Since the SRP_LOGIN_REQ defined in the SRP standard is larger than
what fits in the RDMA/CM login request private data, introduce a new
login request format for the RDMA/CM.

Note: since srp_daemon and ibsrpdm rely on the subnet manager and
since there is no equivalent of the IB subnet manager in non-IB
networks, login has to be performed manually for non-IB networks.
Signed-off-by: NBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

The SCSI standard defines 64-bit values for LUNs. Large arrays
employing large or hierarchical LUN numbers become more and more
common. So update the SRP initiator to use 64-bit LUN numbers.
See also Hannes Reinecke, commit 9cb78c16 ("scsi: use 64-bit LUNs"),
June 2014.

The largest LUN number that has been tested is 0xd2003fff00000000.

Checked the following structure sizes with gdb:
* sizeof(struct srp_cmd) = 48
* sizeof(struct srp_tsk_mgmt) = 48
* sizeof(struct srp_aer_req) = 36

The ibmvscsi changes have been compile tested only (on a PPC system).
Signed-off-by: NBart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NSagi Grimberg <sagig@mellanox.com>
Reviewed-by: NYann Droneaud <ydroneaud@opteya.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: Brian King <brking@linux.vnet.ibm.com>
Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

This patch adds support for SRP_CRED_REQ to avoid a lockup by targets
that use that mechanism to return credits to the initiator. This
prevents a lockup observed in the field where we would never add the
credits from the SRP_CRED_REQ to our current count, and would therefore
never send another command to the target.

Minimal support for SRP_AER_REQ is also added, as these messages can
also be used to convey additional credits to the initiator.

Based upon extensive debugging and code by Bart Van Assche and a bug
report by Chris Worley.
Signed-off-by: NDavid Dillow <dillowda@ornl.gov>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add enum values for I/O Class values from rev. 10 and rev. 16a SRP
drafts.  The values are used to detect targets that implement obsolete
revisions of SRP, so that the initiator can use the old format for
port identifier when connecting to them.
Signed-off-by: NRamachandra K <rkuchimanchi@silverstorm.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Several structs in <scsi/srp.h> get padded to a multiple of 8 bytes on
64-bit architectures and end up with a size that does not match the
definition in the SRP spec:

                                     SRP spec     64-bit
    sizeof (struct indirect_buf)        20          24
    sizeof (struct srp_login_rsp)       52          56
    sizeof (struct srp_rsp)             36          40

Fix this by adding __attribute__((packed)) to the offending structs.

Problem pointed out by Arne Redlich <arne.redlich@xiranet.com>.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Add an InfiniBand SCSI RDMA Protocol (SRP) initiator.  This driver is
used to talk talk to InfiniBand SRP targets (storage devices).
Signed-off-by: NRoland Dreier <rolandd@cisco.com>