drm/tegra: Acquire a reference to the IOVA cache (24cfdc1a) · Commits · 戴 / test

The IOVA API uses a memory cache to allocate IOVA nodes from. To make sure that this cache is available, obtain a reference to it and release the reference when the cache is no longer needed. On 64-bit ARM this is hidden by the fact that the DMA mapping API gets that reference and never releases it. On 32-bit ARM, however, the DMA mapping API doesn't do that, so allocation of IOVA nodes fails. Fixes: ("drm/tegra: Add Tegra DRM allocation API") Reviewed-by:

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

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

Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/drm.c

+9 −1

Original line number	Diff line number	Diff line
		@@ -113,6 +113,10 @@ static int tegra_drm_load(struct drm_device *drm, unsigned long flags)
		goto free;
		}

		err = iova_cache_get();
		if (err < 0)
		goto domain;

		geometry = &tegra->domain->geometry;
		gem_start = geometry->aperture_start;
		gem_end = geometry->aperture_end - CARVEOUT_SZ;
		@@ -207,8 +211,11 @@ config:
		mutex_destroy(&tegra->mm_lock);
		drm_mm_takedown(&tegra->mm);
		put_iova_domain(&tegra->carveout.domain);
		iommu_domain_free(tegra->domain);
		iova_cache_put();
		}
		domain:
		if (tegra->domain)
		iommu_domain_free(tegra->domain);
		free:
		kfree(tegra);
		return err;
		@@ -233,6 +240,7 @@ static void tegra_drm_unload(struct drm_device *drm)
		mutex_destroy(&tegra->mm_lock);
		drm_mm_takedown(&tegra->mm);
		put_iova_domain(&tegra->carveout.domain);
		iova_cache_put();
		iommu_domain_free(tegra->domain);
		}

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