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authorLinus Torvalds <torvalds@linux-foundation.org>2018-08-13 22:23:39 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-13 22:23:39 +0300
commitde5d1b39ea0b38a9f4dfb08966042b7b91e2df30 (patch)
tree3591bdac4fe6756b4e3dc68b2ed1c792c4104218 /arch/arm
parent1c594774283a7cfe6dc0f8ffdfb2dbfc497502c4 (diff)
parentfd2efaa4eb5317c3a86357a83a7d456a1b86a0ac (diff)
downloadlinux-de5d1b39ea0b38a9f4dfb08966042b7b91e2df30.tar.xz
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking/atomics update from Thomas Gleixner: "The locking, atomics and memory model brains delivered: - A larger update to the atomics code which reworks the ordering barriers, consolidates the atomic primitives, provides the new atomic64_fetch_add_unless() primitive and cleans up the include hell. - Simplify cmpxchg() instrumentation and add instrumentation for xchg() and cmpxchg_double(). - Updates to the memory model and documentation" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits) locking/atomics: Rework ordering barriers locking/atomics: Instrument cmpxchg_double*() locking/atomics: Instrument xchg() locking/atomics: Simplify cmpxchg() instrumentation locking/atomics/x86: Reduce arch_cmpxchg64*() instrumentation tools/memory-model: Rename litmus tests to comply to norm7 tools/memory-model/Documentation: Fix typo, smb->smp sched/Documentation: Update wake_up() & co. memory-barrier guarantees locking/spinlock, sched/core: Clarify requirements for smp_mb__after_spinlock() sched/core: Use smp_mb() in wake_woken_function() tools/memory-model: Add informal LKMM documentation to MAINTAINERS locking/atomics/Documentation: Describe atomic_set() as a write operation tools/memory-model: Make scripts executable tools/memory-model: Remove ACCESS_ONCE() from model tools/memory-model: Remove ACCESS_ONCE() from recipes locking/memory-barriers.txt/kokr: Update Korean translation to fix broken DMA vs. MMIO ordering example MAINTAINERS: Add Daniel Lustig as an LKMM reviewer tools/memory-model: Fix ISA2+pooncelock+pooncelock+pombonce name tools/memory-model: Add litmus test for full multicopy atomicity locking/refcount: Always allow checked forms ...
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/include/asm/atomic.h55
1 files changed, 14 insertions, 41 deletions
diff --git a/arch/arm/include/asm/atomic.h b/arch/arm/include/asm/atomic.h
index 66d0e215a773..f74756641410 100644
--- a/arch/arm/include/asm/atomic.h
+++ b/arch/arm/include/asm/atomic.h
@@ -130,7 +130,7 @@ static inline int atomic_cmpxchg_relaxed(atomic_t *ptr, int old, int new)
}
#define atomic_cmpxchg_relaxed atomic_cmpxchg_relaxed
-static inline int __atomic_add_unless(atomic_t *v, int a, int u)
+static inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
{
int oldval, newval;
unsigned long tmp;
@@ -156,6 +156,7 @@ static inline int __atomic_add_unless(atomic_t *v, int a, int u)
return oldval;
}
+#define atomic_fetch_add_unless atomic_fetch_add_unless
#else /* ARM_ARCH_6 */
@@ -215,15 +216,7 @@ static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
return ret;
}
-static inline int __atomic_add_unless(atomic_t *v, int a, int u)
-{
- int c, old;
-
- c = atomic_read(v);
- while (c != u && (old = atomic_cmpxchg((v), c, c + a)) != c)
- c = old;
- return c;
-}
+#define atomic_fetch_andnot atomic_fetch_andnot
#endif /* __LINUX_ARM_ARCH__ */
@@ -254,17 +247,6 @@ ATOMIC_OPS(xor, ^=, eor)
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
-#define atomic_inc(v) atomic_add(1, v)
-#define atomic_dec(v) atomic_sub(1, v)
-
-#define atomic_inc_and_test(v) (atomic_add_return(1, v) == 0)
-#define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0)
-#define atomic_inc_return_relaxed(v) (atomic_add_return_relaxed(1, v))
-#define atomic_dec_return_relaxed(v) (atomic_sub_return_relaxed(1, v))
-#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
-
-#define atomic_add_negative(i,v) (atomic_add_return(i, v) < 0)
-
#ifndef CONFIG_GENERIC_ATOMIC64
typedef struct {
long long counter;
@@ -494,12 +476,13 @@ static inline long long atomic64_dec_if_positive(atomic64_t *v)
return result;
}
+#define atomic64_dec_if_positive atomic64_dec_if_positive
-static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u)
+static inline long long atomic64_fetch_add_unless(atomic64_t *v, long long a,
+ long long u)
{
- long long val;
+ long long oldval, newval;
unsigned long tmp;
- int ret = 1;
smp_mb();
prefetchw(&v->counter);
@@ -508,33 +491,23 @@ static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u)
"1: ldrexd %0, %H0, [%4]\n"
" teq %0, %5\n"
" teqeq %H0, %H5\n"
-" moveq %1, #0\n"
" beq 2f\n"
-" adds %Q0, %Q0, %Q6\n"
-" adc %R0, %R0, %R6\n"
-" strexd %2, %0, %H0, [%4]\n"
+" adds %Q1, %Q0, %Q6\n"
+" adc %R1, %R0, %R6\n"
+" strexd %2, %1, %H1, [%4]\n"
" teq %2, #0\n"
" bne 1b\n"
"2:"
- : "=&r" (val), "+r" (ret), "=&r" (tmp), "+Qo" (v->counter)
+ : "=&r" (oldval), "=&r" (newval), "=&r" (tmp), "+Qo" (v->counter)
: "r" (&v->counter), "r" (u), "r" (a)
: "cc");
- if (ret)
+ if (oldval != u)
smp_mb();
- return ret;
+ return oldval;
}
-
-#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
-#define atomic64_inc(v) atomic64_add(1LL, (v))
-#define atomic64_inc_return_relaxed(v) atomic64_add_return_relaxed(1LL, (v))
-#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
-#define atomic64_sub_and_test(a, v) (atomic64_sub_return((a), (v)) == 0)
-#define atomic64_dec(v) atomic64_sub(1LL, (v))
-#define atomic64_dec_return_relaxed(v) atomic64_sub_return_relaxed(1LL, (v))
-#define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0)
-#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL)
+#define atomic64_fetch_add_unless atomic64_fetch_add_unless
#endif /* !CONFIG_GENERIC_ATOMIC64 */
#endif