/*	$OpenBSD: atomic.h,v 1.7 2014/06/17 19:49:53 kettenis Exp $	*/

/* Public Domain */

#ifndef _MACHINE_ATOMIC_H_
#define _MACHINE_ATOMIC_H_

#if defined(_KERNEL)

#include <sys/mutex.h>

#ifdef MULTIPROCESSOR
extern struct mutex mtx_atomic;
#define ATOMIC_LOCK	mtx_enter(&mtx_atomic)
#define ATOMIC_UNLOCK	mtx_leave(&mtx_atomic)
#else
#define ATOMIC_LOCK
#define ATOMIC_UNLOCK
#endif

static __inline void
atomic_setbits_int(volatile unsigned int *uip, unsigned int v)
{
	register_t eiem;

	__asm volatile("mfctl	%%cr15, %0": "=r" (eiem));
	__asm volatile("mtctl	%r0, %cr15");
	ATOMIC_LOCK;
	*uip |= v;
	ATOMIC_UNLOCK;
	__asm volatile("mtctl	%0, %%cr15":: "r" (eiem));
}

static __inline void
atomic_clearbits_int(volatile unsigned int *uip, unsigned int v)
{
	register_t eiem;

	__asm volatile("mfctl	%%cr15, %0": "=r" (eiem));
	__asm volatile("mtctl	%r0, %cr15");
	ATOMIC_LOCK;
	*uip &= ~v;
	ATOMIC_UNLOCK;
	__asm volatile("mtctl	%0, %%cr15":: "r" (eiem));
}

static __inline void
atomic_setbits_long(volatile unsigned long *uip, unsigned long v)
{
	register_t eiem;

	__asm volatile("mfctl	%%cr15, %0": "=r" (eiem));
	__asm volatile("mtctl	%r0, %cr15");
	ATOMIC_LOCK;
	*uip |= v;
	ATOMIC_UNLOCK;
	__asm volatile("mtctl	%0, %%cr15":: "r" (eiem));
}

static __inline void
atomic_clearbits_long(volatile unsigned long *uip, unsigned long v)
{
	register_t eiem;

	__asm volatile("mfctl	%%cr15, %0": "=r" (eiem));
	__asm volatile("mtctl	%r0, %cr15");
	ATOMIC_LOCK;
	*uip &= ~v;
	ATOMIC_UNLOCK;
	__asm volatile("mtctl	%0, %%cr15":: "r" (eiem));
}

/*
 * Although the PA-RISC 2.0 architecture allows an implementation to
 * be weakly ordered, all PA-RISC processers to date implement a
 * strong memory ordering model.  So all we need is a compiler
 * barrier.
 */

static inline void
__insn_barrier(void)
{
	__asm volatile("" : : : "memory");
}

#define membar_enter()		__insn_barrier()
#define membar_exit()		__insn_barrier()
#define membar_producer()	__insn_barrier()
#define membar_consumer()	__insn_barrier()
#define membar_sync()		__insn_barrier()

#endif /* defined(_KERNEL) */
#endif /* _MACHINE_ATOMIC_H_ */