ixgbevf: only DMA sync frame length

Based on commit 64f2525ca4e7 ("igb: Only DMA sync frame length")

On some architectures synching a buffer for DMA may be expensive.
Instead of the entire 2K receive buffer only synchronize the length of
the frame, which will typically be the MTU or smaller.

Signed-off-by: Emil Tantilov <emil.s.tantilov@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/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index 7ffd429..0cc2688 100644 (file)
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -803,12 +803,12 @@ static bool ixgbevf_can_reuse_rx_page(struct ixgbevf_rx_buffer *rx_buffer,
  **/
 static bool ixgbevf_add_rx_frag(struct ixgbevf_ring *rx_ring,
                                struct ixgbevf_rx_buffer *rx_buffer,
+                               u16 size,
                                union ixgbe_adv_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->wb.upper.length);
 #if (PAGE_SIZE < 8192)
        unsigned int truesize = IXGBEVF_RX_BUFSZ;
 #else
@@ -856,6 +856,7 @@ static struct sk_buff *ixgbevf_fetch_rx_buffer(struct ixgbevf_ring *rx_ring,
 {
        struct ixgbevf_rx_buffer *rx_buffer;
        struct page *page;
+       u16 size = le16_to_cpu(rx_desc->wb.upper.length);
 
        rx_buffer = &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
        page = rx_buffer->page;
@@ -890,11 +891,11 @@ static struct sk_buff *ixgbevf_fetch_rx_buffer(struct ixgbevf_ring *rx_ring,
        dma_sync_single_range_for_cpu(rx_ring->dev,
                                      rx_buffer->dma,
                                      rx_buffer->page_offset,
-                                     IXGBEVF_RX_BUFSZ,
+                                     size,
                                      DMA_FROM_DEVICE);
 
        /* pull page into skb */
-       if (ixgbevf_add_rx_frag(rx_ring, rx_buffer, rx_desc, skb)) {
+       if (ixgbevf_add_rx_frag(rx_ring, rx_buffer, size, rx_desc, skb)) {
                /* hand second half of page back to the ring */
                ixgbevf_reuse_rx_page(rx_ring, rx_buffer);
        } else {