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=-2.2 required=3.0 tests=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 535DECA9EC0 for ; Mon, 28 Oct 2019 18:52:00 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 2215D208C0 for ; Mon, 28 Oct 2019 18:52:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2215D208C0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id E0E30E04; Mon, 28 Oct 2019 18:51:59 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id E4E28CCA for ; Mon, 28 Oct 2019 18:51:57 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 837E3876 for ; Mon, 28 Oct 2019 18:51:57 +0000 (UTC) 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 EDA7B1F1; Mon, 28 Oct 2019 11:51:56 -0700 (PDT) Received: from [10.1.197.57] (e110467-lin.cambridge.arm.com [10.1.197.57]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 61A103F71F; Mon, 28 Oct 2019 11:51:56 -0700 (PDT) Subject: Re: [PATCH v2 08/10] iommu/io-pgtable-arm: Rationalise TTBRn handling To: Steven Price , will@kernel.org References: <74ada0e6c488a2310206a553eb108cc28fd52457.1572024120.git.robin.murphy@arm.com> <5324d888-857a-b07c-439c-4ae4ea3a9784@arm.com> From: Robin Murphy Message-ID: Date: Mon, 28 Oct 2019 18:51:55 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <5324d888-857a-b07c-439c-4ae4ea3a9784@arm.com> Content-Language: en-GB Cc: iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On 28/10/2019 15:09, Steven Price wrote: [...] >> --- a/drivers/iommu/io-pgtable-arm-v7s.c >> +++ b/drivers/iommu/io-pgtable-arm-v7s.c >> @@ -822,15 +822,13 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg, >> /* Ensure the empty pgd is visible before any actual TTBR write */ >> wmb(); >> >> - /* TTBRs */ >> - cfg->arm_v7s_cfg.ttbr[0] = virt_to_phys(data->pgd) | >> - ARM_V7S_TTBR_S | ARM_V7S_TTBR_NOS | >> - (cfg->coherent_walk ? >> - (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_WBWA) | >> - ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_WBWA)) : >> - (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_NC) | >> - ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_NC))); >> - cfg->arm_v7s_cfg.ttbr[1] = 0; >> + /* TTBR */ >> + cfg->arm_v7s_cfg.ttbr = virt_to_phys(data->pgd) | ARM_V7S_TTBR_S | >> + (cfg->coherent_walk ? (ARM_V7S_TTBR_NOS | >> + ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_WBWA) | >> + ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_WBWA)) : >> + (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_NC) | >> + ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_NC))); > > ARM_V7S_TTBR_NOS seems to have sneaked into the cfg->coherent_walk > condition here - which you haven't mentioned in the commit log, so it > doesn't look like it should be in this commit. Ah, yes, it's taken a while to remember whether this was something important that got muddled up in rebasing, but it's actually just trivial cleanup. For !coherent_walk, the non-cacheable output attribute makes shareable accesses implicitly outer-shareable, so setting TTBR.NOS for that case actually does nothing except look misleading. Thus this is essentially just a cosmetic change included in the reformatting for clarity and consistency with the LPAE version. I'll call that out in the commit message, thanks for spotting! Robin. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu 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 62A04CA9EC0 for ; Mon, 28 Oct 2019 18:52:02 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 423C8214B2 for ; Mon, 28 Oct 2019 18:52:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="nusHJslx" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 423C8214B2 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+infradead-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=bombadil.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=LjTOf0hebv08dOtkuY4R0c7wjSlufVEEXB8tOryt2lc=; b=nusHJslx5NORr/gbx3LU3/nNV QCWt4hZ6Wk9ztZ14JHL1nR6Vpu8LKlbbS2KvZE8K5KybLLOuKVmyHlne8Htn5qORq4+r9OR3yJsv3 MQAhnaNAmuq1W2pOUV0Ee1NpoI0ceJ3fMkytGmIOUb7tR928qkeEgttB3evTQxi0exUKwxrvohXUH Umn9A89JG4M6QFu6YmfK7jsa2C2KJuyY36U2ffPK5/zCHcIReYgBjG2/G/0l1iqov2YYq50+Fn7wd IbYw1pSjRvoyECtrA8Gn6iI/ozSAJKeEWtGjgEXPU+XXI+pcH1j51PJj0VjTtVmrZ7E6owyFkgamk zzO4v3CbA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iPA7V-0004C8-2B; Mon, 28 Oct 2019 18:52:01 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iPA7S-0004Bk-5m for linux-arm-kernel@lists.infradead.org; Mon, 28 Oct 2019 18:51:59 +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 EDA7B1F1; Mon, 28 Oct 2019 11:51:56 -0700 (PDT) Received: from [10.1.197.57] (e110467-lin.cambridge.arm.com [10.1.197.57]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 61A103F71F; Mon, 28 Oct 2019 11:51:56 -0700 (PDT) Subject: Re: [PATCH v2 08/10] iommu/io-pgtable-arm: Rationalise TTBRn handling To: Steven Price , will@kernel.org References: <74ada0e6c488a2310206a553eb108cc28fd52457.1572024120.git.robin.murphy@arm.com> <5324d888-857a-b07c-439c-4ae4ea3a9784@arm.com> From: Robin Murphy Message-ID: Date: Mon, 28 Oct 2019 18:51:55 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <5324d888-857a-b07c-439c-4ae4ea3a9784@arm.com> Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191028_115158_262045_1AD51F1D X-CRM114-Status: GOOD ( 15.96 ) 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: iommu@lists.linux-foundation.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+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 28/10/2019 15:09, Steven Price wrote: [...] >> --- a/drivers/iommu/io-pgtable-arm-v7s.c >> +++ b/drivers/iommu/io-pgtable-arm-v7s.c >> @@ -822,15 +822,13 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg, >> /* Ensure the empty pgd is visible before any actual TTBR write */ >> wmb(); >> >> - /* TTBRs */ >> - cfg->arm_v7s_cfg.ttbr[0] = virt_to_phys(data->pgd) | >> - ARM_V7S_TTBR_S | ARM_V7S_TTBR_NOS | >> - (cfg->coherent_walk ? >> - (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_WBWA) | >> - ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_WBWA)) : >> - (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_NC) | >> - ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_NC))); >> - cfg->arm_v7s_cfg.ttbr[1] = 0; >> + /* TTBR */ >> + cfg->arm_v7s_cfg.ttbr = virt_to_phys(data->pgd) | ARM_V7S_TTBR_S | >> + (cfg->coherent_walk ? (ARM_V7S_TTBR_NOS | >> + ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_WBWA) | >> + ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_WBWA)) : >> + (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_NC) | >> + ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_NC))); > > ARM_V7S_TTBR_NOS seems to have sneaked into the cfg->coherent_walk > condition here - which you haven't mentioned in the commit log, so it > doesn't look like it should be in this commit. Ah, yes, it's taken a while to remember whether this was something important that got muddled up in rebasing, but it's actually just trivial cleanup. For !coherent_walk, the non-cacheable output attribute makes shareable accesses implicitly outer-shareable, so setting TTBR.NOS for that case actually does nothing except look misleading. Thus this is essentially just a cosmetic change included in the reformatting for clarity and consistency with the LPAE version. I'll call that out in the commit message, thanks for spotting! Robin. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel