Disintegrate asm/system.h for M32R

Disintegrate asm/system.h for M32R.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-m32r@ml.linux-m32r.org

1 files changed, 51 insertions, 0 deletions

diff --git a/arch/m32r/include/asm/switch_to.h b/arch/m32r/include/asm/switch_to.h
new file mode 100644
index 000000000000..4b262f7a8fe9
--- /dev/null
+++ b/arch/m32r/include/asm/switch_to.h
@@ -0,0 +1,51 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001  Hiroyuki Kondo, Hirokazu Takata, and Hitoshi Yamamoto
+ * Copyright (C) 2004, 2006  Hirokazu Takata <takata at linux-m32r.org>
+ */
+#ifndef _ASM_M32R_SWITCH_TO_H
+#define _ASM_M32R_SWITCH_TO_H
+
+/*
+ * switch_to(prev, next) should switch from task `prev' to `next'
+ * `prev' will never be the same as `next'.
+ *
+ * `next' and `prev' should be struct task_struct, but it isn't always defined
+ */
+
+#if defined(CONFIG_FRAME_POINTER) || \
+	!defined(CONFIG_SCHED_OMIT_FRAME_POINTER)
+#define M32R_PUSH_FP "	push fp\n"
+#define M32R_POP_FP  "	pop  fp\n"
+#else
+#define M32R_PUSH_FP ""
+#define M32R_POP_FP  ""
+#endif
+
+#define switch_to(prev, next, last)  do { \
+	__asm__ __volatile__ ( \
+		"	seth	lr, #high(1f)				\n" \
+		"	or3	lr, lr, #low(1f)			\n" \
+		"	st	lr, @%4  ; store old LR			\n" \
+		"	ld	lr, @%5  ; load new LR			\n" \
+			M32R_PUSH_FP \
+		"	st	sp, @%2  ; store old SP			\n" \
+		"	ld	sp, @%3  ; load new SP			\n" \
+		"	push	%1  ; store `prev' on new stack		\n" \
+		"	jmp	lr					\n" \
+		"	.fillinsn					\n" \
+		"1:							\n" \
+		"	pop	%0  ; restore `__last' from new stack	\n" \
+			M32R_POP_FP \
+		: "=r" (last) \
+		: "0" (prev), \
+		  "r" (&(prev->thread.sp)), "r" (&(next->thread.sp)), \
+		  "r" (&(prev->thread.lr)), "r" (&(next->thread.lr)) \
+		: "memory", "lr" \
+	); \
+} while(0)
+
+#endif /* _ASM_M32R_SWITCH_TO_H */