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/*

 * logdisk.h - Physical and logical block devices (disks) support

 *

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

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

 *

 * @(#) diskdevs.h,v 1.1 2002/02/28 20:39:54 joel Exp

 */

#ifndef __RTEMS_LIBBLOCK_LOGDISK_H__

#define __RTEMS_LIBBLOCK_LOGDISK_H__

#ifdef __cplusplus

extern "C" {

#endif

#include <rtems.h>

#include <rtems/libio.h>

#include <stdlib.h>

#include "rtems/blkdev.h"

/* Buffer pool identifier */

typedef int rtems_bdpool_id;

/* Block device ioctl handler */

typedef int (* block_device_ioctl) (dev_t dev, int req, void *argp);

/* disk_device: Entry of this type created for every disk device (both for

 * logical and physical disks).

 * Array of arrays of pointers to disk_device structures maintained. First

 * table indexed by major number and second table indexed by minor number.

 * Such data organization allow quick lookup using data structure of

 * moderated size.

 */

typedef struct disk_device {

    dev_t               dev;              /* Device ID (major + minor) */

    struct disk_device *phys_dev;         /* Physical device ID (the same

                                             as dev if this entry specifies

                                             the physical device) */

    char               *name;             /* Disk device name */

    int                 uses;             /* Use counter. Device couldn't be

                                             removed if it is in use. */

    int                 start;            /* Starting block number (0 for

                                             physical devices, block offset

                                             on the related physical device

                                             for logical device) */

    int                 size;             /* Size of physical or logical disk

                                             in disk blocks */

    int                 block_size;       /* Size of device block (minimum

                                             transfer unit) in bytes

                                             (must be power of 2) */

    int                 block_size_log2;  /* log2 of block_size */

    rtems_bdpool_id     pool;             /* Buffer pool assigned to this

                                             device */

    block_device_ioctl  ioctl;            /* ioctl handler for this block

                                             device */

} disk_device;

/* rtems_disk_create_phys --

 *     Create physical disk entry. This function usually invoked from

 *     block device driver initialization code when physical device

 *     detected in the system. Device driver should provide ioctl handler

 *     to allow block device access operations. This primitive will register

 *     device in rtems (invoke rtems_io_register_name).

 *

 * PARAMETERS:

 *     dev        - device identifier (major, minor numbers)

 *     block_size - size of disk block (minimum data transfer unit); must be

 *                  power of 2

 *     disk_size  - number of blocks on device

 *     handler    - IOCTL handler (function providing basic block input/output

 *                  request handling BIOREQUEST and other device management

 *                  operations)

 *     name       - character name of device (e.g. /dev/hda)

 *

 * RETURNS:

 *     RTEMS_SUCCESSFUL if information about new physical disk added, or

 *     error code if error occured (device already registered, wrong block

 *     size value, no memory available).

 */

rtems_status_code

rtems_disk_create_phys(dev_t dev, int block_size, int disk_size,

                       block_device_ioctl handler,

                       char *name);

/* rtems_disk_create_log --

 *     Create logical disk entry. Logical disk is contiguous area on physical

 *     disk. Disk may be splitted to several logical disks in several ways:

 *     manually or using information stored in blocks on physical disk

 *     (DOS-like partition table, BSD disk label, etc). This function usually

 *     invoked from application when application-specific splitting are in use,

 *     or from generic code which handle different logical disk organizations.

 *     This primitive will register device in rtems (invoke

 *     rtems_io_register_name).

 *

 * PARAMETERS:

 *     dev   - logical device identifier (major, minor numbers)

 *     phys  - physical device (block device which holds this logical disk)

 *             identifier

 *     start - starting block number on the physical device

 *     size  - logical disk size in blocks

 *     name  - logical disk name

 *

 * RETURNS:

 *     RTEMS_SUCCESSFUL if logical device successfully added, or error code

 *     if error occured (device already registered, no physical device

 *     exists, logical disk is out of physical disk boundaries, no memory

 *     available).

 */

rtems_status_code

rtems_disk_create_log(dev_t dev, dev_t phys, int start, int size, char *name);

/* rtems_disk_delete --

 *     Delete physical or logical disk device. Device may be deleted if its

 *     use counter (and use counters of all logical devices - if it is

 *     physical device) equal to 0. When physical device deleted,

 *     all logical devices deleted inherently. Appropriate devices removed

 *     from "/dev" filesystem.

 *

 * PARAMETERS:

 *     dev - device identifier (major, minor numbers)

 *

 * RETURNS:

 *     RTEMS_SUCCESSFUL if block device successfully deleted, or error code

 *     if error occured (device is not defined, device is in use).

 */

rtems_status_code

rtems_disk_delete(dev_t dev);

/* rtems_disk_lookup --

 *     Find block device descriptor by its device identifier. This function

 *     increment usage counter to 1. User should release disk_device structure

 *     by invoking rtems_disk_release primitive.

 *

 * PARAMETERS:

 *     dev - device identifier (major, minor numbers)

 *

 * RETURNS:

 *     pointer to the block device descriptor, or NULL if no such device

 *     exists.

 */

disk_device *

rtems_disk_lookup(dev_t dev);

/* rtems_disk_release --

 *     Release disk_device structure (decrement usage counter to 1).

 *

 * PARAMETERS:

 *     dd - pointer to disk device structure

 *

 * RETURNS:

 *     RTEMS_SUCCESSFUL

 *

 * NOTE:

 *     It should be implemented as inline function.

 */

rtems_status_code

rtems_disk_release(disk_device *dd);

/* rtems_disk_next --

 *     Disk device enumerator. Looking for device having device number larger

 *     than dev and return disk device descriptor for it. If there are no

 *     such device, NULL value returned.

 *

 * PARAMETERS:

 *     dev - device number (use -1 to start search)

 *

 * RETURNS:

 *     Pointer to the disk descriptor for next disk device, or NULL if all

 *     devices enumerated. */

disk_device *

rtems_disk_next(dev_t dev);

/* rtems_diskio_initialize --

 *     Initialization of disk device library (initialize all data structures,

 *     etc.)

 *

 * PARAMETERS:

 *     none

 *

 * RETURNS:

 *     RTEMS_SUCCESSFUL if library initialized, or error code if error

 *     occured.

 */

rtems_status_code

rtems_disk_io_initialize(void);

/* rtems_diskio_done --

 *     Release all resources allocated for disk device interface.

 *

 * PARAMETERS:

 *     none

 *

 * RETURNS:

 *     RTEMS_SUCCESSFUL if all resources released, or error code if error

 *     occured.

 */

rtems_status_code

rtems_disk_io_done(void);

#ifdef __cplusplus

}

#endif

#endif