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=-5.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 12B79C4363A for ; Mon, 21 Sep 2020 17:57:28 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (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 9823120BED for ; Mon, 21 Sep 2020 17:57:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="b3e4bLWq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9823120BED Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 4E0A8870AE; Mon, 21 Sep 2020 17:57:27 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id k8FveY7PE5L0; Mon, 21 Sep 2020 17:57:26 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by hemlock.osuosl.org (Postfix) with ESMTP id D8CB88706C; Mon, 21 Sep 2020 17:57:26 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id B1154C0895; Mon, 21 Sep 2020 17:57:26 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id DC400C1AD4 for ; Mon, 21 Sep 2020 17:57:25 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id BE91F226F3 for ; Mon, 21 Sep 2020 17:57:25 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id E7No8qSe0pj4 for ; Mon, 21 Sep 2020 17:57:24 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by silver.osuosl.org (Postfix) with ESMTPS id 9E9721FC94 for ; Mon, 21 Sep 2020 17:57:24 +0000 (UTC) Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 35E5B20BED; Mon, 21 Sep 2020 17:57:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600711044; bh=MViJLr32Rfq7YAhifD5/NIE9W+70lqX9C47Hh7THkOA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=b3e4bLWq5uf1a8R/Zqrvx5GkxrmWFkVBJ7bYxNE+krlPNWfqlQf3S3tTvNN0+xB28 CxpT0M0IBlW+szKcCIPx5TFtZcwgWVBp8MOHvIS4TTWK1EOcQWjVDDWz/daGwhF3q9 l5v3MQq16B/JXdNNa/Qs+ZKHN5sUIxuisx9oOSbM= Date: Mon, 21 Sep 2020 18:57:19 +0100 From: Will Deacon To: Robin Murphy Subject: Re: [PATCH 1/3] iommu/io-pgtable-arm: Support coherency for Mali LPAE Message-ID: <20200921175717.GF3141@willie-the-truck> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Cc: robh@kernel.org, tomeu.vizoso@collabora.com, narmstrong@baylibre.com, khilman@baylibre.com, dri-devel@lists.freedesktop.org, steven.price@arm.com, iommu@lists.linux-foundation.org, alyssa.rosenzweig@collabora.com, linux-amlogic@lists.infradead.org, linux-arm-kernel@lists.infradead.org, jbrunet@baylibre.com X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Wed, Sep 16, 2020 at 12:51:05AM +0100, Robin Murphy wrote: > Midgard GPUs have ACE-Lite master interfaces which allows systems to > integrate them in an I/O-coherent manner. It seems that from the GPU's > viewpoint, the rest of the system is its outer shareable domain, and so > even when snoop signals are wired up, they are only emitted for outer > shareable accesses. As such, setting the TTBR_SHARE_OUTER bit does > indeed get coherent pagetable walks working nicely for the coherent > T620 in the Arm Juno SoC. I can't help but think some of this commentary deserves to be in the code as well. Do you know if this sort of thing is done for other SoCs too, or is this just a Juno quirk? Will _______________________________________________ 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=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 C3CD1C4363C for ; Mon, 21 Sep 2020 17:58:45 +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 6A31C2193E for ; Mon, 21 Sep 2020 17:58:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="yQc6JhDC"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="b3e4bLWq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6A31C2193E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject: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=/ThRZdHcx9FtY7fn4uBxCYzu+frl96eaXHogzrIY2c4=; b=yQc6JhDCsnvnbtNZLbcadrWnE 6DAezWftLia3bT/SlWoxuLhGAlhL3m8n+5SDVb3Qf3/VxX4yViLzGJ7UZ/UZSpINkiOdg/5Pm4jK9 +R/Bd3PgnljyDUdWWK5rQnZ/hzicnyOJbRCaT2GT5fkewK3aibN4eu1Jl49vOF5FCJ0Dyt9hZs78O cNKeXHxvnjZd04XmjAEL40e3dOzGjaGS2DsmFMmSdpnCDdbRj30y/9zMViEf/LFhmH2aOTxaaoNey /6AIc0t166u7uH2r9w/6tBrywvpiuyJqXXh6XhOEsY4v03SNigA5fXLAsMyTobQqUijmKyW5rF5LW lZCrK6YPQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kKQ49-0005pB-1v; Mon, 21 Sep 2020 17:57:29 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kKQ45-0005oH-GT; Mon, 21 Sep 2020 17:57:26 +0000 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 35E5B20BED; Mon, 21 Sep 2020 17:57:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600711044; bh=MViJLr32Rfq7YAhifD5/NIE9W+70lqX9C47Hh7THkOA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=b3e4bLWq5uf1a8R/Zqrvx5GkxrmWFkVBJ7bYxNE+krlPNWfqlQf3S3tTvNN0+xB28 CxpT0M0IBlW+szKcCIPx5TFtZcwgWVBp8MOHvIS4TTWK1EOcQWjVDDWz/daGwhF3q9 l5v3MQq16B/JXdNNa/Qs+ZKHN5sUIxuisx9oOSbM= Date: Mon, 21 Sep 2020 18:57:19 +0100 From: Will Deacon To: Robin Murphy Subject: Re: [PATCH 1/3] iommu/io-pgtable-arm: Support coherency for Mali LPAE Message-ID: <20200921175717.GF3141@willie-the-truck> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200921_135725_622219_3AB093DB X-CRM114-Status: GOOD ( 13.28 ) 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: robh@kernel.org, tomeu.vizoso@collabora.com, narmstrong@baylibre.com, khilman@baylibre.com, dri-devel@lists.freedesktop.org, steven.price@arm.com, iommu@lists.linux-foundation.org, alyssa.rosenzweig@collabora.com, linux-amlogic@lists.infradead.org, linux-arm-kernel@lists.infradead.org, jbrunet@baylibre.com 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 Wed, Sep 16, 2020 at 12:51:05AM +0100, Robin Murphy wrote: > Midgard GPUs have ACE-Lite master interfaces which allows systems to > integrate them in an I/O-coherent manner. It seems that from the GPU's > viewpoint, the rest of the system is its outer shareable domain, and so > even when snoop signals are wired up, they are only emitted for outer > shareable accesses. As such, setting the TTBR_SHARE_OUTER bit does > indeed get coherent pagetable walks working nicely for the coherent > T620 in the Arm Juno SoC. I can't help but think some of this commentary deserves to be in the code as well. Do you know if this sort of thing is done for other SoCs too, or is this just a Juno quirk? Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel 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=-5.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 123F6C4363C for ; Mon, 21 Sep 2020 17:57:27 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 A02362193E for ; Mon, 21 Sep 2020 17:57:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="b3e4bLWq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A02362193E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D11796E10F; Mon, 21 Sep 2020 17:57:25 +0000 (UTC) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by gabe.freedesktop.org (Postfix) with ESMTPS id 956A56E10F for ; Mon, 21 Sep 2020 17:57:24 +0000 (UTC) Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 35E5B20BED; Mon, 21 Sep 2020 17:57:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600711044; bh=MViJLr32Rfq7YAhifD5/NIE9W+70lqX9C47Hh7THkOA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=b3e4bLWq5uf1a8R/Zqrvx5GkxrmWFkVBJ7bYxNE+krlPNWfqlQf3S3tTvNN0+xB28 CxpT0M0IBlW+szKcCIPx5TFtZcwgWVBp8MOHvIS4TTWK1EOcQWjVDDWz/daGwhF3q9 l5v3MQq16B/JXdNNa/Qs+ZKHN5sUIxuisx9oOSbM= Date: Mon, 21 Sep 2020 18:57:19 +0100 From: Will Deacon To: Robin Murphy Subject: Re: [PATCH 1/3] iommu/io-pgtable-arm: Support coherency for Mali LPAE Message-ID: <20200921175717.GF3141@willie-the-truck> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: tomeu.vizoso@collabora.com, narmstrong@baylibre.com, khilman@baylibre.com, dri-devel@lists.freedesktop.org, steven.price@arm.com, iommu@lists.linux-foundation.org, alyssa.rosenzweig@collabora.com, linux-amlogic@lists.infradead.org, linux-arm-kernel@lists.infradead.org, jbrunet@baylibre.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Wed, Sep 16, 2020 at 12:51:05AM +0100, Robin Murphy wrote: > Midgard GPUs have ACE-Lite master interfaces which allows systems to > integrate them in an I/O-coherent manner. It seems that from the GPU's > viewpoint, the rest of the system is its outer shareable domain, and so > even when snoop signals are wired up, they are only emitted for outer > shareable accesses. As such, setting the TTBR_SHARE_OUTER bit does > indeed get coherent pagetable walks working nicely for the coherent > T620 in the Arm Juno SoC. I can't help but think some of this commentary deserves to be in the code as well. Do you know if this sort of thing is done for other SoCs too, or is this just a Juno quirk? Will _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel 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=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 A54E2C4363A for ; Mon, 21 Sep 2020 17:57:41 +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 407E120BED for ; Mon, 21 Sep 2020 17:57:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="WxpoCeJ8"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="b3e4bLWq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 407E120BED Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-amlogic-bounces+linux-amlogic=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-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject: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=FTj6WapVibp2EqeHAnLVl7TB1k2Zk85QTrg5aaFYFdg=; b=WxpoCeJ8xssrJTtKg0FyBWBdv N0xLtSyJQXuDYIQgmpzmeInE41i+UesL4u43oVIxmYAYHUiJMOMicKYE8IZcAubCNAWyo3M/WvUnY D77+5m92LFIVnSVQwZITffpVnYctOgAHIkQSsXtZM1hs6fQoargVy4GI972xAa87u6hqdwzGBFfgo Ln4Jk0+u4MGP6pFKFn4DE00/IxFWfuz7fHqqvMx8pPzZ2FkL4T4j0XTSRjMSQdF7bdEL+pCa1Ntkp YYYoifPAA47raC5fgaa3s550RpkLpXHn3CsMnCmtO/ikQPecHH2EUZgZrKY3zhAytg30GB9IHqccV jAIY31GXw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kKQ47-0005oo-MB; Mon, 21 Sep 2020 17:57:27 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kKQ45-0005oH-GT; Mon, 21 Sep 2020 17:57:26 +0000 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 35E5B20BED; Mon, 21 Sep 2020 17:57:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600711044; bh=MViJLr32Rfq7YAhifD5/NIE9W+70lqX9C47Hh7THkOA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=b3e4bLWq5uf1a8R/Zqrvx5GkxrmWFkVBJ7bYxNE+krlPNWfqlQf3S3tTvNN0+xB28 CxpT0M0IBlW+szKcCIPx5TFtZcwgWVBp8MOHvIS4TTWK1EOcQWjVDDWz/daGwhF3q9 l5v3MQq16B/JXdNNa/Qs+ZKHN5sUIxuisx9oOSbM= Date: Mon, 21 Sep 2020 18:57:19 +0100 From: Will Deacon To: Robin Murphy Subject: Re: [PATCH 1/3] iommu/io-pgtable-arm: Support coherency for Mali LPAE Message-ID: <20200921175717.GF3141@willie-the-truck> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200921_135725_622219_3AB093DB X-CRM114-Status: GOOD ( 13.28 ) X-BeenThere: linux-amlogic@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: robh@kernel.org, tomeu.vizoso@collabora.com, narmstrong@baylibre.com, khilman@baylibre.com, dri-devel@lists.freedesktop.org, steven.price@arm.com, iommu@lists.linux-foundation.org, alyssa.rosenzweig@collabora.com, linux-amlogic@lists.infradead.org, linux-arm-kernel@lists.infradead.org, jbrunet@baylibre.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-amlogic" Errors-To: linux-amlogic-bounces+linux-amlogic=archiver.kernel.org@lists.infradead.org On Wed, Sep 16, 2020 at 12:51:05AM +0100, Robin Murphy wrote: > Midgard GPUs have ACE-Lite master interfaces which allows systems to > integrate them in an I/O-coherent manner. It seems that from the GPU's > viewpoint, the rest of the system is its outer shareable domain, and so > even when snoop signals are wired up, they are only emitted for outer > shareable accesses. As such, setting the TTBR_SHARE_OUTER bit does > indeed get coherent pagetable walks working nicely for the coherent > T620 in the Arm Juno SoC. I can't help but think some of this commentary deserves to be in the code as well. Do you know if this sort of thing is done for other SoCs too, or is this just a Juno quirk? Will _______________________________________________ linux-amlogic mailing list linux-amlogic@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-amlogic