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>

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.c b/drivers/net/ethernet/pensando/ionic/ionic_dev.c
index 626b9113e7c4113d34c12edd9eec0d10dea31c87..d911f4fd9af61a122b8e4db8e51204fbcd2fba54 100644 (file)
--- a/drivers/net/ethernet/pensando/ionic/ionic_dev.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.c
@@ -708,9 +708,16 @@ void ionic_q_post(struct ionic_queue *q, bool ring_doorbell, ionic_desc_cb cb,
                q->lif->index, q->name, q->hw_type, q->hw_index,
                q->head_idx, ring_doorbell);
 
-       if (ring_doorbell)
+       if (ring_doorbell) {
                ionic_dbell_ring(lif->kern_dbpage, q->hw_type,
                                 q->dbval | q->head_idx);
+
+               q->dbell_jiffies = jiffies;
+
+               if (q_to_qcq(q)->napi_qcq)
+                       mod_timer(&q_to_qcq(q)->napi_qcq->napi_deadline,
+                                 jiffies + IONIC_NAPI_DEADLINE);
+       }
 }
 
 static bool ionic_q_is_posted(struct ionic_queue *q, unsigned int pos)

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.h b/drivers/net/ethernet/pensando/ionic/ionic_dev.h
index 2a1d7b9c07e7ffadc997a51ae72de100b3f4070f..bce3ca38669bdcc24d11d64068dcd5b425da3bd4 100644 (file)
--- a/drivers/net/ethernet/pensando/ionic/ionic_dev.h
+++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.h
@@ -25,6 +25,12 @@
 #define IONIC_DEV_INFO_REG_COUNT       32
 #define IONIC_DEV_CMD_REG_COUNT                32
 
+#define IONIC_NAPI_DEADLINE            (HZ / 200)      /* 5ms */
+#define IONIC_ADMIN_DOORBELL_DEADLINE  (HZ / 2)        /* 500ms */
+#define IONIC_TX_DOORBELL_DEADLINE     (HZ / 100)      /* 10ms */
+#define IONIC_RX_MIN_DOORBELL_DEADLINE (HZ / 100)      /* 10ms */
+#define IONIC_RX_MAX_DOORBELL_DEADLINE (HZ * 5)        /* 5s */
+
 struct ionic_dev_bar {
        void __iomem *vaddr;
        phys_addr_t bus_addr;
@@ -216,6 +222,8 @@ struct ionic_queue {
        struct ionic_lif *lif;
        struct ionic_desc_info *info;
        u64 dbval;
+       unsigned long dbell_deadline;
+       unsigned long dbell_jiffies;
        u16 head_idx;
        u16 tail_idx;
        unsigned int index;
@@ -361,4 +369,8 @@ void ionic_q_service(struct ionic_queue *q, struct ionic_cq_info *cq_info,
 int ionic_heartbeat_check(struct ionic *ionic);
 bool ionic_is_fw_running(struct ionic_dev *idev);
 
+bool ionic_adminq_poke_doorbell(struct ionic_queue *q);
+bool ionic_txq_poke_doorbell(struct ionic_queue *q);
+bool ionic_rxq_poke_doorbell(struct ionic_queue *q);
+
 #endif /* _IONIC_DEV_H_ */

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_lif.c b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
index e51d8be7911c33ea69786ad7874dfa4f1e948969..63a78a9ac241ad87244323eef234a4cb52298ae1 100644 (file)
--- 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)

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_lif.h b/drivers/net/ethernet/pensando/ionic/ionic_lif.h
index a53984bf3544831756e7c15df89a2d0a48f42644..734519895614f462c282b981e2d29fa1b38ab112 100644 (file)
--- a/drivers/net/ethernet/pensando/ionic/ionic_lif.h
+++ b/drivers/net/ethernet/pensando/ionic/ionic_lif.h
@@ -74,8 +74,10 @@ struct ionic_qcq {
        struct ionic_queue q;
        struct ionic_cq cq;
        struct ionic_intr_info intr;
+       struct timer_list napi_deadline;
        struct napi_struct napi;
        unsigned int flags;
+       struct ionic_qcq *napi_qcq;
        struct dentry *dentry;
 };
 

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_main.c b/drivers/net/ethernet/pensando/ionic/ionic_main.c
index a13530ec4dd8fccd401e06de1fe7582049dce8ac..08c42b039d92db0acc09ce845a0c25abf356c400 100644 (file)
--- a/drivers/net/ethernet/pensando/ionic/ionic_main.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_main.c
@@ -289,6 +289,35 @@ static void ionic_adminq_cb(struct ionic_queue *q,
        complete_all(&ctx->work);
 }
 
+bool ionic_adminq_poke_doorbell(struct ionic_queue *q)
+{
+       struct ionic_lif *lif = q->lif;
+       unsigned long now, then, dif;
+       unsigned long irqflags;
+
+       spin_lock_irqsave(&lif->adminq_lock, irqflags);
+
+       if (q->tail_idx == q->head_idx) {
+               spin_unlock_irqrestore(&lif->adminq_lock, irqflags);
+               return false;
+       }
+
+       now = READ_ONCE(jiffies);
+       then = q->dbell_jiffies;
+       dif = now - then;
+
+       if (dif > q->dbell_deadline) {
+               ionic_dbell_ring(q->lif->kern_dbpage, q->hw_type,
+                                q->dbval | q->head_idx);
+
+               q->dbell_jiffies = now;
+       }
+
+       spin_unlock_irqrestore(&lif->adminq_lock, irqflags);
+
+       return true;
+}
+
 int ionic_adminq_post(struct ionic_lif *lif, struct ionic_admin_ctx *ctx)
 {
        struct ionic_desc_info *desc_info;

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
index 0c3977416cd1c319e8bfda66de76e902dc39b633..f761780f016244855061f0ef2dcf5a1107783188 100644 (file)
--- a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
@@ -22,6 +22,67 @@ static inline void ionic_rxq_post(struct ionic_queue *q, bool ring_dbell,
        ionic_q_post(q, ring_dbell, cb_func, cb_arg);
 }
 
+bool ionic_txq_poke_doorbell(struct ionic_queue *q)
+{
+       unsigned long now, then, dif;
+       struct netdev_queue *netdev_txq;
+       struct net_device *netdev;
+
+       netdev = q->lif->netdev;
+       netdev_txq = netdev_get_tx_queue(netdev, q->index);
+
+       HARD_TX_LOCK(netdev, netdev_txq, smp_processor_id());
+
+       if (q->tail_idx == q->head_idx) {
+               HARD_TX_UNLOCK(netdev, netdev_txq);
+               return false;
+       }
+
+       now = READ_ONCE(jiffies);
+       then = q->dbell_jiffies;
+       dif = now - then;
+
+       if (dif > q->dbell_deadline) {
+               ionic_dbell_ring(q->lif->kern_dbpage, q->hw_type,
+                                q->dbval | q->head_idx);
+
+               q->dbell_jiffies = now;
+       }
+
+       HARD_TX_UNLOCK(netdev, netdev_txq);
+
+       return true;
+}
+
+bool ionic_rxq_poke_doorbell(struct ionic_queue *q)
+{
+       unsigned long now, then, dif;
+
+       /* no lock, called from rx napi or txrx napi, nothing else can fill */
+
+       if (q->tail_idx == q->head_idx)
+               return false;
+
+       now = READ_ONCE(jiffies);
+       then = q->dbell_jiffies;
+       dif = now - then;
+
+       if (dif > q->dbell_deadline) {
+               ionic_dbell_ring(q->lif->kern_dbpage, q->hw_type,
+                                q->dbval | q->head_idx);
+
+               q->dbell_jiffies = now;
+
+               dif = 2 * q->dbell_deadline;
+               if (dif > IONIC_RX_MAX_DOORBELL_DEADLINE)
+                       dif = IONIC_RX_MAX_DOORBELL_DEADLINE;
+
+               q->dbell_deadline = dif;
+       }
+
+       return true;
+}
+
 static inline struct netdev_queue *q_to_ndq(struct ionic_queue *q)
 {
        return netdev_get_tx_queue(q->lif->netdev, q->index);
@@ -424,6 +485,12 @@ void ionic_rx_fill(struct ionic_queue *q)
 
        ionic_dbell_ring(q->lif->kern_dbpage, q->hw_type,
                         q->dbval | q->head_idx);
+
+       q->dbell_deadline = IONIC_RX_MIN_DOORBELL_DEADLINE;
+       q->dbell_jiffies = jiffies;
+
+       mod_timer(&q_to_qcq(q)->napi_qcq->napi_deadline,
+                 jiffies + IONIC_NAPI_DEADLINE);
 }
 
 void ionic_rx_empty(struct ionic_queue *q)
@@ -511,6 +578,9 @@ int ionic_tx_napi(struct napi_struct *napi, int budget)
                                   work_done, flags);
        }
 
+       if (!work_done && ionic_txq_poke_doorbell(&qcq->q))
+               mod_timer(&qcq->napi_deadline, jiffies + IONIC_NAPI_DEADLINE);
+
        return work_done;
 }
 
@@ -544,23 +614,29 @@ int ionic_rx_napi(struct napi_struct *napi, int budget)
                                   work_done, flags);
        }
 
+       if (!work_done && ionic_rxq_poke_doorbell(&qcq->q))
+               mod_timer(&qcq->napi_deadline, jiffies + IONIC_NAPI_DEADLINE);
+
        return work_done;
 }
 
 int ionic_txrx_napi(struct napi_struct *napi, int budget)
 {
-       struct ionic_qcq *qcq = napi_to_qcq(napi);
+       struct ionic_qcq *rxqcq = napi_to_qcq(napi);
        struct ionic_cq *rxcq = napi_to_cq(napi);
        unsigned int qi = rxcq->bound_q->index;
+       struct ionic_qcq *txqcq;
        struct ionic_dev *idev;
        struct ionic_lif *lif;
        struct ionic_cq *txcq;
+       bool resched = false;
        u32 rx_work_done = 0;
        u32 tx_work_done = 0;
        u32 flags = 0;
 
        lif = rxcq->bound_q->lif;
        idev = &lif->ionic->idev;
+       txqcq = lif->txqcqs[qi];
        txcq = &lif->txqcqs[qi]->cq;
 
        tx_work_done = ionic_cq_service(txcq, IONIC_TX_BUDGET_DEFAULT,
@@ -572,7 +648,7 @@ int ionic_txrx_napi(struct napi_struct *napi, int budget)
        ionic_rx_fill(rxcq->bound_q);
 
        if (rx_work_done < budget && napi_complete_done(napi, rx_work_done)) {
-               ionic_dim_update(qcq, 0);
+               ionic_dim_update(rxqcq, 0);
                flags |= IONIC_INTR_CRED_UNMASK;
                rxcq->bound_intr->rearm_count++;
        }
@@ -583,6 +659,13 @@ int ionic_txrx_napi(struct napi_struct *napi, int budget)
                                   tx_work_done + rx_work_done, flags);
        }
 
+       if (!rx_work_done && ionic_rxq_poke_doorbell(&rxqcq->q))
+               resched = true;
+       if (!tx_work_done && ionic_txq_poke_doorbell(&txqcq->q))
+               resched = true;
+       if (resched)
+               mod_timer(&rxqcq->napi_deadline, jiffies + IONIC_NAPI_DEADLINE);
+
        return rx_work_done;
 }