1#ifndef _LINUX_BYTEORDER_GENERIC_H
2#define _LINUX_BYTEORDER_GENERIC_H
3
4/*
5 * linux/byteorder_generic.h
6 * Generic Byte-reordering support
7 *
8 * Francois-Rene Rideau <fare@tunes.org> 19970707
9 *    gathered all the good ideas from all asm-foo/byteorder.h into one file,
10 *    cleaned them up.
11 *    I hope it is compliant with non-GCC compilers.
12 *    I decided to put __BYTEORDER_HAS_U64__ in byteorder.h,
13 *    because I wasn't sure it would be ok to put it in types.h
14 *    Upgraded it to 2.1.43
15 * Francois-Rene Rideau <fare@tunes.org> 19971012
16 *    Upgraded it to 2.1.57
17 *    to please Linus T., replaced huge #ifdef's between little/big endian
18 *    by nestedly #include'd files.
19 * Francois-Rene Rideau <fare@tunes.org> 19971205
20 *    Made it to 2.1.71; now a facelift:
21 *    Put files under include/linux/byteorder/
22 *    Split swab from generic support.
23 *
24 * TODO:
25 *   = Regular kernel maintainers could also replace all these manual
26 *    byteswap macros that remain, disseminated among drivers,
27 *    after some grep or the sources...
28 *   = Linus might want to rename all these macros and files to fit his taste,
29 *    to fit his personal naming scheme.
30 *   = it seems that a few drivers would also appreciate
31 *    nybble swapping support...
32 *   = every architecture could add their byteswap macro in asm/byteorder.h
33 *    see how some architectures already do (i386, alpha, ppc, etc)
34 *   = cpu_to_beXX and beXX_to_cpu might some day need to be well
35 *    distinguished throughout the kernel. This is not the case currently,
36 *    since little endian, big endian, and pdp endian machines needn't it.
37 *    But this might be the case for, say, a port of Linux to 20/21 bit
38 *    architectures (and F21 Linux addict around?).
39 */
40
41/*
42 * The following macros are to be defined by <asm/byteorder.h>:
43 *
44 * Conversion of long and short int between network and host format
45 *	ntohl(__u32 x)
46 *	ntohs(__u16 x)
47 *	htonl(__u32 x)
48 *	htons(__u16 x)
49 * It seems that some programs (which? where? or perhaps a standard? POSIX?)
50 * might like the above to be functions, not macros (why?).
51 * if that's true, then detect them, and take measures.
52 * Anyway, the measure is: define only ___ntohl as a macro instead,
53 * and in a separate file, have
54 * unsigned long inline ntohl(x){return ___ntohl(x);}
55 *
56 * The same for constant arguments
57 *	__constant_ntohl(__u32 x)
58 *	__constant_ntohs(__u16 x)
59 *	__constant_htonl(__u32 x)
60 *	__constant_htons(__u16 x)
61 *
62 * Conversion of XX-bit integers (16- 32- or 64-)
63 * between native CPU format and little/big endian format
64 * 64-bit stuff only defined for proper architectures
65 *	cpu_to_[bl]eXX(__uXX x)
66 *	[bl]eXX_to_cpu(__uXX x)
67 *
68 * The same, but takes a pointer to the value to convert
69 *	cpu_to_[bl]eXXp(__uXX x)
70 *	[bl]eXX_to_cpup(__uXX x)
71 *
72 * The same, but change in situ
73 *	cpu_to_[bl]eXXs(__uXX x)
74 *	[bl]eXX_to_cpus(__uXX x)
75 *
76 * See asm-foo/byteorder.h for examples of how to provide
77 * architecture-optimized versions
78 *
79 */
80
81
82#if defined(__KERNEL__)
83/*
84 * inside the kernel, we can use nicknames;
85 * outside of it, we must avoid POSIX namespace pollution...
86 */
87#define cpu_to_le64 __cpu_to_le64
88#define le64_to_cpu __le64_to_cpu
89#define cpu_to_le32 __cpu_to_le32
90#define le32_to_cpu __le32_to_cpu
91#define cpu_to_le16 __cpu_to_le16
92#define le16_to_cpu __le16_to_cpu
93#define cpu_to_be64 __cpu_to_be64
94#define be64_to_cpu __be64_to_cpu
95#define cpu_to_be32 __cpu_to_be32
96#define be32_to_cpu __be32_to_cpu
97#define cpu_to_be16 __cpu_to_be16
98#define be16_to_cpu __be16_to_cpu
99#define cpu_to_le64p __cpu_to_le64p
100#define le64_to_cpup __le64_to_cpup
101#define cpu_to_le32p __cpu_to_le32p
102#define le32_to_cpup __le32_to_cpup
103#define cpu_to_le16p __cpu_to_le16p
104#define le16_to_cpup __le16_to_cpup
105#define cpu_to_be64p __cpu_to_be64p
106#define be64_to_cpup __be64_to_cpup
107#define cpu_to_be32p __cpu_to_be32p
108#define be32_to_cpup __be32_to_cpup
109#define cpu_to_be16p __cpu_to_be16p
110#define be16_to_cpup __be16_to_cpup
111#define cpu_to_le64s __cpu_to_le64s
112#define le64_to_cpus __le64_to_cpus
113#define cpu_to_le32s __cpu_to_le32s
114#define le32_to_cpus __le32_to_cpus
115#define cpu_to_le16s __cpu_to_le16s
116#define le16_to_cpus __le16_to_cpus
117#define cpu_to_be64s __cpu_to_be64s
118#define be64_to_cpus __be64_to_cpus
119#define cpu_to_be32s __cpu_to_be32s
120#define be32_to_cpus __be32_to_cpus
121#define cpu_to_be16s __cpu_to_be16s
122#define be16_to_cpus __be16_to_cpus
123#endif
124
125
126/*
127 * Handle ntohl and suches. These have various compatibility
128 * issues - like we want to give the prototype even though we
129 * also have a macro for them in case some strange program
130 * wants to take the address of the thing or something..
131 *
132 * Note that these used to return a "long" in libc5, even though
133 * long is often 64-bit these days.. Thus the casts.
134 *
135 * They have to be macros in order to do the constant folding
136 * correctly - if the argument passed into a inline function
137 * it is no longer constant according to gcc..
138 */
139
140#undef ntohl
141#undef ntohs
142#undef htonl
143#undef htons
144
145/*
146 * Do the prototypes. Somebody might want to take the
147 * address or some such sick thing..
148 */
149#if defined(__KERNEL__) || (defined(__GLIBC__) && __GLIBC__ >= 2)
150extern __u32			ntohl(__u32);
151extern __u32			htonl(__u32);
152#else
153extern unsigned long int	ntohl(unsigned long int);
154extern unsigned long int	htonl(unsigned long int);
155#endif
156extern unsigned short int	ntohs(unsigned short int);
157extern unsigned short int	htons(unsigned short int);
158
159
160#if defined(__GNUC__) && (__GNUC__ >= 2) && defined(__OPTIMIZE__) && !defined(__STRICT_ANSI__)
161
162#define ___htonl(x) __cpu_to_be32(x)
163#define ___htons(x) __cpu_to_be16(x)
164#define ___ntohl(x) __be32_to_cpu(x)
165#define ___ntohs(x) __be16_to_cpu(x)
166
167#if defined(__KERNEL__) || (defined(__GLIBC__) && __GLIBC__ >= 2)
168#define htonl(x) ___htonl(x)
169#define ntohl(x) ___ntohl(x)
170#else
171#define htonl(x) ((unsigned long)___htonl(x))
172#define ntohl(x) ((unsigned long)___ntohl(x))
173#endif
174#define htons(x) ___htons(x)
175#define ntohs(x) ___ntohs(x)
176
177#endif /* OPTIMIZE */
178
179
180#endif /* _LINUX_BYTEORDER_GENERIC_H */
181