drivers/net/ethernet/mellanox/mlx5/core/en_tx.c

root/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
/*
 * Copyright (c) 2015-2016, 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 <linux/tcp.h>
#include <linux/if_vlan.h>
#include <net/geneve.h>
#include <net/dsfield.h>
#include "en.h"
#include "en/txrx.h"
#include "ipoib/ipoib.h"
#include "en_accel/en_accel.h"
#include "en_accel/ipsec_rxtx.h"
#include "en_accel/psp_rxtx.h"
#include "en_accel/macsec.h"
#include "en/ptp.h"
#include <net/ipv6.h>

static void mlx5e_dma_unmap_wqe_err(struct mlx5e_txqsq *sq, u8 num_dma)
{
        int i;

        for (i = 0; i < num_dma; i++) {
                struct mlx5e_sq_dma *last_pushed_dma =
                        mlx5e_dma_get(sq, --sq->dma_fifo_pc);

                mlx5e_tx_dma_unmap(sq->pdev, last_pushed_dma);
        }
}

static inline int mlx5e_skb_l2_header_offset(struct sk_buff *skb)
{
#define MLX5E_MIN_INLINE (ETH_HLEN + VLAN_HLEN)

        return max(skb_network_offset(skb), MLX5E_MIN_INLINE);
}

static inline int mlx5e_skb_l3_header_offset(struct sk_buff *skb)
{
        if (skb_transport_header_was_set(skb))
                return skb_transport_offset(skb);
        else
                return mlx5e_skb_l2_header_offset(skb);
}

static inline u16 mlx5e_calc_min_inline(enum mlx5_inline_modes mode,
                                        struct sk_buff *skb)
{
        u16 hlen;

        switch (mode) {
        case MLX5_INLINE_MODE_NONE:
                return 0;
        case MLX5_INLINE_MODE_TCP_UDP:
                hlen = eth_get_headlen(skb->dev, skb->data, skb_headlen(skb));
                if (hlen == ETH_HLEN && !skb_vlan_tag_present(skb))
                        hlen += VLAN_HLEN;
                break;
        case MLX5_INLINE_MODE_IP:
                hlen = mlx5e_skb_l3_header_offset(skb);
                break;
        case MLX5_INLINE_MODE_L2:
        default:
                hlen = mlx5e_skb_l2_header_offset(skb);
        }
        return min_t(u16, hlen, skb_headlen(skb));
}

#define MLX5_UNSAFE_MEMCPY_DISCLAIMER                           \
        "This copy has been bounds-checked earlier in "         \
        "mlx5i_sq_calc_wqe_attr() and intentionally "           \
        "crosses a flex array boundary. Since it is "           \
        "performance sensitive, splitting the copy is "         \
        "undesirable."

static inline void mlx5e_insert_vlan(void *start, struct sk_buff *skb, u16 ihs)
{
        struct vlan_ethhdr *vhdr = (struct vlan_ethhdr *)start;
        int cpy1_sz = 2 * ETH_ALEN;
        int cpy2_sz = ihs - cpy1_sz;

        memcpy(&vhdr->addrs, skb->data, cpy1_sz);
        vhdr->h_vlan_proto = skb->vlan_proto;
        vhdr->h_vlan_TCI = cpu_to_be16(skb_vlan_tag_get(skb));
        unsafe_memcpy(&vhdr->h_vlan_encapsulated_proto,
                      skb->data + cpy1_sz,
                      cpy2_sz,
                      MLX5_UNSAFE_MEMCPY_DISCLAIMER);
}

static inline void
mlx5e_txwqe_build_eseg_csum(struct mlx5e_txqsq *sq, struct sk_buff *skb,
                            struct mlx5e_accel_tx_state *accel,
                            struct mlx5_wqe_eth_seg *eseg)
{
#ifdef CONFIG_MLX5_EN_PSP
        if (unlikely(mlx5e_psp_txwqe_build_eseg_csum(sq, skb, &accel->psp_st, eseg)))
                return;
#endif

        if (unlikely(mlx5e_ipsec_txwqe_build_eseg_csum(sq, skb, eseg)))
                return;

        if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
                eseg->cs_flags = MLX5_ETH_WQE_L3_CSUM;
                if (skb->encapsulation) {
                        eseg->cs_flags |= MLX5_ETH_WQE_L3_INNER_CSUM |
                                          MLX5_ETH_WQE_L4_INNER_CSUM;
                        sq->stats->csum_partial_inner++;
                } else {
                        eseg->cs_flags |= MLX5_ETH_WQE_L4_CSUM;
                        sq->stats->csum_partial++;
                }
#ifdef CONFIG_MLX5_EN_TLS
        } else if (unlikely(accel && accel->tls.tls_tisn)) {
                eseg->cs_flags = MLX5_ETH_WQE_L3_CSUM | MLX5_ETH_WQE_L4_CSUM;
                sq->stats->csum_partial++;
#endif
        } else
                sq->stats->csum_none++;
}

/* Returns the number of header bytes that we plan
 * to inline later in the transmit descriptor
 */
static inline u16
mlx5e_tx_get_gso_ihs(struct mlx5e_txqsq *sq, struct sk_buff *skb)
{
        struct mlx5e_sq_stats *stats = sq->stats;
        u16 ihs;

        if (skb->encapsulation) {
                if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
                        ihs = skb_inner_transport_offset(skb) +
                              sizeof(struct udphdr);
                else
                        ihs = skb_inner_tcp_all_headers(skb);
                stats->tso_inner_packets++;
                stats->tso_inner_bytes += skb->len - ihs;
        } else {
                if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
                        ihs = skb_transport_offset(skb) + sizeof(struct udphdr);
                else
                        ihs = skb_tcp_all_headers(skb);
                stats->tso_packets++;
                stats->tso_bytes += skb->len - ihs;
        }

        return ihs;
}

static inline int
mlx5e_txwqe_build_dsegs(struct mlx5e_txqsq *sq, struct sk_buff *skb,
                        unsigned char *skb_data, u16 headlen,
                        struct mlx5_wqe_data_seg *dseg)
{
        dma_addr_t dma_addr = 0;
        u8 num_dma          = 0;
        int i;

        if (headlen) {
                dma_addr = dma_map_single(sq->pdev, skb_data, headlen,
                                          DMA_TO_DEVICE);
                if (unlikely(dma_mapping_error(sq->pdev, dma_addr)))
                        goto dma_unmap_wqe_err;

                dseg->addr       = cpu_to_be64(dma_addr);
                dseg->lkey       = sq->mkey_be;
                dseg->byte_count = cpu_to_be32(headlen);

                mlx5e_dma_push_single(sq, dma_addr, headlen);
                num_dma++;
                dseg++;
        }

        for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
                skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
                int fsz = skb_frag_size(frag);

                dma_addr = skb_frag_dma_map(sq->pdev, frag, 0, fsz,
                                            DMA_TO_DEVICE);
                if (unlikely(dma_mapping_error(sq->pdev, dma_addr)))
                        goto dma_unmap_wqe_err;

                dseg->addr       = cpu_to_be64(dma_addr);
                dseg->lkey       = sq->mkey_be;
                dseg->byte_count = cpu_to_be32(fsz);

                mlx5e_dma_push_netmem(sq, skb_frag_netmem(frag), dma_addr, fsz);
                num_dma++;
                dseg++;
        }

        return num_dma;

dma_unmap_wqe_err:
        mlx5e_dma_unmap_wqe_err(sq, num_dma);
        return -ENOMEM;
}

struct mlx5e_tx_attr {
        u32 num_bytes;
        u16 headlen;
        u16 ihs;
        __be16 mss;
        u16 insz;
        u8 opcode;
};

struct mlx5e_tx_wqe_attr {
        u16 ds_cnt;
        u16 ds_cnt_inl;
        u16 ds_cnt_ids;
        u8 num_wqebbs;
};

static u8
mlx5e_tx_wqe_inline_mode(struct mlx5e_txqsq *sq, struct sk_buff *skb,
                         struct mlx5e_accel_tx_state *accel)
{
        u8 mode;

#ifdef CONFIG_MLX5_EN_TLS
        if (accel->tls.tls_tisn)
                return MLX5_INLINE_MODE_TCP_UDP;
#endif

        mode = sq->min_inline_mode;

        if (skb_vlan_tag_present(skb))
                mode = max_t(u8, MLX5_INLINE_MODE_L2, mode);

        return mode;
}

static void mlx5e_sq_xmit_prepare(struct mlx5e_txqsq *sq, struct sk_buff *skb,
                                  struct mlx5e_accel_tx_state *accel,
                                  struct mlx5e_tx_attr *attr)
{
        struct mlx5e_sq_stats *stats = sq->stats;

        if (skb_is_gso(skb)) {
                u16 ihs = mlx5e_tx_get_gso_ihs(sq, skb);

                *attr = (struct mlx5e_tx_attr) {
                        .opcode    = MLX5_OPCODE_LSO,
                        .mss       = cpu_to_be16(skb_shinfo(skb)->gso_size),
                        .ihs       = ihs,
                        .num_bytes = skb->len + (skb_shinfo(skb)->gso_segs - 1) * ihs,
                        .headlen   = skb_headlen(skb) - ihs,
                };

                stats->packets += skb_shinfo(skb)->gso_segs;
        } else {
                u8 mode = mlx5e_tx_wqe_inline_mode(sq, skb, accel);
                u16 ihs = mlx5e_calc_min_inline(mode, skb);

                *attr = (struct mlx5e_tx_attr) {
                        .opcode    = MLX5_OPCODE_SEND,
                        .mss       = cpu_to_be16(0),
                        .ihs       = ihs,
                        .num_bytes = max_t(unsigned int, skb->len, ETH_ZLEN),
                        .headlen   = skb_headlen(skb) - ihs,
                };

                stats->packets++;
        }

        attr->insz = mlx5e_accel_tx_ids_len(sq, skb, accel);
        stats->bytes += attr->num_bytes;
}

static void mlx5e_sq_calc_wqe_attr(struct sk_buff *skb, const struct mlx5e_tx_attr *attr,
                                   struct mlx5e_tx_wqe_attr *wqe_attr)
{
        u16 ds_cnt = MLX5E_TX_WQE_EMPTY_DS_COUNT;
        u16 ds_cnt_inl = 0;
        u16 ds_cnt_ids = 0;

        /* Sync the calculation with MLX5E_MAX_TX_WQEBBS. */

        if (attr->insz)
                ds_cnt_ids = DIV_ROUND_UP(sizeof(struct mlx5_wqe_inline_seg) + attr->insz,
                                          MLX5_SEND_WQE_DS);

        ds_cnt += !!attr->headlen + skb_shinfo(skb)->nr_frags + ds_cnt_ids;
        if (attr->ihs) {
                u16 inl = attr->ihs - INL_HDR_START_SZ;

                if (skb_vlan_tag_present(skb))
                        inl += VLAN_HLEN;

                ds_cnt_inl = DIV_ROUND_UP(inl, MLX5_SEND_WQE_DS);
                if (WARN_ON_ONCE(ds_cnt_inl > MLX5E_MAX_TX_INLINE_DS))
                        netdev_warn(skb->dev, "ds_cnt_inl = %u > max %u\n", ds_cnt_inl,
                                    (u16)MLX5E_MAX_TX_INLINE_DS);
                ds_cnt += ds_cnt_inl;
        }

        *wqe_attr = (struct mlx5e_tx_wqe_attr) {
                .ds_cnt     = ds_cnt,
                .ds_cnt_inl = ds_cnt_inl,
                .ds_cnt_ids = ds_cnt_ids,
                .num_wqebbs = DIV_ROUND_UP(ds_cnt, MLX5_SEND_WQEBB_NUM_DS),
        };
}

static void mlx5e_tx_skb_update_ts_flags(struct sk_buff *skb)
{
        if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP))
                skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
        skb_tx_timestamp(skb);
}

static void mlx5e_tx_check_stop(struct mlx5e_txqsq *sq)
{
        if (unlikely(!mlx5e_wqc_has_room_for(&sq->wq, sq->cc, sq->pc, sq->stop_room))) {
                netif_tx_stop_queue(sq->txq);
                sq->stats->stopped++;
        }
}

static void mlx5e_tx_flush(struct mlx5e_txqsq *sq)
{
        struct mlx5e_tx_wqe_info *wi;
        struct mlx5e_tx_wqe *wqe;
        u16 pi;

        /* Must not be called when a MPWQE session is active but empty. */
        mlx5e_tx_mpwqe_ensure_complete(sq);

        pi = mlx5_wq_cyc_ctr2ix(&sq->wq, sq->pc);
        wi = &sq->db.wqe_info[pi];

        *wi = (struct mlx5e_tx_wqe_info) {
                .num_wqebbs = 1,
        };

        wqe = mlx5e_post_nop(&sq->wq, sq->sqn, &sq->pc);
        mlx5e_notify_hw(&sq->wq, sq->pc, sq->uar_map, &wqe->ctrl);
}

static inline void
mlx5e_txwqe_complete(struct mlx5e_txqsq *sq, struct sk_buff *skb,
                     const struct mlx5e_tx_attr *attr,
                     const struct mlx5e_tx_wqe_attr *wqe_attr, u8 num_dma,
                     struct mlx5e_tx_wqe_info *wi, struct mlx5_wqe_ctrl_seg *cseg,
                     struct mlx5_wqe_eth_seg *eseg, bool xmit_more)
{
        struct mlx5_wq_cyc *wq = &sq->wq;
        bool send_doorbell;

        *wi = (struct mlx5e_tx_wqe_info) {
                .skb = skb,
                .num_bytes = attr->num_bytes,
                .num_dma = num_dma,
                .num_wqebbs = wqe_attr->num_wqebbs,
                .num_fifo_pkts = 0,
        };

        cseg->opmod_idx_opcode = cpu_to_be32((sq->pc << 8) | attr->opcode);
        cseg->qpn_ds           = cpu_to_be32((sq->sqn << 8) | wqe_attr->ds_cnt);

        mlx5e_tx_skb_update_ts_flags(skb);

        sq->pc += wi->num_wqebbs;

        mlx5e_tx_check_stop(sq);

        if (unlikely(sq->ptpsq &&
                     (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP))) {
                u8 metadata_index = be32_to_cpu(eseg->flow_table_metadata);

                mlx5e_ptp_metadata_fifo_pop(&sq->ptpsq->metadata_freelist);

                mlx5e_skb_cb_hwtstamp_init(skb);
                mlx5e_ptp_metadata_map_put(&sq->ptpsq->metadata_map, skb,
                                           metadata_index);
                /* ensure skb is put on metadata_map before tracking the index */
                wmb();
                mlx5e_ptpsq_track_metadata(sq->ptpsq, metadata_index);
                if (!netif_tx_queue_stopped(sq->txq) &&
                    mlx5e_ptpsq_metadata_freelist_empty(sq->ptpsq)) {
                        netif_tx_stop_queue(sq->txq);
                        sq->stats->stopped++;
                }
                skb_get(skb);
        }

        send_doorbell = __netdev_tx_sent_queue(sq->txq, attr->num_bytes, xmit_more);
        if (send_doorbell)
                mlx5e_notify_hw(wq, sq->pc, sq->uar_map, cseg);
}

static void
mlx5e_sq_xmit_wqe(struct mlx5e_txqsq *sq, struct sk_buff *skb,
                  const struct mlx5e_tx_attr *attr, const struct mlx5e_tx_wqe_attr *wqe_attr,
                  struct mlx5e_tx_wqe *wqe, u16 pi, bool xmit_more)
{
        struct mlx5_wqe_ctrl_seg *cseg;
        struct mlx5_wqe_eth_seg  *eseg;
        struct mlx5_wqe_data_seg *dseg;
        struct mlx5e_tx_wqe_info *wi;
        u16 ihs = attr->ihs;
        struct mlx5e_sq_stats *stats = sq->stats;
        int num_dma;

        stats->xmit_more += xmit_more;

        /* fill wqe */
        wi   = &sq->db.wqe_info[pi];
        cseg = &wqe->ctrl;
        eseg = &wqe->eth;
        dseg =  wqe->data;

        eseg->mss = attr->mss;

        if (ihs) {
                u8 *start = eseg->inline_hdr.start;

                if (skb_vlan_tag_present(skb)) {
                        mlx5e_insert_vlan(start, skb, ihs);
                        ihs += VLAN_HLEN;
                        stats->added_vlan_packets++;
                } else {
                        unsafe_memcpy(eseg->inline_hdr.start, skb->data,
                                      attr->ihs,
                                      MLX5_UNSAFE_MEMCPY_DISCLAIMER);
                }
                eseg->inline_hdr.sz |= cpu_to_be16(ihs);
                dseg += wqe_attr->ds_cnt_inl;
        }

        dseg += wqe_attr->ds_cnt_ids;
        num_dma = mlx5e_txwqe_build_dsegs(sq, skb, skb->data + attr->ihs,
                                          attr->headlen, dseg);
        if (unlikely(num_dma < 0))
                goto err_drop;

        mlx5e_txwqe_complete(sq, skb, attr, wqe_attr, num_dma, wi, cseg, eseg, xmit_more);

        return;

err_drop:
        stats->dropped++;
        dev_kfree_skb_any(skb);
        mlx5e_tx_flush(sq);
}

static bool mlx5e_tx_skb_supports_mpwqe(struct sk_buff *skb, struct mlx5e_tx_attr *attr)
{
        return !skb_is_nonlinear(skb) && !skb_vlan_tag_present(skb) && !attr->ihs &&
               !attr->insz && !mlx5e_macsec_skb_is_offload(skb);
}

static bool mlx5e_tx_mpwqe_same_eseg(struct mlx5e_txqsq *sq, struct mlx5_wqe_eth_seg *eseg)
{
        struct mlx5e_tx_mpwqe *session = &sq->mpwqe;

        /* Assumes the session is already running and has at least one packet. */
        return !memcmp(&session->wqe->eth, eseg, MLX5E_ACCEL_ESEG_LEN);
}

static void mlx5e_tx_mpwqe_session_start(struct mlx5e_txqsq *sq,
                                         struct mlx5_wqe_eth_seg *eseg)
{
        struct mlx5e_tx_mpwqe *session = &sq->mpwqe;
        struct mlx5e_tx_wqe *wqe;
        u16 pi, num_wqebbs;

        pi = mlx5e_txqsq_get_next_pi_anysize(sq, &num_wqebbs);
        wqe = MLX5E_TX_FETCH_WQE(sq, pi);
        net_prefetchw(wqe->data);

        *session = (struct mlx5e_tx_mpwqe) {
                .wqe = wqe,
                .bytes_count = 0,
                .ds_count = MLX5E_TX_WQE_EMPTY_DS_COUNT,
                .ds_count_max = num_wqebbs * MLX5_SEND_WQEBB_NUM_DS,
                .pkt_count = 0,
                .inline_on = 0,
        };

        memcpy(&session->wqe->eth, eseg, MLX5E_ACCEL_ESEG_LEN);

        sq->stats->mpwqe_blks++;
}

static bool mlx5e_tx_mpwqe_session_is_active(struct mlx5e_txqsq *sq)
{
        return sq->mpwqe.wqe;
}

static void mlx5e_tx_mpwqe_add_dseg(struct mlx5e_txqsq *sq, struct mlx5e_xmit_data *txd)
{
        struct mlx5e_tx_mpwqe *session = &sq->mpwqe;
        struct mlx5_wqe_data_seg *dseg;

        dseg = (struct mlx5_wqe_data_seg *)session->wqe + session->ds_count;

        session->pkt_count++;
        session->bytes_count += txd->len;

        dseg->addr = cpu_to_be64(txd->dma_addr);
        dseg->byte_count = cpu_to_be32(txd->len);
        dseg->lkey = sq->mkey_be;
        session->ds_count++;

        sq->stats->mpwqe_pkts++;
}

static struct mlx5_wqe_ctrl_seg *mlx5e_tx_mpwqe_session_complete(struct mlx5e_txqsq *sq)
{
        struct mlx5e_tx_mpwqe *session = &sq->mpwqe;
        u8 ds_count = session->ds_count;
        struct mlx5_wqe_ctrl_seg *cseg;
        struct mlx5e_tx_wqe_info *wi;
        u16 pi;

        cseg = &session->wqe->ctrl;
        cseg->opmod_idx_opcode = cpu_to_be32((sq->pc << 8) | MLX5_OPCODE_ENHANCED_MPSW);
        cseg->qpn_ds = cpu_to_be32((sq->sqn << 8) | ds_count);

        pi = mlx5_wq_cyc_ctr2ix(&sq->wq, sq->pc);
        wi = &sq->db.wqe_info[pi];
        *wi = (struct mlx5e_tx_wqe_info) {
                .skb = NULL,
                .num_bytes = session->bytes_count,
                .num_wqebbs = DIV_ROUND_UP(ds_count, MLX5_SEND_WQEBB_NUM_DS),
                .num_dma = session->pkt_count,
                .num_fifo_pkts = session->pkt_count,
        };

        sq->pc += wi->num_wqebbs;

        session->wqe = NULL;

        mlx5e_tx_check_stop(sq);

        return cseg;
}

static void
mlx5e_sq_xmit_mpwqe(struct mlx5e_txqsq *sq, struct sk_buff *skb,
                    struct mlx5_wqe_eth_seg *eseg, bool xmit_more)
{
        struct mlx5_wqe_ctrl_seg *cseg;
        struct mlx5e_xmit_data txd;

        txd.data = skb->data;
        txd.len = skb->len;

        txd.dma_addr = dma_map_single(sq->pdev, txd.data, txd.len, DMA_TO_DEVICE);
        if (unlikely(dma_mapping_error(sq->pdev, txd.dma_addr)))
                goto err_unmap;

        if (!mlx5e_tx_mpwqe_session_is_active(sq)) {
                mlx5e_tx_mpwqe_session_start(sq, eseg);
        } else if (!mlx5e_tx_mpwqe_same_eseg(sq, eseg)) {
                mlx5e_tx_mpwqe_session_complete(sq);
                mlx5e_tx_mpwqe_session_start(sq, eseg);
        }

        sq->stats->xmit_more += xmit_more;

        mlx5e_dma_push_single(sq, txd.dma_addr, txd.len);
        mlx5e_skb_fifo_push(&sq->db.skb_fifo, skb);
        mlx5e_tx_mpwqe_add_dseg(sq, &txd);
        mlx5e_tx_skb_update_ts_flags(skb);

        if (unlikely(mlx5e_tx_mpwqe_is_full(&sq->mpwqe))) {
                /* Might stop the queue and affect the retval of __netdev_tx_sent_queue. */
                cseg = mlx5e_tx_mpwqe_session_complete(sq);

                if (__netdev_tx_sent_queue(sq->txq, txd.len, xmit_more))
                        mlx5e_notify_hw(&sq->wq, sq->pc, sq->uar_map, cseg);
        } else if (__netdev_tx_sent_queue(sq->txq, txd.len, xmit_more)) {
                /* Might stop the queue, but we were asked to ring the doorbell anyway. */
                cseg = mlx5e_tx_mpwqe_session_complete(sq);

                mlx5e_notify_hw(&sq->wq, sq->pc, sq->uar_map, cseg);
        }

        return;

err_unmap:
        sq->stats->dropped++;
        dev_kfree_skb_any(skb);
        mlx5e_tx_flush(sq);
}

void mlx5e_tx_mpwqe_ensure_complete(struct mlx5e_txqsq *sq)
{
        /* Unlikely in non-MPWQE workloads; not important in MPWQE workloads. */
        if (unlikely(mlx5e_tx_mpwqe_session_is_active(sq)))
                mlx5e_tx_mpwqe_session_complete(sq);
}

static void mlx5e_cqe_ts_id_eseg(struct mlx5e_ptpsq *ptpsq, struct sk_buff *skb,
                                 struct mlx5_wqe_eth_seg *eseg)
{
        if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP))
                eseg->flow_table_metadata |=
                        cpu_to_be32(mlx5e_ptp_metadata_fifo_peek(&ptpsq->metadata_freelist));
}

static void mlx5e_txwqe_build_eseg(struct mlx5e_priv *priv, struct mlx5e_txqsq *sq,
                                   struct sk_buff *skb, struct mlx5e_accel_tx_state *accel,
                                   struct mlx5_wqe_eth_seg *eseg, u16 ihs)
{
        mlx5e_accel_tx_eseg(priv, skb, accel, eseg, ihs);
        mlx5e_txwqe_build_eseg_csum(sq, skb, accel, eseg);
        if (unlikely(sq->ptpsq))
                mlx5e_cqe_ts_id_eseg(sq->ptpsq, skb, eseg);
}

netdev_tx_t mlx5e_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct mlx5e_priv *priv = netdev_priv(dev);
        struct mlx5e_accel_tx_state accel = {};
        struct mlx5e_tx_wqe_attr wqe_attr;
        struct mlx5e_tx_attr attr;
        struct mlx5e_tx_wqe *wqe;
        struct mlx5e_txqsq *sq;
        u16 pi;

        /* All changes to txq2sq are performed in sync with mlx5e_xmit, when the
         * queue being changed is disabled, and smp_wmb guarantees that the
         * changes are visible before mlx5e_xmit tries to read from txq2sq. It
         * guarantees that the value of txq2sq[qid] doesn't change while
         * mlx5e_xmit is running on queue number qid. smb_wmb is paired with
         * HARD_TX_LOCK around ndo_start_xmit, which serves as an ACQUIRE.
         */
        sq = priv->txq2sq[skb_get_queue_mapping(skb)];
        if (unlikely(!sq)) {
                /* Two cases when sq can be NULL:
                 * 1. The HTB node is registered, and mlx5e_select_queue
                 * selected its queue ID, but the SQ itself is not yet created.
                 * 2. HTB SQ creation failed. Similar to the previous case, but
                 * the SQ won't be created.
                 */
                dev_kfree_skb_any(skb);
                return NETDEV_TX_OK;
        }

        /* May send SKBs and WQEs. */
        if (unlikely(!mlx5e_accel_tx_begin(dev, sq, skb, &accel)))
                return NETDEV_TX_OK;

        mlx5e_sq_xmit_prepare(sq, skb, &accel, &attr);

        if (test_bit(MLX5E_SQ_STATE_MPWQE, &sq->state)) {
                if (mlx5e_tx_skb_supports_mpwqe(skb, &attr)) {
                        struct mlx5_wqe_eth_seg eseg = {};

                        mlx5e_txwqe_build_eseg(priv, sq, skb, &accel, &eseg, attr.ihs);
                        mlx5e_sq_xmit_mpwqe(sq, skb, &eseg, netdev_xmit_more());
                        return NETDEV_TX_OK;
                }

                mlx5e_tx_mpwqe_ensure_complete(sq);
        }

        mlx5e_sq_calc_wqe_attr(skb, &attr, &wqe_attr);
        pi = mlx5e_txqsq_get_next_pi(sq, wqe_attr.num_wqebbs);
        wqe = MLX5E_TX_FETCH_WQE(sq, pi);

        /* May update the WQE, but may not post other WQEs. */
        mlx5e_accel_tx_finish(sq, wqe, &accel,
                              (struct mlx5_wqe_inline_seg *)(wqe->data + wqe_attr.ds_cnt_inl));
        mlx5e_txwqe_build_eseg(priv, sq, skb, &accel, &wqe->eth, attr.ihs);
        mlx5e_sq_xmit_wqe(sq, skb, &attr, &wqe_attr, wqe, pi, netdev_xmit_more());

        return NETDEV_TX_OK;
}

static void mlx5e_tx_wi_dma_unmap(struct mlx5e_txqsq *sq, struct mlx5e_tx_wqe_info *wi,
                                  u32 *dma_fifo_cc)
{
        int i;

        for (i = 0; i < wi->num_dma; i++) {
                struct mlx5e_sq_dma *dma = mlx5e_dma_get(sq, (*dma_fifo_cc)++);

                mlx5e_tx_dma_unmap(sq->pdev, dma);
        }
}

static void mlx5e_consume_skb(struct mlx5e_txqsq *sq, struct sk_buff *skb,
                              struct mlx5_cqe64 *cqe, int napi_budget)
{
        if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)) {
                struct skb_shared_hwtstamps hwts = {};
                u64 ts = get_cqe_ts(cqe);

                hwts.hwtstamp = mlx5e_cqe_ts_to_ns(sq->ptp_cyc2time, sq->clock, ts);
                if (sq->ptpsq) {
                        mlx5e_skb_cb_hwtstamp_handler(skb, MLX5E_SKB_CB_CQE_HWTSTAMP,
                                                      hwts.hwtstamp, sq->ptpsq);
                } else {
                        skb_tstamp_tx(skb, &hwts);
                        sq->stats->timestamps++;
                }
        }

        napi_consume_skb(skb, napi_budget);
}

static void mlx5e_tx_wi_consume_fifo_skbs(struct mlx5e_txqsq *sq, struct mlx5e_tx_wqe_info *wi,
                                          struct mlx5_cqe64 *cqe, int napi_budget)
{
        int i;

        for (i = 0; i < wi->num_fifo_pkts; i++) {
                struct sk_buff *skb = mlx5e_skb_fifo_pop(&sq->db.skb_fifo);

                mlx5e_consume_skb(sq, skb, cqe, napi_budget);
        }
}

void mlx5e_txqsq_wake(struct mlx5e_txqsq *sq)
{
        if (netif_tx_queue_stopped(sq->txq) &&
            mlx5e_wqc_has_room_for(&sq->wq, sq->cc, sq->pc, sq->stop_room) &&
            !mlx5e_ptpsq_metadata_freelist_empty(sq->ptpsq) &&
            !test_bit(MLX5E_SQ_STATE_RECOVERING, &sq->state)) {
                netif_tx_wake_queue(sq->txq);
                sq->stats->wake++;
        }
}

bool mlx5e_poll_tx_cq(struct mlx5e_cq *cq, int napi_budget)
{
        struct mlx5e_sq_stats *stats;
        struct mlx5e_txqsq *sq;
        struct mlx5_cqe64 *cqe;
        u32 dma_fifo_cc;
        u32 nbytes;
        u16 npkts;
        u16 sqcc;
        int i;

        sq = container_of(cq, struct mlx5e_txqsq, cq);

        if (unlikely(!test_bit(MLX5E_SQ_STATE_ENABLED, &sq->state)))
                return false;

        cqe = mlx5_cqwq_get_cqe(&cq->wq);
        if (!cqe)
                return false;

        stats = sq->stats;

        npkts = 0;
        nbytes = 0;

        /* sq->cc must be updated only after mlx5_cqwq_update_db_record(),
         * otherwise a cq overrun may occur
         */
        sqcc = sq->cc;

        /* avoid dirtying sq cache line every cqe */
        dma_fifo_cc = sq->dma_fifo_cc;

        i = 0;
        do {
                struct mlx5e_tx_wqe_info *wi;
                u16 wqe_counter;
                bool last_wqe;
                u16 ci;

                mlx5_cqwq_pop(&cq->wq);

                wqe_counter = be16_to_cpu(cqe->wqe_counter);

                do {
                        last_wqe = (sqcc == wqe_counter);

                        ci = mlx5_wq_cyc_ctr2ix(&sq->wq, sqcc);
                        wi = &sq->db.wqe_info[ci];

                        sqcc += wi->num_wqebbs;

                        if (likely(wi->skb)) {
                                mlx5e_tx_wi_dma_unmap(sq, wi, &dma_fifo_cc);
                                mlx5e_consume_skb(sq, wi->skb, cqe, napi_budget);

                                npkts++;
                                nbytes += wi->num_bytes;
                                continue;
                        }

                        if (unlikely(mlx5e_ktls_tx_try_handle_resync_dump_comp(sq, wi,
                                                                               &dma_fifo_cc)))
                                continue;

                        if (wi->num_fifo_pkts) {
                                mlx5e_tx_wi_dma_unmap(sq, wi, &dma_fifo_cc);
                                mlx5e_tx_wi_consume_fifo_skbs(sq, wi, cqe, napi_budget);

                                npkts += wi->num_fifo_pkts;
                                nbytes += wi->num_bytes;
                        }
                } while (!last_wqe);

                if (unlikely(get_cqe_opcode(cqe) == MLX5_CQE_REQ_ERR)) {
                        if (!test_and_set_bit(MLX5E_SQ_STATE_RECOVERING,
                                              &sq->state)) {
                                mlx5e_dump_error_cqe(&sq->cq, sq->sqn,
                                                     (struct mlx5_err_cqe *)cqe);
                                mlx5_wq_cyc_wqe_dump(&sq->wq, ci, wi->num_wqebbs);
                                queue_work(cq->workqueue, &sq->recover_work);
                        }
                        stats->cqe_err++;
                }

        } while ((++i < MLX5E_TX_CQ_POLL_BUDGET) && (cqe = mlx5_cqwq_get_cqe(&cq->wq)));

        stats->cqes += i;

        mlx5_cqwq_update_db_record(&cq->wq);

        /* ensure cq space is freed before enabling more cqes */
        wmb();

        sq->dma_fifo_cc = dma_fifo_cc;
        sq->cc = sqcc;

        netdev_tx_completed_queue(sq->txq, npkts, nbytes);

        mlx5e_txqsq_wake(sq);

        return (i == MLX5E_TX_CQ_POLL_BUDGET);
}

static void mlx5e_tx_wi_kfree_fifo_skbs(struct mlx5e_txqsq *sq, struct mlx5e_tx_wqe_info *wi)
{
        int i;

        for (i = 0; i < wi->num_fifo_pkts; i++)
                dev_kfree_skb_any(mlx5e_skb_fifo_pop(&sq->db.skb_fifo));
}

void mlx5e_free_txqsq_descs(struct mlx5e_txqsq *sq)
{
        struct mlx5e_tx_wqe_info *wi;
        u32 dma_fifo_cc, nbytes = 0;
        u16 ci, sqcc, npkts = 0;

        sqcc = sq->cc;
        dma_fifo_cc = sq->dma_fifo_cc;

        while (sqcc != sq->pc) {
                ci = mlx5_wq_cyc_ctr2ix(&sq->wq, sqcc);
                wi = &sq->db.wqe_info[ci];

                sqcc += wi->num_wqebbs;

                if (likely(wi->skb)) {
                        mlx5e_tx_wi_dma_unmap(sq, wi, &dma_fifo_cc);
                        dev_kfree_skb_any(wi->skb);

                        npkts++;
                        nbytes += wi->num_bytes;
                        continue;
                }

                if (unlikely(mlx5e_ktls_tx_try_handle_resync_dump_comp(sq, wi, &dma_fifo_cc)))
                        continue;

                if (wi->num_fifo_pkts) {
                        mlx5e_tx_wi_dma_unmap(sq, wi, &dma_fifo_cc);
                        mlx5e_tx_wi_kfree_fifo_skbs(sq, wi);

                        npkts += wi->num_fifo_pkts;
                        nbytes += wi->num_bytes;
                }
        }

        sq->dma_fifo_cc = dma_fifo_cc;
        sq->cc = sqcc;

        /* Do not update BQL for TXQs that got replaced by new active ones, as
         * netdev_tx_reset_queue() is called for them in mlx5e_activate_txqsq().
         */
        if (sq == sq->priv->txq2sq[sq->txq_ix])
                netdev_tx_completed_queue(sq->txq, npkts, nbytes);
}

#ifdef CONFIG_MLX5_CORE_IPOIB
static inline void
mlx5i_txwqe_build_datagram(struct mlx5_av *av, u32 dqpn, u32 dqkey,
                           struct mlx5_wqe_datagram_seg *dseg)
{
        memcpy(&dseg->av, av, sizeof(struct mlx5_av));
        dseg->av.dqp_dct = cpu_to_be32(dqpn | MLX5_EXTENDED_UD_AV);
        dseg->av.key.qkey.qkey = cpu_to_be32(dqkey);
}

static void mlx5i_sq_calc_wqe_attr(struct sk_buff *skb,
                                   const struct mlx5e_tx_attr *attr,
                                   struct mlx5e_tx_wqe_attr *wqe_attr)
{
        u16 ds_cnt = sizeof(struct mlx5i_tx_wqe) / MLX5_SEND_WQE_DS;
        u16 ds_cnt_inl = 0;

        ds_cnt += !!attr->headlen + skb_shinfo(skb)->nr_frags;

        if (attr->ihs) {
                u16 inl = attr->ihs - INL_HDR_START_SZ;

                ds_cnt_inl = DIV_ROUND_UP(inl, MLX5_SEND_WQE_DS);
                ds_cnt += ds_cnt_inl;
        }

        *wqe_attr = (struct mlx5e_tx_wqe_attr) {
                .ds_cnt     = ds_cnt,
                .ds_cnt_inl = ds_cnt_inl,
                .num_wqebbs = DIV_ROUND_UP(ds_cnt, MLX5_SEND_WQEBB_NUM_DS),
        };
}

void mlx5i_sq_xmit(struct mlx5e_txqsq *sq, struct sk_buff *skb,
                   struct mlx5_av *av, u32 dqpn, u32 dqkey, bool xmit_more)
{
        struct mlx5e_tx_wqe_attr wqe_attr;
        struct mlx5e_tx_attr attr;
        struct mlx5i_tx_wqe *wqe;

        struct mlx5e_accel_tx_state accel = {};
        struct mlx5_wqe_datagram_seg *datagram;
        struct mlx5_wqe_ctrl_seg *cseg;
        struct mlx5_wqe_eth_seg  *eseg;
        struct mlx5_wqe_data_seg *dseg;
        struct mlx5e_tx_wqe_info *wi;

        struct mlx5e_sq_stats *stats = sq->stats;
        int num_dma;
        u16 pi;

        mlx5e_sq_xmit_prepare(sq, skb, &accel, &attr);
        mlx5i_sq_calc_wqe_attr(skb, &attr, &wqe_attr);

        pi = mlx5e_txqsq_get_next_pi(sq, wqe_attr.num_wqebbs);
        wqe = MLX5I_SQ_FETCH_WQE(sq, pi);

        stats->xmit_more += xmit_more;

        /* fill wqe */
        wi       = &sq->db.wqe_info[pi];
        cseg     = &wqe->ctrl;
        datagram = &wqe->datagram;
        eseg     = &wqe->eth;
        dseg     =  wqe->data;

        mlx5i_txwqe_build_datagram(av, dqpn, dqkey, datagram);

        mlx5e_txwqe_build_eseg_csum(sq, skb, &accel, eseg);

        eseg->mss = attr.mss;

        if (attr.ihs) {
                unsafe_memcpy(eseg->inline_hdr.start, skb->data,
                              attr.ihs,
                              MLX5_UNSAFE_MEMCPY_DISCLAIMER);
                eseg->inline_hdr.sz = cpu_to_be16(attr.ihs);
                dseg += wqe_attr.ds_cnt_inl;
        }

        num_dma = mlx5e_txwqe_build_dsegs(sq, skb, skb->data + attr.ihs,
                                          attr.headlen, dseg);
        if (unlikely(num_dma < 0))
                goto err_drop;

        mlx5e_txwqe_complete(sq, skb, &attr, &wqe_attr, num_dma, wi, cseg, eseg, xmit_more);

        return;

err_drop:
        stats->dropped++;
        dev_kfree_skb_any(skb);
        mlx5e_tx_flush(sq);
}
#endif
Linux
