ethtool: add PAUSE_NTF notification

Send ETHTOOL_MSG_PAUSE_NTF notification whenever pause parameters of
a network device are modified using ETHTOOL_MSG_PAUSE_SET netlink message
or ETHTOOL_SPAUSEPARAM ioctl request.
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/ethtool-netlink.rst

@@ -228,6 +228,7 @@ Kernel to userspace:
   ``ETHTOOL_MSG_COALESCE_GET_REPLY``    coalescing parameters
   ``ETHTOOL_MSG_COALESCE_NTF``          coalescing parameters
   ``ETHTOOL_MSG_PAUSE_GET_REPLY``       pause parameters
+  ``ETHTOOL_MSG_PAUSE_NTF``             pause parameters
   ===================================== =================================
 
 ``GET`` requests are sent by userspace applications to retrieve device

include/uapi/linux/ethtool_netlink.h

@@ -67,6 +67,7 @@ enum {
 	ETHTOOL_MSG_COALESCE_GET_REPLY,
 	ETHTOOL_MSG_COALESCE_NTF,
 	ETHTOOL_MSG_PAUSE_GET_REPLY,
+	ETHTOOL_MSG_PAUSE_NTF,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_KERNEL_CNT,

net/ethtool/ioctl.c

@@ -1705,6 +1705,7 @@ static int ethtool_get_pauseparam(struct net_device *dev, void __user *useraddr)
 static int ethtool_set_pauseparam(struct net_device *dev, void __user *useraddr)
 {
 	struct ethtool_pauseparam pauseparam;
+	int ret;
 
 	if (!dev->ethtool_ops->set_pauseparam)
 		return -EOPNOTSUPP;
@@ -1712,7 +1713,10 @@ static int ethtool_set_pauseparam(struct net_device *dev, void __user *useraddr)
 	if (copy_from_user(&pauseparam, useraddr, sizeof(pauseparam)))
 		return -EFAULT;
 
-	return dev->ethtool_ops->set_pauseparam(dev, &pauseparam);
+	ret = dev->ethtool_ops->set_pauseparam(dev, &pauseparam);
+	if (!ret)
+		ethtool_notify(dev, ETHTOOL_MSG_PAUSE_NTF, NULL);
+	return ret;
 }
 
 static int ethtool_self_test(struct net_device *dev, char __user *useraddr)

net/ethtool/netlink.c

@@ -546,6 +546,7 @@ ethnl_default_notify_ops[ETHTOOL_MSG_KERNEL_MAX + 1] = {
 	[ETHTOOL_MSG_RINGS_NTF]		= &ethnl_rings_request_ops,
 	[ETHTOOL_MSG_CHANNELS_NTF]	= &ethnl_channels_request_ops,
 	[ETHTOOL_MSG_COALESCE_NTF]	= &ethnl_coalesce_request_ops,
+	[ETHTOOL_MSG_PAUSE_NTF]		= &ethnl_pause_request_ops,
 };
 
 /* default notification handler */
@@ -636,6 +637,7 @@ static const ethnl_notify_handler_t ethnl_notify_handlers[] = {
 	[ETHTOOL_MSG_RINGS_NTF]		= ethnl_default_notify,
 	[ETHTOOL_MSG_CHANNELS_NTF]	= ethnl_default_notify,
 	[ETHTOOL_MSG_COALESCE_NTF]	= ethnl_default_notify,
+	[ETHTOOL_MSG_PAUSE_NTF]		= ethnl_default_notify,
 };
 
 void ethtool_notify(struct net_device *dev, unsigned int cmd, const void *data)

net/ethtool/pause.c

@@ -131,6 +131,9 @@ int ethnl_set_pause(struct sk_buff *skb, struct genl_info *info)
 		goto out_ops;
 
 	ret = dev->ethtool_ops->set_pauseparam(dev, &params);
+	if (ret < 0)
+		goto out_ops;
+	ethtool_notify(dev, ETHTOOL_MSG_PAUSE_NTF, NULL);
 
 out_ops:
 	ethnl_ops_complete(dev);