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[142.167.56.70]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-4abb4980463sm6903981cf.12.2025.07.18.06.26.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 18 Jul 2025 06:26:23 -0700 (PDT) Received: from jgg by wakko with local (Exim 4.97) (envelope-from ) id 1ucl6U-00000009yt2-29EA; Fri, 18 Jul 2025 10:26:22 -0300 Date: Fri, 18 Jul 2025 10:26:22 -0300 From: Jason Gunthorpe To: Robin Murphy Cc: Will Deacon , Benjamin Gaignard , joro@8bytes.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, heiko@sntech.de, nicolas.dufresne@collabora.com, 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 Subject: Re: [PATCH v6 3/5] iommu: Add verisilicon IOMMU driver Message-ID: <20250718132622.GC2206214@ziepe.ca> References: <20250710082450.125585-1-benjamin.gaignard@collabora.com> <20250710082450.125585-4-benjamin.gaignard@collabora.com> 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=us-ascii Content-Disposition: inline In-Reply-To: On Fri, Jul 18, 2025 at 01:56:36PM +0100, Robin Murphy wrote: > All they really have in common is that they're 2-level formats with 32-bit > PTEs and 10 bits per level (as is tegra-smmu too). The permission encodings > have some overlap but are not fully equivalent. Crucially, the schemes for > packing >32-bit PAs into PTEs are incompatibly different, so if you're > really keen to genericise things to *that* extent, that's what Jason's > already working on. Right, I agree with this. The page table code is duplicated extensively across iommu and the way to fix it is what I'm working on. It is all the same code, same patterns, same problems, same bugs :) I think it is best to leave this as is for now. Jason