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Commit 803f4e1e authored by Arnd Bergmann's avatar Arnd Bergmann
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asm-generic: simplify asm/unaligned.h 

The get_unaligned()/put_unaligned() implementations are much more complex
than necessary, now that all architectures use the same code.

Move everything into one file and use a much more compact way to express
the same logic.

I've compared the binary output using gcc-11 across defconfig builds for
all architectures and found this patch to make no difference, except for
a single function on powerpc that needs two additional register moves
because of random differences in register allocation.

There are a handful of callers of the low-level __get_unaligned_cpu32,
so leave that in place for the time being even though the common code
no longer uses it.

This adds a warning for any caller of get_unaligned()/put_unaligned()
that passes in a single-byte pointer, but I've sent patches for all
instances that show up in x86 and randconfig builds. It would be nice
to change the arguments of the endian-specific accessors to take the
matching __be16/__be32/__be64/__le16/__le32/__le64 arguments instead of
a void pointer, but that requires more changes to the rest of the kernel.

This new version does allow aggregate types into get_unaligned(), which
was not the original goal but might come in handy.
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent d40d8179
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include/asm-generic/unaligned.h
View file @ 803f4e1e
......@@ -6,20 +6,124 @@
* This is the most generic implementation of unaligned accesses
* and should work almost anywhere.
*/
#include <linux/unaligned/packed_struct.h>
#include <asm/byteorder.h>
#if defined(__LITTLE_ENDIAN)
# include <linux/unaligned/le_struct.h>
# include <linux/unaligned/generic.h>
# define get_unaligned __get_unaligned_le
# define put_unaligned __put_unaligned_le
#elif defined(__BIG_ENDIAN)
# include <linux/unaligned/be_struct.h>
# include <linux/unaligned/generic.h>
# define get_unaligned __get_unaligned_be
# define put_unaligned __put_unaligned_be
#else
# error need to define endianess
#endif
#define __get_unaligned_t(type, ptr) ({ \
const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr); \
__pptr->x; \
})
#define __put_unaligned_t(type, val, ptr) do { \
struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr); \
__pptr->x = (val); \
} while (0)
#define get_unaligned(ptr) __get_unaligned_t(typeof(*(ptr)), (ptr))
#define put_unaligned(val, ptr) __put_unaligned_t(typeof(*(ptr)), (val), (ptr))
static inline u16 get_unaligned_le16(const void *p)
{
return le16_to_cpu(__get_unaligned_t(__le16, p));
}
static inline u32 get_unaligned_le32(const void *p)
{
return le32_to_cpu(__get_unaligned_t(__le32, p));
}
static inline u64 get_unaligned_le64(const void *p)
{
return le64_to_cpu(__get_unaligned_t(__le64, p));
}
static inline void put_unaligned_le16(u16 val, void *p)
{
__put_unaligned_t(__le16, cpu_to_le16(val), p);
}
static inline void put_unaligned_le32(u32 val, void *p)
{
__put_unaligned_t(__le32, cpu_to_le32(val), p);
}
static inline void put_unaligned_le64(u64 val, void *p)
{
__put_unaligned_t(__le64, cpu_to_le64(val), p);
}
static inline u16 get_unaligned_be16(const void *p)
{
return be16_to_cpu(__get_unaligned_t(__be16, p));
}
static inline u32 get_unaligned_be32(const void *p)
{
return be32_to_cpu(__get_unaligned_t(__be32, p));
}
static inline u64 get_unaligned_be64(const void *p)
{
return be64_to_cpu(__get_unaligned_t(__be64, p));
}
static inline void put_unaligned_be16(u16 val, void *p)
{
__put_unaligned_t(__be16, cpu_to_be16(val), p);
}
static inline void put_unaligned_be32(u32 val, void *p)
{
__put_unaligned_t(__be32, cpu_to_be32(val), p);
}
static inline void put_unaligned_be64(u64 val, void *p)
{
__put_unaligned_t(__be64, cpu_to_be64(val), p);
}
static inline u32 __get_unaligned_be24(const u8 *p)
{
return p[0] << 16 | p[1] << 8 | p[2];
}
static inline u32 get_unaligned_be24(const void *p)
{
return __get_unaligned_be24(p);
}
static inline u32 __get_unaligned_le24(const u8 *p)
{
return p[0] | p[1] << 8 | p[2] << 16;
}
static inline u32 get_unaligned_le24(const void *p)
{
return __get_unaligned_le24(p);
}
static inline void __put_unaligned_be24(const u32 val, u8 *p)
{
*p++ = val >> 16;
*p++ = val >> 8;
*p++ = val;
}
static inline void put_unaligned_be24(const u32 val, void *p)
{
__put_unaligned_be24(val, p);
}
static inline void __put_unaligned_le24(const u32 val, u8 *p)
{
*p++ = val;
*p++ = val >> 8;
*p++ = val >> 16;
}
static inline void put_unaligned_le24(const u32 val, void *p)
{
__put_unaligned_le24(val, p);
}
#endif /* __ASM_GENERIC_UNALIGNED_H */
include/linux/unaligned/be_struct.h deleted 100644 → 0
View file @ d40d8179
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_UNALIGNED_BE_STRUCT_H
#define _LINUX_UNALIGNED_BE_STRUCT_H
#include <linux/unaligned/packed_struct.h>
static inline u16 get_unaligned_be16(const void *p)
{
return __get_unaligned_cpu16((const u8 *)p);
}
static inline u32 get_unaligned_be32(const void *p)
{
return __get_unaligned_cpu32((const u8 *)p);
}
static inline u64 get_unaligned_be64(const void *p)
{
return __get_unaligned_cpu64((const u8 *)p);
}
static inline void put_unaligned_be16(u16 val, void *p)
{
__put_unaligned_cpu16(val, p);
}
static inline void put_unaligned_be32(u32 val, void *p)
{
__put_unaligned_cpu32(val, p);
}
static inline void put_unaligned_be64(u64 val, void *p)
{
__put_unaligned_cpu64(val, p);
}
static inline u16 get_unaligned_le16(const void *p)
{
return swab16(__get_unaligned_cpu16((const u8 *)p));
}
static inline u32 get_unaligned_le32(const void *p)
{
return swab32(__get_unaligned_cpu32((const u8 *)p));
}
static inline u64 get_unaligned_le64(const void *p)
{
return swab64(__get_unaligned_cpu64((const u8 *)p));
}
static inline void put_unaligned_le16(u16 val, void *p)
{
__put_unaligned_cpu16(swab16(val), p);
}
static inline void put_unaligned_le32(u32 val, void *p)
{
__put_unaligned_cpu32(swab32(val), p);
}
static inline void put_unaligned_le64(u64 val, void *p)
{
__put_unaligned_cpu64(swab64(val), p);
}
#endif /* _LINUX_UNALIGNED_BE_STRUCT_H */
include/linux/unaligned/generic.h deleted 100644 → 0
View file @ d40d8179
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_UNALIGNED_GENERIC_H
#define _LINUX_UNALIGNED_GENERIC_H
#include <linux/types.h>
/*
* Cause a link-time error if we try an unaligned access other than
* 1,2,4 or 8 bytes long
*/
extern void __bad_unaligned_access_size(void);
#define __get_unaligned_le(ptr) ((__force typeof(*(ptr)))({ \
__builtin_choose_expr(sizeof(*(ptr)) == 1, *(ptr), \
__builtin_choose_expr(sizeof(*(ptr)) == 2, get_unaligned_le16((ptr)), \
__builtin_choose_expr(sizeof(*(ptr)) == 4, get_unaligned_le32((ptr)), \
__builtin_choose_expr(sizeof(*(ptr)) == 8, get_unaligned_le64((ptr)), \
__bad_unaligned_access_size())))); \
}))
#define __get_unaligned_be(ptr) ((__force typeof(*(ptr)))({ \
__builtin_choose_expr(sizeof(*(ptr)) == 1, *(ptr), \
__builtin_choose_expr(sizeof(*(ptr)) == 2, get_unaligned_be16((ptr)), \
__builtin_choose_expr(sizeof(*(ptr)) == 4, get_unaligned_be32((ptr)), \
__builtin_choose_expr(sizeof(*(ptr)) == 8, get_unaligned_be64((ptr)), \
__bad_unaligned_access_size())))); \
}))
#define __put_unaligned_le(val, ptr) ({ \
void *__gu_p = (ptr); \
switch (sizeof(*(ptr))) { \
case 1: \
*(u8 *)__gu_p = (__force u8)(val); \
break; \
case 2: \
put_unaligned_le16((__force u16)(val), __gu_p); \
break; \
case 4: \
put_unaligned_le32((__force u32)(val), __gu_p); \
break; \
case 8: \
put_unaligned_le64((__force u64)(val), __gu_p); \
break; \
default: \
__bad_unaligned_access_size(); \
break; \
} \
(void)0; })
#define __put_unaligned_be(val, ptr) ({ \
void *__gu_p = (ptr); \
switch (sizeof(*(ptr))) { \
case 1: \
*(u8 *)__gu_p = (__force u8)(val); \
break; \
case 2: \
put_unaligned_be16((__force u16)(val), __gu_p); \
break; \
case 4: \
put_unaligned_be32((__force u32)(val), __gu_p); \
break; \
case 8: \
put_unaligned_be64((__force u64)(val), __gu_p); \
break; \
default: \
__bad_unaligned_access_size(); \
break; \
} \
(void)0; })
static inline u32 __get_unaligned_be24(const u8 *p)
{
return p[0] << 16 | p[1] << 8 | p[2];
}
static inline u32 get_unaligned_be24(const void *p)
{
return __get_unaligned_be24(p);
}
static inline u32 __get_unaligned_le24(const u8 *p)
{
return p[0] | p[1] << 8 | p[2] << 16;
}
static inline u32 get_unaligned_le24(const void *p)
{
return __get_unaligned_le24(p);
}
static inline void __put_unaligned_be24(const u32 val, u8 *p)
{
*p++ = val >> 16;
*p++ = val >> 8;
*p++ = val;
}
static inline void put_unaligned_be24(const u32 val, void *p)
{
__put_unaligned_be24(val, p);
}
static inline void __put_unaligned_le24(const u32 val, u8 *p)
{
*p++ = val;
*p++ = val >> 8;
*p++ = val >> 16;
}
static inline void put_unaligned_le24(const u32 val, void *p)
{
__put_unaligned_le24(val, p);
}
#endif /* _LINUX_UNALIGNED_GENERIC_H */
include/linux/unaligned/le_struct.h deleted 100644 → 0
View file @ d40d8179
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_UNALIGNED_LE_STRUCT_H
#define _LINUX_UNALIGNED_LE_STRUCT_H
#include <linux/unaligned/packed_struct.h>
static inline u16 get_unaligned_le16(const void *p)
{
return __get_unaligned_cpu16((const u8 *)p);
}
static inline u32 get_unaligned_le32(const void *p)
{
return __get_unaligned_cpu32((const u8 *)p);
}
static inline u64 get_unaligned_le64(const void *p)
{
return __get_unaligned_cpu64((const u8 *)p);
}
static inline void put_unaligned_le16(u16 val, void *p)
{
__put_unaligned_cpu16(val, p);
}
static inline void put_unaligned_le32(u32 val, void *p)
{
__put_unaligned_cpu32(val, p);
}
static inline void put_unaligned_le64(u64 val, void *p)
{
__put_unaligned_cpu64(val, p);
}
static inline u16 get_unaligned_be16(const void *p)
{
return swab16(__get_unaligned_cpu16((const u8 *)p));
}
static inline u32 get_unaligned_be32(const void *p)
{
return swab32(__get_unaligned_cpu32((const u8 *)p));
}
static inline u64 get_unaligned_be64(const void *p)
{
return swab64(__get_unaligned_cpu64((const u8 *)p));
}
static inline void put_unaligned_be16(u16 val, void *p)
{
__put_unaligned_cpu16(swab16(val), p);
}
static inline void put_unaligned_be32(u32 val, void *p)
{
__put_unaligned_cpu32(swab32(val), p);
}
static inline void put_unaligned_be64(u64 val, void *p)
{
__put_unaligned_cpu64(swab64(val), p);
}
#endif /* _LINUX_UNALIGNED_LE_STRUCT_H */
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