTSUPP;
 363
 364                mfi->mode = MTD_FILE_MODE_OTP_FACTORY;
 365                break;
 366        case MTD_OTP_USER:
 367                if (mtd_read_user_prot_reg(mtd, -1, 0, &retlen, NULL) ==
 368                                -EOPNOTSUPP)
 369                        return -EOPNOTSUPP;
 370
 371                mfi->mode = MTD_FILE_MODE_OTP_USER;
 372                break;
 373        case MTD_OTP_OFF:
 374                mfi->mode = MTD_FILE_MODE_NORMAL;
 375                break;
 376        default:
 377                return -EINVAL;
 378        }
 379
 380        return 0;
 381}
 382
 383static int mtdchar_writeoob(struct file *file, struct mtd_info *mtd,
 384        uint64_t start, uint32_t length, void __user *ptr,
 385        uint32_t __user *retp)
 386{
 387        struct mtd_file_info *mfi = file->private_data;
 388        struct mtd_oob_ops ops;
 389        uint32_t retlen;
 390        int ret = 0;
 391
 392        if (!(file->f_mode & FMODE_WRITE))
 393                return -EPERM;
 394
 395        if (length > 4096)
 396                return -EINVAL;
 397
 398        if (!mtd->_write_oob)
 399                ret = -EOPNOTSUPP;
 400        else
 401                ret = access_ok(VERIFY_READ, ptr, length) ? 0 : -EFAULT;
 402
 403        if (ret)
 404                return ret;
 405
 406        ops.ooblen = length;
 407        ops.ooboffs = start & (mtd->writesize - 1);
 408        ops.datbuf = NULL;
 409        ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 410                MTD_OPS_PLACE_OOB;
 411
 412        if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 413                return -EINVAL;
 414
 415        ops.oobbuf = memdup_user(ptr, length);
 416        if (IS_ERR(ops.oobbuf))
 417                return PTR_ERR(ops.oobbuf);
 418
 419        start &= ~((uint64_t)mtd->writesize - 1);
 420        ret = mtd_write_oob(mtd, start, &ops);
 421
 422        if (ops.oobretlen > 0xFFFFFFFFU)
 423                ret = -EOVERFLOW;
 424        retlen = ops.oobretlen;
 425        if (copy_to_user(retp, &retlen, sizeof(length)))
 426                ret = -EFAULT;
 427
 428        kfree(ops.oobbuf);
 429        return ret;
 430}
 431
 432static int mtdchar_readoob(struct file *file, struct mtd_info *mtd,
 433        uint64_t start, uint32_t length, void __user *ptr,
 434        uint32_t __user *retp)
 435{
 436        struct mtd_file_info *mfi = file->private_data;
 437        struct mtd_oob_ops ops;
 438        int ret = 0;
 439
 440        if (length > 4096)
 441                return -EINVAL;
 442
 443        if (!access_ok(VERIFY_WRITE, ptr, length))
 444                return -EFAULT;
 445
 446        ops.ooblen = length;
 447        ops.ooboffs = start & (mtd->writesize - 1);
 448        ops.datbuf = NULL;
 449        ops.mode = (mfi->mode == MTD_FILE_MODE_RAW) ? MTD_OPS_RAW :
 450                MTD_OPS_PLACE_OOB;
 451
 452        if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 453                return -EINVAL;
 454
 455        ops.oobbuf = kmalloc(length, GFP_KERNEL);
 456        if (!ops.oobbuf)
 457                return -ENOMEM;
 458
 459        start &= ~((uint64_t)mtd->writesize - 1);
 460        ret = mtd_read_oob(mtd, start, &ops);
 461
 462        if (put_user(ops.oobretlen, retp))
 463                ret = -EFAULT;
 464        else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
 465                                            ops.oobretlen))
 466                ret = -EFAULT;
 467
 468        kfree(ops.oobbuf);
 469
 470        /*
 471         * NAND returns -EBADMSG on ECC errors, but it returns the OOB
 472         * data. For our userspace tools it is important to dump areas
 473         * with ECC errors!
 474         * For kernel internal usage it also might return -EUCLEAN
 475         * to signal the caller that a bitflip has occured and has
 476         * been corrected by the ECC algorithm.
 477         *
 478         * Note: currently the standard NAND function, nand_read_oob_std,
 479         * does not calculate ECC for the OOB area, so do not rely on
 480         * this behavior unless you have replaced it with your own.
 481         */
 482        if (mtd_is_bitflip_or_eccerr(ret))
 483                return 0;
 484
 485        return ret;
 486}
 487
 488/*
 489 * Copies (and truncates, if necessary) data from the larger struct,
 490 * nand_ecclayout, to the smaller, deprecated layout struct,
 491 * nand_ecclayout_user. This is necessary only to support the deprecated
 492 * API ioctl ECCGETLAYOUT while allowing all new functionality to use
 493 * nand_ecclayout flexibly (i.e. the struct may change size in new
 494 * releases without requiring major rewrites).
 495 */
 496static int shrink_ecclayout(const struct nand_ecclayout *from,
 497                struct nand_ecclayout_user *to)
 498{
 499        int i;
 500
 501        if (!from || !to)
 502                return -EINVAL;
 503
 504        memset(to, 0, sizeof(*to));
 505
 506        to->eccbytes = min((int)from->eccbytes, MTD_MAX_ECCPOS_ENTRIES);
 507        for (i = 0; i < to->eccbytes; i++)
 508                to->eccpos[i] = from->eccpos[i];
 509
 510        for (i = 0; i < MTD_MAX_OOBFREE_ENTRIES; i++) {
 511                if (from->oobfree[i].length == 0 &&
 512                                from->oobfree[i].offset == 0)
 513                        break;
 514                to->oobavail += from->oobfree[i].length;
 515                to->oobfree[i] = from->oobfree[i];
 516        }
 517
 518        return 0;
 519}
 520
 521static int mtdchar_blkpg_ioctl(struct mtd_info *mtd,
 522                           struct blkpg_ioctl_arg __user *arg)
 523{
 524        struct blkpg_ioctl_arg a;
 525        struct blkpg_partition p;
 526
 527        if (!capable(CAP_SYS_ADMIN))
 528                return -EPERM;
 529
 530        if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
 531                return -EFAULT;
 532
 533        if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
 534                return -EFAULT;
 535
 536        switch (a.op) {
 537        case BLKPG_ADD_PARTITION:
 538
 539                /* Only master mtd device must be used to add partitions */
 540                if (mtd_is_partition(mtd))
 541                        return -EINVAL;
 542
 543                return mtd_add_partition(mtd, p.devname, p.start, p.length);
 544
 545        case BLKPG_DEL_PARTITION:
 546
 547                if (p.pno < 0)
 548                        return -EINVAL;
 549
 550                return mtd_del_partition(mtd, p.pno);
 551
 552        default:
 553                return -EINVAL;
 554        }
 555}
 556
 557static int mtdchar_write_ioctl(struct mtd_info *mtd,
 558                struct mtd_write_req __user *argp)
 559{
 560        struct mtd_write_req req;
 561        struct mtd_oob_ops ops;
 562        void __user *usr_data, *usr_oob;
 563        int ret;
 564
 565        if (copy_from_user(&req, argp, sizeof(req)) ||
 566                        !access_ok(VERIFY_READ, req.usr_data, req.len) ||
 567                        !access_ok(VERIFY_READ, req.usr_oob, req.ooblen))
 568                return -EFAULT;
 569        if (!mtd->_write_oob)
 570                return -EOPNOTSUPP;
 571
 572        ops.mode = req.mode;
 573        ops.len = (size_t)req.len;
 574        ops.ooblen = (size_t)req.ooblen;
 575        ops.ooboffs = 0;
 576
 577        usr_data = (void __user *)(uintptr_t)req.usr_data;
 578        usr_oob = (void __user *)(uintptr_t)req.usr_oob;
 579
 580        if (req.usr_data) {
 581                ops.datbuf = memdup_user(usr_data, ops.len);
 582                if (IS_ERR(ops.datbuf))
 583                        return PTR_ERR(ops.datbuf);
 584        } else {
 585                ops.datbuf = NULL;
 586        }
 587
 588        if (req.usr_oob) {
 589                ops.oobbuf = memdup_user(usr_oob, ops.ooblen);
 590                if (IS_ERR(ops.oobbuf)) {
 591                        kfree(ops.datbuf);
 592                        return PTR_ERR(ops.oobbuf);
 593                }
 594        } else {
 595                ops.oobbuf = NULL;
 596        }
 597
 598        ret = mtd_write_oob(mtd, (loff_t)req.start, &ops);
 599
 600        kfree(ops.datbuf);
 601        kfree(ops.oobbuf);
 602
 603        return ret;
 604}
 605
 606static int mtdchar_ioctl(struct file *file, u_int cmd, u_long arg)
 607{
 608        struct mtd_file_info *mfi = file->private_data;
 609        struct mtd_info *mtd = mfi->mtd;
 610        void __user *argp = (void __user *)arg;
 611        int ret = 0;
 612        u_long size;
 613        struct mtd_info_user info;
 614
 615        pr_debug("MTD_ioctl\n");
 616
 617        size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
 618        if (cmd & IOC_IN) {
 619                if (!access_ok(VERIFY_READ, argp, size))
 620                        return -EFAULT;
 621        }
 622        if (cmd & IOC_OUT) {
 623                if (!access_ok(VERIFY_WRITE, argp, size))
 624                        return -EFAULT;
 625        }
 626
 627        switch (cmd) {
 628        case MEMGETREGIONCOUNT:
 629                if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
 630                        return -EFAULT;
 631                break;
 632
 633        case MEMGETREGIONINFO:
 634        {
 635                uint32_t ur_idx;
 636                struct mtd_erase_region_info *kr;
 637                struct region_info_user __user *ur = argp;
 638
 639                if (get_user(ur_idx, &(ur->regionindex)))
 640                        return -EFAULT;
 641
 642                if (ur_idx >= mtd->numeraseregions)
 643                        return -EINVAL;
 644
 645                kr = &(mtd->eraseregions[ur_idx]);
 646
 647                if (put_user(kr->offset, &(ur->offset))
 648                    || put_user(kr->erasesize, &(ur->erasesize))
 649                    || put_user(kr->numblocks, &(ur->numblocks)))
 650                        return -EFAULT;
 651
 652                break;
 653        }
 654
 655        case MEMGETINFO:
 656                memset(&info, 0, sizeof(info));
 657                info.type       = mtd->type;
 658                info.flags      = mtd->flags;
 659                info.size       = mtd->size;
 660                info.erasesize  = mtd->erasesize;
 661                info.writesize  = mtd->writesize;
 662                info.oobsize    = mtd->oobsize;
 663                /* The below field is obsolete */
 664                info.padding    = 0;
 665                if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
 666                        return -EFAULT;
 667                break;
 668
 669        case MEMERASE:
 670        case MEMERASE64:
 671        {
 672                struct erase_info *erase;
 673
 674                if(!(file->f_mode & FMODE_WRITE))
 675                        return -EPERM;
 676
 677                erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
 678                if (!erase)
 679                        ret = -ENOMEM;
 680                else {
 681                        wait_queue_head_t waitq;
 682                        DECLARE_WAITQUEUE(wait, current);
 683
 684                        init_waitqueue_head(&waitq);
 685
 686                        if (cmd == MEMERASE64) {
 687                                struct erase_info_user64 einfo64;
 688
 689                                if (copy_from_user(&einfo64, argp,
 690                                            sizeof(struct erase_info_user64))) {
 691                                        kfree(erase);
 692                                        return -EFAULT;
 693                                }
 694                                erase->addr = einfo64.start;
 695                                erase->len = einfo64.length;
 696                        } else {
 697                                struct erase_info_user einfo32;
 698
 699                                if (copy_from_user(&einfo32, argp,
 700                                            sizeof(struct erase_info_user))) {
 701                                        kfree(erase);
 702                                        return -EFAULT;
 703                                }
 704                                erase->addr = einfo32.start;
 705                                erase->len = einfo32.length;
 706                        }
 707                        erase->mtd = mtd;
 708                        erase->callback = mtdchar_erase_callback;
 709                        erase->priv = (unsigned long)&waitq;
 710
 711                        /*
 712                          FIXME: Allow INTERRUPTIBLE. Which means
 713                          not having the wait_queue head on the stack.
 714
 715                          If the wq_head is on the stack, and we
 716                          leave because we got interrupted, then the
 717                          wq_head is no longer there when the
 718                          callback routine tries to wake us up.
 719                        */
 720                        ret = mtd_erase(mtd, erase);
 721                        if (!ret) {
 722                                set_current_state(TASK_UNINTERRUPTIBLE);
 723                                add_wait_queue(&waitq, &wait);
 724                                if (erase->state != MTD_ERASE_DONE &&
 725                                    erase->state != MTD_ERASE_FAILED)
 726                                        schedule();
 727                                remove_wait_queue(&waitq, &wait);
 728                                set_current_state(TASK_RUNNING);
 729
 730                                ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
 731                        }
 732                        kfree(erase);
 733                }
 734                break;
 735        }
 736
 737        case MEMWRITEOOB:
 738        {
 739                struct mtd_oob_buf buf;
 740                struct mtd_oob_buf __user *buf_user = argp;
 741
 742                /* NOTE: writes return length to buf_user->length */
 743                if (copy_from_user(&buf, argp, sizeof(buf)))
 744                        ret = -EFAULT;
 745                else
 746                        ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 747                                buf.ptr, &buf_user->length);
 748                break;
 749        }
 750
 751        case MEMREADOOB:
 752        {
 753                struct mtd_oob_buf buf;
 754                struct mtd_oob_buf __user *buf_user = argp;
 755
 756                /* NOTE: writes return length to buf_user->start */
 757                if (copy_from_user(&buf, argp, sizeof(buf)))
 758                        ret = -EFAULT;
 759                else
 760                        ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 761                                buf.ptr, &buf_user->start);
 762                break;
 763        }
 764
 765        case MEMWRITEOOB64:
 766        {
 767                struct mtd_oob_buf64 buf;
 768                struct mtd_oob_buf64 __user *buf_user = argp;
 769
 770                if (copy_from_user(&buf, argp, sizeof(buf)))
 771                        ret = -EFAULT;
 772                else
 773                        ret = mtdchar_writeoob(file, mtd, buf.start, buf.length,
 774                                (void __user *)(uintptr_t)buf.usr_ptr,
 775                                &buf_user->length);
 776                break;
 777        }
 778
 779        case MEMREADOOB64:
 780        {
 781                struct mtd_oob_buf64 buf;
 782                struct mtd_oob_buf64 __user *buf_user = argp;
 783
 784                if (copy_from_user(&buf, argp, sizeof(buf)))
 785                        ret = -EFAULT;
 786                else
 787                        ret = mtdchar_readoob(file, mtd, buf.start, buf.length,
 788                                (void __user *)(uintptr_t)buf.usr_ptr,
 789                                &buf_user->length);
 790                break;
 791        }
 792
 793        case MEMWRITE:
 794        {
 795                ret = mtdchar_write_ioctl(mtd,
 796                      (struct mtd_write_req __user *)arg);
 797                break;
 798        }
 799
 800        case MEMLOCK:
 801        {
 802                struct erase_info_user einfo;
 803
 804                if (copy_from_user(&einfo, argp, sizeof(einfo)))
 805                        return -EFAULT;
 806
 807                ret = mtd_lock(mtd, einfo.start, einfo.length);
 808                break;
 809        }
 810
 811        case MEMUNLOCK:
 812        {
 813                struct erase_info_user einfo;
 814
 815                if (copy_from_user(&einfo, argp, sizeof(einfo)))
 816                        return -EFAULT;
 817
 818                ret = mtd_unlock(mtd, einfo.start, einfo.length);
 819                break;
 820        }
 821
 822        case MEMISLOCKED:
 823        {
 824                struct erase_info_user einfo;
 825
 826                if (copy_from_user(&einfo, argp, sizeof(einfo)))
 827                        return -EFAULT;
 828
 829                ret = mtd_is_locked(mtd, einfo.start, einfo.length);
 830                break;
 831        }
 832
 833        /* Legacy interface */
 834        case MEMGETOOBSEL:
 835        {
 836                struct nand_oobinfo oi;
 837
 838                if (!mtd->ecclayout)
 839                        return -EOPNOTSUPP;
 840                if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
 841                        return -EINVAL;
 842
 843                oi.useecc = MTD_NANDECC_AUTOPLACE;
 844                memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
 845                memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
 846                       sizeof(oi.oobfree));
 847                oi.eccbytes = mtd->ecclayout->eccbytes;
 848
 849                if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
 850                        return -EFAULT;
 851                break;
 852        }
 853
 854        case MEMGETBADBLOCK:
 855        {
 856                loff_t offs;
 857
 858                if (copy_from_user(&offs, argp, sizeof(loff_t)))
 859                        return -EFAULT;
 860                return mtd_block_isbad(mtd, offs);
 861                break;
 862        }
 863
 864        case MEMSETBADBLOCK:
 865        {
 866                loff_t offs;
 867
 868                if (copy_from_user(&offs, argp, sizeof(loff_t)))
 869                        return -EFAULT;
 870                return mtd_block_markbad(mtd, offs);
 871                break;
 872        }
 873
 874        case OTPSELECT:
 875        {
 876                int mode;
 877                if (copy_from_user(&mode, argp, sizeof(int)))
 878                        return -EFAULT;
 879
 880                mfi->mode = MTD_FILE_MODE_NORMAL;
 881
 882                ret = otp_select_filemode(mfi, mode);
 883
 884                file->f_pos = 0;
 885                break;
 886        }
 887
 888        case OTPGETREGIONCOUNT:
 889        case OTPGETREGIONINFO:
 890        {
 891                struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
 892                if (!buf)
 893                        return -ENOMEM;
 894                switch (mfi->mode) {
 895                case MTD_FILE_MODE_OTP_FACTORY:
 896                        ret = mtd_get_fact_prot_info(mtd, buf, 4096);
 897                        break;
 898                case MTD_FILE_MODE_OTP_USER:
 899                        ret = mtd_get_user_prot_info(mtd, buf, 4096);
 900                        break;
 901                default:
 902                        ret = -EINVAL;
 903                        break;
 904                }
 905                if (ret >= 0) {
 906                        if (cmd == OTPGETREGIONCOUNT) {
 907                                int nbr = ret / sizeof(struct otp_info);
 908                                ret = copy_to_user(argp, &nbr, sizeof(int));
 909                        } else
 910                                ret = copy_to_user(argp, buf, ret);
 911                        if (ret)
 912                                ret = -EFAULT;
 913                }
 914                kfree(buf);
 915                break;
 916        }
 917
 918        case OTPLOCK:
 919        {
 920                struct otp_info oinfo;
 921
 922                if (mfi->mode != MTD_FILE_MODE_OTP_USER)
 923                        return -EINVAL;
 924                if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
 925                        return -EFAULT;
 926                ret = mtd_lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
 927                break;
 928        }
 929
 930        /* This ioctl is being deprecated - it truncates the ECC layout */
 931        case ECCGETLAYOUT:
 932        {
 933                struct nand_ecclayout_user *usrlay;
 934
 935                if (!mtd->ecclayout)
 936                        return -EOPNOTSUPP;
 937
 938                usrlay = kmalloc(sizeof(*usrlay), GFP_KERNEL);
 939                if (!usrlay)
 940                        return -ENOMEM;
 941
 942                shrink_ecclayout(mtd->ecclayout, usrlay);
 943
 944                if (copy_to_user(argp, usrlay, sizeof(*usrlay)))
 945                        ret = -EFAULT;
 946                kfree(usrlay);
 947                break;
 948        }
 949
 950        case ECCGETSTATS:
 951        {
 952                if (copy_to_user(argp, &mtd->ecc_stats,
 953                                 sizeof(struct mtd_ecc_stats)))
 954                        return -EFAULT;
 955                break;
 956        }
 957
 958        case MTDFILEMODE:
 959        {
 960                mfi->mode = 0;
 961
 962                switch(arg) {
 963                case MTD_FILE_MODE_OTP_FACTORY:
 964                case MTD_FILE_MODE_OTP_USER:
 965                        ret = otp_select_filemode(mfi, arg);
 966                        break;
 967
 968                case MTD_FILE_MODE_RAW:
 969                        if (!mtd_has_oob(mtd))
 970                                return -EOPNOTSUPP;
 971                        mfi->mode = arg;
 972
 973                case MTD_FILE_MODE_NORMAL:
 974                        break;
 975                default:
 976                        ret = -EINVAL;
 977                }
 978                file->f_pos = 0;
 979                break;
 980        }
 981
 982        case BLKPG:
 983        {
 984                ret = mtdchar_blkpg_ioctl(mtd,
 985                      (struct blkpg_ioctl_arg __user *)arg);
 986                break;
 987        }
 988
 989        case BLKRRPART:
 990        {
 991                /* No reread partition feature. Just return ok */
 992                ret = 0;
 993                break;
 994        }
 995
 996        default:
 997                ret = -ENOTTY;
 998        }
 999
1000        return ret;
1001} /* memory_ioctl */
1002
1003static long mtdchar_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
1004{
1005        int ret;
1006
1007        mutex_lock(&mtd_mutex);
1008        ret = mtdchar_ioctl(file, cmd, arg);
1009        mutex_unlock(&mtd_mutex);
1010
1011        return ret;
1012}
1013
1014#ifdef CONFIG_COMPAT
1015
1016struct mtd_oob_buf32 {
1017        u_int32_t start;
1018        u_int32_t length;
1019        compat_caddr_t ptr;     /* unsigned char* */
1020};
1021
1022#define MEMWRITEOOB32           _IOWR('M', 3, struct mtd_oob_buf32)
1023#define MEMREADOOB32            _IOWR('M', 4, struct mtd_oob_buf32)
1024
1025static long mtdchar_compat_ioctl(struct file *file, unsigned int cmd,
1026        unsigned long arg)
1027{
1028        struct mtd_file_info *mfi = file->private_data;
1029        struct mtd_info *mtd = mfi->mtd;
1030        void __user *argp = compat_ptr(arg);
1031        int ret = 0;
1032
1033        mutex_lock(&mtd_mutex);
1034
1035        switch (cmd) {
1036        case MEMWRITEOOB32:
1037        {
1038                struct mtd_oob_buf32 buf;
1039                struct mtd_oob_buf32 __user *buf_user = argp;
1040
1041                if (copy_from_user(&buf, argp, sizeof(buf)))
1042                        ret = -EFAULT;
1043                else
1044                        ret = mtdchar_writeoob(file, mtd, buf.start,
1045                                buf.length, compat_ptr(buf.ptr),
1046                                &buf_user->length);
1047                break;
1048        }
1049
1050        case MEMREADOOB32:
1051        {
1052                struct mtd_oob_buf32 buf;
1053                struct mtd_oob_buf32 __user *buf_user = argp;
1054
1055                /* NOTE: writes return length to buf->start */
1056                if (copy_from_user(&buf, argp, sizeof(buf)))
1057                        ret = -EFAULT;
1058                else
1059                        ret = mtdchar_readoob(file, mtd, buf.start,
1060                                buf.length, compat_ptr(buf.ptr),
1061                                &buf_user->start);
1062                break;
1063        }
1064        default:
1065                ret = mtdchar_ioctl(file, cmd, (unsigned long)argp);
1066        }
1067
1068        mutex_unlock(&mtd_mutex);
1069
1070        return ret;
1071}
1072
1073#endif /* CONFIG_COMPAT */
1074
1075/*
1076 * try to determine where a shared mapping can be made
1077 * - only supported for NOMMU at the moment (MMU can't doesn't copy private
1078 *   mappings)
1079 */
1080#ifndef CONFIG_MMU
1081static unsigned long mtdchar_get_unmapped_area(struct file *file,
1082                                           unsigned long addr,
1083                                           unsigned long len,
1084                                           unsigned long pgoff,
1085                                           unsigned long flags)
1086{
1087        struct mtd_file_info *mfi = file->private_data;
1088        struct mtd_info *mtd = mfi->mtd;
1089        unsigned long offset;
1090        int ret;
1091
1092        if (addr != 0)
1093                return (unsigned long) -EINVAL;
1094
1095        if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
1096                return (unsigned long) -EINVAL;
1097
1098        offset = pgoff << PAGE_SHIFT;
1099        if (offset > mtd->size - len)
1100                return (unsigned long) -EINVAL;
1101
1102        ret = mtd_get_unmapped_area(mtd, len, offset, flags);
1103        return ret == -EOPNOTSUPP ? -ENODEV : ret;
1104}
1105#endif
1106
1107/*
1108 * set up a mapping for shared memory segments
1109 */
1110static int mtdchar_mmap(struct file *file, struct vm_area_struct *vma)
1111{
1112#ifdef CONFIG_MMU
1113        struct mtd_file_info *mfi = file->private_data;
1114        struct mtd_info *mtd = mfi->mtd;
1115        struct map_info *map = mtd->priv;
1116
1117        /* This is broken because it assumes the MTD device is map-based
1118           and that mtd->priv is a valid struct map_info.  It should be
1119           replaced with something that uses the mtd_get_unmapped_area()
1120           operation properly. */
1121        if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
1122#ifdef pgprot_noncached
1123                if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
1124                        vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1125#endif
1126                return vm_iomap_memory(vma, map->phys, map->size);
1127        }
1128        return -ENODEV;
1129#else
1130        return vma->vm_flags & VM_SHARED ? 0 : -EACCES;
1131#endif
1132}
1133
1134static const struct file_operations mtd_fops = {
1135        .owner          = THIS_MODULE,
1136        .llseek         = mtdchar_lseek,
1137        .read           = mtdchar_read,
1138        .write          = mtdchar_write,
1139        .unlocked_ioctl = mtdchar_unlocked_ioctl,
1140#ifdef CONFIG_COMPAT
1141        .compat_ioctl   = mtdchar_compat_ioctl,
1142#endif
1143        .open           = mtdchar_open,
1144        .release        = mtdchar_close,
1145        .mmap           = mtdchar_mmap,
1146#ifndef CONFIG_MMU
1147        .get_unmapped_area = mtdchar_get_unmapped_area,
1148#endif
1149};
1150
1151static const struct super_operations mtd_ops = {
1152        .drop_inode = generic_delete_inode,
1153        .statfs = simple_statfs,
1154};
1155
1156static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
1157                                int flags, const char *dev_name, void *data)
1158{
1159        return mount_pseudo(fs_type, "mtd_inode:", &mtd_ops, NULL, MTD_INODE_FS_MAGIC);
1160}
1161
1162static struct file_system_type mtd_inodefs_type = {
1163       .name = "mtd_inodefs",
1164       .mount = mtd_inodefs_mount,
1165       .kill_sb = kill_anon_super,
1166};
1167MODULE_ALIAS_FS("mtd_inodefs");
1168
1169int __init init_mtdchar(void)
1170{
1171        int ret;
1172
1173        ret = __register_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS,
1174                                   "mtd", &mtd_fops);
1175        if (ret < 0) {
1176                pr_err("Can't allocate major number %d for MTD\n",
1177                       MTD_CHAR_MAJOR);
1178                return ret;
1179        }
1180
1181        ret = register_filesystem(&mtd_inodefs_type);
1182        if (ret) {
1183                pr_err("Can't register mtd_inodefs filesystem, error %d\n",
1184                       ret);
1185                goto err_unregister_chdev;
1186        }
1187
1188        return ret;
1189
1190err_unregister_chdev:
1191        __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1192        return ret;
1193}
1194
1195void __exit cleanup_mtdchar(void)
1196{
1197        unregister_filesystem(&mtd_inodefs_type);
1198        __unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
1199}
1200
1201MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);
1202
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