From: Magnus Damm <magnus.damm@gmail.com>
Date: Thu, 7 Feb 2008 10:58:46 +0000 (+0900)
Subject: sh: add byte support to the sign extension code
X-Git-Tag: v2.6.25-rc2~5^2~31
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4252c659a4e7f4260e4bdc87538578236c51ab2d;p=linux-2.6

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>
---

diff --git a/arch/sh/kernel/traps_32.c b/arch/sh/kernel/traps_32.c
index 7154a7b213..2e7dd2ebec 100644
--- a/arch/sh/kernel/traps_32.c
+++ b/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
 }