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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-generic/unaligned.h
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/asm-generic/unaligned.h')
-rw-r--r--include/asm-generic/unaligned.h121
1 files changed, 121 insertions, 0 deletions
diff --git a/include/asm-generic/unaligned.h b/include/asm-generic/unaligned.h
new file mode 100644
index 000000000000..c856a43e3b45
--- /dev/null
+++ b/include/asm-generic/unaligned.h
@@ -0,0 +1,121 @@
1#ifndef _ASM_GENERIC_UNALIGNED_H_
2#define _ASM_GENERIC_UNALIGNED_H_
3
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 */
12
13#include <linux/types.h>
14
15/*
16 * The main single-value unaligned transfer routines.
17 */
18#define get_unaligned(ptr) \
19 ((__typeof__(*(ptr)))__get_unaligned((ptr), sizeof(*(ptr))))
20#define put_unaligned(x,ptr) \
21 __put_unaligned((unsigned long)(x), (ptr), sizeof(*(ptr)))
22
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 */
29extern void bad_unaligned_access_length(void) __attribute__((noreturn));
30
31struct __una_u64 { __u64 x __attribute__((packed)); };
32struct __una_u32 { __u32 x __attribute__((packed)); };
33struct __una_u16 { __u16 x __attribute__((packed)); };
34
35/*
36 * Elemental unaligned loads
37 */
38
39static inline unsigned long __uldq(const __u64 *addr)
40{
41 const struct __una_u64 *ptr = (const struct __una_u64 *) addr;
42 return ptr->x;
43}
44
45static inline unsigned long __uldl(const __u32 *addr)
46{
47 const struct __una_u32 *ptr = (const struct __una_u32 *) addr;
48 return ptr->x;
49}
50
51static inline unsigned long __uldw(const __u16 *addr)
52{
53 const struct __una_u16 *ptr = (const struct __una_u16 *) addr;
54 return ptr->x;
55}
56
57/*
58 * Elemental unaligned stores
59 */
60
61static inline void __ustq(__u64 val, __u64 *addr)
62{
63 struct __una_u64 *ptr = (struct __una_u64 *) addr;
64 ptr->x = val;
65}
66
67static inline void __ustl(__u32 val, __u32 *addr)
68{
69 struct __una_u32 *ptr = (struct __una_u32 *) addr;
70 ptr->x = val;
71}
72
73static inline void __ustw(__u16 val, __u16 *addr)
74{
75 struct __una_u16 *ptr = (struct __una_u16 *) addr;
76 ptr->x = val;
77}
78
79static inline unsigned long __get_unaligned(const void *ptr, size_t size)
80{
81 unsigned long val;
82 switch (size) {
83 case 1:
84 val = *(const __u8 *)ptr;
85 break;
86 case 2:
87 val = __uldw((const __u16 *)ptr);
88 break;
89 case 4:
90 val = __uldl((const __u32 *)ptr);
91 break;
92 case 8:
93 val = __uldq((const __u64 *)ptr);
94 break;
95 default:
96 bad_unaligned_access_length();
97 };
98 return val;
99}
100
101static inline void __put_unaligned(unsigned long val, void *ptr, size_t size)
102{
103 switch (size) {
104 case 1:
105 *(__u8 *)ptr = val;
106 break;
107 case 2:
108 __ustw(val, (__u16 *)ptr);
109 break;
110 case 4:
111 __ustl(val, (__u32 *)ptr);
112 break;
113 case 8:
114 __ustq(val, (__u64 *)ptr);
115 break;
116 default:
117 bad_unaligned_access_length();
118 };
119}
120
121#endif /* _ASM_GENERIC_UNALIGNED_H */