3 files changed, 53 insertions, 1 deletions

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 055e93a417b6..7513618793da 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -10530,7 +10530,7 @@ static void bnxt_accumulate_stats(struct bnxt_stats_mem *stats)
 				stats->hw_masks, stats->len / 8, false);
 }
 
-static void bnxt_accumulate_all_stats(struct bnxt *bp)
+static void bnxt_accumulate_ring_stats(struct bnxt *bp)
 {
 	struct bnxt_stats_mem *ring0_stats;
 	bool ignore_zero = false;
@@ -10553,6 +10553,10 @@ static void bnxt_accumulate_all_stats(struct bnxt *bp)
 					ring0_stats->hw_masks,
 					ring0_stats->len / 8, ignore_zero);
 	}
+}
+
+static void bnxt_accumulate_port_stats(struct bnxt *bp)
+{
 	if (bp->flags & BNXT_FLAG_PORT_STATS) {
 		struct bnxt_stats_mem *stats = &bp->port_stats;
 		__le64 *hw_stats = stats->hw_stats;
@@ -10575,6 +10579,41 @@ static void bnxt_accumulate_all_stats(struct bnxt *bp)
 	}
 }
 
+static void bnxt_accumulate_all_stats(struct bnxt *bp)
+{
+	bnxt_accumulate_ring_stats(bp);
+	bnxt_accumulate_port_stats(bp);
+}
+
+/* Re-accumulate ring stats from DMA buffers if stale.
+ * uAPIs for reading sw_stats should call this first.
+ *
+ * We promise user space update frequency of bp->stats_coal_ticks but
+ * the update is a two step process - first device updates the DMA buffer,
+ * then we have to update from that buffer to driver stats in the service work.
+ * Worst case we would be 2x off from the desired frequency.
+ * Sync the stats sooner, if stale. The 20% threshold was chosen arbitrarily.
+ *
+ * Ideally we would split the user-configured time into two portions,
+ * i.e. also lower the DMA period by the 20%. But the DMA timer seems to have
+ * too coarse granularity to play such tricks.
+ */
+void bnxt_sync_ring_stats(struct bnxt *bp)
+{
+	unsigned long stale;
+
+	if (!netif_running(bp->dev) || !bp->stats_coal_ticks)
+		return;
+
+	spin_lock(&bp->stats_lock);
+	stale = usecs_to_jiffies(bp->stats_coal_ticks / 5);
+	if (time_after_eq(jiffies, bp->stats_updated_jiffies + stale)) {
+		bnxt_accumulate_ring_stats(bp);
+		bp->stats_updated_jiffies = jiffies;
+	}
+	spin_unlock(&bp->stats_lock);
+}
+
 static int bnxt_hwrm_port_qstats(struct bnxt *bp, u8 flags)
 {
 	struct hwrm_port_qstats_input *req;
@@ -13577,6 +13616,7 @@ bnxt_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
 		return;
 	}
 
+	bnxt_sync_ring_stats(bp);
 	bnxt_get_ring_stats(bp, stats);
 	bnxt_add_prev_stats(bp, stats);
 
@@ -14753,7 +14793,10 @@ static void bnxt_sp_task(struct work_struct *work)
 	if (test_and_clear_bit(BNXT_PERIODIC_STATS_SP_EVENT, &bp->sp_event)) {
 		bnxt_hwrm_port_qstats(bp, 0);
 		bnxt_hwrm_port_qstats_ext(bp, 0);
+		spin_lock(&bp->stats_lock);
 		bnxt_accumulate_all_stats(bp);
+		bp->stats_updated_jiffies = jiffies;
+		spin_unlock(&bp->stats_lock);
 	}
 
 	if (test_and_clear_bit(BNXT_LINK_CHNG_SP_EVENT, &bp->sp_event)) {
@@ -15488,6 +15531,7 @@ static int bnxt_init_board(struct pci_dev *pdev, struct net_device *dev)
 	INIT_DELAYED_WORK(&bp->fw_reset_task, bnxt_fw_reset_task);
 
 	spin_lock_init(&bp->ntp_fltr_lock);
+	spin_lock_init(&bp->stats_lock);
 #if BITS_PER_LONG == 32
 	spin_lock_init(&bp->db_lock);
 #endif
@@ -16056,6 +16100,7 @@ static void bnxt_get_queue_stats_rx(struct net_device *dev, int i,
 	if (!bp->bnapi)
 		return;
 
+	bnxt_sync_ring_stats(bp);
 	cpr = &bp->bnapi[i]->cp_ring;
 	sw = cpr->stats.sw_stats;
 
@@ -16084,6 +16129,7 @@ static void bnxt_get_queue_stats_tx(struct net_device *dev, int i,
 	if (!bp->tx_ring)
 		return;
 
+	bnxt_sync_ring_stats(bp);
 	bnapi = bp->tx_ring[bp->tx_ring_map[i]].bnapi;
 	sw = bnapi->cp_ring.stats.sw_stats;
 
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index 6d312259f852..6335dfc14c98 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -2620,6 +2620,10 @@ struct bnxt {
 #define BNXT_MIN_STATS_COAL_TICKS	  250000
 #define BNXT_MAX_STATS_COAL_TICKS	 1000000
 
+	/* Protects stats_updated_jiffies and writes to sw_stats */
+	spinlock_t		stats_lock;
+	unsigned long		stats_updated_jiffies;
+
 	struct work_struct	sp_task;
 	unsigned long		sp_event;
 #define BNXT_RX_NTP_FLTR_SP_EVENT	1
@@ -3027,6 +3031,7 @@ void bnxt_reenable_sriov(struct bnxt *bp);
 void bnxt_close_nic(struct bnxt *, bool, bool);
 void bnxt_get_ring_drv_stats(struct bnxt *bp,
 			     struct bnxt_total_ring_drv_stats *stats);
+void bnxt_sync_ring_stats(struct bnxt *bp);
 bool bnxt_rfs_capable(struct bnxt *bp, bool new_rss_ctx);
 int bnxt_dbg_hwrm_rd_reg(struct bnxt *bp, u32 reg_off, u16 num_words,
 			 u32 *reg_buf);
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
index 56d74a3c24b7..62bc9cae613c 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
@@ -606,6 +606,7 @@ static void bnxt_get_ethtool_stats(struct net_device *dev,
 		goto skip_ring_stats;
 	}
 
+	bnxt_sync_ring_stats(bp);
 	tpa_stats = bnxt_get_num_tpa_ring_stats(bp);
 	for (i = 0; i < bp->cp_nr_rings; i++) {
 		struct bnxt_napi *bnapi = bp->bnapi[i];