/*
* Copyright (c) 2001-2004 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
*/
/** @addtogroup amd64
* @{
*/
/** @file
*/
#ifndef KERN_amd64_ATOMIC_H_
#define KERN_amd64_ATOMIC_H_
#include <arch/types.h>
#include <arch/barrier.h>
#include <preemption.h>
#include <typedefs.h>
static inline void atomic_inc(atomic_t *val) {
#ifdef CONFIG_SMP
asm volatile ("lock incq %0\n" : "=m" (val->count));
#else
asm volatile ("incq %0\n" : "=m" (val->count));
#endif /* CONFIG_SMP */
}
static inline void atomic_dec(atomic_t *val) {
#ifdef CONFIG_SMP
asm volatile ("lock decq %0\n" : "=m" (val->count));
#else
asm volatile ("decq %0\n" : "=m" (val->count));
#endif /* CONFIG_SMP */
}
static inline long atomic_postinc(atomic_t *val)
{
long r = 1;
asm volatile (
"lock xaddq %1, %0\n"
: "=m" (val->count), "+r" (r)
);
return r;
}
static inline long atomic_postdec(atomic_t *val)
{
long r = -1;
asm volatile (
"lock xaddq %1, %0\n"
: "=m" (val->count), "+r" (r)
);
return r;
}
#define atomic_preinc(val) (atomic_postinc(val)+1)
#define atomic_predec(val) (atomic_postdec(val)-1)
static inline uint64_t test_and_set(atomic_t *val) {
uint64_t v;
asm volatile (
"movq $1, %0\n"
"xchgq %0, %1\n"
: "=r" (v),"=m" (val->count)
);
return v;
}
/** amd64 specific fast spinlock */
static inline void atomic_lock_arch(atomic_t *val)
{
uint64_t tmp;
preemption_disable();
asm volatile (
"0:;"
#ifdef CONFIG_HT
"pause;"
#endif
"mov %0, %1;"
"testq %1, %1;"
"jnz 0b;" /* Lightweight looping on locked spinlock */
"incq %1;" /* now use the atomic operation */
"xchgq %0, %1;"
"testq %1, %1;"
"jnz 0b;"
: "=m"(val->count),"=r"(tmp)
);
/*
* Prevent critical section code from bleeding out this way up.
*/
CS_ENTER_BARRIER();
}
#endif
/** @}
*/