- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

After extensive QA cycles at 3ware, bring the driver in-line with all the
issues which they found and asked to be changed so 3ware can offcially
support the driver.

Summary of the most significant changes:

- TWE_OVERRIDE is no longer supported
- If twe_getparam failed, bogus data would be returned to the caller
- Cache the device unit in the twe_drive structure to aid debugging
- Add the 3ware driver version.
- Proper return error codes for many functions.
- Track the minimum queue length statistics
- 4.x compat: use the cached unit number from the twe_drive structure
instead of the the cached si_drv2. 3ware found that after many loads
and unloads that si_drv2 became corrupted. This did not happen in
-current.

Submitted by: Vinod Kashyap (with modifications by me)
Approved by: re (rwatson)

Properly support the 3ware generic API.

- Build SGL's for ATA_PASSTHROUGH commands
- Fallback to using the sgl_offset when the opcode is unknown for building
SGL's/
- Add ioctl calls for adding and removing units.
- Define previously undefined AEN's
- Allocate memory for the ioctl payload in multiples of 512bytes.

MFC after: 1 week

Update for the 6.9 firmware family (6xxx controllers), as well as for
the upcoming 7.4 family (7xxx controllers).

- improved error reporting and handling
- more diagnostic output
- add extra command packet definitions
- merge sources again with -stable

Major update to the 'twe' driver.

- Layout reorganisation to enhance portability. The driver now has
a relatively MI 'core' and a FreeBSD-specific layer over the top.
Since the NetBSD people have already done their own port, this is
largely just to help me with the BSD/OS port.

- Request ID allocation changed to improve performance (I'd been
considering switching to this approach after having failed to come
up with a better way to dynamically allocate request IDs, and seeing
Andy Doran use it in the NetBSD port of the driver convinced me
that I was wasting my time doing it any other way). Now we just
allocate all the requests up front.

- Maximum request count bumped back to 255 after characterisation
of a firmware issue (off-by-one causing it to crash with 256
outstanding commands).

- Control interface implemented. This allows 3ware's '3dm' utility to
talk to the controller. 3dm will be available from 3ware shortly.

- Controller soft-reset feature added; if the controller signals a
firmware or protocol error, the controller will be reset and all
outstanding commands will be retried.