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 /**
  * @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

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