bnx2: Call pci_enable_msix() with actual number of vectors.

Based on original patch by Breno Leitão <leitao@linux.vnet.ibm.com>.

Allocate the actual number of vectors and make use of fewer vectors
if pci_enable_msix() returns > 0.  We must allocate one additional
vector for the cnic driver.

Cc: Breno Leitão <leitao@linux.vnet.ibm.com>
Reviewed-by: Benjamin Li <benli@broadcom.com>
Reviewed-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bnx2.c

@@ -864,7 +864,7 @@ bnx2_alloc_mem(struct bnx2 *bp)
 	bnapi->hw_rx_cons_ptr =
 		&bnapi->status_blk.msi->status_rx_quick_consumer_index0;
 	if (bp->flags & BNX2_FLAG_MSIX_CAP) {
-		for (i = 1; i < BNX2_MAX_MSIX_VEC; i++) {
+		for (i = 1; i < bp->irq_nvecs; i++) {
 			struct status_block_msix *sblk;
 
 			bnapi = &bp->bnx2_napi[i];
@@ -6152,7 +6152,7 @@ bnx2_free_irq(struct bnx2 *bp)
 static void
 bnx2_enable_msix(struct bnx2 *bp, int msix_vecs)
 {
-	int i, rc;
+	int i, total_vecs, rc;
 	struct msix_entry msix_ent[BNX2_MAX_MSIX_VEC];
 	struct net_device *dev = bp->dev;
 	const int len = sizeof(bp->irq_tbl[0].name);
@@ -6171,13 +6171,29 @@ bnx2_enable_msix(struct bnx2 *bp, int msix_vecs)
 		msix_ent[i].vector = 0;
 	}
 
-	rc = pci_enable_msix(bp->pdev, msix_ent, BNX2_MAX_MSIX_VEC);
+	total_vecs = msix_vecs;
+#ifdef BCM_CNIC
+	total_vecs++;
+#endif
+	rc = -ENOSPC;
+	while (total_vecs >= BNX2_MIN_MSIX_VEC) {
+		rc = pci_enable_msix(bp->pdev, msix_ent, total_vecs);
+		if (rc <= 0)
+			break;
+		if (rc > 0)
+			total_vecs = rc;
+	}
+
 	if (rc != 0)
 		return;
 
+	msix_vecs = total_vecs;
+#ifdef BCM_CNIC
+	msix_vecs--;
+#endif
 	bp->irq_nvecs = msix_vecs;
 	bp->flags |= BNX2_FLAG_USING_MSIX | BNX2_FLAG_ONE_SHOT_MSI;
-	for (i = 0; i < BNX2_MAX_MSIX_VEC; i++) {
+	for (i = 0; i < total_vecs; i++) {
 		bp->irq_tbl[i].vector = msix_ent[i].vector;
 		snprintf(bp->irq_tbl[i].name, len, "%s-%d", dev->name, i);
 		bp->irq_tbl[i].handler = bnx2_msi_1shot;

drivers/net/bnx2.h

@@ -6637,9 +6637,12 @@ struct flash_spec {
 
 #define BNX2_MAX_MSIX_HW_VEC	9
 #define BNX2_MAX_MSIX_VEC	9
-#define BNX2_BASE_VEC		0
-#define BNX2_TX_VEC		1
-#define BNX2_TX_INT_NUM	(BNX2_TX_VEC << BNX2_PCICFG_INT_ACK_CMD_INT_NUM_SHIFT)
+#ifdef BCM_CNIC
+#define BNX2_MIN_MSIX_VEC	2
+#else
+#define BNX2_MIN_MSIX_VEC	1
+#endif
+
 
 struct bnx2_irq {
 	irq_handler_t	handler;