--- /dev/null
+From 3cbf7530a163d048a6376cd22fecb9cdcb23b192 Mon Sep 17 00:00:00 2001
+From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
+Date: Wed, 31 Mar 2021 05:36:42 +0100
+Subject: qrtr: Convert qrtr_ports from IDR to XArray
+
+From: Matthew Wilcox (Oracle) <willy@infradead.org>
+
+commit 3cbf7530a163d048a6376cd22fecb9cdcb23b192 upstream.
+
+The XArray interface is easier for this driver to use. Also fixes a
+bug reported by the improper use of GFP_ATOMIC.
+
+Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
+Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Stanislav Goriainov <goriainov@ispras.ru>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ net/qrtr/qrtr.c | 42 ++++++++++++++----------------------------
+ 1 file changed, 14 insertions(+), 28 deletions(-)
+
+--- a/net/qrtr/qrtr.c
++++ b/net/qrtr/qrtr.c
+@@ -20,6 +20,8 @@
+ /* auto-bind range */
+ #define QRTR_MIN_EPH_SOCKET 0x4000
+ #define QRTR_MAX_EPH_SOCKET 0x7fff
++#define QRTR_EPH_PORT_RANGE \
++ XA_LIMIT(QRTR_MIN_EPH_SOCKET, QRTR_MAX_EPH_SOCKET)
+
+ /**
+ * struct qrtr_hdr_v1 - (I|R)PCrouter packet header version 1
+@@ -106,8 +108,7 @@ static LIST_HEAD(qrtr_all_nodes);
+ static DEFINE_MUTEX(qrtr_node_lock);
+
+ /* local port allocation management */
+-static DEFINE_IDR(qrtr_ports);
+-static DEFINE_MUTEX(qrtr_port_lock);
++static DEFINE_XARRAY_ALLOC(qrtr_ports);
+
+ /**
+ * struct qrtr_node - endpoint node
+@@ -635,7 +636,7 @@ static struct qrtr_sock *qrtr_port_looku
+ port = 0;
+
+ rcu_read_lock();
+- ipc = idr_find(&qrtr_ports, port);
++ ipc = xa_load(&qrtr_ports, port);
+ if (ipc)
+ sock_hold(&ipc->sk);
+ rcu_read_unlock();
+@@ -677,9 +678,7 @@ static void qrtr_port_remove(struct qrtr
+
+ __sock_put(&ipc->sk);
+
+- mutex_lock(&qrtr_port_lock);
+- idr_remove(&qrtr_ports, port);
+- mutex_unlock(&qrtr_port_lock);
++ xa_erase(&qrtr_ports, port);
+
+ /* Ensure that if qrtr_port_lookup() did enter the RCU read section we
+ * wait for it to up increment the refcount */
+@@ -698,29 +697,20 @@ static void qrtr_port_remove(struct qrtr
+ */
+ static int qrtr_port_assign(struct qrtr_sock *ipc, int *port)
+ {
+- u32 min_port;
+ int rc;
+
+- mutex_lock(&qrtr_port_lock);
+ if (!*port) {
+- min_port = QRTR_MIN_EPH_SOCKET;
+- rc = idr_alloc_u32(&qrtr_ports, ipc, &min_port, QRTR_MAX_EPH_SOCKET, GFP_ATOMIC);
+- if (!rc)
+- *port = min_port;
++ rc = xa_alloc(&qrtr_ports, port, ipc, QRTR_EPH_PORT_RANGE,
++ GFP_KERNEL);
+ } else if (*port < QRTR_MIN_EPH_SOCKET && !capable(CAP_NET_ADMIN)) {
+ rc = -EACCES;
+ } else if (*port == QRTR_PORT_CTRL) {
+- min_port = 0;
+- rc = idr_alloc_u32(&qrtr_ports, ipc, &min_port, 0, GFP_ATOMIC);
++ rc = xa_insert(&qrtr_ports, 0, ipc, GFP_KERNEL);
+ } else {
+- min_port = *port;
+- rc = idr_alloc_u32(&qrtr_ports, ipc, &min_port, *port, GFP_ATOMIC);
+- if (!rc)
+- *port = min_port;
++ rc = xa_insert(&qrtr_ports, *port, ipc, GFP_KERNEL);
+ }
+- mutex_unlock(&qrtr_port_lock);
+
+- if (rc == -ENOSPC)
++ if (rc == -EBUSY)
+ return -EADDRINUSE;
+ else if (rc < 0)
+ return rc;
+@@ -734,20 +724,16 @@ static int qrtr_port_assign(struct qrtr_
+ static void qrtr_reset_ports(void)
+ {
+ struct qrtr_sock *ipc;
+- int id;
+-
+- mutex_lock(&qrtr_port_lock);
+- idr_for_each_entry(&qrtr_ports, ipc, id) {
+- /* Don't reset control port */
+- if (id == 0)
+- continue;
++ unsigned long index;
+
++ rcu_read_lock();
++ xa_for_each_start(&qrtr_ports, index, ipc, 1) {
+ sock_hold(&ipc->sk);
+ ipc->sk.sk_err = ENETRESET;
+ ipc->sk.sk_error_report(&ipc->sk);
+ sock_put(&ipc->sk);
+ }
+- mutex_unlock(&qrtr_port_lock);
++ rcu_read_unlock();
+ }
+
+ /* Bind socket to address.