From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-3580-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [66.179.20.138]) by lists.oasis-open.org (Postfix) with ESMTP id 333F45818FBB for ; Fri, 16 Mar 2018 04:07:21 -0700 (PDT) From: Wei Wang Date: Fri, 16 Mar 2018 18:48:25 +0800 Message-Id: <1521197309-13544-2-git-send-email-wei.w.wang@intel.com> In-Reply-To: <1521197309-13544-1-git-send-email-wei.w.wang@intel.com> References: <1521197309-13544-1-git-send-email-wei.w.wang@intel.com> Subject: [virtio-dev] [PATCH v5 1/5] bitmap: bitmap_count_one_with_offset To: qemu-devel@nongnu.org, virtio-dev@lists.oasis-open.org, mst@redhat.com, quintela@redhat.com, dgilbert@redhat.com Cc: pbonzini@redhat.com, wei.w.wang@intel.com, liliang.opensource@gmail.com, yang.zhang.wz@gmail.com, quan.xu0@gmail.com, nilal@redhat.com, riel@redhat.com List-ID: Count the number of 1s in a bitmap starting from an offset. Signed-off-by: Wei Wang CC: Dr. David Alan Gilbert CC: Juan Quintela CC: Michael S. Tsirkin Reviewed-by: Dr. David Alan Gilbert --- 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 --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org