ixgbe: Don't bother clearing buffer memory for descriptor rings

This patch makes it so that we don't need to bother with clearing the
memory out for the descriptor rings.  The general idea is to only free
buffers associated with buffers in use which are located between the
next_to_clean and next_to_use or next_to_alloc values.  Everything outside
of those regions can be safely ignored since they should have no buffers
associated with them.

The advantage to doing things this way is that is should speed up bring-up
and tear-down of the rings.  Specifically we can avoid the 512 or more
cycles required to memset the rings in tear-down.  In the bring-up phase we
then clear the memory as a part of initialization.  The general idea is
that the clearing in initialization can act as a prefetch of sorts for the
buffer info structures so they are in the local CPU when we go to populate
them.  This should help to improve overall time needed to perform a
suspend/resume.

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>

1 files changed, 10 insertions, 1 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
index 68500881cbc0..a7574c7b12af 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c
@@ -1904,7 +1904,16 @@ static u16 ixgbe_clean_test_rings(struct ixgbe_ring *rx_ring,
 
 		/* unmap buffer on Tx side */
 		tx_buffer = &tx_ring->tx_buffer_info[tx_ntc];
-		ixgbe_unmap_and_free_tx_resource(tx_ring, tx_buffer);
+
+		/* Free all the Tx ring sk_buffs */
+		dev_kfree_skb_any(tx_buffer->skb);
+
+		/* unmap skb header data */
+		dma_unmap_single(tx_ring->dev,
+				 dma_unmap_addr(tx_buffer, dma),
+				 dma_unmap_len(tx_buffer, len),
+				 DMA_TO_DEVICE);
+		dma_unmap_len_set(tx_buffer, len, 0);
 
 		/* increment Rx/Tx next to clean counters */
 		rx_ntc++;