[PATCH 12/15] ib_srp: Document sysfs attributes

Bart Van Assche
2012-03-25T15:00:17Z

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 <bvanassche-HInyCGIudOg@public.gmane.org>
Cc: David Dillow <dillowda-1Heg1YXhbW8@public.gmane.org>
Cc: Roland Dreier <roland-BHEL68pLQRGGvPXPguhicg@public.gmane.org>
---
Documentation/ABI/stable/sysfs-driver-ib_srp | 156 ++++++++++++++++++++++++++
1 files changed, 156 insertions(+), 0 deletions(-)
create mode 100644 Documentation/ABI/stable/sysfs-driver-ib_srp

diff --git a/Documentation/ABI/stable/sysfs-driver-ib_srp b/Documentation/ABI/stable/sysfs-driver-ib_srp
new file mode 100644
index 0000000..cfc1ce2
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-driver-ib_srp
@@ -0,0 +1,156 @@
+What: /sys/class/infiniband_srp/srp-<hca>-<port_number>/add_target
+Date: January 2, 2006
+KernelVersion: 2.6.15
+Contact: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.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-<hca>-<port_number>/ibdev
+Date: January 2, 2006
+KernelVersion: 2.6.15
+Contact: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
+Description: HCA name (<hca>).
+
+What: /sys/class/infiniband_srp/srp-<hca>-<port_number>/port
+Date: January 2, 2006
+KernelVersion: 2.6.15
+Contact: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
+Description: HCA port number (<port_number>).
+
+What: /sys/class/scsi_host/host<n>/allow_ext_sg
+Date: May 19, 2011
+KernelVersion: 2.6.39
+Contact: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.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<n>/cmd_sg_entries
+Date: May 19, 2011
+KernelVersion: 2.6.39
+Contact: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.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<n>/dgid
+Date: June 17, 2006
+KernelVersion: 2.6.17
+Contact: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.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<n>/id_ext
+Date: June 17, 2006
+KernelVersion: 2.6.17
+Contact: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
+Description: Eight-byte identifier extension portion of the 16-byte target
+ port identifier.
+
+What: /sys/class/scsi_host/host<n>/ioc_guid
+Date: June 17, 2006
+KernelVersion: 2.6.17
+Contact: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
+Description: Eight-byte I/O controller GUID portion of the 16-byte target
+ port identifier.
+
+What: /sys/class/scsi_host/host<n>/local_ib_device
+Date: November 29, 2006
+KernelVersion: 2.6.19
+Contact: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
+Description: Name of the InfiniBand HCA used for communicating with the
+ SRP target.
+
+What: /sys/class/scsi_host/host<n>/local_ib_port
+Date: November 29, 2006
+KernelVersion: 2.6.19
+Contact: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
+Description: Number of the HCA port used for communicating with the
+ SRP target.
+
+What: /sys/class/scsi_host/host<n>/orig_dgid
+Date: June 17, 2006
+KernelVersion: 2.6.17
+Contact: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
+Description: InfiniBand destination GID specified in the parameters
+ written to the add_target sysfs attribute.
+
+What: /sys/class/scsi_host/host<n>/pkey
+Date: June 17, 2006
+KernelVersion: 2.6.17
+Contact: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
+Description: A 16-bit number representing the InfiniBand partition key used
+ for communication with the SRP target.
+
+What: /sys/class/scsi_host/host<n>/req_lim
+Date: October 20, 2010
+KernelVersion: 2.6.36
+Contact: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.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<n>/service_id
+Date: June 17, 2006
+KernelVersion: 2.6.17
+Contact: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
+Description: InfiniBand service ID used for establishing communication with
+ the SRP target.
+
+What: /sys/class/scsi_host/host<n>/zero_req_lim
+Date: September 20, 2006
+KernelVersion: 2.6.18
+Contact: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
+Description: Number of times the initiator had to wait with 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.