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 #ifndef __WORDSIZE
   9 #define __WORDSIZE (__SIZEOF_LONG__ * 8)
  10 #endif
  11
  12 #define BITS_PER_LONG __WORDSIZE
  13 #define BITS_PER_BYTE           8
  14 #define BITS_TO_LONGS(nr)       DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
  15 #define BITS_TO_U64(nr)         DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u64))
  16 #define BITS_TO_U32(nr)         DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(u32))
  17 #define BITS_TO_BYTES(nr)       DIV_ROUND_UP(nr, BITS_PER_BYTE)
  18 #define BIT_WORD(nr)            ((nr) / BITS_PER_LONG)
  19 #define BIT_MASK(nr)            (1UL << ((nr) % BITS_PER_LONG))
  20
  21 #define for_each_set_bit(bit, addr, size) \
  22         for ((bit) = find_first_bit((addr), (size));            \
  23              (bit) < (size);                                    \
  24              (bit) = find_next_bit((addr), (size), (bit) + 1))
  25
  26 /* same as for_each_set_bit() but use bit as value to start with */
  27 #define for_each_set_bit_from(bit, addr, size) \
  28         for ((bit) = find_next_bit((addr), (size), (bit));      \
  29              (bit) < (size);                                    \
  30              (bit) = find_next_bit((addr), (size), (bit) + 1))
  31
  32 static inline void set_bit(int nr, unsigned long *addr)
  33 {
  34         addr[nr / BITS_PER_LONG] |= 1UL << (nr % BITS_PER_LONG);
  35 }
  36
  37 static inline void clear_bit(int nr, unsigned long *addr)
  38 {
  39         addr[nr / BITS_PER_LONG] &= ~(1UL << (nr % BITS_PER_LONG));
  40 }
  41
  42 static __always_inline int test_bit(unsigned int nr, const unsigned long *addr)
  43 {
  44         return ((1UL << (nr % BITS_PER_LONG)) &
  45                 (((unsigned long *)addr)[nr / BITS_PER_LONG])) != 0;
  46 }
  47
  48 static inline unsigned long hweight_long(unsigned long w)
  49 {
  50         return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
  51 }
  52
  53 #define BITOP_WORD(nr)          ((nr) / BITS_PER_LONG)
  54
  55 /**
  56  * __ffs - find first bit in word.
  57  * @word: The word to search
  58  *
  59  * Undefined if no bit exists, so code should check against 0 first.
  60  */
  61 static __always_inline unsigned long __ffs(unsigned long word)
  62 {
  63         int num = 0;
  64
  65 #if BITS_PER_LONG == 64
  66         if ((word & 0xffffffff) == 0) {
  67                 num += 32;
  68                 word >>= 32;
  69         }
  70 #endif
  71         if ((word & 0xffff) == 0) {
  72                 num += 16;
  73                 word >>= 16;
  74         }
  75         if ((word & 0xff) == 0) {
  76                 num += 8;
  77                 word >>= 8;
  78         }
  79         if ((word & 0xf) == 0) {
  80                 num += 4;
  81                 word >>= 4;
  82         }
  83         if ((word & 0x3) == 0) {
  84                 num += 2;
  85                 word >>= 2;
  86         }
  87         if ((word & 0x1) == 0)
  88                 num += 1;
  89         return num;
  90 }
  91
  92 typedef const unsigned long __attribute__((__may_alias__)) long_alias_t;
  93
  94 /*
  95  * Find the first set bit in a memory region.
  96  */
  97 static inline unsigned long
  98 find_first_bit(const unsigned long *addr, unsigned long size)
  99 {
 100         long_alias_t *p = (long_alias_t *) addr;
 101         unsigned long result = 0;
 102         unsigned long tmp;
 103
 104         while (size & ~(BITS_PER_LONG-1)) {
 105                 if ((tmp = *(p++)))
 106                         goto found;
 107                 result += BITS_PER_LONG;
 108                 size -= BITS_PER_LONG;
 109         }
 110         if (!size)
 111                 return result;
 112
 113         tmp = (*p) & (~0UL >> (BITS_PER_LONG - size));
 114         if (tmp == 0UL)         /* Are any bits set? */
 115                 return result + size;   /* Nope. */
 116 found:
 117         return result + __ffs(tmp);
 118 }
 119
 120 /*
 121  * Find the next set bit in a memory region.
 122  */
 123 static inline unsigned long
 124 find_next_bit(const unsigned long *addr, unsigned long size, unsigned long offset)
 125 {
 126         const unsigned long *p = addr + BITOP_WORD(offset);
 127         unsigned long result = offset & ~(BITS_PER_LONG-1);
 128         unsigned long tmp;
 129
 130         if (offset >= size)
 131                 return size;
 132         size -= result;
 133         offset %= BITS_PER_LONG;
 134         if (offset) {
 135                 tmp = *(p++);
 136                 tmp &= (~0UL << offset);
 137                 if (size < BITS_PER_LONG)
 138                         goto found_first;
 139                 if (tmp)
 140                         goto found_middle;
 141                 size -= BITS_PER_LONG;
 142                 result += BITS_PER_LONG;
 143         }
 144         while (size & ~(BITS_PER_LONG-1)) {
 145                 if ((tmp = *(p++)))
 146                         goto found_middle;
 147                 result += BITS_PER_LONG;
 148                 size -= BITS_PER_LONG;
 149         }
 150         if (!size)
 151                 return result;
 152         tmp = *p;
 153
 154 found_first:
 155         tmp &= (~0UL >> (BITS_PER_LONG - size));
 156         if (tmp == 0UL)         /* Are any bits set? */
 157                 return result + size;   /* Nope. */
 158 found_middle:
 159         return result + __ffs(tmp);
 160 }
 161
 162 #endif