1 files changed, 71 insertions, 0 deletions
diff --git a/arch/mn10300/kernel/switch_to.S b/arch/mn10300/kernel/switch_to.S
new file mode 100644
index 0000000..630aad7
--- /dev/null
+++ b/arch/mn10300/kernel/switch_to.S
@@ -0,0 +1,71 @@
+###############################################################################
+#
+# MN10300 Context switch operation
+#
+# 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.
+#
+###############################################################################
+#include <linux/sys.h>
+#include <linux/linkage.h>
+#include <asm/thread_info.h>
+#include <asm/cpu-regs.h>
+
+	.text
+
+###############################################################################
+#
+# struct task_struct *__switch_to(struct thread_struct *prev,
+#				  struct thread_struct *next,
+#				  struct task_struct *prev_task)
+#
+###############################################################################
+ENTRY(__switch_to)
+	movm	[d2,d3,a2,a3,exreg1],(sp)
+	or	EPSW_NMID,epsw
+
+	mov	(44,sp),d2
+
+	mov	d0,a0
+	mov	d1,a1
+
+	# save prev context
+	mov	(__frame),d0
+	mov	d0,(THREAD_FRAME,a0)
+	mov	__switch_back,d0
+	mov	d0,(THREAD_PC,a0)
+	mov	sp,a2
+	mov	a2,(THREAD_SP,a0)
+	mov	a3,(THREAD_A3,a0)
+
+	mov	(THREAD_A3,a1),a3
+	mov	(THREAD_SP,a1),a2
+
+	# switch
+	mov	a2,sp
+
+	# load next context
+	GET_THREAD_INFO a2
+	mov	a2,(__current_ti)
+	mov	(TI_task,a2),a2
+	mov	a2,(__current)
+#ifdef CONFIG_MN10300_CURRENT_IN_E2
+	mov	a2,e2
+#endif
+
+	mov	(THREAD_FRAME,a1),a2
+	mov	a2,(__frame)
+	mov	(THREAD_PC,a1),a2
+	mov	d2,d0			# for ret_from_fork
+	mov	d0,a0			# for __switch_to
+
+	jmp	(a2)
+
+__switch_back:
+	and	~EPSW_NMID,epsw
+	ret	[d2,d3,a2,a3,exreg1],32