[Intel-wired-lan] [PATCH net v2] 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 (for example
a tx hang occourred triggering a reset), statistics set to zero, and the
user checks ring statistics expecting them to be populated.

In the case of changing queues (for example "ethtool -L ethX combined 5"),
this change caused statistics in the remaining queues (0-4) to persist. In
this case, statistics should reset.

Fix this by clearing 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>
---
v2: Edited commit message

 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