linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * 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))