www.pudn.com > efs.rar > fs_ftl_cache_i.h

#ifndef __FTL_CACHE_I_H__
#define __FTL_CACHE_I_H__
/******************************************************************************
 * fs_ftl_cache_i.h
 *
 * This file declares the internal data and functions used by the FTL cache.
 *
 * Copyright (C) 2006 Qualcomm, Inc.  All Rights Reserved
 *
 *****************************************************************************/

/*=============================================================================

                        EDIT HISTORY FOR MODULE

  This section contains comments describing changes made to the module.
  Notice that changes are listed in reverse chronological order.

  $Header: //depot/asic/MSMSHARED/services/efs/MSM_EFS.01.02/fs_ftl_cache_i.h#4 $
  $DateTime: 2006/10/10 12:20:07 $
  $Author: davidb $

when         who     what, where, why
--------     ---     ----------------------------------------------------------
2006-09-28   yg      Changed age field to uint32.
2006-09-16   yg      Fixed compilation issue for non FTL enabled builds.
2006-08-31   dlb     Fix RCS header.
2006-07-21   yg      Initial file for FTL cache layer
=============================================================================*/

/*
 *    SECTOR : Is a 512 byte page unit.
 *    Page   : Is the smallest writable unit of the flash device (can be 2k).
 *
 */

#include "fs_ftl_cache.h"
#include "fs_ftl_i.h"

#ifdef FEATURE_EFS_FTL

/* This is in order to support 2k page device */
#define MAX_SECTORS_PER_DEV_PAGE              4

/* 2k page device has 64 pages per block */
#define MAX_DEV_PAGES_PER_BLOCK              64


#define MAX_SECTORS_PER_BLOCK   (MAX_DEV_PAGES_PER_BLOCK  \
                                 * MAX_SECTORS_PER_DEV_PAGE)

/* This could be something const or relative size of the total cache size */
#define MAX_ADDITIONAL_SECTOR_CACHE_COUNT      32


#define FTL_CACHE_PAGE_COUNT  (MAX_ADDITIONAL_SECTOR_CACHE_COUNT \
                               + MAX_SECTORS_PER_BLOCK)


#define MAX_CACHE_BLOCKS                 4

#define INVALID_BLOCK                    0xFFFF

/* How many maximum buffers FTL can handle. Since count is not passed
 * and the length is determined by the invalid identifier, we need
 * atlest 1 more than what FTL can really handle */
#define MAX_FTL_BUFFER_LIST              (256 + 1)

typedef struct __cached_page_type
{
  struct __cached_page_type * next;

  uint32   sector_num;
  uint8    dirty;
  uint8    attrib;
  uint16   dummy;
  uint8    buffer [DEFAULT_MS_PAGE_SIZE];
}
cached_page_type;

typedef struct
{
  uint16  block_number;
  uint16  sector_count;
  uint32  dirty;
  uint32  age;
  cached_page_type * cached_pages;
}
block_cache_type;

#define INVALID_CACHE_PAGE             ((cached_page_type *)0)
#define INVALID_BLOCK_CACHE            ((block_cache_type *)0)

#define CACHED_PAGE_IS_VALID(x)        ((x) != INVALID_CACHE_PAGE)
#define CACHED_PAGE_IS_NOT_VALID(x)    ((x) == INVALID_CACHE_PAGE)

#define BLOCK_CACHE_IS_VALID(x)        ((x) != INVALID_BLOCK_CACHE)
#define BLOCK_CACHE_IS_NOT_VALID(x)    ((x) == INVALID_BLOCK_CACHE)

/******************************************************************************
*
*      Local private function prototypes
*
******************************************************************************/

static
cached_page_type * lookup_sector_in_cache (uint32 sector);

static
block_cache_type * lookup_block_in_cache (uint32 block);

static
cached_page_type * lookup_sector_in_cache_list (uint32 sector,
                                                cached_page_type * cache_list);

static
cached_page_type * get_free_cache_page (void);

static
cached_page_type * insert_page_into_list (cached_page_type * src_page_list,
                                          cached_page_type * dest_page_list);

static
block_cache_type * alloc_cached_block (void);

static
int flush_block_cache (block_cache_type * blk_cache);

static
int add_page_to_cache (cached_page_type * new_cached_page);

static
uint32 cache_sync_oldest_block (void);

static
boolean compare_less_than (uint32 x, uint32 y);

#endif /* FEATURE_EFS_FTL */

#endif /* __FTL_CACHE_I_H_ */