scsi: mpi3mr: Avoid memcpy field-spanning write WARNING

When the "storcli2 show" command is executed for eHBA-9600, mpi3mr driver
prints this WARNING message:

memcpy: detected field-spanning write (size 128) of single field "bsg_reply_buf->reply_buf" at drivers/scsi/mpi3mr/mpi3mr_app.c:1658 (size 1)
WARNING: CPU: 0 PID: 12760 at drivers/scsi/mpi3mr/mpi3mr_app.c:1658 mpi3mr_bsg_request+0x6b12/0x7f10 [mpi3mr]

The cause of the WARN is 128 bytes memcpy to the 1 byte size array "__u8
replay_buf[1]" in the struct mpi3mr_bsg_in_reply_buf. The array is intended
to be a flexible length array, so the WARN is a false positive.

To suppress the WARN, remove the constant number '1' from the array
declaration and clarify that it has flexible length. Also, adjust the
memory allocation size to match the change.

Suggested-by: Sathya Prakash Veerichetty <sathya.prakash@broadcom.com>
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20240323084155.166835-1-shinichiro.kawasaki@wdc.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: mpi3mr: Support for preallocation of SGL BSG data buffers part-3

The driver acquires the required NVMe SGLs from the pre-allocated
pool.

Co-developed-by: Sathya Prakash <sathya.prakash@broadcom.com>
Signed-off-by: Sathya Prakash <sathya.prakash@broadcom.com>
Signed-off-by: Chandrakanth patil <chandrakanth.patil@broadcom.com>
Link: https://lore.kernel.org/r/20231205191630.12201-4-chandrakanth.patil@broadcom.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: mpi3mr: Replace 1-element array with flex-array

Nothing else defined MPI3_NVME_ENCAP_CMD_MAX, so the "command" buffer was
being defined as a fake flexible array of size 1. Replace this with a
proper flex array. Avoids this GCC 13 warning under -fstrict-flex-arrays=3:

In function 'fortify_memset_chk',
inlined from 'mpi3mr_build_nvme_sgl' at ../drivers/scsi/mpi3mr/mpi3mr_app.c:693:2,
inlined from 'mpi3mr_bsg_process_mpt_cmds.constprop' at ../drivers/scsi/mpi3mr/mpi3mr_app.c:1214:8:
../include/linux/fortify-string.h:430:25: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
430 | __write_overflow_field(p_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Link: https://lore.kernel.org/r/20230204183715.never.937-kees@kernel.org
Cc: Sumit Saxena <sumit.saxena@broadcom.com>
Cc: Himanshu Madhani <himanshu.madhani@oracle.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: mpi3mr: Add support for NVMe passthrough

Add support for management applications to send an MPI3 Encapsulated NVMe
passthru command to the NVMe devices attached to an Avenger controller.
Since the NVMe drives are exposed as SCSI devices by the controller, the
standard NVMe applications cannot be used to interact with the drives and
the command sets supported are also limited by the controller firmware.
Special handling is required for MPI3 Encapsulated NVMe passthru commands
for PRP/SGL setup in the commands.

Link: https://lore.kernel.org/r/20220429211641.642010-8-sumit.saxena@broadcom.com
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: mpi3mr: Move data structures/definitions from MPI headers to uapi header

This patch moves the data structures/definitions which are used by
userspace applications from MPI headers to uapi/scsi/scsi_bsg_mpi3mr.h

Link: https://lore.kernel.org/r/20220429211641.642010-4-sumit.saxena@broadcom.com
Reported by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: mpi3mr: Add support for driver commands

There are certain bsg commands which need to be completed by the driver
without involving firmware. These requests are termed driver commands. Add
support for these.

Link: https://lore.kernel.org/r/20220429211641.642010-3-sumit.saxena@broadcom.com
Reported by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>