[PATCH 0/9] arm64: tegra: Prevent early SMMU faults

From: Thierry Reding <thierry.reding@gmail.com>
To: Thierry Reding <thierry.reding@gmail.com>,
	Will Deacon <will@kernel.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Joerg Roedel <joro@8bytes.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Cc: Jon Hunter <jonathanh@nvidia.com>,
	Nicolin Chen <nicolinc@nvidia.com>,
	Krishna Reddy <vdumpa@nvidia.com>,
	linux-tegra@vger.kernel.org, iommu@lists.linux-foundation.org,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH 0/9] arm64: tegra: Prevent early SMMU faults
Date: Thu, 25 Mar 2021 14:03:23 +0100	[thread overview]
Message-ID: <20210325130332.778208-1-thierry.reding@gmail.com> (raw)

From: Thierry Reding <treding@nvidia.com>

Hi,

this is a set of patches that is the result of earlier discussions
regarding early identity mappings that are needed to avoid SMMU faults
during early boot.

The goal here is to avoid early identity mappings altogether and instead
postpone the need for the identity mappings to when devices are attached
to the SMMU. This works by making the SMMU driver coordinate with the
memory controller driver on when to start enforcing SMMU translations.
This makes Tegra behave in a more standard way and pushes the code to
deal with the Tegra-specific programming into the NVIDIA SMMU
implementation.

Patches 1 and 2 are preparatory work that is used in patch 3 to provide
a mechanism to program SID overrides at runtime. Patches 4 and 5 create
the fundamentals in the SMMU driver to support this and also make this
functionality available on Tegra186. Patch 6 hooks the ARM SMMU up to
the memory controller so that the memory overrides can be programmed at
the right time.

Patch 7 extends this mechanism to Tegra186 and patches 8-9 enable all of
this through device tree updates.

The end result is that various peripherals will have SMMU enabled, while
the display controllers will keep using passthrough, as initially set up
by firmware. Once the device tree bindings have been accepted and the
SMMU driver has been updated to create identity mappings for the display
controllers, they can be hooked up to the SMMU and the code in this
series will automatically program the SID overrides to enable SMMU
translations at the right time.

Thierry

Thierry Reding (9):
  memory: tegra: Move internal data structures into separate header
  memory: tegra: Add memory client IDs to tables
  memory: tegra: Implement SID override programming
  iommu/arm-smmu: Implement ->probe_finalize()
  iommu/arm-smmu: tegra: Detect number of instances at runtime
  iommu/arm-smmu: tegra: Implement SID override programming
  iommu/arm-smmu: Use Tegra implementation on Tegra186
  arm64: tegra: Hook up memory controller to SMMU on Tegra186
  arm64: tegra: Enable SMMU support on Tegra194

 arch/arm64/boot/dts/nvidia/tegra186.dtsi     |   2 +
 arch/arm64/boot/dts/nvidia/tegra194.dtsi     |  86 ++++++
 drivers/iommu/arm/arm-smmu/arm-smmu-impl.c   |   3 +-
 drivers/iommu/arm/arm-smmu/arm-smmu-nvidia.c |  81 ++++--
 drivers/iommu/arm/arm-smmu/arm-smmu.c        |  17 ++
 drivers/iommu/arm/arm-smmu/arm-smmu.h        |   1 +
 drivers/iommu/tegra-gart.c                   |   2 +-
 drivers/iommu/tegra-smmu.c                   |   2 +-
 drivers/memory/tegra/mc.h                    |   2 +-
 drivers/memory/tegra/tegra186.c              | 288 ++++++++++++++++++-
 include/soc/tegra/mc-internal.h              |  62 ++++
 include/soc/tegra/mc.h                       |  60 +---
 12 files changed, 529 insertions(+), 77 deletions(-)
 create mode 100644 include/soc/tegra/mc-internal.h

-- 
2.30.2