net/mlx5: Introduce bulk reading of flow counters

This commit utilize the ability of ConnectX-4 to bulk read flow counters.
Few bulk counter queries could be done instead of issuing thousands of
firmware commands per second to get statistics of all flows set to HW,
such as those programmed when we offload tc filters.

Counters are stored sorted by hardware id, and queried in blocks (id +
number of counters).

Due to hardware requirement, start of block and number of counters in a
block must be four aligned.

Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Amir Vadai <amir@vadai.me>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 61 insertions, 22 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fs_counters.c b/drivers/net/ethernet/mellanox/mlx5/core/fs_counters.c
index aaf8fd149cc6..c2877e9de8a1 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/fs_counters.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fs_counters.c
@@ -90,16 +90,66 @@ static void mlx5_fc_stats_insert(struct rb_root *root, struct mlx5_fc *counter)
 	rb_insert_color(&counter->node, root);
 }
 
+static struct rb_node *mlx5_fc_stats_query(struct mlx5_core_dev *dev,
+					   struct mlx5_fc *first,
+					   u16 last_id)
+{
+	struct mlx5_cmd_fc_bulk *b;
+	struct rb_node *node = NULL;
+	u16 afirst_id;
+	int num;
+	int err;
+	int max_bulk = 1 << MLX5_CAP_GEN(dev, log_max_flow_counter_bulk);
+
+	/* first id must be aligned to 4 when using bulk query */
+	afirst_id = first->id & ~0x3;
+
+	/* number of counters to query inc. the last counter */
+	num = ALIGN(last_id - afirst_id + 1, 4);
+	if (num > max_bulk) {
+		num = max_bulk;
+		last_id = afirst_id + num - 1;
+	}
+
+	b = mlx5_cmd_fc_bulk_alloc(dev, afirst_id, num);
+	if (!b) {
+		mlx5_core_err(dev, "Error allocating resources for bulk query\n");
+		return NULL;
+	}
+
+	err = mlx5_cmd_fc_bulk_query(dev, b);
+	if (err) {
+		mlx5_core_err(dev, "Error doing bulk query: %d\n", err);
+		goto out;
+	}
+
+	for (node = &first->node; node; node = rb_next(node)) {
+		struct mlx5_fc *counter = rb_entry(node, struct mlx5_fc, node);
+		struct mlx5_fc_cache *c = &counter->cache;
+
+		if (counter->id > last_id)
+			break;
+
+		mlx5_cmd_fc_bulk_get(dev, b,
+				     counter->id, &c->packets, &c->bytes);
+	}
+
+out:
+	mlx5_cmd_fc_bulk_free(b);
+
+	return node;
+}
+
 static void mlx5_fc_stats_work(struct work_struct *work)
 {
 	struct mlx5_core_dev *dev = container_of(work, struct mlx5_core_dev,
 						 priv.fc_stats.work.work);
 	struct mlx5_fc_stats *fc_stats = &dev->priv.fc_stats;
 	unsigned long now = jiffies;
-	struct mlx5_fc *counter;
+	struct mlx5_fc *counter = NULL;
+	struct mlx5_fc *last = NULL;
 	struct rb_node *node;
 	LIST_HEAD(tmplist);
-	int err = 0;
 
 	spin_lock(&fc_stats->addlist_lock);
 
@@ -115,12 +165,7 @@ static void mlx5_fc_stats_work(struct work_struct *work)
 
 	node = rb_first(&fc_stats->counters);
 	while (node) {
-		struct mlx5_fc_cache *c;
-		u64 packets;
-		u64 bytes;
-
 		counter = rb_entry(node, struct mlx5_fc, node);
-		c = &counter->cache;
 
 		node = rb_next(node);
 
@@ -133,26 +178,20 @@ static void mlx5_fc_stats_work(struct work_struct *work)
 			continue;
 		}
 
-		if (time_before(now, fc_stats->next_query))
-			continue;
+		last = counter;
+	}
 
-		err = mlx5_cmd_fc_query(dev, counter->id, &packets, &bytes);
-		if (err) {
-			pr_err("Error querying stats for counter id %d\n",
-			       counter->id);
-			continue;
-		}
+	if (time_before(now, fc_stats->next_query) || !last)
+		return;
 
-		if (packets == c->packets)
-			continue;
+	node = rb_first(&fc_stats->counters);
+	while (node) {
+		counter = rb_entry(node, struct mlx5_fc, node);
 
-		c->lastuse = jiffies;
-		c->packets = packets;
-		c->bytes   = bytes;
+		node = mlx5_fc_stats_query(dev, counter, last->id);
 	}
 
-	if (time_after_eq(now, fc_stats->next_query))
-		fc_stats->next_query = now + MLX5_FC_STATS_PERIOD;
+	fc_stats->next_query = now + MLX5_FC_STATS_PERIOD;
 }
 
 struct mlx5_fc *mlx5_fc_create(struct mlx5_core_dev *dev, bool aging)