Commit 22d842e3 authored by Vladimir Oltean's avatar Vladimir Oltean Committed by Jakub Kicinski
Browse files

net: mscc: ocelot: turn stats_lock into a spinlock 



ocelot_get_stats64() currently runs unlocked and therefore may collide
with ocelot_port_update_stats() which indirectly accesses the same
counters. However, ocelot_get_stats64() runs in atomic context, and we
cannot simply take the sleepable ocelot->stats_lock mutex. We need to
convert it to an atomic spinlock first. Do that as a preparatory change.

Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 173ca866

drivers/net/dsa/ocelot/felix_vsc9959.c

+2 −2
Original line number Diff line number Diff line
@@ -2171,7 +2171,7 @@ static void vsc9959_psfp_sgi_table_del(struct ocelot *ocelot, 
static void vsc9959_psfp_counters_get(struct ocelot *ocelot, u32 index,

				      struct felix_stream_filter_counters *counters)

{

	mutex_lock(&ocelot->stats_lock);

	spin_lock(&ocelot->stats_lock);



	ocelot_rmw(ocelot, SYS_STAT_CFG_STAT_VIEW(index),

		   SYS_STAT_CFG_STAT_VIEW_M,
@@ -2188,7 +2188,7 @@ static void vsc9959_psfp_counters_get(struct ocelot *ocelot, u32 index, 
		     SYS_STAT_CFG_STAT_CLEAR_SHOT(0x10),

		     SYS_STAT_CFG);



	mutex_unlock(&ocelot->stats_lock);

	spin_unlock(&ocelot->stats_lock);

}



static int vsc9959_psfp_filter_add(struct ocelot *ocelot, int port,

drivers/net/ethernet/mscc/ocelot.c

+5 −6
Original line number Diff line number Diff line
@@ -1906,13 +1906,13 @@ static void ocelot_check_stats_work(struct work_struct *work) 
					     stats_work);

	int i, err;



	mutex_lock(&ocelot->stats_lock);

	spin_lock(&ocelot->stats_lock);

	for (i = 0; i < ocelot->num_phys_ports; i++) {

		err = ocelot_port_update_stats(ocelot, i);

		if (err)

			break;

	}

	mutex_unlock(&ocelot->stats_lock);

	spin_unlock(&ocelot->stats_lock);



	if (err)

		dev_err(ocelot->dev, "Error %d updating ethtool stats\n",  err);
@@ -1925,7 +1925,7 @@ void ocelot_get_ethtool_stats(struct ocelot *ocelot, int port, u64 *data) 
{

	int i, err;



	mutex_lock(&ocelot->stats_lock);

	spin_lock(&ocelot->stats_lock);



	/* check and update now */

	err = ocelot_port_update_stats(ocelot, port);
@@ -1934,7 +1934,7 @@ void ocelot_get_ethtool_stats(struct ocelot *ocelot, int port, u64 *data) 
	for (i = 0; i < ocelot->num_stats; i++)

		*data++ = ocelot->stats[port * ocelot->num_stats + i];



	mutex_unlock(&ocelot->stats_lock);

	spin_unlock(&ocelot->stats_lock);



	if (err)

		dev_err(ocelot->dev, "Error %d updating ethtool stats\n", err);
@@ -3363,7 +3363,7 @@ int ocelot_init(struct ocelot *ocelot) 
	if (!ocelot->stats)

		return -ENOMEM;



	mutex_init(&ocelot->stats_lock);

	spin_lock_init(&ocelot->stats_lock);

	mutex_init(&ocelot->ptp_lock);

	mutex_init(&ocelot->mact_lock);

	mutex_init(&ocelot->fwd_domain_lock);
@@ -3511,7 +3511,6 @@ 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);

include/soc/mscc/ocelot.h

+1 −1
Original line number Diff line number Diff line
@@ -752,7 +752,7 @@ struct ocelot { 
	struct ocelot_psfp_list		psfp;



	/* Workqueue to check statistics for overflow with its lock */

	struct mutex			stats_lock;

	spinlock_t			stats_lock;

	u64				*stats;

	struct delayed_work		stats_work;

	struct workqueue_struct		*stats_queue;