devink dpipe implementation

devink dpipe implementation

[Lucero Palau, Alejandro]

Hi,

I'm looking at the devlink dpipe functionality for considering using it 
with AMD ef100.

There is just one driver using it, Mellanox spectrum switch, as a 
reference apart from the devlink core code.

I wonder if due to this limited usage the implementation is not covering 
other needs or maybe I'm missing something.

For example:

enum devlink_dpipe_match_type {
     DEVLINK_DPIPE_MATCH_TYPE_FIELD_EXACT,
};

It seems obvious other matches should be supported, at least for 
supporting matching based on masks. Is this because spectrum switch does 
only have BCAMs?


Other examples:

enum devlink_dpipe_field_ethernet_id {
     DEVLINK_DPIPE_FIELD_ETHERNET_DST_MAC,
};

enum devlink_dpipe_field_ipv4_id {
     DEVLINK_DPIPE_FIELD_IPV4_DST_IP,
};

Again, I guess other fields should be support.

If this is because only that needed by the only driver using it was 
added, I guess using dpipe for ef100 would need to add more support to 
the devlink dpipe core.

Can someone clarify this to me?

Thanks.

Re: devink dpipe implementation

[Jiri Pirko]

Mon, Feb 27, 2023 at 01:05:14PM CET, alejandro.lucero-palau@amd.com wrote:
>Hi,
>
>I'm looking at the devlink dpipe functionality for considering using it 
>with AMD ef100.

What is your goal?


>
>There is just one driver using it, Mellanox spectrum switch, as a 
>reference apart from the devlink core code.
>
>I wonder if due to this limited usage the implementation is not covering 
>other needs or maybe I'm missing something.
>
>For example:
>
>enum devlink_dpipe_match_type {
>     DEVLINK_DPIPE_MATCH_TYPE_FIELD_EXACT,
>};
>
>It seems obvious other matches should be supported, at least for 
>supporting matching based on masks. Is this because spectrum switch does 
>only have BCAMs?

dpipe exposes ASIC pipeline to the user to provide visibility. In case
of mlxsw, there are only some fragments exposed. There the exact match
is enough.


>
>
>Other examples:
>
>enum devlink_dpipe_field_ethernet_id {
>     DEVLINK_DPIPE_FIELD_ETHERNET_DST_MAC,
>};
>
>enum devlink_dpipe_field_ipv4_id {
>     DEVLINK_DPIPE_FIELD_IPV4_DST_IP,
>};
>
>Again, I guess other fields should be support.
>
>If this is because only that needed by the only driver using it was 
>added, I guess using dpipe for ef100 would need to add more support to 
>the devlink dpipe core.

Sure.


>
>Can someone clarify this to me?
>
>Thanks.
>