ethtool: Veto some operations during firmware flashing process

Some operations cannot be performed during the firmware flashing
process.

For example:

- Port must be down during the whole flashing process to avoid packet loss
  while committing reset for example.

- Writing to EEPROM interrupts the flashing process, so operations like
  ethtool dump, module reset, get and set power mode should be vetoed.

- Split port firmware flashing should be vetoed.

In order to veto those scenarios, add a flag in 'struct net_device' that
indicates when a firmware flash is taking place on the module and use it
to prevent interruptions during the process.

Signed-off-by: Danielle Ratson <danieller@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 0 deletions

diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 393ce668fb04..a5907bbde427 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -765,10 +765,22 @@ static void ethnl_notify_features(struct netdev_notifier_info *info)
 static int ethnl_netdev_event(struct notifier_block *this, unsigned long event,
 			      void *ptr)
 {
+	struct netdev_notifier_info *info = ptr;
+	struct netlink_ext_ack *extack;
+	struct net_device *dev;
+
+	dev = netdev_notifier_info_to_dev(info);
+	extack = netdev_notifier_info_to_extack(info);
+
 	switch (event) {
 	case NETDEV_FEAT_CHANGE:
 		ethnl_notify_features(ptr);
 		break;
+	case NETDEV_PRE_UP:
+		if (dev->module_fw_flash_in_progress) {
+			NL_SET_ERR_MSG(extack, "Can't set port up while flashing module firmware");
+			return NOTIFY_BAD;
+		}
 	}
 
 	return NOTIFY_DONE;