cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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__ffs.h (844B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2#ifndef _TOOLS_LINUX_ASM_GENERIC_BITOPS___FFS_H_
      3#define _TOOLS_LINUX_ASM_GENERIC_BITOPS___FFS_H_
      4
      5#include <asm/types.h>
      6#include <asm/bitsperlong.h>
      7
      8/**
      9 * __ffs - find first bit in word.
     10 * @word: The word to search
     11 *
     12 * Undefined if no bit exists, so code should check against 0 first.
     13 */
     14static __always_inline unsigned long __ffs(unsigned long word)
     15{
     16	int num = 0;
     17
     18#if __BITS_PER_LONG == 64
     19	if ((word & 0xffffffff) == 0) {
     20		num += 32;
     21		word >>= 32;
     22	}
     23#endif
     24	if ((word & 0xffff) == 0) {
     25		num += 16;
     26		word >>= 16;
     27	}
     28	if ((word & 0xff) == 0) {
     29		num += 8;
     30		word >>= 8;
     31	}
     32	if ((word & 0xf) == 0) {
     33		num += 4;
     34		word >>= 4;
     35	}
     36	if ((word & 0x3) == 0) {
     37		num += 2;
     38		word >>= 2;
     39	}
     40	if ((word & 0x1) == 0)
     41		num += 1;
     42	return num;
     43}
     44
     45#endif /* _TOOLS_LINUX_ASM_GENERIC_BITOPS___FFS_H_ */