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
--- a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
@@ -978,6 +978,27 @@
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 @@
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 @@
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 @@
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 @@
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)