From: Magnus Damm <magnus.damm@gmail.com>
To: linux-sh@vger.kernel.org
Subject: [PATCH] sh: break out unaligned sign extension code
Date: Wed, 06 Feb 2008 15:02:50 +0000 [thread overview]
Message-ID: <20080206150250.27073.50160.sendpatchset@clockwork.opensource.se> (raw)
Break out the sign extension code since it's used in multiple places.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
---
arch/sh/kernel/traps_32.c | 68 +++++++++++++++------------------------------
1 file changed, 23 insertions(+), 45 deletions(-)
--- 0001/arch/sh/kernel/traps_32.c
+++ work/arch/sh/kernel/traps_32.c 2008-02-05 14:18:19.000000000 +0900
@@ -147,6 +147,21 @@ static int die_if_no_fixup(const char *
return -EFAULT;
}
+static inline void sign_extend(unsigned int count, unsigned char *dst)
+{
+#ifdef __LITTLE_ENDIAN__
+ if ((count = 2) && dst[1] & 0x80) {
+ dst[2] = 0xff;
+ dst[3] = 0xff;
+ }
+#else
+ if ((count = 2) && dst[2] & 0x80) {
+ dst[0] = 0xff;
+ dst[1] = 0xff;
+ }
+#endif
+}
+
/*
* handle an instruction that does an unaligned memory access by emulating the
* desired behaviour
@@ -178,25 +193,13 @@ static int handle_unaligned_ins(u16 inst
dst = (unsigned char*) rn;
*(unsigned long*)dst = 0;
-#ifdef __LITTLE_ENDIAN__
- if (copy_from_user(dst, src, count))
- goto fetch_fault;
-
- if ((count = 2) && dst[1] & 0x80) {
- dst[2] = 0xff;
- dst[3] = 0xff;
- }
-#else
+#if !defined(__LITTLE_ENDIAN__)
dst += 4-count;
-
- if (__copy_user(dst, src, count))
+#endif
+ if (copy_from_user(dst, src, count))
goto fetch_fault;
- if ((count = 2) && dst[2] & 0x80) {
- dst[0] = 0xff;
- dst[1] = 0xff;
- }
-#endif
+ sign_extend(count, dst);
} else {
/* to memory */
src = (unsigned char*) rm;
@@ -253,25 +256,12 @@ static int handle_unaligned_ins(u16 inst
dst = (unsigned char*) rn;
*(unsigned long*)dst = 0;
-#ifdef __LITTLE_ENDIAN__
- if (copy_from_user(dst, src, count))
- goto fetch_fault;
-
- if ((count = 2) && dst[1] & 0x80) {
- dst[2] = 0xff;
- dst[3] = 0xff;
- }
-#else
+#if !defined(__LITTLE_ENDIAN__)
dst += 4-count;
-
+#endif
if (copy_from_user(dst, src, count))
goto fetch_fault;
-
- if ((count = 2) && dst[2] & 0x80) {
- dst[0] = 0xff;
- dst[1] = 0xff;
- }
-#endif
+ sign_extend(count, dst);
ret = 0;
break;
@@ -299,21 +289,9 @@ static int handle_unaligned_ins(u16 inst
#if !defined(__LITTLE_ENDIAN__)
dst += 2;
#endif
-
if (copy_from_user(dst, src, 2))
goto fetch_fault;
-
-#ifdef __LITTLE_ENDIAN__
- if (dst[1] & 0x80) {
- dst[2] = 0xff;
- dst[3] = 0xff;
- }
-#else
- if (dst[2] & 0x80) {
- dst[0] = 0xff;
- dst[1] = 0xff;
- }
-#endif
+ sign_extend(2, dst);
ret = 0;
break;
}
reply other threads:[~2008-02-06 15:02 UTC|newest]
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