net: mscc: ocelot: extend ocelot->fwd_domain_lock to cover ocelot->tas_lock

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 <vladimir.oltean@nxp.com>
Message-ID: <20230705104422.49025-2-vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
index 70c0e2b1936b335caa7cbff616a25a54834f2067..0c1207613aa4c8084f9aaf6d4994a591b6869f49 100644 (file)
--- 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 bb39fedd46c72370c796d21b7e36a9b6a57c8919..56b8bcac969014f88f18f628641d7730aad7532d 100644 (file)
--- 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 2fa833d041baa0c5f9101b9ed379aba58acd518b..56ccbd4c37fe6dab5c4df89d9c036270e3719455 100644 (file)
--- 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 fb3145118d686fd7c3fa77748a34566a987601a5..f3c0e6c3293445be6f289715b2670064523b4dc8 100644 (file)
--- 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 22aae505c813b32df6cc1e6f7060c4abcd0b2410..eb5f8914a66ca724915f2e9619b9617b72b20d51 100644 (file)
--- 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;