drm/tegra: Acquire a reference to the IOVA cache
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: ad92601521ea ("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>
diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index 7b9f73b..3cdef65 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -113,6 +113,10 @@
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 @@
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 @@
mutex_destroy(&tegra->mm_lock);
drm_mm_takedown(&tegra->mm);
put_iova_domain(&tegra->carveout.domain);
+ iova_cache_put();
iommu_domain_free(tegra->domain);
}