Vladimir Oltean says:
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Accomodate DSA front-end into Ocelot
After the nice "change-my-mind" discussion about Ocelot, Felix and
LS1028A (which can be read here: https://lkml.org/lkml/2019/6/21/630),
we have decided to take the route of reworking the Ocelot implementation
in a way that is DSA-compatible.
This is a large series, but hopefully is easy enough to digest, since it
contains mostly code refactoring. What needs to be changed:
- The struct net_device, phy_device needs to be isolated from Ocelot
private structures (struct ocelot, struct ocelot_port). These will
live as 1-to-1 equivalents to struct dsa_switch and struct dsa_port.
- The function prototypes need to be compatible with DSA (of course,
struct dsa_switch will become struct ocelot).
- The CPU port needs to be assigned via a higher-level API, not
hardcoded in the driver.
What is going to be interesting is that the new DSA front-end of Ocelot
will need to have features in lockstep with the DSA core itself. At the
moment, some more advanced tc offloading features of Ocelot (tc-flower,
etc) are not available in the DSA front-end due to lack of API in the
DSA core. It also means that Ocelot practically re-implements large
parts of DSA (although it is not a DSA switch per se) - see the FDB API
for example.
The code has been only compile-tested on Ocelot, since I don't have
access to any VSC7514 hardware. It was proven to work on NXP LS1028A,
which instantiates a DSA derivative of Ocelot. So I would like to ask
Alex Belloni if you could confirm this series causes no regression on
the Ocelot MIPS SoC.
The goal is to get this rework upstream as quickly as possible,
precisely because it is a large volume of code that risks gaining merge
conflicts if we keep it for too long.
This is but the first chunk of the LS1028A Felix DSA driver upstreaming.
For those who are interested, the concept can be seen on my private
Github repo, the user of this reworked Ocelot driver living under
drivers/net/dsa/vitesse/:
https://github.com/vladimiroltean/ls1028ardb-linux
====================
Acked-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>