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// See LICENSE for license details.
#ifndef _RISCV_ATOMIC_H
#define _RISCV_ATOMIC_H
#include "config.h"
#include "encoding.h"
typedef struct { volatile long val; } atomic_t;
typedef struct { atomic_t lock; } spinlock_t;
#define SPINLOCK_INIT {{0}}
#define mb() __sync_synchronize()
static inline void atomic_set(atomic_t* a, long val)
{
a->val = val;
}
static inline long atomic_read(atomic_t* a)
{
return a->val;
}
static inline long atomic_add(atomic_t* a, long inc)
{
#ifdef PK_ENABLE_ATOMICS
return __sync_fetch_and_add(&a->val, inc);
#else
long ret = atomic_read(a);
atomic_set(a, ret + inc);
return ret;
#endif
}
static inline long atomic_swap(atomic_t* a, long val)
{
#ifdef PK_ENABLE_ATOMICS
return __sync_lock_test_and_set(&a->val, val);
#else
long ret = atomic_read(a);
atomic_set(a, val);
return ret;
#endif
}
static inline long atomic_cas(atomic_t* a, long compare, long swap)
{
#ifdef PK_ENABLE_ATOMICS
return __sync_val_compare_and_swap(&a->val, compare, swap);
#else
long ret = atomic_read(a);
if (ret == compare)
atomic_set(a, swap);
return ret;
#endif
}
static inline void spinlock_lock(spinlock_t* lock)
{
do
{
while (atomic_read(&lock->lock))
;
} while (atomic_swap(&lock->lock, -1));
mb();
}
static inline void spinlock_unlock(spinlock_t* lock)
{
mb();
atomic_set(&lock->lock,0);
}
static inline long spinlock_lock_irqsave(spinlock_t* lock)
{
long flags = clear_csr(mstatus, MSTATUS_IE);
spinlock_lock(lock);
return flags;
}
static inline void spinlock_unlock_irqrestore(spinlock_t* lock, long flags)
{
spinlock_unlock(lock);
set_csr(mstatus, flags & MSTATUS_IE);
}
#endif
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