net: ionic: Replace in_interrupt() usage.

The in_interrupt() usage in this driver tries to figure out which context
may sleep and which context may not sleep. in_interrupt() is not really
suitable as it misses both preemption disabled and interrupt disabled
invocations from task context.

Conditionals like that in driver code are frowned upon in general because
invocations of functions from invalid contexts might not be detected
as the conditional papers over it.

ionic_lif_addr() and _ionoc_lif_rx_mode() can be called from:

 1) ->ndo_set_rx_mode() which is under netif_addr_lock_bh()) so it must not
    sleep.

 2) Init and setup functions which are in fully preemptible task context.

ionic_link_status_check_request() has two call paths:

 1) NAPI which obviously cannot sleep

 2) Setup which is again fully preemptible task context

Add arguments which convey the execution context to the affected functions
and let the callers provide the context instead of letting the functions
deduce it.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/pensando/ionic/ionic_dev.c

@@ -22,7 +22,7 @@ static void ionic_watchdog_cb(struct timer_list *t)
 	hb = ionic_heartbeat_check(ionic);
 
 	if (hb >= 0 && ionic->lif)
-		ionic_link_status_check_request(ionic->lif);
+		ionic_link_status_check_request(ionic->lif, false);
 }
 
 void ionic_init_devinfo(struct ionic *ionic)

drivers/net/ethernet/pensando/ionic/ionic_lif.c

@@ -151,7 +151,7 @@ static void ionic_link_status_check(struct ionic_lif *lif)
 	clear_bit(IONIC_LIF_F_LINK_CHECK_REQUESTED, lif->state);
 }
 
-void ionic_link_status_check_request(struct ionic_lif *lif)
+void ionic_link_status_check_request(struct ionic_lif *lif, bool can_sleep)
 {
 	struct ionic_deferred_work *work;
 
@@ -159,7 +159,7 @@ void ionic_link_status_check_request(struct ionic_lif *lif)
 	if (test_and_set_bit(IONIC_LIF_F_LINK_CHECK_REQUESTED, lif->state))
 		return;
 
-	if (in_interrupt()) {
+	if (!can_sleep) {
 		work = kzalloc(sizeof(*work), GFP_ATOMIC);
 		if (!work)
 			return;
@@ -798,7 +798,7 @@ static bool ionic_notifyq_service(struct ionic_cq *cq,
 
 	switch (le16_to_cpu(comp->event.ecode)) {
 	case IONIC_EVENT_LINK_CHANGE:
-		ionic_link_status_check_request(lif);
+		ionic_link_status_check_request(lif, false);
 		break;
 	case IONIC_EVENT_RESET:
 		work = kzalloc(sizeof(*work), GFP_ATOMIC);
@@ -981,7 +981,8 @@ static int ionic_lif_addr_del(struct ionic_lif *lif, const u8 *addr)
 	return 0;
 }
 
-static int ionic_lif_addr(struct ionic_lif *lif, const u8 *addr, bool add)
+static int ionic_lif_addr(struct ionic_lif *lif, const u8 *addr, bool add,
+			  bool can_sleep)
 {
 	struct ionic *ionic = lif->ionic;
 	struct ionic_deferred_work *work;
@@ -1010,7 +1011,7 @@ static int ionic_lif_addr(struct ionic_lif *lif, const u8 *addr, bool add)
 			lif->nucast--;
 	}
 
-	if (in_interrupt()) {
+	if (!can_sleep) {
 		work = kzalloc(sizeof(*work), GFP_ATOMIC);
 		if (!work) {
 			netdev_err(lif->netdev, "%s OOM\n", __func__);
@@ -1036,12 +1037,22 @@ static int ionic_lif_addr(struct ionic_lif *lif, const u8 *addr, bool add)
 
 static int ionic_addr_add(struct net_device *netdev, const u8 *addr)
 {
-	return ionic_lif_addr(netdev_priv(netdev), addr, true);
+	return ionic_lif_addr(netdev_priv(netdev), addr, true, true);
+}
+
+static int ionic_ndo_addr_add(struct net_device *netdev, const u8 *addr)
+{
+	return ionic_lif_addr(netdev_priv(netdev), addr, true, false);
 }
 
 static int ionic_addr_del(struct net_device *netdev, const u8 *addr)
 {
-	return ionic_lif_addr(netdev_priv(netdev), addr, false);
+	return ionic_lif_addr(netdev_priv(netdev), addr, false, true);
+}
+
+static int ionic_ndo_addr_del(struct net_device *netdev, const u8 *addr)
+{
+	return ionic_lif_addr(netdev_priv(netdev), addr, false, false);
 }
 
 static void ionic_lif_rx_mode(struct ionic_lif *lif, unsigned int rx_mode)
@@ -1081,11 +1092,12 @@ static void ionic_lif_rx_mode(struct ionic_lif *lif, unsigned int rx_mode)
 		lif->rx_mode = rx_mode;
 }
 
-static void _ionic_lif_rx_mode(struct ionic_lif *lif, unsigned int rx_mode)
+static void _ionic_lif_rx_mode(struct ionic_lif *lif, unsigned int rx_mode,
+			       bool from_ndo)
 {
 	struct ionic_deferred_work *work;
 
-	if (in_interrupt()) {
+	if (from_ndo) {
 		work = kzalloc(sizeof(*work), GFP_ATOMIC);
 		if (!work) {
 			netdev_err(lif->netdev, "%s OOM\n", __func__);
@@ -1100,7 +1112,16 @@ static void _ionic_lif_rx_mode(struct ionic_lif *lif, unsigned int rx_mode)
 	}
 }
 
-static void ionic_set_rx_mode(struct net_device *netdev)
+static void ionic_dev_uc_sync(struct net_device *netdev, bool from_ndo)
+{
+	if (from_ndo)
+		__dev_uc_sync(netdev, ionic_ndo_addr_add, ionic_ndo_addr_del);
+	else
+		__dev_uc_sync(netdev, ionic_addr_add, ionic_addr_del);
+
+}
+
+static void ionic_set_rx_mode(struct net_device *netdev, bool from_ndo)
 {
 	struct ionic_lif *lif = netdev_priv(netdev);
 	struct ionic_identity *ident;
@@ -1122,7 +1143,7 @@ static void ionic_set_rx_mode(struct net_device *netdev)
 	 *       we remove our overflow flag and check the netdev flags
 	 *       to see if we can disable NIC PROMISC
 	 */
-	__dev_uc_sync(netdev, ionic_addr_add, ionic_addr_del);
+	ionic_dev_uc_sync(netdev, from_ndo);
 	nfilters = le32_to_cpu(ident->lif.eth.max_ucast_filters);
 	if (netdev_uc_count(netdev) + 1 > nfilters) {
 		rx_mode |= IONIC_RX_MODE_F_PROMISC;
@@ -1134,7 +1155,7 @@ static void ionic_set_rx_mode(struct net_device *netdev)
 	}
 
 	/* same for multicast */
-	__dev_mc_sync(netdev, ionic_addr_add, ionic_addr_del);
+	ionic_dev_uc_sync(netdev, from_ndo);
 	nfilters = le32_to_cpu(ident->lif.eth.max_mcast_filters);
 	if (netdev_mc_count(netdev) > nfilters) {
 		rx_mode |= IONIC_RX_MODE_F_ALLMULTI;
@@ -1146,7 +1167,12 @@ static void ionic_set_rx_mode(struct net_device *netdev)
 	}
 
 	if (lif->rx_mode != rx_mode)
-		_ionic_lif_rx_mode(lif, rx_mode);
+		_ionic_lif_rx_mode(lif, rx_mode, from_ndo);
+}
+
+static void ionic_ndo_set_rx_mode(struct net_device *netdev)
+{
+	ionic_set_rx_mode(netdev, true);
 }
 
 static __le64 ionic_netdev_features_to_nic(netdev_features_t features)
@@ -1391,7 +1417,7 @@ static int ionic_start_queues_reconfig(struct ionic_lif *lif)
 	 */
 	err = ionic_txrx_init(lif);
 	mutex_unlock(&lif->queue_lock);
-	ionic_link_status_check_request(lif);
+	ionic_link_status_check_request(lif, true);
 	netif_device_attach(lif->netdev);
 
 	return err;
@@ -1720,7 +1746,7 @@ static int ionic_txrx_init(struct ionic_lif *lif)
 	if (lif->netdev->features & NETIF_F_RXHASH)
 		ionic_lif_rss_init(lif);
 
-	ionic_set_rx_mode(lif->netdev);
+	ionic_set_rx_mode(lif->netdev, false);
 
 	return 0;
 
@@ -2093,7 +2119,7 @@ static const struct net_device_ops ionic_netdev_ops = {
 	.ndo_stop               = ionic_stop,
 	.ndo_start_xmit		= ionic_start_xmit,
 	.ndo_get_stats64	= ionic_get_stats64,
-	.ndo_set_rx_mode	= ionic_set_rx_mode,
+	.ndo_set_rx_mode	= ionic_ndo_set_rx_mode,
 	.ndo_set_features	= ionic_set_features,
 	.ndo_set_mac_address	= ionic_set_mac_address,
 	.ndo_validate_addr	= eth_validate_addr,
@@ -2521,7 +2547,7 @@ static void ionic_lif_handle_fw_up(struct ionic_lif *lif)
 	}
 
 	clear_bit(IONIC_LIF_F_FW_RESET, lif->state);
-	ionic_link_status_check_request(lif);
+	ionic_link_status_check_request(lif, true);
 	netif_device_attach(lif->netdev);
 	dev_info(ionic->dev, "FW Up: LIFs restarted\n");
 
@@ -2713,7 +2739,7 @@ static int ionic_station_set(struct ionic_lif *lif)
 		 */
 		if (!ether_addr_equal(ctx.comp.lif_getattr.mac,
 				      netdev->dev_addr))
-			ionic_lif_addr(lif, netdev->dev_addr, true);
+			ionic_lif_addr(lif, netdev->dev_addr, true, true);
 	} else {
 		/* Update the netdev mac with the device's mac */
 		memcpy(addr.sa_data, ctx.comp.lif_getattr.mac, netdev->addr_len);
@@ -2730,7 +2756,7 @@ static int ionic_station_set(struct ionic_lif *lif)
 
 	netdev_dbg(lif->netdev, "adding station MAC addr %pM\n",
 		   netdev->dev_addr);
-	ionic_lif_addr(lif, netdev->dev_addr, true);
+	ionic_lif_addr(lif, netdev->dev_addr, true, true);
 
 	return 0;
 }

drivers/net/ethernet/pensando/ionic/ionic_lif.h

@@ -245,7 +245,7 @@ static inline u32 ionic_coal_usec_to_hw(struct ionic *ionic, u32 usecs)
 
 typedef void (*ionic_reset_cb)(struct ionic_lif *lif, void *arg);
 
-void ionic_link_status_check_request(struct ionic_lif *lif);
+void ionic_link_status_check_request(struct ionic_lif *lif, bool can_sleep);
 void ionic_get_stats64(struct net_device *netdev,
 		       struct rtnl_link_stats64 *ns);
 void ionic_lif_deferred_enqueue(struct ionic_deferred *def,