byteorder: only use linux/swab.h

The first step to make swab.h a regular header that will
include an asm/swab.h with arch overrides.

Avoid the gratuitous differences introduced in the new
linux/swab.h by naming the ___constant_swabXX bits and
__fswabXX bits exactly as found in the old implementation
in byteorder/swab[b].h

Use this new swab.h in byteorder/[big|little]_endian.h and
remove the two old swab headers.

Although the inclusion of asm/byteorder.h looks strange in
linux/swab.h, this will allow each arch to move the actual
arch overrides for the swab bits in an asm file and then
the includes can be cleaned up without requiring a flag day
for all arches at once.

Keep providing __fswabXX in case some userspace was using them
directly, but the revised __swabXX should be used instead in
any new code and will always do constant folding not dependent
on the optimization level, which means the __constant versions
can be phased out in-kernel.

Arches that use the old-style arch macros will lose their
optimized versions until they move to the new style, but at
least they will still compile.  Many arches have already moved
and the patches to move the remaining arches are trivial.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

6 files changed, 27 insertions, 388 deletions

diff --git a/include/linux/byteorder/Kbuild b/include/linux/byteorder/Kbuild
index fbaa7f9cee32..38437225b092 100644
--- a/include/linux/byteorder/Kbuild
+++ b/include/linux/byteorder/Kbuild
@@ -1,4 +1,2 @@
 unifdef-y += big_endian.h
 unifdef-y += little_endian.h
-unifdef-y += swab.h
-unifdef-y += swabb.h
diff --git a/include/linux/byteorder/big_endian.h b/include/linux/byteorder/big_endian.h
index 1cba3f3efe5f..3c80fd7e8b56 100644
--- a/include/linux/byteorder/big_endian.h
+++ b/include/linux/byteorder/big_endian.h
@@ -9,8 +9,7 @@
 #endif
 
 #include <linux/types.h>
-#include <linux/byteorder/swab.h>
-#include <linux/byteorder/swabb.h>
+#include <linux/swab.h>
 
 #define __constant_htonl(x) ((__force __be32)(__u32)(x))
 #define __constant_ntohl(x) ((__force __u32)(__be32)(x))
diff --git a/include/linux/byteorder/little_endian.h b/include/linux/byteorder/little_endian.h
index cedc1b5a289c..83195fb82962 100644
--- a/include/linux/byteorder/little_endian.h
+++ b/include/linux/byteorder/little_endian.h
@@ -9,8 +9,7 @@
 #endif
 
 #include <linux/types.h>
-#include <linux/byteorder/swab.h>
-#include <linux/byteorder/swabb.h>
+#include <linux/swab.h>
 
 #define __constant_htonl(x) ((__force __be32)___constant_swab32((x)))
 #define __constant_ntohl(x) ___constant_swab32((__force __be32)(x))
diff --git a/include/linux/byteorder/swab.h b/include/linux/byteorder/swab.h
deleted file mode 100644
index 142134ff1645..000000000000
--- a/include/linux/byteorder/swab.h
+++ /dev/null
@@ -1,222 +0,0 @@
-#ifndef _LINUX_BYTEORDER_SWAB_H
-#define _LINUX_BYTEORDER_SWAB_H
-
-/*
- * linux/byteorder/swab.h
- * Byte-swapping, independently from CPU endianness
- *      swabXX[ps]?(foo)
- *
- * Francois-Rene Rideau <fare@tunes.org> 19971205
- *    separated swab functions from cpu_to_XX,
- *    to clean up support for bizarre-endian architectures.
- *
- * Trent Piepho <xyzzy@speakeasy.org> 2007114
- *    make constant-folding work, provide C versions that
- *    gcc can optimize better, explain different versions
- *
- * See asm-i386/byteorder.h and suches for examples of how to provide
- * architecture-dependent optimized versions
- *
- */
-
-#include <linux/compiler.h>
-
-/* Functions/macros defined, there are a lot:
- *
- * ___swabXX
- *    Generic C versions of the swab functions.
- *
- * ___constant_swabXX
- *    C versions that gcc can fold into a compile-time constant when
- *    the argument is a compile-time constant.
- *
- * __arch__swabXX[sp]?
- *    Architecture optimized versions of all the swab functions
- *    (including the s and p versions).  These can be defined in
- *    asm-arch/byteorder.h.  Any which are not, are defined here.
- *    __arch__swabXXs() is defined in terms of __arch__swabXXp(), which
- *    is defined in terms of __arch__swabXX(), which is in turn defined
- *    in terms of ___swabXX(x).
- *    These must be macros.  They may be unsafe for arguments with
- *    side-effects.
- *
- * __fswabXX
- *    Inline function versions of the __arch__ macros.  These _are_ safe
- *    if the arguments have side-effects.  Note there are no s and p
- *    versions of these.
- *
- * __swabXX[sb]
- *    There are the ones you should actually use.  The __swabXX versions
- *    will be a constant given a constant argument and use the arch
- *    specific code (if any) for non-constant arguments.  The s and p
- *    versions always use the arch specific code (constant folding
- *    doesn't apply).  They are safe to use with arguments with
- *    side-effects.
- *
- * swabXX[sb]
- *    Nicknames for __swabXX[sb] to use in the kernel.
- */
-
-/* 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.
- */
-
-static __inline__ __attribute_const__ __u16 ___swab16(__u16 x)
-{
-        return x<<8 | x>>8;
-}
-static __inline__ __attribute_const__ __u32 ___swab32(__u32 x)
-{
-        return x<<24 | x>>24 |
-                (x & (__u32)0x0000ff00UL)<<8 |
-                (x & (__u32)0x00ff0000UL)>>8;
-}
-static __inline__ __attribute_const__ __u64 ___swab64(__u64 x)
-{
-        return x<<56 | x>>56 |
-                (x & (__u64)0x000000000000ff00ULL)<<40 |
-                (x & (__u64)0x0000000000ff0000ULL)<<24 |
-                (x & (__u64)0x00000000ff000000ULL)<< 8 |
-                (x & (__u64)0x000000ff00000000ULL)>> 8 |
-                (x & (__u64)0x0000ff0000000000ULL)>>24 |
-                (x & (__u64)0x00ff000000000000ULL)>>40;
-}
-
-#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)(((__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) ))
-
-/*
- * 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) __arch__swab16(*(x))
-#endif
-#ifndef __arch__swab32p
-#  define __arch__swab32p(x) __arch__swab32(*(x))
-#endif
-#ifndef __arch__swab64p
-#  define __arch__swab64p(x) __arch__swab64(*(x))
-#endif
-
-#ifndef __arch__swab16s
-#  define __arch__swab16s(x) ((void)(*(x) = __arch__swab16p(x)))
-#endif
-#ifndef __arch__swab32s
-#  define __arch__swab32s(x) ((void)(*(x) = __arch__swab32p(x)))
-#endif
-#ifndef __arch__swab64s
-#  define __arch__swab64s(x) ((void)(*(x) = __arch__swab64p(x)))
-#endif
-
-
-/*
- * Allow constant folding
- */
-#if defined(__GNUC__) && defined(__OPTIMIZE__)