#ifndef _ASM_IA64_CMPXCHG_H
#define _ASM_IA64_CMPXCHG_H
/*
* Compare/Exchange, forked from asm/intrinsics.h
* which was:
*
* Copyright (C) 2002-2003 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*/
#ifndef __ASSEMBLY__
#include <linux/types.h>
/* include compiler specific intrinsics */
#include <asm/ia64regs.h>
#ifdef __INTEL_COMPILER
# include <asm/intel_intrin.h>
#else
# include <asm/gcc_intrin.h>
#endif
/*
* This function doesn't exist, so you'll get a linker error if
* something tries to do an invalid xchg().
*/
extern void ia64_xchg_called_with_bad_pointer(void);
#define __xchg(x, ptr, size) \
({ \
unsigned long __xchg_result; \
\
switch (size) { \
case 1: \
__xchg_result = ia64_xchg1((__u8 *)ptr, x); \
break; \
\
case 2: \
__xchg_result = ia64_xchg2((__u16 *)ptr, x); \
break; \
\
case 4: \
__xchg_result = ia64_xchg4((__u32 *)ptr, x); \
break; \
\
case 8: \
__xchg_result = ia64_xchg8((__u64 *)ptr, x); \
break; \
default: \
ia64_xchg_called_with_bad_pointer(); \
} \
__xchg_result; \
})
#define xchg(ptr, x) \
((__typeof__(*(ptr))) __xchg((unsigned long) (x), (ptr), sizeof(*(ptr))))
/*
* 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.
*/
/*
* This function doesn't exist, so you'll get a linker error
* if something tries to do an invalid cmpxchg().
*/
extern long ia64_cmpxchg_called_with_bad_pointer(void);
#define ia64_cmpxchg(sem, ptr, old, new, size) \
({ \
__u64 _o_, _r_; \
\
switch (size) { \
case 1: \
_o_ = (__u8) (long) (old); \
break; \
case 2: \
_o_ = (__u16) (long) (old); \
break; \
case 4: \
_o_ = (__u32) (long) (old); \
break; \
case 8: \
_o_ = (__u64) (long) (old); \
break; \
default: \
break; \
} \
switch (size) { \
case 1: \
_r_ = ia64_cmpxchg1_##sem((__u8 *) ptr, new, _o_); \
break; \
\
case 2: \
_r_ = ia64_cmpxchg2_##sem((__u16 *) ptr, new, _o_); \
break; \
\
case 4: \
_r_ = ia64_cmpxchg4_##sem((__u32 *) ptr, new, _o_); \
break; \
\
case 8: \
_r_ = ia64_cmpxchg8_##sem((__u64 *) ptr, new, _o_); \
break; \
\
default: \
_r_ = ia64_cmpxchg_called_with_bad_pointer(); \
break; \
} \
(__typeof__(old)) _r_; \
})
#define cmpxchg_acq(ptr, o, n) \
ia64_cmpxchg(acq, (ptr), (o), (n), sizeof(*(ptr)))
#define cmpxchg_rel(ptr, o, n) \
ia64_cmpxchg(rel, (ptr), (o), (n), sizeof(*(ptr)))
/*
* Worse still - early processor implementations actually just ignored
* the acquire/release and did a full fence all the time. Unfortunately
* this meant a lot of badly written code that used .acq when they really
* wanted .rel became legacy out in the wild - so when we made a cpu
* that strictly did the .acq or .rel ... all that code started breaking - so
* we had to back-pedal and keep the "legacy" behavior of a full fence :-(
*/
/* for compatibility with other platforms: */
#define cmpxchg(ptr, o, n) cmpxchg_acq((ptr), (o), (n))
#define cmpxchg64(ptr, o, n) cmpxchg_acq((ptr), (o), (n))
#define cmpxchg_local cmpxchg
#define cmpxchg64_local cmpxchg64
#ifdef CONFIG_IA64_DEBUG_CMPXCHG
# define CMPXCHG_BUGCHECK_DECL int _cmpxchg_bugcheck_count = 128;
# define CMPXCHG_BUGCHECK(v) \
do { \
if (_cmpxchg_bugcheck_count-- <= 0) { \
void *ip; \
extern int printk(const char *fmt, ...); \
ip = (void *) ia64_getreg(_IA64_REG_IP); \
printk("CMPXCHG_BUGCHECK: stuck at %p on word %p\n", ip, (v));\
break; \
} \
} while (0)
#else /* !CONFIG_IA64_DEBUG_CMPXCHG */
# define CMPXCHG_BUGCHECK_DECL
# define CMPXCHG_BUGCHECK(v)
#endif /* !CONFIG_IA64_DEBUG_CMPXCHG */
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_IA64_CMPXCHG_H */
