ice: Fix interrupt moderation settings getting cleared

Adaptive-rx and Adaptive-tx are interrupt moderation settings
that can be enabled/disabled using ethtool:
ethtool -C ethX adaptive-rx on/off adaptive-tx on/off

Unfortunately those settings are getting cleared after
changing number of queues, or in ethtool world 'channels':
ethtool -L ethX rx 1 tx 1

Clearing was happening due to introduction of bit fields
in ice_ring_container struct. This way only itr_setting
bits were rebuilt during ice_vsi_rebuild_set_coalesce().

Introduce an anonymous struct of bitfields and create a
union to refer to them as a single variable.
This way variable can be easily saved and restored.

Fixes: 61dc79ce ("ice: Restore interrupt throttle settings after VSI rebuild")
Signed-off-by: Michal Wilczynski <michal.wilczynski@intel.com>
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/ice/ice_lib.c

@@ -3043,8 +3043,8 @@ ice_vsi_rebuild_get_coalesce(struct ice_vsi *vsi,
 	ice_for_each_q_vector(vsi, i) {
 		struct ice_q_vector *q_vector = vsi->q_vectors[i];
 
-		coalesce[i].itr_tx = q_vector->tx.itr_setting;
-		coalesce[i].itr_rx = q_vector->rx.itr_setting;
+		coalesce[i].itr_tx = q_vector->tx.itr_settings;
+		coalesce[i].itr_rx = q_vector->rx.itr_settings;
 		coalesce[i].intrl = q_vector->intrl;
 
 		if (i < vsi->num_txq)
@@ -3100,21 +3100,21 @@ ice_vsi_rebuild_set_coalesce(struct ice_vsi *vsi,
 		 */
 		if (i < vsi->alloc_rxq && coalesce[i].rx_valid) {
 			rc = &vsi->q_vectors[i]->rx;
-			rc->itr_setting = coalesce[i].itr_rx;
+			rc->itr_settings = coalesce[i].itr_rx;
 			ice_write_itr(rc, rc->itr_setting);
 		} else if (i < vsi->alloc_rxq) {
 			rc = &vsi->q_vectors[i]->rx;
-			rc->itr_setting = coalesce[0].itr_rx;
+			rc->itr_settings = coalesce[0].itr_rx;
 			ice_write_itr(rc, rc->itr_setting);
 		}
 
 		if (i < vsi->alloc_txq && coalesce[i].tx_valid) {
 			rc = &vsi->q_vectors[i]->tx;
-			rc->itr_setting = coalesce[i].itr_tx;
+			rc->itr_settings = coalesce[i].itr_tx;
 			ice_write_itr(rc, rc->itr_setting);
 		} else if (i < vsi->alloc_txq) {
 			rc = &vsi->q_vectors[i]->tx;
-			rc->itr_setting = coalesce[0].itr_tx;
+			rc->itr_settings = coalesce[0].itr_tx;
 			ice_write_itr(rc, rc->itr_setting);
 		}
 
@@ -3128,12 +3128,12 @@ ice_vsi_rebuild_set_coalesce(struct ice_vsi *vsi,
 	for (; i < vsi->num_q_vectors; i++) {
 		/* transmit */
 		rc = &vsi->q_vectors[i]->tx;
-		rc->itr_setting = coalesce[0].itr_tx;
+		rc->itr_settings = coalesce[0].itr_tx;
 		ice_write_itr(rc, rc->itr_setting);
 
 		/* receive */
 		rc = &vsi->q_vectors[i]->rx;
-		rc->itr_setting = coalesce[0].itr_rx;
+		rc->itr_settings = coalesce[0].itr_rx;
 		ice_write_itr(rc, rc->itr_setting);
 
 		vsi->q_vectors[i]->intrl = coalesce[0].intrl;

drivers/net/ethernet/intel/ice/ice_txrx.h

@@ -384,9 +384,14 @@ struct ice_ring_container {
 	/* this matches the maximum number of ITR bits, but in usec
 	 * values, so it is shifted left one bit (bit zero is ignored)
 	 */
+	union {
+		struct {
 			u16 itr_setting:13;
 			u16 itr_reserved:2;
 			u16 itr_mode:1;
+		};
+		u16 itr_settings;
+	};
 	enum ice_container_type type;
 };