drm/tegra: Detach devices from IOMMU DMA domain on arm32 (5ac93f81) · Commits · 戴 / test

All Tegra DRM devices are getting attached to an implicit IOMMU DMA domain if CONFIG_ARM_DMA_USE_IOMMU=y. Since Tegra DRM driver manages IOMMU by itself, the devices must be detached from the implicit domain using arch-specific IOMMU-API. Note that this works only for arm32 and not for arm64, which will remain broken if CONFIG_IOMMU_DMA is enabled. Signed-off-by:

Dmitry Osipenko <digetx@gmail.com> Signed-off-by:

Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/drm.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -15,6 +15,10 @@
		#include <drm/drm_atomic.h>
		#include <drm/drm_atomic_helper.h>

		#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
		#include <asm/dma-iommu.h>
		#endif

		#include "drm.h"
		#include "gem.h"

		@@ -1068,6 +1072,14 @@ struct iommu_group host1x_client_iommu_attach(struct host1x_client client,
		}

		if (!shared \|\| (shared && (group != tegra->group))) {
		#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
		if (client->dev->archdata.mapping) {
		struct dma_iommu_mapping *mapping =
		to_dma_iommu_mapping(client->dev);
		arm_iommu_detach_device(client->dev);
		arm_iommu_release_mapping(mapping);
		}
		#endif
		err = iommu_attach_group(tegra->domain, group);
		if (err < 0) {
		iommu_group_put(group);

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