#ifndef _ASM_GENERIC_BITOPS_FLS64_H_
  #define _ASM_GENERIC_BITOPS_FLS64_H_
  
  #include <asm/types.h>
  
  /**
   * fls64 - find last set bit in a 64-bit word
   * @x: the word to search
   *
   * This is defined in a similar way as the libc and compiler builtin
   * ffsll, but returns the position of the most significant set bit.
   *
   * fls64(value) returns 0 if value is 0 or the position of the last
   * set bit if value is nonzero. The last (most significant) bit is
   * at position 64.
   */
  #if BITS_PER_LONG == 32
  static __always_inline int fls64(__u64 x)
  {
  	__u32 h = x >> 32;
  	if (h)
  		return fls(h) + 32;
  	return fls(x);
  }
  #elif BITS_PER_LONG == 64
  static __always_inline int fls64(__u64 x)
  {
  	if (x == 0)
  		return 0;
  	return __fls(x) + 1;
  }
  #else
  #error BITS_PER_LONG not 32 or 64
  #endif
  
  #endif /* _ASM_GENERIC_BITOPS_FLS64_H_ */