1 #ifndef _LWK_BYTEORDER_GENERIC_H
2 #define _LWK_BYTEORDER_GENERIC_H
5 * lwk/byteorder/generic.h
6 * Generic Byte-reordering support
8 * The "... p" macros, like le64_to_cpup, can be used with pointers
9 * to unaligned data, but there will be a performance penalty on
10 * some architectures. Use get_unaligned for unaligned data.
12 * Francois-Rene Rideau <fare@tunes.org> 19970707
13 * gathered all the good ideas from all asm-foo/byteorder.h into one file,
15 * I hope it is compliant with non-GCC compilers.
16 * I decided to put __BYTEORDER_HAS_U64__ in byteorder.h,
17 * because I wasn't sure it would be ok to put it in types.h
18 * Upgraded it to 2.1.43
19 * Francois-Rene Rideau <fare@tunes.org> 19971012
20 * Upgraded it to 2.1.57
21 * to please Linus T., replaced huge #ifdef's between little/big endian
22 * by nestedly #include'd files.
23 * Francois-Rene Rideau <fare@tunes.org> 19971205
24 * Made it to 2.1.71; now a facelift:
25 * Put files under include/linux/byteorder/
26 * Split swab from generic support.
29 * = Regular kernel maintainers could also replace all these manual
30 * byteswap macros that remain, disseminated among drivers,
31 * after some grep or the sources...
32 * = Linus might want to rename all these macros and files to fit his taste,
33 * to fit his personal naming scheme.
34 * = it seems that a few drivers would also appreciate
35 * nybble swapping support...
36 * = every architecture could add their byteswap macro in asm/byteorder.h
37 * see how some architectures already do (i386, alpha, ppc, etc)
38 * = cpu_to_beXX and beXX_to_cpu might some day need to be well
39 * distinguished throughout the kernel. This is not the case currently,
40 * since little endian, big endian, and pdp endian machines needn't it.
41 * But this might be the case for, say, a port of Linux to 20/21 bit
42 * architectures (and F21 Linux addict around?).
46 * The following macros are to be defined by <asm/byteorder.h>:
48 * Conversion of long and short int between network and host format
53 * It seems that some programs (which? where? or perhaps a standard? POSIX?)
54 * might like the above to be functions, not macros (why?).
55 * if that's true, then detect them, and take measures.
56 * Anyway, the measure is: define only ___ntohl as a macro instead,
57 * and in a separate file, have
58 * unsigned long inline ntohl(x){return ___ntohl(x);}
60 * The same for constant arguments
61 * __constant_ntohl(__u32 x)
62 * __constant_ntohs(__u16 x)
63 * __constant_htonl(__u32 x)
64 * __constant_htons(__u16 x)
66 * Conversion of XX-bit integers (16- 32- or 64-)
67 * between native CPU format and little/big endian format
68 * 64-bit stuff only defined for proper architectures
69 * cpu_to_[bl]eXX(__uXX x)
70 * [bl]eXX_to_cpu(__uXX x)
72 * The same, but takes a pointer to the value to convert
73 * cpu_to_[bl]eXXp(__uXX x)
74 * [bl]eXX_to_cpup(__uXX x)
76 * The same, but change in situ
77 * cpu_to_[bl]eXXs(__uXX x)
78 * [bl]eXX_to_cpus(__uXX x)
80 * See asm-foo/byteorder.h for examples of how to provide
81 * architecture-optimized versions
86 #if defined(__KERNEL__)
88 * inside the kernel, we can use nicknames;
89 * outside of it, we must avoid POSIX namespace pollution...
91 #define cpu_to_le64 __cpu_to_le64
92 #define le64_to_cpu __le64_to_cpu
93 #define cpu_to_le32 __cpu_to_le32
94 #define le32_to_cpu __le32_to_cpu
95 #define cpu_to_le16 __cpu_to_le16
96 #define le16_to_cpu __le16_to_cpu
97 #define cpu_to_be64 __cpu_to_be64
98 #define be64_to_cpu __be64_to_cpu
99 #define cpu_to_be32 __cpu_to_be32
100 #define be32_to_cpu __be32_to_cpu
101 #define cpu_to_be16 __cpu_to_be16
102 #define be16_to_cpu __be16_to_cpu
103 #define cpu_to_le64p __cpu_to_le64p
104 #define le64_to_cpup __le64_to_cpup
105 #define cpu_to_le32p __cpu_to_le32p
106 #define le32_to_cpup __le32_to_cpup
107 #define cpu_to_le16p __cpu_to_le16p
108 #define le16_to_cpup __le16_to_cpup
109 #define cpu_to_be64p __cpu_to_be64p
110 #define be64_to_cpup __be64_to_cpup
111 #define cpu_to_be32p __cpu_to_be32p
112 #define be32_to_cpup __be32_to_cpup
113 #define cpu_to_be16p __cpu_to_be16p
114 #define be16_to_cpup __be16_to_cpup
115 #define cpu_to_le64s __cpu_to_le64s
116 #define le64_to_cpus __le64_to_cpus
117 #define cpu_to_le32s __cpu_to_le32s
118 #define le32_to_cpus __le32_to_cpus
119 #define cpu_to_le16s __cpu_to_le16s
120 #define le16_to_cpus __le16_to_cpus
121 #define cpu_to_be64s __cpu_to_be64s
122 #define be64_to_cpus __be64_to_cpus
123 #define cpu_to_be32s __cpu_to_be32s
124 #define be32_to_cpus __be32_to_cpus
125 #define cpu_to_be16s __cpu_to_be16s
126 #define be16_to_cpus __be16_to_cpus
130 #if defined(__KERNEL__)
132 * Handle ntohl and suches. These have various compatibility
133 * issues - like we want to give the prototype even though we
134 * also have a macro for them in case some strange program
135 * wants to take the address of the thing or something..
137 * Note that these used to return a "long" in libc5, even though
138 * long is often 64-bit these days.. Thus the casts.
140 * They have to be macros in order to do the constant folding
141 * correctly - if the argument passed into a inline function
142 * it is no longer constant according to gcc..
151 * Do the prototypes. Somebody might want to take the
152 * address or some such sick thing..
154 extern __u32 ntohl(__be32);
155 extern __be32 htonl(__u32);
156 extern __u16 ntohs(__be16);
157 extern __be16 htons(__u16);
159 #if defined(__GNUC__) && defined(__OPTIMIZE__)
161 #define ___htonl(x) __cpu_to_be32(x)
162 #define ___htons(x) __cpu_to_be16(x)
163 #define ___ntohl(x) __be32_to_cpu(x)
164 #define ___ntohs(x) __be16_to_cpu(x)
166 #define htonl(x) ___htonl(x)
167 #define ntohl(x) ___ntohl(x)
168 #define htons(x) ___htons(x)
169 #define ntohs(x) ___ntohs(x)
171 #endif /* OPTIMIZE */
176 #endif /* _LWK_BYTEORDER_GENERIC_H */
