From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51161) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ewnCt-0008NN-7z for qemu-devel@nongnu.org; Fri, 16 Mar 2018 07:07:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ewnCp-00075t-8K for qemu-devel@nongnu.org; Fri, 16 Mar 2018 07:07:31 -0400 Received: from mga02.intel.com ([134.134.136.20]:53867) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ewnCo-0006zV-Sn for qemu-devel@nongnu.org; Fri, 16 Mar 2018 07:07:27 -0400 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: [Qemu-devel] [PATCH v5 1/5] bitmap: bitmap_count_one_with_offset List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 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