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    Subject[PATCH 01/10] lib: bitmap: Added alignment offset for bitmap_find_next_zero_area()
    From: Michal Nazarewicz <m.nazarewicz@samsung.com>

    This commit adds a bitmap_find_next_zero_area_off() function which
    works like bitmap_find_next_zero_area() function expect it allows an
    offset to be specified when alignment is checked. This lets caller
    request a bit such that its number plus the offset is aligned
    according to the mask.

    Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
    Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
    Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
    CC: Michal Nazarewicz <mina86@mina86.com>
    ---
    include/linux/bitmap.h | 24 +++++++++++++++++++-----
    lib/bitmap.c | 22 ++++++++++++----------
    2 files changed, 31 insertions(+), 15 deletions(-)

    diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
    index dcafe0b..50e2c16 100644
    --- a/include/linux/bitmap.h
    +++ b/include/linux/bitmap.h
    @@ -45,6 +45,7 @@
    * 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
    + * bitmap_find_next_zero_area_off(buf, len, pos, n, mask) as above
    * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
    * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
    * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
    @@ -114,11 +115,24 @@ extern int __bitmap_weight(const unsigned long *bitmap, int bits);

    extern void bitmap_set(unsigned long *map, int i, int len);
    extern void bitmap_clear(unsigned long *map, int start, int nr);
    -extern unsigned long bitmap_find_next_zero_area(unsigned long *map,
    - unsigned long size,
    - unsigned long start,
    - unsigned int nr,
    - unsigned long align_mask);
    +
    +extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
    + unsigned long size,
    + unsigned long start,
    + unsigned int nr,
    + unsigned long align_mask,
    + unsigned long align_offset);
    +
    +static inline unsigned long
    +bitmap_find_next_zero_area(unsigned long *map,
    + unsigned long size,
    + unsigned long start,
    + unsigned int nr,
    + unsigned long align_mask)
    +{
    + return bitmap_find_next_zero_area_off(map, size, start, nr,
    + align_mask, 0);
    +}

    extern int bitmap_scnprintf(char *buf, unsigned int len,
    const unsigned long *src, int nbits);
    diff --git a/lib/bitmap.c b/lib/bitmap.c
    index 41baf02..bad4f20 100644
    --- a/lib/bitmap.c
    +++ b/lib/bitmap.c
    @@ -315,30 +315,32 @@ void bitmap_clear(unsigned long *map, int start, int nr)
    }
    EXPORT_SYMBOL(bitmap_clear);

    -/*
    +/**
    * bitmap_find_next_zero_area - find a contiguous aligned zero area
    * @map: The address to base the search on
    * @size: The bitmap size in bits
    * @start: The bitnumber to start searching at
    * @nr: The number of zeroed bits we're looking for
    * @align_mask: Alignment mask for zero area
    + * @align_offset: Alignment offset for zero area.
    *
    * The @align_mask should be one less than a power of 2; the effect is that
    - * the bit offset of all zero areas this function finds is multiples of that
    - * power of 2. A @align_mask of 0 means no alignment is required.
    + * the bit offset of all zero areas this function finds plus @align_offset
    + * is multiple of that power of 2.
    */
    -unsigned long bitmap_find_next_zero_area(unsigned long *map,
    - unsigned long size,
    - unsigned long start,
    - unsigned int nr,
    - unsigned long align_mask)
    +unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
    + unsigned long size,
    + unsigned long start,
    + unsigned int nr,
    + unsigned long align_mask,
    + unsigned long align_offset)
    {
    unsigned long index, end, i;
    again:
    index = find_next_zero_bit(map, size, start);

    /* Align allocation */
    - index = __ALIGN_MASK(index, align_mask);
    + index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset;

    end = index + nr;
    if (end > size)
    @@ -350,7 +352,7 @@ again:
    }
    return index;
    }
    -EXPORT_SYMBOL(bitmap_find_next_zero_area);
    +EXPORT_SYMBOL(bitmap_find_next_zero_area_off);

    /*
    * Bitmap printing & parsing functions: first version by Bill Irwin,
    --
    1.7.1.569.g6f426


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