#ifndef _ASM_GENERIC_UNALIGNED_H_ #define _ASM_GENERIC_UNALIGNED_H_ /* * For the benefit of those who are trying to port Linux to another * architecture, here are some C-language equivalents. * * This is based almost entirely upon Richard Henderson's * asm-alpha/unaligned.h implementation. Some comments were * taken from David Mosberger's asm-ia64/unaligned.h header. */ #include <linux/types.h> /* * The main single-value unaligned transfer routines. */ #define get_unaligned(ptr) \ __get_unaligned((ptr), sizeof(*(ptr))) #define put_unaligned(x,ptr) \ __put_unaligned((__u64)(x), (ptr), sizeof(*(ptr))) /* * This function doesn't actually exist. The idea is that when * someone uses the macros below with an unsupported size (datatype), * the linker will alert us to the problem via an unresolved reference * error. */ extern void bad_unaligned_access_length(void) __attribute__((noreturn)); struct __una_u64 { __u64 x __attribute__((packed)); }; struct __una_u32 { __u32 x __attribute__((packed)); }; struct __una_u16 { __u16 x __attribute__((packed)); }; /* * Elemental unaligned loads */ static inline __u64 __uldq(const __u64 *addr) { const struct __una_u64 *ptr = (const struct __una_u64 *) addr; return ptr->x; } static inline __u32 __uldl(const __u32 *addr) { const struct __una_u32 *ptr = (const struct __una_u32 *) addr; return ptr->x; } static inline __u16 __uldw(const __u16 *addr) { const struct __una_u16 *ptr = (const struct __una_u16 *) addr; return ptr->x; } /* * Elemental unaligned stores */ static inline void __ustq(__u64 val, __u64 *addr) { struct __una_u64 *ptr = (struct __una_u64 *) addr; ptr->x = val; } static inline void __ustl(__u32 val, __u32 *addr) { struct __una_u32 *ptr = (struct __una_u32 *) addr; ptr->x = val; } static inline void __ustw(__u16 val, __u16 *addr) { struct __una_u16 *ptr = (struct __una_u16 *) addr; ptr->x = val; } #define __get_unaligned(ptr, size) ({ \ const void *__gu_p = ptr; \ __typeof__(*(ptr)) val; \ switch (size) { \ case 1: \ val = *(const __u8 *)__gu_p; \ break; \ case 2: \ val = __uldw(__gu_p); \ break; \ case 4: \ val = __uldl(__gu_p); \ break; \ case 8: \ val = __uldq(__gu_p); \ break; \ default: \ bad_unaligned_access_length(); \ }; \ val; \ }) #define __put_unaligned(val, ptr, size) \ do { \ void *__gu_p = ptr; \ switch (size) { \ case 1: \ *(__u8 *)__gu_p = val; \ break; \ case 2: \ __ustw(val, __gu_p); \ break; \ case 4: \ __ustl(val, __gu_p); \ break; \ case 8: \ __ustq(val, __gu_p); \ break; \ default: \ bad_unaligned_access_length(); \ }; \ } while(0) #endif /* _ASM_GENERIC_UNALIGNED_H */