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Diffstat (limited to 'include/linux/byteorder/generic.h')
| -rw-r--r-- | include/linux/byteorder/generic.h | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/include/linux/byteorder/generic.h b/include/linux/byteorder/generic.h new file mode 100644 index 000000000000..5fde6f4d6c1e --- /dev/null +++ b/include/linux/byteorder/generic.h @@ -0,0 +1,172 @@ +#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 + + +#if defined(__KERNEL__) +/* + * 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.. + */ +extern __u32 ntohl(__be32); +extern __be32 htonl(__u32); +extern __u16 ntohs(__be16); +extern __be16 htons(__u16); + +#if defined(__GNUC__) && (__GNUC__ >= 2) && defined(__OPTIMIZE__) + +#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) + +#define htonl(x) ___htonl(x) +#define ntohl(x) ___ntohl(x) +#define htons(x) ___htons(x) +#define ntohs(x) ___ntohs(x) + +#endif /* OPTIMIZE */ + +#endif /* KERNEL */ + + +#endif /* _LINUX_BYTEORDER_GENERIC_H */ |