net/ncsi: Add generic netlink family

Add a generic netlink family for NCSI. This supports three commands;
NCSI_CMD_PKG_INFO which returns information on packages and their
associated channels, NCSI_CMD_SET_INTERFACE which allows a specific
package or package/channel combination to be set as the preferred
choice, and NCSI_CMD_CLEAR_INTERFACE which clears any preferred setting.
Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/ncsi.h

+/*
+ * Copyright Samuel Mendoza-Jonas, IBM Corporation 2018.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __UAPI_NCSI_NETLINK_H__
+#define __UAPI_NCSI_NETLINK_H__
+
+/**
+ * enum ncsi_nl_commands - supported NCSI commands
+ *
+ * @NCSI_CMD_UNSPEC: unspecified command to catch errors
+ * @NCSI_CMD_PKG_INFO: list package and channel attributes. Requires
+ *	NCSI_ATTR_IFINDEX. If NCSI_ATTR_PACKAGE_ID is specified returns the
+ *	specific package and its channels - otherwise a dump request returns
+ *	all packages and their associated channels.
+ * @NCSI_CMD_SET_INTERFACE: set preferred package and channel combination.
+ *	Requires NCSI_ATTR_IFINDEX and the preferred NCSI_ATTR_PACKAGE_ID and
+ *	optionally the preferred NCSI_ATTR_CHANNEL_ID.
+ * @NCSI_CMD_CLEAR_INTERFACE: clear any preferred package/channel combination.
+ *	Requires NCSI_ATTR_IFINDEX.
+ * @NCSI_CMD_MAX: highest command number
+ */
+enum ncsi_nl_commands {
+	NCSI_CMD_UNSPEC,
+	NCSI_CMD_PKG_INFO,
+	NCSI_CMD_SET_INTERFACE,
+	NCSI_CMD_CLEAR_INTERFACE,
+
+	__NCSI_CMD_AFTER_LAST,
+	NCSI_CMD_MAX = __NCSI_CMD_AFTER_LAST - 1
+};
+
+/**
+ * enum ncsi_nl_attrs - General NCSI netlink attributes
+ *
+ * @NCSI_ATTR_UNSPEC: unspecified attributes to catch errors
+ * @NCSI_ATTR_IFINDEX: ifindex of network device using NCSI
+ * @NCSI_ATTR_PACKAGE_LIST: nested array of NCSI_PKG_ATTR attributes
+ * @NCSI_ATTR_PACKAGE_ID: package ID
+ * @NCSI_ATTR_CHANNEL_ID: channel ID
+ * @NCSI_ATTR_MAX: highest attribute number
+ */
+enum ncsi_nl_attrs {
+	NCSI_ATTR_UNSPEC,
+	NCSI_ATTR_IFINDEX,
+	NCSI_ATTR_PACKAGE_LIST,
+	NCSI_ATTR_PACKAGE_ID,
+	NCSI_ATTR_CHANNEL_ID,
+
+	__NCSI_ATTR_AFTER_LAST,
+	NCSI_ATTR_MAX = __NCSI_ATTR_AFTER_LAST - 1
+};
+
+/**
+ * enum ncsi_nl_pkg_attrs - NCSI netlink package-specific attributes
+ *
+ * @NCSI_PKG_ATTR_UNSPEC: unspecified attributes to catch errors
+ * @NCSI_PKG_ATTR: nested array of package attributes
+ * @NCSI_PKG_ATTR_ID: package ID
+ * @NCSI_PKG_ATTR_FORCED: flag signifying a package has been set as preferred
+ * @NCSI_PKG_ATTR_CHANNEL_LIST: nested array of NCSI_CHANNEL_ATTR attributes
+ * @NCSI_PKG_ATTR_MAX: highest attribute number
+ */
+enum ncsi_nl_pkg_attrs {
+	NCSI_PKG_ATTR_UNSPEC,
+	NCSI_PKG_ATTR,
+	NCSI_PKG_ATTR_ID,
+	NCSI_PKG_ATTR_FORCED,
+	NCSI_PKG_ATTR_CHANNEL_LIST,
+
+	__NCSI_PKG_ATTR_AFTER_LAST,
+	NCSI_PKG_ATTR_MAX = __NCSI_PKG_ATTR_AFTER_LAST - 1
+};
+
+/**
+ * enum ncsi_nl_channel_attrs - NCSI netlink channel-specific attributes
+ *
+ * @NCSI_CHANNEL_ATTR_UNSPEC: unspecified attributes to catch errors
+ * @NCSI_CHANNEL_ATTR: nested array of channel attributes
+ * @NCSI_CHANNEL_ATTR_ID: channel ID
+ * @NCSI_CHANNEL_ATTR_VERSION_MAJOR: channel major version number
+ * @NCSI_CHANNEL_ATTR_VERSION_MINOR: channel minor version number
+ * @NCSI_CHANNEL_ATTR_VERSION_STR: channel version string
+ * @NCSI_CHANNEL_ATTR_LINK_STATE: channel link state flags
+ * @NCSI_CHANNEL_ATTR_ACTIVE: channels with this flag are in
+ *	NCSI_CHANNEL_ACTIVE state
+ * @NCSI_CHANNEL_ATTR_FORCED: flag signifying a channel has been set as
+ *	preferred
+ * @NCSI_CHANNEL_ATTR_VLAN_LIST: nested array of NCSI_CHANNEL_ATTR_VLAN_IDs
+ * @NCSI_CHANNEL_ATTR_VLAN_ID: VLAN ID being filtered on this channel
+ * @NCSI_CHANNEL_ATTR_MAX: highest attribute number
+ */
+enum ncsi_nl_channel_attrs {
+	NCSI_CHANNEL_ATTR_UNSPEC,
+	NCSI_CHANNEL_ATTR,
+	NCSI_CHANNEL_ATTR_ID,
+	NCSI_CHANNEL_ATTR_VERSION_MAJOR,
+	NCSI_CHANNEL_ATTR_VERSION_MINOR,
+	NCSI_CHANNEL_ATTR_VERSION_STR,
+	NCSI_CHANNEL_ATTR_LINK_STATE,
+	NCSI_CHANNEL_ATTR_ACTIVE,
+	NCSI_CHANNEL_ATTR_FORCED,
+	NCSI_CHANNEL_ATTR_VLAN_LIST,
+	NCSI_CHANNEL_ATTR_VLAN_ID,
+
+	__NCSI_CHANNEL_ATTR_AFTER_LAST,
+	NCSI_CHANNEL_ATTR_MAX = __NCSI_CHANNEL_ATTR_AFTER_LAST - 1
+};
+
+#endif /* __UAPI_NCSI_NETLINK_H__ */

net/ncsi/Makefile

 #
 # Makefile for NCSI API
 #
-obj-$(CONFIG_NET_NCSI) += ncsi-cmd.o ncsi-rsp.o ncsi-aen.o ncsi-manage.o
+obj-$(CONFIG_NET_NCSI) += ncsi-cmd.o ncsi-rsp.o ncsi-aen.o ncsi-manage.o ncsi-netlink.o

net/ncsi/internal.h

@@ -276,6 +276,8 @@ struct ncsi_dev_priv {
 	unsigned int        package_num;     /* Number of packages         */
 	struct list_head    packages;        /* List of packages           */
 	struct ncsi_channel *hot_channel;    /* Channel was ever active    */
+	struct ncsi_package *force_package;  /* Force a specific package   */
+	struct ncsi_channel *force_channel;  /* Force a specific channel   */
 	struct ncsi_request requests[256];   /* Request table              */
 	unsigned int        request_id;      /* Last used request ID       */
 #define NCSI_REQ_START_IDX	1
@@ -318,6 +320,7 @@ extern spinlock_t ncsi_dev_lock;
 	list_for_each_entry_rcu(nc, &np->channels, node)
 
 /* Resources */
+u32 *ncsi_get_filter(struct ncsi_channel *nc, int table, int index);
 int ncsi_find_filter(struct ncsi_channel *nc, int table, void *data);
 int ncsi_add_filter(struct ncsi_channel *nc, int table, void *data);
 int ncsi_remove_filter(struct ncsi_channel *nc, int table, int index);

net/ncsi/ncsi-manage.c

@@ -12,7 +12,6 @@
 #include <linux/init.h>
 #include <linux/netdevice.h>
 #include <linux/skbuff.h>
-#include <linux/netlink.h>
 
 #include <net/ncsi.h>
 #include <net/net_namespace.h>
@@ -23,6 +22,7 @@
 
 #include "internal.h"
 #include "ncsi-pkt.h"
+#include "ncsi-netlink.h"
 
 LIST_HEAD(ncsi_dev_list);
 DEFINE_SPINLOCK(ncsi_dev_lock);
@@ -38,7 +38,7 @@ static inline int ncsi_filter_size(int table)
 	return sizes[table];
 }
 
-static u32 *ncsi_get_filter(struct ncsi_channel *nc, int table, int index)
+u32 *ncsi_get_filter(struct ncsi_channel *nc, int table, int index)
 {
 	struct ncsi_channel_filter *ncf;
 	int size;
@@ -965,20 +965,37 @@ static void ncsi_configure_channel(struct ncsi_dev_priv *ndp)
 
 static int ncsi_choose_active_channel(struct ncsi_dev_priv *ndp)
 {
-	struct ncsi_package *np;
-	struct ncsi_channel *nc, *found, *hot_nc;
+	struct ncsi_package *np, *force_package;
+	struct ncsi_channel *nc, *found, *hot_nc, *force_channel;
 	struct ncsi_channel_mode *ncm;
 	unsigned long flags;
 
 	spin_lock_irqsave(&ndp->lock, flags);
 	hot_nc = ndp->hot_channel;
+	force_channel = ndp->force_channel;
+	force_package = ndp->force_package;
 	spin_unlock_irqrestore(&ndp->lock, flags);
 
+	/* Force a specific channel whether or not it has link if we have been
+	 * configured to do so
+	 */
+	if (force_package && force_channel) {
+		found = force_channel;
+		ncm = &found->modes[NCSI_MODE_LINK];
+		if (!(ncm->data[2] & 0x1))
+			netdev_info(ndp->ndev.dev,
+				    "NCSI: Channel %u forced, but it is link down\n",
+				    found->id);
+		goto out;
+	}
+
 	/* The search is done once an inactive channel with up
 	 * link is found.
 	 */
 	found = NULL;
 	NCSI_FOR_EACH_PACKAGE(ndp, np) {
+		if (ndp->force_package && np != ndp->force_package)
+			continue;
 		NCSI_FOR_EACH_CHANNEL(np, nc) {
 			spin_lock_irqsave(&nc->lock, flags);
 
@@ -1594,6 +1611,9 @@ struct ncsi_dev *ncsi_register_dev(struct net_device *dev,
 	ndp->ptype.dev = dev;
 	dev_add_pack(&ndp->ptype);
 
+	/* Set up generic netlink interface */
+	ncsi_init_netlink(dev);
+
 	return nd;
 }
 EXPORT_SYMBOL_GPL(ncsi_register_dev);
@@ -1673,6 +1693,8 @@ void ncsi_unregister_dev(struct ncsi_dev *nd)
 #endif
 	spin_unlock_irqrestore(&ncsi_dev_lock, flags);
 
+	ncsi_unregister_netlink(nd->dev);
+
 	kfree(ndp);
 }
 EXPORT_SYMBOL_GPL(ncsi_unregister_dev);

net/ncsi/ncsi-netlink.h

+/*
+ * Copyright Samuel Mendoza-Jonas, IBM Corporation 2018.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __NCSI_NETLINK_H__
+#define __NCSI_NETLINK_H__
+
+#include <linux/netdevice.h>
+
+#include "internal.h"
+
+int ncsi_init_netlink(struct net_device *dev);
+int ncsi_unregister_netlink(struct net_device *dev);
+
+#endif /* __NCSI_NETLINK_H__ */