ice: stop hard coding the ICE_VSI_CTRL location

When allocating the ICE_VSI_CTRL, the allocated struct ice_vsi pointer is
stored into the PF's pf->vsi array at a fixed location. This was
historically done on the basis that it could provide an O(1) lookup for the
special control VSI.

Since we store the ctrl_vsi_idx, we already have O(1) lookup regardless of
where in the array we store this VSI.

Simplify the logic in ice_vsi_alloc by using the same method of storing the
control VSI as other types of VSIs.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Tested-by: Gurucharan G <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

@@ -479,10 +479,7 @@ int ice_vsi_free(struct ice_vsi *vsi)
 	/* updates the PF for this cleared VSI */
 
 	pf->vsi[vsi->idx] = NULL;
-	if (vsi->idx < pf->next_vsi && vsi->type != ICE_VSI_CTRL)
-		pf->next_vsi = vsi->idx;
-	if (vsi->idx < pf->next_vsi && vsi->type == ICE_VSI_CTRL && vsi->vf)
-		pf->next_vsi = vsi->idx;
+	pf->next_vsi = vsi->idx;
 
 	ice_vsi_free_stats(vsi);
 	ice_vsi_free_arrays(vsi);
@@ -690,23 +687,22 @@ ice_vsi_alloc(struct ice_pf *pf, struct ice_port_info *pi,
 	vsi->vf = vf;
 	set_bit(ICE_VSI_DOWN, vsi->state);
 
-	if (vsi->type == ICE_VSI_CTRL && !vf) {
-		/* Use the last VSI slot as the index for PF control VSI */
-		vsi->idx = pf->num_alloc_vsi - 1;
-		pf->ctrl_vsi_idx = vsi->idx;
-		pf->vsi[vsi->idx] = vsi;
-	} else {
-		/* fill slot and make note of the index */
-		vsi->idx = pf->next_vsi;
-		pf->vsi[pf->next_vsi] = vsi;
+	/* fill slot and make note of the index */
+	vsi->idx = pf->next_vsi;
+	pf->vsi[pf->next_vsi] = vsi;
 
-		/* prepare pf->next_vsi for next use */
-		pf->next_vsi = ice_get_free_slot(pf->vsi, pf->num_alloc_vsi,
-						 pf->next_vsi);
-	}
+	/* prepare pf->next_vsi for next use */
+	pf->next_vsi = ice_get_free_slot(pf->vsi, pf->num_alloc_vsi,
+					 pf->next_vsi);
 
-	if (vsi->type == ICE_VSI_CTRL && vf)
-		vf->ctrl_vsi_idx = vsi->idx;
+	if (vsi->type == ICE_VSI_CTRL) {
+		if (vf) {
+			vf->ctrl_vsi_idx = vsi->idx;
+		} else {
+			WARN_ON(pf->ctrl_vsi_idx != ICE_NO_VSI);
+			pf->ctrl_vsi_idx = vsi->idx;
+		}
+	}
 
 unlock_pf:
 	mutex_unlock(&pf->sw_mutex);