fm10k: 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.

Signed-off-by: Scott Peterson <scott.d.peterson@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Krishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_main.c b/drivers/net/ethernet/intel/fm10k/fm10k_main.c
index 509514d..8f90c6d 100644 (file)
--- a/drivers/net/ethernet/intel/fm10k/fm10k_main.c
+++ b/drivers/net/ethernet/intel/fm10k/fm10k_main.c
@@ -251,6 +251,7 @@ static bool fm10k_can_reuse_rx_page(struct fm10k_rx_buffer *rx_buffer,
 /**
  * fm10k_add_rx_frag - Add contents of Rx buffer to sk_buff
  * @rx_buffer: buffer containing page to add
+ * @size: packet size from rx_desc
  * @rx_desc: descriptor containing length of buffer written by hardware
  * @skb: sk_buff to place the data into
  *
@@ -263,12 +264,12 @@ static bool fm10k_can_reuse_rx_page(struct fm10k_rx_buffer *rx_buffer,
  * true if the buffer can be reused by the interface.
  **/
 static bool fm10k_add_rx_frag(struct fm10k_rx_buffer *rx_buffer,
+                             unsigned int size,
                              union fm10k_rx_desc *rx_desc,
                              struct sk_buff *skb)
 {
        struct page *page = rx_buffer->page;
        unsigned char *va = page_address(page) + rx_buffer->page_offset;
-       unsigned int size = le16_to_cpu(rx_desc->w.length);
 #if (PAGE_SIZE < 8192)
        unsigned int truesize = FM10K_RX_BUFSZ;
 #else
@@ -314,6 +315,7 @@ static struct sk_buff *fm10k_fetch_rx_buffer(struct fm10k_ring *rx_ring,
                                             union fm10k_rx_desc *rx_desc,
                                             struct sk_buff *skb)
 {
+       unsigned int size = le16_to_cpu(rx_desc->w.length);
        struct fm10k_rx_buffer *rx_buffer;
        struct page *page;
 
@@ -350,11 +352,11 @@ static struct sk_buff *fm10k_fetch_rx_buffer(struct fm10k_ring *rx_ring,
        dma_sync_single_range_for_cpu(rx_ring->dev,
                                      rx_buffer->dma,
                                      rx_buffer->page_offset,
-                                     FM10K_RX_BUFSZ,
+                                     size,
                                      DMA_FROM_DEVICE);
 
        /* pull page into skb */
-       if (fm10k_add_rx_frag(rx_buffer, rx_desc, skb)) {
+       if (fm10k_add_rx_frag(rx_buffer, size, rx_desc, skb)) {
                /* hand second half of page back to the ring */
                fm10k_reuse_rx_page(rx_ring, rx_buffer);
        } else {