From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 AFCE13C65F2; Thu, 2 Jul 2026 09:20:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782984005; cv=none; b=HQdXlC/XM74p6u1VAG3YRv30o0PvT3w9DIx7kfkHLA/HTsRNdcvhSeg58Tj5xg/sACyiJFzIxd5mcZM2MeeROGFyNVH2sNfeEwL1BZF5f6g7+QfazIw9CHV78qi3dC2C04VchC1vhcFdqzisnzNri2cD3csb5qvc0fvnFg/0EoE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782984005; c=relaxed/simple; bh=S8HugMjxHFbPNvLg+AAYFwaWDIzsdO1q5qMD3yZa1ic=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cEAcNiscdh08ooM8IVI1gm3Nnm3z34qmbLmS9Nqk++BoAkfTSSE7QQ5bmopQwsGVJhjvbZO2Fyj9It9Qg3IUkIDrLdJ9P+bf7plUvY30qHceF11itzrQs8CP6Lu0Yg6gwSfrMwUd/Zch+Dzu5hpqVf1xaxPGZytXURxF20OAXus= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=csWmZYUC; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="csWmZYUC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3179D1F000E9; Thu, 2 Jul 2026 09:19:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782984004; bh=krb+dDOShP/VdQBJzNgKxbwj/+Edag23SSgoQwI13H8=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=csWmZYUC4S9Nl6WrP1bTUNqSv20R6fPVTF+KG1Cmg4Dj4DYI1f3yts+zZ5SFuSxLE 1zPcsdAMtlXsGeuD40TVFAs2oF468naHHJOCp0j/1bFoVDTNF6O7cSdv1QHcUl8cr1 EW6MIUu8XQAwz74SIdBY2YpAOeihb71togX+9u2JNdB6lg2m2cPNh6B+BHirU09w5I RKwcx2Ycjot9IrFfgVli3rPKjJzw+RV8X3QtfO29MXfAD1a8jPLHvfU0nHbSXEKo7Z 7pwjC3c7iadUtI3cUSa0bj4W+vUlp5rmb1/SIDADt3Q/PVKz8CiTd3VtiiPObNQSHp ybamgLGQIRuGw== Date: Thu, 2 Jul 2026 10:18:47 +0100 From: Will Deacon 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 , 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 , Chun Ng Subject: Re: [PATCH v3 04/11] arm64/mm: Add set_memory_device() and set_memory_normal() Message-ID: References: <20260701-tegra-vpr-v3-0-d80f7b871bb4@nvidia.com> <20260701-tegra-vpr-v3-4-d80f7b871bb4@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: <20260701-tegra-vpr-v3-4-d80f7b871bb4@nvidia.com> On Wed, Jul 01, 2026 at 06:08:15PM +0200, Thierry Reding wrote: > From: Chun Ng > > Add helpers to swap PROT_NORMAL and PROT_DEVICE_nGnRnE protection bits > on a kernel-linear-map range. That sounds like a really terrible idea. Why is this necessary and how does it interact with things like load_unaligned_zeropad()? I think you should unmap the memory from the linear map and memremap() it instead. Will