arch/cris/include/arch-v32/arch/bitops.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_CRIS_ARCH_BITOPS_H
   3 #define _ASM_CRIS_ARCH_BITOPS_H
   4
   5 /*
   6  * Helper functions for the core of the ff[sz] functions. They compute the
   7  * number of leading zeroes of a bits-in-byte, byte-in-word and
   8  * word-in-dword-swapped number. They differ in that the first function also
   9  * inverts all bits in the input.
  10  */
  11
  12 static inline unsigned long
  13 cris_swapnwbrlz(unsigned long w)
  14 {
  15         unsigned long res;
  16
  17         __asm__ __volatile__ ("swapnwbr %0\n\t"
  18                               "lz %0,%0"
  19                               : "=r" (res) : "0" (w));
  20
  21         return res;
  22 }
  23
  24 static inline unsigned long
  25 cris_swapwbrlz(unsigned long w)
  26 {
  27         unsigned long res;
  28
  29         __asm__ __volatile__ ("swapwbr %0\n\t"
  30                               "lz %0,%0"
  31                               : "=r" (res) : "0" (w));
  32
  33         return res;
  34 }
  35
  36 /*
  37  * Find First Zero in word. Undefined if no zero exist, so the caller should
  38  * check against ~0 first.
  39  */
  40 static inline unsigned long
  41 ffz(unsigned long w)
  42 {
  43         return cris_swapnwbrlz(w);
  44 }
  45
  46 /*
  47  * Find First Set bit in word. Undefined if no 1 exist, so the caller
  48  * should check against 0 first.
  49  */
  50 static inline unsigned long
  51 __ffs(unsigned long w)
  52 {
  53         return cris_swapnwbrlz(~w);
  54 }
  55
  56 /*
  57  * Find First Bit that is set.
  58  */
  59 static inline unsigned long
  60 kernel_ffs(unsigned long w)
  61 {
  62         return w ? cris_swapwbrlz (w) + 1 : 0;
  63 }
  64
  65 #endif /* _ASM_CRIS_ARCH_BITOPS_H */