i40e: add parsing of flexible filter fields from userdef

Add code to parse the user-def field into a data structure format. This
code is intended to allow future extensions of the user-def field by
keeping all code that actually reads and writes the field into a single
location. This ensures that we do not litter the driver with references
to the user-def field and minimizes the amount of bitwise operations we
need to do on the data.

Add code which parses the lower 32bits into a flexible word and its
offset. This will be used in a future patch to enable flexible filters
which can match on some arbitrary data in the packet payload. For now,
we just return -EOPNOTSUPP when this is used.

Add code to fill in the user-def field when reporting the filter back,
even though we don't actually implement any user-def fields yet.

Additionally, ensure that we mask the extended FLOW_EXT bit from the
flow_type now that we will be accepting filters which have the FLOW_EXT
bit set (and thus make use of the user-def field).

Change-Id: I238845035c179380a347baa8db8223304f5f6dd7
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
index 95b1a1e..3bf0e7e 100644
--- a/drivers/net/ethernet/intel/i40e/i40e.h
+++ b/drivers/net/ethernet/intel/i40e/i40e.h
@@ -202,6 +202,15 @@ enum i40e_fd_stat_idx {
 #define I40E_FD_ATR_TUNNEL_STAT_IDX(pf_id) \
 			(I40E_FD_STAT_PF_IDX(pf_id) + I40E_FD_STAT_ATR_TUNNEL)
 
+/* The following structure contains the data parsed from the user-defined
+ * field of the ethtool_rx_flow_spec structure.
+ */
+struct i40e_rx_flow_userdef {
+	bool flex_filter;
+	u16 flex_word;
+	u16 flex_offset;
+};
+
 struct i40e_fdir_filter {
 	struct hlist_node fdir_node;
 	/* filter ipnut set */