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mirror of https://git.FreeBSD.org/src.git synced 2024-12-15 10:17:20 +00:00

Introduce atomic_cmpset_int() and atomic_cmpset_long() from SMPng a

few hours earlier than the rest.

The next DEVFS commit needs these functions.

Alpha versions by: dfr
i386 versions by: jakeb

Approved by:    SMPng
This commit is contained in:
Poul-Henning Kamp 2000-09-06 11:21:14 +00:00
parent aada671ef0
commit 819e370c3b
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=65514
5 changed files with 229 additions and 16 deletions

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@ -34,25 +34,25 @@
* of interrupts and SMP safe.
*/
void atomic_set_8(u_int8_t *, u_int8_t);
void atomic_clear_8(u_int8_t *, u_int8_t);
void atomic_add_8(u_int8_t *, u_int8_t);
void atomic_subtract_8(u_int8_t *, u_int8_t);
void atomic_set_8(volatile u_int8_t *, u_int8_t);
void atomic_clear_8(volatile u_int8_t *, u_int8_t);
void atomic_add_8(volatile u_int8_t *, u_int8_t);
void atomic_subtract_8(volatile u_int8_t *, u_int8_t);
void atomic_set_16(u_int16_t *, u_int16_t);
void atomic_clear_16(u_int16_t *, u_int16_t);
void atomic_add_16(u_int16_t *, u_int16_t);
void atomic_subtract_16(u_int16_t *, u_int16_t);
void atomic_set_16(volatile u_int16_t *, u_int16_t);
void atomic_clear_16(volatile u_int16_t *, u_int16_t);
void atomic_add_16(volatile u_int16_t *, u_int16_t);
void atomic_subtract_16(volatile u_int16_t *, u_int16_t);
void atomic_set_32(u_int32_t *, u_int32_t);
void atomic_clear_32(u_int32_t *, u_int32_t);
void atomic_add_32(u_int32_t *, u_int32_t);
void atomic_subtract_32(u_int32_t *, u_int32_t);
void atomic_set_32(volatile u_int32_t *, u_int32_t);
void atomic_clear_32(volatile u_int32_t *, u_int32_t);
void atomic_add_32(volatile u_int32_t *, u_int32_t);
void atomic_subtract_32(volatile u_int32_t *, u_int32_t);
void atomic_set_64(u_int64_t *, u_int64_t);
void atomic_clear_64(u_int64_t *, u_int64_t);
void atomic_add_64(u_int64_t *, u_int64_t);
void atomic_subtract_64(u_int64_t *, u_int64_t);
void atomic_set_64(volatile u_int64_t *, u_int64_t);
void atomic_clear_64(volatile u_int64_t *, u_int64_t);
void atomic_add_64(volatile u_int64_t *, u_int64_t);
void atomic_subtract_64(volatile u_int64_t *, u_int64_t);
#define atomic_set_char atomic_set_8
#define atomic_clear_char atomic_clear_8
@ -74,4 +74,71 @@ void atomic_subtract_64(u_int64_t *, u_int64_t);
#define atomic_add_long atomic_add_64
#define atomic_subtract_long atomic_subtract_64
/*
* Atomically compare the value stored at *p with cmpval and if the
* two values are equal, update the value of *p with newval. Returns
* zero if the compare failed, nonzero otherwise.
*/
static __inline u_int32_t
atomic_cmpset_32(volatile u_int32_t* p, u_int32_t cmpval, u_int32_t newval)
{
u_int32_t ret, temp;
__asm __volatile (
"1:\tldl_l %1, %5\n\t" /* load old value */
"cmpeq %1, %3, %0\n\t" /* compare */
"beq %0, 2f\n\t" /* exit if not equal */
"mov %4, %1\n\t" /* value to store */
"stl_c %1, %2\n\t" /* attempt to store */
"beq %1, 3f\n\t" /* if it failed, spin */
"2:\n" /* done */
".section .text3,\"ax\"\n" /* improve branch prediction */
"3:\tbr 1b\n" /* try again */
".previous\n"
: "=&r" (ret), "=r" (temp), "=m" (*p)
: "r" (cmpval), "r" (newval), "m" (*p)
: "memory");
return ret;
}
/*
* Atomically compare the value stored at *p with cmpval and if the
* two values are equal, update the value of *p with newval. Returns
* zero if the compare failed, nonzero otherwise.
*/
static __inline u_int64_t
atomic_cmpset_64(volatile u_int64_t* p, u_int64_t cmpval, u_int64_t newval)
{
u_int64_t ret, temp;
__asm __volatile (
"1:\tldq_l %1, %5\n\t" /* load old value */
"cmpeq %1, %3, %0\n\t" /* compare */
"beq %0, 2f\n\t" /* exit if not equal */
"mov %4, %1\n\t" /* value to store */
"stq_c %1, %2\n\t" /* attempt to store */
"beq %1, 3f\n\t" /* if it failed, spin */
"2:\n" /* done */
".section .text3,\"ax\"\n" /* improve branch prediction */
"3:\tbr 1b\n" /* try again */
".previous\n"
: "=&r" (ret), "=r" (temp), "=m" (*p)
: "r" (cmpval), "r" (newval), "m" (*p)
: "memory");
return ret;
}
#define atomic_cmpset_int atomic_cmpset_32
#define atomic_cmpset_long atomic_cmpset_64
static __inline int
atomic_cmpset_ptr(volatile void *dst, void *exp, void *src)
{
return (
atomic_cmpset_long((volatile u_long *)dst, (u_long)exp, (u_long)src));
}
#endif /* ! _MACHINE_ATOMIC_H_ */

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@ -40,6 +40,7 @@
#undef ATOMIC_ASM
/* Make atomic.h generate public functions */
#define WANT_FUNCTIONS
#define static
#undef __inline
#define __inline

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@ -65,9 +65,15 @@
#define ATOMIC_ASM(NAME, TYPE, OP, V) \
extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v);
extern int atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src);
#else /* !KLD_MODULE */
#if defined(SMP)
#if defined(LOCORE)
#define MPLOCKED lock ;
#else
#define MPLOCKED "lock ; "
#endif
#else
#define MPLOCKED
#endif
@ -87,6 +93,62 @@ atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
: "0" (*p), "ir" (V)); \
}
/*
* 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(I386_CPU)
static __inline int
atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
{
int res = exp;
__asm __volatile(
" pushfl ; "
" cli ; "
" cmpl %1,%3 ; "
" jne 1f ; "
" movl %2,%3 ; "
"1: "
" sete %%al; "
" movzbl %%al,%0 ; "
" popfl ; "
"# atomic_cmpset_int"
: "=a" (res) /* 0 (result) */
: "0" (exp), /* 1 */
"r" (src), /* 2 */
"m" (*(dst)) /* 3 */
: "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 (
" " MPLOCKED " "
" cmpxchgl %2,%3 ; "
" setz %%al ; "
" movzbl %%al,%0 ; "
"1: "
"# atomic_cmpset_int"
: "=a" (res) /* 0 (result) */
: "0" (exp), /* 1 */
"r" (src), /* 2 */
"m" (*(dst)) /* 3 */
: "memory");
return (res);
}
#endif /* defined(I386_CPU) */
#else
/* gcc <= 2.8 version */
#define ATOMIC_ASM(NAME, TYPE, OP, V) \
@ -148,4 +210,14 @@ ATOMIC_ASM(subtract, long, "subl %1,%0", v)
#endif
#ifndef 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));
}
#endif
#endif /* ! _MACHINE_ATOMIC_H_ */

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@ -40,6 +40,7 @@
#undef ATOMIC_ASM
/* Make atomic.h generate public functions */
#define WANT_FUNCTIONS
#define static
#undef __inline
#define __inline

View File

@ -65,9 +65,15 @@
#define ATOMIC_ASM(NAME, TYPE, OP, V) \
extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v);
extern int atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src);
#else /* !KLD_MODULE */
#if defined(SMP)
#if defined(LOCORE)
#define MPLOCKED lock ;
#else
#define MPLOCKED "lock ; "
#endif
#else
#define MPLOCKED
#endif
@ -87,6 +93,62 @@ atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
: "0" (*p), "ir" (V)); \
}
/*
* 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(I386_CPU)
static __inline int
atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
{
int res = exp;
__asm __volatile(
" pushfl ; "
" cli ; "
" cmpl %1,%3 ; "
" jne 1f ; "
" movl %2,%3 ; "
"1: "
" sete %%al; "
" movzbl %%al,%0 ; "
" popfl ; "
"# atomic_cmpset_int"
: "=a" (res) /* 0 (result) */
: "0" (exp), /* 1 */
"r" (src), /* 2 */
"m" (*(dst)) /* 3 */
: "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 (
" " MPLOCKED " "
" cmpxchgl %2,%3 ; "
" setz %%al ; "
" movzbl %%al,%0 ; "
"1: "
"# atomic_cmpset_int"
: "=a" (res) /* 0 (result) */
: "0" (exp), /* 1 */
"r" (src), /* 2 */
"m" (*(dst)) /* 3 */
: "memory");
return (res);
}
#endif /* defined(I386_CPU) */
#else
/* gcc <= 2.8 version */
#define ATOMIC_ASM(NAME, TYPE, OP, V) \
@ -148,4 +210,14 @@ ATOMIC_ASM(subtract, long, "subl %1,%0", v)
#endif
#ifndef 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));
}
#endif
#endif /* ! _MACHINE_ATOMIC_H_ */