On Wed, Nov 05 2014, Gregory Fong wrote: > From: Michal Nazarewicz <[email protected]>
Please change to [email protected]. My Samsung address is no longer valid. Ditto on signed-off-by line. > > 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 <[email protected]> > Signed-off-by: Kyungmin Park <[email protected]> > Signed-off-by: Marek Szyprowski <[email protected]> > CC: Michal Nazarewicz <[email protected]> > [[email protected]: Retrieved from > https://patchwork.linuxtv.org/patch/6254/ and updated documentation] > Signed-off-by: Gregory Fong <[email protected]> > --- > include/linux/bitmap.h | 36 +++++++++++++++++++++++++++++++----- > lib/bitmap.c | 24 +++++++++++++----------- > 2 files changed, 44 insertions(+), 16 deletions(-) > > diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h > index e1c8d08..34e020c 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 +115,36 @@ extern int __bitmap_weight(const unsigned long *bitmap, > unsigned int nbits); > > extern void bitmap_set(unsigned long *map, unsigned int start, int len); > extern void bitmap_clear(unsigned long *map, unsigned int start, int len); > -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); > + > +/** > + * 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 > + * > + * 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. > + */ > +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 b499ab6..969ae8f 100644 > --- a/lib/bitmap.c > +++ b/lib/bitmap.c > @@ -326,30 +326,32 @@ void bitmap_clear(unsigned long *map, unsigned int > start, int len) > } > EXPORT_SYMBOL(bitmap_clear); > > -/* > - * bitmap_find_next_zero_area - find a contiguous aligned zero area > +/** > + * bitmap_find_next_zero_area_off - 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) > @@ -361,7 +363,7 @@ 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 Nadia Yvette > Chambers, > -- > 1.9.1 > -- Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o ..o | Computer Science, Michał “mina86” Nazarewicz (o o) ooo +--<[email protected]>--<xmpp:[email protected]>--ooO--(_)--Ooo-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
