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       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             : 
     144             : static inline void le16_add_cpu(__le16 *var, u16 val)
     145             : {
     146             :         *var = cpu_to_le16(le16_to_cpu(*var) + val);
     147             : }
     148             : 
     149             : static inline void le32_add_cpu(__le32 *var, u32 val)
     150             : {
     151             :         *var = cpu_to_le32(le32_to_cpu(*var) + val);
     152             : }
     153             : 
     154             : static 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 */
     160             : static inline void le32_to_cpu_array(u32 *buf, unsigned int words)
     161             : {
     162        2527 :         while (words--) {
     163             :                 __le32_to_cpus(buf);
     164             :                 buf++;
     165             :         }
     166             : }
     167             : 
     168             : static inline void cpu_to_le32_array(u32 *buf, unsigned int words)
     169             : {
     170         548 :         while (words--) {
     171             :                 __cpu_to_le32s(buf);
     172             :                 buf++;
     173             :         }
     174             : }
     175             : 
     176             : static inline void be16_add_cpu(__be16 *var, u16 val)
     177             : {
     178             :         *var = cpu_to_be16(be16_to_cpu(*var) + val);
     179             : }
     180             : 
     181             : static inline void be32_add_cpu(__be32 *var, u32 val)
     182             : {
     183             :         *var = cpu_to_be32(be32_to_cpu(*var) + val);
     184             : }
     185             : 
     186             : static inline void be64_add_cpu(__be64 *var, u64 val)
     187             : {
     188             :         *var = cpu_to_be64(be64_to_cpu(*var) + val);
     189             : }
     190             : 
     191             : static inline void cpu_to_be32_array(__be32 *dst, const u32 *src, size_t len)
     192             : {
     193             :         size_t i;
     194             : 
     195             :         for (i = 0; i < len; i++)
     196             :                 dst[i] = cpu_to_be32(src[i]);
     197             : }
     198             : 
     199             : static inline void be32_to_cpu_array(u32 *dst, const __be32 *src, size_t len)
     200             : {
     201             :         size_t 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 */