[PATCH net-next v3 10/10] ethtool: Veto some operations during firmware flashing process

[Danielle Ratson <danieller@nvidia.com>]

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.

- Flashing firmware on a device which is already in a flashing process
  should be forbidden.

Use the 'module_fw_flashing_in_progress' flag introduced in a previous
patch to veto those operations and prevent interruptions while preforming
module firmware flash.

Signed-off-by: Danielle Ratson <danieller@nvidia.com>
---
 net/ethtool/eeprom.c  |  6 ++++++
 net/ethtool/ioctl.c   | 12 ++++++++++++
 net/ethtool/module.c  | 29 +++++++++++++++++++++++++++++
 net/ethtool/netlink.c | 30 +++++++++++++++++++++++++++++-
 4 files changed, 76 insertions(+), 1 deletion(-)

diff --git a/net/ethtool/eeprom.c b/net/ethtool/eeprom.c
index 6209c3a9c8f7..f36811b3ecf1 100644
--- a/net/ethtool/eeprom.c
+++ b/net/ethtool/eeprom.c
@@ -91,6 +91,12 @@ static int get_module_eeprom_by_page(struct net_device *dev,
 {
 	const struct ethtool_ops *ops = dev->ethtool_ops;
 
+	if (dev->module_fw_flash_in_progress) {
+		NL_SET_ERR_MSG(extack,
+			       "Module firmware flashing is in progress");
+		return -EBUSY;
+	}
+
 	if (dev->sfp_bus)
 		return sfp_get_module_eeprom_by_page(dev->sfp_bus, page_data, extack);
 
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 5a55270aa86e..02b23805d2be 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -658,6 +658,9 @@ static int ethtool_get_settings(struct net_device *dev, void __user *useraddr)
 	if (!dev->ethtool_ops->get_link_ksettings)
 		return -EOPNOTSUPP;
 
+	if (dev->module_fw_flash_in_progress)
+		return -EBUSY;
+
 	memset(&link_ksettings, 0, sizeof(link_ksettings));
 	err = dev->ethtool_ops->get_link_ksettings(dev, &link_ksettings);
 	if (err < 0)
@@ -1449,6 +1452,9 @@ static int ethtool_reset(struct net_device *dev, char __user *useraddr)
 	if (!dev->ethtool_ops->reset)
 		return -EOPNOTSUPP;
 
+	if (dev->module_fw_flash_in_progress)
+		return -EBUSY;
+
 	if (copy_from_user(&reset, useraddr, sizeof(reset)))
 		return -EFAULT;
 
@@ -2462,6 +2468,9 @@ int ethtool_get_module_info_call(struct net_device *dev,
 	const struct ethtool_ops *ops = dev->ethtool_ops;
 	struct phy_device *phydev = dev->phydev;
 
+	if (dev->module_fw_flash_in_progress)
+		return -EBUSY;
+
 	if (dev->sfp_bus)
 		return sfp_get_module_info(dev->sfp_bus, modinfo);
 
@@ -2499,6 +2508,9 @@ int ethtool_get_module_eeprom_call(struct net_device *dev,
 	const struct ethtool_ops *ops = dev->ethtool_ops;
 	struct phy_device *phydev = dev->phydev;
 
+	if (dev->module_fw_flash_in_progress)
+		return -EBUSY;
+
 	if (dev->sfp_bus)
 		return sfp_get_module_eeprom(dev->sfp_bus, ee, data);
 
diff --git a/net/ethtool/module.c b/net/ethtool/module.c
index 836c198d2cc4..239e7974f952 100644
--- a/net/ethtool/module.c
+++ b/net/ethtool/module.c
@@ -3,6 +3,7 @@
 #include <linux/ethtool.h>
 #include <linux/firmware.h>
 #include <linux/sfp.h>
+#include <net/devlink.h>
 
 #include "netlink.h"
 #include "common.h"
@@ -36,6 +37,12 @@ static int module_get_power_mode(struct net_device *dev,
 	if (!ops->get_module_power_mode)
 		return 0;
 
+	if (dev->module_fw_flash_in_progress) {
+		NL_SET_ERR_MSG(extack,
+			       "Module firmware flashing is in progress");
+		return -EBUSY;
+	}
+
 	return ops->get_module_power_mode(dev, &data->power, extack);
 }
 
@@ -112,6 +119,12 @@ ethnl_set_module_validate(struct ethnl_req_info *req_info,
 	if (!tb[ETHTOOL_A_MODULE_POWER_MODE_POLICY])
 		return 0;
 
+	if (req_info->dev->module_fw_flash_in_progress) {
+		NL_SET_ERR_MSG(info->extack,
+			       "Module firmware flashing is in progress");
+		return -EBUSY;
+	}
+
 	if (!ops->get_module_power_mode || !ops->set_module_power_mode) {
 		NL_SET_ERR_MSG_ATTR(info->extack,
 				    tb[ETHTOOL_A_MODULE_POWER_MODE_POLICY],
@@ -219,6 +232,7 @@ static int module_flash_fw_work_init(struct ethtool_module_fw_flash *module_fw,
 static int __module_flash_fw_schedule(struct net_device *dev,
 				      struct netlink_ext_ack *extack)
 {
+	struct devlink_port *devlink_port = dev->devlink_port;
 	const struct ethtool_ops *ops = dev->ethtool_ops;
 
 	if (!ops->set_module_eeprom_by_page ||
@@ -234,6 +248,21 @@ static int __module_flash_fw_schedule(struct net_device *dev,
 		return -EOPNOTSUPP;
 	}
 
+	if (dev->module_fw_flash_in_progress) {
+		NL_SET_ERR_MSG(extack, "Module firmware flashing already in progress");
+		return -EBUSY;
+	}
+
+	if (dev->flags & IFF_UP) {
+		NL_SET_ERR_MSG(extack, "Netdevice is up, so flashing is not permitted");
+		return -EBUSY;
+	}
+
+	if (devlink_port && devlink_port->attrs.split) {
+		NL_SET_ERR_MSG(extack, "Can't perform firmware flashing on a split port");
+		return -EOPNOTSUPP;
+	}
+
 	return 0;
 }
 
diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c
index 1a4f6bd1ec7f..90e5b5312aa2 100644
--- a/net/ethtool/netlink.c
+++ b/net/ethtool/netlink.c
@@ -1194,6 +1194,29 @@ static struct genl_family ethtool_genl_family __ro_after_init = {
 	.n_mcgrps	= ARRAY_SIZE(ethtool_nl_mcgrps),
 };
 
+static int module_netdev_pre_up_event(struct notifier_block *this,
+				      unsigned long event, void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	struct netdev_notifier_info *info = ptr;
+	struct netlink_ext_ack *extack;
+
+	extack = netdev_notifier_info_to_extack(info);
+
+	if (event == 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;
+}
+
+static struct notifier_block ethtool_module_netdev_pre_up_notifier = {
+	.notifier_call = module_netdev_pre_up_event,
+};
+
 /* module setup */
 
 static int __init ethnl_init(void)
@@ -1206,7 +1229,12 @@ static int __init ethnl_init(void)
 	ethnl_ok = true;
 
 	ret = register_netdevice_notifier(&ethnl_netdev_notifier);
-	WARN(ret < 0, "ethtool: net device notifier registration failed");
+	if (WARN(ret < 0, "ethtool: net device notifier registration failed"))
+		return ret;
+
+	ret = register_netdevice_notifier(&ethtool_module_netdev_pre_up_notifier);
+	WARN(ret < 0, "ethtool: net device port up notifier registration failed");
+
 	return ret;
 }
 
-- 
2.43.0