| Message ID | 1520426065-40265-2-git-send-email-wei.w.wang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
* Wei Wang (wei.w.wang@intel.com) wrote: > Count the number of 1s in a bitmap starting from an offset. > > Signed-off-by: Wei Wang <wei.w.wang@intel.com> > CC: Dr. David Alan Gilbert <dgilbert@redhat.com> > CC: Juan Quintela <quintela@redhat.com> > CC: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > --- > include/qemu/bitmap.h | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h > index 509eedd..e3f31f1 100644 > --- a/include/qemu/bitmap.h > +++ b/include/qemu/bitmap.h > @@ -228,6 +228,19 @@ static inline long bitmap_count_one(const unsigned long *bitmap, long nbits) > } > } > > +static inline long bitmap_count_one_with_offset(const unsigned long *bitmap, > + long offset, long nbits) > +{ > + long aligned_offset = QEMU_ALIGN_DOWN(offset, BITS_PER_LONG); > + long redundant_bits = offset - aligned_offset; > + long bits_to_count = nbits + redundant_bits; > + const unsigned long *bitmap_start = bitmap + > + aligned_offset / BITS_PER_LONG; > + > + return bitmap_count_one(bitmap_start, bits_to_count) - > + bitmap_count_one(bitmap_start, redundant_bits); > +} > + > void bitmap_set(unsigned long *map, long i, long len); > void bitmap_set_atomic(unsigned long *map, long i, long len); > void bitmap_clear(unsigned long *map, long start, long nr); > -- > 1.8.3.1 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h index 509eedd..e3f31f1 100644 --- a/include/qemu/bitmap.h +++ b/include/qemu/bitmap.h @@ -228,6 +228,19 @@ static inline long bitmap_count_one(const unsigned long *bitmap, long nbits) } } +static inline long bitmap_count_one_with_offset(const unsigned long *bitmap, + long offset, long nbits) +{ + long aligned_offset = QEMU_ALIGN_DOWN(offset, BITS_PER_LONG); + long redundant_bits = offset - aligned_offset; + long bits_to_count = nbits + redundant_bits; + const unsigned long *bitmap_start = bitmap + + aligned_offset / BITS_PER_LONG; + + return bitmap_count_one(bitmap_start, bits_to_count) - + bitmap_count_one(bitmap_start, redundant_bits); +} + void bitmap_set(unsigned long *map, long i, long len); void bitmap_set_atomic(unsigned long *map, long i, long len); void bitmap_clear(unsigned long *map, long start, long nr);
Count the number of 1s in a bitmap starting from an offset. Signed-off-by: Wei Wang <wei.w.wang@intel.com> CC: Dr. David Alan Gilbert <dgilbert@redhat.com> CC: Juan Quintela <quintela@redhat.com> CC: Michael S. Tsirkin <mst@redhat.com> --- include/qemu/bitmap.h | 13 +++++++++++++ 1 file changed, 13 insertions(+)