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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57974CCA47F for ; Thu, 23 Jun 2022 07:13:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230199AbiFWHNl (ORCPT ); Thu, 23 Jun 2022 03:13:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229904AbiFWHNj (ORCPT ); Thu, 23 Jun 2022 03:13:39 -0400 Received: from mail-lf1-x135.google.com (mail-lf1-x135.google.com [IPv6:2a00:1450:4864:20::135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 43E1E457AF; Thu, 23 Jun 2022 00:13:38 -0700 (PDT) Received: by mail-lf1-x135.google.com with SMTP id f39so16144887lfv.3; Thu, 23 Jun 2022 00:13:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version; bh=HKFgy2ePSsWBd5WuvWRCAAgtGzNsGiovMzKJw9WuAWA=; b=YHqD16i1gy7q5AU1NQ3/V1N310bWjVPrieL93A3boF19PSadG6dWxkVlfmG842U47g 74r/2zMgBXhaCoa8PyF27NUbb49451lSdYuvYHjO1SH4Z7CLaEO7qbFB8v5IYhWSq3in KAlV+lxQcrfa+6sMhYT/L1EEvAMQgiFeRS4Ppis5ftyOo2GJrVhQLlSIG4NkPzHWUcP0 n5aIft2UUuStF45XBP1WPOoleMZ3qWKjk3iqQKtHYN7iDfelqf+/GRsPE5atiyleDAH6 FLhnCHEU0i85+0ALhH3ZHYriyxt0/Wh58BDqsU/4rm1kv/x79LyFg0fQpqcCnbxFvr39 M9HA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version; bh=HKFgy2ePSsWBd5WuvWRCAAgtGzNsGiovMzKJw9WuAWA=; b=fztBsPh7Bkwa+Oqu3oHXs/Rqi/zxmIHsAs9KNW7g0es7csAxrdlqgh0QzicgMNkrVg 9lVdBhv5GgB4u2YeZO9GuqlryW5swIhpOgUPgnzVDaRnn8xEsDpvoniMaJqS7hf2AFp0 cQMpMrN/AOgFrsifF2mkny83HK4MKQH3vrbADzTLwQTNKVECG3NFCOOjYDvEG3sgGK2I 2xL6niUXnfpguW46O1IoxIjwzcnIDMvSP3GGJ4QC1v+5clkPcgvOFuYzXO6d4mM7ziLK hHCK/ZEuczTyb2muQLEXMOsNmGn6JfW7fb+mBnxHHd+Wz4EB2sMoNqmjt+pQ40C0+y3V qa4g== X-Gm-Message-State: AJIora+ks9bcNgdt3tnGzT3g8++1xAUiprBG/dfnI0FfZOyQQ8eVGMdP GAxzwrQ0IO2GTuyB2jgsST8= X-Google-Smtp-Source: AGRyM1tQKqOwQskRGxDVvZp5ecHNyZRyMLFkiEcuNVszS7TJ5maJeX2lgHeXtpbyA72kS7dUtzTlrQ== X-Received: by 2002:a05:6512:3f15:b0:477:ce24:4e1f with SMTP id y21-20020a0565123f1500b00477ce244e1fmr4473530lfa.355.1655968416440; Thu, 23 Jun 2022 00:13:36 -0700 (PDT) Received: from eldfell ([194.136.85.206]) by smtp.gmail.com with ESMTPSA id q20-20020a2eb4b4000000b0025a6a8bdcc7sm1655874ljm.1.2022.06.23.00.13.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Jun 2022 00:13:36 -0700 (PDT) Date: Thu, 23 Jun 2022 10:13:26 +0300 From: Pekka Paalanen To: Christian =?UTF-8?B?S8O2bmln?= Cc: Daniel Stone , Nicolas Dufresne , Daniel Vetter , "Sharma, Shashank" , lkml , dri-devel , linaro-mm-sig@lists.linaro.org, Sumit Semwal , linux-media Subject: Re: DMA-buf and uncached system memory Message-ID: <20220623101326.18beeab3@eldfell> In-Reply-To: References: <91ff0bbb-ea3a-2663-3453-dea96ccd6dd8@amd.com> <9178e19f5c0e141772b61b759abaa0d176f902b6.camel@ndufresne.ca> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: multipart/signed; boundary="Sig_/QmOTkLNi2kJF4_bkXoJdUR3"; protocol="application/pgp-signature"; micalg=pgp-sha256 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --Sig_/QmOTkLNi2kJF4_bkXoJdUR3 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Thu, 23 Jun 2022 08:59:41 +0200 Christian K=C3=B6nig wrote: > The exporter isn't doing anything wrong here. DMA-buf are supposed to be= =20 > CPU cached and can also be cache hot. Hi, what is that statement based on? Were the (mandatory for CPU access) cpu_access_begin/end functions & ioctls not supposed to ensure that CPU cache is up-to-date / CPU cache is fully flushed out? Thanks, pq --Sig_/QmOTkLNi2kJF4_bkXoJdUR3 Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEJQjwWQChkWOYOIONI1/ltBGqqqcFAmK0EpYACgkQI1/ltBGq qqcw7w//QVXYLoKhIBnGN34yEmHzycIRr1pys6yOt0O61O+o3mO+5B9sUxkiNZT7 AOtn1CRxJMBYC0sTSWhi6TZyN6MP0GW80CMGtCLmLCb8T19U7CBsBflVtc8e0aM8 GXiSbIW3BJEt2pXAUa+jVDeI7TyVjw6it6k21PVv6EV/iIR84BYuGZIBbOwRi/UU A3aNvFyTfhbi5fHwZJxgkv6SLsRBgTkHnyAVOcJ90FJgz1mHYONcsZKGp6q77tAt r9+jBo+5HWfPZSzAAcJg9tIGr77VNjq0YX/jj4R7MWd5Sb2EPFR0df3mXvIIQNR+ 7LqslvdNaaQkfh23bcGXvtbOgceboy+DUj/rPvC0eHQnGUop/hTJySw9p6n7QU3Z q8ubKBzmWllcwNhwnb/aun23LBuBh4Nx5RI+oxg8Bwz4uvMg9WK0cjGm+AInFLTU +GmmjUw2NK7jLF13Iu8n+5Z2SsxjAojoIsKQSkdH1buFdEcQNp2lzZH8RjIAkOGC 4D5AQMl0t891tH0XXRWxC3HOGi1RdfS1NzgG/mrG41NLdCG/bq79xsP56cFVUceb ACGl3uxrxlabcFxEiP9peR8ebtEnRn0ZCRcpd02RgIgsM7+jzuuOZ8EdBGBK+fVz fuz2KKG0X7sQT/03x7Zbi0VQWf8SAR1C9JBkiJsLjvOkFBZV4Gc= =WrtI -----END PGP SIGNATURE----- --Sig_/QmOTkLNi2kJF4_bkXoJdUR3-- 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 74A23C433EF for ; Thu, 23 Jun 2022 07:13:40 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E20BB113BC2; Thu, 23 Jun 2022 07:13:39 +0000 (UTC) Received: from mail-lf1-x132.google.com (mail-lf1-x132.google.com [IPv6:2a00:1450:4864:20::132]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5A827113BCE for ; Thu, 23 Jun 2022 07:13:38 +0000 (UTC) Received: by mail-lf1-x132.google.com with SMTP id i18so18140989lfu.8 for ; Thu, 23 Jun 2022 00:13:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version; bh=HKFgy2ePSsWBd5WuvWRCAAgtGzNsGiovMzKJw9WuAWA=; b=YHqD16i1gy7q5AU1NQ3/V1N310bWjVPrieL93A3boF19PSadG6dWxkVlfmG842U47g 74r/2zMgBXhaCoa8PyF27NUbb49451lSdYuvYHjO1SH4Z7CLaEO7qbFB8v5IYhWSq3in KAlV+lxQcrfa+6sMhYT/L1EEvAMQgiFeRS4Ppis5ftyOo2GJrVhQLlSIG4NkPzHWUcP0 n5aIft2UUuStF45XBP1WPOoleMZ3qWKjk3iqQKtHYN7iDfelqf+/GRsPE5atiyleDAH6 FLhnCHEU0i85+0ALhH3ZHYriyxt0/Wh58BDqsU/4rm1kv/x79LyFg0fQpqcCnbxFvr39 M9HA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version; bh=HKFgy2ePSsWBd5WuvWRCAAgtGzNsGiovMzKJw9WuAWA=; b=FEGym+5Q21tNPH87FCvW1eKPqs0jtt7msagFu5DnzJIjtP8qk+z0buM5nfT7fGhdnz 9rAMIUgDyan0YwFlQAF+wnEzL4cby22SmJ99Orq4Gb4sGMcGjKZJv41d5xz/redbMnkN /XMbpf9t/4TvvL3eWyAB9efi/1RNj/iAwSKZNeqju65NnTMs6/AmT3Mfp9Qwke44YfPF Fee2xOWcG1mNMUeEoP1SWaY4y+osbpft/sTX3wcDX57GuMh0Pwh/J94DreHQNCIf1g2I 7imlSVbttANMJRfqihkMKLvD0l605CZA+AX3u4w9lN7C2/u4l+u1qdrtf+cWYnKnAXCl 2xEg== X-Gm-Message-State: AJIora/7L0E+6bKmljDEdtplxOTK7nXNLz4Lh/xvyxy9R1IyzciDGTYi 1sNJyHLo5X1utfidTBLEuvg= X-Google-Smtp-Source: AGRyM1tQKqOwQskRGxDVvZp5ecHNyZRyMLFkiEcuNVszS7TJ5maJeX2lgHeXtpbyA72kS7dUtzTlrQ== X-Received: by 2002:a05:6512:3f15:b0:477:ce24:4e1f with SMTP id y21-20020a0565123f1500b00477ce244e1fmr4473530lfa.355.1655968416440; Thu, 23 Jun 2022 00:13:36 -0700 (PDT) Received: from eldfell ([194.136.85.206]) by smtp.gmail.com with ESMTPSA id q20-20020a2eb4b4000000b0025a6a8bdcc7sm1655874ljm.1.2022.06.23.00.13.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Jun 2022 00:13:36 -0700 (PDT) Date: Thu, 23 Jun 2022 10:13:26 +0300 From: Pekka Paalanen To: Christian =?UTF-8?B?S8O2bmln?= Subject: Re: DMA-buf and uncached system memory Message-ID: <20220623101326.18beeab3@eldfell> In-Reply-To: References: <91ff0bbb-ea3a-2663-3453-dea96ccd6dd8@amd.com> <9178e19f5c0e141772b61b759abaa0d176f902b6.camel@ndufresne.ca> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: multipart/signed; boundary="Sig_/QmOTkLNi2kJF4_bkXoJdUR3"; protocol="application/pgp-signature"; micalg=pgp-sha256 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: "Sharma, Shashank" , lkml , dri-devel , Nicolas Dufresne , linaro-mm-sig@lists.linaro.org, Sumit Semwal , linux-media Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" --Sig_/QmOTkLNi2kJF4_bkXoJdUR3 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Thu, 23 Jun 2022 08:59:41 +0200 Christian K=C3=B6nig wrote: > The exporter isn't doing anything wrong here. DMA-buf are supposed to be= =20 > CPU cached and can also be cache hot. Hi, what is that statement based on? Were the (mandatory for CPU access) cpu_access_begin/end functions & ioctls not supposed to ensure that CPU cache is up-to-date / CPU cache is fully flushed out? Thanks, pq --Sig_/QmOTkLNi2kJF4_bkXoJdUR3 Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEJQjwWQChkWOYOIONI1/ltBGqqqcFAmK0EpYACgkQI1/ltBGq qqcw7w//QVXYLoKhIBnGN34yEmHzycIRr1pys6yOt0O61O+o3mO+5B9sUxkiNZT7 AOtn1CRxJMBYC0sTSWhi6TZyN6MP0GW80CMGtCLmLCb8T19U7CBsBflVtc8e0aM8 GXiSbIW3BJEt2pXAUa+jVDeI7TyVjw6it6k21PVv6EV/iIR84BYuGZIBbOwRi/UU A3aNvFyTfhbi5fHwZJxgkv6SLsRBgTkHnyAVOcJ90FJgz1mHYONcsZKGp6q77tAt r9+jBo+5HWfPZSzAAcJg9tIGr77VNjq0YX/jj4R7MWd5Sb2EPFR0df3mXvIIQNR+ 7LqslvdNaaQkfh23bcGXvtbOgceboy+DUj/rPvC0eHQnGUop/hTJySw9p6n7QU3Z q8ubKBzmWllcwNhwnb/aun23LBuBh4Nx5RI+oxg8Bwz4uvMg9WK0cjGm+AInFLTU +GmmjUw2NK7jLF13Iu8n+5Z2SsxjAojoIsKQSkdH1buFdEcQNp2lzZH8RjIAkOGC 4D5AQMl0t891tH0XXRWxC3HOGi1RdfS1NzgG/mrG41NLdCG/bq79xsP56cFVUceb ACGl3uxrxlabcFxEiP9peR8ebtEnRn0ZCRcpd02RgIgsM7+jzuuOZ8EdBGBK+fVz fuz2KKG0X7sQT/03x7Zbi0VQWf8SAR1C9JBkiJsLjvOkFBZV4Gc= =WrtI -----END PGP SIGNATURE----- --Sig_/QmOTkLNi2kJF4_bkXoJdUR3--