#ifndef _M68K_SEMAPHORE_H
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#ifndef _M68K_SEMAPHORE_H
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#define _M68K_SEMAPHORE_H
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#define _M68K_SEMAPHORE_H
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#include <linux/linkage.h>
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#include <linux/linkage.h>
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/*
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/*
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* SMP- and interrupt-safe semaphores..
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* SMP- and interrupt-safe semaphores..
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*
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*
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* (C) Copyright 1996 Linus Torvalds
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* (C) Copyright 1996 Linus Torvalds
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*
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*
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* m68k version by Andreas Schwab
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* m68k version by Andreas Schwab
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*/
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*/
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struct semaphore {
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struct semaphore {
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int count;
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int count;
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int waking;
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int waking;
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int lock; /* to make waking testing atomic */
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int lock; /* to make waking testing atomic */
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struct wait_queue * wait;
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struct wait_queue * wait;
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};
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};
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#define MUTEX ((struct semaphore) { 1, 0, 0, NULL })
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#define MUTEX ((struct semaphore) { 1, 0, 0, NULL })
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#define MUTEX_LOCKED ((struct semaphore) { 0, 0, 0, NULL })
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#define MUTEX_LOCKED ((struct semaphore) { 0, 0, 0, NULL })
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asmlinkage void __down_failed(void /* special register calling convention */);
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asmlinkage void __down_failed(void /* special register calling convention */);
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asmlinkage int __down_failed_interruptible(void); /* params in registers */
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asmlinkage int __down_failed_interruptible(void); /* params in registers */
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asmlinkage void __up_wakeup(void /* special register calling convention */);
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asmlinkage void __up_wakeup(void /* special register calling convention */);
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extern void __down(struct semaphore * sem);
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extern void __down(struct semaphore * sem);
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extern void __up(struct semaphore * sem);
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extern void __up(struct semaphore * sem);
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/*
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/*
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* This is ugly, but we want the default case to fall through.
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* This is ugly, but we want the default case to fall through.
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* "down_failed" is a special asm handler that calls the C
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* "down_failed" is a special asm handler that calls the C
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* routine that actually waits. See arch/m68k/lib/semaphore.S
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* routine that actually waits. See arch/m68k/lib/semaphore.S
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*/
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*/
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extern inline void down(struct semaphore * sem)
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extern inline void down(struct semaphore * sem)
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{
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{
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register struct semaphore *sem1 __asm__ ("%a1") = sem;
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register struct semaphore *sem1 __asm__ ("%a1") = sem;
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__asm__ __volatile__(
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__asm__ __volatile__(
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"| atomic down operation\n\t"
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"| atomic down operation\n\t"
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"lea %%pc@(1f),%%a0\n\t"
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"lea %%pc@(1f),%%a0\n\t"
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"subql #1,%0@\n\t"
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"subql #1,%0@\n\t"
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"jmi " SYMBOL_NAME_STR(__down_failed) "\n"
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"jmi " SYMBOL_NAME_STR(__down_failed) "\n"
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"1:"
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"1:"
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: /* no outputs */
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: /* no outputs */
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: "a" (sem1)
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: "a" (sem1)
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: "%a0", "memory");
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: "%a0", "memory");
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}
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}
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/*
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/*
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* This version waits in interruptible state so that the waiting
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* This version waits in interruptible state so that the waiting
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* process can be killed. The down_failed_interruptible routine
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* process can be killed. The down_failed_interruptible routine
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* returns negative for signalled and zero for semaphore acquired.
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* returns negative for signalled and zero for semaphore acquired.
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*/
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*/
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extern inline int down_interruptible(struct semaphore * sem)
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extern inline int down_interruptible(struct semaphore * sem)
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{
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{
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register int ret __asm__ ("%d0");
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register int ret __asm__ ("%d0");
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register struct semaphore *sem1 __asm__ ("%a1") = sem;
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register struct semaphore *sem1 __asm__ ("%a1") = sem;
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__asm__ __volatile__(
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__asm__ __volatile__(
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"| atomic down operation\n\t"
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"| atomic down operation\n\t"
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"lea %%pc@(1f),%%a0\n\t"
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"lea %%pc@(1f),%%a0\n\t"
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"subql #1,%1@\n\t"
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"subql #1,%1@\n\t"
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"jmi " SYMBOL_NAME_STR(__down_failed_interruptible) "\n"
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"jmi " SYMBOL_NAME_STR(__down_failed_interruptible) "\n"
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"clrl %0\n"
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"clrl %0\n"
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"1:"
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"1:"
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: "=d" (ret)
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: "=d" (ret)
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: "a" (sem1)
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: "a" (sem1)
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: "%a0", "memory");
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: "%a0", "memory");
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return(ret);
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return(ret);
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}
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}
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/*
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/*
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* Primitives to spin on a lock. Needed only for SMP version ... so
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* Primitives to spin on a lock. Needed only for SMP version ... so
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* somebody should start playing with one of those Sony NeWS stations.
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* somebody should start playing with one of those Sony NeWS stations.
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*/
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*/
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extern inline void get_buzz_lock(int *lock_ptr)
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extern inline void get_buzz_lock(int *lock_ptr)
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{
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{
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#ifdef __SMP__
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#ifdef __SMP__
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while (xchg(lock_ptr,1) != 0) ;
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while (xchg(lock_ptr,1) != 0) ;
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#endif
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#endif
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}
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}
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extern inline void give_buzz_lock(int *lock_ptr)
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extern inline void give_buzz_lock(int *lock_ptr)
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{
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{
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#ifdef __SMP__
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#ifdef __SMP__
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*lock_ptr = 0 ;
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*lock_ptr = 0 ;
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#endif
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#endif
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}
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}
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/*
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/*
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* Note! This is subtle. We jump to wake people up only if
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* Note! This is subtle. We jump to wake people up only if
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* the semaphore was negative (== somebody was waiting on it).
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* the semaphore was negative (== somebody was waiting on it).
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* The default case (no contention) will result in NO
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* The default case (no contention) will result in NO
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* jumps for both down() and up().
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* jumps for both down() and up().
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*/
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*/
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extern inline void up(struct semaphore * sem)
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extern inline void up(struct semaphore * sem)
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{
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{
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register struct semaphore *sem1 __asm__ ("%a1") = sem;
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register struct semaphore *sem1 __asm__ ("%a1") = sem;
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__asm__ __volatile__(
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__asm__ __volatile__(
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"| atomic up operation\n\t"
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"| atomic up operation\n\t"
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"lea %%pc@(1f),%%a0\n\t"
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"lea %%pc@(1f),%%a0\n\t"
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"addql #1,%0@\n\t"
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"addql #1,%0@\n\t"
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"jle " SYMBOL_NAME_STR(__up_wakeup) "\n"
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"jle " SYMBOL_NAME_STR(__up_wakeup) "\n"
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"1:"
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"1:"
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: /* no outputs */
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: /* no outputs */
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: "a" (sem1)
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: "a" (sem1)
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: "%a0", "memory");
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: "%a0", "memory");
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}
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}
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#endif
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#endif
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