net core: Add protodown support.

This patch introduces the proto_down flag that can be used by user space
applications to notify switch drivers that errors have been detected on the
device.

The switch driver can react to protodown notification by doing a phys down
on the associated switch port.

Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>
Signed-off-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: Wilson Kok <wkok@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 34 insertions, 0 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 69445a33ace6..8810b6bbebfe 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6075,6 +6075,26 @@ int dev_get_phys_port_name(struct net_device *dev,
 EXPORT_SYMBOL(dev_get_phys_port_name);
 
 /**
+ *      dev_change_proto_down - update protocol port state information
+ *      @dev: device
+ *      @proto_down: new value
+ *
+ *      This info can be used by switch drivers to set the phys state of the
+ *      port.
+ */
+int dev_change_proto_down(struct net_device *dev, bool proto_down)
+{
+        const struct net_device_ops *ops = dev->netdev_ops;
+
+        if (!ops->ndo_change_proto_down)
+                return -EOPNOTSUPP;
+        if (!netif_device_present(dev))
+                return -ENODEV;
+        return ops->ndo_change_proto_down(dev, proto_down);
+}
+EXPORT_SYMBOL(dev_change_proto_down);
+
+/**
  *      dev_new_index   -       allocate an ifindex
  *      @net: the applicable net namespace
  *
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 18b34d771ed4..194c1d03b2b3 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -404,6 +404,19 @@ static ssize_t group_store(struct device *dev, struct device_attribute *attr,
 NETDEVICE_SHOW(group, fmt_dec);
 static DEVICE_ATTR(netdev_group, S_IRUGO | S_IWUSR, group_show, group_store);
 
+static int change_proto_down(struct net_device *dev, unsigned long proto_down)
+{
+        return dev_change_proto_down(dev, (bool) proto_down);
+}
+
+static ssize_t proto_down_store(struct device *dev,
+                                struct device_attribute *attr,
+                                const char *buf, size_t len)
+{
+        return netdev_store(dev, attr, buf, len, change_proto_down);
+}
+NETDEVICE_SHOW_RW(proto_down, fmt_dec);
+
 static ssize_t phys_port_id_show(struct device *dev,
                                  struct device_attribute *attr, char *buf)
 {
@@ -501,6 +514,7 @@ static struct attribute *net_class_attrs[] = {
         &dev_attr_phys_port_id.attr,
         &dev_attr_phys_port_name.attr,
         &dev_attr_phys_switch_id.attr,
+        &dev_attr_proto_down.attr,
         NULL,
 };
 ATTRIBUTE_GROUPS(net_class);