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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>

extern inline unsigned long rdusp(void) {

        unsigned long usp;

        __asm__ __volatile__("movec %/usp,%0"

                             : "=d" (usp));

        return usp;

}

extern inline void wrusp(unsigned long usp) {

        __asm__ __volatile__("movec %0,%/usp"

                             :

                             : "d" (usp));

}

/*

 * 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)

 */

asmlinkage void resume(void);

#define switch_to(prev,next) { \

  register int k __asm__ ("a1") = (int)&((struct task_struct *)0)->tss; \

  register int n __asm__ ("d1") = (int)next; \

  __asm__ __volatile__("jbsr " SYMBOL_NAME_STR(resume) "\n\t" \

                       : : "a" (k), "d" (n) \

                       : "d0", "d1", "d2", "d3", "d4", "d5", "a0", "a1"); \

}

#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))

#if defined(CONFIG_ATARI) && !defined(CONFIG_AMIGA) && !defined(CONFIG_MAC)

/* block out HSYNC on the atari */

#define sti() __asm__ __volatile__ ("andiw #0xfbff,%/sr": : : "memory")

#else /* portable version */

#define sti() __asm__ __volatile__ ("andiw #0xf8ff,%/sr": : : "memory")

#endif /* machine compilation types */ 

#define cli() __asm__ __volatile__ ("oriw  #0x0700,%/sr": : : "memory")

#define nop() __asm__ __volatile__ ("nop"::)

#define mb()  __asm__ __volatile__ (""   : : :"memory")

#define save_flags(x) \

__asm__ __volatile__("movew %/sr,%0":"=d" (x) : /* no input */ :"memory")

#define restore_flags(x) \

__asm__ __volatile__("movew %0,%/sr": /* no outputs */ :"d" (x) : "memory")

#define iret() __asm__ __volatile__ ("rte": : :"memory", "sp", "cc")

#if 1

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 */