Merge branch 'introduce-ndo_hwtstamp_get-and-ndo_hwtstamp_set'

Vladimir Oltean says:

====================
Introduce ndo_hwtstamp_get() and ndo_hwtstamp_set()

Based on previous RFCs from Maxim Georgiev:
https://lore.kernel.org/netdev/20230502043150.17097-1-glipus@gmail.com/

this series attempts to introduce new API for the hardware timestamping
control path (SIOCGHWTSTAMP and SIOCSHWTSTAMP handling).

I don't have any board with phylib hardware timestamping, so I would
appreciate testing (especially on lan966x, the most intricate
conversion). I was, however, able to test netdev level timestamping,
because I also have some more unsubmitted conversions in progress:

https://github.com/vladimiroltean/linux/commits/ndo-hwtstamp-v9

I hope that the concerns expressed in the comments of previous series
were addressed, and that Köry Maincent's series:
https://lore.kernel.org/netdev/20230406173308.401924-1-kory.maincent@bootlin.com/
can make progress in parallel with the conversion of the rest of drivers.
====================

Link: https://lore.kernel.org/r/20230801142824.1772134-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

4 files changed, 130 insertions, 0 deletions

diff --git a/include/linux/net_tstamp.h b/include/linux/net_tstamp.h
index fd67f3cc0c4b..eb01c37e71e0 100644
--- a/include/linux/net_tstamp.h
+++ b/include/linux/net_tstamp.h
@@ -5,12 +5,23 @@
 
 #include <uapi/linux/net_tstamp.h>
 
+enum hwtstamp_source {
+	HWTSTAMP_SOURCE_NETDEV,
+	HWTSTAMP_SOURCE_PHYLIB,
+};
+
 /**
  * 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
+ * @ifr: pointer to ifreq structure from the original ioctl request, to pass to
+ *	a legacy implementation of a lower driver
+ * @copied_to_user: request was passed to a legacy implementation which already
+ *	copied the ioctl request back to user space
+ * @source: indication whether timestamps should come from the netdev or from
+ *	an attached phylib PHY
  *
  * Prefer using this structure for in-kernel processing of hardware
  * timestamping configuration, over the inextensible struct hwtstamp_config
@@ -20,6 +31,9 @@ struct kernel_hwtstamp_config {
 	int flags;
 	int tx_type;
 	int rx_filter;
+	struct ifreq *ifr;
+	bool copied_to_user;
+	enum hwtstamp_source source;
 };
 
 static inline void hwtstamp_config_to_kernel(struct kernel_hwtstamp_config *kernel_cfg,
@@ -30,4 +44,20 @@ static inline void hwtstamp_config_to_kernel(struct kernel_hwtstamp_config *kern
 	kernel_cfg->rx_filter = cfg->rx_filter;
 }
 
+static inline void hwtstamp_config_from_kernel(struct hwtstamp_config *cfg,
+					       const struct kernel_hwtstamp_config *kernel_cfg)
+{
+	cfg->flags = kernel_cfg->flags;
+	cfg->tx_type = kernel_cfg->tx_type;
+	cfg->rx_filter = kernel_cfg->rx_filter;
+}
+
+static inline bool kernel_hwtstamp_config_changed(const struct kernel_hwtstamp_config *a,
+						  const struct kernel_hwtstamp_config *b)
+{
+	return a->flags != b->flags ||
+	       a->tx_type != b->tx_type ||
+	       a->rx_filter != b->rx_filter;
+}
+
 #endif /* _LINUX_NET_TIMESTAMPING_H_ */
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 84c36a7f873f..85d594460c66 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -57,6 +57,7 @@
 struct netpoll_info;
 struct device;
 struct ethtool_ops;
+struct kernel_hwtstamp_config;
 struct phy_device;
 struct dsa_port;
 struct ip_tunnel_parm;
@@ -1418,6 +1419,16 @@ struct netdev_net_notifier {
  *	Get hardware timestamp based on normal/adjustable time or free running
  *	cycle counter. This function is required if physical clock supports a
  *	free running cycle counter.
+ *
+ * int (*ndo_hwtstamp_get)(struct net_device *dev,
+ *			   struct kernel_hwtstamp_config *kernel_config);
+ *	Get the currently configured hardware timestamping parameters for the
+ *	NIC device.
+ *
+ * int (*ndo_hwtstamp_set)(struct net_device *dev,
+ *			   struct kernel_hwtstamp_config *kernel_config,
+ *			   struct netlink_ext_ack *extack);
+ *	Change the hardware timestamping parameters for NIC device.
  */
 struct net_device_ops {
 	int			(*ndo_init)(struct net_device *dev);
@@ -1652,6 +1663,11 @@ struct net_device_ops {
 	ktime_t			(*ndo_get_tstamp)(struct net_device *dev,
 						  const struct skb_shared_hwtstamps *hwtstamps,
 						  bool cycles);
+	int			(*ndo_hwtstamp_get)(struct net_device *dev,
+						    struct kernel_hwtstamp_config *kernel_config);
+	int			(*ndo_hwtstamp_set)(struct net_device *dev,
+						    struct kernel_hwtstamp_config *kernel_config,
+						    struct netlink_ext_ack *extack);
 };
 
 struct xdp_metadata_ops {
@@ -1708,6 +1724,9 @@ struct xdp_metadata_ops {
  * @IFF_TX_SKB_NO_LINEAR: device/driver is capable of xmitting frames with
  *	skb_headlen(skb) == 0 (data starts from frag0)
  * @IFF_CHANGE_PROTO_DOWN: device supports setting carrier via IFLA_PROTO_DOWN
+ * @IFF_SEE_ALL_HWTSTAMP_REQUESTS: device wants to see calls to
+ *	ndo_hwtstamp_set() for all timestamp requests regardless of source,
+ *	even if those aren't HWTSTAMP_SOURCE_NETDEV.
  */
 enum netdev_priv_flags {
 	IFF_802_1Q_VLAN			= 1<<0,
@@ -1743,6 +1762,7 @@ enum netdev_priv_flags {
 	IFF_NO_ADDRCONF			= BIT_ULL(30),
 	IFF_TX_SKB_NO_LINEAR		= BIT_ULL(31),
 	IFF_CHANGE_PROTO_DOWN		= BIT_ULL(32),
+	IFF_SEE_ALL_HWTSTAMP_REQUESTS	= BIT_ULL(33),
 };
 
 #define IFF_802_1Q_VLAN			IFF_802_1Q_VLAN
@@ -3934,6 +3954,11 @@ int put_user_ifreq(struct ifreq *ifr, void __user *arg);
 int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr,
 		void __user *data, bool *need_copyout);
 int dev_ifconf(struct net *net, struct ifconf __user *ifc);
+int generic_hwtstamp_get_lower(struct net_device *dev,
+			       struct kernel_hwtstamp_config *kernel_cfg);
+int generic_hwtstamp_set_lower(struct net_device *dev,
+			       struct kernel_hwtstamp_config *kernel_cfg,
+			       struct netlink_ext_ack *extack);
 int dev_ethtool(struct net *net, struct ifreq *ifr, void __user *userdata);
 unsigned int dev_get_flags(const struct net_device *);
 int __dev_change_flags(struct net_device *dev, unsigned int flags,
diff --git a/include/linux/phy.h b/include/linux/phy.h
index b254848a9c99..ba08b0e60279 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -298,6 +298,7 @@ static inline const char *phy_modes(phy_interface_t interface)
 #define MII_BUS_ID_SIZE	61
 
 struct device;
+struct kernel_hwtstamp_config;
 struct phylink;
 struct sfp_bus;
 struct sfp_upstream_ops;
@@ -1955,6 +1956,12 @@ int phy_ethtool_set_plca_cfg(struct phy_device *phydev,
 int phy_ethtool_get_plca_status(struct phy_device *phydev,
 				struct phy_plca_status *plca_st);
 
+int __phy_hwtstamp_get(struct phy_device *phydev,
+		       struct kernel_hwtstamp_config *config);
+int __phy_hwtstamp_set(struct phy_device *phydev,
+		       struct kernel_hwtstamp_config *config,
+		       struct netlink_ext_ack *extack);
+
 static inline int phy_package_read(struct phy_device *phydev, u32 regnum)
 {
 	struct phy_package_shared *shared = phydev->shared;
diff --git a/include/linux/phylib_stubs.h b/include/linux/phylib_stubs.h
new file mode 100644
index 000000000000..1279f48c8a70
--- /dev/null
+++ b/include/linux/phylib_stubs.h
@@ -0,0 +1,68 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Stubs for the Network PHY library
+ */
+
+#include <linux/rtnetlink.h>
+
+struct kernel_hwtstamp_config;
+struct netlink_ext_ack;
+struct phy_device;
+
+#if IS_ENABLED(CONFIG_PHYLIB)
+
+extern const struct phylib_stubs *phylib_stubs;
+
+struct phylib_stubs {
+	int (*hwtstamp_get)(struct phy_device *phydev,
+			    struct kernel_hwtstamp_config *config);
+	int (*hwtstamp_set)(struct phy_device *phydev,
+			    struct kernel_hwtstamp_config *config,
+			    struct netlink_ext_ack *extack);
+};
+
+static inline int phy_hwtstamp_get(struct phy_device *phydev,
+				   struct kernel_hwtstamp_config *config)
+{
+	/* phylib_register_stubs() and phylib_unregister_stubs()
+	 * also run under rtnl_lock().
+	 */
+	ASSERT_RTNL();
+
+	if (!phylib_stubs)
+		return -EOPNOTSUPP;
+
+	return phylib_stubs->hwtstamp_get(phydev, config);
+}
+
+static inline int phy_hwtstamp_set(struct phy_device *phydev,
+				   struct kernel_hwtstamp_config *config,
+				   struct netlink_ext_ack *extack)
+{
+	/* phylib_register_stubs() and phylib_unregister_stubs()
+	 * also run under rtnl_lock().
+	 */
+	ASSERT_RTNL();
+
+	if (!phylib_stubs)
+		return -EOPNOTSUPP;
+
+	return phylib_stubs->hwtstamp_set(phydev, config, extack);
+}
+
+#else
+
+static inline int phy_hwtstamp_get(struct phy_device *phydev,
+				   struct kernel_hwtstamp_config *config)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int phy_hwtstamp_set(struct phy_device *phydev,
+				   struct kernel_hwtstamp_config *config,
+				   struct netlink_ext_ack *extack)
+{
+	return -EOPNOTSUPP;
+}
+
+#endif