FreeBSD-5.3/sys/i386/include/atomic.h
/*-
* Copyright (c) 1998 Doug Rabson
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD: src/sys/i386/include/atomic.h,v 1.32 2004/03/12 21:45:29 trhodes Exp $
*/
#ifndef _MACHINE_ATOMIC_H_
#define _MACHINE_ATOMIC_H_
/*
* Various simple arithmetic on memory which is atomic in the presence
* of interrupts and multiple processors.
*
* atomic_set_char(P, V) (*(u_char*)(P) |= (V))
* atomic_clear_char(P, V) (*(u_char*)(P) &= ~(V))
* atomic_add_char(P, V) (*(u_char*)(P) += (V))
* atomic_subtract_char(P, V) (*(u_char*)(P) -= (V))
*
* atomic_set_short(P, V) (*(u_short*)(P) |= (V))
* atomic_clear_short(P, V) (*(u_short*)(P) &= ~(V))
* atomic_add_short(P, V) (*(u_short*)(P) += (V))
* atomic_subtract_short(P, V) (*(u_short*)(P) -= (V))
*
* atomic_set_int(P, V) (*(u_int*)(P) |= (V))
* atomic_clear_int(P, V) (*(u_int*)(P) &= ~(V))
* atomic_add_int(P, V) (*(u_int*)(P) += (V))
* atomic_subtract_int(P, V) (*(u_int*)(P) -= (V))
* atomic_readandclear_int(P) (return *(u_int*)P; *(u_int*)P = 0;)
*
* atomic_set_long(P, V) (*(u_long*)(P) |= (V))
* atomic_clear_long(P, V) (*(u_long*)(P) &= ~(V))
* atomic_add_long(P, V) (*(u_long*)(P) += (V))
* atomic_subtract_long(P, V) (*(u_long*)(P) -= (V))
* atomic_readandclear_long(P) (return *(u_long*)P; *(u_long*)P = 0;)
*/
/*
* The above functions are expanded inline in the statically-linked
* kernel. Lock prefixes are generated if an SMP kernel is being
* built.
*
* Kernel modules call real functions which are built into the kernel.
* This allows kernel modules to be portable between UP and SMP systems.
*/
#if defined(KLD_MODULE)
#define ATOMIC_ASM(NAME, TYPE, OP, CONS, V) \
void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
int atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src);
#define ATOMIC_STORE_LOAD(TYPE, LOP, SOP) \
u_##TYPE atomic_load_acq_##TYPE(volatile u_##TYPE *p); \
void atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
#else /* !KLD_MODULE */
#if defined(__GNUC__) || defined(__INTEL_COMPILER)
/*
* For userland, assume the SMP case and use lock prefixes so that
* the binaries will run on both types of systems.
*/
#if defined(SMP) || !defined(_KERNEL)
#define MPLOCKED lock ;
#else
#define MPLOCKED
#endif
/*
* The assembly is volatilized to demark potential before-and-after side
* effects if an interrupt or SMP collision were to occur.
*/
#define ATOMIC_ASM(NAME, TYPE, OP, CONS, V) \
static __inline void \
atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
{ \
__asm __volatile(__XSTRING(MPLOCKED) OP \
: "+m" (*p) \
: CONS (V)); \
} \
struct __hack
#else /* !(__GNUC__ || __INTEL_COMPILER) */
#define ATOMIC_ASM(NAME, TYPE, OP, CONS, V) \
extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
#endif /* __GNUC__ || __INTEL_COMPILER */
/*
* Atomic compare and set, used by the mutex functions
*
* if (*dst == exp) *dst = src (all 32 bit words)
*
* Returns 0 on failure, non-zero on success
*/
#if defined(__GNUC__) || defined(__INTEL_COMPILER)
#if defined(I386_CPU) || defined(CPU_DISABLE_CMPXCHG)
static __inline int
atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
{
int res = exp;
__asm __volatile(
" pushfl ; "
" cli ; "
" cmpl %0,%2 ; "
" jne 1f ; "
" movl %1,%2 ; "
"1: "
" sete %%al; "
" movzbl %%al,%0 ; "
" popfl ; "
"# atomic_cmpset_int"
: "+a" (res) /* 0 (result) */
: "r" (src), /* 1 */
"m" (*(dst)) /* 2 */
: "memory");
return (res);
}
#else /* defined(I386_CPU) */
static __inline int
atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
{
int res = exp;
__asm __volatile (
" " __XSTRING(MPLOCKED) " "
" cmpxchgl %1,%2 ; "
" setz %%al ; "
" movzbl %%al,%0 ; "
"1: "
"# atomic_cmpset_int"
: "+a" (res) /* 0 (result) */
: "r" (src), /* 1 */
"m" (*(dst)) /* 2 */
: "memory");
return (res);
}
#endif /* defined(I386_CPU) */
#endif /* defined(__GNUC__) || defined(__INTEL_COMPILER) */
#if defined(__GNUC__) || defined(__INTEL_COMPILER)
#if defined(I386_CPU)
/*
* We assume that a = b will do atomic loads and stores.
*
* XXX: This is _NOT_ safe on a P6 or higher because it does not guarantee
* memory ordering. These should only be used on a 386.
*/
#define ATOMIC_STORE_LOAD(TYPE, LOP, SOP) \
static __inline u_##TYPE \
atomic_load_acq_##TYPE(volatile u_##TYPE *p) \
{ \
return (*p); \
} \
\
static __inline void \
atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
{ \
*p = v; \
__asm __volatile("" : : : "memory"); \
} \
struct __hack
#else /* !defined(I386_CPU) */
#define ATOMIC_STORE_LOAD(TYPE, LOP, SOP) \
static __inline u_##TYPE \
atomic_load_acq_##TYPE(volatile u_##TYPE *p) \
{ \
u_##TYPE res; \
\
__asm __volatile(__XSTRING(MPLOCKED) LOP \
: "=a" (res), /* 0 (result) */\
"+m" (*p) /* 1 */ \
: : "memory"); \
\
return (res); \
} \
\
/* \
* The XCHG instruction asserts LOCK automagically. \
*/ \
static __inline void \
atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
{ \
__asm __volatile(SOP \
: "+m" (*p), /* 0 */ \
"+r" (v) /* 1 */ \
: : "memory"); \
} \
struct __hack
#endif /* defined(I386_CPU) */
#else /* !(defined(__GNUC__) || defined(__INTEL_COMPILER)) */
extern int atomic_cmpset_int(volatile u_int *, u_int, u_int);
#define ATOMIC_STORE_LOAD(TYPE, LOP, SOP) \
extern u_##TYPE atomic_load_acq_##TYPE(volatile u_##TYPE *p); \
extern void atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
#endif /* defined(__GNUC__) || defined(__INTEL_COMPILER) */
#endif /* KLD_MODULE */
ATOMIC_ASM(set, char, "orb %b1,%0", "iq", v);
ATOMIC_ASM(clear, char, "andb %b1,%0", "iq", ~v);
ATOMIC_ASM(add, char, "addb %b1,%0", "iq", v);
ATOMIC_ASM(subtract, char, "subb %b1,%0", "iq", v);
ATOMIC_ASM(set, short, "orw %w1,%0", "ir", v);
ATOMIC_ASM(clear, short, "andw %w1,%0", "ir", ~v);
ATOMIC_ASM(add, short, "addw %w1,%0", "ir", v);
ATOMIC_ASM(subtract, short, "subw %w1,%0", "ir", v);
ATOMIC_ASM(set, int, "orl %1,%0", "ir", v);
ATOMIC_ASM(clear, int, "andl %1,%0", "ir", ~v);
ATOMIC_ASM(add, int, "addl %1,%0", "ir", v);
ATOMIC_ASM(subtract, int, "subl %1,%0", "ir", v);
ATOMIC_ASM(set, long, "orl %1,%0", "ir", v);
ATOMIC_ASM(clear, long, "andl %1,%0", "ir", ~v);
ATOMIC_ASM(add, long, "addl %1,%0", "ir", v);
ATOMIC_ASM(subtract, long, "subl %1,%0", "ir", v);
ATOMIC_STORE_LOAD(char, "cmpxchgb %b0,%1", "xchgb %b1,%0");
ATOMIC_STORE_LOAD(short,"cmpxchgw %w0,%1", "xchgw %w1,%0");
ATOMIC_STORE_LOAD(int, "cmpxchgl %0,%1", "xchgl %1,%0");
ATOMIC_STORE_LOAD(long, "cmpxchgl %0,%1", "xchgl %1,%0");
#undef ATOMIC_ASM
#undef ATOMIC_STORE_LOAD
#define atomic_set_acq_char atomic_set_char
#define atomic_set_rel_char atomic_set_char
#define atomic_clear_acq_char atomic_clear_char
#define atomic_clear_rel_char atomic_clear_char
#define atomic_add_acq_char atomic_add_char
#define atomic_add_rel_char atomic_add_char
#define atomic_subtract_acq_char atomic_subtract_char
#define atomic_subtract_rel_char atomic_subtract_char
#define atomic_set_acq_short atomic_set_short
#define atomic_set_rel_short atomic_set_short
#define atomic_clear_acq_short atomic_clear_short
#define atomic_clear_rel_short atomic_clear_short
#define atomic_add_acq_short atomic_add_short
#define atomic_add_rel_short atomic_add_short
#define atomic_subtract_acq_short atomic_subtract_short
#define atomic_subtract_rel_short atomic_subtract_short
#define atomic_set_acq_int atomic_set_int
#define atomic_set_rel_int atomic_set_int
#define atomic_clear_acq_int atomic_clear_int
#define atomic_clear_rel_int atomic_clear_int
#define atomic_add_acq_int atomic_add_int
#define atomic_add_rel_int atomic_add_int
#define atomic_subtract_acq_int atomic_subtract_int
#define atomic_subtract_rel_int atomic_subtract_int
#define atomic_cmpset_acq_int atomic_cmpset_int
#define atomic_cmpset_rel_int atomic_cmpset_int
#define atomic_set_acq_long atomic_set_long
#define atomic_set_rel_long atomic_set_long
#define atomic_clear_acq_long atomic_clear_long
#define atomic_clear_rel_long atomic_clear_long
#define atomic_add_acq_long atomic_add_long
#define atomic_add_rel_long atomic_add_long
#define atomic_subtract_acq_long atomic_subtract_long
#define atomic_subtract_rel_long atomic_subtract_long
#define atomic_cmpset_long atomic_cmpset_int
#define atomic_cmpset_acq_long atomic_cmpset_acq_int
#define atomic_cmpset_rel_long atomic_cmpset_rel_int
#define atomic_cmpset_acq_ptr atomic_cmpset_ptr
#define atomic_cmpset_rel_ptr atomic_cmpset_ptr
#define atomic_set_8 atomic_set_char
#define atomic_set_acq_8 atomic_set_acq_char
#define atomic_set_rel_8 atomic_set_rel_char
#define atomic_clear_8 atomic_clear_char
#define atomic_clear_acq_8 atomic_clear_acq_char
#define atomic_clear_rel_8 atomic_clear_rel_char
#define atomic_add_8 atomic_add_char
#define atomic_add_acq_8 atomic_add_acq_char
#define atomic_add_rel_8 atomic_add_rel_char
#define atomic_subtract_8 atomic_subtract_char
#define atomic_subtract_acq_8 atomic_subtract_acq_char
#define atomic_subtract_rel_8 atomic_subtract_rel_char
#define atomic_load_acq_8 atomic_load_acq_char
#define atomic_store_rel_8 atomic_store_rel_char
#define atomic_set_16 atomic_set_short
#define atomic_set_acq_16 atomic_set_acq_short
#define atomic_set_rel_16 atomic_set_rel_short
#define atomic_clear_16 atomic_clear_short
#define atomic_clear_acq_16 atomic_clear_acq_short
#define atomic_clear_rel_16 atomic_clear_rel_short
#define atomic_add_16 atomic_add_short
#define atomic_add_acq_16 atomic_add_acq_short
#define atomic_add_rel_16 atomic_add_rel_short
#define atomic_subtract_16 atomic_subtract_short
#define atomic_subtract_acq_16 atomic_subtract_acq_short
#define atomic_subtract_rel_16 atomic_subtract_rel_short
#define atomic_load_acq_16 atomic_load_acq_short
#define atomic_store_rel_16 atomic_store_rel_short
#define atomic_set_32 atomic_set_int
#define atomic_set_acq_32 atomic_set_acq_int
#define atomic_set_rel_32 atomic_set_rel_int
#define atomic_clear_32 atomic_clear_int
#define atomic_clear_acq_32 atomic_clear_acq_int
#define atomic_clear_rel_32 atomic_clear_rel_int
#define atomic_add_32 atomic_add_int
#define atomic_add_acq_32 atomic_add_acq_int
#define atomic_add_rel_32 atomic_add_rel_int
#define atomic_subtract_32 atomic_subtract_int
#define atomic_subtract_acq_32 atomic_subtract_acq_int
#define atomic_subtract_rel_32 atomic_subtract_rel_int
#define atomic_load_acq_32 atomic_load_acq_int
#define atomic_store_rel_32 atomic_store_rel_int
#define atomic_cmpset_32 atomic_cmpset_int
#define atomic_cmpset_acq_32 atomic_cmpset_acq_int
#define atomic_cmpset_rel_32 atomic_cmpset_rel_int
#define atomic_readandclear_32 atomic_readandclear_int
#if !defined(WANT_FUNCTIONS)
static __inline int
atomic_cmpset_ptr(volatile void *dst, void *exp, void *src)
{
return (atomic_cmpset_int((volatile u_int *)dst, (u_int)exp,
(u_int)src));
}
static __inline void *
atomic_load_acq_ptr(volatile void *p)
{
/*
* The apparently-bogus cast to intptr_t in the following is to
* avoid a warning from "gcc -Wbad-function-cast".
*/
return ((void *)(intptr_t)atomic_load_acq_int((volatile u_int *)p));
}
static __inline void
atomic_store_rel_ptr(volatile void *p, void *v)
{
atomic_store_rel_int((volatile u_int *)p, (u_int)v);
}
#define ATOMIC_PTR(NAME) \
static __inline void \
atomic_##NAME##_ptr(volatile void *p, uintptr_t v) \
{ \
atomic_##NAME##_int((volatile u_int *)p, v); \
} \
\
static __inline void \
atomic_##NAME##_acq_ptr(volatile void *p, uintptr_t v) \
{ \
atomic_##NAME##_acq_int((volatile u_int *)p, v);\
} \
\
static __inline void \
atomic_##NAME##_rel_ptr(volatile void *p, uintptr_t v) \
{ \
atomic_##NAME##_rel_int((volatile u_int *)p, v);\
}
ATOMIC_PTR(set)
ATOMIC_PTR(clear)
ATOMIC_PTR(add)
ATOMIC_PTR(subtract)
#undef ATOMIC_PTR
#if defined(__GNUC__) || defined(__INTEL_COMPILER)
static __inline u_int
atomic_readandclear_int(volatile u_int *addr)
{
u_int result;
__asm __volatile (
" xorl %0,%0 ; "
" xchgl %1,%0 ; "
"# atomic_readandclear_int"
: "=&r" (result) /* 0 (result) */
: "m" (*addr)); /* 1 (addr) */
return (result);
}
static __inline u_long
atomic_readandclear_long(volatile u_long *addr)
{
u_long result;
__asm __volatile (
" xorl %0,%0 ; "
" xchgl %1,%0 ; "
"# atomic_readandclear_int"
: "=&r" (result) /* 0 (result) */
: "m" (*addr)); /* 1 (addr) */
return (result);
}
#else /* !(defined(__GNUC__) || defined(__INTEL_COMPILER)) */
extern u_long atomic_readandclear_long(volatile u_long *);
extern u_int atomic_readandclear_int(volatile u_int *);
#endif /* defined(__GNUC__) || defined(__INTEL_COMPILER) */
#endif /* !defined(WANT_FUNCTIONS) */
#endif /* ! _MACHINE_ATOMIC_H_ */