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/*

 * MC68360 buffer descriptor allocation routines

 *

 * W. Eric Norum

 * Saskatchewan Accelerator Laboratory

 * University of Saskatchewan

 * Saskatoon, Saskatchewan, CANADA

 * eric@skatter.usask.ca

 *

 *  $Id: alloc360.c,v 1.2 2001-09-27 12:00:08 chris Exp $

 */

#include <rtems.h>

#include <bsp.h>

#include <m68360.h>

#include <rtems/error.h>

/*

 * Allocation order:

 *      - Dual-Port RAM section 1

 *      - Dual-Port RAM section 3

 *      - Dual-Port RAM section 0

 *      - Dual-Port RAM section 2

 */

static struct {

        char            *base;

        unsigned int    size;

        unsigned int    used;

} bdregions[] = {

        { (char *)&m360.dpram1[0],       sizeof m360.dpram1,     0 },

        { (char *)&m360.dpram3[0],       sizeof m360.dpram3,     0 },

        { (char *)&m360.dpram0[0],       sizeof m360.dpram0,     0 },

        { (char *)&m360.dpram2[0],       sizeof m360.dpram2,     0 },

};

/*

 * Send a command to the CPM RISC processer

 */

void *

M360AllocateBufferDescriptors (int count)

{

        unsigned int i;

        ISR_Level level;

        void *bdp = NULL;

        unsigned int want = count * sizeof(m360BufferDescriptor_t);

        /*

         * Running with interrupts disabled is usually considered bad

         * form, but this routine is probably being run as part of an

         * initialization sequence so the effect shouldn't be too severe.

         */

        _ISR_Disable (level);

        for (i = 0 ; i < sizeof(bdregions) / sizeof(bdregions[0]) ; i++) {

                /*

                 * Verify that the region exists.

                 * This test is necessary since some chips have

                 * less dual-port RAM.

                 */

                if (bdregions[i].used == 0) {

                        volatile unsigned char *cp = bdregions[i].base;

                        *cp = 0xAA;

                        if (*cp != 0xAA) {

                                bdregions[i].used = bdregions[i].size;

                                continue;

                        }

                        *cp = 0x55;

                        if (*cp != 0x55) {

                                bdregions[i].used = bdregions[i].size;

                                continue;

                        }

                        *cp = 0x0;

                }

                if (bdregions[i].size - bdregions[i].used >= want) {

                        bdp = bdregions[i].base + bdregions[i].used;

                        bdregions[i].used += want;

                        break;

                }

        }

        _ISR_Enable (level);

        if (bdp == NULL)

                rtems_panic ("Can't allocate %d buffer descriptor(s).\n", count);

        return bdp;

}

void *

M360AllocateRiscTimers (int count)

{

        /*

         * Convert the count to the number of buffer descriptors

         * of equal or larger size.  This ensures that all buffer

         * descriptors are allocated with appropriate alignment.

         */

        return M360AllocateBufferDescriptors (((count * 4) +

                                        sizeof(m360BufferDescriptor_t) - 1) /

                                        sizeof(m360BufferDescriptor_t));

}