summaryrefslogtreecommitdiffstats
path: root/arch/nios2/include/asm/switch_to.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/nios2/include/asm/switch_to.h')
-rw-r--r--arch/nios2/include/asm/switch_to.h31
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/nios2/include/asm/switch_to.h b/arch/nios2/include/asm/switch_to.h
new file mode 100644
index 000000000..c47b3f4af
--- /dev/null
+++ b/arch/nios2/include/asm/switch_to.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2004 Microtronix Datacom Ltd.
+ *
+ * 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.
+ */
+#ifndef _ASM_NIOS2_SWITCH_TO_H
+#define _ASM_NIOS2_SWITCH_TO_H
+
+/*
+ * switch_to(n) should switch tasks to task ptr, first checking that
+ * ptr isn't the current task, in which case it does nothing. This
+ * also clears the TS-flag if the task we switched to has used the
+ * math co-processor latest.
+ */
+#define switch_to(prev, next, last) \
+{ \
+ void *_last; \
+ __asm__ __volatile__ ( \
+ "mov r4, %1\n" \
+ "mov r5, %2\n" \
+ "call resume\n" \
+ "mov %0,r4\n" \
+ : "=r" (_last) \
+ : "r" (prev), "r" (next) \
+ : "r4", "r5", "r7", "r8", "ra"); \
+ (last) = _last; \
+}
+
+#endif /* _ASM_NIOS2_SWITCH_TO_H */