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atomics/treewide: Make test ops optional

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Some of the atomics return the result of a test applied after the atomic
operation, and almost all architectures implement these as trivial
wrappers around the underlying atomic. Specifically:

 * <atomic>_inc_and_test(v)    is (<atomic>_inc_return(v)    == 0)
 * <atomic>_dec_and_test(v)    is (<atomic>_dec_return(v)    == 0)
 * <atomic>_sub_and_test(i, v) is (<atomic>_sub_return(i, v) == 0)
 * <atomic>_add_negative(i, v) is (<atomic>_add_return(i, v)  < 0)

Rather than have these definitions duplicated in all architectures, with
minor inconsistencies in formatting and documentation, let's make these
operations optional, with default fallbacks as above. Implementations
must now provide a preprocessor symbol.

The instrumented atomics are updated accordingly.

Both x86 and m68k have custom implementations, which are left as-is,
given preprocessor symbols to avoid being overridden.

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: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Palmer Dabbelt <palmer@sifive.com>
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/20180621121321.4761-16-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Mark Rutland
2018-06-21 13:13:18 +01:00
committed by Ingo Molnar
parent 356701329f
commit 18cc1814d4
24 changed files with 160 additions and 410 deletions
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15
arch/sparc/include/asm/atomic_32.h
View File

@@ -51,19 +51,4 @@ void atomic_set(atomic_t *, int);
#define atomic_inc_return(v) (atomic_add_return( 1, (v)))
#define atomic_dec_return(v) (atomic_add_return( -1, (v)))
#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
/*
* atomic_inc_and_test - increment and test
* @v: pointer of type atomic_t
*
* Atomically increments @v by 1
* and returns true if the result is zero, or false for all
* other cases.
*/
#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
#endif /* !(__ARCH_SPARC_ATOMIC__) */

20
arch/sparc/include/asm/atomic_64.h
View File

@@ -56,32 +56,12 @@ ATOMIC_OPS(xor)
#define atomic_inc_return(v) atomic_add_return(1, v)
#define atomic64_inc_return(v) atomic64_add_return(1, v)
/*
* atomic_inc_and_test - increment and test
* @v: pointer of type atomic_t
*
* Atomically increments @v by 1
* and returns true if the result is zero, or false for all
* other cases.
*/
#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
#define atomic64_sub_and_test(i, v) (atomic64_sub_return(i, v) == 0)
#define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0)
#define atomic64_dec_and_test(v) (atomic64_sub_return(1, v) == 0)
#define atomic_inc(v) atomic_add(1, v)
#define atomic64_inc(v) atomic64_add(1, v)
#define atomic_dec(v) atomic_sub(1, v)
#define atomic64_dec(v) atomic64_sub(1, v)
#define atomic_add_negative(i, v) (atomic_add_return(i, v) < 0)
#define atomic64_add_negative(i, v) (atomic64_add_return(i, v) < 0)
#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
static inline int atomic_xchg(atomic_t *v, int new)