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/**
* @file rtems/diskdevs.h
* Physical and logical block devices (disks) support
*/
/*
* Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia
* Author: Victor V. Vengerov <vvv@oktet.ru>
*
* @(#) $Id$
*/
#ifndef _RTEMS_DISKDEVS_H
#define _RTEMS_DISKDEVS_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, uint32_t 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
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