Lines Matching +full:cpu +full:- +full:viewed
22 An Ethernet switch typically comprises multiple front-panel ports and one
23 or more CPU or management ports. The DSA subsystem currently relies on the
27 gateways, or even top-of-rack switches. This host Ethernet controller will
28 be later referred to as "conduit" and "cpu" in DSA terminology and code.
36 For each front-panel port, DSA creates specialized network devices which are
37 used as controlling and data-flowing endpoints for use by the Linux networking
46 - what port is this frame coming from
47 - what was the reason why this frame got forwarded
48 - how to send CPU originated traffic to specific ports
52 on Port-based VLAN IDs).
54 Note that DSA does not currently create network interfaces for the "cpu" and
57 - the "cpu" port is the Ethernet switch facing side of the management
59 would get two interfaces for the same conduit: conduit netdev, and "cpu" netdev
61 - the "dsa" port(s) are just conduits between two or more switches, and as such
63 downstream, or the top-most upstream interface makes sense with that model
70 ------------------------
72 DSA supports many vendor-specific tagging protocols, one software-defined
73 tagging protocol, and a tag-less mode as well (``DSA_TAG_PROTO_NONE``).
78 - identifies which port the Ethernet frame came from/should be sent to
79 - provides a reason why this frame was forwarded to the management interface
86 1. The switch-specific frame header is located before the Ethernet header,
89 2. The switch-specific frame header is located before the EtherType, keeping
92 3. The switch-specific frame header is located at the tail of the packet,
106 on a best-effort basis, the allocation of packets with enough extra space such
110 Even though applications are not expected to parse DSA-specific frame headers,
122 fabric with more than one switch, the switch-specific frame header is inserted
125 frame that must be trapped to the CPU, or a data frame to be forwarded).
132 by a leaf switch (not connected directly to the CPU) is not the same as what
134 CPU port can be configured to use either the DSA or the Ethertype DSA (EDSA)
138 EDSA tagging protocol, the operating system sees EDSA-tagged packets from the
140 because the Marvell switch connected directly to the CPU is configured to
147 tree. The DSA links are viewed as simply a pair of a DSA conduit (the out-facing
148 port of the upstream DSA switch) and a CPU port (the in-facing port of the
151 The tagging protocol of the attached DSA switch tree can be viewed through the
169 The passed ``struct sk_buff *skb`` has ``skb->data`` pointing at
181 passed ``struct sk_buff *skb`` has ``skb->data`` pointing at
184 method is to consume the frame header, adjust ``skb->data`` to really point at
185 the first octet after the EtherType, and to change ``skb->dev`` to point to the
186 virtual DSA user network interface corresponding to the physical front-facing
218 with DSA-unaware conduits, mangling what the conduit perceives as MAC DA), the
222 Note that this assumes a DSA-unaware conduit driver, which is the norm.
225 -----------------------
228 the CPU/management Ethernet interface. Such a driver might occasionally need to
237 ----------------------
242 specific (and fake) Ethernet type (later becoming ``skb->protocol``) with the
250 - receive function is invoked
251 - basic packet processing is done: getting length, status etc.
252 - packet is prepared to be processed by the Ethernet layer by calling
258 if (dev->dsa_ptr != NULL)
259 -> skb->protocol = ETH_P_XDSA
264 -> iterate over registered packet_type
265 -> invoke handler for ETH_P_XDSA, calls dsa_switch_rcv()
269 -> dsa_switch_rcv()
270 -> invoke switch tag specific protocol handler in 'net/dsa/tag_*.c'
274 - inspect and strip switch tag protocol to determine originating port
275 - locate per-port network device
276 - invoke ``eth_type_trans()`` with the DSA user network device
277 - invoked ``netif_receive_skb()``
283 --------------------
287 controlling and data-flowing end-point for each front-panel port of the switch.
290 - insert/remove the switch tag protocol (if it exists) when sending traffic
292 - query the switch for ethtool operations: statistics, link state,
293 Wake-on-LAN, register dumps...
294 - manage external/internal PHY: link, auto-negotiation, etc.
310 When using multiple CPU ports, it is possible to stack a LAG (bonding/team)
325 ------------------------
334 +-----------v--|--------------------+
335 |+------+ +------+ +------+ +------+|
337 |+------+-+------+-+------+-+------+|
339 +-----------------------------------+
344 +-----------------------------------+
346 --------+-----------------------------------+------------
348 +-----------------------------------+
353 +-----------------------------------+
355 |+------+ +------+ +------+ +------+|
357 ++------+-+------+-+------+-+------++
360 -------------
364 MDIO reads/writes towards specific PHY addresses. In most MDIO-connected
367 library and/or to return link status, link partner pages, auto-negotiation
376 ---------------
381 - ``dsa_chip_data``: platform data configuration for a given switch device,
386 - ``dsa_platform_data``: platform device configuration data which can reference
391 - ``dsa_switch_tree``: structure assigned to the conduit network device under
395 switch is also provided: CPU port. Finally, a collection of dsa_switch are
398 - ``dsa_switch``: structure describing a switch device in the tree, referencing
402 - ``dsa_switch_ops``: structure referencing function pointers, see below for a
408 Lack of CPU/DSA network devices
409 -------------------------------
411 DSA does not currently create user network devices for the CPU or DSA ports, as
414 - inability to fetch switch CPU port statistics counters using ethtool, which
417 - inability to configure the CPU port link parameters based on the Ethernet
420 - inability to configure specific VLAN IDs / trunking VLANs between switches
424 --------------------------------
426 Once a conduit network device is configured to use DSA (dev->dsa_ptr becomes
427 non-NULL), and the switch behind it expects a tagging protocol, this network
439 - MDIO/PHY library: ``drivers/net/phy/phy.c``, ``mdio_bus.c``
440 - Switchdev:``net/switchdev/*``
441 - Device Tree for various of_* functions
442 - Devlink: ``net/core/devlink.c``
445 ----------------
451 - internal PHY devices, built into the Ethernet switch hardware
452 - external PHY devices, connected via an internal or external MDIO bus
453 - internal PHY devices, connected via an internal MDIO bus
454 - special, non-autonegotiated or non MDIO-managed PHY devices: SFPs, MoCA; a.k.a
460 - if Device Tree is used, the PHY device is looked up using the standard
461 "phy-handle" property, if found, this PHY device is created and registered
464 - if Device Tree is used and the PHY device is "fixed", that is, conforms to
465 the definition of a non-MDIO managed PHY as defined in
466 ``Documentation/devicetree/bindings/net/fixed-link.txt``, the PHY is registered
469 - finally, if the PHY is built into the switch, as is very common with
475 ---------
479 of per-port user network devices. As of today, the only SWITCHDEV objects
483 -------
486 For each devlink device, every physical port (i.e. user ports, CPU ports, DSA
491 - Regions: debugging feature which allows user space to dump driver-defined
492 areas of hardware information in a low-level, binary format. Both global
493 regions as well as per-port regions are supported. It is possible to export
495 to the standard iproute2 user space programs (ip-link, bridge), like address
497 contain additional hardware-specific details which are not visible through
499 the non-user ports too, which are invisible to iproute2 because no network
501 - Params: a feature which enables user to configure certain low-level tunable
503 devlink params, or may add new device-specific devlink params.
504 - Resources: a monitoring feature which enables users to see the degree of
506 - Shared buffers: a QoS feature for adjusting and partitioning memory and frame
508 directions, such that low-priority bulk traffic does not impede the
509 processing of high-priority critical traffic.
514 -----------
519 per-port PHY specific details: interface connection, MDIO bus location, etc.
528 -----------------------------------------
539 - ``ds->dev``: will be used to parse the switch's OF node or platform data.
541 - ``ds->num_ports``: will be used to create the port list for this switch, and
544 - ``ds->ops``: a pointer to the ``dsa_switch_ops`` structure holding the DSA
547 - ``ds->priv``: backpointer to a driver-private data structure which can be
551 be configured to obtain driver-specific behavior from the DSA core. Their
554 - ``ds->vlan_filtering_is_global``
556 - ``ds->needs_standalone_vlan_filtering``
558 - ``ds->configure_vlan_while_not_filtering``
560 - ``ds->untag_bridge_pvid``
562 - ``ds->assisted_learning_on_cpu_port``
564 - ``ds->mtu_enforcement_ingress``
566 - ``ds->fdb_isolation``
578 The first N-1 callers of ``dsa_register_switch()`` only add their ports to the
579 port list of the tree (``dst->ports``), each port having a backpointer to its
580 associated switch (``dp->ds``). Then, these switches exit their
585 continuation of initialization (including the call to ``ds->ops->setup()``) for
612 --------------------
614 - ``get_tag_protocol``: this is to indicate what kind of tagging protocol is
617 CPU port number, as well as the tagging protocol of a possibly stacked
621 - ``change_tag_protocol``: when the default tagging protocol has compatibility
627 - ``setup``: setup function for the switch, this function is responsible for setting
632 a Port-based VLAN ID for each port and allowing only the CPU port and the
641 - ``port_setup`` and ``port_teardown``: methods for initialization and
642 destruction of per-port data structures. It is mandatory for some operations
650 - ``port_change_conduit``: method through which the affinity (association used
651 for traffic termination purposes) between a user port and a CPU port can be
653 available CPU port that makes sense for them (most of the times this means
654 the user ports of a tree are all assigned to the same CPU port, except for H
657 the new DSA conduit ``net_device``. The CPU port associated with the new
659 conduit->dsa_ptr``. Additionally, the conduit can also be a LAG device where
661 valid ``conduit->dsa_ptr`` pointer, however this is not unique, but rather a
664 separately for the physical CPU ports associated with the physical DSA
669 -------------------------------
671 - ``get_phy_flags``: Some switches are interfaced to various kinds of Ethernet PHYs,
674 should return a 32-bit bitmask of "flags" that is private between the switch
677 - ``phy_read``: Function invoked by the DSA user MDIO bus when attempting to read
680 status, auto-negotiation results, link partner pages, etc.
682 - ``phy_write``: Function invoked by the DSA user MDIO bus when attempting to write
686 - ``adjust_link``: Function invoked by the PHY library when a user network device
691 - ``fixed_link_update``: Function invoked by the PHY library, and specifically by
693 not be auto-negotiated, or obtained by reading the PHY registers through MDIO.
695 MoCA or other kinds of non-MDIO managed PHYs where out of band link
699 ------------------
701 - ``get_strings``: ethtool function used to query the driver's strings, will
704 - ``get_ethtool_stats``: ethtool function used to query per-port statistics and
709 - ``get_sset_count``: ethtool function used to query the number of statistics items
711 - ``get_wol``: ethtool function used to obtain Wake-on-LAN settings per-port, this
713 Wake-on-LAN settings if this interface needs to participate in Wake-on-LAN
715 - ``set_wol``: ethtool function used to configure Wake-on-LAN settings per-port,
718 - ``set_eee``: ethtool function which is used to configure a switch port EEE (Green
721 controller and data-processing logic
723 - ``get_eee``: ethtool function which is used to query a switch port EEE settings,
725 and data-processing logic as well as query the PHY for its currently configured
728 - ``get_eeprom_len``: ethtool function returning for a given switch the EEPROM
731 - ``get_eeprom``: ethtool function returning for a given switch the EEPROM contents
733 - ``set_eeprom``: ethtool function writing specified data to a given switch EEPROM
735 - ``get_regs_len``: ethtool function returning the register length for a given
738 - ``get_regs``: ethtool function returning the Ethernet switch internal register
739 contents. This function might require user-land code in ethtool to
740 pretty-print register values and registers
743 ----------------
745 - ``suspend``: function invoked by the DSA platform device when the system goes to
747 participating in Wake-on-LAN active as well as additional wake-up logic if
750 - ``resume``: function invoked by the DSA platform device when the system resumes,
751 should resume all Ethernet switch activities and re-configure the switch to be
754 - ``port_enable``: function invoked by the DSA user network device ndo_open
760 - ``port_disable``: function invoked by the DSA user network device ndo_close
767 -----------------
776 For example, all ports that belong to a VLAN-unaware bridge (which is
777 *currently* VLAN-unaware) are expected to learn source addresses in the
779 VLAN-unaware bridges). During forwarding and FDB lookup, a packet received on a
780 VLAN-unaware bridge port should be able to find a VLAN-unaware FDB entry having
784 a port which is a member of a different VLAN-unaware bridge (and is therefore
787 Similarly, each VLAN of each offloaded VLAN-aware bridge should have an
792 In this context, a VLAN-unaware database means that all packets are expected to
794 VLAN-aware database means that packets are supposed to match based on the VLAN
797 At the bridge layer, VLAN-unaware FDB entries have the special VID value of 0,
798 whereas VLAN-aware FDB entries have non-zero VID values. Note that a
799 VLAN-unaware bridge may have VLAN-aware (non-zero VID) FDB entries, and a
800 VLAN-aware bridge may have VLAN-unaware FDB entries. As in hardware, the
808 (packet in, packet out to the CPU port) as little as possible. For example,
813 received packets should be trivially flooded to the CPU port.
815 DSA (cascade) and CPU ports are also called "shared" ports because they service
817 to is usually embedded in the DSA tag. This means that the CPU port may
823 configuration by removing the CPU port from the flooding domain of the switch,
824 and just program the hardware with FDB entries pointing towards the CPU port
826 Packets which do not match a known FDB entry will not be delivered to the CPU,
827 which will save CPU cycles required for creating an skb just to drop it.
832 - Primary unicast MAC addresses of ports (``dev->dev_addr``). These are
835 the CPU port.
837 - Secondary unicast and multicast MAC addresses of ports (addresses added
841 - Local/permanent bridge FDB entries (``BR_FDB_LOCAL``). These are the MAC
846 - Static bridge FDB entries installed towards foreign (non-DSA) interfaces
850 - Dynamically learned FDB entries on foreign interfaces present in the same
851 bridge as some DSA switch ports, only if ``ds->assisted_learning_on_cpu_port``
858 - ``DSA_DB_PORT``: the FDB (or MDB) entry to be installed or deleted belongs to
859 the port private database of user port ``db->dp``.
860 - ``DSA_DB_BRIDGE``: the entry belongs to one of the address databases of bridge
861 ``db->bridge``. Separation between the VLAN-unaware database and the per-VID
863 - ``DSA_DB_LAG``: the entry belongs to the address database of LAG ``db->lag``.
867 ``port_mdb_add`` etc should declare ``ds->fdb_isolation`` as true.
869 DSA associates each offloaded bridge and each offloaded LAG with a one-based ID
872 scheme (the ID is readable through ``db->bridge.num`` and ``db->lag.id`` or may
876 entries on the CPU port belonging to ``DSA_DB_PORT`` databases.
878 drivers even if they do not support FDB isolation. However, ``db->bridge.num``
879 and ``db->lag.id`` are always set to 0 in that case (to denote the lack of
884 the port private databases will always point to the CPU port, there is no risk
886 share the same database, but the reference counting of host-filtered addresses
897 ------------
900 below. They may be absent, return -EOPNOTSUPP, or ``ds->max_num_bridges`` may
901 be non-zero and exceeded, and in this case, joining a bridge port is still
905 learning etc) disabled, and send all received packets to the CPU port only.
911 autonomously forwarding (or flooding) received packets without CPU intervention.
926 packets and have ``skb->offload_fwd_mark`` set to true in the tag protocol
928 hardware learning on the CPU port, and do not override the port STP state.
936 VLAN-unaware, and in this case the FID must be equal to the FID used by the
937 driver for its VLAN-unaware address database associated with that bridge.
938 Alternatively, the bridge may be VLAN-aware, and in that case, it is guaranteed
939 that the packet is also VLAN-tagged with the VLAN ID that the bridge processed
941 the egress-untagged ports, or keep the tag on the egress-tagged ones.
943 - ``port_bridge_join``: bridge layer function invoked when a given switch port is
950 - ``port_bridge_leave``: bridge layer function invoked when a given switch port is
955 - ``port_stp_state_set``: bridge layer function invoked when a given switch port STP
959 - ``port_bridge_flags``: bridge layer function invoked when a port must
965 the bridge port flags for the CPU port. The assumption is that address
967 CPU port, and flooding towards the CPU port should also be enabled, due to a
970 - ``port_fast_age``: bridge layer function invoked when flushing the
977 ---------------------
979 - ``port_vlan_filtering``: bridge layer function invoked when the bridge gets
989 - ``port_vlan_add``: bridge layer function invoked when a VLAN is configured
990 (tagged or untagged) for the given switch port. The CPU port becomes a member
996 to manually install a VLAN on the CPU port.
998 - ``port_vlan_del``: bridge layer function invoked when a VLAN is removed from the
1001 - ``port_fdb_add``: bridge layer function invoked when the bridge wants to install a
1006 - ``port_fdb_del``: bridge layer function invoked when the bridge wants to remove a
1011 - ``port_fdb_dump``: bridge bypass function invoked by ``ndo_fdb_dump`` on the
1018 - ``port_mdb_add``: bridge layer function invoked when the bridge wants to install
1023 - ``port_mdb_del``: bridge layer function invoked when the bridge wants to remove a
1029 ----------------
1046 - ``port_lag_join``: function invoked when a given switch port is added to a
1047 LAG. The driver may return ``-EOPNOTSUPP``, and in this case, DSA will fall
1049 the CPU.
1050 - ``port_lag_leave``: function invoked when a given switch port leaves a LAG
1052 - ``port_lag_change``: function invoked when the link state of any member of
1057 can optionally populate ``ds->num_lag_ids`` from the ``dsa_switch_ops::setup``
1061 IEC 62439-2 (MRP)
1062 -----------------
1077 necessary for the hardware, even if it is not MRP-aware, to be able to extract
1079 implementation. DSA today has no driver which is MRP-aware, therefore it only
1083 - ``port_mrp_add`` and ``port_mrp_del``: notifies driver when an MRP instance
1086 - ``port_mrp_add_ring_role`` and ``port_mrp_del_ring_role``: function invoked
1091 IEC 62439-3 (HSR/PRP)
1092 ---------------------
1097 eliminating the duplicates at the receiver. The High-availability Seamless
1099 the redundant traffic are aware of the fact that it is HSR-tagged (because HSR
1113 ``Documentation/networking/netdev-features.rst``. Additionally, the following
1116 - ``port_hsr_join``: function invoked when a given switch port is added to a
1117 DANP/DANH. The driver may return ``-EOPNOTSUPP`` and in this case, DSA will
1119 sent to the CPU.
1120 - ``port_hsr_leave``: function invoked when a given switch port leaves a
1127 -------------------------------------------------------------