src/ppu/internal/dma/imoc_dma-iput_ppu.c

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#include <string.h>
#include <stdlib.h>

#include <moc.h>
#include <ppu/moc_dma_ppu.h>
#include <internal/imoc_macros.h>
#include <internal/ppu/imoc_dma_ppu.h>
#include <internal/ppu/imoc_core_ppu.h>

/*

 * This function actually always reads a multiple of 16 from the source, and copies it to target.
 * This means however that up to 15 bytes are written to and invalid location, so if one wants to
 * use it with such sizes precautions have to be taken in order to make it safe.
 * On the ppu the system for tag reservation is not present, so a hardcoded tag is used.
 * It has also to be noted that the dma calls are actually initiated on the spu by the ppu.
 */

int IMOC_iput_data(void* source, uint64_t target, uint32_t size, uint32_t dest,
        imoc_dma_request* request)
    {
    uint32_t remainder_16b;
    uint32_t remainder_16kb;
    uint32_t offset;
    int err;
    int tag_id;

    if ((tag_id = moc_tag_reserve(dest - moc_ppu_thread_count)) < 0)
        {
        return MOC_ERR_INTERN;
        }

    /* transfers have to be multiples of 16 bytes */
    remainder_16b = size % 16;

    request->remainder = 0;
    request->dest = dest;
    request->size = size;
    request->target = target;
    request->tag_id = tag_id;

    /* subtracting remainder means the transfer has a valid size now */
    size -= remainder_16b;
    offset = 0;

    /* first case: transfer of size smaller than maximum allowed one (16kbyte) */
    if (size <= MAX_DMA_CALL_SIZE)
        {
        err = spe_mfcio_get(
                moc_spu_thread_list[dest - moc_ppu_thread_count].speid, target,
                source, size, tag_id, 0, 0);

        if (err)
            return MOC_ERR_INTERN;
        }

    /* second case: transfer of bigger size is simply split into parts of 16kb */
    else
        {
        remainder_16kb = size % MAX_DMA_CALL_SIZE;
        while (offset + MAX_DMA_CALL_SIZE <= size)
            {
            err = spe_mfcio_get(
                    moc_spu_thread_list[dest - moc_ppu_thread_count].speid,
                    target + offset, source + offset, MAX_DMA_CALL_SIZE,
                    tag_id, 0, 0);

            if (err)
                return MOC_ERR_INTERN;

            offset += MAX_DMA_CALL_SIZE;
            }

        if (remainder_16kb > 0)
            {
            err = spe_mfcio_get(
                    moc_spu_thread_list[dest - moc_ppu_thread_count].speid,
                    target + offset, source + offset, remainder_16kb, tag_id,
                    0, 0);

            if (err)
                return MOC_ERR_INTERN;
            }
        }

    /* if size was reduced previously the remaining bytes have to be transfered */
    if (remainder_16b > 0)
        {
        /* minimum allowed transfer is 16bytes so transfer this size */
        err = spe_mfcio_get(
                moc_spu_thread_list[dest - moc_ppu_thread_count].speid, target
                        + size, source + size, 16, tag_id, 0, 0);

        if (err)
            return MOC_ERR_INTERN;
        }

    return MOC_SUCCESS;

    }

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