i40e: reinit flow for the main VSI

This patch is the first in a 3 series patchset to implement
dynamically changing the queue count for the main VSI.

This patch starts by adding a reinit flow. This flow is designed
to be able to change just the queue count and not the number of
interrupt vectors that the device originally came up with.

Change-Id: I0634aaebf7dc4dd6c66af8f9dbbef89d7beac438
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

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

@@ -48,7 +48,7 @@ static void i40e_vsi_reinit_locked(struct i40e_vsi *vsi);
 static void i40e_handle_reset_warning(struct i40e_pf *pf);
 static int i40e_add_vsi(struct i40e_vsi *vsi);
 static int i40e_add_veb(struct i40e_veb *veb, struct i40e_vsi *vsi);
-static int i40e_setup_pf_switch(struct i40e_pf *pf);
+static int i40e_setup_pf_switch(struct i40e_pf *pf, bool reinit);
 static int i40e_setup_misc_vector(struct i40e_pf *pf);
 static void i40e_determine_queue_usage(struct i40e_pf *pf);
 static int i40e_setup_pf_filter_control(struct i40e_pf *pf);
@@ -354,6 +354,9 @@ static struct rtnl_link_stats64 *i40e_get_netdev_stats_struct(
 	struct rtnl_link_stats64 *vsi_stats = i40e_get_vsi_stats_struct(vsi);
 	int i;
 
+	if (test_bit(__I40E_DOWN, &vsi->state))
+		return stats;
+
 	rcu_read_lock();
 	for (i = 0; i < vsi->num_queue_pairs; i++) {
 		struct i40e_ring *tx_ring, *rx_ring;
@@ -4767,8 +4770,9 @@ static int i40e_prep_for_reset(struct i40e_pf *pf)
 /**
  * i40e_reset_and_rebuild - reset and rebuid using a saved config
  * @pf: board private structure
+ * @reinit: if the Main VSI needs to re-initialized.
  **/
-static void i40e_reset_and_rebuild(struct i40e_pf *pf)
+static void i40e_reset_and_rebuild(struct i40e_pf *pf, bool reinit)
 {
 	struct i40e_driver_version dv;
 	struct i40e_hw *hw = &pf->hw;
@@ -4816,7 +4820,7 @@ static void i40e_reset_and_rebuild(struct i40e_pf *pf)
 	}
 
 	/* do basic switch setup */
-	ret = i40e_setup_pf_switch(pf);
+	ret = i40e_setup_pf_switch(pf, reinit);
 	if (ret)
 		goto end_core_reset;
 
@@ -4907,7 +4911,7 @@ static void i40e_handle_reset_warning(struct i40e_pf *pf)
 
 	ret = i40e_prep_for_reset(pf);
 	if (!ret)
-		i40e_reset_and_rebuild(pf);
+		i40e_reset_and_rebuild(pf, false);
 }
 
 /**
@@ -5088,11 +5092,12 @@ static int i40e_set_num_rings_in_vsi(struct i40e_vsi *vsi)
 /**
  * i40e_vsi_alloc_arrays - Allocate queue and vector pointer arrays for the vsi
  * @type: VSI pointer
+ * @alloc_qvectors: a bool to specify if q_vectors need to be allocated.
  *
  * On error: returns error code (negative)
  * On success: returns 0
  **/
-static int i40e_vsi_alloc_arrays(struct i40e_vsi *vsi)
+static int i40e_vsi_alloc_arrays(struct i40e_vsi *vsi, bool alloc_qvectors)
 {
 	int size;
 	int ret = 0;
@@ -5104,12 +5109,14 @@ static int i40e_vsi_alloc_arrays(struct i40e_vsi *vsi)
 		return -ENOMEM;
 	vsi->rx_rings = &vsi->tx_rings[vsi->alloc_queue_pairs];
 
-	/* allocate memory for q_vector pointers */
-	size = sizeof(struct i40e_q_vectors *) * vsi->num_q_vectors;
-	vsi->q_vectors = kzalloc(size, GFP_KERNEL);
-	if (!vsi->q_vectors) {
-		ret = -ENOMEM;
-		goto err_vectors;
+	if (alloc_qvectors) {
+		/* allocate memory for q_vector pointers */
+		size = sizeof(struct i40e_q_vectors *) * vsi->num_q_vectors;
+		vsi->q_vectors = kzalloc(size, GFP_KERNEL);
+		if (!vsi->q_vectors) {
+			ret = -ENOMEM;
+			goto err_vectors;
+		}
 	}
 	return ret;
 
@@ -5179,7 +5186,7 @@ static int i40e_vsi_mem_alloc(struct i40e_pf *pf, enum i40e_vsi_type type)
 	if (ret)
 		goto err_rings;
 
-	ret = i40e_vsi_alloc_arrays(vsi);
+	ret = i40e_vsi_alloc_arrays(vsi, true);
 	if (ret)
 		goto err_rings;
 
@@ -5201,15 +5208,18 @@ static int i40e_vsi_mem_alloc(struct i40e_pf *pf, enum i40e_vsi_type type)
 /**
  * i40e_vsi_free_arrays - Free queue and vector pointer arrays for the VSI
  * @type: VSI pointer
+ * @free_qvectors: a bool to specify if q_vectors need to be freed.
  *
  * On error: returns error code (negative)
  * On success: returns 0
  **/
-static void i40e_vsi_free_arrays(struct i40e_vsi *vsi)
+static void i40e_vsi_free_arrays(struct i40e_vsi *vsi, bool free_qvectors)
 {
 	/* free the ring and vector containers */
-	kfree(vsi->q_vectors);
-	vsi->q_vectors = NULL;
+	if (free_qvectors) {
+		kfree(vsi->q_vectors);
+		vsi->q_vectors = NULL;
+	}
 	kfree(vsi->tx_rings);
 	vsi->tx_rings = NULL;
 	vsi->rx_rings = NULL;
@@ -5251,7 +5261,7 @@ static int i40e_vsi_clear(struct i40e_vsi *vsi)
 	i40e_put_lump(pf->qp_pile, vsi->base_queue, vsi->idx);
 	i40e_put_lump(pf->irq_pile, vsi->base_vector, vsi->idx);
 
-	i40e_vsi_free_arrays(vsi);
+	i40e_vsi_free_arrays(vsi, true);
 
 	pf->vsi[vsi->idx] = NULL;
 	if (vsi->idx < pf->next_vsi)
@@ -6262,6 +6272,69 @@ static int i40e_vsi_setup_vectors(struct i40e_vsi *vsi)
 	return ret;
 }
 
+/**
+ * i40e_vsi_reinit_setup - return and reallocate resources for a VSI
+ * @vsi: pointer to the vsi.
+ *
+ * This re-allocates a vsi's queue resources.
+ *
+ * Returns pointer to the successfully allocated and configured VSI sw struct
+ * on success, otherwise returns NULL on failure.
+ **/
+static struct i40e_vsi *i40e_vsi_reinit_setup(struct i40e_vsi *vsi)
+{
+	struct i40e_pf *pf = vsi->back;
+	u8 enabled_tc;
+	int ret;
+
+	i40e_put_lump(pf->qp_pile, vsi->base_queue, vsi->idx);
+	i40e_vsi_clear_rings(vsi);
+
+	i40e_vsi_free_arrays(vsi, false);
+	i40e_set_num_rings_in_vsi(vsi);
+	ret = i40e_vsi_alloc_arrays(vsi, false);
+	if (ret)
+		goto err_vsi;
+
+	ret = i40e_get_lump(pf, pf->qp_pile, vsi->alloc_queue_pairs, vsi->idx);
+	if (ret < 0) {
+		dev_info(&pf->pdev->dev, "VSI %d get_lump failed %d\n",
+			 vsi->seid, ret);
+		goto err_vsi;
+	}
+	vsi->base_queue = ret;
+
+	/* Update the FW view of the VSI. Force a reset of TC and queue
+	 * layout configurations.
+	 */
+	enabled_tc = pf->vsi[pf->lan_vsi]->tc_config.enabled_tc;
+	pf->vsi[pf->lan_vsi]->tc_config.enabled_tc = 0;
+	pf->vsi[pf->lan_vsi]->seid = pf->main_vsi_seid;
+	i40e_vsi_config_tc(pf->vsi[pf->lan_vsi], enabled_tc);
+
+	/* assign it some queues */
+	ret = i40e_alloc_rings(vsi);
+	if (ret)
+		goto err_rings;
+
+	/* map all of the rings to the q_vectors */
+	i40e_vsi_map_rings_to_vectors(vsi);
+	return vsi;
+
+err_rings:
+	i40e_vsi_free_q_vectors(vsi);
+	if (vsi->netdev_registered) {
+		vsi->netdev_registered = false;
+		unregister_netdev(vsi->netdev);
+		free_netdev(vsi->netdev);
+		vsi->netdev = NULL;
+	}
+	i40e_aq_delete_element(&pf->hw, vsi->seid, NULL);
+err_vsi:
+	i40e_vsi_clear(vsi);
+	return NULL;
+}
+
 /**
  * i40e_vsi_setup - Set up a VSI by a given type
  * @pf: board private structure
@@ -6905,10 +6978,11 @@ int i40e_fetch_switch_configuration(struct i40e_pf *pf, bool printconfig)
 /**
  * i40e_setup_pf_switch - Setup the HW switch on startup or after reset
  * @pf: board private structure
+ * @reinit: if the Main VSI needs to re-initialized.
  *
  * Returns 0 on success, negative value on failure
  **/
-static int i40e_setup_pf_switch(struct i40e_pf *pf)
+static int i40e_setup_pf_switch(struct i40e_pf *pf, bool reinit)
 {
 	u32 rxfc = 0, txfc = 0, rxfc_reg;
 	int ret;
@@ -6930,7 +7004,7 @@ static int i40e_setup_pf_switch(struct i40e_pf *pf)
 		i40e_fdir_setup(pf);
 
 	/* first time setup */
-	if (pf->lan_vsi == I40E_NO_VSI) {
+	if (pf->lan_vsi == I40E_NO_VSI || reinit) {
 		struct i40e_vsi *vsi = NULL;
 		u16 uplink_seid;
 
@@ -6941,8 +7015,10 @@ static int i40e_setup_pf_switch(struct i40e_pf *pf)
 			uplink_seid = pf->veb[pf->lan_veb]->seid;
 		else
 			uplink_seid = pf->mac_seid;
-
-		vsi = i40e_vsi_setup(pf, I40E_VSI_MAIN, uplink_seid, 0);
+		if (pf->lan_vsi == I40E_NO_VSI)
+			vsi = i40e_vsi_setup(pf, I40E_VSI_MAIN, uplink_seid, 0);
+		else if (reinit)
+			vsi = i40e_vsi_reinit_setup(pf->vsi[pf->lan_vsi]);
 		if (!vsi) {
 			dev_info(&pf->pdev->dev, "setup of MAIN VSI failed\n");
 			i40e_fdir_teardown(pf);
@@ -7413,7 +7489,7 @@ static int i40e_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		goto err_switch_setup;
 	}
 
-	err = i40e_setup_pf_switch(pf);
+	err = i40e_setup_pf_switch(pf, false);
 	if (err) {
 		dev_info(&pdev->dev, "setup_pf_switch failed: %d\n", err);
 		goto err_vsis;