Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / net / ethernet / mellanox / mlx4 / en_tx.c
diff --git a/kernel/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/kernel/drivers/net/ethernet/mellanox/mlx4/en_tx.c
new file mode 100644 (file)
index 0000000..c10d98f
--- /dev/null
@@ -0,0 +1,1021 @@
+/*
+ * Copyright (c) 2007 Mellanox Technologies. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+
+#include <asm/page.h>
+#include <linux/mlx4/cq.h>
+#include <linux/slab.h>
+#include <linux/mlx4/qp.h>
+#include <linux/skbuff.h>
+#include <linux/if_vlan.h>
+#include <linux/prefetch.h>
+#include <linux/vmalloc.h>
+#include <linux/tcp.h>
+#include <linux/ip.h>
+#include <linux/moduleparam.h>
+
+#include "mlx4_en.h"
+
+int mlx4_en_create_tx_ring(struct mlx4_en_priv *priv,
+                          struct mlx4_en_tx_ring **pring, u32 size,
+                          u16 stride, int node, int queue_index)
+{
+       struct mlx4_en_dev *mdev = priv->mdev;
+       struct mlx4_en_tx_ring *ring;
+       int tmp;
+       int err;
+
+       ring = kzalloc_node(sizeof(*ring), GFP_KERNEL, node);
+       if (!ring) {
+               ring = kzalloc(sizeof(*ring), GFP_KERNEL);
+               if (!ring) {
+                       en_err(priv, "Failed allocating TX ring\n");
+                       return -ENOMEM;
+               }
+       }
+
+       ring->size = size;
+       ring->size_mask = size - 1;
+       ring->stride = stride;
+       ring->full_size = ring->size - HEADROOM - MAX_DESC_TXBBS;
+
+       tmp = size * sizeof(struct mlx4_en_tx_info);
+       ring->tx_info = kmalloc_node(tmp, GFP_KERNEL | __GFP_NOWARN, node);
+       if (!ring->tx_info) {
+               ring->tx_info = vmalloc(tmp);
+               if (!ring->tx_info) {
+                       err = -ENOMEM;
+                       goto err_ring;
+               }
+       }
+
+       en_dbg(DRV, priv, "Allocated tx_info ring at addr:%p size:%d\n",
+                ring->tx_info, tmp);
+
+       ring->bounce_buf = kmalloc_node(MAX_DESC_SIZE, GFP_KERNEL, node);
+       if (!ring->bounce_buf) {
+               ring->bounce_buf = kmalloc(MAX_DESC_SIZE, GFP_KERNEL);
+               if (!ring->bounce_buf) {
+                       err = -ENOMEM;
+                       goto err_info;
+               }
+       }
+       ring->buf_size = ALIGN(size * ring->stride, MLX4_EN_PAGE_SIZE);
+
+       /* Allocate HW buffers on provided NUMA node */
+       set_dev_node(&mdev->dev->persist->pdev->dev, node);
+       err = mlx4_alloc_hwq_res(mdev->dev, &ring->wqres, ring->buf_size,
+                                2 * PAGE_SIZE);
+       set_dev_node(&mdev->dev->persist->pdev->dev, mdev->dev->numa_node);
+       if (err) {
+               en_err(priv, "Failed allocating hwq resources\n");
+               goto err_bounce;
+       }
+
+       err = mlx4_en_map_buffer(&ring->wqres.buf);
+       if (err) {
+               en_err(priv, "Failed to map TX buffer\n");
+               goto err_hwq_res;
+       }
+
+       ring->buf = ring->wqres.buf.direct.buf;
+
+       en_dbg(DRV, priv, "Allocated TX ring (addr:%p) - buf:%p size:%d buf_size:%d dma:%llx\n",
+              ring, ring->buf, ring->size, ring->buf_size,
+              (unsigned long long) ring->wqres.buf.direct.map);
+
+       err = mlx4_qp_reserve_range(mdev->dev, 1, 1, &ring->qpn,
+                                   MLX4_RESERVE_ETH_BF_QP);
+       if (err) {
+               en_err(priv, "failed reserving qp for TX ring\n");
+               goto err_map;
+       }
+
+       err = mlx4_qp_alloc(mdev->dev, ring->qpn, &ring->qp, GFP_KERNEL);
+       if (err) {
+               en_err(priv, "Failed allocating qp %d\n", ring->qpn);
+               goto err_reserve;
+       }
+       ring->qp.event = mlx4_en_sqp_event;
+
+       err = mlx4_bf_alloc(mdev->dev, &ring->bf, node);
+       if (err) {
+               en_dbg(DRV, priv, "working without blueflame (%d)\n", err);
+               ring->bf.uar = &mdev->priv_uar;
+               ring->bf.uar->map = mdev->uar_map;
+               ring->bf_enabled = false;
+               ring->bf_alloced = false;
+               priv->pflags &= ~MLX4_EN_PRIV_FLAGS_BLUEFLAME;
+       } else {
+               ring->bf_alloced = true;
+               ring->bf_enabled = !!(priv->pflags &
+                                     MLX4_EN_PRIV_FLAGS_BLUEFLAME);
+       }
+
+       ring->hwtstamp_tx_type = priv->hwtstamp_config.tx_type;
+       ring->queue_index = queue_index;
+
+       if (queue_index < priv->num_tx_rings_p_up)
+               cpumask_set_cpu(cpumask_local_spread(queue_index,
+                                                    priv->mdev->dev->numa_node),
+                               &ring->affinity_mask);
+
+       *pring = ring;
+       return 0;
+
+err_reserve:
+       mlx4_qp_release_range(mdev->dev, ring->qpn, 1);
+err_map:
+       mlx4_en_unmap_buffer(&ring->wqres.buf);
+err_hwq_res:
+       mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
+err_bounce:
+       kfree(ring->bounce_buf);
+       ring->bounce_buf = NULL;
+err_info:
+       kvfree(ring->tx_info);
+       ring->tx_info = NULL;
+err_ring:
+       kfree(ring);
+       *pring = NULL;
+       return err;
+}
+
+void mlx4_en_destroy_tx_ring(struct mlx4_en_priv *priv,
+                            struct mlx4_en_tx_ring **pring)
+{
+       struct mlx4_en_dev *mdev = priv->mdev;
+       struct mlx4_en_tx_ring *ring = *pring;
+       en_dbg(DRV, priv, "Destroying tx ring, qpn: %d\n", ring->qpn);
+
+       if (ring->bf_alloced)
+               mlx4_bf_free(mdev->dev, &ring->bf);
+       mlx4_qp_remove(mdev->dev, &ring->qp);
+       mlx4_qp_free(mdev->dev, &ring->qp);
+       mlx4_qp_release_range(priv->mdev->dev, ring->qpn, 1);
+       mlx4_en_unmap_buffer(&ring->wqres.buf);
+       mlx4_free_hwq_res(mdev->dev, &ring->wqres, ring->buf_size);
+       kfree(ring->bounce_buf);
+       ring->bounce_buf = NULL;
+       kvfree(ring->tx_info);
+       ring->tx_info = NULL;
+       kfree(ring);
+       *pring = NULL;
+}
+
+int mlx4_en_activate_tx_ring(struct mlx4_en_priv *priv,
+                            struct mlx4_en_tx_ring *ring,
+                            int cq, int user_prio)
+{
+       struct mlx4_en_dev *mdev = priv->mdev;
+       int err;
+
+       ring->cqn = cq;
+       ring->prod = 0;
+       ring->cons = 0xffffffff;
+       ring->last_nr_txbb = 1;
+       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 = 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);
+       if (ring->bf_alloced)
+               ring->context.usr_page = cpu_to_be32(ring->bf.uar->index);
+
+       err = mlx4_qp_to_ready(mdev->dev, &ring->wqres.mtt, &ring->context,
+                              &ring->qp, &ring->qp_state);
+       if (!cpumask_empty(&ring->affinity_mask))
+               netif_set_xps_queue(priv->dev, &ring->affinity_mask,
+                                   ring->queue_index);
+
+       return err;
+}
+
+void mlx4_en_deactivate_tx_ring(struct mlx4_en_priv *priv,
+                               struct mlx4_en_tx_ring *ring)
+{
+       struct mlx4_en_dev *mdev = priv->mdev;
+
+       mlx4_qp_modify(mdev->dev, NULL, ring->qp_state,
+                      MLX4_QP_STATE_RST, NULL, 0, 0, &ring->qp);
+}
+
+static inline bool mlx4_en_is_tx_ring_full(struct mlx4_en_tx_ring *ring)
+{
+       return ring->prod - ring->cons > ring->full_size;
+}
+
+static void mlx4_en_stamp_wqe(struct mlx4_en_priv *priv,
+                             struct mlx4_en_tx_ring *ring, int index,
+                             u8 owner)
+{
+       __be32 stamp = cpu_to_be32(STAMP_VAL | (!!owner << STAMP_SHIFT));
+       struct mlx4_en_tx_desc *tx_desc = ring->buf + index * TXBB_SIZE;
+       struct mlx4_en_tx_info *tx_info = &ring->tx_info[index];
+       void *end = ring->buf + ring->buf_size;
+       __be32 *ptr = (__be32 *)tx_desc;
+       int i;
+
+       /* Optimize the common case when there are no wraparounds */
+       if (likely((void *)tx_desc + tx_info->nr_txbb * TXBB_SIZE <= end)) {
+               /* Stamp the freed descriptor */
+               for (i = 0; i < tx_info->nr_txbb * TXBB_SIZE;
+                    i += STAMP_STRIDE) {
+                       *ptr = stamp;
+                       ptr += STAMP_DWORDS;
+               }
+       } else {
+               /* Stamp the freed descriptor */
+               for (i = 0; i < tx_info->nr_txbb * TXBB_SIZE;
+                    i += STAMP_STRIDE) {
+                       *ptr = stamp;
+                       ptr += STAMP_DWORDS;
+                       if ((void *)ptr >= end) {
+                               ptr = ring->buf;
+                               stamp ^= cpu_to_be32(0x80000000);
+                       }
+               }
+       }
+}
+
+
+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_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;
+       void *end = ring->buf + ring->buf_size;
+       struct sk_buff *skb = tx_info->skb;
+       int nr_maps = tx_info->nr_maps;
+       int i;
+
+       /* 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)
+                               dma_unmap_single(priv->ddev,
+                                               tx_info->map0_dma,
+                                               tx_info->map0_byte_count,
+                                               PCI_DMA_TODEVICE);
+                       else
+                               dma_unmap_page(priv->ddev,
+                                              tx_info->map0_dma,
+                                              tx_info->map0_byte_count,
+                                              PCI_DMA_TODEVICE);
+                       for (i = 1; i < nr_maps; i++) {
+                               data++;
+                               dma_unmap_page(priv->ddev,
+                                       (dma_addr_t)be64_to_cpu(data->addr),
+                                       be32_to_cpu(data->byte_count),
+                                       PCI_DMA_TODEVICE);
+                       }
+               }
+       } else {
+               if (!tx_info->inl) {
+                       if ((void *) data >= end) {
+                               data = ring->buf + ((void *)data - end);
+                       }
+
+                       if (tx_info->linear)
+                               dma_unmap_single(priv->ddev,
+                                               tx_info->map0_dma,
+                                               tx_info->map0_byte_count,
+                                               PCI_DMA_TODEVICE);
+                       else
+                               dma_unmap_page(priv->ddev,
+                                              tx_info->map0_dma,
+                                              tx_info->map0_byte_count,
+                                              PCI_DMA_TODEVICE);
+                       for (i = 1; i < nr_maps; i++) {
+                               data++;
+                               /* Check for wraparound before unmapping */
+                               if ((void *) data >= end)
+                                       data = ring->buf;
+                               dma_unmap_page(priv->ddev,
+                                       (dma_addr_t)be64_to_cpu(data->addr),
+                                       be32_to_cpu(data->byte_count),
+                                       PCI_DMA_TODEVICE);
+                       }
+               }
+       }
+       dev_consume_skb_any(skb);
+       return tx_info->nr_txbb;
+}
+
+
+int mlx4_en_free_tx_buf(struct net_device *dev, struct mlx4_en_tx_ring *ring)
+{
+       struct mlx4_en_priv *priv = netdev_priv(dev);
+       int cnt = 0;
+
+       /* Skip last polled descriptor */
+       ring->cons += ring->last_nr_txbb;
+       en_dbg(DRV, priv, "Freeing Tx buf - cons:0x%x prod:0x%x\n",
+                ring->cons, ring->prod);
+
+       if ((u32) (ring->prod - ring->cons) > ring->size) {
+               if (netif_msg_tx_err(priv))
+                       en_warn(priv, "Tx consumer passed producer!\n");
+               return 0;
+       }
+
+       while (ring->cons != ring->prod) {
+               ring->last_nr_txbb = mlx4_en_free_tx_desc(priv, ring,
+                                               ring->cons & ring->size_mask,
+                                               !!(ring->cons & ring->size), 0);
+               ring->cons += ring->last_nr_txbb;
+               cnt++;
+       }
+
+       netdev_tx_reset_queue(ring->tx_queue);
+
+       if (cnt)
+               en_dbg(DRV, priv, "Freed %d uncompleted tx descriptors\n", cnt);
+
+       return cnt;
+}
+
+static bool mlx4_en_process_tx_cq(struct net_device *dev,
+                                struct mlx4_en_cq *cq)
+{
+       struct mlx4_en_priv *priv = netdev_priv(dev);
+       struct mlx4_cq *mcq = &cq->mcq;
+       struct mlx4_en_tx_ring *ring = priv->tx_ring[cq->ring];
+       struct mlx4_cqe *cqe;
+       u16 index;
+       u16 new_index, ring_index, stamp_index;
+       u32 txbbs_skipped = 0;
+       u32 txbbs_stamp = 0;
+       u32 cons_index = mcq->cons_index;
+       int size = cq->size;
+       u32 size_mask = ring->size_mask;
+       struct mlx4_cqe *buf = cq->buf;
+       u32 packets = 0;
+       u32 bytes = 0;
+       int factor = priv->cqe_factor;
+       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;
+
+       netdev_txq_bql_complete_prefetchw(ring->tx_queue);
+
+       index = cons_index & size_mask;
+       cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor;
+       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 */
+       while (XNOR(cqe->owner_sr_opcode & MLX4_CQE_OWNER_MASK,
+                       cons_index & size) && (done < budget)) {
+               /*
+                * make sure we read the CQE after we read the
+                * ownership bit
+                */
+               dma_rmb();
+
+               if (unlikely((cqe->owner_sr_opcode & MLX4_CQE_OPCODE_MASK) ==
+                            MLX4_CQE_OPCODE_ERROR)) {
+                       struct mlx4_err_cqe *cqe_err = (struct mlx4_err_cqe *)cqe;
+
+                       en_err(priv, "CQE error - vendor syndrome: 0x%x syndrome: 0x%x\n",
+                              cqe_err->vendor_err_syndrome,
+                              cqe_err->syndrome);
+               }
+
+               /* Skip over last polled CQE */
+               new_index = be16_to_cpu(cqe->wqe_index) & size_mask;
+
+               do {
+                       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 */
+                       last_nr_txbb = mlx4_en_free_tx_desc(
+                                       priv, ring, ring_index,
+                                       !!((ring_cons + txbbs_skipped) &
+                                       ring->size), timestamp);
+
+                       mlx4_en_stamp_wqe(priv, ring, stamp_index,
+                                         !!((ring_cons + txbbs_stamp) &
+                                               ring->size));
+                       stamp_index = ring_index;
+                       txbbs_stamp = txbbs_skipped;
+                       packets++;
+                       bytes += ring->tx_info[ring_index].nr_bytes;
+               } while ((++done < budget) && (ring_index != new_index));
+
+               ++cons_index;
+               index = cons_index & size_mask;
+               cqe = mlx4_en_get_cqe(buf, index, priv->cqe_size) + factor;
+       }
+
+
+       /*
+        * To prevent CQ overflow we first update CQ consumer and only then
+        * the ring consumer.
+        */
+       mcq->cons_index = cons_index;
+       mlx4_cq_set_ci(mcq);
+       wmb();
+
+       /* 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);
+
+       /* Wakeup Tx queue if this stopped, and ring is not full.
+        */
+       if (netif_tx_queue_stopped(ring->tx_queue) &&
+           !mlx4_en_is_tx_ring_full(ring)) {
+               netif_tx_wake_queue(ring->tx_queue);
+               ring->wake_queue++;
+       }
+       return done < budget;
+}
+
+void mlx4_en_tx_irq(struct mlx4_cq *mcq)
+{
+       struct mlx4_en_cq *cq = container_of(mcq, struct mlx4_en_cq, mcq);
+       struct mlx4_en_priv *priv = netdev_priv(cq->dev);
+
+       if (likely(priv->port_up))
+               napi_schedule_irqoff(&cq->napi);
+       else
+               mlx4_en_arm_cq(priv, cq);
+}
+
+/* TX CQ polling - called by NAPI */
+int mlx4_en_poll_tx_cq(struct napi_struct *napi, int budget)
+{
+       struct mlx4_en_cq *cq = container_of(napi, struct mlx4_en_cq, napi);
+       struct net_device *dev = cq->dev;
+       struct mlx4_en_priv *priv = netdev_priv(dev);
+       int clean_complete;
+
+       clean_complete = mlx4_en_process_tx_cq(dev, cq);
+       if (!clean_complete)
+               return budget;
+
+       napi_complete(napi);
+       mlx4_en_arm_cq(priv, cq);
+
+       return 0;
+}
+
+static struct mlx4_en_tx_desc *mlx4_en_bounce_to_desc(struct mlx4_en_priv *priv,
+                                                     struct mlx4_en_tx_ring *ring,
+                                                     u32 index,
+                                                     unsigned int desc_size)
+{
+       u32 copy = (ring->size - index) * TXBB_SIZE;
+       int i;
+
+       for (i = desc_size - copy - 4; i >= 0; i -= 4) {
+               if ((i & (TXBB_SIZE - 1)) == 0)
+                       wmb();
+
+               *((u32 *) (ring->buf + i)) =
+                       *((u32 *) (ring->bounce_buf + copy + i));
+       }
+
+       for (i = copy - 4; i >= 4 ; i -= 4) {
+               if ((i & (TXBB_SIZE - 1)) == 0)
+                       wmb();
+
+               *((u32 *) (ring->buf + index * TXBB_SIZE + i)) =
+                       *((u32 *) (ring->bounce_buf + i));
+       }
+
+       /* Return real descriptor location */
+       return ring->buf + index * TXBB_SIZE;
+}
+
+/* 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 (skb->len > inline_thold || !inline_thold)
+               return false;
+
+       if (shinfo->nr_frags == 1) {
+               ptr = skb_frag_address_safe(&shinfo->frags[0]);
+               if (unlikely(!ptr))
+                       return false;
+               *pfrag = ptr;
+               return true;
+       }
+       if (shinfo->nr_frags)
+               return false;
+       return true;
+}
+
+static int inline_size(const struct sk_buff *skb)
+{
+       if (skb->len + CTRL_SIZE + sizeof(struct mlx4_wqe_inline_seg)
+           <= MLX4_INLINE_ALIGN)
+               return ALIGN(skb->len + CTRL_SIZE +
+                            sizeof(struct mlx4_wqe_inline_seg), 16);
+       else
+               return ALIGN(skb->len + CTRL_SIZE + 2 *
+                            sizeof(struct mlx4_wqe_inline_seg), 16);
+}
+
+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 (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 + 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
+                        * it contains data */
+                       if (*lso_header_size < skb_headlen(skb))
+                               real_size += DS_SIZE;
+                       else {
+                               if (netif_msg_tx_err(priv))
+                                       en_warn(priv, "Non-linear headers\n");
+                               return 0;
+                       }
+               }
+       } else {
+               *lso_header_size = 0;
+               *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,
+                            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;
+       unsigned int hlen = skb_headlen(skb);
+
+       if (skb->len <= spc) {
+               if (likely(skb->len >= MIN_PKT_LEN)) {
+                       inl->byte_count = cpu_to_be32(1 << 31 | skb->len);
+               } else {
+                       inl->byte_count = cpu_to_be32(1 << 31 | MIN_PKT_LEN);
+                       memset(((void *)(inl + 1)) + skb->len, 0,
+                              MIN_PKT_LEN - skb->len);
+               }
+               skb_copy_from_linear_data(skb, inl + 1, hlen);
+               if (shinfo->nr_frags)
+                       memcpy(((void *)(inl + 1)) + hlen, fragptr,
+                              skb_frag_size(&shinfo->frags[0]));
+
+       } else {
+               inl->byte_count = cpu_to_be32(1 << 31 | spc);
+               if (hlen <= spc) {
+                       skb_copy_from_linear_data(skb, inl + 1, hlen);
+                       if (hlen < spc) {
+                               memcpy(((void *)(inl + 1)) + hlen,
+                                      fragptr, spc - hlen);
+                               fragptr +=  spc - hlen;
+                       }
+                       inl = (void *) (inl + 1) + spc;
+                       memcpy(((void *)(inl + 1)), fragptr, skb->len - spc);
+               } else {
+                       skb_copy_from_linear_data(skb, inl + 1, spc);
+                       inl = (void *) (inl + 1) + spc;
+                       skb_copy_from_linear_data_offset(skb, spc, inl + 1,
+                                                        hlen - spc);
+                       if (shinfo->nr_frags)
+                               memcpy(((void *)(inl + 1)) + hlen - spc,
+                                      fragptr,
+                                      skb_frag_size(&shinfo->frags[0]));
+               }
+
+               dma_wmb();
+               inl->byte_count = cpu_to_be32(1 << 31 | (skb->len - spc));
+       }
+}
+
+u16 mlx4_en_select_queue(struct net_device *dev, struct sk_buff *skb,
+                        void *accel_priv, select_queue_fallback_t fallback)
+{
+       struct mlx4_en_priv *priv = netdev_priv(dev);
+       u16 rings_p_up = priv->num_tx_rings_p_up;
+       u8 up = 0;
+
+       if (dev->num_tc)
+               return skb_tx_hash(dev, skb);
+
+       if (skb_vlan_tag_present(skb))
+               up = skb_vlan_tag_get(skb) >> VLAN_PRIO_SHIFT;
+
+       return fallback(dev, skb) % rings_p_up + up * rings_p_up;
+}
+
+static void mlx4_bf_copy(void __iomem *dst, const void *src,
+                        unsigned int bytecnt)
+{
+       __iowrite64_copy(dst, src, bytecnt / 8);
+}
+
+netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+       struct skb_shared_info *shinfo = skb_shinfo(skb);
+       struct mlx4_en_priv *priv = netdev_priv(dev);
+       struct device *ddev = priv->ddev;
+       struct mlx4_en_tx_ring *ring;
+       struct mlx4_en_tx_desc *tx_desc;
+       struct mlx4_wqe_data_seg *data;
+       struct mlx4_en_tx_info *tx_info;
+       int tx_ind = 0;
+       int nr_txbb;
+       int desc_size;
+       int real_size;
+       u32 index, bf_index;
+       __be32 op_own;
+       u16 vlan_tag = 0;
+       int i_frag;
+       int lso_header_size;
+       void *fragptr = NULL;
+       bool bounce = false;
+       bool send_doorbell;
+       bool stop_queue;
+       bool inline_ok;
+       u32 ring_cons;
+
+       if (!priv->port_up)
+               goto tx_drop;
+
+       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;
+
+       /* Align descriptor to TXBB size */
+       desc_size = ALIGN(real_size, TXBB_SIZE);
+       nr_txbb = desc_size / TXBB_SIZE;
+       if (unlikely(nr_txbb > MAX_DESC_TXBBS)) {
+               if (netif_msg_tx_err(priv))
+                       en_warn(priv, "Oversized header or SG list\n");
+               goto tx_drop;
+       }
+
+       if (skb_vlan_tag_present(skb))
+               vlan_tag = skb_vlan_tag_get(skb);
+
+
+       netdev_txq_bql_enqueue_prefetchw(ring->tx_queue);
+
+       /* Track current inflight packets for performance analysis */
+       AVG_PERF_COUNTER(priv->pstats.inflight_avg,
+                        (u32)(ring->prod - ring_cons - 1));
+
+       /* Packet is good - grab an index and transmit it */
+       index = ring->prod & ring->size_mask;
+       bf_index = ring->prod;
+
+       /* See if we have enough space for whole descriptor TXBB for setting
+        * SW ownership on next descriptor; if not, use a bounce buffer. */
+       if (likely(index + nr_txbb <= ring->size))
+               tx_desc = ring->buf + index * TXBB_SIZE;
+       else {
+               tx_desc = (struct mlx4_en_tx_desc *) ring->bounce_buf;
+               bounce = true;
+       }
+
+       /* Save skb in tx_info ring */
+       tx_info = &ring->tx_info[index];
+       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));
+
+       /* 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) &&
+                          !inline_ok) ? 1 : 0;
+
+       tx_info->nr_maps = shinfo->nr_frags + tx_info->linear;
+       data += tx_info->nr_maps - 1;
+
+       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--) {
+                       const struct skb_frag_struct *frag;
+
+                       frag = &shinfo->frags[i_frag];
+                       byte_count = skb_frag_size(frag);
+                       dma = skb_frag_dma_map(ddev, frag,
+                                              0, byte_count,
+                                              DMA_TO_DEVICE);
+                       if (dma_mapping_error(ddev, dma))
+                               goto tx_drop_unmap;
+
+                       data->addr = cpu_to_be64(dma);
+                       data->lkey = ring->mr_key;
+                       dma_wmb();
+                       data->byte_count = cpu_to_be32(byte_count);
+                       --data;
+               }
+
+               /* Map linear part if needed */
+               if (tx_info->linear) {
+                       byte_count = skb_headlen(skb) - lso_header_size;
+
+                       dma = dma_map_single(ddev, skb->data +
+                                            lso_header_size, byte_count,
+                                            PCI_DMA_TODEVICE);
+                       if (dma_mapping_error(ddev, dma))
+                               goto tx_drop_unmap;
+
+                       data->addr = cpu_to_be64(dma);
+                       data->lkey = ring->mr_key;
+                       dma_wmb();
+                       data->byte_count = cpu_to_be32(byte_count);
+               }
+               /* tx completion can avoid cache line miss for common cases */
+               tx_info->map0_dma = dma;
+               tx_info->map0_byte_count = byte_count;
+       }
+
+       /*
+        * For timestamping add flag to skb_shinfo and
+        * set flag for further reference
+        */
+       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.srcrb_flags = priv->ctrl_flags;
+       if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
+               if (!skb->encapsulation)
+                       tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM |
+                                                                MLX4_WQE_CTRL_TCP_UDP_CSUM);
+               else
+                       tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM);
+               ring->tx_csum++;
+       }
+
+       if (priv->flags & MLX4_EN_FLAG_ENABLE_HW_LOOPBACK) {
+               struct ethhdr *ethh;
+
+               /* Copy dst mac address to wqe. This allows loopback in eSwitch,
+                * so that VFs and PF can communicate with each other
+                */
+               ethh = (struct ethhdr *)skb->data;
+               tx_desc->ctrl.srcrb_flags16[0] = get_unaligned((__be16 *)ethh->h_dest);
+               tx_desc->ctrl.imm = get_unaligned((__be32 *)(ethh->h_dest + 2));
+       }
+
+       /* 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) ?
+                               cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
+
+               /* Fill in the LSO prefix */
+               tx_desc->lso.mss_hdr_size = cpu_to_be32(
+                       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);
+
+               ring->tso_packets++;
+
+               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 {
+               /* Normal (Non LSO) packet */
+               op_own = cpu_to_be32(MLX4_OPCODE_SEND) |
+                       ((ring->prod & ring->size) ?
+                        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, shinfo, real_size, &vlan_tag,
+                                tx_ind, fragptr);
+
+       if (skb->encapsulation) {
+               struct iphdr *ipv4 = (struct iphdr *)skb_inner_network_header(skb);
+               if (ipv4->protocol == IPPROTO_TCP || ipv4->protocol == IPPROTO_UDP)
+                       op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP | MLX4_WQE_CTRL_ILP);
+               else
+                       op_own |= cpu_to_be32(MLX4_WQE_CTRL_IIP);
+       }
+
+       ring->prod += nr_txbb;
+
+       /* If we used a bounce buffer then copy descriptor back into place */
+       if (unlikely(bounce))
+               tx_desc = mlx4_en_bounce_to_desc(priv, ring, index, desc_size);
+
+       skb_tx_timestamp(skb);
+
+       /* Check available TXBBs And 2K spare for prefetch */
+       stop_queue = mlx4_en_is_tx_ring_full(ring);
+       if (unlikely(stop_queue)) {
+               netif_tx_stop_queue(ring->tx_queue);
+               ring->queue_stopped++;
+       }
+       send_doorbell = !skb->xmit_more || netif_xmit_stopped(ring->tx_queue);
+
+       real_size = (real_size / 16) & 0x3f;
+
+       if (ring->bf_enabled && desc_size <= MAX_BF && !bounce &&
+           !skb_vlan_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 descriptor hits memory
+                * before setting ownership of this descriptor to HW
+                */
+               dma_wmb();
+               tx_desc->ctrl.owner_opcode = op_own;
+
+               wmb();
+
+               mlx4_bf_copy(ring->bf.reg + ring->bf.offset, &tx_desc->ctrl,
+                            desc_size);
+
+               wmb();
+
+               ring->bf.offset ^= ring->bf.buf_size;
+       } else {
+               tx_desc->ctrl.vlan_tag = cpu_to_be16(vlan_tag);
+               tx_desc->ctrl.ins_vlan = MLX4_WQE_CTRL_INS_VLAN *
+                       !!skb_vlan_tag_present(skb);
+               tx_desc->ctrl.fence_size = real_size;
+
+               /* Ensure new descriptor hits memory
+                * before setting ownership of this descriptor to HW
+                */
+               dma_wmb();
+               tx_desc->ctrl.owner_opcode = op_own;
+               if (send_doorbell) {
+                       wmb();
+                       /* Since there is no iowrite*_native() that writes the
+                        * value as is, without byteswapping - using the one
+                        * the doesn't do byteswapping in the relevant arch
+                        * endianness.
+                        */
+#if defined(__LITTLE_ENDIAN)
+                       iowrite32(
+#else
+                       iowrite32be(
+#endif
+                                 ring->doorbell_qpn,
+                                 ring->bf.uar->map + MLX4_SEND_DOORBELL);
+               } else {
+                       ring->xmit_more++;
+               }
+       }
+
+       if (unlikely(stop_queue)) {
+               /* If queue was emptied after the if (stop_queue) , and before
+                * the netif_tx_stop_queue() - need to wake the queue,
+                * or else it will remain stopped forever.
+                * Need a memory barrier to make sure ring->cons was not
+                * updated before queue was stopped.
+                */
+               smp_rmb();
+
+               ring_cons = ACCESS_ONCE(ring->cons);
+               if (unlikely(!mlx4_en_is_tx_ring_full(ring))) {
+                       netif_tx_wake_queue(ring->tx_queue);
+                       ring->wake_queue++;
+               }
+       }
+       return NETDEV_TX_OK;
+
+tx_drop_unmap:
+       en_err(priv, "DMA mapping error\n");
+
+       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);
+       }
+
+tx_drop:
+       dev_kfree_skb_any(skb);
+       priv->stats.tx_dropped++;
+       return NETDEV_TX_OK;
+}
+