blob: 133b76d0d2c0349bd47544360673e2ebf332d5d7 [file] [log] [blame]
/* SPDX-License-Identifier: GPL-2.0 */
* linux/byteorder/generic.h
* Generic Byte-reordering support
* The "... p" macros, like le64_to_cpup, can be used with pointers
* to unaligned data, but there will be a performance penalty on
* some architectures. Use get_unaligned for unaligned data.
* Francois-Rene Rideau <> 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 <> 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 <> 19971205
* Made it to 2.1.71; now a facelift:
* Put files under include/linux/byteorder/
* Split swab from generic support.
* = 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
#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
* 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
#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)
static inline void le16_add_cpu(__le16 *var, u16 val)
*var = cpu_to_le16(le16_to_cpu(*var) + val);
static inline void le32_add_cpu(__le32 *var, u32 val)
*var = cpu_to_le32(le32_to_cpu(*var) + val);
static inline void le64_add_cpu(__le64 *var, u64 val)
*var = cpu_to_le64(le64_to_cpu(*var) + val);
static inline void be16_add_cpu(__be16 *var, u16 val)
*var = cpu_to_be16(be16_to_cpu(*var) + val);
static inline void be32_add_cpu(__be32 *var, u32 val)
*var = cpu_to_be32(be32_to_cpu(*var) + val);
static inline void be64_add_cpu(__be64 *var, u64 val)
*var = cpu_to_be64(be64_to_cpu(*var) + val);