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kernel/linux-imx6_3.14.28/arch/x86/boot/bitops.h 1.13 KB
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  /* -*- linux-c -*- ------------------------------------------------------- *
   *
   *   Copyright (C) 1991, 1992 Linus Torvalds
   *   Copyright 2007 rPath, Inc. - All Rights Reserved
   *
   *   This file is part of the Linux kernel, and is made available under
   *   the terms of the GNU General Public License version 2.
   *
   * ----------------------------------------------------------------------- */
  
  /*
   * Very simple bitops for the boot code.
   */
  
  #ifndef BOOT_BITOPS_H
  #define BOOT_BITOPS_H
  #define _LINUX_BITOPS_H		/* Inhibit inclusion of <linux/bitops.h> */
  
  static inline int constant_test_bit(int nr, const void *addr)
  {
  	const u32 *p = (const u32 *)addr;
  	return ((1UL << (nr & 31)) & (p[nr >> 5])) != 0;
  }
  static inline int variable_test_bit(int nr, const void *addr)
  {
  	u8 v;
  	const u32 *p = (const u32 *)addr;
  
  	asm("btl %2,%1; setc %0" : "=qm" (v) : "m" (*p), "Ir" (nr));
  	return v;
  }
  
  #define test_bit(nr,addr) \
  (__builtin_constant_p(nr) ? \
   constant_test_bit((nr),(addr)) : \
   variable_test_bit((nr),(addr)))
  
  static inline void set_bit(int nr, void *addr)
  {
  	asm("btsl %1,%0" : "+m" (*(u32 *)addr) : "Ir" (nr));
  }
  
  #endif /* BOOT_BITOPS_H */