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Arnaldo Carvalho de Melo 549042f167 tools headers asm: Sync fls headers header with the kernel sources
To pick the changes in:

  6606c8c7e8188656 ("bitops: Add __attribute_const__ to generic ffs()-family implementations")

This addresses these tools build warnings:

  Warning: Kernel ABI header differences:
    diff -u tools/include/asm-generic/bitops/__fls.h include/asm-generic/bitops/__fls.h
    diff -u tools/include/asm-generic/bitops/fls.h include/asm-generic/bitops/fls.h
    diff -u tools/include/asm-generic/bitops/fls64.h include/asm-generic/bitops/fls64.h

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

Cc: Kees Cook <kees@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-11-03 13:35:06 -03:00

49 lines
1.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_GENERIC_BITOPS___FLS_H_
#define _ASM_GENERIC_BITOPS___FLS_H_
#include <asm/types.h>
/**
* generic___fls - find last (most-significant) set bit in a long word
* @word: the word to search
*
* Undefined if no set bit exists, so code should check against 0 first.
*/
static __always_inline __attribute_const__ unsigned int generic___fls(unsigned long word)
{
unsigned int num = BITS_PER_LONG - 1;
#if BITS_PER_LONG == 64
if (!(word & (~0ul << 32))) {
num -= 32;
word <<= 32;
}
#endif
if (!(word & (~0ul << (BITS_PER_LONG-16)))) {
num -= 16;
word <<= 16;
}
if (!(word & (~0ul << (BITS_PER_LONG-8)))) {
num -= 8;
word <<= 8;
}
if (!(word & (~0ul << (BITS_PER_LONG-4)))) {
num -= 4;
word <<= 4;
}
if (!(word & (~0ul << (BITS_PER_LONG-2)))) {
num -= 2;
word <<= 2;
}
if (!(word & (~0ul << (BITS_PER_LONG-1))))
num -= 1;
return num;
}
#ifndef __HAVE_ARCH___FLS
#define __fls(word) generic___fls(word)
#endif
#endif /* _ASM_GENERIC_BITOPS___FLS_H_ */