diff mbox series

hw/dma/xilinx_axidma: Check DMASR.HALTED to prevent infinite loop.

Message ID 20230519062137.1251741-1-tommy.wu@sifive.com (mailing list archive)
State New, archived
Headers show
Series hw/dma/xilinx_axidma: Check DMASR.HALTED to prevent infinite loop. | expand

Commit Message

Tommy Wu May 19, 2023, 6:21 a.m. UTC
When we receive a packet from the xilinx_axienet and then try to s2mem
through the xilinx_axidma, if the descriptor ring buffer is full in the
xilinx axidma driver, we’ll assert the DMASR.HALTED in the
function : stream_process_s2mem and return 0. In the end, we’ll be stuck in
an infinite loop in axienet_eth_rx_notify.

This patch checks the DMASR.HALTED state when we try to push data
from xilinx axi-enet to xilinx axi-dma. When the DMASR.HALTED is asserted,
we will not keep pushing the data and then prevent the infinte loop.

Signed-off-by: Tommy Wu <tommy.wu@sifive.com>
---
 hw/dma/xilinx_axidma.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

Comments

Edgar E. Iglesias May 19, 2023, 6:39 a.m. UTC | #1
On Fri, May 19, 2023 at 8:21 AM Tommy Wu <tommy.wu@sifive.com> wrote:

> When we receive a packet from the xilinx_axienet and then try to s2mem
> through the xilinx_axidma, if the descriptor ring buffer is full in the
> xilinx axidma driver, we’ll assert the DMASR.HALTED in the
> function : stream_process_s2mem and return 0. In the end, we’ll be stuck in
> an infinite loop in axienet_eth_rx_notify.
>
> This patch checks the DMASR.HALTED state when we try to push data
> from xilinx axi-enet to xilinx axi-dma. When the DMASR.HALTED is asserted,
> we will not keep pushing the data and then prevent the infinte loop.
>
> Signed-off-by: Tommy Wu <tommy.wu@sifive.com>
> ---
>  hw/dma/xilinx_axidma.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/hw/dma/xilinx_axidma.c b/hw/dma/xilinx_axidma.c
> index 6030c76435..12c90267df 100644
> --- a/hw/dma/xilinx_axidma.c
> +++ b/hw/dma/xilinx_axidma.c
> @@ -168,6 +168,11 @@ static inline int stream_idle(struct Stream *s)
>      return !!(s->regs[R_DMASR] & DMASR_IDLE);
>  }
>
> +static inline int stream_halted(struct Stream *s)
>

At some point we should probably change all of these helpers to return
booleans...
Anyway, this fix looks good to me:

Reviewed-by: Edgar E. Iglesias <edgar@zeroasic.com>




> +{
> +    return !!(s->regs[R_DMASR] & DMASR_HALTED);
> +}
> +
>  static void stream_reset(struct Stream *s)
>  {
>      s->regs[R_DMASR] = DMASR_HALTED;  /* starts up halted.  */
> @@ -269,7 +274,7 @@ static void stream_process_mem2s(struct Stream *s,
> StreamSink *tx_data_dev,
>      uint64_t addr;
>      bool eop;
>
> -    if (!stream_running(s) || stream_idle(s)) {
> +    if (!stream_running(s) || stream_idle(s) || stream_halted(s)) {
>          return;
>      }
>
> @@ -326,7 +331,7 @@ static size_t stream_process_s2mem(struct Stream *s,
> unsigned char *buf,
>      unsigned int rxlen;
>      size_t pos = 0;
>
> -    if (!stream_running(s) || stream_idle(s)) {
> +    if (!stream_running(s) || stream_idle(s) || stream_halted(s)) {
>          return 0;
>      }
>
> @@ -407,7 +412,7 @@ xilinx_axidma_data_stream_can_push(StreamSink *obj,
>      XilinxAXIDMAStreamSink *ds = XILINX_AXI_DMA_DATA_STREAM(obj);
>      struct Stream *s = &ds->dma->streams[1];
>
> -    if (!stream_running(s) || stream_idle(s)) {
> +    if (!stream_running(s) || stream_idle(s) || stream_halted(s)) {
>          ds->dma->notify = notify;
>          ds->dma->notify_opaque = notify_opaque;
>          return false;
> --
> 2.31.1
>
>
Tommy Wu May 19, 2023, 2:19 p.m. UTC | #2
Thank Edgar E. Iglesias for the advice.
I can submit another patch to do that.

On Fri, May 19, 2023 at 2:39 PM Edgar E. Iglesias <edgar.iglesias@gmail.com>
wrote:

>
> On Fri, May 19, 2023 at 8:21 AM Tommy Wu <tommy.wu@sifive.com> wrote:
>
>> When we receive a packet from the xilinx_axienet and then try to s2mem
>> through the xilinx_axidma, if the descriptor ring buffer is full in the
>> xilinx axidma driver, we’ll assert the DMASR.HALTED in the
>> function : stream_process_s2mem and return 0. In the end, we’ll be stuck
>> in
>> an infinite loop in axienet_eth_rx_notify.
>>
>> This patch checks the DMASR.HALTED state when we try to push data
>> from xilinx axi-enet to xilinx axi-dma. When the DMASR.HALTED is asserted,
>> we will not keep pushing the data and then prevent the infinte loop.
>>
>> Signed-off-by: Tommy Wu <tommy.wu@sifive.com>
>> ---
>>  hw/dma/xilinx_axidma.c | 11 ++++++++---
>>  1 file changed, 8 insertions(+), 3 deletions(-)
>>
>> diff --git a/hw/dma/xilinx_axidma.c b/hw/dma/xilinx_axidma.c
>> index 6030c76435..12c90267df 100644
>> --- a/hw/dma/xilinx_axidma.c
>> +++ b/hw/dma/xilinx_axidma.c
>> @@ -168,6 +168,11 @@ static inline int stream_idle(struct Stream *s)
>>      return !!(s->regs[R_DMASR] & DMASR_IDLE);
>>  }
>>
>> +static inline int stream_halted(struct Stream *s)
>>
>
> At some point we should probably change all of these helpers to return
> booleans...
> Anyway, this fix looks good to me:
>
> Reviewed-by: Edgar E. Iglesias <edgar@zeroasic.com>
>
>
>
>
>> +{
>> +    return !!(s->regs[R_DMASR] & DMASR_HALTED);
>> +}
>> +
>>  static void stream_reset(struct Stream *s)
>>  {
>>      s->regs[R_DMASR] = DMASR_HALTED;  /* starts up halted.  */
>> @@ -269,7 +274,7 @@ static void stream_process_mem2s(struct Stream *s,
>> StreamSink *tx_data_dev,
>>      uint64_t addr;
>>      bool eop;
>>
>> -    if (!stream_running(s) || stream_idle(s)) {
>> +    if (!stream_running(s) || stream_idle(s) || stream_halted(s)) {
>>          return;
>>      }
>>
>> @@ -326,7 +331,7 @@ static size_t stream_process_s2mem(struct Stream *s,
>> unsigned char *buf,
>>      unsigned int rxlen;
>>      size_t pos = 0;
>>
>> -    if (!stream_running(s) || stream_idle(s)) {
>> +    if (!stream_running(s) || stream_idle(s) || stream_halted(s)) {
>>          return 0;
>>      }
>>
>> @@ -407,7 +412,7 @@ xilinx_axidma_data_stream_can_push(StreamSink *obj,
>>      XilinxAXIDMAStreamSink *ds = XILINX_AXI_DMA_DATA_STREAM(obj);
>>      struct Stream *s = &ds->dma->streams[1];
>>
>> -    if (!stream_running(s) || stream_idle(s)) {
>> +    if (!stream_running(s) || stream_idle(s) || stream_halted(s)) {
>>          ds->dma->notify = notify;
>>          ds->dma->notify_opaque = notify_opaque;
>>          return false;
>> --
>> 2.31.1
>>
>>
Frank Chang May 20, 2023, 10:33 a.m. UTC | #3
Reviewed-by: Frank Chang <frank.chang@sifive.com>

On Fri, May 19, 2023 at 2:23 PM Tommy Wu <tommy.wu@sifive.com> wrote:

> When we receive a packet from the xilinx_axienet and then try to s2mem
> through the xilinx_axidma, if the descriptor ring buffer is full in the
> xilinx axidma driver, we’ll assert the DMASR.HALTED in the
> function : stream_process_s2mem and return 0. In the end, we’ll be stuck in
> an infinite loop in axienet_eth_rx_notify.
>
> This patch checks the DMASR.HALTED state when we try to push data
> from xilinx axi-enet to xilinx axi-dma. When the DMASR.HALTED is asserted,
> we will not keep pushing the data and then prevent the infinte loop.
>
> Signed-off-by: Tommy Wu <tommy.wu@sifive.com>
> ---
>  hw/dma/xilinx_axidma.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/hw/dma/xilinx_axidma.c b/hw/dma/xilinx_axidma.c
> index 6030c76435..12c90267df 100644
> --- a/hw/dma/xilinx_axidma.c
> +++ b/hw/dma/xilinx_axidma.c
> @@ -168,6 +168,11 @@ static inline int stream_idle(struct Stream *s)
>      return !!(s->regs[R_DMASR] & DMASR_IDLE);
>  }
>
> +static inline int stream_halted(struct Stream *s)
> +{
> +    return !!(s->regs[R_DMASR] & DMASR_HALTED);
> +}
> +
>  static void stream_reset(struct Stream *s)
>  {
>      s->regs[R_DMASR] = DMASR_HALTED;  /* starts up halted.  */
> @@ -269,7 +274,7 @@ static void stream_process_mem2s(struct Stream *s,
> StreamSink *tx_data_dev,
>      uint64_t addr;
>      bool eop;
>
> -    if (!stream_running(s) || stream_idle(s)) {
> +    if (!stream_running(s) || stream_idle(s) || stream_halted(s)) {
>          return;
>      }
>
> @@ -326,7 +331,7 @@ static size_t stream_process_s2mem(struct Stream *s,
> unsigned char *buf,
>      unsigned int rxlen;
>      size_t pos = 0;
>
> -    if (!stream_running(s) || stream_idle(s)) {
> +    if (!stream_running(s) || stream_idle(s) || stream_halted(s)) {
>          return 0;
>      }
>
> @@ -407,7 +412,7 @@ xilinx_axidma_data_stream_can_push(StreamSink *obj,
>      XilinxAXIDMAStreamSink *ds = XILINX_AXI_DMA_DATA_STREAM(obj);
>      struct Stream *s = &ds->dma->streams[1];
>
> -    if (!stream_running(s) || stream_idle(s)) {
> +    if (!stream_running(s) || stream_idle(s) || stream_halted(s)) {
>          ds->dma->notify = notify;
>          ds->dma->notify_opaque = notify_opaque;
>          return false;
> --
> 2.31.1
>
>
>
Peter Maydell May 23, 2023, 1:51 p.m. UTC | #4
On Fri, 19 May 2023 at 07:21, Tommy Wu <tommy.wu@sifive.com> wrote:
>
> When we receive a packet from the xilinx_axienet and then try to s2mem
> through the xilinx_axidma, if the descriptor ring buffer is full in the
> xilinx axidma driver, we’ll assert the DMASR.HALTED in the
> function : stream_process_s2mem and return 0. In the end, we’ll be stuck in
> an infinite loop in axienet_eth_rx_notify.
>
> This patch checks the DMASR.HALTED state when we try to push data
> from xilinx axi-enet to xilinx axi-dma. When the DMASR.HALTED is asserted,
> we will not keep pushing the data and then prevent the infinte loop.
>
> Signed-off-by: Tommy Wu <tommy.wu@sifive.com>



Applied to target-arm.next, thanks.

-- PMM
diff mbox series

Patch

diff --git a/hw/dma/xilinx_axidma.c b/hw/dma/xilinx_axidma.c
index 6030c76435..12c90267df 100644
--- a/hw/dma/xilinx_axidma.c
+++ b/hw/dma/xilinx_axidma.c
@@ -168,6 +168,11 @@  static inline int stream_idle(struct Stream *s)
     return !!(s->regs[R_DMASR] & DMASR_IDLE);
 }
 
+static inline int stream_halted(struct Stream *s)
+{
+    return !!(s->regs[R_DMASR] & DMASR_HALTED);
+}
+
 static void stream_reset(struct Stream *s)
 {
     s->regs[R_DMASR] = DMASR_HALTED;  /* starts up halted.  */
@@ -269,7 +274,7 @@  static void stream_process_mem2s(struct Stream *s, StreamSink *tx_data_dev,
     uint64_t addr;
     bool eop;
 
-    if (!stream_running(s) || stream_idle(s)) {
+    if (!stream_running(s) || stream_idle(s) || stream_halted(s)) {
         return;
     }
 
@@ -326,7 +331,7 @@  static size_t stream_process_s2mem(struct Stream *s, unsigned char *buf,
     unsigned int rxlen;
     size_t pos = 0;
 
-    if (!stream_running(s) || stream_idle(s)) {
+    if (!stream_running(s) || stream_idle(s) || stream_halted(s)) {
         return 0;
     }
 
@@ -407,7 +412,7 @@  xilinx_axidma_data_stream_can_push(StreamSink *obj,
     XilinxAXIDMAStreamSink *ds = XILINX_AXI_DMA_DATA_STREAM(obj);
     struct Stream *s = &ds->dma->streams[1];
 
-    if (!stream_running(s) || stream_idle(s)) {
+    if (!stream_running(s) || stream_idle(s) || stream_halted(s)) {
         ds->dma->notify = notify;
         ds->dma->notify_opaque = notify_opaque;
         return false;