Disintegrate asm/system.h for ARM

Disintegrate asm/system.h for ARM.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Russell King <linux@arm.linux.org.uk>
cc: linux-arm-kernel@lists.infradead.org

arch/arm/include/asm/switch_to.h

@@ -0,0 +1,18 @@
+#ifndef __ASM_ARM_SWITCH_TO_H
+#define __ASM_ARM_SWITCH_TO_H
+
+#include <linux/thread_info.h>
+
+/*
+ * switch_to(prev, next) should switch from task `prev' to `next'
+ * `prev' will never be the same as `next'.  schedule() itself
+ * contains the memory barrier to tell GCC not to cache `current'.
+ */
+extern struct task_struct *__switch_to(struct task_struct *, struct thread_info *, struct thread_info *);
+
+#define switch_to(prev,next,last)					\
+do {									\
+	last = __switch_to(prev,task_thread_info(prev), task_thread_info(next));	\
+} while (0)
+
+#endif /* __ASM_ARM_SWITCH_TO_H */