/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 2005-2009. 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 PowerPC.
* Author: Mikael Pettersson.
*
* Based on the examples in Appendix E of Motorola's
* "Programming Environments Manual For 32-Bit Implementations
* of the PowerPC Architecture".
*/
#ifndef ETHREAD_PPC_ATOMIC_H
#define ETHREAD_PPC_ATOMIC_H
typedef struct {
volatile int counter;
} ethr_native_atomic_t;
#ifdef ETHR_TRY_INLINE_FUNCS
static ETHR_INLINE void
ethr_native_atomic_init(ethr_native_atomic_t *var, int i)
{
var->counter = i;
}
#define ethr_native_atomic_set(v, i) ethr_native_atomic_init((v), (i))
static ETHR_INLINE int
ethr_native_atomic_read(ethr_native_atomic_t *var)
{
return var->counter;
}
static ETHR_INLINE int
ethr_native_atomic_add_return(ethr_native_atomic_t *var, int incr)
{
int tmp;
__asm__ __volatile__(
"eieio\n\t"
"1:\t"
"lwarx %0,0,%1\n\t"
"add %0,%2,%0\n\t"
"stwcx. %0,0,%1\n\t"
"bne- 1b\n\t"
"isync"
: "=&r"(tmp)
: "r"(&var->counter), "r"(incr)
: "cc", "memory");
return tmp;
}
static ETHR_INLINE void
ethr_native_atomic_add(ethr_native_atomic_t *var, int incr)
{
/* XXX: could use weaker version here w/o eieio+isync */
(void)ethr_native_atomic_add_return(var, incr);
}
static ETHR_INLINE int
ethr_native_atomic_inc_return(ethr_native_atomic_t *var)
{
int tmp;
__asm__ __volatile__(
"eieio\n\t"
"1:\t"
"lwarx %0,0,%1\n\t"
"addic %0,%0,1\n\t" /* due to addi's (rA|0) behaviour */
"stwcx. %0,0,%1\n\t"
"bne- 1b\n\t"
"isync"
: "=&r"(tmp)
: "r"(&var->counter)
: "cc", "memory");
return tmp;
}
static ETHR_INLINE void
ethr_native_atomic_inc(ethr_native_atomic_t *var)
{
/* XXX: could use weaker version here w/o eieio+isync */
(void)ethr_native_atomic_inc_return(var);
}
static ETHR_INLINE int
ethr_native_atomic_dec_return(ethr_native_atomic_t *var)
{
int tmp;
__asm__ __volatile__(
"eieio\n\t"
"1:\t"
"lwarx %0,0,%1\n\t"
"addic %0,%0,-1\n\t"
"stwcx. %0,0,%1\n\t"
"bne- 1b\n\t"
"isync"
: "=&r"(tmp)
: "r"(&var->counter)
: "cc", "memory");
return tmp;
}
static ETHR_INLINE void
ethr_native_atomic_dec(ethr_native_atomic_t *var)
{
/* XXX: could use weaker version here w/o eieio+isync */
(void)ethr_native_atomic_dec_return(var);
}
static ETHR_INLINE int
ethr_native_atomic_and_retold(ethr_native_atomic_t *var, int mask)
{
int old, new;
__asm__ __volatile__(
"eieio\n\t"
"1:\t"
"lwarx %0,0,%2\n\t"
"and %1,%0,%3\n\t"
"stwcx. %1,0,%2\n\t"
"bne- 1b\n\t"
"isync"
: "=&r"(old), "=&r"(new)
: "r"(&var->counter), "r"(mask)
: "cc", "memory");
return old;
}
static ETHR_INLINE int
ethr_native_atomic_or_retold(ethr_native_atomic_t *var, int mask)
{
int old, new;
__asm__ __volatile__(
"eieio\n\t"
"1:\t"
"lwarx %0,0,%2\n\t"
"or %1,%0,%3\n\t"
"stwcx. %1,0,%2\n\t"
"bne- 1b\n\t"
"isync"
: "=&r"(old), "=&r"(new)
: "r"(&var->counter), "r"(mask)
: "cc", "memory");
return old;
}
static ETHR_INLINE int
ethr_native_atomic_xchg(ethr_native_atomic_t *var, int val)
{
int tmp;
__asm__ __volatile__(
"eieio\n\t"
"1:\t"
"lwarx %0,0,%1\n\t"
"stwcx. %2,0,%1\n\t"
"bne- 1b\n\t"
"isync"
: "=&r"(tmp)
: "r"(&var->counter), "r"(val)
: "cc", "memory");
return tmp;
}
static ETHR_INLINE int
ethr_native_atomic_cmpxchg(ethr_native_atomic_t *var, int new, int expected)
{
int old;
__asm__ __volatile__(
"eieio\n\t"
"1:\t"
"lwarx %0,0,%2\n\t"
"cmpw 0,%0,%3\n\t"
"bne 2f\n\t"
"stwcx. %1,0,%2\n\t"
"bne- 1b\n\t"
"isync\n"
"2:"
: "=&r"(old)
: "r"(new), "r"(&var->counter), "r"(expected)
: "cc", "memory");
return old;
}
#endif /* ETHR_TRY_INLINE_FUNCS */
#endif /* ETHREAD_PPC_ATOMIC_H */
