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/*

 * Bitmap Module

 *

 * Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com>

 *

 * Mostly inspired by (stolen from) linux/bitmap.h and linux/bitops.h

 *

 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.

 * See the COPYING.LIB file in the top-level directory.

 */

#ifndef BITMAP_H

#define BITMAP_H

#include "qemu-common.h"

#include "bitops.h"

/*

 * The available bitmap operations and their rough meaning in the

 * case that the bitmap is a single unsigned long are thus:

 *

 * Note that nbits should be always a compile time evaluable constant.

 * Otherwise many inlines will generate horrible code.

 *

 * 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_empty(src, nbits)                        Are all bits zero in *src?

 * bitmap_full(src, nbits)                        Are all bits set in *src?

 * bitmap_set(dst, pos, nbits)                        Set specified bit area

 * bitmap_clear(dst, pos, nbits)                Clear specified bit area

 * bitmap_find_next_zero_area(buf, len, pos, n, mask)        Find bit free area

 */

/*

 * Also the following operations 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

 */

#define BITMAP_LAST_WORD_MASK(nbits)                                    \

    (                                                                   \

        ((nbits) % BITS_PER_LONG) ?                                     \

        (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL                       \

        )

#define DECLARE_BITMAP(name,bits)                  \

        unsigned long name[BITS_TO_LONGS(bits)]

#define small_nbits(nbits)                      \

        ((nbits) <= BITS_PER_LONG)

int slow_bitmap_empty(const unsigned long *bitmap, int bits);

int slow_bitmap_full(const unsigned long *bitmap, int bits);

int slow_bitmap_equal(const unsigned long *bitmap1,

                   const unsigned long *bitmap2, int bits);

void slow_bitmap_complement(unsigned long *dst, const unsigned long *src,

                         int bits);

void slow_bitmap_shift_right(unsigned long *dst,

                          const unsigned long *src, int shift, int bits);

void slow_bitmap_shift_left(unsigned long *dst,

                         const unsigned long *src, int shift, int bits);

int slow_bitmap_and(unsigned long *dst, const unsigned long *bitmap1,

                 const unsigned long *bitmap2, int bits);

void slow_bitmap_or(unsigned long *dst, const unsigned long *bitmap1,

                 const unsigned long *bitmap2, int bits);

void slow_bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,

                  const unsigned long *bitmap2, int bits);

int slow_bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,

                    const unsigned long *bitmap2, int bits);

int slow_bitmap_intersects(const unsigned long *bitmap1,

                        const unsigned long *bitmap2, int bits);

static inline unsigned long *bitmap_new(int nbits)

{

    int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);

    return qemu_mallocz(len);

}

static inline void bitmap_zero(unsigned long *dst, int nbits)

{

    if (small_nbits(nbits)) {

        *dst = 0UL;

    } else {

        int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);

        memset(dst, 0, len);

    }

}

static inline void bitmap_fill(unsigned long *dst, int nbits)

{

    size_t nlongs = BITS_TO_LONGS(nbits);

    if (!small_nbits(nbits)) {

        int len = (nlongs - 1) * sizeof(unsigned long);

        memset(dst, 0xff,  len);

    }

    dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);

}

static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,

                               int nbits)

{

    if (small_nbits(nbits)) {

        *dst = *src;

    } else {

        int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);

        memcpy(dst, src, len);

    }

}

static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,

                             const unsigned long *src2, int nbits)

{

    if (small_nbits(nbits)) {

        return (*dst = *src1 & *src2) != 0;

    }

    return slow_bitmap_and(dst, src1, src2, nbits);

}

static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,

                        const unsigned long *src2, int nbits)

{

    if (small_nbits(nbits)) {

        *dst = *src1 | *src2;

    } else {

        slow_bitmap_or(dst, src1, src2, nbits);

    }

}

static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,

                        const unsigned long *src2, int nbits)

{

    if (small_nbits(nbits)) {

        *dst = *src1 ^ *src2;

    } else {

        slow_bitmap_xor(dst, src1, src2, nbits);

    }

}

static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,

                        const unsigned long *src2, int nbits)

{

    if (small_nbits(nbits)) {

        return (*dst = *src1 & ~(*src2)) != 0;

    }

    return slow_bitmap_andnot(dst, src1, src2, nbits);

}

static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,

                        int nbits)

{

    if (small_nbits(nbits)) {

        *dst = ~(*src) & BITMAP_LAST_WORD_MASK(nbits);

    } else {

        slow_bitmap_complement(dst, src, nbits);

    }

}

static inline int bitmap_equal(const unsigned long *src1,

                        const unsigned long *src2, int nbits)

{

    if (small_nbits(nbits)) {

        return ! ((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));

    } else {

        return slow_bitmap_equal(src1, src2, nbits);

    }

}

static inline int bitmap_empty(const unsigned long *src, int nbits)

{

    if (small_nbits(nbits)) {

        return ! (*src & BITMAP_LAST_WORD_MASK(nbits));

    } else {

        return slow_bitmap_empty(src, nbits);

    }

}

static inline int bitmap_full(const unsigned long *src, int nbits)

{

    if (small_nbits(nbits)) {

        return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));

    } else {

        return slow_bitmap_full(src, nbits);

    }

}

static inline int bitmap_intersects(const unsigned long *src1,

                        const unsigned long *src2, int nbits)

{

    if (small_nbits(nbits)) {

        return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;

    } else {

        return slow_bitmap_intersects(src1, src2, nbits);

    }

}

void bitmap_set(unsigned long *map, int i, int len);

void bitmap_clear(unsigned long *map, int start, int nr);

unsigned long bitmap_find_next_zero_area(unsigned long *map,

                                         unsigned long size,

                                         unsigned long start,

                                         unsigned int nr,

                                         unsigned long align_mask);

#endif /* BITMAP_H */