Commit ca0b272b authored by Vladimir Oltean's avatar Vladimir Oltean Committed by Jakub Kicinski
Browse files

net: mscc: ocelot: install MAC addresses in .ndo_set_rx_mode from process context 



Currently ocelot_set_rx_mode calls ocelot_mact_learn directly, which has
a very nice ocelot_mact_wait_for_completion at the end. Introduced in
commit 639c1b26 ("net: mscc: ocelot: Register poll timeout should be
wall time not attempts"), this function uses readx_poll_timeout which
triggers a lot of lockdep warnings and is also dangerous to use from
atomic context, potentially leading to lockups and panics.

Steen Hegelund added a poll timeout of 100 ms for checking the MAC
table, a duration which is clearly absurd to poll in atomic context.
So we need to defer the MAC table access to process context, which we do
via a dynamically allocated workqueue which contains all there is to
know about the MAC table operation it has to do.

Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20201212191612.222019-1-vladimir.oltean@nxp.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent a4485bae

drivers/net/ethernet/mscc/ocelot.c

+7 −0
Original line number Diff line number Diff line
@@ -1513,6 +1513,12 @@ int ocelot_init(struct ocelot *ocelot) 
	if (!ocelot->stats_queue)

		return -ENOMEM;



	ocelot->owq = alloc_ordered_workqueue("ocelot-owq", 0);

	if (!ocelot->owq) {

		destroy_workqueue(ocelot->stats_queue);

		return -ENOMEM;

	}



	INIT_LIST_HEAD(&ocelot->multicast);

	INIT_LIST_HEAD(&ocelot->pgids);

	ocelot_mact_init(ocelot);
@@ -1619,6 +1625,7 @@ void ocelot_deinit(struct ocelot *ocelot) 
{

	cancel_delayed_work(&ocelot->stats_work);

	destroy_workqueue(ocelot->stats_queue);

	destroy_workqueue(ocelot->owq);

	mutex_destroy(&ocelot->stats_lock);

}

EXPORT_SYMBOL(ocelot_deinit);

drivers/net/ethernet/mscc/ocelot_net.c

+77 −3
Original line number Diff line number Diff line
@@ -414,13 +414,81 @@ static int ocelot_port_xmit(struct sk_buff *skb, struct net_device *dev) 
	return NETDEV_TX_OK;

}



enum ocelot_action_type {

	OCELOT_MACT_LEARN,

	OCELOT_MACT_FORGET,

};



struct ocelot_mact_work_ctx {

	struct work_struct work;

	struct ocelot *ocelot;

	enum ocelot_action_type type;

	union {

		/* OCELOT_MACT_LEARN */

		struct {

			unsigned char addr[ETH_ALEN];

			u16 vid;

			enum macaccess_entry_type entry_type;

			int pgid;

		} learn;

		/* OCELOT_MACT_FORGET */

		struct {

			unsigned char addr[ETH_ALEN];

			u16 vid;

		} forget;

	};

};



#define ocelot_work_to_ctx(x) \

	container_of((x), struct ocelot_mact_work_ctx, work)



static void ocelot_mact_work(struct work_struct *work)

{

	struct ocelot_mact_work_ctx *w = ocelot_work_to_ctx(work);

	struct ocelot *ocelot = w->ocelot;



	switch (w->type) {

	case OCELOT_MACT_LEARN:

		ocelot_mact_learn(ocelot, w->learn.pgid, w->learn.addr,

				  w->learn.vid, w->learn.entry_type);

		break;

	case OCELOT_MACT_FORGET:

		ocelot_mact_forget(ocelot, w->forget.addr, w->forget.vid);

		break;

	default:

		break;

	};



	kfree(w);

}



static int ocelot_enqueue_mact_action(struct ocelot *ocelot,

				      const struct ocelot_mact_work_ctx *ctx)

{

	struct ocelot_mact_work_ctx *w = kmemdup(ctx, sizeof(*w), GFP_ATOMIC);



	if (!w)

		return -ENOMEM;



	w->ocelot = ocelot;

	INIT_WORK(&w->work, ocelot_mact_work);

	queue_work(ocelot->owq, &w->work);



	return 0;

}



static int ocelot_mc_unsync(struct net_device *dev, const unsigned char *addr)

{

	struct ocelot_port_private *priv = netdev_priv(dev);

	struct ocelot_port *ocelot_port = &priv->port;

	struct ocelot *ocelot = ocelot_port->ocelot;

	struct ocelot_mact_work_ctx w;



	return ocelot_mact_forget(ocelot, addr, ocelot_port->pvid_vlan.vid);

	ether_addr_copy(w.forget.addr, addr);

	w.forget.vid = ocelot_port->pvid_vlan.vid;

	w.type = OCELOT_MACT_FORGET;



	return ocelot_enqueue_mact_action(ocelot, &w);

}



static int ocelot_mc_sync(struct net_device *dev, const unsigned char *addr)
@@ -428,9 +496,15 @@ static int ocelot_mc_sync(struct net_device *dev, const unsigned char *addr) 
	struct ocelot_port_private *priv = netdev_priv(dev);

	struct ocelot_port *ocelot_port = &priv->port;

	struct ocelot *ocelot = ocelot_port->ocelot;

	struct ocelot_mact_work_ctx w;



	return ocelot_mact_learn(ocelot, PGID_CPU, addr,

				 ocelot_port->pvid_vlan.vid, ENTRYTYPE_LOCKED);

	ether_addr_copy(w.learn.addr, addr);

	w.learn.vid = ocelot_port->pvid_vlan.vid;

	w.learn.pgid = PGID_CPU;

	w.learn.entry_type = ENTRYTYPE_LOCKED;

	w.type = OCELOT_MACT_LEARN;



	return ocelot_enqueue_mact_action(ocelot, &w);

}



static void ocelot_set_rx_mode(struct net_device *dev)

include/soc/mscc/ocelot.h

+2 −0
Original line number Diff line number Diff line
@@ -650,6 +650,8 @@ struct ocelot { 
	struct delayed_work		stats_work;

	struct workqueue_struct		*stats_queue;



	struct workqueue_struct		*owq;



	u8				ptp:1;

	struct ptp_clock		*ptp_clock;

	struct ptp_clock_info		ptp_info;

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