From 73017f4e051c86985cf4647eceee34de7c13b1b1 Mon Sep 17 00:00:00 2001 From: Venkatesh Srinivas Date: Fri, 25 May 2018 00:13:21 -0400 Subject: [PATCH] igb: Use dma_wmb() instead of wmb() before doorbell writes igb writes to doorbells to post transmit and receive descriptors; after writing descriptors to memory but before writing to doorbells, use dma_wmb() rather than wmb(). wmb() is more heavyweight than necessary before doorbell writes. On x86, this avoids SFENCEs before doorbell writes in both the tx and rx refill paths. Signed-off-by: Venkatesh Srinivas Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/igb/igb_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index e3a0c02..25720d9 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -6031,7 +6031,7 @@ static int igb_tx_map(struct igb_ring *tx_ring, * We also need this memory barrier to make certain all of the * status bits have been updated before next_to_watch is written. */ - wmb(); + dma_wmb(); /* set next_to_watch value indicating a packet is present */ first->next_to_watch = tx_desc; @@ -8531,7 +8531,7 @@ void igb_alloc_rx_buffers(struct igb_ring *rx_ring, u16 cleaned_count) * applicable for weak-ordered memory model archs, * such as IA-64). */ - wmb(); + dma_wmb(); writel(i, rx_ring->tail); } } -- 2.7.4