aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/byteorder/generic.h
blob: cff850f8502fe3af9e39771c100fd9f798df6574 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
#ifndef _LINUX_BYTEORDER_GENERIC_H
#define _LINUX_BYTEORDER_GENERIC_H

/*
 * linux/byteorder_generic.h
 * Generic Byte-reordering support
 *
 * Francois-Rene Rideau <fare@tunes.org> 19970707
 *    gathered all the good ideas from all asm-foo/byteorder.h into one file,
 *    cleaned them up.
 *    I hope it is compliant with non-GCC compilers.
 *    I decided to put __BYTEORDER_HAS_U64__ in byteorder.h,
 *    because I wasn't sure it would be ok to put it in types.h
 *    Upgraded it to 2.1.43
 * Francois-Rene Rideau <fare@tunes.org> 19971012
 *    Upgraded it to 2.1.57
 *    to please Linus T., replaced huge #ifdef's between little/big endian
 *    by nestedly #include'd files.
 * Francois-Rene Rideau <fare@tunes.org> 19971205
 *    Made it to 2.1.71; now a facelift:
 *    Put files under include/linux/byteorder/
 *    Split swab from generic support.
 *
 * TODO:
 *   = Regular kernel maintainers could also replace all these manual
 *    byteswap macros that remain, disseminated among drivers,
 *    after some grep or the sources...
 *   = Linus might want to rename all these macros and files to fit his taste,
 *    to fit his personal naming scheme.
 *   = it seems that a few drivers would also appreciate
 *    nybble swapping support...
 *   = every architecture could add their byteswap macro in asm/byteorder.h
 *    see how some architectures already do (i386, alpha, ppc, etc)
 *   = cpu_to_beXX and beXX_to_cpu might some day need to be well
 *    distinguished throughout the kernel. This is not the case currently,
 *    since little endian, big endian, and pdp endian machines needn't it.
 *    But this might be the case for, say, a port of Linux to 20/21 bit
 *    architectures (and F21 Linux addict around?).
 */

/*
 * The following macros are to be defined by <asm/byteorder.h>:
 *
 * Conversion of long and short int between network and host format
 *	ntohl(__u32 x)
 *	ntohs(__u16 x)
 *	htonl(__u32 x)
 *	htons(__u16 x)
 * It seems that some programs (which? where? or perhaps a standard? POSIX?)
 * might like the above to be functions, not macros (why?).
 * if that's true, then detect them, and take measures.
 * Anyway, the measure is: define only ___ntohl as a macro instead,
 * and in a separate file, have
 * unsigned long inline ntohl(x){return ___ntohl(x);}
 *
 * The same for constant arguments
 *	__constant_ntohl(__u32 x)
 *	__constant_ntohs(__u16 x)
 *	__constant_htonl(__u32 x)
 *	__constant_htons(__u16 x)
 *
 * Conversion of XX-bit integers (16- 32- or 64-)
 * between native CPU format and little/big endian format
 * 64-bit stuff only defined for proper architectures
 *	cpu_to_[bl]eXX(__uXX x)
 *	[bl]eXX_to_cpu(__uXX x)
 *
 * The same, but takes a pointer to the value to convert
 *	cpu_to_[bl]eXXp(__uXX x)
 *	[bl]eXX_to_cpup(__uXX x)
 *
 * The same, but change in situ
 *	cpu_to_[bl]eXXs(__uXX x)
 *	[bl]eXX_to_cpus(__uXX x)
 *
 * See asm-foo/byteorder.h for examples of how to provide
 * architecture-optimized versions
 *
 */


#if defined(__KERNEL__)
/*
 * inside the kernel, we can use nicknames;
 * outside of it, we must avoid POSIX namespace pollution...
 */
#define cpu_to_le64 __cpu_to_le64
#define le64_to_cpu __le64_to_cpu
#define cpu_to_le32 __cpu_to_le32
#define le32_to_cpu __le32_to_cpu
#define cpu_to_le16 __cpu_to_le16
#define le16_to_cpu __le16_to_cpu
#define cpu_to_be64 __cpu_to_be64
#define be64_to_cpu __be64_to_cpu
#define cpu_to_be32 __cpu_to_be32
#define be32_to_cpu __be32_to_cpu
#define cpu_to_be16 __cpu_to_be16
#define be16_to_cpu __be16_to_cpu
#define cpu_to_le64p __cpu_to_le64p
#define le64_to_cpup __le64_to_cpup
#define cpu_to_le32p __cpu_to_le32p
#define le32_to_cpup __le32_to_cpup
#define cpu_to_le16p __cpu_to_le16p
#define le16_to_cpup __le16_to_cpup
#define cpu_to_be64p __cpu_to_be64p
#define be64_to_cpup __be64_to_cpup
#define cpu_to_be32p __cpu_to_be32p
#define be32_to_cpup __be32_to_cpup
#define cpu_to_be16p __cpu_to_be16p
#define be16_to_cpup __be16_to_cpup
#define cpu_to_le64s __cpu_to_le64s
#define le64_to_cpus __le64_to_cpus
#define cpu_to_le32s __cpu_to_le32s
#define le32_to_cpus __le32_to_cpus
#define cpu_to_le16s __cpu_to_le16s
#define le16_to_cpus __le16_to_cpus
#define cpu_to_be64s __cpu_to_be64s
#define be64_to_cpus __be64_to_cpus
#define cpu_to_be32s __cpu_to_be32s
#define be32_to_cpus __be32_to_cpus
#define cpu_to_be16s __cpu_to_be16s
#define be16_to_cpus __be16_to_cpus
#endif


/*
 * Handle ntohl and suches. These have various compatibility
 * issues - like we want to give the prototype even though we
 * also have a macro for them in case some strange program
 * wants to take the address of the thing or something..
 *
 * Note that these used to return a "long" in libc5, even though
 * long is often 64-bit these days.. Thus the casts.
 *
 * They have to be macros in order to do the constant folding
 * correctly - if the argument passed into a inline function
 * it is no longer constant according to gcc..
 */

#undef ntohl
#undef ntohs
#undef htonl
#undef htons

/*
 * Do the prototypes. Somebody might want to take the
 * address or some such sick thing..
 */
#if defined(__KERNEL__) || (defined (__GLIBC__) && __GLIBC__ >= 2)
extern __u32			ntohl(__u32);
extern __u32			htonl(__u32);
#else
extern unsigned long int	ntohl(unsigned long int);
extern unsigned long int	htonl(unsigned long int);
#endif
extern unsigned short int	ntohs(unsigned short int);
extern unsigned short int	htons(unsigned short int);


#if defined(__GNUC__) && (__GNUC__ >= 2)

#define ___htonl(x) __cpu_to_be32(x)
#define ___htons(x) __cpu_to_be16(x)
#define ___ntohl(x) __be32_to_cpu(x)
#define ___ntohs(x) __be16_to_cpu(x)

#if defined(__KERNEL__) || (defined (__GLIBC__) && __GLIBC__ >= 2)
#define htonl(x) ___htonl(x)
#define ntohl(x) ___ntohl(x)
#else
#define htonl(x) ((unsigned long)___htonl(x))
#define ntohl(x) ((unsigned long)___ntohl(x))
#endif
#define htons(x) ___htons(x)
#define ntohs(x) ___ntohs(x)

#endif /* OPTIMIZE */


#endif /* _LINUX_BYTEORDER_GENERIC_H */