scsi: mpi3mr: Create operational request and reply queue pair

scsi: mpi3mr: Create operational request and reply queue pair

Create operational request and reply queue pair.

The MPI3 transport interface consists of an Administrative Request Queue,
an Administrative Reply Queue, and Operational Messaging Queues.  The
Operational Messaging Queues are the primary communication mechanism
between the host and the I/O Controller (IOC).  Request messages, allocated
in host memory, identify I/O operations to be performed by the IOC. These
operations are queued on an Operational Request Queue by the host driver.
Reply descriptors track I/O operations as they complete.  The IOC queues
these completions in an Operational Reply Queue.

To fulfil large contiguous memory requirement, driver creates multiple
segments and provide the list of segments. Each segment size should be 4K
which is a hardware requirement. An element array is contiguous or
segmented.  A contiguous element array is located in contiguous physical
memory.  A contiguous element array must be aligned on an element size
boundary.  An element's physical address within the array may be directly
calculated from the base address, the Producer/Consumer index, and the
element size.

Expected phased identifier bit is used to find out valid entry on reply
queue. Driver sets <ephase> bit and IOC inverts the value of this bit on
each pass.

Link: https://lore.kernel.org/r/20210520152545.2710479-4-kashyap.desai@broadcom.com
Cc: sathya.prakash@broadcom.com
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>