From a4605a93696ee0768e55e4bce1ff7f0ee39bcf79 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Sun, 9 Oct 2011 14:09:07 +0200 Subject: IB/srp: Document sysfs attributes Document the sysfs attributes of the SRP initiator (ib_srp) according to the rules specified in Documentation/ABI/README. Signed-off-by: Bart Van Assche Acked-by: David Dillow Signed-off-by: Roland Dreier diff --git a/Documentation/ABI/stable/sysfs-driver-ib_srp b/Documentation/ABI/stable/sysfs-driver-ib_srp new file mode 100644 index 0000000..481aae9 --- /dev/null +++ b/Documentation/ABI/stable/sysfs-driver-ib_srp @@ -0,0 +1,156 @@ +What: /sys/class/infiniband_srp/srp--/add_target +Date: January 2, 2006 +KernelVersion: 2.6.15 +Contact: linux-rdma@vger.kernel.org +Description: Interface for making ib_srp connect to a new target. + One can request ib_srp to connect to a new target by writing + a comma-separated list of login parameters to this sysfs + attribute. The supported parameters are: + * id_ext, a 16-digit hexadecimal number specifying the eight + byte identifier extension in the 16-byte SRP target port + identifier. The target port identifier is sent by ib_srp + to the target in the SRP_LOGIN_REQ request. + * ioc_guid, a 16-digit hexadecimal number specifying the eight + byte I/O controller GUID portion of the 16-byte target port + identifier. + * dgid, a 32-digit hexadecimal number specifying the + destination GID. + * pkey, a four-digit hexadecimal number specifying the + InfiniBand partition key. + * service_id, a 16-digit hexadecimal number specifying the + InfiniBand service ID used to establish communication with + the SRP target. How to find out the value of the service ID + is specified in the documentation of the SRP target. + * max_sect, a decimal number specifying the maximum number of + 512-byte sectors to be transferred via a single SCSI command. + * max_cmd_per_lun, a decimal number specifying the maximum + number of outstanding commands for a single LUN. + * io_class, a hexadecimal number specifying the SRP I/O class. + Must be either 0xff00 (rev 10) or 0x0100 (rev 16a). The I/O + class defines the format of the SRP initiator and target + port identifiers. + * initiator_ext, a 16-digit hexadecimal number specifying the + identifier extension portion of the SRP initiator port + identifier. This data is sent by the initiator to the target + in the SRP_LOGIN_REQ request. + * cmd_sg_entries, a number in the range 1..255 that specifies + the maximum number of data buffer descriptors stored in the + SRP_CMD information unit itself. With allow_ext_sg=0 the + parameter cmd_sg_entries defines the maximum S/G list length + for a single SRP_CMD, and commands whose S/G list length + exceeds this limit after S/G list collapsing will fail. + * allow_ext_sg, whether ib_srp is allowed to include a partial + memory descriptor list in an SRP_CMD instead of the entire + list. If a partial memory descriptor list has been included + in an SRP_CMD the remaining memory descriptors are + communicated from initiator to target via an additional RDMA + transfer. Setting allow_ext_sg to 1 increases the maximum + amount of data that can be transferred between initiator and + target via a single SCSI command. Since not all SRP target + implementations support partial memory descriptor lists the + default value for this option is 0. + * sg_tablesize, a number in the range 1..2048 specifying the + maximum S/G list length the SCSI layer is allowed to pass to + ib_srp. Specifying a value that exceeds cmd_sg_entries is + only safe with partial memory descriptor list support enabled + (allow_ext_sg=1). + +What: /sys/class/infiniband_srp/srp--/ibdev +Date: January 2, 2006 +KernelVersion: 2.6.15 +Contact: linux-rdma@vger.kernel.org +Description: HCA name (). + +What: /sys/class/infiniband_srp/srp--/port +Date: January 2, 2006 +KernelVersion: 2.6.15 +Contact: linux-rdma@vger.kernel.org +Description: HCA port number (). + +What: /sys/class/scsi_host/host/allow_ext_sg +Date: May 19, 2011 +KernelVersion: 2.6.39 +Contact: linux-rdma@vger.kernel.org +Description: Whether ib_srp is allowed to include a partial memory + descriptor list in an SRP_CMD when communicating with an SRP + target. + +What: /sys/class/scsi_host/host/cmd_sg_entries +Date: May 19, 2011 +KernelVersion: 2.6.39 +Contact: linux-rdma@vger.kernel.org +Description: Maximum number of data buffer descriptors that may be sent to + the target in a single SRP_CMD request. + +What: /sys/class/scsi_host/host/dgid +Date: June 17, 2006 +KernelVersion: 2.6.17 +Contact: linux-rdma@vger.kernel.org +Description: InfiniBand destination GID used for communication with the SRP + target. Differs from orig_dgid if port redirection has happened. + +What: /sys/class/scsi_host/host/id_ext +Date: June 17, 2006 +KernelVersion: 2.6.17 +Contact: linux-rdma@vger.kernel.org +Description: Eight-byte identifier extension portion of the 16-byte target + port identifier. + +What: /sys/class/scsi_host/host/ioc_guid +Date: June 17, 2006 +KernelVersion: 2.6.17 +Contact: linux-rdma@vger.kernel.org +Description: Eight-byte I/O controller GUID portion of the 16-byte target + port identifier. + +What: /sys/class/scsi_host/host/local_ib_device +Date: November 29, 2006 +KernelVersion: 2.6.19 +Contact: linux-rdma@vger.kernel.org +Description: Name of the InfiniBand HCA used for communicating with the + SRP target. + +What: /sys/class/scsi_host/host/local_ib_port +Date: November 29, 2006 +KernelVersion: 2.6.19 +Contact: linux-rdma@vger.kernel.org +Description: Number of the HCA port used for communicating with the + SRP target. + +What: /sys/class/scsi_host/host/orig_dgid +Date: June 17, 2006 +KernelVersion: 2.6.17 +Contact: linux-rdma@vger.kernel.org +Description: InfiniBand destination GID specified in the parameters + written to the add_target sysfs attribute. + +What: /sys/class/scsi_host/host/pkey +Date: June 17, 2006 +KernelVersion: 2.6.17 +Contact: linux-rdma@vger.kernel.org +Description: A 16-bit number representing the InfiniBand partition key used + for communication with the SRP target. + +What: /sys/class/scsi_host/host/req_lim +Date: October 20, 2010 +KernelVersion: 2.6.36 +Contact: linux-rdma@vger.kernel.org +Description: Number of requests ib_srp can send to the target before it has + to wait for more credits. For more information see also the + SRP credit algorithm in the SRP specification. + +What: /sys/class/scsi_host/host/service_id +Date: June 17, 2006 +KernelVersion: 2.6.17 +Contact: linux-rdma@vger.kernel.org +Description: InfiniBand service ID used for establishing communication with + the SRP target. + +What: /sys/class/scsi_host/host/zero_req_lim +Date: September 20, 2006 +KernelVersion: 2.6.18 +Contact: linux-rdma@vger.kernel.org +Description: Number of times the initiator had to wait before sending a + request to the target because it ran out of credits. For more + information see also the SRP credit algorithm in the SRP + specification. -- cgit v0.10.2