uboot-1.1.4-kirkwood/board/mv_feroceon/mv_hal/cesa/mvLru.c

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#include "mvOs.h"
#include "mvLru.h"
/* LRU Cache support */


/* Init LRU cache database */
MV_LRU_CACHE*   mvLruCacheInit(int numOfEntries)
{
    int             i;
    MV_LRU_CACHE*   pLruCache;

    pLruCache = mvOsMalloc(sizeof(MV_LRU_CACHE));
    if(pLruCache == NULL)
    {
        return NULL;
    }
    memset(pLruCache, 0, sizeof(MV_LRU_CACHE));

    pLruCache->table = mvOsMalloc(numOfEntries*sizeof(MV_LRU_ENTRY));
    if(pLruCache->table == NULL)
    {
        mvOsFree(pLruCache);
        return NULL;
    }
    memset(pLruCache->table, 0, numOfEntries*sizeof(MV_LRU_ENTRY));
    pLruCache->tableSize = numOfEntries;

    for(i=0; i<numOfEntries; i++)
    {
        pLruCache->table[i].next = i+1;
        pLruCache->table[i].prev = i-1;         
    }
    pLruCache->least = 0;
    pLruCache->most = numOfEntries-1;   

    return pLruCache;
}

void    mvLruCacheFinish(MV_LRU_CACHE* pLruCache)
{
    mvOsFree(pLruCache->table);
    mvOsFree(pLruCache);
}

/* Update LRU cache database after using cache Index */
void    mvLruCacheIdxUpdate(MV_LRU_CACHE* pLruHndl, int cacheIdx)
{
    int prev, next;

    if(cacheIdx == pLruHndl->most)
        return;

    next = pLruHndl->table[cacheIdx].next;
    if(cacheIdx == pLruHndl->least)
    {
        pLruHndl->least = next;
    }
    else
    {
        prev = pLruHndl->table[cacheIdx].prev;

        pLruHndl->table[next].prev = prev;
        pLruHndl->table[prev].next = next;
    }

    pLruHndl->table[pLruHndl->most].next = cacheIdx;
    pLruHndl->table[cacheIdx].prev = pLruHndl->most;
    pLruHndl->most = cacheIdx;
}

/* Delete LRU cache entry */
void    mvLruCacheIdxDelete(MV_LRU_CACHE* pLruHndl, int cacheIdx)
{
    int prev, next;

    if(cacheIdx == pLruHndl->least)
        return;

    prev = pLruHndl->table[cacheIdx].prev;
    if(cacheIdx == pLruHndl->most)
    {
        pLruHndl->most = prev;
    }
    else
    {
        next = pLruHndl->table[cacheIdx].next;

        pLruHndl->table[next].prev = prev;
        pLruHndl->table[prev].next = next;
    }
    pLruHndl->table[pLruHndl->least].prev = cacheIdx;
    pLruHndl->table[cacheIdx].next = pLruHndl->least;
    pLruHndl->least = cacheIdx;
}