Experimental Physics and
Industrial Control System

Jeff Hill <[email protected]> · Thu, 05 Sep 1996 16:55:53 -0600

Dear all,

I made the attached additions to the Heurikon Nitro60  
vxWorks BSP in order to get DVX 2502 A24 DMAs working. Most 
of this code isnt Heurikon specific (excepting tests which verify
that the A24 available pool is within 2MB of sysMemTop()).
The API here follows the model developed by John Winans of APS
for the mv167.

All comments appreciated.

Jeff

-- 

/******************************************************************************
 *
 * hk nitro 60 specific A24 memory management routines - joh 9-4-96
 *
 * A user may call sysA24MapRam() to allocate a block of system ram
 * available to VME A24 of the specified size which is non-cacheable.
 * If space is available, then a memory pool is created for future use
 * by device drivers via devLibA24Malloc() and devLibA24Free().
 *
 * sysA24MapRam() should be called early during the system boot in
 * order to guarantee that the allocation will occur in the upper two
 * megs of system ram since:
 * 1) this is all that can be seen by VME A24  within the hk nitro 60.
 * 2) wrs free memory allocation occurs from the top of pool down.
 * A warning message is printed if a suitable block of memory cannot
 * be allocated.
 *
 ******************************************************************************/

static PART_ID          a24DmaPartId = NULL;

 /*
  * hk nitro sysA24MapRam()
  * joh 9-4-96
  *
  */
STATUS sysA24MapRam(unsigned long size)
{
        void    *pBufDMA;

        /*
         * only one init allowed
         */
        if (a24DmaPartId != NULL){
                fprintf(stderr,
"sysA24MapRam: attempt to initialize twice was ignored\n");
                return(ERROR);
        }

        /*
         * verify that we can get a non-cacheable region
         */
        if (!CACHE_DMA_IS_WRITE_COHERENT() ||
                !CACHE_DMA_IS_READ_COHERENT()) {
                fprintf(stderr,
"sysA24MapRam: Warning - unable to create non-cacheable region\n");
                return ERROR;
        }

        /*
         * clip to 2MB boundary
         */
        if (size >= 0x200000)
        { /* Maximum size is 2MB clip it */
                fprintf(stderr,
"sysA24MapRam: Warning - hk nitro A24 pool clipped to 2MB\n");
                size  = 0x200000;
        }

        /*
         * Allocate the non-cacheable region
         */
        pBufDMA = cacheDmaMalloc( (size_t) size);
        if (pBufDMA==NULL) {
                fprintf(stderr,
"sysA24MapRam: Warning - unable to allocate non-cacheable region\n");
                return ERROR;
        }
        /*
         * Memory must be in the upper 2 Megs inorder to be available
         * on VME A24
         */
        if (pBufDMA < (void *) (sysMemTop() - 0x200000) ) {
                fprintf(stderr,
"sysA24MapRam: Warning - unable to allocate within A24 accessable window\n");
                cacheDmaFree(pBufDMA);
                return ERROR;
        }

#ifdef EPICS_DEBUG
        printf("sysA24MapRam: buf =%8.8lX size = %8.8lX\n");
#endif

        /*
         * Build A24 memory pool
         */
        a24DmaPartId = memPartCreate(pBufDMA, size);
        if (a24DmaPartId == NULL)
        {
                cacheDmaFree(pBufDMA);
                return ERROR;
        }

        return(OK);
}

/*
 * hk nitro sysA24Malloc()
 * joh 9-4-96
 *
 */
void *sysA24Malloc(unsigned long size)
{
        if (a24DmaPartId == NULL)
                return(NULL);

        return memPartAlloc(a24DmaPartId, (size_t) size);

}

/*
 * hk nitro sysA24Free()
 * joh 9-4-96
 *
 */
STATUS sysA24Free(void *pBlock)
{
        if (a24DmaPartId == NULL)
                return(ERROR);

        return memPartFree(a24DmaPartId, pBlock);
}

______________________________________________________________________
Jeffrey O. Hill			Internet	[email protected]
LANL MS H820			Voice		505 665 1831
Los Alamos, NM 87545 USA 	FAX		505 665 5107

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System