Merge branch 'Ethernet-Cable-test-support'

Andrew Lunn says:

====================
Ethernet Cable test support

any copper Ethernet PHY have support for performing diagnostics of
the cable. Are the cable shorted, broken, not plugged into anything at
the other end? And they can report roughly how far along the cable any
fault is.

Add infrastructure in ethtool and phylib support for triggering a
cable test and reporting the results. The Marvell 1G PHY driver is
then extended to make use of this infrastructure.

For testing, a modified ethtool(1) can be found here:
https://github.com/lunn/ethtool.git feature/cable-test-v4. This also
contains extra code for TDR dump, which will be added to the kernel in
a later patch series.

Thanks to Chris Healy for extensive testing.

v2:
See individual patches but:

Remove _REPLY messages
Change length into a u32
Grammar fixes
Rename functions for consistency
Extack for cable test already running
Remove ethnl_cable_test_act_ops
Add status attributes
Rename pairs from numbers to letters

v3:

See individual patches but:
Remove ETHTOOL_MSG_CABLE_TEST_ACT_REPLY from documentation
Remove unused cable_test_get_policy
Fixed example in document
Add ETHTOOL_A_CABLE_NEST_* enum
Add ETHTOOL_MSG_CABLE_TEST_NTF to documentation
Poison phydev->skb
Return -EMSGSIZE when ethnl_bcastmsg_put() fails
Return valid error code when nla_nest_start() fails
Use u8 for results
Actually put u32 length into message
s/mavell/marvell/g
Remove include of <uapi/linux/ethtool_netlink.h>
EMSGSIZE when ethnl_bcastmsg_put() fails
Print an error message on failure, since this is a void function.

v4:
See individual patches but:
Remove unwanted blank line
ENOTSUPP->EOPNOTSUPP
Move EINVAL->EMSGSIZE fix to correct patch
====================

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 146 insertions, 0 deletions

diff --git a/include/linux/ethtool_netlink.h b/include/linux/ethtool_netlink.h
index d01b77887f82..e317fc99565e 100644
--- a/include/linux/ethtool_netlink.h
+++ b/include/linux/ethtool_netlink.h
@@ -14,4 +14,37 @@ enum ethtool_multicast_groups {
 	ETHNL_MCGRP_MONITOR,
 };
 
+struct phy_device;
+
+#if IS_ENABLED(CONFIG_ETHTOOL_NETLINK)
+int ethnl_cable_test_alloc(struct phy_device *phydev);
+void ethnl_cable_test_free(struct phy_device *phydev);
+void ethnl_cable_test_finished(struct phy_device *phydev);
+int ethnl_cable_test_result(struct phy_device *phydev, u8 pair, u8 result);
+int ethnl_cable_test_fault_length(struct phy_device *phydev, u8 pair, u32 cm);
+#else
+static inline int ethnl_cable_test_alloc(struct phy_device *phydev)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline void ethnl_cable_test_free(struct phy_device *phydev)
+{
+}
+
+static inline void ethnl_cable_test_finished(struct phy_device *phydev)
+{
+}
+static inline int ethnl_cable_test_result(struct phy_device *phydev, u8 pair,
+					  u8 result)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int ethnl_cable_test_fault_length(struct phy_device *phydev,
+						u8 pair, u32 cm)
+{
+	return -EOPNOTSUPP;
+}
+#endif /* IS_ENABLED(ETHTOOL_NETLINK) */
 #endif /* _LINUX_ETHTOOL_NETLINK_H_ */
diff --git a/include/linux/phy.h b/include/linux/phy.h
index a2b91b5f9d0a..5d8ff5428010 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -15,6 +15,7 @@
 #include <linux/spinlock.h>
 #include <linux/ethtool.h>
 #include <linux/linkmode.h>
+#include <linux/netlink.h>
 #include <linux/mdio.h>
 #include <linux/mii.h>
 #include <linux/mii_timestamper.h>
@@ -78,6 +79,7 @@ extern const int phy_10gbit_features_array[1];
 
 #define PHY_IS_INTERNAL		0x00000001
 #define PHY_RST_AFTER_CLK_EN	0x00000002
+#define PHY_POLL_CABLE_TEST	0x00000004
 #define MDIO_DEVICE_IS_PHY	0x80000000
 
 /* Interface Mode definitions */
@@ -372,6 +374,12 @@ struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr);
  * - irq or timer will set NOLINK if link goes down
  * - phy_stop moves to HALTED
  *
+ * CABLETEST: PHY is performing a cable test. Packet reception/sending
+ * is not expected to work, carrier will be indicated as down. PHY will be
+ * poll once per second, or on interrupt for it current state.
+ * Once complete, move to UP to restart the PHY.
+ * - phy_stop aborts the running test and moves to HALTED
+ *
  * HALTED: PHY is up, but no polling or interrupts are done. Or
  * PHY is in an error state.
  * - phy_start moves to UP
@@ -383,6 +391,7 @@ enum phy_state {
 	PHY_UP,
 	PHY_RUNNING,
 	PHY_NOLINK,
+	PHY_CABLETEST,
 };
 
 /**
@@ -514,6 +523,11 @@ struct phy_device {
 	/* For use by PHYs inside the same package that need a shared state. */
 	struct phy_package_shared *shared;
 
+	/* Reporting cable test results */
+	struct sk_buff *skb;
+	void *ehdr;
+	struct nlattr *nest;
+
 	/* Interrupt and Polling infrastructure */
 	struct delayed_work state_queue;
 
@@ -689,6 +703,13 @@ struct phy_driver {
 	int (*module_eeprom)(struct phy_device *dev,
 			     struct ethtool_eeprom *ee, u8 *data);
 
+	/* Start a cable test */
+	int (*cable_test_start)(struct phy_device *dev);
+	/* Once per second, or on interrupt, request the status of the
+	 * test.
+	 */
+	int (*cable_test_get_status)(struct phy_device *dev, bool *finished);
+
 	/* Get statistics from the phy using ethtool */
 	int (*get_sset_count)(struct phy_device *dev);
 	void (*get_strings)(struct phy_device *dev, u8 *data);
@@ -1046,6 +1067,10 @@ static inline bool phy_interrupt_is_valid(struct phy_device *phydev)
  */
 static inline bool phy_polling_mode(struct phy_device *phydev)
 {
+	if (phydev->state == PHY_CABLETEST)
+		if (phydev->drv->flags & PHY_POLL_CABLE_TEST)
+			return true;
+
 	return phydev->irq == PHY_POLL;
 }
 
@@ -1227,6 +1252,23 @@ int phy_speed_up(struct phy_device *phydev);
 int phy_restart_aneg(struct phy_device *phydev);
 int phy_reset_after_clk_enable(struct phy_device *phydev);
 
+#if IS_ENABLED(CONFIG_PHYLIB)
+int phy_start_cable_test(struct phy_device *phydev,
+			 struct netlink_ext_ack *extack);
+#else
+static inline
+int phy_start_cable_test(struct phy_device *phydev,
+			 struct netlink_ext_ack *extack)
+{
+	NL_SET_ERR_MSG(extack, "Kernel not compiled with PHYLIB support");
+	return -EOPNOTSUPP;
+}
+#endif
+
+int phy_cable_test_result(struct phy_device *phydev, u8 pair, u16 result);
+int phy_cable_test_fault_length(struct phy_device *phydev, u8 pair,
+				u16 cm);
+
 static inline void phy_device_reset(struct phy_device *phydev, int value)
 {
 	mdio_device_reset(&phydev->mdio, value);
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index bf1d310e20bc..2881af411f76 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -39,6 +39,7 @@ enum {
 	ETHTOOL_MSG_EEE_GET,
 	ETHTOOL_MSG_EEE_SET,
 	ETHTOOL_MSG_TSINFO_GET,
+	ETHTOOL_MSG_CABLE_TEST_ACT,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_USER_CNT,
@@ -74,6 +75,7 @@ enum {
 	ETHTOOL_MSG_EEE_GET_REPLY,
 	ETHTOOL_MSG_EEE_NTF,
 	ETHTOOL_MSG_TSINFO_GET_REPLY,
+	ETHTOOL_MSG_CABLE_TEST_NTF,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_KERNEL_CNT,
@@ -405,6 +407,75 @@ enum {
 	ETHTOOL_A_TSINFO_MAX = (__ETHTOOL_A_TSINFO_CNT - 1)
 };
 
+/* CABLE TEST */
+
+enum {
+	ETHTOOL_A_CABLE_TEST_UNSPEC,
+	ETHTOOL_A_CABLE_TEST_HEADER,		/* nest - _A_HEADER_* */
+
+	/* add new constants above here */
+	__ETHTOOL_A_CABLE_TEST_CNT,
+	ETHTOOL_A_CABLE_TEST_MAX = __ETHTOOL_A_CABLE_TEST_CNT - 1
+};
+
+/* CABLE TEST NOTIFY */
+enum {
+	ETHTOOL_A_CABLE_RESULT_CODE_UNSPEC,
+	ETHTOOL_A_CABLE_RESULT_CODE_OK,
+	ETHTOOL_A_CABLE_RESULT_CODE_OPEN,
+	ETHTOOL_A_CABLE_RESULT_CODE_SAME_SHORT,
+	ETHTOOL_A_CABLE_RESULT_CODE_CROSS_SHORT,
+};
+
+enum {
+	ETHTOOL_A_CABLE_PAIR_A,
+	ETHTOOL_A_CABLE_PAIR_B,
+	ETHTOOL_A_CABLE_PAIR_C,
+	ETHTOOL_A_CABLE_PAIR_D,
+};
+
+enum {
+	ETHTOOL_A_CABLE_RESULT_UNSPEC,
+	ETHTOOL_A_CABLE_RESULT_PAIR,		/* u8 ETHTOOL_A_CABLE_PAIR_ */
+	ETHTOOL_A_CABLE_RESULT_CODE,		/* u8 ETHTOOL_A_CABLE_RESULT_CODE_ */
+
+	__ETHTOOL_A_CABLE_RESULT_CNT,
+	ETHTOOL_A_CABLE_RESULT_MAX = (__ETHTOOL_A_CABLE_RESULT_CNT - 1)
+};
+
+enum {
+	ETHTOOL_A_CABLE_FAULT_LENGTH_UNSPEC,
+	ETHTOOL_A_CABLE_FAULT_LENGTH_PAIR,	/* u8 ETHTOOL_A_CABLE_PAIR_ */
+	ETHTOOL_A_CABLE_FAULT_LENGTH_CM,	/* u32 */
+
+	__ETHTOOL_A_CABLE_FAULT_LENGTH_CNT,
+	ETHTOOL_A_CABLE_FAULT_LENGTH_MAX = (__ETHTOOL_A_CABLE_FAULT_LENGTH_CNT - 1)
+};
+
+enum {
+	ETHTOOL_A_CABLE_TEST_NTF_STATUS_UNSPEC,
+	ETHTOOL_A_CABLE_TEST_NTF_STATUS_STARTED,
+	ETHTOOL_A_CABLE_TEST_NTF_STATUS_COMPLETED
+};
+
+enum {
+	ETHTOOL_A_CABLE_NEST_UNSPEC,
+	ETHTOOL_A_CABLE_NEST_RESULT,		/* nest - ETHTOOL_A_CABLE_RESULT_ */
+	ETHTOOL_A_CABLE_NEST_FAULT_LENGTH,	/* nest - ETHTOOL_A_CABLE_FAULT_LENGTH_ */
+	__ETHTOOL_A_CABLE_NEST_CNT,
+	ETHTOOL_A_CABLE_NEST_MAX = (__ETHTOOL_A_CABLE_NEST_CNT - 1)
+};
+
+enum {
+	ETHTOOL_A_CABLE_TEST_NTF_UNSPEC,
+	ETHTOOL_A_CABLE_TEST_NTF_HEADER,	/* nest - ETHTOOL_A_HEADER_* */
+	ETHTOOL_A_CABLE_TEST_NTF_STATUS,	/* u8 - _STARTED/_COMPLETE */
+	ETHTOOL_A_CABLE_TEST_NTF_NEST,		/* nest - of results: */
+
+	__ETHTOOL_A_CABLE_TEST_NTF_CNT,
+	ETHTOOL_A_CABLE_TEST_NTF_MAX = (__ETHTOOL_A_CABLE_TEST_NTF_CNT - 1)
+};
+
 /* generic netlink info */
 #define ETHTOOL_GENL_NAME "ethtool"
 #define ETHTOOL_GENL_VERSION 1