--- /dev/null
+.. SPDX-License-Identifier: GPL-2.0
+
+=================================
+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.
+++ /dev/null
-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.
projects / linux-2.6-block.git / commitdiff