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: 342666 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=ham 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 0953BC4167B for ; Thu, 10 Dec 2020 19:45:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD3BA23DB4 for ; Thu, 10 Dec 2020 19:45:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393604AbgLJTpH (ORCPT ); Thu, 10 Dec 2020 14:45:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53332 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404345AbgLJTnp (ORCPT ); Thu, 10 Dec 2020 14:43:45 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6FC9EC061794; Thu, 10 Dec 2020 11:42:51 -0800 (PST) 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 Cc: Peter Zijlstra , Marc Zyngier , Boris Ostrovsky , Juergen Gross , Stefano Stabellini , xen-devel@lists.xenproject.org, "James E.J. Bottomley" , Helge Deller , afzal mohammed , linux-parisc@vger.kernel.org, Russell King , linux-arm-kernel@lists.infradead.org, Mark Rutland , Catalin Marinas , Will Deacon , Christian Borntraeger , Heiko Carstens , linux-s390@vger.kernel.org, Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , David Airlie , Daniel Vetter , Pankaj Bharadiya , Chris Wilson , Wambui Karuga , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, Tvrtko Ursulin , Linus Walleij , linux-gpio@vger.kernel.org, Lee Jones , Jon Mason , Dave Jiang , Allen Hubbe , linux-ntb@googlegroups.com, Lorenzo Pieralisi , Rob Herring , Bjorn Helgaas , Michal Simek , linux-pci@vger.kernel.org, Karthikeyan Mitran , Hou Zhiqiang , Tariq Toukan , "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org, linux-rdma@vger.kernel.org, Saeed Mahameed , Leon Romanovsky Subject: [patch 28/30] xen/events: Reduce irq_info::spurious_cnt storage size References: <20201210192536.118432146@linutronix.de> MIME-Version: 1.0 Content-transfer-encoding: 8-bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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)