bnxt_en: Keep track of reserved IRQs.

The new 57500 chips use 1 NQ per MSIX vector, whereas legacy chips use
1 CP ring per MSIX vector.  To better unify this, add a resv_irqs
field to struct bnxt_hw_resc.  On legacy chips, we initialize resv_irqs
with resv_cp_rings.  On new chips, we initialize it with the allocated
MSIX resources.
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

@@ -5162,6 +5162,7 @@ static int bnxt_hwrm_get_rings(struct bnxt *bp)
 		cp = le16_to_cpu(resp->alloc_cmpl_rings);
 		stats = le16_to_cpu(resp->alloc_stat_ctx);
 		cp = min_t(u16, cp, stats);
+		hw_resc->resv_irqs = cp;
 		if (bp->flags & BNXT_FLAG_CHIP_P5) {
 			int rx = hw_resc->resv_rx_rings;
 			int tx = hw_resc->resv_tx_rings;
@@ -5175,7 +5176,7 @@ static int bnxt_hwrm_get_rings(struct bnxt *bp)
 				hw_resc->resv_rx_rings = rx;
 				hw_resc->resv_tx_rings = tx;
 			}
-			cp = le16_to_cpu(resp->alloc_msix);
+			hw_resc->resv_irqs = le16_to_cpu(resp->alloc_msix);
 			hw_resc->resv_hw_ring_grps = rx;
 		}
 		hw_resc->resv_cp_rings = cp;
@@ -7055,7 +7056,9 @@ int bnxt_get_avail_msix(struct bnxt *bp, int num)
 	int total_req = bp->cp_nr_rings + num;
 	int max_idx, avail_msix;
 
-	max_idx = min_t(int, bp->total_irqs, max_cp);
+	max_idx = bp->total_irqs;
+	if (!(bp->flags & BNXT_FLAG_CHIP_P5))
+		max_idx = min_t(int, bp->total_irqs, max_cp);
 	avail_msix = max_idx - bp->cp_nr_rings;
 	if (!BNXT_NEW_RM(bp) || avail_msix >= num)
 		return avail_msix;
@@ -7801,6 +7804,7 @@ static int bnxt_hwrm_if_change(struct bnxt *bp, bool up)
 
 		rc = bnxt_hwrm_func_resc_qcaps(bp, true);
 		hw_resc->resv_cp_rings = 0;
+		hw_resc->resv_irqs = 0;
 		hw_resc->resv_tx_rings = 0;
 		hw_resc->resv_rx_rings = 0;
 		hw_resc->resv_hw_ring_grps = 0;

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

@@ -928,6 +928,7 @@ struct bnxt_hw_resc {
 	u16	min_stat_ctxs;
 	u16	max_stat_ctxs;
 	u16	max_irqs;
+	u16	resv_irqs;
 };
 
 #if defined(CONFIG_BNXT_SRIOV)

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

@@ -168,7 +168,7 @@ static int bnxt_req_msix_vecs(struct bnxt_en_dev *edev, int ulp_id,
 	if (BNXT_NEW_RM(bp)) {
 		struct bnxt_hw_resc *hw_resc = &bp->hw_resc;
 
-		avail_msix = hw_resc->resv_cp_rings - bp->cp_nr_rings;
+		avail_msix = hw_resc->resv_irqs - bp->cp_nr_rings;
 		edev->ulp_tbl[ulp_id].msix_requested = avail_msix;
 	}
 	bnxt_fill_msix_vecs(bp, ent);