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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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84
arch/mips/include/asm/atomic.h
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@@ -277,37 +277,6 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
#define atomic_dec_return(v) atomic_sub_return(1, (v))
#define atomic_inc_return(v) atomic_add_return(1, (v))
/*
* atomic_sub_and_test - subtract value from variable and test result
* @i: integer value to subtract
* @v: pointer of type atomic_t
*
* Atomically subtracts @i from @v and returns
* true if the result is zero, or false for all
* other cases.
*/
#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (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)
/*
* atomic_dec_and_test - decrement by 1 and test
* @v: pointer of type atomic_t
*
* Atomically decrements @v by 1 and
* returns true if the result is 0, or false for all other
* cases.
*/
#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
/*
* atomic_dec_if_positive - decrement by 1 if old value positive
* @v: pointer of type atomic_t
@@ -330,17 +299,6 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v)
*/
#define atomic_dec(v) atomic_sub(1, (v))
/*
* atomic_add_negative - add and test if negative
* @v: pointer of type atomic_t
* @i: integer value to add
*
* Atomically adds @i to @v and returns true
* if the result is negative, or false when
* result is greater than or equal to zero.
*/
#define atomic_add_negative(i, v) (atomic_add_return(i, (v)) < 0)
#ifdef CONFIG_64BIT
#define ATOMIC64_INIT(i) { (i) }
@@ -599,37 +557,6 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
#define atomic64_dec_return(v) atomic64_sub_return(1, (v))
#define atomic64_inc_return(v) atomic64_add_return(1, (v))
/*
* atomic64_sub_and_test - subtract value from variable and test result
* @i: integer value to subtract
* @v: pointer of type atomic64_t
*
* Atomically subtracts @i from @v and returns
* true if the result is zero, or false for all
* other cases.
*/
#define atomic64_sub_and_test(i, v) (atomic64_sub_return((i), (v)) == 0)
/*
* atomic64_inc_and_test - increment and test
* @v: pointer of type atomic64_t
*
* Atomically increments @v by 1
* and returns true if the result is zero, or false for all
* other cases.
*/
#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
/*
* atomic64_dec_and_test - decrement by 1 and test
* @v: pointer of type atomic64_t
*
* Atomically decrements @v by 1 and
* returns true if the result is 0, or false for all other
* cases.
*/
#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
/*
* atomic64_dec_if_positive - decrement by 1 if old value positive
* @v: pointer of type atomic64_t
@@ -652,17 +579,6 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v)
*/
#define atomic64_dec(v) atomic64_sub(1, (v))
/*
* atomic64_add_negative - add and test if negative
* @v: pointer of type atomic64_t
* @i: integer value to add
*
* Atomically adds @i to @v and returns true
* if the result is negative, or false when
* result is greater than or equal to zero.
*/
#define atomic64_add_negative(i, v) (atomic64_add_return(i, (v)) < 0)
#endif /* CONFIG_64BIT */
#endif /* _ASM_ATOMIC_H */