/*-
 * Copyright (c) 2002-2018 The UbixOS Project.
 * All rights reserved.
 *
 * This was developed by Christopher W. Olsen for the UbixOS Project.
 *
 * 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, the following disclaimer and the list of authors.
 * 2) Redistributions in binary form must reproduce the above copyright notice, this list of
 *    conditions, the following disclaimer and the list of authors in the documentation and/or
 *    other materials provided with the distribution.
 * 3) Neither the name of the UbixOS Project nor the names of its contributors may be used to
 *    endorse or promote products derived from this software without specific prior written
 *    permission.
 *
 * 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 COPYRIGHT OWNER 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.
 */

#ifndef _UBIXOS_SPINLOCK_H
#define _UBIXOS_SPINLOCK_H

#include <sys/types.h>

#define LOCKED   1
#define UNLOCKED 0
#define SPIN_LOCK_INITIALIZER {NULL, 0}
#define LLOCK_FLAG (void *)1

//typedef volatile int spinLock_t;

struct spinLock {
    struct spinLock *next;
    uint32_t locked;
};

typedef struct spinLock *spinLock_t;

extern struct spinLock Master;

void spinLockInit(spinLock_t);
void spinUnlock(spinLock_t);
int spinTryLock(spinLock_t);
void spinLock(spinLock_t);

void spinLock_scheduler(spinLock_t *); /* Only use this spinlock in the sched. */

int spinLockLocked(spinLock_t *);

/* Atomic exchange (of various sizes) */
static inline u_long xchg_64(volatile uint32_t *ptr, u_long x) {
  __asm__ __volatile__("xchgq %1,%0"
    :"+r" (x),
    "+m" (*ptr));

  return x;
}

static inline unsigned xchg_32(volatile uint32_t *ptr, uint32_t x) {
  __asm__ __volatile__("xchgl %1,%0"
    :"+r" (x),
    "+m" (*ptr));

  return x;
}

static inline unsigned short xchg_16(volatile uint32_t *ptr, uint16_t x) {
  __asm__ __volatile__("xchgw %1,%0"
    :"+r" (x),
    "+m" (*ptr));

  return x;
}

/* Test and set a bit */
static inline char atomic_bitsetandtest(void *ptr, int x) {
  char out;
  __asm__ __volatile__("lock; bts %2,%1\n"
    "sbb %0,%0\n"
    :"=r" (out), "=m" (*(volatile long long *)ptr)
    :"Ir" (x)
    :"memory");

  return out;
}

#endif