From 471fe8a2520272253adec1cc099e26f04958e301 Mon Sep 17 00:00:00 2001 From: "Edgar E. Iglesias" Date: Wed, 6 May 2020 10:25:11 +0200 Subject: [PATCH] hw/dma/xilinx_axidma: mm2s: Stream descriptor by descriptor 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. Reviewed-by: Alistair Francis Signed-off-by: Edgar E. Iglesias Message-Id: <20200506082513.18751-8-edgar.iglesias@gmail.com> --- 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); + + 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; } - address_space_read(&s->dma->as, s->desc.buffer_address, - MEMTXATTRS_UNSPECIFIED, - s->txbuf + s->pos, txlen); - s->pos += txlen; - - if (stream_desc_eof(&s->desc)) { - stream_push(tx_data_dev, s->txbuf, s->pos, true); - s->pos = 0; + if (eop) { stream_complete(s); }