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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-cris/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-cris/semaphore-helper.h')
-rw-r--r--include/asm-cris/semaphore-helper.h81
1 files changed, 81 insertions, 0 deletions
diff --git a/include/asm-cris/semaphore-helper.h b/include/asm-cris/semaphore-helper.h
new file mode 100644
index 00000000000..dbd0f30b85b
--- /dev/null
+++ b/include/asm-cris/semaphore-helper.h
@@ -0,0 +1,81 @@
+/* $Id: semaphore-helper.h,v 1.3 2001/03/26 15:00:33 orjanf Exp $
+ *
+ * SMP- and interrupt-safe semaphores helper functions. Generic versions, no
+ * optimizations whatsoever...
+ *
+ */
+
+#ifndef _ASM_SEMAPHORE_HELPER_H
+#define _ASM_SEMAPHORE_HELPER_H
+
+#include <asm/atomic.h>
+#include <linux/errno.h>
+
+#define read(a) ((a)->counter)
+#define inc(a) (((a)->counter)++)
+#define dec(a) (((a)->counter)--)
+
+#define count_inc(a) ((*(a))++)
+
+/*
+ * These two _must_ execute atomically wrt each other.
+ */
+extern inline void wake_one_more(struct semaphore * sem)
+{
+ atomic_inc(&sem->waking);
+}
+
+extern inline int waking_non_zero(struct semaphore *sem)
+{
+ unsigned long flags;
+ int ret = 0;
+
+ local_save_flags(flags);
+ local_irq_disable();
+ if (read(&sem->waking) > 0) {
+ dec(&sem->waking);
+ ret = 1;
+ }
+ local_irq_restore(flags);
+ return ret;
+}
+
+extern inline int waking_non_zero_interruptible(struct semaphore *sem,
+ struct task_struct *tsk)
+{
+ int ret = 0;
+ unsigned long flags;
+
+ local_save_flags(flags);
+ local_irq_disable();
+ if (read(&sem->waking) > 0) {
+ dec(&sem->waking);
+ ret = 1;
+ } else if (signal_pending(tsk)) {
+ inc(&sem->count);
+ ret = -EINTR;
+ }
+ local_irq_restore(flags);
+ return ret;
+}
+
+extern inline int waking_non_zero_trylock(struct semaphore *sem)
+{
+ int ret = 1;
+ unsigned long flags;
+
+ local_save_flags(flags);
+ local_irq_disable();
+ if (read(&sem->waking) <= 0)
+ inc(&sem->count);
+ else {
+ dec(&sem->waking);
+ ret = 0;
+ }
+ local_irq_restore(flags);
+ return ret;
+}
+
+#endif /* _ASM_SEMAPHORE_HELPER_H */
+
+