/*
* Copyright IBM Corp. 1999, 2011
*
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
*/
#ifndef __ASM_CMPXCHG_H
#define __ASM_CMPXCHG_H
#include <linux/types.h>
extern void __xchg_called_with_bad_pointer(void);
static inline unsigned long __xchg(unsigned long x, void *ptr, int size)
{
unsigned long addr, old;
int shift;
switch (size) {
case 1:
addr = (unsigned long) ptr;
shift = (3 ^ (addr & 3)) << 3;
addr ^= addr & 3;
asm volatile(
" l %0,%4\n"
"0: lr 0,%0\n"
" nr 0,%3\n"
" or 0,%2\n"
" cs %0,0,%4\n"
" jl 0b\n"
: "=&d" (old), "=Q" (*(int *) addr)
: "d" (x << shift), "d" (~(255 << shift)),
"Q" (*(int *) addr) : "memory", "cc", "0");
return old >> shift;
case 2:
addr = (unsigned long) ptr;
shift = (2 ^ (addr & 2)) << 3;
addr ^= addr & 2;
asm volatile(
" l %0,%4\n"
"0: lr 0,%0\n"
" nr 0,%3\n"
" or 0,%2\n"
" cs %0,0,%4\n"
" jl 0b\n"
: "=&d" (old), "=Q" (*(int *) addr)
: "d" (x << shift), "d" (~(65535 << shift)),
"Q" (*(int *) addr) : "memory", "cc", "0");
return old >> shift;
case 4:
asm volatile(
" l %0,%3\n"
"0: cs %0,%2,%3\n"
" jl 0b\n"
: "=&d" (old), "=Q" (*(int *) ptr)
: "d" (x), "Q" (*(int *) ptr)
: "memory", "cc");
return old;
#ifdef CONFIG_64BIT
case 8:
asm volatile(
" lg %0,%3\n"
"0: csg %0,%2,%3\n"
" jl 0b\n"
: "=&d" (old), "=m" (*(long *) ptr)
: "d" (x), "Q" (*(long *) ptr)
: "memory", "cc");
return old;
#endif /* CONFIG_64BIT */
}
__xchg_called_with_bad_pointer();
return x;
}
#define xchg(ptr, x) \
({ \
__typeof__(*(ptr)) __ret; \
__ret = (__typeof__(*(ptr))) \
__xchg((unsigned long)(x), (void *)(ptr), sizeof(*(ptr)));\
__ret; \
})
/*
* Atomic compare and exchange. Compare OLD with MEM, if identical,
* store NEW in MEM. Return the initial value in MEM. Success is
* indicated by comparing RETURN with OLD.
*/
#define __HAVE_ARCH_CMPXCHG
extern void __cmpxchg_called_with_bad_pointer(void);
static inline unsigned long __cmpxchg(void *ptr, unsigned long old,
unsigned long new, int size)
{
unsigned long addr, prev, tmp;
int shift;
switch (size) {
case 1:
addr = (unsigned long) ptr;
shift = (3 ^ (addr & 3)) << 3;
addr ^= addr & 3;
asm volatile(
" l %0,%2\n"
"0: nr %0,%5\n"
" lr %1,%0\n"
" or %0,%3\n"
" or %1,%4\n"
" cs %0,%1,%2\n"
" jnl 1f\n"
" xr %1,%0\n"
" nr %1,%5\n"
" jnz 0b\n"
"1:"
: "=&d" (prev), "=&d" (tmp), "=Q" (*(int *) ptr)
: "d" (old << shift), "d" (new << shift),
"d" (~(255 << shift)), "Q" (*(int *) ptr)
: "memory", "cc");
return prev >> shift;
case 2:
addr = (unsigned long) ptr;
shift = (2 ^ (addr & 2)) << 3;
addr ^= addr & 2;
asm volatile(
" l %0,%2\n"
"0: nr %0,%5\n"
" lr %1,%0\n"
" or %0,%3\n"
" or %1,%4\n"
" cs %0,%1,%2\n"
" jnl 1f\n"
" xr %1,%0\n"
" nr %1,%5\n"
" jnz 0b\n"
"1:"
: "=&d" (prev), "=&d" (tmp), "=Q" (*(int *) ptr)
: "d" (old << shift), "d" (new << shift),
"d" (~(65535 << shift)), "Q" (*(int *) ptr)
: "memory", "cc");
return prev >> shift;
case 4:
asm volatile(
" cs %0,%3,%1\n"
: "=&d" (prev), "=Q" (*(int *) ptr)
: "0" (old), "d" (new), "Q" (*(int *) ptr)
: "memory", "cc");
return prev;
#ifdef CONFIG_64BIT
case 8:
asm volatile(
" csg %0,%3,%1\n"
: "=&d" (prev), "=Q" (*(long *) ptr)
: "0" (old), "d" (new), "Q" (*(long *) ptr)
: "memory", "cc");
return prev;
#endif /* CONFIG_64BIT */
}
__cmpxchg_called_with_bad_pointer();
return old;
}
#define cmpxchg(ptr, o, n) \
((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o), \
(unsigned long)(n), sizeof(*(ptr))))
#ifdef CONFIG_64BIT
#define cmpxchg64(ptr, o, n) \
({ \
BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
cmpxchg((ptr), (o), (n)); \
})
#else /* CONFIG_64BIT */
static inline unsigned long long __cmpxchg64(void *ptr,
unsigned long long old,
unsigned long long new)
{
register_pair rp_old = {.pair = old};
register_pair rp_new = {.pair = new};
asm volatile(
" cds %0,%2,%1"
: "+&d" (rp_old), "=Q" (ptr)
: "d" (rp_new), "Q" (ptr)
: "cc");
return rp_old.pair;
}
#define cmpxchg64(ptr, o, n) \
((__typeof__(*(ptr)))__cmpxchg64((ptr), \
(unsigned long long)(o), \
(unsigned long long)(n)))
#endif /* CONFIG_64BIT */
#include <asm-generic/cmpxchg-local.h>
static inline unsigned long __cmpxchg_local(void *ptr,
unsigned long old,
unsigned long new, int size)
{
switch (size) {
case 1:
case 2:
case 4:
#ifdef CONFIG_64BIT
case 8:
#endif
return __cmpxchg(ptr, old, new, size);
default:
return __cmpxchg_local_generic(ptr, old, new, size);
}
return old;
}
/*
* cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
* them available.
*/
#define cmpxchg_local(ptr, o, n) \
((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
(unsigned long)(n), sizeof(*(ptr))))
#define cmpxchg64_local(ptr, o, n) cmpxchg64((ptr), (o), (n))
#endif /* __ASM_CMPXCHG_H */
