i40e: fix configuration of RSS table with DCB

There exists a bug in the driver where the calculation of the
RSS size was not taking into account the number of traffic classes
enabled. This patch factors in the traffic classes both in
the initial configuration of the table as well as reconfiguration.

Change-ID: I34dcd345ce52faf1d6b9614bea28d450cfd5f621
Signed-off-by: Harshitha Ramamurthy <[email protected]>
Tested-by: Andrew Bowers <[email protected]>
Signed-off-by: Jeff Kirsher <[email protected]>

Author: hramamu1

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -8577,9 +8577,12 @@ static int i40e_pf_config_rss(struct i40e_pf *pf)
 	i40e_write_rx_ctl(hw, I40E_PFQF_CTL_0, reg_val);
 
 	/* Determine the RSS size of the VSI */
-	if (!vsi->rss_size)
-		vsi->rss_size = min_t(int, pf->alloc_rss_size,
-				      vsi->num_queue_pairs);
+	if (!vsi->rss_size) {
+		u16 qcount;
+
+		qcount = vsi->num_queue_pairs / vsi->tc_config.numtc;
+		vsi->rss_size = min_t(int, pf->alloc_rss_size, qcount);
+	}
 	if (!vsi->rss_size)
 		return -EINVAL;
 
@@ -8625,6 +8628,8 @@ int i40e_reconfig_rss_queues(struct i40e_pf *pf, int queue_count)
 	new_rss_size = min_t(int, queue_count, pf->rss_size_max);
 
 	if (queue_count != vsi->num_queue_pairs) {
+		u16 qcount;
+
 		vsi->req_queue_pairs = queue_count;
 		i40e_prep_for_reset(pf);
 
@@ -8642,8 +8647,8 @@ int i40e_reconfig_rss_queues(struct i40e_pf *pf, int queue_count)
 		}
 
 		/* Reset vsi->rss_size, as number of enabled queues changed */
-		vsi->rss_size = min_t(int, pf->alloc_rss_size,
-				      vsi->num_queue_pairs);
+		qcount = vsi->num_queue_pairs / vsi->tc_config.numtc;
+		vsi->rss_size = min_t(int, pf->alloc_rss_size, qcount);
 
 		i40e_pf_config_rss(pf);
 	}