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Commit 5692e4d1 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
Browse files

s390/atomic: optimize atomic_add() for constant values 



If the interlocked-access facility 1 is available we can use the asi
and agsi instructions for interlocked updates if the to be added
value is a contanst and small (in the range of -128..127).
asi and agsi do not not return the old or new value, therefore these
instructions can only be used for atomic_(add|sub|inc|dec)[64].

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent eddf0d5b

arch/s390/include/asm/atomic.h

+40 −8
Original line number Original line Diff line number Diff line
@@ -82,15 +82,31 @@ static inline int atomic_add_return(int i, atomic_t *v) 
	return __ATOMIC_LOOP(v, i, __ATOMIC_ADD) + i;

	return __ATOMIC_LOOP(v, i, __ATOMIC_ADD) + i;

}

}





#define atomic_add(_i, _v)		atomic_add_return(_i, _v)

static inline void atomic_add(int i, atomic_t *v)

{

#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES

	if (__builtin_constant_p(i) && (i > -129) && (i < 128)) {

		asm volatile(

			"asi	%0,%1\n"

			: "+Q" (v->counter)

			: "i" (i)

			: "cc", "memory");

	} else {

		atomic_add_return(i, v);

	}

#else

	atomic_add_return(i, v);

#endif

}



#define atomic_add_negative(_i, _v)	(atomic_add_return(_i, _v) < 0)

#define atomic_add_negative(_i, _v)	(atomic_add_return(_i, _v) < 0)

#define atomic_inc(_v)			atomic_add_return(1, _v)

#define atomic_inc(_v)			atomic_add(1, _v)

#define atomic_inc_return(_v)		atomic_add_return(1, _v)

#define atomic_inc_return(_v)		atomic_add_return(1, _v)

#define atomic_inc_and_test(_v)		(atomic_add_return(1, _v) == 0)

#define atomic_inc_and_test(_v)		(atomic_add_return(1, _v) == 0)

#define atomic_sub(_i, _v)		atomic_add(-(int)(_i), _v)

#define atomic_sub_return(_i, _v)	atomic_add_return(-(int)(_i), _v)

#define atomic_sub_return(_i, _v)	atomic_add_return(-(int)(_i), _v)

#define atomic_sub(_i, _v)		atomic_sub_return(_i, _v)

#define atomic_sub_and_test(_i, _v)	(atomic_sub_return(_i, _v) == 0)

#define atomic_sub_and_test(_i, _v)	(atomic_sub_return(_i, _v) == 0)

#define atomic_dec(_v)			atomic_sub_return(1, _v)

#define atomic_dec(_v)			atomic_sub(1, _v)

#define atomic_dec_return(_v)		atomic_sub_return(1, _v)

#define atomic_dec_return(_v)		atomic_sub_return(1, _v)

#define atomic_dec_and_test(_v)		(atomic_sub_return(1, _v) == 0)

#define atomic_dec_and_test(_v)		(atomic_sub_return(1, _v) == 0)
@@ -314,6 +330,23 @@ static inline void atomic64_clear_mask(unsigned long long mask, atomic64_t *v) 




#endif /* CONFIG_64BIT */

#endif /* CONFIG_64BIT */





static inline void atomic64_add(long long i, atomic64_t *v)

{

#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES

	if (__builtin_constant_p(i) && (i > -129) && (i < 128)) {

		asm volatile(

			"agsi	%0,%1\n"

			: "+Q" (v->counter)

			: "i" (i)

			: "cc", "memory");

	} else {

		atomic64_add_return(i, v);

	}

#else

	atomic64_add_return(i, v);

#endif

}



static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u)

static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u)

{

{

	long long c, old;

	long long c, old;
@@ -347,15 +380,14 @@ static inline long long atomic64_dec_if_positive(atomic64_t *v) 
	return dec;

	return dec;

}

}





#define atomic64_add(_i, _v)		atomic64_add_return(_i, _v)

#define atomic64_add_negative(_i, _v)	(atomic64_add_return(_i, _v) < 0)

#define atomic64_add_negative(_i, _v)	(atomic64_add_return(_i, _v) < 0)

#define atomic64_inc(_v)		atomic64_add_return(1, _v)

#define atomic64_inc(_v)		atomic64_add(1, _v)

#define atomic64_inc_return(_v)		atomic64_add_return(1, _v)

#define atomic64_inc_return(_v)		atomic64_add_return(1, _v)

#define atomic64_inc_and_test(_v)	(atomic64_add_return(1, _v) == 0)

#define atomic64_inc_and_test(_v)	(atomic64_add_return(1, _v) == 0)

#define atomic64_sub_return(_i, _v)	atomic64_add_return(-(long long)(_i), _v)

#define atomic64_sub_return(_i, _v)	atomic64_add_return(-(long long)(_i), _v)

#define atomic64_sub(_i, _v)		atomic64_sub_return(_i, _v)

#define atomic64_sub(_i, _v)		atomic64_add(-(long long)(_i), _v)

#define atomic64_sub_and_test(_i, _v)	(atomic64_sub_return(_i, _v) == 0)

#define atomic64_sub_and_test(_i, _v)	(atomic64_sub_return(_i, _v) == 0)

#define atomic64_dec(_v)		atomic64_sub_return(1, _v)

#define atomic64_dec(_v)		atomic64_sub(1, _v)

#define atomic64_dec_return(_v)		atomic64_sub_return(1, _v)

#define atomic64_dec_return(_v)		atomic64_sub_return(1, _v)

#define atomic64_dec_and_test(_v)	(atomic64_sub_return(1, _v) == 0)

#define atomic64_dec_and_test(_v)	(atomic64_sub_return(1, _v) == 0)

#define atomic64_inc_not_zero(v)	atomic64_add_unless((v), 1, 0)

#define atomic64_inc_not_zero(v)	atomic64_add_unless((v), 1, 0)