/**
* @file rtems/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_BLKDEV_H
#define _RTEMS_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 uint32_t rtems_blkdev_bnum;
/* Block device request type */
typedef enum rtems_blkdev_request_op {
RTEMS_BLKDEV_REQ_READ, /* Read operation */
RTEMS_BLKDEV_REQ_WRITE, /* Write operation */
RTEMS_BLKDEV_CAPABILITIES /* Capabilities request */
} rtems_blkdev_request_op;
/**
* ATA multi-sector buffer requests only supported. This option
* means the cache will only supply multiple buffers that are
* inorder so the ATA multi-sector command can be used. This is a
* hack to work around the current ATA driver.
*/
#define RTEMS_BLKDEV_CAP_MULTISECTOR_CONT (1 << 0)
/*
* @typedef rtems_blkdev_request_cb
*
* Type for block device request done callback function.
*
* @param arg Argument supplied in blkdev_request
* @param status RTEMS status code for this operation
* @param errno errno value to be passed to the user when
* status != RTEMS_SUCCESSFUL
*/
typedef void (* rtems_blkdev_request_cb)(void *arg,
rtems_status_code status,
int error);
/**
* @struct rtems_blkdev_sg_buffer
* Block device scatter/gather buffer structure
*/
typedef struct rtems_blkdev_sg_buffer {
uint32_t block; /* The block number */
uint32_t length; /* Buffer length */
void *buffer; /* Buffer pointer */
void *user; /* User pointer */
} rtems_blkdev_sg_buffer;
/* blkdev_request (Block Device Request) structure is
* used to read/write a number of blocks from/to device.
*/
typedef struct rtems_blkdev_request {
/* Block device operation (read or write) */
rtems_blkdev_request_op req;
/* Callback function */
rtems_blkdev_request_cb req_done;
/* Argument to be passed to callback function*/
void *done_arg;
/* Last I/O operation completion status */
rtems_status_code status;
/* If status != RTEMS_SUCCESSFUL, this field contains error code */
int error;
/* Start block number */
rtems_blkdev_bnum start;
/* Number of blocks to be exchanged */
uint32_t count;
/* Number of buffers provided */
uint32_t bufnum;
/* The task requesting the IO operation. */
rtems_id io_task;
/* List of scatter/gather buffers */
rtems_blkdev_sg_buffer bufs[0];
} rtems_blkdev_request;
/* Block device IOCTL request codes */
#define RTEMS_BLKIO_REQUEST _IOWR('B', 1, rtems_blkdev_request)
#define RTEMS_BLKIO_GETBLKSIZE _IO('B', 2)
#define RTEMS_BLKIO_GETSIZE _IO('B', 3)
#define RTEMS_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 RTEMS_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
