#ifndef __ARCH_S390_ATOMIC__
#define __ARCH_S390_ATOMIC__
/*
* include/asm-s390/atomic.h
*
* S390 version
* Copyright (C) 1999 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; } atomic_t __attribute__ ((aligned (4)));
#define ATOMIC_INIT(i) { (i) }
#define atomic_eieio() __asm__ __volatile__ ("BCR 15,0")
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)
{
__asm__ __volatile__(" la 2,%0\n"
" l 0,%0\n"
"0: lr 1,0\n"
" ar 1,%1\n"
" cs 0,1,0(2)\n"
" jl 0b"
: "+m" (*v) : "d" (i) : "0", "1", "2", "cc" );
}
static __inline__ void atomic_sub(int i, atomic_t *v)
{
__asm__ __volatile__(" la 2,%0\n"
" l 0,%0\n"
"0: lr 1,0\n"
" sr 1,%1\n"
" cs 0,1,0(2)\n"
" jl 0b"
: "+m" (*v) : "d" (i) : "0", "1", "2", "cc" );
}
static __inline__ void atomic_inc(volatile atomic_t *v)
{
__asm__ __volatile__(" la 2,%0\n"
" l 0,%0\n"
"0: lr 1,0\n"
" ahi 1,1\n"
" cs 0,1,0(2)\n"
" jl 0b"
: "+m" (*v) : : "0", "1", "2", "cc" );
}
static __inline__ int atomic_inc_return(volatile atomic_t *v)
{
int i;
__asm__ __volatile__(" la 1,%0\n"
" l 0,%0\n"
"0: lr %1,0\n"
" ahi %1,1\n"
" cs 0,%1,0(1)\n"
" jl 0b"
: "+m" (*v), "=&d" (i) : : "0", "1", "cc" );
return i;
}
static __inline__ void atomic_dec(volatile atomic_t *v)
{
__asm__ __volatile__(" la 2,%0\n"
" l 0,%0\n"
"0: lr 1,0\n"
" ahi 1,-1\n"
" cs 0,1,0(2)\n"
" jl 0b"
: "+m" (*v) : : "0", "1", "2", "cc" );
}
static __inline__ int atomic_dec_return(volatile atomic_t *v)
{
int i;
__asm__ __volatile__(" la 1,%0\n"
" l 0,%0\n"
"0: lr %1,0\n"
" ahi %1,-1\n"
" cs 0,%1,0(1)\n"
" jl 0b"
: "+m" (*v), "=&d" (i) : : "0", "1", "cc" );
return i;
}
static __inline__ int atomic_dec_and_test(volatile atomic_t *v)
{
int i;
__asm__ __volatile__(" la 1,%0\n"
" l 0,%0\n"
"0: lr %1,0\n"
" ahi %1,-1\n"
" cs 0,%1,0(1)\n"
" jl 0b"
: "+m" (*v), "=&d" (i) : : "0", "1", "cc");
return i == 0;
}
static __inline__ void atomic_clear_mask(unsigned long mask, atomic_t *v)
{
__asm__ __volatile__(" la 2,%0\n"
" l 0,%0\n"
"0: lr 1,0\n"
" nr 1,%1\n"
" cs 0,1,0(2)\n"
" jl 0b"
: "+m" (*v) : "d" (~(mask)) : "0", "1", "2", "cc" );
}
static __inline__ void atomic_set_mask(unsigned long mask, atomic_t *v)
{
__asm__ __volatile__(" la 2,%0\n"
" l 0,%0\n"
"0: lr 1,0\n"
" or 1,%1\n"
" cs 0,1,0(2)\n"
" jl 0b"
: "+m" (*v) : "d" (mask) : "0", "1", "2", "cc" );
}
/*
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__(
" la 1,%1\n"
" lr 0,%2\n"
" cs 0,%3,0(1)\n"
" ipm %0\n"
" srl %0,28\n"
"0:"
: "=&r" (retval), "+m" (*v)
: "d" (expected_oldval) , "d" (new_val)
: "0", "1", "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__(
" la 2,%0\n"
"0: lr 1,%1\n"
" cs 1,%2,0(2)\n"
" jl 0b\n"
: "+m" (*v)
: "d" (expected_oldval) , "d" (new_val)
: "cc", "1", "2");
}
/*
* Increase and test if atomic counter > 0
*/
extern __inline__ int atomic_inc_and_test_greater_zero(atomic_t *v)
{
int i;
__asm__ __volatile__(" la 1,%0\n"
" l 0,%0\n"
"0: lr %1,0\n"
" ahi %1,1\n"
" cs 0,%1,0(1)\n"
" jl 0b"
: "+m" (*v), "=&d" (i) : : "0", "1", "cc" );
return i > 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));\
}
#endif /* __ARCH_S390_ATOMIC __ */
