[PATCH for-rc v3 1/2] RDMA/bnxt_re: Fix the usage of control path spin locks

[Selvin Xavier <selvin.xavier@broadcom.com>]

Control path completion processing always runs in
tasklet context. To synchronize with the posting
thread, there is no need to use the irq variant of
spin lock. Use spin_lock_bh instead.

Fixes: 1ac5a4047975 ("RDMA/bnxt_re: Add bnxt_re RoCE driver")
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
---
 drivers/infiniband/hw/bnxt_re/qplib_rcfw.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
index 7294221..ca26b88 100644
--- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
+++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
@@ -290,7 +290,6 @@ static int __send_message(struct bnxt_qplib_rcfw *rcfw,
 	struct bnxt_qplib_hwq *hwq;
 	u32 sw_prod, cmdq_prod;
 	struct pci_dev *pdev;
-	unsigned long flags;
 	u16 cookie;
 	u8 *preq;
 
@@ -301,7 +300,7 @@ static int __send_message(struct bnxt_qplib_rcfw *rcfw,
 	/* Cmdq are in 16-byte units, each request can consume 1 or more
 	 * cmdqe
 	 */
-	spin_lock_irqsave(&hwq->lock, flags);
+	spin_lock_bh(&hwq->lock);
 	required_slots = bnxt_qplib_get_cmd_slots(msg->req);
 	free_slots = HWQ_FREE_SLOTS(hwq);
 	cookie = cmdq->seq_num & RCFW_MAX_COOKIE_VALUE;
@@ -311,7 +310,7 @@ static int __send_message(struct bnxt_qplib_rcfw *rcfw,
 		dev_info_ratelimited(&pdev->dev,
 				     "CMDQ is full req/free %d/%d!",
 				     required_slots, free_slots);
-		spin_unlock_irqrestore(&hwq->lock, flags);
+		spin_unlock_bh(&hwq->lock);
 		return -EAGAIN;
 	}
 	if (msg->block)
@@ -367,7 +366,7 @@ static int __send_message(struct bnxt_qplib_rcfw *rcfw,
 	wmb();
 	writel(cmdq_prod, cmdq->cmdq_mbox.prod);
 	writel(RCFW_CMDQ_TRIG_VAL, cmdq->cmdq_mbox.db);
-	spin_unlock_irqrestore(&hwq->lock, flags);
+	spin_unlock_bh(&hwq->lock);
 	/* Return the CREQ response pointer */
 	return 0;
 }
@@ -486,7 +485,6 @@ static int __bnxt_qplib_rcfw_send_message(struct bnxt_qplib_rcfw *rcfw,
 {
 	struct creq_qp_event *evnt = (struct creq_qp_event *)msg->resp;
 	struct bnxt_qplib_crsqe *crsqe;
-	unsigned long flags;
 	u16 cookie;
 	int rc;
 	u8 opcode;
@@ -512,12 +510,12 @@ static int __bnxt_qplib_rcfw_send_message(struct bnxt_qplib_rcfw *rcfw,
 		rc = __poll_for_resp(rcfw, cookie);
 
 	if (rc) {
-		spin_lock_irqsave(&rcfw->cmdq.hwq.lock, flags);
+		spin_lock_bh(&rcfw->cmdq.hwq.lock);
 		crsqe = &rcfw->crsqe_tbl[cookie];
 		crsqe->is_waiter_alive = false;
 		if (rc == -ENODEV)
 			set_bit(FIRMWARE_STALL_DETECTED, &rcfw->cmdq.flags);
-		spin_unlock_irqrestore(&rcfw->cmdq.hwq.lock, flags);
+		spin_unlock_bh(&rcfw->cmdq.hwq.lock);
 		return -ETIMEDOUT;
 	}
 
@@ -628,7 +626,6 @@ static int bnxt_qplib_process_qp_event(struct bnxt_qplib_rcfw *rcfw,
 	u16 cookie, blocked = 0;
 	bool is_waiter_alive;
 	struct pci_dev *pdev;
-	unsigned long flags;
 	u32 wait_cmds = 0;
 	int rc = 0;
 
@@ -659,8 +656,7 @@ static int bnxt_qplib_process_qp_event(struct bnxt_qplib_rcfw *rcfw,
 		 *
 		 */
 
-		spin_lock_irqsave_nested(&hwq->lock, flags,
-					 SINGLE_DEPTH_NESTING);
+		spin_lock_nested(&hwq->lock, SINGLE_DEPTH_NESTING);
 		cookie = le16_to_cpu(qp_event->cookie);
 		blocked = cookie & RCFW_CMD_IS_BLOCKING;
 		cookie &= RCFW_MAX_COOKIE_VALUE;
@@ -672,7 +668,7 @@ static int bnxt_qplib_process_qp_event(struct bnxt_qplib_rcfw *rcfw,
 			dev_info(&pdev->dev,
 				 "rcfw timedout: cookie = %#x, free_slots = %d",
 				 cookie, crsqe->free_slots);
-			spin_unlock_irqrestore(&hwq->lock, flags);
+			spin_unlock(&hwq->lock);
 			return rc;
 		}
 
@@ -720,7 +716,7 @@ static int bnxt_qplib_process_qp_event(struct bnxt_qplib_rcfw *rcfw,
 			__destroy_timedout_ah(rcfw,
 					      (struct creq_create_ah_resp *)
 					      qp_event);
-		spin_unlock_irqrestore(&hwq->lock, flags);
+		spin_unlock(&hwq->lock);
 	}
 	*num_wait += wait_cmds;
 	return rc;
@@ -734,12 +730,11 @@ static void bnxt_qplib_service_creq(struct tasklet_struct *t)
 	u32 type, budget = CREQ_ENTRY_POLL_BUDGET;
 	struct bnxt_qplib_hwq *hwq = &creq->hwq;
 	struct creq_base *creqe;
-	unsigned long flags;
 	u32 num_wakeup = 0;
 	u32 hw_polled = 0;
 
 	/* Service the CREQ until budget is over */
-	spin_lock_irqsave(&hwq->lock, flags);
+	spin_lock_bh(&hwq->lock);
 	while (budget > 0) {
 		creqe = bnxt_qplib_get_qe(hwq, hwq->cons, NULL);
 		if (!CREQ_CMP_VALID(creqe, creq->creq_db.dbinfo.flags))
@@ -782,7 +777,7 @@ static void bnxt_qplib_service_creq(struct tasklet_struct *t)
 	if (hw_polled)
 		bnxt_qplib_ring_nq_db(&creq->creq_db.dbinfo,
 				      rcfw->res->cctx, true);
-	spin_unlock_irqrestore(&hwq->lock, flags);
+	spin_unlock_bh(&hwq->lock);
 	if (num_wakeup)
 		wake_up_nr(&rcfw->cmdq.waitq, num_wakeup);
 }
-- 
2.5.5