atomics: Make conditional ops return 'bool'

Some of the atomics return a status value, which is a boolean value
describing whether the operation was performed. To make it clear that
this is a boolean value, let's update the common fallbacks to return
bool, fixing up the return values and comments likewise.

At the same time, let's simplify the description of the operations in
their respective comments.

The instrumented atomics and generic atomic64 implementation are updated
accordingly.

Note that atomic64_dec_if_positive() doesn't follow the usual test op
pattern, and returns the would-be decremented value. This is not
changed.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-5-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/asm-generic/atomic-instrumented.h b/include/asm-generic/atomic-instrumented.h
index b8b14cc2df6c..497faa4a05e3 100644
--- a/include/asm-generic/atomic-instrumented.h
+++ b/include/asm-generic/atomic-instrumented.h
@@ -205,7 +205,7 @@ static __always_inline s64 atomic64_dec_return(atomic64_t *v)
 	return arch_atomic64_dec_return(v);
 }
 
-static __always_inline s64 atomic64_inc_not_zero(atomic64_t *v)
+static __always_inline bool atomic64_inc_not_zero(atomic64_t *v)
 {
 	kasan_check_write(v, sizeof(*v));
 	return arch_atomic64_inc_not_zero(v);