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author | Arnd Bergmann <arnd@arndb.de> | 2021-05-08 00:07:57 +0200 |
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committer | Arnd Bergmann <arnd@arndb.de> | 2021-05-17 13:30:29 +0200 |
commit | 803f4e1eab7a8938ba3a3c30dd4eb5e9eeef5e63 (patch) | |
tree | 4a7096939a4a914eedad1fba212cee0e88ba3ec5 /include/asm-generic/unaligned.h | |
parent | d40d8179482c330df5b9049797fe94c2e8eb4f6e (diff) | |
download | linux-803f4e1eab7a8938ba3a3c30dd4eb5e9eeef5e63.tar.gz |
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: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'include/asm-generic/unaligned.h')
-rw-r--r-- | include/asm-generic/unaligned.h | 130 |
1 files changed, 117 insertions, 13 deletions
diff --git a/include/asm-generic/unaligned.h b/include/asm-generic/unaligned.h index 36bf03aaa674..1c4242416c9f 100644 --- a/include/asm-generic/unaligned.h +++ b/include/asm-generic/unaligned.h @@ -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 */ |