/root/src/xen/xen/include/xen/bitmap.h

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#ifndef __XEN_BITMAP_H
#define __XEN_BITMAP_H

#ifndef __ASSEMBLY__

#include <xen/lib.h>
#include <xen/types.h>
#include <xen/bitops.h>

/*
 * bitmaps provide bit arrays that consume one or more unsigned
 * longs.  The bitmap interface and available operations are listed
 * here, in bitmap.h
 *
 * Function implementations generic to all architectures are in
 * lib/bitmap.c.  Functions implementations that are architecture
 * specific are in various include/asm-<arch>/bitops.h headers
 * and other arch/<arch> specific files.
 *
 * See lib/bitmap.c for more details.
 */

/*
 * The available bitmap operations and their rough meaning in the
 * case that the bitmap is a single unsigned long are thus:
 *
 * bitmap_zero(dst, nbits)      *dst = 0UL
 * bitmap_fill(dst, nbits)      *dst = ~0UL
 * bitmap_copy(dst, src, nbits)     *dst = *src
 * bitmap_and(dst, src1, src2, nbits)   *dst = *src1 & *src2
 * bitmap_or(dst, src1, src2, nbits)    *dst = *src1 | *src2
 * bitmap_xor(dst, src1, src2, nbits)   *dst = *src1 ^ *src2
 * bitmap_andnot(dst, src1, src2, nbits)  *dst = *src1 & ~(*src2)
 * bitmap_complement(dst, src, nbits)   *dst = ~(*src)
 * bitmap_equal(src1, src2, nbits)    Are *src1 and *src2 equal?
 * bitmap_intersects(src1, src2, nbits)   Do *src1 and *src2 overlap?
 * bitmap_subset(src1, src2, nbits)   Is *src1 a subset of *src2?
 * bitmap_empty(src, nbits)     Are all bits zero in *src?
 * bitmap_full(src, nbits)      Are all bits set in *src?
 * bitmap_weight(src, nbits)      Hamming Weight: number set bits
 * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
 * bitmap_shift_left(dst, src, n, nbits)  *dst = *src << n
 * bitmap_scnprintf(buf, len, src, nbits) Print bitmap src to buf
 * bitmap_scnlistprintf(buf, len, src, nbits) Print bitmap src as list to buf
 */

/*
 * Also the following operations in asm/bitops.h apply to bitmaps.
 *
 * set_bit(bit, addr)     *addr |= bit
 * clear_bit(bit, addr)     *addr &= ~bit
 * change_bit(bit, addr)    *addr ^= bit
 * test_bit(bit, addr)      Is bit set in *addr?
 * test_and_set_bit(bit, addr)    Set bit and return old value
 * test_and_clear_bit(bit, addr)  Clear bit and return old value
 * test_and_change_bit(bit, addr) Change bit and return old value
 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
 * find_first_bit(addr, nbits)    Position first set bit in *addr
 * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
 * find_next_bit(addr, nbits, bit)  Position next set bit in *addr >= bit
 */

/*
 * The DECLARE_BITMAP(name,bits) macro, in xen/types.h, can be used
 * to declare an array named 'name' of just enough unsigned longs to
 * contain all bit positions from 0 to 'bits' - 1.
 */

/*
 * lib/bitmap.c provides these functions:
 */

extern int __bitmap_empty(const unsigned long *bitmap, int bits);
extern int __bitmap_full(const unsigned long *bitmap, int bits);
extern int __bitmap_equal(const unsigned long *bitmap1,
                  const unsigned long *bitmap2, int bits);
extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
      int bits);
extern void __bitmap_shift_right(unsigned long *dst,
                        const unsigned long *src, int shift, int bits);
extern void __bitmap_shift_left(unsigned long *dst,
                        const unsigned long *src, int shift, int bits);
extern void __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
      const unsigned long *bitmap2, int bits);
extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
      const unsigned long *bitmap2, int bits);
extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
      const unsigned long *bitmap2, int bits);
extern void __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
      const unsigned long *bitmap2, int bits);
extern int __bitmap_intersects(const unsigned long *bitmap1,
      const unsigned long *bitmap2, int bits);
extern int __bitmap_subset(const unsigned long *bitmap1,
      const unsigned long *bitmap2, int bits);
extern int __bitmap_weight(const unsigned long *bitmap, int bits);

extern int bitmap_scnprintf(char *buf, unsigned int len,
      const unsigned long *src, int nbits);
extern int bitmap_scnlistprintf(char *buf, unsigned int len,
      const unsigned long *src, int nbits);
extern int bitmap_find_free_region(unsigned long *bitmap, int bits, int order);
extern void bitmap_release_region(unsigned long *bitmap, int pos, int order);
extern int bitmap_allocate_region(unsigned long *bitmap, int pos, int order);

#define BITMAP_LAST_WORD_MASK(nbits)          \
(                 \
  ((nbits) % BITS_PER_LONG) ?         \
    (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL    \
)

#define bitmap_bytes(nbits) (BITS_TO_LONGS(nbits) * sizeof(unsigned long))

#define bitmap_switch(nbits, zero, small, large)        \
  unsigned int n__ = (nbits);           \
  if (__builtin_constant_p(nbits) && !n__) {       \
    zero;               \
  } else if (__builtin_constant_p(nbits) && n__ <= BITS_PER_LONG) { \
    small;               \
  } else {               \
    large;                \
  }

static inline void bitmap_zero(unsigned long *dst, int nbits)
{
  bitmap_switch(nbits,,
    *dst = 0UL,
    memset(dst, 0, bitmap_bytes(nbits)));
}

static inline void bitmap_fill(unsigned long *dst, int nbits)
{
  size_t nlongs = BITS_TO_LONGS(nbits);

  switch (nlongs) {
  default:
    memset(dst, -1, (nlongs - 1) * sizeof(unsigned long));
    /* fall through */
  case 1:
    dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
    break;
  }
}

static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
      int nbits)
{
  bitmap_switch(nbits,,
    *dst = *src,
    memcpy(dst, src, bitmap_bytes(nbits)));
}

static inline void bitmap_and(unsigned long *dst, const unsigned long *src1,
      const unsigned long *src2, int nbits)
{
  bitmap_switch(nbits,,
    *dst = *src1 & *src2,
    __bitmap_and(dst, src1, src2, nbits));
}

static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
      const unsigned long *src2, int nbits)
{
  bitmap_switch(nbits,,
    *dst = *src1 | *src2,
    __bitmap_or(dst, src1, src2, nbits));
}

static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
      const unsigned long *src2, int nbits)
{
  bitmap_switch(nbits,,
    *dst = *src1 ^ *src2,
    __bitmap_xor(dst, src1, src2, nbits));
}

static inline void bitmap_andnot(unsigned long *dst, const unsigned long *src1,
      const unsigned long *src2, int nbits)
{
  bitmap_switch(nbits,,
    *dst = *src1 & ~*src2,
    __bitmap_andnot(dst, src1, src2, nbits));
}

static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
      int nbits)
{
  bitmap_switch(nbits,,
    *dst = ~*src & BITMAP_LAST_WORD_MASK(nbits),
    __bitmap_complement(dst, src, nbits));
}

static inline int bitmap_equal(const unsigned long *src1,
      const unsigned long *src2, int nbits)
{
  bitmap_switch(nbits,
    return -1,
    return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits)),
    return __bitmap_equal(src1, src2, nbits));
}

static inline int bitmap_intersects(const unsigned long *src1,
      const unsigned long *src2, int nbits)
{
  bitmap_switch(nbits,
    return -1,
    return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0,
    return __bitmap_intersects(src1, src2, nbits));
}

static inline int bitmap_subset(const unsigned long *src1,
      const unsigned long *src2, int nbits)
{
  bitmap_switch(nbits,
    return -1,
    return !((*src1 & ~*src2) & BITMAP_LAST_WORD_MASK(nbits)),
    return __bitmap_subset(src1, src2, nbits));
}

static inline int bitmap_empty(const unsigned long *src, int nbits)
{
  bitmap_switch(nbits,
    return -1,
    return !(*src & BITMAP_LAST_WORD_MASK(nbits)),
    return __bitmap_empty(src, nbits));
}

static inline int bitmap_full(const unsigned long *src, int nbits)
{
  bitmap_switch(nbits,
    return -1,
    return !(~*src & BITMAP_LAST_WORD_MASK(nbits)),
    return __bitmap_full(src, nbits));
}

static inline int bitmap_weight(const unsigned long *src, int nbits)
{
  return __bitmap_weight(src, nbits);
}

static inline void bitmap_shift_right(unsigned long *dst,
      const unsigned long *src, int n, int nbits)
{
  bitmap_switch(nbits,,
    *dst = *src >> n,
    __bitmap_shift_right(dst, src, n, nbits));
}

static inline void bitmap_shift_left(unsigned long *dst,
      const unsigned long *src, int n, int nbits)
{
  bitmap_switch(nbits,,
    *dst = (*src << n) & BITMAP_LAST_WORD_MASK(nbits),
    __bitmap_shift_left(dst, src, n, nbits));
}

#undef bitmap_switch
#undef bitmap_bytes

void bitmap_long_to_byte(uint8_t *bp, const unsigned long *lp, int nbits);
void bitmap_byte_to_long(unsigned long *lp, const uint8_t *bp, int nbits);

#endif /* __ASSEMBLY__ */

#endif /* __XEN_BITMAP_H */

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Created: 2017-10-25 09:10