source: soft/giet_vm/giet_drivers/mmc_driver.c @ 258

///////////////////////////////////////////////////////////////////////////////////
// File     : mmc_driver.c
// Date     : 23/05/2013
// Author   : alain greiner
// Copyright (c) UPMC-LIP6
///////////////////////////////////////////////////////////////////////////////////
// The mmc_driver.c and mmc_driver.h files are part ot the GIET-VM nano-kernel.
// This driver supports the vci_mem_cache component used in the TSAR architecture.
//
// This component is replicated in all clusters, and can be accessed through 
// a configuration interface as a set of uncached, memory mapped registers.
///////////////////////////////////////////////////////////////////////////////////
// The (virtual) base address of the associated segment is:
//
//       seg_mmc_base + cluster_id * vseg_cluster_increment
//
// The seg_mmc_base and vseg_cluster_increment values must be defined 
// in the giet_vsegs.ld file.
////////////////////////////////////////////////////////////////////////////////

#include <giet_config.h>
#include <mmc_driver.h>
#include <utils.h>

#if !defined(NB_CLUSTERS) 
# error: You must define NB_CLUSTERS in the hard_config.h file
#endif

#if (NB_CLUSTERS > 256)
# error: NB_CLUSTERS cannot be larger than 256!
#endif

///////////////////////////////////////////////////////////////////////////////////
// _memc_inval()
// This function invalidates all cache lines covering a memory buffer defined
// by the physical base address, and the length.
// The buffer address MSB are used to compute the cluster index.
///////////////////////////////////////////////////////////////////////////////////
void _memc_inval( paddr_t      buf_paddr,
                  unsigned int buf_length )
{
    unsigned int cluster_id    = (unsigned int)((buf_paddr>>32)/(256/NB_CLUSTERS));

    unsigned int* mmc_address = (unsigned int*)((unsigned int)&seg_mmc_base + 
                                (cluster_id * (unsigned int)&vseg_cluster_increment));

    // get the hard lock protecting exclusive access to MEMC
    while ( mmc_address[MEMC_LOCK] ) { asm volatile("nop"); }

    // write inval arguments
    mmc_address[MEMC_ADDR_LO]    = (unsigned int)buf_paddr;
    mmc_address[MEMC_ADDR_HI]    = (unsigned int)(buf_paddr>>32);
    mmc_address[MEMC_BUF_LENGTH] = buf_length;
    mmc_address[MEMC_CMD_TYPE]   = MEMC_CMD_INVAL;

    // release the lock 
    mmc_address[MEMC_LOCK] = 0;
}
///////////////////////////////////////////////////////////////////////////////////
// _memc_sync()
// This function copies to external RAM all cache lines covering a memory buffer 
// defined by the physical base address, and the length, if they are dirty.
// The buffer address MSB are used to compute the cluster index.
///////////////////////////////////////////////////////////////////////////////////
void _memc_sync( paddr_t      buf_paddr,
                 unsigned int buf_length )
{
    unsigned int cluster_id    = (unsigned int)((buf_paddr>>32)/(256/NB_CLUSTERS));

    unsigned int * mmc_address = (unsigned int *) ((unsigned int)&seg_mmc_base + 
                                 (cluster_id * (unsigned int)&vseg_cluster_increment));

    // get the hard lock protecting exclusive access to MEMC
    while ( mmc_address[MEMC_LOCK] ) { asm volatile("nop"); }

    // write inval arguments
    mmc_address[MEMC_ADDR_LO]    = (unsigned int)buf_paddr;
    mmc_address[MEMC_ADDR_HI]    = (unsigned int)(buf_paddr>>32);
    mmc_address[MEMC_BUF_LENGTH] = buf_length;
    mmc_address[MEMC_CMD_TYPE]   = MEMC_CMD_SYNC;

    // release the lock protecting MEMC
    mmc_address[MEMC_LOCK] = 0;
}

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