patch-2.2.8 linux/include/asm-m68k/semaphore-helper.h

• Lines: 137
• Date: Tue May 11 09:57:14 1999
• Orig file: v2.2.7/linux/include/asm-m68k/semaphore-helper.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.2.7/linux/include/asm-m68k/semaphore-helper.h linux/include/asm-m68k/semaphore-helper.h
@@ -0,0 +1,136 @@
+#ifndef _M68K_SEMAPHORE_HELPER_H
+#define _M68K_SEMAPHORE_HELPER_H
+
+/*
+ * SMP- and interrupt-safe semaphores helper functions.
+ *
+ * (C) Copyright 1996 Linus Torvalds
+ *
+ * m68k version by Andreas Schwab
+ */
+
+/*
+ * These two _must_ execute atomically wrt each other.
+ */
+static inline void wake_one_more(struct semaphore * sem)
+{
+	atomic_inc(&sem->waking);
+}
+
+static inline int waking_non_zero(struct semaphore *sem)
+{
+	int ret;
+#ifndef CONFIG_RMW_INSNS
+	unsigned long flags;
+
+	spin_lock_irqsave(&semaphore_wake_lock, flags);
+	ret = 0;
+	if (atomic_read(&sem->waking) > 0) {
+		atomic_dec(&sem->waking);
+		ret = 1;
+	}
+	spin_unlock_irqrestore(&semaphore_wake_lock, flags);
+#else
+	int tmp1, tmp2;
+
+	__asm__ __volatile__
+	  ("1:	movel	%1,%2\n"
+	   "    jle	2f\n"
+	   "	subql	#1,%2\n"
+	   "	casl	%1,%2,%3\n"
+	   "	jne	1b\n"
+	   "	moveq	#1,%0\n"
+	   "2:"
+	   : "=d" (ret), "=d" (tmp1), "=d" (tmp2)
+	   : "m" (sem->waking), "0" (0), "1" (sem->waking));
+#endif
+
+	return ret;
+}
+
+/*
+ * waking_non_zero_interruptible:
+ *	1	got the lock
+ *	0	go to sleep
+ *	-EINTR	interrupted
+ */
+static inline int waking_non_zero_interruptible(struct semaphore *sem,
+						struct task_struct *tsk)
+{
+	int ret;
+#ifndef CONFIG_RMW_INSNS
+	unsigned long flags;
+
+	spin_lock_irqsave(&semaphore_wake_lock, flags);
+	ret = 0;
+	if (atomic_read(&sem->waking) > 0) {
+		atomic_dec(&sem->waking);
+		ret = 1;
+	} else if (signal_pending(tsk)) {
+		atomic_inc(&sem->count);
+		ret = -EINTR;
+	}
+	spin_unlock_irqrestore(&semaphore_wake_lock, flags);
+#else
+	int tmp1, tmp2;
+
+	__asm__ __volatile__
+	  ("1:	movel	%1,%2\n"
+	   "	jle	2f\n"
+	   "	subql	#1,%2\n"
+	   "	casl	%1,%2,%3\n"
+	   "	jne	1b\n"
+	   "	moveq	#1,%0\n"
+	   "	jra	%a4\n"
+	   "2:"
+	   : "=d" (ret), "=d" (tmp1), "=d" (tmp2)
+	   : "m" (sem->waking), "i" (&&next), "0" (0), "1" (sem->waking));
+	if (signal_pending(tsk)) {
+		atomic_inc(&sem->count);
+		ret = -EINTR;
+	}
+next:
+#endif
+
+	return ret;
+}
+
+/*
+ * waking_non_zero_trylock:
+ *	1	failed to lock
+ *	0	got the lock
+ */
+static inline int waking_non_zero_trylock(struct semaphore *sem)
+{
+	int ret;
+#ifndef CONFIG_RMW_INSNS
+	unsigned long flags;
+
+	spin_lock_irqsave(&semaphore_wake_lock, flags);
+	ret = 1;
+	if (atomic_read(&sem->waking) > 0) {
+		atomic_dec(&sem->waking);
+		ret = 0;
+	} else
+		atomic_inc(&sem->count);
+	spin_unlock_irqrestore(&semaphore_wake_lock, flags);
+#else
+	int tmp1, tmp2;
+
+	__asm__ __volatile__
+	  ("1:	movel	%1,%2\n"
+	   "    jle	2f\n"
+	   "	subql	#1,%2\n"
+	   "	casl	%1,%2,%3\n"
+	   "	jne	1b\n"
+	   "	moveq	#0,%0\n"
+	   "2:"
+	   : "=d" (ret), "=d" (tmp1), "=d" (tmp2)
+	   : "m" (sem->waking), "0" (1), "1" (sem->waking));
+	if (ret)
+		atomic_inc(&sem->count);
+#endif
+	return ret;
+}
+
+#endif