LXR linux/include/linux/byteorder/generic.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _LINUX_BYTEORDER_GENERIC_H
   3#define _LINUX_BYTEORDER_GENERIC_H
   4
   5/*
   6 * linux/byteorder/generic.h
   7 * Generic Byte-reordering support
   8 *
   9 * The "... p" macros, like le64_to_cpup, can be used with pointers
  10 * to unaligned data, but there will be a performance penalty on 
  11 * some architectures.  Use get_unaligned for unaligned data.
  12 *
  13 * Francois-Rene Rideau <fare@tunes.org> 19970707
  14 *    gathered all the good ideas from all asm-foo/byteorder.h into one file,
  15 *    cleaned them up.
  16 *    I hope it is compliant with non-GCC compilers.
  17 *    I decided to put __BYTEORDER_HAS_U64__ in byteorder.h,
  18 *    because I wasn't sure it would be ok to put it in types.h
  19 *    Upgraded it to 2.1.43
  20 * Francois-Rene Rideau <fare@tunes.org> 19971012
  21 *    Upgraded it to 2.1.57
  22 *    to please Linus T., replaced huge #ifdef's between little/big endian
  23 *    by nestedly #include'd files.
  24 * Francois-Rene Rideau <fare@tunes.org> 19971205
  25 *    Made it to 2.1.71; now a facelift:
  26 *    Put files under include/linux/byteorder/
  27 *    Split swab from generic support.
  28 *
  29 * TODO:
  30 *   = Regular kernel maintainers could also replace all these manual
  31 *    byteswap macros that remain, disseminated among drivers,
  32 *    after some grep or the sources...
  33 *   = Linus might want to rename all these macros and files to fit his taste,
  34 *    to fit his personal naming scheme.
  35 *   = it seems that a few drivers would also appreciate
  36 *    nybble swapping support...
  37 *   = every architecture could add their byteswap macro in asm/byteorder.h
  38 *    see how some architectures already do (i386, alpha, ppc, etc)
  39 *   = cpu_to_beXX and beXX_to_cpu might some day need to be well
  40 *    distinguished throughout the kernel. This is not the case currently,
  41 *    since little endian, big endian, and pdp endian machines needn't it.
  42 *    But this might be the case for, say, a port of Linux to 20/21 bit
  43 *    architectures (and F21 Linux addict around?).
  44 */
  45
  46/*
  47 * The following macros are to be defined by <asm/byteorder.h>:
  48 *
  49 * Conversion of long and short int between network and host format
  50 *      ntohl(__u32 x)
  51 *      ntohs(__u16 x)
  52 *      htonl(__u32 x)
  53 *      htons(__u16 x)
  54 * It seems that some programs (which? where? or perhaps a standard? POSIX?)
  55 * might like the above to be functions, not macros (why?).
  56 * if that's true, then detect them, and take measures.
  57 * Anyway, the measure is: define only ___ntohl as a macro instead,
  58 * and in a separate file, have
  59 * unsigned long inline ntohl(x){return ___ntohl(x);}
  60 *
  61 * The same for constant arguments
  62 *      __constant_ntohl(__u32 x)
  63 *      __constant_ntohs(__u16 x)
  64 *      __constant_htonl(__u32 x)
  65 *      __constant_htons(__u16 x)
  66 *
  67 * Conversion of XX-bit integers (16- 32- or 64-)
  68 * between native CPU format and little/big endian format
  69 * 64-bit stuff only defined for proper architectures
  70 *      cpu_to_[bl]eXX(__uXX x)
  71 *      [bl]eXX_to_cpu(__uXX x)
  72 *
  73 * The same, but takes a pointer to the value to convert
  74 *      cpu_to_[bl]eXXp(__uXX x)
  75 *      [bl]eXX_to_cpup(__uXX x)
  76 *
  77 * The same, but change in situ
  78 *      cpu_to_[bl]eXXs(__uXX x)
  79 *      [bl]eXX_to_cpus(__uXX x)
  80 *
  81 * See asm-foo/byteorder.h for examples of how to provide
  82 * architecture-optimized versions
  83 *
  84 */
  85
  86#define cpu_to_le64 __cpu_to_le64
  87#define le64_to_cpu __le64_to_cpu
  88#define cpu_to_le32 __cpu_to_le32
  89#define le32_to_cpu __le32_to_cpu
  90#define cpu_to_le16 __cpu_to_le16
  91#define le16_to_cpu __le16_to_cpu
  92#define cpu_to_be64 __cpu_to_be64
  93#define be64_to_cpu __be64_to_cpu
  94#define cpu_to_be32 __cpu_to_be32
  95#define be32_to_cpu __be32_to_cpu
  96#define cpu_to_be16 __cpu_to_be16
  97#define be16_to_cpu __be16_to_cpu
  98#define cpu_to_le64p __cpu_to_le64p
  99#define le64_to_cpup __le64_to_cpup
 100#define cpu_to_le32p __cpu_to_le32p
 101#define le32_to_cpup __le32_to_cpup
 102#define cpu_to_le16p __cpu_to_le16p
 103#define le16_to_cpup __le16_to_cpup
 104#define cpu_to_be64p __cpu_to_be64p
 105#define be64_to_cpup __be64_to_cpup
 106#define cpu_to_be32p __cpu_to_be32p
 107#define be32_to_cpup __be32_to_cpup
 108#define cpu_to_be16p __cpu_to_be16p
 109#define be16_to_cpup __be16_to_cpup
 110#define cpu_to_le64s __cpu_to_le64s
 111#define le64_to_cpus __le64_to_cpus
 112#define cpu_to_le32s __cpu_to_le32s
 113#define le32_to_cpus __le32_to_cpus
 114#define cpu_to_le16s __cpu_to_le16s
 115#define le16_to_cpus __le16_to_cpus
 116#define cpu_to_be64s __cpu_to_be64s
 117#define be64_to_cpus __be64_to_cpus
 118#define cpu_to_be32s __cpu_to_be32s
 119#define be32_to_cpus __be32_to_cpus
 120#define cpu_to_be16s __cpu_to_be16s
 121#define be16_to_cpus __be16_to_cpus
 122
 123/*
 124 * They have to be macros in order to do the constant folding
 125 * correctly - if the argument passed into a inline function
 126 * it is no longer constant according to gcc..
 127 */
 128
 129#undef ntohl
 130#undef ntohs
 131#undef htonl
 132#undef htons
 133
 134#define ___htonl(x) __cpu_to_be32(x)
 135#define ___htons(x) __cpu_to_be16(x)
 136#define ___ntohl(x) __be32_to_cpu(x)
 137#define ___ntohs(x) __be16_to_cpu(x)
 138
 139#define htonl(x) ___htonl(x)
 140#define ntohl(x) ___ntohl(x)
 141#define htons(x) ___htons(x)
 142#define ntohs(x) ___ntohs(x)
 143
 144static inline void le16_add_cpu(__le16 *var, u16 val)
 145{
 146        *var = cpu_to_le16(le16_to_cpu(*var) + val);
 147}
 148
 149static inline void le32_add_cpu(__le32 *var, u32 val)
 150{
 151        *var = cpu_to_le32(le32_to_cpu(*var) + val);
 152}
 153
 154static inline void le64_add_cpu(__le64 *var, u64 val)
 155{
 156        *var = cpu_to_le64(le64_to_cpu(*var) + val);
 157}
 158
 159/* XXX: this stuff can be optimized */
 160static inline void le32_to_cpu_array(u32 *buf, unsigned int words)
 161{
 162        while (words--) {
 163                __le32_to_cpus(buf);
 164                buf++;
 165        }
 166}
 167
 168static inline void cpu_to_le32_array(u32 *buf, unsigned int words)
 169{
 170        while (words--) {
 171                __cpu_to_le32s(buf);
 172                buf++;
 173        }
 174}
 175
 176static inline void be16_add_cpu(__be16 *var, u16 val)
 177{
 178        *var = cpu_to_be16(be16_to_cpu(*var) + val);
 179}
 180
 181static inline void be32_add_cpu(__be32 *var, u32 val)
 182{
 183        *var = cpu_to_be32(be32_to_cpu(*var) + val);
 184}
 185
 186static inline void be64_add_cpu(__be64 *var, u64 val)
 187{
 188        *var = cpu_to_be64(be64_to_cpu(*var) + val);
 189}
 190
 191static inline void cpu_to_be32_array(__be32 *dst, const u32 *src, size_t len)
 192{
 193        int i;
 194
 195        for (i = 0; i < len; i++)
 196                dst[i] = cpu_to_be32(src[i]);
 197}
 198
 199static inline void be32_to_cpu_array(u32 *dst, const __be32 *src, size_t len)
 200{
 201        int i;
 202
 203        for (i = 0; i < len; i++)
 204                dst[i] = be32_to_cpu(src[i]);
 205}
 206
 207#endif /* _LINUX_BYTEORDER_GENERIC_H */
 208