2 files changed, 31 insertions, 1 deletions
diff --git a/rust/helpers/dma.c b/rust/helpers/dma.c
index 6e741c197242..2afa32c21c94 100644
--- a/rust/helpers/dma.c
+++ b/rust/helpers/dma.c
@@ -19,3 +19,24 @@ int rust_helper_dma_set_mask_and_coherent(struct device *dev, u64 mask)
 {
 	return dma_set_mask_and_coherent(dev, mask);
 }
+
+int rust_helper_dma_set_mask(struct device *dev, u64 mask)
+{
+	return dma_set_mask(dev, mask);
+}
+
+int rust_helper_dma_set_coherent_mask(struct device *dev, u64 mask)
+{
+	return dma_set_coherent_mask(dev, mask);
+}
+
+int rust_helper_dma_map_sgtable(struct device *dev, struct sg_table *sgt,
+				enum dma_data_direction dir, unsigned long attrs)
+{
+	return dma_map_sgtable(dev, sgt, dir, attrs);
+}
+
+size_t rust_helper_dma_max_mapping_size(struct device *dev)
+{
+	return dma_max_mapping_size(dev);
+}
diff --git a/rust/kernel/maple_tree.rs b/rust/kernel/maple_tree.rs
index e72eec56bf57..265d6396a78a 100644
--- a/rust/kernel/maple_tree.rs
+++ b/rust/kernel/maple_tree.rs
@@ -265,7 +265,16 @@ impl<T: ForeignOwnable> MapleTree<T> {
         loop {
             // This uses the raw accessor because we're destroying pointers without removing them
             // from the maple tree, which is only valid because this is the destructor.
-            let ptr = ma_state.mas_find_raw(usize::MAX);
+            //
+            // Take the rcu lock because mas_find_raw() requires that you hold either the spinlock
+            // or the rcu read lock. This is only really required if memory reclaim might
+            // reallocate entries in the tree, as we otherwise have exclusive access. That feature
+            // doesn't exist yet, so for now, taking the rcu lock only serves the purpose of
+            // silencing lockdep.
+            let ptr = {
+                let _rcu = kernel::sync::rcu::Guard::new();
+                ma_state.mas_find_raw(usize::MAX)
+            };
             if ptr.is_null() {
                 break;
             }