[net-next PATCH v2 0/3] CPSW interrupt handling cleanup and performance improvement

[net-next PATCH v2 0/3] CPSW interrupt handling cleanup and performance improvement

[Mugunthan V N]

This patch series removes the irq controller disable interrupt and
adding a napi for tx event handling which improves the performance by
~180Mbps on dra7-evm

[  5] local 192.168.10.116 port 5001 connected with 192.168.10.165 port 44176
[  5]  0.0-60.0 sec  1.48 GBytes   210 Mbits/sec
[  4] local 192.168.10.116 port 5001 connected with 192.168.10.165 port 33257
[  4]  0.0-60.0 sec  2.71 GBytes   386 Mbits/sec

Changes from initial version: 
* Added a patch to have napi only for first interface as there is
  no use of having seperate napis for each interface as the
  interrupt is shared by both interface and only one napi is
  scheduled for each interrupt.

Mugunthan V N (3):
  drivers: net: cpsw: remove  disable_irq/enable_irq as irq can be
    masked from cpsw itself
  drivers: net: cpsw: dual_emac: simplify napi usage
  drivers: net: cpsw: add separate napi for tx

 drivers/net/ethernet/ti/cpsw.c | 83 ++++++++++++++++++------------------------
 1 file changed, 35 insertions(+), 48 deletions(-)

-- 
2.5.0.234.gefc8a62

[net-next PATCH v2 1/3] drivers: net: cpsw: remove disable_irq/enable_irq as irq can be masked from cpsw itself

[Mugunthan V N]

CPSW interrupts can be disabled by masking CPSW interrupts and
clearing interrupt by writing appropriate EOI. So removing all
disable_irq/enable_irq as discussed in [1]

[1] http://patchwork.ozlabs.org/patch/492741/

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
---
 drivers/net/ethernet/ti/cpsw.c | 27 ++-------------------------
 1 file changed, 2 insertions(+), 25 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index d155bf2..d68d759 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -389,7 +389,6 @@ struct cpsw_priv {
 	/* snapshot of IRQ numbers */
 	u32 irqs_table[4];
 	u32 num_irqs;
-	bool irq_enabled;
 	struct cpts *cpts;
 	u32 emac_port;
 };
@@ -767,12 +766,7 @@ static irqreturn_t cpsw_rx_interrupt(int irq, void *dev_id)
 	struct cpsw_priv *priv = dev_id;
 
 	cpdma_ctlr_eoi(priv->dma, CPDMA_EOI_RX);
-
-	cpsw_intr_disable(priv);
-	if (priv->irq_enabled == true) {
-		disable_irq_nosync(priv->irqs_table[0]);
-		priv->irq_enabled = false;
-	}
+	writel(0, &priv->wr_regs->rx_en);
 
 	if (netif_running(priv->ndev)) {
 		napi_schedule(&priv->napi);
@@ -797,15 +791,8 @@ static int cpsw_poll(struct napi_struct *napi, int budget)
 
 	num_rx = cpdma_chan_process(priv->rxch, budget);
 	if (num_rx < budget) {
-		struct cpsw_priv *prim_cpsw;
-
 		napi_complete(napi);
-		cpsw_intr_enable(priv);
-		prim_cpsw = cpsw_get_slave_priv(priv, 0);
-		if (prim_cpsw->irq_enabled == false) {
-			prim_cpsw->irq_enabled = true;
-			enable_irq(priv->irqs_table[0]);
-		}
+		writel(0xff, &priv->wr_regs->rx_en);
 	}
 
 	if (num_rx)
@@ -1230,7 +1217,6 @@ static void cpsw_slave_stop(struct cpsw_slave *slave, struct cpsw_priv *priv)
 static int cpsw_ndo_open(struct net_device *ndev)
 {
 	struct cpsw_priv *priv = netdev_priv(ndev);
-	struct cpsw_priv *prim_cpsw;
 	int i, ret;
 	u32 reg;
 
@@ -1315,14 +1301,6 @@ static int cpsw_ndo_open(struct net_device *ndev)
 	cpdma_ctlr_start(priv->dma);
 	cpsw_intr_enable(priv);
 
-	prim_cpsw = cpsw_get_slave_priv(priv, 0);
-	if (prim_cpsw->irq_enabled == false) {
-		if ((priv == prim_cpsw) || !netif_running(prim_cpsw->ndev)) {
-			prim_cpsw->irq_enabled = true;
-			enable_irq(prim_cpsw->irqs_table[0]);
-		}
-	}
-
 	if (priv->data.dual_emac)
 		priv->slaves[priv->emac_port].open_stat = true;
 	return 0;
@@ -2169,7 +2147,6 @@ static int cpsw_probe(struct platform_device *pdev)
 	priv->msg_enable = netif_msg_init(debug_level, CPSW_DEBUG);
 	priv->rx_packet_max = max(rx_packet_max, 128);
 	priv->cpts = devm_kzalloc(&pdev->dev, sizeof(struct cpts), GFP_KERNEL);
-	priv->irq_enabled = true;
 	if (!priv->cpts) {
 		dev_err(&pdev->dev, "error allocating cpts\n");
 		ret = -ENOMEM;
-- 
2.5.0.234.gefc8a62

[net-next PATCH v2 2/3] drivers: net: cpsw: dual_emac: simplify napi usage

[Mugunthan V N]

Since interrupt is shared between the two ethernet interface and
in isr only one napi is scheduled at an instance so having two
napis doesn't make any difference. So making napi also as a
common resource for the dual ethernet interfaces.

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
---
 drivers/net/ethernet/ti/cpsw.c | 26 +++++++++-----------------
 1 file changed, 9 insertions(+), 17 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index d68d759..1d923e8 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -768,20 +768,8 @@ static irqreturn_t cpsw_rx_interrupt(int irq, void *dev_id)
 	cpdma_ctlr_eoi(priv->dma, CPDMA_EOI_RX);
 	writel(0, &priv->wr_regs->rx_en);
 
-	if (netif_running(priv->ndev)) {
-		napi_schedule(&priv->napi);
-		return IRQ_HANDLED;
-	}
-
-	priv = cpsw_get_slave_priv(priv, 1);
-	if (!priv)
-		return IRQ_NONE;
-
-	if (netif_running(priv->ndev)) {
-		napi_schedule(&priv->napi);
-		return IRQ_HANDLED;
-	}
-	return IRQ_NONE;
+	napi_schedule(&priv->napi);
+	return IRQ_HANDLED;
 }
 
 static int cpsw_poll(struct napi_struct *napi, int budget)
@@ -1246,6 +1234,8 @@ static int cpsw_ndo_open(struct net_device *ndev)
 				  ALE_ALL_PORTS << priv->host_port, 0, 0);
 
 	if (!cpsw_common_res_usage_state(priv)) {
+		struct cpsw_priv *priv_sl0 = cpsw_get_slave_priv(priv, 0);
+
 		/* setup tx dma to fixed prio and zero offset */
 		cpdma_control_set(priv->dma, CPDMA_TX_PRIO_FIXED, 1);
 		cpdma_control_set(priv->dma, CPDMA_RX_BUFFER_OFFSET, 0);
@@ -1259,6 +1249,8 @@ static int cpsw_ndo_open(struct net_device *ndev)
 		/* Enable internal fifo flow control */
 		writel(0x7, &priv->regs->flow_control);
 
+		napi_enable(&priv_sl0->napi);
+
 		if (WARN_ON(!priv->data.rx_descs))
 			priv->data.rx_descs = 128;
 
@@ -1297,7 +1289,6 @@ static int cpsw_ndo_open(struct net_device *ndev)
 		cpsw_set_coalesce(ndev, &coal);
 	}
 
-	napi_enable(&priv->napi);
 	cpdma_ctlr_start(priv->dma);
 	cpsw_intr_enable(priv);
 
@@ -1319,10 +1310,12 @@ static int cpsw_ndo_stop(struct net_device *ndev)
 
 	cpsw_info(priv, ifdown, "shutting down cpsw device\n");
 	netif_stop_queue(priv->ndev);
-	napi_disable(&priv->napi);
 	netif_carrier_off(priv->ndev);
 
 	if (cpsw_common_res_usage_state(priv) <= 1) {
+		struct cpsw_priv *priv_sl0 = cpsw_get_slave_priv(priv, 0);
+
+		napi_disable(&priv_sl0->napi);
 		cpts_unregister(priv->cpts);
 		cpsw_intr_disable(priv);
 		cpdma_ctlr_stop(priv->dma);
@@ -2105,7 +2098,6 @@ static int cpsw_probe_dual_emac(struct platform_device *pdev,
 
 	ndev->netdev_ops = &cpsw_netdev_ops;
 	ndev->ethtool_ops = &cpsw_ethtool_ops;
-	netif_napi_add(ndev, &priv_sl2->napi, cpsw_poll, CPSW_POLL_WEIGHT);
 
 	/* register the network device */
 	SET_NETDEV_DEV(ndev, &pdev->dev);
-- 
2.5.0.234.gefc8a62

[net-next PATCH v2 3/3] drivers: net: cpsw: add separate napi for tx

[Mugunthan V N]

Instead of processing tx events in isr adding separate napi for
tx which improves performance by ~180Mbps with
omap2plus_defconfig on DRA74x platform. Also cleaning up rx napis
by renaming to napi_rx for better understanding the code.

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
---
 drivers/net/ethernet/ti/cpsw.c | 44 +++++++++++++++++++++++++++++-------------
 1 file changed, 31 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index 1d923e8..3b81b39 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -365,7 +365,8 @@ struct cpsw_priv {
 	spinlock_t			lock;
 	struct platform_device		*pdev;
 	struct net_device		*ndev;
-	struct napi_struct		napi;
+	struct napi_struct		napi_rx;
+	struct napi_struct		napi_tx;
 	struct device			*dev;
 	struct cpsw_platform_data	data;
 	struct cpsw_ss_regs __iomem	*regs;
@@ -751,13 +752,10 @@ static irqreturn_t cpsw_tx_interrupt(int irq, void *dev_id)
 {
 	struct cpsw_priv *priv = dev_id;
 
+	writel(0, &priv->wr_regs->tx_en);
 	cpdma_ctlr_eoi(priv->dma, CPDMA_EOI_TX);
-	cpdma_chan_process(priv->txch, 128);
-
-	priv = cpsw_get_slave_priv(priv, 1);
-	if (priv)
-		cpdma_chan_process(priv->txch, 128);
 
+	napi_schedule(&priv->napi_tx);
 	return IRQ_HANDLED;
 }
 
@@ -768,18 +766,35 @@ static irqreturn_t cpsw_rx_interrupt(int irq, void *dev_id)
 	cpdma_ctlr_eoi(priv->dma, CPDMA_EOI_RX);
 	writel(0, &priv->wr_regs->rx_en);
 
-	napi_schedule(&priv->napi);
+	napi_schedule(&priv->napi_rx);
 	return IRQ_HANDLED;
 }
 
-static int cpsw_poll(struct napi_struct *napi, int budget)
+static int cpsw_tx_poll(struct napi_struct *napi_tx, int budget)
+{
+	struct cpsw_priv	*priv = napi_to_priv(napi_tx);
+	int			num_tx;
+
+	num_tx = cpdma_chan_process(priv->txch, budget);
+	if (num_tx < budget) {
+		napi_complete(napi_tx);
+		writel(0xff, &priv->wr_regs->tx_en);
+	}
+
+	if (num_tx)
+		cpsw_dbg(priv, intr, "poll %d tx pkts\n", num_tx);
+
+	return num_tx;
+}
+
+static int cpsw_rx_poll(struct napi_struct *napi_rx, int budget)
 {
-	struct cpsw_priv	*priv = napi_to_priv(napi);
+	struct cpsw_priv	*priv = napi_to_priv(napi_rx);
 	int			num_rx;
 
 	num_rx = cpdma_chan_process(priv->rxch, budget);
 	if (num_rx < budget) {
-		napi_complete(napi);
+		napi_complete(napi_rx);
 		writel(0xff, &priv->wr_regs->rx_en);
 	}
 
@@ -1249,7 +1264,8 @@ static int cpsw_ndo_open(struct net_device *ndev)
 		/* Enable internal fifo flow control */
 		writel(0x7, &priv->regs->flow_control);
 
-		napi_enable(&priv_sl0->napi);
+		napi_enable(&priv_sl0->napi_rx);
+		napi_enable(&priv_sl0->napi_tx);
 
 		if (WARN_ON(!priv->data.rx_descs))
 			priv->data.rx_descs = 128;
@@ -1315,7 +1331,8 @@ static int cpsw_ndo_stop(struct net_device *ndev)
 	if (cpsw_common_res_usage_state(priv) <= 1) {
 		struct cpsw_priv *priv_sl0 = cpsw_get_slave_priv(priv, 0);
 
-		napi_disable(&priv_sl0->napi);
+		napi_disable(&priv_sl0->napi_rx);
+		napi_disable(&priv_sl0->napi_tx);
 		cpts_unregister(priv->cpts);
 		cpsw_intr_disable(priv);
 		cpdma_ctlr_stop(priv->dma);
@@ -2349,7 +2366,8 @@ static int cpsw_probe(struct platform_device *pdev)
 
 	ndev->netdev_ops = &cpsw_netdev_ops;
 	ndev->ethtool_ops = &cpsw_ethtool_ops;
-	netif_napi_add(ndev, &priv->napi, cpsw_poll, CPSW_POLL_WEIGHT);
+	netif_napi_add(ndev, &priv->napi_rx, cpsw_rx_poll, CPSW_POLL_WEIGHT);
+	netif_napi_add(ndev, &priv->napi_tx, cpsw_tx_poll, CPSW_POLL_WEIGHT);
 
 	/* register the network device */
 	SET_NETDEV_DEV(ndev, &pdev->dev);
-- 
2.5.0.234.gefc8a62

Re: [net-next PATCH v2 0/3] CPSW interrupt handling cleanup and performance improvement

[David Miller]

From: Mugunthan V N <mugunthanvnm@ti.com>
Date: Tue, 4 Aug 2015 16:06:17 +0530

> This patch series removes the irq controller disable interrupt and
> adding a napi for tx event handling which improves the performance by
> ~180Mbps on dra7-evm
> 
> [  5] local 192.168.10.116 port 5001 connected with 192.168.10.165 port 44176
> [  5]  0.0-60.0 sec  1.48 GBytes   210 Mbits/sec
> [  4] local 192.168.10.116 port 5001 connected with 192.168.10.165 port 33257
> [  4]  0.0-60.0 sec  2.71 GBytes   386 Mbits/sec
> 
> Changes from initial version: 
> * Added a patch to have napi only for first interface as there is
>   no use of having seperate napis for each interface as the
>   interrupt is shared by both interface and only one napi is
>   scheduled for each interrupt.

Series applied, thanks.