i40e: Add support for 64 bit netstats
This change brings support for 64 bit netstats to the driver. Previously
the stats were 64 bit but highly racy due to the fact that 64 bit
transactions are not atomic on 32 bit systems. This change makes is so
that the 64 bit byte and packet stats are reliable on all architectures.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
index 50153ea..1b86138 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
@@ -579,6 +579,7 @@
char *p;
int j;
struct rtnl_link_stats64 *net_stats = i40e_get_vsi_stats_struct(vsi);
+ unsigned int start;
i40e_update_stats(vsi);
@@ -587,12 +588,30 @@
data[i++] = (i40e_gstrings_net_stats[j].sizeof_stat ==
sizeof(u64)) ? *(u64 *)p : *(u32 *)p;
}
+ rcu_read_lock();
for (j = 0; j < vsi->num_queue_pairs; j++, i += 4) {
- data[i] = vsi->tx_rings[j]->stats.packets;
- data[i + 1] = vsi->tx_rings[j]->stats.bytes;
- data[i + 2] = vsi->rx_rings[j]->stats.packets;
- data[i + 3] = vsi->rx_rings[j]->stats.bytes;
+ struct i40e_ring *tx_ring = ACCESS_ONCE(vsi->tx_rings[j]);
+ struct i40e_ring *rx_ring;
+
+ if (!tx_ring)
+ continue;
+
+ /* process Tx ring statistics */
+ do {
+ start = u64_stats_fetch_begin_bh(&tx_ring->syncp);
+ data[i] = tx_ring->stats.packets;
+ data[i + 1] = tx_ring->stats.bytes;
+ } while (u64_stats_fetch_retry_bh(&tx_ring->syncp, start));
+
+ /* Rx ring is the 2nd half of the queue pair */
+ rx_ring = &tx_ring[1];
+ do {
+ start = u64_stats_fetch_begin_bh(&rx_ring->syncp);
+ data[i + 2] = rx_ring->stats.packets;
+ data[i + 3] = rx_ring->stats.bytes;
+ } while (u64_stats_fetch_retry_bh(&rx_ring->syncp, start));
}
+ rcu_read_unlock();
if (vsi == pf->vsi[pf->lan_vsi]) {
for (j = 0; j < I40E_GLOBAL_STATS_LEN; j++) {
p = (char *)pf + i40e_gstrings_stats[j].stat_offset;