tools/perf/util/include/linux/bitops.h

   1 #ifndef _PERF_LINUX_BITOPS_H_
   2 #define _PERF_LINUX_BITOPS_H_
   3
   4 #include <linux/kernel.h>
   5 #include <linux/compiler.h>
   6 #include <asm/hweight.h>
   7
   8 #define BITS_PER_LONG __WORDSIZE
   9 #define BITS_PER_BYTE           8
  10 #define BITS_TO_LONGS(nr)       DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
  11 #define BITS_TO_U64(nr)         DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u64))
  12 #define BITS_TO_U32(nr)         DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u32))
  13
  14 #define for_each_set_bit(bit, addr, size) \
  15         for ((bit) = find_first_bit((addr), (size));            \
  16              (bit) < (size);                                    \
  17              (bit) = find_next_bit((addr), (size), (bit) + 1))
  18
  19 /* same as for_each_set_bit() but use bit as value to start with */
  20 #define for_each_set_bit_from(bit, addr, size) \
  21         for ((bit) = find_next_bit((addr), (size), (bit));      \
  22              (bit) < (size);                                    \
  23              (bit) = find_next_bit((addr), (size), (bit) + 1))
  24
  25 static inline void set_bit(int nr, unsigned long *addr)
  26 {
  27         addr[nr / BITS_PER_LONG] |= 1UL << (nr % BITS_PER_LONG);
  28 }
  29
  30 static inline void clear_bit(int nr, unsigned long *addr)
  31 {
  32         addr[nr / BITS_PER_LONG] &= ~(1UL << (nr % BITS_PER_LONG));
  33 }
  34
  35 static __always_inline int test_bit(unsigned int nr, const unsigned long *addr)
  36 {
  37         return ((1UL << (nr % BITS_PER_LONG)) &
  38                 (((unsigned long *)addr)[nr / BITS_PER_LONG])) != 0;
  39 }
  40
  41 static inline unsigned long hweight_long(unsigned long w)
  42 {
  43         return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
  44 }
  45
  46 #define BITOP_WORD(nr)          ((nr) / BITS_PER_LONG)
  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 __always_inline unsigned long __ffs(unsigned long word)
  55 {
  56         int num = 0;
  57
  58 #if BITS_PER_LONG == 64
  59         if ((word & 0xffffffff) == 0) {
  60                 num += 32;
  61                 word >>= 32;
  62         }
  63 #endif
  64         if ((word & 0xffff) == 0) {
  65                 num += 16;
  66                 word >>= 16;
  67         }
  68         if ((word & 0xff) == 0) {
  69                 num += 8;
  70                 word >>= 8;
  71         }
  72         if ((word & 0xf) == 0) {
  73                 num += 4;
  74                 word >>= 4;
  75         }
  76         if ((word & 0x3) == 0) {
  77                 num += 2;
  78                 word >>= 2;
  79         }
  80         if ((word & 0x1) == 0)
  81                 num += 1;
  82         return num;
  83 }
  84
  85 /*
  86  * Find the first set bit in a memory region.
  87  */
  88 static inline unsigned long
  89 find_first_bit(const unsigned long *addr, unsigned long size)
  90 {
  91         const unsigned long *p = addr;
  92         unsigned long result = 0;
  93         unsigned long tmp;
  94
  95         while (size & ~(BITS_PER_LONG-1)) {
  96                 if ((tmp = *(p++)))
  97                         goto found;
  98                 result += BITS_PER_LONG;
  99                 size -= BITS_PER_LONG;
 100         }
 101         if (!size)
 102                 return result;
 103
 104         tmp = (*p) & (~0UL >> (BITS_PER_LONG - size));
 105         if (tmp == 0UL)         /* Are any bits set? */
 106                 return result + size;   /* Nope. */
 107 found:
 108         return result + __ffs(tmp);
 109 }
 110
 111 /*
 112  * Find the next set bit in a memory region.
 113  */
 114 static inline unsigned long
 115 find_next_bit(const unsigned long *addr, unsigned long size, unsigned long offset)
 116 {
 117         const unsigned long *p = addr + BITOP_WORD(offset);
 118         unsigned long result = offset & ~(BITS_PER_LONG-1);
 119         unsigned long tmp;
 120
 121         if (offset >= size)
 122                 return size;
 123         size -= result;
 124         offset %= BITS_PER_LONG;
 125         if (offset) {
 126                 tmp = *(p++);
 127                 tmp &= (~0UL << offset);
 128                 if (size < BITS_PER_LONG)
 129                         goto found_first;
 130                 if (tmp)
 131                         goto found_middle;
 132                 size -= BITS_PER_LONG;
 133                 result += BITS_PER_LONG;
 134         }
 135         while (size & ~(BITS_PER_LONG-1)) {
 136                 if ((tmp = *(p++)))
 137                         goto found_middle;
 138                 result += BITS_PER_LONG;
 139                 size -= BITS_PER_LONG;
 140         }
 141         if (!size)
 142                 return result;
 143         tmp = *p;
 144
 145 found_first:
 146         tmp &= (~0UL >> (BITS_PER_LONG - size));
 147         if (tmp == 0UL)         /* Are any bits set? */
 148                 return result + size;   /* Nope. */
 149 found_middle:
 150         return result + __ffs(tmp);
 151 }
 152
 153 #endif