From patchwork Thu Nov 15 10:07:58 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wang, Wei W" X-Patchwork-Id: 10684125 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B218313B5 for ; Thu, 15 Nov 2018 10:46:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9894A2C041 for ; Thu, 15 Nov 2018 10:46:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8C5872C059; Thu, 15 Nov 2018 10:46:04 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 6ECAB2C041 for ; Thu, 15 Nov 2018 10:46:03 +0000 (UTC) Received: from localhost ([::1]:37994 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gNF9u-00087s-3z for patchwork-qemu-devel@patchwork.kernel.org; Thu, 15 Nov 2018 05:46:02 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57605) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gNF5D-0003is-U4 for qemu-devel@nongnu.org; Thu, 15 Nov 2018 05:41:12 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gNF59-0000pt-Bw for qemu-devel@nongnu.org; Thu, 15 Nov 2018 05:41:11 -0500 Received: from mga03.intel.com ([134.134.136.65]:14567) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gNF59-0000oM-3F for qemu-devel@nongnu.org; Thu, 15 Nov 2018 05:41:07 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Nov 2018 02:41:07 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,236,1539673200"; d="scan'208";a="106467277" Received: from devel-ww.sh.intel.com ([10.239.48.119]) by fmsmga004.fm.intel.com with ESMTP; 15 Nov 2018 02:41:04 -0800 From: Wei Wang To: qemu-devel@nongnu.org, virtio-dev@lists.oasis-open.org, mst@redhat.com, quintela@redhat.com, dgilbert@redhat.com Date: Thu, 15 Nov 2018 18:07:58 +0800 Message-Id: <1542276484-25508-3-git-send-email-wei.w.wang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1542276484-25508-1-git-send-email-wei.w.wang@intel.com> References: <1542276484-25508-1-git-send-email-wei.w.wang@intel.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.65 Subject: [Qemu-devel] [PATCH v9 2/8] bitmap: bitmap_count_one_with_offset X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: liliang.opensource@gmail.com, peterx@redhat.com, wei.w.wang@intel.com, pbonzini@redhat.com, nilal@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP 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 679f1bd..5c31334 100644 --- a/include/qemu/bitmap.h +++ b/include/qemu/bitmap.h @@ -232,6 +232,19 @@ 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);