/*
* include/asm-v850/system.h -- Low-level interrupt/thread ops
*
* Copyright (C) 2001,02,03 NEC Electronics Corporation
* Copyright (C) 2001,02,03 Miles Bader <miles@gnu.org>
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file COPYING in the main directory of this
* archive for more details.
*
* Written by Miles Bader <miles@gnu.org>
*/
#ifndef __V850_SYSTEM_H__
#define __V850_SYSTEM_H__
#include <linux/linkage.h>
#include <asm/ptrace.h>
#define prepare_to_switch() do { } while (0)
/*
* switch_to(n) should switch tasks to task ptr, first checking that
* ptr isn't the current task, in which case it does nothing.
*/
struct thread_struct;
extern void *switch_thread (struct thread_struct *last,
struct thread_struct *next);
#define switch_to(prev,next,last) \
do { \
if (prev != next) { \
(last) = switch_thread (&prev->thread, &next->thread); \
} \
} while (0)
/* Enable/disable interrupts. */
#define local_irq_enable() __asm__ __volatile__ ("ei")
#define local_irq_disable() __asm__ __volatile__ ("di")
#define local_save_flags(flags) \
__asm__ __volatile__ ("stsr %1, %0" : "=r" (flags) : "i" (SR_PSW))
#define local_restore_flags(flags) \
__asm__ __volatile__ ("ldsr %0, %1" :: "r" (flags), "i" (SR_PSW))
/* For spinlocks etc */
#define local_irq_save(flags) \
do { local_save_flags (flags); local_irq_disable (); } while (0)
#define local_irq_restore(flags) \
local_restore_flags (flags);
static inline int irqs_disabled (void)
{
unsigned flags;
local_save_flags (flags);
return !!(flags & 0x20);
}
/*
* Force strict CPU ordering.
* Not really required on v850...
*/
#define nop() __asm__ __volatile__ ("nop")
#define mb() __asm__ __volatile__ ("" ::: "memory")
#define rmb() mb ()
#define wmb() mb ()
#define read_barrier_depends() ((void)0)
#define set_rmb(var, value) do { xchg (&var, value); } while (0)
#define set_mb(var, value) set_rmb (var, value)
#define set_wmb(var, value) do { var = value; wmb (); } while (0)
#define smp_mb() mb ()
#define smp_rmb() rmb ()
#define smp_wmb() wmb ()
#define smp_read_barrier_depends() read_barrier_depends()
#define xchg(ptr, with) \
((__typeof__ (*(ptr)))__xchg ((unsigned long)(with), (ptr), sizeof (*(ptr))))
#define tas(ptr) (xchg ((ptr), 1))
extern inline unsigned long __xchg (unsigned long with,
__volatile__ void *ptr, int size)
{
unsigned long tmp, flags;
local_irq_save (flags);
switch (size) {
case 1:
tmp = *(unsigned char *)ptr;
*(unsigned char *)ptr = with;
break;
case 2:
tmp = *(unsigned short *)ptr;
*(unsigned short *)ptr = with;
break;
case 4:
tmp = *(unsigned long *)ptr;
*(unsigned long *)ptr = with;
break;
}
local_irq_restore (flags);
return tmp;
}
#define arch_align_stack(x) (x)
#endif /* __V850_SYSTEM_H__ */
