[PATCH net-next 1/2] enic: add adaptive coalescing intr for intx and msi poll

[PATCH net-next 1/2] enic: add adaptive coalescing intr for intx and msi poll

[Govindarajulu Varadarajan]

Adaptive interrupt coalescing is available for msix. This patch adds the support
for msi poll. Interface for adaptive interrupt coalescing is already added in
driver. We just did not enable it for legacy intr & msi.

enic_calc_int_moderation() & enic_set_int_moderation() are defined as static
after enic_poll. Since enic_poll needs it, move both of these function
definitions above enic_poll. No change in functionality.

Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com>
---
 drivers/net/ethernet/cisco/enic/enic_main.c | 135 ++++++++++++++--------------
 1 file changed, 67 insertions(+), 68 deletions(-)

diff --git a/drivers/net/ethernet/cisco/enic/enic_main.c b/drivers/net/ethernet/cisco/enic/enic_main.c
index 918a8e4..8f646e4 100644
--- a/drivers/net/ethernet/cisco/enic/enic_main.c
+++ b/drivers/net/ethernet/cisco/enic/enic_main.c
@@ -1149,6 +1149,64 @@ static int enic_rq_service(struct vnic_dev *vdev, struct cq_desc *cq_desc,
 	return 0;
 }
 
+static void enic_set_int_moderation(struct enic *enic, struct vnic_rq *rq)
+{
+	unsigned int intr = enic_msix_rq_intr(enic, rq->index);
+	struct vnic_cq *cq = &enic->cq[enic_cq_rq(enic, rq->index)];
+	u32 timer = cq->tobe_rx_coal_timeval;
+
+	if (cq->tobe_rx_coal_timeval != cq->cur_rx_coal_timeval) {
+		vnic_intr_coalescing_timer_set(&enic->intr[intr], timer);
+		cq->cur_rx_coal_timeval = cq->tobe_rx_coal_timeval;
+	}
+}
+
+static void enic_calc_int_moderation(struct enic *enic, struct vnic_rq *rq)
+{
+	struct enic_rx_coal *rx_coal = &enic->rx_coalesce_setting;
+	struct vnic_cq *cq = &enic->cq[enic_cq_rq(enic, rq->index)];
+	struct vnic_rx_bytes_counter *pkt_size_counter = &cq->pkt_size_counter;
+	int index;
+	u32 timer;
+	u32 range_start;
+	u32 traffic;
+	u64 delta;
+	ktime_t now = ktime_get();
+
+	delta = ktime_us_delta(now, cq->prev_ts);
+	if (delta < ENIC_AIC_TS_BREAK)
+		return;
+	cq->prev_ts = now;
+
+	traffic = pkt_size_counter->large_pkt_bytes_cnt +
+		  pkt_size_counter->small_pkt_bytes_cnt;
+	/* The table takes Mbps
+	 * traffic *= 8    => bits
+	 * traffic *= (10^6 / delta)    => bps
+	 * traffic /= 10^6     => Mbps
+	 *
+	 * Combining, traffic *= (8 / delta)
+	 */
+
+	traffic <<= 3;
+	traffic = delta > UINT_MAX ? 0 : traffic / (u32)delta;
+
+	for (index = 0; index < ENIC_MAX_COALESCE_TIMERS; index++)
+		if (traffic < mod_table[index].rx_rate)
+			break;
+	range_start = (pkt_size_counter->small_pkt_bytes_cnt >
+		       pkt_size_counter->large_pkt_bytes_cnt << 1) ?
+		      rx_coal->small_pkt_range_start :
+		      rx_coal->large_pkt_range_start;
+	timer = range_start + ((rx_coal->range_end - range_start) *
+			       mod_table[index].range_percent / 100);
+	/* Damping */
+	cq->tobe_rx_coal_timeval = (timer + cq->tobe_rx_coal_timeval) >> 1;
+
+	pkt_size_counter->large_pkt_bytes_cnt = 0;
+	pkt_size_counter->small_pkt_bytes_cnt = 0;
+}
+
 static int enic_poll(struct napi_struct *napi, int budget)
 {
 	struct net_device *netdev = napi->dev;
@@ -1199,6 +1257,11 @@ static int enic_poll(struct napi_struct *napi, int budget)
 
 	if (err)
 		rq_work_done = rq_work_to_do;
+	if (enic->rx_coalesce_setting.use_adaptive_rx_coalesce)
+		/* Call the function which refreshes the intr coalescing timer
+		 * value based on the traffic.
+		 */
+		enic_calc_int_moderation(enic, &enic->rq[0]);
 
 	if (rq_work_done < rq_work_to_do) {
 
@@ -1207,70 +1270,14 @@ static int enic_poll(struct napi_struct *napi, int budget)
 		 */
 
 		napi_complete(napi);
+		if (enic->rx_coalesce_setting.use_adaptive_rx_coalesce)
+			enic_set_int_moderation(enic, &enic->rq[0]);
 		vnic_intr_unmask(&enic->intr[intr]);
 	}
 
 	return rq_work_done;
 }
 
-static void enic_set_int_moderation(struct enic *enic, struct vnic_rq *rq)
-{
-	unsigned int intr = enic_msix_rq_intr(enic, rq->index);
-	struct vnic_cq *cq = &enic->cq[enic_cq_rq(enic, rq->index)];
-	u32 timer = cq->tobe_rx_coal_timeval;
-
-	if (cq->tobe_rx_coal_timeval != cq->cur_rx_coal_timeval) {
-		vnic_intr_coalescing_timer_set(&enic->intr[intr], timer);
-		cq->cur_rx_coal_timeval = cq->tobe_rx_coal_timeval;
-	}
-}
-
-static void enic_calc_int_moderation(struct enic *enic, struct vnic_rq *rq)
-{
-	struct enic_rx_coal *rx_coal = &enic->rx_coalesce_setting;
-	struct vnic_cq *cq = &enic->cq[enic_cq_rq(enic, rq->index)];
-	struct vnic_rx_bytes_counter *pkt_size_counter = &cq->pkt_size_counter;
-	int index;
-	u32 timer;
-	u32 range_start;
-	u32 traffic;
-	u64 delta;
-	ktime_t now = ktime_get();
-
-	delta = ktime_us_delta(now, cq->prev_ts);
-	if (delta < ENIC_AIC_TS_BREAK)
-		return;
-	cq->prev_ts = now;
-
-	traffic = pkt_size_counter->large_pkt_bytes_cnt +
-		  pkt_size_counter->small_pkt_bytes_cnt;
-	/* The table takes Mbps
-	 * traffic *= 8    => bits
-	 * traffic *= (10^6 / delta)    => bps
-	 * traffic /= 10^6     => Mbps
-	 *
-	 * Combining, traffic *= (8 / delta)
-	 */
-
-	traffic <<= 3;
-	traffic = delta > UINT_MAX ? 0 : traffic / (u32)delta;
-
-	for (index = 0; index < ENIC_MAX_COALESCE_TIMERS; index++)
-		if (traffic < mod_table[index].rx_rate)
-			break;
-	range_start = (pkt_size_counter->small_pkt_bytes_cnt >
-		       pkt_size_counter->large_pkt_bytes_cnt << 1) ?
-		      rx_coal->small_pkt_range_start :
-		      rx_coal->large_pkt_range_start;
-	timer = range_start + ((rx_coal->range_end - range_start) *
-			       mod_table[index].range_percent / 100);
-	/* Damping */
-	cq->tobe_rx_coal_timeval = (timer + cq->tobe_rx_coal_timeval) >> 1;
-
-	pkt_size_counter->large_pkt_bytes_cnt = 0;
-	pkt_size_counter->small_pkt_bytes_cnt = 0;
-}
-
 #ifdef CONFIG_RFS_ACCEL
 static void enic_free_rx_cpu_rmap(struct enic *enic)
 {
@@ -1407,10 +1414,8 @@ static int enic_poll_msix_rq(struct napi_struct *napi, int budget)
 	if (err)
 		work_done = work_to_do;
 	if (enic->rx_coalesce_setting.use_adaptive_rx_coalesce)
-		/* Call the function which refreshes
-		 * the intr coalescing timer value based on
-		 * the traffic.  This is supported only in
-		 * the case of MSI-x mode
+		/* Call the function which refreshes the intr coalescing timer
+		 * value based on the traffic.
 		 */
 		enic_calc_int_moderation(enic, &enic->rq[rq]);
 
@@ -1569,12 +1574,6 @@ static void enic_set_rx_coal_setting(struct enic *enic)
 	int index = -1;
 	struct enic_rx_coal *rx_coal = &enic->rx_coalesce_setting;
 
-	/* If intr mode is not MSIX, do not do adaptive coalescing */
-	if (VNIC_DEV_INTR_MODE_MSIX != vnic_dev_get_intr_mode(enic->vdev)) {
-		netdev_info(enic->netdev, "INTR mode is not MSIX, Not initializing adaptive coalescing");
-		return;
-	}
-
 	/* 1. Read the link speed from fw
 	 * 2. Pick the default range for the speed
 	 * 3. Update it in enic->rx_coalesce_setting
-- 
2.4.5

[PATCH net-next 2/2] enic: allow adaptive coalesce setting for msi/legacy intr

[Govindarajulu Varadarajan]

* Allow setting of adaptive coalescing setting for all types of interrupt.

* In msi & legacy intr, we use single interrupt for rx & tx. In this case
  tx_coalesce_usecs is invalid. We should use only rx_coalesce_usecs.
  Do not display tx_coal values for msi/intx. And do not allow user to set
  this as well.

* Driver supports only tx/rx_coalesce_usec and adaptive coalesce settings.
  For other values, driver does not return error. So ethtool succeeds for
  unsupported values. Introduce enic_coalesce_valid() function to validate
  the coalescing values.

* If user requests for coalesce value greater than what adaptor supports,
  driver uses the max value. We should at least log this.

Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com>
---
 drivers/net/ethernet/cisco/enic/enic_ethtool.c | 113 ++++++++++++++-----------
 1 file changed, 65 insertions(+), 48 deletions(-)

diff --git a/drivers/net/ethernet/cisco/enic/enic_ethtool.c b/drivers/net/ethernet/cisco/enic/enic_ethtool.c
index f3f1601..f44a39c 100644
--- a/drivers/net/ethernet/cisco/enic/enic_ethtool.c
+++ b/drivers/net/ethernet/cisco/enic/enic_ethtool.c
@@ -224,7 +224,8 @@ static int enic_get_coalesce(struct net_device *netdev,
 	struct enic *enic = netdev_priv(netdev);
 	struct enic_rx_coal *rxcoal = &enic->rx_coalesce_setting;
 
-	ecmd->tx_coalesce_usecs = enic->tx_coalesce_usecs;
+	if (vnic_dev_get_intr_mode(enic->vdev) == VNIC_DEV_INTR_MODE_MSIX)
+		ecmd->tx_coalesce_usecs = enic->tx_coalesce_usecs;
 	ecmd->rx_coalesce_usecs = enic->rx_coalesce_usecs;
 	if (rxcoal->use_adaptive_rx_coalesce)
 		ecmd->use_adaptive_rx_coalesce = 1;
@@ -234,6 +235,53 @@ static int enic_get_coalesce(struct net_device *netdev,
 	return 0;
 }
 
+static int enic_coalesce_valid(struct enic *enic,
+			       struct ethtool_coalesce *ec)
+{
+	u32 coalesce_usecs_max = vnic_dev_get_intr_coal_timer_max(enic->vdev);
+	u32 rx_coalesce_usecs_high = min_t(u32, coalesce_usecs_max,
+					   ec->rx_coalesce_usecs_high);
+	u32 rx_coalesce_usecs_low = min_t(u32, coalesce_usecs_max,
+					  ec->rx_coalesce_usecs_low);
+
+	if (ec->rx_max_coalesced_frames		||
+	    ec->rx_coalesce_usecs_irq		||
+	    ec->rx_max_coalesced_frames_irq	||
+	    ec->tx_max_coalesced_frames		||
+	    ec->tx_coalesce_usecs_irq		||
+	    ec->tx_max_coalesced_frames_irq	||
+	    ec->stats_block_coalesce_usecs	||
+	    ec->use_adaptive_tx_coalesce	||
+	    ec->pkt_rate_low			||
+	    ec->rx_max_coalesced_frames_low	||
+	    ec->tx_coalesce_usecs_low		||
+	    ec->tx_max_coalesced_frames_low	||
+	    ec->pkt_rate_high			||
+	    ec->rx_max_coalesced_frames_high	||
+	    ec->tx_coalesce_usecs_high		||
+	    ec->tx_max_coalesced_frames_high	||
+	    ec->rate_sample_interval)
+		return -EINVAL;
+
+	if ((vnic_dev_get_intr_mode(enic->vdev) != VNIC_DEV_INTR_MODE_MSIX) &&
+	    ec->tx_coalesce_usecs)
+		return -EINVAL;
+
+	if ((ec->tx_coalesce_usecs > coalesce_usecs_max)	||
+	    (ec->rx_coalesce_usecs > coalesce_usecs_max)	||
+	    (ec->rx_coalesce_usecs_low > coalesce_usecs_max)	||
+	    (ec->rx_coalesce_usecs_high > coalesce_usecs_max))
+		netdev_info(enic->netdev, "ethtool_set_coalesce: adaptor supports max coalesce value of %d. Setting max value.\n",
+			    coalesce_usecs_max);
+
+	if (ec->rx_coalesce_usecs_high &&
+	    (rx_coalesce_usecs_high <
+	     rx_coalesce_usecs_low + ENIC_AIC_LARGE_PKT_DIFF))
+		return -EINVAL;
+
+	return 0;
+}
+
 static int enic_set_coalesce(struct net_device *netdev,
 	struct ethtool_coalesce *ecmd)
 {
@@ -244,8 +292,12 @@ static int enic_set_coalesce(struct net_device *netdev,
 	u32 rx_coalesce_usecs_high;
 	u32 coalesce_usecs_max;
 	unsigned int i, intr;
+	int ret;
 	struct enic_rx_coal *rxcoal = &enic->rx_coalesce_setting;
 
+	ret = enic_coalesce_valid(enic, ecmd);
+	if (ret)
+		return ret;
 	coalesce_usecs_max = vnic_dev_get_intr_coal_timer_max(enic->vdev);
 	tx_coalesce_usecs = min_t(u32, ecmd->tx_coalesce_usecs,
 				  coalesce_usecs_max);
@@ -257,59 +309,24 @@ static int enic_set_coalesce(struct net_device *netdev,
 	rx_coalesce_usecs_high = min_t(u32, ecmd->rx_coalesce_usecs_high,
 				       coalesce_usecs_max);
 
-	switch (vnic_dev_get_intr_mode(enic->vdev)) {
-	case VNIC_DEV_INTR_MODE_INTX:
-		if (tx_coalesce_usecs != rx_coalesce_usecs)
-			return -EINVAL;
-		if (ecmd->use_adaptive_rx_coalesce	||
-		    ecmd->rx_coalesce_usecs_low		||
-		    ecmd->rx_coalesce_usecs_high)
-			return -EINVAL;
-
-		intr = enic_legacy_io_intr();
-		vnic_intr_coalescing_timer_set(&enic->intr[intr],
-			tx_coalesce_usecs);
-		break;
-	case VNIC_DEV_INTR_MODE_MSI:
-		if (tx_coalesce_usecs != rx_coalesce_usecs)
-			return -EINVAL;
-		if (ecmd->use_adaptive_rx_coalesce	||
-		    ecmd->rx_coalesce_usecs_low		||
-		    ecmd->rx_coalesce_usecs_high)
-			return -EINVAL;
-
-		vnic_intr_coalescing_timer_set(&enic->intr[0],
-			tx_coalesce_usecs);
-		break;
-	case VNIC_DEV_INTR_MODE_MSIX:
-		if (ecmd->rx_coalesce_usecs_high &&
-		    (rx_coalesce_usecs_high <
-		     rx_coalesce_usecs_low + ENIC_AIC_LARGE_PKT_DIFF))
-				return -EINVAL;
-
+	if (vnic_dev_get_intr_mode(enic->vdev) == VNIC_DEV_INTR_MODE_MSIX) {
 		for (i = 0; i < enic->wq_count; i++) {
 			intr = enic_msix_wq_intr(enic, i);
 			vnic_intr_coalescing_timer_set(&enic->intr[intr],
-				tx_coalesce_usecs);
-		}
-
-		rxcoal->use_adaptive_rx_coalesce =
-					!!ecmd->use_adaptive_rx_coalesce;
-		if (!rxcoal->use_adaptive_rx_coalesce)
-			enic_intr_coal_set_rx(enic, rx_coalesce_usecs);
-
-		if (ecmd->rx_coalesce_usecs_high) {
-			rxcoal->range_end = rx_coalesce_usecs_high;
-			rxcoal->small_pkt_range_start = rx_coalesce_usecs_low;
-			rxcoal->large_pkt_range_start = rx_coalesce_usecs_low +
-							ENIC_AIC_LARGE_PKT_DIFF;
+						       tx_coalesce_usecs);
 		}
-		break;
-	default:
-		break;
+		enic->tx_coalesce_usecs = tx_coalesce_usecs;
+	}
+	rxcoal->use_adaptive_rx_coalesce = !!ecmd->use_adaptive_rx_coalesce;
+	if (!rxcoal->use_adaptive_rx_coalesce)
+		enic_intr_coal_set_rx(enic, rx_coalesce_usecs);
+	if (ecmd->rx_coalesce_usecs_high) {
+		rxcoal->range_end = rx_coalesce_usecs_high;
+		rxcoal->small_pkt_range_start = rx_coalesce_usecs_low;
+		rxcoal->large_pkt_range_start = rx_coalesce_usecs_low +
+						ENIC_AIC_LARGE_PKT_DIFF;
 	}
 
-	enic->tx_coalesce_usecs = tx_coalesce_usecs;
 	enic->rx_coalesce_usecs = rx_coalesce_usecs;
 
 	return 0;
-- 
2.4.5

Re: [PATCH net-next 1/2] enic: add adaptive coalescing intr for intx and msi poll

[David Miller]

From: Govindarajulu Varadarajan <_govind@gmx.com>
Date: Wed, 15 Jul 2015 15:34:39 +0530

> Adaptive interrupt coalescing is available for msix. This patch adds the support
> for msi poll. Interface for adaptive interrupt coalescing is already added in
> driver. We just did not enable it for legacy intr & msi.
> 
> enic_calc_int_moderation() & enic_set_int_moderation() are defined as static
> after enic_poll. Since enic_poll needs it, move both of these function
> definitions above enic_poll. No change in functionality.
> 
> Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com>

Applied.

Re: [PATCH net-next 2/2] enic: allow adaptive coalesce setting for msi/legacy intr

[David Miller]

From: Govindarajulu Varadarajan <_govind@gmx.com>
Date: Wed, 15 Jul 2015 15:34:40 +0530

> * Allow setting of adaptive coalescing setting for all types of interrupt.
> 
> * In msi & legacy intr, we use single interrupt for rx & tx. In this case
>   tx_coalesce_usecs is invalid. We should use only rx_coalesce_usecs.
>   Do not display tx_coal values for msi/intx. And do not allow user to set
>   this as well.
> 
> * Driver supports only tx/rx_coalesce_usec and adaptive coalesce settings.
>   For other values, driver does not return error. So ethtool succeeds for
>   unsupported values. Introduce enic_coalesce_valid() function to validate
>   the coalescing values.
> 
> * If user requests for coalesce value greater than what adaptor supports,
>   driver uses the max value. We should at least log this.
> 
> Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com>

Applied.