i40iw: Receive notification events correctly

Device notifications are not received after the first interface is
closed; since there is an unregister for notifications on every
interface close. Correct this by unregistering for device
notifications only when the last interface is closed. Also, make
all operations on the i40iw_notifiers_registered atomic as it
can be read/modified concurrently.

Fixes: 8e06af711bf2 ("i40iw: add main, hdr, status")
Signed-off-by: Mustafa Ismail <mustafa.ismail@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/hw/i40iw/i40iw_main.c b/drivers/infiniband/hw/i40iw/i40iw_main.c
index 0cbbe40382982479e608aca0edbe5a9ab1c267d7..445e230d5ff88f6de4e1b0e5d0d81160028842cf 100644 (file)
--- a/drivers/infiniband/hw/i40iw/i40iw_main.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_main.c
@@ -100,7 +100,7 @@ static struct notifier_block i40iw_net_notifier = {
        .notifier_call = i40iw_net_event
 };
 
-static int i40iw_notifiers_registered;
+static atomic_t i40iw_notifiers_registered;
 
 /**
  * i40iw_find_i40e_handler - find a handler given a client info
@@ -1342,12 +1342,11 @@ static enum i40iw_status_code i40iw_initialize_dev(struct i40iw_device *iwdev,
  */
 static void i40iw_register_notifiers(void)
 {
-       if (!i40iw_notifiers_registered) {
+       if (atomic_inc_return(&i40iw_notifiers_registered) == 1) {
                register_inetaddr_notifier(&i40iw_inetaddr_notifier);
                register_inet6addr_notifier(&i40iw_inetaddr6_notifier);
                register_netevent_notifier(&i40iw_net_notifier);
        }
-       i40iw_notifiers_registered++;
 }
 
 /**
@@ -1429,8 +1428,7 @@ static void i40iw_deinit_device(struct i40iw_device *iwdev, bool reset, bool del
                        i40iw_del_macip_entry(iwdev, (u8)iwdev->mac_ip_table_idx);
                /* fallthrough */
        case INET_NOTIFIER:
-               if (i40iw_notifiers_registered > 0) {
-                       i40iw_notifiers_registered--;
+               if (!atomic_dec_return(&i40iw_notifiers_registered)) {
                        unregister_netevent_notifier(&i40iw_net_notifier);
                        unregister_inetaddr_notifier(&i40iw_inetaddr_notifier);
                        unregister_inet6addr_notifier(&i40iw_inetaddr6_notifier);