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linux/include/asm-s390/atomic.h
Heiko Carstens c51b962179 [S390] Change atomic_read/set to inline functions with barrier semantics. 
After doing some tests this seems to be the best variant for s390 and
should be correct as well. With gcc 4.2.1 we get the following kernel
image sizes using the default configuration:

atomic_t type volatile, atomic_read/set defines   5311824 bytes
atomic_t type int, atomic_read/set defines        5270864 bytes
atomic_t type int, atomic_read/set inline asm     5279056 bytes
atomic_t type int, atomic_read/set inline barrier 5270864 bytes

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2007-08-22 13:51:49 +02:00

286 lines
7.1 KiB
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#ifndef __ARCH_S390_ATOMIC__
#define __ARCH_S390_ATOMIC__
#include <linux/compiler.h>
/*
* include/asm-s390/atomic.h
*
* S390 version
* Copyright (C) 1999-2005 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
* Denis Joseph Barrow,
* Arnd Bergmann (arndb@de.ibm.com)
*
* Derived from "include/asm-i386/bitops.h"
* Copyright (C) 1992, Linus Torvalds
*
*/
/*
* Atomic operations that C can't guarantee us. Useful for
* resource counting etc..
* S390 uses 'Compare And Swap' for atomicity in SMP enviroment
*/
typedef struct {
int counter;
} __attribute__ ((aligned (4))) atomic_t;
#define ATOMIC_INIT(i) { (i) }
#ifdef __KERNEL__
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
#define __CS_LOOP(ptr, op_val, op_string) ({ \
typeof(ptr->counter) old_val, new_val; \
asm volatile( \
" l %0,%2\n" \
"0: lr %1,%0\n" \
op_string " %1,%3\n" \
" cs %0,%1,%2\n" \
" jl 0b" \
: "=&d" (old_val), "=&d" (new_val), \
"=Q" (((atomic_t *)(ptr))->counter) \
: "d" (op_val), "Q" (((atomic_t *)(ptr))->counter) \
: "cc", "memory"); \
new_val; \
})
#else /* __GNUC__ */
#define __CS_LOOP(ptr, op_val, op_string) ({ \
typeof(ptr->counter) old_val, new_val; \
asm volatile( \
" l %0,0(%3)\n" \
"0: lr %1,%0\n" \
op_string " %1,%4\n" \
" cs %0,%1,0(%3)\n" \
" jl 0b" \
: "=&d" (old_val), "=&d" (new_val), \
"=m" (((atomic_t *)(ptr))->counter) \
: "a" (ptr), "d" (op_val), \
"m" (((atomic_t *)(ptr))->counter) \
: "cc", "memory"); \
new_val; \
})
#endif /* __GNUC__ */
static inline int atomic_read(const atomic_t *v)
{
barrier();
return v->counter;
}
static inline void atomic_set(atomic_t *v, int i)
{
v->counter = i;
barrier();
}
static __inline__ int atomic_add_return(int i, atomic_t * v)
{
return __CS_LOOP(v, i, "ar");
}
#define atomic_add(_i, _v) atomic_add_return(_i, _v)
#define atomic_add_negative(_i, _v) (atomic_add_return(_i, _v) < 0)
#define atomic_inc(_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)
static __inline__ int atomic_sub_return(int i, atomic_t * v)
{
return __CS_LOOP(v, i, "sr");
}
#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_dec(_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)
static __inline__ void atomic_clear_mask(unsigned long mask, atomic_t * v)
{
__CS_LOOP(v, ~mask, "nr");
}
static __inline__ void atomic_set_mask(unsigned long mask, atomic_t * v)
{
__CS_LOOP(v, mask, "or");
}
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
static __inline__ int atomic_cmpxchg(atomic_t *v, int old, int new)
{
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
asm volatile(
" cs %0,%2,%1"
: "+d" (old), "=Q" (v->counter)
: "d" (new), "Q" (v->counter)
: "cc", "memory");
#else /* __GNUC__ */
asm volatile(
" cs %0,%3,0(%2)"
: "+d" (old), "=m" (v->counter)
: "a" (v), "d" (new), "m" (v->counter)
: "cc", "memory");
#endif /* __GNUC__ */
return old;
}
static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
{
int c, old;
c = atomic_read(v);
for (;;) {
if (unlikely(c == u))
break;
old = atomic_cmpxchg(v, c, c + a);
if (likely(old == c))
break;
c = old;
}
return c != u;
}
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
#undef __CS_LOOP
#ifdef __s390x__
typedef struct {
long long counter;
} __attribute__ ((aligned (8))) atomic64_t;
#define ATOMIC64_INIT(i) { (i) }
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
#define __CSG_LOOP(ptr, op_val, op_string) ({ \
typeof(ptr->counter) old_val, new_val; \
asm volatile( \
" lg %0,%2\n" \
"0: lgr %1,%0\n" \
op_string " %1,%3\n" \
" csg %0,%1,%2\n" \
" jl 0b" \
: "=&d" (old_val), "=&d" (new_val), \
"=Q" (((atomic_t *)(ptr))->counter) \
: "d" (op_val), "Q" (((atomic_t *)(ptr))->counter) \
: "cc", "memory" ); \
new_val; \
})
#else /* __GNUC__ */
#define __CSG_LOOP(ptr, op_val, op_string) ({ \
typeof(ptr->counter) old_val, new_val; \
asm volatile( \
" lg %0,0(%3)\n" \
"0: lgr %1,%0\n" \
op_string " %1,%4\n" \
" csg %0,%1,0(%3)\n" \
" jl 0b" \
: "=&d" (old_val), "=&d" (new_val), \
"=m" (((atomic_t *)(ptr))->counter) \
: "a" (ptr), "d" (op_val), \
"m" (((atomic_t *)(ptr))->counter) \
: "cc", "memory" ); \
new_val; \
})
#endif /* __GNUC__ */
static inline long long atomic64_read(const atomic64_t *v)
{
barrier();
return v->counter;
}
static inline void atomic64_set(atomic64_t *v, long long i)
{
v->counter = i;
barrier();
}
static __inline__ long long atomic64_add_return(long long i, atomic64_t * v)
{
return __CSG_LOOP(v, i, "agr");
}
#define atomic64_add(_i, _v) atomic64_add_return(_i, _v)
#define atomic64_add_negative(_i, _v) (atomic64_add_return(_i, _v) < 0)
#define atomic64_inc(_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)
static __inline__ long long atomic64_sub_return(long long i, atomic64_t * v)
{
return __CSG_LOOP(v, i, "sgr");
}
#define atomic64_sub(_i, _v) atomic64_sub_return(_i, _v)
#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_return(_v) atomic64_sub_return(1, _v)
#define atomic64_dec_and_test(_v) (atomic64_sub_return(1, _v) == 0)
static __inline__ void atomic64_clear_mask(unsigned long mask, atomic64_t * v)
{
__CSG_LOOP(v, ~mask, "ngr");
}
static __inline__ void atomic64_set_mask(unsigned long mask, atomic64_t * v)
{
__CSG_LOOP(v, mask, "ogr");
}
#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
static __inline__ long long atomic64_cmpxchg(atomic64_t *v,
long long old, long long new)
{
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
asm volatile(
" csg %0,%2,%1"
: "+d" (old), "=Q" (v->counter)
: "d" (new), "Q" (v->counter)
: "cc", "memory");
#else /* __GNUC__ */
asm volatile(
" csg %0,%3,0(%2)"
: "+d" (old), "=m" (v->counter)
: "a" (v), "d" (new), "m" (v->counter)
: "cc", "memory");
#endif /* __GNUC__ */
return old;
}
static __inline__ int atomic64_add_unless(atomic64_t *v,
long long a, long long u)
{
long 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_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
#undef __CSG_LOOP
#endif
#define smp_mb__before_atomic_dec() smp_mb()
#define smp_mb__after_atomic_dec() smp_mb()
#define smp_mb__before_atomic_inc() smp_mb()
#define smp_mb__after_atomic_inc() smp_mb()
#include <asm-generic/atomic.h>
#endif /* __KERNEL__ */
#endif /* __ARCH_S390_ATOMIC__ */
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