[Intel-wired-lan] [PATCH net v1] ice: Reset stats on queue change

[Benjamin Mikailenko]

Commit 288ecf491b16 ("ice: Accumulate ring statistics over reset")
implemented functionality for interface statistics to persist over reset.
This avoided the case where a reset happens in the background, statistics
set to zero, and the user checks ring statistics expecting them to be
populated.

In the case of changing the number of queues, statistics should reset.
This is because old data should clear after parameter reconfiguration.

Fix this by resetting statistics when the number of queues changes.

Fixes: 288ecf491b16 ("ice: Accumulate ring statistics over reset")
Signed-off-by: Benjamin Mikailenko <benjamin.mikailenko at intel.com>
---
 drivers/net/ethernet/intel/ice/ice_lib.c | 65 ++++++++++++++++++++++++
 1 file changed, 65 insertions(+)

diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c
index 703f73e54561..ce791d90800d 100644
--- a/drivers/net/ethernet/intel/ice/ice_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_lib.c
@@ -1683,6 +1683,67 @@ static int ice_vsi_alloc_ring_stats(struct ice_vsi *vsi)
 	return -ENOMEM;
 }
 
+/**
+ * ice_reset_tx_ring_stats - Reset all Tx ring stats of a given ring
+ * @tx_ring: the ring whose stats needs to be cleared
+ */
+static void ice_reset_tx_ring_stats(struct ice_tx_ring *tx_ring)
+{
+	struct ice_ring_stats *ring_stats;
+
+	ring_stats = tx_ring->ring_stats;
+	if (!ring_stats)
+		return;
+
+	memset(&ring_stats->stats, 0,
+	       sizeof(ring_stats->stats));
+	memset(&ring_stats->tx_stats, 0,
+	       sizeof(ring_stats->tx_stats));
+	ring_stats->tx_stats.prev_pkt = -1;
+}
+
+/**
+ * ice_reset_rx_ring_stats - Reset all Rx ring stats of a given ring
+ * @rx_ring: the ring whose stats needs to be cleared
+ */
+static void ice_reset_rx_ring_stats(struct ice_rx_ring *rx_ring)
+{
+	struct ice_ring_stats *ring_stats;
+
+	ring_stats = rx_ring->ring_stats;
+	if (!ring_stats)
+		return;
+
+	memset(&ring_stats->stats, 0,
+	       sizeof(ring_stats->stats));
+	memset(&ring_stats->rx_stats, 0,
+	       sizeof(ring_stats->rx_stats));
+}
+
+/**
+ * ice_vsi_reset_stats - Reset all stats of a given VSI
+ * @vsi: the VSI whose stats needs to be cleared
+ */
+static void ice_vsi_reset_stats(struct ice_vsi *vsi)
+{
+	int i;
+
+	if (vsi->type == ICE_VSI_CHNL)
+		return;
+
+	memset(&vsi->net_stats, 0, sizeof(vsi->net_stats));
+	memset(&vsi->eth_stats, 0, sizeof(vsi->eth_stats));
+	memset(&vsi->eth_stats_prev, 0, sizeof(vsi->eth_stats_prev));
+
+	ice_for_each_txq(vsi, i)
+		ice_reset_tx_ring_stats(vsi->tx_rings[i]);
+
+	ice_for_each_rxq(vsi, i)
+		ice_reset_rx_ring_stats(vsi->rx_rings[i]);
+
+	vsi->stat_offsets_loaded = false;
+}
+
 /**
  * ice_vsi_manage_rss_lut - disable/enable RSS
  * @vsi: the VSI being changed
@@ -3608,6 +3669,10 @@ int ice_vsi_rebuild(struct ice_vsi *vsi, bool init_vsi)
 	if (ice_vsi_realloc_stat_arrays(vsi, prev_txq, prev_rxq))
 		goto err_vectors;
 
+	/* Reset stats if queues changed */
+	if (vsi->num_txq != prev_txq || vsi->num_rxq != prev_rxq)
+		ice_vsi_reset_stats(vsi);
+
 	ice_vsi_rebuild_set_coalesce(vsi, coalesce, prev_num_q_vectors);
 	kfree(coalesce);
 
-- 
2.34.3