On Thu, Apr 30, 2020 at 9:31 AM Edgar E. Iglesias
wrote:
>
> From: "Edgar E. Iglesias"
>
> Stream descriptor by descriptor from memory instead of
> buffering entire packets before pushing. This enables
> non-packet streaming clients to work and also lifts the
> limitation that our internal DMA buffer needs to be able
> to hold entire packets.
>
> Signed-off-by: Edgar E. Iglesias
Reviewed-by: Alistair Francis
Alistair
> ---
> hw/dma/xilinx_axidma.c | 31 +--
> 1 file changed, 17 insertions(+), 14 deletions(-)
>
> diff --git a/hw/dma/xilinx_axidma.c b/hw/dma/xilinx_axidma.c
> index a770e12c96..101d32a965 100644
> --- a/hw/dma/xilinx_axidma.c
> +++ b/hw/dma/xilinx_axidma.c
> @@ -111,7 +111,6 @@ struct Stream {
> int nr;
>
> struct SDesc desc;
> -int pos;
> unsigned int complete_cnt;
> uint32_t regs[R_MAX];
> uint8_t app[20];
> @@ -267,7 +266,9 @@ static void stream_process_mem2s(struct Stream *s,
> StreamSlave *tx_data_dev,
> StreamSlave *tx_control_dev)
> {
> uint32_t prev_d;
> -unsigned int txlen;
> +uint32_t txlen;
> +uint64_t addr;
> +bool eop;
>
> if (!stream_running(s) || stream_idle(s)) {
> return;
> @@ -282,24 +283,26 @@ static void stream_process_mem2s(struct Stream *s,
> StreamSlave *tx_data_dev,
> }
>
> if (stream_desc_sof(&s->desc)) {
> -s->pos = 0;
> stream_push(tx_control_dev, s->desc.app, sizeof(s->desc.app),
> true);
> }
>
> txlen = s->desc.control & SDESC_CTRL_LEN_MASK;
> -if ((txlen + s->pos) > sizeof s->txbuf) {
> -hw_error("%s: too small internal txbuf! %d\n", __func__,
> - txlen + s->pos);
> -}
>
> -address_space_read(&s->dma->as, s->desc.buffer_address,
> - MEMTXATTRS_UNSPECIFIED,
> - s->txbuf + s->pos, txlen);
> -s->pos += txlen;
> +eop = stream_desc_eof(&s->desc);
> +addr = s->desc.buffer_address;
> +while (txlen) {
> +unsigned int len;
> +
> +len = txlen > sizeof s->txbuf ? sizeof s->txbuf : txlen;
> +address_space_read(&s->dma->as, addr,
> + MEMTXATTRS_UNSPECIFIED,
> + s->txbuf, len);
> +stream_push(tx_data_dev, s->txbuf, len, eop && len == txlen);
> +txlen -= len;
> +addr += len;
> +}
>
> -if (stream_desc_eof(&s->desc)) {
> -stream_push(tx_data_dev, s->txbuf, s->pos, true);
> -s->pos = 0;
> +if (eop) {
> stream_complete(s);
> }
>
> --
> 2.20.1
>
>
