diff options
Diffstat (limited to 'Documentation/scsi')
-rw-r--r-- | Documentation/scsi/ChangeLog.megaraid | 6 | ||||
-rw-r--r-- | Documentation/scsi/aacraid.txt | 2 | ||||
-rw-r--r-- | Documentation/scsi/cxgb3i.txt | 85 |
3 files changed, 89 insertions, 4 deletions
diff --git a/Documentation/scsi/ChangeLog.megaraid b/Documentation/scsi/ChangeLog.megaraid index 37796fe45bd0..eaa4801f2ce6 100644 --- a/Documentation/scsi/ChangeLog.megaraid +++ b/Documentation/scsi/ChangeLog.megaraid @@ -409,7 +409,7 @@ i. Function reordering so that inline functions are defined before they megaraid_mbox_prepare_pthru, megaraid_mbox_prepare_epthru, megaraid_busywait_mbox - - Andrew Morton <akpm@osdl.org>, 08.19.2004 + - Andrew Morton, 08.19.2004 linux-scsi mailing list "Something else to clean up after inclusion: every instance of an @@ -471,13 +471,13 @@ vi. Add support for 64-bit applications. Current drivers assume only vii. Move the function declarations for the management module from megaraid_mm.h to megaraid_mm.c - - Andrew Morton <akpm@osdl.org>, 08.19.2004 + - Andrew Morton, 08.19.2004 linux-scsi mailing list viii. Change default values for MEGARAID_NEWGEN, MEGARAID_MM, and MEGARAID_MAILBOX to 'n' in Kconfig.megaraid - - Andrew Morton <akpm@osdl.org>, 08.19.2004 + - Andrew Morton, 08.19.2004 linux-scsi mailing list ix. replace udelay with msleep diff --git a/Documentation/scsi/aacraid.txt b/Documentation/scsi/aacraid.txt index 709ca991a451..ddace3afc83b 100644 --- a/Documentation/scsi/aacraid.txt +++ b/Documentation/scsi/aacraid.txt @@ -128,7 +128,7 @@ Supported Cards/Chipsets People ------------------------- -Alan Cox <alan@redhat.com> +Alan Cox <alan@lxorguk.ukuu.org.uk> Christoph Hellwig <hch@infradead.org> (updates for new-style PCI probing and SCSI host registration, small cleanups/fixes) Matt Domsch <matt_domsch@dell.com> (revision ioctl, adapter messages) diff --git a/Documentation/scsi/cxgb3i.txt b/Documentation/scsi/cxgb3i.txt new file mode 100644 index 000000000000..8141fa01978e --- /dev/null +++ b/Documentation/scsi/cxgb3i.txt @@ -0,0 +1,85 @@ +Chelsio S3 iSCSI Driver for Linux + +Introduction +============ + +The Chelsio T3 ASIC based Adapters (S310, S320, S302, S304, Mezz cards, etc. +series of products) supports 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 receving, S3 h/w recovers the iSCSI PDU by reassembling TCP + segments, separating the header and data, calculating and verifying + the digests, then forwards 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 "node.conn[0].iscsi.MaxRecvDataSegmentLength" to be 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. |