net/mlx5_core: Flow counters infrastructure

If a counter has the aging flag set when created, it is added to a list
of counters that will be queried periodically from a workqueue.  query
result and last use timestamp are cached.
add/del counter must be very efficient since thousands of such
operations might be issued in a second.
There is only a single reference to counters without aging, therefore
no need for locks.
But, counters with aging enabled are stored in a list. In order to make
code as lockless as possible, all the list manipulation and access to
hardware is done from a single context - the periodic counters query
thread.

The hardware supports multiple counters per FTE, however currently we
are using one counter for each FTE.

Signed-off-by: Amir Vadai <amirva@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 19 insertions, 0 deletions

diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
index 9613143f0561..07b504f7eb84 100644
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -41,6 +41,7 @@
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/radix-tree.h>
+#include <linux/workqueue.h>
 
 #include <linux/mlx5/device.h>
 #include <linux/mlx5/doorbell.h>
@@ -457,6 +458,17 @@ struct mlx5_irq_info {
         char name[MLX5_MAX_IRQ_NAME];
 };
 
+struct mlx5_fc_stats {
+        struct list_head list;
+        struct list_head addlist;
+        /* protect addlist add/splice operations */
+        spinlock_t addlist_lock;
+
+        struct workqueue_struct *wq;
+        struct delayed_work work;
+        unsigned long next_query;
+};
+
 struct mlx5_eswitch;
 
 struct mlx5_priv {
@@ -520,6 +532,8 @@ struct mlx5_priv {
         struct mlx5_flow_root_namespace *fdb_root_ns;
         struct mlx5_flow_root_namespace *esw_egress_root_ns;
         struct mlx5_flow_root_namespace *esw_ingress_root_ns;
+
+        struct mlx5_fc_stats            fc_stats;
 };
 
 enum mlx5_device_state {
diff --git a/include/linux/mlx5/fs.h b/include/linux/mlx5/fs.h
index c8b9ede1c20a..4b7a107d9c19 100644
--- a/include/linux/mlx5/fs.h
+++ b/include/linux/mlx5/fs.h
@@ -127,4 +127,9 @@ int mlx5_modify_rule_destination(struct mlx5_flow_rule *rule,
                                  struct mlx5_flow_destination *dest);
 
 struct mlx5_fc *mlx5_flow_rule_counter(struct mlx5_flow_rule *rule);
+struct mlx5_fc *mlx5_fc_create(struct mlx5_core_dev *dev, bool aging);
+void mlx5_fc_destroy(struct mlx5_core_dev *dev, struct mlx5_fc *counter);
+void mlx5_fc_query_cached(struct mlx5_fc *counter,
+                          u64 *bytes, u64 *packets, u64 *lastuse);
+
 #endif