64-bit variables might not be atomic on 32-bit architectures, and could lead to load/store tearing. Use u64_stats_t to ensure consistency. Signed-off-by: David Yang --- drivers/net/dsa/yt921x.c | 197 +++++++++++++++++++++++---------------- drivers/net/dsa/yt921x.h | 114 ++++++++++++---------- 2 files changed, 178 insertions(+), 133 deletions(-) diff --git a/drivers/net/dsa/yt921x.c b/drivers/net/dsa/yt921x.c index a968a3fb56f8..8129c278e224 100644 --- a/drivers/net/dsa/yt921x.c +++ b/drivers/net/dsa/yt921x.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include @@ -670,22 +671,20 @@ yt921x_mbus_ext_init(struct yt921x_priv *priv, struct device_node *mnp) static int yt921x_read_mib(struct yt921x_priv *priv, int port) { struct yt921x_port *pp = &priv->ports[port]; + struct yt921x_mib *mib_new = &pp->mib_new; struct device *dev = to_device(priv); struct yt921x_mib *mib = &pp->mib; + u64 rx_frames; + u64 tx_frames; int res = 0; - /* Reading of yt921x_port::mib is not protected by a lock and it's vain - * to keep its consistency, since we have to read registers one by one - * and there is no way to make a snapshot of MIB stats. - * - * Writing (by this function only) is and should be protected by - * reg_lock. + /* u64_stats_read/set is redundant for mib_new, but I don't want to + * declare a plain u64 yt921x_mib variant. */ for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) { const struct yt921x_mib_desc *desc = &yt921x_mib_descs[i]; u32 reg = YT921X_MIBn_DATA0(port) + desc->offset; - u64 *valp = &((u64 *)mib)[i]; u32 val0; u64 val; @@ -694,7 +693,7 @@ static int yt921x_read_mib(struct yt921x_priv *priv, int port) break; if (desc->size <= 1) { - u64 old_val = *valp; + u64 old_val = u64_stats_read(&mib->stats[i]); val = (old_val & ~(u64)U32_MAX) | val0; if (val < old_val) @@ -708,7 +707,7 @@ static int yt921x_read_mib(struct yt921x_priv *priv, int port) val = ((u64)val1 << 32) | val0; } - WRITE_ONCE(*valp, val); + u64_stats_set(&mib_new->stats[i], val); } if (res) { @@ -717,14 +716,29 @@ static int yt921x_read_mib(struct yt921x_priv *priv, int port) return res; } - pp->rx_frames = mib->rx_64byte + mib->rx_65_127byte + - mib->rx_128_255byte + mib->rx_256_511byte + - mib->rx_512_1023byte + mib->rx_1024_1518byte + - mib->rx_jumbo; - pp->tx_frames = mib->tx_64byte + mib->tx_65_127byte + - mib->tx_128_255byte + mib->tx_256_511byte + - mib->tx_512_1023byte + mib->tx_1024_1518byte + - mib->tx_jumbo; + rx_frames = u64_stats_read(&mib_new->rx_64byte) + + u64_stats_read(&mib_new->rx_65_127byte) + + u64_stats_read(&mib_new->rx_128_255byte) + + u64_stats_read(&mib_new->rx_256_511byte) + + u64_stats_read(&mib_new->rx_512_1023byte) + + u64_stats_read(&mib_new->rx_1024_1518byte) + + u64_stats_read(&mib_new->rx_jumbo); + tx_frames = u64_stats_read(&mib_new->tx_64byte) + + u64_stats_read(&mib_new->tx_65_127byte) + + u64_stats_read(&mib_new->tx_128_255byte) + + u64_stats_read(&mib_new->tx_256_511byte) + + u64_stats_read(&mib_new->tx_512_1023byte) + + u64_stats_read(&mib_new->tx_1024_1518byte) + + u64_stats_read(&mib_new->tx_jumbo); + + u64_stats_update_begin(&pp->syncp); + for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) { + u64_stats_set(&mib->stats[i], + u64_stats_read(&mib_new->stats[i])); + } + u64_stats_set(&pp->rx_frames, rx_frames); + u64_stats_set(&pp->tx_frames, tx_frames); + u64_stats_update_end(&pp->syncp); return 0; } @@ -772,8 +786,8 @@ yt921x_dsa_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *data) size_t j; mutex_lock(&priv->reg_lock); + yt921x_read_mib(priv, port); - mutex_unlock(&priv->reg_lock); j = 0; for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) { @@ -782,9 +796,11 @@ yt921x_dsa_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *data) if (!desc->name) continue; - data[j] = ((u64 *)mib)[i]; + data[j] = u64_stats_read(&((u64_stats_t *)mib)[i]); j++; } + + mutex_unlock(&priv->reg_lock); } static int yt921x_dsa_get_sset_count(struct dsa_switch *ds, int port, int sset) @@ -813,31 +829,33 @@ yt921x_dsa_get_eth_mac_stats(struct dsa_switch *ds, int port, struct yt921x_mib *mib = &pp->mib; mutex_lock(&priv->reg_lock); + yt921x_read_mib(priv, port); - mutex_unlock(&priv->reg_lock); - mac_stats->FramesTransmittedOK = pp->tx_frames; - mac_stats->SingleCollisionFrames = mib->tx_single_collisions; - mac_stats->MultipleCollisionFrames = mib->tx_multiple_collisions; - mac_stats->FramesReceivedOK = pp->rx_frames; - mac_stats->FrameCheckSequenceErrors = mib->rx_crc_errors; - mac_stats->AlignmentErrors = mib->rx_alignment_errors; - mac_stats->OctetsTransmittedOK = mib->tx_good_bytes; - mac_stats->FramesWithDeferredXmissions = mib->tx_deferred; - mac_stats->LateCollisions = mib->tx_late_collisions; - mac_stats->FramesAbortedDueToXSColls = mib->tx_aborted_errors; + mac_stats->FramesTransmittedOK = u64_stats_read(&pp->tx_frames); + mac_stats->SingleCollisionFrames = u64_stats_read(&mib->tx_single_collisions); + mac_stats->MultipleCollisionFrames = u64_stats_read(&mib->tx_multiple_collisions); + mac_stats->FramesReceivedOK = u64_stats_read(&pp->rx_frames); + mac_stats->FrameCheckSequenceErrors = u64_stats_read(&mib->rx_crc_errors); + mac_stats->AlignmentErrors = u64_stats_read(&mib->rx_alignment_errors); + mac_stats->OctetsTransmittedOK = u64_stats_read(&mib->tx_good_bytes); + mac_stats->FramesWithDeferredXmissions = u64_stats_read(&mib->tx_deferred); + mac_stats->LateCollisions = u64_stats_read(&mib->tx_late_collisions); + mac_stats->FramesAbortedDueToXSColls = u64_stats_read(&mib->tx_aborted_errors); /* mac_stats->FramesLostDueToIntMACXmitError */ /* mac_stats->CarrierSenseErrors */ - mac_stats->OctetsReceivedOK = mib->rx_good_bytes; + mac_stats->OctetsReceivedOK = u64_stats_read(&mib->rx_good_bytes); /* mac_stats->FramesLostDueToIntMACRcvError */ - mac_stats->MulticastFramesXmittedOK = mib->tx_multicast; - mac_stats->BroadcastFramesXmittedOK = mib->tx_broadcast; + mac_stats->MulticastFramesXmittedOK = u64_stats_read(&mib->tx_multicast); + mac_stats->BroadcastFramesXmittedOK = u64_stats_read(&mib->tx_broadcast); /* mac_stats->FramesWithExcessiveDeferral */ - mac_stats->MulticastFramesReceivedOK = mib->rx_multicast; - mac_stats->BroadcastFramesReceivedOK = mib->rx_broadcast; + mac_stats->MulticastFramesReceivedOK = u64_stats_read(&mib->rx_multicast); + mac_stats->BroadcastFramesReceivedOK = u64_stats_read(&mib->rx_broadcast); /* mac_stats->InRangeLengthErrors */ /* mac_stats->OutOfRangeLengthField */ - mac_stats->FrameTooLongErrors = mib->rx_oversize_errors; + mac_stats->FrameTooLongErrors = u64_stats_read(&mib->rx_oversize_errors); + + mutex_unlock(&priv->reg_lock); } static void @@ -849,12 +867,14 @@ yt921x_dsa_get_eth_ctrl_stats(struct dsa_switch *ds, int port, struct yt921x_mib *mib = &pp->mib; mutex_lock(&priv->reg_lock); + yt921x_read_mib(priv, port); - mutex_unlock(&priv->reg_lock); - ctrl_stats->MACControlFramesTransmitted = mib->tx_pause; - ctrl_stats->MACControlFramesReceived = mib->rx_pause; + ctrl_stats->MACControlFramesTransmitted = u64_stats_read(&mib->tx_pause); + ctrl_stats->MACControlFramesReceived = u64_stats_read(&mib->rx_pause); /* ctrl_stats->UnsupportedOpcodesReceived */ + + mutex_unlock(&priv->reg_lock); } static const struct ethtool_rmon_hist_range yt921x_rmon_ranges[] = { @@ -878,31 +898,33 @@ yt921x_dsa_get_rmon_stats(struct dsa_switch *ds, int port, struct yt921x_mib *mib = &pp->mib; mutex_lock(&priv->reg_lock); + yt921x_read_mib(priv, port); - mutex_unlock(&priv->reg_lock); *ranges = yt921x_rmon_ranges; - rmon_stats->undersize_pkts = mib->rx_undersize_errors; - rmon_stats->oversize_pkts = mib->rx_oversize_errors; - rmon_stats->fragments = mib->rx_alignment_errors; + rmon_stats->undersize_pkts = u64_stats_read(&mib->rx_undersize_errors); + rmon_stats->oversize_pkts = u64_stats_read(&mib->rx_oversize_errors); + rmon_stats->fragments = u64_stats_read(&mib->rx_alignment_errors); /* rmon_stats->jabbers */ - rmon_stats->hist[0] = mib->rx_64byte; - rmon_stats->hist[1] = mib->rx_65_127byte; - rmon_stats->hist[2] = mib->rx_128_255byte; - rmon_stats->hist[3] = mib->rx_256_511byte; - rmon_stats->hist[4] = mib->rx_512_1023byte; - rmon_stats->hist[5] = mib->rx_1024_1518byte; - rmon_stats->hist[6] = mib->rx_jumbo; + rmon_stats->hist[0] = u64_stats_read(&mib->rx_64byte); + rmon_stats->hist[1] = u64_stats_read(&mib->rx_65_127byte); + rmon_stats->hist[2] = u64_stats_read(&mib->rx_128_255byte); + rmon_stats->hist[3] = u64_stats_read(&mib->rx_256_511byte); + rmon_stats->hist[4] = u64_stats_read(&mib->rx_512_1023byte); + rmon_stats->hist[5] = u64_stats_read(&mib->rx_1024_1518byte); + rmon_stats->hist[6] = u64_stats_read(&mib->rx_jumbo); + + rmon_stats->hist_tx[0] = u64_stats_read(&mib->tx_64byte); + rmon_stats->hist_tx[1] = u64_stats_read(&mib->tx_65_127byte); + rmon_stats->hist_tx[2] = u64_stats_read(&mib->tx_128_255byte); + rmon_stats->hist_tx[3] = u64_stats_read(&mib->tx_256_511byte); + rmon_stats->hist_tx[4] = u64_stats_read(&mib->tx_512_1023byte); + rmon_stats->hist_tx[5] = u64_stats_read(&mib->tx_1024_1518byte); + rmon_stats->hist_tx[6] = u64_stats_read(&mib->tx_jumbo); - rmon_stats->hist_tx[0] = mib->tx_64byte; - rmon_stats->hist_tx[1] = mib->tx_65_127byte; - rmon_stats->hist_tx[2] = mib->tx_128_255byte; - rmon_stats->hist_tx[3] = mib->tx_256_511byte; - rmon_stats->hist_tx[4] = mib->tx_512_1023byte; - rmon_stats->hist_tx[5] = mib->tx_1024_1518byte; - rmon_stats->hist_tx[6] = mib->tx_jumbo; + mutex_unlock(&priv->reg_lock); } static void @@ -912,33 +934,41 @@ yt921x_dsa_get_stats64(struct dsa_switch *ds, int port, struct yt921x_priv *priv = to_yt921x_priv(ds); struct yt921x_port *pp = &priv->ports[port]; struct yt921x_mib *mib = &pp->mib; + unsigned int start; + + do { + start = u64_stats_fetch_begin(&pp->syncp); + + stats->rx_length_errors = u64_stats_read(&mib->rx_undersize_errors) + + u64_stats_read(&mib->rx_fragment_errors); + stats->rx_over_errors = u64_stats_read(&mib->rx_oversize_errors); + stats->rx_crc_errors = u64_stats_read(&mib->rx_crc_errors); + stats->rx_frame_errors = u64_stats_read(&mib->rx_alignment_errors); + /* stats->rx_fifo_errors */ + /* stats->rx_missed_errors */ + + stats->tx_aborted_errors = u64_stats_read(&mib->tx_aborted_errors); + /* stats->tx_carrier_errors */ + stats->tx_fifo_errors = u64_stats_read(&mib->tx_undersize_errors); + /* stats->tx_heartbeat_errors */ + stats->tx_window_errors = u64_stats_read(&mib->tx_late_collisions); + + stats->rx_packets = u64_stats_read(&pp->rx_frames); + stats->tx_packets = u64_stats_read(&pp->tx_frames); + stats->rx_bytes = u64_stats_read(&mib->rx_good_bytes) - + ETH_FCS_LEN * stats->rx_packets; + stats->tx_bytes = u64_stats_read(&mib->tx_good_bytes) - + ETH_FCS_LEN * stats->tx_packets; + stats->rx_dropped = u64_stats_read(&mib->rx_dropped); + /* stats->tx_dropped */ + stats->multicast = u64_stats_read(&mib->rx_multicast); + stats->collisions = u64_stats_read(&mib->tx_collisions); + } while (u64_stats_fetch_retry(&pp->syncp, start)); - stats->rx_length_errors = mib->rx_undersize_errors + - mib->rx_fragment_errors; - stats->rx_over_errors = mib->rx_oversize_errors; - stats->rx_crc_errors = mib->rx_crc_errors; - stats->rx_frame_errors = mib->rx_alignment_errors; - /* stats->rx_fifo_errors */ - /* stats->rx_missed_errors */ - - stats->tx_aborted_errors = mib->tx_aborted_errors; - /* stats->tx_carrier_errors */ - stats->tx_fifo_errors = mib->tx_undersize_errors; - /* stats->tx_heartbeat_errors */ - stats->tx_window_errors = mib->tx_late_collisions; - - stats->rx_packets = pp->rx_frames; - stats->tx_packets = pp->tx_frames; - stats->rx_bytes = mib->rx_good_bytes - ETH_FCS_LEN * stats->rx_packets; - stats->tx_bytes = mib->tx_good_bytes - ETH_FCS_LEN * stats->tx_packets; stats->rx_errors = stats->rx_length_errors + stats->rx_over_errors + stats->rx_crc_errors + stats->rx_frame_errors; stats->tx_errors = stats->tx_aborted_errors + stats->tx_fifo_errors + stats->tx_window_errors; - stats->rx_dropped = mib->rx_dropped; - /* stats->tx_dropped */ - stats->multicast = mib->rx_multicast; - stats->collisions = mib->tx_collisions; } static void @@ -950,11 +980,13 @@ yt921x_dsa_get_pause_stats(struct dsa_switch *ds, int port, struct yt921x_mib *mib = &pp->mib; mutex_lock(&priv->reg_lock); + yt921x_read_mib(priv, port); - mutex_unlock(&priv->reg_lock); - pause_stats->tx_pause_frames = mib->tx_pause; - pause_stats->rx_pause_frames = mib->rx_pause; + pause_stats->tx_pause_frames = u64_stats_read(&mib->tx_pause); + pause_stats->rx_pause_frames = u64_stats_read(&mib->rx_pause); + + mutex_unlock(&priv->reg_lock); } static int @@ -3423,6 +3455,7 @@ static int yt921x_mdio_probe(struct mdio_device *mdiodev) pp->index = i; INIT_DELAYED_WORK(&pp->mib_read, yt921x_poll_mib); + u64_stats_init(&pp->syncp); } ds = &priv->ds; diff --git a/drivers/net/dsa/yt921x.h b/drivers/net/dsa/yt921x.h index 3f129b8d403f..0f4231accf3e 100644 --- a/drivers/net/dsa/yt921x.h +++ b/drivers/net/dsa/yt921x.h @@ -6,6 +6,8 @@ #ifndef __YT921X_H #define __YT921X_H +#include + #include #define YT921X_SMI_SWITCHID_M GENMASK(3, 2) @@ -530,55 +532,61 @@ enum yt921x_fdb_entry_status { #define yt921x_port_is_external(port) (8 <= (port) && (port) < 9) struct yt921x_mib { - u64 rx_broadcast; - u64 rx_pause; - u64 rx_multicast; - u64 rx_crc_errors; - - u64 rx_alignment_errors; - u64 rx_undersize_errors; - u64 rx_fragment_errors; - u64 rx_64byte; - - u64 rx_65_127byte; - u64 rx_128_255byte; - u64 rx_256_511byte; - u64 rx_512_1023byte; - - u64 rx_1024_1518byte; - u64 rx_jumbo; - u64 rx_good_bytes; - - u64 rx_bad_bytes; - u64 rx_oversize_errors; - - u64 rx_dropped; - u64 tx_broadcast; - u64 tx_pause; - u64 tx_multicast; - - u64 tx_undersize_errors; - u64 tx_64byte; - u64 tx_65_127byte; - u64 tx_128_255byte; - - u64 tx_256_511byte; - u64 tx_512_1023byte; - u64 tx_1024_1518byte; - u64 tx_jumbo; - - u64 tx_good_bytes; - u64 tx_collisions; - - u64 tx_aborted_errors; - u64 tx_multiple_collisions; - u64 tx_single_collisions; - u64 tx_good; - - u64 tx_deferred; - u64 tx_late_collisions; - u64 rx_oam; - u64 tx_oam; + union { + struct { + u64_stats_t rx_broadcast; + u64_stats_t rx_pause; + u64_stats_t rx_multicast; + u64_stats_t rx_crc_errors; + + u64_stats_t rx_alignment_errors; + u64_stats_t rx_undersize_errors; + u64_stats_t rx_fragment_errors; + u64_stats_t rx_64byte; + + u64_stats_t rx_65_127byte; + u64_stats_t rx_128_255byte; + u64_stats_t rx_256_511byte; + u64_stats_t rx_512_1023byte; + + u64_stats_t rx_1024_1518byte; + u64_stats_t rx_jumbo; + u64_stats_t rx_good_bytes; + + u64_stats_t rx_bad_bytes; + u64_stats_t rx_oversize_errors; + + u64_stats_t rx_dropped; + u64_stats_t tx_broadcast; + u64_stats_t tx_pause; + u64_stats_t tx_multicast; + + u64_stats_t tx_undersize_errors; + u64_stats_t tx_64byte; + u64_stats_t tx_65_127byte; + u64_stats_t tx_128_255byte; + + u64_stats_t tx_256_511byte; + u64_stats_t tx_512_1023byte; + u64_stats_t tx_1024_1518byte; + u64_stats_t tx_jumbo; + + u64_stats_t tx_good_bytes; + u64_stats_t tx_collisions; + + u64_stats_t tx_aborted_errors; + u64_stats_t tx_multiple_collisions; + u64_stats_t tx_single_collisions; + u64_stats_t tx_good; + + u64_stats_t tx_deferred; + u64_stats_t tx_late_collisions; + u64_stats_t rx_oam; + u64_stats_t tx_oam; + }; + + u64_stats_t stats[39]; + }; }; struct yt921x_port { @@ -588,9 +596,13 @@ struct yt921x_port { bool isolated; struct delayed_work mib_read; + struct u64_stats_sync syncp; struct yt921x_mib mib; - u64 rx_frames; - u64 tx_frames; + u64_stats_t rx_frames; + u64_stats_t tx_frames; + + /* only used by read routine to avoid huge allocations on the stack */ + struct yt921x_mib mib_new; }; struct yt921x_reg_ops { -- 2.51.0