with the CPU that processes transmit completions for that queue
(transmit interrupts).
+Per TX Queue rate limitation:
+=============================
+
+These are rate-limitation mechanisms implemented by HW, where currently
+a max-rate attribute is supported, by setting a Mbps value to
+
+/sys/class/net/<dev>/queues/tx-<n>/tx_maxrate
+
+A value of zero means disabled, and this is the default.
Further Information
===================
#ifdef CONFIG_BQL
struct dql dql;
#endif
+ unsigned long tx_maxrate;
} ____cacheline_aligned_in_smp;
static inline int netdev_queue_numa_node_read(const struct netdev_queue *q)
* be otherwise expressed by feature flags. The check is called with
* the set of features that the stack has calculated and it returns
* those the driver believes to be appropriate.
+ * int (*ndo_set_tx_maxrate)(struct net_device *dev,
+ * int queue_index, u32 maxrate);
+ * Called when a user wants to set a max-rate limitation of specific
+ * TX queue.
*/
struct net_device_ops {
int (*ndo_init)(struct net_device *dev);
netdev_features_t (*ndo_features_check) (struct sk_buff *skb,
struct net_device *dev,
netdev_features_t features);
+ int (*ndo_set_tx_maxrate)(struct net_device *dev,
+ int queue_index,
+ u32 maxrate);
};
/**
return sprintf(buf, "%lu", trans_timeout);
}
+#ifdef CONFIG_XPS
+static inline unsigned int get_netdev_queue_index(struct netdev_queue *queue)
+{
+ struct net_device *dev = queue->dev;
+ int i;
+
+ for (i = 0; i < dev->num_tx_queues; i++)
+ if (queue == &dev->_tx[i])
+ break;
+
+ BUG_ON(i >= dev->num_tx_queues);
+
+ return i;
+}
+
+static ssize_t show_tx_maxrate(struct netdev_queue *queue,
+ struct netdev_queue_attribute *attribute,
+ char *buf)
+{
+ return sprintf(buf, "%lu\n", queue->tx_maxrate);
+}
+
+static ssize_t set_tx_maxrate(struct netdev_queue *queue,
+ struct netdev_queue_attribute *attribute,
+ const char *buf, size_t len)
+{
+ struct net_device *dev = queue->dev;
+ int err, index = get_netdev_queue_index(queue);
+ u32 rate = 0;
+
+ err = kstrtou32(buf, 10, &rate);
+ if (err < 0)
+ return err;
+
+ if (!rtnl_trylock())
+ return restart_syscall();
+
+ err = -EOPNOTSUPP;
+ if (dev->netdev_ops->ndo_set_tx_maxrate)
+ err = dev->netdev_ops->ndo_set_tx_maxrate(dev, index, rate);
+
+ rtnl_unlock();
+ if (!err) {
+ queue->tx_maxrate = rate;
+ return len;
+ }
+ return err;
+}
+
+static struct netdev_queue_attribute queue_tx_maxrate =
+ __ATTR(tx_maxrate, S_IRUGO | S_IWUSR,
+ show_tx_maxrate, set_tx_maxrate);
+#endif
+
static struct netdev_queue_attribute queue_trans_timeout =
__ATTR(tx_timeout, S_IRUGO, show_trans_timeout, NULL);
#endif /* CONFIG_BQL */
#ifdef CONFIG_XPS
-static unsigned int get_netdev_queue_index(struct netdev_queue *queue)
-{
- struct net_device *dev = queue->dev;
- unsigned int i;
-
- i = queue - dev->_tx;
- BUG_ON(i >= dev->num_tx_queues);
-
- return i;
-}
-
-
static ssize_t show_xps_map(struct netdev_queue *queue,
struct netdev_queue_attribute *attribute, char *buf)
{
&queue_trans_timeout.attr,
#ifdef CONFIG_XPS
&xps_cpus_attribute.attr,
+ &queue_tx_maxrate.attr,
#endif
NULL
};