Commit b6224a36 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'net-lan966x-fix-issues-with-mac-table' 

Horatiu Vultur says:

====================
net: lan966x: Fix issues with MAC table

The patch series fixes 2 issues:
- when an entry was forgotten the irq thread was holding a spin lock and then
  was talking also rtnl_lock.
- the access to the HW MAC table is indirect, so the access to the HW MAC
  table was not synchronized, which means that there could be race conditions.
====================

Link: https://lore.kernel.org/r/20220714194040.231651-1-horatiu.vultur@microchip.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents c32349f3 675c807a

drivers/net/ethernet/microchip/lan966x/lan966x_mac.c

+80 −32
Original line number Diff line number Diff line
@@ -75,6 +75,9 @@ static int __lan966x_mac_learn(struct lan966x *lan966x, int pgid, 
			       unsigned int vid,

			       enum macaccess_entry_type type)

{

	int ret;



	spin_lock(&lan966x->mac_lock);

	lan966x_mac_select(lan966x, mac, vid);



	/* Issue a write command */
@@ -86,7 +89,10 @@ static int __lan966x_mac_learn(struct lan966x *lan966x, int pgid, 
	       ANA_MACACCESS_MAC_TABLE_CMD_SET(MACACCESS_CMD_LEARN),

	       lan966x, ANA_MACACCESS);



	return lan966x_mac_wait_for_completion(lan966x);

	ret = lan966x_mac_wait_for_completion(lan966x);

	spin_unlock(&lan966x->mac_lock);



	return ret;

}



/* The mask of the front ports is encoded inside the mac parameter via a call
@@ -113,11 +119,13 @@ int lan966x_mac_learn(struct lan966x *lan966x, int port, 
	return __lan966x_mac_learn(lan966x, port, false, mac, vid, type);

}



int lan966x_mac_forget(struct lan966x *lan966x,

static int lan966x_mac_forget_locked(struct lan966x *lan966x,

				     const unsigned char mac[ETH_ALEN],

				     unsigned int vid,

				     enum macaccess_entry_type type)

{

	lockdep_assert_held(&lan966x->mac_lock);



	lan966x_mac_select(lan966x, mac, vid);



	/* Issue a forget command */
@@ -128,6 +136,20 @@ int lan966x_mac_forget(struct lan966x *lan966x, 
	return lan966x_mac_wait_for_completion(lan966x);

}



int lan966x_mac_forget(struct lan966x *lan966x,

		       const unsigned char mac[ETH_ALEN],

		       unsigned int vid,

		       enum macaccess_entry_type type)

{

	int ret;



	spin_lock(&lan966x->mac_lock);

	ret = lan966x_mac_forget_locked(lan966x, mac, vid, type);

	spin_unlock(&lan966x->mac_lock);



	return ret;

}



int lan966x_mac_cpu_learn(struct lan966x *lan966x, const char *addr, u16 vid)

{

	return lan966x_mac_learn(lan966x, PGID_CPU, addr, vid, ENTRYTYPE_LOCKED);
@@ -161,7 +183,7 @@ static struct lan966x_mac_entry *lan966x_mac_alloc_entry(const unsigned char *ma 
{

	struct lan966x_mac_entry *mac_entry;



	mac_entry = kzalloc(sizeof(*mac_entry), GFP_KERNEL);

	mac_entry = kzalloc(sizeof(*mac_entry), GFP_ATOMIC);

	if (!mac_entry)

		return NULL;
@@ -179,7 +201,6 @@ static struct lan966x_mac_entry *lan966x_mac_find_entry(struct lan966x *lan966x, 
	struct lan966x_mac_entry *res = NULL;

	struct lan966x_mac_entry *mac_entry;



	spin_lock(&lan966x->mac_lock);

	list_for_each_entry(mac_entry, &lan966x->mac_entries, list) {

		if (mac_entry->vid == vid &&

		    ether_addr_equal(mac, mac_entry->mac) &&
@@ -188,7 +209,6 @@ static struct lan966x_mac_entry *lan966x_mac_find_entry(struct lan966x *lan966x, 
			break;

		}

	}

	spin_unlock(&lan966x->mac_lock);



	return res;

}
@@ -231,8 +251,11 @@ int lan966x_mac_add_entry(struct lan966x *lan966x, struct lan966x_port *port, 
{

	struct lan966x_mac_entry *mac_entry;



	if (lan966x_mac_lookup(lan966x, addr, vid, ENTRYTYPE_NORMAL))

	spin_lock(&lan966x->mac_lock);

	if (lan966x_mac_lookup(lan966x, addr, vid, ENTRYTYPE_NORMAL)) {

		spin_unlock(&lan966x->mac_lock);

		return 0;

	}



	/* In case the entry already exists, don't add it again to SW,

	 * just update HW, but we need to look in the actual HW because
@@ -241,21 +264,25 @@ int lan966x_mac_add_entry(struct lan966x *lan966x, struct lan966x_port *port, 
	 * add the entry but without the extern_learn flag.

	 */

	mac_entry = lan966x_mac_find_entry(lan966x, addr, vid, port->chip_port);

	if (mac_entry)

		return lan966x_mac_learn(lan966x, port->chip_port,

					 addr, vid, ENTRYTYPE_LOCKED);

	if (mac_entry) {

		spin_unlock(&lan966x->mac_lock);

		goto mac_learn;

	}



	mac_entry = lan966x_mac_alloc_entry(addr, vid, port->chip_port);

	if (!mac_entry)

	if (!mac_entry) {

		spin_unlock(&lan966x->mac_lock);

		return -ENOMEM;

	}



	spin_lock(&lan966x->mac_lock);

	list_add_tail(&mac_entry->list, &lan966x->mac_entries);

	spin_unlock(&lan966x->mac_lock);



	lan966x_mac_learn(lan966x, port->chip_port, addr, vid, ENTRYTYPE_LOCKED);

	lan966x_fdb_call_notifiers(SWITCHDEV_FDB_OFFLOADED, addr, vid, port->dev);



mac_learn:

	lan966x_mac_learn(lan966x, port->chip_port, addr, vid, ENTRYTYPE_LOCKED);



	return 0;

}
@@ -269,7 +296,8 @@ int lan966x_mac_del_entry(struct lan966x *lan966x, const unsigned char *addr, 
				 list) {

		if (mac_entry->vid == vid &&

		    ether_addr_equal(addr, mac_entry->mac)) {

			lan966x_mac_forget(lan966x, mac_entry->mac, mac_entry->vid,

			lan966x_mac_forget_locked(lan966x, mac_entry->mac,

						  mac_entry->vid,

						  ENTRYTYPE_LOCKED);



			list_del(&mac_entry->list);
@@ -288,8 +316,8 @@ void lan966x_mac_purge_entries(struct lan966x *lan966x) 
	spin_lock(&lan966x->mac_lock);

	list_for_each_entry_safe(mac_entry, tmp, &lan966x->mac_entries,

				 list) {

		lan966x_mac_forget(lan966x, mac_entry->mac, mac_entry->vid,

				   ENTRYTYPE_LOCKED);

		lan966x_mac_forget_locked(lan966x, mac_entry->mac,

					  mac_entry->vid, ENTRYTYPE_LOCKED);



		list_del(&mac_entry->list);

		kfree(mac_entry);
@@ -325,10 +353,13 @@ static void lan966x_mac_irq_process(struct lan966x *lan966x, u32 row, 
{

	struct lan966x_mac_entry *mac_entry, *tmp;

	unsigned char mac[ETH_ALEN] __aligned(2);

	struct list_head mac_deleted_entries;

	u32 dest_idx;

	u32 column;

	u16 vid;



	INIT_LIST_HEAD(&mac_deleted_entries);



	spin_lock(&lan966x->mac_lock);

	list_for_each_entry_safe(mac_entry, tmp, &lan966x->mac_entries, list) {

		bool found = false;
@@ -362,19 +393,25 @@ static void lan966x_mac_irq_process(struct lan966x *lan966x, u32 row, 
		}



		if (!found) {

			list_del(&mac_entry->list);

			/* Move the entry from SW list to a tmp list such that

			 * it would be deleted later

			 */

			list_add_tail(&mac_entry->list, &mac_deleted_entries);

		}

	}

	spin_unlock(&lan966x->mac_lock);



	list_for_each_entry_safe(mac_entry, tmp, &mac_deleted_entries, list) {

		/* Notify the bridge that the entry doesn't exist

			 * anymore in the HW and remove the entry from the SW

			 * list

		 * anymore in the HW

		 */

		lan966x_mac_notifiers(SWITCHDEV_FDB_DEL_TO_BRIDGE,

				      mac_entry->mac, mac_entry->vid,

				      lan966x->ports[mac_entry->port_index]->dev);



		list_del(&mac_entry->list);

		kfree(mac_entry);

	}

	}

	spin_unlock(&lan966x->mac_lock);



	/* Now go to the list of columns and see if any entry was not in the SW

	 * list, then that means that the entry is new so it needs to notify the
@@ -396,13 +433,20 @@ static void lan966x_mac_irq_process(struct lan966x *lan966x, u32 row, 
		if (WARN_ON(dest_idx >= lan966x->num_phys_ports))

			continue;



		spin_lock(&lan966x->mac_lock);

		mac_entry = lan966x_mac_find_entry(lan966x, mac, vid, dest_idx);

		if (mac_entry) {

			spin_unlock(&lan966x->mac_lock);

			continue;

		}



		mac_entry = lan966x_mac_alloc_entry(mac, vid, dest_idx);

		if (!mac_entry)

		if (!mac_entry) {

			spin_unlock(&lan966x->mac_lock);

			return;

		}



		mac_entry->row = row;



		spin_lock(&lan966x->mac_lock);

		list_add_tail(&mac_entry->list, &lan966x->mac_entries);

		spin_unlock(&lan966x->mac_lock);
@@ -424,6 +468,7 @@ irqreturn_t lan966x_mac_irq_handler(struct lan966x *lan966x) 
	       lan966x, ANA_MACTINDX);



	while (1) {

		spin_lock(&lan966x->mac_lock);

		lan_rmw(ANA_MACACCESS_MAC_TABLE_CMD_SET(MACACCESS_CMD_SYNC_GET_NEXT),

			ANA_MACACCESS_MAC_TABLE_CMD,

			lan966x, ANA_MACACCESS);
@@ -447,12 +492,15 @@ irqreturn_t lan966x_mac_irq_handler(struct lan966x *lan966x) 
			stop = false;



		if (column == LAN966X_MAC_COLUMNS - 1 &&

		    index == 0 && stop)

		    index == 0 && stop) {

			spin_unlock(&lan966x->mac_lock);

			break;

		}



		entry[column].mach = lan_rd(lan966x, ANA_MACHDATA);

		entry[column].macl = lan_rd(lan966x, ANA_MACLDATA);

		entry[column].maca = lan_rd(lan966x, ANA_MACACCESS);

		spin_unlock(&lan966x->mac_lock);



		/* Once all the columns are read process them */

		if (column == LAN966X_MAC_COLUMNS - 1) {