alistair23-linux/include/uapi/linux/swab.h
Greg Kroah-Hartman 6f52b16c5b License cleanup: add SPDX license identifier to uapi header files with no license
Many user space API headers are missing licensing information, which
makes it hard for compliance tools to determine the correct license.

By default are files without license information under the default
license of the kernel, which is GPLV2.  Marking them GPLV2 would exclude
them from being included in non GPLV2 code, which is obviously not
intended. The user space API headers fall under the syscall exception
which is in the kernels COPYING file:

   NOTE! This copyright does *not* cover user programs that use kernel
   services by normal system calls - this is merely considered normal use
   of the kernel, and does *not* fall under the heading of "derived work".

otherwise syscall usage would not be possible.

Update the files which contain no license information with an SPDX
license identifier.  The chosen identifier is 'GPL-2.0 WITH
Linux-syscall-note' which is the officially assigned identifier for the
Linux syscall exception.  SPDX license identifiers are a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.  See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:19:54 +01:00

296 lines
6.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef _UAPI_LINUX_SWAB_H
#define _UAPI_LINUX_SWAB_H
#include <linux/types.h>
#include <linux/compiler.h>
#include <asm/swab.h>
/*
* casts are necessary for constants, because we never know how for sure
* how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way.
*/
#define ___constant_swab16(x) ((__u16)( \
(((__u16)(x) & (__u16)0x00ffU) << 8) | \
(((__u16)(x) & (__u16)0xff00U) >> 8)))
#define ___constant_swab32(x) ((__u32)( \
(((__u32)(x) & (__u32)0x000000ffUL) << 24) | \
(((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \
(((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \
(((__u32)(x) & (__u32)0xff000000UL) >> 24)))
#define ___constant_swab64(x) ((__u64)( \
(((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) | \
(((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) | \
(((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) | \
(((__u64)(x) & (__u64)0x00000000ff000000ULL) << 8) | \
(((__u64)(x) & (__u64)0x000000ff00000000ULL) >> 8) | \
(((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) | \
(((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) | \
(((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56)))
#define ___constant_swahw32(x) ((__u32)( \
(((__u32)(x) & (__u32)0x0000ffffUL) << 16) | \
(((__u32)(x) & (__u32)0xffff0000UL) >> 16)))
#define ___constant_swahb32(x) ((__u32)( \
(((__u32)(x) & (__u32)0x00ff00ffUL) << 8) | \
(((__u32)(x) & (__u32)0xff00ff00UL) >> 8)))
/*
* Implement the following as inlines, but define the interface using
* macros to allow constant folding when possible:
* ___swab16, ___swab32, ___swab64, ___swahw32, ___swahb32
*/
static inline __attribute_const__ __u16 __fswab16(__u16 val)
{
#if defined (__arch_swab16)
return __arch_swab16(val);
#else
return ___constant_swab16(val);
#endif
}
static inline __attribute_const__ __u32 __fswab32(__u32 val)
{
#if defined(__arch_swab32)
return __arch_swab32(val);
#else
return ___constant_swab32(val);
#endif
}
static inline __attribute_const__ __u64 __fswab64(__u64 val)
{
#if defined (__arch_swab64)
return __arch_swab64(val);
#elif defined(__SWAB_64_THRU_32__)
__u32 h = val >> 32;
__u32 l = val & ((1ULL << 32) - 1);
return (((__u64)__fswab32(l)) << 32) | ((__u64)(__fswab32(h)));
#else
return ___constant_swab64(val);
#endif
}
static inline __attribute_const__ __u32 __fswahw32(__u32 val)
{
#ifdef __arch_swahw32
return __arch_swahw32(val);
#else
return ___constant_swahw32(val);
#endif
}
static inline __attribute_const__ __u32 __fswahb32(__u32 val)
{
#ifdef __arch_swahb32
return __arch_swahb32(val);
#else
return ___constant_swahb32(val);
#endif
}
/**
* __swab16 - return a byteswapped 16-bit value
* @x: value to byteswap
*/
#ifdef __HAVE_BUILTIN_BSWAP16__
#define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
#else
#define __swab16(x) \
(__builtin_constant_p((__u16)(x)) ? \
___constant_swab16(x) : \
__fswab16(x))
#endif
/**
* __swab32 - return a byteswapped 32-bit value
* @x: value to byteswap
*/
#ifdef __HAVE_BUILTIN_BSWAP32__
#define __swab32(x) (__u32)__builtin_bswap32((__u32)(x))
#else
#define __swab32(x) \
(__builtin_constant_p((__u32)(x)) ? \
___constant_swab32(x) : \
__fswab32(x))
#endif
/**
* __swab64 - return a byteswapped 64-bit value
* @x: value to byteswap
*/
#ifdef __HAVE_BUILTIN_BSWAP64__
#define __swab64(x) (__u64)__builtin_bswap64((__u64)(x))
#else
#define __swab64(x) \
(__builtin_constant_p((__u64)(x)) ? \
___constant_swab64(x) : \
__fswab64(x))
#endif
/**
* __swahw32 - return a word-swapped 32-bit value
* @x: value to wordswap
*
* __swahw32(0x12340000) is 0x00001234
*/
#define __swahw32(x) \
(__builtin_constant_p((__u32)(x)) ? \
___constant_swahw32(x) : \
__fswahw32(x))
/**
* __swahb32 - return a high and low byte-swapped 32-bit value
* @x: value to byteswap
*
* __swahb32(0x12345678) is 0x34127856
*/
#define __swahb32(x) \
(__builtin_constant_p((__u32)(x)) ? \
___constant_swahb32(x) : \
__fswahb32(x))
/**
* __swab16p - return a byteswapped 16-bit value from a pointer
* @p: pointer to a naturally-aligned 16-bit value
*/
static __always_inline __u16 __swab16p(const __u16 *p)
{
#ifdef __arch_swab16p
return __arch_swab16p(p);
#else
return __swab16(*p);
#endif
}
/**
* __swab32p - return a byteswapped 32-bit value from a pointer
* @p: pointer to a naturally-aligned 32-bit value
*/
static __always_inline __u32 __swab32p(const __u32 *p)
{
#ifdef __arch_swab32p
return __arch_swab32p(p);
#else
return __swab32(*p);
#endif
}
/**
* __swab64p - return a byteswapped 64-bit value from a pointer
* @p: pointer to a naturally-aligned 64-bit value
*/
static __always_inline __u64 __swab64p(const __u64 *p)
{
#ifdef __arch_swab64p
return __arch_swab64p(p);
#else
return __swab64(*p);
#endif
}
/**
* __swahw32p - return a wordswapped 32-bit value from a pointer
* @p: pointer to a naturally-aligned 32-bit value
*
* See __swahw32() for details of wordswapping.
*/
static inline __u32 __swahw32p(const __u32 *p)
{
#ifdef __arch_swahw32p
return __arch_swahw32p(p);
#else
return __swahw32(*p);
#endif
}
/**
* __swahb32p - return a high and low byteswapped 32-bit value from a pointer
* @p: pointer to a naturally-aligned 32-bit value
*
* See __swahb32() for details of high/low byteswapping.
*/
static inline __u32 __swahb32p(const __u32 *p)
{
#ifdef __arch_swahb32p
return __arch_swahb32p(p);
#else
return __swahb32(*p);
#endif
}
/**
* __swab16s - byteswap a 16-bit value in-place
* @p: pointer to a naturally-aligned 16-bit value
*/
static inline void __swab16s(__u16 *p)
{
#ifdef __arch_swab16s
__arch_swab16s(p);
#else
*p = __swab16p(p);
#endif
}
/**
* __swab32s - byteswap a 32-bit value in-place
* @p: pointer to a naturally-aligned 32-bit value
*/
static __always_inline void __swab32s(__u32 *p)
{
#ifdef __arch_swab32s
__arch_swab32s(p);
#else
*p = __swab32p(p);
#endif
}
/**
* __swab64s - byteswap a 64-bit value in-place
* @p: pointer to a naturally-aligned 64-bit value
*/
static __always_inline void __swab64s(__u64 *p)
{
#ifdef __arch_swab64s
__arch_swab64s(p);
#else
*p = __swab64p(p);
#endif
}
/**
* __swahw32s - wordswap a 32-bit value in-place
* @p: pointer to a naturally-aligned 32-bit value
*
* See __swahw32() for details of wordswapping
*/
static inline void __swahw32s(__u32 *p)
{
#ifdef __arch_swahw32s
__arch_swahw32s(p);
#else
*p = __swahw32p(p);
#endif
}
/**
* __swahb32s - high and low byteswap a 32-bit value in-place
* @p: pointer to a naturally-aligned 32-bit value
*
* See __swahb32() for details of high and low byte swapping
*/
static inline void __swahb32s(__u32 *p)
{
#ifdef __arch_swahb32s
__arch_swahb32s(p);
#else
*p = __swahb32p(p);
#endif
}
#endif /* _UAPI_LINUX_SWAB_H */