Merge branch 'broadcom-Adaptive-interrupt-coalescing'

Florian Fainelli says:

====================
net: broadcom: Adaptive interrupt coalescing

This patch series adds adaptive interrupt coalescing for the Gigabit Ethernet
drivers SYSTEMPORT and GENET.

This really helps lower the interrupt count and system load, as measured by
vmstat for a Gigabit TCP RX session:

SYSTEMPORT:

without:

 1  0      0 192188      0  25472    0    0     0     0 122100 38870  1 42 57  0  0
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  1.03 GBytes   884 Mbits/sec

with:

 1  0      0 192288      0  25468    0    0     0     0 58806 44401  0 100  0  0  0
[  5]  0.0-10.0 sec  1.04 GBytes   888 Mbits/sec

GENET:

without:

 1  0      0 1170404      0  25420    0    0     0     0 130785 63402  2 85 12  0  0
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  1.04 GBytes   888 Mbits/sec

with:

 1  0      0 1170560      0  25420    0    0     0     0 50610 48477  0 100  0  0  0
[  5]  0.0-10.0 sec  1.05 GBytes   899 Mbits/sec

Please look at the implementation and let me know if you see any problems, this
was largely inspired by bnxt_en.
====================

Signed-off-by: David S. Miller <[email protected]>

Author: davem330

drivers/net/ethernet/broadcom/bcmsysport.c

@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/netdevice.h>
+#include <linux/net_dim.h>
 #include <linux/etherdevice.h>
 #include <linux/platform_device.h>
 #include <linux/of.h>
@@ -574,21 +575,55 @@ static int bcm_sysport_set_wol(struct net_device *dev,
 	return 0;
 }
 
+static void bcm_sysport_set_rx_coalesce(struct bcm_sysport_priv *priv)
+{
+	u32 reg;
+
+	reg = rdma_readl(priv, RDMA_MBDONE_INTR);
+	reg &= ~(RDMA_INTR_THRESH_MASK |
+		 RDMA_TIMEOUT_MASK << RDMA_TIMEOUT_SHIFT);
+	reg |= priv->dim.coal_pkts;
+	reg |= DIV_ROUND_UP(priv->dim.coal_usecs * 1000, 8192) <<
+			    RDMA_TIMEOUT_SHIFT;
+	rdma_writel(priv, reg, RDMA_MBDONE_INTR);
+}
+
+static void bcm_sysport_set_tx_coalesce(struct bcm_sysport_tx_ring *ring)
+{
+	struct bcm_sysport_priv *priv = ring->priv;
+	u32 reg;
+
+	reg = tdma_readl(priv, TDMA_DESC_RING_INTR_CONTROL(ring->index));
+	reg &= ~(RING_INTR_THRESH_MASK |
+		 RING_TIMEOUT_MASK << RING_TIMEOUT_SHIFT);
+	reg |= ring->dim.coal_pkts;
+	reg |= DIV_ROUND_UP(ring->dim.coal_usecs * 1000, 8192) <<
+			    RING_TIMEOUT_SHIFT;
+	tdma_writel(priv, reg, TDMA_DESC_RING_INTR_CONTROL(ring->index));
+}
+
 static int bcm_sysport_get_coalesce(struct net_device *dev,
 				    struct ethtool_coalesce *ec)
 {
 	struct bcm_sysport_priv *priv = netdev_priv(dev);
+	struct bcm_sysport_tx_ring *ring;
+	unsigned int i;
 	u32 reg;
 
 	reg = tdma_readl(priv, TDMA_DESC_RING_INTR_CONTROL(0));
 
 	ec->tx_coalesce_usecs = (reg >> RING_TIMEOUT_SHIFT) * 8192 / 1000;
 	ec->tx_max_coalesced_frames = reg & RING_INTR_THRESH_MASK;
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		ring = &priv->tx_rings[i];
+		ec->use_adaptive_tx_coalesce |= ring->dim.use_dim;
+	}
 
 	reg = rdma_readl(priv, RDMA_MBDONE_INTR);
 
 	ec->rx_coalesce_usecs = (reg >> RDMA_TIMEOUT_SHIFT) * 8192 / 1000;
 	ec->rx_max_coalesced_frames = reg & RDMA_INTR_THRESH_MASK;
+	ec->use_adaptive_rx_coalesce = priv->dim.use_dim;
 
 	return 0;
 }
@@ -597,8 +632,8 @@ static int bcm_sysport_set_coalesce(struct net_device *dev,
 				    struct ethtool_coalesce *ec)
 {
 	struct bcm_sysport_priv *priv = netdev_priv(dev);
+	struct bcm_sysport_tx_ring *ring;
 	unsigned int i;
-	u32 reg;
 
 	/* Base system clock is 125Mhz, DMA timeout is this reference clock
 	 * divided by 1024, which yield roughly 8.192 us, our maximum value has
@@ -615,22 +650,26 @@ static int bcm_sysport_set_coalesce(struct net_device *dev,
 		return -EINVAL;
 
 	for (i = 0; i < dev->num_tx_queues; i++) {
-		reg = tdma_readl(priv, TDMA_DESC_RING_INTR_CONTROL(i));
-		reg &= ~(RING_INTR_THRESH_MASK |
-			 RING_TIMEOUT_MASK << RING_TIMEOUT_SHIFT);
-		reg |= ec->tx_max_coalesced_frames;
-		reg |= DIV_ROUND_UP(ec->tx_coalesce_usecs * 1000, 8192) <<
-			 RING_TIMEOUT_SHIFT;
-		tdma_writel(priv, reg, TDMA_DESC_RING_INTR_CONTROL(i));
+		ring = &priv->tx_rings[i];
+		ring->dim.coal_pkts = ec->tx_max_coalesced_frames;
+		ring->dim.coal_usecs = ec->tx_coalesce_usecs;
+		if (!ec->use_adaptive_tx_coalesce && ring->dim.use_dim) {
+			ring->dim.coal_pkts = 1;
+			ring->dim.coal_usecs = 0;
+		}
+		ring->dim.use_dim = ec->use_adaptive_tx_coalesce;
+		bcm_sysport_set_tx_coalesce(ring);
 	}
 
-	reg = rdma_readl(priv, RDMA_MBDONE_INTR);
-	reg &= ~(RDMA_INTR_THRESH_MASK |
-		 RDMA_TIMEOUT_MASK << RDMA_TIMEOUT_SHIFT);
-	reg |= ec->rx_max_coalesced_frames;
-	reg |= DIV_ROUND_UP(ec->rx_coalesce_usecs * 1000, 8192) <<
-			    RDMA_TIMEOUT_SHIFT;
-	rdma_writel(priv, reg, RDMA_MBDONE_INTR);
+	priv->dim.coal_usecs = ec->rx_coalesce_usecs;
+	priv->dim.coal_pkts = ec->rx_max_coalesced_frames;
+
+	if (!ec->use_adaptive_rx_coalesce && priv->dim.use_dim) {
+		priv->dim.coal_pkts = 1;
+		priv->dim.coal_usecs = 0;
+	}
+	priv->dim.use_dim = ec->use_adaptive_rx_coalesce;
+	bcm_sysport_set_rx_coalesce(priv);
 
 	return 0;
 }
@@ -709,6 +748,7 @@ static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv,
 	struct bcm_sysport_stats64 *stats64 = &priv->stats64;
 	struct net_device *ndev = priv->netdev;
 	unsigned int processed = 0, to_process;
+	unsigned int processed_bytes = 0;
 	struct bcm_sysport_cb *cb;
 	struct sk_buff *skb;
 	unsigned int p_index;
@@ -800,6 +840,7 @@ static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv,
 		 */
 		skb_pull(skb, sizeof(*rsb) + 2);
 		len -= (sizeof(*rsb) + 2);
+		processed_bytes += len;
 
 		/* UniMAC may forward CRC */
 		if (priv->crc_fwd) {
@@ -824,6 +865,9 @@ static unsigned int bcm_sysport_desc_rx(struct bcm_sysport_priv *priv,
 			priv->rx_read_ptr = 0;
 	}
 
+	priv->dim.packets = processed;
+	priv->dim.bytes = processed_bytes;
+
 	return processed;
 }
 
@@ -896,6 +940,8 @@ static unsigned int __bcm_sysport_tx_reclaim(struct bcm_sysport_priv *priv,
 	ring->packets += pkts_compl;
 	ring->bytes += bytes_compl;
 	u64_stats_update_end(&priv->syncp);
+	ring->dim.packets = pkts_compl;
+	ring->dim.bytes = bytes_compl;
 
 	ring->c_index = c_index;
 
@@ -941,6 +987,7 @@ static int bcm_sysport_tx_poll(struct napi_struct *napi, int budget)
 {
 	struct bcm_sysport_tx_ring *ring =
 		container_of(napi, struct bcm_sysport_tx_ring, napi);
+	struct net_dim_sample dim_sample;
 	unsigned int work_done = 0;
 
 	work_done = bcm_sysport_tx_reclaim(ring->priv, ring);
@@ -957,6 +1004,12 @@ static int bcm_sysport_tx_poll(struct napi_struct *napi, int budget)
 		return 0;
 	}
 
+	if (ring->dim.use_dim) {
+		net_dim_sample(ring->dim.event_ctr, ring->dim.packets,
+			       ring->dim.bytes, &dim_sample);
+		net_dim(&ring->dim.dim, dim_sample);
+	}
+
 	return budget;
 }
 
@@ -972,6 +1025,7 @@ static int bcm_sysport_poll(struct napi_struct *napi, int budget)
 {
 	struct bcm_sysport_priv *priv =
 		container_of(napi, struct bcm_sysport_priv, napi);
+	struct net_dim_sample dim_sample;
 	unsigned int work_done = 0;
 
 	work_done = bcm_sysport_desc_rx(priv, budget);
@@ -994,6 +1048,12 @@ static int bcm_sysport_poll(struct napi_struct *napi, int budget)
 		intrl2_0_mask_clear(priv, INTRL2_0_RDMA_MBDONE);
 	}
 
+	if (priv->dim.use_dim) {
+		net_dim_sample(priv->dim.event_ctr, priv->dim.packets,
+			       priv->dim.bytes, &dim_sample);
+		net_dim(&priv->dim.dim, dim_sample);
+	}
+
 	return work_done;
 }
 
@@ -1012,6 +1072,40 @@ static void bcm_sysport_resume_from_wol(struct bcm_sysport_priv *priv)
 	netif_dbg(priv, wol, priv->netdev, "resumed from WOL\n");
 }
 
+static void bcm_sysport_dim_work(struct work_struct *work)
+{
+	struct net_dim *dim = container_of(work, struct net_dim, work);
+	struct bcm_sysport_net_dim *ndim =
+			container_of(dim, struct bcm_sysport_net_dim, dim);
+	struct bcm_sysport_priv *priv =
+			container_of(ndim, struct bcm_sysport_priv, dim);
+	struct net_dim_cq_moder cur_profile =
+				net_dim_get_profile(dim->mode, dim->profile_ix);
+
+	priv->dim.coal_usecs = cur_profile.usec;
+	priv->dim.coal_pkts = cur_profile.pkts;
+
+	bcm_sysport_set_rx_coalesce(priv);
+	dim->state = NET_DIM_START_MEASURE;
+}
+
+static void bcm_sysport_dim_tx_work(struct work_struct *work)
+{
+	struct net_dim *dim = container_of(work, struct net_dim, work);
+	struct bcm_sysport_net_dim *ndim =
+			container_of(dim, struct bcm_sysport_net_dim, dim);
+	struct bcm_sysport_tx_ring *ring =
+			container_of(ndim, struct bcm_sysport_tx_ring, dim);
+	struct net_dim_cq_moder cur_profile =
+				net_dim_get_profile(dim->mode, dim->profile_ix);
+
+	ring->dim.coal_usecs = cur_profile.usec;
+	ring->dim.coal_pkts = cur_profile.pkts;
+
+	bcm_sysport_set_tx_coalesce(ring);
+	dim->state = NET_DIM_START_MEASURE;
+}
+
 /* RX and misc interrupt routine */
 static irqreturn_t bcm_sysport_rx_isr(int irq, void *dev_id)
 {
@@ -1030,6 +1124,7 @@ static irqreturn_t bcm_sysport_rx_isr(int irq, void *dev_id)
 	}
 
 	if (priv->irq0_stat & INTRL2_0_RDMA_MBDONE) {
+		priv->dim.event_ctr++;
 		if (likely(napi_schedule_prep(&priv->napi))) {
 			/* disable RX interrupts */
 			intrl2_0_mask_set(priv, INTRL2_0_RDMA_MBDONE);
@@ -1057,6 +1152,7 @@ static irqreturn_t bcm_sysport_rx_isr(int irq, void *dev_id)
 			continue;
 
 		txr = &priv->tx_rings[ring];
+		txr->dim.event_ctr++;
 
 		if (likely(napi_schedule_prep(&txr->napi))) {
 			intrl2_0_mask_set(priv, ring_bit);
@@ -1089,6 +1185,7 @@ static irqreturn_t bcm_sysport_tx_isr(int irq, void *dev_id)
 			continue;
 
 		txr = &priv->tx_rings[ring];
+		txr->dim.event_ctr++;
 
 		if (likely(napi_schedule_prep(&txr->napi))) {
 			intrl2_1_mask_set(priv, BIT(ring));
@@ -1354,6 +1451,16 @@ static void bcm_sysport_adj_link(struct net_device *dev)
 		phy_print_status(phydev);
 }
 
+static void bcm_sysport_init_dim(struct bcm_sysport_net_dim *dim,
+				 void (*cb)(struct work_struct *work))
+{
+	INIT_WORK(&dim->dim.work, cb);
+	dim->dim.mode = NET_DIM_CQ_PERIOD_MODE_START_FROM_EQE;
+	dim->event_ctr = 0;
+	dim->packets = 0;
+	dim->bytes = 0;
+}
+
 static int bcm_sysport_init_tx_ring(struct bcm_sysport_priv *priv,
 				    unsigned int index)
 {
@@ -1444,6 +1551,7 @@ static int bcm_sysport_init_tx_ring(struct bcm_sysport_priv *priv,
 	reg |= (1 << index);
 	tdma_writel(priv, reg, TDMA_TIER1_ARB_0_QUEUE_EN);
 
+	bcm_sysport_init_dim(&ring->dim, bcm_sysport_dim_tx_work);
 	napi_enable(&ring->napi);
 
 	netif_dbg(priv, hw, priv->netdev,
@@ -1474,6 +1582,7 @@ static void bcm_sysport_fini_tx_ring(struct bcm_sysport_priv *priv,
 		return;
 
 	napi_disable(&ring->napi);
+	cancel_work_sync(&ring->dim.dim.work);
 	netif_napi_del(&ring->napi);
 
 	bcm_sysport_tx_clean(priv, ring);
@@ -1763,6 +1872,7 @@ static void bcm_sysport_netif_start(struct net_device *dev)
 	struct bcm_sysport_priv *priv = netdev_priv(dev);
 
 	/* Enable NAPI */
+	bcm_sysport_init_dim(&priv->dim, bcm_sysport_dim_work);
 	napi_enable(&priv->napi);
 
 	/* Enable RX interrupt and TX ring full interrupt */
@@ -1948,6 +2058,7 @@ static void bcm_sysport_netif_stop(struct net_device *dev)
 	/* stop all software from updating hardware */
 	netif_tx_stop_all_queues(dev);
 	napi_disable(&priv->napi);
+	cancel_work_sync(&priv->dim.dim.work);
 	phy_stop(dev->phydev);
 
 	/* mask all interrupts */

drivers/net/ethernet/broadcom/bcmsysport.h

@@ -12,6 +12,7 @@
 #define __BCM_SYSPORT_H
 
 #include <linux/if_vlan.h>
+#include <linux/net_dim.h>
 
 /* Receive/transmit descriptor format */
 #define DESC_ADDR_HI_STATUS_LEN	0x00
@@ -695,6 +696,16 @@ struct bcm_sysport_hw_params {
 	unsigned int	num_rx_desc_words;
 };
 
+struct bcm_sysport_net_dim {
+	u16			use_dim;
+	u16			event_ctr;
+	unsigned long		packets;
+	unsigned long		bytes;
+	u32			coal_usecs;
+	u32			coal_pkts;
+	struct net_dim		dim;
+};
+
 /* Software view of the TX ring */
 struct bcm_sysport_tx_ring {
 	spinlock_t	lock;		/* Ring lock for tx reclaim/xmit */
@@ -712,6 +723,7 @@ struct bcm_sysport_tx_ring {
 	struct bcm_sysport_priv *priv;	/* private context backpointer */
 	unsigned long	packets;	/* packets statistics */
 	unsigned long	bytes;		/* bytes statistics */
+	struct bcm_sysport_net_dim dim;	/* Net DIM context */
 	unsigned int	switch_queue;	/* switch port queue number */
 	unsigned int	switch_port;	/* switch port queue number */
 	bool		inspect;	/* inspect switch port and queue */
@@ -743,6 +755,8 @@ struct bcm_sysport_priv {
 	unsigned int		rx_read_ptr;
 	unsigned int		rx_c_index;
 
+	struct bcm_sysport_net_dim	dim;
+
 	/* PHY device */
 	struct device_node	*phy_dn;
 	phy_interface_t		phy_interface;