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diff --git a/Documentation/networking/device_drivers/ethernet/freescale/dpaa2/switch-driver.rst b/Documentation/networking/device_drivers/ethernet/freescale/dpaa2/switch-driver.rst new file mode 100644 index 000000000000..8bf411b857d4 --- /dev/null +++ b/Documentation/networking/device_drivers/ethernet/freescale/dpaa2/switch-driver.rst @@ -0,0 +1,217 @@ +.. SPDX-License-Identifier: GPL-2.0 +.. include:: <isonum.txt> + +=================== +DPAA2 Switch driver +=================== + +:Copyright: |copy| 2021 NXP + +The DPAA2 Switch driver probes on the Datapath Switch (DPSW) object which can +be instantiated on the following DPAA2 SoCs and their variants: LS2088A and +LX2160A. + +The driver uses the switch device driver model and exposes each switch port as +a network interface, which can be included in a bridge or used as a standalone +interface. Traffic switched between ports is offloaded into the hardware. + +The DPSW can have ports connected to DPNIs or to DPMACs for external access. +:: + + [ethA] [ethB] [ethC] [ethD] [ethE] [ethF] + : : : : : : + : : : : : : + [dpaa2-eth] [dpaa2-eth] [ dpaa2-switch ] + : : : : : : kernel + ============================================================================= + : : : : : : hardware + [DPNI] [DPNI] [============= DPSW =================] + | | | | | | + | ---------- | [DPMAC] [DPMAC] + ------------------------------- | | + | | + [PHY] [PHY] + +Creating an Ethernet Switch +=========================== + +The dpaa2-switch driver probes on DPSW devices found on the fsl-mc bus. These +devices can be either created statically through the boot time configuration +file - DataPath Layout (DPL) - or at runtime using the DPAA2 object APIs +(incorporated already into the restool userspace tool). + +At the moment, the dpaa2-switch driver imposes the following restrictions on +the DPSW object that it will probe: + + * The minimum number of FDBs should be at least equal to the number of switch + interfaces. This is necessary so that separation of switch ports can be + done, ie when not under a bridge, each switch port will have its own FDB. + :: + + fsl_dpaa2_switch dpsw.0: The number of FDBs is lower than the number of ports, cannot probe + + * Both the broadcast and flooding configuration should be per FDB. This + enables the driver to restrict the broadcast and flooding domains of each + FDB depending on the switch ports that are sharing it (aka are under the + same bridge). + :: + + fsl_dpaa2_switch dpsw.0: Flooding domain is not per FDB, cannot probe + fsl_dpaa2_switch dpsw.0: Broadcast domain is not per FDB, cannot probe + + * The control interface of the switch should not be disabled + (DPSW_OPT_CTRL_IF_DIS not passed as a create time option). Without the + control interface, the driver is not capable to provide proper Rx/Tx traffic + support on the switch port netdevices. + :: + + fsl_dpaa2_switch dpsw.0: Control Interface is disabled, cannot probe + +Besides the configuration of the actual DPSW object, the dpaa2-switch driver +will need the following DPAA2 objects: + + * 1 DPMCP - A Management Command Portal object is needed for any interraction + with the MC firmware. + + * 1 DPBP - A Buffer Pool is used for seeding buffers intended for the Rx path + on the control interface. + + * Access to at least one DPIO object (Software Portal) is needed for any + enqueue/dequeue operation to be performed on the control interface queues. + The DPIO object will be shared, no need for a private one. + +Switching features +================== + +The driver supports the configuration of L2 forwarding rules in hardware for +port bridging as well as standalone usage of the independent switch interfaces. + +The hardware is not configurable with respect to VLAN awareness, thus any DPAA2 +switch port should be used only in usecases with a VLAN aware bridge:: + + $ ip link add dev br0 type bridge vlan_filtering 1 + + $ ip link add dev br1 type bridge + $ ip link set dev ethX master br1 + Error: fsl_dpaa2_switch: Cannot join a VLAN-unaware bridge + +Topology and loop detection through STP is supported when ``stp_state 1`` is +used at bridge create :: + + $ ip link add dev br0 type bridge vlan_filtering 1 stp_state 1 + +L2 FDB manipulation (add/delete/dump) is supported. + +HW FDB learning can be configured on each switch port independently through +bridge commands. When the HW learning is disabled, a fast age procedure will be +run and any previously learnt addresses will be removed. +:: + + $ bridge link set dev ethX learning off + $ bridge link set dev ethX learning on + +Restricting the unknown unicast and multicast flooding domain is supported, but +not independently of each other:: + + $ ip link set dev ethX type bridge_slave flood off mcast_flood off + $ ip link set dev ethX type bridge_slave flood off mcast_flood on + Error: fsl_dpaa2_switch: Cannot configure multicast flooding independently of unicast. + +Broadcast flooding on a switch port can be disabled/enabled through the brport sysfs:: + + $ echo 0 > /sys/bus/fsl-mc/devices/dpsw.Y/net/ethX/brport/broadcast_flood + +Offloads +======== + +Routing actions (redirect, trap, drop) +-------------------------------------- + +The DPAA2 switch is able to offload flow-based redirection of packets making +use of ACL tables. Shared filter blocks are supported by sharing a single ACL +table between multiple ports. + +The following flow keys are supported: + + * Ethernet: dst_mac/src_mac + * IPv4: dst_ip/src_ip/ip_proto/tos + * VLAN: vlan_id/vlan_prio/vlan_tpid/vlan_dei + * L4: dst_port/src_port + +Also, the matchall filter can be used to redirect the entire traffic received +on a port. + +As per flow actions, the following are supported: + + * drop + * mirred egress redirect + * trap + +Each ACL entry (filter) can be setup with only one of the listed +actions. + +Example 1: send frames received on eth4 with a SA of 00:01:02:03:04:05 to the +CPU:: + + $ tc qdisc add dev eth4 clsact + $ tc filter add dev eth4 ingress flower src_mac 00:01:02:03:04:05 skip_sw action trap + +Example 2: drop frames received on eth4 with VID 100 and PCP of 3:: + + $ tc filter add dev eth4 ingress protocol 802.1q flower skip_sw vlan_id 100 vlan_prio 3 action drop + +Example 3: redirect all frames received on eth4 to eth1:: + + $ tc filter add dev eth4 ingress matchall action mirred egress redirect dev eth1 + +Example 4: Use a single shared filter block on both eth5 and eth6:: + + $ tc qdisc add dev eth5 ingress_block 1 clsact + $ tc qdisc add dev eth6 ingress_block 1 clsact + $ tc filter add block 1 ingress flower dst_mac 00:01:02:03:04:04 skip_sw \ + action trap + $ tc filter add block 1 ingress protocol ipv4 flower src_ip 192.168.1.1 skip_sw \ + action mirred egress redirect dev eth3 + +Mirroring +~~~~~~~~~ + +The DPAA2 switch supports only per port mirroring and per VLAN mirroring. +Adding mirroring filters in shared blocks is also supported. + +When using the tc-flower classifier with the 802.1q protocol, only the +''vlan_id'' key will be accepted. Mirroring based on any other fields from the +802.1q protocol will be rejected:: + + $ tc qdisc add dev eth8 ingress_block 1 clsact + $ tc filter add block 1 ingress protocol 802.1q flower skip_sw vlan_prio 3 action mirred egress mirror dev eth6 + Error: fsl_dpaa2_switch: Only matching on VLAN ID supported. + We have an error talking to the kernel + +If a mirroring VLAN filter is requested on a port, the VLAN must to be +installed on the switch port in question either using ''bridge'' or by creating +a VLAN upper device if the switch port is used as a standalone interface:: + + $ tc qdisc add dev eth8 ingress_block 1 clsact + $ tc filter add block 1 ingress protocol 802.1q flower skip_sw vlan_id 200 action mirred egress mirror dev eth6 + Error: VLAN must be installed on the switch port. + We have an error talking to the kernel + + $ bridge vlan add vid 200 dev eth8 + $ tc filter add block 1 ingress protocol 802.1q flower skip_sw vlan_id 200 action mirred egress mirror dev eth6 + + $ ip link add link eth8 name eth8.200 type vlan id 200 + $ tc filter add block 1 ingress protocol 802.1q flower skip_sw vlan_id 200 action mirred egress mirror dev eth6 + +Also, it should be noted that the mirrored traffic will be subject to the same +egress restrictions as any other traffic. This means that when a mirrored +packet will reach the mirror port, if the VLAN found in the packet is not +installed on the port it will get dropped. + +The DPAA2 switch supports only a single mirroring destination, thus multiple +mirror rules can be installed but their ''to'' port has to be the same:: + + $ tc filter add block 1 ingress protocol 802.1q flower skip_sw vlan_id 200 action mirred egress mirror dev eth6 + $ tc filter add block 1 ingress protocol 802.1q flower skip_sw vlan_id 100 action mirred egress mirror dev eth7 + Error: fsl_dpaa2_switch: Multiple mirror ports not supported. + We have an error talking to the kernel |