sh: 16-bit get_unaligned() sh4a fix

This patch fixes the 16-bit case of the sh4a specific
unaligned access implementation. Without this patch
the 16-bit version of sh4a get_unaligned() results in
a 32-bit read which may read more data than intended
and/or cross page boundaries.

Unbreaks mtd NOR write handling on Migo-R.

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 2009-06-04 20:20:24 +09:00 committed by Paul Mundt
parent 138f025267
commit 48c72fccbf

View File

@ -3,9 +3,9 @@
/*
* SH-4A has support for unaligned 32-bit loads, and 32-bit loads only.
* Support for 16 and 64-bit accesses are done through shifting and
* masking relative to the endianness. Unaligned stores are not supported
* by the instruction encoding, so these continue to use the packed
* Support for 64-bit accesses are done through shifting and masking
* relative to the endianness. Unaligned stores are not supported by the
* instruction encoding, so these continue to use the packed
* struct.
*
* The same note as with the movli.l/movco.l pair applies here, as long
@ -41,9 +41,9 @@ struct __una_u64 { u64 x __attribute__((packed)); };
static inline u16 __get_unaligned_cpu16(const u8 *p)
{
#ifdef __LITTLE_ENDIAN
return __get_unaligned_cpu32(p) & 0xffff;
return p[0] | p[1] << 8;
#else
return __get_unaligned_cpu32(p) >> 16;
return p[0] << 8 | p[1];
#endif
}