Hi Remy,
On Wednesday 28 October 2009 22:13:38 Remy Bohmer wrote:
The current generic code for handling unaligned access assumes that the processor can properly handle unaligned accesses itself. This is at least not the case for ARM, which results in runtime errors.
Rewrite it such that it works for ARM as well.
I introduced this header some time ago for UBIFS support (for PowerPC). As you may have noticed, it's a copy from the Linux version. And I would like to keep it this way if possible. Looking at the Linux ARM version, the basic difference seems to be the header "include/asm-arm/unaligned.h" which includes this file. The Linux version of "unaligned.h" does *not* include "access_ok.h" at all. It includes "le_byteshift.h" and "be_byteshift.h" instead. And I would really like to keep this in sync with Linux if possible.
So why not do it this way (totally untested):
From 3e9aa23a66041f05b94f94b1326941331248a487 Mon Sep 17 00:00:00 2001 From: Stefan Roese sr@denx.de Date: Thu, 29 Oct 2009 05:57:53 +0100 Subject: [PATCH] arm: Use Linux version for unaligned access code
Signed-off-by: Stefan Roese sr@denx.de --- include/asm-arm/unaligned.h | 3 +- include/linux/unaligned/be_byteshift.h | 70 ++++++++++++++++++++++++++++++++ include/linux/unaligned/le_byteshift.h | 70 ++++++++++++++++++++++++++++++++ 3 files changed, 142 insertions(+), 1 deletions(-) create mode 100644 include/linux/unaligned/be_byteshift.h create mode 100644 include/linux/unaligned/le_byteshift.h
diff --git a/include/asm-arm/unaligned.h b/include/asm-arm/unaligned.h index d644df7..44593a8 100644 --- a/include/asm-arm/unaligned.h +++ b/include/asm-arm/unaligned.h @@ -1,7 +1,8 @@ #ifndef _ASM_ARM_UNALIGNED_H #define _ASM_ARM_UNALIGNED_H
-#include <linux/unaligned/access_ok.h> +#include <linux/unaligned/le_byteshift.h> +#include <linux/unaligned/be_byteshift.h> #include <linux/unaligned/generic.h>
/* diff --git a/include/linux/unaligned/be_byteshift.h b/include/linux/unaligned/be_byteshift.h new file mode 100644 index 0000000..9356b24 --- /dev/null +++ b/include/linux/unaligned/be_byteshift.h @@ -0,0 +1,70 @@ +#ifndef _LINUX_UNALIGNED_BE_BYTESHIFT_H +#define _LINUX_UNALIGNED_BE_BYTESHIFT_H + +#include <linux/types.h> + +static inline u16 __get_unaligned_be16(const u8 *p) +{ + return p[0] << 8 | p[1]; +} + +static inline u32 __get_unaligned_be32(const u8 *p) +{ + return p[0] << 24 | p[1] << 16 | p[2] << 8 | p[3]; +} + +static inline u64 __get_unaligned_be64(const u8 *p) +{ + return (u64)__get_unaligned_be32(p) << 32 | + __get_unaligned_be32(p + 4); +} + +static inline void __put_unaligned_be16(u16 val, u8 *p) +{ + *p++ = val >> 8; + *p++ = val; +} + +static inline void __put_unaligned_be32(u32 val, u8 *p) +{ + __put_unaligned_be16(val >> 16, p); + __put_unaligned_be16(val, p + 2); +} + +static inline void __put_unaligned_be64(u64 val, u8 *p) +{ + __put_unaligned_be32(val >> 32, p); + __put_unaligned_be32(val, p + 4); +} + +static inline u16 get_unaligned_be16(const void *p) +{ + return __get_unaligned_be16((const u8 *)p); +} + +static inline u32 get_unaligned_be32(const void *p) +{ + return __get_unaligned_be32((const u8 *)p); +} + +static inline u64 get_unaligned_be64(const void *p) +{ + return __get_unaligned_be64((const u8 *)p); +} + +static inline void put_unaligned_be16(u16 val, void *p) +{ + __put_unaligned_be16(val, p); +} + +static inline void put_unaligned_be32(u32 val, void *p) +{ + __put_unaligned_be32(val, p); +} + +static inline void put_unaligned_be64(u64 val, void *p) +{ + __put_unaligned_be64(val, p); +} + +#endif /* _LINUX_UNALIGNED_BE_BYTESHIFT_H */ diff --git a/include/linux/unaligned/le_byteshift.h b/include/linux/unaligned/le_byteshift.h new file mode 100644 index 0000000..be376fb --- /dev/null +++ b/include/linux/unaligned/le_byteshift.h @@ -0,0 +1,70 @@ +#ifndef _LINUX_UNALIGNED_LE_BYTESHIFT_H +#define _LINUX_UNALIGNED_LE_BYTESHIFT_H + +#include <linux/types.h> + +static inline u16 __get_unaligned_le16(const u8 *p) +{ + return p[0] | p[1] << 8; +} + +static inline u32 __get_unaligned_le32(const u8 *p) +{ + return p[0] | p[1] << 8 | p[2] << 16 | p[3] << 24; +} + +static inline u64 __get_unaligned_le64(const u8 *p) +{ + return (u64)__get_unaligned_le32(p + 4) << 32 | + __get_unaligned_le32(p); +} + +static inline void __put_unaligned_le16(u16 val, u8 *p) +{ + *p++ = val; + *p++ = val >> 8; +} + +static inline void __put_unaligned_le32(u32 val, u8 *p) +{ + __put_unaligned_le16(val >> 16, p + 2); + __put_unaligned_le16(val, p); +} + +static inline void __put_unaligned_le64(u64 val, u8 *p) +{ + __put_unaligned_le32(val >> 32, p + 4); + __put_unaligned_le32(val, p); +} + +static inline u16 get_unaligned_le16(const void *p) +{ + return __get_unaligned_le16((const u8 *)p); +} + +static inline u32 get_unaligned_le32(const void *p) +{ + return __get_unaligned_le32((const u8 *)p); +} + +static inline u64 get_unaligned_le64(const void *p) +{ + return __get_unaligned_le64((const u8 *)p); +} + +static inline void put_unaligned_le16(u16 val, void *p) +{ + __put_unaligned_le16(val, p); +} + +static inline void put_unaligned_le32(u32 val, void *p) +{ + __put_unaligned_le32(val, p); +} + +static inline void put_unaligned_le64(u64 val, void *p) +{ + __put_unaligned_le64(val, p); +} + +#endif /* _LINUX_UNALIGNED_LE_BYTESHIFT_H */