net: mscc: ocelot: refactor enum ocelot_reg decoding to helper

ocelot_io.c duplicates the decoding of an enum ocelot_reg (which holds
an enum ocelot_target in the upper bits and an index into a regmap array
in the lower bits) 4 times.

We'd like to reuse that logic once more, from ocelot.c. In order to do
that, let's consolidate the existing 4 instances into a header
accessible both by ocelot.c as well as by ocelot_io.c.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: mscc: ocelot: strengthen type of "u32 reg" in I/O accessors

The "u32 reg" argument that is passed to these functions is not a plain
address, but rather a driver-specific encoding of another enum
ocelot_target target in the upper bits, and an index into the
u32 ocelot->map[target][] array in the lower bits. That encoded value
takes the type "enum ocelot_reg" and is what is passed to these I/O
functions, so let's actually use that to prevent type confusion.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: mscc: ocelot: add ability to perform bulk reads

Regmap supports bulk register reads. Ocelot does not. This patch adds
support for Ocelot to invoke bulk regmap reads. That will allow any driver
that performs consecutive reads over memory regions to optimize that
access.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mscc: Fix non-GPL export of regmap APIs

The ocelot driver makes use of regmap, wrapping it with driver specific
operations that are thin wrappers around the core regmap APIs. These are
exported with EXPORT_SYMBOL, dropping the _GPL from the core regmap
exports which is frowned upon. Add _GPL suffixes to at least the APIs that
are doing register I/O.

Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210810123748.47871-1-broonie@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: mscc: Fix non-GPL export of regmap APIs

The ocelot driver makes use of regmap, wrapping it with driver specific
operations that are thin wrappers around the core regmap APIs. These are
exported with EXPORT_SYMBOL, dropping the _GPL from the core regmap
exports which is frowned upon. Add _GPL suffixes to at least the APIs that
are doing register I/O.

Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dsa: felix: implement port flushing on .phylink_mac_link_down

There are several issues which may be seen when the link goes down while
forwarding traffic, all of which can be attributed to the fact that the
port flushing procedure from the reference manual was not closely
followed.

With flow control enabled on both the ingress port and the egress port,
it may happen when a link goes down that Ethernet packets are in flight.
In flow control mode, frames are held back and not dropped. When there
is enough traffic in flight (example: iperf3 TCP), then the ingress port
might enter congestion and never exit that state. This is a problem,
because it is the egress port's link that went down, and that has caused
the inability of the ingress port to send packets to any other port.
This is solved by flushing the egress port's queues when it goes down.

There is also a problem when performing stream splitting for
IEEE 802.1CB traffic (not yet upstream, but a sort of multicast,
basically). There, if one port from the destination ports mask goes
down, splitting the stream towards the other destinations will no longer
be performed. This can be traced down to this line:

ocelot_port_writel(ocelot_port, 0, DEV_MAC_ENA_CFG);

which should have been instead, as per the reference manual:

ocelot_port_rmwl(ocelot_port, 0, DEV_MAC_ENA_CFG_RX_ENA,
DEV_MAC_ENA_CFG);

Basically only DEV_MAC_ENA_CFG_RX_ENA should be disabled, but not
DEV_MAC_ENA_CFG_TX_ENA - I don't have further insight into why that is
the case, but apparently multicasting to several ports will cause issues
if at least one of them doesn't have DEV_MAC_ENA_CFG_TX_ENA set.

I am not sure what the state of the Ocelot VSC7514 driver is, but
probably not as bad as Felix/Seville, since VSC7514 uses phylib and has
the following in ocelot_adjust_link:

if (!phydev->link)
return;

therefore the port is not really put down when the link is lost, unlike
the DSA drivers which use .phylink_mac_link_down for that.

Nonetheless, I put ocelot_port_flush() in the common ocelot.c because it
needs to access some registers from drivers/net/ethernet/mscc/ocelot_rew.h
which are not exported in include/soc/mscc/ and a bugfix patch should
probably not move headers around.

Fixes: bdeced75b13f ("net: dsa: felix: Add PCS operations for PHYLINK")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mscc: ocelot: introduce a new ocelot_target_{read,write} API

There are some targets (register blocks) in the Ocelot switch that are
instantiated more than once. For example, the VCAP IS1, IS2 and ES0
blocks all share the same register layout for interacting with the cache
for the TCAM and the action RAM.

For the VCAPs, the procedure for servicing them is actually common. We
just need an API specifying which VCAP we are talking to, and we do that
via these raw ocelot_target_read and ocelot_target_write accessors.

In plain ocelot_read, the target is encoded into the register enum
itself:

u16 target = reg >> TARGET_OFFSET;

For the VCAPs, the registers are currently defined like this:

enum ocelot_reg {
[...]
S2_CORE_UPDATE_CTRL = S2 << TARGET_OFFSET,
S2_CORE_MV_CFG,
S2_CACHE_ENTRY_DAT,
S2_CACHE_MASK_DAT,
S2_CACHE_ACTION_DAT,
S2_CACHE_CNT_DAT,
S2_CACHE_TG_DAT,
[...]
};

which is precisely what we want to avoid, because we'd have to duplicate
the same register map for S1 and for S0, and then figure out how to pass
VCAP instance-specific registers to the ocelot_read calls (basically
another lookup table that undoes the effect of shifting with
TARGET_OFFSET).

So for some targets, propose a more raw API, similar to what is
currently done with ocelot_port_readl and ocelot_port_writel. Those
targets can only be accessed with ocelot_target_{read,write} and not
with ocelot_{read,write} after the conversion, which is fine.

The VCAP registers are not actually modified to use this new API as of
this patch. They will be modified in the next one.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mscc: ocelot: convert QSYS_SWITCH_PORT_MODE and SYS_PORT_MODE to regfields

Currently Felix and Ocelot share the same bit layout in these per-port
registers, but Seville does not. So we need reg_fields for that.

Actually since these are per-port registers, we need to also specify the
number of ports, and register size per port, and use the regmap API for
multiple ports.

There's a more subtle point to be made about the other 2 register
fields:
- QSYS_SWITCH_PORT_MODE_SCH_NEXT_CFG
- QSYS_SWITCH_PORT_MODE_INGRESS_DROP_MODE
which we are not writing any longer, for 2 reasons:
- Using the previous API (ocelot_write_rix), we were only writing 1 for
Felix and Ocelot, which was their hardware-default value, and which
there wasn't any intention in changing.
- In the case of SCH_NEXT_CFG, in fact Seville does not have this
register field at all, and therefore, if we want to have common code
we would be required to not write to it.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mscc: ocelot: convert port registers to regmap

At the moment, there are some minimal register differences between
VSC7514 Ocelot and VSC9959 Felix. To be precise, the PCS1G registers are
missing from Felix because it was integrated with an NXP PCS.

But with VSC9953 Seville (not yet introduced), the register differences
are more pronounced. The MAC registers are located at different offsets
within the DEV_GMII target. So we need to refactor the driver to keep a
regmap even for per-port registers. The callers of the ocelot_port_readl
and ocelot_port_writel were kept unchanged, only the implementation is
now more generic.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mscc: ocelot: move resource ioremap and regmap init to common code

Let's make this ioremap and regmap init code common. It should not
be platform dependent as it should be usable by PCI devices too.
Use better names where necessary to avoid clashes.

Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: mscc: Add initial Ocelot switch support

Add a driver for Microsemi Ocelot Ethernet switch support.

This makes two modules:
mscc_ocelot_common handles all the common features that doesn't depend on
how the switch is integrated in the SoC. Currently, it handles offloading
bridging to the hardware. ocelot_io.c handles register accesses. This is
unfortunately needed because the register layout is packed and then depends
on the number of ports available on the switch. The register definition
files are automatically generated.

ocelot_board handles the switch integration on the SoC and on the board.

Frame injection and extraction to/from the CPU port is currently done using
register accesses which is quite slow. DMA is possible but the port is not
able to absorb the whole switch bandwidth.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>