drm/tegra: gem: Take into account IOMMU aperture (4553f733) · Commits · 戴 / test

The IOMMU may not always be able to address 2 GiB of memory. On Tegra20, the GART supports 32 MiB starting at 0x58000000. Also the aperture on Tegra30 and later is in fact the full 4 GiB, rather than just 2 GiB as currently assumed. Signed-off-by:

Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/drm.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -124,14 +124,22 @@ static int tegra_drm_load(struct drm_device *drm, unsigned long flags)
		return -ENOMEM;

		if (iommu_present(&platform_bus_type)) {
		struct iommu_domain_geometry *geometry;
		u64 start, end;

		tegra->domain = iommu_domain_alloc(&platform_bus_type);
		if (!tegra->domain) {
		err = -ENOMEM;
		goto free;
		}

		DRM_DEBUG("IOMMU context initialized\n");
		drm_mm_init(&tegra->mm, 0, SZ_2G);
		geometry = &tegra->domain->geometry;
		start = geometry->aperture_start;
		end = geometry->aperture_end;

		DRM_DEBUG("IOMMU context initialized (aperture: %#llx-%#llx)\n",
		start, end);
		drm_mm_init(&tegra->mm, start, end - start + 1);
		}

		mutex_init(&tegra->clients_lock);

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