LXR linux/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
  30static inline void set_bit(int nr, unsigned long *addr)
  31{
  32        addr[nr / BITS_PER_LONG] |= 1UL << (nr % BITS_PER_LONG);
  33}
  34
  35static inline void clear_bit(int nr, unsigned long *addr)
  36{
  37        addr[nr / BITS_PER_LONG] &= ~(1UL << (nr % BITS_PER_LONG));
  38}
  39
  40static __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
  46static 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 */
  59static __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
  90typedef const unsigned long __attribute__((__may_alias__)) long_alias_t;
  91
  92/*
  93 * Find the first set bit in a memory region.
  94 */
  95static inline unsigned long
  96find_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. */
 114found:
 115        return result + __ffs(tmp);
 116}
 117
 118/*
 119 * Find the next set bit in a memory region.
 120 */
 121static inline unsigned long
 122find_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
 152found_first:
 153        tmp &= (~0UL >> (BITS_PER_LONG - size));
 154        if (tmp == 0UL)         /* Are any bits set? */
 155                return result + size;   /* Nope. */
 156found_middle:
 157        return result + __ffs(tmp);
 158}
 159
 160#endif
 161