mlx4_en: multiqueue support

By default the driver opens 8 TX queues (defined by MLX4_EN_NUM_TX_RINGS).
If the driver is configured to support Per Priority Flow Control, we open
8 additional TX rings.
dev->real_num_tx_queues is always set to be MLX4_EN_NUM_TX_RINGS.
The mlx4_en_select_queue() function uses standard hashing (skb_tx_hash)
in case that PPFC is not supported or the skb contain a vlan tag,
otherwise the queue is selected according to vlan priority.

Signed-off-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 28 insertions, 71 deletions

diff --git a/drivers/net/mlx4/en_main.c b/drivers/net/mlx4/en_main.c
index b510000d8391..9ed4a158f895 100644
--- a/drivers/net/mlx4/en_main.c
+++ b/drivers/net/mlx4/en_main.c
@@ -93,13 +93,8 @@ static int mlx4_en_get_profile(struct mlx4_en_dev *mdev)
                 params->prof[i].tx_ppp = pfctx;
                 params->prof[i].tx_ring_size = MLX4_EN_DEF_TX_RING_SIZE;
                 params->prof[i].rx_ring_size = MLX4_EN_DEF_RX_RING_SIZE;
-        }
-        if (pfcrx || pfctx) {
-                params->prof[1].tx_ring_num = MLX4_EN_TX_RING_NUM;
-                params->prof[2].tx_ring_num = MLX4_EN_TX_RING_NUM;
-        } else {
-                params->prof[1].tx_ring_num = 1;
-                params->prof[2].tx_ring_num = 1;
+                params->prof[i].tx_ring_num = MLX4_EN_NUM_TX_RINGS +
+                        (!!pfcrx) * MLX4_EN_NUM_PPP_RINGS;
         }
 
         return 0;
diff --git a/drivers/net/mlx4/en_netdev.c b/drivers/net/mlx4/en_netdev.c
index 16a634ffbcdf..37e4d30cbf04 100644
--- a/drivers/net/mlx4/en_netdev.c
+++ b/drivers/net/mlx4/en_netdev.c
@@ -934,6 +934,7 @@ static const struct net_device_ops mlx4_netdev_ops = {
         .ndo_open               = mlx4_en_open,
         .ndo_stop               = mlx4_en_close,
         .ndo_start_xmit         = mlx4_en_xmit,
+        .ndo_select_queue       = mlx4_en_select_queue,
         .ndo_get_stats          = mlx4_en_get_stats,
         .ndo_set_multicast_list = mlx4_en_set_multicast,
         .ndo_set_mac_address    = mlx4_en_set_mac,
@@ -956,7 +957,7 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
         int i;
         int err;
 
-        dev = alloc_etherdev(sizeof(struct mlx4_en_priv));
+        dev = alloc_etherdev_mq(sizeof(struct mlx4_en_priv), prof->tx_ring_num);
         if (dev == NULL) {
                 mlx4_err(mdev, "Net device allocation failed\n");
                 return -ENOMEM;
@@ -1018,14 +1019,12 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
         }
         priv->allocated = 1;
 
-        /* Populate Tx priority mappings */
-        mlx4_en_set_prio_map(priv, priv->tx_prio_map, prof->tx_ring_num);
-
         /*
          * Initialize netdev entry points
          */
         dev->netdev_ops = &mlx4_netdev_ops;
         dev->watchdog_timeo = MLX4_EN_WATCHDOG_TIMEOUT;
+        dev->real_num_tx_queues = MLX4_EN_NUM_TX_RINGS;
 
         SET_ETHTOOL_OPS(dev, &mlx4_en_ethtool_ops);
 
diff --git a/drivers/net/mlx4/en_tx.c b/drivers/net/mlx4/en_tx.c
index 95703f90c1b9..3719d1ac3950 100644
--- a/drivers/net/mlx4/en_tx.c
+++ b/drivers/net/mlx4/en_tx.c
@@ -297,34 +297,6 @@ int mlx4_en_free_tx_buf(struct net_device *dev, struct mlx4_en_tx_ring *ring)
         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;
-                en_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)
 {
@@ -386,18 +358,8 @@ static void mlx4_en_process_tx_cq(struct net_device *dev, struct mlx4_en_cq *cq)
         if (unlikely(ring->blocked)) {
                 if ((u32) (ring->prod - ring->cons) <=
                      ring->size - HEADROOM - MAX_DESC_TXBBS) {
-
-                        /* 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);
+                        netif_tx_wake_queue(netdev_get_tx_queue(dev, cq->ring));
                         priv->port_stats.wake_queue++;
                 }
         }
@@ -616,21 +578,20 @@ static void build_inline_wqe(struct mlx4_en_tx_desc *tx_desc, struct sk_buff *sk
         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)
+u16 mlx4_en_select_queue(struct net_device *dev, struct sk_buff *skb)
 {
-        int tx_ind;
+        struct mlx4_en_priv *priv = netdev_priv(dev);
+        u16 vlan_tag = 0;
 
-        /* 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;
+        /* 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 tx_ind;
+
+        return skb_tx_hash(dev, skb);
 }
 
 int mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
@@ -650,7 +611,7 @@ int mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
         dma_addr_t dma;
         u32 index;
         __be32 op_own;
-        u16 vlan_tag;
+        u16 vlan_tag = 0;
         int i;
         int lso_header_size;
         void *fragptr;
@@ -673,15 +634,16 @@ int mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
                 return NETDEV_TX_OK;
         }
 
-        tx_ind = get_vlan_info(priv, skb, &vlan_tag);
+        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.
-                 * TODO: implement multi-queue support (per-queue stop) */
-                netif_stop_queue(dev);
+                /* 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++;
 
diff --git a/drivers/net/mlx4/mlx4_en.h b/drivers/net/mlx4/mlx4_en.h
index fcbfcfc11568..4de8db00809d 100644
--- a/drivers/net/mlx4/mlx4_en.h
+++ b/drivers/net/mlx4/mlx4_en.h
@@ -139,8 +139,10 @@ enum {
 #define MLX4_EN_MIN_RX_SIZE     (MLX4_EN_ALLOC_SIZE / SMP_CACHE_BYTES)
 #define MLX4_EN_MIN_TX_SIZE     (4096 / TXBB_SIZE)
 
-#define MLX4_EN_TX_RING_NUM             9
-#define MLX4_EN_DEF_TX_RING_SIZE        1024
+#define MLX4_EN_SMALL_PKT_SIZE          64
+#define MLX4_EN_NUM_TX_RINGS            8
+#define MLX4_EN_NUM_PPP_RINGS           8
+#define MLX4_EN_DEF_TX_RING_SIZE        512
 #define MLX4_EN_DEF_RX_RING_SIZE        1024
 
 /* Target number of packets to coalesce with interrupt moderation */
@@ -478,7 +480,6 @@ struct mlx4_en_priv {
         int base_qpn;
 
         struct mlx4_en_rss_map rss_map;
-        u16 tx_prio_map[8];
         u32 flags;
 #define MLX4_EN_FLAG_PROMISC    0x1
         u32 tx_ring_num;
@@ -526,6 +527,7 @@ int mlx4_en_arm_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq);
 
 void mlx4_en_poll_tx_cq(unsigned long data);
 void mlx4_en_tx_irq(struct mlx4_cq *mcq);
+u16 mlx4_en_select_queue(struct net_device *dev, struct sk_buff *skb);
 int mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev);
 
 int mlx4_en_create_tx_ring(struct mlx4_en_priv *priv, struct mlx4_en_tx_ring *ring,
@@ -560,7 +562,6 @@ void mlx4_en_calc_rx_buf(struct net_device *dev);
 void mlx4_en_set_default_rss_map(struct mlx4_en_priv *priv,
                                  struct mlx4_en_rss_map *rss_map,
                                  int num_entries, int num_rings);
-void mlx4_en_set_prio_map(struct mlx4_en_priv *priv, u16 *prio_map, u32 ring_num);
 int mlx4_en_config_rss_steer(struct mlx4_en_priv *priv);
 void mlx4_en_release_rss_steer(struct mlx4_en_priv *priv);
 int mlx4_en_free_tx_buf(struct net_device *dev, struct mlx4_en_tx_ring *ring);