#ifndef _PERF_LINUX_BITOPS_H_
  #define _PERF_LINUX_BITOPS_H_

  #include <linux/kernel.h>

  #include <linux/compiler.h>

  #include <asm/hweight.h>

  #ifndef __WORDSIZE
  #define __WORDSIZE (__SIZEOF_LONG__ * 8)
  #endif

  #define BITS_PER_LONG __WORDSIZE
  #define BITS_PER_BYTE           8
  #define BITS_TO_LONGS(nr)       DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))

  #define BITS_TO_U64(nr)         DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u64))
  #define BITS_TO_U32(nr)         DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u32))

  #define BITS_TO_BYTES(nr)       DIV_ROUND_UP(nr, BITS_PER_BYTE)

  #define BIT_WORD(nr)            ((nr) / BITS_PER_LONG)
  #define BIT_MASK(nr)            (1UL << ((nr) % BITS_PER_LONG))

  #define for_each_set_bit(bit, addr, size) \
  	for ((bit) = find_first_bit((addr), (size));		\
  	     (bit) < (size);					\
  	     (bit) = find_next_bit((addr), (size), (bit) + 1))
  
  /* same as for_each_set_bit() but use bit as value to start with */

  #define for_each_set_bit_from(bit, addr, size) \

  	for ((bit) = find_next_bit((addr), (size), (bit));	\
  	     (bit) < (size);					\
  	     (bit) = find_next_bit((addr), (size), (bit) + 1))

  static inline void set_bit(int nr, unsigned long *addr)
  {
  	addr[nr / BITS_PER_LONG] |= 1UL << (nr % BITS_PER_LONG);
  }

  static inline void clear_bit(int nr, unsigned long *addr)
  {
  	addr[nr / BITS_PER_LONG] &= ~(1UL << (nr % BITS_PER_LONG));
  }

  static __always_inline int test_bit(unsigned int nr, const unsigned long *addr)
  {
  	return ((1UL << (nr % BITS_PER_LONG)) &
  		(((unsigned long *)addr)[nr / BITS_PER_LONG])) != 0;
  }

  static inline unsigned long hweight_long(unsigned long w)
  {
  	return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
  }

  #define BITOP_WORD(nr)		((nr) / BITS_PER_LONG)
  
  /**
   * __ffs - find first bit in word.
   * @word: The word to search
   *
   * Undefined if no bit exists, so code should check against 0 first.
   */
  static __always_inline unsigned long __ffs(unsigned long word)
  {
  	int num = 0;
  
  #if BITS_PER_LONG == 64
  	if ((word & 0xffffffff) == 0) {
  		num += 32;
  		word >>= 32;
  	}
  #endif
  	if ((word & 0xffff) == 0) {
  		num += 16;
  		word >>= 16;
  	}
  	if ((word & 0xff) == 0) {
  		num += 8;
  		word >>= 8;
  	}
  	if ((word & 0xf) == 0) {
  		num += 4;
  		word >>= 4;
  	}
  	if ((word & 0x3) == 0) {
  		num += 2;
  		word >>= 2;
  	}
  	if ((word & 0x1) == 0)
  		num += 1;
  	return num;
  }

  typedef const unsigned long __attribute__((__may_alias__)) long_alias_t;

  /*
   * Find the first set bit in a memory region.
   */
  static inline unsigned long
  find_first_bit(const unsigned long *addr, unsigned long size)
  {

  	long_alias_t *p = (long_alias_t *) addr;

  	unsigned long result = 0;
  	unsigned long tmp;
  
  	while (size & ~(BITS_PER_LONG-1)) {
  		if ((tmp = *(p++)))
  			goto found;
  		result += BITS_PER_LONG;
  		size -= BITS_PER_LONG;
  	}
  	if (!size)
  		return result;
  
  	tmp = (*p) & (~0UL >> (BITS_PER_LONG - size));
  	if (tmp == 0UL)		/* Are any bits set? */
  		return result + size;	/* Nope. */
  found:
  	return result + __ffs(tmp);
  }
  
  /*
   * Find the next set bit in a memory region.
   */
  static inline unsigned long
  find_next_bit(const unsigned long *addr, unsigned long size, unsigned long offset)
  {
  	const unsigned long *p = addr + BITOP_WORD(offset);
  	unsigned long result = offset & ~(BITS_PER_LONG-1);
  	unsigned long tmp;
  
  	if (offset >= size)
  		return size;
  	size -= result;
  	offset %= BITS_PER_LONG;
  	if (offset) {
  		tmp = *(p++);
  		tmp &= (~0UL << offset);
  		if (size < BITS_PER_LONG)
  			goto found_first;
  		if (tmp)
  			goto found_middle;
  		size -= BITS_PER_LONG;
  		result += BITS_PER_LONG;
  	}
  	while (size & ~(BITS_PER_LONG-1)) {
  		if ((tmp = *(p++)))
  			goto found_middle;
  		result += BITS_PER_LONG;
  		size -= BITS_PER_LONG;
  	}
  	if (!size)
  		return result;
  	tmp = *p;
  
  found_first:
  	tmp &= (~0UL >> (BITS_PER_LONG - size));
  	if (tmp == 0UL)		/* Are any bits set? */
  		return result + size;	/* Nope. */
  found_middle:
  	return result + __ffs(tmp);
  }

  #endif