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Diffstat (limited to 'Documentation/networking/dsa/sja1105.rst')
| -rw-r--r-- | Documentation/networking/dsa/sja1105.rst | 218 |
1 files changed, 1 insertions, 217 deletions
diff --git a/Documentation/networking/dsa/sja1105.rst b/Documentation/networking/dsa/sja1105.rst index da4057ba37f1..564caeebe2b2 100644 --- a/Documentation/networking/dsa/sja1105.rst +++ b/Documentation/networking/dsa/sja1105.rst @@ -65,199 +65,6 @@ If that changed setting can be transmitted to the switch through the dynamic reconfiguration interface, it is; otherwise the switch is reset and reprogrammed with the updated static configuration. -Traffic support -=============== - -The switches do not have hardware support for DSA tags, except for "slow -protocols" for switch control as STP and PTP. For these, the switches have two -programmable filters for link-local destination MACs. -These are used to trap BPDUs and PTP traffic to the master netdevice, and are -further used to support STP and 1588 ordinary clock/boundary clock -functionality. For frames trapped to the CPU, source port and switch ID -information is encoded by the hardware into the frames. - -But by leveraging ``CONFIG_NET_DSA_TAG_8021Q`` (a software-defined DSA tagging -format based on VLANs), general-purpose traffic termination through the network -stack can be supported under certain circumstances. - -Depending on VLAN awareness state, the following operating modes are possible -with the switch: - -- Mode 1 (VLAN-unaware): a port is in this mode when it is used as a standalone - net device, or when it is enslaved to a bridge with ``vlan_filtering=0``. -- Mode 2 (fully VLAN-aware): a port is in this mode when it is enslaved to a - bridge with ``vlan_filtering=1``. Access to the entire VLAN range is given to - the user through ``bridge vlan`` commands, but general-purpose (anything - other than STP, PTP etc) traffic termination is not possible through the - switch net devices. The other packets can be still by user space processed - through the DSA master interface (similar to ``DSA_TAG_PROTO_NONE``). -- Mode 3 (best-effort VLAN-aware): a port is in this mode when enslaved to a - bridge with ``vlan_filtering=1``, and the devlink property of its parent - switch named ``best_effort_vlan_filtering`` is set to ``true``. When - configured like this, the range of usable VIDs is reduced (0 to 1023 and 3072 - to 4094), so is the number of usable VIDs (maximum of 7 non-pvid VLANs per - port*), and shared VLAN learning is performed (FDB lookup is done only by - DMAC, not also by VID). - -To summarize, in each mode, the following types of traffic are supported over -the switch net devices: - -+-------------+-----------+--------------+------------+ -| | Mode 1 | Mode 2 | Mode 3 | -+=============+===========+==============+============+ -| Regular | Yes | No | Yes | -| traffic | | (use master) | | -+-------------+-----------+--------------+------------+ -| Management | Yes | Yes | Yes | -| traffic | | | | -| (BPDU, PTP) | | | | -+-------------+-----------+--------------+------------+ - -To configure the switch to operate in Mode 3, the following steps can be -followed:: - - ip link add dev br0 type bridge - # swp2 operates in Mode 1 now - ip link set dev swp2 master br0 - # swp2 temporarily moves to Mode 2 - ip link set dev br0 type bridge vlan_filtering 1 - [ 61.204770] sja1105 spi0.1: Reset switch and programmed static config. Reason: VLAN filtering - [ 61.239944] sja1105 spi0.1: Disabled switch tagging - # swp3 now operates in Mode 3 - devlink dev param set spi/spi0.1 name best_effort_vlan_filtering value true cmode runtime - [ 64.682927] sja1105 spi0.1: Reset switch and programmed static config. Reason: VLAN filtering - [ 64.711925] sja1105 spi0.1: Enabled switch tagging - # Cannot use VLANs in range 1024-3071 while in Mode 3. - bridge vlan add dev swp2 vid 1025 untagged pvid - RTNETLINK answers: Operation not permitted - bridge vlan add dev swp2 vid 100 - bridge vlan add dev swp2 vid 101 untagged - bridge vlan - port vlan ids - swp5 1 PVID Egress Untagged - - swp2 1 PVID Egress Untagged - 100 - 101 Egress Untagged - - swp3 1 PVID Egress Untagged - - swp4 1 PVID Egress Untagged - - br0 1 PVID Egress Untagged - bridge vlan add dev swp2 vid 102 - bridge vlan add dev swp2 vid 103 - bridge vlan add dev swp2 vid 104 - bridge vlan add dev swp2 vid 105 - bridge vlan add dev swp2 vid 106 - bridge vlan add dev swp2 vid 107 - # Cannot use mode than 7 VLANs per port while in Mode 3. - [ 3885.216832] sja1105 spi0.1: No more free subvlans - -\* "maximum of 7 non-pvid VLANs per port": Decoding VLAN-tagged packets on the -CPU in mode 3 is possible through VLAN retagging of packets that go from the -switch to the CPU. In cross-chip topologies, the port that goes to the CPU -might also go to other switches. In that case, those other switches will see -only a retagged packet (which only has meaning for the CPU). So if they are -interested in this VLAN, they need to apply retagging in the reverse direction, -to recover the original value from it. This consumes extra hardware resources -for this switch. There is a maximum of 32 entries in the Retagging Table of -each switch device. - -As an example, consider this cross-chip topology:: - - +-------------------------------------------------+ - | Host SoC | - | +-------------------------+ | - | | DSA master for embedded | | - | | switch (non-sja1105) | | - | +--------+-------------------------+--------+ | - | | embedded L2 switch | | - | | | | - | | +--------------+ +--------------+ | | - | | |DSA master for| |DSA master for| | | - | | | SJA1105 1 | | SJA1105 2 | | | - +--+---+--------------+-----+--------------+---+--+ - - +-----------------------+ +-----------------------+ - | SJA1105 switch 1 | | SJA1105 switch 2 | - +-----+-----+-----+-----+ +-----+-----+-----+-----+ - |sw1p0|sw1p1|sw1p2|sw1p3| |sw2p0|sw2p1|sw2p2|sw2p3| - +-----+-----+-----+-----+ +-----+-----+-----+-----+ - -To reach the CPU, SJA1105 switch 1 (spi/spi2.1) uses the same port as is uses -to reach SJA1105 switch 2 (spi/spi2.2), which would be port 4 (not drawn). -Similarly for SJA1105 switch 2. - -Also consider the following commands, that add VLAN 100 to every sja1105 user -port:: - - devlink dev param set spi/spi2.1 name best_effort_vlan_filtering value true cmode runtime - devlink dev param set spi/spi2.2 name best_effort_vlan_filtering value true cmode runtime - ip link add dev br0 type bridge - for port in sw1p0 sw1p1 sw1p2 sw1p3 \ - sw2p0 sw2p1 sw2p2 sw2p3; do - ip link set dev $port master br0 - done - ip link set dev br0 type bridge vlan_filtering 1 - for port in sw1p0 sw1p1 sw1p2 sw1p3 \ - sw2p0 sw2p1 sw2p2; do - bridge vlan add dev $port vid 100 - done - ip link add link br0 name br0.100 type vlan id 100 && ip link set dev br0.100 up - ip addr add 192.168.100.3/24 dev br0.100 - bridge vlan add dev br0 vid 100 self - - bridge vlan - port vlan ids - sw1p0 1 PVID Egress Untagged - 100 - - sw1p1 1 PVID Egress Untagged - 100 - - sw1p2 1 PVID Egress Untagged - 100 - - sw1p3 1 PVID Egress Untagged - 100 - - sw2p0 1 PVID Egress Untagged - 100 - - sw2p1 1 PVID Egress Untagged - 100 - - sw2p2 1 PVID Egress Untagged - 100 - - sw2p3 1 PVID Egress Untagged - - br0 1 PVID Egress Untagged - 100 - -SJA1105 switch 1 consumes 1 retagging entry for each VLAN on each user port -towards the CPU. It also consumes 1 retagging entry for each non-pvid VLAN that -it is also interested in, which is configured on any port of any neighbor -switch. - -In this case, SJA1105 switch 1 consumes a total of 11 retagging entries, as -follows: - -- 8 retagging entries for VLANs 1 and 100 installed on its user ports - (``sw1p0`` - ``sw1p3``) -- 3 retagging entries for VLAN 100 installed on the user ports of SJA1105 - switch 2 (``sw2p0`` - ``sw2p2``), because it also has ports that are - interested in it. The VLAN 1 is a pvid on SJA1105 switch 2 and does not need - reverse retagging. - -SJA1105 switch 2 also consumes 11 retagging entries, but organized as follows: - -- 7 retagging entries for the bridge VLANs on its user ports (``sw2p0`` - - ``sw2p3``). -- 4 retagging entries for VLAN 100 installed on the user ports of SJA1105 - switch 1 (``sw1p0`` - ``sw1p3``). - Switching features ================== @@ -282,33 +89,10 @@ untagged), and therefore this mode is also supported. Segregating the switch ports in multiple bridges is supported (e.g. 2 + 2), but all bridges should have the same level of VLAN awareness (either both have -``vlan_filtering`` 0, or both 1). Also an inevitable limitation of the fact -that VLAN awareness is global at the switch level is that once a bridge with -``vlan_filtering`` enslaves at least one switch port, the other un-bridged -ports are no longer available for standalone traffic termination. +``vlan_filtering`` 0, or both 1). Topology and loop detection through STP is supported. -L2 FDB manipulation (add/delete/dump) is currently possible for the first -generation devices. Aging time of FDB entries, as well as enabling fully static -management (no address learning and no flooding of unknown traffic) is not yet -configurable in the driver. - -A special comment about bridging with other netdevices (illustrated with an -example): - -A board has eth0, eth1, swp0@eth1, swp1@eth1, swp2@eth1, swp3@eth1. -The switch ports (swp0-3) are under br0. -It is desired that eth0 is turned into another switched port that communicates -with swp0-3. - -If br0 has vlan_filtering 0, then eth0 can simply be added to br0 with the -intended results. -If br0 has vlan_filtering 1, then a new br1 interface needs to be created that -enslaves eth0 and eth1 (the DSA master of the switch ports). This is because in -this mode, the switch ports beneath br0 are not capable of regular traffic, and -are only used as a conduit for switchdev operations. - Offloads ======== |