diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 1ce84a0..022b0d0 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -39,11 +39,13 @@
 #include <linux/mutex.h>
 #include <linux/random.h>
 #include <linux/idr.h>
+#include <linux/radix-tree.h>
 #include <linux/inetdevice.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <net/route.h>
 
+#include <net/netns/hash.h>
 #include <net/tcp.h>
 #include <net/ipv6.h>
 
@@ -80,10 +82,83 @@ static LIST_HEAD(dev_list);
 static LIST_HEAD(listen_any_list);
 static DEFINE_MUTEX(lock);
 static struct workqueue_struct *cma_wq;
-static DEFINE_IDR(tcp_ps);
-static DEFINE_IDR(udp_ps);
-static DEFINE_IDR(ipoib_ps);
-static DEFINE_IDR(ib_ps);
+static RADIX_TREE(tcp_ps, GFP_KERNEL);
+static RADIX_TREE(udp_ps, GFP_KERNEL);
+static RADIX_TREE(ipoib_ps, GFP_KERNEL);
+static RADIX_TREE(ib_ps, GFP_KERNEL);
+
+static LIST_HEAD(idrs_list);
+
+struct idr_ll {
+	unsigned net_val;
+	struct net *net;
+	struct radix_tree_root *ps;
+	struct idr idr;
+};
+
+static void zap_ps_idr(struct idr_ll *idr_ll)
+{
+	radix_tree_delete(idr_ll->ps, idr_ll->net_val);
+	idr_destroy(&idr_ll->idr);
+	kfree(idr_ll);
+}
+
+static int cma_ps_alloc(struct radix_tree_root *ps, struct net *net, void *ptr,
+			int snum)
+{
+	struct idr_ll *idr_ll;
+	int err;
+	int res;
+
+	idr_ll = radix_tree_lookup(ps, net_hash_mix(net));
+	if (!idr_ll) {
+		idr_ll = kmalloc(sizeof(*idr_ll), GFP_KERNEL);
+		if (!idr_ll)
+			return -ENOMEM;
+		idr_init(&idr_ll->idr);
+		idr_ll->net_val = net_hash_mix(net);
+		idr_ll->net = net;
+		idr_ll->ps = ps;
+		err = radix_tree_insert(ps, idr_ll->net_val, idr_ll);
+		if (err) {
+			idr_destroy(&idr_ll->idr);
+			kfree(idr_ll);
+			return err;
+		}
+	}
+	res = idr_alloc(&idr_ll->idr, ptr, snum, snum + 1, GFP_KERNEL);
+	if (unlikely((res < 0) && idr_is_empty(&idr_ll->idr))) {
+		zap_ps_idr(idr_ll);
+		return res;
+	}
+	return res;
+}
+
+static void *cma_ps_find(struct radix_tree_root *ps, struct net *net, int snum)
+{
+	struct idr_ll *idr_ll;
+
+	idr_ll = radix_tree_lookup(ps, net_hash_mix(net));
+	if (!idr_ll)
+		return NULL;
+	return idr_find(&idr_ll->idr, snum);
+}
+
+static void cma_ps_remove(struct radix_tree_root *ps, struct net *net, int snum)
+{
+	struct idr_ll *idr_ll;
+
+	idr_ll = radix_tree_lookup(ps, net_hash_mix(net));
+	if (unlikely(!idr_ll)) {
+		WARN(1, "cma_ps_removed can't find expected net ns 0x%lx\n",
+		     (unsigned long)net);
+		return;
+	}
+	idr_remove(&idr_ll->idr, snum);
+	if (idr_is_empty(&idr_ll->idr)) {
+		zap_ps_idr(idr_ll);
+	}
+}
 
 struct cma_device {
 	struct list_head	list;
@@ -94,9 +169,9 @@ struct cma_device {
 };
 
 struct rdma_bind_list {
-	struct idr		*ps;
-	struct hlist_head	owners;
-	unsigned short		port;
+	struct radix_tree_root	*ps;
+	struct hlist_head		owners;
+	unsigned short			port;
 };
 
 enum {
@@ -885,7 +960,7 @@ static void cma_release_port(struct rdma_id_private *id_priv)
 	mutex_lock(&lock);
 	hlist_del(&id_priv->node);
 	if (hlist_empty(&bind_list->owners)) {
-		idr_remove(bind_list->ps, bind_list->port);
+		cma_ps_remove(bind_list->ps, &init_net, bind_list->port);
 		kfree(bind_list);
 	}
 	mutex_unlock(&lock);
@@ -2198,8 +2273,8 @@ static void cma_bind_port(struct rdma_bind_list *bind_list,
 	hlist_add_head(&id_priv->node, &bind_list->owners);
 }
 
-static int cma_alloc_port(struct idr *ps, struct rdma_id_private *id_priv,
-			  unsigned short snum)
+static int cma_alloc_port(struct radix_tree_root *ps,
+			  struct rdma_id_private *id_priv, unsigned short snum)
 {
 	struct rdma_bind_list *bind_list;
 	int ret;
@@ -2208,7 +2283,7 @@ static int cma_alloc_port(struct idr *ps, struct rdma_id_private *id_priv,
 	if (!bind_list)
 		return -ENOMEM;
 
-	ret = idr_alloc(ps, bind_list, snum, snum + 1, GFP_KERNEL);
+	ret = cma_ps_alloc(ps, &init_net, bind_list, snum);
 	if (ret < 0)
 		goto err;
 
@@ -2221,7 +2296,8 @@ err:
 	return ret == -ENOSPC ? -EADDRNOTAVAIL : ret;
 }
 
-static int cma_alloc_any_port(struct idr *ps, struct rdma_id_private *id_priv)
+static int cma_alloc_any_port(struct radix_tree_root *ps,
+			      struct rdma_id_private *id_priv)
 {
 	static unsigned int last_used_port;
 	int low, high, remaining;
@@ -2232,7 +2308,7 @@ static int cma_alloc_any_port(struct idr *ps, struct rdma_id_private *id_priv)
 	rover = prandom_u32() % remaining + low;
 retry:
 	if (last_used_port != rover &&
-	    !idr_find(ps, (unsigned short) rover)) {
+	    !cma_ps_find(ps, &init_net, (unsigned short)rover)) {
 		int ret = cma_alloc_port(ps, id_priv, rover);
 		/*
 		 * Remember previously used port number in order to avoid
@@ -2257,6 +2333,8 @@ retry:
  * bind to a specific port, or when trying to listen on a bound port.  In
  * the latter case, the provided id_priv may already be on the bind_list, but
  * we still need to check that it's okay to start listening.
+ *
+ * Assume the bind_list contains only services from the correct name space.
  */
 static int cma_check_port(struct rdma_bind_list *bind_list,
 			  struct rdma_id_private *id_priv, uint8_t reuseaddr)
@@ -2287,7 +2365,8 @@ static int cma_check_port(struct rdma_bind_list *bind_list,
 	return 0;
 }
 
-static int cma_use_port(struct idr *ps, struct rdma_id_private *id_priv)
+static int cma_use_port(struct radix_tree_root *ps,
+			struct rdma_id_private *id_priv)
 {
 	struct rdma_bind_list *bind_list;
 	unsigned short snum;
@@ -2297,7 +2376,7 @@ static int cma_use_port(struct idr *ps, struct rdma_id_private *id_priv)
 	if (snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
 		return -EACCES;
 
-	bind_list = idr_find(ps, snum);
+	bind_list = cma_ps_find(ps, &init_net, snum);
 	if (!bind_list) {
 		ret = cma_alloc_port(ps, id_priv, snum);
 	} else {
@@ -2320,7 +2399,8 @@ static int cma_bind_listen(struct rdma_id_private *id_priv)
 	return ret;
 }
 
-static struct idr *cma_select_inet_ps(struct rdma_id_private *id_priv)
+static struct radix_tree_root *cma_select_inet_ps(
+		struct rdma_id_private *id_priv)
 {
 	switch (id_priv->id.ps) {
 	case RDMA_PS_TCP:
@@ -2336,9 +2416,9 @@ static struct idr *cma_select_inet_ps(struct rdma_id_private *id_priv)
 	}
 }
 
-static struct idr *cma_select_ib_ps(struct rdma_id_private *id_priv)
+static struct radix_tree_root *cma_select_ib_ps(struct rdma_id_private *id_priv)
 {
-	struct idr *ps = NULL;
+	struct radix_tree_root *ps = NULL;
 	struct sockaddr_ib *sib;
 	u64 sid_ps, mask, sid;
 
@@ -2369,7 +2449,7 @@ static struct idr *cma_select_ib_ps(struct rdma_id_private *id_priv)
 
 static int cma_get_port(struct rdma_id_private *id_priv)
 {
-	struct idr *ps;
+	struct radix_tree_root *ps;
 	int ret;
 
 	if (cma_family(id_priv) != AF_IB)
@@ -3567,10 +3647,6 @@ static void __exit cma_cleanup(void)
 	rdma_addr_unregister_client(&addr_client);
 	ib_sa_unregister_client(&sa_client);
 	destroy_workqueue(cma_wq);
-	idr_destroy(&tcp_ps);
-	idr_destroy(&udp_ps);
-	idr_destroy(&ipoib_ps);
-	idr_destroy(&ib_ps);
 }
 
 module_init(cma_init);
