From: Harvey Harrison Date: Tue, 29 Apr 2008 08:03:27 +0000 (-0700) Subject: kernel: add common infrastructure for unaligned access X-Git-Tag: v2.6.26-rc1~411 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=064106a91be5e76cb42c1ddf5d3871e3a1bd2a23;p=linux-2.6-omap-h63xx.git kernel: add common infrastructure for unaligned access 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 Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/include/linux/unaligned/access_ok.h b/include/linux/unaligned/access_ok.h new file mode 100644 index 00000000000..99c1b4d20b0 --- /dev/null +++ b/include/linux/unaligned/access_ok.h @@ -0,0 +1,67 @@ +#ifndef _LINUX_UNALIGNED_ACCESS_OK_H +#define _LINUX_UNALIGNED_ACCESS_OK_H + +#include +#include + +static inline u16 get_unaligned_le16(const void *p) +{ + return le16_to_cpup((__le16 *)p); +} + +static inline u32 get_unaligned_le32(const void *p) +{ + return le32_to_cpup((__le32 *)p); +} + +static inline u64 get_unaligned_le64(const void *p) +{ + return le64_to_cpup((__le64 *)p); +} + +static inline u16 get_unaligned_be16(const void *p) +{ + return be16_to_cpup((__be16 *)p); +} + +static inline u32 get_unaligned_be32(const void *p) +{ + return be32_to_cpup((__be32 *)p); +} + +static inline u64 get_unaligned_be64(const void *p) +{ + return be64_to_cpup((__be64 *)p); +} + +static inline void put_unaligned_le16(u16 val, void *p) +{ + *((__le16 *)p) = cpu_to_le16(val); +} + +static inline void put_unaligned_le32(u32 val, void *p) +{ + *((__le32 *)p) = cpu_to_le32(val); +} + +static inline void put_unaligned_le64(u64 val, void *p) +{ + *((__le64 *)p) = cpu_to_le64(val); +} + +static inline void put_unaligned_be16(u16 val, void *p) +{ + *((__be16 *)p) = cpu_to_be16(val); +} + +static inline void put_unaligned_be32(u32 val, void *p) +{ + *((__be32 *)p) = cpu_to_be32(val); +} + +static inline void put_unaligned_be64(u64 val, void *p) +{ + *((__be64 *)p) = cpu_to_be64(val); +} + +#endif /* _LINUX_UNALIGNED_ACCESS_OK_H */ diff --git a/include/linux/unaligned/be_byteshift.h b/include/linux/unaligned/be_byteshift.h new file mode 100644 index 00000000000..46dd12c5709 --- /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 + +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/be_memmove.h b/include/linux/unaligned/be_memmove.h new file mode 100644 index 00000000000..c2a76c5c9ed --- /dev/null +++ b/include/linux/unaligned/be_memmove.h @@ -0,0 +1,36 @@ +#ifndef _LINUX_UNALIGNED_BE_MEMMOVE_H +#define _LINUX_UNALIGNED_BE_MEMMOVE_H + +#include + +static inline u16 get_unaligned_be16(const void *p) +{ + return __get_unaligned_memmove16((const u8 *)p); +} + +static inline u32 get_unaligned_be32(const void *p) +{ + return __get_unaligned_memmove32((const u8 *)p); +} + +static inline u64 get_unaligned_be64(const void *p) +{ + return __get_unaligned_memmove64((const u8 *)p); +} + +static inline void put_unaligned_be16(u16 val, void *p) +{ + __put_unaligned_memmove16(val, p); +} + +static inline void put_unaligned_be32(u32 val, void *p) +{ + __put_unaligned_memmove32(val, p); +} + +static inline void put_unaligned_be64(u64 val, void *p) +{ + __put_unaligned_memmove64(val, p); +} + +#endif /* _LINUX_UNALIGNED_LE_MEMMOVE_H */ diff --git a/include/linux/unaligned/be_struct.h b/include/linux/unaligned/be_struct.h new file mode 100644 index 00000000000..132415836c5 --- /dev/null +++ b/include/linux/unaligned/be_struct.h @@ -0,0 +1,36 @@ +#ifndef _LINUX_UNALIGNED_BE_STRUCT_H +#define _LINUX_UNALIGNED_BE_STRUCT_H + +#include + +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); +} + +#endif /* _LINUX_UNALIGNED_BE_STRUCT_H */ diff --git a/include/linux/unaligned/generic.h b/include/linux/unaligned/generic.h new file mode 100644 index 00000000000..02d97ff3df7 --- /dev/null +++ b/include/linux/unaligned/generic.h @@ -0,0 +1,68 @@ +#ifndef _LINUX_UNALIGNED_GENERIC_H +#define _LINUX_UNALIGNED_GENERIC_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; }) + +#endif /* _LINUX_UNALIGNED_GENERIC_H */ diff --git a/include/linux/unaligned/le_byteshift.h b/include/linux/unaligned/le_byteshift.h new file mode 100644 index 00000000000..59777e951ba --- /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 + +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 */ diff --git a/include/linux/unaligned/le_memmove.h b/include/linux/unaligned/le_memmove.h new file mode 100644 index 00000000000..269849bee4e --- /dev/null +++ b/include/linux/unaligned/le_memmove.h @@ -0,0 +1,36 @@ +#ifndef _LINUX_UNALIGNED_LE_MEMMOVE_H +#define _LINUX_UNALIGNED_LE_MEMMOVE_H + +#include + +static inline u16 get_unaligned_le16(const void *p) +{ + return __get_unaligned_memmove16((const u8 *)p); +} + +static inline u32 get_unaligned_le32(const void *p) +{ + return __get_unaligned_memmove32((const u8 *)p); +} + +static inline u64 get_unaligned_le64(const void *p) +{ + return __get_unaligned_memmove64((const u8 *)p); +} + +static inline void put_unaligned_le16(u16 val, void *p) +{ + __put_unaligned_memmove16(val, p); +} + +static inline void put_unaligned_le32(u32 val, void *p) +{ + __put_unaligned_memmove32(val, p); +} + +static inline void put_unaligned_le64(u64 val, void *p) +{ + __put_unaligned_memmove64(val, p); +} + +#endif /* _LINUX_UNALIGNED_LE_MEMMOVE_H */ diff --git a/include/linux/unaligned/le_struct.h b/include/linux/unaligned/le_struct.h new file mode 100644 index 00000000000..088c4572faa --- /dev/null +++ b/include/linux/unaligned/le_struct.h @@ -0,0 +1,36 @@ +#ifndef _LINUX_UNALIGNED_LE_STRUCT_H +#define _LINUX_UNALIGNED_LE_STRUCT_H + +#include + +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); +} + +#endif /* _LINUX_UNALIGNED_LE_STRUCT_H */ diff --git a/include/linux/unaligned/memmove.h b/include/linux/unaligned/memmove.h new file mode 100644 index 00000000000..eeb5a779a4f --- /dev/null +++ b/include/linux/unaligned/memmove.h @@ -0,0 +1,45 @@ +#ifndef _LINUX_UNALIGNED_MEMMOVE_H +#define _LINUX_UNALIGNED_MEMMOVE_H + +#include +#include + +/* Use memmove here, so gcc does not insert a __builtin_memcpy. */ + +static inline u16 __get_unaligned_memmove16(const void *p) +{ + u16 tmp; + memmove(&tmp, p, 2); + return tmp; +} + +static inline u32 __get_unaligned_memmove32(const void *p) +{ + u32 tmp; + memmove(&tmp, p, 4); + return tmp; +} + +static inline u64 __get_unaligned_memmove64(const void *p) +{ + u64 tmp; + memmove(&tmp, p, 8); + return tmp; +} + +static inline void __put_unaligned_memmove16(u16 val, void *p) +{ + memmove(p, &val, 2); +} + +static inline void __put_unaligned_memmove32(u32 val, void *p) +{ + memmove(p, &val, 4); +} + +static inline void __put_unaligned_memmove64(u64 val, void *p) +{ + memmove(p, &val, 8); +} + +#endif /* _LINUX_UNALIGNED_MEMMOVE_H */ diff --git a/include/linux/unaligned/packed_struct.h b/include/linux/unaligned/packed_struct.h new file mode 100644 index 00000000000..2498bb9fe00 --- /dev/null +++ b/include/linux/unaligned/packed_struct.h @@ -0,0 +1,46 @@ +#ifndef _LINUX_UNALIGNED_PACKED_STRUCT_H +#define _LINUX_UNALIGNED_PACKED_STRUCT_H + +#include + +struct __una_u16 { u16 x __attribute__((packed)); }; +struct __una_u32 { u32 x __attribute__((packed)); }; +struct __una_u64 { u64 x __attribute__((packed)); }; + +static inline u16 __get_unaligned_cpu16(const void *p) +{ + const struct __una_u16 *ptr = (const struct __una_u16 *)p; + return ptr->x; +} + +static inline u32 __get_unaligned_cpu32(const void *p) +{ + const struct __una_u32 *ptr = (const struct __una_u32 *)p; + return ptr->x; +} + +static inline u64 __get_unaligned_cpu64(const void *p) +{ + const struct __una_u64 *ptr = (const struct __una_u64 *)p; + return ptr->x; +} + +static inline void __put_unaligned_cpu16(u16 val, void *p) +{ + struct __una_u16 *ptr = (struct __una_u16 *)p; + ptr->x = val; +} + +static inline void __put_unaligned_cpu32(u32 val, void *p) +{ + struct __una_u32 *ptr = (struct __una_u32 *)p; + ptr->x = val; +} + +static inline void __put_unaligned_cpu64(u64 val, void *p) +{ + struct __una_u64 *ptr = (struct __una_u64 *)p; + ptr->x = val; +} + +#endif /* _LINUX_UNALIGNED_PACKED_STRUCT_H */