diff mbox series

[1/8] net/txgbe: fix Rx buffer size in configure register

Message ID 20230118060039.3074016-2-jiawenwu@trustnetic.com (mailing list archive)
State Superseded, archived
Delegated to: Ferruh Yigit
Headers
Series Wangxun fixes and new supports |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Jiawen Wu Jan. 18, 2023, 6 a.m. UTC 
  When round up buffer size to 1K, to configure the register, hardware will
receive packets exceeding the buffer size in LRO mode. It will cause a
segment fault in the receive function.

Fixes: be797cbf4582 ("net/txgbe: add Rx and Tx init")
Cc: stable@dpdk.org

Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
---
 drivers/net/txgbe/txgbe_rxtx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Ferruh Yigit Jan. 27, 2023, 3:36 p.m. UTC | #1 
On 1/18/2023 6:00 AM, Jiawen Wu wrote:
> When round up buffer size to 1K, to configure the register, hardware will
> receive packets exceeding the buffer size in LRO mode. It will cause a
> segment fault in the receive function.
> 
> Fixes: be797cbf4582 ("net/txgbe: add Rx and Tx init")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
> ---
>  drivers/net/txgbe/txgbe_rxtx.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/txgbe/txgbe_rxtx.c b/drivers/net/txgbe/txgbe_rxtx.c
> index ac1bba08a3..ae70ca3beb 100644
> --- a/drivers/net/txgbe/txgbe_rxtx.c
> +++ b/drivers/net/txgbe/txgbe_rxtx.c
> @@ -4382,7 +4382,7 @@ txgbe_dev_rx_init(struct rte_eth_dev *dev)
>  		 */
>  		buf_size = (uint16_t)(rte_pktmbuf_data_room_size(rxq->mb_pool) -
>  			RTE_PKTMBUF_HEADROOM);
> -		buf_size = ROUND_UP(buf_size, 0x1 << 10);
> +		buf_size = ROUND_DOWN(buf_size, 0x1 << 10);
>  		srrctl |= TXGBE_RXCFG_PKTLEN(buf_size);
>  

What if 'buf_size' is less than 1K, won't 'ROUND_DOWN' make it 0, and I
assume setting 0 to register may cause problem.

And according to the code comment for 'buf_size' [1], buffer size can't
be more than 16K, but technically 'buf_size' can be more than 16K.
Does the HW constrain values larger than 16K? If not the 'buf_size'
value needs to be checked against the 16K limit.




[1]
 /*
  * Configure the RX buffer size in the PKTLEN field of
  * the RXCFG register of the queue.
  * The value is in 1 KB resolution. Valid values can be from
  * 1 KB to 16 KB.
  */
Jiawen Wu Feb. 1, 2023, 2:34 a.m. UTC | #2 
On Friday, January 27, 2023 11:36 PM, Ferruh Yigit wrote:
> On 1/18/2023 6:00 AM, Jiawen Wu wrote:
> > When round up buffer size to 1K, to configure the register, hardware
> > will receive packets exceeding the buffer size in LRO mode. It will
> > cause a segment fault in the receive function.
> >
> > Fixes: be797cbf4582 ("net/txgbe: add Rx and Tx init")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
> > ---
> >  drivers/net/txgbe/txgbe_rxtx.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/txgbe/txgbe_rxtx.c
> > b/drivers/net/txgbe/txgbe_rxtx.c index ac1bba08a3..ae70ca3beb 100644
> > --- a/drivers/net/txgbe/txgbe_rxtx.c
> > +++ b/drivers/net/txgbe/txgbe_rxtx.c
> > @@ -4382,7 +4382,7 @@ txgbe_dev_rx_init(struct rte_eth_dev *dev)
> >  		 */
> >  		buf_size = (uint16_t)(rte_pktmbuf_data_room_size(rxq->mb_pool) -
> >  			RTE_PKTMBUF_HEADROOM);
> > -		buf_size = ROUND_UP(buf_size, 0x1 << 10);
> > +		buf_size = ROUND_DOWN(buf_size, 0x1 << 10);
> >  		srrctl |= TXGBE_RXCFG_PKTLEN(buf_size);
> >
> 
> What if 'buf_size' is less than 1K, won't 'ROUND_DOWN' make it 0, and I assume
> setting 0 to register may cause problem.
> 

It is indeed a problem, I will fix it.

> And according to the code comment for 'buf_size' [1], buffer size can't be more than
> 16K, but technically 'buf_size' can be more than 16K.
> Does the HW constrain values larger than 16K? If not the 'buf_size'
> value needs to be checked against the 16K limit.
> 

There is a macro that defines the conversion to limit 16K.

#define PKTLEN(v)     ROUND_OVER(v, 14, 10)
#define ROUND_OVER(x, maxbits, unitbits) \
	((x) >= 1 << (maxbits) ? 0 : (x) >> (unitbits))

> 
> 
> 
> [1]
>  /*
>   * Configure the RX buffer size in the PKTLEN field of
>   * the RXCFG register of the queue.
>   * The value is in 1 KB resolution. Valid values can be from
>   * 1 KB to 16 KB.
>   */
>
Ferruh Yigit Feb. 1, 2023, 10:40 a.m. UTC | #3 
On 2/1/2023 2:34 AM, Jiawen Wu wrote:
> On Friday, January 27, 2023 11:36 PM, Ferruh Yigit wrote:
>> On 1/18/2023 6:00 AM, Jiawen Wu wrote:
>>> When round up buffer size to 1K, to configure the register, hardware
>>> will receive packets exceeding the buffer size in LRO mode. It will
>>> cause a segment fault in the receive function.
>>>
>>> Fixes: be797cbf4582 ("net/txgbe: add Rx and Tx init")
>>> Cc: stable@dpdk.org
>>>
>>> Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
>>> ---
>>>  drivers/net/txgbe/txgbe_rxtx.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/net/txgbe/txgbe_rxtx.c
>>> b/drivers/net/txgbe/txgbe_rxtx.c index ac1bba08a3..ae70ca3beb 100644
>>> --- a/drivers/net/txgbe/txgbe_rxtx.c
>>> +++ b/drivers/net/txgbe/txgbe_rxtx.c
>>> @@ -4382,7 +4382,7 @@ txgbe_dev_rx_init(struct rte_eth_dev *dev)
>>>  		 */
>>>  		buf_size = (uint16_t)(rte_pktmbuf_data_room_size(rxq->mb_pool) -
>>>  			RTE_PKTMBUF_HEADROOM);
>>> -		buf_size = ROUND_UP(buf_size, 0x1 << 10);
>>> +		buf_size = ROUND_DOWN(buf_size, 0x1 << 10);
>>>  		srrctl |= TXGBE_RXCFG_PKTLEN(buf_size);
>>>
>>
>> What if 'buf_size' is less than 1K, won't 'ROUND_DOWN' make it 0, and I assume
>> setting 0 to register may cause problem.
>>
> 
> It is indeed a problem, I will fix it.
> 
>> And according to the code comment for 'buf_size' [1], buffer size can't be more than
>> 16K, but technically 'buf_size' can be more than 16K.
>> Does the HW constrain values larger than 16K? If not the 'buf_size'
>> value needs to be checked against the 16K limit.
>>
> 
> There is a macro that defines the conversion to limit 16K.
> 
> #define PKTLEN(v)     ROUND_OVER(v, 14, 10)
> #define ROUND_OVER(x, maxbits, unitbits) \
> 	((x) >= 1 << (maxbits) ? 0 : (x) >> (unitbits))
> 

ack
diff mbox series

Patch

diff --git a/drivers/net/txgbe/txgbe_rxtx.c b/drivers/net/txgbe/txgbe_rxtx.c
index ac1bba08a3..ae70ca3beb 100644
--- a/drivers/net/txgbe/txgbe_rxtx.c
+++ b/drivers/net/txgbe/txgbe_rxtx.c
@@ -4382,7 +4382,7 @@  txgbe_dev_rx_init(struct rte_eth_dev *dev)
 		 */
 		buf_size = (uint16_t)(rte_pktmbuf_data_room_size(rxq->mb_pool) -
 			RTE_PKTMBUF_HEADROOM);
-		buf_size = ROUND_UP(buf_size, 0x1 << 10);
+		buf_size = ROUND_DOWN(buf_size, 0x1 << 10);
 		srrctl |= TXGBE_RXCFG_PKTLEN(buf_size);
 
 		wr32(hw, TXGBE_RXCFG(rxq->reg_idx), srrctl);