| From foo@baz Thu Jun 30 03:22:27 PM CEST 2022 |
| From: Vladimir Oltean <vladimir.oltean@nxp.com> |
| Date: Tue, 28 Jun 2022 20:20:13 +0300 |
| Subject: net: mscc: ocelot: allow unregistered IP multicast flooding |
| To: stable <stable@vger.kernel.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Sasha Levin <sashal@kernel.org> |
| Cc: netdev@vger.kernel.org, "David S. Miller" <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>, Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>, Xiaoliang Yang <xiaoliang.yang_1@nxp.com>, Claudiu Manoil <claudiu.manoil@nxp.com>, Alexandre Belloni <alexandre.belloni@bootlin.com>, UNGLinuxDriver@microchip.com, Andrew Lunn <andrew@lunn.ch>, Vivien Didelot <vivien.didelot@gmail.com>, Florian Fainelli <f.fainelli@gmail.com>, Maxim Kochetkov <fido_max@inbox.ru>, Colin Foster <colin.foster@in-advantage.com>, stable@kernel.org |
| Message-ID: <20220628172016.3373243-2-vladimir.oltean@nxp.com> |
| |
| From: Vladimir Oltean <vladimir.oltean@nxp.com> |
| |
| Flooding of unregistered IP multicast has been broken (both to other |
| switch ports and to the CPU) since the ocelot driver introduction, and |
| up until commit 4cf35a2b627a ("net: mscc: ocelot: fix broken IP |
| multicast flooding"), a bug fix for commit 421741ea5672 ("net: mscc: |
| ocelot: offload bridge port flags to device") from v5.12. |
| |
| The driver used to set PGID_MCIPV4 and PGID_MCIPV6 to the empty port |
| mask (0), which made unregistered IPv4/IPv6 multicast go nowhere, and |
| without ever modifying that port mask at runtime. |
| |
| The expectation is that such packets are treated as broadcast, and |
| flooded according to the forwarding domain (to the CPU if the port is |
| standalone, or to the CPU and other bridged ports, if under a bridge). |
| |
| Since the aforementioned commit, the limitation has been lifted by |
| responding to SWITCHDEV_ATTR_ID_PORT_BRIDGE_FLAGS events emitted by the |
| bridge. As for host flooding, DSA synthesizes another call to |
| ocelot_port_bridge_flags() on the NPI port which ensures that the CPU |
| gets the unregistered multicast traffic it might need, for example for |
| smcroute to work between standalone ports. |
| |
| But between v4.18 and v5.12, IP multicast flooding has remained unfixed. |
| |
| Delete the inexplicable premature optimization of clearing PGID_MCIPV4 |
| and PGID_MCIPV6 as part of the init sequence, and allow unregistered IP |
| multicast to be flooded freely according to the forwarding domain |
| established by PGID_SRC, by explicitly programming PGID_MCIPV4 and |
| PGID_MCIPV6 towards all physical ports plus the CPU port module. |
| |
| Fixes: a556c76adc05 ("net: mscc: Add initial Ocelot switch support") |
| Cc: stable@kernel.org |
| Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/net/ethernet/mscc/ocelot.c | 8 ++++++-- |
| 1 file changed, 6 insertions(+), 2 deletions(-) |
| |
| --- a/drivers/net/ethernet/mscc/ocelot.c |
| +++ b/drivers/net/ethernet/mscc/ocelot.c |
| @@ -1733,8 +1733,12 @@ int ocelot_init(struct ocelot *ocelot) |
| ocelot_write_rix(ocelot, |
| ANA_PGID_PGID_PGID(GENMASK(ocelot->num_phys_ports, 0)), |
| ANA_PGID_PGID, PGID_MC); |
| - ocelot_write_rix(ocelot, 0, ANA_PGID_PGID, PGID_MCIPV4); |
| - ocelot_write_rix(ocelot, 0, ANA_PGID_PGID, PGID_MCIPV6); |
| + ocelot_write_rix(ocelot, |
| + ANA_PGID_PGID_PGID(GENMASK(ocelot->num_phys_ports, 0)), |
| + ANA_PGID_PGID, PGID_MCIPV4); |
| + ocelot_write_rix(ocelot, |
| + ANA_PGID_PGID_PGID(GENMASK(ocelot->num_phys_ports, 0)), |
| + ANA_PGID_PGID, PGID_MCIPV6); |
| |
| /* CPU port Injection/Extraction configuration */ |
| ocelot_write_rix(ocelot, QSYS_SWITCH_PORT_MODE_INGRESS_DROP_MODE | |
