net: stmmac: Implement RX Coalesce Frames setting

Add support for coalescing RX path by specifying number of frames which
don't need to have interrupt on completion bit set.

This is only available when RX Watchdog is enabled.

Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
index 2403a65..dfd47fd 100644
--- a/drivers/net/ethernet/stmicro/stmmac/common.h
+++ b/drivers/net/ethernet/stmicro/stmmac/common.h
@@ -252,6 +252,7 @@
 #define STMMAC_MAX_COAL_TX_TICK	100000
 #define STMMAC_TX_MAX_FRAMES	256
 #define STMMAC_TX_FRAMES	1
+#define STMMAC_RX_FRAMES	25
 
 /* Packets types */
 enum packets_types {
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index 1238982..513f4e2 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -55,6 +55,7 @@
 };
 
 struct stmmac_rx_queue {
+	u32 rx_count_frames;
 	u32 queue_index;
 	struct stmmac_priv *priv_data;
 	struct dma_extended_desc *dma_erx;
@@ -110,6 +111,7 @@
 	/* Frequently used values are kept adjacent for cache effect */
 	u32 tx_coal_frames;
 	u32 tx_coal_timer;
+	u32 rx_coal_frames;
 
 	int tx_coalesce;
 	int hwts_tx_en;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
index cfd93ee..6efb668 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
@@ -701,8 +701,10 @@
 	ec->tx_coalesce_usecs = priv->tx_coal_timer;
 	ec->tx_max_coalesced_frames = priv->tx_coal_frames;
 
-	if (priv->use_riwt)
+	if (priv->use_riwt) {
+		ec->rx_max_coalesced_frames = priv->rx_coal_frames;
 		ec->rx_coalesce_usecs = stmmac_riwt2usec(priv->rx_riwt, priv);
+	}
 
 	return 0;
 }
@@ -715,7 +717,7 @@
 	unsigned int rx_riwt;
 
 	/* Check not supported parameters  */
-	if ((ec->rx_max_coalesced_frames) || (ec->rx_coalesce_usecs_irq) ||
+	if ((ec->rx_coalesce_usecs_irq) ||
 	    (ec->rx_max_coalesced_frames_irq) || (ec->tx_coalesce_usecs_irq) ||
 	    (ec->use_adaptive_rx_coalesce) || (ec->use_adaptive_tx_coalesce) ||
 	    (ec->pkt_rate_low) || (ec->rx_coalesce_usecs_low) ||
@@ -749,6 +751,7 @@
 	/* Only copy relevant parameters, ignore all others. */
 	priv->tx_coal_frames = ec->tx_max_coalesced_frames;
 	priv->tx_coal_timer = ec->tx_coalesce_usecs;
+	priv->rx_coal_frames = ec->rx_max_coalesced_frames;
 	priv->rx_riwt = rx_riwt;
 	stmmac_rx_watchdog(priv, priv->ioaddr, priv->rx_riwt, rx_cnt);
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index bdedde9..c142e93 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2268,20 +2268,21 @@
 }
 
 /**
- * stmmac_init_tx_coalesce - init tx mitigation options.
+ * stmmac_init_coalesce - init mitigation options.
  * @priv: driver private structure
  * Description:
- * This inits the transmit coalesce parameters: i.e. timer rate,
+ * This inits the coalesce parameters: i.e. timer rate,
  * timer handler and default threshold used for enabling the
  * interrupt on completion bit.
  */
-static void stmmac_init_tx_coalesce(struct stmmac_priv *priv)
+static void stmmac_init_coalesce(struct stmmac_priv *priv)
 {
 	u32 tx_channel_count = priv->plat->tx_queues_to_use;
 	u32 chan;
 
 	priv->tx_coal_frames = STMMAC_TX_FRAMES;
 	priv->tx_coal_timer = STMMAC_COAL_TX_TIMER;
+	priv->rx_coal_frames = STMMAC_RX_FRAMES;
 
 	for (chan = 0; chan < tx_channel_count; chan++) {
 		struct stmmac_tx_queue *tx_q = &priv->tx_queue[chan];
@@ -2651,7 +2652,7 @@
 		goto init_error;
 	}
 
-	stmmac_init_tx_coalesce(priv);
+	stmmac_init_coalesce(priv);
 
 	phylink_start(priv->phylink);
 
@@ -3289,6 +3290,7 @@
 
 	while (dirty-- > 0) {
 		struct dma_desc *p;
+		bool use_rx_wd;
 
 		if (priv->extend_desc)
 			p = (struct dma_desc *)(rx_q->dma_erx + entry);
@@ -3331,7 +3333,11 @@
 		}
 		dma_wmb();
 
-		stmmac_set_rx_owner(priv, p, priv->use_riwt);
+		rx_q->rx_count_frames++;
+		rx_q->rx_count_frames %= priv->rx_coal_frames;
+		use_rx_wd = priv->use_riwt && rx_q->rx_count_frames;
+
+		stmmac_set_rx_owner(priv, p, use_rx_wd);
 
 		dma_wmb();
 
@@ -4631,7 +4637,7 @@
 	stmmac_clear_descriptors(priv);
 
 	stmmac_hw_setup(ndev, false);
-	stmmac_init_tx_coalesce(priv);
+	stmmac_init_coalesce(priv);
 	stmmac_set_rx_mode(ndev);
 
 	stmmac_enable_all_queues(priv);