[SCSI] mv_sas: OCZ RevoDrive3 & zDrive R4 support

[SCSI] mv_sas: OCZ RevoDrive3 & zDrive R4 support

In the OCZ RevoDrive3/zDrive R4 series, the "OCZ SuperScale Storage
Controller" with "Virtualized Controller Architecture 2.0" really seems
to be a Marvell 88SE9485 part, with OCZ firmware/BIOS.

Developed and tested on OCZ RevoDrive3 120GB [PCI 1b85:1021]

Should work on:
- OCZ RevoDrive3 (2x SandForce 2281)
- OCZ RevoDrive3 X2 (4x SandForce 2281)
- OCZ zDrive R4 CM84 (4x SandForce 2281)
- OCZ zDrive R4 CM88 (8x SandForce 2281)
- OCZ zDrive R4 RM84 (4x SandForce 2582)
- OCZ zDrive R4 RM88 (8x SandForce 2582)

All of this because a friend recently bought a OCZ RevoDrive3 and was
bitten by the lack of Linux support.

Notes from testing:
-------------------
- SMART works.
- VPD Device Identification is "OCZ-REVODRIVE3"
- Thin provisioning/TRIM seems to be implemented as WRITE SAME UNMAP,
  with deterministic (non-zero) read after TRIM, but I'm not sure if it
  works 100% in my testing.
- Some of the tuning in the firmware seems to ensure much better
  performance when in a RAID0 setup than using the two devices
  seperately.

I have not tested booting from the SSD, because all of this was
developed and tested remotely from the actual hardware.

Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
Thanks-To: Gordon Pritchard <gordp@sfu.ca>
Acked-by: Xiangliang Yu <yuxiangl@marvell.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>