net/mlx5: qos: Refactor locking to a qos domain mutex

E-Switch qos changes used the esw state_lock to serialize qos changes.
With the introduction of cross-esw scheduling, multiple E-Switches might
be involved in a qos operation, so prepare for that by switching locking
to use a qos domain mutex.
Add three helper functions:
- esw_qos_lock
- esw_qos_unlock
- esw_assert_qos_lock_held

Convert existing direct lock/unlock/lockdep calls to them. Also call
esw_assert_qos_lock_held in a couple more places.

mlx5_esw_qos_set_vport_rate expected to be called with the esw
state_lock already held.
Change it to instead acquire the qos lock directly.

mlx5_eswitch_get_vport_config also accessed qos properties with the esw
state lock. Introduce a new function mlx5_esw_qos_get_vport_rate to
access those with the correct lock and change get_vport_config to use
it.

Finally, mlx5_vport_disable is called from the cleanup path with the esw
state_lock held, so have it additionally acquire the qos lock to make
sure there are no races.

Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/esw/legacy.c b/drivers/net/ethernet/mellanox/mlx5/core/esw/legacy.c
index 3c8388706e152917092bf69b5e8af5bfbbf7fc36..288c797e4a78a052602be0fb1eb0db16942c71fe 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/esw/legacy.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/esw/legacy.c
@@ -513,15 +513,11 @@ int mlx5_eswitch_set_vport_rate(struct mlx5_eswitch *esw, u16 vport,
                                u32 max_rate, u32 min_rate)
 {
        struct mlx5_vport *evport = mlx5_eswitch_get_vport(esw, vport);
-       int err;
 
        if (!mlx5_esw_allowed(esw))
                return -EPERM;
        if (IS_ERR(evport))
                return PTR_ERR(evport);
 
-       mutex_lock(&esw->state_lock);
-       err = mlx5_esw_qos_set_vport_rate(evport, max_rate, min_rate);
-       mutex_unlock(&esw->state_lock);
-       return err;
+       return mlx5_esw_qos_set_vport_rate(evport, max_rate, min_rate);
 }

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
index 06b3a21a7475ecba8847a11a3904f316baa7f49c..be9abeb6e4aa096f76dff1eab866ff4a62d9d6f3 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.c
@@ -13,10 +13,27 @@
 
 /* Holds rate groups associated with an E-Switch. */
 struct mlx5_qos_domain {
+       /* Serializes access to all qos changes in the qos domain. */
+       struct mutex lock;
        /* List of all mlx5_esw_rate_groups. */
        struct list_head groups;
 };
 
+static void esw_qos_lock(struct mlx5_eswitch *esw)
+{
+       mutex_lock(&esw->qos.domain->lock);
+}
+
+static void esw_qos_unlock(struct mlx5_eswitch *esw)
+{
+       mutex_unlock(&esw->qos.domain->lock);
+}
+
+static void esw_assert_qos_lock_held(struct mlx5_eswitch *esw)
+{
+       lockdep_assert_held(&esw->qos.domain->lock);
+}
+
 static struct mlx5_qos_domain *esw_qos_domain_alloc(void)
 {
        struct mlx5_qos_domain *qos_domain;
@@ -25,6 +42,7 @@ static struct mlx5_qos_domain *esw_qos_domain_alloc(void)
        if (!qos_domain)
                return NULL;
 
+       mutex_init(&qos_domain->lock);
        INIT_LIST_HEAD(&qos_domain->groups);
 
        return qos_domain;
@@ -249,7 +267,7 @@ static int esw_qos_set_vport_min_rate(struct mlx5_vport *vport,
        bool min_rate_supported;
        int err;
 
-       lockdep_assert_held(&esw->state_lock);
+       esw_assert_qos_lock_held(esw);
        fw_max_bw_share = MLX5_CAP_QOS(vport->dev, max_tsar_bw_share);
        min_rate_supported = MLX5_CAP_QOS(vport->dev, esw_bw_share) &&
                                fw_max_bw_share >= MLX5_MIN_BW_SHARE;
@@ -275,7 +293,7 @@ static int esw_qos_set_vport_max_rate(struct mlx5_vport *vport,
        bool max_rate_supported;
        int err;
 
-       lockdep_assert_held(&esw->state_lock);
+       esw_assert_qos_lock_held(esw);
        max_rate_supported = MLX5_CAP_QOS(vport->dev, esw_rate_limit);
 
        if (max_rate && !max_rate_supported)
@@ -451,9 +469,7 @@ static int esw_qos_vport_update_group(struct mlx5_vport *vport,
        struct mlx5_esw_rate_group *new_group, *curr_group;
        int err;
 
-       if (!vport->enabled)
-               return -EINVAL;
-
+       esw_assert_qos_lock_held(esw);
        curr_group = vport->qos.group;
        new_group = group ?: esw->qos.group0;
        if (curr_group == new_group)
@@ -552,6 +568,7 @@ esw_qos_create_rate_group(struct mlx5_eswitch *esw, struct netlink_ext_ack *exta
        struct mlx5_esw_rate_group *group;
        int err;
 
+       esw_assert_qos_lock_held(esw);
        if (!MLX5_CAP_QOS(esw->dev, log_esw_max_sched_depth))
                return ERR_PTR(-EOPNOTSUPP);
 
@@ -665,8 +682,7 @@ static int esw_qos_get(struct mlx5_eswitch *esw, struct netlink_ext_ack *extack)
 {
        int err = 0;
 
-       lockdep_assert_held(&esw->state_lock);
-
+       esw_assert_qos_lock_held(esw);
        if (!refcount_inc_not_zero(&esw->qos.refcnt)) {
                /* esw_qos_create() set refcount to 1 only on success.
                 * No need to decrement on failure.
@@ -679,7 +695,7 @@ static int esw_qos_get(struct mlx5_eswitch *esw, struct netlink_ext_ack *extack)
 
 static void esw_qos_put(struct mlx5_eswitch *esw)
 {
-       lockdep_assert_held(&esw->state_lock);
+       esw_assert_qos_lock_held(esw);
        if (refcount_dec_and_test(&esw->qos.refcnt))
                esw_qos_destroy(esw);
 }
@@ -690,7 +706,7 @@ static int esw_qos_vport_enable(struct mlx5_vport *vport,
        struct mlx5_eswitch *esw = vport->dev->priv.eswitch;
        int err;
 
-       lockdep_assert_held(&esw->state_lock);
+       esw_assert_qos_lock_held(esw);
        if (vport->qos.enabled)
                return 0;
 
@@ -723,8 +739,9 @@ void mlx5_esw_qos_vport_disable(struct mlx5_vport *vport)
        int err;
 
        lockdep_assert_held(&esw->state_lock);
+       esw_qos_lock(esw);
        if (!vport->qos.enabled)
-               return;
+               goto unlock;
        WARN(vport->qos.group != esw->qos.group0,
             "Disabling QoS on port before detaching it from group");
 
@@ -741,6 +758,8 @@ void mlx5_esw_qos_vport_disable(struct mlx5_vport *vport)
        trace_mlx5_esw_vport_qos_destroy(dev, vport);
 
        esw_qos_put(esw);
+unlock:
+       esw_qos_unlock(esw);
 }
 
 int mlx5_esw_qos_set_vport_rate(struct mlx5_vport *vport, u32 max_rate, u32 min_rate)
@@ -748,17 +767,34 @@ int mlx5_esw_qos_set_vport_rate(struct mlx5_vport *vport, u32 max_rate, u32 min_
        struct mlx5_eswitch *esw = vport->dev->priv.eswitch;
        int err;
 
-       lockdep_assert_held(&esw->state_lock);
+       esw_qos_lock(esw);
        err = esw_qos_vport_enable(vport, 0, 0, NULL);
        if (err)
-               return err;
+               goto unlock;
 
        err = esw_qos_set_vport_min_rate(vport, min_rate, NULL);
        if (!err)
                err = esw_qos_set_vport_max_rate(vport, max_rate, NULL);
+unlock:
+       esw_qos_unlock(esw);
        return err;
 }
 
+bool mlx5_esw_qos_get_vport_rate(struct mlx5_vport *vport, u32 *max_rate, u32 *min_rate)
+{
+       struct mlx5_eswitch *esw = vport->dev->priv.eswitch;
+       bool enabled;
+
+       esw_qos_lock(esw);
+       enabled = vport->qos.enabled;
+       if (enabled) {
+               *max_rate = vport->qos.max_rate;
+               *min_rate = vport->qos.min_rate;
+       }
+       esw_qos_unlock(esw);
+       return enabled;
+}
+
 static u32 mlx5_esw_qos_lag_link_speed_get_locked(struct mlx5_core_dev *mdev)
 {
        struct ethtool_link_ksettings lksettings;
@@ -846,7 +882,7 @@ int mlx5_esw_qos_modify_vport_rate(struct mlx5_eswitch *esw, u16 vport_num, u32
                        return err;
        }
 
-       mutex_lock(&esw->state_lock);
+       esw_qos_lock(esw);
        if (!vport->qos.enabled) {
                /* Eswitch QoS wasn't enabled yet. Enable it and vport QoS. */
                err = esw_qos_vport_enable(vport, rate_mbps, vport->qos.bw_share, NULL);
@@ -861,7 +897,7 @@ int mlx5_esw_qos_modify_vport_rate(struct mlx5_eswitch *esw, u16 vport_num, u32
                                                         vport->qos.esw_sched_elem_ix,
                                                         bitmask);
        }
-       mutex_unlock(&esw->state_lock);
+       esw_qos_unlock(esw);
 
        return err;
 }
@@ -927,14 +963,14 @@ int mlx5_esw_devlink_rate_leaf_tx_share_set(struct devlink_rate *rate_leaf, void
        if (err)
                return err;
 
-       mutex_lock(&esw->state_lock);
+       esw_qos_lock(esw);
        err = esw_qos_vport_enable(vport, 0, 0, extack);
        if (err)
                goto unlock;
 
        err = esw_qos_set_vport_min_rate(vport, tx_share, extack);
 unlock:
-       mutex_unlock(&esw->state_lock);
+       esw_qos_unlock(esw);
        return err;
 }
 
@@ -953,14 +989,14 @@ int mlx5_esw_devlink_rate_leaf_tx_max_set(struct devlink_rate *rate_leaf, void *
        if (err)
                return err;
 
-       mutex_lock(&esw->state_lock);
+       esw_qos_lock(esw);
        err = esw_qos_vport_enable(vport, 0, 0, extack);
        if (err)
                goto unlock;
 
        err = esw_qos_set_vport_max_rate(vport, tx_max, extack);
 unlock:
-       mutex_unlock(&esw->state_lock);
+       esw_qos_unlock(esw);
        return err;
 }
 
@@ -975,9 +1011,9 @@ int mlx5_esw_devlink_rate_node_tx_share_set(struct devlink_rate *rate_node, void
        if (err)
                return err;
 
-       mutex_lock(&esw->state_lock);
+       esw_qos_lock(esw);
        err = esw_qos_set_group_min_rate(group, tx_share, extack);
-       mutex_unlock(&esw->state_lock);
+       esw_qos_unlock(esw);
        return err;
 }
 
@@ -992,9 +1028,9 @@ int mlx5_esw_devlink_rate_node_tx_max_set(struct devlink_rate *rate_node, void *
        if (err)
                return err;
 
-       mutex_lock(&esw->state_lock);
+       esw_qos_lock(esw);
        err = esw_qos_set_group_max_rate(group, tx_max, extack);
-       mutex_unlock(&esw->state_lock);
+       esw_qos_unlock(esw);
        return err;
 }
 
@@ -1009,7 +1045,7 @@ int mlx5_esw_devlink_rate_node_new(struct devlink_rate *rate_node, void **priv,
        if (IS_ERR(esw))
                return PTR_ERR(esw);
 
-       mutex_lock(&esw->state_lock);
+       esw_qos_lock(esw);
        if (esw->mode != MLX5_ESWITCH_OFFLOADS) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Rate node creation supported only in switchdev mode");
@@ -1025,7 +1061,7 @@ int mlx5_esw_devlink_rate_node_new(struct devlink_rate *rate_node, void **priv,
 
        *priv = group;
 unlock:
-       mutex_unlock(&esw->state_lock);
+       esw_qos_unlock(esw);
        return err;
 }
 
@@ -1036,10 +1072,10 @@ int mlx5_esw_devlink_rate_node_del(struct devlink_rate *rate_node, void *priv,
        struct mlx5_eswitch *esw = group->esw;
        int err;
 
-       mutex_lock(&esw->state_lock);
+       esw_qos_lock(esw);
        err = __esw_qos_destroy_rate_group(group, extack);
        esw_qos_put(esw);
-       mutex_unlock(&esw->state_lock);
+       esw_qos_unlock(esw);
        return err;
 }
 
@@ -1055,7 +1091,7 @@ int mlx5_esw_qos_vport_update_group(struct mlx5_vport *vport,
                return -EOPNOTSUPP;
        }
 
-       mutex_lock(&esw->state_lock);
+       esw_qos_lock(esw);
        if (!vport->qos.enabled && !group)
                goto unlock;
 
@@ -1063,7 +1099,7 @@ int mlx5_esw_qos_vport_update_group(struct mlx5_vport *vport,
        if (!err)
                err = esw_qos_vport_update_group(vport, group, extack);
 unlock:
-       mutex_unlock(&esw->state_lock);
+       esw_qos_unlock(esw);
        return err;
 }
 

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.h b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.h
index 44fb339c5dcc88bede4b9c1eb3e2264f8a162003..b4045efbaf9e931876028e30b532db1232160191 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/esw/qos.h
@@ -10,6 +10,7 @@ int mlx5_esw_qos_init(struct mlx5_eswitch *esw);
 void mlx5_esw_qos_cleanup(struct mlx5_eswitch *esw);
 
 int mlx5_esw_qos_set_vport_rate(struct mlx5_vport *evport, u32 max_rate, u32 min_rate);
+bool mlx5_esw_qos_get_vport_rate(struct mlx5_vport *vport, u32 *max_rate, u32 *min_rate);
 void mlx5_esw_qos_vport_disable(struct mlx5_vport *vport);
 
 int mlx5_esw_devlink_rate_leaf_tx_share_set(struct devlink_rate *rate_leaf, void *priv,

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c
index 9de819c45d3357942c8cef8fd0cd469862ddbacb..2bcd42305f46bb382ed877709282ba203fe4d41d 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c
@@ -2068,6 +2068,7 @@ int mlx5_eswitch_get_vport_config(struct mlx5_eswitch *esw,
                                  u16 vport, struct ifla_vf_info *ivi)
 {
        struct mlx5_vport *evport = mlx5_eswitch_get_vport(esw, vport);
+       u32 max_rate, min_rate;
 
        if (IS_ERR(evport))
                return PTR_ERR(evport);
@@ -2082,9 +2083,10 @@ int mlx5_eswitch_get_vport_config(struct mlx5_eswitch *esw,
        ivi->qos = evport->info.qos;
        ivi->spoofchk = evport->info.spoofchk;
        ivi->trusted = evport->info.trusted;
-       if (evport->qos.enabled) {
-               ivi->min_tx_rate = evport->qos.min_rate;
-               ivi->max_tx_rate = evport->qos.max_rate;
+
+       if (mlx5_esw_qos_get_vport_rate(evport, &max_rate, &min_rate)) {
+               ivi->max_tx_rate = max_rate;
+               ivi->min_tx_rate = min_rate;
        }
        mutex_unlock(&esw->state_lock);
 

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
index e57be2eeec85b4e6df41051143749ac6fb4d73e8..3b901bd36d4b1c70505b756f23389b1777328607 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
@@ -212,6 +212,7 @@ struct mlx5_vport {
 
        struct mlx5_vport_info  info;
 
+       /* Protected with the E-Switch qos domain lock. */
        struct {
                /* Initially false, set to true whenever any QoS features are used. */
                bool enabled;
@@ -363,10 +364,9 @@ struct mlx5_eswitch {
        struct rw_semaphore mode_lock;
        atomic64_t user_count;
 
+       /* Protected with the E-Switch qos domain lock. */
        struct {
-               /* Protected by esw->state_lock.
-                * Initially 0, meaning no QoS users and QoS is disabled.
-                */
+               /* Initially 0, meaning no QoS users and QoS is disabled. */
                refcount_t refcnt;
                u32 root_tsar_ix;
                struct mlx5_qos_domain *domain;