net: stmmac: use per-queue 64 bit statistics where necessary

Currently, there are two major issues with stmmac driver statistics
First of all, statistics in stmmac_extra_stats, stmmac_rxq_stats
and stmmac_txq_stats are 32 bit variables on 32 bit platforms. This
can cause some stats to overflow after several minutes of
high traffic, for example rx_pkt_n, tx_pkt_n and so on.

Secondly, if HW supports multiqueues, there are frequent cacheline
ping pongs on some driver statistic vars, for example, normal_irq_n,
tx_pkt_n and so on. What's more, frequent cacheline ping pongs on
normal_irq_n happens in ISR, this makes the situation worse.

To improve the driver, we convert those statistics to 64 bit, implement
ndo_get_stats64 and update .get_ethtool_stats implementation
accordingly. We also use per-queue statistics where necessary to remove
the cacheline ping pongs as much as possible to make multiqueue
operations faster. Those statistics which are not possible to overflow
and not frequently updated are kept as is.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Link: https://lore.kernel.org/r/20230717160630.1892-3-jszhang@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 7 insertions, 13 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/enh_desc.c b/drivers/net/ethernet/stmicro/stmmac/enh_desc.c
index a91d8f13a931..937b7a0466fc 100644
--- a/drivers/net/ethernet/stmicro/stmmac/enh_desc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/enh_desc.c
@@ -12,8 +12,7 @@
 #include "common.h"
 #include "descs_com.h"
 
-static int enh_desc_get_tx_status(struct net_device_stats *stats,
-				  struct stmmac_extra_stats *x,
+static int enh_desc_get_tx_status(struct stmmac_extra_stats *x,
 				  struct dma_desc *p, void __iomem *ioaddr)
 {
 	unsigned int tdes0 = le32_to_cpu(p->des0);
@@ -38,15 +37,13 @@ static int enh_desc_get_tx_status(struct net_device_stats *stats,
 
 		if (unlikely(tdes0 & ETDES0_LOSS_CARRIER)) {
 			x->tx_losscarrier++;
-			stats->tx_carrier_errors++;
 		}
 		if (unlikely(tdes0 & ETDES0_NO_CARRIER)) {
 			x->tx_carrier++;
-			stats->tx_carrier_errors++;
 		}
 		if (unlikely((tdes0 & ETDES0_LATE_COLLISION) ||
 			     (tdes0 & ETDES0_EXCESSIVE_COLLISIONS)))
-			stats->collisions +=
+			x->tx_collision +=
 				(tdes0 & ETDES0_COLLISION_COUNT_MASK) >> 3;
 
 		if (unlikely(tdes0 & ETDES0_EXCESSIVE_DEFERRAL))
@@ -117,8 +114,7 @@ static int enh_desc_coe_rdes0(int ipc_err, int type, int payload_err)
 	return ret;
 }
 
-static void enh_desc_get_ext_status(struct net_device_stats *stats,
-				    struct stmmac_extra_stats *x,
+static void enh_desc_get_ext_status(struct stmmac_extra_stats *x,
 				    struct dma_extended_desc *p)
 {
 	unsigned int rdes0 = le32_to_cpu(p->basic.des0);
@@ -182,8 +178,7 @@ static void enh_desc_get_ext_status(struct net_device_stats *stats,
 	}
 }
 
-static int enh_desc_get_rx_status(struct net_device_stats *stats,
-				  struct stmmac_extra_stats *x,
+static int enh_desc_get_rx_status(struct stmmac_extra_stats *x,
 				  struct dma_desc *p)
 {
 	unsigned int rdes0 = le32_to_cpu(p->des0);
@@ -193,14 +188,14 @@ static int enh_desc_get_rx_status(struct net_device_stats *stats,
 		return dma_own;
 
 	if (unlikely(!(rdes0 & RDES0_LAST_DESCRIPTOR))) {
-		stats->rx_length_errors++;
+		x->rx_length++;
 		return discard_frame;
 	}
 
 	if (unlikely(rdes0 & RDES0_ERROR_SUMMARY)) {
 		if (unlikely(rdes0 & RDES0_DESCRIPTOR_ERROR)) {
 			x->rx_desc++;
-			stats->rx_length_errors++;
+			x->rx_length++;
 		}
 		if (unlikely(rdes0 & RDES0_OVERFLOW_ERROR))
 			x->rx_gmac_overflow++;
@@ -209,7 +204,7 @@ static int enh_desc_get_rx_status(struct net_device_stats *stats,
 			pr_err("\tIPC Csum Error/Giant frame\n");
 
 		if (unlikely(rdes0 & RDES0_COLLISION))
-			stats->collisions++;
+			x->rx_collision++;
 		if (unlikely(rdes0 & RDES0_RECEIVE_WATCHDOG))
 			x->rx_watchdog++;
 
@@ -218,7 +213,6 @@ static int enh_desc_get_rx_status(struct net_device_stats *stats,
 
 		if (unlikely(rdes0 & RDES0_CRC_ERROR)) {
 			x->rx_crc_errors++;
-			stats->rx_crc_errors++;
 		}
 		ret = discard_frame;
 	}