[PATCH net-next 15/16] bnxt_en: Reserve completion rings and MSIX for bnxt_re RDMA driver.

[Michael Chan <michael.chan@broadcom.com>]

Add additional logic to reserve completion rings for the bnxt_re driver
when it requests MSIX vectors.  The function bnxt_cp_rings_in_use()
will return the total number of completion rings used by both drivers
that need to be reserved.  If the network interface in up, we will
close and open the NIC to reserve the new set of completion rings and
re-initialize the vectors.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c     | 39 ++++++++++++++++++++-------
 drivers/net/ethernet/broadcom/bnxt/bnxt.h     |  3 +++
 drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c | 39 ++++++++++++++++++++++-----
 3 files changed, 65 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index a6237dd..6a1d18f 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -4756,7 +4756,7 @@ static int bnxt_cp_rings_in_use(struct bnxt *bp)
 static bool bnxt_need_reserve_rings(struct bnxt *bp)
 {
 	struct bnxt_hw_resc *hw_resc = &bp->hw_resc;
-	int cp = bp->cp_nr_rings;
+	int cp = bnxt_cp_rings_in_use(bp);
 	int rx = bp->rx_nr_rings;
 	int vnic = 1, grp = rx;
 
@@ -4783,9 +4783,9 @@ static int bnxt_trim_rings(struct bnxt *bp, int *rx, int *tx, int max,
 static int __bnxt_reserve_rings(struct bnxt *bp)
 {
 	struct bnxt_hw_resc *hw_resc = &bp->hw_resc;
+	int cp = bnxt_cp_rings_in_use(bp);
 	int tx = bp->tx_nr_rings;
 	int rx = bp->rx_nr_rings;
-	int cp = bp->cp_nr_rings;
 	int grp, rx_rings, rc;
 	bool sh = false;
 	int vnic = 1;
@@ -5908,7 +5908,7 @@ void bnxt_set_max_func_cp_rings(struct bnxt *bp, unsigned int max)
 	bp->hw_resc.max_cp_rings = max;
 }
 
-static unsigned int bnxt_get_max_func_irqs(struct bnxt *bp)
+unsigned int bnxt_get_max_func_irqs(struct bnxt *bp)
 {
 	struct bnxt_hw_resc *hw_resc = &bp->hw_resc;
 
@@ -5920,6 +5920,26 @@ void bnxt_set_max_func_irqs(struct bnxt *bp, unsigned int max_irqs)
 	bp->hw_resc.max_irqs = max_irqs;
 }
 
+int bnxt_get_avail_msix(struct bnxt *bp, int num)
+{
+	int max_cp = bnxt_get_max_func_cp_rings(bp);
+	int max_irq = bnxt_get_max_func_irqs(bp);
+	int total_req = bp->cp_nr_rings + num;
+	int max_idx, avail_msix;
+
+	max_idx = min_t(int, bp->total_irqs, max_cp);
+	avail_msix = max_idx - bp->cp_nr_rings;
+	if (!(bp->flags & BNXT_FLAG_NEW_RM) || avail_msix >= num)
+		return avail_msix;
+
+	if (max_irq < total_req) {
+		num = max_irq - bp->cp_nr_rings;
+		if (num <= 0)
+			return 0;
+	}
+	return num;
+}
+
 static int bnxt_get_num_msix(struct bnxt *bp)
 {
 	if (!(bp->flags & BNXT_FLAG_NEW_RM))
@@ -5930,7 +5950,7 @@ static int bnxt_get_num_msix(struct bnxt *bp)
 
 static int bnxt_init_msix(struct bnxt *bp)
 {
-	int i, total_vecs, max, rc = 0, min = 1;
+	int i, total_vecs, max, rc = 0, min = 1, ulp_msix;
 	struct msix_entry *msix_ent;
 
 	total_vecs = bnxt_get_num_msix(bp);
@@ -5951,7 +5971,8 @@ static int bnxt_init_msix(struct bnxt *bp)
 		min = 2;
 
 	total_vecs = pci_enable_msix_range(bp->pdev, msix_ent, min, total_vecs);
-	if (total_vecs < 0) {
+	ulp_msix = bnxt_get_ulp_msix_num(bp);
+	if (total_vecs < 0 || total_vecs < ulp_msix) {
 		rc = -ENODEV;
 		goto msix_setup_exit;
 	}
@@ -5964,7 +5985,7 @@ static int bnxt_init_msix(struct bnxt *bp)
 		bp->total_irqs = total_vecs;
 		/* Trim rings based upon num of vectors allocated */
 		rc = bnxt_trim_rings(bp, &bp->rx_nr_rings, &bp->tx_nr_rings,
-				     total_vecs, min == 1);
+				     total_vecs - ulp_msix, min == 1);
 		if (rc)
 			goto msix_setup_exit;
 
@@ -6028,9 +6049,8 @@ static void bnxt_clear_int_mode(struct bnxt *bp)
 	bp->flags &= ~BNXT_FLAG_USING_MSIX;
 }
 
-static int bnxt_reserve_rings(struct bnxt *bp)
+int bnxt_reserve_rings(struct bnxt *bp)
 {
-	int orig_cp = bp->hw_resc.resv_cp_rings;
 	int tcs = netdev_get_num_tc(bp->dev);
 	int rc;
 
@@ -6042,7 +6062,8 @@ static int bnxt_reserve_rings(struct bnxt *bp)
 		netdev_err(bp->dev, "ring reservation failure rc: %d\n", rc);
 		return rc;
 	}
-	if ((bp->flags & BNXT_FLAG_NEW_RM) && bp->cp_nr_rings > orig_cp) {
+	if ((bp->flags & BNXT_FLAG_NEW_RM) &&
+	    (bnxt_get_num_msix(bp) != bp->total_irqs)) {
 		bnxt_clear_int_mode(bp);
 		rc = bnxt_init_int_mode(bp);
 		if (rc)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index e0cd0cb..3d55d3b 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -1454,7 +1454,10 @@ int bnxt_hwrm_func_rgtr_async_events(struct bnxt *bp, unsigned long *bmap,
 void bnxt_set_max_func_stat_ctxs(struct bnxt *bp, unsigned int max);
 unsigned int bnxt_get_max_func_cp_rings(struct bnxt *bp);
 void bnxt_set_max_func_cp_rings(struct bnxt *bp, unsigned int max);
+unsigned int bnxt_get_max_func_irqs(struct bnxt *bp);
 void bnxt_set_max_func_irqs(struct bnxt *bp, unsigned int max);
+int bnxt_get_avail_msix(struct bnxt *bp, int num);
+int bnxt_reserve_rings(struct bnxt *bp);
 void bnxt_tx_disable(struct bnxt *bp);
 void bnxt_tx_enable(struct bnxt *bp);
 int bnxt_hwrm_set_pause(struct bnxt *);
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c
index 62636cd..2583923 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c
@@ -108,6 +108,7 @@ static int bnxt_req_msix_vecs(struct bnxt_en_dev *edev, int ulp_id,
 	struct bnxt *bp = netdev_priv(dev);
 	int max_idx, max_cp_rings;
 	int avail_msix, i, idx;
+	int rc = 0;
 
 	ASSERT_RTNL();
 	if (ulp_id != BNXT_ROCE_ULP)
@@ -120,26 +121,46 @@ static int bnxt_req_msix_vecs(struct bnxt_en_dev *edev, int ulp_id,
 		return -EAGAIN;
 
 	max_cp_rings = bnxt_get_max_func_cp_rings(bp);
-	max_idx = min_t(int, bp->total_irqs, max_cp_rings);
-	avail_msix = max_idx - bp->cp_nr_rings;
+	avail_msix = bnxt_get_avail_msix(bp, num_msix);
 	if (!avail_msix)
 		return -ENOMEM;
 	if (avail_msix > num_msix)
 		avail_msix = num_msix;
 
-	if (bp->flags & BNXT_FLAG_NEW_RM)
+	if (bp->flags & BNXT_FLAG_NEW_RM) {
 		idx = bp->cp_nr_rings;
-	else
+	} else {
+		max_idx = min_t(int, bp->total_irqs, max_cp_rings);
 		idx = max_idx - avail_msix;
+	}
 	edev->ulp_tbl[ulp_id].msix_base = idx;
+	edev->ulp_tbl[ulp_id].msix_requested = avail_msix;
+	if (bp->total_irqs < (idx + avail_msix)) {
+		if (netif_running(dev)) {
+			bnxt_close_nic(bp, true, false);
+			rc = bnxt_open_nic(bp, true, false);
+		} else {
+			rc = bnxt_reserve_rings(bp);
+		}
+	}
+	if (rc) {
+		edev->ulp_tbl[ulp_id].msix_requested = 0;
+		return -EAGAIN;
+	}
+
+	if (bp->flags & BNXT_FLAG_NEW_RM) {
+		struct bnxt_hw_resc *hw_resc = &bp->hw_resc;
+
+		avail_msix = hw_resc->resv_cp_rings - bp->cp_nr_rings;
+		edev->ulp_tbl[ulp_id].msix_requested = avail_msix;
+	}
 	for (i = 0; i < avail_msix; i++) {
 		ent[i].vector = bp->irq_tbl[idx + i].vector;
 		ent[i].ring_idx = idx + i;
 		ent[i].db_offset = (idx + i) * 0x80;
 	}
-	bnxt_set_max_func_irqs(bp, max_idx - avail_msix);
+	bnxt_set_max_func_irqs(bp, bnxt_get_max_func_irqs(bp) - avail_msix);
 	bnxt_set_max_func_cp_rings(bp, max_cp_rings - avail_msix);
-	edev->ulp_tbl[ulp_id].msix_requested = avail_msix;
 	return avail_msix;
 }
 
@@ -157,7 +178,11 @@ static int bnxt_free_msix_vecs(struct bnxt_en_dev *edev, int ulp_id)
 	msix_requested = edev->ulp_tbl[ulp_id].msix_requested;
 	bnxt_set_max_func_cp_rings(bp, max_cp_rings + msix_requested);
 	edev->ulp_tbl[ulp_id].msix_requested = 0;
-	bnxt_set_max_func_irqs(bp, bp->total_irqs);
+	bnxt_set_max_func_irqs(bp, bnxt_get_max_func_irqs(bp) + msix_requested);
+	if (netif_running(dev)) {
+		bnxt_close_nic(bp, true, false);
+		bnxt_open_nic(bp, true, false);
+	}
 	return 0;
 }
 
-- 
1.8.3.1