ixgbe: add ipsec offload add and remove SA

Add the functions for setting up and removing offloaded SAs (Security
Associations) with the x540 hardware.  We set up the callback structure
but we don't yet set the hardware feature bit to be sure the XFRM service
won't actually try to use us for an offload yet.

The software tables are made up to mimic the hardware tables to make it
easier to track what's in the hardware, and the SA table index is used
for the XFRM offload handle.  However, there is a hashing field in the
Rx SA tracking that will be used to facilitate faster table searches in
the Rx fast path.

Signed-off-by: Shannon Nelson <shannon.nelson@oracle.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbe/ixgbe.h

@@ -1019,7 +1019,9 @@ s32 ixgbe_negotiate_fc(struct ixgbe_hw *hw, u32 adv_reg, u32 lp_reg,
 		       u32 adv_sym, u32 adv_asm, u32 lp_sym, u32 lp_asm);
 #ifdef CONFIG_XFRM_OFFLOAD
 void ixgbe_init_ipsec_offload(struct ixgbe_adapter *adapter);
+void ixgbe_stop_ipsec_offload(struct ixgbe_adapter *adapter);
 #else
 static inline void ixgbe_init_ipsec_offload(struct ixgbe_adapter *adapter) { };
+static inline void ixgbe_stop_ipsec_offload(struct ixgbe_adapter *adapter) { };
 #endif /* CONFIG_XFRM_OFFLOAD */
 #endif /* _IXGBE_H_ */