i40e, xsk: Diversify return values from xsk_wakeup call paths

Currently, when debugging AF_XDP workloads, one can correlate the -ENXIO
return code as the case that XSK is not in the bound state. Returning
same code from ndo_xsk_wakeup can be misleading and simply makes it
harder to follow what is going on.

Change ENXIOs in i40e's ndo_xsk_wakeup() implementation to EINVALs, so
that when probing it is clear that something is wrong on the driver
side, not the xsk_{recv,send}msg.

There is a -ENETDOWN that can happen from both kernel/driver sides
though, but I don't have a correct replacement for this on one of the
sides, so let's keep it that way.
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220413153015.453864-10-maciej.fijalkowski@intel.com

drivers/net/ethernet/intel/i40e/i40e_xsk.c

@@ -606,13 +606,13 @@ int i40e_xsk_wakeup(struct net_device *dev, u32 queue_id, u32 flags)
 		return -ENETDOWN;
 
 	if (!i40e_enabled_xdp_vsi(vsi))
-		return -ENXIO;
+		return -EINVAL;
 
 	if (queue_id >= vsi->num_queue_pairs)
-		return -ENXIO;
+		return -EINVAL;
 
 	if (!vsi->xdp_rings[queue_id]->xsk_pool)
-		return -ENXIO;
+		return -EINVAL;
 
 	ring = vsi->xdp_rings[queue_id];