MIPS will soon not be a part of Imagination Technologies, and as such
many @imgtec.com email addresses will no longer be valid. This patch
updates the addresses for those who:

 - Have 10 or more patches in mainline authored using an @imgtec.com
   email address, or any patches dated within the past year.

 - Are still with Imagination but leaving as part of the MIPS business
   unit, as determined from an internal email address list.

 - Haven't already updated their email address (ie. JamesH) or expressed
   a desire to be excluded (ie. Maciej).

 - Acked v2 or earlier of this patch, which leaves Deng-Cheng, Matt &
   myself.

New addresses are of the form firstname.lastname@mips.com, and all
verified against an internal email address list.  An entry is added to
.mailmap for each person such that get_maintainer.pl will report the new
addresses rather than @imgtec.com addresses which will soon be dead.

Instances of the affected addresses throughout the tree are then
mechanically replaced with the new @mips.com address.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@mips.com>
Acked-by: Dengcheng Zhu <dengcheng.zhu@mips.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@mips.com>
Acked-by: Matt Redfearn <matt.redfearn@mips.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: trivial@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Implement support for 1 & 2 byte cmpxchg() using read-modify-write atop
a 4 byte cmpxchg(). This allows us to support these atomic operations
despite the MIPS ISA only providing 4 & 8 byte atomic operations.

This is required in order to support queued rwlocks (qrwlock) in a later
patch, since these make use of a 1 byte cmpxchg() in their slow path.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16355/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Implement 1 & 2 byte xchg() using read-modify-write atop a 4 byte
cmpxchg(). This allows us to support these atomic operations despite the
MIPS ISA only providing for 4 & 8 byte atomic operations.

This is required in order to support queued spinlocks (qspinlock) in a
later patch, since these make use of a 2 byte xchg() in their slow path.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16354/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>