Disintegrate asm/system.h for MN10300

Disintegrate asm/system.h for MN10300.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-am33-list@redhat.com

arch/mn10300/include/asm/switch_to.h

@@ -0,0 +1,49 @@
+/* MN10300 task switching definitions
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#ifndef _ASM_SWITCH_TO_H
+#define _ASM_SWITCH_TO_H
+
+#include <asm/barrier.h>
+
+struct task_struct;
+struct thread_struct;
+
+#if !defined(CONFIG_LAZY_SAVE_FPU)
+struct fpu_state_struct;
+extern asmlinkage void fpu_save(struct fpu_state_struct *);
+#define switch_fpu(prev, next)						\
+	do {								\
+		if ((prev)->thread.fpu_flags & THREAD_HAS_FPU) {	\
+			(prev)->thread.fpu_flags &= ~THREAD_HAS_FPU;	\
+			(prev)->thread.uregs->epsw &= ~EPSW_FE;		\
+			fpu_save(&(prev)->thread.fpu_state);		\
+		}							\
+	} while (0)
+#else
+#define switch_fpu(prev, next) do {} while (0)
+#endif
+
+/* context switching is now performed out-of-line in switch_to.S */
+extern asmlinkage
+struct task_struct *__switch_to(struct thread_struct *prev,
+				struct thread_struct *next,
+				struct task_struct *prev_task);
+
+#define switch_to(prev, next, last)					\
+do {									\
+	switch_fpu(prev, next);						\
+	current->thread.wchan = (u_long) __builtin_return_address(0);	\
+	(last) = __switch_to(&(prev)->thread, &(next)->thread, (prev));	\
+	mb();								\
+	current->thread.wchan = 0;					\
+} while (0)
+
+#endif /* _ASM_SWITCH_TO_H */