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 68DDAC54EBC for ; Tue, 10 Jan 2023 11:12:58 +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:In-Reply-To:MIME-Version:References: 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=qqBrmhFes+Lu4/6M7uINIABZQYS6a5p80EVPtB5UqM0=; b=BniOAmml9BC4YA 0GVwyaDPWqE9SYYSmVjHdb6YNGNiBEwjz4uGglYfY82T4MXAKOM3mlmEhXwuyTLISB1gEwHJxr+mt kScpitvFM6PtAq43W3iTZepr2qnpk+WroRGqSqMEFGmRJ0VD3O+8UWDWCyTM0QtLE21epQukBJprA HnGZYbg8n5xYYkFRcpfTUJ1ycj5eJHeJr9/n2Tn4LIlYQ8/e9LtUCHJqFN/SUF0FHTrxcJ1TZFoMD YFgwWdAFZoonckBD1PQIed0A/arTTzowh78gM+cWg77lEHTHyvdIIWuqH8UFTXWtbm9OwFMLi1LP3 2m2Kgpd4M3DL1tMeZeXg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pFCXe-006ZV4-8a; Tue, 10 Jan 2023 11:11:43 +0000 Received: from ams.source.kernel.org ([145.40.68.75]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pFCWw-006Z8x-JW for linux-arm-kernel@lists.infradead.org; Tue, 10 Jan 2023 11:11:00 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 8FD65B811F5; Tue, 10 Jan 2023 11:10:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D6E67C433D2; Tue, 10 Jan 2023 11:10:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673349054; bh=XhcDIdamWlk8EP3uFzZmuFirRRVx4AkOTeNQJtnlEwM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=cGur0OOJqRfo8MpHsMEOzXFbs+nDkkzR7dySApVpVxLf8DO7rMjcPatK6WkVVIZgO B5Q4WM+jYB41tPALdRNFgSppw3JjVbbceoM/RMypOAnrodkwtnVc4GdPbkH8Sjgdi0 UGVPfCFRB3pI6MdKJyvg61xmJH4BLE8+Y5dgK0YNp/XsQ8HnYHwJ+hKxPpxjyidVcU /IxtBbdZ2ISR2mF5jHqbI8P+1Wp2J/zoTR5kKs9T3H3ZxwtlK8dlyPYrnyT5VnGM90 Obf9WFG50rfcwWARLeSmwKgxZ+9rA0bRt1azFehaIbXJp4/XwyN0hd7ZIjhnbMFB2/ m/BV/ha/xE1vw== Date: Tue, 10 Jan 2023 11:10:50 +0000 From: Will Deacon To: Vladimir Oltean Cc: Robin Murphy , joro@8bytes.org, iommu@lists.linux.dev, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] iommu/arm-smmu: Report IOMMU_CAP_CACHE_COHERENCY even betterer Message-ID: <20230110111049.GA8986@willie-the-truck> References: <20230110105625.ououvyfj2g6ttkmf@skbuf> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20230110105625.ououvyfj2g6ttkmf@skbuf> 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-20230110_031058_833480_106EA1A0 X-CRM114-Status: GOOD ( 20.02 ) 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 Tue, Jan 10, 2023 at 12:56:25PM +0200, Vladimir Oltean wrote: > On Thu, Dec 15, 2022 at 04:51:55PM +0000, Robin Murphy wrote: > > Although it's vanishingly unlikely that anyone would integrate an SMMU > > within a coherent interconnect without also making the pagetable walk > > interface coherent, the same effect happens if a coherent SMMU fails to > > advertise CTTW correctly. This turns out to be the case on some popular > > NXP SoCs, where VFIO started failing the IOMMU_CAP_CACHE_COHERENCY test, > > even though IOMMU_CACHE *was* previously achieving the desired effect > > anyway thanks to the underlying integration. > > > > While those SoCs stand to gain some more general benefits from a > > firmware update to override CTTW correctly in DT/ACPI, it's also easy > > to work around this in Linux as well, to avoid imposing too much on > > affected users - since the upstream client devices *are* correctly > > marked as coherent, we can trivially infer their coherent paths through > > the SMMU as well. > > > > Reported-by: Vladimir Oltean > > Fixes: df198b37e72c ("iommu/arm-smmu: Report IOMMU_CAP_CACHE_COHERENCY better") > > Signed-off-by: Robin Murphy > > --- > > Could someone please apply this patch? Sorry, I missed that this was fixing a recent regression. I'll pick it up today and send it to Joerg. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel