linux/drivers/net/mlx4/en_tx.c
Dongdong Deng 4871953c0e drivers/net: fixed drivers that support netpoll use ndo_start_xmit()
The NETPOLL API requires that interrupts remain disabled in
netpoll_send_skb(). The use of "A functions set" in the NETPOLL API
callbacks causes the interrupts to get enabled and can lead to kernel
instability.

The solution is to use "B functions set" to prevent the irqs from
getting enabled while in netpoll_send_skb().

A functions set:
local_irq_disable()/local_irq_enable()
spin_lock_irq()/spin_unlock_irq()
spin_trylock_irq()/spin_unlock_irq()

B functions set:
local_irq_save()/local_irq_restore()
spin_lock_irqsave()/spin_unlock_irqrestore()
spin_trylock_irqsave()/spin_unlock_irqrestore()

Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-08-23 19:51:03 -07:00

776 lines
22 KiB
C

/*
* 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) {
en_err(priv, "Failed allocating tx_info ring\n");
return -ENOMEM;
}
en_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) {
en_err(priv, "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) {
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);
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);
if (err) {
en_err(priv, "Failed allocating qp %d\n", ring->qpn);
goto err_reserve;
}
ring->qp.event = mlx4_en_sqp_event;
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;
en_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->inl) {
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 (!tx_info->inl) {
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);
++data;
}
}
/* 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;
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));
ring->cons += ring->last_nr_txbb;
cnt++;
}
if (cnt)
en_dbg(DRV, priv, "Freed %d uncompleted tx descriptors\n", cnt);
return cnt;
}
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) {
ring->blocked = 0;
netif_tx_wake_queue(netdev_get_tx_queue(dev, cq->ring));
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];
if (!spin_trylock(&ring->comp_lock))
return;
mlx4_en_process_tx_cq(cq->dev, cq);
mod_timer(&cq->timer, jiffies + 1);
spin_unlock(&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);
if (!spin_trylock_irq(&ring->comp_lock)) {
mod_timer(&cq->timer, jiffies + MLX4_EN_TX_POLL_TIMEOUT);
return;
}
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);
}
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];
unsigned long flags;
/* 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)
if (spin_trylock_irqsave(&ring->comp_lock, flags)) {
mlx4_en_process_tx_cq(priv->dev, cq);
spin_unlock_irqrestore(&ring->comp_lock, flags);
}
}
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);
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))
en_warn(priv, "Non-linear headers\n");
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;
}
u16 mlx4_en_select_queue(struct net_device *dev, struct sk_buff *skb)
{
struct mlx4_en_priv *priv = netdev_priv(dev);
u16 vlan_tag = 0;
/* If we support per priority flow control and the packet contains
* a vlan tag, send the packet to the TX ring assigned to that priority
*/
if (priv->prof->rx_ppp && priv->vlgrp && vlan_tx_tag_present(skb)) {
vlan_tag = vlan_tx_tag_get(skb);
return MLX4_EN_NUM_TX_RINGS + (vlan_tag >> 13);
}
return skb_tx_hash(dev, skb);
}
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 = 0;
int i;
int lso_header_size;
void *fragptr;
real_size = get_real_size(skb, dev, &lso_header_size);
if (unlikely(!real_size))
goto tx_drop;
/* 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))
en_warn(priv, "Oversized header or SG list\n");
goto tx_drop;
}
tx_ind = skb->queue_mapping;
ring = &priv->tx_ring[tx_ind];
if (priv->vlgrp && 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)) >
ring->size - HEADROOM - MAX_DESC_TXBBS)) {
/* every full Tx ring stops queue */
netif_tx_stop_queue(netdev_get_tx_queue(dev, tx_ind));
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;
}
/* 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);
}
tx_info->inl = 0;
} else {
build_inline_wqe(tx_desc, skb, real_size, &vlan_tag, tx_ind, fragptr);
tx_info->inl = 1;
}
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);
/* Poll CQ here */
mlx4_en_xmit_poll(priv, tx_ind);
return 0;
tx_drop:
dev_kfree_skb_any(skb);
priv->stats.tx_dropped++;
return NETDEV_TX_OK;
}