net: mana: Move NAPI from EQ to CQ

The existing code has NAPI threads polling on EQ directly. To prepare for EQ sharing among vPorts, move NAPI from EQ to CQ so that one EQ can serve multiple CQs from different vPorts. The "arm bit" is only set when CQ processing is completed to reduce the number of EQ entries, which in turn reduce the number of interrupts on EQ. Signed-off-by: Haiyang Zhang <[email protected]> Signed-off-by: David S. Miller <[email protected]>
bignaux · Aug 25, 2021 · e1b5683 · e1b5683
1 parent 807d103
commit e1b5683
Show file tree

Hide file tree

Showing 5 changed files with 74 additions and 103 deletions.
diff --git a/drivers/net/ethernet/microsoft/mana/gdma.h b/drivers/net/ethernet/microsoft/mana/gdma.h
@@ -239,10 +239,8 @@ struct gdma_event {
 
 struct gdma_queue;
 
-#define CQE_POLLING_BUFFER 512
 struct mana_eq {
 	struct gdma_queue *eq;
-	struct gdma_comp cqe_poll[CQE_POLLING_BUFFER];
 };
 
 typedef void gdma_eq_callback(void *context, struct gdma_queue *q,
@@ -291,11 +289,6 @@ struct gdma_queue {
 			unsigned int msix_index;
 
 			u32 log2_throttle_limit;
-
-			/* NAPI data */
-			struct napi_struct napi;
-			int work_done;
-			int budget;
 		} eq;
 
 		struct {
@@ -406,7 +399,7 @@ void mana_gd_destroy_queue(struct gdma_context *gc, struct gdma_queue *queue);
 
 int mana_gd_poll_cq(struct gdma_queue *cq, struct gdma_comp *comp, int num_cqe);
 
-void mana_gd_arm_cq(struct gdma_queue *cq);
+void mana_gd_ring_cq(struct gdma_queue *cq, u8 arm_bit);
 
 struct gdma_wqe {
 	u32 reserved	:24;

diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c b/drivers/net/ethernet/microsoft/mana/gdma_main.c
@@ -267,7 +267,7 @@ void mana_gd_wq_ring_doorbell(struct gdma_context *gc, struct gdma_queue *queue)
 			      queue->id, queue->head * GDMA_WQE_BU_SIZE, 1);
 }
 
-void mana_gd_arm_cq(struct gdma_queue *cq)
+void mana_gd_ring_cq(struct gdma_queue *cq, u8 arm_bit)
 {
 	struct gdma_context *gc = cq->gdma_dev->gdma_context;
 
@@ -276,7 +276,7 @@ void mana_gd_arm_cq(struct gdma_queue *cq)
 	u32 head = cq->head % (num_cqe << GDMA_CQE_OWNER_BITS);
 
 	mana_gd_ring_doorbell(gc, cq->gdma_dev->doorbell, cq->type, cq->id,
-			      head, SET_ARM_BIT);
+			      head, arm_bit);
 }
 
 static void mana_gd_process_eqe(struct gdma_queue *eq)
@@ -339,7 +339,6 @@ static void mana_gd_process_eq_events(void *arg)
 	struct gdma_queue *eq = arg;
 	struct gdma_context *gc;
 	struct gdma_eqe *eqe;
-	unsigned int arm_bit;
 	u32 head, num_eqe;
 	int i;
 
@@ -370,48 +369,16 @@ static void mana_gd_process_eq_events(void *arg)
 		eq->head++;
 	}
 
-	/* Always rearm the EQ for HWC. For MANA, rearm it when NAPI is done. */
-	if (mana_gd_is_hwc(eq->gdma_dev)) {
-		arm_bit = SET_ARM_BIT;
-	} else if (eq->eq.work_done < eq->eq.budget &&
-		   napi_complete_done(&eq->eq.napi, eq->eq.work_done)) {
-		arm_bit = SET_ARM_BIT;
-	} else {
-		arm_bit = 0;
-	}
-
 	head = eq->head % (num_eqe << GDMA_EQE_OWNER_BITS);
 
 	mana_gd_ring_doorbell(gc, eq->gdma_dev->doorbell, eq->type, eq->id,
-			      head, arm_bit);
-}
-
-static int mana_poll(struct napi_struct *napi, int budget)
-{
-	struct gdma_queue *eq = container_of(napi, struct gdma_queue, eq.napi);
-
-	eq->eq.work_done = 0;
-	eq->eq.budget = budget;
-
-	mana_gd_process_eq_events(eq);
-
-	return min(eq->eq.work_done, budget);
-}
-
-static void mana_gd_schedule_napi(void *arg)
-{
-	struct gdma_queue *eq = arg;
-	struct napi_struct *napi;
-
-	napi = &eq->eq.napi;
-	napi_schedule_irqoff(napi);
+			      head, SET_ARM_BIT);
 }
 
 static int mana_gd_register_irq(struct gdma_queue *queue,
 				const struct gdma_queue_spec *spec)
 {
 	struct gdma_dev *gd = queue->gdma_dev;
-	bool is_mana = mana_gd_is_mana(gd);
 	struct gdma_irq_context *gic;
 	struct gdma_context *gc;
 	struct gdma_resource *r;
@@ -442,20 +409,11 @@ static int mana_gd_register_irq(struct gdma_queue *queue,
 
 	gic = &gc->irq_contexts[msi_index];
 
-	if (is_mana) {
-		netif_napi_add(spec->eq.ndev, &queue->eq.napi, mana_poll,
-			       NAPI_POLL_WEIGHT);
-		napi_enable(&queue->eq.napi);
-	}
-
 	WARN_ON(gic->handler || gic->arg);
 
 	gic->arg = queue;
 
-	if (is_mana)
-		gic->handler = mana_gd_schedule_napi;
-	else
-		gic->handler = mana_gd_process_eq_events;
+	gic->handler = mana_gd_process_eq_events;
 
 	return 0;
 }
@@ -549,11 +507,6 @@ static void mana_gd_destroy_eq(struct gdma_context *gc, bool flush_evenets,
 
 	mana_gd_deregiser_irq(queue);
 
-	if (mana_gd_is_mana(queue->gdma_dev)) {
-		napi_disable(&queue->eq.napi);
-		netif_napi_del(&queue->eq.napi);
-	}
-
 	if (queue->eq.disable_needed)
 		mana_gd_disable_queue(queue);
 }

diff --git a/drivers/net/ethernet/microsoft/mana/hw_channel.c b/drivers/net/ethernet/microsoft/mana/hw_channel.c
@@ -304,7 +304,7 @@ static void mana_hwc_comp_event(void *ctx, struct gdma_queue *q_self)
 						&comp_data);
 	}
 
-	mana_gd_arm_cq(q_self);
+	mana_gd_ring_cq(q_self, SET_ARM_BIT);
 }
 
 static void mana_hwc_destroy_cq(struct gdma_context *gc, struct hwc_cq *hwc_cq)

diff --git a/drivers/net/ethernet/microsoft/mana/mana.h b/drivers/net/ethernet/microsoft/mana/mana.h
@@ -225,6 +225,8 @@ struct mana_tx_comp_oob {
 
 struct mana_rxq;
 
+#define CQE_POLLING_BUFFER 512
+
 struct mana_cq {
 	struct gdma_queue *gdma_cq;
 
@@ -244,8 +246,13 @@ struct mana_cq {
 	 */
 	struct mana_txq *txq;
 
-	/* Pointer to a buffer which the CQ handler can copy the CQE's into. */
-	struct gdma_comp *gdma_comp_buf;
+	/* Buffer which the CQ handler can copy the CQE's into. */
+	struct gdma_comp gdma_comp_buf[CQE_POLLING_BUFFER];
+
+	/* NAPI data */
+	struct napi_struct napi;
+	int work_done;
+	int budget;
 };
 
 #define GDMA_MAX_RQE_SGES 15