From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4DEE0288C08; Tue, 16 Sep 2025 08:48:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758012520; cv=none; b=rcNOtwuHPP3S0UMv56fiTC9zx+oiJUvIpmQJrTB5t520FjSki26tNENeNI5JGIuapfi6/1Zq+qxAXoiQMtm9uaC5M5JiwCpml+k8WQEsHcef2VURLht/riUVJxiG3QEUSxKpanAzx6/ToF8aFY2h07kTihCqOYn2Jmz8w6IYJk8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758012520; c=relaxed/simple; bh=gBC89acRt2ZWThI6GiBXUA4qAUTNm8vCd8qyDvzjiZE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=u5W+aFDMTUogwMSg58UBKNBUnxGI5STyoYkqqAPu8jiu+mwAiLod0UuISxxC/gFQqbdKw5yeEXtkQ82OSpI6/rtxlrxWF1shwYZMa78FVH9JEivDeXc/qIjPQUByQtrXw7Mt+aWlaib9g27j4lw95W9b5tm5Texi1CI/kmGi8lY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=m7LdLz0v; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="m7LdLz0v" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A88BFC4CEEB; Tue, 16 Sep 2025 08:48:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1758012519; bh=gBC89acRt2ZWThI6GiBXUA4qAUTNm8vCd8qyDvzjiZE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=m7LdLz0vXRu1QDRO3ZuQvA3+jqh3JxhTQHX8IW4VHNOE6jLAJTC8Gk87eluIh4jMT bli4cXARt8ZQ6n6iqCiYQqtVy69DTegtOxc8LKakwQKUEqA2ZHBE2k+mYufiJ3o/h7 qesqNhorL9QrNX78rRFFprSYoXlFml9tgAj1rkmlm6pyvZupIiXfDuOty7eTB9qDqo CouLVJhpNf8Pm+Q7rzYldmyitAeHqbukysVTR/mjP/u05hEnXKBbZCt/KRGpHXsHfJ +n8uUiWSVq10XIvunL3dTV/12Q4aEpBQsfBiiIxiFvqrecpRpSlZT0oZuc1Pk+VoTO +1DIAmhw7/dug== Date: Tue, 16 Sep 2025 09:48:33 +0100 From: Will Deacon To: Jason Gunthorpe Cc: =?iso-8859-1?Q?J=F6rg_R=F6del?= , Nicolas Dufresne , Benjamin Gaignard , robin.murphy@arm.com, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, heiko@sntech.de, 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, kernel@collabora.com, linux-media@vger.kernel.org Subject: Re: [PATCH v9 3/7] iommu: Add verisilicon IOMMU driver Message-ID: References: <20250911155720.180465-1-benjamin.gaignard@collabora.com> <20250911155720.180465-4-benjamin.gaignard@collabora.com> <694b9ba15cd67f41a38f4a65a3811f035cf8e99d.camel@collabora.com> <20250915225806.GM882933@ziepe.ca> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250915225806.GM882933@ziepe.ca> On Mon, Sep 15, 2025 at 07:58:06PM -0300, Jason Gunthorpe wrote: > On Sat, Sep 13, 2025 at 07:58:04AM +0200, Jörg Rödel wrote: > > [Adding Will back to Cc] > > > > On Fri, Sep 12, 2025 at 01:37:11PM -0400, Nicolas Dufresne wrote: > > > To me this rejection isn't about Benjamin's driver, all iommu seems to look > > > alike, so anyone else that would have sent new driver would have face the same > > > issue. > > > > This is about ignoring comments from one of the IOMMU maintainers. I am not > > going to merge a driver with open comments/objections[1] from Will (and a few > > others), so resolve this with him and get his Ack. > > I would strongly object to trying to share map_pages, unmap_pages, > iova_to_phys, free and other iommu pt related functions in some > limited way instead of helping on the much more complete iommu pt > work. Which is what I said to Will, but for some reason he suggested > it anyhow. If the answer is to convert this to iommu pt, then so be it. My understanding was that was still premature at this stage but you know better than me. When I bothered to look at this driver side-by-side with the rockchip driver which, despite apparently being totally different IP (honest!), is *remarkably* similar, I summarised the similarity in the default domain ops: https://lore.kernel.org/all/aH5yR9CkYSJ4PaZV@willie-the-truck/ But rather than respond to that, Benjamin just sent a new version. I was hoping for a bit more discussion... > Sorry, but it doesn't make sense to complain about duplication in > drivers and then not help advance one of the biggest projects to > actually concretely and comprehensively address that duplication. I don't think it needs to be one or the other. afaict, these drivers should share the default domain ops and if the page-table code is using iommu-pt then that's even better. Will