i40e: Lock for VSI's MAC filter list

This patch introduces a spinlock which is to be used for synchronizing
access to VSI's MAC filter list.

This patch also synchronizes execution of other codepaths which are
accessing VSI's MAC filter list with execution of
service_task:sync_vsi_filters.

In function i40e_add_vsi, copied out LAA MAC address instead of cloning
MAC filter entry because only MAC address is needed to remove MAC VLAN
filter from FW/HW.

Change-ID: I0e10ac7c715d44aa994239642aa4d57c998573a2
Signed-off-by: Kiran Patil <kiran.patil@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 87a5d09..36cca7b 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -1355,6 +1355,9 @@
  * @is_netdev: make sure its a netdev filter, else doesn't matter
  *
  * Returns ptr to the filter object or NULL when no memory available.
+ *
+ * NOTE: This function is expected to be called with mac_filter_list_lock
+ * being held.
  **/
 struct i40e_mac_filter *i40e_add_filter(struct i40e_vsi *vsi,
 					u8 *macaddr, s16 vlan,
@@ -1413,6 +1416,9 @@
  * @vlan: the vlan
  * @is_vf: make sure it's a VF filter, else doesn't matter
  * @is_netdev: make sure it's a netdev filter, else doesn't matter
+ *
+ * NOTE: This function is expected to be called with mac_filter_list_lock
+ * being held.
  **/
 void i40e_del_filter(struct i40e_vsi *vsi,
 		     u8 *macaddr, s16 vlan,
@@ -1519,8 +1525,10 @@
 		element.flags = I40E_AQC_MACVLAN_DEL_PERFECT_MATCH;
 		i40e_aq_remove_macvlan(&pf->hw, vsi->seid, &element, 1, NULL);
 	} else {
+		spin_lock_bh(&vsi->mac_filter_list_lock);
 		i40e_del_filter(vsi, netdev->dev_addr, I40E_VLAN_ANY,
 				false, false);
+		spin_unlock_bh(&vsi->mac_filter_list_lock);
 	}
 
 	if (ether_addr_equal(addr->sa_data, hw->mac.addr)) {
@@ -1531,10 +1539,12 @@
 		element.flags = cpu_to_le16(I40E_AQC_MACVLAN_ADD_PERFECT_MATCH);
 		i40e_aq_add_macvlan(&pf->hw, vsi->seid, &element, 1, NULL);
 	} else {
+		spin_lock_bh(&vsi->mac_filter_list_lock);
 		f = i40e_add_filter(vsi, addr->sa_data, I40E_VLAN_ANY,
 				    false, false);
 		if (f)
 			f->is_laa = true;
+		spin_unlock_bh(&vsi->mac_filter_list_lock);
 	}
 
 	i40e_sync_vsi_filters(vsi, false);
@@ -1707,6 +1717,8 @@
 	struct netdev_hw_addr *mca;
 	struct netdev_hw_addr *ha;
 
+	spin_lock_bh(&vsi->mac_filter_list_lock);
+
 	/* add addr if not already in the filter list */
 	netdev_for_each_uc_addr(uca, netdev) {
 		if (!i40e_find_mac(vsi, uca->addr, false, true)) {
@@ -1754,6 +1766,7 @@
 bottom_of_search_loop:
 		continue;
 	}
+	spin_unlock_bh(&vsi->mac_filter_list_lock);
 
 	/* check for other flag changes */
 	if (vsi->current_netdev_flags != vsi->netdev->flags) {
@@ -1763,6 +1776,79 @@
 }
 
 /**
+ * i40e_mac_filter_entry_clone - Clones a MAC filter entry
+ * @src: source MAC filter entry to be clones
+ *
+ * Returns the pointer to newly cloned MAC filter entry or NULL
+ * in case of error
+ **/
+static struct i40e_mac_filter *i40e_mac_filter_entry_clone(
+					struct i40e_mac_filter *src)
+{
+	struct i40e_mac_filter *f;
+
+	f = kzalloc(sizeof(*f), GFP_ATOMIC);
+	if (!f)
+		return NULL;
+	*f = *src;
+
+	INIT_LIST_HEAD(&f->list);
+
+	return f;
+}
+
+/**
+ * i40e_undo_del_filter_entries - Undo the changes made to MAC filter entries
+ * @vsi: pointer to vsi struct
+ * @from: Pointer to list which contains MAC filter entries - changes to
+ *        those entries needs to be undone.
+ *
+ * MAC filter entries from list were slated to be removed from device.
+ **/
+static void i40e_undo_del_filter_entries(struct i40e_vsi *vsi,
+					 struct list_head *from)
+{
+	struct i40e_mac_filter *f, *ftmp;
+
+	list_for_each_entry_safe(f, ftmp, from, list) {
+		f->changed = true;
+		/* Move the element back into MAC filter list*/
+		list_move_tail(&f->list, &vsi->mac_filter_list);
+	}
+}
+
+/**
+ * i40e_undo_add_filter_entries - Undo the changes made to MAC filter entries
+ * @vsi: pointer to vsi struct
+ *
+ * MAC filter entries from list were slated to be added from device.
+ **/
+static void i40e_undo_add_filter_entries(struct i40e_vsi *vsi)
+{
+	struct i40e_mac_filter *f, *ftmp;
+
+	list_for_each_entry_safe(f, ftmp, &vsi->mac_filter_list, list) {
+		if (!f->changed && f->counter)
+			f->changed = true;
+	}
+}
+
+/**
+ * i40e_cleanup_add_list - Deletes the element from add list and release
+ *			memory
+ * @add_list: Pointer to list which contains MAC filter entries
+ **/
+static void i40e_cleanup_add_list(struct list_head *add_list)
+{
+	struct i40e_mac_filter *f, *ftmp;
+
+	list_for_each_entry_safe(f, ftmp, add_list, list) {
+		list_del(&f->list);
+		kfree(f);
+	}
+}
+
+/**
  * i40e_sync_vsi_filters - Update the VSI filter list to the HW
  * @vsi: ptr to the VSI
  * @grab_rtnl: whether RTNL needs to be grabbed
@@ -1773,11 +1859,13 @@
  **/
 int i40e_sync_vsi_filters(struct i40e_vsi *vsi, bool grab_rtnl)
 {
-	struct i40e_mac_filter *f, *ftmp;
+	struct list_head tmp_del_list, tmp_add_list;
+	struct i40e_mac_filter *f, *ftmp, *fclone;
 	bool promisc_forced_on = false;
 	bool add_happened = false;
 	int filter_list_len = 0;
 	u32 changed_flags = 0;
+	bool err_cond = false;
 	i40e_status ret = 0;
 	struct i40e_pf *pf;
 	int num_add = 0;
@@ -1798,17 +1886,13 @@
 		vsi->current_netdev_flags = vsi->netdev->flags;
 	}
 
+	INIT_LIST_HEAD(&tmp_del_list);
+	INIT_LIST_HEAD(&tmp_add_list);
+
 	if (vsi->flags & I40E_VSI_FLAG_FILTER_CHANGED) {
 		vsi->flags &= ~I40E_VSI_FLAG_FILTER_CHANGED;
 
-		filter_list_len = pf->hw.aq.asq_buf_size /
-			    sizeof(struct i40e_aqc_remove_macvlan_element_data);
-		del_list = kcalloc(filter_list_len,
-			    sizeof(struct i40e_aqc_remove_macvlan_element_data),
-			    GFP_KERNEL);
-		if (!del_list)
-			return -ENOMEM;
-
+		spin_lock_bh(&vsi->mac_filter_list_lock);
 		list_for_each_entry_safe(f, ftmp, &vsi->mac_filter_list, list) {
 			if (!f->changed)
 				continue;
@@ -1816,6 +1900,58 @@
 			if (f->counter != 0)
 				continue;
 			f->changed = false;
+
+			/* Move the element into temporary del_list */
+			list_move_tail(&f->list, &tmp_del_list);
+		}
+
+		list_for_each_entry_safe(f, ftmp, &vsi->mac_filter_list, list) {
+			if (!f->changed)
+				continue;
+
+			if (f->counter == 0)
+				continue;
+			f->changed = false;
+
+			/* Clone MAC filter entry and add into temporary list */
+			fclone = i40e_mac_filter_entry_clone(f);
+			if (!fclone) {
+				err_cond = true;
+				break;
+			}
+			list_add_tail(&fclone->list, &tmp_add_list);
+		}
+
+		/* if failed to clone MAC filter entry - undo */
+		if (err_cond) {
+			i40e_undo_del_filter_entries(vsi, &tmp_del_list);
+			i40e_undo_add_filter_entries(vsi);
+		}
+		spin_unlock_bh(&vsi->mac_filter_list_lock);
+
+		if (err_cond)
+			i40e_cleanup_add_list(&tmp_add_list);
+	}
+
+	/* Now process 'del_list' outside the lock */
+	if (!list_empty(&tmp_del_list)) {
+		filter_list_len = pf->hw.aq.asq_buf_size /
+			    sizeof(struct i40e_aqc_remove_macvlan_element_data);
+		del_list = kcalloc(filter_list_len,
+			    sizeof(struct i40e_aqc_remove_macvlan_element_data),
+			    GFP_KERNEL);
+		if (!del_list) {
+			i40e_cleanup_add_list(&tmp_add_list);
+
+			/* Undo VSI's MAC filter entry element updates */
+			spin_lock_bh(&vsi->mac_filter_list_lock);
+			i40e_undo_del_filter_entries(vsi, &tmp_del_list);
+			i40e_undo_add_filter_entries(vsi);
+			spin_unlock_bh(&vsi->mac_filter_list_lock);
+			return -ENOMEM;
+		}
+
+		list_for_each_entry_safe(f, ftmp, &tmp_del_list, list) {
 			cmd_flags = 0;
 
 			/* add to delete list */
@@ -1828,10 +1964,6 @@
 			del_list[num_del].flags = cmd_flags;
 			num_del++;
 
-			/* unlink from filter list */
-			list_del(&f->list);
-			kfree(f);
-
 			/* flush a full buffer */
 			if (num_del == filter_list_len) {
 				ret = i40e_aq_remove_macvlan(&pf->hw,
@@ -1842,12 +1974,18 @@
 				memset(del_list, 0, sizeof(*del_list));
 
 				if (ret && aq_err != I40E_AQ_RC_ENOENT)
-					dev_info(&pf->pdev->dev,
-						 "ignoring delete macvlan error, err %s, aq_err %s while flushing a full buffer\n",
-						 i40e_stat_str(&pf->hw, ret),
-						 i40e_aq_str(&pf->hw, aq_err));
+					dev_err(&pf->pdev->dev,
+						"ignoring delete macvlan error, err %s, aq_err %s while flushing a full buffer\n",
+						i40e_stat_str(&pf->hw, ret),
+						i40e_aq_str(&pf->hw, aq_err));
 			}
+			/* Release memory for MAC filter entries which were
+			 * synced up with HW.
+			 */
+			list_del(&f->list);
+			kfree(f);
 		}
+
 		if (num_del) {
 			ret = i40e_aq_remove_macvlan(&pf->hw, vsi->seid,
 						     del_list, num_del, NULL);
@@ -1863,6 +2001,9 @@
 
 		kfree(del_list);
 		del_list = NULL;
+	}
+
+	if (!list_empty(&tmp_add_list)) {
 
 		/* do all the adds now */
 		filter_list_len = pf->hw.aq.asq_buf_size /
@@ -1870,16 +2011,19 @@
 		add_list = kcalloc(filter_list_len,
 			       sizeof(struct i40e_aqc_add_macvlan_element_data),
 			       GFP_KERNEL);
-		if (!add_list)
+		if (!add_list) {
+			/* Purge element from temporary lists */
+			i40e_cleanup_add_list(&tmp_add_list);
+
+			/* Undo add filter entries from VSI MAC filter list */
+			spin_lock_bh(&vsi->mac_filter_list_lock);
+			i40e_undo_add_filter_entries(vsi);
+			spin_unlock_bh(&vsi->mac_filter_list_lock);
 			return -ENOMEM;
+		}
 
-		list_for_each_entry_safe(f, ftmp, &vsi->mac_filter_list, list) {
-			if (!f->changed)
-				continue;
+		list_for_each_entry_safe(f, ftmp, &tmp_add_list, list) {
 
-			if (f->counter == 0)
-				continue;
-			f->changed = false;
 			add_happened = true;
 			cmd_flags = 0;
 
@@ -1906,7 +2050,13 @@
 					break;
 				memset(add_list, 0, sizeof(*add_list));
 			}
+			/* Entries from tmp_add_list were cloned from MAC
+			 * filter list, hence clean those cloned entries
+			 */
+			list_del(&f->list);
+			kfree(f);
 		}
+
 		if (num_add) {
 			ret = i40e_aq_add_macvlan(&pf->hw, vsi->seid,
 						  add_list, num_add, NULL);
@@ -2158,6 +2308,9 @@
 	is_vf = (vsi->type == I40E_VSI_SRIOV);
 	is_netdev = !!(vsi->netdev);
 
+	/* Locked once because all functions invoked below iterates list*/
+	spin_lock_bh(&vsi->mac_filter_list_lock);
+
 	if (is_netdev) {
 		add_f = i40e_add_filter(vsi, vsi->netdev->dev_addr, vid,
 					is_vf, is_netdev);
@@ -2165,6 +2318,7 @@
 			dev_info(&vsi->back->pdev->dev,
 				 "Could not add vlan filter %d for %pM\n",
 				 vid, vsi->netdev->dev_addr);
+			spin_unlock_bh(&vsi->mac_filter_list_lock);
 			return -ENOMEM;
 		}
 	}
@@ -2175,6 +2329,7 @@
 			dev_info(&vsi->back->pdev->dev,
 				 "Could not add vlan filter %d for %pM\n",
 				 vid, f->macaddr);
+			spin_unlock_bh(&vsi->mac_filter_list_lock);
 			return -ENOMEM;
 		}
 	}
@@ -2196,6 +2351,7 @@
 				dev_info(&vsi->back->pdev->dev,
 					 "Could not add filter 0 for %pM\n",
 					 vsi->netdev->dev_addr);
+				spin_unlock_bh(&vsi->mac_filter_list_lock);
 				return -ENOMEM;
 			}
 		}
@@ -2204,22 +2360,28 @@
 	/* Do not assume that I40E_VLAN_ANY should be reset to VLAN 0 */
 	if (vid > 0 && !vsi->info.pvid) {
 		list_for_each_entry(f, &vsi->mac_filter_list, list) {
-			if (i40e_find_filter(vsi, f->macaddr, I40E_VLAN_ANY,
-					     is_vf, is_netdev)) {
-				i40e_del_filter(vsi, f->macaddr, I40E_VLAN_ANY,
-						is_vf, is_netdev);
-				add_f = i40e_add_filter(vsi, f->macaddr,
-							0, is_vf, is_netdev);
-				if (!add_f) {
-					dev_info(&vsi->back->pdev->dev,
-						 "Could not add filter 0 for %pM\n",
-						 f->macaddr);
-					return -ENOMEM;
-				}
+			if (!i40e_find_filter(vsi, f->macaddr, I40E_VLAN_ANY,
+					      is_vf, is_netdev))
+				continue;
+			i40e_del_filter(vsi, f->macaddr, I40E_VLAN_ANY,
+					is_vf, is_netdev);
+			add_f = i40e_add_filter(vsi, f->macaddr,
+						0, is_vf, is_netdev);
+			if (!add_f) {
+				dev_info(&vsi->back->pdev->dev,
+					 "Could not add filter 0 for %pM\n",
+					f->macaddr);
+				spin_unlock_bh(&vsi->mac_filter_list_lock);
+				return -ENOMEM;
 			}
 		}
 	}
 
+	/* Make sure to release before sync_vsi_filter because that
+	 * function will lock/unlock as necessary
+	 */
+	spin_unlock_bh(&vsi->mac_filter_list_lock);
+
 	if (test_bit(__I40E_DOWN, &vsi->back->state) ||
 	    test_bit(__I40E_RESET_RECOVERY_PENDING, &vsi->back->state))
 		return 0;
@@ -2244,6 +2406,9 @@
 	is_vf = (vsi->type == I40E_VSI_SRIOV);
 	is_netdev = !!(netdev);
 
+	/* Locked once because all functions invoked below iterates list */
+	spin_lock_bh(&vsi->mac_filter_list_lock);
+
 	if (is_netdev)
 		i40e_del_filter(vsi, netdev->dev_addr, vid, is_vf, is_netdev);
 
@@ -2274,6 +2439,7 @@
 			dev_info(&vsi->back->pdev->dev,
 				 "Could not add filter %d for %pM\n",
 				 I40E_VLAN_ANY, netdev->dev_addr);
+			spin_unlock_bh(&vsi->mac_filter_list_lock);
 			return -ENOMEM;
 		}
 	}
@@ -2282,16 +2448,22 @@
 		list_for_each_entry(f, &vsi->mac_filter_list, list) {
 			i40e_del_filter(vsi, f->macaddr, 0, is_vf, is_netdev);
 			add_f = i40e_add_filter(vsi, f->macaddr, I40E_VLAN_ANY,
-					    is_vf, is_netdev);
+						is_vf, is_netdev);
 			if (!add_f) {
 				dev_info(&vsi->back->pdev->dev,
 					 "Could not add filter %d for %pM\n",
 					 I40E_VLAN_ANY, f->macaddr);
+				spin_unlock_bh(&vsi->mac_filter_list_lock);
 				return -ENOMEM;
 			}
 		}
 	}
 
+	/* Make sure to release before sync_vsi_filter because that
+	 * function with lock/unlock as necessary
+	 */
+	spin_unlock_bh(&vsi->mac_filter_list_lock);
+
 	if (test_bit(__I40E_DOWN, &vsi->back->state) ||
 	    test_bit(__I40E_RESET_RECOVERY_PENDING, &vsi->back->state))
 		return 0;
@@ -7062,6 +7234,8 @@
 	/* Setup default MSIX irq handler for VSI */
 	i40e_vsi_setup_irqhandler(vsi, i40e_msix_clean_rings);
 
+	/* Initialize VSI lock */
+	spin_lock_init(&vsi->mac_filter_list_lock);
 	pf->vsi[vsi_idx] = vsi;
 	ret = vsi_idx;
 	goto unlock_pf;
@@ -8477,17 +8651,26 @@
 		 * default a MAC-VLAN filter that accepts any tagged packet
 		 * which must be replaced by a normal filter.
 		 */
-		if (!i40e_rm_default_mac_filter(vsi, mac_addr))
+		if (!i40e_rm_default_mac_filter(vsi, mac_addr)) {
+			spin_lock_bh(&vsi->mac_filter_list_lock);
 			i40e_add_filter(vsi, mac_addr,
 					I40E_VLAN_ANY, false, true);
+			spin_unlock_bh(&vsi->mac_filter_list_lock);
+		}
 	} else {
 		/* relate the VSI_VMDQ name to the VSI_MAIN name */
 		snprintf(netdev->name, IFNAMSIZ, "%sv%%d",
 			 pf->vsi[pf->lan_vsi]->netdev->name);
 		random_ether_addr(mac_addr);
+
+		spin_lock_bh(&vsi->mac_filter_list_lock);
 		i40e_add_filter(vsi, mac_addr, I40E_VLAN_ANY, false, false);
+		spin_unlock_bh(&vsi->mac_filter_list_lock);
 	}
+
+	spin_lock_bh(&vsi->mac_filter_list_lock);
 	i40e_add_filter(vsi, brdcast, I40E_VLAN_ANY, false, false);
+	spin_unlock_bh(&vsi->mac_filter_list_lock);
 
 	ether_addr_copy(netdev->dev_addr, mac_addr);
 	ether_addr_copy(netdev->perm_addr, mac_addr);
@@ -8561,10 +8744,13 @@
 static int i40e_add_vsi(struct i40e_vsi *vsi)
 {
 	int ret = -ENODEV;
-	struct i40e_mac_filter *f, *ftmp;
+	u8 laa_macaddr[ETH_ALEN];
+	bool found_laa_mac_filter = false;
 	struct i40e_pf *pf = vsi->back;
 	struct i40e_hw *hw = &pf->hw;
 	struct i40e_vsi_context ctxt;
+	struct i40e_mac_filter *f, *ftmp;
+
 	u8 enabled_tc = 0x1; /* TC0 enabled */
 	int f_count = 0;
 
@@ -8736,32 +8922,41 @@
 		vsi->id = ctxt.vsi_number;
 	}
 
+	spin_lock_bh(&vsi->mac_filter_list_lock);
 	/* If macvlan filters already exist, force them to get loaded */
 	list_for_each_entry_safe(f, ftmp, &vsi->mac_filter_list, list) {
 		f->changed = true;
 		f_count++;
 
+		/* Expected to have only one MAC filter entry for LAA in list */
 		if (f->is_laa && vsi->type == I40E_VSI_MAIN) {
-			struct i40e_aqc_remove_macvlan_element_data element;
-
-			memset(&element, 0, sizeof(element));
-			ether_addr_copy(element.mac_addr, f->macaddr);
-			element.flags = I40E_AQC_MACVLAN_DEL_PERFECT_MATCH;
-			ret = i40e_aq_remove_macvlan(hw, vsi->seid,
-						     &element, 1, NULL);
-			if (ret) {
-				/* some older FW has a different default */
-				element.flags |=
-					       I40E_AQC_MACVLAN_DEL_IGNORE_VLAN;
-				i40e_aq_remove_macvlan(hw, vsi->seid,
-						       &element, 1, NULL);
-			}
-
-			i40e_aq_mac_address_write(hw,
-						  I40E_AQC_WRITE_TYPE_LAA_WOL,
-						  f->macaddr, NULL);
+			ether_addr_copy(laa_macaddr, f->macaddr);
+			found_laa_mac_filter = true;
 		}
 	}
+	spin_unlock_bh(&vsi->mac_filter_list_lock);
+
+	if (found_laa_mac_filter) {
+		struct i40e_aqc_remove_macvlan_element_data element;
+
+		memset(&element, 0, sizeof(element));
+		ether_addr_copy(element.mac_addr, laa_macaddr);
+		element.flags = I40E_AQC_MACVLAN_DEL_PERFECT_MATCH;
+		ret = i40e_aq_remove_macvlan(hw, vsi->seid,
+					     &element, 1, NULL);
+		if (ret) {
+			/* some older FW has a different default */
+			element.flags |=
+				       I40E_AQC_MACVLAN_DEL_IGNORE_VLAN;
+			i40e_aq_remove_macvlan(hw, vsi->seid,
+					       &element, 1, NULL);
+		}
+
+		i40e_aq_mac_address_write(hw,
+					  I40E_AQC_WRITE_TYPE_LAA_WOL,
+					  laa_macaddr, NULL);
+	}
+
 	if (f_count) {
 		vsi->flags |= I40E_VSI_FLAG_FILTER_CHANGED;
 		pf->flags |= I40E_FLAG_FILTER_SYNC;
@@ -8824,9 +9019,12 @@
 		i40e_vsi_disable_irq(vsi);
 	}
 
+	spin_lock_bh(&vsi->mac_filter_list_lock);
 	list_for_each_entry_safe(f, ftmp, &vsi->mac_filter_list, list)
 		i40e_del_filter(vsi, f->macaddr, f->vlan,
 				f->is_vf, f->is_netdev);
+	spin_unlock_bh(&vsi->mac_filter_list_lock);
+
 	i40e_sync_vsi_filters(vsi, false);
 
 	i40e_vsi_delete(vsi);