path: root/net/devlink/rate.c

// 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 "devl_internal.h"

static inline bool
devlink_rate_is_leaf(struct devlink_rate *devlink_rate)
{
	return devlink_rate->type == DEVLINK_RATE_TYPE_LEAF;
}

bool devlink_rate_is_node(const struct devlink_rate *devlink_rate)
{
	return devlink_rate->type == DEVLINK_RATE_TYPE_NODE;
}

static struct devlink_rate *
devlink_rate_leaf_get_from_info(struct devlink *devlink, struct genl_info *info)
{
	struct devlink_rate *devlink_rate;
	struct devlink_port *devlink_port;

	devlink_port = devlink_port_get_from_attrs(devlink, info->attrs);
	if (IS_ERR(devlink_port))
		return ERR_CAST(devlink_port);
	devlink_rate = devlink_port->devlink_rate;
	return devlink_rate ?: ERR_PTR(-ENODEV);
}

/* Repeatedly walks the nested devlink chain while cross device rate nodes are
 * supported and finds the topmost instance where rates should be stored.
 * That instance is locked, referenced and returned.
 * When cross device rate nodes aren't supported the original devlink instance
 * is returned.
 */
static struct devlink *devl_rate_lock(struct devlink *devlink)
{
	struct devlink *rate_devlink = devlink, *parent;

	devl_assert_locked(devlink);

	while (rate_devlink->ops &&
	       rate_devlink->ops->supported_cross_device_rate_nodes) {
		parent = devlink_nested_in_get_lock(rate_devlink);
		if (!parent)
			break;
		if (rate_devlink != devlink) {
			/* Unlock intermediate instances. */
			devl_unlock(rate_devlink);
			devlink_put(rate_devlink);
		}
		rate_devlink = parent;
	}
	return rate_devlink;
}

/* Unlocks and puts 'rate devlink' if different than 'devlink'. */
static void devl_rate_unlock(struct devlink *devlink,
			     struct devlink *rate_devlink)
{
	if (devlink == rate_devlink)
		return;

	devl_unlock(rate_devlink);
	devlink_put(rate_devlink);
}

static struct devlink_rate *
devlink_rate_node_get_by_name(struct devlink *rate_devlink,
			      struct devlink *devlink, const char *node_name)
{
	struct devlink_rate *devlink_rate;

	list_for_each_entry(devlink_rate, &rate_devlink->rate_list, list) {
		if (devlink_rate->devlink == devlink &&
		    devlink_rate_is_node(devlink_rate) &&
		    !strcmp(node_name, devlink_rate->name))
			return devlink_rate;
	}
	return ERR_PTR(-ENODEV);
}

static struct devlink_rate *
devlink_rate_node_get_from_attrs(struct devlink *rate_devlink,
				 struct devlink *devlink, struct nlattr **attrs)
{
	const char *rate_node_name;
	size_t len;

	if (!attrs[DEVLINK_ATTR_RATE_NODE_NAME])
		return ERR_PTR(-EINVAL);
	rate_node_name = nla_data(attrs[DEVLINK_ATTR_RATE_NODE_NAME]);
	len = strlen(rate_node_name);
	/* Name cannot be empty or decimal number */
	if (!len || strspn(rate_node_name, "0123456789") == len)
		return ERR_PTR(-EINVAL);

	return devlink_rate_node_get_by_name(rate_devlink, devlink,
					     rate_node_name);
}

static struct devlink_rate *
devlink_rate_node_get_from_info(struct devlink *rate_devlink,
				struct devlink *devlink,
				struct genl_info *info)
{
	return devlink_rate_node_get_from_attrs(rate_devlink, devlink,
						info->attrs);
}

static struct devlink_rate *
devlink_rate_get_from_info(struct devlink *rate_devlink,
			   struct devlink *devlink, struct genl_info *info)
{
	struct nlattr **attrs = info->attrs;

	if (attrs[DEVLINK_ATTR_PORT_INDEX])
		return devlink_rate_leaf_get_from_info(devlink, info);
	else if (attrs[DEVLINK_ATTR_RATE_NODE_NAME])
		return devlink_rate_node_get_from_info(rate_devlink, devlink,
						       info);
	else
		return ERR_PTR(-EINVAL);
}

static int devlink_rate_put_tc_bws(struct sk_buff *msg, u32 *tc_bw)
{
	struct nlattr *nla_tc_bw;
	int i;

	for (i = 0; i < DEVLINK_RATE_TCS_MAX; i++