nds32: add header files support for nds32

Add generic header files support for nds32 architecture.
Cache, ptregs, data type and other definitions are included.

Signed-off-by: Macpaul Lin <macpaul@andestech.com>
diff --git a/arch/nds32/include/asm/system.h b/arch/nds32/include/asm/system.h
new file mode 100644
index 0000000..97f59e9
--- /dev/null
+++ b/arch/nds32/include/asm/system.h
@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2011 Andes Technology Corporation
+ * Macpaul Lin, Andes Technology Corporation <macpaul@andestech.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+
+#ifndef __ASM_NDS_SYSTEM_H
+#define __ASM_NDS_SYSTEM_H
+
+/*
+ * Interrupt configuring macros.
+ */
+
+extern int irq_flags;
+
+#define local_irq_enable() \
+	__asm__ __volatile__ ( \
+		"mfsr	%0, $psw\n\t" \
+		"andi	%0, %0, 0x1\n\t" \
+		"setgie.e\n\t" \
+		: \
+		: "r" (irq_flags) \
+	)
+
+#define local_irq_disable() \
+	do { \
+		int __tmp_dummy; \
+		__asm__ __volatile__ ( \
+			"mfsr	%0, $psw\n\t" \
+			"andi	%0, %0, 0x1\n\t" \
+			"setgie.d\n\t" \
+			"dsb\n\t" \
+			: "=r" (__tmp_dummy) \
+		); \
+	} while (0)
+
+#define local_irq_save(x) \
+	__asm__ __volatile__ ( \
+		"mfsr	%0, $psw\n\t" \
+		"andi	%0, %0, 0x1\n\t" \
+		"setgie.d\n\t" \
+		"dsb\n\t" \
+		: "=&r" (x) \
+	)
+
+#define local_save_flags(x) \
+	__asm__ __volatile__ ( \
+		"mfsr	%0, $psw\n\t" \
+		"andi	%0, %0, 0x1\n\t" \
+		"setgie.e\n\t" \
+		"setgie.d\n\t" \
+		: "=r" (x) \
+	)
+
+#define irqs_enabled_from_flags(x) ((x) != 0x1f)
+
+#define local_irq_restore(x) \
+	do { \
+		if (irqs_enabled_from_flags(x)) \
+			local_irq_enable(); \
+	} while (0)
+
+/*
+ * Force strict CPU ordering.
+ */
+#define nop()			asm volatile ("nop;\n\t" : : )
+#define mb()			asm volatile (""   : : : "memory")
+#define rmb()			asm volatile (""   : : : "memory")
+#define wmb()			asm volatile (""   : : : "memory")
+
+#endif	/* __ASM_NDS_SYSTEM_H */