text: /* SPDX-License-Identifier: GPL-2.0 */
  #ifndef __ASM_ARM_WORD_AT_A_TIME_H
  #define __ASM_ARM_WORD_AT_A_TIME_H
  
  #ifndef __ARMEB__
  
  /*
   * Little-endian word-at-a-time zero byte handling.
   * Heavily based on the x86 algorithm.
   */
  #include <linux/kernel.h>
  
  struct word_at_a_time {
  	const unsigned long one_bits, high_bits;
  };
  
  #define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }
  
  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;
  }
  
  #define prep_zero_mask(a, bits, c) (bits)
  
  static inline unsigned long create_zero_mask(unsigned long bits)
  {
  	bits = (bits - 1) & ~bits;
  	return bits >> 7;
  }
  
  static inline unsigned long find_zero(unsigned long mask)
  {
  	unsigned long ret;
  
  #if __LINUX_ARM_ARCH__ >= 5
  	/* We have clz available. */
  	ret = fls(mask) >> 3;
  #else
  	/* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */
  	ret = (0x0ff0001 + mask) >> 23;
  	/* Fix the 1 for 00 case */
  	ret &= mask;
  #endif
  
  	return ret;
  }
  
  #define zero_bytemask(mask) (mask)
  
  #else	/* __ARMEB__ */
  #include <asm-generic/word-at-a-time.h>
  #endif
  
  #ifdef CONFIG_DCACHE_WORD_ACCESS
  
  /*
   * Load an unaligned word from kernel space.
   *
   * In the (very unlikely) case of the word being a page-crosser
   * and the next page not being mapped, take the exception and
   * return zeroes in the non-existing part.
   */
  static inline unsigned long load_unaligned_zeropad(const void *addr)
  {
  	unsigned long ret, offset;
  
  	/* Load word from unaligned pointer addr */
  	asm(
  	"1:	ldr	%0, [%2]\n"
  	"2:\n"
  	"	.pushsection .text.fixup,\"ax\"\n"
  	"	.align 2\n"
  	"3:	and	%1, %2, #0x3\n"
  	"	bic	%2, %2, #0x3\n"
  	"	ldr	%0, [%2]\n"
  	"	lsl	%1, %1, #0x3\n"
  #ifndef __ARMEB__
  	"	lsr	%0, %0, %1\n"
  #else
  	"	lsl	%0, %0, %1\n"
  #endif
  	"	b	2b\n"
  	"	.popsection\n"
  	"	.pushsection __ex_table,\"a\"\n"
  	"	.align	3\n"
  	"	.long	1b, 3b\n"
  	"	.popsection"
  	: "=&r" (ret), "=&r" (offset)
  	: "r" (addr), "Qo" (*(unsigned long *)addr));
  
  	return ret;
  }
  
  #endif	/* DCACHE_WORD_ACCESS */
  #endif /* __ASM_ARM_WORD_AT_A_TIME_H */
  