net: atlantic: use u64_stats_update_* to protect access to 64-bit stats

This patch adds u64_stats_update_* usage to protect access to 64-bit stats,
where necessary.

This is necessary for per-ring stats, because they are updated by the
driver directly, so there is a possibility for a partial read.

Other stats require no additional protection, e.g.:
 * all MACSec stats are fetched directly from HW (under semaphore);
 * nic/ndev stats (aq_stats_s) are fetched directly from FW (under mutex).

Signed-off-by: Mark Starovoytov <mstarovoitov@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_ptp.c b/drivers/net/ethernet/aquantia/atlantic/aq_ptp.c
index 116b889..ec6aa9b 100644 (file)
--- a/drivers/net/ethernet/aquantia/atlantic/aq_ptp.c
+++ b/drivers/net/ethernet/aquantia/atlantic/aq_ptp.c
@@ -782,8 +782,10 @@ int aq_ptp_xmit(struct aq_nic_s *aq_nic, struct sk_buff *skb)
                err = aq_nic->aq_hw_ops->hw_ring_tx_xmit(aq_nic->aq_hw,
                                                       ring, frags);
                if (err >= 0) {
+                       u64_stats_update_begin(&ring->stats.tx.syncp);
                        ++ring->stats.tx.packets;
                        ring->stats.tx.bytes += skb->len;
+                       u64_stats_update_end(&ring->stats.tx.syncp);
                }
        } else {
                err = NETDEV_TX_BUSY;

diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_ring.c b/drivers/net/ethernet/aquantia/atlantic/aq_ring.c
index fc4e10b..b51ab2d 100644 (file)
--- a/drivers/net/ethernet/aquantia/atlantic/aq_ring.c
+++ b/drivers/net/ethernet/aquantia/atlantic/aq_ring.c
@@ -70,18 +70,24 @@ static int aq_get_rxpages(struct aq_ring_s *self, struct aq_ring_buff_s *rxbuf,
                        rxbuf->rxdata.pg_off += AQ_CFG_RX_FRAME_MAX;
                        if (rxbuf->rxdata.pg_off + AQ_CFG_RX_FRAME_MAX <=
                                (PAGE_SIZE << order)) {
+                               u64_stats_update_begin(&self->stats.rx.syncp);
                                self->stats.rx.pg_flips++;
+                               u64_stats_update_end(&self->stats.rx.syncp);
                        } else {
                                /* Buffer exhausted. We have other users and
                                 * should release this page and realloc
                                 */
                                aq_free_rxpage(&rxbuf->rxdata,
                                               aq_nic_get_dev(self->aq_nic));
+                               u64_stats_update_begin(&self->stats.rx.syncp);
                                self->stats.rx.pg_losts++;
+                               u64_stats_update_end(&self->stats.rx.syncp);
                        }
                } else {
                        rxbuf->rxdata.pg_off = 0;
+                       u64_stats_update_begin(&self->stats.rx.syncp);
                        self->stats.rx.pg_reuses++;
+                       u64_stats_update_end(&self->stats.rx.syncp);
                }
        }
 
@@ -213,6 +219,11 @@ int aq_ring_init(struct aq_ring_s *self, const enum atl_ring_type ring_type)
        self->sw_tail = 0;
        self->ring_type = ring_type;
 
+       if (self->ring_type == ATL_RING_RX)
+               u64_stats_init(&self->stats.rx.syncp);
+       else
+               u64_stats_init(&self->stats.tx.syncp);
+
        return 0;
 }
 
@@ -239,7 +250,9 @@ void aq_ring_queue_wake(struct aq_ring_s *ring)
                                                      ring->idx))) {
                netif_wake_subqueue(ndev,
                                    AQ_NIC_RING2QMAP(ring->aq_nic, ring->idx));
+               u64_stats_update_begin(&ring->stats.tx.syncp);
                ring->stats.tx.queue_restarts++;
+               u64_stats_update_end(&ring->stats.tx.syncp);
        }
 }
 
@@ -281,8 +294,10 @@ bool aq_ring_tx_clean(struct aq_ring_s *self)
                }
 
                if (unlikely(buff->is_eop)) {
+                       u64_stats_update_begin(&self->stats.tx.syncp);
                        ++self->stats.tx.packets;
                        self->stats.tx.bytes += buff->skb->len;
+                       u64_stats_update_end(&self->stats.tx.syncp);
 
                        dev_kfree_skb_any(buff->skb);
                }
@@ -302,7 +317,9 @@ static void aq_rx_checksum(struct aq_ring_s *self,
                return;
 
        if (unlikely(buff->is_cso_err)) {
+               u64_stats_update_begin(&self->stats.rx.syncp);
                ++self->stats.rx.errors;
+               u64_stats_update_end(&self->stats.rx.syncp);
                skb->ip_summed = CHECKSUM_NONE;
                return;
        }
@@ -372,13 +389,17 @@ int aq_ring_rx_clean(struct aq_ring_s *self,
                                        buff_->is_cleaned = true;
                                } while (!buff_->is_eop);
 
+                               u64_stats_update_begin(&self->stats.rx.syncp);
                                ++self->stats.rx.errors;
+                               u64_stats_update_end(&self->stats.rx.syncp);
                                continue;
                        }
                }
 
                if (buff->is_error) {
+                       u64_stats_update_begin(&self->stats.rx.syncp);
                        ++self->stats.rx.errors;
+                       u64_stats_update_end(&self->stats.rx.syncp);
                        continue;
                }
 
@@ -479,8 +500,10 @@ int aq_ring_rx_clean(struct aq_ring_s *self,
                                                : AQ_NIC_RING2QMAP(self->aq_nic,
                                                                   self->idx));
 
+               u64_stats_update_begin(&self->stats.rx.syncp);
                ++self->stats.rx.packets;
                self->stats.rx.bytes += skb->len;
+               u64_stats_update_end(&self->stats.rx.syncp);
 
                napi_gro_receive(napi, skb);
        }
@@ -564,18 +587,27 @@ void aq_ring_free(struct aq_ring_s *self)
 
 unsigned int aq_ring_fill_stats_data(struct aq_ring_s *self, u64 *data)
 {
-       unsigned int count = 0U;
+       unsigned int count;
+       unsigned int start;
 
        if (self->ring_type == ATL_RING_RX) {
                /* This data should mimic aq_ethtool_queue_rx_stat_names structure */
-               data[count] = self->stats.rx.packets;
-               data[++count] = self->stats.rx.jumbo_packets;
-               data[++count] = self->stats.rx.lro_packets;
-               data[++count] = self->stats.rx.errors;
+               do {
+                       count = 0;
+                       start = u64_stats_fetch_begin_irq(&self->stats.rx.syncp);
+                       data[count] = self->stats.rx.packets;
+                       data[++count] = self->stats.rx.jumbo_packets;
+                       data[++count] = self->stats.rx.lro_packets;
+                       data[++count] = self->stats.rx.errors;
+               } while (u64_stats_fetch_retry_irq(&self->stats.rx.syncp, start));
        } else {
                /* This data should mimic aq_ethtool_queue_tx_stat_names structure */
-               data[count] = self->stats.tx.packets;
-               data[++count] = self->stats.tx.queue_restarts;
+               do {
+                       count = 0;
+                       start = u64_stats_fetch_begin_irq(&self->stats.tx.syncp);
+                       data[count] = self->stats.tx.packets;
+                       data[++count] = self->stats.tx.queue_restarts;
+               } while (u64_stats_fetch_retry_irq(&self->stats.tx.syncp, start));
        }
 
        return ++count;

diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_ring.h b/drivers/net/ethernet/aquantia/atlantic/aq_ring.h
index 0cd761b..c92c3a0 100644 (file)
--- a/drivers/net/ethernet/aquantia/atlantic/aq_ring.h
+++ b/drivers/net/ethernet/aquantia/atlantic/aq_ring.h
@@ -1,7 +1,8 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * aQuantia Corporation Network Driver
- * Copyright (C) 2014-2019 aQuantia Corporation. All rights reserved
+/* Atlantic Network Driver
+ *
+ * Copyright (C) 2014-2019 aQuantia Corporation
+ * Copyright (C) 2019-2020 Marvell International Ltd.
  */
 
 /* File aq_ring.h: Declaration of functions for Rx/Tx rings. */
@@ -88,6 +89,7 @@ struct __packed aq_ring_buff_s {
 };
 
 struct aq_ring_stats_rx_s {
+       struct u64_stats_sync syncp;    /* must be first */
        u64 errors;
        u64 packets;
        u64 bytes;
@@ -99,6 +101,7 @@ struct aq_ring_stats_rx_s {
 };
 
 struct aq_ring_stats_tx_s {
+       struct u64_stats_sync syncp;    /* must be first */
        u64 errors;
        u64 packets;
        u64 bytes;