1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 #ifndef _UAPI_ASM_IA64_CMPXCHG_H
3 #define _UAPI_ASM_IA64_CMPXCHG_H
6 * Compare/Exchange, forked from asm/intrinsics.h
9 * Copyright (C) 2002-2003 Hewlett-Packard Co
10 * David Mosberger-Tang <davidm@hpl.hp.com>
15 #include <linux/types.h>
16 /* include compiler specific intrinsics */
17 #include <asm/ia64regs.h>
18 #ifdef __INTEL_COMPILER
19 # include <asm/intel_intrin.h>
21 # include <asm/gcc_intrin.h>
25 * This function doesn't exist, so you'll get a linker error if
26 * something tries to do an invalid xchg().
28 extern void ia64_xchg_called_with_bad_pointer(void);
30 #define __xchg(x, ptr, size) \
32 unsigned long __xchg_result; \
36 __xchg_result = ia64_xchg1((__u8 __force *)ptr, x); \
40 __xchg_result = ia64_xchg2((__u16 __force *)ptr, x); \
44 __xchg_result = ia64_xchg4((__u32 __force *)ptr, x); \
48 __xchg_result = ia64_xchg8((__u64 __force *)ptr, x); \
51 ia64_xchg_called_with_bad_pointer(); \
53 (__typeof__ (*(ptr)) __force) __xchg_result; \
57 #define xchg(ptr, x) \
58 ({(__typeof__(*(ptr))) __xchg((unsigned long) (x), (ptr), sizeof(*(ptr)));})
62 * Atomic compare and exchange. Compare OLD with MEM, if identical,
63 * store NEW in MEM. Return the initial value in MEM. Success is
64 * indicated by comparing RETURN with OLD.
68 * This function doesn't exist, so you'll get a linker error
69 * if something tries to do an invalid cmpxchg().
71 extern long ia64_cmpxchg_called_with_bad_pointer(void);
73 #define ia64_cmpxchg(sem, ptr, old, new, size) \
79 _o_ = (__u8) (long __force) (old); \
82 _o_ = (__u16) (long __force) (old); \
85 _o_ = (__u32) (long __force) (old); \
88 _o_ = (__u64) (long __force) (old); \
95 _r_ = ia64_cmpxchg1_##sem((__u8 __force *) ptr, new, _o_); \
99 _r_ = ia64_cmpxchg2_##sem((__u16 __force *) ptr, new, _o_); \
103 _r_ = ia64_cmpxchg4_##sem((__u32 __force *) ptr, new, _o_); \
107 _r_ = ia64_cmpxchg8_##sem((__u64 __force *) ptr, new, _o_); \
111 _r_ = ia64_cmpxchg_called_with_bad_pointer(); \
114 (__typeof__(old) __force) _r_; \
117 #define cmpxchg_acq(ptr, o, n) \
118 ia64_cmpxchg(acq, (ptr), (o), (n), sizeof(*(ptr)))
119 #define cmpxchg_rel(ptr, o, n) \
120 ia64_cmpxchg(rel, (ptr), (o), (n), sizeof(*(ptr)))
123 * Worse still - early processor implementations actually just ignored
124 * the acquire/release and did a full fence all the time. Unfortunately
125 * this meant a lot of badly written code that used .acq when they really
126 * wanted .rel became legacy out in the wild - so when we made a cpu
127 * that strictly did the .acq or .rel ... all that code started breaking - so
128 * we had to back-pedal and keep the "legacy" behavior of a full fence :-(
132 /* for compatibility with other platforms: */
133 #define cmpxchg(ptr, o, n) cmpxchg_acq((ptr), (o), (n))
134 #define cmpxchg64(ptr, o, n) cmpxchg_acq((ptr), (o), (n))
136 #define cmpxchg_local cmpxchg
137 #define cmpxchg64_local cmpxchg64
140 #ifdef CONFIG_IA64_DEBUG_CMPXCHG
141 # define CMPXCHG_BUGCHECK_DECL int _cmpxchg_bugcheck_count = 128;
142 # define CMPXCHG_BUGCHECK(v) \
144 if (_cmpxchg_bugcheck_count-- <= 0) { \
146 extern int _printk(const char *fmt, ...); \
147 ip = (void *) ia64_getreg(_IA64_REG_IP); \
148 _printk("CMPXCHG_BUGCHECK: stuck at %p on word %p\n", ip, (v));\
152 #else /* !CONFIG_IA64_DEBUG_CMPXCHG */
153 # define CMPXCHG_BUGCHECK_DECL
154 # define CMPXCHG_BUGCHECK(v)
155 #endif /* !CONFIG_IA64_DEBUG_CMPXCHG */
157 #endif /* !__ASSEMBLY__ */
159 #endif /* _UAPI_ASM_IA64_CMPXCHG_H */