devlink: Add devlink_param register and unregister

Define configuration parameters data structure.
Add functions to register and unregister the driver supported
configuration parameters table.
For each parameter registered, the driver should fill all the parameter's
fields. In case the only supported configuration mode is "driverinit"
the parameter's get()/set() functions are not required and should be set
to NULL, for any other configuration mode, these functions are required
and should be set by the driver.

Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 148 insertions, 0 deletions

diff --git a/net/core/devlink.c b/net/core/devlink.c
index 22099705cc41..41b1a5d1c992 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -2604,6 +2604,82 @@ static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info)
 	return devlink->ops->reload(devlink, info->extack);
 }
 
+static const struct devlink_param devlink_param_generic[] = {};
+
+static int devlink_param_generic_verify(const struct devlink_param *param)
+{
+	/* verify it match generic parameter by id and name */
+	if (param->id > DEVLINK_PARAM_GENERIC_ID_MAX)
+		return -EINVAL;
+	if (strcmp(param->name, devlink_param_generic[param->id].name))
+		return -ENOENT;
+
+	WARN_ON(param->type != devlink_param_generic[param->id].type);
+
+	return 0;
+}
+
+static int devlink_param_driver_verify(const struct devlink_param *param)
+{
+	int i;
+
+	if (param->id <= DEVLINK_PARAM_GENERIC_ID_MAX)
+		return -EINVAL;
+	/* verify no such name in generic params */
+	for (i = 0; i <= DEVLINK_PARAM_GENERIC_ID_MAX; i++)
+		if (!strcmp(param->name, devlink_param_generic[i].name))
+			return -EEXIST;
+
+	return 0;
+}
+
+static struct devlink_param_item *
+devlink_param_find_by_name(struct list_head *param_list,
+			   const char *param_name)
+{
+	struct devlink_param_item *param_item;
+
+	list_for_each_entry(param_item, param_list, list)
+		if (!strcmp(param_item->param->name, param_name))
+			return param_item;
+	return NULL;
+}
+
+static int devlink_param_register_one(struct devlink *devlink,
+				      const struct devlink_param *param)
+{
+	struct devlink_param_item *param_item;
+
+	if (devlink_param_find_by_name(&devlink->param_list,
+				       param->name))
+		return -EEXIST;
+
+	if (param->supported_cmodes == BIT(DEVLINK_PARAM_CMODE_DRIVERINIT))
+		WARN_ON(param->get || param->set);
+	else
+		WARN_ON(!param->get || !param->set);
+
+	param_item = kzalloc(sizeof(*param_item), GFP_KERNEL);
+	if (!param_item)
+		return -ENOMEM;
+	param_item->param = param;
+
+	list_add_tail(&param_item->list, &devlink->param_list);
+	return 0;
+}
+
+static void devlink_param_unregister_one(struct devlink *devlink,
+					 const struct devlink_param *param)
+{
+	struct devlink_param_item *param_item;
+
+	param_item = devlink_param_find_by_name(&devlink->param_list,
+						param->name);
+	WARN_ON(!param_item);
+	list_del(&param_item->list);
+	kfree(param_item);
+}
+
 static const struct nla_policy devlink_nl_policy[DEVLINK_ATTR_MAX + 1] = {
 	[DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING },
 	[DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING },
@@ -2845,6 +2921,7 @@ struct devlink *devlink_alloc(const struct devlink_ops *ops, size_t priv_size)
 	INIT_LIST_HEAD(&devlink->sb_list);
 	INIT_LIST_HEAD_RCU(&devlink->dpipe_table_list);
 	INIT_LIST_HEAD(&devlink->resource_list);
+	INIT_LIST_HEAD(&devlink->param_list);
 	mutex_init(&devlink->lock);
 	return devlink;
 }
@@ -3434,6 +3511,77 @@ out:
 }
 EXPORT_SYMBOL_GPL(devlink_resource_occ_get_unregister);
 
+/**
+ *	devlink_params_register - register configuration parameters
+ *
+ *	@devlink: devlink
+ *	@params: configuration parameters array
+ *	@params_count: number of parameters provided
+ *
+ *	Register the configuration parameters supported by the driver.
+ */
+int devlink_params_register(struct devlink *devlink,
+			    const struct devlink_param *params,
+			    size_t params_count)
+{
+	const struct devlink_param *param = params;
+	int i;
+	int err;
+
+	mutex_lock(&devlink->lock);
+	for (i = 0; i < params_count; i++, param++) {
+		if (!param || !param->name || !param->supported_cmodes) {
+			err = -EINVAL;
+			goto rollback;
+		}
+		if (param->generic) {
+			err = devlink_param_generic_verify(param);
+			if (err)
+				goto rollback;
+		} else {
+			err = devlink_param_driver_verify(param);
+			if (err)
+				goto rollback;
+		}
+		err = devlink_param_register_one(devlink, param);
+		if (err)
+			goto rollback;
+	}
+
+	mutex_unlock(&devlink->lock);
+	return 0;
+
+rollback:
+	if (!i)
+		goto unlock;
+	for (param--; i > 0; i--, param--)
+		devlink_param_unregister_one(devlink, param);
+unlock:
+	mutex_unlock(&devlink->lock);
+	return err;
+}
+EXPORT_SYMBOL_GPL(devlink_params_register);
+
+/**
+ *	devlink_params_unregister - unregister configuration parameters
+ *	@devlink: devlink
+ *	@params: configuration parameters to unregister
+ *	@params_count: number of parameters provided
+ */
+void devlink_params_unregister(struct devlink *devlink,
+			       const struct devlink_param *params,
+			       size_t params_count)
+{
+	const struct devlink_param *param = params;
+	int i;
+
+	mutex_lock(&devlink->lock);
+	for (i = 0; i < params_count; i++, param++)
+		devlink_param_unregister_one(devlink, param);
+	mutex_unlock(&devlink->lock);
+}
+EXPORT_SYMBOL_GPL(devlink_params_unregister);
+
 static int __init devlink_module_init(void)
 {
 	return genl_register_family(&devlink_nl_family);