RDMA/bnxt_re: Disable/kill tasklet only if it is enabled

When the ulp hook to start the IRQ fails because the rings are not
available, tasklets are not enabled. In this case when the driver is
unloaded, driver calls CREQ tasklet_kill. This causes an indefinite hang
as the tasklet is not enabled.

Driver shouldn't call tasklet_kill if it is not enabled. So using the
creq->requested and nq->requested flags to identify if both tasklets/irqs
are registered. Checking this flag while scheduling the tasklet from
ISR. Also, added a cleanup for disabling tasklet, in case request_irq
fails during start_irq.

Check for return value for bnxt_qplib_rcfw_start_irq and in case the
bnxt_qplib_rcfw_start_irq fails, return bnxt_re_start_irq without
attempting to start NQ IRQs.

Fixes: 1ac5a404 ("RDMA/bnxt_re: Add bnxt_re RoCE driver")
Link: https://lore.kernel.org/r/1684478897-12247-2-git-send-email-selvin.xavier@broadcom.comSigned-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/bnxt_re/main.c

@@ -283,15 +283,21 @@ static void bnxt_re_start_irq(void *handle, struct bnxt_msix_entry *ent)
 	for (indx = 0; indx < rdev->num_msix; indx++)
 		rdev->en_dev->msix_entries[indx].vector = ent[indx].vector;
 
-	bnxt_qplib_rcfw_start_irq(rcfw, msix_ent[BNXT_RE_AEQ_IDX].vector,
-				  false);
+	rc = bnxt_qplib_rcfw_start_irq(rcfw, msix_ent[BNXT_RE_AEQ_IDX].vector,
+				       false);
+	if (rc) {
+		ibdev_warn(&rdev->ibdev, "Failed to reinit CREQ\n");
+		return;
+	}
 	for (indx = BNXT_RE_NQ_IDX ; indx < rdev->num_msix; indx++) {
 		nq = &rdev->nq[indx - 1];
 		rc = bnxt_qplib_nq_start_irq(nq, indx - 1,
 					     msix_ent[indx].vector, false);
-		if (rc)
+		if (rc) {
 			ibdev_warn(&rdev->ibdev, "Failed to reinit NQ index %d\n",
 				   indx - 1);
+			return;
+		}
 	}
 }
 

drivers/infiniband/hw/bnxt_re/qplib_fp.c

@@ -399,6 +399,9 @@ static irqreturn_t bnxt_qplib_nq_irq(int irq, void *dev_instance)
 
 void bnxt_qplib_nq_stop_irq(struct bnxt_qplib_nq *nq, bool kill)
 {
+	if (!nq->requested)
+		return;
+
 	tasklet_disable(&nq->nq_tasklet);
 	/* Mask h/w interrupt */
 	bnxt_qplib_ring_nq_db(&nq->nq_db.dbinfo, nq->res->cctx, false);
@@ -406,11 +409,10 @@ void bnxt_qplib_nq_stop_irq(struct bnxt_qplib_nq *nq, bool kill)
 	synchronize_irq(nq->msix_vec);
 	if (kill)
 		tasklet_kill(&nq->nq_tasklet);
-	if (nq->requested) {
-		irq_set_affinity_hint(nq->msix_vec, NULL);
-		free_irq(nq->msix_vec, nq);
-		nq->requested = false;
-	}
+
+	irq_set_affinity_hint(nq->msix_vec, NULL);
+	free_irq(nq->msix_vec, nq);
+	nq->requested = false;
 }
 
 void bnxt_qplib_disable_nq(struct bnxt_qplib_nq *nq)
@@ -449,8 +451,10 @@ int bnxt_qplib_nq_start_irq(struct bnxt_qplib_nq *nq, int nq_indx,
 
 	snprintf(nq->name, sizeof(nq->name), "bnxt_qplib_nq-%d", nq_indx);
 	rc = request_irq(nq->msix_vec, bnxt_qplib_nq_irq, 0, nq->name, nq);
-	if (rc)
+	if (rc) {
+		tasklet_disable(&nq->nq_tasklet);
 		return rc;
+	}
 
 	cpumask_clear(&nq->mask);
 	cpumask_set_cpu(nq_indx, &nq->mask);

drivers/infiniband/hw/bnxt_re/qplib_rcfw.c

@@ -636,6 +636,10 @@ void bnxt_qplib_rcfw_stop_irq(struct bnxt_qplib_rcfw *rcfw, bool kill)
 	struct bnxt_qplib_creq_ctx *creq;
 
 	creq = &rcfw->creq;
+
+	if (!creq->requested)
+		return;
+
 	tasklet_disable(&creq->creq_tasklet);
 	/* Mask h/w interrupts */
 	bnxt_qplib_ring_nq_db(&creq->creq_db.dbinfo, rcfw->res->cctx, false);
@@ -644,10 +648,8 @@ void bnxt_qplib_rcfw_stop_irq(struct bnxt_qplib_rcfw *rcfw, bool kill)
 	if (kill)
 		tasklet_kill(&creq->creq_tasklet);
 
-	if (creq->requested) {
-		free_irq(creq->msix_vec, rcfw);
-		creq->requested = false;
-	}
+	free_irq(creq->msix_vec, rcfw);
+	creq->requested = false;
 }
 
 void bnxt_qplib_disable_rcfw_channel(struct bnxt_qplib_rcfw *rcfw)
@@ -693,8 +695,10 @@ int bnxt_qplib_rcfw_start_irq(struct bnxt_qplib_rcfw *rcfw, int msix_vector,
 		tasklet_enable(&creq->creq_tasklet);
 	rc = request_irq(creq->msix_vec, bnxt_qplib_creq_irq, 0,
 			 "bnxt_qplib_creq", rcfw);
-	if (rc)
+	if (rc) {
+		tasklet_disable(&creq->creq_tasklet);
 		return rc;
+	}
 	creq->requested = true;
 
 	bnxt_qplib_ring_nq_db(&creq->creq_db.dbinfo, rcfw->res->cctx, true);