064106a91b
Create a linux/unaligned directory similar in spirit to the linux/byteorder
folder to hold generic implementations collected from various arches.
Currently there are five implementations:
1) packed_struct.h: C-struct based, from asm-generic/unaligned.h
2) le_byteshift.h: Open coded byte-swapping, heavily based on asm-arm
3) be_byteshift.h: Open coded byte-swapping, heavily based on asm-arm
4) memmove.h: taken from multiple implementations in tree
5) access_ok.h: taken from x86 and others, unaligned access is ok.
All of the new implementations checks for sizes not equal to 1,2,4,8
and will fail to link.
API additions:
get_unaligned_{le16|le32|le64|be16|be32|be64}(p) which is meant to replace
code of the form:
le16_to_cpu(get_unaligned((__le16 *)p));
put_unaligned_{le16|le32|le64|be16|be32|be64}(val, pointer) which is meant to
replace code of the form:
put_unaligned(cpu_to_le16(val), (__le16 *)p);
The headers that arches should include from their asm/unaligned.h:
access_ok.h : Wrappers of the byteswapping functions in asm/byteorder
Choose a particular implementation for little-endian access:
le_byteshift.h
le_memmove.h (arch must be LE)
le_struct.h (arch must be LE)
Choose a particular implementation for big-endian access:
be_byteshift.h
be_memmove.h (arch must be BE)
be_struct.h (arch must be BE)
After including as needed from the above, include unaligned/generic.h and
define your arch's get/put_unaligned as (for LE):
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
71 lines
1.4 KiB
C
71 lines
1.4 KiB
C
#ifndef _LINUX_UNALIGNED_LE_BYTESHIFT_H
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#define _LINUX_UNALIGNED_LE_BYTESHIFT_H
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#include <linux/kernel.h>
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static inline u16 __get_unaligned_le16(const u8 *p)
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{
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return p[0] | p[1] << 8;
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}
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static inline u32 __get_unaligned_le32(const u8 *p)
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{
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return p[0] | p[1] << 8 | p[2] << 16 | p[3] << 24;
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}
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static inline u64 __get_unaligned_le64(const u8 *p)
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{
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return (u64)__get_unaligned_le32(p + 4) << 32 |
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__get_unaligned_le32(p);
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}
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static inline void __put_unaligned_le16(u16 val, u8 *p)
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{
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*p++ = val;
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*p++ = val >> 8;
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}
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static inline void __put_unaligned_le32(u32 val, u8 *p)
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{
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__put_unaligned_le16(val >> 16, p + 2);
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__put_unaligned_le16(val, p);
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}
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static inline void __put_unaligned_le64(u64 val, u8 *p)
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{
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__put_unaligned_le32(val >> 32, p + 4);
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__put_unaligned_le32(val, p);
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}
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static inline u16 get_unaligned_le16(const void *p)
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{
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return __get_unaligned_le16((const u8 *)p);
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}
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static inline u32 get_unaligned_le32(const void *p)
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{
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return __get_unaligned_le32((const u8 *)p);
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}
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static inline u64 get_unaligned_le64(const void *p)
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{
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return __get_unaligned_le64((const u8 *)p);
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}
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static inline void put_unaligned_le16(u16 val, void *p)
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{
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__put_unaligned_le16(val, p);
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}
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static inline void put_unaligned_le32(u32 val, void *p)
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{
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__put_unaligned_le32(val, p);
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}
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static inline void put_unaligned_le64(u64 val, void *p)
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{
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__put_unaligned_le64(val, p);
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}
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#endif /* _LINUX_UNALIGNED_LE_BYTESHIFT_H */
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