[illumos-Developer] Webrev: New ARECA arcmsr driver

[Garrett D'Amore]

Recently, ARECA supplied me with a code drop of their latest Solaris
code, which supports the Areca 1880 cards, as well as adding support for
the newer interrupt model and fixing some bugs.

I want to give a great big *THANK YOU* to Areca for supporting illumos
in this way!

That said the code had a number of issues, which I've addressed (if
anyone wants the original code drop, or the list of issues that I've
fixed, let me know.)

The updated driver is posted here in webrev form:

http://mexico.purplecow.org/gdamore/webrev/arcmsr/

(Some of the changes are gratuitous reordering... I've not tried to
remove that reordering... the job was big enough as it was.)

This code is lint and cstyle clean.

There are a few more changes I'd like to consider making, but would like
feedback on, and am thinking would better be done as part of a later
change set:

a) removal of the special firmware passthrough support.  It isn't safe,
and from what I can tell doesn't work.  (Their utility crashes, and I
cannot get source code for it, limiting my ability to do any debug.)  If
anyone uses the Areca CLI or archttp utilities with arcmsr, I would
*really* like to know.  (You can configure and manage the RAID mode
cards using system BIOS, of course.)

b) Possibly refactor the code into object oriented bits for each of the
type A, B, C variants.  (I had done this, but the changes were too
large, and risky, and so I want to proceed with these lower risk changes
first.)

c) Switch to SCSAv3.  This would give some performance boost and remove
a lot of complexity in the driver.  I've already got a version with
these changes, but they were again rather large and sweeping, and so
I've shelved them for a future integration as part of my attempt to
mitigate risk, and also make the review task a bit more manageable.

d) remove reset(9e) and replace with quiesce(9e) -- testing needed for
this.

e) The code has support for handling 64-bit CDB addressing, but uses DMA
attributes that prevent it (for good reason!).  We should simply that
code by removal of the special cases for 64-bit CDB handling.  (Note
that this does not relate to the *buffer* addresses, which are fully
64-bit capable.)

Anyway, I would really, really like feedback on this driver.  Ideally I
will be integrating this soon.

	- Garrett