diff options
Diffstat (limited to 'drivers/net/mlx4/en_tx.c')
| -rw-r--r-- | drivers/net/mlx4/en_tx.c | 820 |
1 files changed, 820 insertions, 0 deletions
diff --git a/drivers/net/mlx4/en_tx.c b/drivers/net/mlx4/en_tx.c new file mode 100644 index 00000000000..8592f8fb847 --- /dev/null +++ b/drivers/net/mlx4/en_tx.c @@ -0,0 +1,820 @@ +/* + * 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/mlx4/qp.h> +#include <linux/skbuff.h> +#include <linux/if_vlan.h> +#include <linux/vmalloc.h> + +#include "mlx4_en.h" + +enum { + MAX_INLINE = 104, /* 128 - 16 - 4 - 4 */ +}; + +static int inline_thold __read_mostly = MAX_INLINE; + +module_param_named(inline_thold, inline_thold, int, 0444); +MODULE_PARM_DESC(inline_thold, "treshold for using inline data"); + +int mlx4_en_create_tx_ring(struct mlx4_en_priv *priv, + struct mlx4_en_tx_ring *ring, u32 size, + u16 stride) +{ + struct mlx4_en_dev *mdev = priv->mdev; + int tmp; + int err; + + ring->size = size; + ring->size_mask = size - 1; + ring->stride = stride; + + inline_thold = min(inline_thold, MAX_INLINE); + + spin_lock_init(&ring->comp_lock); + + tmp = size * sizeof(struct mlx4_en_tx_info); + ring->tx_info = vmalloc(tmp); + if (!ring->tx_info) { + mlx4_err(mdev, "Failed allocating tx_info ring\n"); + return -ENOMEM; + } + mlx4_dbg(DRV, priv, "Allocated tx_info ring at addr:%p size:%d\n", + ring->tx_info, tmp); + + ring->bounce_buf = kmalloc(MAX_DESC_SIZE, GFP_KERNEL); + if (!ring->bounce_buf) { + mlx4_err(mdev, "Failed allocating bounce buffer\n"); + err = -ENOMEM; + goto err_tx; + } + ring->buf_size = ALIGN(size * ring->stride, MLX4_EN_PAGE_SIZE); + + err = mlx4_alloc_hwq_res(mdev->dev, &ring->wqres, ring->buf_size, + 2 * PAGE_SIZE); + if (err) { + mlx4_err(mdev, "Failed allocating hwq resources\n"); + goto err_bounce; + } + + err = mlx4_en_map_buffer(&ring->wqres.buf); + if (err) { + mlx4_err(mdev, "Failed to map TX buffer\n"); + goto err_hwq_res; + } + + ring->buf = ring->wqres.buf.direct.buf; + + mlx4_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); + if (err) { + mlx4_err(mdev, "Failed reserving qp for tx ring.\n"); + goto err_map; + } + + err = mlx4_qp_alloc(mdev->dev, ring->qpn, &ring->qp); + if (err) { + mlx4_err(mdev, "Failed allocating qp %d\n", ring->qpn); + goto err_reserve; + } + + 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_tx: + vfree(ring->tx_info); + ring->tx_info = NULL; + return err; +} + +void mlx4_en_destroy_tx_ring(struct mlx4_en_priv *priv, + struct mlx4_en_tx_ring *ring) +{ + struct mlx4_en_dev *mdev = priv->mdev; + mlx4_dbg(DRV, priv, "Destroying tx ring, qpn: %d\n", ring->qpn); + + mlx4_qp_remove(mdev->dev, &ring->qp); + mlx4_qp_free(mdev->dev, &ring->qp); + mlx4_qp_release_range(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; + vfree(ring->tx_info); + ring->tx_info = NULL; +} + +int mlx4_en_activate_tx_ring(struct mlx4_en_priv *priv, + struct mlx4_en_tx_ring *ring, + int cq, int srqn) +{ + struct mlx4_en_dev *mdev = priv->mdev; + int err; + + ring->cqn = cq; + ring->prod = 0; + ring->cons = 0xffffffff; + ring->last_nr_txbb = 1; + ring->poll_cnt = 0; + ring->blocked = 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 = swab32(ring->qp.qpn << 8); + + mlx4_en_fill_qp_context(priv, ring->size, ring->stride, 1, 0, ring->qpn, + ring->cqn, srqn, &ring->context); + + err = mlx4_qp_to_ready(mdev->dev, &ring->wqres.mtt, &ring->context, + &ring->qp, &ring->qp_state); + + 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 u32 mlx4_en_free_tx_desc(struct mlx4_en_priv *priv, + struct mlx4_en_tx_ring *ring, + int index, u8 owner) +{ + 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; + int i; + __be32 *ptr = (__be32 *)tx_desc; + __be32 stamp = cpu_to_be32(STAMP_VAL | (!!owner << STAMP_SHIFT)); + + /* Optimize the common case when there are no wraparounds */ + if (likely((void *) tx_desc + tx_info->nr_txbb * TXBB_SIZE <= end)) { + if (tx_info->linear) { + pci_unmap_single(mdev->pdev, + (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]; + pci_unmap_page(mdev->pdev, + (dma_addr_t) be64_to_cpu(data[i].addr), + frag->size, PCI_DMA_TODEVICE); + } + /* Stamp the freed descriptor */ + for (i = 0; i < tx_info->nr_txbb * TXBB_SIZE; i += STAMP_STRIDE) { + *ptr = stamp; + ptr += STAMP_DWORDS; + } + + } else { + if ((void *) data >= end) { + data = (struct mlx4_wqe_data_seg *) + (ring->buf + ((void *) data - end)); + } + + if (tx_info->linear) { + pci_unmap_single(mdev->pdev, + (dma_addr_t) be64_to_cpu(data->addr), + be32_to_cpu(data->byte_count), + PCI_DMA_TODEVICE); + ++data; + } + + for (i = 0; i < frags; i++) { + /* Check for wraparound before unmapping */ + if ((void *) data >= end) + data = (struct mlx4_wqe_data_seg *) ring->buf; + frag = &skb_shinfo(skb)->frags[i]; + pci_unmap_page(mdev->pdev, + (dma_addr_t) be64_to_cpu(data->addr), + frag->size, PCI_DMA_TODEVICE); + } + /* 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); + } + } + + } + dev_kfree_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; + mlx4_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)) + mlx4_warn(priv->mdev, "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)); + ring->cons += ring->last_nr_txbb; + cnt++; + } + + if (cnt) + mlx4_dbg(DRV, priv, "Freed %d uncompleted tx descriptors\n", cnt); + + return cnt; +} + +void mlx4_en_set_prio_map(struct mlx4_en_priv *priv, u16 *prio_map, u32 ring_num) +{ + int block = 8 / ring_num; + int extra = 8 - (block * ring_num); + int num = 0; + u16 ring = 1; + int prio; + + if (ring_num == 1) { + for (prio = 0; prio < 8; prio++) + prio_map[prio] = 0; + return; + } + + for (prio = 0; prio < 8; prio++) { + if (extra && (num == block + 1)) { + ring++; + num = 0; + extra--; + } else if (!extra && (num == block)) { + ring++; + num = 0; + } + prio_map[prio] = ring; + mlx4_dbg(DRV, priv, " prio:%d --> ring:%d\n", prio, ring); + num++; + } +} + +static void 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 = cq->buf; + u16 index; + u16 new_index; + u32 txbbs_skipped = 0; + u32 cq_last_sav; + + /* index always points to the first TXBB of the last polled descriptor */ + index = ring->cons & ring->size_mask; + new_index = be16_to_cpu(cqe->wqe_index) & ring->size_mask; + if (index == new_index) + return; + + if (!priv->port_up) + return; + + /* + * We use a two-stage loop: + * - the first samples the HW-updated CQE + * - the second frees TXBBs until the last sample + * This lets us amortize CQE cache misses, while still polling the CQ + * until is quiescent. + */ + cq_last_sav = mcq->cons_index; + do { + do { + /* Skip over last polled CQE */ + index = (index + ring->last_nr_txbb) & ring->size_mask; + txbbs_skipped += ring->last_nr_txbb; + + /* Poll next CQE */ + ring->last_nr_txbb = mlx4_en_free_tx_desc( + priv, ring, index, + !!((ring->cons + txbbs_skipped) & + ring->size)); + ++mcq->cons_index; + + } while (index != new_index); + + new_index = be16_to_cpu(cqe->wqe_index) & ring->size_mask; + } while (index != new_index); + AVG_PERF_COUNTER(priv->pstats.tx_coal_avg, + (u32) (mcq->cons_index - cq_last_sav)); + + /* + * To prevent CQ overflow we first update CQ consumer and only then + * the ring consumer. + */ + mlx4_cq_set_ci(mcq); + wmb(); + ring->cons += txbbs_skipped; + + /* Wakeup Tx queue if this ring stopped it */ + if (unlikely(ring->blocked)) { + if (((u32) (ring->prod - ring->cons) <= + ring->size - HEADROOM - MAX_DESC_TXBBS) && !cq->armed) { + + /* TODO: support multiqueue netdevs. Currently, we block + * when *any* ring is full. Note that: + * - 2 Tx rings can unblock at the same time and call + * netif_wake_queue(), which is OK since this + * operation is idempotent. + * - We might wake the queue just after another ring + * stopped it. This is no big deal because the next + * transmission on that ring would stop the queue. + */ + ring->blocked = 0; + netif_wake_queue(dev); + priv->port_stats.wake_queue++; + } + } +} + +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); + struct mlx4_en_tx_ring *ring = &priv->tx_ring[cq->ring]; + + spin_lock_irq(&ring->comp_lock); + cq->armed = 0; + mlx4_en_process_tx_cq(cq->dev, cq); + if (ring->blocked) + mlx4_en_arm_cq(priv, cq); + else + mod_timer(&cq->timer, jiffies + 1); + spin_unlock_irq(&ring->comp_lock); +} + + +void mlx4_en_poll_tx_cq(unsigned long data) +{ + struct mlx4_en_cq *cq = (struct mlx4_en_cq *) data; + struct mlx4_en_priv *priv = netdev_priv(cq->dev); + struct mlx4_en_tx_ring *ring = &priv->tx_ring[cq->ring]; + u32 inflight; + + INC_PERF_COUNTER(priv->pstats.tx_poll); + + netif_tx_lock(priv->dev); + spin_lock_irq(&ring->comp_lock); + mlx4_en_process_tx_cq(cq->dev, cq); + inflight = (u32) (ring->prod - ring->cons - ring->last_nr_txbb); + + /* If there are still packets in flight and the timer has not already + * been scheduled by the Tx routine then schedule it here to guarantee + * completion processing of these packets */ + if (inflight && priv->port_up) + mod_timer(&cq->timer, jiffies + MLX4_EN_TX_POLL_TIMEOUT); + + spin_unlock_irq(&ring->comp_lock); + netif_tx_unlock(priv->dev); +} + +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; +} + +static inline void mlx4_en_xmit_poll(struct mlx4_en_priv *priv, int tx_ind) +{ + struct mlx4_en_cq *cq = &priv->tx_cq[tx_ind]; + struct mlx4_en_tx_ring *ring = &priv->tx_ring[tx_ind]; + + /* If we don't have a pending timer, set one up to catch our recent + post in case the interface becomes idle */ + if (!timer_pending(&cq->timer)) + mod_timer(&cq->timer, jiffies + MLX4_EN_TX_POLL_TIMEOUT); + + /* Poll the CQ every mlx4_en_TX_MODER_POLL packets */ + if ((++ring->poll_cnt & (MLX4_EN_TX_POLL_MODER - 1)) == 0) + mlx4_en_process_tx_cq(priv->dev, cq); +} + +static void *get_frag_ptr(struct sk_buff *skb) +{ + struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[0]; + struct page *page = frag->page; + void *ptr; + + ptr = page_address(page); + if (unlikely(!ptr)) + return NULL; + + return ptr + frag->page_offset; +} + +static int is_inline(struct sk_buff *skb, void **pfrag) +{ + void *ptr; + + if (inline_thold && !skb_is_gso(skb) && skb->len <= inline_thold) { + if (skb_shinfo(skb)->nr_frags == 1) { + ptr = get_frag_ptr(skb); + if (unlikely(!ptr)) + return 0; + + if (pfrag) + *pfrag = ptr; + + return 1; + } else if (unlikely(skb_shinfo(skb)->nr_frags)) + return 0; + else + return 1; + } + + return 0; +} + +static int inline_size(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(struct sk_buff *skb, struct net_device *dev, + int *lso_header_size) +{ + struct mlx4_en_priv *priv = netdev_priv(dev); + struct mlx4_en_dev *mdev = priv->mdev; + int real_size; + + if (skb_is_gso(skb)) { + *lso_header_size = skb_transport_offset(skb) + tcp_hdrlen(skb); + real_size = CTRL_SIZE + skb_shinfo(skb)->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)) + mlx4_warn(mdev, "Non-linear headers\n"); + dev_kfree_skb_any(skb); + return 0; + } + } + if (unlikely(*lso_header_size > MAX_LSO_HDR_SIZE)) { + if (netif_msg_tx_err(priv)) + mlx4_warn(mdev, "LSO header size too big\n"); + dev_kfree_skb_any(skb); + return 0; + } + } else { + *lso_header_size = 0; + if (!is_inline(skb, NULL)) + real_size = CTRL_SIZE + (skb_shinfo(skb)->nr_frags + 1) * DS_SIZE; + else + real_size = inline_size(skb); + } + + 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) +{ + struct mlx4_wqe_inline_seg *inl = &tx_desc->inl; + int spc = MLX4_INLINE_ALIGN - CTRL_SIZE - sizeof *inl; + + if (skb->len <= spc) { + inl->byte_count = cpu_to_be32(1 << 31 | skb->len); + skb_copy_from_linear_data(skb, inl + 1, skb_headlen(skb)); + if (skb_shinfo(skb)->nr_frags) + memcpy(((void *)(inl + 1)) + skb_headlen(skb), fragptr, + skb_shinfo(skb)->frags[0].size); + + } else { + inl->byte_count = cpu_to_be32(1 << 31 | spc); + if (skb_headlen(skb) <= spc) { + skb_copy_from_linear_data(skb, inl + 1, skb_headlen(skb)); + if (skb_headlen(skb) < spc) { + memcpy(((void *)(inl + 1)) + skb_headlen(skb), + fragptr, spc - skb_headlen(skb)); + fragptr += spc - skb_headlen(skb); + } + 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, + skb_headlen(skb) - spc); + if (skb_shinfo(skb)->nr_frags) + memcpy(((void *)(inl + 1)) + skb_headlen(skb) - spc, + fragptr, skb_shinfo(skb)->frags[0].size); + } + + wmb(); + inl->byte_count = cpu_to_be32(1 << 31 | (skb->len - spc)); + } + tx_desc->ctrl.vlan_tag = cpu_to_be16(*vlan_tag); + tx_desc->ctrl.ins_vlan = MLX4_WQE_CTRL_INS_VLAN * !!(*vlan_tag); + tx_desc->ctrl.fence_size = (real_size / 16) & 0x3f; +} + +static int get_vlan_info(struct mlx4_en_priv *priv, struct sk_buff *skb, + u16 *vlan_tag) +{ + int tx_ind; + + /* Obtain VLAN information if present */ + if (priv->vlgrp && vlan_tx_tag_present(skb)) { + *vlan_tag = vlan_tx_tag_get(skb); + /* Set the Tx ring to use according to vlan priority */ + tx_ind = priv->tx_prio_map[*vlan_tag >> 13]; + } else { + *vlan_tag = 0; + tx_ind = 0; + } + return tx_ind; +} + +int mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct mlx4_en_priv *priv = netdev_priv(dev); + struct mlx4_en_dev *mdev = priv->mdev; + struct mlx4_en_tx_ring *ring; + struct mlx4_en_cq *cq; + struct mlx4_en_tx_desc *tx_desc; + struct mlx4_wqe_data_seg *data; + struct skb_frag_struct *frag; + struct mlx4_en_tx_info *tx_info; + int tx_ind = 0; + int nr_txbb; + int desc_size; + int real_size; + dma_addr_t dma; + u32 index; + __be32 op_own; + u16 vlan_tag; + int i; + int lso_header_size; + void *fragptr; + + if (unlikely(!skb->len)) { + dev_kfree_skb_any(skb); + return NETDEV_TX_OK; + } + real_size = get_real_size(skb, dev, &lso_header_size); + if (unlikely(!real_size)) + return NETDEV_TX_OK; + + /* Allign 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)) + mlx4_warn(mdev, "Oversized header or SG list\n"); + dev_kfree_skb_any(skb); + return NETDEV_TX_OK; + } + + tx_ind = get_vlan_info(priv, skb, &vlan_tag); + ring = &priv->tx_ring[tx_ind]; + + /* Check available TXBBs And 2K spare for prefetch */ + if (unlikely(((int)(ring->prod - ring->cons)) > + ring->size - HEADROOM - MAX_DESC_TXBBS)) { + /* every full Tx ring stops queue. + * TODO: implement multi-queue support (per-queue stop) */ + netif_stop_queue(dev); + ring->blocked = 1; + priv->port_stats.queue_stopped++; + + /* Use interrupts to find out when queue opened */ + cq = &priv->tx_cq[tx_ind]; + mlx4_en_arm_cq(priv, cq); + return NETDEV_TX_BUSY; + } + + /* Now that we know what Tx ring to use */ + if (unlikely(!priv->port_up)) { + if (netif_msg_tx_err(priv)) + mlx4_warn(mdev, "xmit: port down!\n"); + dev_kfree_skb_any(skb); + return NETDEV_TX_OK; + } + + /* 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; + + /* 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; + + /* Save skb in tx_info ring */ + tx_info = &ring->tx_info[index]; + tx_info->skb = skb; + tx_info->nr_txbb = nr_txbb; + + /* 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_tag; + tx_desc->ctrl.fence_size = (real_size / 16) & 0x3f; + tx_desc->ctrl.srcrb_flags = cpu_to_be32(MLX4_WQE_CTRL_CQ_UPDATE | + MLX4_WQE_CTRL_SOLICITED); + if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) { + tx_desc->ctrl.srcrb_flags |= cpu_to_be32(MLX4_WQE_CTRL_IP_CSUM | + MLX4_WQE_CTRL_TCP_UDP_CSUM); + priv->port_stats.tx_chksum_offload++; + } + + /* Handle LSO (TSO) packets */ + if (lso_header_size) { + /* 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( + skb_shinfo(skb)->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); + data = ((void *) &tx_desc->lso + + ALIGN(lso_header_size + 4, DS_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); + ring->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); + data = &tx_desc->data; + ring->bytes += max(skb->len, (unsigned int) ETH_ZLEN); + ring->packets++; + + } + AVG_PERF_COUNTER(priv->pstats.tx_pktsz_avg, skb->len); + + + /* valid only for none inline segments */ + tx_info->data_offset = (void *) data - (void *) tx_desc; + + tx_info->linear = (lso_header_size < skb_headlen(skb) && !is_inline(skb, NULL)) ? 1 : 0; + data += skb_shinfo(skb)->nr_frags + tx_info->linear - 1; + + if (!is_inline(skb, &fragptr)) { + /* Map fragments */ + for (i = skb_shinfo(skb)->nr_frags - 1; i >= 0; i--) { + frag = &skb_shinfo(skb)->frags[i]; + dma = pci_map_page(mdev->dev->pdev, frag->page, frag->page_offset, + frag->size, PCI_DMA_TODEVICE); + data->addr = cpu_to_be64(dma); + data->lkey = cpu_to_be32(mdev->mr.key); + wmb(); + data->byte_count = cpu_to_be32(frag->size); + --data; + } + + /* Map linear part */ + if (tx_info->linear) { + dma = pci_map_single(mdev->dev->pdev, skb->data + lso_header_size, + skb_headlen(skb) - lso_header_size, PCI_DMA_TODEVICE); + data->addr = cpu_to_be64(dma); + data->lkey = cpu_to_be32(mdev->mr.key); + wmb(); + data->byte_count = cpu_to_be32(skb_headlen(skb) - lso_header_size); + } + } else + build_inline_wqe(tx_desc, skb, real_size, &vlan_tag, tx_ind, fragptr); + + ring->prod += nr_txbb; + + /* If we used a bounce buffer then copy descriptor back into place */ + if (tx_desc == (struct mlx4_en_tx_desc *) ring->bounce_buf) + tx_desc = mlx4_en_bounce_to_desc(priv, ring, index, desc_size); + + /* Run destructor before passing skb to HW */ + if (likely(!skb_shared(skb))) + skb_orphan(skb); + + /* Ensure new descirptor hits memory + * before setting ownership of this descriptor to HW */ + wmb(); + tx_desc->ctrl.owner_opcode = op_own; + + /* Ring doorbell! */ + wmb(); + writel(ring->doorbell_qpn, mdev->uar_map + MLX4_SEND_DOORBELL); + dev->trans_start = jiffies; + + /* Poll CQ here */ + mlx4_en_xmit_poll(priv, tx_ind); + + return 0; +} + |