nfp: general representor implementation

Provide infrastructure to create and destroy representors of a given type.

Parts based on work by Bert van Leeuwen, Benjamin LaHaise,
and Jakub Kicinski.
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/Makefile

@@ -22,6 +22,7 @@ nfp-objs := \
 	    nfp_net_common.o \
 	    nfp_net_ethtool.o \
 	    nfp_net_main.o \
+	    nfp_net_repr.o \
 	    nfp_netvf_main.o \
 	    nfp_port.o \
 	    bpf/main.o \

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

@@ -38,6 +38,7 @@
 #include "nfpcore/nfp_nffw.h"
 #include "nfp_app.h"
 #include "nfp_main.h"
+#include "nfp_net_repr.h"
 
 static const struct nfp_app_type *apps[] = {
 	&app_nic,
@@ -68,6 +69,25 @@ struct sk_buff *nfp_app_ctrl_msg_alloc(struct nfp_app *app, unsigned int size)
 	return skb;
 }
 
+struct nfp_reprs *
+nfp_app_reprs_set(struct nfp_app *app, enum nfp_repr_type type,
+		  struct nfp_reprs *reprs)
+{
+	struct nfp_reprs *old;
+
+	old = rcu_dereference_protected(app->reprs[type],
+					lockdep_is_held(&app->pf->lock));
+	if (reprs && old) {
+		old = ERR_PTR(-EBUSY);
+		goto exit_unlock;
+	}
+
+	rcu_assign_pointer(app->reprs[type], reprs);
+
+exit_unlock:
+	return old;
+}
+
 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

@@ -36,6 +36,8 @@
 
 #include <net/devlink.h>
 
+#include "nfp_net_repr.h"
+
 struct bpf_prog;
 struct net_device;
 struct pci_dev;
@@ -73,6 +75,7 @@ extern const struct nfp_app_type app_bpf;
  * @tc_busy:	TC HW offload busy (rules loaded)
  * @xdp_offload:    offload an XDP program
  * @eswitch_mode_get:    get SR-IOV eswitch mode
+ * @repr_get:	get representor netdev
  */
 struct nfp_app_type {
 	enum nfp_app_id id;
@@ -100,6 +103,7 @@ struct nfp_app_type {
 			   struct bpf_prog *prog);
 
 	enum devlink_eswitch_mode (*eswitch_mode_get)(struct nfp_app *app);
+	struct net_device *(*repr_get)(struct nfp_app *app, u32 id);
 };
 
 /**
@@ -108,6 +112,7 @@ struct nfp_app_type {
  * @pf:		backpointer to NFP PF structure
  * @cpp:	pointer to the CPP handle
  * @ctrl:	pointer to ctrl vNIC struct
+ * @reprs:	array of pointers to representors
  * @type:	pointer to const application ops and info
  */
 struct nfp_app {
@@ -116,6 +121,7 @@ struct nfp_app {
 	struct nfp_cpp *cpp;
 
 	struct nfp_net *ctrl;
+	struct nfp_reprs __rcu *reprs[NFP_REPR_TYPE_MAX + 1];
 
 	const struct nfp_app_type *type;
 };
@@ -231,6 +237,18 @@ static inline int nfp_app_eswitch_mode_get(struct nfp_app *app, u16 *mode)
 	return 0;
 }
 
+static inline struct net_device *nfp_app_repr_get(struct nfp_app *app, u32 id)
+{
+	if (unlikely(!app || !app->type->repr_get))
+		return NULL;
+
+	return app->type->repr_get(app, id);
+}
+
+struct nfp_reprs *
+nfp_app_reprs_set(struct nfp_app *app, enum nfp_repr_type type,
+		  struct nfp_reprs *reprs);
+
 const char *nfp_app_mip_name(struct nfp_app *app);
 struct sk_buff *nfp_app_ctrl_msg_alloc(struct nfp_app *app, unsigned int size);
 

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

+/*
+ * Copyright (C) 2017 Netronome Systems, Inc.
+ *
+ * This software is dual licensed under the GNU General License Version 2,
+ * June 1991 as shown in the file COPYING in the top-level directory of this
+ * source tree or the BSD 2-Clause License provided below.  You have the
+ * option to license this software under the complete terms of either license.
+ *
+ * The BSD 2-Clause License:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      1. Redistributions of source code must retain the above
+ *         copyright notice, this list of conditions and the following
+ *         disclaimer.
+ *
+ *      2. Redistributions in binary form must reproduce the above
+ *         copyright notice, this list of conditions and the following
+ *         disclaimer in the documentation and/or other materials
+ *         provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/etherdevice.h>
+#include <linux/lockdep.h>
+#include <net/dst_metadata.h>
+
+#include "nfpcore/nfp_cpp.h"
+#include "nfp_app.h"
+#include "nfp_main.h"
+#include "nfp_net_repr.h"
+#include "nfp_port.h"
+
+static void nfp_repr_clean(struct nfp_repr *repr)
+{
+	unregister_netdev(repr->netdev);
+	dst_release((struct dst_entry *)repr->dst);
+	nfp_port_free(repr->port);
+}
+
+static struct lock_class_key nfp_repr_netdev_xmit_lock_key;
+static struct lock_class_key nfp_repr_netdev_addr_lock_key;
+
+static void nfp_repr_set_lockdep_class_one(struct net_device *dev,
+					   struct netdev_queue *txq,
+					   void *_unused)
+{
+	lockdep_set_class(&txq->_xmit_lock, &nfp_repr_netdev_xmit_lock_key);
+}
+
+static void nfp_repr_set_lockdep_class(struct net_device *dev)
+{
+	lockdep_set_class(&dev->addr_list_lock, &nfp_repr_netdev_addr_lock_key);
+	netdev_for_each_tx_queue(dev, nfp_repr_set_lockdep_class_one, NULL);
+}
+
+int nfp_repr_init(struct nfp_app *app, struct net_device *netdev,
+		  const struct net_device_ops *netdev_ops, u32 cmsg_port_id,
+		  struct nfp_port *port, struct net_device *pf_netdev)
+{
+	struct nfp_repr *repr = netdev_priv(netdev);
+	int err;
+
+	nfp_repr_set_lockdep_class(netdev);
+
+	repr->port = port;
+	repr->dst = metadata_dst_alloc(0, METADATA_HW_PORT_MUX, GFP_KERNEL);
+	if (!repr->dst)
+		return -ENOMEM;
+	repr->dst->u.port_info.port_id = cmsg_port_id;
+	repr->dst->u.port_info.lower_dev = pf_netdev;
+
+	netdev->netdev_ops = netdev_ops;
+
+	err = register_netdev(netdev);
+	if (err)
+		goto err_clean;
+
+	return 0;
+
+err_clean:
+	dst_release((struct dst_entry *)repr->dst);
+	return err;
+}
+
+struct net_device *nfp_repr_alloc(struct nfp_app *app)
+{
+	struct net_device *netdev;
+	struct nfp_repr *repr;
+
+	netdev = alloc_etherdev(sizeof(*repr));
+	if (!netdev)
+		return NULL;
+
+	repr = netdev_priv(netdev);
+	repr->netdev = netdev;
+	repr->app = app;
+
+	return netdev;
+}
+
+static void nfp_repr_clean_and_free(struct nfp_repr *repr)
+{
+	nfp_info(repr->app->cpp, "Destroying Representor(%s)\n",
+		 repr->netdev->name);
+	nfp_repr_clean(repr);
+	free_netdev(repr->netdev);
+}
+
+void nfp_reprs_clean_and_free(struct nfp_reprs *reprs)
+{
+	unsigned int i;
+
+	for (i = 0; i < reprs->num_reprs; i++)
+		if (reprs->reprs[i])
+			nfp_repr_clean_and_free(netdev_priv(reprs->reprs[i]));
+
+	kfree(reprs);
+}
+
+void
+nfp_reprs_clean_and_free_by_type(struct nfp_app *app,
+				 enum nfp_repr_type type)
+{
+	struct nfp_reprs *reprs;
+
+	reprs = nfp_app_reprs_set(app, type, NULL);
+	if (!reprs)
+		return;
+
+	synchronize_rcu();
+	nfp_reprs_clean_and_free(reprs);
+}
+
+struct nfp_reprs *nfp_reprs_alloc(unsigned int num_reprs)
+{
+	struct nfp_reprs *reprs;
+
+	reprs = kzalloc(sizeof(*reprs) +
+			num_reprs * sizeof(struct net_device *), GFP_KERNEL);
+	if (!reprs)
+		return NULL;
+	reprs->num_reprs = num_reprs;
+
+	return reprs;
+}

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

+/*
+ * Copyright (C) 2017 Netronome Systems, Inc.
+ *
+ * This software is dual licensed under the GNU General License Version 2,
+ * June 1991 as shown in the file COPYING in the top-level directory of this
+ * source tree or the BSD 2-Clause License provided below.  You have the
+ * option to license this software under the complete terms of either license.
+ *
+ * The BSD 2-Clause License:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      1. Redistributions of source code must retain the above
+ *         copyright notice, this list of conditions and the following
+ *         disclaimer.
+ *
+ *      2. Redistributions in binary form must reproduce the above
+ *         copyright notice, this list of conditions and the following
+ *         disclaimer in the documentation and/or other materials
+ *         provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef NFP_NET_REPR_H
+#define NFP_NET_REPR_H
+
+struct metadata_dst;
+struct nfp_net;
+struct nfp_port;
+
+/**
+ * struct nfp_reprs - container for representor netdevs
+ * @num_reprs:	Number of elements in reprs array
+ * @reprs:	Array of representor netdevs
+ */
+struct nfp_reprs {
+	unsigned int num_reprs;
+	struct net_device *reprs[0];
+};
+
+/**
+ * struct nfp_repr - priv data for representor netdevs
+ * @netdev:	Back pointer to netdev
+ * @dst:	Destination for packet TX
+ * @port:	Port of representor
+ * @app:	APP handle
+ */
+struct nfp_repr {
+	struct net_device *netdev;
+	struct metadata_dst *dst;
+	struct nfp_port *port;
+	struct nfp_app *app;
+};
+
+/**
+ * enum nfp_repr_type - type of representor
+ * @NFP_REPR_TYPE_PHYS_PORT:	external NIC port
+ * @NFP_REPR_TYPE_PF:		physical function
+ * @NFP_REPR_TYPE_VF:		virtual function
+ */
+enum nfp_repr_type {
+	NFP_REPR_TYPE_PHYS_PORT,
+	NFP_REPR_TYPE_PF,
+	NFP_REPR_TYPE_VF,
+
+	__NFP_REPR_TYPE_MAX,
+};
+#define NFP_REPR_TYPE_MAX (__NFP_REPR_TYPE_MAX - 1)
+
+int nfp_repr_init(struct nfp_app *app, struct net_device *netdev,
+		  const struct net_device_ops *netdev_ops,
+		  u32 cmsg_port_id, struct nfp_port *port,
+		  struct net_device *pf_netdev);
+struct net_device *nfp_repr_alloc(struct nfp_app *app);
+void
+nfp_reprs_clean_and_free(struct nfp_reprs *reprs);
+void
+nfp_reprs_clean_and_free_by_type(struct nfp_app *app,
+				 enum nfp_repr_type type);
+struct nfp_reprs *nfp_reprs_alloc(unsigned int num_reprs);
+
+#endif /* NFP_NET_REPR_H */