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sh: break out unaligned sign extension code

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Break out the sign extension code since it's used in multiple places.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This commit is contained in:
Magnus Damm 2008-02-07 00:02:50 +09:00 committed by Paul Mundt
parent 1cfb629cfa
commit 86c0179c93
1 changed files with 23 additions and 45 deletions
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68
arch/sh/kernel/traps_32.c
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@ -147,6 +147,21 @@ static int die_if_no_fixup(const char * str, struct pt_regs * regs, long err)
return -EFAULT; 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 * handle an instruction that does an unaligned memory access by emulating the
* desired behaviour * desired behaviour
@ -178,25 +193,13 @@ static int handle_unaligned_ins(u16 instruction, struct pt_regs *regs)
dst = (unsigned char*) rn; dst = (unsigned char*) rn;
*(unsigned long*)dst = 0; *(unsigned long*)dst = 0;
#ifdef __LITTLE_ENDIAN__ #if !defined(__LITTLE_ENDIAN__)
dst += 4-count;
#endif
if (copy_from_user(dst, src, count)) if (copy_from_user(dst, src, count))
goto fetch_fault; goto fetch_fault;
if ((count == 2) && dst[1] & 0x80) { sign_extend(count, dst);
dst[2] = 0xff;
dst[3] = 0xff;
}
#else
dst += 4-count;
if (__copy_user(dst, src, count))
goto fetch_fault;
if ((count == 2) && dst[2] & 0x80) {
dst[0] = 0xff;
dst[1] = 0xff;
}
#endif
} else { } else {
/* to memory */ /* to memory */
src = (unsigned char*) rm; src = (unsigned char*) rm;
@ -253,25 +256,12 @@ static int handle_unaligned_ins(u16 instruction, struct pt_regs *regs)
dst = (unsigned char*) rn; dst = (unsigned char*) rn;
*(unsigned long*)dst = 0; *(unsigned long*)dst = 0;
#ifdef __LITTLE_ENDIAN__ #if !defined(__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
dst += 4-count; dst += 4-count;
#endif
if (copy_from_user(dst, src, count)) if (copy_from_user(dst, src, count))
goto fetch_fault; goto fetch_fault;
sign_extend(count, dst);
if ((count == 2) && dst[2] & 0x80) {
dst[0] = 0xff;
dst[1] = 0xff;
}
#endif
ret = 0; ret = 0;
break; break;
@ -299,21 +289,9 @@ static int handle_unaligned_ins(u16 instruction, struct pt_regs *regs)
#if !defined(__LITTLE_ENDIAN__) #if !defined(__LITTLE_ENDIAN__)
dst += 2; dst += 2;
#endif #endif
if (copy_from_user(dst, src, 2)) if (copy_from_user(dst, src, 2))
goto fetch_fault; goto fetch_fault;
sign_extend(2, dst);
#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
ret = 0; ret = 0;
break; break;
} }