ixgbe: Refactor MSI-X allocation mechanism

Our current MSI-X allocation mechanism does not support new hardware
at all.  It also isn't getting the actual number of supported MSI-X vectors
from the device.

This patch allows the number of MSI-X vectors to be specific to a device,
plus it gets the number of MSI-X vectors available from PCIe configuration
space.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index 82afc60..7bbafa3 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -2421,7 +2421,13 @@
 		ixgbe_set_num_queues(adapter);
 	} else {
 		adapter->flags |= IXGBE_FLAG_MSIX_ENABLED; /* Woot! */
-		adapter->num_msix_vectors = vectors;
+		/*
+		 * Adjust for only the vectors we'll use, which is minimum
+		 * of max_msix_q_vectors + NON_Q_VECTORS, or the number of
+		 * vectors we were allocated.
+		 */
+		adapter->num_msix_vectors = min(vectors,
+		                   adapter->max_msix_q_vectors + NON_Q_VECTORS);
 	}
 }
 
@@ -2746,6 +2752,7 @@
 	adapter->ring_feature[RING_F_RSS].indices = rss;
 	adapter->flags |= IXGBE_FLAG_RSS_ENABLED;
 	adapter->ring_feature[RING_F_DCB].indices = IXGBE_MAX_DCB_INDICES;
+	adapter->max_msix_q_vectors = MAX_MSIX_Q_VECTORS_82598;
 
 #ifdef CONFIG_IXGBE_DCB
 	/* Configure DCB traffic classes */