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 DE80ACCF2DC for ; Mon, 19 Jan 2026 10:28:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=EsuevJkgsl5C8dp30TcVS68HeqiqukUtd3I4/TFexqc=; b=VwwFPBa2LJ3afRCdqEeRPeIZbl fT2K26KWdBFidwitfliS+L9QsXfF7bYx2E9hD3QHsad6rRSvTJBv4p9iGz+Xs2OCXxy2xs1x6HHIR IxcrFSFB4DIBDCDKzJ0cL5XZYCb3j8TS1fdQds5jl7Ph3E9wZsfz9raNrcWL5SeS117cjZbWAJJPh x+6a9lIxdPeCpO0UmPxl+Mczx2qXbhmRmHUNiitTLh5I1m6HdBMgOJn1mdwYA8cKW9Gw9GNoDuCzf GYLN68XYvtjwrkR4/ken5OzI+F0ExoAH4oofgY7wahmrWdmnL42Qe154sC1Bu9Wn/GgLCsRx17xx0 pgb47Ybg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vhmUs-00000001m60-3SEh; Mon, 19 Jan 2026 10:28:34 +0000 Received: from sender4-pp-f112.zoho.com ([136.143.188.112]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vhmUq-00000001m5X-1Mnl; Mon, 19 Jan 2026 10:28:33 +0000 ARC-Seal: i=1; a=rsa-sha256; t=1768818497; cv=none; d=zohomail.com; s=zohoarc; b=c2+Oc9wLMk54ge9fXvqUDFJyAAT7ec7rGEzKziR5QaN+z1z+rYOLC4VTelqvmOGmxAWYdKRr6O6s6MNKpwLXDhlL5lcGObgtP0rdHil9Vb0BGdsnIs4YglM6IDmVEaxWfWUQUdSpnEvc+N1CvCq+b7wf0NJz67YVdzuQZegORwk= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1768818497; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=EsuevJkgsl5C8dp30TcVS68HeqiqukUtd3I4/TFexqc=; b=PCpgNlj7n6I5+jp2Tf7Tr7dHfDi1tCAjsYDvdzMx5yFgbzZX6WT/h8sBwDUjW/hCqwYF0Ev65ozoN4kome1DuU0c3HYx8O/Q3KClOtdpMKpcdvH15iWcsAngNGweP3xIAGbiJSVfDmHKROVyhsDbXAFuGlYofF0jcARnDjD9J1M= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=benjamin.gaignard@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1768818497; s=zohomail; d=collabora.com; i=benjamin.gaignard@collabora.com; h=Message-ID:Date:Date:MIME-Version:Subject:Subject:To:To:Cc:Cc:References:From:From:In-Reply-To:Content-Type:Content-Transfer-Encoding:Message-Id:Reply-To; bh=EsuevJkgsl5C8dp30TcVS68HeqiqukUtd3I4/TFexqc=; b=IzMYIQ9xcILSyPL5IEgFBFGVo7j1D7ZBB9+pLkD8TJou1OhxL5m2aeY0mUG8sBsv Wv1ahwlZ/JxKsdyJ4LI5HiTSJL64r53/U8Kqgk1RJy/0aMnZ+lBkwQr9s8a6uXe7Fe1 Ncr7UNildBZ9+LxfW3aXn6Ywt29jhDAL6JPF1W+g= Received: by mx.zohomail.com with SMTPS id 1768818497079716.4924558723245; Mon, 19 Jan 2026 02:28:17 -0800 (PST) Message-ID: Date: Mon, 19 Jan 2026 11:28:11 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v11 3/7] iommu: Add verisilicon IOMMU driver To: =?UTF-8?B?SsO2cmcgUsO2ZGVs?= , Will Deacon Cc: robin.murphy@arm.com, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, heiko@sntech.de, nicolas.dufresne@collabora.com, p.zabel@pengutronix.de, mchehab@kernel.org, iommu@lists.linux.dev, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-media@vger.kernel.org, kernel@collabora.com References: <20260107101005.84039-1-benjamin.gaignard@collabora.com> <20260107101005.84039-4-benjamin.gaignard@collabora.com> Content-Language: en-US From: Benjamin Gaignard In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260119_022832_424923_03159957 X-CRM114-Status: GOOD ( 15.66 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Le 18/01/2026 à 10:41, Jörg Rödel a écrit : > Benjamin, > > On Tue, Jan 13, 2026 at 04:10:51PM +0000, Will Deacon wrote: >> I took another look at this to see whether it had changed significantly >> from v6 when compared to the rockchip driver. Sadly, they still look >> very similar to me and I continue to suspect that the hardware is a >> derivative. I really don't understand why having a shared implementation >> of the default domain ops is difficult or controversial. Have you tried >> to write it? > When updating for v12, can you please put an explanatory comment at the top of > the file explaining the relationship of the IP this driver is for to the > RockChip IOMMU and the rationale for having it as a separate driver? I want > this part of the discussion documented in the code in case it comes up again. Does the follow wording summarize the situation correctly for you if I put it in header comment ? * This hardware block is using a 2 pages tables allocation structure. * That make very similar to Rockhip iommu hardware blocks but it has * it own driver because the registers offset and configuration bits * are completely different. An additional raison is that this hardware * has been developped by Verisilicon to be used by their hardware video * decoders and for a general purpose like Rockchip iommus. Regards, Benjamin > > > -Joerg >