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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-m68k/semaphore-helper.h
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/asm-m68k/semaphore-helper.h')
-rw-r--r--include/asm-m68k/semaphore-helper.h143
1 files changed, 143 insertions, 0 deletions
diff --git a/include/asm-m68k/semaphore-helper.h b/include/asm-m68k/semaphore-helper.h
new file mode 100644
index 00000000000..1516a642f9a
--- /dev/null
+++ b/include/asm-m68k/semaphore-helper.h
@@ -0,0 +1,143 @@
+#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
+ */
+
+#include <linux/config.h>
+#include <linux/errno.h>
+
+/*
+ * These two _must_ execute atomically wrt each other.
+ */
+static inline void wake_one_more(struct semaphore * sem)
+{
+ atomic_inc(&sem->waking);
+}
+
+#ifndef CONFIG_RMW_INSNS
+extern spinlock_t semaphore_wake_lock;
+#endif
+
+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