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>
47 lines
1.1 KiB
C
47 lines
1.1 KiB
C
#ifndef _LINUX_UNALIGNED_PACKED_STRUCT_H
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#define _LINUX_UNALIGNED_PACKED_STRUCT_H
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#include <linux/kernel.h>
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struct __una_u16 { u16 x __attribute__((packed)); };
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struct __una_u32 { u32 x __attribute__((packed)); };
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struct __una_u64 { u64 x __attribute__((packed)); };
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static inline u16 __get_unaligned_cpu16(const void *p)
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{
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const struct __una_u16 *ptr = (const struct __una_u16 *)p;
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return ptr->x;
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}
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static inline u32 __get_unaligned_cpu32(const void *p)
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{
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const struct __una_u32 *ptr = (const struct __una_u32 *)p;
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return ptr->x;
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}
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static inline u64 __get_unaligned_cpu64(const void *p)
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{
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const struct __una_u64 *ptr = (const struct __una_u64 *)p;
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return ptr->x;
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}
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static inline void __put_unaligned_cpu16(u16 val, void *p)
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{
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struct __una_u16 *ptr = (struct __una_u16 *)p;
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ptr->x = val;
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}
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static inline void __put_unaligned_cpu32(u32 val, void *p)
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{
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struct __una_u32 *ptr = (struct __una_u32 *)p;
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ptr->x = val;
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}
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static inline void __put_unaligned_cpu64(u64 val, void *p)
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{
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struct __una_u64 *ptr = (struct __una_u64 *)p;
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ptr->x = val;
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}
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#endif /* _LINUX_UNALIGNED_PACKED_STRUCT_H */
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