nfp: add support for control messages for flower app

In preparation for adding a new flower app - targeted at offloading
the flower classifier - provide support for control message that it will
use to communicate with the NFP.

Based in part on work by Bert van Leeuwen.

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

@@ -27,6 +27,7 @@ nfp-objs := \
 	    nfp_port.o \
 	    bpf/main.o \
 	    bpf/offload.o \
+	    flower/cmsg.o \
 	    nic/main.o
 
 ifeq ($(CONFIG_BPF_SYSCALL),y)

drivers/net/ethernet/netronome/nfp/flower/cmsg.c

@@ -0,0 +1,159 @@
+/*
+ * Copyright (C) 2015-2017 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/bitfield.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <net/dst_metadata.h>
+
+#include "../nfpcore/nfp_cpp.h"
+#include "../nfp_net_repr.h"
+#include "./cmsg.h"
+
+#define nfp_flower_cmsg_warn(app, fmt, args...)				\
+	do {								\
+		if (net_ratelimit())					\
+			nfp_warn((app)->cpp, fmt, ## args);		\
+	} while (0)
+
+static struct nfp_flower_cmsg_hdr *
+nfp_flower_cmsg_get_hdr(struct sk_buff *skb)
+{
+	return (struct nfp_flower_cmsg_hdr *)skb->data;
+}
+
+static void *nfp_flower_cmsg_get_data(struct sk_buff *skb)
+{
+	return (unsigned char *)skb->data + NFP_FLOWER_CMSG_HLEN;
+}
+
+static struct sk_buff *
+nfp_flower_cmsg_alloc(struct nfp_app *app, unsigned int size,
+		      enum nfp_flower_cmsg_type_port type)
+{
+	struct nfp_flower_cmsg_hdr *ch;
+	struct sk_buff *skb;
+
+	size += NFP_FLOWER_CMSG_HLEN;
+
+	skb = nfp_app_ctrl_msg_alloc(app, size, GFP_KERNEL);
+	if (!skb)
+		return NULL;
+
+	ch = nfp_flower_cmsg_get_hdr(skb);
+	ch->pad = 0;
+	ch->version = NFP_FLOWER_CMSG_VER1;
+	ch->type = type;
+	skb_put(skb, size);
+
+	return skb;
+}
+
+int nfp_flower_cmsg_portmod(struct net_device *netdev, bool carrier_ok)
+{
+	struct nfp_repr *repr = netdev_priv(netdev);
+	struct nfp_flower_cmsg_portmod *msg;
+	struct sk_buff *skb;
+
+	skb = nfp_flower_cmsg_alloc(repr->app, sizeof(*msg),
+				    NFP_FLOWER_CMSG_TYPE_PORT_MOD);
+	if (!skb)
+		return -ENOMEM;
+
+	msg = nfp_flower_cmsg_get_data(skb);
+	msg->portnum = cpu_to_be32(repr->dst->u.port_info.port_id);
+	msg->reserved = 0;
+	msg->info = carrier_ok;
+	msg->mtu = cpu_to_be16(netdev->mtu);
+
+	nfp_ctrl_tx(repr->app->ctrl, skb);
+
+	return 0;
+}
+
+static void
+nfp_flower_cmsg_portmod_rx(struct nfp_app *app, struct sk_buff *skb)
+{
+	struct nfp_flower_cmsg_portmod *msg;
+	struct net_device *netdev;
+	bool link;
+
+	msg = nfp_flower_cmsg_get_data(skb);
+	link = msg->info & NFP_FLOWER_CMSG_PORTMOD_INFO_LINK;
+
+	rcu_read_lock();
+	netdev = nfp_app_repr_get(app, be32_to_cpu(msg->portnum));
+	if (!netdev) {
+		nfp_flower_cmsg_warn(app, "ctrl msg for unknown port 0x%08x\n",
+				     be32_to_cpu(msg->portnum));
+		rcu_read_unlock();
+		return;
+	}
+
+	if (link) {
+		netif_carrier_on(netdev);
+		rtnl_lock();
+		dev_set_mtu(netdev, be16_to_cpu(msg->mtu));
+		rtnl_unlock();
+	} else {
+		netif_carrier_off(netdev);
+	}
+	rcu_read_unlock();
+}
+
+void nfp_flower_cmsg_rx(struct nfp_app *app, struct sk_buff *skb)
+{
+	struct nfp_flower_cmsg_hdr *cmsg_hdr;
+	enum nfp_flower_cmsg_type_port type;
+
+	cmsg_hdr = nfp_flower_cmsg_get_hdr(skb);
+
+	if (unlikely(cmsg_hdr->version != NFP_FLOWER_CMSG_VER1)) {
+		nfp_flower_cmsg_warn(app, "Cannot handle repr control version %u\n",
+				     cmsg_hdr->version);
+		goto out;
+	}
+
+	type = cmsg_hdr->type;
+	switch (type) {
+	case NFP_FLOWER_CMSG_TYPE_PORT_MOD:
+		nfp_flower_cmsg_portmod_rx(app, skb);
+		break;
+	default:
+		nfp_flower_cmsg_warn(app, "Cannot handle invalid repr control type %u\n",
+				     type);
+	}
+
+out:
+	dev_kfree_skb_any(skb);
+}

drivers/net/ethernet/netronome/nfp/flower/cmsg.h

@@ -0,0 +1,116 @@
+/*
+ * 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_FLOWER_CMSG_H
+#define NFP_FLOWER_CMSG_H
+
+#include <linux/bitfield.h>
+#include <linux/skbuff.h>
+#include <linux/types.h>
+
+#include "../nfp_app.h"
+
+/* The base header for a control message packet.
+ * Defines an 8-bit version, and an 8-bit type, padded
+ * to a 32-bit word. Rest of the packet is type-specific.
+ */
+struct nfp_flower_cmsg_hdr {
+	__be16 pad;
+	u8 type;
+	u8 version;
+};
+
+#define NFP_FLOWER_CMSG_HLEN		sizeof(struct nfp_flower_cmsg_hdr)
+#define NFP_FLOWER_CMSG_VER1		1
+
+/* Types defined for port related control messages  */
+enum nfp_flower_cmsg_type_port {
+	NFP_FLOWER_CMSG_TYPE_PORT_MOD =		8,
+	NFP_FLOWER_CMSG_TYPE_PORT_ECHO =	16,
+	NFP_FLOWER_CMSG_TYPE_MAX =		32,
+};
+
+/* NFP_FLOWER_CMSG_TYPE_PORT_MOD */
+struct nfp_flower_cmsg_portmod {
+	__be32 portnum;
+	u8 reserved;
+	u8 info;
+	__be16 mtu;
+};
+
+#define NFP_FLOWER_CMSG_PORTMOD_INFO_LINK	BIT(0)
+
+enum nfp_flower_cmsg_port_type {
+	NFP_FLOWER_CMSG_PORT_TYPE_UNSPEC =	0x0,
+	NFP_FLOWER_CMSG_PORT_TYPE_PHYS_PORT =	0x1,
+	NFP_FLOWER_CMSG_PORT_TYPE_PCIE_PORT =	0x2,
+};
+
+enum nfp_flower_cmsg_port_vnic_type {
+	NFP_FLOWER_CMSG_PORT_VNIC_TYPE_VF =	0x0,
+	NFP_FLOWER_CMSG_PORT_VNIC_TYPE_PF =	0x1,
+	NFP_FLOWER_CMSG_PORT_VNIC_TYPE_CTRL =	0x2,
+};
+
+#define NFP_FLOWER_CMSG_PORT_TYPE		GENMASK(31, 28)
+#define NFP_FLOWER_CMSG_PORT_SYS_ID		GENMASK(27, 24)
+#define NFP_FLOWER_CMSG_PORT_NFP_ID		GENMASK(23, 22)
+#define NFP_FLOWER_CMSG_PORT_PCI		GENMASK(15, 14)
+#define NFP_FLOWER_CMSG_PORT_VNIC_TYPE		GENMASK(13, 12)
+#define NFP_FLOWER_CMSG_PORT_VNIC		GENMASK(11, 6)
+#define NFP_FLOWER_CMSG_PORT_PCIE_Q		GENMASK(5, 0)
+#define NFP_FLOWER_CMSG_PORT_PHYS_PORT_NUM	GENMASK(7, 0)
+
+static inline u32 nfp_flower_cmsg_phys_port(u8 phys_port)
+{
+	return FIELD_PREP(NFP_FLOWER_CMSG_PORT_PHYS_PORT_NUM, phys_port) |
+		FIELD_PREP(NFP_FLOWER_CMSG_PORT_TYPE,
+			   NFP_FLOWER_CMSG_PORT_TYPE_PHYS_PORT);
+}
+
+static inline u32
+nfp_flower_cmsg_pcie_port(u8 nfp_pcie, enum nfp_flower_cmsg_port_vnic_type type,
+			  u8 vnic, u8 q)
+{
+	return FIELD_PREP(NFP_FLOWER_CMSG_PORT_PCI, nfp_pcie) |
+		FIELD_PREP(NFP_FLOWER_CMSG_PORT_VNIC_TYPE, type) |
+		FIELD_PREP(NFP_FLOWER_CMSG_PORT_VNIC, vnic) |
+		FIELD_PREP(NFP_FLOWER_CMSG_PORT_PCIE_Q, q) |
+		FIELD_PREP(NFP_FLOWER_CMSG_PORT_TYPE,
+			   NFP_FLOWER_CMSG_PORT_TYPE_PCIE_PORT);
+}
+
+int nfp_flower_cmsg_portmod(struct net_device *netdev, bool carrier_ok);
+void nfp_flower_cmsg_rx(struct nfp_app *app, struct sk_buff *skb);
+
+#endif

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

@@ -52,14 +52,15 @@ const char *nfp_app_mip_name(struct nfp_app *app)
 	return nfp_mip_name(app->pf->mip);
 }
 
-struct sk_buff *nfp_app_ctrl_msg_alloc(struct nfp_app *app, unsigned int size)
+struct sk_buff *
+nfp_app_ctrl_msg_alloc(struct nfp_app *app, unsigned int size, gfp_t priority)
 {
 	struct sk_buff *skb;
 
 	if (nfp_app_ctrl_has_meta(app))
 		size += 8;
 
-	skb = alloc_skb(size, GFP_ATOMIC);
+	skb = alloc_skb(size, priority);
 	if (!skb)
 		return NULL;
 

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

@@ -268,7 +268,8 @@ 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);
+struct sk_buff *
+nfp_app_ctrl_msg_alloc(struct nfp_app *app, unsigned int size, gfp_t priority);
 
 struct nfp_app *nfp_app_alloc(struct nfp_pf *pf, enum nfp_app_id id);
 void nfp_app_free(struct nfp_app *app);