[PATCH 0/6] Enable queued rwlock and queued spinlock for SPARC

[Babu Moger <babu.moger@oracle.com>]

This series of patches enables queued rwlock and queued spinlock support
for SPARC. These features were introduced some time ago in upstream.
Here are some of the earlier discussions.
https://lwn.net/Articles/572765/
https://lwn.net/Articles/582200/
https://lwn.net/Articles/561775/
https://lwn.net/Articles/590243/

Tests: Ran AIM7 benchmark to verify the performance on various workloads.
https://github.com/davidlohr/areaim. Same benchmark was used when this
feature was introduced and enabled on x86. Here are the test results.

Kernel				4.11.0-rc6     4.11.0-rc6 + 	Change
				baseline	queued locks
			      (Avg No.of jobs) (Avg No.of jobs)
Workload
High systime 10-100 user	 17290.48	 17295.18	+0.02
High systime 200-1000 users	109814.95	110248.87	+0.39
High systime 1200-2000 users	107912.40	127923.16	+18.54

Disk IO 10-100 users		168910.16	158834.17	-5.96
Disk IO 200-1000 users		242781.74	281285.80	+15.85
Disk IO 1200-2000 users		228518.23	218421.23	-4.41

Disk IO 10-100 users		183933.77	207928.67	+13.04
Disk IO 200-1000 users		491981.56	500162.33	+1.66
Disk IO 1200-2000 users		463395.66	467312.70	+0.84

fserver 10-100 users		254177.53	270283.08	+6.33
fserver IO 200-1000 users	269017.35	324812.2	+20.74
fserver IO 1200-2000 users	229538.87	284713.77	+24.03

Disk I/O results are little bit in negative territory. But majority of the 
performance changes are in positive and it is significant in some cases.

Babu Moger (6):
  kernel/locking: Fix compile error with qrwlock.c
  arch/sparc: Define config parameter CPU_BIG_ENDIAN
  arch/sparc: Introduce cmpxchg_u8 SPARC
  arch/sparc: Enable queued rwlocks for SPARC
  arch/sparc: Introduce xchg16 for SPARC
  arch/sparc: Enable queued spinlock support for SPARC

 arch/sparc/Kconfig                      |    6 +++
 arch/sparc/include/asm/cmpxchg_64.h     |   76 +++++++++++++++++++++++++++----
 arch/sparc/include/asm/qrwlock.h        |    7 +++
 arch/sparc/include/asm/qspinlock.h      |    7 +++
 arch/sparc/include/asm/spinlock_64.h    |   13 ++++-
 arch/sparc/include/asm/spinlock_types.h |   10 ++++-
 include/asm-generic/qrwlock_types.h     |    6 +-
 kernel/locking/qrwlock.c                |    1 +
 8 files changed, 110 insertions(+), 16 deletions(-)
 create mode 100644 arch/sparc/include/asm/qrwlock.h
 create mode 100644 arch/sparc/include/asm/qspinlock.h