i40e: KISS the client interface

(KISS is Keep It Simple, Stupid. Or is it?)

The client interface vastly overengineered for what it needs to do.
It was originally designed to support multiple clients on multiple
netdevs, possibly even with multiple drivers. None of this happened,
and now we know that there will only ever be one client for i40e
(i40iw) and one for i40evf (i40iwvf). So, time for some KISS. Since
i40e and i40evf are a Dynasty, we'll simplify this one to match the
VF interface.

First, be a Destroyer and remove all of the lists and locks required
to support multiple clients. Keep one static around to keep track of
one client, and track the client instances for each netdev in the
driver's pf (or adapter) struct. Now it's Almost Human.

Since we already know the client type is iWarp, get rid of any checks
for this. Same for VSI type - it's always going to be the same type,
so it's just a Parasite.

While we're at it, fix up some comments. This makes the function
headers actually match the functions.

These changes reduce code complexity, simplify maintenance,
squash some lurking timing bugs, and allow us to Rock and Roll All
Nite.

Change-ID: I1ea79948ad73b8685272451440a34507f9a9012e
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e.h

@@ -348,8 +348,10 @@ struct i40e_pf {
 #define I40E_FLAG_TRUE_PROMISC_SUPPORT		BIT_ULL(51)
 #define I40E_FLAG_HAVE_CRT_RETIMER		BIT_ULL(52)
 #define I40E_FLAG_PTP_L4_CAPABLE		BIT_ULL(53)
-#define I40E_FLAG_WOL_MC_MAGIC_PKT_WAKE		BIT_ULL(54)
+#define I40E_FLAG_CLIENT_RESET			BIT_ULL(54)
 #define I40E_FLAG_TEMP_LINK_POLLING		BIT_ULL(55)
+#define I40E_FLAG_CLIENT_L2_CHANGE		BIT_ULL(56)
+#define I40E_FLAG_WOL_MC_MAGIC_PKT_WAKE		BIT_ULL(57)
 
 	/* tracks features that get auto disabled by errors */
 	u64 auto_disable_flags;
@@ -358,6 +360,7 @@ struct i40e_pf {
 	struct i40e_fcoe fcoe;
 
 #endif /* I40E_FCOE */
+	struct i40e_client_instance *cinst;
 	bool stat_offsets_loaded;
 	struct i40e_hw_port_stats stats;
 	struct i40e_hw_port_stats stats_offsets;
@@ -813,8 +816,7 @@ void i40e_notify_client_of_l2_param_changes(struct i40e_vsi *vsi);
 void i40e_notify_client_of_netdev_close(struct i40e_vsi *vsi, bool reset);
 void i40e_notify_client_of_vf_enable(struct i40e_pf *pf, u32 num_vfs);
 void i40e_notify_client_of_vf_reset(struct i40e_pf *pf, u32 vf_id);
-int i40e_vf_client_capable(struct i40e_pf *pf, u32 vf_id,
-			   enum i40e_client_type type);
+int i40e_vf_client_capable(struct i40e_pf *pf, u32 vf_id);
 /**
  * i40e_irq_dynamic_enable - Enable default interrupt generation settings
  * @vsi: pointer to a vsi

drivers/net/ethernet/intel/i40e/i40e_client.h

@@ -57,11 +57,6 @@ enum i40e_client_instance_state {
 	__I40E_CLIENT_INSTANCE_OPENED,
 };
 
-enum i40e_client_type {
-	I40E_CLIENT_IWARP,
-	I40E_CLIENT_VMDQ2
-};
-
 struct i40e_ops;
 struct i40e_client;
 
@@ -214,7 +209,8 @@ struct i40e_client {
 	u32 flags;
 #define I40E_CLIENT_FLAGS_LAUNCH_ON_PROBE	BIT(0)
 #define I40E_TX_FLAGS_NOTIFY_OTHER_EVENTS	BIT(2)
-	enum i40e_client_type type;
+	u8 type;
+#define I40E_CLIENT_IWARP 0
 	const struct i40e_client_ops *ops; /* client ops provided by the client */
 };
 

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

@@ -2487,13 +2487,15 @@ static int i40e_change_mtu(struct net_device *netdev, int new_mtu)
 {
 	struct i40e_netdev_priv *np = netdev_priv(netdev);
 	struct i40e_vsi *vsi = np->vsi;
+	struct i40e_pf *pf = vsi->back;
 
 	netdev_info(netdev, "changing MTU from %d to %d\n",
 		    netdev->mtu, new_mtu);
 	netdev->mtu = new_mtu;
 	if (netif_running(netdev))
 		i40e_vsi_reinit_locked(vsi);
-	i40e_notify_client_of_l2_param_changes(vsi);
+	pf->flags |= (I40E_FLAG_SERVICE_CLIENT_REQUESTED |
+		      I40E_FLAG_CLIENT_L2_CHANGE);
 	return 0;
 }
 
@@ -4463,17 +4465,16 @@ static void i40e_napi_disable_all(struct i40e_vsi *vsi)
  **/
 static void i40e_vsi_close(struct i40e_vsi *vsi)
 {
-	bool reset = false;
-
+	struct i40e_pf *pf = vsi->back;
 	if (!test_and_set_bit(__I40E_DOWN, &vsi->state))
 		i40e_down(vsi);
 	i40e_vsi_free_irq(vsi);
 	i40e_vsi_free_tx_resources(vsi);
 	i40e_vsi_free_rx_resources(vsi);
 	vsi->current_netdev_flags = 0;
-	if (test_bit(__I40E_RESET_RECOVERY_PENDING, &vsi->back->state))
-		reset = true;
-	i40e_notify_client_of_netdev_close(vsi, reset);
+	pf->flags |= I40E_FLAG_SERVICE_CLIENT_REQUESTED;
+	if (test_bit(__I40E_RESET_RECOVERY_PENDING, &pf->state))
+		pf->flags |=  I40E_FLAG_CLIENT_RESET;
 }
 
 /**
@@ -5542,8 +5543,6 @@ void i40e_down(struct i40e_vsi *vsi)
 		i40e_clean_rx_ring(vsi->rx_rings[i]);
 	}
 
-	i40e_notify_client_of_netdev_close(vsi, false);
-
 }
 
 /**
@@ -6021,8 +6020,8 @@ static int i40e_handle_lldp_event(struct i40e_pf *pf,
 		i40e_service_event_schedule(pf);
 	} else {
 		i40e_pf_unquiesce_all_vsi(pf);
-		/* Notify the client for the DCB changes */
-		i40e_notify_client_of_l2_param_changes(pf->vsi[pf->lan_vsi]);
+	pf->flags |= (I40E_FLAG_SERVICE_CLIENT_REQUESTED |
+		      I40E_FLAG_CLIENT_L2_CHANGE);
 	}
 
 exit:
@@ -7411,7 +7410,18 @@ static void i40e_service_task(struct work_struct *work)
 	i40e_vc_process_vflr_event(pf);
 	i40e_watchdog_subtask(pf);
 	i40e_fdir_reinit_subtask(pf);
-	i40e_client_subtask(pf);
+	if (pf->flags & I40E_FLAG_CLIENT_RESET) {
+		/* Client subtask will reopen next time through. */
+		i40e_notify_client_of_netdev_close(pf->vsi[pf->lan_vsi], true);
+		pf->flags &= ~I40E_FLAG_CLIENT_RESET;
+	} else {
+		i40e_client_subtask(pf);
+		if (pf->flags & I40E_FLAG_CLIENT_L2_CHANGE) {
+			i40e_notify_client_of_l2_param_changes(
+							pf->vsi[pf->lan_vsi]);
+			pf->flags &= ~I40E_FLAG_CLIENT_L2_CHANGE;
+		}
+	}
 	i40e_sync_filters_subtask(pf);
 	i40e_sync_udp_filters_subtask(pf);
 	i40e_clean_adminq_subtask(pf);

drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c

@@ -1359,7 +1359,7 @@ static int i40e_vc_get_vf_resources_msg(struct i40e_vf *vf, u8 *msg)
 	if (!vsi->info.pvid)
 		vfres->vf_offload_flags |= I40E_VIRTCHNL_VF_OFFLOAD_VLAN;
 
-	if (i40e_vf_client_capable(pf, vf->vf_id, I40E_CLIENT_IWARP) &&
+	if (i40e_vf_client_capable(pf, vf->vf_id) &&
 	    (vf->driver_caps & I40E_VIRTCHNL_VF_OFFLOAD_IWARP)) {
 		vfres->vf_offload_flags |= I40E_VIRTCHNL_VF_OFFLOAD_IWARP;
 		set_bit(I40E_VF_STAT_IWARPENA, &vf->vf_states);