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kernel/linux-rt-4.4.41/arch/sh/include/asm/word-at-a-time.h 1.25 KB
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  #ifndef __ASM_SH_WORD_AT_A_TIME_H
  #define __ASM_SH_WORD_AT_A_TIME_H
  
  #ifdef CONFIG_CPU_BIG_ENDIAN
  # include <asm-generic/word-at-a-time.h>
  #else
  /*
   * Little-endian version cribbed from x86.
   */
  struct word_at_a_time {
  	const unsigned long one_bits, high_bits;
  };
  
  #define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }
  
  /* Carl Chatfield / Jan Achrenius G+ version for 32-bit */
  static inline long count_masked_bytes(long mask)
  {
  	/* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */
  	long a = (0x0ff0001+mask) >> 23;
  	/* Fix the 1 for 00 case */
  	return a & mask;
  }
  
  /* Return nonzero if it has a zero */
  static inline unsigned long has_zero(unsigned long a, unsigned long *bits, const struct word_at_a_time *c)
  {
  	unsigned long mask = ((a - c->one_bits) & ~a) & c->high_bits;
  	*bits = mask;
  	return mask;
  }
  
  static inline unsigned long prep_zero_mask(unsigned long a, unsigned long bits, const struct word_at_a_time *c)
  {
  	return bits;
  }
  
  static inline unsigned long create_zero_mask(unsigned long bits)
  {
  	bits = (bits - 1) & ~bits;
  	return bits >> 7;
  }
  
  /* The mask we created is directly usable as a bytemask */
  #define zero_bytemask(mask) (mask)
  
  static inline unsigned long find_zero(unsigned long mask)
  {
  	return count_masked_bytes(mask);
  }
  #endif
  
  #endif