[PATCH v2 0/3] iommu: Enable non-strict DMA on QCom SD/MMC

From: Douglas Anderson <dianders@chromium.org>
To: will@kernel.org, robin.murphy@arm.com, joro@8bytes.org,
	bjorn.andersson@linaro.org, ulf.hansson@linaro.org,
	adrian.hunter@intel.com, bhelgaas@google.com
Cc: john.garry@huawei.com, robdclark@chromium.org,
	quic_c_gdjako@quicinc.com, saravanak@google.com,
	rajatja@google.com, saiprakash.ranjan@codeaurora.org,
	vbadigan@codeaurora.org, linux-mmc@vger.kernel.org,
	linux-arm-msm@vger.kernel.org, linux-pci@vger.kernel.org,
	iommu@lists.linux-foundation.org, sonnyrao@chromium.org,
	joel@joelfernandes.org, Douglas Anderson <dianders@chromium.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Jonathan Corbet <corbet@lwn.net>,
	Jordan Crouse <jordan@cosmicpenguin.net>,
	Konrad Dybcio <konrad.dybcio@somainline.org>,
	Krishna Reddy <vdumpa@nvidia.com>,
	"Maciej W. Rozycki" <macro@orcam.me.uk>,
	Nicolin Chen <nicoleotsuka@gmail.com>,
	"Paul E. McKenney" <paulmck@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	Thierry Reding <thierry.reding@gmail.com>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Vlastimil Babka <vbabka@suse.cz>,
	linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v2 0/3] iommu: Enable non-strict DMA on QCom SD/MMC
Date: Thu, 24 Jun 2021 10:17:56 -0700	[thread overview]
Message-ID: <20210624171759.4125094-1-dianders@chromium.org> (raw)

The goal of this patch series is to get better SD/MMC performance on
Qualcomm eMMC controllers and in generally nudge us forward on the
path of allowing some devices to be in strict mode and others to be in
non-strict mode. This patch series doesn't save the world but
hopefully at least moves us in the right direction while accomplishing
something useful. Specifically:
- No attempt is made to touch the PCI subsystem or cleanup the way
  that it requests strict vs. non-strict.
- No fully generic mechanism is come up with that makes it super easy
  for everyone to be in non-strict mode.

This patch conflicts with a few other patch series that are in
flight. I've tried to call them out "after the cut" in patches. I
assume other in flight patches will land before this one, so I'd
expect to send a rebased version when that happens, assuming that this
series isn't NAKed into the ground.

Changes in v2:
- No longer based on changes adding strictness to "struct device"
- Updated kernel-parameters docs.
- Patch moving check for strictness in arm-smmu new for v2.
- Now accomplish the goal by putting rules in the IOMMU driver.
- Reworded commit message to clarify things pointed out by Greg.

Douglas Anderson (3):
  iommu: Add per-domain strictness and combine with the global default
  iommu/arm-smmu: Check for strictness after calling
    impl->init_context()
  mmc: sdhci-msm: Request non-strict IOMMU mode

 .../admin-guide/kernel-parameters.txt         |  5 ++-
 drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c    | 19 ++++++++
 drivers/iommu/arm/arm-smmu/arm-smmu.c         |  6 +--
 drivers/iommu/iommu.c                         | 43 +++++++++++++++----
 include/linux/iommu.h                         |  7 +++
 5 files changed, 67 insertions(+), 13 deletions(-)

-- 
2.32.0.93.g670b81a890-goog