ide-floppy_ioctl.c

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/*
 * ide-floppy IOCTLs handling.
 */

#include <linux/kernel.h>
#include <linux/ide.h>
#include <linux/cdrom.h>
#include <linux/mutex.h>

#include <asm/unaligned.h>

#include <scsi/scsi_ioctl.h>

#include "ide-floppy.h"

/*
 * Obtain the list of formattable capacities.
 * Very similar to ide_floppy_get_capacity, except that we push the capacity
 * descriptors to userland, instead of our own structures.
 *
 * Userland gives us the following structure:
 *
 * struct idefloppy_format_capacities {
 *  int nformats;
 *  struct {
 *      int nblocks;
 *      int blocksize;
 *  } formats[];
 * };
 *
 * userland initializes nformats to the number of allocated formats[] records.
 * On exit we set nformats to the number of records we've actually initialized.
 */

static DEFINE_MUTEX(ide_floppy_ioctl_mutex);
static int ide_floppy_get_format_capacities(ide_drive_t *drive,
                        struct ide_atapi_pc *pc,
                        int __user *arg)
{
    struct ide_disk_obj *floppy = drive->driver_data;
    int i, blocks, length, u_array_size, u_index;
    int __user *argp;
    u8 pc_buf[256], header_len, desc_cnt;

    if (get_user(u_array_size, arg))
        return -EFAULT;

    if (u_array_size <= 0)
        return -EINVAL;

    ide_floppy_create_read_capacity_cmd(pc);

    if (ide_queue_pc_tail(drive, floppy->disk, pc, pc_buf, pc->req_xfer)) {
        printk(KERN_ERR "ide-floppy: Can't get floppy parameters\n");
        return -EIO;
    }

    header_len = pc_buf[3];
    desc_cnt = header_len / 8; /* capacity descriptor of 8 bytes */

    u_index = 0;
    argp = arg + 1;

    /*
     * We always skip the first capacity descriptor.  That's the current
     * capacity.  We are interested in the remaining descriptors, the
     * formattable capacities.
     */
    for (i = 1; i < desc_cnt; i++) {
        unsigned int desc_start = 4 + i*8;

        if (u_index >= u_array_size)
            break;  /* User-supplied buffer too small */

        blocks = be32_to_cpup((__be32 *)&pc_buf[desc_start]);
        length = be16_to_cpup((__be16 *)&pc_buf[desc_start + 6]);

        if (put_user(blocks, argp))
            return -EFAULT;

        ++argp;

        if (put_user(length, argp))
            return -EFAULT;

        ++argp;

        ++u_index;
    }

    if (put_user(u_index, arg))
        return -EFAULT;

    return 0;
}

static void ide_floppy_create_format_unit_cmd(struct ide_atapi_pc *pc,
                          u8 *buf, int b, int l,
                          int flags)
{
    ide_init_pc(pc);
    pc->c[0] = GPCMD_FORMAT_UNIT;
    pc->c[1] = 0x17;

    memset(buf, 0, 12);
    buf[1] = 0xA2;
    /* Default format list header, u8 1: FOV/DCRT/IMM bits set */

    if (flags & 1)              /* Verify bit on... */
        buf[1] ^= 0x20;         /* ... turn off DCRT bit */
    buf[3] = 8;

    put_unaligned(cpu_to_be32(b), (unsigned int *)(&buf[4]));
    put_unaligned(cpu_to_be32(l), (unsigned int *)(&buf[8]));
    pc->req_xfer = 12;
    pc->flags |= PC_FLAG_WRITING;
}

static int ide_floppy_get_sfrp_bit(ide_drive_t *drive, struct ide_atapi_pc *pc)
{
    struct ide_disk_obj *floppy = drive->driver_data;
    u8 buf[20];

    drive->atapi_flags &= ~IDE_AFLAG_SRFP;

    ide_floppy_create_mode_sense_cmd(pc, IDEFLOPPY_CAPABILITIES_PAGE);
    pc->flags |= PC_FLAG_SUPPRESS_ERROR;

    if (ide_queue_pc_tail(drive, floppy->disk, pc, buf, pc->req_xfer))
        return 1;

    if (buf[8 + 2] & 0x40)
        drive->atapi_flags |= IDE_AFLAG_SRFP;

    return 0;
}

static int ide_floppy_format_unit(ide_drive_t *drive, struct ide_atapi_pc *pc,
                  int __user *arg)
{
    struct ide_disk_obj *floppy = drive->driver_data;
    u8 buf[12];
    int blocks, length, flags, err = 0;

    if (floppy->openers > 1) {
        /* Don't format if someone is using the disk */
        drive->dev_flags &= ~IDE_DFLAG_FORMAT_IN_PROGRESS;
        return -EBUSY;
    }

    drive->dev_flags |= IDE_DFLAG_FORMAT_IN_PROGRESS;

    /*
     * Send ATAPI_FORMAT_UNIT to the drive.
     *
     * Userland gives us the following structure:
     *
     * struct idefloppy_format_command {
     *        int nblocks;
     *        int blocksize;
     *        int flags;
     *        } ;
     *
     * flags is a bitmask, currently, the only defined flag is:
     *
     *        0x01 - verify media after format.
     */
    if (get_user(blocks, arg) ||
            get_user(length, arg+1) ||
            get_user(flags, arg+2)) {
        err = -EFAULT;
        goto out;
    }

    ide_floppy_get_sfrp_bit(drive, pc);
    ide_floppy_create_format_unit_cmd(pc, buf, blocks, length, flags);

    if (ide_queue_pc_tail(drive, floppy->disk, pc, buf, pc->req_xfer))
        err = -EIO;

out:
    if (err)
        drive->dev_flags &= ~IDE_DFLAG_FORMAT_IN_PROGRESS;
    return err;
}

/*
 * Get ATAPI_FORMAT_UNIT progress indication.
 *
 * Userland gives a pointer to an int.  The int is set to a progress
 * indicator 0-65536, with 65536=100%.
 *
 * If the drive does not support format progress indication, we just check
 * the dsc bit, and return either 0 or 65536.
 */

static int ide_floppy_get_format_progress(ide_drive_t *drive,
                      struct ide_atapi_pc *pc,
                      int __user *arg)
{
    struct ide_disk_obj *floppy = drive->driver_data;
    u8 sense_buf[18];
    int progress_indication = 0x10000;

    if (drive->atapi_flags & IDE_AFLAG_SRFP) {
        ide_create_request_sense_cmd(drive, pc);
        if (ide_queue_pc_tail(drive, floppy->disk, pc, sense_buf,
                      pc->req_xfer))
            return -EIO;

        if (floppy->sense_key == 2 &&
            floppy->asc == 4 &&
            floppy->ascq == 4)
            progress_indication = floppy->progress_indication;

        /* Else assume format_unit has finished, and we're at 0x10000 */
    } else {
        ide_hwif_t *hwif = drive->hwif;
        unsigned long flags;
        u8 stat;

        local_irq_save(flags);
        stat = hwif->tp_ops->read_status(hwif);
        local_irq_restore(flags);

        progress_indication = ((stat & ATA_DSC) == 0) ? 0 : 0x10000;
    }

    if (put_user(progress_indication, arg))
        return -EFAULT;

    return 0;
}

static int ide_floppy_lockdoor(ide_drive_t *drive, struct ide_atapi_pc *pc,
                   unsigned long arg, unsigned int cmd)
{
    struct ide_disk_obj *floppy = drive->driver_data;
    struct gendisk *disk = floppy->disk;
    int prevent = (arg && cmd != CDROMEJECT) ? 1 : 0;

    if (floppy->openers > 1)
        return -EBUSY;

    ide_set_media_lock(drive, disk, prevent);

    if (cmd == CDROMEJECT)
        ide_do_start_stop(drive, disk, 2);

    return 0;
}

static int ide_floppy_format_ioctl(ide_drive_t *drive, struct ide_atapi_pc *pc,
                   fmode_t mode, unsigned int cmd,
                   void __user *argp)
{
    switch (cmd) {
    case IDEFLOPPY_IOCTL_FORMAT_SUPPORTED:
        return 0;
    case IDEFLOPPY_IOCTL_FORMAT_GET_CAPACITY:
        return ide_floppy_get_format_capacities(drive, pc, argp);
    case IDEFLOPPY_IOCTL_FORMAT_START:
        if (!(mode & FMODE_WRITE))
            return -EPERM;
        return ide_floppy_format_unit(drive, pc, (int __user *)argp);
    case IDEFLOPPY_IOCTL_FORMAT_GET_PROGRESS:
        return ide_floppy_get_format_progress(drive, pc, argp);
    default:
        return -ENOTTY;
    }
}

int ide_floppy_ioctl(ide_drive_t *drive, struct block_device *bdev,
             fmode_t mode, unsigned int cmd, unsigned long arg)
{
    struct ide_atapi_pc pc;
    void __user *argp = (void __user *)arg;
    int err;

    mutex_lock(&ide_floppy_ioctl_mutex);
    if (cmd == CDROMEJECT || cmd == CDROM_LOCKDOOR) {
        err = ide_floppy_lockdoor(drive, &pc, arg, cmd);
        goto out;
    }

    err = ide_floppy_format_ioctl(drive, &pc, mode, cmd, argp);
    if (err != -ENOTTY)
        goto out;

    /*
     * skip SCSI_IOCTL_SEND_COMMAND (deprecated)
     * and CDROM_SEND_PACKET (legacy) ioctls
     */
    if (cmd != CDROM_SEND_PACKET && cmd != SCSI_IOCTL_SEND_COMMAND)
        err = scsi_cmd_blk_ioctl(bdev, mode, cmd, argp);

    if (err == -ENOTTY)
        err = generic_ide_ioctl(drive, bdev, cmd, arg);

out:
    mutex_unlock(&ide_floppy_ioctl_mutex);
    return err;
}