[PATCH 5.5 322/367] net: mvneta: move rx_dropped and rx_errors in per-cpu stats

Greg Kroah-Hartman
2020-02-10T12:47:00Z

From: Lorenzo Bianconi <lorenzo@kernel.org>

[ Upstream commit c35947b8ff8acca33134ee39c31708233765c31a ]

Move rx_dropped and rx_errors counters in mvneta_pcpu_stats in order to
avoid possible races updating statistics

Fixes: 562e2f467e71 ("net: mvneta: Improve the buffer allocation method for SWBM")
Fixes: dc35a10f68d3 ("net: mvneta: bm: add support for hardware buffer management")
Fixes: c5aff18204da ("net: mvneta: driver for Marvell Armada 370/XP network unit")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/marvell/mvneta.c | 31 ++++++++++++++++++++++---------
1 file changed, 22 insertions(+), 9 deletions(-)

--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -401,6 +401,8 @@ struct mvneta_pcpu_stats {
struct u64_stats_sync syncp;
u64 rx_packets;
u64 rx_bytes;
+ u64 rx_dropped;
+ u64 rx_errors;
u64 tx_packets;
u64 tx_bytes;
};
@@ -738,6 +740,8 @@ mvneta_get_stats64(struct net_device *de
struct mvneta_pcpu_stats *cpu_stats;
u64 rx_packets;
u64 rx_bytes;
+ u64 rx_dropped;
+ u64 rx_errors;
u64 tx_packets;
u64 tx_bytes;

@@ -746,19 +750,20 @@ mvneta_get_stats64(struct net_device *de
start = u64_stats_fetch_begin_irq(&cpu_stats->syncp);
rx_packets = cpu_stats->rx_packets;
rx_bytes = cpu_stats->rx_bytes;
+ rx_dropped = cpu_stats->rx_dropped;
+ rx_errors = cpu_stats->rx_errors;
tx_packets = cpu_stats->tx_packets;
tx_bytes = cpu_stats->tx_bytes;
} while (u64_stats_fetch_retry_irq(&cpu_stats->syncp, start));

stats->rx_packets += rx_packets;
stats->rx_bytes += rx_bytes;
+ stats->rx_dropped += rx_dropped;
+ stats->rx_errors += rx_errors;
stats->tx_packets += tx_packets;
stats->tx_bytes += tx_bytes;
}

- stats->rx_errors = dev->stats.rx_errors;
- stats->rx_dropped = dev->stats.rx_dropped;
-
stats->tx_dropped = dev->stats.tx_dropped;
}

@@ -1736,8 +1741,14 @@ static u32 mvneta_txq_desc_csum(int l3_o
static void mvneta_rx_error(struct mvneta_port *pp,
struct mvneta_rx_desc *rx_desc)
{
+ struct mvneta_pcpu_stats *stats = this_cpu_ptr(pp->stats);
u32 status = rx_desc->status;

+ /* update per-cpu counter */
+ u64_stats_update_begin(&stats->syncp);
+ stats->rx_errors++;
+ u64_stats_update_end(&stats->syncp);
+
switch (status & MVNETA_RXD_ERR_CODE_MASK) {
case MVNETA_RXD_ERR_CRC:
netdev_err(pp->dev, "bad rx status %08x (crc error), size=%d\n",
@@ -2179,11 +2190,15 @@ mvneta_swbm_rx_frame(struct mvneta_port

rxq->skb = build_skb(xdp->data_hard_start, PAGE_SIZE);
if (unlikely(!rxq->skb)) {
- netdev_err(dev,
- "Can't allocate skb on queue %d\n",
- rxq->id);
- dev->stats.rx_dropped++;
+ struct mvneta_pcpu_stats *stats = this_cpu_ptr(pp->stats);
+
+ netdev_err(dev, "Can't allocate skb on queue %d\n", rxq->id);
rxq->skb_alloc_err++;
+
+ u64_stats_update_begin(&stats->syncp);
+ stats->rx_dropped++;
+ u64_stats_update_end(&stats->syncp);
+
return -ENOMEM;
}
page_pool_release_page(rxq->page_pool, page);
@@ -2270,7 +2285,6 @@ static int mvneta_rx_swbm(struct napi_st
/* Check errors only for FIRST descriptor */
if (rx_status & MVNETA_RXD_ERR_SUMMARY) {
mvneta_rx_error(pp, rx_desc);
- dev->stats.rx_errors++;
/* leave the descriptor untouched */
continue;
}
@@ -2372,7 +2386,6 @@ err_drop_frame_ret_pool:
mvneta_bm_pool_put_bp(pp->bm_priv, bm_pool,
rx_desc->buf_phys_addr);
err_drop_frame:
- dev->stats.rx_errors++;
mvneta_rx_error(pp, rx_desc);
/* leave the descriptor untouched */
continue;