/*
* blkdev.h - block device driver interface definitions
*
* Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia
* Author: Victor V. Vengerov <vvv@oktet.ru>
*
* @(#) $Id$
*/
#ifndef __RTEMS_LIBBLOCK_BLKDEV_H__
#define __RTEMS_LIBBLOCK_BLKDEV_H__
#include <rtems.h>
#include <sys/ioctl.h>
#ifdef __cplusplus
extern "C" {
#endif
/* Interface with device drivers
* Block device looks, initialized and behaves like traditional RTEMS device
* driver. Heart of the block device driver is in BIOREQUEST ioctl. This call
* puts I/O request to the block device queue, in priority order, for
* asynchronous processing. When driver executes request, req_done
* function invoked, so callee knows about it. Look for details below.
*/
/* Block device block number datatype */
typedef rtems_unsigned32 blkdev_bnum;
/* Block device request type */
typedef enum blkdev_request_op {
BLKDEV_REQ_READ, /* Read operation */
BLKDEV_REQ_WRITE /* Write operation */
} blkdev_request_op;
/* Type for block device request done callback function.
*
* PARAMETERS:
* arg - argument supplied in blkdev_request
* status - rtems status code for this operation
* errno - errno value to be passed to the user when
* status != RTEMS_SUCCESSFUL
*/
typedef void (* blkdev_request_cb)(void *arg,
rtems_status_code status,
int error);
/* blkdev_sg_buffer
* Block device scatter/gather buffer structure
*/
typedef struct blkdev_sg_buffer {
rtems_unsigned32 length; /* Buffer length */
void *buffer; /* Buffer pointer */
} blkdev_sg_buffer;
/* blkdev_request (Block Device Request) structure is
* used to read/write a number of blocks from/to device.
*/
typedef struct blkdev_request {
blkdev_request_op req; /* Block device operation (read or write) */
blkdev_request_cb req_done; /* Callback function */
void *done_arg; /* Argument to be passed to callback function*/
blkdev_bnum start; /* Start block number */
rtems_unsigned32 count; /* Number of blocks to be exchanged */
rtems_unsigned32 bufnum; /* Number of buffers provided */
blkdev_sg_buffer bufs[0];/* List of scatter/gather buffers */
} blkdev_request;
/* Block device IOCTL request codes */
#define BLKIO_REQUEST _IOWR('B', 1, blkdev_request)
#define BLKIO_GETBLKSIZE _IO('B', 2)
#define BLKIO_GETSIZE _IO('B', 3)
#define BLKIO_SYNCDEV _IO('B', 4)
/* Device driver interface conventions suppose that driver may
* contain initialize/open/close/read/write/ioctl entry points. These
* primitives (except initialize) can be implemented in generic fashion,
* based upon supplied block device driver ioctl handler. Every block
* device driver should provide initialize entry point, which is register
* all block devices and appropriate ioctl handlers.
*/
#define GENERIC_BLOCK_DEVICE_DRIVER_ENTRIES \
rtems_blkdev_generic_open, rtems_blkdev_generic_close, \
rtems_blkdev_generic_read, rtems_blkdev_generic_write, \
rtems_blkdev_generic_ioctl
/* 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
);
/* blkdev_generic_write --
* Generic block device driver 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
);
/* 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
);
/* 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
);
/* 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
);
#ifdef __cplusplus
}
#endif
#endif
