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#ifndef __ARCH_S390_ATOMIC__
#define __ARCH_S390_ATOMIC__
/*
* include/asm-s390x/atomic.h
*
* S390 version
* Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
* Denis Joseph Barrow
*
* 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) }
#define atomic_eieio() __asm__ __volatile__ ("BCR 15,0")
#define __CS_LOOP(old_val, new_val, ptr, op_val, op_string) \
__asm__ __volatile__(" l %0,0(%2)\n" \
"0: lr %1,%0\n" \
op_string " %1,%3\n" \
" cs %0,%1,0(%2)\n" \
" jl 0b" \
: "=&d" (old_val), "=&d" (new_val) \
: "a" (ptr), "d" (op_val) : "cc" );
static __inline__ int atomic_read(atomic_t *v)
{
int retval;
__asm__ __volatile__("bcr 15,0\n\t"
"l %0,%1"
: "=d" (retval) : "m" (*v) );
return retval;
}
static __inline__ void atomic_set(atomic_t *v, int i)
{
__asm__ __volatile__("st %1,%0\n\t"
"bcr 15,0"
: "=m" (*v) : "d" (i) );
}
static __inline__ void atomic_add(int i, atomic_t *v)
{
int old_val, new_val;
__CS_LOOP(old_val, new_val, v, i, "ar");
}
static __inline__ int atomic_add_return (int i, atomic_t *v)
{
int old_val, new_val;
__CS_LOOP(old_val, new_val, v, i, "ar");
return new_val;
}
static __inline__ int atomic_add_negative(int i, atomic_t *v)
{
int old_val, new_val;
__CS_LOOP(old_val, new_val, v, i, "ar");
return new_val < 0;
}
static __inline__ void atomic_sub(int i, atomic_t *v)
{
int old_val, new_val;
__CS_LOOP(old_val, new_val, v, i, "sr");
}
static __inline__ void atomic_inc(volatile atomic_t *v)
{
int old_val, new_val;
__CS_LOOP(old_val, new_val, v, 1, "ar");
}
static __inline__ int atomic_inc_return(volatile atomic_t *v)
{
int old_val, new_val;
__CS_LOOP(old_val, new_val, v, 1, "ar");
return new_val;
}
static __inline__ int atomic_inc_and_test(volatile atomic_t *v)
{
int old_val, new_val;
__CS_LOOP(old_val, new_val, v, 1, "ar");
return new_val != 0;
}
static __inline__ void atomic_dec(volatile atomic_t *v)
{
int old_val, new_val;
__CS_LOOP(old_val, new_val, v, 1, "sr");
}
static __inline__ int atomic_dec_return(volatile atomic_t *v)
{
int old_val, new_val;
__CS_LOOP(old_val, new_val, v, 1, "sr");
return new_val;
}
static __inline__ int atomic_dec_and_test(volatile atomic_t *v)
{
int old_val, new_val;
__CS_LOOP(old_val, new_val, v, 1, "sr");
return new_val == 0;
}
static __inline__ void atomic_clear_mask(unsigned long mask, atomic_t *v)
{
int old_val, new_val;
__CS_LOOP(old_val, new_val, v, ~mask, "nr");
}
static __inline__ void atomic_set_mask(unsigned long mask, atomic_t *v)
{
int old_val, new_val;
__CS_LOOP(old_val, new_val, v, mask, "or");
}
/*
returns 0 if expected_oldval==value in *v ( swap was successful )
returns 1 if unsuccessful.
*/
static __inline__ int
atomic_compare_and_swap(int expected_oldval,int new_val,atomic_t *v)
{
int retval;
__asm__ __volatile__(
" lr 0,%2\n"
" cs 0,%3,0(%1)\n"
" ipm %0\n"
" srl %0,28\n"
"0:"
: "=&d" (retval)
: "a" (v), "d" (expected_oldval) , "d" (new_val)
: "0", "cc");
return retval;
}
/*
Spin till *v = expected_oldval then swap with newval.
*/
static __inline__ void
atomic_compare_and_swap_spin(int expected_oldval,int new_val,atomic_t *v)
{
__asm__ __volatile__(
"0: lr 0,%1\n"
" cs 0,%2,0(%0)\n"
" jl 0b\n"
: : "a" (v), "d" (expected_oldval) , "d" (new_val)
: "cc", "0" );
}
#define atomic_compare_and_swap_debug(where,from,to) \
if (atomic_compare_and_swap ((from), (to), (where))) {\
printk (KERN_WARNING"%s/%d atomic counter:%s couldn't be changed from %d(%s) to %d(%s), was %d\n",\
__FILE__,__LINE__,#where,(from),#from,(to),#to,atomic_read (where));\
atomic_set(where,(to));\
}
#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 /* __ARCH_S390_ATOMIC __ */
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