path: root/erts/include/internal/sparc32/atomic.h

/* 
 * %CopyrightBegin%
 *
 * Copyright Ericsson AB 2005-2010. All Rights Reserved.
 *
 * The contents of this file are subject to the Erlang Public License,
 * Version 1.1, (the "License"); you may not use this file except in
 * compliance with the License. You should have received a copy of the
 * Erlang Public License along with this software. If not, it can be
 * retrieved online at http://www.erlang.org/.
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * %CopyrightEnd%
 */

/*
 * Native ethread atomics on SPARC V9.
 * Author: Mikael Pettersson.
 */
#ifndef ETHR_SPARC32_ATOMIC_H
#define ETHR_SPARC32_ATOMIC_H

#if ETHR_SIZEOF_LONG != ETHR_SIZEOF_PTR
#  error "Incompatible size of 'long'"
#endif

typedef struct {
    volatile long counter;
} ethr_native_atomic_t;

#define ETHR_MEMORY_BARRIER \
  __asm__ __volatile__("membar #LoadLoad|#LoadStore|#StoreLoad|#StoreStore\n" \
                       : : : "memory")

#if defined(ETHR_TRY_INLINE_FUNCS) || defined(ETHR_ATOMIC_IMPL__)

#if defined(__arch64__)
#define CASX "casx"
#else
#define CASX "cas"
#endif

static ETHR_INLINE void
ethr_native_atomic_init(ethr_native_atomic_t *var, long i)
{
    var->counter = i;
}
#define ethr_native_atomic_set(v, i)	ethr_native_atomic_init((v), (i))

static ETHR_INLINE long
ethr_native_atomic_read(ethr_native_atomic_t *var)
{
    return var->counter;
}

static ETHR_INLINE long
ethr_native_atomic_add_return(ethr_native_atomic_t *var, long incr)
{
    long old, tmp;

    __asm__ __volatile__("membar #LoadLoad|#StoreLoad\n");
    do {
	old = var->counter;
	tmp = old+incr;
	__asm__ __volatile__(
	    CASX " [%2], %1, %0"
	    : "=&r"(tmp)
	    : "r"(old), "r"(&var->counter), "0"(tmp)
	    : "memory");
    } while (__builtin_expect(old != tmp, 0));
    __asm__ __volatile__("membar #StoreLoad|#StoreStore");
    return old+incr;
}

static ETHR_INLINE void
ethr_native_atomic_add(ethr_native_atomic_t *var, long incr)
{
    (void)ethr_native_atomic_add_return(var, incr);
}

static ETHR_INLINE long
ethr_native_atomic_inc_return(ethr_native_atomic_t *var)
{
    return ethr_native_atomic_add_return(var, 1);
}

static ETHR_INLINE void
ethr_native_atomic_inc(ethr_native_atomic_t *var)
{
    (void)ethr_native_atomic_add_return(var, 1);
}

static ETHR_INLINE long
ethr_native_atomic_dec_return(ethr_native_atomic_t *var)
{
    return ethr_native_atomic_add_return(var, -1);
}

static ETHR_INLINE void
ethr_native_atomic_dec(ethr_native_atomic_t *var)
{
    (void)ethr_native_atomic_add_return(var, -1);
}

static ETHR_INLINE long
ethr_native_atomic_and_retold(ethr_native_atomic_t *var, long mask)
{
    long old, tmp;

    __asm__ __volatile__("membar #LoadLoad|#StoreLoad\n");
    do {
	old = var->counter;
	tmp = old & mask;
	__asm__ __volatile__(
	    CASX " [%2], %1, %0"
	    : "=&r"(tmp)
	    : "r"(old), "r"(&var->counter), "0"(tmp)
	    : "memory");
    } while (__builtin_expect(old != tmp, 0));
    __asm__ __volatile__("membar #StoreLoad|#StoreStore");
    return old;
}

static ETHR_INLINE long
ethr_native_atomic_or_retold(ethr_native_atomic_t *var, long mask)
{
    long old, tmp;

    __asm__ __volatile__("membar #LoadLoad|#StoreLoad\n");
    do {
	old = var->counter;
	tmp = old | mask;
	__asm__ __volatile__(
	    CASX " [%2], %1, %0"
	    : "=&r"(tmp)
	    : "r"(old), "r"(&var->counter), "0"(tmp)
	    : "memory");
    } while (__builtin_expect(old != tmp, 0));
    __asm__ __volatile__("membar #StoreLoad|#StoreStore");
    return old;
}

static ETHR_INLINE long
ethr_native_atomic_xchg(ethr_native_atomic_t *var, long val)
{
    long old, new;

    __asm__ __volatile__("membar #LoadLoad|#StoreLoad");
    do {
	old = var->counter;
	new = val;
	__asm__ __volatile__(
	    CASX " [%2], %1, %0"
	    : "=&r"(new)
	    : "r"(old), "r"(&var->counter), "0"(new)
	    : "memory");
    } while (__builtin_expect(old != new, 0));
    __asm__ __volatile__("membar #StoreLoad|#StoreStore");
    return old;
}

static ETHR_INLINE long
ethr_native_atomic_cmpxchg(ethr_native_atomic_t *var, long new, long old)
{
    __asm__ __volatile__("membar #LoadLoad|#StoreLoad\n");
    __asm__ __volatile__(
      CASX " [%2], %1, %0"
      : "=&r"(new)
      : "r"(old), "r"(&var->counter), "0"(new)
      : "memory");
    __asm__ __volatile__("membar #StoreLoad|#StoreStore");
    return new;
}

/*
 * Atomic ops with at least specified barriers.
 */

/* TODO: relax acquire barriers */

static ETHR_INLINE long
ethr_native_atomic_read_acqb(ethr_native_atomic_t *var)
{
    long res = ethr_native_atomic_read(var);
    __asm__ __volatile__("membar #LoadLoad|#LoadStore|#StoreLoad|#StoreStore" : : : "memory");
    return res;
}

static ETHR_INLINE void
ethr_native_atomic_set_relb(ethr_native_atomic_t *var, long i)
{
    __asm__ __volatile__("membar #LoadStore|#StoreStore" : : : "memory");
    ethr_native_atomic_set(var, i);
}

static ETHR_INLINE long
ethr_native_atomic_inc_return_acqb(ethr_native_atomic_t *var)
{
    long res = ethr_native_atomic_inc_return(var);
    __asm__ __volatile__("membar #LoadLoad|#LoadStore" : : : "memory");
    return res;
}

static ETHR_INLINE void
ethr_native_atomic_dec_relb(ethr_native_atomic_t *var)
{
    __asm__ __volatile__("membar #LoadStore|#StoreStore" : : : "memory");
    ethr_native_atomic_dec(var);
}

static ETHR_INLINE long
ethr_native_atomic_dec_return_relb(ethr_native_atomic_t *var)
{
    __asm__ __volatile__("membar #LoadStore|#StoreStore" : : : "memory");
    return ethr_native_atomic_dec_return(var);
}

static ETHR_INLINE long
ethr_native_atomic_cmpxchg_acqb(ethr_native_atomic_t *var, long new, long old)
{
    long res = ethr_native_atomic_cmpxchg(var, new, old);
    __asm__ __volatile__("membar #LoadLoad|#LoadStore" : : : "memory");
    return res;
}

static ETHR_INLINE long
ethr_native_atomic_cmpxchg_relb(ethr_native_atomic_t *var, long new, long old)
{
    __asm__ __volatile__("membar #LoadStore|#StoreStore" : : : "memory");
    return ethr_native_atomic_cmpxchg(var, new, old);
}

#endif /* ETHR_TRY_INLINE_FUNCS */

#endif /* ETHR_SPARC32_ATOMIC_H */