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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 931D9C4332F for ; Thu, 14 Dec 2023 15:22:03 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1F0AA8D00C9; Thu, 14 Dec 2023 10:22:03 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 17B1B8D00C7; Thu, 14 Dec 2023 10:22:03 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 019518D00C9; Thu, 14 Dec 2023 10:22:02 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id DF6988D00C7 for ; Thu, 14 Dec 2023 10:22:02 -0500 (EST) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id A951E160C18 for ; Thu, 14 Dec 2023 15:22:02 +0000 (UTC) X-FDA: 81565789284.15.27B0870 Received: from mail-wr1-f44.google.com (mail-wr1-f44.google.com [209.85.221.44]) by imf20.hostedemail.com (Postfix) with ESMTP id B341B1C0017 for ; Thu, 14 Dec 2023 15:22:00 +0000 (UTC) Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=linaro.org header.s=google header.b=Q6OmVgbc; spf=pass (imf20.hostedemail.com: domain of jean-philippe@linaro.org designates 209.85.221.44 as permitted sender) smtp.mailfrom=jean-philippe@linaro.org; dmarc=pass (policy=none) header.from=linaro.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1702567320; h=from:from:sender: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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=/bSSRhAXdmXAROOGjFIgArjcRM7oqtGCLaLHkAUJnSg=; b=hbPVPD4TFD/Q+EG5rI5J/i8fxMpG3jLDimaSZhsKKKAd8fEe/ErP8g36/50Mc9ObF29DEE dq4srLjcC403PWf0qXyqh/OM0wyCiEF0NT0D3MVmlUKurrPuu/R+4nrdgegBqHD20rjmH5 Y9w1/wMWTrUmGhplftZufCDsMGcKte0= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1702567320; a=rsa-sha256; cv=none; b=gXGipP6D87z5QvL8whucoKjebTT579KeVriVbt7t1anjPrY6ZAJlDtJZqvhrGriIR338aX JebaVEzupZUh7NFQ6QI6WKje2cSbyUHcvAMoHvSOCJJRKxXTX+zgqSDuSQ/2q4yhaQDGbN RI2WFexVRv1TA23ZK1bbIvUAjj7t6Ok= ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=pass header.d=linaro.org header.s=google header.b=Q6OmVgbc; spf=pass (imf20.hostedemail.com: domain of jean-philippe@linaro.org designates 209.85.221.44 as permitted sender) smtp.mailfrom=jean-philippe@linaro.org; dmarc=pass (policy=none) header.from=linaro.org Received: by mail-wr1-f44.google.com with SMTP id ffacd0b85a97d-3333074512bso439231f8f.1 for ; Thu, 14 Dec 2023 07:22:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1702567319; x=1703172119; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=/bSSRhAXdmXAROOGjFIgArjcRM7oqtGCLaLHkAUJnSg=; b=Q6OmVgbcw0CjpN8ycJySHtqN3sj+8di2PzClhVcv03xy0tet5BMc2TkLNaA/Jexznp beyyxSxu26IPDXCqgj92jN1dgkR2UhOWp5RT1+SyT5TVtL34kT1Yu0ZAsGSUlijjnP+T BnjB0QTVBJ77l80NMMXhE8PLvdsa9pCGcRHqdiCxkqfEScLhD94fK+9NhAzdiJBpRZxL OSShNvTc6EufGeeXkuCIoi+fpAj1jXtGA0ApcAP/omZDiphTZLNMXLn+19dE3zQBeHf+ Oe4SVYV1X9wbO3IQiUAofaYx8o5l31SA+sNs2go1W632Z2KpujSiqs6jmzqc4IvPQtZV fXOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702567319; x=1703172119; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=/bSSRhAXdmXAROOGjFIgArjcRM7oqtGCLaLHkAUJnSg=; b=EDInZVggkSu8+lgGQe5jY7bblej16K6BcI9QqVOn+htSnVn7ekkwuZMtej9pNFSKcO nqd+X6wUgJZ7cEPpJ+RQzGg4YSATX0LD9zE9rI0rfEKuBiWwdHYv3+3Io/oqaBysROSc NQlEs2e1uz1zqxwvIMGXRhW76xMuS2lTQqMVQrq5HQd7u6OJ9fRxrYim8rl4D6E39f/A f+NBpJwmNlZc9IyoardSQM1onwqor6IC6rGd0aS69svM1OE9180+BKpu23kAxEIPV8j/ sWdes3J/MOe9xhOuWm9cXs21TMcfnyIgXMb+3I1WzX59BmkRjbWcYp20ppJpDOrSB7mn 48Kw== X-Gm-Message-State: AOJu0YxGGldD6Q58wp7+D5Mq8rKGwiRKNSZgDAOiVl92SOHkW9mHHPfE C7nyhGsXyEuJlrjASd/DAMo/DQ== X-Google-Smtp-Source: AGHT+IFNYdxveqf3zoi/Rky5KhkHGvNYerFKbxknnd39XZPaV13yasmExLP0rV2+gBo1TMNuyKiYqA== X-Received: by 2002:a7b:cb93:0:b0:40b:5e4a:2348 with SMTP id m19-20020a7bcb93000000b0040b5e4a2348mr5298274wmi.74.1702567319038; Thu, 14 Dec 2023 07:21:59 -0800 (PST) Received: from myrica ([2.221.137.100]) by smtp.gmail.com with ESMTPSA id m14-20020a05600c4f4e00b0040b30be6244sm25072367wmq.24.2023.12.14.07.21.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 14 Dec 2023 07:21:58 -0800 (PST) Date: Thu, 14 Dec 2023 15:22:06 +0000 From: Jean-Philippe Brucker To: Robin Murphy Cc: 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 , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 12/15] arm64/mm: Split __flush_tlb_range() to elide trailing DSB Message-ID: <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: B341B1C0017 X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: 8okbfjn8fo7rfweko1sy4ko3c7x5oe37 X-HE-Tag: 1702567320-583401 X-HE-Meta: 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 rIm0Kkmf oiVDcmk877ju1qmoG1bVNT9SzSRQHH/MhYD3ZpHQ4Z5cHSSWcgYyMrLcrNJLuPM1+FCdIW2Lb2By3Vj7byM+Af/SaD6aU4WNcdvNNqtbvz5kz56Lak5aigay682hGiKtDAD/BuGw1DRBwjwGFa8/L6CC14r4F2YxtnoosQ4mrE4cAEt/jpYjHq1He/7RodKa8Raiur1hZiqHtB8GDXTjp5E0qWJHsy/33biEXq+bUdqDoKVxnmh7H0wU4pvILLVIwsK77QNx5qIaclsiP7Y8IMavGn81wH+mxWpVvaI0U/zkte38fXNXymtOKtyrp759F1FyhQlxIGXMDmrtYF+HpNeZrwk6EDQqewi/z7a/6/DxJ7f/japva0kOeRPvAv/aE1EqWVqfo34vP14J142pVRno4KRY3JX2p96zGm9a3SwlL4AJsAOTI8ezgDOeJKYaDtiAntNDVUX+ixTO8wDNLjV5lqA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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. Thanks, Jean