From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH net-next] mlx4: optimize xmit path Date: Sat, 27 Sep 2014 15:56:33 -0700 Message-ID: <1411858593.15768.51.camel@edumazet-glaptop2.roam.corp.google.com> References: <1411692382-8898-1-git-send-email-ast@plumgrid.com> <1411694414.16953.70.camel@edumazet-glaptop2.roam.corp.google.com> <1411717322.16953.99.camel@edumazet-glaptop2.roam.corp.google.com> <1411850590.15768.6.camel@edumazet-glaptop2.roam.corp.google.com> <1411853441.15768.13.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Alexei Starovoitov , "David S. Miller" , Jesper Dangaard Brouer , Eric Dumazet , John Fastabend , Linux Netdev List , Amir Vadai , Or Gerlitz To: Or Gerlitz Return-path: Received: from mail-pa0-f42.google.com ([209.85.220.42]:48569 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753178AbaI0W4f (ORCPT ); Sat, 27 Sep 2014 18:56:35 -0400 Received: by mail-pa0-f42.google.com with SMTP id bj1so4741949pad.15 for ; Sat, 27 Sep 2014 15:56:34 -0700 (PDT) In-Reply-To: <1411853441.15768.13.camel@edumazet-glaptop2.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet First I implemented skb->xmit_more support, and pktgen throughput went from ~5Mpps to ~10Mpps. Then, looking closely at this driver I found false sharing problems that should be addressed by this patch, as my pktgen now reaches 14.7 Mpps on a single TX queue, with a burst factor of 8. So this patch in a whole permits to improve raw performance on a single TX queue from about 5 Mpps to 14.7 Mpps. Note that if packets are below the inline_thold threshold (104 bytes), driver copies packets content into tx descriptor, and throughput is lowered to ~7 Mpps : -> We might reconsider inlining strategy in a followup patch. I could split this patch into multiple components, but I prefer not spend days on this work. Lets instead list all changes I did : 1) align struct mlx4_en_tx_info to a cache line 2) add frag0_dma/frag0_byte_count into mlx4_en_tx_info to avoid a cache line miss in TX completion for frames having one dma element. (We avoid reading back the tx descriptor) Note this could be extended to 2/3 dma elements later, as we have free room in mlx4_en_tx_info 3) reorganize struct mlx4_en_tx_ring to have 3.1 - One cache line containing last_nr_txbb & cons, used by tx completion. 3.2 - One cache line containing fields dirtied by mlx4_en_xmit() 3.3 - Following part is read mostly and shared by cpus. 4) struct mlx4_bf @offset field reduced to unsigned int to save space so that the 3.2 part is only 64 bytes, or one cache line on x86. 5) doorbell_qpn is stored in the cpu_to_be32() way to avoid bswap() in fast path 6) mdev->mr.key stored in ring->mr_key to also avoid bswap() and access to cold cache line. 7) mlx4_en_free_tx_desc() no longer accesses skb_shinfo(). We use a new nr_frags fields in mlx4_en_tx_info to avoid 2 or 3 cache misses. 8) mlx4_en_free_tx_desc() uses a prefetchw(&skb->users) to speed up consume_skb() 9) mlx4_en_process_tx_cq() carefully fetches and writes ring->last_nr_txbb & ring->cons only one time to avoid false sharing 10) mlx4_en_xmit() reads ring->cons once, and ahead of time to avoid stalls. 11) prefetchw(&ring->tx_queue->dql) to speed up BQL update 12) properly clears tx_info->ts_requested : This field was never cleared. 13) Support skb->xmit_more to avoid the expensive doorbell 14) reorganize code to call is_inline() once, so compiler can inline it. 15) rename @i variable to @i_frag to avoid confusion, as the "goto tx_drop_unmap;" relied on this @i variable. Signed-off-by: Eric Dumazet --- drivers/net/ethernet/mellanox/mlx4/en_tx.c | 312 ++++++++++------- drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 89 ++-- include/linux/mlx4/device.h | 2 3 files changed, 241 insertions(+), 162 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c index c44f4237b9be..fa29d53860a6 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c @@ -191,12 +191,12 @@ int mlx4_en_activate_tx_ring(struct mlx4_en_priv *priv, ring->prod = 0; ring->cons = 0xffffffff; ring->last_nr_txbb = 1; - ring->poll_cnt = 0; memset(ring->tx_info, 0, ring->size * sizeof(struct mlx4_en_tx_info)); memset(ring->buf, 0, ring->buf_size); ring->qp_state = MLX4_QP_STATE_RST; - ring->doorbell_qpn = ring->qp.qpn << 8; + ring->doorbell_qpn = cpu_to_be32(ring->qp.qpn << 8); + ring->mr_key = cpu_to_be32(mdev->mr.key); mlx4_en_fill_qp_context(priv, ring->size, ring->stride, 1, 0, ring->qpn, ring->cqn, user_prio, &ring->context); @@ -259,38 +259,45 @@ static u32 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv, struct mlx4_en_tx_ring *ring, int index, u8 owner, u64 timestamp) { - struct mlx4_en_dev *mdev = priv->mdev; struct mlx4_en_tx_info *tx_info = &ring->tx_info[index]; struct mlx4_en_tx_desc *tx_desc = ring->buf + index * TXBB_SIZE; struct mlx4_wqe_data_seg *data = (void *) tx_desc + tx_info->data_offset; - struct sk_buff *skb = tx_info->skb; - struct skb_frag_struct *frag; void *end = ring->buf + ring->buf_size; - int frags = skb_shinfo(skb)->nr_frags; + struct sk_buff *skb = tx_info->skb; + int nr_frags = tx_info->nr_frags; int i; - struct skb_shared_hwtstamps hwts; - if (timestamp) { - mlx4_en_fill_hwtstamps(mdev, &hwts, timestamp); + /* We do not touch skb here, so prefetch skb->users location + * to speedup consume_skb() + */ + prefetchw(&skb->users); + + if (unlikely(timestamp)) { + struct skb_shared_hwtstamps hwts; + + mlx4_en_fill_hwtstamps(priv->mdev, &hwts, timestamp); skb_tstamp_tx(skb, &hwts); } /* Optimize the common case when there are no wraparounds */ if (likely((void *) tx_desc + tx_info->nr_txbb * TXBB_SIZE <= end)) { if (!tx_info->inl) { - if (tx_info->linear) { + if (tx_info->linear) dma_unmap_single(priv->ddev, - (dma_addr_t) be64_to_cpu(data->addr), - be32_to_cpu(data->byte_count), - PCI_DMA_TODEVICE); - ++data; - } - - for (i = 0; i < frags; i++) { - frag = &skb_shinfo(skb)->frags[i]; + tx_info->frag0_dma, + tx_info->frag0_byte_count, + PCI_DMA_TODEVICE); + else + dma_unmap_page(priv->ddev, + tx_info->frag0_dma, + tx_info->frag0_byte_count, + PCI_DMA_TODEVICE); + for (i = 1; i < nr_frags; i++) { + data++; dma_unmap_page(priv->ddev, - (dma_addr_t) be64_to_cpu(data[i].addr), - skb_frag_size(frag), PCI_DMA_TODEVICE); + (dma_addr_t)be64_to_cpu(data->addr), + be32_to_cpu(data->byte_count), + PCI_DMA_TODEVICE); } } } else { @@ -299,22 +306,24 @@ static u32 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv, data = ring->buf + ((void *)data - end); } - if (tx_info->linear) { + if (tx_info->linear) dma_unmap_single(priv->ddev, - (dma_addr_t) be64_to_cpu(data->addr), - be32_to_cpu(data->byte_count), - PCI_DMA_TODEVICE); - ++data; - } - - for (i = 0; i < frags; i++) { + tx_info->frag0_dma, + tx_info->frag0_byte_count, + PCI_DMA_TODEVICE); + else + dma_unmap_page(priv->ddev, + tx_info->frag0_dma, + tx_info->frag0_byte_count, + PCI_DMA_TODEVICE); + for (i = 1; i < nr_frags; i++) { /* Check for wraparound before unmapping */ if ((void *) data >= end) data = ring->buf; - frag = &skb_shinfo(skb)->frags[i]; dma_unmap_page(priv->ddev, - (dma_addr_t) be64_to_cpu(data->addr), - skb_frag_size(frag), PCI_DMA_TODEVICE); + (dma_addr_t)be64_to_cpu(data->addr), + be32_to_cpu(data->byte_count), + PCI_DMA_TODEVICE); ++data; } } @@ -377,13 +386,18 @@ static bool mlx4_en_process_tx_cq(struct net_device *dev, u64 timestamp = 0; int done = 0; int budget = priv->tx_work_limit; + u32 last_nr_txbb; + u32 ring_cons; if (!priv->port_up) return true; + prefetchw(&ring->tx_queue->dql.limit); index = cons_index & size_mask; cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor; - ring_index = ring->cons & size_mask; + last_nr_txbb = ACCESS_ONCE(ring->last_nr_txbb); + ring_cons = ACCESS_ONCE(ring->cons); + ring_index = ring_cons & size_mask; stamp_index = ring_index; /* Process all completed CQEs */ @@ -408,19 +422,19 @@ static bool mlx4_en_process_tx_cq(struct net_device *dev, new_index = be16_to_cpu(cqe->wqe_index) & size_mask; do { - txbbs_skipped += ring->last_nr_txbb; - ring_index = (ring_index + ring->last_nr_txbb) & size_mask; + txbbs_skipped += last_nr_txbb; + ring_index = (ring_index + last_nr_txbb) & size_mask; if (ring->tx_info[ring_index].ts_requested) timestamp = mlx4_en_get_cqe_ts(cqe); /* free next descriptor */ - ring->last_nr_txbb = mlx4_en_free_tx_desc( + last_nr_txbb = mlx4_en_free_tx_desc( priv, ring, ring_index, - !!((ring->cons + txbbs_skipped) & + !!((ring_cons + txbbs_skipped) & ring->size), timestamp); mlx4_en_stamp_wqe(priv, ring, stamp_index, - !!((ring->cons + txbbs_stamp) & + !!((ring_cons + txbbs_stamp) & ring->size)); stamp_index = ring_index; txbbs_stamp = txbbs_skipped; @@ -441,7 +455,11 @@ static bool mlx4_en_process_tx_cq(struct net_device *dev, mcq->cons_index = cons_index; mlx4_cq_set_ci(mcq); wmb(); - ring->cons += txbbs_skipped; + + /* we want to dirty this cache line once */ + ACCESS_ONCE(ring->last_nr_txbb) = last_nr_txbb; + ACCESS_ONCE(ring->cons) = ring_cons + txbbs_skipped; + netdev_tx_completed_queue(ring->tx_queue, packets, bytes); /* @@ -512,30 +530,35 @@ static struct mlx4_en_tx_desc *mlx4_en_bounce_to_desc(struct mlx4_en_priv *priv, return ring->buf + index * TXBB_SIZE; } -static int is_inline(int inline_thold, struct sk_buff *skb, void **pfrag) +/* Decide if skb can be inlined in tx descriptor to avoid dma mapping + * + * It seems strange we do not simply use skb_copy_bits(). + * This would allow to inline all skbs iff skb->len <= inline_thold + * + * Note that caller already checked skb was not a gso packet + */ +static bool is_inline(int inline_thold, const struct sk_buff *skb, + const struct skb_shared_info *shinfo, + void **pfrag) { void *ptr; - if (inline_thold && !skb_is_gso(skb) && skb->len <= inline_thold) { - if (skb_shinfo(skb)->nr_frags == 1) { - ptr = skb_frag_address_safe(&skb_shinfo(skb)->frags[0]); - if (unlikely(!ptr)) - return 0; - - if (pfrag) - *pfrag = ptr; + if (skb->len > inline_thold || !inline_thold) + return false; - return 1; - } else if (unlikely(skb_shinfo(skb)->nr_frags)) - return 0; - else - return 1; + if (shinfo->nr_frags == 1) { + ptr = skb_frag_address_safe(&shinfo->frags[0]); + if (unlikely(!ptr)) + return false; + *pfrag = ptr; + return true; } - - return 0; + if (shinfo->nr_frags) + return false; + return true; } -static int inline_size(struct sk_buff *skb) +static int inline_size(const struct sk_buff *skb) { if (skb->len + CTRL_SIZE + sizeof(struct mlx4_wqe_inline_seg) <= MLX4_INLINE_ALIGN) @@ -546,18 +569,23 @@ static int inline_size(struct sk_buff *skb) sizeof(struct mlx4_wqe_inline_seg), 16); } -static int get_real_size(struct sk_buff *skb, struct net_device *dev, - int *lso_header_size) +static int get_real_size(const struct sk_buff *skb, + const struct skb_shared_info *shinfo, + struct net_device *dev, + int *lso_header_size, + bool *inline_ok, + void **pfrag) { struct mlx4_en_priv *priv = netdev_priv(dev); int real_size; - if (skb_is_gso(skb)) { + if (shinfo->gso_size) { + *inline_ok = false; if (skb->encapsulation) *lso_header_size = (skb_inner_transport_header(skb) - skb->data) + inner_tcp_hdrlen(skb); else *lso_header_size = skb_transport_offset(skb) + tcp_hdrlen(skb); - real_size = CTRL_SIZE + skb_shinfo(skb)->nr_frags * DS_SIZE + + real_size = CTRL_SIZE + shinfo->nr_frags * DS_SIZE + ALIGN(*lso_header_size + 4, DS_SIZE); if (unlikely(*lso_header_size != skb_headlen(skb))) { /* We add a segment for the skb linear buffer only if @@ -572,17 +600,24 @@ static int get_real_size(struct sk_buff *skb, struct net_device *dev, } } else { *lso_header_size = 0; - if (!is_inline(priv->prof->inline_thold, skb, NULL)) - real_size = CTRL_SIZE + (skb_shinfo(skb)->nr_frags + 1) * DS_SIZE; - else + *inline_ok = is_inline(priv->prof->inline_thold, skb, + shinfo, pfrag); + + if (*inline_ok) real_size = inline_size(skb); + else + real_size = CTRL_SIZE + + (shinfo->nr_frags + 1) * DS_SIZE; } return real_size; } -static void build_inline_wqe(struct mlx4_en_tx_desc *tx_desc, struct sk_buff *skb, - int real_size, u16 *vlan_tag, int tx_ind, void *fragptr) +static void build_inline_wqe(struct mlx4_en_tx_desc *tx_desc, + const struct sk_buff *skb, + const struct skb_shared_info *shinfo, + int real_size, u16 *vlan_tag, + int tx_ind, void *fragptr) { struct mlx4_wqe_inline_seg *inl = &tx_desc->inl; int spc = MLX4_INLINE_ALIGN - CTRL_SIZE - sizeof *inl; @@ -596,9 +631,9 @@ static void build_inline_wqe(struct mlx4_en_tx_desc *tx_desc, struct sk_buff *sk MIN_PKT_LEN - skb->len); } skb_copy_from_linear_data(skb, inl + 1, skb_headlen(skb)); - if (skb_shinfo(skb)->nr_frags) + if (shinfo->nr_frags) memcpy(((void *)(inl + 1)) + skb_headlen(skb), fragptr, - skb_frag_size(&skb_shinfo(skb)->frags[0])); + skb_frag_size(&shinfo->frags[0])); } else { inl->byte_count = cpu_to_be32(1 << 31 | spc); @@ -616,9 +651,10 @@ static void build_inline_wqe(struct mlx4_en_tx_desc *tx_desc, struct sk_buff *sk inl = (void *) (inl + 1) + spc; skb_copy_from_linear_data_offset(skb, spc, inl + 1, skb_headlen(skb) - spc); - if (skb_shinfo(skb)->nr_frags) + if (shinfo->nr_frags) memcpy(((void *)(inl + 1)) + skb_headlen(skb) - spc, - fragptr, skb_frag_size(&skb_shinfo(skb)->frags[0])); + fragptr, + skb_frag_size(&shinfo->frags[0])); } wmb(); @@ -642,7 +678,8 @@ u16 mlx4_en_select_queue(struct net_device *dev, struct sk_buff *skb, return fallback(dev, skb) % rings_p_up + up * rings_p_up; } -static void mlx4_bf_copy(void __iomem *dst, unsigned long *src, unsigned bytecnt) +static void mlx4_bf_copy(void __iomem *dst, const void *src, + unsigned int bytecnt) { __iowrite64_copy(dst, src, bytecnt / 8); } @@ -663,15 +700,26 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) u32 index, bf_index; __be32 op_own; u16 vlan_tag = 0; - int i; + int i_frag; int lso_header_size; - void *fragptr; + void *fragptr = NULL; bool bounce = false; + bool send_doorbell; + u32 ring_cons; + struct skb_shared_info *shinfo = skb_shinfo(skb); + bool inline_ok; if (!priv->port_up) goto tx_drop; - real_size = get_real_size(skb, dev, &lso_header_size); + tx_ind = skb_get_queue_mapping(skb); + ring = priv->tx_ring[tx_ind]; + + /* fetch ring->cons far ahead before needing it to avoid stall */ + ring_cons = ACCESS_ONCE(ring->cons); + + real_size = get_real_size(skb, shinfo, dev, &lso_header_size, + &inline_ok, &fragptr); if (unlikely(!real_size)) goto tx_drop; @@ -684,13 +732,11 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) goto tx_drop; } - tx_ind = skb->queue_mapping; - ring = priv->tx_ring[tx_ind]; if (vlan_tx_tag_present(skb)) vlan_tag = vlan_tx_tag_get(skb); /* Check available TXBBs And 2K spare for prefetch */ - if (unlikely(((int)(ring->prod - ring->cons)) > + if (unlikely(((int)(ring->prod - ring_cons)) > ring->size - HEADROOM - MAX_DESC_TXBBS)) { /* every full Tx ring stops queue */ netif_tx_stop_queue(ring->tx_queue); @@ -704,7 +750,8 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) */ wmb(); - if (unlikely(((int)(ring->prod - ring->cons)) <= + ring_cons = ACCESS_ONCE(ring->cons); + if (unlikely(((int)(ring->prod - ring_cons)) <= ring->size - HEADROOM - MAX_DESC_TXBBS)) { netif_tx_wake_queue(ring->tx_queue); ring->wake_queue++; @@ -713,9 +760,11 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) } } + prefetchw(&ring->tx_queue->dql); + /* Track current inflight packets for performance analysis */ AVG_PERF_COUNTER(priv->pstats.inflight_avg, - (u32) (ring->prod - ring->cons - 1)); + (u32)(ring->prod - ring_cons - 1)); /* Packet is good - grab an index and transmit it */ index = ring->prod & ring->size_mask; @@ -735,31 +784,34 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) tx_info->skb = skb; tx_info->nr_txbb = nr_txbb; + data = &tx_desc->data; if (lso_header_size) data = ((void *)&tx_desc->lso + ALIGN(lso_header_size + 4, DS_SIZE)); - else - data = &tx_desc->data; /* valid only for none inline segments */ tx_info->data_offset = (void *)data - (void *)tx_desc; + tx_info->inl = inline_ok; + tx_info->linear = (lso_header_size < skb_headlen(skb) && - !is_inline(ring->inline_thold, skb, NULL)) ? 1 : 0; + !inline_ok) ? 1 : 0; - data += skb_shinfo(skb)->nr_frags + tx_info->linear - 1; + tx_info->nr_frags = shinfo->nr_frags + tx_info->linear; + data += tx_info->nr_frags - 1; - if (is_inline(ring->inline_thold, skb, &fragptr)) { - tx_info->inl = 1; - } else { - /* Map fragments */ - for (i = skb_shinfo(skb)->nr_frags - 1; i >= 0; i--) { + if (!tx_info->inl) { + dma_addr_t dma = 0; + u32 byte_count = 0; + + /* Map fragments if any */ + for (i_frag = shinfo->nr_frags - 1; i_frag >= 0; i_frag--) { struct skb_frag_struct *frag; - dma_addr_t dma; - frag = &skb_shinfo(skb)->frags[i]; + frag = &shinfo->frags[i_frag]; + byte_count = skb_frag_size(frag); dma = skb_frag_dma_map(ddev, frag, - 0, skb_frag_size(frag), + 0, byte_count, DMA_TO_DEVICE); if (dma_mapping_error(ddev, dma)) goto tx_drop_unmap; @@ -767,14 +819,13 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) data->addr = cpu_to_be64(dma); data->lkey = cpu_to_be32(mdev->mr.key); wmb(); - data->byte_count = cpu_to_be32(skb_frag_size(frag)); + data->byte_count = cpu_to_be32(byte_count); --data; } - /* Map linear part */ + /* Map linear part if needed */ if (tx_info->linear) { - u32 byte_count = skb_headlen(skb) - lso_header_size; - dma_addr_t dma; + byte_count = skb_headlen(skb) - lso_header_size; dma = dma_map_single(ddev, skb->data + lso_header_size, byte_count, @@ -787,25 +838,24 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) wmb(); data->byte_count = cpu_to_be32(byte_count); } - tx_info->inl = 0; + /* tx completion can avoid cache line miss for common cases */ + tx_info->frag0_dma = dma; + tx_info->frag0_byte_count = byte_count; } /* * For timestamping add flag to skb_shinfo and * set flag for further reference */ - if (ring->hwtstamp_tx_type == HWTSTAMP_TX_ON && - skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) { - skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS; + tx_info->ts_requested = 0; + if (unlikely(ring->hwtstamp_tx_type == HWTSTAMP_TX_ON && + shinfo->tx_flags & SKBTX_HW_TSTAMP)) { + shinfo->tx_flags |= SKBTX_IN_PROGRESS; tx_info->ts_requested = 1; } /* Prepare ctrl segement apart opcode+ownership, which depends on * whether LSO is used */ - tx_desc->ctrl.vlan_tag = cpu_to_be16(vlan_tag); - tx_desc->ctrl.ins_vlan = MLX4_WQE_CTRL_INS_VLAN * - !!vlan_tx_tag_present(skb); - tx_desc->ctrl.fence_size = (real_size / 16) & 0x3f; tx_desc->ctrl.srcrb_flags = priv->ctrl_flags; if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) { tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM | @@ -826,6 +876,8 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) /* Handle LSO (TSO) packets */ if (lso_header_size) { + int i; + /* Mark opcode as LSO */ op_own = cpu_to_be32(MLX4_OPCODE_LSO | (1 << 6)) | ((ring->prod & ring->size) ? @@ -833,15 +885,15 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) /* Fill in the LSO prefix */ tx_desc->lso.mss_hdr_size = cpu_to_be32( - skb_shinfo(skb)->gso_size << 16 | lso_header_size); + shinfo->gso_size << 16 | lso_header_size); /* Copy headers; * note that we already verified that it is linear */ memcpy(tx_desc->lso.header, skb->data, lso_header_size); priv->port_stats.tso_packets++; - i = ((skb->len - lso_header_size) / skb_shinfo(skb)->gso_size) + - !!((skb->len - lso_header_size) % skb_shinfo(skb)->gso_size); + i = ((skb->len - lso_header_size) / shinfo->gso_size) + + !!((skb->len - lso_header_size) % shinfo->gso_size); tx_info->nr_bytes = skb->len + (i - 1) * lso_header_size; ring->packets += i; } else { @@ -851,16 +903,14 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0); tx_info->nr_bytes = max_t(unsigned int, skb->len, ETH_ZLEN); ring->packets++; - } ring->bytes += tx_info->nr_bytes; netdev_tx_sent_queue(ring->tx_queue, tx_info->nr_bytes); AVG_PERF_COUNTER(priv->pstats.tx_pktsz_avg, skb->len); - if (tx_info->inl) { - build_inline_wqe(tx_desc, skb, real_size, &vlan_tag, tx_ind, fragptr); - tx_info->inl = 1; - } + if (tx_info->inl) + build_inline_wqe(tx_desc, skb, shinfo, real_size, + &vlan_tag, tx_ind, fragptr); if (skb->encapsulation) { struct iphdr *ipv4 = (struct iphdr *)skb_inner_network_header(skb); @@ -873,35 +923,53 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) ring->prod += nr_txbb; /* If we used a bounce buffer then copy descriptor back into place */ - if (bounce) + if (unlikely(bounce)) tx_desc = mlx4_en_bounce_to_desc(priv, ring, index, desc_size); skb_tx_timestamp(skb); - if (ring->bf_enabled && desc_size <= MAX_BF && !bounce && !vlan_tx_tag_present(skb)) { - tx_desc->ctrl.bf_qpn |= cpu_to_be32(ring->doorbell_qpn); + real_size = (real_size / 16) & 0x3f; + + send_doorbell = !skb->xmit_more || netif_xmit_stopped(ring->tx_queue); + + if (ring->bf_enabled && desc_size <= MAX_BF && !bounce && + !vlan_tx_tag_present(skb) && send_doorbell) { + tx_desc->ctrl.bf_qpn = ring->doorbell_qpn | + cpu_to_be32(real_size); op_own |= htonl((bf_index & 0xffff) << 8); - /* Ensure new descirptor hits memory - * before setting ownership of this descriptor to HW */ + /* Ensure new descriptor hits memory + * before setting ownership of this descriptor to HW + */ wmb(); tx_desc->ctrl.owner_opcode = op_own; wmb(); - mlx4_bf_copy(ring->bf.reg + ring->bf.offset, (unsigned long *) &tx_desc->ctrl, - desc_size); + mlx4_bf_copy(ring->bf.reg + ring->bf.offset, + &tx_desc->ctrl, + desc_size); wmb(); ring->bf.offset ^= ring->bf.buf_size; } else { - /* Ensure new descirptor hits memory - * before setting ownership of this descriptor to HW */ + tx_desc->ctrl.vlan_tag = cpu_to_be16(vlan_tag); + tx_desc->ctrl.ins_vlan = MLX4_WQE_CTRL_INS_VLAN * + !!vlan_tx_tag_present(skb); + tx_desc->ctrl.fence_size = real_size; + + /* Ensure new descriptor hits memory + * before setting ownership of this descriptor to HW + */ wmb(); tx_desc->ctrl.owner_opcode = op_own; - wmb(); - iowrite32be(ring->doorbell_qpn, ring->bf.uar->map + MLX4_SEND_DOORBELL); + + if (send_doorbell) { + wmb(); /* ensure owner_opcode is written */ + iowrite32(ring->doorbell_qpn, + ring->bf.uar->map + MLX4_SEND_DOORBELL); + } } return NETDEV_TX_OK; @@ -909,8 +977,8 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) tx_drop_unmap: en_err(priv, "DMA mapping error\n"); - for (i++; i < skb_shinfo(skb)->nr_frags; i++) { - data++; + while (++i_frag < shinfo->nr_frags) { + ++data; dma_unmap_page(ddev, (dma_addr_t) be64_to_cpu(data->addr), be32_to_cpu(data->byte_count), PCI_DMA_TODEVICE); diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h index 6a4fc2394cf2..8025e3c0b14e 100644 --- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h +++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h @@ -216,13 +216,16 @@ enum cq_type { struct mlx4_en_tx_info { struct sk_buff *skb; - u32 nr_txbb; - u32 nr_bytes; - u8 linear; - u8 data_offset; - u8 inl; - u8 ts_requested; -}; + dma_addr_t frag0_dma; + u32 frag0_byte_count; + u32 nr_txbb; + u32 nr_bytes; + u8 linear; + u8 data_offset; + u8 inl; + u8 ts_requested; + u8 nr_frags; +} ____cacheline_aligned_in_smp; #define MLX4_EN_BIT_DESC_OWN 0x80000000 @@ -253,39 +256,47 @@ struct mlx4_en_rx_alloc { }; struct mlx4_en_tx_ring { + /* cache line used and dirtied in tx completion + * (mlx4_en_free_tx_buf()) + */ + u32 last_nr_txbb; + u32 cons; + + /* cache line used and dirtied in mlx4_en_xmit() + */ + u32 prod ____cacheline_aligned_in_smp; + unsigned long bytes; + unsigned long packets; + unsigned long tx_csum; + struct mlx4_bf bf; + unsigned long queue_stopped; + unsigned long wake_queue; + + /* Following part should be mostly read + */ + cpumask_t affinity_mask; + struct mlx4_qp qp; struct mlx4_hwq_resources wqres; - u32 size ; /* number of TXBBs */ - u32 size_mask; - u16 stride; - u16 cqn; /* index of port CQ associated with this ring */ - u32 prod; - u32 cons; - u32 buf_size; - u32 doorbell_qpn; - void *buf; - u16 poll_cnt; - struct mlx4_en_tx_info *tx_info; - u8 *bounce_buf; - u8 queue_index; - cpumask_t affinity_mask; - u32 last_nr_txbb; - struct mlx4_qp qp; - struct mlx4_qp_context context; - int qpn; - enum mlx4_qp_state qp_state; - struct mlx4_srq dummy; - unsigned long bytes; - unsigned long packets; - unsigned long tx_csum; - unsigned long queue_stopped; - unsigned long wake_queue; - struct mlx4_bf bf; - bool bf_enabled; - bool bf_alloced; - struct netdev_queue *tx_queue; - int hwtstamp_tx_type; - int inline_thold; -}; + u32 size ; /* number of TXBBs */ + u32 size_mask; + u16 stride; + u16 cqn; /* index of port CQ associated with this ring */ + u32 buf_size; + __be32 doorbell_qpn; + __be32 mr_key; + void *buf; + struct mlx4_en_tx_info *tx_info; + u8 *bounce_buf; + struct mlx4_qp_context context; + int qpn; + enum mlx4_qp_state qp_state; + u8 queue_index; + bool bf_enabled; + bool bf_alloced; + struct netdev_queue *tx_queue; + int hwtstamp_tx_type; + int inline_thold; +} ____cacheline_aligned_in_smp; struct mlx4_en_rx_desc { /* actual number of entries depends on rx ring stride */ diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h index 03b5608a4329..5e5ad07548b8 100644 --- a/include/linux/mlx4/device.h +++ b/include/linux/mlx4/device.h @@ -583,7 +583,7 @@ struct mlx4_uar { }; struct mlx4_bf { - unsigned long offset; + unsigned int offset; int buf_size; struct mlx4_uar *uar; void __iomem *reg;