[Intel-wired-lan] [RFC PATCH] i40e: enable PCIe relax ordering for SPARC
tndave
tushar.n.dave at oracle.com
Tue Dec 27 22:27:52 UTC 2016
On 12/26/2016 03:39 AM, maowenan wrote:
>
>
>> -----Original Message-----
>> From: netdev-owner at vger.kernel.org [mailto:netdev-owner at vger.kernel.org]
>> On Behalf Of Tushar Dave
>> Sent: Tuesday, December 06, 2016 1:07 AM
>> To: jeffrey.t.kirsher at intel.com; intel-wired-lan at lists.osuosl.org
>> Cc: netdev at 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?
Yes.
i40e datasheet mentions some CSR that can be used to enable/disable PCIe
relaxed ordering in device; however I don't see the exact definition of
those register in datasheet.
(https://www.mail-archive.com/netdev@vger.kernel.org/msg117219.html).
> Is DMA_ATTR_WEAK_ORDERING the same as TX&RX control register in
> 82599?
No.
DMA_ATTR_WEAK_ORDERING applies to the PCIe root complex of the system.
-Tushar
>
> 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 at 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 at 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.dave at 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
>
>
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