ionic: missed doorbell workaround

In one version of the HW there is a remote possibility that it
will miss the doorbell ring.  This adds a bit of protection to
be sure we don't stall a queue from a missed doorbell.

Fixes: 0f3154e6bcb3 ("ionic: Add Tx and Rx handling")
Signed-off-by: Allen Hubbe <allen.hubbe@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 40 insertions, 1 deletions

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_lif.c b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
index e51d8be7911c..63a78a9ac241 100644
--- a/drivers/net/ethernet/pensando/ionic/ionic_lif.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
@@ -16,6 +16,7 @@
 
 #include "ionic.h"
 #include "ionic_bus.h"
+#include "ionic_dev.h"
 #include "ionic_lif.h"
 #include "ionic_txrx.h"
 #include "ionic_ethtool.h"
@@ -200,6 +201,13 @@ void ionic_link_status_check_request(struct ionic_lif *lif, bool can_sleep)
 	}
 }
 
+static void ionic_napi_deadline(struct timer_list *timer)
+{
+	struct ionic_qcq *qcq = container_of(timer, struct ionic_qcq, napi_deadline);
+
+	napi_schedule(&qcq->napi);
+}
+
 static irqreturn_t ionic_isr(int irq, void *data)
 {
 	struct napi_struct *napi = data;
@@ -325,6 +333,7 @@ static int ionic_qcq_disable(struct ionic_lif *lif, struct ionic_qcq *qcq, int f
 		synchronize_irq(qcq->intr.vector);
 		irq_set_affinity_hint(qcq->intr.vector, NULL);
 		napi_disable(&qcq->napi);
+		del_timer_sync(&qcq->napi_deadline);
 	}
 
 	/* If there was a previous fw communcation error, don't bother with
@@ -460,6 +469,7 @@ static void ionic_link_qcq_interrupts(struct ionic_qcq *src_qcq,
 
 	n_qcq->intr.vector = src_qcq->intr.vector;
 	n_qcq->intr.index = src_qcq->intr.index;
+	n_qcq->napi_qcq = src_qcq->napi_qcq;
 }
 
 static int ionic_alloc_qcq_interrupt(struct ionic_lif *lif, struct ionic_qcq *qcq)
@@ -784,8 +794,14 @@ static int ionic_lif_txq_init(struct ionic_lif *lif, struct ionic_qcq *qcq)
 	dev_dbg(dev, "txq->hw_type %d\n", q->hw_type);
 	dev_dbg(dev, "txq->hw_index %d\n", q->hw_index);
 
-	if (test_bit(IONIC_LIF_F_SPLIT_INTR, lif->state))
+	q->dbell_deadline = IONIC_TX_DOORBELL_DEADLINE;
+	q->dbell_jiffies = jiffies;
+
+	if (test_bit(IONIC_LIF_F_SPLIT_INTR, lif->state)) {
 		netif_napi_add(lif->netdev, &qcq->napi, ionic_tx_napi);
+		qcq->napi_qcq = qcq;
+		timer_setup(&qcq->napi_deadline, ionic_napi_deadline, 0);
+	}
 
 	qcq->flags |= IONIC_QCQ_F_INITED;
 
@@ -839,11 +855,17 @@ static int ionic_lif_rxq_init(struct ionic_lif *lif, struct ionic_qcq *qcq)
 	dev_dbg(dev, "rxq->hw_type %d\n", q->hw_type);
 	dev_dbg(dev, "rxq->hw_index %d\n", q->hw_index);
 
+	q->dbell_deadline = IONIC_RX_MIN_DOORBELL_DEADLINE;
+	q->dbell_jiffies = jiffies;
+
 	if (test_bit(IONIC_LIF_F_SPLIT_INTR, lif->state))
 		netif_napi_add(lif->netdev, &qcq->napi, ionic_rx_napi);
 	else
 		netif_napi_add(lif->netdev, &qcq->napi, ionic_txrx_napi);
 
+	qcq->napi_qcq = qcq;
+	timer_setup(&qcq->napi_deadline, ionic_napi_deadline, 0);
+
 	qcq->flags |= IONIC_QCQ_F_INITED;
 
 	return 0;
@@ -1161,6 +1183,7 @@ static int ionic_adminq_napi(struct napi_struct *napi, int budget)
 	struct ionic_dev *idev = &lif->ionic->idev;
 	unsigned long irqflags;
 	unsigned int flags = 0;
+	bool resched = false;
 	int rx_work = 0;
 	int tx_work = 0;
 	int n_work = 0;
@@ -1198,6 +1221,16 @@ static int ionic_adminq_napi(struct napi_struct *napi, int budget)
 		ionic_intr_credits(idev->intr_ctrl, intr->index, credits, flags);
 	}
 
+	if (!a_work && ionic_adminq_poke_doorbell(&lif->adminqcq->q))
+		resched = true;
+	if (lif->hwstamp_rxq && !rx_work && ionic_rxq_poke_doorbell(&lif->hwstamp_rxq->q))
+		resched = true;
+	if (lif->hwstamp_txq && !tx_work && ionic_txq_poke_doorbell(&lif->hwstamp_txq->q))
+		resched = true;
+	if (resched)
+		mod_timer(&lif->adminqcq->napi_deadline,
+			  jiffies + IONIC_NAPI_DEADLINE);
+
 	return work_done;
 }
 
@@ -3256,8 +3289,14 @@ static int ionic_lif_adminq_init(struct ionic_lif *lif)
 	dev_dbg(dev, "adminq->hw_type %d\n", q->hw_type);
 	dev_dbg(dev, "adminq->hw_index %d\n", q->hw_index);
 
+	q->dbell_deadline = IONIC_ADMIN_DOORBELL_DEADLINE;
+	q->dbell_jiffies = jiffies;
+
 	netif_napi_add(lif->netdev, &qcq->napi, ionic_adminq_napi);
 
+	qcq->napi_qcq = qcq;
+	timer_setup(&qcq->napi_deadline, ionic_napi_deadline, 0);
+
 	napi_enable(&qcq->napi);
 
 	if (qcq->flags & IONIC_QCQ_F_INTR)