bitops.h 1.1 KB

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  1. /* -*- linux-c -*- ------------------------------------------------------- *
  2. *
  3. * Copyright (C) 1991, 1992 Linus Torvalds
  4. * Copyright 2007 rPath, Inc. - All Rights Reserved
  5. *
  6. * This file is part of the Linux kernel, and is made available under
  7. * the terms of the GNU General Public License version 2.
  8. *
  9. * ----------------------------------------------------------------------- */
  10. /*
  11. * Very simple bitops for the boot code.
  12. */
  13. #ifndef BOOT_BITOPS_H
  14. #define BOOT_BITOPS_H
  15. #define _LINUX_BITOPS_H /* Inhibit inclusion of <linux/bitops.h> */
  16. static inline int constant_test_bit(int nr, const void *addr)
  17. {
  18. const u32 *p = (const u32 *)addr;
  19. return ((1UL << (nr & 31)) & (p[nr >> 5])) != 0;
  20. }
  21. static inline int variable_test_bit(int nr, const void *addr)
  22. {
  23. u8 v;
  24. const u32 *p = (const u32 *)addr;
  25. asm("btl %2,%1; setc %0" : "=qm" (v) : "m" (*p), "Ir" (nr));
  26. return v;
  27. }
  28. #define test_bit(nr,addr) \
  29. (__builtin_constant_p(nr) ? \
  30. constant_test_bit((nr),(addr)) : \
  31. variable_test_bit((nr),(addr)))
  32. static inline void set_bit(int nr, void *addr)
  33. {
  34. asm("btsl %1,%0" : "+m" (*(u32 *)addr) : "Ir" (nr));
  35. }
  36. #endif /* BOOT_BITOPS_H */