The __ice_update_sample and __ice_get_ethtool_stats functions directly accesses the pkts and bytes counters from the ring stats. A following change is going to update the fields to be u64_stats_t type, and will need to be accessed appropriately. This will ensure that the accesses do not cause load/store tearing.
Add helper functions similar to the ones used for updating the stats values, and use them. This ensures use of the syncp pointer on 32-bit architectures. Once the fields are updated to u64_stats_t, it will then properly avoid tears on all architectures. Signed-off-by: Jacob Keller <[email protected]> --- drivers/net/ethernet/intel/ice/ice_lib.h | 6 +++++ drivers/net/ethernet/intel/ice/ice_ethtool.c | 26 +++++++++++++------- drivers/net/ethernet/intel/ice/ice_lib.c | 36 ++++++++++++++++++++++++++++ drivers/net/ethernet/intel/ice/ice_txrx.c | 29 +++++++++++----------- 4 files changed, 75 insertions(+), 22 deletions(-) diff --git a/drivers/net/ethernet/intel/ice/ice_lib.h b/drivers/net/ethernet/intel/ice/ice_lib.h index 2cb1eb98b9da..49454d98dcfe 100644 --- a/drivers/net/ethernet/intel/ice/ice_lib.h +++ b/drivers/net/ethernet/intel/ice/ice_lib.h @@ -92,6 +92,12 @@ void ice_update_tx_ring_stats(struct ice_tx_ring *ring, u64 pkts, u64 bytes); void ice_update_rx_ring_stats(struct ice_rx_ring *ring, u64 pkts, u64 bytes); +void ice_fetch_tx_ring_stats(const struct ice_tx_ring *ring, + u64 *pkts, u64 *bytes); + +void ice_fetch_rx_ring_stats(const struct ice_rx_ring *ring, + u64 *pkts, u64 *bytes); + void ice_write_intrl(struct ice_q_vector *q_vector, u8 intrl); void ice_write_itr(struct ice_ring_container *rc, u16 itr); void ice_set_q_vector_intrl(struct ice_q_vector *q_vector); diff --git a/drivers/net/ethernet/intel/ice/ice_ethtool.c b/drivers/net/ethernet/intel/ice/ice_ethtool.c index 0bc6f31a2b06..6c93e0e91ef5 100644 --- a/drivers/net/ethernet/intel/ice/ice_ethtool.c +++ b/drivers/net/ethernet/intel/ice/ice_ethtool.c @@ -1942,25 +1942,35 @@ __ice_get_ethtool_stats(struct net_device *netdev, rcu_read_lock(); ice_for_each_alloc_txq(vsi, j) { + u64 pkts, bytes; + tx_ring = READ_ONCE(vsi->tx_rings[j]); - if (tx_ring && tx_ring->ring_stats) { - data[i++] = tx_ring->ring_stats->stats.pkts; - data[i++] = tx_ring->ring_stats->stats.bytes; - } else { + if (!tx_ring || !tx_ring->ring_stats) { data[i++] = 0; data[i++] = 0; + continue; } + + ice_fetch_tx_ring_stats(tx_ring, &pkts, &bytes); + + data[i++] = pkts; + data[i++] = bytes; } ice_for_each_alloc_rxq(vsi, j) { + u64 pkts, bytes; + rx_ring = READ_ONCE(vsi->rx_rings[j]); - if (rx_ring && rx_ring->ring_stats) { - data[i++] = rx_ring->ring_stats->stats.pkts; - data[i++] = rx_ring->ring_stats->stats.bytes; - } else { + if (!rx_ring || !rx_ring->ring_stats) { data[i++] = 0; data[i++] = 0; + continue; } + + ice_fetch_rx_ring_stats(rx_ring, &pkts, &bytes); + + data[i++] = pkts; + data[i++] = bytes; } rcu_read_unlock(); diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c index c6dd297582c1..1c8b6129835d 100644 --- a/drivers/net/ethernet/intel/ice/ice_lib.c +++ b/drivers/net/ethernet/intel/ice/ice_lib.c @@ -3470,6 +3470,42 @@ void ice_update_rx_ring_stats(struct ice_rx_ring *rx_ring, u64 pkts, u64 bytes) u64_stats_update_end(&rx_ring->ring_stats->syncp); } +/** + * ice_fetch_tx_ring_stats - Fetch Tx ring packet and byte counters + * @ring: ring to update + * @pkts: number of processed packets + * @bytes: number of processed bytes + */ +void ice_fetch_tx_ring_stats(const struct ice_tx_ring *ring, + u64 *pkts, u64 *bytes) +{ + unsigned int start; + + do { + start = u64_stats_fetch_begin(&ring->ring_stats->syncp); + *pkts = ring->ring_stats->pkts; + *bytes = ring->ring_stats->bytes; + } while (u64_stats_fetch_retry(&ring->ring_stats->syncp, start)); +} + +/** + * ice_fetch_rx_ring_stats - Fetch Rx ring packet and byte counters + * @ring: ring to read + * @pkts: number of processed packets + * @bytes: number of processed bytes + */ +void ice_fetch_rx_ring_stats(const struct ice_rx_ring *ring, + u64 *pkts, u64 *bytes) +{ + unsigned int start; + + do { + start = u64_stats_fetch_begin(&ring->ring_stats->syncp); + *pkts = ring->ring_stats->pkts; + *bytes = ring->ring_stats->bytes; + } while (u64_stats_fetch_retry(&ring->ring_stats->syncp, start)); +} + /** * ice_is_dflt_vsi_in_use - check if the default forwarding VSI is being used * @pi: port info of the switch with default VSI diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c index 30073ed9ca99..f0f5133c389f 100644 --- a/drivers/net/ethernet/intel/ice/ice_txrx.c +++ b/drivers/net/ethernet/intel/ice/ice_txrx.c @@ -1087,35 +1087,36 @@ static void __ice_update_sample(struct ice_q_vector *q_vector, struct dim_sample *sample, bool is_tx) { - u64 packets = 0, bytes = 0; + u64 total_packets = 0, total_bytes = 0, pkts, bytes; if (is_tx) { struct ice_tx_ring *tx_ring; ice_for_each_tx_ring(tx_ring, *rc) { - struct ice_ring_stats *ring_stats; - - ring_stats = tx_ring->ring_stats; - if (!ring_stats) + if (!tx_ring->ring_stats) continue; - packets += ring_stats->stats.pkts; - bytes += ring_stats->stats.bytes; + + ice_fetch_tx_ring_stats(tx_ring, &pkts, &bytes); + + total_packets += pkts; + total_bytes += bytes; } } else { struct ice_rx_ring *rx_ring; ice_for_each_rx_ring(rx_ring, *rc) { - struct ice_ring_stats *ring_stats; - - ring_stats = rx_ring->ring_stats; - if (!ring_stats) + if (!rx_ring->ring_stats) continue; - packets += ring_stats->stats.pkts; - bytes += ring_stats->stats.bytes; + + ice_fetch_rx_ring_stats(rx_ring, &pkts, &bytes); + + total_packets += pkts; + total_bytes += bytes; } } - dim_update_sample(q_vector->total_events, packets, bytes, sample); + dim_update_sample(q_vector->total_events, + total_packets, total_bytes, sample); sample->comp_ctr = 0; /* if dim settings get stale, like when not updated for 1 -- 2.51.0.rc1.197.g6d975e95c9d7
