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 000000000000..630aad71b946
--- /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