?? generic.h
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#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);#elseextern unsigned long int ntohl(unsigned long int);extern unsigned long int htonl(unsigned long int);#endifextern 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 */
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