From nobody Sat Sep 28 21:08:00 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1551872868895934.3296078623312; Wed, 6 Mar 2019 03:47:48 -0800 (PST) Received: from localhost ([127.0.0.1]:59922 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h1V1X-0001FY-PZ for importer@patchew.org; Wed, 06 Mar 2019 06:47:47 -0500 Received: from eggs.gnu.org ([209.51.188.92]:43652) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1h1UxC-0006Qp-3F for qemu-devel@nongnu.org; Wed, 06 Mar 2019 06:43:18 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1h1UxB-0005CG-6m for qemu-devel@nongnu.org; Wed, 06 Mar 2019 06:43:18 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39846) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1h1UxB-00059p-0Z for qemu-devel@nongnu.org; Wed, 06 Mar 2019 06:43:17 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3DB3987622; Wed, 6 Mar 2019 11:43:16 +0000 (UTC) Received: from dgilbert-t580.localhost (ovpn-117-163.ams2.redhat.com [10.36.117.163]) by smtp.corp.redhat.com (Postfix) with ESMTP id 64D041001DDE; Wed, 6 Mar 2019 11:43:14 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, quintela@redhat.com, peterx@redhat.com, marcel.apfelbaum@gmail.com, wei.w.wang@intel.com, yury-kotov@yandex-team.ru, chen.zhang@intel.com Date: Wed, 6 Mar 2019 11:42:18 +0000 Message-Id: <20190306114227.9125-14-dgilbert@redhat.com> In-Reply-To: <20190306114227.9125-1-dgilbert@redhat.com> References: <20190306114227.9125-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Wed, 06 Mar 2019 11:43:16 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 13/22] bitmap: fix bitmap_count_one 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: armbru@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" From: Wei Wang BITMAP_LAST_WORD_MASK(nbits) returns 0xffffffff when "nbits=3D0", which makes bitmap_count_one fail to handle the "nbits=3D0" case. It appears to be preferred to remain BITMAP_LAST_WORD_MASK identical to the kernel implementation that it is ported from. So this patch fixes bitmap_count_one to handle the nbits=3D0 case. Inital Discussion Link: https://www.mail-archive.com/qemu-devel@nongnu.org/msg554316.html Signed-off-by: Wei Wang CC: Juan Quintela CC: Dr. David Alan Gilbert CC: Peter Xu Message-Id: <1544516693-5395-2-git-send-email-wei.w.wang@intel.com> Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Dr. David Alan Gilbert --- include/qemu/bitmap.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/include/qemu/bitmap.h b/include/qemu/bitmap.h index 509eeddece..679f1bdce4 100644 --- a/include/qemu/bitmap.h +++ b/include/qemu/bitmap.h @@ -221,6 +221,10 @@ static inline int bitmap_intersects(const unsigned lon= g *src1, =20 static inline long bitmap_count_one(const unsigned long *bitmap, long nbit= s) { + if (unlikely(!nbits)) { + return 0; + } + if (small_nbits(nbits)) { return ctpopl(*bitmap & BITMAP_LAST_WORD_MASK(nbits)); } else { --=20 2.20.1