linux-imx

/*

 * bsg.c - block layer implementation of the sg v4 interface

 *

 * Copyright (C) 2004 Jens Axboe <axboe@suse.de> SUSE Labs

 * Copyright (C) 2004 Peter M. Jones <pjones@redhat.com>

 *

 *  This file is subject to the terms and conditions of the GNU General Public

 *  License version 2.  See the file "COPYING" in the main directory of this

 *  archive for more details.

 *

 */

#include <linux/module.h>

#include <linux/init.h>

#include <linux/file.h>

#include <linux/blkdev.h>

#include <linux/cdev.h>

#include <linux/jiffies.h>

#include <linux/percpu.h>

#include <linux/idr.h>

#include <linux/bsg.h>

#include <linux/slab.h>

​

#include <scsi/scsi.h>

#include <scsi/scsi_ioctl.h>

#include <scsi/scsi_cmnd.h>

#include <scsi/scsi_device.h>

#include <scsi/scsi_driver.h>

#include <scsi/sg.h>

​

#define BSG_DESCRIPTION "Block layer SCSI generic (bsg) driver"

#define BSG_VERSION "0.4"

​

#define bsg_dbg(bd, fmt, ...) \

    pr_debug("%s: " fmt, (bd)->name, ##__VA_ARGS__)

​

struct bsg_device {

    struct request_queue *queue;

    spinlock_t lock;

    struct hlist_node dev_list;

    refcount_t ref_count;

    char name[20];

    int max_queue;

};

​

#define BSG_DEFAULT_CMDS    64

#define BSG_MAX_DEVS        32768

​

static DEFINE_MUTEX(bsg_mutex);

static DEFINE_IDR(bsg_minor_idr);

​

#define BSG_LIST_ARRAY_SIZE 8

static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE];

​

static struct class *bsg_class;

static int bsg_major;

​

static inline struct hlist_head *bsg_dev_idx_hash(int index)

{

    return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)];

}

​

#define uptr64(val) ((void __user *)(uintptr_t)(val))

​

static int bsg_scsi_check_proto(struct sg_io_v4 *hdr)

{

    if (hdr->protocol != BSG_PROTOCOL_SCSI  ||

        hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_CMD)

        return -EINVAL;

    return 0;

}

​

static int bsg_scsi_fill_hdr(struct request *rq, struct sg_io_v4 *hdr,

        fmode_t mode)

{

    struct scsi_request *sreq = scsi_req(rq);

​

    if (hdr->dout_xfer_len && hdr->din_xfer_len) {

        pr_warn_once("BIDI support in bsg has been removed.\n");

        return -EOPNOTSUPP;

    }

​

    sreq->cmd_len = hdr->request_len;

    if (sreq->cmd_len > BLK_MAX_CDB) {

        sreq->cmd = kzalloc(sreq->cmd_len, GFP_KERNEL);

        if (!sreq->cmd)

            return -ENOMEM;

    }

​

    if (copy_from_user(sreq->cmd, uptr64(hdr->request), sreq->cmd_len))

        return -EFAULT;

    if (blk_verify_command(sreq->cmd, mode))

        return -EPERM;