ixgbe: Only DMA sync frame length

On some platforms, syncing a buffer for DMA is expensive. Rather than
sync the whole 2K receive buffer, only synchronise the length of the
frame, which will typically be the MTU, or a much smaller TCP ACK.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
This commit is contained in:
Alexander Duyck 2017-01-17 08:35:44 -08:00 committed by Jeff Kirsher
parent af43da0dba
commit f215af8cae

View file

@ -1841,7 +1841,7 @@ static void ixgbe_dma_sync_frag(struct ixgbe_ring *rx_ring,
dma_sync_single_range_for_cpu(rx_ring->dev,
IXGBE_CB(skb)->dma,
frag->page_offset,
ixgbe_rx_bufsz(rx_ring),
skb_frag_size(frag),
DMA_FROM_DEVICE);
}
IXGBE_CB(skb)->dma = 0;
@ -1983,12 +1983,11 @@ static bool ixgbe_can_reuse_rx_page(struct ixgbe_ring *rx_ring,
**/
static bool ixgbe_add_rx_frag(struct ixgbe_ring *rx_ring,
struct ixgbe_rx_buffer *rx_buffer,
union ixgbe_adv_rx_desc *rx_desc,
unsigned int size,
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 = ixgbe_rx_bufsz(rx_ring);
#else
@ -2020,6 +2019,7 @@ static bool ixgbe_add_rx_frag(struct ixgbe_ring *rx_ring,
static struct sk_buff *ixgbe_fetch_rx_buffer(struct ixgbe_ring *rx_ring,
union ixgbe_adv_rx_desc *rx_desc)
{
unsigned int size = le16_to_cpu(rx_desc->wb.upper.length);
struct ixgbe_rx_buffer *rx_buffer;
struct sk_buff *skb;
struct page *page;
@ -2074,14 +2074,14 @@ static struct sk_buff *ixgbe_fetch_rx_buffer(struct ixgbe_ring *rx_ring,
dma_sync_single_range_for_cpu(rx_ring->dev,
rx_buffer->dma,
rx_buffer->page_offset,
ixgbe_rx_bufsz(rx_ring),
size,
DMA_FROM_DEVICE);
rx_buffer->skb = NULL;
}
/* pull page into skb */
if (ixgbe_add_rx_frag(rx_ring, rx_buffer, rx_desc, skb)) {
if (ixgbe_add_rx_frag(rx_ring, rx_buffer, size, skb)) {
/* hand second half of page back to the ring */
ixgbe_reuse_rx_page(rx_ring, rx_buffer);
} else if (IXGBE_CB(skb)->dma == rx_buffer->dma) {