xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

atomics/treewide: Make conditional inc/dec ops optional

Browse Source 
The conditional inc/dec ops differ for atomic_t and atomic64_t:

- atomic_inc_unless_positive() is optional for atomic_t, and doesn't exist for atomic64_t.
- atomic_dec_unless_negative() is optional for atomic_t, and doesn't exist for atomic64_t.
- atomic_dec_if_positive is optional for atomic_t, and is mandatory for atomic64_t.

Let's make these consistently optional for both. At the same time, let's
clean up the existing fallbacks to use atomic_try_cmpxchg().

The instrumented atomics are updated accordingly.

There should be no functional change as a result of this patch.

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: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-18-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Mark Rutland
2018-06-21 13:13:20 +01:00
committed by Ingo Molnar
parent 9837559d8e
commit b3a2a05f91
14 changed files with 85 additions and 98 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
arch/s390/include/asm/atomic.h
View File

@@ -145,23 +145,6 @@ ATOMIC64_OPS(xor)
#undef ATOMIC64_OPS
static inline long atomic64_dec_if_positive(atomic64_t *v)
{
long c, old, dec;
c = atomic64_read(v);
for (;;) {
dec = c - 1;
if (unlikely(dec < 0))
break;
old = atomic64_cmpxchg((v), c, dec);
if (likely(old == c))
break;
c = old;
}
return dec;
}
#define atomic64_sub_return(_i, _v) atomic64_add_return(-(long)(_i), _v)
#define atomic64_fetch_sub(_i, _v) atomic64_fetch_add(-(long)(_i), _v)
#define atomic64_sub(_i, _v) atomic64_add(-(long)(_i), _v)