> -----Original Message----- > From: netdev-ow...@vger.kernel.org [mailto:netdev-ow...@vger.kernel.org] > On Behalf Of Jeff Kirsher > Sent: Thursday, February 16, 2017 8:51 PM > To: da...@davemloft.net > Cc: Alexander Duyck; netdev@vger.kernel.org; nhor...@redhat.com; > sassm...@redhat.com; jogre...@redhat.com; Jeff Kirsher > Subject: [net-next 06/14] ixgbe: Update driver to make use of DMA attributes > in > Rx path > > From: Alexander Duyck <alexander.h.du...@intel.com> > > This patch adds support for DMA_ATTR_SKIP_CPU_SYNC and > DMA_ATTR_WEAK_ORDERING. By enabling both of these for the Rx path we > are able to see performance improvements on architectures that implement > either one due to the fact that page mapping and unmapping only has to sync > what is actually being used instead of the entire buffer. In addition by > enabling the weak ordering attribute enables a performance improvement for > architectures that can associate a memory ordering with a DMA buffer such as > Sparc. > > Signed-off-by: Alexander Duyck <alexander.h.du...@intel.com> > Tested-by: Andrew Bowers <andrewx.bow...@intel.com> > Signed-off-by: Jeff Kirsher <jeffrey.t.kirs...@intel.com> > --- > drivers/net/ethernet/intel/ixgbe/ixgbe.h | 3 ++ > drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 56 > ++++++++++++++++++--------- > 2 files changed, 40 insertions(+), 19 deletions(-) > > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h > b/drivers/net/ethernet/intel/ixgbe/ixgbe.h > index 6530eff01a0b..8167e77b924f 100644 > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h > @@ -104,6 +104,9 @@ > /* How many Rx Buffers do we bundle into one write to the hardware ? */ > #define IXGBE_RX_BUFFER_WRITE 16 /* Must be power of 2 */ > > +#define IXGBE_RX_DMA_ATTR \ > + (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING) > + > enum ixgbe_tx_flags { > /* cmd_type flags */ > IXGBE_TX_FLAGS_HW_VLAN = 0x01, > diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > index dde2c852e01d..ddde6759f094 100644 > --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c > @@ -1570,8 +1570,10 @@ static bool ixgbe_alloc_mapped_page(struct > ixgbe_ring *rx_ring, > } > > /* map page for use */ > - dma = dma_map_page(rx_ring->dev, page, 0, > - ixgbe_rx_pg_size(rx_ring), DMA_FROM_DEVICE); > + dma = dma_map_page_attrs(rx_ring->dev, page, 0, > + ixgbe_rx_pg_size(rx_ring), > + DMA_FROM_DEVICE, > + IXGBE_RX_DMA_ATTR); > > /* > * if mapping failed free memory back to system since @@ -1614,6 > +1616,12 @@ void ixgbe_alloc_rx_buffers(struct ixgbe_ring *rx_ring, u16 > cleaned_count) > if (!ixgbe_alloc_mapped_page(rx_ring, bi)) > break; > > + /* sync the buffer for use by the device */ > + dma_sync_single_range_for_device(rx_ring->dev, bi->dma, > + bi->page_offset, > + ixgbe_rx_bufsz(rx_ring), > + DMA_FROM_DEVICE); > + > /* > * Refresh the desc even if buffer_addrs didn't change > * because each write-back erases this info. > @@ -1832,8 +1840,10 @@ static void ixgbe_dma_sync_frag(struct ixgbe_ring > *rx_ring, { > /* if the page was released unmap it, else just sync our portion */ > if (unlikely(IXGBE_CB(skb)->page_released)) { > - dma_unmap_page(rx_ring->dev, IXGBE_CB(skb)->dma, > - ixgbe_rx_pg_size(rx_ring), DMA_FROM_DEVICE); > + dma_unmap_page_attrs(rx_ring->dev, IXGBE_CB(skb)->dma, > + ixgbe_rx_pg_size(rx_ring), > + DMA_FROM_DEVICE, > + IXGBE_RX_DMA_ATTR); > IXGBE_CB(skb)->page_released = false; > } else { > struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[0]; @@ > -1917,12 +1927,6 @@ static void ixgbe_reuse_rx_page(struct ixgbe_ring > *rx_ring, > > /* transfer page from old buffer to new buffer */ > *new_buff = *old_buff; > - > - /* sync the buffer for use by the device */ > - dma_sync_single_range_for_device(rx_ring->dev, new_buff->dma, > - new_buff->page_offset, > - ixgbe_rx_bufsz(rx_ring), > - DMA_FROM_DEVICE); > } > > static inline bool ixgbe_page_is_reserved(struct page *page) @@ -2089,9 > +2093,10 @@ static struct sk_buff *ixgbe_fetch_rx_buffer(struct ixgbe_ring > *rx_ring, > IXGBE_CB(skb)->page_released = true; > } else { > /* we are not reusing the buffer so unmap it */ > - dma_unmap_page(rx_ring->dev, rx_buffer->dma, > - ixgbe_rx_pg_size(rx_ring), > - DMA_FROM_DEVICE); > + dma_unmap_page_attrs(rx_ring->dev, rx_buffer->dma, > + ixgbe_rx_pg_size(rx_ring), > + DMA_FROM_DEVICE, > + IXGBE_RX_DMA_ATTR); > } > > /* clear contents of buffer_info */ > @@ -4883,10 +4888,11 @@ static void ixgbe_clean_rx_ring(struct ixgbe_ring > *rx_ring) > if (rx_buffer->skb) { > struct sk_buff *skb = rx_buffer->skb; > if (IXGBE_CB(skb)->page_released) > - dma_unmap_page(dev, > - IXGBE_CB(skb)->dma, > - ixgbe_rx_bufsz(rx_ring), > - DMA_FROM_DEVICE); > + dma_unmap_page_attrs(dev, > + IXGBE_CB(skb)->dma, > + ixgbe_rx_pg_size(rx_ring), > + DMA_FROM_DEVICE, > + IXGBE_RX_DMA_ATTR); > dev_kfree_skb(skb); > rx_buffer->skb = NULL; > } > @@ -4894,8 +4900,20 @@ static void ixgbe_clean_rx_ring(struct ixgbe_ring > *rx_ring) > if (!rx_buffer->page) > continue; > > - dma_unmap_page(dev, rx_buffer->dma, > - ixgbe_rx_pg_size(rx_ring), 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(rx_ring->dev, > + rx_buffer->dma, > + rx_buffer->page_offset, > + ixgbe_rx_bufsz(rx_ring), > + DMA_FROM_DEVICE); > + > + /* free resources associated with mapping */ > + dma_unmap_page_attrs(dev, rx_buffer->dma, > + ixgbe_rx_pg_size(rx_ring), > + DMA_FROM_DEVICE, > + IXGBE_RX_DMA_ATTR); > __free_pages(rx_buffer->page, ixgbe_rx_pg_order(rx_ring)); > > rx_buffer->page = NULL; > -- > 2.11.0
Hi Alex, Is this patch available for arm64? I remember that it needs IOMMU support, right?
