diff options
Diffstat (limited to 'Documentation')
16 files changed, 1081 insertions, 55 deletions
diff --git a/Documentation/devicetree/bindings/net/dsa/dsa.txt b/Documentation/devicetree/bindings/net/dsa/dsa.txt index f0b4cd7..04e6bef 100644 --- a/Documentation/devicetree/bindings/net/dsa/dsa.txt +++ b/Documentation/devicetree/bindings/net/dsa/dsa.txt @@ -44,9 +44,10 @@ Note that a port labelled "dsa" will imply checking for the uplink phandle described below. Optionnal property: -- link : Should be a phandle to another switch's DSA port. +- link : Should be a list of phandles to another switch's DSA port. This property is only used when switches are being - chained/cascaded together. + chained/cascaded together. This port is used as outgoing port + towards the phandle port, which can be more than one hop away. - phy-handle : Phandle to a PHY on an external MDIO bus, not the switch internal one. See @@ -58,6 +59,10 @@ Optionnal property: Documentation/devicetree/bindings/net/ethernet.txt for details. +- mii-bus : Should be a phandle to a valid MDIO bus device node. + This mii-bus will be used in preference to the + global dsa,mii-bus defined above, for this switch. + Optional subnodes: - fixed-link : Fixed-link subnode describing a link to a non-MDIO managed entity. See @@ -96,10 +101,11 @@ Example: label = "cpu"; }; - switch0uplink: port@6 { + switch0port6: port@6 { reg = <6>; label = "dsa"; - link = <&switch1uplink>; + link = <&switch1port0 + &switch2port0>; }; }; @@ -107,11 +113,31 @@ Example: #address-cells = <1>; #size-cells = <0>; reg = <17 1>; /* MDIO address 17, switch 1 in tree */ + mii-bus = <&mii_bus1>; + + switch1port0: port@0 { + reg = <0>; + label = "dsa"; + link = <&switch0port6>; + }; + switch1port1: port@1 { + reg = <1>; + label = "dsa"; + link = <&switch2port1>; + }; + }; + + switch@2 { + #address-cells = <1>; + #size-cells = <0>; + reg = <18 2>; /* MDIO address 18, switch 2 in tree */ + mii-bus = <&mii_bus1>; - switch1uplink: port@0 { + switch2port0: port@0 { reg = <0>; label = "dsa"; - link = <&switch0uplink>; + link = <&switch1port1 + &switch0port6>; }; }; }; diff --git a/Documentation/devicetree/bindings/net/ethernet.txt b/Documentation/devicetree/bindings/net/ethernet.txt index 41b3f3f..5d88f37 100644 --- a/Documentation/devicetree/bindings/net/ethernet.txt +++ b/Documentation/devicetree/bindings/net/ethernet.txt @@ -25,7 +25,11 @@ The following properties are common to the Ethernet controllers: flow control thresholds. - tx-fifo-depth: the size of the controller's transmit fifo in bytes. This is used for components that can have configurable fifo sizes. +- managed: string, specifies the PHY management type. Supported values are: + "auto", "in-band-status". "auto" is the default, it usess MDIO for + management if fixed-link is not specified. Child nodes of the Ethernet controller are typically the individual PHY devices connected via the MDIO bus (sometimes the MDIO bus controller is separate). They are described in the phy.txt file in this same directory. +For non-MDIO PHY management see fixed-link.txt. diff --git a/Documentation/devicetree/bindings/net/fixed-link.txt b/Documentation/devicetree/bindings/net/fixed-link.txt index 82bf7e0..ec5d889 100644 --- a/Documentation/devicetree/bindings/net/fixed-link.txt +++ b/Documentation/devicetree/bindings/net/fixed-link.txt @@ -17,6 +17,8 @@ properties: enabled. * 'asym-pause' (boolean, optional), to indicate that asym_pause should be enabled. +* 'link-gpios' ('gpio-list', optional), to indicate if a gpio can be read + to determine if the link is up. Old, deprecated 'fixed-link' binding: @@ -30,7 +32,7 @@ Old, deprecated 'fixed-link' binding: - e: asymmetric pause configuration: 0 for no asymmetric pause, 1 for asymmetric pause -Example: +Examples: ethernet@0 { ... @@ -40,3 +42,13 @@ ethernet@0 { }; ... }; + +ethernet@1 { + ... + fixed-link { + speed = <1000>; + pause; + link-gpios = <&gpio0 12 GPIO_ACTIVE_HIGH>; + }; + ... +}; diff --git a/Documentation/devicetree/bindings/net/keystone-netcp.txt b/Documentation/devicetree/bindings/net/keystone-netcp.txt index d0e6fa3..b30ab6b 100644 --- a/Documentation/devicetree/bindings/net/keystone-netcp.txt +++ b/Documentation/devicetree/bindings/net/keystone-netcp.txt @@ -130,7 +130,11 @@ Required properties: Optional properties: - efuse-mac: If this is 1, then the MAC address for the interface is - obtained from the device efuse mac address register + obtained from the device efuse mac address register. + If this is 2, the two DWORDs occupied by the MAC address + are swapped. The netcp driver will swap the two DWORDs + back to the proper order when this property is set to 2 + when it obtains the mac address from efuse. - local-mac-address: the driver is designed to use the of_get_mac_address api only if efuse-mac is 0. When efuse-mac is 0, the MAC address is obtained from local-mac-address. If this diff --git a/Documentation/devicetree/bindings/net/nfc/s3fwrn5.txt b/Documentation/devicetree/bindings/net/nfc/s3fwrn5.txt new file mode 100644 index 0000000..fb1e75f --- /dev/null +++ b/Documentation/devicetree/bindings/net/nfc/s3fwrn5.txt @@ -0,0 +1,27 @@ +* Samsung S3FWRN5 NCI NFC Controller + +Required properties: +- compatible: Should be "samsung,s3fwrn5-i2c". +- reg: address on the bus +- interrupt-parent: phandle for the interrupt gpio controller +- interrupts: GPIO interrupt to which the chip is connected +- s3fwrn5,en-gpios: Output GPIO pin used for enabling/disabling the chip +- s3fwrn5,fw-gpios: Output GPIO pin used to enter firmware mode and + sleep/wakeup control + +Example: + +&hsi2c_4 { + status = "okay"; + s3fwrn5@27 { + compatible = "samsung,s3fwrn5-i2c"; + + reg = <0x27>; + + interrupt-parent = <&gpa1>; + interrupts = <3 0 0>; + + s3fwrn5,en-gpios = <&gpf1 4 0>; + s3fwrn5,fw-gpios = <&gpj0 2 0>; + }; +}; diff --git a/Documentation/devicetree/bindings/net/nfc/st-nci.txt b/Documentation/devicetree/bindings/net/nfc/st-nci-i2c.txt index d707588..d707588 100644 --- a/Documentation/devicetree/bindings/net/nfc/st-nci.txt +++ b/Documentation/devicetree/bindings/net/nfc/st-nci-i2c.txt diff --git a/Documentation/devicetree/bindings/net/nfc/st-nci-spi.txt b/Documentation/devicetree/bindings/net/nfc/st-nci-spi.txt new file mode 100644 index 0000000..525681b --- /dev/null +++ b/Documentation/devicetree/bindings/net/nfc/st-nci-spi.txt @@ -0,0 +1,31 @@ +* STMicroelectronics SAS. ST NCI NFC Controller + +Required properties: +- compatible: Should be "st,st21nfcb-spi" +- spi-max-frequency: Maximum SPI frequency (<= 10000000). +- interrupt-parent: phandle for the interrupt gpio controller +- interrupts: GPIO interrupt to which the chip is connected +- reset-gpios: Output GPIO pin used to reset the ST21NFCB + +Optional SoC Specific Properties: +- pinctrl-names: Contains only one value - "default". +- pintctrl-0: Specifies the pin control groups used for this controller. + +Example (for ARM-based BeagleBoard xM with ST21NFCB on SPI4): + +&mcspi4 { + + status = "okay"; + + st21nfcb: st21nfcb@0 { + + compatible = "st,st21nfcb-spi"; + + clock-frequency = <4000000>; + + interrupt-parent = <&gpio5>; + interrupts = <2 IRQ_TYPE_EDGE_RISING>; + + reset-gpios = <&gpio5 29 GPIO_ACTIVE_HIGH>; + }; +}; diff --git a/Documentation/devicetree/bindings/net/snps,dwc-qos-ethernet.txt b/Documentation/devicetree/bindings/net/snps,dwc-qos-ethernet.txt new file mode 100644 index 0000000..51f8d2e --- /dev/null +++ b/Documentation/devicetree/bindings/net/snps,dwc-qos-ethernet.txt @@ -0,0 +1,75 @@ +* Synopsys DWC Ethernet QoS IP version 4.10 driver (GMAC) + + +Required properties: +- compatible: Should be "snps,dwc-qos-ethernet-4.10" +- reg: Address and length of the register set for the device +- clocks: Phandles to the reference clock and the bus clock +- clock-names: Should be "phy_ref_clk" for the reference clock and "apb_pclk" + for the bus clock. +- interrupt-parent: Should be the phandle for the interrupt controller + that services interrupts for this device +- interrupts: Should contain the core's combined interrupt signal +- phy-mode: See ethernet.txt file in the same directory + +Optional properties: +- dma-coherent: Present if dma operations are coherent +- mac-address: See ethernet.txt in the same directory +- local-mac-address: See ethernet.txt in the same directory +- snps,en-lpi: If present it enables use of the AXI low-power interface +- snps,write-requests: Number of write requests that the AXI port can issue. + It depends on the SoC configuration. +- snps,read-requests: Number of read requests that the AXI port can issue. + It depends on the SoC configuration. +- snps,burst-map: Bitmap of allowed AXI burst lengts, with the LSB + representing 4, then 8 etc. +- snps,txpbl: DMA Programmable burst length for the TX DMA +- snps,rxpbl: DMA Programmable burst length for the RX DMA +- snps,en-tx-lpi-clockgating: Enable gating of the MAC TX clock during + TX low-power mode. +- phy-handle: See ethernet.txt file in the same directory +- mdio device tree subnode: When the GMAC has a phy connected to its local + mdio, there must be device tree subnode with the following + required properties: + - compatible: Must be "snps,dwc-qos-ethernet-mdio". + - #address-cells: Must be <1>. + - #size-cells: Must be <0>. + + For each phy on the mdio bus, there must be a node with the following + fields: + + - reg: phy id used to communicate to phy. + - device_type: Must be "ethernet-phy". + - fixed-mode device tree subnode: see fixed-link.txt in the same directory + +Examples: +ethernet2@40010000 { + clock-names = "phy_ref_clk", "apb_pclk"; + clocks = <&clkc 17>, <&clkc 15>; + compatible = "snps,dwc-qos-ethernet-4.10"; + interrupt-parent = <&intc>; + interrupts = <0x0 0x1e 0x4>; + reg = <0x40010000 0x4000>; + phy-handle = <&phy2>; + phy-mode = "gmii"; + + snps,en-tx-lpi-clockgating; + snps,en-lpi; + snps,write-requests = <2>; + snps,read-requests = <16>; + snps,burst-map = <0x7>; + snps,txpbl = <8>; + snps,rxpbl = <2>; + + dma-coherent; + + mdio { + #address-cells = <0x1>; + #size-cells = <0x0>; + phy2: phy@1 { + compatible = "ethernet-phy-ieee802.3-c22"; + device_type = "ethernet-phy"; + reg = <0x1>; + }; + }; +}; diff --git a/Documentation/networking/6lowpan.txt b/Documentation/networking/6lowpan.txt new file mode 100644 index 0000000..a7dc7e9 --- /dev/null +++ b/Documentation/networking/6lowpan.txt @@ -0,0 +1,50 @@ + +Netdev private dataroom for 6lowpan interfaces: + +All 6lowpan able net devices, means all interfaces with ARPHRD_6LOWPAN, +must have "struct lowpan_priv" placed at beginning of netdev_priv. + +The priv_size of each interface should be calculate by: + + dev->priv_size = LOWPAN_PRIV_SIZE(LL_6LOWPAN_PRIV_DATA); + +Where LL_PRIV_6LOWPAN_DATA is sizeof linklayer 6lowpan private data struct. +To access the LL_PRIV_6LOWPAN_DATA structure you can cast: + + lowpan_priv(dev)-priv; + +to your LL_6LOWPAN_PRIV_DATA structure. + +Before registering the lowpan netdev interface you must run: + + lowpan_netdev_setup(dev, LOWPAN_LLTYPE_FOOBAR); + +wheres LOWPAN_LLTYPE_FOOBAR is a define for your 6LoWPAN linklayer type of +enum lowpan_lltypes. + +Example to evaluate the private usually you can do: + +static inline sturct lowpan_priv_foobar * +lowpan_foobar_priv(struct net_device *dev) +{ + return (sturct lowpan_priv_foobar *)lowpan_priv(dev)->priv; +} + +switch (dev->type) { +case ARPHRD_6LOWPAN: + lowpan_priv = lowpan_priv(dev); + /* do great stuff which is ARPHRD_6LOWPAN related */ + switch (lowpan_priv->lltype) { + case LOWPAN_LLTYPE_FOOBAR: + /* do 802.15.4 6LoWPAN handling here */ + lowpan_foobar_priv(dev)->bar = foo; + break; + ... + } + break; +... +} + +In case of generic 6lowpan branch ("net/6lowpan") you can remove the check +on ARPHRD_6LOWPAN, because you can be sure that these function are called +by ARPHRD_6LOWPAN interfaces. diff --git a/Documentation/networking/dsa/bcm_sf2.txt b/Documentation/networking/dsa/bcm_sf2.txt new file mode 100644 index 0000000..d999d0c --- /dev/null +++ b/Documentation/networking/dsa/bcm_sf2.txt @@ -0,0 +1,114 @@ +Broadcom Starfighter 2 Ethernet switch driver +============================================= + +Broadcom's Starfighter 2 Ethernet switch hardware block is commonly found and +deployed in the following products: + +- xDSL gateways such as BCM63138 +- streaming/multimedia Set Top Box such as BCM7445 +- Cable Modem/residential gateways such as BCM7145/BCM3390 + +The switch is typically deployed in a configuration involving between 5 to 13 +ports, offering a range of built-in and customizable interfaces: + +- single integrated Gigabit PHY +- quad integrated Gigabit PHY +- quad external Gigabit PHY w/ MDIO multiplexer +- integrated MoCA PHY +- several external MII/RevMII/GMII/RGMII interfaces + +The switch also supports specific congestion control features which allow MoCA +fail-over not to lose packets during a MoCA role re-election, as well as out of +band back-pressure to the host CPU network interface when downstream interfaces +are connected at a lower speed. + +The switch hardware block is typically interfaced using MMIO accesses and +contains a bunch of sub-blocks/registers: + +* SWITCH_CORE: common switch registers +* SWITCH_REG: external interfaces switch register +* SWITCH_MDIO: external MDIO bus controller (there is another one in SWITCH_CORE, + which is used for indirect PHY accesses) +* SWITCH_INDIR_RW: 64-bits wide register helper block +* SWITCH_INTRL2_0/1: Level-2 interrupt controllers +* SWITCH_ACB: Admission control block +* SWITCH_FCB: Fail-over control block + +Implementation details +====================== + +The driver is located in drivers/net/dsa/bcm_sf2.c and is implemented as a DSA +driver; see Documentation/networking/dsa/dsa.txt for details on the subsytem +and what it provides. + +The SF2 switch is configured to enable a Broadcom specific 4-bytes switch tag +which gets inserted by the switch for every packet forwarded to the CPU +interface, conversely, the CPU network interface should insert a similar tag for +packets entering the CPU port. The tag format is described in +net/dsa/tag_brcm.c. + +Overall, the SF2 driver is a fairly regular DSA driver; there are a few +specifics covered below. + +Device Tree probing +------------------- + +The DSA platform device driver is probed using a specific compatible string +provided in net/dsa/dsa.c. The reason for that is because the DSA subsystem gets +registered as a platform device driver currently. DSA will provide the needed +device_node pointers which are then accessible by the switch driver setup +function to setup resources such as register ranges and interrupts. This +currently works very well because none of the of_* functions utilized by the +driver require a struct device to be bound to a struct device_node, but things +may change in the future. + +MDIO indirect accesses +---------------------- + +Due to a limitation in how Broadcom switches have been designed, external +Broadcom switches connected to a SF2 require the use of the DSA slave MDIO bus +in order to properly configure them. By default, the SF2 pseudo-PHY address, and +an external switch pseudo-PHY address will both be snooping for incoming MDIO +transactions, since they are at the same address (30), resulting in some kind of +"double" programming. Using DSA, and setting ds->phys_mii_mask accordingly, we +selectively divert reads and writes towards external Broadcom switches +pseudo-PHY addresses. Newer revisions of the SF2 hardware have introduced a +configurable pseudo-PHY address which circumvents the initial design limitation. + +Multimedia over CoAxial (MoCA) interfaces +----------------------------------------- + +MoCA interfaces are fairly specific and require the use of a firmware blob which +gets loaded onto the MoCA processor(s) for packet processing. The switch +hardware contains logic which will assert/de-assert link states accordingly for +the MoCA interface whenever the MoCA coaxial cable gets disconnected or the +firmware gets reloaded. The SF2 driver relies on such events to properly set its +MoCA interface carrier state and properly report this to the networking stack. + +The MoCA interfaces are supported using the PHY library's fixed PHY/emulated PHY +device and the switch driver registers a fixed_link_update callback for such +PHYs which reflects the link state obtained from the interrupt handler. + + +Power Management +---------------- + +Whenever possible, the SF2 driver tries to minimize the overall switch power +consumption by applying a combination of: + +- turning off internal buffers/memories +- disabling packet processing logic +- putting integrated PHYs in IDDQ/low-power +- reducing the switch core clock based on the active port count +- enabling and advertising EEE +- turning off RGMII data processing logic when the link goes down + +Wake-on-LAN +----------- + +Wake-on-LAN is currently implemented by utilizing the host processor Ethernet +MAC controller wake-on logic. Whenever Wake-on-LAN is requested, an intersection +between the user request and the supported host Ethernet interface WoL +capabilities is done and the intersection result gets configured. During +system-wide suspend/resume, only ports not participating in Wake-on-LAN are +disabled. diff --git a/Documentation/networking/dsa/dsa.txt b/Documentation/networking/dsa/dsa.txt new file mode 100644 index 0000000..aa9c1f9 --- /dev/null +++ b/Documentation/networking/dsa/dsa.txt @@ -0,0 +1,615 @@ +Distributed Switch Architecture +=============================== + +Introduction +============ + +This document describes the Distributed Switch Architecture (DSA) subsystem +design principles, limitations, interactions with other subsystems, and how to +develop drivers for this subsystem as well as a TODO for developers interested +in joining the effort. + +Design principles +================= + +The Distributed Switch Architecture is a subsystem which was primarily designed +to support Marvell Ethernet switches (MV88E6xxx, a.k.a Linkstreet product line) +using Linux, but has since evolved to support other vendors as well. + +The original philosophy behind this design was to be able to use unmodified +Linux tools such as bridge, iproute2, ifconfig to work transparently whether +they configured/queried a switch port network device or a regular network +device. + +An Ethernet switch is typically comprised of multiple front-panel ports, and one +or more CPU or management port. The DSA subsystem currently relies on the +presence of a management port connected to an Ethernet controller capable of +receiving Ethernet frames from the switch. This is a very common setup for all +kinds of Ethernet switches found in Small Home and Office products: routers, +gateways, or even top-of-the rack switches. This host Ethernet controller will +be later referred to as "master" and "cpu" in DSA terminology and code. + +The D in DSA stands for Distributed, because the subsystem has been designed +with the ability to configure and manage cascaded switches on top of each other +using upstream and downstream Ethernet links between switches. These specific +ports are referred to as "dsa" ports in DSA terminology and code. A collection +of multiple switches connected to each other is called a "switch tree". + +For each front-panel port, DSA will create specialized network devices which are +used as controlling and data-flowing endpoints for use by the Linux networking +stack. These specialized network interfaces are referred to as "slave" network +interfaces in DSA terminology and code. + +The ideal case for using DSA is when an Ethernet switch supports a "switch tag" +which is a hardware feature making the switch insert a specific tag for each +Ethernet frames it received to/from specific ports to help the management +interface figure out: + +- what port is this frame coming from +- what was the reason why this frame got forwarded +- how to send CPU originated traffic to specific ports + +The subsystem does support switches not capable of inserting/stripping tags, but +the features might be slightly limited in that case (traffic separation relies +on Port-based VLAN IDs). + +Note that DSA does not currently create network interfaces for the "cpu" and +"dsa" ports because: + +- the "cpu" port is the Ethernet switch facing side of the management + controller, and as such, would create a duplication of feature, since you + would get two interfaces for the same conduit: master netdev, and "cpu" netdev + +- the "dsa" port(s) are just conduits between two or more switches, and as such + cannot really be used as proper network interfaces either, only the + downstream, or the top-most upstream interface makes sense with that model + +Switch tagging protocols +------------------------ + +DSA currently supports 4 different tagging protocols, and a tag-less mode as +well. The different protocols are implemented in: + +net/dsa/tag_trailer.c: Marvell's 4 trailer tag mode (legacy) +net/dsa/tag_dsa.c: Marvell's original DSA tag +net/dsa/tag_edsa.c: Marvell's enhanced DSA tag +net/dsa/tag_brcm.c: Broadcom's 4 bytes tag + +The exact format of the tag protocol is vendor specific, but in general, they +all contain something which: + +- identifies which port the Ethernet frame came from/should be sent to +- provides a reason why this frame was forwarded to the management interface + +Master network devices +---------------------- + +Master network devices are regular, unmodified Linux network device drivers for +the CPU/management Ethernet interface. Such a driver might occasionally need to +know whether DSA is enabled (e.g.: to enable/disable specific offload features), +but the DSA subsystem has been proven to work with industry standard drivers: +e1000e, mv643xx_eth etc. without having to introduce modifications to these +drivers. Such network devices are also often referred to as conduit network +devices since they act as a pipe between the host processor and the hardware +Ethernet switch. + +Networking stack hooks +---------------------- + +When a master netdev is used with DSA, a small hook is placed in in the +networking stack is in order to have the DSA subsystem process the Ethernet +switch specific tagging protocol. DSA accomplishes this by registering a +specific (and fake) Ethernet type (later becoming skb->protocol) with the +networking stack, this is also known as a ptype or packet_type. A typical +Ethernet Frame receive sequence looks like this: + +Master network device (e.g.: e1000e): + +Receive interrupt fires: +- receive function is invoked +- basic packet processing is done: getting length, status etc. +- packet is prepared to be processed by the Ethernet layer by calling + eth_type_trans + +net/ethernet/eth.c: + +eth_type_trans(skb, dev) + if (dev->dsa_ptr != NULL) + -> skb->protocol = ETH_P_XDSA + +drivers/net/ethernet/*: + +netif_receive_skb(skb) + -> iterate over registered packet_type + -> invoke handler for ETH_P_XDSA, calls dsa_switch_rcv() + +net/dsa/dsa.c: + -> dsa_switch_rcv() + -> invoke switch tag specific protocol handler in + net/dsa/tag_*.c + +net/dsa/tag_*.c: + -> inspect and strip switch tag protocol to determine originating port + -> locate per-port network device + -> invoke eth_type_trans() with the DSA slave network device + -> invoked netif_receive_skb() + +Past this point, the DSA slave network devices get delivered regular Ethernet +frames that can be processed by the networking stack. + +Slave network devices +--------------------- + +Slave network devices created by DSA are stacked on top of their master network +device, each of these network interfaces will be responsible for being a +controlling and data-flowing end-point for each front-panel port of the switch. +These interfaces are specialized in order to: + +- insert/remove the switch tag protocol (if it exists) when sending traffic + to/from specific switch ports +- query the switch for ethtool operations: statistics, link state, + Wake-on-LAN, register dumps... +- external/internal PHY management: link, auto-negotiation etc. + +These slave network devices have custom net_device_ops and ethtool_ops function +pointers which allow DSA to introduce a level of layering between the networking +stack/ethtool, and the switch driver implementation. + +Upon frame transmission from these slave network devices, DSA will look up which +switch tagging protocol is currently registered with these network devices, and +invoke a specific transmit routine which takes care of adding the relevant +switch tag in the Ethernet frames. + +These frames are then queued for transmission using the master network device +ndo_start_xmit() function, since they contain the appropriate switch tag, the +Ethernet switch will be able to process these incoming frames from the +management interface and delivers these frames to the physical switch port. + +Graphical representation +------------------------ + +Summarized, this is basically how DSA looks like from a network device +perspective: + + + |--------------------------- + | CPU network device (eth0)| + ---------------------------- + | <tag added by switch | + | | + | | + | tag added by CPU> | + |--------------------------------------------| + | Switch driver | + |--------------------------------------------| + || || || + |-------| |-------| |-------| + | sw0p0 | | sw0p1 | | sw0p2 | + |-------| |-------| |-------| + +Slave MDIO bus +-------------- + +In order to be able to read to/from a switch PHY built into it, DSA creates a +slave MDIO bus which allows a specific switch driver to divert and intercept +MDIO reads/writes towards specific PHY addresses. In most MDIO-connected +switches, these functions would utilize direct or indirect PHY addressing mode +to return standard MII registers from the switch builtin PHYs, allowing the PHY +library and/or to return link status, link partner pages, auto-negotiation +results etc.. + +For Ethernet switches which have both external and internal MDIO busses, the +slave MII bus can be utilized to mux/demux MDIO reads and writes towards either +internal or external MDIO devices this switch might be connected to: internal +PHYs, external PHYs, or even external switches. + +Data structures +--------------- + +DSA data structures are defined in include/net/dsa.h as well as +net/dsa/dsa_priv.h. + +dsa_chip_data: platform data configuration for a given switch device, this +structure describes a switch device's parent device, its address, as well as +various properties of its ports: names/labels, and finally a routing table +indication (when cascading switches) + +dsa_platform_data: platform device configuration data which can reference a +collection of dsa_chip_data structure if multiples switches are cascaded, the +master network device this switch tree is attached to needs to be referenced + +dsa_switch_tree: structure assigned to the master network device under +"dsa_ptr", this structure references a dsa_platform_data structure as well as +the tagging protocol supported by the switch tree, and which receive/transmit +function hooks should be invoked, information about the directly attached switch +is also provided: CPU port. Finally, a collection of dsa_switch are referenced +to address individual switches in the tree. + +dsa_switch: structure describing a switch device in the tree, referencing a +dsa_switch_tree as a backpointer, slave network devices, master network device, +and a reference to the backing dsa_switch_driver + +dsa_switch_driver: structure referencing function pointers, see below for a full +description. + +Design limitations +================== + +DSA is a platform device driver +------------------------------- + +DSA is implemented as a DSA platform device driver which is convenient because +it will register the entire DSA switch tree attached to a master network device +in one-shot, facilitating the device creation and simplifying the device driver +model a bit, this comes however with a number of limitations: + +- building DSA and its switch drivers as modules is currently not working +- the device driver parenting does not necessarily reflect the original + bus/device the switch can be created from +- supporting non-MDIO and non-MMIO (platform) switches is not possible + +Limits on the number of devices and ports +----------------------------------------- + +DSA currently limits the number of maximum switches within a tree to 4 +(DSA_MAX_SWITCHES), and the number of ports per switch to 12 (DSA_MAX_PORTS). +These limits could be extended to support larger configurations would this need +arise. + +Lack of CPU/DSA network devices +------------------------------- + +DSA does not currently create slave network devices for the CPU or DSA ports, as +described before. This might be an issue in the following cases: + +- inability to fetch switch CPU port statistics counters using ethtool, which + can make it harder to debug MDIO switch connected using xMII interfaces + +- inability to configure the CPU port link parameters based on the Ethernet + controller capabilities attached to it: http://patchwork.ozlabs.org/patch/509806/ + +- inability to configure specific VLAN IDs / trunking VLANs between switches + when using a cascaded setup + +Common pitfalls using DSA setups +-------------------------------- + +Once a master network device is configured to use DSA (dev->dsa_ptr becomes +non-NULL), and the switch behind it expects a tagging protocol, this network +interface can only exclusively be used as a conduit interface. Sending packets +directly through this interface (e.g.: opening a socket using this interface) +will not make us go through the switch tagging protocol transmit function, so +the Ethernet switch on the other end, expecting a tag will typically drop this +frame. + +Slave network devices check that the master network device is UP before allowing +you to administratively bring UP these slave network devices. A common +configuration mistake is forgetting to bring UP the master network device first. + +Interactions with other subsystems +================================== + +DSA currently leverages the following subsystems: + +- MDIO/PHY library: drivers/net/phy/phy.c, mdio_bus.c +- Switchdev: net/switchdev/* +- Device Tree for various of_* functions +- HWMON: drivers/hwmon/* + +MDIO/PHY library +---------------- + +Slave network devices exposed by DSA may or may not be interfacing with PHY +devices (struct phy_device as defined in include/linux/phy.h), but the DSA +subsystem deals with all possible combinations: + +- internal PHY devices, built into the Ethernet switch hardware +- external PHY devices, connected via an internal or external MDIO bus +- internal PHY devices, connected via an internal MDIO bus +- special, non-autonegotiated or non MDIO-managed PHY devices: SFPs, MoCA; a.k.a + fixed PHYs + +The PHY configuration is done by the dsa_slave_phy_setup() function and the +logic basically looks like this: + +- if Device Tree is used, the PHY device is looked up using the standard + "phy-handle" property, if found, this PHY device is created and registered + using of_phy_connect() + +- if Device Tree is used, and the PHY device is "fixed", that is, conforms to + the definition of a non-MDIO managed PHY as defined in + Documentation/devicetree/bindings/net/fixed-link.txt, the PHY is registered + and connected transparently using the special fixed MDIO bus driver + +- finally, if the PHY is built into the switch, as is very common with + standalone switch packages, the PHY is probed using the slave MII bus created + by DSA + + +SWITCHDEV +--------- + +DSA directly utilizes SWITCHDEV when interfacing with the bridge layer, and +more specifically with its VLAN filtering portion when configuring VLANs on top +of per-port slave network devices. Since DSA primarily deals with +MDIO-connected switches, although not exclusively, SWITCHDEV's +prepare/abort/commit phases are often simplified into a prepare phase which +checks whether the operation is supporte by the DSA switch driver, and a commit +phase which applies the changes. + +As of today, the only SWITCHDEV objects supported by DSA are the FDB and VLAN +objects. + +Device Tree +----------- + +DSA features a standardized binding which is documented in +Documentation/devicetree/bindings/net/dsa/dsa.txt. PHY/MDIO library helper +functions such as of_get_phy_mode(), of_phy_connect() are also used to query +per-port PHY specific details: interface connection, MDIO bus location etc.. + +HWMON +----- + +Some switch drivers feature internal temperature sensors which are exposed as +regular HWMON devices in /sys/class/hwmon/. + +Driver development +================== + +DSA switch drivers need to implement a dsa_switch_driver structure which will +contain the various members described below. + +register_switch_driver() registers this dsa_switch_driver in its internal list +of drivers to probe for. unregister_switch_driver() does the exact opposite. + +Unless requested differently by setting the priv_size member accordingly, DSA +does not allocate any driver private context space. + +Switch configuration +-------------------- + +- priv_size: additional size needed by the switch driver for its private context + +- tag_protocol: this is to indicate what kind of tagging protocol is supported, + should be a valid value from the dsa_tag_protocol enum + +- probe: probe routine which will be invoked by the DSA platform device upon + registration to test for the presence/absence of a switch device. For MDIO + devices, it is recommended to issue a read towards internal registers using + the switch pseudo-PHY and return whether this is a supported device. For other + buses, return a non-NULL string + +- setup: setup function for the switch, this function is responsible for setting + up the dsa_switch_driver private structure with all it needs: register maps, + interrupts, mutexes, locks etc.. This function is also expected to properly + configure the switch to separate all network interfaces from each other, that + is, they should be isolated by the switch hardware itself, typically by creating + a Port-based VLAN ID for each port and allowing only the CPU port and the + specific port to be in the forwarding vector. Ports that are unused by the + platform should be disabled. Past this function, the switch is expected to be + fully configured and ready to serve any kind of request. It is recommended + to issue a software reset of the switch during this setup function in order to + avoid relying on what a previous software agent such as a bootloader/firmware + may have previously configured. + +- set_addr: Some switches require the programming of the management interface's + Ethernet MAC address, switch drivers can also disable ageing of MAC addresses + on the management interface and "hardcode"/"force" this MAC address for the + CPU/management interface as an optimization + +PHY devices and link management +------------------------------- + +- get_phy_flags: Some switches are interfaced to various kinds of Ethernet PHYs, + if the PHY library PHY driver needs to know about information it cannot obtain + on its own (e.g.: coming from switch memory mapped registers), this function + should return a 32-bits bitmask of "flags", that is private between the switch + driver and the Ethernet PHY driver in drivers/net/phy/*. + +- phy_read: Function invoked by the DSA slave MDIO bus when attempting to read + the switch port MDIO registers. If unavailable, return 0xffff for each read. + For builtin switch Ethernet PHYs, this function should allow reading the link + status, auto-negotiation results, link partner pages etc.. + +- phy_write: Function invoked by the DSA slave MDIO bus when attempting to write + to the switch port MDIO registers. If unavailable return a negative error + code. + +- poll_link: Function invoked by DSA to query the link state of the switch + builtin Ethernet PHYs, per port. This function is responsible for calling + netif_carrier_{on,off} when appropriate, and can be used to poll all ports in a + single call. Executes from workqueue context. + +- adjust_link: Function invoked by the PHY library when a slave network device + is attached to a PHY device. This function is responsible for appropriately + configuring the switch port link parameters: speed, duplex, pause based on + what the phy_device is providing. + +- fixed_link_update: Function invoked by the PHY library, and specifically by + the fixed PHY driver asking the switch driver for link parameters that could + not be auto-negotiated, or obtained by reading the PHY registers through MDIO. + This is particularly useful for specific kinds of hardware such as QSGMII, + MoCA or other kinds of non-MDIO managed PHYs where out of band link + information is obtained + +Ethtool operations +------------------ + +- get_strings: ethtool function used to query the driver's strings, will + typically return statistics strings, private flags strings etc. + +- get_ethtool_stats: ethtool function used to query per-port statistics and + return their values. DSA overlays slave network devices general statistics: + RX/TX counters from the network device, with switch driver specific statistics + per port + +- get_sset_count: ethtool function used to query the number of statistics items + +- get_wol: ethtool function used to obtain Wake-on-LAN settings per-port, this + function may, for certain implementations also query the master network device + Wake-on-LAN settings if this interface needs to participate in Wake-on-LAN + +- set_wol: ethtool function used to configure Wake-on-LAN settings per-port, + direct counterpart to set_wol with similar restrictions + +- set_eee: ethtool function which is used to configure a switch port EEE (Green + Ethernet) settings, can optionally invoke the PHY library to enable EEE at the + PHY level if relevant. This function should enable EEE at the switch port MAC + controller and data-processing logic + +- get_eee: ethtool function which is used to query a switch port EEE settings, + this function should return the EEE state of the switch port MAC controller + and data-processing logic as well as query the PHY for its currently configured + EEE settings + +- get_eeprom_len: ethtool function returning for a given switch the EEPROM + length/size in bytes + +- get_eeprom: ethtool function returning for a given switch the EEPROM contents + +- set_eeprom: ethtool function writing specified data to a given switch EEPROM + +- get_regs_len: ethtool function returning the register length for a given + switch + +- get_regs: ethtool function returning the Ethernet switch internal register + contents. This function might require user-land code in ethtool to + pretty-print register values and registers + +Power management +---------------- + +- suspend: function invoked by the DSA platform device when the system goes to + suspend, should quiesce all Ethernet switch activities, but keep ports + participating in Wake-on-LAN active as well as additional wake-up logic if + supported + +- resume: function invoked by the DSA platform device when the system resumes, + should resume all Ethernet switch activities and re-configure the switch to be + in a fully active state + +- port_enable: function invoked by the DSA slave network device ndo_open + function when a port is administratively brought up, this function should be + fully enabling a given switch port. DSA takes care of marking the port with + BR_STATE_BLOCKING if the port is a bridge member, or BR_STATE_FORWARDING if it + was not, and propagating these changes down to the hardware + +- port_disable: function invoked by the DSA slave network device ndo_close + function when a port is administratively brought down, this function should be + fully disabling a given switch port. DSA takes care of marking the port with + BR_STATE_DISABLED and propagating changes to the hardware if this port is + disabled while being a bridge member + +Hardware monitoring +------------------- + +These callbacks are only available if CONFIG_NET_DSA_HWMON is enabled: + +- get_temp: this function queries the given switch for its temperature + +- get_temp_limit: this function returns the switch current maximum temperature + limit + +- set_temp_limit: this function configures the maximum temperature limit allowed + +- get_temp_alarm: this function returns the critical temperature threshold + returning an alarm notification + +See Documentation/hwmon/sysfs-interface for details. + +Bridge layer +------------ + +- port_join_bridge: bridge layer function invoked when a given switch port is + added to a bridge, this function should be doing the necessary at the switch + level to permit the joining port from being added to the relevant logical + domain for it to ingress/egress traffic with other members of the bridge. DSA + does nothing but calculate a bitmask of switch ports currently members of the + specified bridge being requested the join + +- port_leave_bridge: bridge layer function invoked when a given switch port is + removed from a bridge, this function should be doing the necessary at the + switch level to deny the leaving port from ingress/egress traffic from the + remaining bridge members. When the port leaves the bridge, it should be aged + out at the switch hardware for the switch to (re) learn MAC addresses behind + this port. DSA calculates the bitmask of ports still members of the bridge + being left + +- port_stp_update: bridge layer function invoked when a given switch port STP + state is computed by the bridge layer and should be propagated to switch + hardware to forward/block/learn traffic. The switch driver is responsible for + computing a STP state change based on current and asked parameters and perform + the relevant ageing based on the intersection results + +Bridge VLAN filtering +--------------------- + +- port_pvid_get: bridge layer function invoked when a Port-based VLAN ID is + queried for the given switch port + +- port_pvid_set: bridge layer function invoked when a Port-based VLAN ID needs + to be configured on the given switch port + +- port_vlan_add: bridge layer function invoked when a VLAN is configured + (tagged or untagged) for the given switch port + +- port_vlan_del: bridge layer function invoked when a VLAN is removed from the + given switch port + +- vlan_getnext: bridge layer function invoked to query the next configured VLAN + in the switch, i.e. returns the bitmaps of members and untagged ports + +- port_fdb_add: bridge layer function invoked when the bridge wants to install a + Forwarding Database entry, the switch hardware should be programmed with the + specified address in the specified VLAN Id in the forwarding database + associated with this VLAN ID + +Note: VLAN ID 0 corresponds to the port private database, which, in the context +of DSA, would be the its port-based VLAN, used by the associated bridge device. + +- port_fdb_del: bridge layer function invoked when the bridge wants to remove a + Forwarding Database entry, the switch hardware should be programmed to delete + the specified MAC address from the specified VLAN ID if it was mapped into + this port forwarding database + +TODO +==== + +The platform device problem +--------------------------- +DSA is currently implemented as a platform device driver which is far from ideal +as was discussed in this thread: + +http://permalink.gmane.org/gmane.linux.network/329848 + +This basically prevents the device driver model to be properly used and applied, +and support non-MDIO, non-MMIO Ethernet connected switches. + +Another problem with the platform device driver approach is that it prevents the +use of a modular switch drivers build due to a circular dependency, illustrated +here: + +http://comments.gmane.org/gmane.linux.network/345803 + +Attempts of reworking this has been done here: + +https://lwn.net/Articles/643149/ + +Making SWITCHDEV and DSA converge towards an unified codebase +------------------------------------------------------------- + +SWITCHDEV properly takes care of abstracting the networking stack with offload +capable hardware, but does not enforce a strict switch device driver model. On +the other DSA enforces a fairly strict device driver model, and deals with most +of the switch specific. At some point we should envision a merger between these +two subsystems and get the best of both worlds. + +Other hanging fruits +-------------------- + +- making the number of ports fully dynamic and not dependent on DSA_MAX_PORTS +- allowing more than one CPU/management interface: + http://comments.gmane.org/gmane.linux.network/365657 +- porting more drivers from other vendors: + http://comments.gmane.org/gmane.linux.network/365510 diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 5fae770..ebe94f2 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -586,6 +586,21 @@ tcp_min_tso_segs - INTEGER if available window is too small. Default: 2 +tcp_pacing_ss_ratio - INTEGER + sk->sk_pacing_rate is set by TCP stack using a ratio applied + to current rate. (current_rate = cwnd * mss / srtt) + If TCP is in slow start, tcp_pacing_ss_ratio is applied + to let TCP probe for bigger speeds, assuming cwnd can be + doubled every other RTT. + Default: 200 + +tcp_pacing_ca_ratio - INTEGER + sk->sk_pacing_rate is set by TCP stack using a ratio applied + to current rate. (current_rate = cwnd * mss / srtt) + If TCP is in congestion avoidance phase, tcp_pacing_ca_ratio + is applied to conservatively probe for bigger throughput. + Default: 120 + tcp_tso_win_divisor - INTEGER This allows control over what percentage of the congestion window can be consumed by a single TSO frame. @@ -1181,6 +1196,16 @@ tag - INTEGER Allows you to write a number, which can be used as required. Default value is 0. +xfrm4_gc_thresh - INTEGER + The threshold at which we will start garbage collecting for IPv4 + destination cache entries. At twice this value the system will + refuse new allocations. + +igmp_link_local_mcast_reports - BOOLEAN + Enable IGMP reports for link local multicast groups in the + 224.0.0.X range. + Default TRUE + Alexey Kuznetsov. kuznet@ms2.inr.ac.ru @@ -1215,14 +1240,20 @@ flowlabel_consistency - BOOLEAN FALSE: disabled Default: TRUE -auto_flowlabels - BOOLEAN - Automatically generate flow labels based based on a flow hash - of the packet. This allows intermediate devices, such as routers, - to idenfify packet flows for mechanisms like Equal Cost Multipath +auto_flowlabels - INTEGER + Automatically generate flow labels based on a flow hash of the + packet. This allows intermediate devices, such as routers, to + identify packet flows for mechanisms like Equal Cost Multipath Routing (see RFC 6438). - TRUE: enabled - FALSE: disabled - Default: false + 0: automatic flow labels are completely disabled + 1: automatic flow labels are enabled by default, they can be + disabled on a per socket basis using the IPV6_AUTOFLOWLABEL + socket option + 2: automatic flow labels are allowed, they may be enabled on a + per socket basis using the IPV6_AUTOFLOWLABEL socket option + 3: automatic flow labels are enabled and enforced, they cannot + be disabled by the socket option + Default: 1 flowlabel_state_ranges - BOOLEAN Split the flow label number space into two ranges. 0-0x7FFFF is @@ -1340,6 +1371,14 @@ accept_ra_from_local - BOOLEAN disabled if accept_ra_from_local is disabled on a specific interface. +accept_ra_min_hop_limit - INTEGER + Minimum hop limit Information in Router Advertisement. + + Hop limit Information in Router Advertisement less than this + variable shall be ignored. + + Default: 1 + accept_ra_pinfo - BOOLEAN Learn Prefix Information in Router Advertisement. @@ -1435,6 +1474,11 @@ mtu - INTEGER Default Maximum Transfer Unit Default: 1280 (IPv6 required minimum) +ip_nonlocal_bind - BOOLEAN + If set, allows processes to bind() to non-local IPv6 addresses, + which can be quite useful - but may break some applications. + Default: 0 + router_probe_interval - INTEGER Minimum interval (in seconds) between Router Probing described in RFC4191. @@ -1455,6 +1499,13 @@ router_solicitations - INTEGER routers are present. Default: 3 +use_oif_addrs_only - BOOLEAN + When enabled, the candidate source addresses for destinations + routed via this interface are restricted to the set of addresses + configured on this interface (vis. RFC 6724, section 4). + + Default: false + use_tempaddr - INTEGER Preference for Privacy Extensions (RFC3041). <= 0 : disable Privacy Extensions @@ -1591,6 +1642,11 @@ ratelimit - INTEGER otherwise the minimal space between responses in milliseconds. Default: 1000 +xfrm6_gc_thresh - INTEGER + The threshold at which we will start garbage collecting for IPv6 + destination cache entries. At twice this value the system will + refuse new allocations. + IPv6 Update by: Pekka Savola <pekkas@netcore.fi> diff --git a/Documentation/networking/stmmac.txt b/Documentation/networking/stmmac.txt index e655e24..d64a147 100644 --- a/Documentation/networking/stmmac.txt +++ b/Documentation/networking/stmmac.txt @@ -135,12 +135,8 @@ struct plat_stmmacenet_data { int maxmtu; void (*fix_mac_speed)(void *priv, unsigned int speed); void (*bus_setup)(void __iomem *ioaddr); - void *(*setup)(struct platform_device *pdev); - void (*free)(struct platform_device *pdev, void *priv); int (*init)(struct platform_device *pdev, void *priv); void (*exit)(struct platform_device *pdev, void *priv); - void *custom_cfg; - void *custom_data; void *bsp_priv; }; @@ -179,15 +175,11 @@ Where: o bus_setup: perform HW setup of the bus. For example, on some ST platforms this field is used to configure the AMBA bridge to generate more efficient STBus traffic. - o setup/init/exit: callbacks used for calling a custom initialization; + o init/exit: callbacks used for calling a custom initialization; this is sometime necessary on some platforms (e.g. ST boxes) where the HW needs to have set some PIO lines or system cfg - registers. setup should return a pointer to private data, - which will be stored in bsp_priv, and then passed to init and - exit callbacks. init/exit callbacks should not use or modify + registers. init/exit callbacks should not use or modify platform data. - o custom_cfg/custom_data: this is a custom configuration that can be passed - while initializing the resources. o bsp_priv: another private pointer. For MDIO bus The we have: @@ -262,7 +254,7 @@ static struct fixed_phy_status stmmac0_fixed_phy_status = { During the board's device_init we can configure the first MAC for fixed_link by calling: - fixed_phy_add(PHY_POLL, 1, &stmmac0_fixed_phy_status));) + fixed_phy_add(PHY_POLL, 1, &stmmac0_fixed_phy_status, -1); and the second one, with a real PHY device attached to the bus, by using the stmmac_mdio_bus_data structure (to provide the id, the reset procedure etc). @@ -278,8 +270,6 @@ capability register can replace what has been passed from the platform. Please see the following document: Documentation/devicetree/bindings/net/stmmac.txt -and the stmmac_of_data structure inside the include/linux/stmmac.h header file. - 4.11) This is a summary of the content of some relevant files: o stmmac_main.c: to implement the main network device driver; o stmmac_mdio.c: to provide mdio functions; diff --git a/Documentation/networking/switchdev.txt b/Documentation/networking/switchdev.txt index c5d7ade..476df04 100644 --- a/Documentation/networking/switchdev.txt +++ b/Documentation/networking/switchdev.txt @@ -279,8 +279,18 @@ and unknown unicast packets to all ports in domain, if allowed by port's current STP state. The switch driver, knowing which ports are within which vlan L2 domain, can program the switch device for flooding. The packet should also be sent to the port netdev for processing by the bridge driver. The -bridge should not reflood the packet to the same ports the device flooded. -XXX: the mechanism to avoid duplicate flood packets is being discuseed. +bridge should not reflood the packet to the same ports the device flooded, +otherwise there will be duplicate packets on the wire. + +To avoid duplicate packets, the device/driver should mark a packet as already +forwarded using skb->offload_fwd_mark. The same mark is set on the device +ports in the domain using dev->offload_fwd_mark. If the skb->offload_fwd_mark +is non-zero and matches the forwarding egress port's dev->skb_mark, the kernel +will drop the skb right before transmit on the egress port, with the +understanding that the device already forwarded the packet on same egress port. +The driver can use switchdev_port_fwd_mark_set() to set a globally unique mark +for port's dev->offload_fwd_mark, based on the port's parent ID (switch ID) and +a group ifindex. It is possible for the switch device to not handle flooding and push the packets up to the bridge driver for flooding. This is not ideal as the number @@ -357,4 +367,5 @@ driver's rocker_port_ipv4_resolve() for an example. The driver can monitor for updates to arp_tbl using the netevent notifier NETEVENT_NEIGH_UPDATE. The device can be programmed with resolved nexthops -for the routes as arp_tbl updates. +for the routes as arp_tbl updates. The driver implements ndo_neigh_destroy +to know when arp_tbl neighbor entries are purged from the port. diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt index 5f09226..a977339 100644 --- a/Documentation/networking/timestamping.txt +++ b/Documentation/networking/timestamping.txt @@ -359,6 +359,13 @@ the requested fine-grained filtering for incoming packets is not supported, the driver may time stamp more than just the requested types of packets. +Drivers are free to use a more permissive configuration than the requested +configuration. It is expected that drivers should only implement directly the +most generic mode that can be supported. For example if the hardware can +support HWTSTAMP_FILTER_V2_EVENT, then it should generally always upscale +HWTSTAMP_FILTER_V2_L2_SYNC_MESSAGE, and so forth, as HWTSTAMP_FILTER_V2_EVENT +is more generic (and more useful to applications). + A driver which supports hardware time stamping shall update the struct with the actual, possibly more permissive configuration. If the requested packets cannot be time stamped, then nothing should be diff --git a/Documentation/networking/vxlan.txt b/Documentation/networking/vxlan.txt index 6d99351..c28f498 100644 --- a/Documentation/networking/vxlan.txt +++ b/Documentation/networking/vxlan.txt @@ -1,32 +1,36 @@ Virtual eXtensible Local Area Networking documentation ====================================================== -The VXLAN protocol is a tunnelling protocol that is designed to -solve the problem of limited number of available VLAN's (4096). -With VXLAN identifier is expanded to 24 bits. - -It is a draft RFC standard, that is implemented by Cisco Nexus, -Vmware and Brocade. The protocol runs over UDP using a single -destination port (still not standardized by IANA). -This document describes the Linux kernel tunnel device, -there is also an implantation of VXLAN for Openvswitch. - -Unlike most tunnels, a VXLAN is a 1 to N network, not just point -to point. A VXLAN device can either dynamically learn the IP address -of the other end, in a manner similar to a learning bridge, or the -forwarding entries can be configured statically. - -The management of vxlan is done in a similar fashion to it's -too closest neighbors GRE and VLAN. Configuring VXLAN requires -the version of iproute2 that matches the kernel release -where VXLAN was first merged upstream. +The VXLAN protocol is a tunnelling protocol designed to solve the +problem of limited VLAN IDs (4096) in IEEE 802.1q. With VXLAN the +size of the identifier is expanded to 24 bits (16777216). + +VXLAN is described by IETF RFC 7348, and has been implemented by a +number of vendors. The protocol runs over UDP using a single +destination port. This document describes the Linux kernel tunnel +device, there is also a separate implementation of VXLAN for +Openvswitch. + +Unlike most tunnels, a VXLAN is a 1 to N network, not just point to +point. A VXLAN device can learn the IP address of the other endpoint +either dynamically in a manner similar to a learning bridge, or make +use of statically-configured forwarding entries. + +The management of vxlan is done in a manner similar to its two closest +neighbors GRE and VLAN. Configuring VXLAN requires the version of +iproute2 that matches the kernel release where VXLAN was first merged +upstream. 1. Create vxlan device - # ip li add vxlan0 type vxlan id 42 group 239.1.1.1 dev eth1 - -This creates a new device (vxlan0). The device uses the -the multicast group 239.1.1.1 over eth1 to handle packets where -no entry is in the forwarding table. + # ip link add vxlan0 type vxlan id 42 group 239.1.1.1 dev eth1 dstport 4789 + +This creates a new device named vxlan0. The device uses the multicast +group 239.1.1.1 over eth1 to handle traffic for which there is no +entry in the forwarding table. The destination port number is set to +the IANA-assigned value of 4789. The Linux implementation of VXLAN +pre-dates the IANA's selection of a standard destination port number +and uses the Linux-selected value by default to maintain backwards +compatibility. 2. Delete vxlan device # ip link delete vxlan0 |
