Merge branch 'net-offloaded-stats'

Jiri Pirko says:

====================
net: return offloaded stats as default and expose original sw stats

The problem we try to handle is about offloaded forwarded packets
which are not seen by kernel. Let me try to draw it:

    port1                       port2 (HW stats are counted here)
      \                          /
       \                        /
        \                      /
         --(A)---- ASIC --(B)--
                    |
                   (C)
                    |
                   CPU (SW stats are counted here)

Now we have couple of flows for TX and RX (direction does not matter here):

1) port1->A->ASIC->C->CPU

   For this flow, HW and SW stats are equal.

2) port1->A->ASIC->C->CPU->C->ASIC->B->port2

   For this flow, HW and SW stats are equal.

3) port1->A->ASIC->B->port2

   For this flow, SW stats are 0.

The purpose of this patchset is to provide facility for user to
find out the difference between flows 1+2 and 3. In other words, user
will be able to see the statistics for the slow-path (through kernel).

Also note that HW stats are what someone calls "accumulated" stats.
Every packet counted by SW is also counted by HW. Not the other way around.

As a default the accumulated stats (HW) will be exposed to user
so the userspace apps can react properly.

This patchset add the SW stats (flows 1+2) under offload related stats, so
in the future we can expose other offload related stat in a similar way.

---
v9->v10:
- patch 2/3
 - removed unnecessary ()s as pointed out by Nik
v8->v9:
- patch 2/3
 - add using of idxattr and prividx
v7->v8:
- patch 2/3
 - move helping const from uapi to rtnetlink
 - cancel driver xstat nesting if it is empty
v6->v7:
- patch 1/3:
 - ndo interface changed to get the wanted stats type as an input.
 - change commit message.
- patch 2/3:
 - create a nesting for offloaded stat and put SW stats under it.
 - change the ndo call to indicate which offload stats we wants.
 - change commit message.
- patch 3/3:
 - change ndo implementation to match the changes in the previous patches.
 - change commit message.
v5->v6:
- patch 2/4 was dropped as requested by Roopa
- patch 1/3:
 - comment changed to indicate that default stats are combined stats
 - commit massage changed
- patch 2/3: (previously 3/4)
 - SW stats return nothing if there is no SW stats ndo
v4->v5:
- updated cover letter
- patch3/4:
  - using memcpy directly to copy stats as requested by DaveM
v3->v4:
- patch1/4:
  - fixed "return ()" pointed out by EricD
- patch2/4:
  - fixed if_nlmsg_size as pointed out by EricD
v2->v3:
- patch1/4:
  - added dev_have_sw_stats helper
- patch2/4:
  - avoided memcpy as requested by DaveM
- patch3/4:
  - use new dev_have_sw_stats helper
v1->v2:
- patch3/4:
  - fixed NULL initialization
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 122 insertions, 7 deletions

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index 27bbcaf9cfcd..171f8dd19efa 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -819,9 +819,9 @@ err_span_port_mtu_update:
 	return err;
 }
 
-static struct rtnl_link_stats64 *
-mlxsw_sp_port_get_stats64(struct net_device *dev,
-			  struct rtnl_link_stats64 *stats)
+int
+mlxsw_sp_port_get_sw_stats64(const struct net_device *dev,
+			     struct rtnl_link_stats64 *stats)
 {
 	struct mlxsw_sp_port *mlxsw_sp_port = netdev_priv(dev);
 	struct mlxsw_sp_port_pcpu_stats *p;
@@ -848,6 +848,107 @@ mlxsw_sp_port_get_stats64(struct net_device *dev,
 		tx_dropped	+= p->tx_dropped;
 	}
 	stats->tx_dropped	= tx_dropped;
+	return 0;
+}
+
+bool mlxsw_sp_port_has_offload_stats(int attr_id)
+{
+	switch (attr_id) {
+	case IFLA_OFFLOAD_XSTATS_CPU_HIT:
+		return true;
+	}
+
+	return false;
+}
+
+int mlxsw_sp_port_get_offload_stats(int attr_id, const struct net_device *dev,
+				    void *sp)
+{
+	switch (attr_id) {
+	case IFLA_OFFLOAD_XSTATS_CPU_HIT:
+		return mlxsw_sp_port_get_sw_stats64(dev, sp);
+	}
+
+	return -EINVAL;
+}
+
+static int mlxsw_sp_port_get_stats_raw(struct net_device *dev, int grp,
+				       int prio, char *ppcnt_pl)
+{
+	struct mlxsw_sp_port *mlxsw_sp_port = netdev_priv(dev);
+	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
+
+	mlxsw_reg_ppcnt_pack(ppcnt_pl, mlxsw_sp_port->local_port, grp, prio);
+	return mlxsw_reg_query(mlxsw_sp->core, MLXSW_REG(ppcnt), ppcnt_pl);
+}
+
+static int mlxsw_sp_port_get_hw_stats(struct net_device *dev,
+				      struct rtnl_link_stats64 *stats)
+{
+	char ppcnt_pl[MLXSW_REG_PPCNT_LEN];
+	int err;
+
+	err = mlxsw_sp_port_get_stats_raw(dev, MLXSW_REG_PPCNT_IEEE_8023_CNT,
+					  0, ppcnt_pl);
+	if (err)
+		goto out;
+
+	stats->tx_packets =
+		mlxsw_reg_ppcnt_a_frames_transmitted_ok_get(ppcnt_pl);
+	stats->rx_packets =
+		mlxsw_reg_ppcnt_a_frames_received_ok_get(ppcnt_pl);
+	stats->tx_bytes =
+		mlxsw_reg_ppcnt_a_octets_transmitted_ok_get(ppcnt_pl);
+	stats->rx_bytes =
+		mlxsw_reg_ppcnt_a_octets_received_ok_get(ppcnt_pl);
+	stats->multicast =
+		mlxsw_reg_ppcnt_a_multicast_frames_received_ok_get(ppcnt_pl);
+
+	stats->rx_crc_errors =
+		mlxsw_reg_ppcnt_a_frame_check_sequence_errors_get(ppcnt_pl);
+	stats->rx_frame_errors =
+		mlxsw_reg_ppcnt_a_alignment_errors_get(ppcnt_pl);
+
+	stats->rx_length_errors = (
+		mlxsw_reg_ppcnt_a_in_range_length_errors_get(ppcnt_pl) +
+		mlxsw_reg_ppcnt_a_out_of_range_length_field_get(ppcnt_pl) +
+		mlxsw_reg_ppcnt_a_frame_too_long_errors_get(ppcnt_pl));
+
+	stats->rx_errors = (stats->rx_crc_errors +
+		stats->rx_frame_errors + stats->rx_length_errors);
+
+out:
+	return err;
+}
+
+static void update_stats_cache(struct work_struct *work)
+{
+	struct mlxsw_sp_port *mlxsw_sp_port =
+		container_of(work, struct mlxsw_sp_port,
+			     hw_stats.update_dw.work);
+
+	if (!netif_carrier_ok(mlxsw_sp_port->dev))
+		goto out;
+
+	mlxsw_sp_port_get_hw_stats(mlxsw_sp_port->dev,
+				   mlxsw_sp_port->hw_stats.cache);
+
+out:
+	mlxsw_core_schedule_dw(&mlxsw_sp_port->hw_stats.update_dw,
+			       MLXSW_HW_STATS_UPDATE_TIME);
+}
+
+/* Return the stats from a cache that is updated periodically,
+ * as this function might get called in an atomic context.
+ */
+static struct rtnl_link_stats64 *
+mlxsw_sp_port_get_stats64(struct net_device *dev,
+			  struct rtnl_link_stats64 *stats)
+{
+	struct mlxsw_sp_port *mlxsw_sp_port = netdev_priv(dev);
+
+	memcpy(stats, mlxsw_sp_port->hw_stats.cache, sizeof(*stats));
+
 	return stats;
 }
 
@@ -1209,6 +1310,8 @@ static const struct net_device_ops mlxsw_sp_port_netdev_ops = {
 	.ndo_set_mac_address	= mlxsw_sp_port_set_mac_address,
 	.ndo_change_mtu		= mlxsw_sp_port_change_mtu,
 	.ndo_get_stats64	= mlxsw_sp_port_get_stats64,
+	.ndo_has_offload_stats	= mlxsw_sp_port_has_offload_stats,
+	.ndo_get_offload_stats	= mlxsw_sp_port_get_offload_stats,
 	.ndo_vlan_rx_add_vid	= mlxsw_sp_port_add_vid,
 	.ndo_vlan_rx_kill_vid	= mlxsw_sp_port_kill_vid,
 	.ndo_neigh_construct	= mlxsw_sp_router_neigh_construct,
@@ -1547,8 +1650,6 @@ static void __mlxsw_sp_port_get_stats(struct net_device *dev,
 				      enum mlxsw_reg_ppcnt_grp grp, int prio,
 				      u64 *data, int data_index)
 {
-	struct mlxsw_sp_port *mlxsw_sp_port = netdev_priv(dev);
-	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
 	struct mlxsw_sp_port_hw_stats *hw_stats;
 	char ppcnt_pl[MLXSW_REG_PPCNT_LEN];
 	int i, len;
@@ -1557,8 +1658,7 @@ static void __mlxsw_sp_port_get_stats(struct net_device *dev,
 	err = mlxsw_sp_get_hw_stats_by_group(&hw_stats, &len, grp);
 	if (err)
 		return;
-	mlxsw_reg_ppcnt_pack(ppcnt_pl, mlxsw_sp_port->local_port, grp, prio);
-	err = mlxsw_reg_query(mlxsw_sp->core, MLXSW_REG(ppcnt), ppcnt_pl);
+	mlxsw_sp_port_get_stats_raw(dev, grp, prio, ppcnt_pl);
 	for (i = 0; i < len; i++)
 		data[data_index + i] = !err ? hw_stats[i].getter(ppcnt_pl) : 0;
 }
@@ -2145,6 +2245,16 @@ static int mlxsw_sp_port_create(struct mlxsw_sp *mlxsw_sp, u8 local_port,
 		goto err_alloc_stats;
 	}
 
+	mlxsw_sp_port->hw_stats.cache =
+		kzalloc(sizeof(*mlxsw_sp_port->hw_stats.cache), GFP_KERNEL);
+
+	if (!mlxsw_sp_port->hw_stats.cache) {
+		err = -ENOMEM;
+		goto err_alloc_hw_stats;
+	}
+	INIT_DELAYED_WORK(&mlxsw_sp_port->hw_stats.update_dw,
+			  &update_stats_cache);
+
 	dev->netdev_ops = &mlxsw_sp_port_netdev_ops;
 	dev->ethtool_ops = &mlxsw_sp_port_ethtool_ops;
 
@@ -2245,6 +2355,7 @@ static int mlxsw_sp_port_create(struct mlxsw_sp *mlxsw_sp, u8 local_port,
 		goto err_core_port_init;
 	}
 
+	mlxsw_core_schedule_dw(&mlxsw_sp_port->hw_stats.update_dw, 0);
 	return 0;
 
 err_core_port_init:
@@ -2265,6 +2376,8 @@ err_port_system_port_mapping_set:
 err_dev_addr_init:
 	mlxsw_sp_port_swid_set(mlxsw_sp_port, MLXSW_PORT_SWID_DISABLED_PORT);
 err_port_swid_set:
+	kfree(mlxsw_sp_port->hw_stats.cache);
+err_alloc_hw_stats:
 	free_percpu(mlxsw_sp_port->pcpu_stats);
 err_alloc_stats:
 	kfree(mlxsw_sp_port->untagged_vlans);
@@ -2281,6 +2394,7 @@ static void mlxsw_sp_port_remove(struct mlxsw_sp *mlxsw_sp, u8 local_port)
 
 	if (!mlxsw_sp_port)
 		return;
+	cancel_delayed_work_sync(&mlxsw_sp_port->hw_stats.update_dw);
 	mlxsw_core_port_fini(&mlxsw_sp_port->core_port);
 	unregister_netdev(mlxsw_sp_port->dev); /* This calls ndo_stop */
 	mlxsw_sp->ports[local_port] = NULL;
@@ -2290,6 +2404,7 @@ static void mlxsw_sp_port_remove(struct mlxsw_sp *mlxsw_sp, u8 local_port)
 	mlxsw_sp_port_swid_set(mlxsw_sp_port, MLXSW_PORT_SWID_DISABLED_PORT);
 	mlxsw_sp_port_module_unmap(mlxsw_sp, mlxsw_sp_port->local_port);
 	free_percpu(mlxsw_sp_port->pcpu_stats);
+	kfree(mlxsw_sp_port->hw_stats.cache);
 	kfree(mlxsw_sp_port->untagged_vlans);
 	kfree(mlxsw_sp_port->active_vlans);
 	WARN_ON_ONCE(!list_empty(&mlxsw_sp_port->vports_list));