ionic: make all rx_mode work threadsafe

Move the bulk of the code from ionic_set_rx_mode(), which
can be called from atomic context, into ionic_lif_rx_mode()
which is a safe context.

A call from the stack will get pushed off into a work thread,
but it is also possible to simultaneously have a call driven
by a queue reconfig request from an ethtool command or fw
recovery event.  We add a mutex around the rx_mode work to be
sure they don't collide.

Fixes: 81dbc241 ("ionic: change set_rx_mode from_ndo to can_sleep")
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -29,7 +29,7 @@ static const u8 ionic_qtype_versions[IONIC_QTYPE_MAX] = {
 				      */
 };
 
-static void ionic_lif_rx_mode(struct ionic_lif *lif, unsigned int rx_mode);
+static void ionic_lif_rx_mode(struct ionic_lif *lif);
 static int ionic_lif_addr_add(struct ionic_lif *lif, const u8 *addr);
 static int ionic_lif_addr_del(struct ionic_lif *lif, const u8 *addr);
 static void ionic_link_status_check(struct ionic_lif *lif);
@@ -77,7 +77,7 @@ static void ionic_lif_deferred_work(struct work_struct *work)
 
 		switch (w->type) {
 		case IONIC_DW_TYPE_RX_MODE:
-			ionic_lif_rx_mode(lif, w->rx_mode);
+			ionic_lif_rx_mode(lif);
 			break;
 		case IONIC_DW_TYPE_RX_ADDR_ADD:
 			ionic_lif_addr_add(lif, w->addr);
@@ -1301,10 +1301,8 @@ 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,
-			  bool can_sleep)
+static int ionic_lif_addr(struct ionic_lif *lif, const u8 *addr, bool add)
 {
-	struct ionic_deferred_work *work;
 	unsigned int nmfilters;
 	unsigned int nufilters;
 
@@ -1330,97 +1328,46 @@ static int ionic_lif_addr(struct ionic_lif *lif, const u8 *addr, bool add,
 			lif->nucast--;
 	}
 
-	if (!can_sleep) {
-		work = kzalloc(sizeof(*work), GFP_ATOMIC);
-		if (!work)
-			return -ENOMEM;
-		work->type = add ? IONIC_DW_TYPE_RX_ADDR_ADD :
-				   IONIC_DW_TYPE_RX_ADDR_DEL;
-		memcpy(work->addr, addr, ETH_ALEN);
-		netdev_dbg(lif->netdev, "deferred: rx_filter %s %pM\n",
-			   add ? "add" : "del", addr);
-		ionic_lif_deferred_enqueue(&lif->deferred, work);
-	} else {
 	netdev_dbg(lif->netdev, "rx_filter %s %pM\n",
 		   add ? "add" : "del", addr);
 	if (add)
 		return ionic_lif_addr_add(lif, addr);
 	else
 		return ionic_lif_addr_del(lif, addr);
-	}
 
 	return 0;
 }
 
 static int ionic_addr_add(struct net_device *netdev, const u8 *addr)
 {
-	return ionic_lif_addr(netdev_priv(netdev), addr, ADD_ADDR, CAN_SLEEP);
-}
-
-static int ionic_ndo_addr_add(struct net_device *netdev, const u8 *addr)
-{
-	return ionic_lif_addr(netdev_priv(netdev), addr, ADD_ADDR, CAN_NOT_SLEEP);
+	return ionic_lif_addr(netdev_priv(netdev), addr, ADD_ADDR);
 }
 
 static int ionic_addr_del(struct net_device *netdev, const u8 *addr)
 {
-	return ionic_lif_addr(netdev_priv(netdev), addr, DEL_ADDR, CAN_SLEEP);
+	return ionic_lif_addr(netdev_priv(netdev), addr, DEL_ADDR);
 }
 
-static int ionic_ndo_addr_del(struct net_device *netdev, const u8 *addr)
+static void ionic_lif_rx_mode(struct ionic_lif *lif)
 {
-	return ionic_lif_addr(netdev_priv(netdev), addr, DEL_ADDR, CAN_NOT_SLEEP);
-}
-
-static void ionic_lif_rx_mode(struct ionic_lif *lif, unsigned int rx_mode)
-{
-	struct ionic_admin_ctx ctx = {
-		.work = COMPLETION_INITIALIZER_ONSTACK(ctx.work),
-		.cmd.rx_mode_set = {
-			.opcode = IONIC_CMD_RX_MODE_SET,
-			.lif_index = cpu_to_le16(lif->index),
-			.rx_mode = cpu_to_le16(rx_mode),
-		},
-	};
+	struct net_device *netdev = lif->netdev;
+	unsigned int nfilters;
+	unsigned int nd_flags;
 	char buf[128];
-	int err;
+	u16 rx_mode;
 	int i;
 #define REMAIN(__x) (sizeof(buf) - (__x))
 
-	i = scnprintf(buf, sizeof(buf), "rx_mode 0x%04x -> 0x%04x:",
-		      lif->rx_mode, rx_mode);
-	if (rx_mode & IONIC_RX_MODE_F_UNICAST)
-		i += scnprintf(&buf[i], REMAIN(i), " RX_MODE_F_UNICAST");
-	if (rx_mode & IONIC_RX_MODE_F_MULTICAST)
-		i += scnprintf(&buf[i], REMAIN(i), " RX_MODE_F_MULTICAST");
-	if (rx_mode & IONIC_RX_MODE_F_BROADCAST)
-		i += scnprintf(&buf[i], REMAIN(i), " RX_MODE_F_BROADCAST");
-	if (rx_mode & IONIC_RX_MODE_F_PROMISC)
-		i += scnprintf(&buf[i], REMAIN(i), " RX_MODE_F_PROMISC");
-	if (rx_mode & IONIC_RX_MODE_F_ALLMULTI)
-		i += scnprintf(&buf[i], REMAIN(i), " RX_MODE_F_ALLMULTI");
-	netdev_dbg(lif->netdev, "lif%d %s\n", lif->index, buf);
+	mutex_lock(&lif->config_lock);
 
-	err = ionic_adminq_post_wait(lif, &ctx);
-	if (err)
-		netdev_warn(lif->netdev, "set rx_mode 0x%04x failed: %d\n",
-			    rx_mode, err);
-	else
-		lif->rx_mode = rx_mode;
-}
-
-static void ionic_set_rx_mode(struct net_device *netdev, bool can_sleep)
-{
-	struct ionic_lif *lif = netdev_priv(netdev);
-	struct ionic_deferred_work *work;
-	unsigned int nfilters;
-	unsigned int rx_mode;
+	/* grab the flags once for local use */
+	nd_flags = netdev->flags;
 
 	rx_mode = IONIC_RX_MODE_F_UNICAST;
-	rx_mode |= (netdev->flags & IFF_MULTICAST) ? IONIC_RX_MODE_F_MULTICAST : 0;
-	rx_mode |= (netdev->flags & IFF_BROADCAST) ? IONIC_RX_MODE_F_BROADCAST : 0;
-	rx_mode |= (netdev->flags & IFF_PROMISC) ? IONIC_RX_MODE_F_PROMISC : 0;
-	rx_mode |= (netdev->flags & IFF_ALLMULTI) ? IONIC_RX_MODE_F_ALLMULTI : 0;
+	rx_mode |= (nd_flags & IFF_MULTICAST) ? IONIC_RX_MODE_F_MULTICAST : 0;
+	rx_mode |= (nd_flags & IFF_BROADCAST) ? IONIC_RX_MODE_F_BROADCAST : 0;
+	rx_mode |= (nd_flags & IFF_PROMISC) ? IONIC_RX_MODE_F_PROMISC : 0;
+	rx_mode |= (nd_flags & IFF_ALLMULTI) ? IONIC_RX_MODE_F_ALLMULTI : 0;
 
 	/* sync unicast addresses
 	 * next check to see if we're in an overflow state
@@ -1429,36 +1376,72 @@ static void ionic_set_rx_mode(struct net_device *netdev, bool can_sleep)
 	 *       we remove our overflow flag and check the netdev flags
 	 *       to see if we can disable NIC PROMISC
 	 */
-	if (can_sleep)
 	__dev_uc_sync(netdev, ionic_addr_add, ionic_addr_del);
-	else
-		__dev_uc_sync(netdev, ionic_ndo_addr_add, ionic_ndo_addr_del);
 	nfilters = le32_to_cpu(lif->identity->eth.max_ucast_filters);
 	if (netdev_uc_count(netdev) + 1 > nfilters) {
 		rx_mode |= IONIC_RX_MODE_F_PROMISC;
 		lif->uc_overflow = true;
 	} else if (lif->uc_overflow) {
 		lif->uc_overflow = false;
-		if (!(netdev->flags & IFF_PROMISC))
+		if (!(nd_flags & IFF_PROMISC))
 			rx_mode &= ~IONIC_RX_MODE_F_PROMISC;
 	}
 
 	/* same for multicast */
-	if (can_sleep)
 	__dev_mc_sync(netdev, ionic_addr_add, ionic_addr_del);
-	else
-		__dev_mc_sync(netdev, ionic_ndo_addr_add, ionic_ndo_addr_del);
 	nfilters = le32_to_cpu(lif->identity->eth.max_mcast_filters);
 	if (netdev_mc_count(netdev) > nfilters) {
 		rx_mode |= IONIC_RX_MODE_F_ALLMULTI;
 		lif->mc_overflow = true;
 	} else if (lif->mc_overflow) {
 		lif->mc_overflow = false;
-		if (!(netdev->flags & IFF_ALLMULTI))
+		if (!(nd_flags & IFF_ALLMULTI))
 			rx_mode &= ~IONIC_RX_MODE_F_ALLMULTI;
 	}
 
+	i = scnprintf(buf, sizeof(buf), "rx_mode 0x%04x -> 0x%04x:",
+		      lif->rx_mode, rx_mode);
+	if (rx_mode & IONIC_RX_MODE_F_UNICAST)
+		i += scnprintf(&buf[i], REMAIN(i), " RX_MODE_F_UNICAST");
+	if (rx_mode & IONIC_RX_MODE_F_MULTICAST)
+		i += scnprintf(&buf[i], REMAIN(i), " RX_MODE_F_MULTICAST");
+	if (rx_mode & IONIC_RX_MODE_F_BROADCAST)
+		i += scnprintf(&buf[i], REMAIN(i), " RX_MODE_F_BROADCAST");
+	if (rx_mode & IONIC_RX_MODE_F_PROMISC)
+		i += scnprintf(&buf[i], REMAIN(i), " RX_MODE_F_PROMISC");
+	if (rx_mode & IONIC_RX_MODE_F_ALLMULTI)
+		i += scnprintf(&buf[i], REMAIN(i), " RX_MODE_F_ALLMULTI");
+	if (rx_mode & IONIC_RX_MODE_F_RDMA_SNIFFER)
+		i += scnprintf(&buf[i], REMAIN(i), " RX_MODE_F_RDMA_SNIFFER");
+	netdev_dbg(netdev, "lif%d %s\n", lif->index, buf);
+
 	if (lif->rx_mode != rx_mode) {
+		struct ionic_admin_ctx ctx = {
+			.work = COMPLETION_INITIALIZER_ONSTACK(ctx.work),
+			.cmd.rx_mode_set = {
+				.opcode = IONIC_CMD_RX_MODE_SET,
+				.lif_index = cpu_to_le16(lif->index),
+			},
+		};
+		int err;
+
+		ctx.cmd.rx_mode_set.rx_mode = cpu_to_le16(rx_mode);
+		err = ionic_adminq_post_wait(lif, &ctx);
+		if (err)
+			netdev_warn(netdev, "set rx_mode 0x%04x failed: %d\n",
+				    rx_mode, err);
+		else
+			lif->rx_mode = rx_mode;
+	}
+
+	mutex_unlock(&lif->config_lock);
+}
+
+static void ionic_set_rx_mode(struct net_device *netdev, bool can_sleep)
+{
+	struct ionic_lif *lif = netdev_priv(netdev);
+	struct ionic_deferred_work *work;
+
 	if (!can_sleep) {
 		work = kzalloc(sizeof(*work), GFP_ATOMIC);
 		if (!work) {
@@ -1466,12 +1449,10 @@ static void ionic_set_rx_mode(struct net_device *netdev, bool can_sleep)
 			return;
 		}
 		work->type = IONIC_DW_TYPE_RX_MODE;
-			work->rx_mode = rx_mode;
 		netdev_dbg(lif->netdev, "deferred: rx_mode\n");
 		ionic_lif_deferred_enqueue(&lif->deferred, work);
 	} else {
-			ionic_lif_rx_mode(lif, rx_mode);
-		}
+		ionic_lif_rx_mode(lif);
 	}
 }
 
@@ -3058,6 +3039,7 @@ void ionic_lif_deinit(struct ionic_lif *lif)
 	ionic_lif_qcq_deinit(lif, lif->notifyqcq);
 	ionic_lif_qcq_deinit(lif, lif->adminqcq);
 
+	mutex_destroy(&lif->config_lock);
 	mutex_destroy(&lif->queue_lock);
 	ionic_lif_reset(lif);
 }
@@ -3185,7 +3167,7 @@ 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, ADD_ADDR, CAN_SLEEP);
+			ionic_lif_addr(lif, netdev->dev_addr, ADD_ADDR);
 	} else {
 		/* Update the netdev mac with the device's mac */
 		memcpy(addr.sa_data, ctx.comp.lif_getattr.mac, netdev->addr_len);
@@ -3202,7 +3184,7 @@ 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, ADD_ADDR, CAN_SLEEP);
+	ionic_lif_addr(lif, netdev->dev_addr, ADD_ADDR);
 
 	return 0;
 }
@@ -3225,6 +3207,7 @@ int ionic_lif_init(struct ionic_lif *lif)
 
 	lif->hw_index = le16_to_cpu(comp.hw_index);
 	mutex_init(&lif->queue_lock);
+	mutex_init(&lif->config_lock);
 
 	/* now that we have the hw_index we can figure out our doorbell page */
 	lif->dbid_count = le32_to_cpu(lif->ionic->ident.dev.ndbpgs_per_lif);

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

@@ -108,7 +108,6 @@ struct ionic_deferred_work {
 	struct list_head list;
 	enum ionic_deferred_work_type type;
 	union {
-		unsigned int rx_mode;
 		u8 addr[ETH_ALEN];
 		u8 fw_status;
 	};
@@ -179,6 +178,7 @@ struct ionic_lif {
 	unsigned int index;
 	unsigned int hw_index;
 	struct mutex queue_lock;	/* lock for queue structures */
+	struct mutex config_lock;	/* lock for config actions */
 	spinlock_t adminq_lock;		/* lock for AdminQ operations */
 	struct ionic_qcq *adminqcq;
 	struct ionic_qcq *notifyqcq;
@@ -199,7 +199,7 @@ struct ionic_lif {
 	unsigned int nrxq_descs;
 	u32 rx_copybreak;
 	u64 rxq_features;
-	unsigned int rx_mode;
+	u16 rx_mode;
 	u64 hw_features;
 	bool registered;
 	bool mc_overflow;