nfp: create control vNICs and wire up rx/tx

When driver encounters an nfp_app which has a control message handler
defined, allocate a control vNIC.  This control channel will be used
to exchange data with the application FW such as flow table programming,
statistics and global datapath control.
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.c

@@ -31,6 +31,7 @@
  * SOFTWARE.
  */
 
+#include <linux/skbuff.h>
 #include <linux/slab.h>
 
 #include "nfpcore/nfp_cpp.h"
@@ -42,6 +43,23 @@ static const struct nfp_app_type *apps[] = {
 	&app_bpf,
 };
 
+struct sk_buff *nfp_app_ctrl_msg_alloc(struct nfp_app *app, unsigned int size)
+{
+	struct sk_buff *skb;
+
+	if (nfp_app_ctrl_has_meta(app))
+		size += 8;
+
+	skb = alloc_skb(size, GFP_ATOMIC);
+	if (!skb)
+		return NULL;
+
+	if (nfp_app_ctrl_has_meta(app))
+		skb_reserve(skb, 8);
+
+	return skb;
+}
+
 struct nfp_app *nfp_app_alloc(struct nfp_pf *pf, enum nfp_app_id id)
 {
 	struct nfp_app *app;

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

@@ -37,6 +37,7 @@
 struct bpf_prog;
 struct net_device;
 struct pci_dev;
+struct sk_buff;
 struct tc_to_netdev;
 struct sk_buff;
 struct nfp_app;
@@ -63,6 +64,9 @@ extern const struct nfp_app_type app_bpf;
  * @extra_cap:	extra capabilities string
  * @vnic_init:	init vNICs (assign port types, etc.)
  * @vnic_clean:	clean up app's vNIC state
+ * @start:	start application logic
+ * @stop:	stop application logic
+ * @ctrl_msg_rx:    control message handler
  * @setup_tc:	setup TC ndo
  * @tc_busy:	TC HW offload busy (rules loaded)
  * @xdp_offload:    offload an XDP program
@@ -81,6 +85,11 @@ struct nfp_app_type {
 			 unsigned int id);
 	void (*vnic_clean)(struct nfp_app *app, struct nfp_net *nn);
 
+	int (*start)(struct nfp_app *app);
+	void (*stop)(struct nfp_app *app);
+
+	void (*ctrl_msg_rx)(struct nfp_app *app, struct sk_buff *skb);
+
 	int (*setup_tc)(struct nfp_app *app, struct net_device *netdev,
 			u32 handle, __be16 proto, struct tc_to_netdev *tc);
 	bool (*tc_busy)(struct nfp_app *app, struct nfp_net *nn);
@@ -93,6 +102,7 @@ struct nfp_app_type {
  * @pdev:	backpointer to PCI device
  * @pf:		backpointer to NFP PF structure
  * @cpp:	pointer to the CPP handle
+ * @ctrl:	pointer to ctrl vNIC struct
  * @type:	pointer to const application ops and info
  */
 struct nfp_app {
@@ -100,6 +110,8 @@ struct nfp_app {
 	struct nfp_pf *pf;
 	struct nfp_cpp *cpp;
 
+	struct nfp_net *ctrl;
+
 	const struct nfp_app_type *type;
 };
 
@@ -124,6 +136,21 @@ static inline void nfp_app_vnic_clean(struct nfp_app *app, struct nfp_net *nn)
 		app->type->vnic_clean(app, nn);
 }
 
+static inline int nfp_app_start(struct nfp_app *app, struct nfp_net *ctrl)
+{
+	app->ctrl = ctrl;
+	if (!app->type->start)
+		return 0;
+	return app->type->start(app);
+}
+
+static inline void nfp_app_stop(struct nfp_app *app)
+{
+	if (!app->type->stop)
+		return;
+	app->type->stop(app);
+}
+
 static inline const char *nfp_app_name(struct nfp_app *app)
 {
 	if (!app)
@@ -131,6 +158,11 @@ static inline const char *nfp_app_name(struct nfp_app *app)
 	return app->type->name;
 }
 
+static inline bool nfp_app_needs_ctrl_vnic(struct nfp_app *app)
+{
+	return app && app->type->ctrl_msg_rx;
+}
+
 static inline bool nfp_app_ctrl_has_meta(struct nfp_app *app)
 {
 	return app->type->ctrl_has_meta;
@@ -174,6 +206,18 @@ static inline int nfp_app_xdp_offload(struct nfp_app *app, struct nfp_net *nn,
 	return app->type->xdp_offload(app, nn, prog);
 }
 
+static inline bool nfp_app_ctrl_tx(struct nfp_app *app, struct sk_buff *skb)
+{
+	return nfp_ctrl_tx(app->ctrl, skb);
+}
+
+static inline void nfp_app_ctrl_rx(struct nfp_app *app, struct sk_buff *skb)
+{
+	app->type->ctrl_msg_rx(app, skb);
+}
+
+struct sk_buff *nfp_app_ctrl_msg_alloc(struct nfp_app *app, unsigned int size);
+
 struct nfp_app *nfp_app_alloc(struct nfp_pf *pf, enum nfp_app_id id);
 void nfp_app_free(struct nfp_app *app);
 

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

@@ -63,11 +63,13 @@ struct nfp_nsp_identify;
  * @cpp:		Pointer to the CPP handle
  * @app:		Pointer to the APP handle
  * @data_vnic_bar:	Pointer to the CPP area for the data vNICs' BARs
+ * @ctrl_vnic_bar:	Pointer to the CPP area for the ctrl vNIC's BAR
  * @qc_area:		Pointer to the CPP area for the queues
  * @irq_entries:	Array of MSI-X entries for all vNICs
  * @limit_vfs:		Number of VFs supported by firmware (~0 for PCI limit)
  * @num_vfs:		Number of SR-IOV VFs enabled
  * @fw_loaded:		Is the firmware loaded?
+ * @ctrl_vnic:		Pointer to the control vNIC if available
  * @eth_tbl:		NSP ETH table
  * @nspi:		NSP identification info
  * @hwmon_dev:		pointer to hwmon device
@@ -87,6 +89,7 @@ struct nfp_pf {
 	struct nfp_app *app;
 
 	struct nfp_cpp_area *data_vnic_bar;
+	struct nfp_cpp_area *ctrl_vnic_bar;
 	struct nfp_cpp_area *qc_area;
 
 	struct msix_entry *irq_entries;
@@ -96,6 +99,8 @@ struct nfp_pf {
 
 	bool fw_loaded;
 
+	struct nfp_net *ctrl_vnic;
+
 	struct nfp_eth_table *eth_tbl;
 	struct nfp_nsp_identify *nspi;
 
@@ -127,4 +132,6 @@ nfp_net_find_port(struct nfp_eth_table *eth_tbl, unsigned int id);
 void
 nfp_net_get_mac_addr(struct nfp_net *nn, struct nfp_cpp *cpp, unsigned int id);
 
+bool nfp_ctrl_tx(struct nfp_net *nn, struct sk_buff *skb);
+
 #endif /* NFP_MAIN_H */

drivers/net/ethernet/netronome/nfp/nfp_net_common.c

@@ -1950,7 +1950,7 @@ nfp_ctrl_rx_one(struct nfp_net *nn, struct nfp_net_dp *dp,
 	skb_reserve(skb, pkt_off);
 	skb_put(skb, pkt_len);
 
-	dev_kfree_skb_any(skb);
+	nfp_app_ctrl_rx(nn->app, skb);
 
 	return true;
 }

drivers/net/ethernet/netronome/nfp/nfp_net_main.c

@@ -266,12 +266,11 @@ static void nfp_net_pf_free_vnic(struct nfp_pf *pf, struct nfp_net *nn)
 
 static void nfp_net_pf_free_vnics(struct nfp_pf *pf)
 {
-	struct nfp_net *nn;
+	struct nfp_net *nn, *next;
 
-	while (!list_empty(&pf->vnics)) {
-		nn = list_first_entry(&pf->vnics, struct nfp_net, vnic_list);
+	list_for_each_entry_safe(nn, next, &pf->vnics, vnic_list)
+		if (nfp_net_is_data_vnic(nn))
 			nfp_net_pf_free_vnic(pf, nn);
-	}
 }
 
 static struct nfp_net *
@@ -302,11 +301,13 @@ nfp_net_pf_alloc_vnic(struct nfp_pf *pf, bool needs_netdev,
 	nn->stride_rx = stride;
 	nn->stride_tx = stride;
 
+	if (needs_netdev) {
 		err = nfp_app_vnic_init(pf->app, nn, eth_id);
 		if (err) {
 			nfp_net_free(nn);
 			return ERR_PTR(err);
 		}
+	}
 
 	pf->num_vnics++;
 	list_add_tail(&nn->vnic_list, &pf->vnics);
@@ -446,6 +447,8 @@ static int nfp_net_pf_init_vnics(struct nfp_pf *pf)
 	/* Finish vNIC init and register */
 	id = 0;
 	list_for_each_entry(nn, &pf->vnics, vnic_list) {
+		if (!nfp_net_is_data_vnic(nn))
+			continue;
 		err = nfp_net_pf_init_vnic(pf, nn, id);
 		if (err)
 			goto err_prev_deinit;
@@ -457,12 +460,15 @@ static int nfp_net_pf_init_vnics(struct nfp_pf *pf)
 
 err_prev_deinit:
 	list_for_each_entry_continue_reverse(nn, &pf->vnics, vnic_list)
+		if (nfp_net_is_data_vnic(nn))
 			nfp_net_pf_clean_vnic(pf, nn);
 	return err;
 }
 
-static int nfp_net_pf_app_init(struct nfp_pf *pf)
+static int
+nfp_net_pf_app_init(struct nfp_pf *pf, u8 __iomem *qc_bar, unsigned int stride)
 {
+	u8 __iomem *ctrl_bar;
 	int err;
 
 	pf->app = nfp_app_alloc(pf, nfp_net_pf_get_app_id(pf));
@@ -473,8 +479,28 @@ static int nfp_net_pf_app_init(struct nfp_pf *pf)
 	if (err)
 		goto err_free;
 
+	if (!nfp_app_needs_ctrl_vnic(pf->app))
 		return 0;
 
+	ctrl_bar = nfp_net_pf_map_rtsym(pf, "net.ctrl", "_pf%u_net_ctrl_bar",
+					NFP_PF_CSR_SLICE_SIZE,
+					&pf->ctrl_vnic_bar);
+	if (IS_ERR(ctrl_bar)) {
+		err = PTR_ERR(ctrl_bar);
+		goto err_free;
+	}
+
+	pf->ctrl_vnic =	nfp_net_pf_alloc_vnic(pf, false, ctrl_bar, qc_bar,
+					      stride, 0);
+	if (IS_ERR(pf->ctrl_vnic)) {
+		err = PTR_ERR(pf->ctrl_vnic);
+		goto err_unmap;
+	}
+
+	return 0;
+
+err_unmap:
+	nfp_cpp_area_release_free(pf->ctrl_vnic_bar);
 err_free:
 	nfp_app_free(pf->app);
 	return err;
@@ -482,12 +508,72 @@ static int nfp_net_pf_app_init(struct nfp_pf *pf)
 
 static void nfp_net_pf_app_clean(struct nfp_pf *pf)
 {
+	if (pf->ctrl_vnic) {
+		nfp_net_pf_free_vnic(pf, pf->ctrl_vnic);
+		nfp_cpp_area_release_free(pf->ctrl_vnic_bar);
+	}
 	nfp_app_free(pf->app);
 	pf->app = NULL;
 }
 
+static int nfp_net_pf_app_start_ctrl(struct nfp_pf *pf)
+{
+	int err;
+
+	if (!pf->ctrl_vnic)
+		return 0;
+	err = nfp_net_pf_init_vnic(pf, pf->ctrl_vnic, 0);
+	if (err)
+		return err;
+
+	err = nfp_ctrl_open(pf->ctrl_vnic);
+	if (err)
+		goto err_clean_ctrl;
+
+	return 0;
+
+err_clean_ctrl:
+	nfp_net_pf_clean_vnic(pf, pf->ctrl_vnic);
+	return err;
+}
+
+static void nfp_net_pf_app_stop_ctrl(struct nfp_pf *pf)
+{
+	if (!pf->ctrl_vnic)
+		return;
+	nfp_ctrl_close(pf->ctrl_vnic);
+	nfp_net_pf_clean_vnic(pf, pf->ctrl_vnic);
+}
+
+static int nfp_net_pf_app_start(struct nfp_pf *pf)
+{
+	int err;
+
+	err = nfp_net_pf_app_start_ctrl(pf);
+	if (err)
+		return err;
+
+	err = nfp_app_start(pf->app, pf->ctrl_vnic);
+	if (err)
+		goto err_ctrl_stop;
+
+	return 0;
+
+err_ctrl_stop:
+	nfp_net_pf_app_stop_ctrl(pf);
+	return err;
+}
+
+static void nfp_net_pf_app_stop(struct nfp_pf *pf)
+{
+	nfp_app_stop(pf->app);
+	nfp_net_pf_app_stop_ctrl(pf);
+}
+
 static void nfp_net_pci_remove_finish(struct nfp_pf *pf)
 {
+	nfp_net_pf_app_stop(pf);
+	/* stop app first, to avoid double free of ctrl vNIC's ddir */
 	nfp_net_debugfs_dir_clean(&pf->ddir);
 
 	nfp_net_pf_free_irqs(pf);
@@ -685,7 +771,7 @@ int nfp_net_pci_probe(struct nfp_pf *pf)
 		goto err_ctrl_unmap;
 	}
 
-	err = nfp_net_pf_app_init(pf);
+	err = nfp_net_pf_app_init(pf, qc_bar, stride);
 	if (err)
 		goto err_unmap_qc;
 
@@ -700,14 +786,20 @@ int nfp_net_pci_probe(struct nfp_pf *pf)
 	if (err)
 		goto err_free_vnics;
 
-	err = nfp_net_pf_init_vnics(pf);
+	err = nfp_net_pf_app_start(pf);
 	if (err)
 		goto err_free_irqs;
 
+	err = nfp_net_pf_init_vnics(pf);
+	if (err)
+		goto err_stop_app;
+
 	mutex_unlock(&pf->lock);
 
 	return 0;
 
+err_stop_app:
+	nfp_net_pf_app_stop(pf);
 err_free_irqs:
 	nfp_net_pf_free_irqs(pf);
 err_free_vnics:
@@ -733,6 +825,7 @@ void nfp_net_pci_remove(struct nfp_pf *pf)
 		goto out;
 
 	list_for_each_entry(nn, &pf->vnics, vnic_list)
+		if (nfp_net_is_data_vnic(nn))
 			nfp_net_pf_clean_vnic(pf, nn);
 
 	nfp_net_pf_free_vnics(pf);