Lines Matching full:switch
5 This document describes the **Distributed Switch Architecture (DSA)** subsystem
13 The Distributed Switch Architecture subsystem was primarily designed to
19 they configured/queried a switch port network device or a regular network
22 An Ethernet switch typically comprises multiple front-panel ports and one
25 receiving Ethernet frames from the switch. This is a very common setup for all
34 of multiple switches connected to each other is called a "switch tree".
41 The ideal case for using DSA is when an Ethernet switch supports a "switch tag"
42 which is a hardware feature making the switch insert a specific tag for each
57 - the "cpu" port is the Ethernet switch facing side of the management
65 Switch tagging protocols
82 1. The switch-specific frame header is located before the Ethernet header,
85 2. The switch-specific frame header is located before the EtherType, keeping
88 3. The switch-specific frame header is located at the tail of the packet,
92 A tagging protocol may tag all packets with switch tags of the same length, or
94 require an extended switch tag, or there might be one tag length on TX and a
97 with the length in octets of the longest switch frame header/trailer. The DSA
103 that the act of pushing the switch tag on transmission of a packet does not
111 characteristics of the interaction required between the switch hardware and the
117 switch tree use the same tagging protocol. In case of a packet transiting a
118 fabric with more than one switch, the switch-specific frame header is inserted
119 by the first switch in the fabric that the packet was received on. This header
124 other switches from the same fabric, and in this case, the outermost switch
128 by a leaf switch (not connected directly to the CPU) is not the same as what
129 the network stack sees. This can be seen with Marvell switch trees, where the
133 It still remains the case that, if the DSA switch tree is configured for the
136 because the Marvell switch connected directly to the CPU is configured to
142 no DSA links in this fabric, and each switch constitutes a disjoint DSA switch
144 port of the upstream DSA switch) and a CPU port (the in-facing port of the
145 downstream DSA switch).
147 The tagging protocol of the attached DSA switch tree can be viewed through the
152 If the hardware and driver are capable, the tagging protocol of the DSA switch
155 all attached switch ports must be down while doing this).
161 regardless of the driver used for the switch control path, and the driver used
169 The job of this method is to prepare the skb in a way that the switch will
183 switch port that the packet was received on.
207 already expect the switch tag in use, the checksum must be calculated before any
210 when the tag gets stripped by the switch during transmission, it will leave an
230 Ethernet switch.
237 switch specific tagging protocol. DSA accomplishes this by registering a
266 -> invoke switch tag specific protocol handler in 'net/dsa/tag_*.c'
270 - inspect and strip switch tag protocol to determine originating port
283 controlling and data-flowing end-point for each front-panel port of the switch.
286 - insert/remove the switch tag protocol (if it exists) when sending traffic
287 to/from specific switch ports
288 - query the switch for ethtool operations: statistics, link state,
294 stack/ethtool and the switch driver implementation.
297 switch tagging protocol is currently registered with these network devices and
299 switch tag in the Ethernet frames.
302 ``ndo_start_xmit()`` function. Since they contain the appropriate switch tag, the
303 Ethernet switch will be able to process these incoming frames from the
304 management interface and deliver them to the physical switch port.
318 towards the switch.
334 | DSA switch driver |
338 switch driver | | switch driver
347 switch hardware | | switch hardware
350 | Switch |
358 In order to be able to read to/from a switch PHY built into it, DSA creates a
359 slave MDIO bus which allows a specific switch driver to divert and intercept
362 to return standard MII registers from the switch builtin PHYs, allowing the PHY
368 internal or external MDIO devices this switch might be connected to: internal
377 - ``dsa_chip_data``: platform data configuration for a given switch device,
378 this structure describes a switch device's parent device, its address, as
384 the master network device this switch tree is attached to needs to be
389 the tagging protocol supported by the switch tree, and which receive/transmit
391 switch is also provided: CPU port. Finally, a collection of dsa_switch are
394 - ``dsa_switch``: structure describing a switch device in the tree, referencing
410 - inability to fetch switch CPU port statistics counters using ethtool, which
411 can make it harder to debug MDIO switch connected using xMII interfaces
423 non-NULL), and the switch behind it expects a tagging protocol, this network
426 will not make us go through the switch tagging protocol transmit function, so
427 the Ethernet switch on the other end, expecting a tag will typically drop this
447 - internal PHY devices, built into the Ethernet switch hardware
465 - finally, if the PHY is built into the switch, as is very common with
466 standalone switch packages, the PHY is probed using the slave MII bus created
481 DSA registers one devlink device per physical switch in the fabric.
520 DSA switch drivers need to implement a ``dsa_switch_ops`` structure which will
530 Switch registration from the perspective of a driver means passing a valid
532 switch driver's probing function. The following members must be valid in the
535 - ``ds->dev``: will be used to parse the switch's OF node or platform data.
537 - ``ds->num_ports``: will be used to create the port list for this switch, and
564 Internally, DSA keeps an array of switch trees (group of switches) global to
566 The tree ID to which the switch is attached is determined by the first u32
567 number of the ``dsa,member`` property of the switch's OF node (0 if missing).
568 The switch ID within the tree is determined by the second u32 number of the
570 switch ID and tree ID is illegal and will cause an error. Using platform data,
571 a single switch and a single switch tree is permitted.
576 associated switch (``dp->ds``). Then, these switches exit their
580 the last switch calls ``dsa_register_switch()``, and this triggers the effective
583 switch's probe function.
586 which removes a switch's ports from the port list of the tree. The entire tree
587 is torn down when the first switch unregisters.
589 It is mandatory for DSA switch drivers to implement the ``shutdown()`` callback
607 Switch configuration
614 upstream switch, in case there are hardware limitations in terms of supported
623 - ``setup``: setup function for the switch, this function is responsible for setting
626 configure the switch to separate all network interfaces from each other, that
627 is, they should be isolated by the switch hardware itself, typically by creating
630 platform should be disabled. Past this function, the switch is expected to be
632 to issue a software reset of the switch during this setup function in order to
643 PHY cannot be found. In this case, probing of the DSA switch continues
669 on its own (e.g.: coming from switch memory mapped registers), this function
670 should return a 32-bit bitmask of "flags" that is private between the switch
674 the switch port MDIO registers. If unavailable, return 0xffff for each read.
675 For builtin switch Ethernet PHYs, this function should allow reading the link
679 to the switch port MDIO registers. If unavailable return a negative error
684 configuring the switch port link parameters: speed, duplex, pause based on
688 the fixed PHY driver asking the switch driver for link parameters that could
702 RX/TX counters from the network device, with switch driver specific statistics
714 - ``set_eee``: ethtool function which is used to configure a switch port EEE (Green
716 PHY level if relevant. This function should enable EEE at the switch port MAC
719 - ``get_eee``: ethtool function which is used to query a switch port EEE settings,
720 this function should return the EEE state of the switch port MAC controller
724 - ``get_eeprom_len``: ethtool function returning for a given switch the EEPROM
727 - ``get_eeprom``: ethtool function returning for a given switch the EEPROM contents
729 - ``set_eeprom``: ethtool function writing specified data to a given switch EEPROM
732 switch
734 - ``get_regs``: ethtool function returning the Ethernet switch internal register
742 suspend, should quiesce all Ethernet switch activities, but keep ports
747 should resume all Ethernet switch activities and re-configure the switch to be
752 fully enable a given switch port. DSA takes care of marking the port with
758 fully disable a given switch port. DSA takes care of marking the port with
818 Switch drivers which satisfy certain criteria are able to optimize the naive
819 configuration by removing the CPU port from the flooding domain of the switch,
843 present in the same bridge as some DSA switch ports. These are also
847 bridge as some DSA switch ports, only if ``ds->assisted_learning_on_cpu_port``
878 Note that it is not mandatory for a switch driver to implement physically
911 ingress switch port. DSA, through ``dsa_port_devlink_setup()``, considers all
912 switch ports part of the same tree ID to be part of the same bridge forwarding
939 - ``port_bridge_join``: bridge layer function invoked when a given switch port is
940 added to a bridge, this function should do what's necessary at the switch
946 - ``port_bridge_leave``: bridge layer function invoked when a given switch port is
948 switch level to deny the leaving port from ingress/egress traffic from the
951 - ``port_stp_state_set``: bridge layer function invoked when a given switch port STP
952 state is computed by the bridge layer and should be propagated to switch
957 learning. The switch driver is responsible for initial setup of the
980 VLAN ID map/rules. If there is no PVID programmed into the switch port,
981 untagged frames must be rejected as well. When turned off the switch must
986 (tagged or untagged) for the given switch port. The CPU port becomes a member
995 given switch port
998 Forwarding Database entry, the switch hardware should be programmed with the
1003 Forwarding Database entry, the switch hardware should be programmed to delete
1015 a multicast database entry. The switch hardware should be programmed with the
1020 multicast database entry, the switch hardware should be programmed to delete
1042 - ``port_lag_join``: function invoked when a given switch port is added to a
1046 - ``port_lag_leave``: function invoked when a given switch port leaves a LAG
1055 retrieved by a DSA switch driver using the ``dsa_lag_id`` function.
1105 interface with a physical switch port does not produce the expected result).
1112 - ``port_hsr_join``: function invoked when a given switch port is added to a
1116 - ``port_hsr_leave``: function invoked when a given switch port leaves a
1126 capable hardware, but does not enforce a strict switch device driver model. On
1128 of the switch specific. At some point we should envision a merger between these