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Diffstat (limited to 'Documentation/scsi/cxgb3i.txt')
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diff --git a/Documentation/scsi/cxgb3i.txt b/Documentation/scsi/cxgb3i.txt deleted file mode 100644 index 7ac8032ee9b2..000000000000 --- a/Documentation/scsi/cxgb3i.txt +++ /dev/null @@ -1,84 +0,0 @@ -Chelsio S3 iSCSI Driver for Linux - -Introduction -============ - -The Chelsio T3 ASIC based Adapters (S310, S320, S302, S304, Mezz cards, etc. -series of products) support iSCSI acceleration and iSCSI Direct Data Placement -(DDP) where the hardware handles the expensive byte touching operations, such -as CRC computation and verification, and direct DMA to the final host memory -destination: - - - iSCSI PDU digest generation and verification - - On transmitting, Chelsio S3 h/w computes and inserts the Header and - Data digest into the PDUs. - On receiving, Chelsio S3 h/w computes and verifies the Header and - Data digest of the PDUs. - - - Direct Data Placement (DDP) - - S3 h/w can directly place the iSCSI Data-In or Data-Out PDU's - payload into pre-posted final destination host-memory buffers based - on the Initiator Task Tag (ITT) in Data-In or Target Task Tag (TTT) - in Data-Out PDUs. - - - PDU Transmit and Recovery - - On transmitting, S3 h/w accepts the complete PDU (header + data) - from the host driver, computes and inserts the digests, decomposes - the PDU into multiple TCP segments if necessary, and transmit all - the TCP segments onto the wire. It handles TCP retransmission if - needed. - - On receiving, S3 h/w recovers the iSCSI PDU by reassembling TCP - segments, separating the header and data, calculating and verifying - the digests, then forwarding the header to the host. The payload data, - if possible, will be directly placed into the pre-posted host DDP - buffer. Otherwise, the payload data will be sent to the host too. - -The cxgb3i driver interfaces with open-iscsi initiator and provides the iSCSI -acceleration through Chelsio hardware wherever applicable. - -Using the cxgb3i Driver -======================= - -The following steps need to be taken to accelerates the open-iscsi initiator: - -1. Load the cxgb3i driver: "modprobe cxgb3i" - - The cxgb3i module registers a new transport class "cxgb3i" with open-iscsi. - - * in the case of recompiling the kernel, the cxgb3i selection is located at - Device Drivers - SCSI device support ---> - [*] SCSI low-level drivers ---> - <M> Chelsio S3xx iSCSI support - -2. Create an interface file located under /etc/iscsi/ifaces/ for the new - transport class "cxgb3i". - - The content of the file should be in the following format: - iface.transport_name = cxgb3i - iface.net_ifacename = <ethX> - iface.ipaddress = <iscsi ip address> - - * if iface.ipaddress is specified, <iscsi ip address> needs to be either the - same as the ethX's ip address or an address on the same subnet. Make - sure the ip address is unique in the network. - -3. edit /etc/iscsi/iscsid.conf - The default setting for MaxRecvDataSegmentLength (131072) is too big; - replace with a value no bigger than 15360 (for example 8192): - - node.conn[0].iscsi.MaxRecvDataSegmentLength = 8192 - - * The login would fail for a normal session if MaxRecvDataSegmentLength is - too big. A error message in the format of - "cxgb3i: ERR! MaxRecvSegmentLength <X> too big. Need to be <= <Y>." - would be logged to dmesg. - -4. To direct open-iscsi traffic to go through cxgb3i's accelerated path, - "-I <iface file name>" option needs to be specified with most of the - iscsiadm command. <iface file name> is the transport interface file created - in step 2. |