[PATCH v2 0/6] ARC: spinlocks/atomics rework

[Vineet Gupta <Vineet.Gupta1@synopsys.com>]

The PREFETCHW workaround for llock/scond livelock was not sufficient after
all and we had to do some work there. Extending testing of quad core FPGA
builds shows things pretty stable, whereas w/o patches some of the LTP tests
(shm_open/23-1) would cause the system to go bonkers.

Changes since v1* (all thx to Peter Zijlstra)

* 3/6 - updated changelog
* 4/6 - updated changelog
	arch_write_unlock() need not use LLOCK/SCOND
* 5/6 - Conditional implementation of SCOND_FAIL_RETRY* in atomics (reduced dup)
	Handle overflow of delay counter in SCOND_FAIL_RETRY_ASM
* 6/6 - updated changelog

[*] http://lkml.kernel.org/r/1438596188-10875-1-git-send-email-vgupta@synopsys.com

Vineet Gupta (6):
  Revert "ARCv2: STAR 9000837815 workaround hardware exclusive
    transactions livelock"
  ARC: refactor atomic inline asm operands with symbolic names
  ARC: LLOCK/SCOND based spin_lock
  ARC: LLOCK/SCOND based rwlock
  ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with
    exponential backoff
  ARCv2: spinlock/rwlock: Reset retry delay when starting a new
    spin-wait cycle

 arch/arc/Kconfig                      |   5 +
 arch/arc/include/asm/atomic.h         |  79 +++--
 arch/arc/include/asm/spinlock.h       | 539 +++++++++++++++++++++++++++++++++-
 arch/arc/include/asm/spinlock_types.h |   2 +
 arch/arc/kernel/setup.c               |   4 +
 5 files changed, 591 insertions(+), 38 deletions(-)

-- 
1.9.1