1 files changed, 74 insertions, 0 deletions

diff --git a/include/linux/spinlock_up.h b/include/linux/spinlock_up.h
new file mode 100644
index 000000000000..31accf2f0b13
--- /dev/null
+++ b/include/linux/spinlock_up.h
@@ -0,0 +1,74 @@
+#ifndef __LINUX_SPINLOCK_UP_H
+#define __LINUX_SPINLOCK_UP_H
+
+#ifndef __LINUX_SPINLOCK_H
+# error "please don't include this file directly"
+#endif
+
+/*
+ * include/linux/spinlock_up.h - UP-debug version of spinlocks.
+ *
+ * portions Copyright 2005, Red Hat, Inc., Ingo Molnar
+ * Released under the General Public License (GPL).
+ *
+ * In the debug case, 1 means unlocked, 0 means locked. (the values
+ * are inverted, to catch initialization bugs)
+ *
+ * No atomicity anywhere, we are on UP.
+ */
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+
+#define __raw_spin_is_locked(x)         ((x)->slock == 0)
+
+static inline void __raw_spin_lock(raw_spinlock_t *lock)
+{
+        lock->slock = 0;
+}
+
+static inline void
+__raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
+{
+        local_irq_save(flags);
+        lock->slock = 0;
+}
+
+static inline int __raw_spin_trylock(raw_spinlock_t *lock)
+{
+        char oldval = lock->slock;
+
+        lock->slock = 0;
+
+        return oldval > 0;
+}
+
+static inline void __raw_spin_unlock(raw_spinlock_t *lock)
+{
+        lock->slock = 1;
+}
+
+/*
+ * Read-write spinlocks. No debug version.
+ */
+#define __raw_read_lock(lock)           do { (void)(lock); } while (0)
+#define __raw_write_lock(lock)          do { (void)(lock); } while (0)
+#define __raw_read_trylock(lock)        ({ (void)(lock); 1; })
+#define __raw_write_trylock(lock)       ({ (void)(lock); 1; })
+#define __raw_read_unlock(lock)         do { (void)(lock); } while (0)
+#define __raw_write_unlock(lock)        do { (void)(lock); } while (0)
+
+#else /* DEBUG_SPINLOCK */
+#define __raw_spin_is_locked(lock)      ((void)(lock), 0)
+/* for sched.c and kernel_lock.c: */
+# define __raw_spin_lock(lock)          do { (void)(lock); } while (0)
+# define __raw_spin_unlock(lock)        do { (void)(lock); } while (0)
+# define __raw_spin_trylock(lock)       ({ (void)(lock); 1; })
+#endif /* DEBUG_SPINLOCK */
+
+#define __raw_read_can_lock(lock)       (((void)(lock), 1))
+#define __raw_write_can_lock(lock)      (((void)(lock), 1))
+
+#define __raw_spin_unlock_wait(lock) \
+                do { cpu_relax(); } while (__raw_spin_is_locked(lock))
+
+#endif /* __LINUX_SPINLOCK_UP_H */