patch-2.1.71 linux/include/linux/byteorder_generic.h

• Lines: 299
• Date: Wed Dec 3 17:13:31 1997
• Orig file: v2.1.70/linux/include/linux/byteorder_generic.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.70/linux/include/linux/byteorder_generic.h linux/include/linux/byteorder_generic.h
@@ -0,0 +1,298 @@
+#ifndef _LINUX_BYTEORDER_GENERIC_H
+#define _LINUX_BYTEORDER_GENERIC_H
+
+/*
+ * linux/byteorder_generic.h
+ * Generic Byteswap support
+ *
+ * Francois-Rene Rideau <[email protected]> 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 <[email protected]> 19971012
+ *    Upgraded it to 2.1.57
+ *    to please Linus T., replaced huge #ifdef's between little/big endian
+ *    by nestedly #include'd files.
+ *
+ * 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 many 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)
+ */
+
+/*
+ * This file is included by both <linux/byteorder_little_endian.h> and
+ * <linux/byteorder_big_endian.h>. People porting from machines with
+ * bizarre bytedisorder (like the VAX?) will have to write a different one.
+ * Actually, this file mostly does byteswapping, and could be named
+ * <byteswap.h> or <swab.h> rather than <linux/byteorder_generic.h>
+ *
+ */
+
+/*
+ * 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)
+ *
+ * Byteswapping, independently from cpu endianness
+ *	swabXX[ps]?(foo)
+ *
+ *
+ * See asm-foo/byteorder.h for examples of how to provide
+ * architecture-optimized versions
+ *
+ */
+
+#include <asm/types.h>
+
+/*
+ * Generic byte swapping routines. We fall back on
+ * these if we don't have any optimized code, and
+ * when we have constants that we want the compiler
+ * to byte swap for us..
+ */
+#define ___swab16(x) \
+	((__u16)( \
+		(((__u16)(x) & 0x00ffU) << 8) | \
+		(((__u16)(x) & 0xff00U) >> 8) ))
+#define ___swab32(x) \
+	((__u32)( \
+		(((__u32)(x) & (__u32)0x000000ffUL) << 24) | \
+		(((__u32)(x) & (__u32)0x0000ff00UL) <<  8) | \
+		(((__u32)(x) & (__u32)0x00ff0000UL) >>  8) | \
+		(((__u32)(x) & (__u32)0xff000000UL) >> 24) ))
+#define ___swab64(x) \
+	((__u64)( \
+		(__u64)(((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) | \
+		(__u64)(((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) | \
+		(__u64)(((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) | \
+		(__u64)(((__u64)(x) & (__u64)0x00000000ff000000ULL) <<  8) | \
+	        (__u64)(((__u64)(x) & (__u64)0x000000ff00000000ULL) >>  8) | \
+		(__u64)(((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) | \
+		(__u64)(((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) | \
+		(__u64)(((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56) ))
+
+/*
+ * These do constant folding - this allows the
+ * compiler to do any constants at compile
+ * time.  Any architecture inline asm optimizations
+ * would be pessimizations.
+ */
+#define __swab16(x) \
+	(__builtin_constant_p((__u16)(x)) ? \
+	 ___swab16((x)) : __fswab16((x)))
+#define __swab32(x) \
+	(__builtin_constant_p((__u32)(x)) ? \
+	 ___swab32((x)) : __fswab32((x)))
+#define __swab64(x) \
+	(__builtin_constant_p((__u64)(x)) ? \
+	 ___swab64((x)) : __fswab64((x)))
+
+
+/*
+ * provide defaults when no architecture-specific optimization is detected
+ */
+#ifndef __arch__swab16
+#  define __arch__swab16(x) ___swab16(x)
+#endif
+#ifndef __arch__swab32
+#  define __arch__swab32(x) ___swab32(x)
+#endif
+#ifndef __arch__swab64
+#  define __arch__swab64(x) ___swab64(x)
+#endif
+
+#ifndef __arch__swab16p
+#  define __arch__swab16p(x) __swab16(*(x))
+#endif
+#ifndef __arch__swab32p
+#  define __arch__swab32p(x) __swab32(*(x))
+#endif
+#ifndef __arch__swab64p
+#  define __arch__swab64p(x) __swab64(*(x))
+#endif
+
+#ifndef __arch__swab16s
+#  define __arch__swab16s(x) *(x) = __swab16p((x))
+#endif
+#ifndef __arch__swab32s
+#  define __arch__swab32s(x) *(x) = __swab32p((x))
+#endif
+#ifndef __arch__swab64s
+#  define __arch__swab64s(x) *(x) = __swab64p((x))
+#endif
+
+
+extern __inline__ __const__ __u16 __fswab16(__u16 x)
+{
+	return __arch__swab16(x);
+}
+extern __inline__ __u16 __swab16p(__u16 *x)
+{
+	return __arch__swab16p(x);
+}
+extern __inline__ void __swab16s(__u16 *addr)
+{
+	__arch__swab16s(addr);
+}
+
+extern __inline__ __const__ __u32 __fswab32(__u32 x)
+{
+	return __arch__swab32(x);
+}
+extern __inline__ __u32 __swab32p(__u32 *x)
+{
+	return __arch__swab32p(x);
+}
+extern __inline__ void __swab32s(__u32 *addr)
+{
+	__arch__swab32s(addr);
+}
+
+#ifdef __BYTEORDER_HAS_U64__
+extern __inline__ __const__ __u64 __fswab64(__u64 x)
+{
+#  ifdef __SWAB_64_THRU_32__
+	__u32 h = x >> 32;
+        __u32 l = x & ((1ULL<<32)-1);
+        return (((__u64)__swab32(l)) << 32) | ((__u64)(__swab32(h)));
+#  else
+	return __arch__swab64(x);
+#  endif
+}
+extern __inline__ __u64 __swab64p(__u64 *x)
+{
+	return __arch__swab64p(x);
+}
+extern __inline__ void __swab64s(__u64 *addr)
+{
+	__arch__swab64s(addr);
+}
+#endif /* __BYTEORDER_HAS_U64__ */
+
+#if defined(__KERNEL__) || defined(__REQUIRE_CPU_TO_XX)
+#define swab16 __swab16
+#define swab32 __swab32
+#define swab64 __swab64
+#define swab16p __swab16p
+#define swab32p __swab32p
+#define swab64p __swab64p
+#define swab16s __swab16s
+#define swab32s __swab32s
+#define swab64s __swab64s
+#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 traditionally return a "long", 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 unsigned long int	ntohl(unsigned long int);
+extern unsigned short int	ntohs(unsigned short int);
+extern unsigned long int	htonl(unsigned long int);
+extern unsigned short int	htons(unsigned short int);
+
+#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) ((unsigned long)___htonl(x))
+#define htons(x) ___htons(x)
+#define ntohl(x) ((unsigned long)___ntohl(x))
+#define ntohs(x) ___ntohs(x)
+
+#endif /* _LINUX_BYTEORDER_H */