[MIPS] Add support for kexec

A tiny userland application loading the kernel and invoking kexec_load for 
mips is available here:

http://chac.le-poulpe.net/~nico/kexec/kexec-2006-10-18.tar.gz

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

include/asm-mips/kexec.h

@@ -0,0 +1,32 @@
+/*
+ * kexec.h for kexec
+ * Created by <nschichan@corp.free.fr> on Thu Oct 12 14:59:34 2006
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2.  See the file COPYING for more details.
+ */
+
+#ifndef _MIPS_KEXEC
+# define _MIPS_KEXEC
+
+/* Maximum physical address we can use pages from */
+#define KEXEC_SOURCE_MEMORY_LIMIT (0x20000000)
+/* Maximum address we can reach in physical address mode */
+#define KEXEC_DESTINATION_MEMORY_LIMIT (0x20000000)
+ /* Maximum address we can use for the control code buffer */
+#define KEXEC_CONTROL_MEMORY_LIMIT (0x20000000)
+
+#define KEXEC_CONTROL_CODE_SIZE 4096
+
+/* The native architecture */
+#define KEXEC_ARCH KEXEC_ARCH_MIPS
+
+#define MAX_NOTE_BYTES 1024
+
+static inline void crash_setup_regs(struct pt_regs *newregs,
+				    struct pt_regs *oldregs)
+{
+	/* Dummy implementation for now */
+}
+
+#endif /* !_MIPS_KEXEC */