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 X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 F2A35C433DF for ; Tue, 7 Jul 2020 18:13:31 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 C2BD32065F for ; Tue, 7 Jul 2020 18:13:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="S4Jb+bll" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C2BD32065F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=uErwh216RVjXwoTrAeySPGH5SCUUIwTKIXlqMJ3nX7c=; b=S4Jb+bllRy0EQ/z9H8SRRVFjz qPR1c2Vnk4JwpoMfj1691TU77crInUhhgAPeplWdS42b5IGSdMTxuNdtKwxgIAxlS1WF8OQjOJY22 qPShXBCr8fEr0KEaDaz1ztowpl+tftuHmUSipZ1EPe2LWICg/TCudqixkosGAUwSHNqkNmFATdlHj uGSNYDxUbBvBVUL8fqtSla8qfCIoZlxTTBE8AJg39Jl3MhFcCP0LP4V4WxBysIMdg5mJWf+sqHWJD xbThzGO84hQUI7CwYqqYY4qmbRFrHg4z8ShNFnQ9wyI80CJMAigFPvoZWwn41zbcmAUYEACCmcXEx NQ2Uwtc1w==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jss4n-0006TQ-Fg; Tue, 07 Jul 2020 18:12:17 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jss4l-0006SL-4C for linux-arm-kernel@lists.infradead.org; Tue, 07 Jul 2020 18:12:16 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4A8541FB; Tue, 7 Jul 2020 11:12:13 -0700 (PDT) Received: from [10.57.21.32] (unknown [10.57.21.32]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D0D963F71E; Tue, 7 Jul 2020 11:12:10 -0700 (PDT) Subject: Re: [RFC PATCH v4 2/2] arm64: tlb: Use the TLBI RANGE feature in arm64 To: Catalin Marinas , Marc Zyngier References: <20200601144713.2222-1-yezhenyu2@huawei.com> <20200601144713.2222-3-yezhenyu2@huawei.com> <20200707173617.GA32331@gaia> <20200707174612.GC32331@gaia> From: Robin Murphy Message-ID: <327b23f9-bc6f-ae68-72aa-b0e4a6da98f0@arm.com> Date: Tue, 7 Jul 2020 19:12:08 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200707174612.GC32331@gaia> Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200707_141215_357919_F8C9B3B6 X-CRM114-Status: GOOD ( 15.09 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, Zhenyu Ye , suzuki.poulose@arm.com, linux-kernel@vger.kernel.org, xiexiangyou@huawei.com, steven.price@arm.com, zhangshaokun@hisilicon.com, linux-mm@kvack.org, arm@kernel.org, prime.zeng@hisilicon.com, guohanjun@huawei.com, olof@lixom.net, kuhn.chenqun@huawei.com, will@kernel.org, linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 2020-07-07 18:46, Catalin Marinas wrote: > On Tue, Jul 07, 2020 at 06:43:35PM +0100, Marc Zyngier wrote: >> On 2020-07-07 18:36, Catalin Marinas wrote: >>> On Mon, Jun 01, 2020 at 10:47:13PM +0800, Zhenyu Ye wrote: >>>> @@ -59,6 +69,47 @@ >>>> __ta; \ >>>> }) >>>> >>>> +/* >>>> + * __TG defines translation granule of the system, which is decided >>>> by >>>> + * PAGE_SHIFT. Used by TTL. >>>> + * - 4KB : 1 >>>> + * - 16KB : 2 >>>> + * - 64KB : 3 >>>> + */ >>>> +#define __TG ((PAGE_SHIFT - 12) / 2 + 1) >>> >>> Nitpick: maybe something like __TLBI_TG to avoid clashes in case someone >>> else defines a __TG macro. >> >> I have commented on this in the past, and still maintain that this >> would be better served by a switch statement similar to what is used >> for TTL already (I don't think this magic formula exists in the >> ARM ARM). > > Good point, it would be cleaner indeed. FWIW, we use the somewhat obtuse "(shift - 10) / 2" in the SMMUv3 driver, but that's because we support multiple different granules at runtime and want to generate efficient code. Anything based on PAGE_SHIFT that resolves to a compile-time constant has no excuse for not being written in a clear and obvious manner ;) Robin. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel