ia64/linux-2.6.18-xen.hg

view include/asm-generic/unaligned.h @ 782:9ab1c319531f

merge with linux-2.6.18-xen.hg
author Isaku Yamahata <yamahata@valinux.co.jp>
date Wed Jan 28 13:07:23 2009 +0900 (2009-01-28)
parents 831230e53067
children
line source
1 #ifndef _ASM_GENERIC_UNALIGNED_H_
2 #define _ASM_GENERIC_UNALIGNED_H_
4 /*
5 * For the benefit of those who are trying to port Linux to another
6 * architecture, here are some C-language equivalents.
7 *
8 * This is based almost entirely upon Richard Henderson's
9 * asm-alpha/unaligned.h implementation. Some comments were
10 * taken from David Mosberger's asm-ia64/unaligned.h header.
11 */
13 #include <linux/types.h>
15 /*
16 * The main single-value unaligned transfer routines.
17 */
18 #define get_unaligned(ptr) \
19 __get_unaligned((ptr), sizeof(*(ptr)))
20 #define put_unaligned(x,ptr) \
21 __put_unaligned((__u64)(x), (ptr), sizeof(*(ptr)))
23 /*
24 * This function doesn't actually exist. The idea is that when
25 * someone uses the macros below with an unsupported size (datatype),
26 * the linker will alert us to the problem via an unresolved reference
27 * error.
28 */
29 extern void bad_unaligned_access_length(void) __attribute__((noreturn));
31 struct __una_u64 { __u64 x __attribute__((packed)); };
32 struct __una_u32 { __u32 x __attribute__((packed)); };
33 struct __una_u16 { __u16 x __attribute__((packed)); };
35 /*
36 * Elemental unaligned loads
37 */
39 static inline __u64 __uldq(const __u64 *addr)
40 {
41 const struct __una_u64 *ptr = (const struct __una_u64 *) addr;
42 return ptr->x;
43 }
45 static inline __u32 __uldl(const __u32 *addr)
46 {
47 const struct __una_u32 *ptr = (const struct __una_u32 *) addr;
48 return ptr->x;
49 }
51 static inline __u16 __uldw(const __u16 *addr)
52 {
53 const struct __una_u16 *ptr = (const struct __una_u16 *) addr;
54 return ptr->x;
55 }
57 /*
58 * Elemental unaligned stores
59 */
61 static inline void __ustq(__u64 val, __u64 *addr)
62 {
63 struct __una_u64 *ptr = (struct __una_u64 *) addr;
64 ptr->x = val;
65 }
67 static inline void __ustl(__u32 val, __u32 *addr)
68 {
69 struct __una_u32 *ptr = (struct __una_u32 *) addr;
70 ptr->x = val;
71 }
73 static inline void __ustw(__u16 val, __u16 *addr)
74 {
75 struct __una_u16 *ptr = (struct __una_u16 *) addr;
76 ptr->x = val;
77 }
79 #define __get_unaligned(ptr, size) ({ \
80 const void *__gu_p = ptr; \
81 __u64 val; \
82 switch (size) { \
83 case 1: \
84 val = *(const __u8 *)__gu_p; \
85 break; \
86 case 2: \
87 val = __uldw(__gu_p); \
88 break; \
89 case 4: \
90 val = __uldl(__gu_p); \
91 break; \
92 case 8: \
93 val = __uldq(__gu_p); \
94 break; \
95 default: \
96 bad_unaligned_access_length(); \
97 }; \
98 (__typeof__(*(ptr)))val; \
99 })
101 #define __put_unaligned(val, ptr, size) \
102 do { \
103 void *__gu_p = ptr; \
104 switch (size) { \
105 case 1: \
106 *(__u8 *)__gu_p = val; \
107 break; \
108 case 2: \
109 __ustw(val, __gu_p); \
110 break; \
111 case 4: \
112 __ustl(val, __gu_p); \
113 break; \
114 case 8: \
115 __ustq(val, __gu_p); \
116 break; \
117 default: \
118 bad_unaligned_access_length(); \
119 }; \
120 } while(0)
122 #endif /* _ASM_GENERIC_UNALIGNED_H */