/*
 * Atomic operation helper include
 *
 *  Copyright (c) 2005 Fabrice Bellard
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#ifndef QEMU_SPINLOCK_H
#define QEMU_SPINLOCK_H

#if defined(__hppa__)

typedef int spinlock_t[4];

#define SPIN_LOCK_UNLOCKED { 1, 1, 1, 1 }

static inline void resetlock (spinlock_t *p)
{
    (*p)[0] = (*p)[1] = (*p)[2] = (*p)[3] = 1;
}

#else

typedef int spinlock_t;

#define SPIN_LOCK_UNLOCKED 0

static inline void resetlock (spinlock_t *p)
{
    *p = SPIN_LOCK_UNLOCKED;
}

#endif

#if defined(__powerpc__)
static inline int testandset (int *p)
{
    int ret;
    __asm__ __volatile__ (
                          "0:    lwarx %0,0,%1\n"
                          "      xor. %0,%3,%0\n"
                          "      bne 1f\n"
                          "      stwcx. %2,0,%1\n"
                          "      bne- 0b\n"
                          "1:    "
                          : "=&r" (ret)
                          : "r" (p), "r" (1), "r" (0)
                          : "cr0", "memory");
    return ret;
}
#elif defined(__i386__)
static inline int testandset (int *p)
{
    long int readval = 0;

    __asm__ __volatile__ ("lock; cmpxchgl %2, %0"
                          : "+m" (*p), "+a" (readval)
                          : "r" (1)
                          : "cc");
    return readval;
}
#elif defined(__x86_64__)
static inline int testandset (int *p)
{
    long int readval = 0;

    __asm__ __volatile__ ("lock; cmpxchgl %2, %0"
                          : "+m" (*p), "+a" (readval)
                          : "r" (1)
                          : "cc");
    return readval;
}
#elif defined(__s390__)
static inline int testandset (int *p)
{
    int ret;

    __asm__ __volatile__ ("0: cs    %0,%1,0(%2)\n"
			  "   jl    0b"
			  : "=&d" (ret)
			  : "r" (1), "a" (p), "0" (*p)
			  : "cc", "memory" );
    return ret;
}
#elif defined(__alpha__)
static inline int testandset (int *p)
{
    int ret;
    unsigned long one;

    __asm__ __volatile__ ("0:	mov 1,%2\n"
			  "	ldl_l %0,%1\n"
			  "	stl_c %2,%1\n"
			  "	beq %2,1f\n"
			  ".subsection 2\n"
			  "1:	br 0b\n"
			  ".previous"
			  : "=r" (ret), "=m" (*p), "=r" (one)
			  : "m" (*p));
    return ret;
}
#elif defined(__sparc__)
static inline int testandset (int *p)
{
	int ret;

	__asm__ __volatile__("ldstub	[%1], %0"
			     : "=r" (ret)
			     : "r" (p)
			     : "memory");

	return (ret ? 1 : 0);
}
#elif defined(__arm__)
static inline int testandset (int *spinlock)
{
    register unsigned int ret;
    __asm__ __volatile__("swp %0, %1, [%2]"
                         : "=r"(ret)
                         : "0"(1), "r"(spinlock));

    return ret;
}
#elif defined(__mc68000)
static inline int testandset (int *p)
{
    char ret;
    __asm__ __volatile__("tas %1; sne %0"
                         : "=r" (ret)
                         : "m" (p)
                         : "cc","memory");
    return ret;
}
#elif defined(__hppa__)

/* Because malloc only guarantees 8-byte alignment for malloc'd data,
   and GCC only guarantees 8-byte alignment for stack locals, we can't
   be assured of 16-byte alignment for atomic lock data even if we
   specify "__attribute ((aligned(16)))" in the type declaration.  So,
   we use a struct containing an array of four ints for the atomic lock
   type and dynamically select the 16-byte aligned int from the array
   for the semaphore.  */
#define __PA_LDCW_ALIGNMENT 16
static inline void *ldcw_align (void *p) {
    unsigned long a = (unsigned long)p;
    a = (a + __PA_LDCW_ALIGNMENT - 1) & ~(__PA_LDCW_ALIGNMENT - 1);
    return (void *)a;
}

static inline int testandset (spinlock_t *p)
{
    unsigned int ret;
    p = ldcw_align(p);
    __asm__ __volatile__("ldcw 0(%1),%0"
                         : "=r" (ret)
                         : "r" (p)
                         : "memory" );
    return !ret;
}

#elif defined(__ia64)

#include <ia64intrin.h>

static inline int testandset (int *p)
{
    return __sync_lock_test_and_set (p, 1);
}
#elif defined(__mips__)
static inline int testandset (int *p)
{
    int ret;

    __asm__ __volatile__ (
	"	.set push		\n"
	"	.set noat		\n"
	"	.set mips2		\n"
	"1:	li	$1, 1		\n"
	"	ll	%0, %1		\n"
	"	sc	$1, %1		\n"
	"	beqz	$1, 1b		\n"
	"	.set pop		"
	: "=r" (ret), "+R" (*p)
	:
	: "memory");

    return ret;
}
#else
#error unimplemented CPU support
#endif

#if defined(CONFIG_USER_ONLY)
static inline void spin_lock(spinlock_t *lock)
{
    while (testandset(lock));
}

static inline void spin_unlock(spinlock_t *lock)
{
    resetlock(lock);
}

static inline int spin_trylock(spinlock_t *lock)
{
    return !testandset(lock);
}
#else
static inline void spin_lock(spinlock_t *lock)
{
}

static inline void spin_unlock(spinlock_t *lock)
{
}

static inline int spin_trylock(spinlock_t *lock)
{
    return 1;
}
#endif

#endif
