> -----Original Message-----
> From: netdev-ow...@vger.kernel.org [mailto:netdev-ow...@vger.kernel.org]
> On Behalf Of Tushar Dave
> Sent: Tuesday, December 06, 2016 1:07 AM
> To: jeffrey.t.kirs...@intel.com; intel-wired-...@lists.osuosl.org
> Cc: netdev@vger.kernel.org
> Subject: [RFC PATCH] i40e: enable PCIe relax ordering for SPARC
>
> Unlike previous generation NIC (e.g. ixgbe) i40e doesn't seem to have standard
> CSR where PCIe relaxed ordering can be set. Without PCIe relax ordering
> enabled, i40e performance is significantly low on SPARC.
>
[Mao Wenan]Hi Tushar, you have referred to i40e doesn't seem to have standard
CSR
to set PCIe relaxed ordering, this CSR like TX&Rx DCA Control Register in
82599, right?
Is DMA_ATTR_WEAK_ORDERING the same as TX&RX control register in 82599?
And to enable relax ordering mode in 82599 for SPARC using below codes:
s32 ixgbe_start_hw_gen2(struct ixgbe_hw *hw)
{
u32 i;
/* Clear the rate limiters */
for (i = 0; i < hw->mac.max_tx_queues; i++) {
IXGBE_WRITE_REG(hw, IXGBE_RTTDQSEL, i);
IXGBE_WRITE_REG(hw, IXGBE_RTTBCNRC, 0);
}
IXGBE_WRITE_FLUSH(hw);
#ifndef CONFIG_SPARC
/* Disable relaxed ordering */
for (i = 0; i < hw->mac.max_tx_queues; i++) {
u32 regval;
regval = IXGBE_READ_REG(hw, IXGBE_DCA_TXCTRL_82599(i));
regval &= ~IXGBE_DCA_TXCTRL_DESC_WRO_EN;
IXGBE_WRITE_REG(hw, IXGBE_DCA_TXCTRL_82599(i), regval);
}
for (i = 0; i < hw->mac.max_rx_queues; i++) {
u32 regval;
regval = IXGBE_READ_REG(hw, IXGBE_DCA_RXCTRL(i));
regval &= ~(IXGBE_DCA_RXCTRL_DATA_WRO_EN |
IXGBE_DCA_RXCTRL_HEAD_WRO_EN);
IXGBE_WRITE_REG(hw, IXGBE_DCA_RXCTRL(i), regval);
}
#endif
return 0;
}
> This patch sets PCIe relax ordering for SPARC arch by setting dma attr
> DMA_ATTR_WEAK_ORDERING for every tx and rx DMA map/unmap.
> This has shown 10x increase in performance numbers.
>
> e.g.
> iperf TCP test with 10 threads on SPARC S7
>
> Test 1: Without this patch
>
> [root@brm-snt1-03 net]# iperf -s
> ------------------------------------------------------------
> Server listening on TCP port 5001
> TCP window size: 85.3 KByte (default)
> ------------------------------------------------------------
> [ 4] local 16.0.0.7 port 5001 connected with 16.0.0.1 port 40926 [ 5] local
> 16.0.0.7 port 5001 connected with 16.0.0.1 port 40934 [ 6] local 16.0.0.7
> port
> 5001 connected with 16.0.0.1 port 40930 [ 7] local 16.0.0.7 port 5001
> connected with 16.0.0.1 port 40928 [ 8] local 16.0.0.7 port 5001 connected
> with 16.0.0.1 port 40922 [ 9] local 16.0.0.7 port 5001 connected with
> 16.0.0.1
> port 40932 [ 10] local 16.0.0.7 port 5001 connected with 16.0.0.1 port 40920
> [ 11] local 16.0.0.7 port 5001 connected with 16.0.0.1 port 40924 [ 14] local
> 16.0.0.7 port 5001 connected with 16.0.0.1 port 40982 [ 12] local 16.0.0.7
> port
> 5001 connected with 16.0.0.1 port 40980
> [ ID] Interval Transfer Bandwidth
> [ 4] 0.0-20.0 sec 566 MBytes 237 Mbits/sec
> [ 5] 0.0-20.0 sec 532 MBytes 223 Mbits/sec
> [ 6] 0.0-20.0 sec 537 MBytes 225 Mbits/sec
> [ 8] 0.0-20.0 sec 546 MBytes 229 Mbits/sec
> [ 11] 0.0-20.0 sec 592 MBytes 248 Mbits/sec
> [ 7] 0.0-20.0 sec 539 MBytes 226 Mbits/sec
> [ 9] 0.0-20.0 sec 572 MBytes 240 Mbits/sec
> [ 10] 0.0-20.0 sec 604 MBytes 253 Mbits/sec
> [ 14] 0.0-20.0 sec 567 MBytes 238 Mbits/sec
> [ 12] 0.0-20.0 sec 511 MBytes 214 Mbits/sec
> [SUM] 0.0-20.0 sec 5.44 GBytes 2.33 Gbits/sec
>
> Test 2: with this patch:
>
> [root@brm-snt1-03 net]# iperf -s
> ------------------------------------------------------------
> Server listening on TCP port 5001
> TCP window size: 85.3 KByte (default)
> ------------------------------------------------------------
> TCP: request_sock_TCP: Possible SYN flooding on port 5001. Sending cookies.
> Check SNMP counters.
> [ 4] local 16.0.0.7 port 5001 connected with 16.0.0.1 port 46876 [ 5] local
> 16.0.0.7 port 5001 connected with 16.0.0.1 port 46874 [ 6] local 16.0.0.7
> port
> 5001 connected with 16.0.0.1 port 46872 [ 7] local 16.0.0.7 port 5001
> connected with 16.0.0.1 port 46880 [ 8] local 16.0.0.7 port 5001 connected
> with 16.0.0.1 port 46878 [ 9] local 16.0.0.7 port 5001 connected with
> 16.0.0.1
> port 46884 [ 10] local 16.0.0.7 port 5001 connected with 16.0.0.1 port 46886
> [ 11] local 16.0.0.7 port 5001 connected with 16.0.0.1 port 46890 [ 12] local
> 16.0.0.7 port 5001 connected with 16.0.0.1 port 46888 [ 13] local 16.0.0.7
> port
> 5001 connected with 16.0.0.1 port 46882
> [ ID] Interval Transfer Bandwidth
> [ 4] 0.0-20.0 sec 7.45 GBytes 3.19 Gbits/sec [ 5] 0.0-20.0 sec 7.48
> GBytes 3.21 Gbits/sec [ 7] 0.0-20.0 sec 7.34 GBytes 3.15 Gbits/sec
> [ 8] 0.0-20.0 sec 7.42 GBytes 3.18 Gbits/sec [ 9] 0.0-20.0 sec 7.24
> GBytes 3.11 Gbits/sec [ 10] 0.0-20.0 sec 7.40 GBytes 3.17 Gbits/sec
> [ 12] 0.0-20.0 sec 7.49 GBytes 3.21 Gbits/sec [ 6] 0.0-20.0 sec 7.30
> GBytes 3.13 Gbits/sec [ 11] 0.0-20.0 sec 7.44 GBytes 3.19 Gbits/sec
> [ 13] 0.0-20.0 sec 7.22 GBytes 3.10 Gbits/sec [SUM] 0.0-20.0 sec 73.8
> GBytes 31.6 Gbits/sec
>
> NOTE: In my testing, this patch does _not_ show any harm to i40e performance
> numbers on x86.
>
> Signed-off-by: Tushar Dave <tushar.n.d...@oracle.com>
> ---
> drivers/net/ethernet/intel/i40e/i40e_txrx.c | 69
> ++++++++++++++++++++--------- drivers/net/ethernet/intel/i40e/i40e_txrx.h |
> 1 +
> 2 files changed, 49 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
> b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
> index 6287bf6..800dca7 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
> @@ -551,15 +551,17 @@ static void
> i40e_unmap_and_free_tx_resource(struct i40e_ring *ring,
> else
> dev_kfree_skb_any(tx_buffer->skb);
> if (dma_unmap_len(tx_buffer, len))
> - dma_unmap_single(ring->dev,
> - dma_unmap_addr(tx_buffer, dma),
> - dma_unmap_len(tx_buffer, len),
> - DMA_TO_DEVICE);
> + dma_unmap_single_attrs(ring->dev,
> + dma_unmap_addr(tx_buffer, dma),
> + dma_unmap_len(tx_buffer, len),
> + DMA_TO_DEVICE,
> + ring->dma_attrs);
> } else if (dma_unmap_len(tx_buffer, len)) {
> - dma_unmap_page(ring->dev,
> - dma_unmap_addr(tx_buffer, dma),
> - dma_unmap_len(tx_buffer, len),
> - DMA_TO_DEVICE);
> + dma_unmap_single_attrs(ring->dev,
> + dma_unmap_addr(tx_buffer, dma),
> + dma_unmap_len(tx_buffer, len),
> + DMA_TO_DEVICE,
> + ring->dma_attrs);
> }
>
> tx_buffer->next_to_watch = NULL;
> @@ -662,6 +664,8 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
> struct i40e_tx_buffer *tx_buf;
> struct i40e_tx_desc *tx_head;
> struct i40e_tx_desc *tx_desc;
> + dma_addr_t addr;
> + size_t size;
> unsigned int total_bytes = 0, total_packets = 0;
> unsigned int budget = vsi->work_limit;
>
> @@ -696,10 +700,11 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
> napi_consume_skb(tx_buf->skb, napi_budget);
>
> /* unmap skb header data */
> - dma_unmap_single(tx_ring->dev,
> - dma_unmap_addr(tx_buf, dma),
> - dma_unmap_len(tx_buf, len),
> - DMA_TO_DEVICE);
> + dma_unmap_single_attrs(tx_ring->dev,
> + dma_unmap_addr(tx_buf, dma),
> + dma_unmap_len(tx_buf, len),
> + DMA_TO_DEVICE,
> + tx_ring->dma_attrs);
>
> /* clear tx_buffer data */
> tx_buf->skb = NULL;
> @@ -717,12 +722,15 @@ static bool i40e_clean_tx_irq(struct i40e_vsi *vsi,
> tx_desc = I40E_TX_DESC(tx_ring, 0);
> }
>
> + addr = dma_unmap_addr(tx_buf, dma);
> + size = dma_unmap_len(tx_buf, len);
> /* unmap any remaining paged data */
> if (dma_unmap_len(tx_buf, len)) {
> - dma_unmap_page(tx_ring->dev,
> - dma_unmap_addr(tx_buf, dma),
> - dma_unmap_len(tx_buf, len),
> - DMA_TO_DEVICE);
> + dma_unmap_single_attrs(tx_ring->dev,
> + addr,
> + size,
> + DMA_TO_DEVICE,
> + tx_ring->dma_attrs);
> dma_unmap_len_set(tx_buf, len, 0);
> }
> }
> @@ -1010,6 +1018,11 @@ int i40e_setup_tx_descriptors(struct i40e_ring
> *tx_ring)
> */
> tx_ring->size += sizeof(u32);
> tx_ring->size = ALIGN(tx_ring->size, 4096);
> +#ifdef CONFIG_SPARC
> + tx_ring->dma_attrs = DMA_ATTR_WEAK_ORDERING; #else
> + tx_ring->dma_attrs = 0;
> +#endif
> tx_ring->desc = dma_alloc_coherent(dev, tx_ring->size,
> &tx_ring->dma, GFP_KERNEL);
> if (!tx_ring->desc) {
> @@ -1053,7 +1066,11 @@ void i40e_clean_rx_ring(struct i40e_ring *rx_ring)
> if (!rx_bi->page)
> continue;
>
> - dma_unmap_page(dev, rx_bi->dma, PAGE_SIZE,
> DMA_FROM_DEVICE);
> + dma_unmap_single_attrs(dev,
> + rx_bi->dma,
> + PAGE_SIZE,
> + DMA_FROM_DEVICE,
> + rx_ring->dma_attrs);
> __free_pages(rx_bi->page, 0);
>
> rx_bi->page = NULL;
> @@ -1113,6 +1130,11 @@ int i40e_setup_rx_descriptors(struct i40e_ring
> *rx_ring)
> /* Round up to nearest 4K */
> rx_ring->size = rx_ring->count * sizeof(union i40e_32byte_rx_desc);
> rx_ring->size = ALIGN(rx_ring->size, 4096);
> +#ifdef CONFIG_SPARC
> + rx_ring->dma_attrs = DMA_ATTR_WEAK_ORDERING; #else
> + rx_ring->dma_attrs = 0;
> +#endif
> rx_ring->desc = dma_alloc_coherent(dev, rx_ring->size,
> &rx_ring->dma, GFP_KERNEL);
>
> @@ -1182,7 +1204,8 @@ static bool i40e_alloc_mapped_page(struct
> i40e_ring *rx_ring,
> }
>
> /* map page for use */
> - dma = dma_map_page(rx_ring->dev, page, 0, PAGE_SIZE,
> DMA_FROM_DEVICE);
> + dma = dma_map_single_attrs(rx_ring->dev, page_address(page),
> PAGE_SIZE,
> + DMA_FROM_DEVICE, rx_ring->dma_attrs);
>
> /* if mapping failed free memory back to system since
> * there isn't much point in holding memory we can't use @@ -1695,8
> +1718,11 @@ struct sk_buff *i40e_fetch_rx_buffer(struct i40e_ring *rx_ring,
> rx_ring->rx_stats.page_reuse_count++;
> } else {
> /* we are not reusing the buffer so unmap it */
> - dma_unmap_page(rx_ring->dev, rx_buffer->dma, PAGE_SIZE,
> - DMA_FROM_DEVICE);
> + dma_unmap_single_attrs(rx_ring->dev,
> + rx_buffer->dma,
> + PAGE_SIZE,
> + DMA_FROM_DEVICE,
> + rx_ring->dma_attrs);
> }
>
> /* clear contents of buffer_info */
> @@ -2737,7 +2763,8 @@ static inline void i40e_tx_map(struct i40e_ring
> *tx_ring, struct sk_buff *skb,
> first->skb = skb;
> first->tx_flags = tx_flags;
>
> - dma = dma_map_single(tx_ring->dev, skb->data, size, DMA_TO_DEVICE);
> + dma = dma_map_single_attrs(tx_ring->dev, skb->data, size,
> + DMA_TO_DEVICE, tx_ring->dma_attrs);
>
> tx_desc = I40E_TX_DESC(tx_ring, i);
> tx_bi = first;
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
> b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
> index 5088405..9a86212 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.h
> +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.h
> @@ -327,6 +327,7 @@ struct i40e_ring {
>
> unsigned int size; /* length of descriptor ring in bytes */
> dma_addr_t dma; /* physical address of ring */
> + unsigned long dma_attrs; /* DMA attributes */
>
> struct i40e_vsi *vsi; /* Backreference to associated VSI */
> struct i40e_q_vector *q_vector; /* Backreference to associated vector
> */
> --
> 1.9.1
