From mboxrd@z Thu Jan 1 00:00:00 1970 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.subspace.kernel.org (Postfix) with ESMTPS id EB7903B14CD; Thu, 10 Sep 2026 05:52:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789019523; cv=none; b=fQjaEACBAGS4joc3ZQopb56QSlVKRUhWFm33/DTC2UZ8hbPhnQ+03bz8I02uwodZdv+FTtzQwG5kEyJBYVdsrm5Br0PwSzWCtwmwlLQ1QOmznZHWIzqgrIDDr9310WLZAeB0qVI/GXfX6vU8VJmoGPxVAI+K+YIpkwB4XZV5KZc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789019523; c=relaxed/simple; bh=eFkoKLMx6CWrBqLzh/2OAEjPMcLMJex/CnSZuYJAeB4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ZSpC9r/5zYKIfGeL5XnmMYlW4WIA5yMRGgqhtFIrE16yueqpxB3spXRaTTqKdiggzuRJm9TnPnEtVvr8v5yWvjazEN0UTJkRsgDqe6naaJzRB6EwotaIIhZsZb+ClXjYNOsUZXOEJalw594//Lx7Kstp6CEJePRMX9nPQj0n8PY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=2YEpsF2d; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="2YEpsF2d" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=dr2hlvGX1oeEKCxfnd5X9ajv/3V1RzuH6f6k+gKLa1I=; b=2YEpsF2dy4dF+E5OuE1/Zk6cNe QCygMlId9eCRm2NVbsLffeSSqzYB99gs9iLF5flp3UVvUh//R01ZysL5QM1R/nsZazvygWachsRy1 kqlHp5S2/99fGgHycoYYi/OGBrD8bvH8pyCKJjzQzmiAWUwSsFVcYy4xcFdR6BHD7Lp5m1LHvtkV2 aEPgjFnNYdipWh0pO1JY2H+aZOpxYJ5lrn1vkFQxdRjHOegKXlWcaGKZq8lUZLXjvjzDBRAklcON3 PWUYt2D20iByPA9g1u6y5Mm9bbo16VIWK8E7NgHiRbGGTdT5Ww4o10UajRwh/yOEqCHg2Jg8tcB6Z b0GhXEgQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.99.1 #2 (Red Hat Linux)) id 1x4XhH-0000000DTvB-33x3; Thu, 10 Sep 2026 05:51:43 +0000 Date: Wed, 9 Sep 2026 22:51:43 -0700 From: Christoph Hellwig To: Thierry Reding Cc: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jonathan Hunter , David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Sowjanya Komatineni , Luca Ceresoli , Mikko Perttunen , Yury Norov , Rasmus Villemoes , Russell King , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Marek Szyprowski , Robin Murphy , Sumit Semwal , Benjamin Gaignard , Brian Starkey , John Stultz , "T.J. Mercier" , Christian =?iso-8859-1?Q?K=F6nig?= , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Catalin Marinas , Will Deacon , Chun Ng , Mark Rutland , Saravana Kannan , Thierry Reding , devicetree@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux.dev, linaro-mm-sig@lists.linaro.org, linux-trace-kernel@vger.kernel.org, Thierry Reding Subject: Re: [PATCH v6 04/12] arm64/mm: Export set_direct_map_*_noflush() APIs Message-ID: References: <20260904-tegra-vpr-v6-0-79042cfa8de5@nvidia.com> <20260904-tegra-vpr-v6-4-79042cfa8de5@nvidia.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260904-tegra-vpr-v6-4-79042cfa8de5@nvidia.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Fri, Sep 04, 2026 at 12:44:55PM +0200, Thierry Reding wrote: > From: Thierry Reding > > Drivers that use this may want to be built as a module, so export them. That's one of the worst commit log ever. No, we don't just export core symbols dealing with the kernel direct map because "Drivers that use this may want to be built as a module". For one exporting this at all needs a very good justification and not just hand waiving. But more importantly if we can't avoid exporting it, it needs to be exported at the tightest sensible scope. E.g. for a given module if it is so special, or a namespace if it's not that special. But in doubt we should have a proper core abstraction instead of opening up direct map manipulation to random modules.