1 files changed, 551 insertions, 0 deletions
diff --git a/net/devlink/core.c b/net/devlink/core.c
new file mode 100644
index 000000000000..58093f49c090
--- /dev/null
+++ b/net/devlink/core.c
@@ -0,0 +1,551 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2016 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2016 Jiri Pirko <jiri@mellanox.com>
+ */
+
+#include <net/genetlink.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/devlink.h>
+
+#include "devl_internal.h"
+
+EXPORT_TRACEPOINT_SYMBOL_GPL(devlink_hwmsg);
+EXPORT_TRACEPOINT_SYMBOL_GPL(devlink_hwerr);
+EXPORT_TRACEPOINT_SYMBOL_GPL(devlink_trap_report);
+
+DEFINE_XARRAY_FLAGS(devlinks, XA_FLAGS_ALLOC);
+
+static struct devlink *devlinks_xa_get(unsigned long index)
+{
+	struct devlink *devlink;
+
+	rcu_read_lock();
+	devlink = xa_find(&devlinks, &index, index, DEVLINK_REGISTERED);
+	if (!devlink || !devlink_try_get(devlink))
+		devlink = NULL;
+	rcu_read_unlock();
+	return devlink;
+}
+
+/* devlink_rels xarray contains 1:1 relationships between
+ * devlink object and related nested devlink instance.
+ * The xarray index is used to get the nested object from
+ * the nested-in object code.
+ */
+static DEFINE_XARRAY_FLAGS(devlink_rels, XA_FLAGS_ALLOC1);
+
+#define DEVLINK_REL_IN_USE XA_MARK_0
+
+struct devlink_rel {
+	u32 index;
+	refcount_t refcount;
+	u32 devlink_index;
+	struct {
+		u32 devlink_index;
+		u32 obj_index;
+		devlink_rel_notify_cb_t *notify_cb;
+		devlink_rel_cleanup_cb_t *cleanup_cb;
+		struct delayed_work notify_work;
+	} nested_in;
+};
+
+static void devlink_rel_free(struct devlink_rel *rel)
+{
+	xa_erase(&devlink_rels, rel->index);
+	kfree(rel);
+}
+
+static void __devlink_rel_get(struct devlink_rel *rel)
+{
+	refcount_inc(&rel->refcount);
+}
+
+static void __devlink_rel_put(struct devlink_rel *rel)
+{
+	if (refcount_dec_and_test(&rel->refcount))
+		devlink_rel_free(rel);
+}
+
+static void devlink_rel_nested_in_notify_work(struct work_struct *work)
+{
+	struct devlink_rel *rel = container_of(work, struct devlink_rel,
+					       nested_in.notify_work.work);
+	struct devlink *devlink;
+
+	devlink = devlinks_xa_get(rel->nested_in.devlink_index);
+	if (!devlink)
+		goto rel_put;
+	if (!devl_trylock(devlink)) {
+		devlink_put(devlink);
+		goto reschedule_work;
+	}
+	if (!devl_is_registered(devlink)) {
+		devl_unlock(devlink);
+		devlink_put(devlink);
+		goto rel_put;
+	}
+	if (!xa_get_mark(&devlink_rels, rel->index, DEVLINK_REL_IN_USE))
+		rel->nested_in.cleanup_cb(devlink, rel->nested_in.obj_index, rel->index);
+	rel->nested_in.notify_cb(devlink, rel->nested_in.obj_index);
+	devl_unlock(devlink);
+	devlink_put(devlink);
+
+rel_put:
+	__devlink_rel_put(rel);
+	return;
+
+reschedule_work:
+	schedule_delayed_work(&rel->nested_in.notify_work, 1);
+}
+
+static void devlink_rel_nested_in_notify_work_schedule(struct devlink_rel *rel)
+{
+	__devlink_rel_get(rel);
+	schedule_delayed_work(&rel->nested_in.notify_work, 0);
+}
+
+static struct devlink_rel *devlink_rel_alloc(void)
+{
+	struct devlink_rel *rel;
+	static u32 next;
+	int err;
+
+	rel = kzalloc(sizeof(*rel), GFP_KERNEL);
+	if (!rel)
+		return ERR_PTR(-ENOMEM);
+
+	err = xa_alloc_cyclic(&devlink_rels, &rel->index, rel,
+			      xa_limit_32b, &next, GFP_KERNEL);
+	if (err < 0) {
+		kfree(rel);
+		return ERR_PTR(err);
+	}
+
+	refcount_set(&rel->refcount, 1);
+	INIT_DELAYED_WORK(&rel->nested_in.notify_work,
+			  &devlink_rel_nested_in_notify_work);
+	return rel;
+}
+
+static void devlink_rel_put(struct devlink *devlink)
+{
+	struct devlink_rel *rel = devlink->rel;
+
+	if (!rel)
+		return;
+	xa_clear_mark(&devlink_rels, rel->index, DEVLINK_REL_IN_USE);
+	devlink_rel_nested_in_notify_work_schedule(rel);
+	__devlink_rel_put(rel);
+	devlink->rel = NULL;
+}
+
+void devlink_rel_nested_in_clear(u32 rel_index)
+{
+	xa_clear_mark(&devlink_rels, rel_index, DEVLINK_REL_IN_USE);
+}
+
+int devlink_rel_nested_in_add(u32 *rel_index, u32 devlink_index,
+			      u32 obj_index, devlink_rel_notify_cb_t *notify_cb,
+			      devlink_rel_cleanup_cb_t *cleanup_cb,
+			      struct devlink *devlink)
+{
+	struct devlink_rel *rel = devlink_rel_alloc();
+
+	ASSERT_DEVLINK_NOT_REGISTERED(devlink);
+
+	if (IS_ERR(rel))
+		return PTR_ERR(rel);
+
+	rel->devlink_index = devlink->index;
+	rel->nested_in.devlink_index = devlink_index;
+	rel->nested_in.obj_index = obj_index;
+	rel->nested_in.notify_cb = notify_cb;
+	rel->nested_in.cleanup_cb = cleanup_cb;
+	*rel_index = rel->index;
+	xa_set_mark(&devlink_rels, rel->index, DEVLINK_REL_IN_USE);
+	devlink->rel = rel;
+	return 0;
+}
+
+/**
+ * devlink_rel_nested_in_notify - Notify the object this devlink
+ *				  instance is nested in.
+ * @devlink: devlink
+ *
+ * This is called upon network namespace change of devlink instance.
+ * In case this devlink instance is nested in another devlink object,
+ * a notification of a change of this object should be sent
+ * over netlink. The parent devlink instance lock needs to be
+ * taken during the notification preparation.
+ * However, since the devlink lock of nested instance is held here,
+ * we would end with wrong devlink instance lock ordering and
+ * deadlock. Therefore the work is utilized to avoid that.
+ */
+void devlink_rel_nested_in_notify(struct devlink *devlink)
+{
+	struct devlink_rel *rel = devlink->rel;
+
+	if (!rel)
+		return;
+	devlink_rel_nested_in_notify_work_schedule(rel);
+}
+
+static struct devlink_rel *devlink_rel_find(unsigned long rel_index)
+{
+	return xa_find(&devlink_rels, &rel_index, rel_index,
+		       DEVLINK_REL_IN_USE);
+}
+
+static struct devlink *devlink_rel_devlink_get(u32 rel_index)
+{
+	struct devlink_rel *rel;
+	u32 devlink_index;
+
+	if (!rel_index)
+		return NULL;
+	xa_lock(&devlink_rels);
+	rel = devlink_rel_find(rel_index);
+	if (rel)
+		devlink_index = rel->devlink_index;
+	xa_unlock(&devlink_rels);
+	if (!rel)
+		return NULL;
+	return devlinks_xa_get(devlink_index);
+}
+
+int devlink_rel_devlink_handle_put(struct sk_buff *msg, struct devlink *devlink,
+				   u32 rel_index, int attrtype,
+				   bool *msg_updated)
+{
+	struct net *net = devlink_net(devlink);
+	struct devlink *rel_devlink;
+	int err;
+
+	rel_devlink = devlink_rel_devlink_get(rel_index);
+	if (!rel_devlink)
+		return 0;
+	err = devlink_nl_put_nested_handle(msg, net, rel_devlink, attrtype);
+	devlink_put(rel_devlink);
+	if (!err && msg_updated)
+		*msg_updated = true;
+	return err;
+}
+
+void *devlink_priv(struct devlink *devlink)
+{
+	return &devlink->priv;
+}
+EXPORT_SYMBOL_GPL(devlink_priv);
+
+struct devlink *priv_to_devlink(void *priv)
+{
+	return container_of(priv, struct devlink, priv);
+}
+EXPORT_SYMBOL_GPL(priv_to_devlink);
+
+struct device *devlink_to_dev(const struct devlink *devlink)
+{
+	return devlink->dev;
+}
+EXPORT_SYMBOL_GPL(devlink_to_dev);
+
+struct net *devlink_net(const struct devlink *devlink)
+{
+	return read_pnet(&devlink->_net);
+}
+EXPORT_SYMBOL_GPL(devlink_net);
+
+void devl_assert_locked(struct devlink *devlink)
+{
+	lockdep_assert_held(&devlink->lock);
+}
+EXPORT_SYMBOL_GPL(devl_assert_locked);
+
+#ifdef CONFIG_LOCKDEP
+/* For use in conjunction with LOCKDEP only e.g. rcu_dereference_protected() */
+bool devl_lock_is_held(struct devlink *devlink)
+{
+	return lockdep_is_held(&devlink->lock);
+}
+EXPORT_SYMBOL_GPL(devl_lock_is_held);
+#endif
+
+void devl_lock(struct devlink *devlink)
+{
+	mutex_lock(&devlink->lock);
+}
+EXPORT_SYMBOL_GPL(devl_lock);
+
+int devl_trylock(struct devlink *devlink)
+{
+	return mutex_trylock(&devlink->lock);
+}
+EXPORT_SYMBOL_GPL(devl_trylock);
+
+void devl_unlock(struct devlink *devlink)
+{
+	mutex_unlock(&devlink->lock);
+}
+EXPORT_SYMBOL_GPL(devl_unlock);
+
+/**
+ * devlink_try_get() - try to obtain a reference on a devlink instance
+ * @devlink: instance to reference
+ *
+ * Obtain a reference on a devlink instance. A reference on a devlink instance
+ * only implies that it's safe to take the instance lock. It does not imply
+ * that the instance is registered, use devl_is_registered() after taking
+ * the instance lock to check registration status.
+ */
+struct devlink *__must_check devlink_try_get(struct devlink *devlink)
+{
+	if (refcount_inc_not_zero(&devlink->refcount))
+		return devlink;
+	return NULL;
+}
+
+static void devlink_release(struct work_struct *work)
+{
+	struct devlink *devlink;
+
+	devlink = container_of(to_rcu_work(work), struct devlink, rwork);
+
+	mutex_destroy(&devlink->lock);
+	lockdep_unregister_key(&devlink->lock_key);
+	put_device(devlink->dev);
+	kvfree(devlink);
+}
+
+void devlink_put(struct devlink *devlink)
+{
+	if (refcount_dec_and_test(&devlink->refcount))
+		queue_rcu_work(system_percpu_wq, &devlink->rwork);
+}
+
+struct devlink *devlinks_xa_find_get(struct net *net, unsigned long *indexp)
+{
+	struct devlink *devlink = NULL;
+
+	rcu_read_lock();
+retry:
+	devlink = xa_find(&devlinks, indexp, ULONG_MAX, DEVLINK_REGISTERED);
+	if (!devlink)
+		goto unlock;
+
+	if (!devlink_try_get(devlink))
+		goto next;
+	if (!net_eq(devlink_net(devlink), net)) {
+		devlink_put(devlink);
+		goto next;
+	}
+unlock:
+	rcu_read_unlock();
+	return devlink;
+
+next:
+	(*indexp)++;
+	goto retry;
+}
+
+/**
+ * devl_register - Register devlink instance
+ * @devlink: devlink
+ */
+int devl_register(struct devlink *devlink)
+{
+	ASSERT_DEVLINK_NOT_REGISTERED(devlink);
+	devl_assert_locked(devlink);
+
+	xa_set_mark(&devlinks, devlink->index, DEVLINK_REGISTERED);
+	devlink_notify_register(devlink);
+	devlink_rel_nested_in_notify(devlink);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devl_register);
+
+void devlink_register(struct devlink *devlink)
+{
+	devl_lock(devlink);
+	devl_register(devlink);
+	devl_unlock(devlink);
+}
+EXPORT_SYMBOL_GPL(devlink_register);
+
+/**
+ * devl_unregister - Unregister devlink instance
+ * @devlink: devlink
+ */
+void devl_unregister(struct devlink *devlink)
+{
+	ASSERT_DEVLINK_REGISTERED(devlink);
+	devl_assert_locked(devlink);
+
+	devlink_notify_unregister(devlink);
+	xa_clear_mark(&devlinks, devlink->index, DEVLINK_REGISTERED);
+	devlink_rel_put(devlink);
+}
+EXPORT_SYMBOL_GPL(devl_unregister);
+
+void devlink_unregister(struct devlink *devlink)
+{
+	devl_lock(devlink);
+	devl_unregister(devlink);
+	devl_unlock(devlink);
+}
+EXPORT_SYMBOL_GPL(devlink_unregister);
+
+/**
+ *	devlink_alloc_ns - Allocate new devlink instance resources
+ *	in specific namespace
+ *
+ *	@ops: ops
+ *	@priv_size: size of user private data
+ *	@net: net namespace
+ *	@dev: parent device
+ *
+ *	Allocate new devlink instance resources, including devlink index
+ *	and name.
+ */
+struct devlink *devlink_alloc_ns(const struct devlink_ops *ops,
+				 size_t priv_size, struct net *net,
+				 struct device *dev)
+{
+	struct devlink *devlink;
+	static u32 last_id;
+	int ret;
+
+	WARN_ON(!ops || !dev);
+	if (!devlink_reload_actions_valid(ops))
+		return NULL;
+
+	devlink = kvzalloc(struct_size(devlink, priv, priv_size), GFP_KERNEL);
+	if (!devlink)
+		return NULL;
+
+	ret = xa_alloc_cyclic(&devlinks, &devlink->index, devlink, xa_limit_31b,
+			      &last_id, GFP_KERNEL);
+	if (ret < 0)
+		goto err_xa_alloc;
+
+	devlink->dev = get_device(dev);
+	devlink->ops = ops;
+	xa_init_flags(&devlink->ports, XA_FLAGS_ALLOC);
+	xa_init_flags(&devlink->params, XA_FLAGS_ALLOC);
+	xa_init_flags(&devlink->snapshot_ids, XA_FLAGS_ALLOC);
+	xa_init_flags(&devlink->nested_rels, XA_FLAGS_ALLOC);
+	write_pnet(&devlink->_net, net);
+	INIT_LIST_HEAD(&devlink->rate_list);
+	INIT_LIST_HEAD(&devlink->linecard_list);
+	INIT_LIST_HEAD(&devlink->sb_list);
+	INIT_LIST_HEAD_RCU(&devlink->dpipe_table_list);
+	INIT_LIST_HEAD(&devlink->resource_list);
+	INIT_LIST_HEAD(&devlink->region_list);
+	INIT_LIST_HEAD(&devlink->reporter_list);
+	INIT_LIST_HEAD(&devlink->trap_list);
+	INIT_LIST_HEAD(&devlink->trap_group_list);
+	INIT_LIST_HEAD(&devlink->trap_policer_list);
+	INIT_RCU_WORK(&devlink->rwork, devlink_release);
+	lockdep_register_key(&devlink->lock_key);
+	mutex_init(&devlink->lock);
+	lockdep_set_class(&devlink->lock, &devlink->lock_key);
+	refcount_set(&devlink->refcount, 1);
+
+	return devlink;
+
+err_xa_alloc:
+	kvfree(devlink);
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(devlink_alloc_ns);
+
+/**
+ *	devlink_free - Free devlink instance resources
+ *
+ *	@devlink: devlink
+ */
+void devlink_free(struct devlink *devlink)
+{
+	ASSERT_DEVLINK_NOT_REGISTERED(devlink);
+
+	WARN_ON(!list_empty(&devlink->trap_policer_list));
+	WARN_ON(!list_empty(&devlink->trap_group_list));
+	WARN_ON(!list_empty(&devlink->trap_list));
+	WARN_ON(!list_empty(&devlink->reporter_list));
+	WARN_ON(!list_empty(&devlink->region_list));
+	WARN_ON(!list_empty(&devlink->resource_list));
+	WARN_ON(!list_empty(&devlink->dpipe_table_list));
+	WARN_ON(!list_empty(&devlink->sb_list));
+	WARN_ON(!list_empty(&devlink->rate_list));
+	WARN_ON(!list_empty(&devlink->linecard_list));
+	WARN_ON(!xa_empty(&devlink->ports));
+
+	xa_destroy(&devlink->nested_rels);
+	xa_destroy(&devlink->snapshot_ids);
+	xa_destroy(&devlink->params);
+	xa_destroy(&devlink->ports);
+
+	xa_erase(&devlinks, devlink->index);
+
+	devlink_put(devlink);
+}
+EXPORT_SYMBOL_GPL(devlink_free);
+
+static void __net_exit devlink_pernet_pre_exit(struct net *net)
+{
+	struct devlink *devlink;
+	u32 actions_performed;
+	unsigned long index;
+	int err;
+
+	/* In case network namespace is getting destroyed, reload
+	 * all devlink instances from this namespace into init_net.
+	 */
+	devlinks_xa_for_each_registered_get(net, index, devlink) {
+		devl_dev_lock(devlink, true);
+		err = 0;
+		if (devl_is_registered(devlink))
+			err = devlink_reload(devlink, &init_net,
+					     DEVLINK_RELOAD_ACTION_DRIVER_REINIT,
+					     DEVLINK_RELOAD_LIMIT_UNSPEC,
+					     &actions_performed, NULL);
+		devl_dev_unlock(devlink, true);
+		devlink_put(devlink);
+		if (err && err != -EOPNOTSUPP)
+			pr_warn("Failed to reload devlink instance into init_net\n");
+	}
+}
+
+static struct pernet_operations devlink_pernet_ops __net_initdata = {
+	.pre_exit = devlink_pernet_pre_exit,
+};
+
+static struct notifier_block devlink_port_netdevice_nb = {
+	.notifier_call = devlink_port_netdevice_event,
+};
+
+static int __init devlink_init(void)
+{
+	int err;
+
+	err = register_pernet_subsys(&devlink_pernet_ops);
+	if (err)
+		goto out;
+	err = genl_register_family(&devlink_nl_family);
+	if (err)
+		goto out_unreg_pernet_subsys;
+	err = register_netdevice_notifier(&devlink_port_netdevice_nb);
+	if (!err)
+		return 0;
+
+	genl_unregister_family(&devlink_nl_family);
+
+out_unreg_pernet_subsys:
+	unregister_pernet_subsys(&devlink_pernet_ops);
+out:
+	WARN_ON(err);
+	return err;
+}
+
+subsys_initcall(devlink_init);