os-k/include/ke/spinlock.h

//----------------------------------------------------------------------------//
//                           GNU GPL OS/K                                     //
//                                                                            //
//  Desc:       Spinlocks                                                     //
//                                                                            //
//                                                                            //
//  Copyright © 2018-2020 The OS/K Team                                       //
//                                                                            //
//  This file is part of OS/K.                                                //
//                                                                            //
//  OS/K is free software: you can redistribute it and/or modify              //
//  it under the terms of the GNU General Public License as published by      //
//  the Free Software Foundation, either version 3 of the License, or         //
//  any later version.                                                        //
//                                                                            //
//  OS/K 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 General Public License for more details.                              //
//                                                                            //
//  You should have received a copy of the GNU General Public License         //
//  along with OS/K.  If not, see <https://www.gnu.org/licenses/>.            //
//----------------------------------------------------------------------------//

#ifndef _KERNEL_H
#include <kernel.h>
#endif

#ifndef _KALKERN_SPINLOCK_H
#define _KALKERN_SPINLOCK_H

#ifdef __cplusplus
extern "C" {
#endif

//----------------------------------------------------------------------------//

static inline void KeInitSpinlock(Spinlock_t *lock) { *lock = 0; }

static inline void KeAcquireSpinlockIRQ(Spinlock_t *lock)
{
    while (1) {
        if (!atomic_xchg_64(lock, (void *)1)) return;
        while (*lock) __relax_cpu();
    }
}

static inline void KeAcquireSpinlock(Spinlock_t *lock)
{
    while (1) {
        if (!atomic_xchg_64(lock, KeCurThread)) return;
        while (*lock) __relax_cpu();
    }
}

static inline void KeReleaseSpinlock(Spinlock_t *lock)
{
    atomic_barrier();
    assert(*lock == (ulong)KeCurThread);
    *lock = 0;
}

static inline ulong KeTestSpinLock(Spinlock_t *lock)
{
    return (ulong)atomic_xchg_64(lock, KeCurThread);
}

//------------------------------------------//

#ifdef __cplusplus
}
#endif

#endif