/*-
 * 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: src/sys/alpha/include/atomic.h,v 1.21.2.3 2005/10/06 18:12:05 jhb Exp $
 */

#ifndef _MACHINE_ATOMIC_H_
#define _MACHINE_ATOMIC_H_

/*
 * Inlines for Alpha instructions normally inaccessible from C.
 */

static __inline void
alpha_mb(void)
{
        __asm__ __volatile__ ("mb");
}

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

void atomic_set_8(volatile uint8_t *, uint8_t);
void atomic_clear_8(volatile uint8_t *, uint8_t);
void atomic_add_8(volatile uint8_t *, uint8_t);
void atomic_subtract_8(volatile uint8_t *, uint8_t);

void atomic_set_16(volatile uint16_t *, uint16_t);
void atomic_clear_16(volatile uint16_t *, uint16_t);
void atomic_add_16(volatile uint16_t *, uint16_t);
void atomic_subtract_16(volatile uint16_t *, uint16_t);

static __inline void atomic_set_32(volatile uint32_t *p, uint32_t v)
{
        uint32_t temp;

        __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");
}

static __inline void atomic_clear_32(volatile uint32_t *p, uint32_t v)
{
        uint32_t temp;

        __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");
}

static __inline void atomic_add_32(volatile uint32_t *p, uint32_t v)
{
        uint32_t temp;

        __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");
}

static __inline void atomic_subtract_32(volatile uint32_t *p, uint32_t v)
{
        uint32_t temp;

        __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");
}

static __inline uint32_t atomic_readandclear_32(volatile uint32_t *addr)
{
        uint32_t result,temp;

        __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");

        return result;
}

static __inline void atomic_set_64(volatile uint64_t *p, uint64_t v)
{
        uint64_t temp;

        __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");
}

static __inline void atomic_clear_64(volatile uint64_t *p, uint64_t v)
{
        uint64_t temp;

        __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");
}

static __inline void atomic_add_64(volatile uint64_t *p, uint64_t v)
{
        uint64_t temp;

        __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");
}

static __inline void atomic_subtract_64(volatile uint64_t *p, uint64_t v)
{
        uint64_t temp;

        __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");
}

static __inline uint64_t atomic_readandclear_64(volatile uint64_t *addr)
{
        uint64_t result,temp;

        __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");

        return result;
}

#define ATOMIC_ACQ_REL(NAME, WIDTH)                                     \
static __inline void                                                    \
atomic_##NAME##_acq_##WIDTH(volatile uint##WIDTH##_t *p, uint##WIDTH##_t v)\
{                                                                       \
        atomic_##NAME##_##WIDTH(p, v);                                  \
        alpha_mb();                                                     \
}                                                                       \
                                                                        \
static __inline void                                                    \
atomic_##NAME##_rel_##WIDTH(volatile uint##WIDTH##_t *p, uint##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 uint##WIDTH##_t                        \
atomic_load_acq_##WIDTH(volatile uint##WIDTH##_t *p)   \
{                                                       \
        uint##WIDTH##_t v;                             \
                                                        \
        v = *p;                                         \
        alpha_mb();                                     \
        return (v);                                     \
}                                                       \
                                                        \
static __inline void                                    \
atomic_store_rel_##WIDTH(volatile uint##WIDTH##_t *p, uint##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 uint32_t
atomic_cmpset_32(volatile uint32_t* p, uint32_t cmpval, uint32_t newval)
{
        uint32_t ret;

        __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");

        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 uint64_t
atomic_cmpset_64(volatile uint64_t* p, uint64_t cmpval, uint64_t newval)
{
        uint64_t ret;

        __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");

        return ret;
}

static __inline uint32_t
atomic_cmpset_acq_32(volatile uint32_t *p, uint32_t cmpval, uint32_t newval)
{
        int retval;

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

static __inline uint32_t
atomic_cmpset_rel_32(volatile uint32_t *p, uint32_t cmpval, uint32_t newval)
{
        alpha_mb();
        return (atomic_cmpset_32(p, cmpval, newval));
}

static __inline uint64_t
atomic_cmpset_acq_64(volatile uint64_t *p, uint64_t cmpval, uint64_t newval)
{
        int retval;

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

static __inline uint64_t
atomic_cmpset_rel_64(volatile uint64_t *p, uint64_t cmpval, uint64_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 uint
atomic_fetchadd_32(volatile uint32_t *p, uint32_t v)
{
        uint32_t value, temp;

        __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));

        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_ */