From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 175CDC4167B for ; Thu, 14 Dec 2023 16:46:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:CC:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=tcM/ClxX7srJGTglgUqs9mrehpbE3Ge3XYfftV2Jd+w=; b=RghCrt+9o7Ps6m UdPqZafGxg/UwU7EgdehDfhTxNEIlaVjGE0VdguRFOxFP5q4J7T5xiEeu9HJVSwq2Hc/jrPo0Io7A WMGgDYKhdA8PGxEWViN/1SZaMpjU1Jix4rUQAUJkfvuqDRYOGmiEnIURhb5zPcSOWiFwnFQ97wXGo gZeb94Hscb6+ZFVt15rBMiss5zh/kWQsP1V3JDys4LhuTRZkJlPXqg5aqsNHG7Ta5NHYe70FuEmyl oHugMrWaiQMWckDPgBklz5MMJIplFtsAEvjbmVk+jWArukOBaACTh05qDZdtmuX2G2KHEdS0ypuR+ sV06PLv1SQe8bGAINdvQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rDoqU-000qOY-37; Thu, 14 Dec 2023 16:45:58 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1rDoqR-000qN7-1p for linux-arm-kernel@lists.infradead.org; Thu, 14 Dec 2023 16:45:57 +0000 Received: from mail.maildlp.com (unknown [172.18.186.216]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4SrdVc6P6Cz67CtB; Fri, 15 Dec 2023 00:44:40 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id AF11C1400CA; Fri, 15 Dec 2023 00:45:43 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Thu, 14 Dec 2023 16:45:43 +0000 Date: Thu, 14 Dec 2023 16:45:41 +0000 From: Jonathan Cameron To: Jean-Philippe Brucker CC: Robin Murphy , Will Deacon , "Ryan Roberts" , Catalin Marinas , Ard Biesheuvel , Marc Zyngier , "Oliver Upton" , James Morse , "Suzuki K Poulose" , Zenghui Yu , "Andrey Ryabinin" , Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , "Andrew Morton" , Anshuman Khandual , Matthew Wilcox , Yu Zhao , Mark Rutland , David Hildenbrand , Kefeng Wang , John Hubbard , Zi Yan , Barry Song <21cnbao@gmail.com>, Alistair Popple , Yang Shi , , , , Subject: Re: [PATCH v3 12/15] arm64/mm: Split __flush_tlb_range() to elide trailing DSB Message-ID: <20231214164541.000027a1@Huawei.com> In-Reply-To: <20231214152206.GA3625745@myrica> References: <20231204105440.61448-1-ryan.roberts@arm.com> <20231204105440.61448-13-ryan.roberts@arm.com> <20231212113517.GA28857@willie-the-truck> <0969c413-bf40-4c46-9f1e-a92101ff2d2e@arm.com> <2e6f06d3-6c8e-4b44-b6f2-e55bd5be83d6@arm.com> <20231214121336.GA1015@willie-the-truck> <20231214152206.GA3625745@myrica> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 X-Originating-IP: [10.202.227.76] X-ClientProxiedBy: lhrpeml500006.china.huawei.com (7.191.161.198) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231214_084555_905588_EF1DA309 X-CRM114-Status: GOOD ( 18.84 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, 14 Dec 2023 15:22:06 +0000 Jean-Philippe Brucker wrote: > On Thu, Dec 14, 2023 at 12:30:55PM +0000, Robin Murphy wrote: > > > Robin, Jean-Philippe -- do we need to make sure that the SMMU has completed > > > its TLB invalidation before issuing an ATC invalidate? My half-baked worry > > > is whether or not an ATS request could refill the ATC before the TLBI > > > has completed, therefore rendering the ATC invalidation useless. > > > > I would agree, and the spec for CMD_ATC_INV does call out a > > TLBI->sync->ATCI->sync sequence. At the moment the SVA notifier is issuing > > its own command-based TLBIs anyway so the necessary sync is implicit there, > > but if and when we get BTM support wired up properly it would be nice not to > > have to bodge in an additional sync/DSB. > > Yes agreed, with BTM the CPU must call the notifier that issues ATC > invalidation after completing the TLBI+DSB instructions. > > SMMU IHI0070F.a 3.9.1 ATS Interface > > Software must ensure that the SMMU TLB invalidation is complete before > initiating the ATC invalidation. > > I'm guessing BTM will be enabled in the SMMU driver sometime soon, given > that there already is one implementation in the wild that could use it. I > think we didn't enable it because of the lack of separation between shared > and private VMIDs, but that may now be solvable with the recent rework of > the VMID allocator. > +CC Shameer. We'll indeed need to fix this when enabling BTM. Thanks for the heads up. Jonathan > Thanks, > Jean > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel