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#ifndef __ARCH_S390_ATOMIC__
#define __ARCH_S390_ATOMIC__
/*
* include/asm-s390/atomic.h
*
* S390 version
* Copyright (C) 1999-2003 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 {
volatile int counter;
} __attribute__ ((aligned (4))) atomic_t;
#define ATOMIC_INIT(i) { (i) }
#ifdef __KERNEL__
#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; \
})
#define atomic_read(v) ((v)->counter)
#define atomic_set(v,i) (((v)->counter) = (i))
static __inline__ void atomic_add(int i, atomic_t * v)
{
__CS_LOOP(v, i, "ar");
}
static __inline__ int atomic_add_return(int i, atomic_t * v)
{
return __CS_LOOP(v, i, "ar");
}
static __inline__ int atomic_add_negative(int i, atomic_t * v)
{
return __CS_LOOP(v, i, "ar") < 0;
}
static __inline__ void atomic_sub(int i, atomic_t * v)
{
__CS_LOOP(v, i, "sr");
}
static __inline__ int atomic_sub_return(int i, atomic_t * v)
{
return __CS_LOOP(v, i, "sr");
}
static __inline__ void atomic_inc(volatile atomic_t * v)
{
__CS_LOOP(v, 1, "ar");
}
static __inline__ int atomic_inc_return(volatile atomic_t * v)
{
return __CS_LOOP(v, 1, "ar");
}
static __inline__ int atomic_inc_and_test(volatile atomic_t * v)
{
return __CS_LOOP(v, 1, "ar") == 0;
}
static __inline__ void atomic_dec(volatile atomic_t * v)
{
__CS_LOOP(v, 1, "sr");
}
static __inline__ int atomic_dec_return(volatile atomic_t * v)
{
return __CS_LOOP(v, 1, "sr");
}
static __inline__ int atomic_dec_and_test(volatile atomic_t * v)
{
return __CS_LOOP(v, 1, "sr") == 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");
}
#undef __CS_LOOP
#ifdef __s390x__
typedef struct {
volatile long long counter;
} __attribute__ ((aligned (8))) atomic64_t;
#define ATOMIC64_INIT(i) { (i) }
#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; \
})
#define atomic64_read(v) ((v)->counter)
#define atomic64_set(v,i) (((v)->counter) = (i))
static __inline__ void atomic64_add(long long i, atomic64_t * v)
{
__CSG_LOOP(v, i, "agr");
}
static __inline__ long long atomic64_add_return(long long i, atomic64_t * v)
{
return __CSG_LOOP(v, i, "agr");
}
static __inline__ long long atomic64_add_negative(long long i, atomic64_t * v)
{
return __CSG_LOOP(v, i, "agr") < 0;
}
static __inline__ void atomic64_sub(long long i, atomic64_t * v)
{
__CSG_LOOP(v, i, "sgr");
}
static __inline__ void atomic64_inc(volatile atomic64_t * v)
{
__CSG_LOOP(v, 1, "agr");
}
static __inline__ long long atomic64_inc_return(volatile atomic64_t * v)
{
return __CSG_LOOP(v, 1, "agr");
}
static __inline__ long long atomic64_inc_and_test(volatile atomic64_t * v)
{
return __CSG_LOOP(v, 1, "agr") == 0;
}
static __inline__ void atomic64_dec(volatile atomic64_t * v)
{
__CSG_LOOP(v, 1, "sgr");
}
static __inline__ long long atomic64_dec_return(volatile atomic64_t * v)
{
return __CSG_LOOP(v, 1, "sgr");
}
static __inline__ long long atomic64_dec_and_test(volatile atomic64_t * v)
{
return __CSG_LOOP(v, 1, "sgr") == 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");
}
#undef __CSG_LOOP
#endif
/*
returns 0 if expected_oldval==value in *v ( swap was successful )
returns 1 if unsuccessful.
This is non-portable, use bitops or spinlocks instead!
*/
static __inline__ int
atomic_compare_and_swap(int expected_oldval,int new_val,atomic_t *v)
{
int retval;
__asm__ __volatile__(
" lr %0,%3\n"
" cs %0,%4,0(%2)\n"
" ipm %0\n"
" srl %0,28\n"
"0:"
: "=&d" (retval), "=m" (v->counter)
: "a" (v), "d" (expected_oldval) , "d" (new_val),
"m" (v->counter) : "cc", "memory" );
return retval;
}
#define atomic_cmpxchg(v, o, n) (atomic_compare_and_swap((o), (n), &((v)->counter)))
#define atomic_add_unless(v, a, u) \
({ \
int c, old; \
c = atomic_read(v); \
while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \
c = old; \
c != (u); \
})
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
#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()
#endif /* __KERNEL__ */
#endif /* __ARCH_S390_ATOMIC__ */
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