net/mlx4_en: Support for configurable RSS hash function

The ConnectX HW is capable of using one of the following hash functions:
Toeplitz and an XOR hash function. This patch extends the implementation
of the mlx4_en driver set/get_rxfh callbacks to support getting and
setting the RSS hash function used by the device.

Signed-off-by: Eyal Perry <eyalpe@mellanox.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
index 28c3fc5..90e0f04 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
@@ -978,6 +978,27 @@ static u32 mlx4_en_get_rxfh_key_size(struct net_device *netdev)
        return MLX4_EN_RSS_KEY_SIZE;
 }
 
+static int mlx4_en_check_rxfh_func(struct net_device *dev, u8 hfunc)
+{
+       struct mlx4_en_priv *priv = netdev_priv(dev);
+
+       /* check if requested function is supported by the device */
+       if ((hfunc == ETH_RSS_HASH_TOP &&
+            !(priv->mdev->dev->caps.flags2 & MLX4_DEV_CAP_FLAG2_RSS_TOP)) ||
+           (hfunc == ETH_RSS_HASH_XOR &&
+            !(priv->mdev->dev->caps.flags2 & MLX4_DEV_CAP_FLAG2_RSS_XOR)))
+               return -EINVAL;
+
+       priv->rss_hash_fn = hfunc;
+       if (hfunc == ETH_RSS_HASH_TOP && !(dev->features & NETIF_F_RXHASH))
+               en_warn(priv,
+                       "Toeplitz hash function should be used in conjunction with RX hashing for optimal performance\n");
+       if (hfunc == ETH_RSS_HASH_XOR && (dev->features & NETIF_F_RXHASH))
+               en_warn(priv,
+                       "Enabling both XOR Hash function and RX Hashing can limit RPS functionality\n");
+       return 0;
+}
+
 static int mlx4_en_get_rxfh(struct net_device *dev, u32 *ring_index, u8 *key,
                            u8 *hfunc)
 {
@@ -999,7 +1020,7 @@ static int mlx4_en_get_rxfh(struct net_device *dev, u32 *ring_index, u8 *key,
        if (key)
                memcpy(key, priv->rss_key, MLX4_EN_RSS_KEY_SIZE);
        if (hfunc)
-               *hfunc = ETH_RSS_HASH_TOP;
+               *hfunc = priv->rss_hash_fn;
        return err;
 }
 
@@ -1013,10 +1034,6 @@ static int mlx4_en_set_rxfh(struct net_device *dev, const u32 *ring_index,
        int i;
        int rss_rings = 0;
 
-       /* We do not allow change in unsupported parameters */
-       if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
-               return -EOPNOTSUPP;
-
        /* Calculate RSS table size and make sure flows are spread evenly
         * between rings
         */
@@ -1037,6 +1054,12 @@ static int mlx4_en_set_rxfh(struct net_device *dev, const u32 *ring_index,
        if (!is_power_of_2(rss_rings))
                return -EINVAL;
 
+       if (hfunc != ETH_RSS_HASH_NO_CHANGE) {
+               err = mlx4_en_check_rxfh_func(dev, hfunc);
+               if (err)
+                       return err;
+       }
+
        mutex_lock(&mdev->state_lock);
        if (priv->port_up) {
                port_up = 1;
@@ -1047,6 +1070,7 @@ static int mlx4_en_set_rxfh(struct net_device *dev, const u32 *ring_index,
                priv->prof->rss_rings = rss_rings;
        if (key)
                memcpy(priv->rss_key, key, MLX4_EN_RSS_KEY_SIZE);
+
        if (port_up) {
                err = mlx4_en_start_port(dev);
                if (err)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
index 1597fb0..dccf0e1 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -2608,6 +2608,17 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
        if (mdev->dev->caps.steering_mode != MLX4_STEERING_MODE_A0)
                dev->priv_flags |= IFF_UNICAST_FLT;
 
+       /* Setting a default hash function value */
+       if (mdev->dev->caps.flags2 & MLX4_DEV_CAP_FLAG2_RSS_TOP) {
+               priv->rss_hash_fn = ETH_RSS_HASH_TOP;
+       } else if (mdev->dev->caps.flags2 & MLX4_DEV_CAP_FLAG2_RSS_XOR) {
+               priv->rss_hash_fn = ETH_RSS_HASH_XOR;
+       } else {
+               en_warn(priv,
+                       "No RSS hash capabilities exposed, using Toeplitz\n");
+               priv->rss_hash_fn = ETH_RSS_HASH_TOP;
+       }
+
        mdev->pndev[port] = dev;
 
        netif_carrier_off(dev);

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index 946d352..4ca396e 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -1223,7 +1223,19 @@ int mlx4_en_config_rss_steer(struct mlx4_en_priv *priv)
 
        rss_context->flags = rss_mask;
        rss_context->hash_fn = MLX4_RSS_HASH_TOP;
-       memcpy(rss_context->rss_key, priv->rss_key, MLX4_EN_RSS_KEY_SIZE);
+       if (priv->rss_hash_fn == ETH_RSS_HASH_XOR) {
+               rss_context->hash_fn = MLX4_RSS_HASH_XOR;
+       } else if (priv->rss_hash_fn == ETH_RSS_HASH_TOP) {
+               rss_context->hash_fn = MLX4_RSS_HASH_TOP;
+               memcpy(rss_context->rss_key, priv->rss_key,
+                      MLX4_EN_RSS_KEY_SIZE);
+               netdev_rss_key_fill(rss_context->rss_key,
+                                   MLX4_EN_RSS_KEY_SIZE);
+       } else {
+               en_err(priv, "Unknown RSS hash function requested\n");
+               err = -EINVAL;
+               goto indir_err;
+       }
        err = mlx4_qp_to_ready(mdev->dev, &priv->res.mtt, &context,
                               &rss_map->indir_qp, &rss_map->indir_state);
        if (err)

diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
index aaa7efb..ac48a8d 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -376,7 +376,6 @@ struct mlx4_en_port_profile {
 };
 
 struct mlx4_en_profile {
-       int rss_xor;
        int udp_rss;
        u8 rss_mask;
        u32 active_ports;
@@ -619,6 +618,7 @@ struct mlx4_en_priv {
 
        u32 pflags;
        u8 rss_key[MLX4_EN_RSS_KEY_SIZE];
+       u8 rss_hash_fn;
 };
 
 enum mlx4_en_wol {