diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c
index e87066f658607d038615438c3ff037b1cc4f8fae..f0f0c20ecc2e3bbb6d7be60bf4225ca8da390628 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c
@@ -19,9 +19,19 @@
#define MLXSW_SP1_PTP_CLOCK_FREQ_KHZ 156257 /* 6.4nSec */
#define MLXSW_SP1_PTP_CLOCK_MASK 64
+#define MLXSW_SP1_PTP_HT_GC_INTERVAL 500 /* ms */
+
+/* How long, approximately, should the unmatched entries stay in the hash table
+ * before they are collected. Should be evenly divisible by the GC interval.
+ */
+#define MLXSW_SP1_PTP_HT_GC_TIMEOUT 1000 /* ms */
+
struct mlxsw_sp_ptp_state {
+ struct mlxsw_sp *mlxsw_sp;
struct rhashtable unmatched_ht;
spinlock_t unmatched_lock; /* protects the HT */
+ struct delayed_work ht_gc_dw;
+ u32 gc_cycle;
};
struct mlxsw_sp1_ptp_key {
@@ -38,6 +48,7 @@ struct mlxsw_sp1_ptp_unmatched {
struct rcu_head rcu;
struct sk_buff *skb;
u64 timestamp;
+ u32 gc_cycle;
};
static const struct rhashtable_params mlxsw_sp1_ptp_unmatched_ht_params = {
@@ -353,6 +364,7 @@ mlxsw_sp1_ptp_unmatched_save(struct mlxsw_sp *mlxsw_sp,
struct sk_buff *skb,
u64 timestamp)
{
+ int cycles = MLXSW_SP1_PTP_HT_GC_TIMEOUT / MLXSW_SP1_PTP_HT_GC_INTERVAL;
struct mlxsw_sp_ptp_state *ptp_state = mlxsw_sp->ptp_state;
struct mlxsw_sp1_ptp_unmatched *unmatched;
struct mlxsw_sp1_ptp_unmatched *conflict;
@@ -364,6 +376,7 @@ mlxsw_sp1_ptp_unmatched_save(struct mlxsw_sp *mlxsw_sp,
unmatched->key = key;
unmatched->skb = skb;
unmatched->timestamp = timestamp;
+ unmatched->gc_cycle = mlxsw_sp->ptp_state->gc_cycle + cycles;
conflict = rhashtable_lookup_get_insert_fast(&ptp_state->unmatched_ht,
&unmatched->ht_node,
@@ -396,6 +409,8 @@ mlxsw_sp1_ptp_unmatched_remove(struct mlxsw_sp *mlxsw_sp,
* 1) When a packet is matched with its timestamp.
* 2) In several situation when it is necessary to immediately pass on
* an SKB without a timestamp.
+ * 3) From GC indirectly through mlxsw_sp1_ptp_unmatched_finish().
+ * This case is similar to 2) above.
*/
static void mlxsw_sp1_ptp_packet_finish(struct mlxsw_sp *mlxsw_sp,
struct sk_buff *skb, u8 local_port,
@@ -637,6 +652,72 @@ void mlxsw_sp1_ptp_transmitted(struct mlxsw_sp *mlxsw_sp,
mlxsw_sp1_ptp_got_packet(mlxsw_sp, skb, local_port, false);
}
+static void
+mlxsw_sp1_ptp_ht_gc_collect(struct mlxsw_sp_ptp_state *ptp_state,
+ struct mlxsw_sp1_ptp_unmatched *unmatched)
+{
+ int err;
+
+ /* If an unmatched entry has an SKB, it has to be handed over to the
+ * networking stack. This is usually done from a trap handler, which is
+ * invoked in a softirq context. Here we are going to do it in process
+ * context. If that were to be interrupted by a softirq, it could cause
+ * a deadlock when an attempt is made to take an already-taken lock
+ * somewhere along the sending path. Disable softirqs to prevent this.
+ */
+ local_bh_disable();
+
+ spin_lock(&ptp_state->unmatched_lock);
+ err = rhashtable_remove_fast(&ptp_state->unmatched_ht,
+ &unmatched->ht_node,
+ mlxsw_sp1_ptp_unmatched_ht_params);
+ spin_unlock(&ptp_state->unmatched_lock);
+
+ if (err)
+ /* The packet was matched with timestamp during the walk. */
+ goto out;
+
+ /* mlxsw_sp1_ptp_unmatched_finish() invokes netif_receive_skb(). While
+ * the comment at that function states that it can only be called in
+ * soft IRQ context, this pattern of local_bh_disable() +
+ * netif_receive_skb(), in process context, is seen elsewhere in the
+ * kernel, notably in pktgen.
+ */
+ mlxsw_sp1_ptp_unmatched_finish(ptp_state->mlxsw_sp, unmatched);
+
+out:
+ local_bh_enable();
+}
+
+static void mlxsw_sp1_ptp_ht_gc(struct work_struct *work)
+{
+ struct delayed_work *dwork = to_delayed_work(work);
+ struct mlxsw_sp1_ptp_unmatched *unmatched;
+ struct mlxsw_sp_ptp_state *ptp_state;
+ struct rhashtable_iter iter;
+ u32 gc_cycle;
+ void *obj;
+
+ ptp_state = container_of(dwork, struct mlxsw_sp_ptp_state, ht_gc_dw);
+ gc_cycle = ptp_state->gc_cycle++;
+
+ rhashtable_walk_enter(&ptp_state->unmatched_ht, &iter);
+ rhashtable_walk_start(&iter);
+ while ((obj = rhashtable_walk_next(&iter))) {
+ if (IS_ERR(obj))
+ continue;
+
+ unmatched = obj;
+ if (unmatched->gc_cycle <= gc_cycle)
+ mlxsw_sp1_ptp_ht_gc_collect(ptp_state, unmatched);
+ }
+ rhashtable_walk_stop(&iter);
+ rhashtable_walk_exit(&iter);
+
+ mlxsw_core_schedule_dw(&ptp_state->ht_gc_dw,
+ MLXSW_SP1_PTP_HT_GC_INTERVAL);
+}
+
struct mlxsw_sp_ptp_state *mlxsw_sp1_ptp_init(struct mlxsw_sp *mlxsw_sp)
{
struct mlxsw_sp_ptp_state *ptp_state;
@@ -645,6 +726,7 @@ struct mlxsw_sp_ptp_state *mlxsw_sp1_ptp_init(struct mlxsw_sp *mlxsw_sp)
ptp_state = kzalloc(sizeof(*ptp_state), GFP_KERNEL);
if (!ptp_state)
return ERR_PTR(-ENOMEM);
+ ptp_state->mlxsw_sp = mlxsw_sp;
spin_lock_init(&ptp_state->unmatched_lock);
@@ -653,6 +735,9 @@ struct mlxsw_sp_ptp_state *mlxsw_sp1_ptp_init(struct mlxsw_sp *mlxsw_sp)
if (err)
goto err_hashtable_init;
+ INIT_DELAYED_WORK(&ptp_state->ht_gc_dw, mlxsw_sp1_ptp_ht_gc);
+ mlxsw_core_schedule_dw(&ptp_state->ht_gc_dw,
+ MLXSW_SP1_PTP_HT_GC_INTERVAL);
return ptp_state;
err_hashtable_init:
@@ -662,6 +747,7 @@ err_hashtable_init:
void mlxsw_sp1_ptp_fini(struct mlxsw_sp_ptp_state *ptp_state)
{
+ cancel_delayed_work_sync(&ptp_state->ht_gc_dw);
rhashtable_free_and_destroy(&ptp_state->unmatched_ht,
&mlxsw_sp1_ptp_unmatched_free_fn, NULL);
kfree(ptp_state);