i40e: use priv flags to control flow director

Some customers wish to be able to control our hardware specific
feature called flow director, at runtime.  This patch enables
ethtool priv flags to control this driver/hardware specific feature.

ethtool --set-priv-flags ethX flow-director-atr off

NOTE: the ethtool ntuple interface controls the flow-director
      sideband rules.

Change-ID: Iba156350b07fa2ce66f53ded51739f9a3781fe0e
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e.h

@@ -102,6 +102,7 @@
 /* Ethtool Private Flags */
 #define I40E_PRIV_FLAGS_NPAR_FLAG	BIT(0)
 #define I40E_PRIV_FLAGS_LINKPOLL_FLAG	BIT(1)
+#define I40E_PRIV_FLAGS_FD_ATR		BIT(2)
 
 #define I40E_NVM_VERSION_LO_SHIFT  0
 #define I40E_NVM_VERSION_LO_MASK   (0xff << I40E_NVM_VERSION_LO_SHIFT)

drivers/net/ethernet/intel/i40e/i40e_ethtool.c

@@ -231,6 +231,7 @@ static const char i40e_gstrings_test[][ETH_GSTRING_LEN] = {
 static const char i40e_priv_flags_strings[][ETH_GSTRING_LEN] = {
 	"NPAR",
 	"LinkPolling",
+	"flow-director-atr",
 };
 
 #define I40E_PRIV_FLAGS_STR_LEN ARRAY_SIZE(i40e_priv_flags_strings)
@@ -2666,6 +2667,8 @@ static u32 i40e_get_priv_flags(struct net_device *dev)
 		I40E_PRIV_FLAGS_NPAR_FLAG : 0;
 	ret_flags |= pf->flags & I40E_FLAG_LINK_POLLING_ENABLED ?
 		I40E_PRIV_FLAGS_LINKPOLL_FLAG : 0;
+	ret_flags |= pf->flags & I40E_FLAG_FD_ATR_ENABLED ?
+		I40E_PRIV_FLAGS_FD_ATR : 0;
 
 	return ret_flags;
 }
@@ -2686,6 +2689,17 @@ static int i40e_set_priv_flags(struct net_device *dev, u32 flags)
 	else
 		pf->flags &= ~I40E_FLAG_LINK_POLLING_ENABLED;
 
+	/* allow the user to control the state of the Flow
+	 * Director ATR (Application Targeted Routing) feature
+	 * of the driver
+	 */
+	if (flags & I40E_PRIV_FLAGS_FD_ATR) {
+		pf->flags |= I40E_FLAG_FD_ATR_ENABLED;
+	} else {
+		pf->flags &= ~I40E_FLAG_FD_ATR_ENABLED;
+		pf->auto_disable_flags |= I40E_FLAG_FD_ATR_ENABLED;
+	}
+
 	return 0;
 }