summaryrefslogtreecommitdiff
path: root/arch/m32r/include/asm/switch_to.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/m32r/include/asm/switch_to.h')
-rw-r--r--arch/m32r/include/asm/switch_to.h51
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 */