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atomics/treewide: Make atomic64_fetch_add_unless() optional

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Architectures with atomic64_fetch_add_unless() provide a preprocessor
symbol if they do so, and all other architectures have trivial C
implementations of atomic64_add_unless() which are near-identical.

Let's unify the trivial definitions of atomic64_fetch_add_unless() in
<linux/atomic.h>, so that we always have both
atomic64_fetch_add_unless() and atomic64_add_unless() with less
boilerplate code.

This means that atomic64_add_unless() is always implemented in core
code, and 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/20180621121321.4761-15-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Mark Rutland 2018-06-21 13:13:17 +01:00 committed by Ingo Molnar
parent 2b523f170e
commit 356701329f
9 changed files with 24 additions and 133 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

12
arch/arm64/include/asm/atomic.h
View file

@ -40,17 +40,6 @@
#include <asm/cmpxchg.h>
#define ___atomic_add_unless(v, a, u, sfx) \
({ \
typeof((v)->counter) c, old; \
\
c = atomic##sfx##_read(v); \
while (c != (u) && \
(old = atomic##sfx##_cmpxchg((v), c, c + (a))) != c) \
c = old; \
c; \
})
#define ATOMIC_INIT(i) { (i) }
#define atomic_read(v) READ_ONCE((v)->counter)
@ -200,7 +189,6 @@
#define atomic64_dec_and_test(v) (atomic64_dec_return(v) == 0)
#define atomic64_sub_and_test(i, v) (atomic64_sub_return((i), (v)) == 0)
#define atomic64_add_negative(i, v) (atomic64_add_return((i), (v)) < 0)
#define atomic64_add_unless(v, a, u) (___atomic_add_unless(v, a, u, 64) != u)
#define atomic64_andnot atomic64_andnot
#endif

15
arch/ia64/include/asm/atomic.h
View file

@ -215,21 +215,6 @@ ATOMIC64_FETCH_OP(xor, ^)
(cmpxchg(&((v)->counter), old, new))
#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
static __inline__ long atomic64_add_unless(atomic64_t *v, long a, long u)
{
long c, old;
c = atomic64_read(v);
for (;;) {
if (unlikely(c == (u)))
break;
old = atomic64_cmpxchg((v), c, c + (a));
if (likely(old == c))
break;
c = old;
}
return c != (u);
}
static __inline__ long atomic64_dec_if_positive(atomic64_t *v)
{
long c, old, dec;

24
arch/mips/include/asm/atomic.h
View file

@ -596,30 +596,6 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
#define atomic64_xchg(v, new) (xchg(&((v)->counter), (new)))
/**
* atomic64_add_unless - add unless the number is a given value
* @v: pointer of type atomic64_t
* @a: the amount to add to v...
* @u: ...unless v is equal to u.
*
* Atomically adds @a to @v, so long as it was not @u.
* Returns true iff @v was not @u.
*/
static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
{
long c, old;
c = atomic64_read(v);
for (;;) {
if (unlikely(c == (u)))
break;
old = atomic64_cmpxchg((v), c, c + (a));
if (likely(old == c))
break;
c = old;
}
return c != (u);
}
#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
#define atomic64_inc_return(v) atomic64_add_return(1, (v))

24
arch/parisc/include/asm/atomic.h
View file

@ -257,30 +257,6 @@ atomic64_read(const atomic64_t *v)
((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
/**
* atomic64_add_unless - add unless the number is a given value
* @v: pointer of type atomic64_t
* @a: the amount to add to v...
* @u: ...unless v is equal to u.
*
* Atomically adds @a to @v, so long as it was not @u.
* Returns the old value of @v.
*/
static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
{
long c, old;
c = atomic64_read(v);
for (;;) {
if (unlikely(c == (u)))
break;
old = atomic64_cmpxchg((v), c, c + (a));
if (likely(old == c))
break;
c = old;
}
return c != (u);
}
/*
* atomic64_dec_if_positive - decrement by 1 if old value positive
* @v: pointer of type atomic_t

16
arch/s390/include/asm/atomic.h
View file

@ -153,22 +153,6 @@ ATOMIC64_OPS(xor)
#undef ATOMIC64_OPS
static inline int atomic64_add_unless(atomic64_t *v, long i, long u)
{
long c, old;
c = atomic64_read(v);
for (;;) {
if (unlikely(c == u))
break;
old = atomic64_cmpxchg(v, c, c + i);
if (likely(old == c))
break;
c = old;
}
return c != u;
}
static inline long atomic64_dec_if_positive(atomic64_t *v)
{
long c, old, dec;

15
arch/sparc/include/asm/atomic_64.h
View file

@ -93,21 +93,6 @@ static inline int atomic_xchg(atomic_t *v, int new)
((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
static inline long atomic64_add_unless(atomic64_t *v, long a, long u)
{
long c, old;
c = atomic64_read(v);
for (;;) {
if (unlikely(c == (u)))
break;
old = atomic64_cmpxchg((v), c, c + (a));
if (likely(old == c))
break;
c = old;
}
return c != (u);
}
long atomic64_dec_if_positive(atomic64_t *v);
#endif /* !(__ARCH_SPARC64_ATOMIC__) */

19
arch/x86/include/asm/atomic64_64.h
View file

@ -188,25 +188,6 @@ static inline long arch_atomic64_xchg(atomic64_t *v, long new)
return xchg(&v->counter, new);
}
/**
* arch_atomic64_add_unless - add unless the number is a given value
* @v: pointer of type atomic64_t
* @a: the amount to add to v...
* @u: ...unless v is equal to u.
*
* Atomically adds @a to @v, so long as it was not @u.
* Returns the old value of @v.
*/
static inline bool arch_atomic64_add_unless(atomic64_t *v, long a, long u)
{
s64 c = arch_atomic64_read(v);
do {
if (unlikely(c == u))
return false;
} while (!arch_atomic64_try_cmpxchg(v, &c, c + a));
return true;
}
/*
* arch_atomic64_dec_if_positive - decrement by 1 if old value positive
* @v: pointer of type atomic_t

6
include/asm-generic/atomic-instrumented.h
View file

@ -100,12 +100,6 @@ static __always_inline s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u
kasan_check_write(v, sizeof(*v));
return arch_atomic64_fetch_add_unless(v, a, u);
}
#else
static __always_inline bool atomic64_add_unless(atomic64_t *v, s64 a, s64 u)
{
kasan_check_write(v, sizeof(*v));
return arch_atomic64_add_unless(v, a, u);
}
#endif
static __always_inline void atomic_inc(atomic_t *v)

26
include/linux/atomic.h
View file

@ -1042,6 +1042,30 @@ static inline int atomic_dec_if_positive(atomic_t *v)
#define atomic64_try_cmpxchg_release atomic64_try_cmpxchg
#endif /* atomic64_try_cmpxchg */
/**
* atomic64_fetch_add_unless - add unless the number is already a given value
* @v: pointer of type atomic64_t
* @a: the amount to add to v...
* @u: ...unless v is equal to u.
*
* Atomically adds @a to @v, if @v was not already @u.
* Returns the original value of @v.
*/
#ifndef atomic64_fetch_add_unless
static inline long long atomic64_fetch_add_unless(atomic64_t *v, long long a,
long long u)
{
long long c = atomic64_read(v);
do {
if (unlikely(c == u))
break;
} while (!atomic64_try_cmpxchg(v, &c, c + a));
return c;
}
#endif
/**
* atomic64_add_unless - add unless the number is already a given value
* @v: pointer of type atomic_t
@ -1051,12 +1075,10 @@ static inline int atomic_dec_if_positive(atomic_t *v)
* Atomically adds @a to @v, if @v was not already @u.
* Returns true if the addition was done.
*/
#ifdef atomic64_fetch_add_unless
static inline bool atomic64_add_unless(atomic64_t *v, long long a, long long u)
{
return atomic64_fetch_add_unless(v, a, u) != u;
}
#endif
/**
* atomic64_inc_not_zero - increment unless the number is zero