Documentation/networking/s2io.txt - kernel/msm-4.9 - Gitiles

 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 ifconfig 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.

 ** 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.)
	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 ifconfig 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.

	** 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.)