/** * @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: diskdevs.h,v 1.6 2005/02/17 08:38:59 ralf Exp $ */#ifndef _RTEMS_DISKDEVS_H#define _RTEMS_DISKDEVS_H#ifdef __cplusplusextern "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_codertems_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_codertems_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_codertems_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_codertems_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_codertems_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_codertems_disk_io_done(void);#ifdef __cplusplus}#endif#endif