1 files changed, 72 insertions, 0 deletions

diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c
index 55e8f5ed8b3c..2aadf5813a40 100644
--- a/drivers/infiniband/core/umem_odp.c
+++ b/drivers/infiniband/core/umem_odp.c
@@ -39,11 +39,44 @@
 #include <linux/export.h>
 #include <linux/vmalloc.h>
 #include <linux/hugetlb.h>
+#include <linux/interval_tree_generic.h>
 
 #include <rdma/ib_verbs.h>
 #include <rdma/ib_umem.h>
 #include <rdma/ib_umem_odp.h>
 
+/*
+ * The ib_umem list keeps track of memory regions for which the HW
+ * device request to receive notification when the related memory
+ * mapping is changed.
+ *
+ * ib_umem_lock protects the list.
+ */
+
+static u64 node_start(struct umem_odp_node *n)
+{
+	struct ib_umem_odp *umem_odp =
+			container_of(n, struct ib_umem_odp, interval_tree);
+
+	return ib_umem_start(umem_odp->umem);
+}
+
+/* Note that the representation of the intervals in the interval tree
+ * considers the ending point as contained in the interval, while the
+ * function ib_umem_end returns the first address which is not contained
+ * in the umem.
+ */
+static u64 node_last(struct umem_odp_node *n)
+{
+	struct ib_umem_odp *umem_odp =
+			container_of(n, struct ib_umem_odp, interval_tree);
+
+	return ib_umem_end(umem_odp->umem) - 1;
+}
+
+INTERVAL_TREE_DEFINE(struct umem_odp_node, rb, u64, __subtree_last,
+		     node_start, node_last, static, rbt_ib_umem)
+
 static void ib_umem_notifier_start_account(struct ib_umem *item)
 {
 	mutex_lock(&item->odp_data->umem_mutex);
@@ -754,3 +787,42 @@ void ib_umem_odp_unmap_dma_pages(struct ib_umem *umem, u64 virt,
 	mutex_unlock(&umem->odp_data->umem_mutex);
 }
 EXPORT_SYMBOL(ib_umem_odp_unmap_dma_pages);
+
+/* @last is not a part of the interval. See comment for function
+ * node_last.
+ */
+int rbt_ib_umem_for_each_in_range(struct rb_root_cached *root,
+				  u64 start, u64 last,
+				  umem_call_back cb,
+				  void *cookie)
+{
+	int ret_val = 0;
+	struct umem_odp_node *node, *next;
+	struct ib_umem_odp *umem;
+
+	if (unlikely(start == last))
+		return ret_val;
+
+	for (node = rbt_ib_umem_iter_first(root, start, last - 1);
+			node; node = next) {
+		next = rbt_ib_umem_iter_next(node, start, last - 1);
+		umem = container_of(node, struct ib_umem_odp, interval_tree);
+		ret_val = cb(umem->umem, start, last, cookie) || ret_val;
+	}
+
+	return ret_val;
+}
+EXPORT_SYMBOL(rbt_ib_umem_for_each_in_range);
+
+struct ib_umem_odp *rbt_ib_umem_lookup(struct rb_root_cached *root,
+				       u64 addr, u64 length)
+{
+	struct umem_odp_node *node;
+
+	node = rbt_ib_umem_iter_first(root, addr, addr + length - 1);
+	if (node)
+		return container_of(node, struct ib_umem_odp, interval_tree);
+	return NULL;
+
+}
+EXPORT_SYMBOL(rbt_ib_umem_lookup);