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Stefano Stabellini
ce75973a27
Backport commit 3714ce1d6655098ee69ede632883e5874d67e4ab "iommu/arm-smmu: Disable stalling faults for all endpoints" from the Linux kernel. This works-around Erratum #842869. Original commit message: Enabling stalling faults can result in hardware deadlock on poorly designed systems, particularly those with a PCI root complex upstream of the SMMU. Although it's not really Linux's job to save hardware integrators from their own misfortune, it *is* our job to stop userspace (e.g. VFIO clients) from hosing the system for everybody else, even if they might already be required to have elevated privileges. Given that the fault handling code currently executes entirely in IRQ context, there is nothing that can sensibly be done to recover from things like page faults anyway, so let's rip this code out for now and avoid the potential for deadlock. Cc: <stable@vger.kernel.org> Fixes: 48ec83bcbcf5 ("iommu/arm-smmu: Add initial driver support for ARM SMMUv3 devices") Reported-by: Matt Evans <matt.evans@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Stefano Stabellini <stefanos@xilinx.com> Acked-by: Julien Grall <julien.grall@arm.com>