From patchwork Wed Feb 20 01:02:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= X-Patchwork-Id: 10820981 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 536566CB for ; Wed, 20 Feb 2019 01:19:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3D5242CF1C for ; Wed, 20 Feb 2019 01:19:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 315BA2CF1F; Wed, 20 Feb 2019 01:19:18 +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=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id D3C242CF20 for ; Wed, 20 Feb 2019 01:19:17 +0000 (UTC) Received: from localhost ([127.0.0.1]:57504 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gwGXd-0003Ya-3X for patchwork-qemu-devel@patchwork.kernel.org; Tue, 19 Feb 2019 20:19:17 -0500 Received: from eggs.gnu.org ([209.51.188.92]:41251) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gwGQP-0005cx-VS for qemu-devel@nongnu.org; Tue, 19 Feb 2019 20:11:50 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gwGN4-0003r2-PH for qemu-devel@nongnu.org; Tue, 19 Feb 2019 20:08:29 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48588) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gwGMz-0002bE-UI; Tue, 19 Feb 2019 20:08:18 -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 9E35F5944D; Wed, 20 Feb 2019 01:06:03 +0000 (UTC) Received: from x1w.redhat.com (unknown [10.40.205.222]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 55C561001E7E; Wed, 20 Feb 2019 01:05:51 +0000 (UTC) From: =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= To: qemu-devel@nongnu.org, Prasad J Pandit , =?utf-8?q?Marc-Andr=C3=A9_Lureau?= , Paolo Bonzini Date: Wed, 20 Feb 2019 02:02:19 +0100 Message-Id: <20190220010232.18731-13-philmd@redhat.com> In-Reply-To: <20190220010232.18731-1-philmd@redhat.com> References: <20190220010232.18731-1-philmd@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 [10.5.110.39]); Wed, 20 Feb 2019 01:06:03 +0000 (UTC) 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] [PATCH v3 12/25] xen: Let buffer_append() return the size consumed 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: Corey Minyard , Stefano Stabellini , Samuel Thibault , Li Zhijian , Amit Shah , "Michael S. Tsirkin" , Jason Wang , Cornelia Huck , Halil Pasic , Christian Borntraeger , qemu-s390x@nongnu.org, Paul Durrant , qemu-ppc@nongnu.org, Gerd Hoffmann , Pavel Dovgalyuk , Zhang Chen , Anthony Perard , xen-devel@lists.xenproject.org, Stefan Berger , =?utf-8?q?Philippe_Mathieu-Daud?= =?utf-8?q?=C3=A9?= , David Gibson Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP The buffer.size and buffer.consumed fields are only updated within the buffer_append() body. We can simply let buffer_append() return the difference (the buffer consumed). Signed-off-by: Philippe Mathieu-Daudé --- hw/char/xen_console.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/hw/char/xen_console.c b/hw/char/xen_console.c index 083b2c8e2a..1a30014a11 100644 --- a/hw/char/xen_console.c +++ b/hw/char/xen_console.c @@ -48,7 +48,7 @@ struct XenConsole { int backlog; }; -static void buffer_append(struct XenConsole *con) +static ssize_t buffer_append(struct XenConsole *con) { struct buffer *buffer = &con->buffer; XENCONS_RING_IDX cons, prod, size; @@ -59,8 +59,9 @@ static void buffer_append(struct XenConsole *con) xen_mb(); size = prod - cons; - if ((size == 0) || (size > sizeof(intf->out))) - return; + if ((size == 0) || (size > sizeof(intf->out))) { + goto out; + } if ((buffer->capacity - buffer->size) < size) { buffer->capacity += (size + 1024); @@ -89,6 +90,9 @@ static void buffer_append(struct XenConsole *con) if (buffer->consumed > buffer->max_capacity - over) buffer->consumed = buffer->max_capacity - over; } + + out: + return buffer->size - buffer->consumed; } static void buffer_advance(struct buffer *buffer, size_t len) @@ -281,8 +285,7 @@ static void con_event(struct XenLegacyDevice *xendev) struct XenConsole *con = container_of(xendev, struct XenConsole, xendev); ssize_t size; - buffer_append(con); - size = con->buffer.size - con->buffer.consumed; + size = buffer_append(con); if (size) { xencons_send(con, size); }