include/kernel/spinlock.h

/*
 * Copyright (c) 2014 Travis Geiselbrecht
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
#pragma once

#include <compiler.h>
#include <arch/spinlock.h>

__BEGIN_CDECLS

/* interrupts should already be disabled */
static inline void spin_lock(spin_lock_t *lock)
{
    arch_spin_lock(lock);
}

/* Returns 0 on success, non-0 on failure */
static inline int spin_trylock(spin_lock_t *lock)
{
    return arch_spin_trylock(lock);
}

/* interrupts should already be disabled */
static inline void spin_unlock(spin_lock_t *lock)
{
    arch_spin_unlock(lock);
}

static inline void spin_lock_init(spin_lock_t *lock)
{
    arch_spin_lock_init(lock);
}

static inline bool spin_lock_held(spin_lock_t *lock)
{
    return arch_spin_lock_held(lock);
}

/* spin lock irq save flags: */

/* Possible future flags:
 * SPIN_LOCK_FLAG_PMR_MASK         = 0x000000ff
 * SPIN_LOCK_FLAG_PREEMPTION       = 0x00000100
 * SPIN_LOCK_FLAG_SET_PMR          = 0x00000200
 */

/* Generic flags */
#define SPIN_LOCK_FLAG_INTERRUPTS ARCH_DEFAULT_SPIN_LOCK_FLAG_INTERRUPTS

/* same as spin lock, but save disable and save interrupt state first */
static inline void spin_lock_save(
    spin_lock_t *lock,
    spin_lock_saved_state_t *statep,
    spin_lock_save_flags_t flags)
{
    arch_interrupt_save(statep, flags);
    spin_lock(lock);
}

/* restore interrupt state before unlocking */
static inline void spin_unlock_restore(
    spin_lock_t *lock,
    spin_lock_saved_state_t old_state,
    spin_lock_save_flags_t flags)
{
    spin_unlock(lock);
    arch_interrupt_restore(old_state, flags);
}

/* hand(ier) routines */
#define spin_lock_irqsave(lock, statep) spin_lock_save(lock, &(statep), SPIN_LOCK_FLAG_INTERRUPTS)
#define spin_unlock_irqrestore(lock, statep) spin_unlock_restore(lock, statep, SPIN_LOCK_FLAG_INTERRUPTS)

__END_CDECLS