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/*

 * blkdev.h - block device driver generic support

 *

 * Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia

 * Author: Victor V. Vengerov <vvv@oktet.ru>

 *

 * @(#) blkdev.c,v 1.2 2002/04/08 18:29:02 joel Exp

 */

#include <string.h>

#include <rtems.h>

#include <rtems/libio.h>

#include <sys/ioctl.h>

#include "rtems/diskdevs.h"

#include "rtems/bdbuf.h"

/* rtems_blkdev_generic_read --

 *     Generic block device read primitive. Implemented using block device

 *     buffer management primitives.

 */

rtems_device_driver

rtems_blkdev_generic_read(

    rtems_device_major_number major,

    rtems_device_minor_number minor,

    void                    * arg)

{

    rtems_libio_rw_args_t *args = arg;

    int block_size_log2;

    int block_size;

    char *buf;

    unsigned int count;

    unsigned int block;

    unsigned int blkofs;

    dev_t dev;

    disk_device *dd;

    dev = rtems_filesystem_make_dev_t(major, minor);

    dd = rtems_disk_lookup(dev);

    if (dd == NULL)

        return RTEMS_INVALID_NUMBER;

    block_size_log2 = dd->block_size_log2;

    block_size = dd->block_size;

    buf = args->buffer;

    count = args->count;

    args->bytes_moved = 0;

    block = args->offset >> block_size_log2;

    blkofs = args->offset & (block_size - 1);

    while (count > 0)

    {

        bdbuf_buffer *diskbuf;

        int copy;

        rtems_status_code rc;

        rc = rtems_bdbuf_read(dev, block, &diskbuf);

        if (rc != RTEMS_SUCCESSFUL)

            return rc;

        copy = block_size - blkofs;

        if (copy > count)

            copy = count;

        memcpy(buf, (char *)diskbuf->buffer + blkofs, copy);

        rc = rtems_bdbuf_release(diskbuf);

        args->bytes_moved += copy;

        if (rc != RTEMS_SUCCESSFUL)

            return rc;

        count -= copy;

        buf += copy;

        blkofs = 0;

        block++;

    }

    return RTEMS_SUCCESSFUL;

}

/* rtems_blkdev_generic_write --

 *     Generic block device write primitive. Implemented using block device

 *     buffer management primitives.

 */

rtems_device_driver

rtems_blkdev_generic_write(

    rtems_device_major_number major,

    rtems_device_minor_number minor,

    void                    * arg)

{

    rtems_libio_rw_args_t *args = arg;

    int block_size_log2;

    int block_size;

    char *buf;

    unsigned int count;

    unsigned int block;

    unsigned int blkofs;

    dev_t dev;

    rtems_status_code rc;

    disk_device *dd;

    dev = rtems_filesystem_make_dev_t(major, minor);

    dd = rtems_disk_lookup(dev);

    if (dd == NULL)

        return RTEMS_INVALID_NUMBER;

    block_size_log2 = dd->block_size_log2;

    block_size = dd->block_size;

    buf = args->buffer;

    count = args->count;

    args->bytes_moved = 0;

    block = args->offset >> block_size_log2;

    blkofs = args->offset & (block_size - 1);

    while (count > 0)

    {

        bdbuf_buffer *diskbuf;

        int copy;

        if ((blkofs == 0) && (count > block_size))

            rc = rtems_bdbuf_get(dev, block, &diskbuf);

        else

            rc = rtems_bdbuf_read(dev, block, &diskbuf);

        if (rc != RTEMS_SUCCESSFUL)

            return rc;

        copy = block_size - blkofs;

        if (copy > count)

            copy = count;

        memcpy((char *)diskbuf->buffer + blkofs, buf, copy);

        args->bytes_moved += copy;

        rc = rtems_bdbuf_release_modified(diskbuf);

        if (rc != RTEMS_SUCCESSFUL)

            return rc;

        count -= copy;

        buf += copy;

        blkofs = 0;

        block++;

    }

    return RTEMS_SUCCESSFUL;

}

/* blkdev_generic_open --

 *     Generic block device open primitive.

 */

rtems_device_driver

rtems_blkdev_generic_open(

    rtems_device_major_number major,

    rtems_device_minor_number minor,

    void                    * arg)

{

    dev_t dev;

    disk_device *dd;

    dev = rtems_filesystem_make_dev_t(major, minor);

    dd = rtems_disk_lookup(dev);

    if (dd == NULL)

        return RTEMS_INVALID_NUMBER;

    dd->uses++;

    rtems_disk_release(dd);

    return RTEMS_SUCCESSFUL;

}

/* blkdev_generic_close --

 *     Generic block device close primitive.

 */

rtems_device_driver

rtems_blkdev_generic_close(

    rtems_device_major_number major,

    rtems_device_minor_number minor,

    void                    * arg)

{

    dev_t dev;

    disk_device *dd;

    dev = rtems_filesystem_make_dev_t(major, minor);

    dd = rtems_disk_lookup(dev);

    if (dd == NULL)

        return RTEMS_INVALID_NUMBER;

    dd->uses--;

    rtems_disk_release(dd);

    return RTEMS_SUCCESSFUL;

}

/* blkdev_generic_ioctl --

 *     Generic block device ioctl primitive.

 */

rtems_device_driver

rtems_blkdev_generic_ioctl(

    rtems_device_major_number major,

    rtems_device_minor_number minor,

    void                    * arg)

{

    rtems_libio_ioctl_args_t *args = arg;

    dev_t dev;

    disk_device *dd;

    int rc;

    dev = rtems_filesystem_make_dev_t(major, minor);

    dd = rtems_disk_lookup(dev);

    if (dd == NULL)

        return RTEMS_INVALID_NUMBER;

    switch (args->command)

    {

        case BLKIO_GETBLKSIZE:

            args->ioctl_return = dd->block_size;

            break;

        case BLKIO_GETSIZE:

            args->ioctl_return = dd->size;

            break;

        case BLKIO_SYNCDEV:

            rc = rtems_bdbuf_syncdev(dd->dev);

            args->ioctl_return = (rc == RTEMS_SUCCESSFUL ? 0 : -1);

            break;

        case BLKIO_REQUEST:

        {

            blkdev_request *req = args->buffer;

            req->start += dd->start;

            args->ioctl_return = dd->ioctl(dd->phys_dev->dev, args->command,

                                           req);

            break;

        }

        default:

            args->ioctl_return = dd->ioctl(dd->phys_dev->dev, args->command,

                                           args->buffer);

            break;

    }

    rtems_disk_release(dd);

    return RTEMS_SUCCESSFUL;

}