From 892311f66f2411b813ca631009356891a0c2b0a1 Mon Sep 17 00:00:00 2001
From: Eyal Perry <eyalpe@mellanox.com>
Date: Tue, 2 Dec 2014 18:12:10 +0200
Subject: 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>
---
 drivers/net/ethernet/emulex/benet/be_ethtool.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

(limited to 'drivers/net/ethernet/emulex')

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;
 
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