1 files changed, 10 insertions, 2 deletions

diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index 8672f5d2f237..424569b53e57 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -128,12 +128,14 @@ static int tegra_bo_iommu_map(struct tegra_drm *tegra, struct tegra_bo *bo)
         if (!bo->mm)
                 return -ENOMEM;
 
+        mutex_lock(&tegra->mm_lock);
+
         err = drm_mm_insert_node_generic(&tegra->mm,
                                          bo->mm, bo->gem.size, PAGE_SIZE, 0, 0);
         if (err < 0) {
                 dev_err(tegra->drm->dev, "out of I/O virtual memory: %zd\n",
                         err);
-                goto free;
+                goto unlock;
         }
 
         bo->paddr = bo->mm->start;
@@ -147,11 +149,14 @@ static int tegra_bo_iommu_map(struct tegra_drm *tegra, struct tegra_bo *bo)
 
         bo->size = err;
 
+        mutex_unlock(&tegra->mm_lock);
+
         return 0;
 
 remove:
         drm_mm_remove_node(bo->mm);
-free:
+unlock:
+        mutex_unlock(&tegra->mm_lock);
         kfree(bo->mm);
         return err;
 }
@@ -161,8 +166,11 @@ static int tegra_bo_iommu_unmap(struct tegra_drm *tegra, struct tegra_bo *bo)
         if (!bo->mm)
                 return 0;
 
+        mutex_lock(&tegra->mm_lock);
         iommu_unmap(tegra->domain, bo->paddr, bo->size);
         drm_mm_remove_node(bo->mm);
+        mutex_unlock(&tegra->mm_lock);
+
         kfree(bo->mm);
 
         return 0;