ice: refactor VF control VSI interrupt handling

All VF control VSIs share the same interrupt vector. Currently, a helper
function dedicated for that directly sets ice_vsi::base_vector.

Use helper that returns pointer to first found VF control VSI instead.
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Piotr Raczynski <piotr.raczynski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

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

@@ -1473,36 +1473,6 @@ ice_get_res(struct ice_pf *pf, struct ice_res_tracker *res, u16 needed, u16 id)
 	return ice_search_res(res, needed, id);
 }
 
-/**
- * ice_get_vf_ctrl_res - Get VF control VSI resource
- * @pf: pointer to the PF structure
- * @vsi: the VSI to allocate a resource for
- *
- * Look up whether another VF has already allocated the control VSI resource.
- * If so, re-use this resource so that we share it among all VFs.
- *
- * Otherwise, allocate the resource and return it.
- */
-static int ice_get_vf_ctrl_res(struct ice_pf *pf, struct ice_vsi *vsi)
-{
-	struct ice_vf *vf;
-	unsigned int bkt;
-	int base;
-
-	rcu_read_lock();
-	ice_for_each_vf_rcu(pf, bkt, vf) {
-		if (vf != vsi->vf && vf->ctrl_vsi_idx != ICE_NO_VSI) {
-			base = pf->vsi[vf->ctrl_vsi_idx]->base_vector;
-			rcu_read_unlock();
-			return base;
-		}
-	}
-	rcu_read_unlock();
-
-	return ice_get_res(pf, pf->irq_tracker, vsi->num_q_vectors,
-			   ICE_RES_VF_CTRL_VEC_ID);
-}
-
 /**
  * ice_vsi_setup_vector_base - Set up the base vector for the given VSI
  * @vsi: ptr to the VSI
@@ -1516,8 +1486,8 @@ static int ice_get_vf_ctrl_res(struct ice_pf *pf, struct ice_vsi *vsi)
 static int ice_vsi_setup_vector_base(struct ice_vsi *vsi)
 {
 	struct ice_pf *pf = vsi->back;
+	u16 num_q_vectors, id;
 	struct device *dev;
-	u16 num_q_vectors;
 	int base;
 
 	dev = ice_pf_to_dev(pf);
@@ -1536,12 +1506,20 @@ static int ice_vsi_setup_vector_base(struct ice_vsi *vsi)
 	num_q_vectors = vsi->num_q_vectors;
 	/* reserve slots from OS requested IRQs */
 	if (vsi->type == ICE_VSI_CTRL && vsi->vf) {
-		base = ice_get_vf_ctrl_res(pf, vsi);
+		struct ice_vsi *ctrl_vsi = ice_get_vf_ctrl_vsi(pf, vsi);
+
+		/* reuse VF control VSI interrupt vector */
+		if (ctrl_vsi) {
+			vsi->base_vector = ctrl_vsi->base_vector;
+			return 0;
+		}
+
+		id = ICE_RES_VF_CTRL_VEC_ID;
 	} else {
-		base = ice_get_res(pf, pf->irq_tracker, num_q_vectors,
-				   vsi->idx);
+		id = vsi->idx;
 	}
 
+	base = ice_get_res(pf, pf->irq_tracker, num_q_vectors, id);
 	if (base < 0) {
 		dev_err(dev, "%d MSI-X interrupts available. %s %d failed to get %d MSI-X vectors\n",
 			ice_get_free_res_count(pf->irq_tracker),
@@ -2611,37 +2589,6 @@ static void ice_set_agg_vsi(struct ice_vsi *vsi)
 		vsi->agg_node->num_vsis);
 }
 
-/**
- * ice_free_vf_ctrl_res - Free the VF control VSI resource
- * @pf: pointer to PF structure
- * @vsi: the VSI to free resources for
- *
- * Check if the VF control VSI resource is still in use. If no VF is using it
- * any more, release the VSI resource. Otherwise, leave it to be cleaned up
- * once no other VF uses it.
- */
-static void ice_free_vf_ctrl_res(struct ice_pf *pf,  struct ice_vsi *vsi)
-{
-	struct ice_vf *vf;
-	unsigned int bkt;
-
-	rcu_read_lock();
-	ice_for_each_vf_rcu(pf, bkt, vf) {
-		if (vf != vsi->vf && vf->ctrl_vsi_idx != ICE_NO_VSI) {
-			rcu_read_unlock();
-			return;
-		}
-	}
-	rcu_read_unlock();
-
-	/* No other VFs left that have control VSI. It is now safe to reclaim
-	 * SW interrupts back to the common pool.
-	 */
-	ice_free_res(pf->irq_tracker, vsi->base_vector,
-		     ICE_RES_VF_CTRL_VEC_ID);
-	pf->num_avail_sw_msix += vsi->num_q_vectors;
-}
-
 static int ice_vsi_cfg_tc_lan(struct ice_pf *pf, struct ice_vsi *vsi)
 {
 	u16 max_txqs[ICE_MAX_TRAFFIC_CLASS] = { 0 };
@@ -2916,7 +2863,13 @@ void ice_vsi_decfg(struct ice_vsi *vsi)
 	 * cleared in the same manner.
 	 */
 	if (vsi->type == ICE_VSI_CTRL && vsi->vf) {
-		ice_free_vf_ctrl_res(pf, vsi);
+		struct ice_vsi *ctrl_vsi = ice_get_vf_ctrl_vsi(pf, vsi);
+
+		if (!ctrl_vsi) {
+			ice_free_res(pf->irq_tracker, vsi->base_vector,
+				     ICE_RES_VF_CTRL_VEC_ID);
+			pf->num_avail_sw_msix += vsi->num_q_vectors;
+		}
 	} else if (vsi->type != ICE_VSI_VF) {
 		/* reclaim SW interrupts back to the common pool */
 		ice_free_res(pf->irq_tracker, vsi->base_vector, vsi->idx);

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

@@ -1310,3 +1310,35 @@ void ice_vf_set_initialized(struct ice_vf *vf)
 	set_bit(ICE_VF_STATE_INIT, vf->vf_states);
 	memset(&vf->vlan_v2_caps, 0, sizeof(vf->vlan_v2_caps));
 }
+
+/**
+ * ice_get_vf_ctrl_vsi - Get first VF control VSI pointer
+ * @pf: the PF private structure
+ * @vsi: pointer to the VSI
+ *
+ * Return first found VF control VSI other than the vsi
+ * passed by parameter. This function is used to determine
+ * whether new resources have to be allocated for control VSI
+ * or they can be shared with existing one.
+ *
+ * Return found VF control VSI pointer other itself. Return
+ * NULL Otherwise.
+ *
+ */
+struct ice_vsi *ice_get_vf_ctrl_vsi(struct ice_pf *pf, struct ice_vsi *vsi)
+{
+	struct ice_vsi *ctrl_vsi = NULL;
+	struct ice_vf *vf;
+	unsigned int bkt;
+
+	rcu_read_lock();
+	ice_for_each_vf_rcu(pf, bkt, vf) {
+		if (vf != vsi->vf && vf->ctrl_vsi_idx != ICE_NO_VSI) {
+			ctrl_vsi = pf->vsi[vf->ctrl_vsi_idx];
+			break;
+		}
+	}
+
+	rcu_read_unlock();
+	return ctrl_vsi;
+}

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

@@ -226,6 +226,7 @@ int
 ice_vf_clear_vsi_promisc(struct ice_vf *vf, struct ice_vsi *vsi, u8 promisc_m);
 int ice_reset_vf(struct ice_vf *vf, u32 flags);
 void ice_reset_all_vfs(struct ice_pf *pf);
+struct ice_vsi *ice_get_vf_ctrl_vsi(struct ice_pf *pf, struct ice_vsi *vsi);
 #else /* CONFIG_PCI_IOV */
 static inline struct ice_vf *ice_get_vf_by_id(struct ice_pf *pf, u16 vf_id)
 {
@@ -290,6 +291,12 @@ static inline int ice_reset_vf(struct ice_vf *vf, u32 flags)
 static inline void ice_reset_all_vfs(struct ice_pf *pf)
 {
 }
+
+static inline struct ice_vsi *
+ice_get_vf_ctrl_vsi(struct ice_pf *pf, struct ice_vsi *vsi)
+{
+	return NULL;
+}
 #endif /* !CONFIG_PCI_IOV */
 
 #endif /* _ICE_VF_LIB_H_ */