1 files changed, 146 insertions, 0 deletions
diff --git a/kernel/arch/metag/include/asm/atomic_lock1.h b/kernel/arch/metag/include/asm/atomic_lock1.h
new file mode 100644
index 000000000..f5d5898c1
--- /dev/null
+++ b/kernel/arch/metag/include/asm/atomic_lock1.h
@@ -0,0 +1,146 @@
+#ifndef __ASM_METAG_ATOMIC_LOCK1_H
+#define __ASM_METAG_ATOMIC_LOCK1_H
+
+#define ATOMIC_INIT(i)	{ (i) }
+
+#include <linux/compiler.h>
+
+#include <asm/barrier.h>
+#include <asm/global_lock.h>
+
+static inline int atomic_read(const atomic_t *v)
+{
+	return (v)->counter;
+}
+
+/*
+ * atomic_set needs to be take the lock to protect atomic_add_unless from a
+ * possible race, as it reads the counter twice:
+ *
+ *  CPU0                               CPU1
+ *  atomic_add_unless(1, 0)
+ *    ret = v->counter (non-zero)
+ *    if (ret != u)                    v->counter = 0
+ *      v->counter += 1 (counter set to 1)
+ *
+ * Making atomic_set take the lock ensures that ordering and logical
+ * consistency is preserved.
+ */
+static inline int atomic_set(atomic_t *v, int i)
+{
+	unsigned long flags;
+
+	__global_lock1(flags);
+	fence();
+	v->counter = i;
+	__global_unlock1(flags);
+	return i;
+}
+
+#define ATOMIC_OP(op, c_op)						\
+static inline void atomic_##op(int i, atomic_t *v)			\
+{									\
+	unsigned long flags;						\
+									\
+	__global_lock1(flags);						\
+	fence();							\
+	v->counter c_op i;						\
+	__global_unlock1(flags);					\
+}									\
+
+#define ATOMIC_OP_RETURN(op, c_op)					\
+static inline int atomic_##op##_return(int i, atomic_t *v)		\
+{									\
+	unsigned long result;						\
+	unsigned long flags;						\
+									\
+	__global_lock1(flags);						\
+	result = v->counter;						\
+	result c_op i;							\
+	fence();							\
+	v->counter = result;						\
+	__global_unlock1(flags);					\
+									\
+	return result;							\
+}
+
+#define ATOMIC_OPS(op, c_op) ATOMIC_OP(op, c_op) ATOMIC_OP_RETURN(op, c_op)
+
+ATOMIC_OPS(add, +=)
+ATOMIC_OPS(sub, -=)
+
+#undef ATOMIC_OPS
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+static inline void atomic_clear_mask(unsigned int mask, atomic_t *v)
+{
+	unsigned long flags;
+
+	__global_lock1(flags);
+	fence();
+	v->counter &= ~mask;
+	__global_unlock1(flags);
+}
+
+static inline void atomic_set_mask(unsigned int mask, atomic_t *v)
+{
+	unsigned long flags;
+
+	__global_lock1(flags);
+	fence();
+	v->counter |= mask;
+	__global_unlock1(flags);
+}
+
+static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
+{
+	int ret;
+	unsigned long flags;
+
+	__global_lock1(flags);
+	ret = v->counter;
+	if (ret == old) {
+		fence();
+		v->counter = new;
+	}
+	__global_unlock1(flags);
+
+	return ret;
+}
+
+#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
+
+static inline int __atomic_add_unless(atomic_t *v, int a, int u)
+{
+	int ret;
+	unsigned long flags;
+
+	__global_lock1(flags);
+	ret = v->counter;
+	if (ret != u) {
+		fence();
+		v->counter += a;
+	}
+	__global_unlock1(flags);
+
+	return ret;
+}
+
+static inline int atomic_sub_if_positive(int i, atomic_t *v)
+{
+	int ret;
+	unsigned long flags;
+
+	__global_lock1(flags);
+	ret = v->counter - 1;
+	if (ret >= 0) {
+		fence();
+		v->counter = ret;
+	}
+	__global_unlock1(flags);
+
+	return ret;
+}
+
+#endif /* __ASM_METAG_ATOMIC_LOCK1_H */