Commit 7987dcd7 authored by Scott Peterson's avatar Scott Peterson Committed by Jeff Kirsher
Browse files

i40e/i40evf: Limit DMA sync of RX buffers to actual packet size 



On packet RX, we perform a DMA sync for CPU before passing the
packet up.  Here we limit that sync to the actual length of the
incoming packet, rather than always syncing the entire buffer.

Change-ID: I626aaf6c37275a8ce9e81efcaa773f327b331487
Signed-off-by: default avatarScott Peterson <scott.d.peterson@intel.com>
Tested-by: default avatarAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
parent e5f77f4a

drivers/net/ethernet/intel/i40e/i40e_txrx.c

+9 −7
Original line number Diff line number Diff line
@@ -1525,7 +1525,7 @@ static inline bool i40e_page_is_reserved(struct page *page) 
 * i40e_add_rx_frag - Add contents of Rx buffer to sk_buff

 * @rx_ring: rx descriptor ring to transact packets on

 * @rx_buffer: buffer containing page to add

 * @rx_desc: descriptor containing length of buffer written by hardware

 * @size: packet length from rx_desc

 * @skb: sk_buff to place the data into

 *

 * This function will add the data contained in rx_buffer->page to the skb.
@@ -1538,13 +1538,10 @@ static inline bool i40e_page_is_reserved(struct page *page) 
 **/

static bool i40e_add_rx_frag(struct i40e_ring *rx_ring,

			     struct i40e_rx_buffer *rx_buffer,

			     union i40e_rx_desc *rx_desc,

			     unsigned int size,

			     struct sk_buff *skb)

{

	struct page *page = rx_buffer->page;

	u64 qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);

	unsigned int size = (qword & I40E_RXD_QW1_LENGTH_PBUF_MASK) >>

			    I40E_RXD_QW1_LENGTH_PBUF_SHIFT;

#if (PAGE_SIZE < 8192)

	unsigned int truesize = I40E_RXBUFFER_2048;

#else
@@ -1613,6 +1610,11 @@ static inline 
struct sk_buff *i40e_fetch_rx_buffer(struct i40e_ring *rx_ring,

				     union i40e_rx_desc *rx_desc)

{

	u64 local_status_error_len =

		le64_to_cpu(rx_desc->wb.qword1.status_error_len);

	unsigned int size =

		(local_status_error_len & I40E_RXD_QW1_LENGTH_PBUF_MASK) >>

		I40E_RXD_QW1_LENGTH_PBUF_SHIFT;

	struct i40e_rx_buffer *rx_buffer;

	struct sk_buff *skb;

	struct page *page;
@@ -1654,11 +1656,11 @@ struct sk_buff *i40e_fetch_rx_buffer(struct i40e_ring *rx_ring, 
	dma_sync_single_range_for_cpu(rx_ring->dev,

				      rx_buffer->dma,

				      rx_buffer->page_offset,

				      I40E_RXBUFFER_2048,

				      size,

				      DMA_FROM_DEVICE);



	/* pull page into skb */

	if (i40e_add_rx_frag(rx_ring, rx_buffer, rx_desc, skb)) {

	if (i40e_add_rx_frag(rx_ring, rx_buffer, size, skb)) {

		/* hand second half of page back to the ring */

		i40e_reuse_rx_page(rx_ring, rx_buffer);

		rx_ring->rx_stats.page_reuse_count++;

drivers/net/ethernet/intel/i40evf/i40e_txrx.c

+9 −7
Original line number Diff line number Diff line
@@ -1003,7 +1003,7 @@ static inline bool i40e_page_is_reserved(struct page *page) 
 * i40e_add_rx_frag - Add contents of Rx buffer to sk_buff

 * @rx_ring: rx descriptor ring to transact packets on

 * @rx_buffer: buffer containing page to add

 * @rx_desc: descriptor containing length of buffer written by hardware

 * @size: packet length from rx_desc

 * @skb: sk_buff to place the data into

 *

 * This function will add the data contained in rx_buffer->page to the skb.
@@ -1016,13 +1016,10 @@ static inline bool i40e_page_is_reserved(struct page *page) 
 **/

static bool i40e_add_rx_frag(struct i40e_ring *rx_ring,

			     struct i40e_rx_buffer *rx_buffer,

			     union i40e_rx_desc *rx_desc,

			     unsigned int size,

			     struct sk_buff *skb)

{

	struct page *page = rx_buffer->page;

	u64 qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);

	unsigned int size = (qword & I40E_RXD_QW1_LENGTH_PBUF_MASK) >>

			    I40E_RXD_QW1_LENGTH_PBUF_SHIFT;

#if (PAGE_SIZE < 8192)

	unsigned int truesize = I40E_RXBUFFER_2048;

#else
@@ -1091,6 +1088,11 @@ static inline 
struct sk_buff *i40evf_fetch_rx_buffer(struct i40e_ring *rx_ring,

				       union i40e_rx_desc *rx_desc)

{

	u64 local_status_error_len =

		le64_to_cpu(rx_desc->wb.qword1.status_error_len);

	unsigned int size =

		(local_status_error_len & I40E_RXD_QW1_LENGTH_PBUF_MASK) >>

		I40E_RXD_QW1_LENGTH_PBUF_SHIFT;

	struct i40e_rx_buffer *rx_buffer;

	struct sk_buff *skb;

	struct page *page;
@@ -1132,11 +1134,11 @@ struct sk_buff *i40evf_fetch_rx_buffer(struct i40e_ring *rx_ring, 
	dma_sync_single_range_for_cpu(rx_ring->dev,

				      rx_buffer->dma,

				      rx_buffer->page_offset,

				      I40E_RXBUFFER_2048,

				      size,

				      DMA_FROM_DEVICE);



	/* pull page into skb */

	if (i40e_add_rx_frag(rx_ring, rx_buffer, rx_desc, skb)) {

	if (i40e_add_rx_frag(rx_ring, rx_buffer, size, skb)) {

		/* hand second half of page back to the ring */

		i40e_reuse_rx_page(rx_ring, rx_buffer);

		rx_ring->rx_stats.page_reuse_count++;