From 9e77a2b837bbd7197da966f0915e8f1ddb2ca850 Mon Sep 17 00:00:00 2001 From: Amir Vadai Date: Tue, 18 Jun 2013 16:18:27 +0300 Subject: [PATCH] net/mlx4_en: Add Low Latency Socket (LLS) support Add basic support for LLS. Signed-off-by: Amir Vadai Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlx4/en_cq.c | 3 + drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 43 ++++++++- drivers/net/ethernet/mellanox/mlx4/en_rx.c | 15 ++- drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 121 +++++++++++++++++++++++++ 4 files changed, 178 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/en_cq.c b/drivers/net/ethernet/mellanox/mlx4/en_cq.c index 1e6c594..3e2d504 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_cq.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_cq.c @@ -139,6 +139,7 @@ int mlx4_en_activate_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq, if (!cq->is_tx) { netif_napi_add(cq->dev, &cq->napi, mlx4_en_poll_rx_cq, 64); + napi_hash_add(&cq->napi); napi_enable(&cq->napi); } @@ -162,6 +163,8 @@ void mlx4_en_deactivate_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq) { if (!cq->is_tx) { napi_disable(&cq->napi); + napi_hash_del(&cq->napi); + synchronize_rcu(); netif_napi_del(&cq->napi); } diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c index ade276c..ab9ec91 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c @@ -38,6 +38,7 @@ #include #include #include +#include #include #include @@ -67,6 +68,30 @@ int mlx4_en_setup_tc(struct net_device *dev, u8 up) return 0; } +#ifdef CONFIG_NET_LL_RX_POLL +/* must be called with local_bh_disable()d */ +static int mlx4_en_low_latency_recv(struct napi_struct *napi) +{ + 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); + struct mlx4_en_rx_ring *rx_ring = &priv->rx_ring[cq->ring]; + int done; + + if (!priv->port_up) + return LL_FLUSH_FAILED; + + if (!mlx4_en_cq_lock_poll(cq)) + return LL_FLUSH_BUSY; + + done = mlx4_en_process_rx_cq(dev, cq, 4); + + mlx4_en_cq_unlock_poll(cq); + + return done; +} +#endif /* CONFIG_NET_LL_RX_POLL */ + #ifdef CONFIG_RFS_ACCEL struct mlx4_en_filter { @@ -1445,6 +1470,8 @@ int mlx4_en_start_port(struct net_device *dev) for (i = 0; i < priv->rx_ring_num; i++) { cq = &priv->rx_cq[i]; + mlx4_en_cq_init_lock(cq); + err = mlx4_en_activate_cq(priv, cq, i); if (err) { en_err(priv, "Failed activating Rx CQ\n"); @@ -1694,10 +1721,19 @@ void mlx4_en_stop_port(struct net_device *dev, int detach) /* Free RX Rings */ for (i = 0; i < priv->rx_ring_num; i++) { + struct mlx4_en_cq *cq = &priv->rx_cq[i]; + + local_bh_disable(); + while (!mlx4_en_cq_lock_napi(cq)) { + pr_info("CQ %d locked\n", i); + mdelay(1); + } + local_bh_enable(); + mlx4_en_deactivate_rx_ring(priv, &priv->rx_ring[i]); - while (test_bit(NAPI_STATE_SCHED, &priv->rx_cq[i].napi.state)) + while (test_bit(NAPI_STATE_SCHED, &cq->napi.state)) msleep(1); - mlx4_en_deactivate_cq(priv, &priv->rx_cq[i]); + mlx4_en_deactivate_cq(priv, cq); } /* close port*/ @@ -2090,6 +2126,9 @@ static const struct net_device_ops mlx4_netdev_ops = { #ifdef CONFIG_RFS_ACCEL .ndo_rx_flow_steer = mlx4_en_filter_rfs, #endif +#ifdef CONFIG_NET_LL_RX_POLL + .ndo_ll_poll = mlx4_en_low_latency_recv, +#endif }; static const struct net_device_ops mlx4_netdev_ops_master = { diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c index 02aee1e..9c57581 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c @@ -31,6 +31,7 @@ * */ +#include #include #include #include @@ -656,8 +657,11 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud * - DIX Ethernet (type interpretation) * - TCP/IP (v4) * - without IP options - * - not an IP fragment */ - if (dev->features & NETIF_F_GRO) { + * - not an IP fragment + * - no LLS polling in progress + */ + if (!mlx4_en_cq_ll_polling(cq) && + (dev->features & NETIF_F_GRO)) { struct sk_buff *gro_skb = napi_get_frags(&cq->napi); if (!gro_skb) goto next; @@ -737,6 +741,8 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct mlx4_en_cq *cq, int bud timestamp); } + skb_mark_ll(skb, &cq->napi); + /* Push it up the stack */ netif_receive_skb(skb); @@ -781,8 +787,13 @@ int mlx4_en_poll_rx_cq(struct napi_struct *napi, int budget) struct mlx4_en_priv *priv = netdev_priv(dev); int done; + if (!mlx4_en_cq_lock_napi(cq)) + return budget; + done = mlx4_en_process_rx_cq(dev, cq, budget); + mlx4_en_cq_unlock_napi(cq); + /* If we used up all the quota - we're probably not done yet... */ if (done == budget) INC_PERF_COUNTER(priv->pstats.napi_quota); diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h index b1f51c1..11c862e 100644 --- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h +++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h @@ -310,6 +310,19 @@ struct mlx4_en_cq { u16 moder_cnt; struct mlx4_cqe *buf; #define MLX4_EN_OPCODE_ERROR 0x1e + +#ifdef CONFIG_NET_LL_RX_POLL + unsigned int state; +#define MLX4_EN_CQ_STATE_IDLE 0 +#define MLX4_EN_CQ_STATE_NAPI 1 /* NAPI owns this CQ */ +#define MLX4_EN_CQ_STATE_POLL 2 /* poll owns this CQ */ +#define MLX4_CQ_LOCKED (MLX4_EN_CQ_STATE_NAPI | MLX4_EN_CQ_STATE_POLL) +#define MLX4_EN_CQ_STATE_NAPI_YIELD 4 /* NAPI yielded this CQ */ +#define MLX4_EN_CQ_STATE_POLL_YIELD 8 /* poll yielded this CQ */ +#define CQ_YIELD (MLX4_EN_CQ_STATE_NAPI_YIELD | MLX4_EN_CQ_STATE_POLL_YIELD) +#define CQ_USER_PEND (MLX4_EN_CQ_STATE_POLL | MLX4_EN_CQ_STATE_POLL_YIELD) + spinlock_t poll_lock; /* protects from LLS/napi conflicts */ +#endif /* CONFIG_NET_LL_RX_POLL */ }; struct mlx4_en_port_profile { @@ -562,6 +575,114 @@ struct mlx4_mac_entry { struct rcu_head rcu; }; +#ifdef CONFIG_NET_LL_RX_POLL +static inline void mlx4_en_cq_init_lock(struct mlx4_en_cq *cq) +{ + spin_lock_init(&cq->poll_lock); + cq->state = MLX4_EN_CQ_STATE_IDLE; +} + +/* called from the device poll rutine to get ownership of a cq */ +static inline bool mlx4_en_cq_lock_napi(struct mlx4_en_cq *cq) +{ + int rc = true; + spin_lock(&cq->poll_lock); + if (cq->state & MLX4_CQ_LOCKED) { + WARN_ON(cq->state & MLX4_EN_CQ_STATE_NAPI); + cq->state |= MLX4_EN_CQ_STATE_NAPI_YIELD; + rc = false; + } else + /* we don't care if someone yielded */ + cq->state = MLX4_EN_CQ_STATE_NAPI; + spin_unlock(&cq->poll_lock); + return rc; +} + +/* returns true is someone tried to get the cq while napi had it */ +static inline bool mlx4_en_cq_unlock_napi(struct mlx4_en_cq *cq) +{ + int rc = false; + spin_lock(&cq->poll_lock); + WARN_ON(cq->state & (MLX4_EN_CQ_STATE_POLL | + MLX4_EN_CQ_STATE_NAPI_YIELD)); + + if (cq->state & MLX4_EN_CQ_STATE_POLL_YIELD) + rc = true; + cq->state = MLX4_EN_CQ_STATE_IDLE; + spin_unlock(&cq->poll_lock); + return rc; +} + +/* called from mlx4_en_low_latency_poll() */ +static inline bool mlx4_en_cq_lock_poll(struct mlx4_en_cq *cq) +{ + int rc = true; + spin_lock_bh(&cq->poll_lock); + if ((cq->state & MLX4_CQ_LOCKED)) { + struct net_device *dev = cq->dev; + struct mlx4_en_priv *priv = netdev_priv(dev); + struct mlx4_en_rx_ring *rx_ring = &priv->rx_ring[cq->ring]; + + cq->state |= MLX4_EN_CQ_STATE_POLL_YIELD; + rc = false; + } else + /* preserve yield marks */ + cq->state |= MLX4_EN_CQ_STATE_POLL; + spin_unlock_bh(&cq->poll_lock); + return rc; +} + +/* returns true if someone tried to get the cq while it was locked */ +static inline bool mlx4_en_cq_unlock_poll(struct mlx4_en_cq *cq) +{ + int rc = false; + spin_lock_bh(&cq->poll_lock); + WARN_ON(cq->state & (MLX4_EN_CQ_STATE_NAPI)); + + if (cq->state & MLX4_EN_CQ_STATE_POLL_YIELD) + rc = true; + cq->state = MLX4_EN_CQ_STATE_IDLE; + spin_unlock_bh(&cq->poll_lock); + return rc; +} + +/* true if a socket is polling, even if it did not get the lock */ +static inline bool mlx4_en_cq_ll_polling(struct mlx4_en_cq *cq) +{ + WARN_ON(!(cq->state & MLX4_CQ_LOCKED)); + return cq->state & CQ_USER_PEND; +} +#else +static inline void mlx4_en_cq_init_lock(struct mlx4_en_cq *cq) +{ +} + +static inline bool mlx4_en_cq_lock_napi(struct mlx4_en_cq *cq) +{ + return true; +} + +static inline bool mlx4_en_cq_unlock_napi(struct mlx4_en_cq *cq) +{ + return false; +} + +static inline bool mlx4_en_cq_lock_poll(struct mlx4_en_cq *cq) +{ + return false; +} + +static inline bool mlx4_en_cq_unlock_poll(struct mlx4_en_cq *cq) +{ + return false; +} + +static inline bool mlx4_en_cq_ll_polling(struct mlx4_en_cq *cq) +{ + return false; +} +#endif /* CONFIG_NET_LL_RX_POLL */ + #define MLX4_EN_WOL_DO_MODIFY (1ULL << 63) void mlx4_en_update_loopback_state(struct net_device *dev, -- 2.7.4