linux-imx

i40e: disallow programming multiple filters with same criteria

Our hardware does not allow situations where two filters might conflict
when matching. Essentially hardware only programs one filter for each
set of matching criteria. We don't support filters with overlapping
input sets, because each flow type can only use a single input set.

Additionally, different flow types will never have overlapping matches,
because of how the hardware parses the flow type before checking
matching criteria.

For this reason, we do not need or use the location number when
programming filters to hardware.

In order to avoid confusing scenarios with filters that match the same
criteria but program the flow to different queues, do not allow multiple
filters that match identical criteria to be programmed.

This ensures that we avoid odd scenarios when deleting filters, and when
programming new filters that match the same criteria.

Instead, users that wish to update the criteria for a filter must use
the same location id, or must delete all the matching filters first.

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>