ixgbe: setup redirection table for multiple packet buffers

Setup RSS redirection table to be compatible with multiple packet
buffers. Currently, this works on 82599 devices because the RSS
redirection index is masked by the number of queues per packet
buffer.

This sets the cap on the RSS table to maxq.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ixgbe/ixgbe_main.c

@@ -2939,14 +2939,18 @@ static void ixgbe_setup_mrqc(struct ixgbe_adapter *adapter)
 	u32 rxcsum;
 	int i, j;
 	u8 tcs = netdev_get_num_tc(adapter->netdev);
+	int maxq = adapter->ring_feature[RING_F_RSS].indices;
+
+	if (tcs)
+		maxq = min(maxq, adapter->num_tx_queues / tcs);
 
 	/* Fill out hash function seeds */
 	for (i = 0; i < 10; i++)
 		IXGBE_WRITE_REG(hw, IXGBE_RSSRK(i), seed[i]);
 
 	/* Fill out redirection table */
 	for (i = 0, j = 0; i < 128; i++, j++) {
-		if (j == adapter->ring_feature[RING_F_RSS].indices)
+		if (j == maxq)
 			j = 0;
 		/* reta = 4-byte sliding window of
 		 * 0x00..(indices-1)(indices-1)00..etc. */