net: ethernet: mtk_eth_soc: add support for page_pool_get_stats

Introduce support for the page_pool stats API into mtk_eth_soc driver.
Report page_pool stats through ethtool.

Signed-off-by: Lorenzo Bianconi <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/mediatek/Kconfig

···
 	select PHYLINK
 	select DIMLIB
 	select PAGE_POOL
+	select PAGE_POOL_STATS
 	help
 	  This driver supports the gigabit ethernet MACs in the
 	  MediaTek SoC family.

drivers/net/ethernet/mediatek/mtk_eth_soc.c

···
 	int i;
 
 	switch (stringset) {
-	case ETH_SS_STATS:
+	case ETH_SS_STATS: {
+		struct mtk_mac *mac = netdev_priv(dev);
+
 		for (i = 0; i < ARRAY_SIZE(mtk_ethtool_stats); i++) {
 			memcpy(data, mtk_ethtool_stats[i].str, ETH_GSTRING_LEN);
 			data += ETH_GSTRING_LEN;
 		}
+		if (mtk_page_pool_enabled(mac->hw))
+			page_pool_ethtool_stats_get_strings(data);
+		break;
+	}
+	default:
 		break;
 	}
 }
···
 static int mtk_get_sset_count(struct net_device *dev, int sset)
 {
 	switch (sset) {
-	case ETH_SS_STATS:
-		return ARRAY_SIZE(mtk_ethtool_stats);
+	case ETH_SS_STATS: {
+		int count = ARRAY_SIZE(mtk_ethtool_stats);
+		struct mtk_mac *mac = netdev_priv(dev);
+
+		if (mtk_page_pool_enabled(mac->hw))
+			count += page_pool_ethtool_stats_get_count();
+		return count;
+	}
 	default:
 		return -EOPNOTSUPP;
 	}
+}
+
+static void mtk_ethtool_pp_stats(struct mtk_eth *eth, u64 *data)
+{
+	struct page_pool_stats stats = {};
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(eth->rx_ring); i++) {
+		struct mtk_rx_ring *ring = &eth->rx_ring[i];
+
+		if (!ring->page_pool)
+			continue;
+
+		page_pool_get_stats(ring->page_pool, &stats);
+	}
+	page_pool_ethtool_stats_get(data, &stats);
 }
 
 static void mtk_get_ethtool_stats(struct net_device *dev,
···
 
 		for (i = 0; i < ARRAY_SIZE(mtk_ethtool_stats); i++)
 			*data_dst++ = *(data_src + mtk_ethtool_stats[i].offset);
+		if (mtk_page_pool_enabled(mac->hw))
+			mtk_ethtool_pp_stats(mac->hw, data_dst);
 	} while (u64_stats_fetch_retry_irq(&hwstats->syncp, start));
 }