Re: [PATCH v8 net-next 11/12] net: phy: provide phylib stubs for hardware timestamping operations
From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: 2023-07-18 08:36:21
Also in:
linux-arm-kernel, lkml
Subsystem:
ethernet phy library, networking drivers, the rest · Maintainers:
Andrew Lunn, Heiner Kallweit, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
On Mon, Jul 17, 2023 at 06:27:08PM +0300, Vladimir Oltean wrote:
net/core/dev_ioctl.c (built-in code) will want to call phy_mii_ioctl()
for hardware timestamping purposes. This is not directly possible,
because phy_mii_ioctl() is a symbol provided under CONFIG_PHYLIB.
Do something similar to what was done in DSA in commit 5a17818682cf
("net: dsa: replace NETDEV_PRE_CHANGE_HWTSTAMP notifier with a stub"),
and arrange some indirect calls to phy_mii_ioctl() through a stub
structure containing function pointers, that's provided by phylib as
built-in even when CONFIG_PHYLIB=m, and which phy_init() populates at
runtime (module insertion).
Note: maybe the ownership of the ethtool_phy_ops singleton is backwards,
and the methods exposed by that should be later merged into phylib_stubs.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---I should use "git add" on new files more often... Annex to this patch:
diff --git a/drivers/net/phy/stubs.c b/drivers/net/phy/stubs.c
new file mode 100644
index 000000000000..06498de2d16a
--- /dev/null
+++ b/drivers/net/phy/stubs.c@@ -0,0 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Stubs for PHY library functionality called by the core network stack. + * These are necessary because CONFIG_PHYLIB can be a module, and built-in + * code cannot directly call symbols exported by modules. + */ +#include <net/dsa_stubs.h> + +const struct phylib_stubs *phylib_stubs; +EXPORT_SYMBOL_GPL(phylib_stubs);
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