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. Mark it volatile to tell gcc not to move it around */
  24         __asm__ __volatile__(
  25                 "movl $-1,%%eax\n\t"
  26                 "xorl %%edx,%%edx\n\t"
  27                 "repe; scasl\n\t"
  28                 "je 1f\n\t"
  29                 "xorl -4(%%edi),%%eax\n\t"
  30                 "subl $4,%%edi\n\t"
  31                 "bsfl %%eax,%%edx\n"
  32                 "1:\tsubl %%ebx,%%edi\n\t"
  33                 "shll $3,%%edi\n\t"
  34                 "addl %%edi,%%edx"
  35                 :"=d" (res), "=&c" (d0), "=&D" (d1), "=&a" (d2)
  36                 :"1" ((size + 31) >> 5), "2" (addr), "b" (addr) : "memory");
  37         return res;
  38 }
  39
  40 /**
  41  * find_next_zero_bit - find the first zero bit in a memory region
  42  * @addr: The address to base the search on
  43  * @offset: The bit number to start searching at
  44  * @size: The maximum size to search
  45  */
  46 int find_next_zero_bit(const unsigned long *addr, int size, int offset);
  47
  48 /**
  49  * __ffs - find first bit in word.
  50  * @word: The word to search
  51  *
  52  * Undefined if no bit exists, so code should check against 0 first.
  53  */
  54 static inline unsigned long __ffs(unsigned long word)
  55 {
  56         __asm__("bsfl %1,%0"
  57                 :"=r" (word)
  58                 :"rm" (word));
  59         return word;
  60 }
  61
  62 /**
  63  * find_first_bit - find the first set bit in a memory region
  64  * @addr: The address to start the search at
  65  * @size: The maximum size to search
  66  *
  67  * Returns the bit number of the first set bit, not the number of the byte
  68  * containing a bit.
  69  */
  70 static inline unsigned find_first_bit(const unsigned long *addr, unsigned size)
  71 {
  72         unsigned x = 0;
  73
  74         while (x < size) {
  75                 unsigned long val = *addr++;
  76                 if (val)
  77                         return __ffs(val) + x;
  78                 x += (sizeof(*addr)<<3);
  79         }
  80         return x;
  81 }
  82
  83 /**
  84  * find_next_bit - find the first set bit in a memory region
  85  * @addr: The address to base the search on
  86  * @offset: The bit number to start searching at
  87  * @size: The maximum size to search
  88  */
  89 int find_next_bit(const unsigned long *addr, int size, int offset);
  90
  91 /**
  92  * ffz - find first zero in word.
  93  * @word: The word to search
  94  *
  95  * Undefined if no zero exists, so code should check against ~0UL first.
  96  */
  97 static inline unsigned long ffz(unsigned long word)
  98 {
  99         __asm__("bsfl %1,%0"
 100                 :"=r" (word)
 101                 :"r" (~word));
 102         return word;
 103 }
 104
 105 #ifdef __KERNEL__
 106
 107 #include <asm-generic/bitops/sched.h>
 108
 109 /**
 110  * ffs - find first bit set
 111  * @x: the word to search
 112  *
 113  * This is defined the same way as
 114  * the libc and compiler builtin ffs routines, therefore
 115  * differs in spirit from the above ffz() (man ffs).
 116  */
 117 static inline int ffs(int x)
 118 {
 119         int r;
 120
 121         __asm__("bsfl %1,%0\n\t"
 122                 "jnz 1f\n\t"
 123                 "movl $-1,%0\n"
 124                 "1:" : "=r" (r) : "rm" (x));
 125         return r+1;
 126 }
 127
 128 /**
 129  * fls - find last bit set
 130  * @x: the word to search
 131  *
 132  * This is defined the same way as ffs().
 133  */
 134 static inline int fls(int x)
 135 {
 136         int r;
 137
 138         __asm__("bsrl %1,%0\n\t"
 139                 "jnz 1f\n\t"
 140                 "movl $-1,%0\n"
 141                 "1:" : "=r" (r) : "rm" (x));
 142         return r+1;
 143 }
 144
 145 #include <asm-generic/bitops/hweight.h>
 146
 147 #endif /* __KERNEL__ */
 148
 149 #include <asm-generic/bitops/fls64.h>
 150
 151 #ifdef __KERNEL__
 152
 153 #include <asm-generic/bitops/ext2-non-atomic.h>
 154
 155 #define ext2_set_bit_atomic(lock, nr, addr) \
 156                 test_and_set_bit((nr), (unsigned long *)addr)
 157 #define ext2_clear_bit_atomic(lock, nr, addr) \
 158                 test_and_clear_bit((nr), (unsigned long *)addr)
 159
 160 #include <asm-generic/bitops/minix.h>
 161
 162 #endif /* __KERNEL__ */
 163
 164 #endif /* _I386_BITOPS_H */