i40e/i40evf: i40e implementation for skb_set_hash

Original comment from Tom Herbert <therbert@google.com>

   Drivers should call skb_set_hash to set the hash and its type
   in an skbuff.

This patch builds upon Tom's original implementation and adds
the L4 type return when we know it is an L4 hash.
This requires use of the ptype decoder ring, so enable it.

Change-ID: I2f9fa86d1a6add58cff13386f7f4238b1abcc468
CC: Tom Herbert <therbert@google.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Acked-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: Mitch Williams <mitch.a.williams@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/i40e/i40e_prototype.h b/drivers/net/ethernet/intel/i40e/i40e_prototype.h
index ed91f93..9cd57e6 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_prototype.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_prototype.h
@@ -231,6 +231,13 @@
 						 u16 *checksum);
 void i40e_set_pci_config_data(struct i40e_hw *hw, u16 link_status);
 
+extern struct i40e_rx_ptype_decoded i40e_ptype_lookup[];
+
+static inline struct i40e_rx_ptype_decoded decode_rx_desc_ptype(u8 ptype)
+{
+	return i40e_ptype_lookup[ptype];
+}
+
 /* prototype for functions used for SW locks */
 
 /* i40e_common for VF drivers*/