ethtool: Support for configurable RSS hash function

This patch extends the set/get_rxfh ethtool-options for getting or
setting the RSS hash function.

It modifies drivers implementation of set/get_rxfh accordingly.

This change also delegates the responsibility of checking whether a
modification to a certain RX flow hash parameter is supported to the
driver implementation of set_rxfh.

User-kernel API is done through the new hfunc bitmask field in the
ethtool_rxfh struct. A bit set in the hfunc field is corresponding to an
index in the new string-set ETH_SS_RSS_HASH_FUNCS.

Got approval from most of the relevant driver maintainers that their
driver is using Toeplitz, and for the few that didn't answered, also
assumed it is Toeplitz.

Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Ariel Elior <ariel.elior@qlogic.com>
Cc: Prashant Sreedharan <prashant@broadcom.com>
Cc: Michael Chan <mchan@broadcom.com>
Cc: Hariprasad S <hariprasad@chelsio.com>
Cc: Sathya Perla <sathya.perla@emulex.com>
Cc: Subbu Seetharaman <subbu.seetharaman@emulex.com>
Cc: Ajit Khaparde <ajit.khaparde@emulex.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Cc: Bruce Allan <bruce.w.allan@intel.com>
Cc: Carolyn Wyborny <carolyn.wyborny@intel.com>
Cc: Don Skidmore <donald.c.skidmore@intel.com>
Cc: Greg Rose <gregory.v.rose@intel.com>
Cc: Matthew Vick <matthew.vick@intel.com>
Cc: John Ronciak <john.ronciak@intel.com>
Cc: Mitch Williams <mitch.a.williams@intel.com>
Cc: Amir Vadai <amirv@mellanox.com>
Cc: Solarflare linux maintainers <linux-net-drivers@solarflare.com>
Cc: Shradha Shah <sshah@solarflare.com>
Cc: Shreyas Bhatewara <sbhatewara@vmware.com>
Cc: "VMware, Inc." <pv-drivers@vmware.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
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>

14 files changed, 223 insertions, 70 deletions

diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-ethtool.c b/drivers/net/ethernet/amd/xgbe/xgbe-ethtool.c
index 95d44538357f..ebf489351555 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-ethtool.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-ethtool.c
@@ -511,7 +511,8 @@ static u32 xgbe_get_rxfh_indir_size(struct net_device *netdev)
         return ARRAY_SIZE(pdata->rss_table);
 }
 
-static int xgbe_get_rxfh(struct net_device *netdev, u32 *indir, u8 *key)
+static int xgbe_get_rxfh(struct net_device *netdev, u32 *indir, u8 *key,
+                         u8 *hfunc)
 {
         struct xgbe_prv_data *pdata = netdev_priv(netdev);
         unsigned int i;
@@ -525,16 +526,22 @@ static int xgbe_get_rxfh(struct net_device *netdev, u32 *indir, u8 *key)
         if (key)
                 memcpy(key, pdata->rss_key, sizeof(pdata->rss_key));
 
+        if (hfunc)
+                *hfunc = ETH_RSS_HASH_TOP;
+
         return 0;
 }
 
 static int xgbe_set_rxfh(struct net_device *netdev, const u32 *indir,
-                         const u8 *key)
+                         const u8 *key, const u8 hfunc)
 {
         struct xgbe_prv_data *pdata = netdev_priv(netdev);
         struct xgbe_hw_if *hw_if = &pdata->hw_if;
         unsigned int ret;
 
+        if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
+                return -EOPNOTSUPP;
+
         if (indir) {
                 ret = hw_if->set_rss_lookup_table(pdata, indir);
                 if (ret)
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c
index 1edc931b1458..ffe4e003e636 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c
@@ -3358,12 +3358,18 @@ static u32 bnx2x_get_rxfh_indir_size(struct net_device *dev)
         return T_ETH_INDIRECTION_TABLE_SIZE;
 }
 
-static int bnx2x_get_rxfh(struct net_device *dev, u32 *indir, u8 *key)
+static int bnx2x_get_rxfh(struct net_device *dev, u32 *indir, u8 *key,
+                          u8 *hfunc)
 {
         struct bnx2x *bp = netdev_priv(dev);
         u8 ind_table[T_ETH_INDIRECTION_TABLE_SIZE] = {0};
         size_t i;
 
+        if (hfunc)
+                *hfunc = ETH_RSS_HASH_TOP;
+        if (!indir)
+                return 0;
+
         /* Get the current configuration of the RSS indirection table */
         bnx2x_get_rss_ind_table(&bp->rss_conf_obj, ind_table);
 
@@ -3383,11 +3389,21 @@ static int bnx2x_get_rxfh(struct net_device *dev, u32 *indir, u8 *key)
 }
 
 static int bnx2x_set_rxfh(struct net_device *dev, const u32 *indir,
-                          const u8 *key)
+                          const u8 *key, const u8 hfunc)
 {
         struct bnx2x *bp = netdev_priv(dev);
         size_t i;
 
+        /* We require at least one supported parameter to be changed and no
+         * change in any of the unsupported parameters
+         */
+        if (key ||
+            (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP))
+                return -EOPNOTSUPP;
+
+        if (!indir)
+                return 0;
+
         for (i = 0; i < T_ETH_INDIRECTION_TABLE_SIZE; i++) {
                 /*
                  * The same as in bnx2x_get_rxfh: we can't use a memcpy()
diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index 43fd1b72c1ea..bb48a610b72a 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -12561,22 +12561,38 @@ static u32 tg3_get_rxfh_indir_size(struct net_device *dev)
         return size;
 }
 
-static int tg3_get_rxfh(struct net_device *dev, u32 *indir, u8 *key)
+static int tg3_get_rxfh(struct net_device *dev, u32 *indir, u8 *key, u8 *hfunc)
 {
         struct tg3 *tp = netdev_priv(dev);
         int i;
 
+        if (hfunc)
+                *hfunc = ETH_RSS_HASH_TOP;
+        if (!indir)
+                return 0;
+
         for (i = 0; i < TG3_RSS_INDIR_TBL_SIZE; i++)
                 indir[i] = tp->rss_ind_tbl[i];
 
         return 0;
 }
 
-static int tg3_set_rxfh(struct net_device *dev, const u32 *indir, const u8 *key)
+static int tg3_set_rxfh(struct net_device *dev, const u32 *indir, const u8 *key,
+                        const u8 hfunc)
 {
         struct tg3 *tp = netdev_priv(dev);
         size_t i;
 
+        /* We require at least one supported parameter to be changed and no
+         * change in any of the unsupported parameters
+         */
+        if (key ||
+            (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP))
+                return -EOPNOTSUPP;
+
+        if (!indir)
+                return 0;
+
         for (i = 0; i < TG3_RSS_INDIR_TBL_SIZE; i++)
                 tp->rss_ind_tbl[i] = indir[i];
 
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
index 3aea82bb9039..e7342bc85026 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
@@ -2923,21 +2923,35 @@ static u32 get_rss_table_size(struct net_device *dev)
         return pi->rss_size;
 }
 
-static int get_rss_table(struct net_device *dev, u32 *p, u8 *key)
+static int get_rss_table(struct net_device *dev, u32 *p, u8 *key, u8 *hfunc)
 {
         const struct port_info *pi = netdev_priv(dev);
         unsigned int n = pi->rss_size;
 
+        if (hfunc)
+                *hfunc = ETH_RSS_HASH_TOP;
+        if (!p)
+                return 0;
         while (n--)
                 p[n] = pi->rss[n];
         return 0;
 }
 
-static int set_rss_table(struct net_device *dev, const u32 *p, const u8 *key)
+static int set_rss_table(struct net_device *dev, const u32 *p, const u8 *key,
+                         const u8 hfunc)
 {
         unsigned int i;
         struct port_info *pi = netdev_priv(dev);
 
+        /* We require at least one supported parameter to be changed and no
+         * change in any of the unsupported parameters
+         */
+        if (key ||
+            (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP))
+                return -EOPNOTSUPP;
+        if (!p)
+                return 0;
+
         for (i = 0; i < pi->rss_size; i++)
                 pi->rss[i] = p[i];
         if (pi->adapter->flags & FULL_INIT_DONE)
diff --git a/drivers/net/ethernet/emulex/benet/be_ethtool.c b/drivers/net/ethernet/emulex/benet/be_ethtool.c
index e42a791c1835..73a500ccbf69 100644
--- a/drivers/net/ethernet/emulex/benet/be_ethtool.c
+++ b/drivers/net/ethernet/emulex/benet/be_ethtool.c
@@ -1171,7 +1171,8 @@ static u32 be_get_rxfh_key_size(struct net_device *netdev)
         return RSS_HASH_KEY_LEN;
 }
 
-static int be_get_rxfh(struct net_device *netdev, u32 *indir, u8 *hkey)
+static int be_get_rxfh(struct net_device *netdev, u32 *indir, u8 *hkey,
+                       u8 *hfunc)
 {
         struct be_adapter *adapter = netdev_priv(netdev);
         int i;
@@ -1185,16 +1186,23 @@ static int be_get_rxfh(struct net_device *netdev, u32 *indir, u8 *hkey)
         if (hkey)
                 memcpy(hkey, rss->rss_hkey, RSS_HASH_KEY_LEN);
 
+        if (hfunc)
+                *hfunc = ETH_RSS_HASH_TOP;
+
         return 0;
 }
 
 static int be_set_rxfh(struct net_device *netdev, const u32 *indir,
-                       const u8 *hkey)
+                       const u8 *hkey, const u8 hfunc)
 {
         int rc = 0, i, j;
         struct be_adapter *adapter = netdev_priv(netdev);
         u8 rsstable[RSS_INDIR_TABLE_LEN];
 
+        /* We do not allow change in unsupported parameters */
+        if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
+                return -EOPNOTSUPP;
+
         if (indir) {
                 struct be_rx_obj *rxo;
 
diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c b/drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c
index 2d04464e6aa3..651f53bc7376 100644
--- a/drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c
+++ b/drivers/net/ethernet/intel/fm10k/fm10k_ethtool.c
@@ -916,11 +916,15 @@ static u32 fm10k_get_rssrk_size(struct net_device *netdev)
         return FM10K_RSSRK_SIZE * FM10K_RSSRK_ENTRIES_PER_REG;
 }
 
-static int fm10k_get_rssh(struct net_device *netdev, u32 *indir, u8 *key)
+static int fm10k_get_rssh(struct net_device *netdev, u32 *indir, u8 *key,
+                          u8 *hfunc)
 {
         struct fm10k_intfc *interface = netdev_priv(netdev);
         int i, err;
 
+        if (hfunc)
+                *hfunc = ETH_RSS_HASH_TOP;
+
         err = fm10k_get_reta(netdev, indir);
         if (err || !key)
                 return err;
@@ -932,12 +936,16 @@ static int fm10k_get_rssh(struct net_device *netdev, u32 *indir, u8 *key)
 }
 
 static int fm10k_set_rssh(struct net_device *netdev, const u32 *indir,
-                          const u8 *key)
+                          const u8 *key, const u8 hfunc)
 {
         struct fm10k_intfc *interface = netdev_priv(netdev);
         struct fm10k_hw *hw = &interface->hw;
         int i, err;
 
+        /* We do not allow change in unsupported parameters */
+        if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP)
+                return -EOPNOTSUPP;
+
         err = fm10k_set_reta(netdev, indir);
         if (err || !key)
                 return err;
diff --git a/drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c b/drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c
index 69a269b23be6..69b97bac182c 100644
--- a/drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c
+++ b/drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c
@@ -627,13 +627,19 @@ static u32 i40evf_get_rxfh_indir_size(struct net_device *netdev)
  *
  * Reads the indirection table directly from the hardware. Always returns 0.
  **/
-static int i40evf_get_rxfh(struct net_device *netdev, u32 *indir, u8 *key)
+static int i40evf_get_rxfh(struct net_device *netdev, u32 *indir, u8 *key,
+                           u8 *hfunc)
 {
         struct i40evf_adapter *adapter = netdev_priv(netdev);
         struct i40e_hw *hw = &adapter->hw;
         u32 hlut_val;
         int i, j;
 
+        if (hfunc)
+                *hfunc = ETH_RSS_HASH_TOP;
+        if (!indir)
+                return 0;
+
         for (i = 0, j = 0; i <= I40E_VFQF_HLUT_MAX_INDEX; i++) {
                 hlut_val = rd32(hw, I40E_VFQF_HLUT(i));
                 indir[j++] = hlut_val & 0xff;
@@ -654,13 +660,20 @@ static int i40evf_get_rxfh(struct net_device *netdev, u32 *indir, u8 *key)
  * returns 0 after programming the table.
  **/
 static int i40evf_set_rxfh(struct net_device *netdev, const u32 *indir,
-                           const u8 *key)
+                           const u8 *key, const u8 hfunc)
 {
         struct i40evf_adapter *adapter = netdev_priv(netdev);
         struct i40e_hw *hw = &adapter->hw;
         u32 hlut_val;
         int i, j;
 
+        /* We do not allow change in unsupported parameters */
+        if (key ||
+            (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP))
+                return -EOPNOTSUPP;
+        if (!indir)
+                return 0;
+
         for (i = 0, j = 0; i <= I40E_VFQF_HLUT_MAX_INDEX; i++) {
                 hlut_val = indir[j++];
                 hlut_val |= indir[j++] << 8;
diff --git a/drivers/net/ethernet/intel/igb/igb_ethtool.c b/drivers/net/ethernet/intel/igb/igb_ethtool.c
index 02cfd3b14762..d5673eb90c54 100644
--- a/drivers/net/ethernet/intel/igb/igb_ethtool.c
+++ b/drivers/net/ethernet/intel/igb/igb_ethtool.c
@@ -2842,11 +2842,16 @@ static u32 igb_get_rxfh_indir_size(struct net_device *netdev)
         return IGB_RETA_SIZE;
 }
 
-static int igb_get_rxfh(struct net_device *netdev, u32 *indir, u8 *key)
+static int igb_get_rxfh(struct net_device *netdev, u32 *indir, u8 *key,
+                        u8 *hfunc)
 {
         struct igb_adapter *adapter = netdev_priv(netdev);
         int i;
 
+        if (hfunc)
+                *hfunc = ETH_RSS_HASH_TOP;
+        if (!indir)
+                return 0;
         for (i = 0; i < IGB_RETA_SIZE; i++)
                 indir[i] = adapter->rss_indir_tbl[i];
 
@@ -2889,13 +2894,20 @@ void igb_write_rss_indir_tbl(struct igb_adapter *adapter)
 }
 
 static int igb_set_rxfh(struct net_device *netdev, const u32 *indir,
-                        const u8 *key)
+                        const u8 *key, const u8 hfunc)
 {
         struct igb_adapter *adapter = netdev_priv(netdev);
         struct e1000_hw *hw = &adapter->hw;
         int i;
         u32 num_queues;
 
+        /* We do not allow change in unsupported parameters */
+        if (key ||
+            (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP))
+                return -EOPNOTSUPP;
+        if (!indir)
+                return 0;
+
         num_queues = adapter->rss_queues;
 
         switch (hw->mac.type) {
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
index c45e06abc073..28c3fc5a0791 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c
@@ -978,7 +978,8 @@ static u32 mlx4_en_get_rxfh_key_size(struct net_device *netdev)
         return MLX4_EN_RSS_KEY_SIZE;
 }
 
-static int mlx4_en_get_rxfh(struct net_device *dev, u32 *ring_index, u8 *key)
+static int mlx4_en_get_rxfh(struct net_device *dev, u32 *ring_index, u8 *key,
+                            u8 *hfunc)
 {
         struct mlx4_en_priv *priv = netdev_priv(dev);
         struct mlx4_en_rss_map *rss_map = &priv->rss_map;
@@ -990,16 +991,20 @@ static int mlx4_en_get_rxfh(struct net_device *dev, u32 *ring_index, u8 *key)
         rss_rings = 1 << ilog2(rss_rings);
 
         while (n--) {
+                if (!ring_index)
+                        break;
                 ring_index[n] = rss_map->qps[n % rss_rings].qpn -
                         rss_map->base_qpn;
         }
         if (key)
                 memcpy(key, priv->rss_key, MLX4_EN_RSS_KEY_SIZE);
+        if (hfunc)
+                *hfunc = ETH_RSS_HASH_TOP;
         return err;
 }
 
 static int mlx4_en_set_rxfh(struct net_device *dev, const u32 *ring_index,
-                            const u8 *key)
+                            const u8 *key, const u8 hfunc)
 {
         struct mlx4_en_priv *priv = netdev_priv(dev);
         struct mlx4_en_dev *mdev = priv->mdev;
@@ -1008,6 +1013,10 @@ 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
          */
diff --git a/drivers/net/ethernet/sfc/ethtool.c b/drivers/net/ethernet/sfc/ethtool.c
index cad258a78708..4835bc0d0de8 100644
--- a/drivers/net/ethernet/sfc/ethtool.c
+++ b/drivers/net/ethernet/sfc/ethtool.c
@@ -1086,19 +1086,29 @@ static u32 efx_ethtool_get_rxfh_indir_size(struct net_device *net_dev)
                 0 : ARRAY_SIZE(efx->rx_indir_table));
 }
 
-static int efx_ethtool_get_rxfh(struct net_device *net_dev, u32 *indir, u8 *key)
+static int efx_ethtool_get_rxfh(struct net_device *net_dev, u32 *indir, u8 *key,
+                                u8 *hfunc)
 {
         struct efx_nic *efx = netdev_priv(net_dev);
 
-        memcpy(indir, efx->rx_indir_table, sizeof(efx->rx_indir_table));
+        if (hfunc)
+                *hfunc = ETH_RSS_HASH_TOP;
+        if (indir)
+                memcpy(indir, efx->rx_indir_table, sizeof(efx->rx_indir_table));
         return 0;
 }
 
-static int efx_ethtool_set_rxfh(struct net_device *net_dev,
-                                const u32 *indir, const u8 *key)
+static int efx_ethtool_set_rxfh(struct net_device *net_dev, const u32 *indir,
+                                const u8 *key, const u8 hfunc)
 {
         struct efx_nic *efx = netdev_priv(net_dev);
 
+        /* We do not allow change in unsupported parameters */
+        if (key ||
+            (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP))
+                return -EOPNOTSUPP;
+        if (!indir)
+                return 0;
         memcpy(efx->rx_indir_table, indir, sizeof(efx->rx_indir_table));
         efx->type->rx_push_rss_config(efx);
         return 0;
diff --git a/drivers/net/vmxnet3/vmxnet3_ethtool.c b/drivers/net/vmxnet3/vmxnet3_ethtool.c
index b725fd9e7803..b7b53329d575 100644
--- a/drivers/net/vmxnet3/vmxnet3_ethtool.c
+++ b/drivers/net/vmxnet3/vmxnet3_ethtool.c
@@ -583,12 +583,16 @@ vmxnet3_get_rss_indir_size(struct net_device *netdev)
 }
 
 static int
-vmxnet3_get_rss(struct net_device *netdev, u32 *p, u8 *key)
+vmxnet3_get_rss(struct net_device *netdev, u32 *p, u8 *key, u8 *hfunc)
 {
         struct vmxnet3_adapter *adapter = netdev_priv(netdev);
         struct UPT1_RSSConf *rssConf = adapter->rss_conf;
         unsigned int n = rssConf->indTableSize;
 
+        if (hfunc)
+                *hfunc = ETH_RSS_HASH_TOP;
+        if (!p)
+                return 0;
         while (n--)
                 p[n] = rssConf->indTable[n];
         return 0;
@@ -596,13 +600,20 @@ vmxnet3_get_rss(struct net_device *netdev, u32 *p, u8 *key)
 }
 
 static int
-vmxnet3_set_rss(struct net_device *netdev, const u32 *p, const u8 *key)
+vmxnet3_set_rss(struct net_device *netdev, const u32 *p, const u8 *key,
+                const u8 hfunc)
 {
         unsigned int i;
         unsigned long flags;
         struct vmxnet3_adapter *adapter = netdev_priv(netdev);
         struct UPT1_RSSConf *rssConf = adapter->rss_conf;
 
+        /* We do not allow change in unsupported parameters */
+        if (key ||
+            (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP))
+                return -EOPNOTSUPP;
+        if (!p)
+                return 0;
         for (i = 0; i < rssConf->indTableSize; i++)
                 rssConf->indTable[i] = p[i];
 
diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index c1a2d60dfb82..653dc9c4ebac 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -59,6 +59,26 @@ enum ethtool_phys_id_state {
         ETHTOOL_ID_OFF
 };
 
+enum {
+        ETH_RSS_HASH_TOP_BIT, /* Configurable RSS hash function - Toeplitz */
+        ETH_RSS_HASH_XOR_BIT, /* Configurable RSS hash function - Xor */
+
+        /*
+         * Add your fresh new hash function bits above and remember to update
+         * rss_hash_func_strings[] in ethtool.c
+         */
+        ETH_RSS_HASH_FUNCS_COUNT
+};
+
+#define __ETH_RSS_HASH_BIT(bit) ((u32)1 << (bit))
+#define __ETH_RSS_HASH(name)    __ETH_RSS_HASH_BIT(ETH_RSS_HASH_##name##_BIT)
+
+#define ETH_RSS_HASH_TOP        __ETH_RSS_HASH(TOP)
+#define ETH_RSS_HASH_XOR        __ETH_RSS_HASH(XOR)
+
+#define ETH_RSS_HASH_UNKNOWN    0
+#define ETH_RSS_HASH_NO_CHANGE  0
+
 struct net_device;
 
 /* Some generic methods drivers may use in their ethtool_ops */
@@ -158,17 +178,14 @@ static inline u32 ethtool_rxfh_indir_default(u32 index, u32 n_rx_rings)
  *      Returns zero if not supported for this specific device.
  * @get_rxfh_indir_size: Get the size of the RX flow hash indirection table.
  *      Returns zero if not supported for this specific device.
- * @get_rxfh: Get the contents of the RX flow hash indirection table and hash
- *      key.
- *      Will only be called if one or both of @get_rxfh_indir_size and
- *      @get_rxfh_key_size are implemented and return non-zero.
- *      Returns a negative error code or zero.
- * @set_rxfh: Set the contents of the RX flow hash indirection table and/or
- *      hash key.  In case only the indirection table or hash key is to be
- *      changed, the other argument will be %NULL.
- *      Will only be called if one or both of @get_rxfh_indir_size and
- *      @get_rxfh_key_size are implemented and return non-zero.
+ * @get_rxfh: Get the contents of the RX flow hash indirection table, hash key
+ *      and/or hash function.
  *      Returns a negative error code or zero.
+ * @set_rxfh: Set the contents of the RX flow hash indirection table, hash
+ *      key, and/or hash function.  Arguments which are set to %NULL or zero
+ *      will remain unchanged.
+ *      Returns a negative error code or zero. An error code must be returned
+ *      if at least one unsupported change was requested.
  * @get_channels: Get number of channels.
  * @set_channels: Set number of channels.  Returns a negative error code or
  *      zero.
@@ -241,9 +258,10 @@ struct ethtool_ops {
         int     (*reset)(struct net_device *, u32 *);
         u32     (*get_rxfh_key_size)(struct net_device *);
         u32     (*get_rxfh_indir_size)(struct net_device *);
-        int     (*get_rxfh)(struct net_device *, u32 *indir, u8 *key);
+        int     (*get_rxfh)(struct net_device *, u32 *indir, u8 *key,
+                            u8 *hfunc);
         int     (*set_rxfh)(struct net_device *, const u32 *indir,
-                            const u8 *key);
+                            const u8 *key, const u8 hfunc);
         void    (*get_channels)(struct net_device *, struct ethtool_channels *);
         int     (*set_channels)(struct net_device *, struct ethtool_channels *);
         int     (*get_dump_flag)(struct net_device *, struct ethtool_dump *);
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index eb2095b42fbb..5f66d9c2889d 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -534,6 +534,7 @@ struct ethtool_pauseparam {
  * @ETH_SS_NTUPLE_FILTERS: Previously used with %ETHTOOL_GRXNTUPLE;
  *      now deprecated
  * @ETH_SS_FEATURES: Device feature names
+ * @ETH_SS_RSS_HASH_FUNCS: RSS hush function names
  */
 enum ethtool_stringset {
         ETH_SS_TEST             = 0,
@@ -541,6 +542,7 @@ enum ethtool_stringset {
         ETH_SS_PRIV_FLAGS,
         ETH_SS_NTUPLE_FILTERS,
         ETH_SS_FEATURES,
+        ETH_SS_RSS_HASH_FUNCS,
 };
 
 /**
@@ -884,6 +886,8 @@ struct ethtool_rxfh_indir {
  * @key_size: On entry, the array size of the user buffer for the hash key,
  *      which may be zero.  On return from %ETHTOOL_GRSSH, the size of the
  *      hardware hash key.
+ * @hfunc: Defines the current RSS hash function used by HW (or to be set to).
+ *      Valid values are one of the %ETH_RSS_HASH_*.
  * @rsvd:       Reserved for future extensions.
  * @rss_config: RX ring/queue index for each hash value i.e., indirection table
  *      of @indir_size __u32 elements, followed by hash key of @key_size
@@ -893,14 +897,16 @@ struct ethtool_rxfh_indir {
  * size should be returned.  For %ETHTOOL_SRSSH, an @indir_size of
  * %ETH_RXFH_INDIR_NO_CHANGE means that indir table setting is not requested
  * and a @indir_size of zero means the indir table should be reset to default
- * values.
+ * values. An hfunc of zero means that hash function setting is not requested.
  */
 struct ethtool_rxfh {
         __u32   cmd;
         __u32   rss_context;
         __u32   indir_size;
         __u32   key_size;
-        __u32   rsvd[2];
+        __u8    hfunc;
+        __u8    rsvd8[3];
+        __u32   rsvd32;
         __u32   rss_config[0];
 };
 #define ETH_RXFH_INDIR_NO_CHANGE        0xffffffff
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 715f51f321e9..550892cd6b3f 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -100,6 +100,12 @@ static const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN]
         [NETIF_F_BUSY_POLL_BIT] =        "busy-poll",
 };
 
+static const char
+rss_hash_func_strings[ETH_RSS_HASH_FUNCS_COUNT][ETH_GSTRING_LEN] = {
+        [ETH_RSS_HASH_TOP_BIT] =        "toeplitz",
+        [ETH_RSS_HASH_XOR_BIT] =        "xor",
+};
+
 static int ethtool_get_features(struct net_device *dev, void __user *useraddr)
 {
         struct ethtool_gfeatures cmd = {
@@ -185,6 +191,9 @@ static int __ethtool_get_sset_count(struct net_device *dev, int sset)
         if (sset == ETH_SS_FEATURES)
                 return ARRAY_SIZE(netdev_features_strings);
 
+        if (sset == ETH_SS_RSS_HASH_FUNCS)
+                return ARRAY_SIZE(rss_hash_func_strings);
+
         if (ops->get_sset_count && ops->get_strings)
                 return ops->get_sset_count(dev, sset);
         else
@@ -199,6 +208,9 @@ static void __ethtool_get_strings(struct net_device *dev,
         if (stringset == ETH_SS_FEATURES)
                 memcpy(data, netdev_features_strings,
                         sizeof(netdev_features_strings));
+        else if (stringset == ETH_SS_RSS_HASH_FUNCS)
+                memcpy(data, rss_hash_func_strings,
+                       sizeof(rss_hash_func_strings));
         else
                 /* ops->get_strings is valid because checked earlier */
                 ops->get_strings(dev, stringset, data);
@@ -618,7 +630,7 @@ static noinline_for_stack int ethtool_get_rxfh_indir(struct net_device *dev,
         if (!indir)
                 return -ENOMEM;
 
-        ret = dev->ethtool_ops->get_rxfh(dev, indir, NULL);
+        ret = dev->ethtool_ops->get_rxfh(dev, indir, NULL, NULL);
         if (ret)
                 goto out;
 
@@ -679,7 +691,7 @@ static noinline_for_stack int ethtool_set_rxfh_indir(struct net_device *dev,
                         goto out;
         }
 
-        ret = ops->set_rxfh(dev, indir, NULL);
+        ret = ops->set_rxfh(dev, indir, NULL, ETH_RSS_HASH_NO_CHANGE);
 
 out:
         kfree(indir);
@@ -697,12 +709,11 @@ static noinline_for_stack int ethtool_get_rxfh(struct net_device *dev,
         u32 total_size;
         u32 indir_bytes;
         u32 *indir = NULL;
+        u8 dev_hfunc = 0;
         u8 *hkey = NULL;
         u8 *rss_config;
 
-        if (!(dev->ethtool_ops->get_rxfh_indir_size ||
-              dev->ethtool_ops->get_rxfh_key_size) ||
-              !dev->ethtool_ops->get_rxfh)
+        if (!ops->get_rxfh)
                 return -EOPNOTSUPP;
 
         if (ops->get_rxfh_indir_size)
@@ -710,16 +721,14 @@ static noinline_for_stack int ethtool_get_rxfh(struct net_device *dev,
         if (ops->get_rxfh_key_size)
                 dev_key_size = ops->get_rxfh_key_size(dev);
 
-        if ((dev_key_size + dev_indir_size) == 0)
-                return -EOPNOTSUPP;
-
         if (copy_from_user(&rxfh, useraddr, sizeof(rxfh)))
                 return -EFAULT;
         user_indir_size = rxfh.indir_size;
         user_key_size = rxfh.key_size;
 
         /* Check that reserved fields are 0 for now */
-        if (rxfh.rss_context || rxfh.rsvd[0] || rxfh.rsvd[1])
+        if (rxfh.rss_context || rxfh.rsvd8[0] || rxfh.rsvd8[1] ||
+            rxfh.rsvd8[2] || rxfh.rsvd32)
                 return -EINVAL;
 
         rxfh.indir_size = dev_indir_size;
@@ -727,13 +736,6 @@ static noinline_for_stack int ethtool_get_rxfh(struct net_device *dev,
         if (copy_to_user(useraddr, &rxfh, sizeof(rxfh)))
                 return -EFAULT;
 
-        /* If the user buffer size is 0, this is just a query for the
-         * device table size and key size.  Otherwise, if the User size is
-         * not equal to device table size or key size it's an error.
-         */
-        if (!user_indir_size && !user_key_size)
-                return 0;
-
         if ((user_indir_size && (user_indir_size != dev_indir_size)) ||
             (user_key_size && (user_key_size != dev_key_size)))
                 return -EINVAL;
@@ -750,14 +752,19 @@ static noinline_for_stack int ethtool_get_rxfh(struct net_device *dev,
         if (user_key_size)
                 hkey = rss_config + indir_bytes;
 
-        ret = dev->ethtool_ops->get_rxfh(dev, indir, hkey);
-        if (!ret) {
-                if (copy_to_user(useraddr +
-                                 offsetof(struct ethtool_rxfh, rss_config[0]),
-                                 rss_config, total_size))
-                        ret = -EFAULT;
-        }
+        ret = dev->ethtool_ops->get_rxfh(dev, indir, hkey, &dev_hfunc);
+        if (ret)
+                goto out;
 
+        if (copy_to_user(useraddr + offsetof(struct ethtool_rxfh, hfunc),
+                         &dev_hfunc, sizeof(rxfh.hfunc))) {
+                ret = -EFAULT;
+        } else if (copy_to_user(useraddr +
+                              offsetof(struct ethtool_rxfh, rss_config[0]),
+                              rss_config, total_size)) {
+                ret = -EFAULT;
+        }
+out:
         kfree(rss_config);
 
         return ret;
@@ -776,33 +783,31 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
         u8 *rss_config;
         u32 rss_cfg_offset = offsetof(struct ethtool_rxfh, rss_config[0]);
 
-        if (!(ops->get_rxfh_indir_size || ops->get_rxfh_key_size) ||
-            !ops->get_rxnfc || !ops->set_rxfh)
+        if (!ops->get_rxnfc || !ops->set_rxfh)
                 return -EOPNOTSUPP;
 
         if (ops->get_rxfh_indir_size)
                 dev_indir_size = ops->get_rxfh_indir_size(dev);
         if (ops->get_rxfh_key_size)
                 dev_key_size = dev->ethtool_ops->get_rxfh_key_size(dev);
-        if ((dev_key_size + dev_indir_size) == 0)
-                return -EOPNOTSUPP;
 
         if (copy_from_user(&rxfh, useraddr, sizeof(rxfh)))
                 return -EFAULT;
 
         /* Check that reserved fields are 0 for now */
-        if (rxfh.rss_context || rxfh.rsvd[0] || rxfh.rsvd[1])
+        if (rxfh.rss_context || rxfh.rsvd8[0] || rxfh.rsvd8[1] ||
+            rxfh.rsvd8[2] || rxfh.rsvd32)
                 return -EINVAL;
 
-        /* If either indir or hash key is valid, proceed further.
-         * It is not valid to request that both be unchanged.
+        /* If either indir, hash key or function is valid, proceed further.
+         * Must request at least one change: indir size, hash key or function.
          */
         if ((rxfh.indir_size &&
              rxfh.indir_size != ETH_RXFH_INDIR_NO_CHANGE &&
              rxfh.indir_size != dev_indir_size) ||
             (rxfh.key_size && (rxfh.key_size != dev_key_size)) ||
             (rxfh.indir_size == ETH_RXFH_INDIR_NO_CHANGE &&
-             rxfh.key_size == 0))
+             rxfh.key_size == 0 && rxfh.hfunc == ETH_RSS_HASH_NO_CHANGE))
                 return -EINVAL;
 
         if (rxfh.indir_size != ETH_RXFH_INDIR_NO_CHANGE)
@@ -845,7 +850,7 @@ static noinline_for_stack int ethtool_set_rxfh(struct net_device *dev,
                 }
         }
 
-        ret = ops->set_rxfh(dev, indir, hkey);
+        ret = ops->set_rxfh(dev, indir, hkey, rxfh.hfunc);
 
 out:
         kfree(rss_config);