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* [PATCH net-next] net: page pool: allow to pass zero flags to page_pool_init()
@ 2020-03-25 14:12 Denis Kirjanov
  2020-03-25 15:02 ` Jesper Dangaard Brouer
  0 siblings, 1 reply; 3+ messages in thread
From: Denis Kirjanov @ 2020-03-25 14:12 UTC (permalink / raw)
  To: netdev; +Cc: hawk, ilias.apalodimas, Denis Kirjanov

page pool API can be useful for non-DMA cases like
xen-netfront driver so let's allow to pass zero flags to
page pool flags.

Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
---
 net/core/page_pool.c | 36 +++++++++++++++++++-----------------
 1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 10d2b25..eeeb0d9 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -39,27 +39,29 @@ static int page_pool_init(struct page_pool *pool,
 	if (ring_qsize > 32768)
 		return -E2BIG;
 
-	/* DMA direction is either DMA_FROM_DEVICE or DMA_BIDIRECTIONAL.
-	 * DMA_BIDIRECTIONAL is for allowing page used for DMA sending,
-	 * which is the XDP_TX use-case.
-	 */
-	if ((pool->p.dma_dir != DMA_FROM_DEVICE) &&
-	    (pool->p.dma_dir != DMA_BIDIRECTIONAL))
-		return -EINVAL;
-
-	if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) {
-		/* In order to request DMA-sync-for-device the page
-		 * needs to be mapped
+	if (pool->p.flags) {
+		/* DMA direction is either DMA_FROM_DEVICE or DMA_BIDIRECTIONAL.
+		 * DMA_BIDIRECTIONAL is for allowing page used for DMA sending,
+		 * which is the XDP_TX use-case.
 		 */
-		if (!(pool->p.flags & PP_FLAG_DMA_MAP))
+		if ((pool->p.dma_dir != DMA_FROM_DEVICE) &&
+		    (pool->p.dma_dir != DMA_BIDIRECTIONAL))
 			return -EINVAL;
 
-		if (!pool->p.max_len)
-			return -EINVAL;
+		if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) {
+			/* In order to request DMA-sync-for-device the page
+			 * needs to be mapped
+			 */
+			if (!(pool->p.flags & PP_FLAG_DMA_MAP))
+				return -EINVAL;
 
-		/* pool->p.offset has to be set according to the address
-		 * offset used by the DMA engine to start copying rx data
-		 */
+			if (!pool->p.max_len)
+				return -EINVAL;
+
+			/* pool->p.offset has to be set according to the address
+			 * offset used by the DMA engine to start copying rx data
+			 */
+		}
 	}
 
 	if (ptr_ring_init(&pool->ring, ring_qsize, GFP_KERNEL) < 0)
-- 
1.8.3.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH net-next] net: page pool: allow to pass zero flags to page_pool_init()
  2020-03-25 14:12 [PATCH net-next] net: page pool: allow to pass zero flags to page_pool_init() Denis Kirjanov
@ 2020-03-25 15:02 ` Jesper Dangaard Brouer
  2020-03-25 19:16   ` Denis Kirjanov
  0 siblings, 1 reply; 3+ messages in thread
From: Jesper Dangaard Brouer @ 2020-03-25 15:02 UTC (permalink / raw)
  To: Denis Kirjanov; +Cc: brouer, netdev, hawk, ilias.apalodimas

On Wed, 25 Mar 2020 17:12:55 +0300
Denis Kirjanov <kda@linux-powerpc.org> wrote:

> page pool API can be useful for non-DMA cases like
> xen-netfront driver so let's allow to pass zero flags to
> page pool flags.
> 
> Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
> ---
>  net/core/page_pool.c | 36 +++++++++++++++++++-----------------
>  1 file changed, 19 insertions(+), 17 deletions(-)

The pool->p.dma_dir is only used when flag PP_FLAG_DMA_MAP is used, so
it looks more simple to do:

$ git diff
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 626db912fce4..ef98372facf6 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -43,9 +43,11 @@ static int page_pool_init(struct page_pool *pool,
         * DMA_BIDIRECTIONAL is for allowing page used for DMA sending,
         * which is the XDP_TX use-case.
         */
-       if ((pool->p.dma_dir != DMA_FROM_DEVICE) &&
-           (pool->p.dma_dir != DMA_BIDIRECTIONAL))
-               return -EINVAL;
+       if (pool->p.flags & PP_FLAG_DMA_MAP) {
+               if ((pool->p.dma_dir != DMA_FROM_DEVICE) &&
+                   (pool->p.dma_dir != DMA_BIDIRECTIONAL))
+                       return -EINVAL;
+       }
 


> diff --git a/net/core/page_pool.c b/net/core/page_pool.c
> index 10d2b25..eeeb0d9 100644
> --- a/net/core/page_pool.c
> +++ b/net/core/page_pool.c
> @@ -39,27 +39,29 @@ static int page_pool_init(struct page_pool *pool,
>  	if (ring_qsize > 32768)
>  		return -E2BIG;
>  
> -	/* DMA direction is either DMA_FROM_DEVICE or DMA_BIDIRECTIONAL.
> -	 * DMA_BIDIRECTIONAL is for allowing page used for DMA sending,
> -	 * which is the XDP_TX use-case.
> -	 */
> -	if ((pool->p.dma_dir != DMA_FROM_DEVICE) &&
> -	    (pool->p.dma_dir != DMA_BIDIRECTIONAL))
> -		return -EINVAL;
> -
> -	if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) {
> -		/* In order to request DMA-sync-for-device the page
> -		 * needs to be mapped
> +	if (pool->p.flags) {
> +		/* DMA direction is either DMA_FROM_DEVICE or DMA_BIDIRECTIONAL.
> +		 * DMA_BIDIRECTIONAL is for allowing page used for DMA sending,
> +		 * which is the XDP_TX use-case.
>  		 */
> -		if (!(pool->p.flags & PP_FLAG_DMA_MAP))
> +		if ((pool->p.dma_dir != DMA_FROM_DEVICE) &&
> +		    (pool->p.dma_dir != DMA_BIDIRECTIONAL))
>  			return -EINVAL;
>  
> -		if (!pool->p.max_len)
> -			return -EINVAL;
> +		if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) {
> +			/* In order to request DMA-sync-for-device the page
> +			 * needs to be mapped
> +			 */
> +			if (!(pool->p.flags & PP_FLAG_DMA_MAP))
> +				return -EINVAL;
>  
> -		/* pool->p.offset has to be set according to the address
> -		 * offset used by the DMA engine to start copying rx data
> -		 */
> +			if (!pool->p.max_len)
> +				return -EINVAL;
> +
> +			/* pool->p.offset has to be set according to the address
> +			 * offset used by the DMA engine to start copying rx data
> +			 */
> +		}
>  	}
>  
>  	if (ptr_ring_init(&pool->ring, ring_qsize, GFP_KERNEL) < 0)



-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  LinkedIn: http://www.linkedin.com/in/brouer


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH net-next] net: page pool: allow to pass zero flags to page_pool_init()
  2020-03-25 15:02 ` Jesper Dangaard Brouer
@ 2020-03-25 19:16   ` Denis Kirjanov
  0 siblings, 0 replies; 3+ messages in thread
From: Denis Kirjanov @ 2020-03-25 19:16 UTC (permalink / raw)
  To: Jesper Dangaard Brouer; +Cc: netdev, hawk, ilias.apalodimas

On 3/25/20, Jesper Dangaard Brouer <brouer@redhat.com> wrote:
> On Wed, 25 Mar 2020 17:12:55 +0300
> Denis Kirjanov <kda@linux-powerpc.org> wrote:
>
>> page pool API can be useful for non-DMA cases like
>> xen-netfront driver so let's allow to pass zero flags to
>> page pool flags.
>>
>> Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
>> ---
>>  net/core/page_pool.c | 36 +++++++++++++++++++-----------------
>>  1 file changed, 19 insertions(+), 17 deletions(-)
>
> The pool->p.dma_dir is only used when flag PP_FLAG_DMA_MAP is used, so
> it looks more simple to do:

Yeap, agreed. Thanks!

>
> $ git diff
> diff --git a/net/core/page_pool.c b/net/core/page_pool.c
> index 626db912fce4..ef98372facf6 100644
> --- a/net/core/page_pool.c
> +++ b/net/core/page_pool.c
> @@ -43,9 +43,11 @@ static int page_pool_init(struct page_pool *pool,
>          * DMA_BIDIRECTIONAL is for allowing page used for DMA sending,
>          * which is the XDP_TX use-case.
>          */
> -       if ((pool->p.dma_dir != DMA_FROM_DEVICE) &&
> -           (pool->p.dma_dir != DMA_BIDIRECTIONAL))
> -               return -EINVAL;
> +       if (pool->p.flags & PP_FLAG_DMA_MAP) {
> +               if ((pool->p.dma_dir != DMA_FROM_DEVICE) &&
> +                   (pool->p.dma_dir != DMA_BIDIRECTIONAL))
> +                       return -EINVAL;
> +       }
>
>
>
>> diff --git a/net/core/page_pool.c b/net/core/page_pool.c
>> index 10d2b25..eeeb0d9 100644
>> --- a/net/core/page_pool.c
>> +++ b/net/core/page_pool.c
>> @@ -39,27 +39,29 @@ static int page_pool_init(struct page_pool *pool,
>>  	if (ring_qsize > 32768)
>>  		return -E2BIG;
>>
>> -	/* DMA direction is either DMA_FROM_DEVICE or DMA_BIDIRECTIONAL.
>> -	 * DMA_BIDIRECTIONAL is for allowing page used for DMA sending,
>> -	 * which is the XDP_TX use-case.
>> -	 */
>> -	if ((pool->p.dma_dir != DMA_FROM_DEVICE) &&
>> -	    (pool->p.dma_dir != DMA_BIDIRECTIONAL))
>> -		return -EINVAL;
>> -
>> -	if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) {
>> -		/* In order to request DMA-sync-for-device the page
>> -		 * needs to be mapped
>> +	if (pool->p.flags) {
>> +		/* DMA direction is either DMA_FROM_DEVICE or DMA_BIDIRECTIONAL.
>> +		 * DMA_BIDIRECTIONAL is for allowing page used for DMA sending,
>> +		 * which is the XDP_TX use-case.
>>  		 */
>> -		if (!(pool->p.flags & PP_FLAG_DMA_MAP))
>> +		if ((pool->p.dma_dir != DMA_FROM_DEVICE) &&
>> +		    (pool->p.dma_dir != DMA_BIDIRECTIONAL))
>>  			return -EINVAL;
>>
>> -		if (!pool->p.max_len)
>> -			return -EINVAL;
>> +		if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV) {
>> +			/* In order to request DMA-sync-for-device the page
>> +			 * needs to be mapped
>> +			 */
>> +			if (!(pool->p.flags & PP_FLAG_DMA_MAP))
>> +				return -EINVAL;
>>
>> -		/* pool->p.offset has to be set according to the address
>> -		 * offset used by the DMA engine to start copying rx data
>> -		 */
>> +			if (!pool->p.max_len)
>> +				return -EINVAL;
>> +
>> +			/* pool->p.offset has to be set according to the address
>> +			 * offset used by the DMA engine to start copying rx data
>> +			 */
>> +		}
>>  	}
>>
>>  	if (ptr_ring_init(&pool->ring, ring_qsize, GFP_KERNEL) < 0)
>
>
>
> --
> Best regards,
>   Jesper Dangaard Brouer
>   MSc.CS, Principal Kernel Engineer at Red Hat
>   LinkedIn: http://www.linkedin.com/in/brouer
>
>

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2020-03-25 19:16 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-25 14:12 [PATCH net-next] net: page pool: allow to pass zero flags to page_pool_init() Denis Kirjanov
2020-03-25 15:02 ` Jesper Dangaard Brouer
2020-03-25 19:16   ` Denis Kirjanov

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