[PATCH 0/5] Provide two-byte cmpxchg() emulation

[Paul E. McKenney]

Hello!

This series provides emulation of two-byte cmpxchg().  Note that this
does not (yet) allow free use of atomic operations on two-byte operands
in core code because there are still a few supported systems that do not
have two-byte store instructions.  However, this emulation does permit use
of wide range of two-byte atomic operations, so is worth putting forward.

This series is being reposted on request in order to ease testing efforts.

The individual patches are as follows:

1.	Add two-byte cmpxchg emulation function, courtesy of Bradley
	Morgan.

2.	sh: Emulate two-byte cmpxchg, courtesy of Bradley Morgan.

3.	ARC: Emulate two-byte cmpxchg, courtesy of Bradley Morgan.

4.	csky: Emulate two-byte cmpxchg, courtesy of Bradley Morgan.

5.	xtensa: Emulate two-byte cmpxchg, courtesy of Bradley Morgan.

#1 and #2 have the acks required to go into the upcoming v7.4 merge
window.

						Thanx, Paul

------------------------------------------------------------------------

 arch/arc/include/asm/cmpxchg.h    |    3 +++
 arch/csky/include/asm/cmpxchg.h   |    9 +++++++++
 arch/sh/include/asm/cmpxchg.h     |    2 ++
 arch/xtensa/include/asm/cmpxchg.h |    1 +
 include/linux/cmpxchg-emu.h       |    4 +++-
 lib/cmpxchg-emu.c                 |   38 ++++++++++++++++++++++++++++++++++----
 6 files changed, 52 insertions(+), 5 deletions(-)