/*-
 * Copyright (c) 1998 Doug Rabson
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
 *
 * $FreeBSD$
 */

#ifndef _MACHINE_ATOMIC_H_
#define	_MACHINE_ATOMIC_H_

#ifndef _SYS_CDEFS_H_
#error this file needs sys/cdefs.h as a prerequisite
#endif

#include <machine/alpha_cpu.h>

/*
 * Various simple arithmetic on memory which is atomic in the presence
 * of interrupts and SMP safe.
 */

void atomic_set_8(volatile u_int8_t *, u_int8_t);
void atomic_clear_8(volatile u_int8_t *, u_int8_t);
void atomic_add_8(volatile u_int8_t *, u_int8_t);
void atomic_subtract_8(volatile u_int8_t *, u_int8_t);

void atomic_set_16(volatile u_int16_t *, u_int16_t);
void atomic_clear_16(volatile u_int16_t *, u_int16_t);
void atomic_add_16(volatile u_int16_t *, u_int16_t);
void atomic_subtract_16(volatile u_int16_t *, u_int16_t);

static __inline void atomic_set_32(volatile u_int32_t *p, u_int32_t v)
{
	u_int32_t temp;

#ifdef __GNUCLIKE_ASM
	__asm __volatile (
		"1:\tldl_l %0, %3\n\t"		/* load old value */
		"bis %0, %2, %0\n\t"		/* calculate new value */
		"stl_c %0, %1\n\t"		/* attempt to store */
		"beq %0, 1b\n"			/* spin if failed */
		: "=&r" (temp), "=m" (*p)
		: "r" (v), "m" (*p)
		: "memory");
#endif
}

static __inline void atomic_clear_32(volatile u_int32_t *p, u_int32_t v)
{
	u_int32_t temp;

#ifdef __GNUCLIKE_ASM
	__asm __volatile (
		"1:\tldl_l %0, %3\n\t"		/* load old value */
		"bic %0, %2, %0\n\t"		/* calculate new value */
		"stl_c %0, %1\n\t"		/* attempt to store */
		"beq %0, 1b\n"			/* spin if failed */
		: "=&r" (temp), "=m" (*p)
		: "r" (v), "m" (*p)
		: "memory");
#endif
}

static __inline void atomic_add_32(volatile u_int32_t *p, u_int32_t v)
{
	u_int32_t temp;

#ifdef __GNUCLIKE_ASM
	__asm __volatile (
		"1:\tldl_l %0, %3\n\t"		/* load old value */
		"addl %0, %2, %0\n\t"		/* calculate new value */
		"stl_c %0, %1\n\t"		/* attempt to store */
		"beq %0, 1b\n"			/* spin if failed */
		: "=&r" (temp), "=m" (*p)
		: "r" (v), "m" (*p)
		: "memory");
#endif
}

static __inline void atomic_subtract_32(volatile u_int32_t *p, u_int32_t v)
{
	u_int32_t temp;

#ifdef __GNUCLIKE_ASM
	__asm __volatile (
		"1:\tldl_l %0, %3\n\t"		/* load old value */
		"subl %0, %2, %0\n\t"		/* calculate new value */
		"stl_c %0, %1\n\t"		/* attempt to store */
		"beq %0, 1b\n"			/* spin if failed */
		: "=&r" (temp), "=m" (*p)
		: "r" (v), "m" (*p)
		: "memory");
#endif
}

static __inline u_int32_t atomic_readandclear_32(volatile u_int32_t *addr)
{
	u_int32_t result,temp;

#ifdef __GNUCLIKE_ASM
	__asm __volatile (
		"wmb\n"			/* ensure pending writes have drained */
		"1:\tldl_l %0,%3\n\t"	/* load current value, asserting lock */
		"ldiq %1,0\n\t"		/* value to store */
		"stl_c %1,%2\n\t"	/* attempt to store */
		"beq %1,1b\n"		/* if the store failed, spin */
		: "=&r"(result), "=&r"(temp), "=m" (*addr)
		: "m" (*addr)
		: "memory");
#endif

	return result;
}

static __inline void atomic_set_64(volatile u_int64_t *p, u_int64_t v)
{
	u_int64_t temp;

#ifdef __GNUCLIKE_ASM
	__asm __volatile (
		"1:\tldq_l %0, %3\n\t"		/* load old value */
		"bis %0, %2, %0\n\t"		/* calculate new value */
		"stq_c %0, %1\n\t"		/* attempt to store */
		"beq %0, 1b\n"			/* spin if failed */
		: "=&r" (temp), "=m" (*p)
		: "r" (v), "m" (*p)
		: "memory");
#endif
}

static __inline void atomic_clear_64(volatile u_int64_t *p, u_int64_t v)
{
	u_int64_t temp;

#ifdef __GNUCLIKE_ASM
	__asm __volatile (
		"1:\tldq_l %0, %3\n\t"		/* load old value */
		"bic %0, %2, %0\n\t"		/* calculate new value */
		"stq_c %0, %1\n\t"		/* attempt to store */
		"beq %0, 1b\n"			/* spin if failed */
		: "=&r" (temp), "=m" (*p)
		: "r" (v), "m" (*p)
		: "memory");
#endif
}

static __inline void atomic_add_64(volatile u_int64_t *p, u_int64_t v)
{
	u_int64_t temp;

#ifdef __GNUCLIKE_ASM
	__asm __volatile (
		"1:\tldq_l %0, %3\n\t"		/* load old value */
		"addq %0, %2, %0\n\t"		/* calculate new value */
		"stq_c %0, %1\n\t"		/* attempt to store */
		"beq %0, 1b\n"			/* spin if failed */
		: "=&r" (temp), "=m" (*p)
		: "r" (v), "m" (*p)
		: "memory");
#endif
}

static __inline void atomic_subtract_64(volatile u_int64_t *p, u_int64_t v)
{
	u_int64_t temp;

#ifdef __GNUCLIKE_ASM
	__asm __volatile (
		"1:\tldq_l %0, %3\n\t"		/* load old value */
		"subq %0, %2, %0\n\t"		/* calculate new value */
		"stq_c %0, %1\n\t"		/* attempt to store */
		"beq %0, 1b\n"			/* spin if failed */
		: "=&r" (temp), "=m" (*p)
		: "r" (v), "m" (*p)
		: "memory");
#endif
}

static __inline u_int64_t atomic_readandclear_64(volatile u_int64_t *addr)
{
	u_int64_t result,temp;

#ifdef __GNUCLIKE_ASM
	__asm __volatile (
		"wmb\n"			/* ensure pending writes have drained */
		"1:\tldq_l %0,%3\n\t"	/* load current value, asserting lock */
		"ldiq %1,0\n\t"		/* value to store */
		"stq_c %1,%2\n\t"	/* attempt to store */
		"beq %1,1b\n"		/* if the store failed, spin */
		: "=&r"(result), "=&r"(temp), "=m" (*addr)
		: "m" (*addr)
		: "memory");
#endif

	return result;
}

#define	ATOMIC_ACQ_REL(NAME, WIDTH)					\
static __inline void							\
atomic_##NAME##_acq_##WIDTH(volatile u_int##WIDTH##_t *p, u_int##WIDTH##_t v)\
{									\
	atomic_##NAME##_##WIDTH(p, v);					\
	alpha_mb(); 							\
}									\
									\
static __inline void							\
atomic_##NAME##_rel_##WIDTH(volatile u_int##WIDTH##_t *p, u_int##WIDTH##_t v)\
{									\
	alpha_mb();							\
	atomic_##NAME##_##WIDTH(p, v);					\
}

/* Variants of simple arithmetic with memory barriers. */
ATOMIC_ACQ_REL(set, 8)
ATOMIC_ACQ_REL(clear, 8)
ATOMIC_ACQ_REL(add, 8)
ATOMIC_ACQ_REL(subtract, 8)
ATOMIC_ACQ_REL(set, 16)
ATOMIC_ACQ_REL(clear, 16)
ATOMIC_ACQ_REL(add, 16)
ATOMIC_ACQ_REL(subtract, 16)
ATOMIC_ACQ_REL(set, 32)
ATOMIC_ACQ_REL(clear, 32)
ATOMIC_ACQ_REL(add, 32)
ATOMIC_ACQ_REL(subtract, 32)
ATOMIC_ACQ_REL(set, 64)
ATOMIC_ACQ_REL(clear, 64)
ATOMIC_ACQ_REL(add, 64)
ATOMIC_ACQ_REL(subtract, 64)

#undef ATOMIC_ACQ_REL

/*
 * We assume that a = b will do atomic loads and stores.
 */
#define	ATOMIC_STORE_LOAD(WIDTH)			\
static __inline u_int##WIDTH##_t			\
atomic_load_acq_##WIDTH(volatile u_int##WIDTH##_t *p)	\
{							\
	u_int##WIDTH##_t v;				\
							\
	v = *p;						\
	alpha_mb();					\
	return (v);					\
}							\
							\
static __inline void					\
atomic_store_rel_##WIDTH(volatile u_int##WIDTH##_t *p, u_int##WIDTH##_t v)\
{							\
	alpha_mb();					\
	*p = v;						\
}

ATOMIC_STORE_LOAD(32)
ATOMIC_STORE_LOAD(64)

#undef ATOMIC_STORE_LOAD

/*
 * Atomically compare the value stored at *p with cmpval and if the
 * two values are equal, update the value of *p with newval. Returns
 * zero if the compare failed, nonzero otherwise.
 */
static __inline u_int32_t
atomic_cmpset_32(volatile u_int32_t* p, u_int32_t cmpval, u_int32_t newval)
{
	u_int32_t ret;

#ifdef __GNUCLIKE_ASM
	__asm __volatile (
		"1:\tldl_l %0, %4\n\t"		/* load old value */
		"cmpeq %0, %2, %0\n\t"		/* compare */
		"beq %0, 2f\n\t"		/* exit if not equal */
		"mov %3, %0\n\t"		/* value to store */
		"stl_c %0, %1\n\t"		/* attempt to store */
		"beq %0, 1b\n\t"		/* if it failed, spin */
		"2:\n"
		: "=&r" (ret), "=m" (*p)
		: "r" ((long)(int)cmpval), "r" (newval), "m" (*p)
		: "memory");
#endif

	return ret;
}

/*
 * Atomically compare the value stored at *p with cmpval and if the
 * two values are equal, update the value of *p with newval. Returns
 * zero if the compare failed, nonzero otherwise.
 */
static __inline u_int64_t
atomic_cmpset_64(volatile u_int64_t* p, u_int64_t cmpval, u_int64_t newval)
{
	u_int64_t ret;

#ifdef __GNUCLIKE_ASM
	__asm __volatile (
		"1:\tldq_l %0, %4\n\t"		/* load old value */
		"cmpeq %0, %2, %0\n\t"		/* compare */
		"beq %0, 2f\n\t"		/* exit if not equal */
		"mov %3, %0\n\t"		/* value to store */
		"stq_c %0, %1\n\t"		/* attempt to store */
		"beq %0, 1b\n\t"		/* if it failed, spin */
		"2:\n"
		: "=&r" (ret), "=m" (*p)
		: "r" (cmpval), "r" (newval), "m" (*p)
		: "memory");
#endif

	return ret;
}

static __inline u_int32_t
atomic_cmpset_acq_32(volatile u_int32_t *p, u_int32_t cmpval, u_int32_t newval)
{
	int retval;

	retval = atomic_cmpset_32(p, cmpval, newval);
	alpha_mb();
	return (retval);
}

static __inline u_int32_t
atomic_cmpset_rel_32(volatile u_int32_t *p, u_int32_t cmpval, u_int32_t newval)
{
	alpha_mb();
	return (atomic_cmpset_32(p, cmpval, newval));
}

static __inline u_int64_t
atomic_cmpset_acq_64(volatile u_int64_t *p, u_int64_t cmpval, u_int64_t newval)
{
	int retval;

	retval = atomic_cmpset_64(p, cmpval, newval);
	alpha_mb();
	return (retval);
}

static __inline u_int64_t
atomic_cmpset_rel_64(volatile u_int64_t *p, u_int64_t cmpval, u_int64_t newval)
{
	alpha_mb();
	return (atomic_cmpset_64(p, cmpval, newval));
}

/*
 * Atomically add the value of v to the integer pointed to by p and return
 * the previous value of *p.
 */
static __inline u_int
atomic_fetchadd_32(volatile u_int32_t *p, u_int32_t v)
{
	u_int32_t value, temp;

#ifdef __GNUCLIKE_ASM
	__asm __volatile (
		"1:\tldl_l %0, %1\n\t"		/* load old value */
		"addl %0, %3, %2\n\t"		/* calculate new value */
		"stl_c %2, %1\n\t"		/* attempt to store */
		"beq %2, 1b\n"			/* spin if failed */
		: "=&r" (value), "=m" (*p), "=r" (temp)
		: "r" (v), "m" (*p));
#endif
	return (value);
}

/* Operations on chars. */
#define	atomic_set_char		atomic_set_8
#define	atomic_set_acq_char	atomic_set_acq_8
#define	atomic_set_rel_char	atomic_set_rel_8
#define	atomic_clear_char	atomic_clear_8
#define	atomic_clear_acq_char	atomic_clear_acq_8
#define	atomic_clear_rel_char	atomic_clear_rel_8
#define	atomic_add_char		atomic_add_8
#define	atomic_add_acq_char	atomic_add_acq_8
#define	atomic_add_rel_char	atomic_add_rel_8
#define	atomic_subtract_char	atomic_subtract_8
#define	atomic_subtract_acq_char	atomic_subtract_acq_8
#define	atomic_subtract_rel_char	atomic_subtract_rel_8

/* Operations on shorts. */
#define	atomic_set_short	atomic_set_16
#define	atomic_set_acq_short	atomic_set_acq_16
#define	atomic_set_rel_short	atomic_set_rel_16
#define	atomic_clear_short	atomic_clear_16
#define	atomic_clear_acq_short	atomic_clear_acq_16
#define	atomic_clear_rel_short	atomic_clear_rel_16
#define	atomic_add_short	atomic_add_16
#define	atomic_add_acq_short	atomic_add_acq_16
#define	atomic_add_rel_short	atomic_add_rel_16
#define	atomic_subtract_short	atomic_subtract_16
#define	atomic_subtract_acq_short	atomic_subtract_acq_16
#define	atomic_subtract_rel_short	atomic_subtract_rel_16

/* Operations on ints. */
#define	atomic_set_int		atomic_set_32
#define	atomic_set_acq_int	atomic_set_acq_32
#define	atomic_set_rel_int	atomic_set_rel_32
#define	atomic_clear_int	atomic_clear_32
#define	atomic_clear_acq_int	atomic_clear_acq_32
#define	atomic_clear_rel_int	atomic_clear_rel_32
#define	atomic_add_int		atomic_add_32
#define	atomic_add_acq_int	atomic_add_acq_32
#define	atomic_add_rel_int	atomic_add_rel_32
#define	atomic_subtract_int	atomic_subtract_32
#define	atomic_subtract_acq_int	atomic_subtract_acq_32
#define	atomic_subtract_rel_int	atomic_subtract_rel_32
#define	atomic_cmpset_int	atomic_cmpset_32
#define	atomic_cmpset_acq_int	atomic_cmpset_acq_32
#define	atomic_cmpset_rel_int	atomic_cmpset_rel_32
#define	atomic_load_acq_int	atomic_load_acq_32
#define	atomic_store_rel_int	atomic_store_rel_32
#define	atomic_readandclear_int	atomic_readandclear_32
#define	atomic_fetchadd_int	atomic_fetchadd_32

/* Operations on longs. */
#define	atomic_set_long		atomic_set_64
#define	atomic_set_acq_long	atomic_set_acq_64
#define	atomic_set_rel_long	atomic_set_rel_64
#define	atomic_clear_long	atomic_clear_64
#define	atomic_clear_acq_long	atomic_clear_acq_64
#define	atomic_clear_rel_long	atomic_clear_rel_64
#define	atomic_add_long		atomic_add_64
#define	atomic_add_acq_long	atomic_add_acq_64
#define	atomic_add_rel_long	atomic_add_rel_64
#define	atomic_subtract_long	atomic_subtract_64
#define	atomic_subtract_acq_long	atomic_subtract_acq_64
#define	atomic_subtract_rel_long	atomic_subtract_rel_64
#define	atomic_cmpset_long	atomic_cmpset_64
#define	atomic_cmpset_acq_long	atomic_cmpset_acq_64
#define	atomic_cmpset_rel_long	atomic_cmpset_rel_64
#define	atomic_load_acq_long	atomic_load_acq_64
#define	atomic_store_rel_long	atomic_store_rel_64
#define	atomic_readandclear_long	atomic_readandclear_64

/* Operations on pointers. */
#define	atomic_set_ptr		atomic_set_64
#define	atomic_set_acq_ptr	atomic_set_acq_64
#define	atomic_set_rel_ptr	atomic_set_rel_64
#define	atomic_clear_ptr	atomic_clear_64
#define	atomic_clear_acq_ptr	atomic_clear_acq_64
#define	atomic_clear_rel_ptr	atomic_clear_rel_64
#define	atomic_add_ptr		atomic_add_64
#define	atomic_add_acq_ptr	atomic_add_acq_64
#define	atomic_add_rel_ptr	atomic_add_rel_64
#define	atomic_subtract_ptr	atomic_subtract_64
#define	atomic_subtract_acq_ptr	atomic_subtract_acq_64
#define	atomic_subtract_rel_ptr	atomic_subtract_rel_64
#define	atomic_cmpset_ptr	atomic_cmpset_64
#define	atomic_cmpset_acq_ptr	atomic_cmpset_acq_64
#define	atomic_cmpset_rel_ptr	atomic_cmpset_rel_64
#define	atomic_load_acq_ptr	atomic_load_acq_64
#define	atomic_store_rel_ptr	atomic_store_rel_64
#define	atomic_readandclear_ptr	atomic_readandclear_64

#endif /* ! _MACHINE_ATOMIC_H_ */