[PATCH v2 5/7] net: mvneta: Handle per-cpu interrupts

Gregory CLEMENT
2015-09-25T16:09:36Z

Now that our interrupt controller is allowing us to use per-CPU interrupts,
actually use it in the mvneta driver.

This involves obviously reworking the driver to have a CPU-local NAPI
structure, and report for incoming packet using that structure.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
---
drivers/net/ethernet/marvell/mvneta.c | 91 ++++++++++++++++++++++++-----------
1 file changed, 62 insertions(+), 29 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index ea587d964c46..a78ca1d6e414 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -285,7 +285,21 @@ struct mvneta_pcpu_stats {
u64 tx_bytes;
};

+struct mvneta_pcpu_port {
+ /* Pointer to the shared port */
+ struct mvneta_port *pp;
+
+ /* Pointer to the CPU-local NAPI struct */
+ struct napi_struct napi;
+
+ /* Cause of the previous interrupt */
+ u32 cause_rx_tx;
+};
+
struct mvneta_port {
+ struct mvneta_pcpu_port __percpu *ports;
+ struct mvneta_pcpu_stats __percpu *stats;
+
int pkt_size;
unsigned int frag_size;
void __iomem *base;
@@ -293,15 +307,11 @@ struct mvneta_port {
struct mvneta_tx_queue *txqs;
struct net_device *dev;

- u32 cause_rx_tx;
- struct napi_struct napi;
-
/* Core clock */
struct clk *clk;
u8 mcast_count[256];
u16 tx_ring_size;
u16 rx_ring_size;
- struct mvneta_pcpu_stats *stats;

struct mii_bus *mii_bus;
struct phy_device *phy_dev;
@@ -1461,6 +1471,7 @@ static void mvneta_rxq_drop_pkts(struct mvneta_port *pp,
static int mvneta_rx(struct mvneta_port *pp, int rx_todo,
struct mvneta_rx_queue *rxq)
{
+ struct mvneta_pcpu_port *port = this_cpu_ptr(pp->ports);
struct net_device *dev = pp->dev;
int rx_done;
u32 rcvd_pkts = 0;
@@ -1513,7 +1524,7 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo,

skb->protocol = eth_type_trans(skb, dev);
mvneta_rx_csum(pp, rx_status, skb);
- napi_gro_receive(&pp->napi, skb);
+ napi_gro_receive(&port->napi, skb);

rcvd_pkts++;
rcvd_bytes += rx_bytes;
@@ -1548,7 +1559,7 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo,

mvneta_rx_csum(pp, rx_status, skb);

- napi_gro_receive(&pp->napi, skb);
+ napi_gro_receive(&port->napi, skb);
}

if (rcvd_pkts) {
@@ -2059,12 +2070,11 @@ static void mvneta_set_rx_mode(struct net_device *dev)
/* Interrupt handling - the callback for request_irq() */
static irqreturn_t mvneta_isr(int irq, void *dev_id)
{
- struct mvneta_port *pp = (struct mvneta_port *)dev_id;
+ struct mvneta_pcpu_port *port = (struct mvneta_pcpu_port *)dev_id;

- /* Mask all interrupts */
- mvreg_write(pp, MVNETA_INTR_NEW_MASK, 0);
+ disable_percpu_irq(port->pp->dev->irq);

- napi_schedule(&pp->napi);
+ napi_schedule(&port->napi);

return IRQ_HANDLED;
}
@@ -2102,11 +2112,11 @@ static int mvneta_poll(struct napi_struct *napi, int budget)
{
int rx_done = 0;
u32 cause_rx_tx;
- unsigned long flags;
struct mvneta_port *pp = netdev_priv(napi->dev);
+ struct mvneta_pcpu_port *port = this_cpu_ptr(pp->ports);

if (!netif_running(pp->dev)) {
- napi_complete(napi);
+ napi_complete(&port->napi);
return rx_done;
}

@@ -2133,7 +2143,7 @@ static int mvneta_poll(struct napi_struct *napi, int budget)
/* For the case where the last mvneta_poll did not process all
* RX packets
*/
- cause_rx_tx |= pp->cause_rx_tx;
+ cause_rx_tx |= port->cause_rx_tx;
if (rxq_number > 1) {
while ((cause_rx_tx & MVNETA_RX_INTR_MASK_ALL) && (budget > 0)) {
int count;
@@ -2164,16 +2174,11 @@ static int mvneta_poll(struct napi_struct *napi, int budget)

if (budget > 0) {
cause_rx_tx = 0;
- napi_complete(napi);
- local_irq_save(flags);
- mvreg_write(pp, MVNETA_INTR_NEW_MASK,
- MVNETA_RX_INTR_MASK(rxq_number) |
- MVNETA_TX_INTR_MASK(txq_number) |
- MVNETA_MISCINTR_INTR_MASK);
- local_irq_restore(flags);
+ napi_complete(&port->napi);
+ enable_percpu_irq(pp->dev->irq, 0);
}

- pp->cause_rx_tx = cause_rx_tx;
+ port->cause_rx_tx = cause_rx_tx;
return rx_done;
}

@@ -2422,6 +2427,8 @@ static int mvneta_setup_txqs(struct mvneta_port *pp)

static void mvneta_start_dev(struct mvneta_port *pp)
{
+ unsigned int cpu;
+
mvneta_max_rx_size_set(pp, pp->pkt_size);
mvneta_txq_max_tx_size_set(pp, pp->pkt_size);

@@ -2429,7 +2436,11 @@ static void mvneta_start_dev(struct mvneta_port *pp)
mvneta_port_enable(pp);

/* Enable polling on the port */
- napi_enable(&pp->napi);
+ for_each_present_cpu(cpu) {
+ struct mvneta_pcpu_port *port = per_cpu_ptr(pp->ports, cpu);
+
+ napi_enable(&port->napi);
+ }

/* Unmask interrupts */
mvreg_write(pp, MVNETA_INTR_NEW_MASK,
@@ -2447,9 +2458,15 @@ static void mvneta_start_dev(struct mvneta_port *pp)

static void mvneta_stop_dev(struct mvneta_port *pp)
{
+ unsigned int cpu;
+
phy_stop(pp->phy_dev);

- napi_disable(&pp->napi);
+ for_each_present_cpu(cpu) {
+ struct mvneta_pcpu_port *port = per_cpu_ptr(pp->ports, cpu);
+
+ napi_disable(&port->napi);
+ }

netif_carrier_off(pp->dev);

@@ -2707,8 +2724,8 @@ static int mvneta_open(struct net_device *dev)
goto err_cleanup_rxqs;

/* Connect to port interrupt line */
- ret = request_irq(pp->dev->irq, mvneta_isr, 0,
- MVNETA_DRIVER_NAME, pp);
+ ret = request_percpu_irq(pp->dev->irq, mvneta_isr,
+ MVNETA_DRIVER_NAME, pp->ports);
if (ret) {
netdev_err(pp->dev, "cannot request irq %d\n", pp->dev->irq);
goto err_cleanup_txqs;
@@ -2728,7 +2745,7 @@ static int mvneta_open(struct net_device *dev)
return 0;

err_free_irq:
- free_irq(pp->dev->irq, pp);
+ free_percpu_irq(pp->dev->irq, pp->ports);
err_cleanup_txqs:
mvneta_cleanup_txqs(pp);
err_cleanup_rxqs:
@@ -2743,7 +2760,7 @@ static int mvneta_stop(struct net_device *dev)

mvneta_stop_dev(pp);
mvneta_mdio_remove(pp);
- free_irq(dev->irq, pp);
+ free_percpu_irq(dev->irq, pp->ports);
mvneta_cleanup_rxqs(pp);
mvneta_cleanup_txqs(pp);

@@ -3030,6 +3047,7 @@ static int mvneta_probe(struct platform_device *pdev)
const char *managed;
int phy_mode;
int err;
+ int cpu;

/* Our multiqueue support is not complete, so for now, only
* allow the usage of the first RX queue
@@ -3105,11 +3123,18 @@ static int mvneta_probe(struct platform_device *pdev)
goto err_clk;
}

+ /* Alloc per-cpu port structure */
+ pp->ports = alloc_percpu(struct mvneta_pcpu_port);
+ if (!pp->ports) {
+ err = -ENOMEM;
+ goto err_clk;
+ }
+
/* Alloc per-cpu stats */
pp->stats = netdev_alloc_pcpu_stats(struct mvneta_pcpu_stats);
if (!pp->stats) {
err = -ENOMEM;
- goto err_clk;
+ goto err_free_ports;
}

dt_mac_addr = of_get_mac_address(dn);
@@ -3150,7 +3175,12 @@ static int mvneta_probe(struct platform_device *pdev)
if (dram_target_info)
mvneta_conf_mbus_windows(pp, dram_target_info);

- netif_napi_add(dev, &pp->napi, mvneta_poll, NAPI_POLL_WEIGHT);
+ for_each_present_cpu(cpu) {
+ struct mvneta_pcpu_port *port = per_cpu_ptr(pp->ports, cpu);
+
+ netif_napi_add(dev, &port->napi, mvneta_poll, NAPI_POLL_WEIGHT);
+ port->pp = pp;
+ }

dev->features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_TSO;
dev->hw_features |= dev->features;
@@ -3179,6 +3209,8 @@ static int mvneta_probe(struct platform_device *pdev)

err_free_stats:
free_percpu(pp->stats);
+err_free_ports:
+ free_percpu(pp->ports);
err_clk:
clk_disable_unprepare(pp->clk);
err_put_phy_node:
@@ -3198,6 +3230,7 @@ static int mvneta_remove(struct platform_device *pdev)

unregister_netdev(dev);
clk_disable_unprepare(pp->clk);
+ free_percpu(pp->ports);
free_percpu(pp->stats);
irq_dispose_mapping(dev->irq);
of_node_put(pp->phy_node);
--
2.1.0