From a65f71fed5add2ec5713fcc605842f5f2dff22a3 Mon Sep 17 00:00:00 2001 From: Maciej Fijalkowski Date: Wed, 13 Feb 2019 10:51:07 -0800 Subject: [PATCH] ice: map Rx buffer pages with DMA attributes Provide DMA_ATTR_WEAK_ORDERING and DMA_ATTR_SKIP_CPU_SYNC attributes to the DMA API during the mapping operations on Rx side. With this change the non-x86 platforms will be able to sync only with what is being used (2k buffer) instead of entire page. This should yield a slight performance improvement. Furthermore, DMA unmap may destroy the changes that were made to the buffer by CPU when platform is not a x86 one. DMA_ATTR_SKIP_CPU_SYNC attribute usage fixes this issue. Also add a sync_single_for_device call during the Rx buffer assignment, to make sure that the cache lines are cleared before device attempting to write to the buffer. Signed-off-by: Maciej Fijalkowski Signed-off-by: Anirudh Venkataramanan Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/ice/ice_txrx.c | 24 +++++++++++++++++++---- drivers/net/ethernet/intel/ice/ice_txrx.h | 3 +++ 2 files changed, 23 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c index 63af5af3c3e8..ea4ec3760f8b 100644 --- a/drivers/net/ethernet/intel/ice/ice_txrx.c +++ b/drivers/net/ethernet/intel/ice/ice_txrx.c @@ -282,7 +282,16 @@ void ice_clean_rx_ring(struct ice_ring *rx_ring) if (!rx_buf->page) continue; - dma_unmap_page(dev, rx_buf->dma, PAGE_SIZE, DMA_FROM_DEVICE); + /* Invalidate cache lines that may have been written to by + * device so that we avoid corrupting memory. + */ + dma_sync_single_range_for_cpu(dev, rx_buf->dma, + rx_buf->page_offset, + ICE_RXBUF_2048, DMA_FROM_DEVICE); + + /* free resources associated with mapping */ + dma_unmap_page_attrs(dev, rx_buf->dma, PAGE_SIZE, + DMA_FROM_DEVICE, ICE_RX_DMA_ATTR); __page_frag_cache_drain(rx_buf->page, rx_buf->pagecnt_bias); rx_buf->page = NULL; @@ -409,7 +418,8 @@ ice_alloc_mapped_page(struct ice_ring *rx_ring, struct ice_rx_buf *bi) } /* map page for use */ - dma = dma_map_page(rx_ring->dev, page, 0, PAGE_SIZE, DMA_FROM_DEVICE); + dma = dma_map_page_attrs(rx_ring->dev, page, 0, PAGE_SIZE, + DMA_FROM_DEVICE, ICE_RX_DMA_ATTR); /* if mapping failed free memory back to system since * there isn't much point in holding memory we can't use @@ -454,6 +464,12 @@ bool ice_alloc_rx_bufs(struct ice_ring *rx_ring, u16 cleaned_count) if (!ice_alloc_mapped_page(rx_ring, bi)) goto no_bufs; + /* sync the buffer for use by the device */ + dma_sync_single_range_for_device(rx_ring->dev, bi->dma, + bi->page_offset, + ICE_RXBUF_2048, + DMA_FROM_DEVICE); + /* Refresh the desc even if buffer_addrs didn't change * because each write-back erases this info. */ @@ -726,8 +742,8 @@ static void ice_put_rx_buf(struct ice_ring *rx_ring, struct ice_rx_buf *rx_buf) rx_ring->rx_stats.page_reuse_count++; } else { /* we are not reusing the buffer so unmap it */ - dma_unmap_page(rx_ring->dev, rx_buf->dma, PAGE_SIZE, - DMA_FROM_DEVICE); + dma_unmap_page_attrs(rx_ring->dev, rx_buf->dma, PAGE_SIZE, + DMA_FROM_DEVICE, ICE_RX_DMA_ATTR); __page_frag_cache_drain(rx_buf->page, rx_buf->pagecnt_bias); } diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.h b/drivers/net/ethernet/intel/ice/ice_txrx.h index 43b39e7ce470..bd446ed423e5 100644 --- a/drivers/net/ethernet/intel/ice/ice_txrx.h +++ b/drivers/net/ethernet/intel/ice/ice_txrx.h @@ -47,6 +47,9 @@ #define ICE_TX_FLAGS_VLAN_M 0xffff0000 #define ICE_TX_FLAGS_VLAN_S 16 +#define ICE_RX_DMA_ATTR \ + (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING) + struct ice_tx_buf { struct ice_tx_desc *next_to_watch; struct sk_buff *skb; -- 2.30.2