Commit fc920999 authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
Browse files

tools headers: Synchronize linux/bits.h with the kernel sources 



To pick up the changes in this cset:

  1e7933a5 ("uapi: Revert "bitops: avoid integer overflow in GENMASK(_ULL)"")
  5b572e8a ("bits: introduce fixed-type BIT_U*()")
  19408200 ("bits: introduce fixed-type GENMASK_U*()")
  31299a5e ("bits: add comments and newlines to #if, #else and #endif directives")

This addresses these perf build warnings:

  Warning: Kernel ABI header differences:
    diff -u tools/include/linux/bits.h include/linux/bits.h

Please see tools/include/uapi/README for further details.

Acked-by: default avatarVincent Mailhol <mailhol.vincent@wanadoo.fr>
Cc: I Hsin Cheng <richard120310@gmail.com>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Yury Norov <yury.norov@gmail.com>
Link: https://lore.kernel.org/r/aEr0ZJ60EbshEy6p@x1


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent bb6b4143

include/uapi/linux/bits.h

+2 −2
Original line number Diff line number Diff line
@@ -4,9 +4,9 @@ 
#ifndef _UAPI_LINUX_BITS_H

#define _UAPI_LINUX_BITS_H



#define __GENMASK(h, l) (((~_UL(0)) << (l)) & (~_UL(0) >> (__BITS_PER_LONG - 1 - (h))))

#define __GENMASK(h, l) (((~_UL(0)) << (l)) & (~_UL(0) >> (BITS_PER_LONG - 1 - (h))))



#define __GENMASK_ULL(h, l) (((~_ULL(0)) << (l)) & (~_ULL(0) >> (__BITS_PER_LONG_LONG - 1 - (h))))

#define __GENMASK_ULL(h, l) (((~_ULL(0)) << (l)) & (~_ULL(0) >> (BITS_PER_LONG_LONG - 1 - (h))))



#define __GENMASK_U128(h, l) \

	((_BIT128((h)) << 1) - (_BIT128(l)))

tools/include/linux/bits.h

+55 −2
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
#define BIT_ULL_MASK(nr)	(ULL(1) << ((nr) % BITS_PER_LONG_LONG))

#define BIT_ULL_WORD(nr)	((nr) / BITS_PER_LONG_LONG)

#define BITS_PER_BYTE		8

#define BITS_PER_TYPE(type)	(sizeof(type) * BITS_PER_BYTE)



/*

 * Create a contiguous bitmask starting at bit position @l and ending at
@@ -19,16 +20,68 @@ 
 * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.

 */

#if !defined(__ASSEMBLY__)



/*

 * Missing asm support

 *

 * GENMASK_U*() and BIT_U*() depend on BITS_PER_TYPE() which relies on sizeof(),

 * something not available in asm. Nevertheless, fixed width integers is a C

 * concept. Assembly code can rely on the long and long long versions instead.

 */



#include <linux/build_bug.h>

#include <linux/compiler.h>

#include <linux/overflow.h>



#define GENMASK_INPUT_CHECK(h, l) BUILD_BUG_ON_ZERO(const_true((l) > (h)))

#else



/*

 * Generate a mask for the specified type @t. Additional checks are made to

 * guarantee the value returned fits in that type, relying on

 * -Wshift-count-overflow compiler check to detect incompatible arguments.

 * For example, all these create build errors or warnings:

 *

 * - GENMASK(15, 20): wrong argument order

 * - GENMASK(72, 15): doesn't fit unsigned long

 * - GENMASK_U32(33, 15): doesn't fit in a u32

 */

#define GENMASK_TYPE(t, h, l)					\

	((t)(GENMASK_INPUT_CHECK(h, l) +			\

	     (type_max(t) << (l) &				\

	      type_max(t) >> (BITS_PER_TYPE(t) - 1 - (h)))))



#define GENMASK_U8(h, l)	GENMASK_TYPE(u8, h, l)

#define GENMASK_U16(h, l)	GENMASK_TYPE(u16, h, l)

#define GENMASK_U32(h, l)	GENMASK_TYPE(u32, h, l)

#define GENMASK_U64(h, l)	GENMASK_TYPE(u64, h, l)



/*

 * Fixed-type variants of BIT(), with additional checks like GENMASK_TYPE(). The

 * following examples generate compiler warnings due to -Wshift-count-overflow:

 *

 * - BIT_U8(8)

 * - BIT_U32(-1)

 * - BIT_U32(40)

 */

#define BIT_INPUT_CHECK(type, nr) \

	BUILD_BUG_ON_ZERO(const_true((nr) >= BITS_PER_TYPE(type)))



#define BIT_TYPE(type, nr) ((type)(BIT_INPUT_CHECK(type, nr) + BIT_ULL(nr)))



#define BIT_U8(nr)	BIT_TYPE(u8, nr)

#define BIT_U16(nr)	BIT_TYPE(u16, nr)

#define BIT_U32(nr)	BIT_TYPE(u32, nr)

#define BIT_U64(nr)	BIT_TYPE(u64, nr)



#else /* defined(__ASSEMBLY__) */



/*

 * BUILD_BUG_ON_ZERO is not available in h files included from asm files,

 * disable the input check if that is the case.

 */

#define GENMASK_INPUT_CHECK(h, l) 0

#endif



#endif /* !defined(__ASSEMBLY__) */



#define GENMASK(h, l) \

	(GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))