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#ifndef _M68K_SYSTEM_H
#define _M68K_SYSTEM_H
#include <linux/config.h> /* get configuration macros */
#include <linux/linkage.h>
#include <asm/segment.h>
#include <asm/entry.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. This
* also clears the TS-flag if the task we switched to has used the
* math co-processor latest.
*/
/*
* switch_to() saves the extra registers, that are not saved
* automatically by SAVE_SWITCH_STACK in resume(), ie. d0-d5 and
* a0-a1. Some of these are used by schedule() and its predecessors
* and so we might get see unexpected behaviors when a task returns
* with unexpected register values.
*
* syscall stores these registers itself and none of them are used
* by syscall after the function in the syscall has been called.
*
* Beware that resume now expects *next to be in d1 and the offset of
* tss to be in a1. This saves a few instructions as we no longer have
* to push them onto the stack and read them back right after.
*
* 02/17/96 - Jes Sorensen (jds@kom.auc.dk)
*
* Changed 96/09/19 by Andreas Schwab
* pass prev in a0, next in a1, offset of tss in d1, and whether
* the mm structures are shared in d2 (to avoid atc flushing).
*/
asmlinkage void resume(void);
#define switch_to(prev,next,last) { \
register void *_prev __asm__ ("a0") = (prev); \
register void *_next __asm__ ("a1") = (next); \
register void *_last __asm__ ("d1"); \
__asm__ __volatile__("jbsr " SYMBOL_NAME_STR(resume) \
: "=d" (_last) : "a" (_prev), "a" (_next) \
: "d0", "d1", "d2", "d3", "d4", "d5", "a0", "a1"); \
(last) = _last; \
}
/* interrupt control.. */
#if 0
#define __sti() asm volatile ("andiw %0,%%sr": : "i" (ALLOWINT) : "memory")
#else
#include <asm/hardirq.h>
#define __sti() ({ \
if (!local_irq_count[smp_processor_id()]) \
asm volatile ("andiw %0,%%sr": : "i" (ALLOWINT) : "memory"); \
})
#endif
#define __cli() asm volatile ("oriw #0x0700,%%sr": : : "memory")
#define __save_flags(x) asm volatile ("movew %%sr,%0":"=d" (x) : : "memory")
#define __restore_flags(x) asm volatile ("movew %0,%%sr": :"d" (x) : "memory")
/* For spinlocks etc */
#define local_irq_save(x) ({ __save_flags(x); __cli(); })
#define local_irq_restore(x) __restore_flags(x)
#define local_irq_disable() __cli()
#define local_irq_enable() __sti()
#define cli() __cli()
#define sti() __sti()
#define save_flags(x) __save_flags(x)
#define restore_flags(x) __restore_flags(x)
/*
* Force strict CPU ordering.
* Not really required on m68k...
*/
#define nop() asm volatile ("nop"::)
#define mb() asm volatile ("" : : :"memory")
#define rmb() asm volatile ("" : : :"memory")
#define wmb() asm volatile ("" : : :"memory")
#define set_mb(var, value) do { xchg(&var, value); } while (0)
#define set_wmb(var, value) do { var = value; wmb(); } while (0)
#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
#define tas(ptr) (xchg((ptr),1))
struct __xchg_dummy { unsigned long a[100]; };
#define __xg(x) ((volatile struct __xchg_dummy *)(x))
#ifndef CONFIG_RMW_INSNS
static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
{
unsigned long tmp, flags;
save_flags(flags);
cli();
switch (size) {
case 1:
__asm__ __volatile__
("moveb %2,%0\n\t"
"moveb %1,%2"
: "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
break;
case 2:
__asm__ __volatile__
("movew %2,%0\n\t"
"movew %1,%2"
: "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
break;
case 4:
__asm__ __volatile__
("movel %2,%0\n\t"
"movel %1,%2"
: "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
break;
}
restore_flags(flags);
return tmp;
}
#else
static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
{
switch (size) {
case 1:
__asm__ __volatile__
("moveb %2,%0\n\t"
"1:\n\t"
"casb %0,%1,%2\n\t"
"jne 1b"
: "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
break;
case 2:
__asm__ __volatile__
("movew %2,%0\n\t"
"1:\n\t"
"casw %0,%1,%2\n\t"
"jne 1b"
: "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
break;
case 4:
__asm__ __volatile__
("movel %2,%0\n\t"
"1:\n\t"
"casl %0,%1,%2\n\t"
"jne 1b"
: "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
break;
}
return x;
}
#endif
#endif /* _M68K_SYSTEM_H */
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