diff options
Diffstat (limited to 'include/asm-mn10300/unaligned.h')
-rw-r--r-- | include/asm-mn10300/unaligned.h | 130 |
1 files changed, 7 insertions, 123 deletions
diff --git a/include/asm-mn10300/unaligned.h b/include/asm-mn10300/unaligned.h index cad3afbd035f..0df671318ae4 100644 --- a/include/asm-mn10300/unaligned.h +++ b/include/asm-mn10300/unaligned.h | |||
@@ -8,129 +8,13 @@ | |||
8 | * as published by the Free Software Foundation; either version | 8 | * as published by the Free Software Foundation; either version |
9 | * 2 of the Licence, or (at your option) any later version. | 9 | * 2 of the Licence, or (at your option) any later version. |
10 | */ | 10 | */ |
11 | #ifndef _ASM_UNALIGNED_H | 11 | #ifndef _ASM_MN10300_UNALIGNED_H |
12 | #define _ASM_UNALIGNED_H | 12 | #define _ASM_MN10300_UNALIGNED_H |
13 | 13 | ||
14 | #include <asm/types.h> | 14 | #include <linux/unaligned/access_ok.h> |
15 | #include <linux/unaligned/generic.h> | ||
15 | 16 | ||
16 | #if 0 | 17 | #define get_unaligned __get_unaligned_le |
17 | extern int __bug_unaligned_x(void *ptr); | 18 | #define put_unaligned __put_unaligned_le |
18 | 19 | ||
19 | /* | 20 | #endif /* _ASM_MN10300_UNALIGNED_H */ |
20 | * What is the most efficient way of loading/storing an unaligned value? | ||
21 | * | ||
22 | * That is the subject of this file. Efficiency here is defined as | ||
23 | * minimum code size with minimum register usage for the common cases. | ||
24 | * It is currently not believed that long longs are common, so we | ||
25 | * trade efficiency for the chars, shorts and longs against the long | ||
26 | * longs. | ||
27 | * | ||
28 | * Current stats with gcc 2.7.2.2 for these functions: | ||
29 | * | ||
30 | * ptrsize get: code regs put: code regs | ||
31 | * 1 1 1 1 2 | ||
32 | * 2 3 2 3 2 | ||
33 | * 4 7 3 7 3 | ||
34 | * 8 20 6 16 6 | ||
35 | * | ||
36 | * gcc 2.95.1 seems to code differently: | ||
37 | * | ||
38 | * ptrsize get: code regs put: code regs | ||
39 | * 1 1 1 1 2 | ||
40 | * 2 3 2 3 2 | ||
41 | * 4 7 4 7 4 | ||
42 | * 8 19 8 15 6 | ||
43 | * | ||
44 | * which may or may not be more efficient (depending upon whether | ||
45 | * you can afford the extra registers). Hopefully the gcc 2.95 | ||
46 | * is inteligent enough to decide if it is better to use the | ||
47 | * extra register, but evidence so far seems to suggest otherwise. | ||
48 | * | ||
49 | * Unfortunately, gcc is not able to optimise the high word | ||
50 | * out of long long >> 32, or the low word from long long << 32 | ||
51 | */ | ||
52 | |||
53 | #define __get_unaligned_2(__p) \ | ||
54 | (__p[0] | __p[1] << 8) | ||
55 | |||
56 | #define __get_unaligned_4(__p) \ | ||
57 | (__p[0] | __p[1] << 8 | __p[2] << 16 | __p[3] << 24) | ||
58 | |||
59 | #define get_unaligned(ptr) \ | ||
60 | ({ \ | ||
61 | unsigned int __v1, __v2; \ | ||
62 | __typeof__(*(ptr)) __v; \ | ||
63 | __u8 *__p = (__u8 *)(ptr); \ | ||
64 | \ | ||
65 | switch (sizeof(*(ptr))) { \ | ||
66 | case 1: __v = *(ptr); break; \ | ||
67 | case 2: __v = __get_unaligned_2(__p); break; \ | ||
68 | case 4: __v = __get_unaligned_4(__p); break; \ | ||
69 | case 8: \ | ||
70 | __v2 = __get_unaligned_4((__p+4)); \ | ||
71 | __v1 = __get_unaligned_4(__p); \ | ||
72 | __v = ((unsigned long long)__v2 << 32 | __v1); \ | ||
73 | break; \ | ||
74 | default: __v = __bug_unaligned_x(__p); break; \ | ||
75 | } \ | ||
76 | __v; \ | ||
77 | }) | ||
78 | |||
79 | |||
80 | static inline void __put_unaligned_2(__u32 __v, register __u8 *__p) | ||
81 | { | ||
82 | *__p++ = __v; | ||
83 | *__p++ = __v >> 8; | ||
84 | } | ||
85 | |||
86 | static inline void __put_unaligned_4(__u32 __v, register __u8 *__p) | ||
87 | { | ||
88 | __put_unaligned_2(__v >> 16, __p + 2); | ||
89 | __put_unaligned_2(__v, __p); | ||
90 | } | ||
91 | |||
92 | static inline void __put_unaligned_8(const unsigned long long __v, __u8 *__p) | ||
93 | { | ||
94 | /* | ||
95 | * tradeoff: 8 bytes of stack for all unaligned puts (2 | ||
96 | * instructions), or an extra register in the long long | ||
97 | * case - go for the extra register. | ||
98 | */ | ||
99 | __put_unaligned_4(__v >> 32, __p + 4); | ||
100 | __put_unaligned_4(__v, __p); | ||
101 | } | ||
102 | |||
103 | /* | ||
104 | * Try to store an unaligned value as efficiently as possible. | ||
105 | */ | ||
106 | #define put_unaligned(val, ptr) \ | ||
107 | ({ \ | ||
108 | switch (sizeof(*(ptr))) { \ | ||
109 | case 1: \ | ||
110 | *(ptr) = (val); \ | ||
111 | break; \ | ||
112 | case 2: \ | ||
113 | __put_unaligned_2((val), (__u8 *)(ptr)); \ | ||
114 | break; \ | ||
115 | case 4: \ | ||
116 | __put_unaligned_4((val), (__u8 *)(ptr)); \ | ||
117 | break; \ | ||
118 | case 8: \ | ||
119 | __put_unaligned_8((val), (__u8 *)(ptr)); \ | ||
120 | break; \ | ||
121 | default: \ | ||
122 | __bug_unaligned_x(ptr); \ | ||
123 | break; \ | ||
124 | } \ | ||
125 | (void) 0; \ | ||
126 | }) | ||
127 | |||
128 | |||
129 | #else | ||
130 | |||
131 | #define get_unaligned(ptr) (*(ptr)) | ||
132 | #define put_unaligned(val, ptr) ({ *(ptr) = (val); (void) 0; }) | ||
133 | |||
134 | #endif | ||
135 | |||
136 | #endif | ||