[PATCH net-next 0/3] mvneta: Introduce RSS support

[PATCH net-next 0/3] mvneta: Introduce RSS support

[Gregory CLEMENT]

Hi,

this series is the first step add RSS support on mvneta.

It will allow associating an ethernet interface to a given CPU through
RSS by using "ethtool -X ethX weight". Indeed, currently I only enable
one entry in the RSS lookup table. Even if it is not really RSS, it
allows to get back the irq affinity feature we lost by using the
percpu interrupt.

Compared to the RFC series I added a missing patch for the series, I
rebased onto v4.4-rc1 and I fixed the mvneta_config_rss. Marcin
pointed that making the interrupt should be done on all the CPUs.

Th first patch make the default queue associate to each port and no
more a global variable.

The second patch really associates the RX queues with the CPUs instead
of masking the percpu interrupts for doing it. All the RX queues are
enabled and are statically associated with the CPUs by using a modulo
of the number of present CPUs. But at this stage only one RX queue
will receive the stream.

I also choose to associate all the TX queues on the same CPU that the
one associated to the RX queue. It allows to contain all the
interrupts on the same CPU. I think that an improvement on this side
would be the support of the XPS.

The last patch introduces a first level of RSS support through the
ethtool functions. As explained in the introduction there is only one
entry in the RSS lookup table which permits at the end to associate an
mvneta port to a CPU through the RX queues because the mapping is
static.

Thanks,

Gregory CLEMENT (3):
  net: mvneta: Make the default queue related for each port
  net: mvneta: Associate RX queues with each CPU
  net: mvneta: Add naive RSS support

 drivers/net/ethernet/marvell/mvneta.c | 298 +++++++++++++++++++++++++++++-----
 1 file changed, 253 insertions(+), 45 deletions(-)

-- 
2.5.0

[PATCH net-next 1/3] net: mvneta: Make the default queue related for each port

[Gregory CLEMENT]

Instead of using the same default queue for all the port. Move it in the
port struct. It will allow have a different default queue for each port.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
---
 drivers/net/ethernet/marvell/mvneta.c | 33 ++++++++++++++++++---------------
 1 file changed, 18 insertions(+), 15 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index e84c7f2634d3..1c7751917d58 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -354,6 +354,7 @@ struct mvneta_port {
 	struct mvneta_tx_queue *txqs;
 	struct net_device *dev;
 	struct notifier_block cpu_notifier;
+	int rxq_def;
 
 	/* Core clock */
 	struct clk *clk;
@@ -817,7 +818,7 @@ static void mvneta_port_up(struct mvneta_port *pp)
 	mvreg_write(pp, MVNETA_TXQ_CMD, q_map);
 
 	/* Enable all initialized RXQs. */
-	mvreg_write(pp, MVNETA_RXQ_CMD, BIT(rxq_def));
+	mvreg_write(pp, MVNETA_RXQ_CMD, BIT(pp->rxq_def));
 }
 
 /* Stop the Ethernet port activity */
@@ -1027,7 +1028,7 @@ static void mvneta_defaults_set(struct mvneta_port *pp)
 	mvreg_write(pp, MVNETA_ACC_MODE, val);
 
 	/* Update val of portCfg register accordingly with all RxQueue types */
-	val = MVNETA_PORT_CONFIG_DEFL_VALUE(rxq_def);
+	val = MVNETA_PORT_CONFIG_DEFL_VALUE(pp->rxq_def);
 	mvreg_write(pp, MVNETA_PORT_CONFIG, val);
 
 	val = 0;
@@ -2076,19 +2077,19 @@ static void mvneta_set_rx_mode(struct net_device *dev)
 	if (dev->flags & IFF_PROMISC) {
 		/* Accept all: Multicast + Unicast */
 		mvneta_rx_unicast_promisc_set(pp, 1);
-		mvneta_set_ucast_table(pp, rxq_def);
-		mvneta_set_special_mcast_table(pp, rxq_def);
-		mvneta_set_other_mcast_table(pp, rxq_def);
+		mvneta_set_ucast_table(pp, pp->rxq_def);
+		mvneta_set_special_mcast_table(pp, pp->rxq_def);
+		mvneta_set_other_mcast_table(pp, pp->rxq_def);
 	} else {
 		/* Accept single Unicast */
 		mvneta_rx_unicast_promisc_set(pp, 0);
 		mvneta_set_ucast_table(pp, -1);
-		mvneta_mac_addr_set(pp, dev->dev_addr, rxq_def);
+		mvneta_mac_addr_set(pp, dev->dev_addr, pp->rxq_def);
 
 		if (dev->flags & IFF_ALLMULTI) {
 			/* Accept all multicast */
-			mvneta_set_special_mcast_table(pp, rxq_def);
-			mvneta_set_other_mcast_table(pp, rxq_def);
+			mvneta_set_special_mcast_table(pp, pp->rxq_def);
+			mvneta_set_other_mcast_table(pp, pp->rxq_def);
 		} else {
 			/* Accept only initialized multicast */
 			mvneta_set_special_mcast_table(pp, -1);
@@ -2097,7 +2098,7 @@ static void mvneta_set_rx_mode(struct net_device *dev)
 			if (!netdev_mc_empty(dev)) {
 				netdev_for_each_mc_addr(ha, dev) {
 					mvneta_mcast_addr_set(pp, ha->addr,
-							      rxq_def);
+							      pp->rxq_def);
 				}
 			}
 		}
@@ -2180,7 +2181,7 @@ static int mvneta_poll(struct napi_struct *napi, int budget)
 	 * RX packets
 	 */
 	cause_rx_tx |= port->cause_rx_tx;
-	rx_done = mvneta_rx(pp, budget, &pp->rxqs[rxq_def]);
+	rx_done = mvneta_rx(pp, budget, &pp->rxqs[pp->rxq_def]);
 	budget -= rx_done;
 
 	if (budget > 0) {
@@ -2393,17 +2394,17 @@ static void mvneta_cleanup_txqs(struct mvneta_port *pp)
 /* Cleanup all Rx queues */
 static void mvneta_cleanup_rxqs(struct mvneta_port *pp)
 {
-	mvneta_rxq_deinit(pp, &pp->rxqs[rxq_def]);
+	mvneta_rxq_deinit(pp, &pp->rxqs[pp->rxq_def]);
 }
 
 
 /* Init all Rx queues */
 static int mvneta_setup_rxqs(struct mvneta_port *pp)
 {
-	int err = mvneta_rxq_init(pp, &pp->rxqs[rxq_def]);
+	int err = mvneta_rxq_init(pp, &pp->rxqs[pp->rxq_def]);
 	if (err) {
 		netdev_err(pp->dev, "%s: can't create rxq=%d\n",
-			   __func__, rxq_def);
+			   __func__, pp->rxq_def);
 		mvneta_cleanup_rxqs(pp);
 		return err;
 	}
@@ -2609,7 +2610,7 @@ static int mvneta_set_mac_addr(struct net_device *dev, void *addr)
 	mvneta_mac_addr_set(pp, dev->dev_addr, -1);
 
 	/* Set new addr in hw */
-	mvneta_mac_addr_set(pp, sockaddr->sa_data, rxq_def);
+	mvneta_mac_addr_set(pp, sockaddr->sa_data, pp->rxq_def);
 
 	eth_commit_mac_addr_change(dev, addr);
 	return 0;
@@ -2728,7 +2729,7 @@ static void mvneta_percpu_elect(struct mvneta_port *pp)
 {
 	int online_cpu_idx, cpu, i = 0;
 
-	online_cpu_idx = rxq_def % num_online_cpus();
+	online_cpu_idx = pp->rxq_def % num_online_cpus();
 
 	for_each_online_cpu(cpu) {
 		if (i == online_cpu_idx)
@@ -3306,6 +3307,8 @@ static int mvneta_probe(struct platform_device *pdev)
 				 strcmp(managed, "in-band-status") == 0);
 	pp->cpu_notifier.notifier_call = mvneta_percpu_notifier;
 
+	pp->rxq_def = rxq_def;
+
 	pp->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(pp->clk)) {
 		err = PTR_ERR(pp->clk);
-- 
2.5.0

[PATCH net-next 2/3] net: mvneta: Associate RX queues with each CPU

[Gregory CLEMENT]

We enable the percpu interrupt for all the CPU and we just associate a
CPU to a few queue at the neta level. The mapping between the CPUs and
the queues is static. The queues are associated to the CPU module the
number of CPUs. However currently we only use on RX queue for a given
Ethernet port.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
---
 drivers/net/ethernet/marvell/mvneta.c | 150 ++++++++++++++++++++++++++--------
 1 file changed, 115 insertions(+), 35 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 1c7751917d58..8974ab084839 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -109,9 +109,16 @@
 #define MVNETA_CPU_MAP(cpu)                      (0x2540 + ((cpu) << 2))
 #define      MVNETA_CPU_RXQ_ACCESS_ALL_MASK      0x000000ff
 #define      MVNETA_CPU_TXQ_ACCESS_ALL_MASK      0x0000ff00
+#define      MVNETA_CPU_RXQ_ACCESS(rxq)		 BIT(rxq)
 #define MVNETA_RXQ_TIME_COAL_REG(q)              (0x2580 + ((q) << 2))
 
-/* Exception Interrupt Port/Queue Cause register */
+/* Exception Interrupt Port/Queue Cause register
+ *
+ * Their behavior depend of the mapping done using the PCPX2Q
+ * registers. For a given CPU if the bit associated to a queue is not
+ * set, then for the register a read from this CPU will always return
+ * 0 and a write won't do anything
+ */
 
 #define MVNETA_INTR_NEW_CAUSE                    0x25a0
 #define MVNETA_INTR_NEW_MASK                     0x25a4
@@ -818,7 +825,13 @@ static void mvneta_port_up(struct mvneta_port *pp)
 	mvreg_write(pp, MVNETA_TXQ_CMD, q_map);
 
 	/* Enable all initialized RXQs. */
-	mvreg_write(pp, MVNETA_RXQ_CMD, BIT(pp->rxq_def));
+	for (queue = 0; queue < rxq_number; queue++) {
+		struct mvneta_rx_queue *rxq = &pp->rxqs[queue];
+
+		if (rxq->descs != NULL)
+			q_map |= (1 << queue);
+	}
+	mvreg_write(pp, MVNETA_RXQ_CMD, q_map);
 }
 
 /* Stop the Ethernet port activity */
@@ -986,6 +999,7 @@ static void mvneta_defaults_set(struct mvneta_port *pp)
 	int cpu;
 	int queue;
 	u32 val;
+	int max_cpu = num_present_cpus();
 
 	/* Clear all Cause registers */
 	mvreg_write(pp, MVNETA_INTR_NEW_CAUSE, 0);
@@ -1001,13 +1015,23 @@ static void mvneta_defaults_set(struct mvneta_port *pp)
 	/* Enable MBUS Retry bit16 */
 	mvreg_write(pp, MVNETA_MBUS_RETRY, 0x20);
 
-	/* Set CPU queue access map - all CPUs have access to all RX
-	 * queues and to all TX queues
+	/* Set CPU queue access map. CPUs are assigned to the RX
+	 * queues modulo their number and all the TX queues are
+	 * assigned to the CPU associated to the default RX queue.
 	 */
-	for_each_present_cpu(cpu)
-		mvreg_write(pp, MVNETA_CPU_MAP(cpu),
-			    (MVNETA_CPU_RXQ_ACCESS_ALL_MASK |
-			     MVNETA_CPU_TXQ_ACCESS_ALL_MASK));
+	for_each_present_cpu(cpu) {
+		int rxq_map = 0, txq_map = 0;
+		int rxq;
+
+		for (rxq = 0; rxq < rxq_number; rxq++)
+			if ((rxq % max_cpu) == cpu)
+				rxq_map |= MVNETA_CPU_RXQ_ACCESS(rxq);
+
+		if (cpu == rxq_def)
+			txq_map = MVNETA_CPU_TXQ_ACCESS_ALL_MASK;
+
+		mvreg_write(pp, MVNETA_CPU_MAP(cpu), rxq_map | txq_map);
+	}
 
 	/* Reset RX and TX DMAs */
 	mvreg_write(pp, MVNETA_PORT_RX_RESET, MVNETA_PORT_RX_DMA_RESET);
@@ -2149,6 +2173,7 @@ static int mvneta_poll(struct napi_struct *napi, int budget)
 {
 	int rx_done = 0;
 	u32 cause_rx_tx;
+	int rx_queue;
 	struct mvneta_port *pp = netdev_priv(napi->dev);
 	struct mvneta_pcpu_port *port = this_cpu_ptr(pp->ports);
 
@@ -2180,8 +2205,15 @@ static int mvneta_poll(struct napi_struct *napi, int budget)
 	/* For the case where the last mvneta_poll did not process all
 	 * RX packets
 	 */
+	rx_queue = fls(((cause_rx_tx >> 8) & 0xff));
+
 	cause_rx_tx |= port->cause_rx_tx;
-	rx_done = mvneta_rx(pp, budget, &pp->rxqs[pp->rxq_def]);
+
+	if (rx_queue) {
+		rx_queue = rx_queue - 1;
+		rx_done = mvneta_rx(pp, budget, &pp->rxqs[rx_queue]);
+	}
+
 	budget -= rx_done;
 
 	if (budget > 0) {
@@ -2394,19 +2426,27 @@ static void mvneta_cleanup_txqs(struct mvneta_port *pp)
 /* Cleanup all Rx queues */
 static void mvneta_cleanup_rxqs(struct mvneta_port *pp)
 {
-	mvneta_rxq_deinit(pp, &pp->rxqs[pp->rxq_def]);
+	int queue;
+
+	for (queue = 0; queue < txq_number; queue++)
+		mvneta_rxq_deinit(pp, &pp->rxqs[queue]);
 }
 
 
 /* Init all Rx queues */
 static int mvneta_setup_rxqs(struct mvneta_port *pp)
 {
-	int err = mvneta_rxq_init(pp, &pp->rxqs[pp->rxq_def]);
-	if (err) {
-		netdev_err(pp->dev, "%s: can't create rxq=%d\n",
-			   __func__, pp->rxq_def);
-		mvneta_cleanup_rxqs(pp);
-		return err;
+	int queue;
+
+	for (queue = 0; queue < rxq_number; queue++) {
+		int err = mvneta_rxq_init(pp, &pp->rxqs[queue]);
+
+		if (err) {
+			netdev_err(pp->dev, "%s: can't create rxq=%d\n",
+				   __func__, queue);
+			mvneta_cleanup_rxqs(pp);
+			return err;
+		}
 	}
 
 	return 0;
@@ -2430,6 +2470,19 @@ static int mvneta_setup_txqs(struct mvneta_port *pp)
 	return 0;
 }
 
+static void mvneta_percpu_unmask_interrupt(void *arg)
+{
+	struct mvneta_port *pp = arg;
+
+	/* All the queue are unmasked, but actually only the ones
+	 * maped to this CPU will be unmasked
+	 */
+	mvreg_write(pp, MVNETA_INTR_NEW_MASK,
+		    MVNETA_RX_INTR_MASK_ALL |
+		    MVNETA_TX_INTR_MASK_ALL |
+		    MVNETA_MISCINTR_INTR_MASK);
+}
+
 static void mvneta_start_dev(struct mvneta_port *pp)
 {
 	unsigned int cpu;
@@ -2447,11 +2500,10 @@ static void mvneta_start_dev(struct mvneta_port *pp)
 		napi_enable(&port->napi);
 	}
 
-	/* Unmask interrupts */
-	mvreg_write(pp, MVNETA_INTR_NEW_MASK,
-		    MVNETA_RX_INTR_MASK(rxq_number) |
-		    MVNETA_TX_INTR_MASK(txq_number) |
-		    MVNETA_MISCINTR_INTR_MASK);
+	/* Unmask interrupts. It has to be done from each CPU */
+	for_each_online_cpu(cpu)
+		smp_call_function_single(cpu, mvneta_percpu_unmask_interrupt,
+					 pp, true);
 	mvreg_write(pp, MVNETA_INTR_MISC_MASK,
 		    MVNETA_CAUSE_PHY_STATUS_CHANGE |
 		    MVNETA_CAUSE_LINK_CHANGE |
@@ -2727,22 +2779,35 @@ static void mvneta_percpu_disable(void *arg)
 
 static void mvneta_percpu_elect(struct mvneta_port *pp)
 {
-	int online_cpu_idx, cpu, i = 0;
+	int online_cpu_idx, max_cpu, cpu, i = 0;
 
 	online_cpu_idx = pp->rxq_def % num_online_cpus();
+	max_cpu = num_present_cpus();
 
 	for_each_online_cpu(cpu) {
-		if (i == online_cpu_idx)
-			/* Enable per-CPU interrupt on the one CPU we
-			 * just elected
+		int rxq_map = 0, txq_map = 0;
+		int rxq;
+
+		for (rxq = 0; rxq < rxq_number; rxq++)
+			if ((rxq % max_cpu) == cpu)
+				rxq_map |= MVNETA_CPU_RXQ_ACCESS(rxq);
+
+		if (i == online_cpu_idx) {
+			/* Map the default receive queue and transmit
+			 * queue to the elected CPU
 			 */
-			smp_call_function_single(cpu, mvneta_percpu_enable,
-						pp, true);
-		else
-			/* Disable per-CPU interrupt on all the other CPU */
-			smp_call_function_single(cpu, mvneta_percpu_disable,
-						pp, true);
+			rxq_map |= MVNETA_CPU_RXQ_ACCESS(pp->rxq_def);
+			txq_map = MVNETA_CPU_TXQ_ACCESS_ALL_MASK;
+		}
+		mvreg_write(pp, MVNETA_CPU_MAP(cpu), rxq_map | txq_map);
+
+		/* Update the interrupt mask on each CPU according the
+		 * new mapping
+		 */
+		smp_call_function_single(cpu, mvneta_percpu_unmask_interrupt,
+					 pp, true);
 		i++;
+
 	}
 };
 
@@ -2777,12 +2842,22 @@ static int mvneta_percpu_notifier(struct notifier_block *nfb,
 		mvreg_write(pp, MVNETA_INTR_MISC_MASK, 0);
 		napi_enable(&port->napi);
 
+
+		/* Enable per-CPU interrupts on the CPU that is
+		 * brought up.
+		 */
+		smp_call_function_single(cpu, mvneta_percpu_enable,
+					 pp, true);
+
 		/* Enable per-CPU interrupt on the one CPU we care
 		 * about.
 		 */
 		mvneta_percpu_elect(pp);
 
-		/* Unmask all ethernet port interrupts */
+		/* Unmask all ethernet port interrupts, as this
+		 * notifier is called for each CPU then the CPU to
+		 * Queue mapping is applied
+		 */
 		mvreg_write(pp, MVNETA_INTR_NEW_MASK,
 			MVNETA_RX_INTR_MASK(rxq_number) |
 			MVNETA_TX_INTR_MASK(txq_number) |
@@ -2833,7 +2908,7 @@ static int mvneta_percpu_notifier(struct notifier_block *nfb,
 static int mvneta_open(struct net_device *dev)
 {
 	struct mvneta_port *pp = netdev_priv(dev);
-	int ret;
+	int ret, cpu;
 
 	pp->pkt_size = MVNETA_RX_PKT_SIZE(pp->dev->mtu);
 	pp->frag_size = SKB_DATA_ALIGN(MVNETA_RX_BUF_SIZE(pp->pkt_size)) +
@@ -2863,8 +2938,13 @@ static int mvneta_open(struct net_device *dev)
 	 */
 	mvneta_percpu_disable(pp);
 
-	/* Elect a CPU to handle our RX queue interrupt */
-	mvneta_percpu_elect(pp);
+	/* Enable per-CPU interrupt on all the CPU to handle our RX
+	 * queue interrupts
+	 */
+	for_each_online_cpu(cpu)
+		smp_call_function_single(cpu, mvneta_percpu_enable,
+					 pp, true);
+
 
 	/* Register a CPU notifier to handle the case where our CPU
 	 * might be taken offline.
-- 
2.5.0

[PATCH net-next 3/3] net: mvneta: Add naive RSS support

[Gregory CLEMENT]

This patch add the support for the RSS related ethtool
function. Currently it only use one entry in the indirection table which
allows associating an mveneta interface to a given CPU.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
---
 drivers/net/ethernet/marvell/mvneta.c | 125 ++++++++++++++++++++++++++++++++++
 1 file changed, 125 insertions(+)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 8974ab084839..b4ed96a639ff 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -259,6 +259,11 @@
 
 #define MVNETA_TX_MTU_MAX		0x3ffff
 
+/* The RSS lookup table actually has 256 entries but we do not use
+ * them yet
+ */
+#define MVNETA_RSS_LU_TABLE_SIZE	1
+
 /* TSO header size */
 #define TSO_HEADER_SIZE 128
 
@@ -380,6 +385,8 @@ struct mvneta_port {
 	int use_inband_status:1;
 
 	u64 ethtool_stats[ARRAY_SIZE(mvneta_statistics)];
+
+	u32 indir[MVNETA_RSS_LU_TABLE_SIZE];
 };
 
 /* The mvneta_tx_desc and mvneta_rx_desc structures describe the
@@ -2483,6 +2490,18 @@ static void mvneta_percpu_unmask_interrupt(void *arg)
 		    MVNETA_MISCINTR_INTR_MASK);
 }
 
+static void mvneta_percpu_mask_interrupt(void *arg)
+{
+	struct mvneta_port *pp = arg;
+
+	/* All the queue are masked, but actually only the ones
+	 * maped to this CPU will be masked
+	 */
+	mvreg_write(pp, MVNETA_INTR_NEW_MASK, 0);
+	mvreg_write(pp, MVNETA_INTR_OLD_MASK, 0);
+	mvreg_write(pp, MVNETA_INTR_MISC_MASK, 0);
+}
+
 static void mvneta_start_dev(struct mvneta_port *pp)
 {
 	unsigned int cpu;
@@ -3173,6 +3192,106 @@ static int mvneta_ethtool_get_sset_count(struct net_device *dev, int sset)
 	return -EOPNOTSUPP;
 }
 
+static u32 mvneta_ethtool_get_rxfh_indir_size(struct net_device *dev)
+{
+	return MVNETA_RSS_LU_TABLE_SIZE;
+}
+
+static int mvneta_ethtool_get_rxnfc(struct net_device *dev,
+				    struct ethtool_rxnfc *info,
+				    u32 *rules __always_unused)
+{
+	switch (info->cmd) {
+	case ETHTOOL_GRXRINGS:
+		info->data =  rxq_number;
+		return 0;
+	case ETHTOOL_GRXFH:
+		return -EOPNOTSUPP;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int  mvneta_config_rss(struct mvneta_port *pp)
+{
+	int cpu;
+	u32 val;
+
+	netif_tx_stop_all_queues(pp->dev);
+
+	for_each_online_cpu(cpu)
+		smp_call_function_single(cpu, mvneta_percpu_mask_interrupt,
+					 pp, true);
+
+	/* We have to synchronise on the napi of each CPU */
+	for_each_online_cpu(cpu) {
+		struct mvneta_pcpu_port *pcpu_port =
+			per_cpu_ptr(pp->ports, cpu);
+
+		napi_synchronize(&pcpu_port->napi);
+		napi_disable(&pcpu_port->napi);
+	}
+
+	pp->rxq_def = pp->indir[0];
+
+	/* update unicast mapping */
+	mvneta_set_rx_mode(pp->dev);
+
+	/* Update val of portCfg register accordingly with all RxQueue types */
+	val = MVNETA_PORT_CONFIG_DEFL_VALUE(pp->rxq_def);
+	mvreg_write(pp, MVNETA_PORT_CONFIG, val);
+
+	/* Update the elected CPU matching the new rxq_def */
+	mvneta_percpu_elect(pp);
+
+	/* We have to synchronise on the napi of each CPU */
+	for_each_online_cpu(cpu) {
+		struct mvneta_pcpu_port *pcpu_port =
+			per_cpu_ptr(pp->ports, cpu);
+
+		napi_enable(&pcpu_port->napi);
+	}
+
+	netif_tx_start_all_queues(pp->dev);
+
+	return 0;
+}
+
+static int mvneta_ethtool_set_rxfh(struct net_device *dev, const u32 *indir,
+				   const u8 *key, const u8 hfunc)
+{
+	struct mvneta_port *pp = netdev_priv(dev);
+	/* We require at least one supported parameter to be changed
+	* and no change in any of the unsupported parameters
+	*/
+	if (key ||
+	    (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP))
+		return -EOPNOTSUPP;
+
+	if (!indir)
+		return 0;
+
+	memcpy(pp->indir, indir, MVNETA_RSS_LU_TABLE_SIZE);
+
+	return mvneta_config_rss(pp);
+}
+
+static int mvneta_ethtool_get_rxfh(struct net_device *dev, u32 *indir, u8 *key,
+				   u8 *hfunc)
+{
+	struct mvneta_port *pp = netdev_priv(dev);
+
+	if (hfunc)
+		*hfunc = ETH_RSS_HASH_TOP;
+
+	if (!indir)
+		return 0;
+
+	memcpy(indir, pp->indir, MVNETA_RSS_LU_TABLE_SIZE);
+
+	return 0;
+}
+
 static const struct net_device_ops mvneta_netdev_ops = {
 	.ndo_open            = mvneta_open,
 	.ndo_stop            = mvneta_stop,
@@ -3197,6 +3316,10 @@ const struct ethtool_ops mvneta_eth_tool_ops = {
 	.get_strings	= mvneta_ethtool_get_strings,
 	.get_ethtool_stats = mvneta_ethtool_get_stats,
 	.get_sset_count	= mvneta_ethtool_get_sset_count,
+	.get_rxfh_indir_size = mvneta_ethtool_get_rxfh_indir_size,
+	.get_rxnfc	= mvneta_ethtool_get_rxnfc,
+	.get_rxfh	= mvneta_ethtool_get_rxfh,
+	.set_rxfh	= mvneta_ethtool_set_rxfh,
 };
 
 /* Initialize hw */
@@ -3389,6 +3512,8 @@ static int mvneta_probe(struct platform_device *pdev)
 
 	pp->rxq_def = rxq_def;
 
+	pp->indir[0] = rxq_def;
+
 	pp->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(pp->clk)) {
 		err = PTR_ERR(pp->clk);
-- 
2.5.0

[PATCH net-next 3/3] net: mvneta: Add naive RSS support

[Thomas Petazzoni]

Gregory,

On Wed, 25 Nov 2015 15:54:03 +0100, Gregory CLEMENT wrote:

>  	pp->rxq_def = rxq_def;
>  
> +	pp->indir[0] = rxq_def;

So now we have the RX queue in both pp->rxq_def and pp->indir[0] ? Is
this really useful ?

Also, if the RX queue becomes a per-port definition, why do you keep
the global rxq_def variable ?

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[PATCH net-next 3/3] net: mvneta: Add naive RSS support

[Gregory CLEMENT]

Hi Thomas,
 
 On mer., nov. 25 2015, Thomas Petazzoni <thomas.petazzoni@free-electrons.com> wrote:

> Gregory,
>
> On Wed, 25 Nov 2015 15:54:03 +0100, Gregory CLEMENT wrote:
>
>>  	pp->rxq_def = rxq_def;
>>  
>> +	pp->indir[0] = rxq_def;
>
> So now we have the RX queue in both pp->rxq_def and pp->indir[0] ? Is
> this really useful ?

Currently pp->rxq_def and pp->indir are the same but only because there
is one entry in the indirection table. When the 256 entries will be used
then there won't be the same. But we will still need the rxq_def as the
mvneta IP need a reference to a default RX queue even for example for
MVNETA_PORT_CONFIG_DEFL_VALUE.

>
> Also, if the RX queue becomes a per-port definition, why do you keep
> the global rxq_def variable ?

The global rxq_def variable is used for the module parameter. Even if
we can change it latter, it is still good to be able to set the default
value, however the parameter is set at module level not at port level,
that why we still need this variable.

Thanks,

Gregory

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[PATCH net-next 3/3] net: mvneta: Add naive RSS support

[Marcin Wojtas]

Hi Gregory,

> +
> +       /* update unicast mapping */
> +       mvneta_set_rx_mode(pp->dev);

I know it may be an ultimate level of nitpicking, but can you start a
comment with capital letter?:)

Best regards,
Marcin

[PATCH net-next 3/3] net: mvneta: Add naive RSS support

[Gregory CLEMENT]

Hi Marcin,
 
 On sam., nov. 28 2015, Marcin Wojtas <mw@semihalf.com> wrote:

> Hi Gregory,
>
>> +
>> +       /* update unicast mapping */
>> +       mvneta_set_rx_mode(pp->dev);
>
> I know it may be an ultimate level of nitpicking, but can you start a
> comment with capital letter?:)

If I got other review, then I can fix it in the next version. But if you
have a look on the otehr commet not all of them start by capital letter.

Thanks,

Greogry

>
> Best regards,
> Marcin

-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com

[PATCH net-next 0/3] mvneta: Introduce RSS support

[Marcin Wojtas]

Hi Gregory,

You can add:
Tested-by: Marcin Wojtas <mw@semihalf.com>

I checked different queues, the traffic passed through, and the irqs
came to proper CPU's. FYI, in my setup with A388-GP as a bridge, after
attaching two ports to different CPU's there was an increase of
~50kpps (almost 9%) for 64B packets.

Best regards,
Marcin

2015-11-25 15:54 GMT+01:00 Gregory CLEMENT <gregory.clement@free-electrons.com>:
> Hi,
>
> this series is the first step add RSS support on mvneta.
>
> It will allow associating an ethernet interface to a given CPU through
> RSS by using "ethtool -X ethX weight". Indeed, currently I only enable
> one entry in the RSS lookup table. Even if it is not really RSS, it
> allows to get back the irq affinity feature we lost by using the
> percpu interrupt.
>
> Compared to the RFC series I added a missing patch for the series, I
> rebased onto v4.4-rc1 and I fixed the mvneta_config_rss. Marcin
> pointed that making the interrupt should be done on all the CPUs.
>
> Th first patch make the default queue associate to each port and no
> more a global variable.
>
> The second patch really associates the RX queues with the CPUs instead
> of masking the percpu interrupts for doing it. All the RX queues are
> enabled and are statically associated with the CPUs by using a modulo
> of the number of present CPUs. But at this stage only one RX queue
> will receive the stream.
>
> I also choose to associate all the TX queues on the same CPU that the
> one associated to the RX queue. It allows to contain all the
> interrupts on the same CPU. I think that an improvement on this side
> would be the support of the XPS.
>
> The last patch introduces a first level of RSS support through the
> ethtool functions. As explained in the introduction there is only one
> entry in the RSS lookup table which permits at the end to associate an
> mvneta port to a CPU through the RX queues because the mapping is
> static.
>
> Thanks,
>
> Gregory CLEMENT (3):
>   net: mvneta: Make the default queue related for each port
>   net: mvneta: Associate RX queues with each CPU
>   net: mvneta: Add naive RSS support
>
>  drivers/net/ethernet/marvell/mvneta.c | 298 +++++++++++++++++++++++++++++-----
>  1 file changed, 253 insertions(+), 45 deletions(-)
>
> --
> 2.5.0
>