Merge branch 'dsa_master_ioctl-notifier'

Vladimir Oltean says:

====================
net: Convert dsa_master_ioctl() to netdev notifier

This is preparatory work in order for Maxim Georgiev to be able to start
the API conversion process of hardware timestamping from ndo_eth_ioctl()
to ndo_hwtstamp_set():
https://lore.kernel.org/netdev/20230331045619.40256-1-glipus@gmail.com/

In turn, Maxim Georgiev's work is a preparation so that Köry Maincent is
able to make the active hardware timestamping layer selectable by user
space.
https://lore.kernel.org/netdev/20230308135936.761794-1-kory.maincent@bootlin.com/

So, quite some dependency chain.

Before this patch set, DSA prevented the conversion of any networking
driver from the ndo_eth_ioctl() API to the ndo_hwtstamp_set() API,
because it wanted to validate the hwtstamping settings on the DSA
master, and it was only coded up to do this using the old API.

After this patch set, a new netdev notifier exists, which does not
depend on anything that would constitute the "soon-to-be-legacy" API,
but rather, it uses a newly introduced struct kernel_hwtstamp_config,
and it doesn't issue any ioctl at all, being thus compatible both with
ndo_eth_ioctl(), and with the not-yet-introduced, but now possible,
ndo_hwtstamp_set().
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 41 insertions, 52 deletions

diff --git a/include/linux/net_tstamp.h b/include/linux/net_tstamp.h
new file mode 100644
index 000000000000..fd67f3cc0c4b
--- /dev/null
+++ b/include/linux/net_tstamp.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _LINUX_NET_TIMESTAMPING_H_
+#define _LINUX_NET_TIMESTAMPING_H_
+
+#include <uapi/linux/net_tstamp.h>
+
+/**
+ * struct kernel_hwtstamp_config - Kernel copy of struct hwtstamp_config
+ *
+ * @flags: see struct hwtstamp_config
+ * @tx_type: see struct hwtstamp_config
+ * @rx_filter: see struct hwtstamp_config
+ *
+ * Prefer using this structure for in-kernel processing of hardware
+ * timestamping configuration, over the inextensible struct hwtstamp_config
+ * exposed to the %SIOCGHWTSTAMP and %SIOCSHWTSTAMP ioctl UAPI.
+ */
+struct kernel_hwtstamp_config {
+	int flags;
+	int tx_type;
+	int rx_filter;
+};
+
+static inline void hwtstamp_config_to_kernel(struct kernel_hwtstamp_config *kernel_cfg,
+					     const struct hwtstamp_config *cfg)
+{
+	kernel_cfg->flags = cfg->flags;
+	kernel_cfg->tx_type = cfg->tx_type;
+	kernel_cfg->rx_filter = cfg->rx_filter;
+}
+
+#endif /* _LINUX_NET_TIMESTAMPING_H_ */
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 62e093a6d6d1..a740be3bb911 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2878,6 +2878,7 @@ enum netdev_cmd {
 	NETDEV_OFFLOAD_XSTATS_REPORT_USED,
 	NETDEV_OFFLOAD_XSTATS_REPORT_DELTA,
 	NETDEV_XDP_FEAT_CHANGE,
+	NETDEV_PRE_CHANGE_HWTSTAMP,
 };
 const char *netdev_cmd_to_name(enum netdev_cmd cmd);
 
@@ -2928,6 +2929,11 @@ struct netdev_notifier_pre_changeaddr_info {
 	const unsigned char *dev_addr;
 };
 
+struct netdev_notifier_hwtstamp_info {
+	struct netdev_notifier_info info; /* must be first */
+	struct kernel_hwtstamp_config *config;
+};
+
 enum netdev_offload_xstats_type {
 	NETDEV_OFFLOAD_XSTATS_TYPE_L3 = 1,
 };
@@ -2984,7 +2990,8 @@ netdev_notifier_info_to_extack(const struct netdev_notifier_info *info)
 }
 
 int call_netdevice_notifiers(unsigned long val, struct net_device *dev);
-
+int call_netdevice_notifiers_info(unsigned long val,
+				  struct netdev_notifier_info *info);
 
 extern rwlock_t				dev_base_lock;		/* Device list lock */
 
diff --git a/include/net/dsa.h b/include/net/dsa.h
index a15f17a38eca..8903053fa5aa 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -109,16 +109,6 @@ struct dsa_device_ops {
 	bool promisc_on_master;
 };
 
-/* This structure defines the control interfaces that are overlayed by the
- * DSA layer on top of the DSA CPU/management net_device instance. This is
- * used by the core net_device layer while calling various net_device_ops
- * function pointers.
- */
-struct dsa_netdevice_ops {
-	int (*ndo_eth_ioctl)(struct net_device *dev, struct ifreq *ifr,
-			     int cmd);
-};
-
 struct dsa_lag {
 	struct net_device *dev;
 	unsigned int id;
@@ -317,11 +307,6 @@ struct dsa_port {
 	 */
 	const struct ethtool_ops *orig_ethtool_ops;
 
-	/*
-	 * Original copy of the master netdev net_device_ops
-	 */
-	const struct dsa_netdevice_ops *netdev_ops;
-
 	/* List of MAC addresses that must be forwarded on this port.
 	 * These are only valid on CPU ports and DSA links.
 	 */
@@ -1339,42 +1324,6 @@ static inline void dsa_tag_generic_flow_dissect(const struct sk_buff *skb,
 #endif
 }
 
-#if IS_ENABLED(CONFIG_NET_DSA)
-static inline int __dsa_netdevice_ops_check(struct net_device *dev)
-{
-	int err = -EOPNOTSUPP;
-
-	if (!dev->dsa_ptr)
-		return err;
-
-	if (!dev->dsa_ptr->netdev_ops)
-		return err;
-
-	return 0;
-}
-
-static inline int dsa_ndo_eth_ioctl(struct net_device *dev, struct ifreq *ifr,
-				    int cmd)
-{
-	const struct dsa_netdevice_ops *ops;
-	int err;
-
-	err = __dsa_netdevice_ops_check(dev);
-	if (err)
-		return err;
-
-	ops = dev->dsa_ptr->netdev_ops;
-
-	return ops->ndo_eth_ioctl(dev, ifr, cmd);
-}
-#else
-static inline int dsa_ndo_eth_ioctl(struct net_device *dev, struct ifreq *ifr,
-				    int cmd)
-{
-	return -EOPNOTSUPP;
-}
-#endif
-
 void dsa_unregister_switch(struct dsa_switch *ds);
 int dsa_register_switch(struct dsa_switch *ds);
 void dsa_switch_shutdown(struct dsa_switch *ds);