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diff --git a/Documentation/networking/device_drivers/ethernet/neterion/s2io.rst b/Documentation/networking/device_drivers/ethernet/neterion/s2io.rst new file mode 100644 index 000000000..c5673ec45 --- /dev/null +++ b/Documentation/networking/device_drivers/ethernet/neterion/s2io.rst @@ -0,0 +1,196 @@ +.. SPDX-License-Identifier: GPL-2.0 + +========================================================= +Neterion's (Formerly S2io) Xframe I/II PCI-X 10GbE driver +========================================================= + +Release notes for Neterion's (Formerly S2io) Xframe I/II PCI-X 10GbE driver. + +.. Contents + - 1. Introduction + - 2. Identifying the adapter/interface + - 3. Features supported + - 4. Command line parameters + - 5. Performance suggestions + - 6. Available Downloads + + +1. Introduction +=============== +This Linux driver supports Neterion's Xframe I PCI-X 1.0 and +Xframe II PCI-X 2.0 adapters. It supports several features +such as jumbo frames, MSI/MSI-X, checksum offloads, TSO, UFO and so on. +See below for complete list of features. + +All features are supported for both IPv4 and IPv6. + +2. Identifying the adapter/interface +==================================== + +a. Insert the adapter(s) in your system. +b. Build and load driver:: + + # insmod s2io.ko + +c. View log messages:: + + # dmesg | tail -40 + +You will see messages similar to:: + + eth3: Neterion Xframe I 10GbE adapter (rev 3), Version 2.0.9.1, Intr type INTA + eth4: Neterion Xframe II 10GbE adapter (rev 2), Version 2.0.9.1, Intr type INTA + eth4: Device is on 64 bit 133MHz PCIX(M1) bus + +The above messages identify the adapter type(Xframe I/II), adapter revision, +driver version, interface name(eth3, eth4), Interrupt type(INTA, MSI, MSI-X). +In case of Xframe II, the PCI/PCI-X bus width and frequency are displayed +as well. + +To associate an interface with a physical adapter use "ethtool -p <ethX>". +The corresponding adapter's LED will blink multiple times. + +3. Features supported +===================== +a. Jumbo frames. Xframe I/II supports MTU up to 9600 bytes, + modifiable using ip command. + +b. Offloads. Supports checksum offload(TCP/UDP/IP) on transmit + and receive, TSO. + +c. Multi-buffer receive mode. Scattering of packet across multiple + buffers. Currently driver supports 2-buffer mode which yields + significant performance improvement on certain platforms(SGI Altix, + IBM xSeries). + +d. MSI/MSI-X. Can be enabled on platforms which support this feature + (IA64, Xeon) resulting in noticeable performance improvement(up to 7% + on certain platforms). + +e. Statistics. Comprehensive MAC-level and software statistics displayed + using "ethtool -S" option. + +f. Multi-FIFO/Ring. Supports up to 8 transmit queues and receive rings, + with multiple steering options. + +4. Command line parameters +========================== + +a. tx_fifo_num + Number of transmit queues + +Valid range: 1-8 + +Default: 1 + +b. rx_ring_num + Number of receive rings + +Valid range: 1-8 + +Default: 1 + +c. tx_fifo_len + Size of each transmit queue + +Valid range: Total length of all queues should not exceed 8192 + +Default: 4096 + +d. rx_ring_sz + Size of each receive ring(in 4K blocks) + +Valid range: Limited by memory on system + +Default: 30 + +e. intr_type + Specifies interrupt type. Possible values 0(INTA), 2(MSI-X) + +Valid values: 0, 2 + +Default: 2 + +5. Performance suggestions +========================== + +General: + +a. Set MTU to maximum(9000 for switch setup, 9600 in back-to-back configuration) +b. Set TCP windows size to optimal value. + +For instance, for MTU=1500 a value of 210K has been observed to result in +good performance:: + + # sysctl -w net.ipv4.tcp_rmem="210000 210000 210000" + # sysctl -w net.ipv4.tcp_wmem="210000 210000 210000" + +For MTU=9000, TCP window size of 10 MB is recommended:: + + # sysctl -w net.ipv4.tcp_rmem="10000000 10000000 10000000" + # sysctl -w net.ipv4.tcp_wmem="10000000 10000000 10000000" + +Transmit performance: + +a. By default, the driver respects BIOS settings for PCI bus parameters. + However, you may want to experiment with PCI bus parameters + max-split-transactions(MOST) and MMRBC (use setpci command). + + A MOST value of 2 has been found optimal for Opterons and 3 for Itanium. + + It could be different for your hardware. + + Set MMRBC to 4K**. + + For example you can set + + For opteron:: + + #setpci -d 17d5:* 62=1d + + For Itanium:: + + #setpci -d 17d5:* 62=3d + + For detailed description of the PCI registers, please see Xframe User Guide. + +b. Ensure Transmit Checksum offload is enabled. Use ethtool to set/verify this + parameter. + +c. Turn on TSO(using "ethtool -K"):: + + # ethtool -K <ethX> tso on + +Receive performance: + +a. By default, the driver respects BIOS settings for PCI bus parameters. + However, you may want to set PCI latency timer to 248:: + + #setpci -d 17d5:* LATENCY_TIMER=f8 + + For detailed description of the PCI registers, please see Xframe User Guide. + +b. Use 2-buffer mode. This results in large performance boost on + certain platforms(eg. SGI Altix, IBM xSeries). + +c. Ensure Receive Checksum offload is enabled. Use "ethtool -K ethX" command to + set/verify this option. + +d. Enable NAPI feature(in kernel configuration Device Drivers ---> Network + device support ---> Ethernet (10000 Mbit) ---> S2IO 10Gbe Xframe NIC) to + bring down CPU utilization. + +.. note:: + + For AMD opteron platforms with 8131 chipset, MMRBC=1 and MOST=1 are + recommended as safe parameters. + +For more information, please review the AMD8131 errata at +http://vip.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/ +26310_AMD-8131_HyperTransport_PCI-X_Tunnel_Revision_Guide_rev_3_18.pdf + +6. Support +========== + +For further support please contact either your 10GbE Xframe NIC vendor (IBM, +HP, SGI etc.) |