path: root/arch/powerpc
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authorLinus Torvalds <torvalds@linux-foundation.org>2014-01-20 18:23:08 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-20 18:23:08 (GMT)
commit6ffbe7d1fabddc768724656f159759cae7818cd9 (patch)
treeece184db0c35bcd9606968303984b430c24b847f /arch/powerpc
parent897aea303fec0c24b2a21b8e29f45dc73a234555 (diff)
parent63b1a81699c2a45c9f737419b1ec1da0ecf92812 (diff)
Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core locking changes from Ingo Molnar: - futex performance increases: larger hashes, smarter wakeups - mutex debugging improvements - lots of SMP ordering documentation updates - introduce the smp_load_acquire(), smp_store_release() primitives. (There are WIP patches that make use of them - not yet merged) - lockdep micro-optimizations - lockdep improvement: better cover IRQ contexts - liblockdep at last. We'll continue to monitor how useful this is * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits) futexes: Fix futex_hashsize initialization arch: Re-sort some Kbuild files to hopefully help avoid some conflicts futexes: Avoid taking the hb->lock if there's nothing to wake up futexes: Document multiprocessor ordering guarantees futexes: Increase hash table size for better performance futexes: Clean up various details arch: Introduce smp_load_acquire(), smp_store_release() arch: Clean up asm/barrier.h implementations using asm-generic/barrier.h arch: Move smp_mb__{before,after}_atomic_{inc,dec}.h into asm/atomic.h locking/doc: Rename LOCK/UNLOCK to ACQUIRE/RELEASE mutexes: Give more informative mutex warning in the !lock->owner case powerpc: Full barrier for smp_mb__after_unlock_lock() rcu: Apply smp_mb__after_unlock_lock() to preserve grace periods Documentation/memory-barriers.txt: Downgrade UNLOCK+BLOCK locking: Add an smp_mb__after_unlock_lock() for UNLOCK+BLOCK barrier Documentation/memory-barriers.txt: Document ACCESS_ONCE() Documentation/memory-barriers.txt: Prohibit speculative writes Documentation/memory-barriers.txt: Add long atomic examples to memory-barriers.txt Documentation/memory-barriers.txt: Add needed ACCESS_ONCE() calls to memory-barriers.txt Revert "smp/cpumask: Make CONFIG_CPUMASK_OFFSTACK=y usable without debug dependency" ...
Diffstat (limited to 'arch/powerpc')
2 files changed, 22 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h
index ae78225..f89da80 100644
--- a/arch/powerpc/include/asm/barrier.h
+++ b/arch/powerpc/include/asm/barrier.h
@@ -45,11 +45,15 @@
# define SMPWMB eieio
+#define __lwsync() __asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory")
#define smp_mb() mb()
-#define smp_rmb() __asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory")
+#define smp_rmb() __lwsync()
#define smp_wmb() __asm__ __volatile__ (stringify_in_c(SMPWMB) : : :"memory")
#define smp_read_barrier_depends() read_barrier_depends()
+#define __lwsync() barrier()
#define smp_mb() barrier()
#define smp_rmb() barrier()
#define smp_wmb() barrier()
@@ -65,4 +69,19 @@
#define data_barrier(x) \
asm volatile("twi 0,%0,0; isync" : : "r" (x) : "memory");
+#define smp_store_release(p, v) \
+do { \
+ compiletime_assert_atomic_type(*p); \
+ __lwsync(); \
+ ACCESS_ONCE(*p) = (v); \
+} while (0)
+#define smp_load_acquire(p) \
+({ \
+ typeof(*p) ___p1 = ACCESS_ONCE(*p); \
+ compiletime_assert_atomic_type(*p); \
+ __lwsync(); \
+ ___p1; \
diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h
index 5f54a74..f6e78d6 100644
--- a/arch/powerpc/include/asm/spinlock.h
+++ b/arch/powerpc/include/asm/spinlock.h
@@ -28,6 +28,8 @@
#include <asm/synch.h>
#include <asm/ppc-opcode.h>
+#define smp_mb__after_unlock_lock() smp_mb() /* Full ordering for lock. */
#define arch_spin_is_locked(x) ((x)->slock != 0)
#ifdef CONFIG_PPC64

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