nfp: add control vNIC datapath

Since control vNICs don't have a netdev, they can't use napi and
queuing stack provides.  Add simple tasklet-based data receive
and send of control messages with queuing on a skb_list.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/nfp_app.h

@@ -38,6 +38,7 @@ struct bpf_prog;
 struct net_device;
 struct pci_dev;
 struct tc_to_netdev;
+struct sk_buff;
 struct nfp_app;
 struct nfp_cpp;
 struct nfp_pf;
@@ -55,6 +56,7 @@ extern const struct nfp_app_type app_bpf;
  * struct nfp_app_type - application definition
  * @id:		application ID
  * @name:	application name
+ * @ctrl_has_meta:  control messages have prepend of type:5/port:CTRL
  *
  * Callbacks
  * @init:	perform basic app checks
@@ -69,6 +71,8 @@ struct nfp_app_type {
 	enum nfp_app_id id;
 	const char *name;
 
+	bool ctrl_has_meta;
+
 	int (*init)(struct nfp_app *app);
 
 	const char *(*extra_cap)(struct nfp_app *app, struct nfp_net *nn);
@@ -99,6 +103,8 @@ struct nfp_app {
 	const struct nfp_app_type *type;
 };
 
+bool nfp_ctrl_tx(struct nfp_net *nn, struct sk_buff *skb);
+
 static inline int nfp_app_init(struct nfp_app *app)
 {
 	if (!app->type->init)
@@ -125,6 +131,11 @@ static inline const char *nfp_app_name(struct nfp_app *app)
 	return app->type->name;
 }
 
+static inline bool nfp_app_ctrl_has_meta(struct nfp_app *app)
+{
+	return app->type->ctrl_has_meta;
+}
+
 static inline const char *nfp_app_extra_cap(struct nfp_app *app,
 					    struct nfp_net *nn)
 {

drivers/net/ethernet/netronome/nfp/nfp_net.h

@@ -405,7 +405,14 @@ struct nfp_net_rx_ring {
  */
 struct nfp_net_r_vector {
 	struct nfp_net *nfp_net;
-	struct napi_struct napi;
+	union {
+		struct napi_struct napi;
+		struct {
+			struct tasklet_struct tasklet;
+			struct sk_buff_head queue;
+			struct spinlock lock;
+		};
+	};
 
 	struct nfp_net_tx_ring *tx_ring;
 	struct nfp_net_rx_ring *rx_ring;
@@ -816,6 +823,11 @@ static inline bool nfp_net_running(struct nfp_net *nn)
 	return nn->dp.ctrl & NFP_NET_CFG_CTRL_ENABLE;
 }
 
+static inline const char *nfp_net_name(struct nfp_net *nn)
+{
+	return nn->dp.netdev ? nn->dp.netdev->name : "ctrl";
+}
+
 /* Globals */
 extern const char nfp_driver_version[];
 
@@ -838,6 +850,9 @@ void nfp_net_free(struct nfp_net *nn);
 int nfp_net_init(struct nfp_net *nn);
 void nfp_net_clean(struct nfp_net *nn);
 
+int nfp_ctrl_open(struct nfp_net *nn);
+void nfp_ctrl_close(struct nfp_net *nn);
+
 void nfp_net_set_ethtool_ops(struct net_device *netdev);
 void nfp_net_info(struct nfp_net *nn);
 int nfp_net_reconfig(struct nfp_net *nn, u32 update);

drivers/net/ethernet/netronome/nfp/nfp_net_ctrl.h

@@ -71,8 +71,11 @@
 #define NFP_NET_META_FIELD_SIZE		4
 #define NFP_NET_META_HASH		1 /* next field carries hash type */
 #define NFP_NET_META_MARK		2
+#define NFP_NET_META_PORTID		5
 #define NFP_NET_META_CSUM		6 /* checksum complete type */
 
+#define	NFP_META_PORT_ID_CTRL		~0U
+
 /**
  * Hash type pre-pended when a RSS hash was computed
  */