/**
* @file
*
* @brief Block Device Disk Management API
*
* @ingroup rtems_disk
*/
/*
* Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia
* Author: Victor V. Vengerov <vvv@oktet.ru>
*/
#ifndef _RTEMS_DISKDEVS_H
#define _RTEMS_DISKDEVS_H
#include <rtems.h>
#include <rtems/libio.h>
#include <rtems/chain.h>
#ifdef __cplusplus
extern "C" {
#endif
typedef struct rtems_disk_device rtems_disk_device;
/**
* @defgroup rtems_disk Block Device Disk Management
*
* @ingroup rtems_libblock
*
* @brief This module provides functions to manage disk devices.
*
* A disk is a set of blocks which are identified by a consecutive set of
* non-negative integers starting at zero. There are also logical disks which
* contain a subset of consecutive disk blocks. The logical disks are used to
* represent the partitions of a disk. The disk devices are accessed via the
* @ref rtems_bdbuf "block device buffer module".
*/
/**@{**/
/**
* @brief Block device block index type.
*/
typedef uint32_t rtems_blkdev_bnum;
/**
* @brief Block device IO control handler type.
*/
typedef int (*rtems_block_device_ioctl)(
rtems_disk_device *dd,
uint32_t req,
void *argp
);
/**
* @brief Trigger value to disable further read-ahead requests.
*/
#define RTEMS_DISK_READ_AHEAD_NO_TRIGGER ((rtems_blkdev_bnum) -1)
/**
* @brief Size value to set number of blocks based on config and disk size.
*/
#define RTEMS_DISK_READ_AHEAD_SIZE_AUTO (0)
/**
* @brief Block device read-ahead control.
*/
typedef struct {
/**
* @brief Chain node for the read-ahead request queue of the read-ahead task.
*/
rtems_chain_node node;
/**
* @brief Block value to trigger the read-ahead request.
*
* A value of @ref RTEMS_DISK_READ_AHEAD_NO_TRIGGER will disable further
* read-ahead requests (except the ones triggered by @a rtems_bdbuf_peek)
* since no valid block can have this value.
*/
rtems_blkdev_bnum trigger;
/**
* @brief Start block for the next read-ahead request.
*
* In case the trigger value is out of range of valid blocks, this value my
* be arbitrary.
*/
rtems_blkdev_bnum next;
/**
* @brief Size of the next read-ahead request in blocks.
*
* A value of @ref RTEMS_DISK_READ_AHEAD_SIZE_AUTO will try to read the rest
* of the disk but at most the configured max_read_ahead_blocks.
*/
uint32_t nr_blocks;
} rtems_blkdev_read_ahead;
/**
* @brief Block device statistics.
*
* Integer overflows in the statistic counters may happen.
*/
typedef struct {
/**
* @brief Read hit count.
*
* A read hit occurs in the rtems_bdbuf_read() function in case the block is
* in the cached or modified state.
*/
uint32_t read_hits;
/**
* @brief Read miss count.
*
* A read miss occurs in the rtems_bdbuf_read() function in case the block is
* in the empty state and a read transfer must be initiated to read the data
* from the device.
*/
uint32_t read_misses;
/**
* @brief Read-ahead transfer count.
*
* Each read-ahead transfer may read multiple blocks. This counts all
* transfers (including peeks).
*/
uint32_t read_ahead_transfers;
/**
* @brief Read-ahead transfers caused by a peek.
*/
uint32_t read_ahead_peeks;
/**
* @brief Count of blocks transfered from the device.
*/
uint32_t read_blocks;
/**
* @brief Read error count.
*
* Error count of transfers issued by the read or read-ahead requests.
*/
uint32_t read_errors;
/**
* @brief Write transfer count.
*
* Each write transfer may write multiple blocks.
*/
uint32_t write_transfers;
/**
* @brief Count of blocks transfered to the device.
*/
uint32_t write_blocks;
/**
* @brief Write error count.
*
* Error count of transfers issued by write requests.
*/
uint32_t write_errors;
} rtems_blkdev_stats;
/**
* @brief Description of a disk device (logical and physical disks).
*
* An array of pointer tables to rtems_disk_device structures is maintained.
* The first table will be indexed by the major number and the second table
* will be indexed by the minor number. This allows quick lookup using a data
* structure of moderated size.
*/
struct rtems_disk_device {
/**
* @brief Device identifier (concatenation of major and minor number).
*/
dev_t dev;
/**
* @brief Physical device identifier (equals the @c dev entry if it specifies a
* physical device).
*/
rtems_disk_device *phys_dev;
/**
* @brief Driver capabilities.
*/
uint32_t capabilities;
/**
* @brief Disk device name.
*/
char *name;
/**
* @brief Usage counter.
*
* Devices cannot be deleted if they are in use.
*/
unsigned uses;
/**
* @brief Start media block number.
*
* Equals zero for physical devices. It is a media block offset to the
* related physical device for logical device.
*/
rtems_blkdev_bnum start;
/**
* @brief Size of the physical or logical disk in media blocks.
*/
rtems_blkdev_bnum size;
/**
* @brief Media block size in bytes.
*
* This is the media transfer unit the hardware defaults to.
*/
uint32_t media_block_size;
/**
* @brief Block size in bytes.
*
* This is the minimum transfer unit. It may be a multiple of the media
* block size. It must be positive.
*
* @see rtems_bdbuf_set_block_size().
*/
uint32_t block_size;
/**
* @brief Block count.
*
* @see rtems_bdbuf_set_block_size().
*/
rtems_blkdev_bnum block_count;
/**
* @brief Media blocks per device blocks.
*
* @see rtems_bdbuf_set_block_size().
*/
uint32_t media_blocks_per_block;
/**
* @brief Block to media block shift.
*
* In case this value is non-negative the media block of a block can be
* calculated as media block = block << block_to_media_block_shift, otherwise
* a 64-bit operation will be used.
*
* @see rtems_bdbuf_set_block_size().
*/
int block_to_media_block_shift;
/**
* @brief Buffer descriptors per group count.
*
* @see rtems_bdbuf_set_block_size().
*/
size_t bds_per_group;
/**
* @brief IO control handler for this disk.
*/
rtems_block_device_ioctl ioctl;
/**
* @brief Private data for the disk driver.
*/
void *driver_data;
/**
* @brief Indicates that this disk should be deleted as soon as the last user
* releases this disk.
*/
bool deleted;
/**
* @brief Device statistics for this disk.
*/
rtems_blkdev_stats stats;
/**
* @brief Read-ahead control for this disk.
*/
rtems_blkdev_read_ahead read_ahead;
};
/**
* @name Disk Device Data
*/
/**@{**/
/* Use fstat() instead */
RTEMS_DEPRECATED static inline dev_t rtems_disk_get_device_identifier(
const rtems_disk_device *dd
)
{
return dd->dev;
}
/* Use fstat() instead */
RTEMS_DEPRECATED static inline rtems_device_major_number rtems_disk_get_major_number(
const rtems_disk_device *dd
)
{
return rtems_filesystem_dev_major_t(dd->dev);
}
/* Use fstat() instead */
RTEMS_DEPRECATED static inline rtems_device_minor_number rtems_disk_get_minor_number(
const rtems_disk_device *dd
)
{
return rtems_filesystem_dev_minor_t(dd->dev);
}
static inline void *rtems_disk_get_driver_data(
const rtems_disk_device *dd
)
{
return dd->driver_data;
}
static inline uint32_t rtems_disk_get_media_block_size(
const rtems_disk_device *dd
)
{
return dd->media_block_size;
}
static inline uint32_t rtems_disk_get_block_size(
const rtems_disk_device *dd
)
{
return dd->block_size;
}
static inline rtems_blkdev_bnum rtems_disk_get_block_begin(
const rtems_disk_device *dd
)
{
return dd->start;
}
static inline rtems_blkdev_bnum rtems_disk_get_block_count(
const rtems_disk_device *dd
)
{
return dd->size;
}
/** @} */
/**
* @name Disk Device Maintainance
*/
/**@{**/
/* Use rtems_blkdev_create() instead */
RTEMS_DEPRECATED rtems_status_code rtems_disk_create_phys(
dev_t dev,
uint32_t block_size,
rtems_blkdev_bnum block_count,
rtems_block_device_ioctl handler,
void *driver_data,
const char *name
);
/* Use rtems_blkdev_create_partition() instead */
RTEMS_DEPRECATED rtems_status_code rtems_disk_create_log(
dev_t dev,
dev_t phys,
rtems_blkdev_bnum block_begin,
rtems_blkdev_bnum block_count,
const char *name
);
/*
* Use rtems_blkdev_create() or rtems_blkdev_create_partition and unlink()
* instead.
*/
RTEMS_DEPRECATED rtems_status_code rtems_disk_delete(dev_t dev);
/*
* Use rtems_blkdev_create() or rtems_blkdev_create_partition and open()
* instead.
*/
RTEMS_DEPRECATED rtems_disk_device *rtems_disk_obtain(dev_t dev);
/*
* Use rtems_blkdev_create() or rtems_blkdev_create_partition and close()
* instead.
*/
RTEMS_DEPRECATED rtems_status_code rtems_disk_release(rtems_disk_device *dd);
/** @} */
/**
* @name Disk Management
*/
/**@{**/
/* Just remove calls to this function */
RTEMS_DEPRECATED rtems_status_code rtems_disk_io_initialize(void);
/* Just remove calls to this function */
RTEMS_DEPRECATED rtems_status_code rtems_disk_io_done(void);
/** @} */
/** @} */
/*
* This functionality no longer available. There is no global registration for
* disk devices.
*/
RTEMS_DEPRECATED rtems_disk_device *rtems_disk_next(dev_t dev);
/* Internal function, do not use */
rtems_status_code rtems_disk_init_phys(
rtems_disk_device *dd,
uint32_t block_size,
rtems_blkdev_bnum block_count,
rtems_block_device_ioctl handler,
void *driver_data
);
/* Internal function, do not use */
rtems_status_code rtems_disk_init_log(
rtems_disk_device *dd,
rtems_disk_device *phys_dd,
rtems_blkdev_bnum block_begin,
rtems_blkdev_bnum block_count
);
#ifdef __cplusplus
}
#endif
#endif
