diff mbox series

[v1,7/9] hw/dma/xilinx_axidma: mm2s: Stream descriptor by descriptor

Message ID 20200430162439.2659-8-edgar.iglesias@gmail.com (mailing list archive)
State New, archived
Headers show
Series hw/core: stream: Add end-of-packet flag | expand

Commit Message

Edgar E. Iglesias April 30, 2020, 4:24 p.m. UTC 
From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>

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 <edgar.iglesias@xilinx.com>
---
 hw/dma/xilinx_axidma.c | 31 +++++++++++++++++--------------
 1 file changed, 17 insertions(+), 14 deletions(-)

Comments

Alistair Francis May 5, 2020, 7:57 p.m. UTC | #1 
On Thu, Apr 30, 2020 at 9:31 AM Edgar E. Iglesias
<edgar.iglesias@gmail.com> wrote:
>
> From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>
>
> 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 <edgar.iglesias@xilinx.com>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

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
>
>
diff mbox series

Patch

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);
         }