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