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authorHarvey Harrison <harvey.harrison@gmail.com>2008-04-29 04:03:30 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-29 11:06:27 -0400
commit6510d41954dc6a9c8b1dbca7eaca0f23195ca727 (patch)
tree868b5fac25c7c5b80cc5a88eaaab8bf3d693420d /include/asm-mn10300
parent064106a91be5e76cb42c1ddf5d3871e3a1bd2a23 (diff)
kernel: Move arches to use common unaligned access
Unaligned access is ok for the following arches: cris, m68k, mn10300, powerpc, s390, x86 Arches that use the memmove implementation for native endian, and the byteshifting for the opposite endianness. h8300, m32r, xtensa Packed struct for native endian, byteshifting for other endian: alpha, blackfin, ia64, parisc, sparc, sparc64, mips, sh m86knommu is generic_be for Coldfire, otherwise unaligned access is ok. frv, arm chooses endianness based on compiler settings, uses the byteshifting versions. Remove the unaligned trap handler from frv as it is now unused. v850 is le, uses the byteshifting versions for both be and le. Remove the now unused asm-generic implementation. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/asm-mn10300')
-rw-r--r--include/asm-mn10300/unaligned.h130
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
17extern 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
80static inline void __put_unaligned_2(__u32 __v, register __u8 *__p)
81{
82 *__p++ = __v;
83 *__p++ = __v >> 8;
84}
85
86static 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
92static 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