[Intel-wired-lan] [PATCH S14 07/15] ice: map rx buffer pages with DMA attributes
Anirudh Venkataramanan
anirudh.venkataramanan at intel.com
Wed Feb 13 18:51:07 UTC 2019
From: Maciej Fijalkowski <maciej.fijalkowski at intel.com>
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 <maciej.fijalkowski at intel.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan at intel.com>
---
[Anirudh Venkataramanan <anirudh.venkataramanan at intel.com> cleaned up commit message]
---
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 aaa29ac18cdb..2f5981dbdff9 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;
--
2.14.5
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