From patchwork Thu Dec 10 19:26:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 11967537 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0DF9AC4361B for ; Fri, 11 Dec 2020 08:17:38 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B040023E56 for ; Fri, 11 Dec 2020 08:17:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B040023E56 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D9CBC6ECC7; Fri, 11 Dec 2020 08:16:25 +0000 (UTC) Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by gabe.freedesktop.org (Postfix) with ESMTPS id 74F436EB26; Thu, 10 Dec 2020 19:42:51 +0000 (UTC) Message-Id: <20201210194045.360198201@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1607629369; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=ZlPg9sxtWavWNstOnduWAE0LJ88d0safrspZWU+Bxkw=; b=K1DERQLLdTNr2zHRckKSlzdGpOu3K2YNmRf/Fd+Me9xL7e1+z/WEZj2/ktZthj5jq1hRc5 H3K05V2lxe1VMwzID4A3YLY85G8CYSpDrmB064IUNRFZIZdMGhdgfMMXJmC2dwy27hx5dv +8AXgD/DGykOcBz1Xa8j76SRM06+jkTJXOvxx9wVIyXxp695f6gHDGbeeV9JlTl+CV+qJz iigE2xdn6yZ1PRpeA5+aMqV0fQZ1NATjbH3H6LTr2G8vwxub7OglAIb7biMKHi/AyccluD JT3nn4CWSg161dQ9jAMQEsqATs9zRWVAVD7sNovXx4fL9L9H47Prx2LPtWUjvw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1607629369; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=ZlPg9sxtWavWNstOnduWAE0LJ88d0safrspZWU+Bxkw=; b=5OkxueAP7qHY2hZdC3q6dEaDkreK0XDmJgigYgkjGtvPF1gC/y/J1hb+Pc7lUaZciQOAo7 alJrfrmEbNVTr+Cw== Date: Thu, 10 Dec 2020 20:26:04 +0100 From: Thomas Gleixner To: LKML Subject: [patch 28/30] xen/events: Reduce irq_info::spurious_cnt storage size References: <20201210192536.118432146@linutronix.de> MIME-Version: 1.0 X-Mailman-Approved-At: Fri, 11 Dec 2020 08:16:08 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Karthikeyan Mitran , Peter Zijlstra , Catalin Marinas , dri-devel@lists.freedesktop.org, Chris Wilson , "James E.J. Bottomley" , Saeed Mahameed , netdev@vger.kernel.org, Jakub Kicinski , Will Deacon , Michal Simek , linux-s390@vger.kernel.org, afzal mohammed , Stefano Stabellini , Dave Jiang , Leon Romanovsky , linux-rdma@vger.kernel.org, Marc Zyngier , Helge Deller , Russell King , Christian Borntraeger , linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, Heiko Carstens , Wambui Karuga , Allen Hubbe , David Airlie , linux-gpio@vger.kernel.org, Lorenzo Pieralisi , Rodrigo Vivi , Bjorn Helgaas , Boris Ostrovsky , linux-arm-kernel@lists.infradead.org, Juergen Gross , Tvrtko Ursulin , Lee Jones , linux-parisc@vger.kernel.org, Pankaj Bharadiya , Hou Zhiqiang , Tariq Toukan , Jon Mason , linux-ntb@googlegroups.com, intel-gfx@lists.freedesktop.org, "David S. Miller" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To prepare for interrupt spreading reduce the storage size of irq_info::spurious_cnt to u8 so the required flag for the spreading logic will not increase the storage size. Protect the usage site against overruns. Signed-off-by: Thomas Gleixner Cc: Boris Ostrovsky Cc: Juergen Gross Cc: Stefano Stabellini Cc: xen-devel@lists.xenproject.org --- drivers/xen/events/events_base.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -95,7 +95,7 @@ struct irq_info { struct list_head list; struct list_head eoi_list; short refcnt; - short spurious_cnt; + u8 spurious_cnt; enum xen_irq_type type; /* type */ unsigned irq; evtchn_port_t evtchn; /* event channel */ @@ -528,8 +528,10 @@ static void xen_irq_lateeoi_locked(struc return; if (spurious) { - if ((1 << info->spurious_cnt) < (HZ << 2)) - info->spurious_cnt++; + if ((1 << info->spurious_cnt) < (HZ << 2)) { + if (info->spurious_cnt != 0xFF) + info->spurious_cnt++; + } if (info->spurious_cnt > 1) { delay = 1 << (info->spurious_cnt - 2); if (delay > HZ)