[PATCH 0/2] iommu: Fix the longstanding probe issues
From: Robin Murphy
Date: Thu Feb 13 2025 - 18:49:28 EST
Hi all,
Finally, it's that thing I've been mentioning on and off for the last 5
years or so! After far too much thinking about "clean" ways to refactor
everything towards an eventual goal of working properly, I finally gave
up and decided to see how bad it would be to just get it working, then
worry about cleaning up afterwards. Frankly I still can't quiet believe
how small the patch turned out to be...
Patch #1 is a fix for what I think is the only "expected" race in the
core API design - we knew we had that window where a default domain is
NULL, but the potential consequences weren't clear until Charan figured
it out the hard way. That should be good to go already, and it's not
strictly a dependency for patch #2, but it seemed worth posting them
together on the common theme.
Patch #2 is then the first big bite out of the problem I feel compelled
to fix because it's my name on d7b0558230e4 ("iommu/of: Prepare for
deferred IOMMU configuration") which, in hindsight, started it. I hope
this will be the only patch which has to touch absolutely everything all
at once. I've not got very far with the follow-up patches yet, but I do
foresee being able to tackle the driver core, firmware subsystems and
bus drivers more independently. I don't expect anyone to love it, but I
hope you can at least see where I'm going and give a bit of leeway for
now :)
I also do rather expect that WARN_ON to be hit, but the intent is that
I'd like to get the attention of any of_dma_configure() abusers so they
can help me figure out what the heck their code *should* be doing...
Thanks,
Robin.
Robin Murphy (2):
iommu: Handle race with default domain setup
iommu: Get DT/ACPI parsing into the proper probe path
drivers/acpi/arm64/dma.c | 5 ++++
drivers/acpi/scan.c | 10 +++----
drivers/amba/bus.c | 2 +-
drivers/base/platform.c | 2 +-
drivers/bus/fsl-mc/fsl-mc-bus.c | 2 +-
drivers/cdx/cdx.c | 2 +-
drivers/iommu/iommu.c | 48 +++++++++++++++++++++++++--------
drivers/iommu/of_iommu.c | 10 ++++++-
drivers/of/device.c | 7 ++++-
drivers/pci/pci-driver.c | 2 +-
10 files changed, 65 insertions(+), 25 deletions(-)
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2.39.2.101.g768bb238c484.dirty