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Provide CAS variants for 16 and 8 bit when running with more that 1 cpu

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This commit is contained in:
martin 2014-02-24 17:18:27 +00:00
parent fdd74dffed
commit 7d33c23876
1 changed files with 45 additions and 3 deletions
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48
common/lib/libc/atomic/atomic_init_testset.c
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@ -1,4 +1,4 @@
/* $NetBSD: atomic_init_testset.c,v 1.13 2014/02/22 17:08:30 martin Exp $ */
/* $NetBSD: atomic_init_testset.c,v 1.14 2014/02/24 17:18:27 martin Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
@ -36,7 +36,7 @@
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: atomic_init_testset.c,v 1.13 2014/02/22 17:08:30 martin Exp $");
__RCSID("$NetBSD: atomic_init_testset.c,v 1.14 2014/02/24 17:18:27 martin Exp $");
#include "atomic_op_namespace.h"
@ -53,6 +53,12 @@ __RCSID("$NetBSD: atomic_init_testset.c,v 1.13 2014/02/22 17:08:30 martin Exp $"
#define I128 I16 I16 I16 I16 I16 I16 I16 I16
static __cpu_simple_lock_t atomic_locks[128] = { I128 };
/*
* Pick a lock out of above array depending on the object address
* passed. Most variables used atomically will not be in the same
* cacheline - and if they are, using the same lock is fine.
*/
#define HASH(PTR) (((uintptr_t)(PTR) >> 3) & 127)
#ifdef __HAVE_ASM_ATOMIC_CAS_UP
extern uint32_t _atomic_cas_up(volatile uint32_t *, uint32_t, uint32_t);
@ -143,7 +149,41 @@ _atomic_cas_mp(volatile uint32_t *ptr, uint32_t old, uint32_t new)
__cpu_simple_lock_t *lock;
uint32_t ret;
lock = &atomic_locks[((uintptr_t)ptr >> 3) & 127];
lock = &atomic_locks[HASH(ptr)];
__cpu_simple_lock(lock);
ret = *ptr;
if (__predict_true(ret == old)) {
*ptr = new;
}
__cpu_simple_unlock(lock);
return ret;
}
static uint16_t
_atomic_cas_16_mp(volatile uint16_t *ptr, uint16_t old, uint16_t new)
{
__cpu_simple_lock_t *lock;
uint16_t ret;
lock = &atomic_locks[HASH(ptr)];
__cpu_simple_lock(lock);
ret = *ptr;
if (__predict_true(ret == old)) {
*ptr = new;
}
__cpu_simple_unlock(lock);
return ret;
}
static uint8_t
_atomic_cas_8_mp(volatile uint8_t *ptr, uint8_t old, uint8_t new)
{
__cpu_simple_lock_t *lock;
uint8_t ret;
lock = &atomic_locks[HASH(ptr)];
__cpu_simple_lock(lock);
ret = *ptr;
if (__predict_true(ret == old)) {
@ -186,6 +226,8 @@ __libc_atomic_init(void)
size_t len;
_atomic_cas_fn = _atomic_cas_mp;
_atomic_cas_16_fn = _atomic_cas_16_mp;
_atomic_cas_8_fn = _atomic_cas_8_mp;
mib[0] = CTL_HW;
mib[1] = HW_NCPU;