In a future commit we will have to call vsc9959_tas_guard_bands_update()
from ocelot_port_update_active_preemptible_tcs(), and that will be
impossible due to the AB/BA locking dependencies between
ocelot->tas_lock and ocelot->fwd_domain_lock.
Just like we did in commit 3ff468ef987e ("net: mscc: ocelot: remove
struct ocelot_mm_state :: lock"), the only solution is to expand the
scope of ocelot->fwd_domain_lock for it to also serialize changes made
to the Time-Aware Shaper, because those will have to result in a
recalculation of cut-through TCs, which is something that depends on the
forwarding domain.
Signed-off-by: Vladimir Oltean <[email protected]>
---
drivers/net/dsa/ocelot/felix.c | 4 +--
drivers/net/dsa/ocelot/felix_vsc9959.c | 36 ++++++++++++++++----------
drivers/net/ethernet/mscc/ocelot.c | 1 -
drivers/net/ethernet/mscc/ocelot_mm.c | 7 ++---
include/soc/mscc/ocelot.h | 8 +++---
5 files changed, 30 insertions(+), 26 deletions(-)
diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
index 70c0e2b1936b..0c1207613aa4 100644
--- a/drivers/net/dsa/ocelot/felix.c
+++ b/drivers/net/dsa/ocelot/felix.c
@@ -1790,12 +1790,12 @@ static int felix_change_mtu(struct dsa_switch *ds, int port, int new_mtu)
ocelot_port_set_maxlen(ocelot, port, new_mtu);
- mutex_lock(&ocelot->tas_lock);
+ mutex_lock(&ocelot->fwd_domain_lock);
if (ocelot_port->taprio && felix->info->tas_guard_bands_update)
felix->info->tas_guard_bands_update(ocelot, port);
- mutex_unlock(&ocelot->tas_lock);
+ mutex_unlock(&ocelot->fwd_domain_lock);
return 0;
}
diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c
index bb39fedd46c7..56b8bcac9690 100644
--- a/drivers/net/dsa/ocelot/felix_vsc9959.c
+++ b/drivers/net/dsa/ocelot/felix_vsc9959.c
@@ -1217,7 +1217,7 @@ static void vsc9959_tas_guard_bands_update(struct ocelot *ocelot, int port)
u8 tas_speed;
int tc;
- lockdep_assert_held(&ocelot->tas_lock);
+ lockdep_assert_held(&ocelot->fwd_domain_lock);
taprio = ocelot_port->taprio;
@@ -1259,8 +1259,6 @@ static void vsc9959_tas_guard_bands_update(struct ocelot *ocelot, int port)
vsc9959_tas_min_gate_lengths(taprio, min_gate_len);
- mutex_lock(&ocelot->fwd_domain_lock);
-
for (tc = 0; tc < OCELOT_NUM_TC; tc++) {
u32 requested_max_sdu = vsc9959_tas_tc_max_sdu(taprio, tc);
u64 remaining_gate_len_ps;
@@ -1323,8 +1321,6 @@ static void vsc9959_tas_guard_bands_update(struct ocelot *ocelot, int port)
ocelot_write_rix(ocelot, maxlen, QSYS_PORT_MAX_SDU, port);
ocelot->ops->cut_through_fwd(ocelot);
-
- mutex_unlock(&ocelot->fwd_domain_lock);
}
static void vsc9959_sched_speed_set(struct ocelot *ocelot, int port,
@@ -1351,7 +1347,7 @@ static void vsc9959_sched_speed_set(struct ocelot *ocelot, int port,
break;
}
- mutex_lock(&ocelot->tas_lock);
+ mutex_lock(&ocelot->fwd_domain_lock);
ocelot_rmw_rix(ocelot,
QSYS_TAG_CONFIG_LINK_SPEED(tas_speed),
@@ -1361,7 +1357,7 @@ static void vsc9959_sched_speed_set(struct ocelot *ocelot, int port,
if (ocelot_port->taprio)
vsc9959_tas_guard_bands_update(ocelot, port);
- mutex_unlock(&ocelot->tas_lock);
+ mutex_unlock(&ocelot->fwd_domain_lock);
}
static void vsc9959_new_base_time(struct ocelot *ocelot, ktime_t base_time,
@@ -1409,7 +1405,7 @@ static int vsc9959_qos_port_tas_set(struct ocelot *ocelot, int port,
int ret, i;
u32 val;
- mutex_lock(&ocelot->tas_lock);
+ mutex_lock(&ocelot->fwd_domain_lock);
if (taprio->cmd == TAPRIO_CMD_DESTROY) {
ocelot_port_mqprio(ocelot, port, &taprio->mqprio);
@@ -1421,7 +1417,7 @@ static int vsc9959_qos_port_tas_set(struct ocelot *ocelot, int port,
vsc9959_tas_guard_bands_update(ocelot, port);
- mutex_unlock(&ocelot->tas_lock);
+ mutex_unlock(&ocelot->fwd_domain_lock);
return 0;
} else if (taprio->cmd != TAPRIO_CMD_REPLACE) {
ret = -EOPNOTSUPP;
@@ -1504,7 +1500,7 @@ static int vsc9959_qos_port_tas_set(struct ocelot *ocelot, int port,
ocelot_port->taprio = taprio_offload_get(taprio);
vsc9959_tas_guard_bands_update(ocelot, port);
- mutex_unlock(&ocelot->tas_lock);
+ mutex_unlock(&ocelot->fwd_domain_lock);
return 0;
@@ -1512,7 +1508,7 @@ static int vsc9959_qos_port_tas_set(struct ocelot *ocelot, int port,
taprio->mqprio.qopt.num_tc = 0;
ocelot_port_mqprio(ocelot, port, &taprio->mqprio);
err_unlock:
- mutex_unlock(&ocelot->tas_lock);
+ mutex_unlock(&ocelot->fwd_domain_lock);
return ret;
}
@@ -1525,7 +1521,7 @@ static void vsc9959_tas_clock_adjust(struct ocelot *ocelot)
int port;
u32 val;
- mutex_lock(&ocelot->tas_lock);
+ mutex_lock(&ocelot->fwd_domain_lock);
for (port = 0; port < ocelot->num_phys_ports; port++) {
ocelot_port = ocelot->ports[port];
@@ -1563,7 +1559,7 @@ static void vsc9959_tas_clock_adjust(struct ocelot *ocelot)
QSYS_TAG_CONFIG_ENABLE,
QSYS_TAG_CONFIG, port);
}
- mutex_unlock(&ocelot->tas_lock);
+ mutex_unlock(&ocelot->fwd_domain_lock);
}
static int vsc9959_qos_port_cbs_set(struct dsa_switch *ds, int port,
@@ -1634,6 +1630,18 @@ static int vsc9959_qos_query_caps(struct tc_query_caps_base *base)
}
}
+static int vsc9959_qos_port_mqprio(struct ocelot *ocelot, int port,
+ struct tc_mqprio_qopt_offload *mqprio)
+{
+ int ret;
+
+ mutex_lock(&ocelot->fwd_domain_lock);
+ ret = ocelot_port_mqprio(ocelot, port, mqprio);
+ mutex_unlock(&ocelot->fwd_domain_lock);
+
+ return ret;
+}
+
static int vsc9959_port_setup_tc(struct dsa_switch *ds, int port,
enum tc_setup_type type,
void *type_data)
@@ -1646,7 +1654,7 @@ static int vsc9959_port_setup_tc(struct dsa_switch *ds, int port,
case TC_SETUP_QDISC_TAPRIO:
return vsc9959_qos_port_tas_set(ocelot, port, type_data);
case TC_SETUP_QDISC_MQPRIO:
- return ocelot_port_mqprio(ocelot, port, type_data);
+ return vsc9959_qos_port_mqprio(ocelot, port, type_data);
case TC_SETUP_QDISC_CBS:
return vsc9959_qos_port_cbs_set(ds, port, type_data);
default:
diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index 2fa833d041ba..56ccbd4c37fe 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -2927,7 +2927,6 @@ int ocelot_init(struct ocelot *ocelot)
mutex_init(&ocelot->mact_lock);
mutex_init(&ocelot->fwd_domain_lock);
- mutex_init(&ocelot->tas_lock);
spin_lock_init(&ocelot->ptp_clock_lock);
spin_lock_init(&ocelot->ts_id_lock);
diff --git a/drivers/net/ethernet/mscc/ocelot_mm.c b/drivers/net/ethernet/mscc/ocelot_mm.c
index fb3145118d68..f3c0e6c32934 100644
--- a/drivers/net/ethernet/mscc/ocelot_mm.c
+++ b/drivers/net/ethernet/mscc/ocelot_mm.c
@@ -89,17 +89,14 @@ void ocelot_port_change_fp(struct ocelot *ocelot, int port,
{
struct ocelot_mm_state *mm = &ocelot->mm[port];
- mutex_lock(&ocelot->fwd_domain_lock);
+ lockdep_assert_held(&ocelot->fwd_domain_lock);
if (mm->preemptible_tcs == preemptible_tcs)
- goto out_unlock;
+ return;
mm->preemptible_tcs = preemptible_tcs;
ocelot_port_update_active_preemptible_tcs(ocelot, port);
-
-out_unlock:
- mutex_unlock(&ocelot->fwd_domain_lock);
}
static void ocelot_mm_update_port_status(struct ocelot *ocelot, int port)
diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h
index 22aae505c813..eb5f8914a66c 100644
--- a/include/soc/mscc/ocelot.h
+++ b/include/soc/mscc/ocelot.h
@@ -863,12 +863,12 @@ struct ocelot {
struct mutex stat_view_lock;
/* Lock for serializing access to the MAC table */
struct mutex mact_lock;
- /* Lock for serializing forwarding domain changes */
+ /* Lock for serializing forwarding domain changes, including the
+ * configuration of the Time-Aware Shaper, MAC Merge layer and
+ * cut-through forwarding, on which it depends
+ */
struct mutex fwd_domain_lock;
- /* Lock for serializing Time-Aware Shaper changes */
- struct mutex tas_lock;
-
struct workqueue_struct *owq;
u8 ptp:1;
--
2.34.1
On Wed, Jul 05, 2023 at 01:44:20PM +0300, Vladimir Oltean wrote:
> In a future commit we will have to call vsc9959_tas_guard_bands_update()
> from ocelot_port_update_active_preemptible_tcs(), and that will be
> impossible due to the AB/BA locking dependencies between
> ocelot->tas_lock and ocelot->fwd_domain_lock.
>
> Just like we did in commit 3ff468ef987e ("net: mscc: ocelot: remove
> struct ocelot_mm_state :: lock"), the only solution is to expand the
> scope of ocelot->fwd_domain_lock for it to also serialize changes made
> to the Time-Aware Shaper, because those will have to result in a
> recalculation of cut-through TCs, which is something that depends on the
> forwarding domain.
>
> Signed-off-by: Vladimir Oltean <[email protected]>
Reviewed-by: Simon Horman <[email protected]>