1 files changed, 41 insertions, 0 deletions
diff --git a/include/linux/bit_spinlock.h b/include/linux/bit_spinlock.h
new file mode 100644
index 0000000..0e88820
--- /dev/null
+++ b/include/linux/bit_spinlock.h
@@ -0,0 +1,41 @@
+#ifndef __LINUX_BIT_SPINLOCK_H
+#define __LINUX_BIT_SPINLOCK_H
+
+#include <linux/kernel.h>
+#include <linux/preempt.h>
+#include <linux/atomic.h>
+#include <linux/bug.h>
+
+static inline void bit_spin_lock(int bitnum, unsigned long *addr)
+{
+	while (unlikely(test_and_set_bit_lock(bitnum, addr))) {
+		do {
+			cpu_relax();
+		} while (test_bit(bitnum, addr));
+	}
+}
+
+static inline int bit_spin_trylock(int bitnum, unsigned long *addr)
+{
+	return !test_and_set_bit_lock(bitnum, addr);
+}
+
+static inline void bit_spin_unlock(int bitnum, unsigned long *addr)
+{
+	BUG_ON(!test_bit(bitnum, addr));
+
+	clear_bit_unlock(bitnum, addr);
+}
+
+static inline void __bit_spin_unlock(int bitnum, unsigned long *addr)
+{
+	bit_spin_unlock(bitnum, addr);
+}
+
+static inline int bit_spin_is_locked(int bitnum, unsigned long *addr)
+{
+	return test_bit(bitnum, addr);
+}
+
+#endif /* __LINUX_BIT_SPINLOCK_H */
+