common/mlx5: add DevX command for flex parsers

common/mlx5: add DevX command for flex parsers

In order to use dynamic flex parser to parse protocols that is not
supported natively, two steps are needed.

Firstly, creating the parse graph node. There are three parts of the
flex parser: node, arc and sample. Node is the whole structure of a
flex parser, when creating, the length of the protocol should be
specified. Then the input arc(s) is(are) mandatory, it will tell the
HW when to use this parser to parse the packet. For a single parser
node, up to 8 input arcs could be supported and it gives SW ability
to support this protocol over multiple layers. The output arc is
optional and also up to 8 arcs could be supported. If the protocol
is the last header of the stack, then output arc should be NULL. Or
else it should be specified. The protocol type in the arc is used to
indicate the parser pointing to or from this flex parser node. For
output arc, the next header type field offset and size should be set
in the node structure, then the HW could get the proper type of the
next header and decide which parser to point to.
Note: the parsers have two types now, native parser and flex parser.
The arc between two flex parsers are not supported in this stage.

Secondly, querying the sample IDs. If the protocol header parsed
with flex parser needs to used in flow rule offloading, the DW
samples are needed when creating the parse graph node. The offset
of bytes starting from the header needs to be set. After creating
the node successfully, a general object handle will be returned.
This object could be queried with Devx command to get the sample
IDs.
When creating a flow, sample IDs could be used to sample a DW from
the parsed header - 4 continuous bytes starting from the offset. The
flow entry could specify some mask to use part of this DW for
matching. Up to 8 samples could be supported for a single parse
graph node. The offset should not exceed the header length.

The HW resources have some limitation, low layer driver error should
be checked once there is a failure of creating parse graph node.

Signed-off-by: Netanel Gonen <netanelg@mellanox.com>
Signed-off-by: Bing Zhao <bingz@mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>