bnxt_en: Improve bnxt_ulp_stop()/bnxt_ulp_start() call sequence.

We call bnxt_ulp_stop() to notify the RDMA driver that some error or
imminent reset is about to happen.  After that we always call
some variants of bnxt_close().

In the next patch, we will integrate the recently added error
recovery with the RDMA driver.  In response to ulp_stop, the
RDMA driver may free MSIX vectors and that will also trigger
bnxt_close().  To avoid bnxt_close() from being called twice,
we set a new flag after ulp_stop is called.  If the RDMA driver
frees MSIX vectors while the new flag is set, we will not call
bnxt_close(), knowing that it will happen in due course.

With this change, we must make sure that the bnxt_close() call
after ulp_stop will reset IRQ.  Modify bnxt_reset_task()
accordingly if we call ulp_stop.
Signed-off-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -9927,12 +9927,15 @@ static void bnxt_reset_task(struct bnxt *bp, bool silent)
 	if (netif_running(bp->dev)) {
 		int rc;
 
-		if (!silent)
+		if (silent) {
+			bnxt_close_nic(bp, false, false);
+			bnxt_open_nic(bp, false, false);
+		} else {
 			bnxt_ulp_stop(bp);
-		bnxt_close_nic(bp, false, false);
-		rc = bnxt_open_nic(bp, false, false);
-		if (!silent && !rc)
-			bnxt_ulp_start(bp);
+			bnxt_close_nic(bp, true, false);
+			rc = bnxt_open_nic(bp, true, false);
+			bnxt_ulp_start(bp, rc);
+		}
 	}
 }
 
@@ -12005,10 +12008,9 @@ static pci_ers_result_t bnxt_io_slot_reset(struct pci_dev *pdev)
 		if (!err && netif_running(netdev))
 			err = bnxt_open(netdev);
 
-		if (!err) {
+		if (!err)
 			result = PCI_ERS_RESULT_RECOVERED;
-			bnxt_ulp_start(bp);
-		}
+		bnxt_ulp_start(bp, err);
 	}
 
 	if (result != PCI_ERS_RESULT_RECOVERED && netif_running(netdev))

drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c

@@ -182,7 +182,7 @@ static int bnxt_free_msix_vecs(struct bnxt_en_dev *edev, int ulp_id)
 
 	edev->ulp_tbl[ulp_id].msix_requested = 0;
 	edev->flags &= ~BNXT_EN_FLAG_MSIX_REQUESTED;
-	if (netif_running(dev)) {
+	if (netif_running(dev) && !(edev->flags & BNXT_EN_FLAG_ULP_STOPPED)) {
 		bnxt_close_nic(bp, true, false);
 		bnxt_open_nic(bp, true, false);
 	}
@@ -266,6 +266,7 @@ void bnxt_ulp_stop(struct bnxt *bp)
 	if (!edev)
 		return;
 
+	edev->flags |= BNXT_EN_FLAG_ULP_STOPPED;
 	for (i = 0; i < BNXT_MAX_ULP; i++) {
 		struct bnxt_ulp *ulp = &edev->ulp_tbl[i];
 
@@ -276,7 +277,7 @@ void bnxt_ulp_stop(struct bnxt *bp)
 	}
 }
 
-void bnxt_ulp_start(struct bnxt *bp)
+void bnxt_ulp_start(struct bnxt *bp, int err)
 {
 	struct bnxt_en_dev *edev = bp->edev;
 	struct bnxt_ulp_ops *ops;
@@ -285,6 +286,11 @@ void bnxt_ulp_start(struct bnxt *bp)
 	if (!edev)
 		return;
 
+	edev->flags &= ~BNXT_EN_FLAG_ULP_STOPPED;
+
+	if (err)
+		return;
+
 	for (i = 0; i < BNXT_MAX_ULP; i++) {
 		struct bnxt_ulp *ulp = &edev->ulp_tbl[i];
 

drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.h

@@ -64,6 +64,7 @@ struct bnxt_en_dev {
 	#define BNXT_EN_FLAG_ROCE_CAP		(BNXT_EN_FLAG_ROCEV1_CAP | \
 						 BNXT_EN_FLAG_ROCEV2_CAP)
 	#define BNXT_EN_FLAG_MSIX_REQUESTED	0x4
+	#define BNXT_EN_FLAG_ULP_STOPPED	0x8
 	const struct bnxt_en_ops	*en_ops;
 	struct bnxt_ulp			ulp_tbl[BNXT_MAX_ULP];
 };
@@ -92,7 +93,7 @@ int bnxt_get_ulp_msix_num(struct bnxt *bp);
 int bnxt_get_ulp_msix_base(struct bnxt *bp);
 int bnxt_get_ulp_stat_ctxs(struct bnxt *bp);
 void bnxt_ulp_stop(struct bnxt *bp);
-void bnxt_ulp_start(struct bnxt *bp);
+void bnxt_ulp_start(struct bnxt *bp, int err);
 void bnxt_ulp_sriov_cfg(struct bnxt *bp, int num_vfs);
 void bnxt_ulp_shutdown(struct bnxt *bp);
 void bnxt_ulp_irq_stop(struct bnxt *bp);