include/asm-x86/bitops_32.h

   1 #ifndef _I386_BITOPS_H
   2 #define _I386_BITOPS_H
   3
   4 /*
   5  * Copyright 1992, Linus Torvalds.
   6  */
   7
   8 /**
   9  * find_first_zero_bit - find the first zero bit in a memory region
  10  * @addr: The address to start the search at
  11  * @size: The maximum size to search
  12  *
  13  * Returns the bit number of the first zero bit, not the number of the byte
  14  * containing a bit.
  15  */
  16 static inline int find_first_zero_bit(const unsigned long *addr, unsigned size)
  17 {
  18         int d0, d1, d2;
  19         int res;
  20
  21         if (!size)
  22                 return 0;
  23         /* This looks at memory.
  24          * Mark it volatile to tell gcc not to move it around
  25          */
  26         asm volatile("movl $-1,%%eax\n\t"
  27                      "xorl %%edx,%%edx\n\t"
  28                      "repe; scasl\n\t"
  29                      "je 1f\n\t"
  30                      "xorl -4(%%edi),%%eax\n\t"
  31                      "subl $4,%%edi\n\t"
  32                      "bsfl %%eax,%%edx\n"
  33                      "1:\tsubl %%ebx,%%edi\n\t"
  34                      "shll $3,%%edi\n\t"
  35                      "addl %%edi,%%edx"
  36                      : "=d" (res), "=&c" (d0), "=&D" (d1), "=&a" (d2)
  37                      : "1" ((size + 31) >> 5), "2" (addr),
  38                        "b" (addr) : "memory");
  39         return res;
  40 }
  41
  42 /**
  43  * find_first_bit - find the first set bit in a memory region
  44  * @addr: The address to start the search at
  45  * @size: The maximum size to search
  46  *
  47  * Returns the bit number of the first set bit, not the number of the byte
  48  * containing a bit.
  49  */
  50 static inline unsigned find_first_bit(const unsigned long *addr, unsigned size)
  51 {
  52         unsigned x = 0;
  53
  54         while (x < size) {
  55                 unsigned long val = *addr++;
  56                 if (val)
  57                         return __ffs(val) + x;
  58                 x += sizeof(*addr) << 3;
  59         }
  60         return x;
  61 }
  62
  63 #ifdef __KERNEL__
  64
  65 #include <asm-generic/bitops/sched.h>
  66
  67 #include <asm-generic/bitops/hweight.h>
  68
  69 #endif /* __KERNEL__ */
  70
  71 #include <asm-generic/bitops/fls64.h>
  72
  73 #ifdef __KERNEL__
  74
  75 #include <asm-generic/bitops/ext2-non-atomic.h>
  76
  77 #define ext2_set_bit_atomic(lock, nr, addr)                     \
  78         test_and_set_bit((nr), (unsigned long *)(addr))
  79 #define ext2_clear_bit_atomic(lock, nr, addr)                   \
  80         test_and_clear_bit((nr), (unsigned long *)(addr))
  81
  82 #include <asm-generic/bitops/minix.h>
  83
  84 #endif /* __KERNEL__ */
  85
  86 #endif /* _I386_BITOPS_H */