sh: add byte support to the sign extension code

This patch adds byte support to the sign extension code. Unaligned access
traps should never be generated on 8-bit io operations, but we will use this
code for trapped io and we do need byte support there.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/traps_32.c

@@ -150,14 +150,24 @@ static int die_if_no_fixup(const char * str, struct pt_regs * regs, long err)
 static inline void sign_extend(unsigned int count, unsigned char *dst)
 {
 #ifdef __LITTLE_ENDIAN__
+	if ((count == 1) && dst[0] & 0x80) {
+		dst[1] = 0xff;
+		dst[2] = 0xff;
+		dst[3] = 0xff;
+	}
 	if ((count == 2) && dst[1] & 0x80) {
 		dst[2] = 0xff;
 		dst[3] = 0xff;
 	}
 #else
-	if ((count == 2) && dst[2] & 0x80) {
+	if ((count == 1) && dst[3] & 0x80) {
+		dst[2] = 0xff;
+		dst[1] = 0xff;
 		dst[0] = 0xff;
+	}
+	if ((count == 2) && dst[2] & 0x80) {
 		dst[1] = 0xff;
+		dst[0] = 0xff;
 	}
 #endif
 }