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>

Documentation/networking/ethtool-netlink.rst

@@ -204,6 +204,7 @@ Userspace to kernel:
   ``ETHTOOL_MSG_EEE_GET``               get EEE settings
   ``ETHTOOL_MSG_EEE_SET``               set EEE settings
   ``ETHTOOL_MSG_TSINFO_GET``		get timestamping info
+  ``ETHTOOL_MSG_CABLE_TEST_ACT``        action start cable test
   ===================================== ================================
 
 Kernel to userspace:
@@ -235,6 +236,7 @@ Kernel to userspace:
   ``ETHTOOL_MSG_EEE_GET_REPLY``         EEE settings
   ``ETHTOOL_MSG_EEE_NTF``               EEE settings
   ``ETHTOOL_MSG_TSINFO_GET_REPLY``	timestamping info
+  ``ETHTOOL_MSG_CABLE_TEST_NTF``        Cable test results
   ===================================== =================================
 
 ``GET`` requests are sent by userspace applications to retrieve device
@@ -958,13 +960,65 @@ Kernel response contents:
 is no special value for this case). The bitset attributes are omitted if they
 would be empty (no bit set).
 
+CABLE_TEST
+==========
+
+Start a cable test.
+
+Request contents:
+
+  ====================================  ======  ==========================
+  ``ETHTOOL_A_CABLE_TEST_HEADER``       nested  request header
+  ====================================  ======  ==========================
+
+Notification contents:
+
+An Ethernet cable typically contains 1, 2 or 4 pairs. The length of
+the pair can only be measured when there is a fault in the pair and
+hence a reflection. Information about the fault may not be available,
+depending on the specific hardware. Hence the contents of the notify
+message are mostly optional. The attributes can be repeated an
+arbitrary number of times, in an arbitrary order, for an arbitrary
+number of pairs.
+
+The example shows the notification sent when the test is completed for
+a T2 cable, i.e. two pairs. One pair is OK and hence has no length
+information. The second pair has a fault and does have length
+information.
+
+ +---------------------------------------------+--------+---------------------+
+ | ``ETHTOOL_A_CABLE_TEST_HEADER``             | nested | reply header        |
+ +---------------------------------------------+--------+---------------------+
+ | ``ETHTOOL_A_CABLE_TEST_STATUS``             | u8     | completed           |
+ +---------------------------------------------+--------+---------------------+
+ | ``ETHTOOL_A_CABLE_TEST_NTF_NEST``           | nested | all the results     |
+ +-+-------------------------------------------+--------+---------------------+
+ | | ``ETHTOOL_A_CABLE_NEST_RESULT``           | nested | cable test result   |
+ +-+-+-----------------------------------------+--------+---------------------+
+ | | | ``ETHTOOL_A_CABLE_RESULTS_PAIR``        | u8     | pair number         |
+ +-+-+-----------------------------------------+--------+---------------------+
+ | | | ``ETHTOOL_A_CABLE_RESULTS_CODE``        | u8     | result code         |
+ +-+-+-----------------------------------------+--------+---------------------+
+ | | ``ETHTOOL_A_CABLE_NEST_RESULT``           | nested | cable test results  |
+ +-+-+-----------------------------------------+--------+---------------------+
+ | | | ``ETHTOOL_A_CABLE_RESULTS_PAIR``        | u8     | pair number         |
+ +-+-+-----------------------------------------+--------+---------------------+
+ | | | ``ETHTOOL_A_CABLE_RESULTS_CODE``        | u8     | result code         |
+ +-+-+-----------------------------------------+--------+---------------------+
+ | | ``ETHTOOL_A_CABLE_NEST_FAULT_LENGTH``     | nested | cable length        |
+ +-+-+-----------------------------------------+--------+---------------------+
+ | | | ``ETHTOOL_A_CABLE_FAULT_LENGTH_PAIR``   | u8     | pair number         |
+ +-+-+-----------------------------------------+--------+---------------------+
+ | | | ``ETHTOOL_A_CABLE_FAULT_LENGTH_CM``     | u32    | length in cm        |
+ +-+-+-----------------------------------------+--------+---------------------+
 
 Request translation
 ===================
 
 The following table maps ioctl commands to netlink commands providing their
 functionality. Entries with "n/a" in right column are commands which do not
-have their netlink replacement yet.
+have their netlink replacement yet. Entries which "n/a" in the left column
+are netlink only.
 
   =================================== =====================================
   ioctl command                       netlink command
@@ -1053,4 +1107,5 @@ have their netlink replacement yet.
   ``ETHTOOL_PHY_STUNABLE``            n/a
   ``ETHTOOL_GFECPARAM``               n/a
   ``ETHTOOL_SFECPARAM``               n/a
+  n/a                                 ''ETHTOOL_MSG_CABLE_TEST_ACT''
   =================================== =====================================

drivers/net/phy/marvell.c

@@ -27,6 +27,7 @@
 #include <linux/module.h>
 #include <linux/mii.h>
 #include <linux/ethtool.h>
+#include <linux/ethtool_netlink.h>
 #include <linux/phy.h>
 #include <linux/marvell_phy.h>
 #include <linux/bitfield.h>
@@ -42,6 +43,7 @@
 #define MII_MARVELL_MSCR_PAGE		0x02
 #define MII_MARVELL_LED_PAGE		0x03
 #define MII_MARVELL_MISC_TEST_PAGE	0x06
+#define MII_MARVELL_VCT7_PAGE		0x07
 #define MII_MARVELL_WOL_PAGE		0x11
 
 #define MII_M1011_IEVENT		0x13
@@ -162,6 +164,36 @@
 #define MII_88E1510_GEN_CTRL_REG_1_MODE_SGMII	0x1	/* SGMII to copper */
 #define MII_88E1510_GEN_CTRL_REG_1_RESET	0x8000	/* Soft reset */
 
+#define MII_VCT7_PAIR_0_DISTANCE	0x10
+#define MII_VCT7_PAIR_1_DISTANCE	0x11
+#define MII_VCT7_PAIR_2_DISTANCE	0x12
+#define MII_VCT7_PAIR_3_DISTANCE	0x13
+
+#define MII_VCT7_RESULTS	0x14
+#define MII_VCT7_RESULTS_PAIR3_MASK	0xf000
+#define MII_VCT7_RESULTS_PAIR2_MASK	0x0f00
+#define MII_VCT7_RESULTS_PAIR1_MASK	0x00f0
+#define MII_VCT7_RESULTS_PAIR0_MASK	0x000f
+#define MII_VCT7_RESULTS_PAIR3_SHIFT	12
+#define MII_VCT7_RESULTS_PAIR2_SHIFT	8
+#define MII_VCT7_RESULTS_PAIR1_SHIFT	4
+#define MII_VCT7_RESULTS_PAIR0_SHIFT	0
+#define MII_VCT7_RESULTS_INVALID	0
+#define MII_VCT7_RESULTS_OK		1
+#define MII_VCT7_RESULTS_OPEN		2
+#define MII_VCT7_RESULTS_SAME_SHORT	3
+#define MII_VCT7_RESULTS_CROSS_SHORT	4
+#define MII_VCT7_RESULTS_BUSY		9
+
+#define MII_VCT7_CTRL		0x15
+#define MII_VCT7_CTRL_RUN_NOW			BIT(15)
+#define MII_VCT7_CTRL_RUN_ANEG			BIT(14)
+#define MII_VCT7_CTRL_DISABLE_CROSS		BIT(13)
+#define MII_VCT7_CTRL_RUN_AFTER_BREAK_LINK	BIT(12)
+#define MII_VCT7_CTRL_IN_PROGRESS		BIT(11)
+#define MII_VCT7_CTRL_METERS			BIT(10)
+#define MII_VCT7_CTRL_CENTIMETERS		0
+
 #define LPA_PAUSE_FIBER		0x180
 #define LPA_PAUSE_ASYM_FIBER	0x100
 
@@ -1658,6 +1690,163 @@ static void marvell_get_stats(struct phy_device *phydev,
 		data[i] = marvell_get_stat(phydev, i);
 }
 
+static int marvell_vct7_cable_test_start(struct phy_device *phydev)
+{
+	int bmcr, bmsr, ret;
+
+	/* If auto-negotiation is enabled, but not complete, the cable
+	 * test never completes. So disable auto-neg.
+	 */
+	bmcr = phy_read(phydev, MII_BMCR);
+	if (bmcr < 0)
+		return bmcr;
+
+	bmsr = phy_read(phydev, MII_BMSR);
+
+	if (bmsr < 0)
+		return bmsr;
+
+	if (bmcr & BMCR_ANENABLE) {
+		ret =  phy_modify(phydev, MII_BMCR, BMCR_ANENABLE, 0);
+		if (ret < 0)
+			return ret;
+		ret = genphy_soft_reset(phydev);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* If the link is up, allow it some time to go down */
+	if (bmsr & BMSR_LSTATUS)
+		msleep(1500);
+
+	return phy_write_paged(phydev, MII_MARVELL_VCT7_PAGE,
+			       MII_VCT7_CTRL,
+			       MII_VCT7_CTRL_RUN_NOW |
+			       MII_VCT7_CTRL_CENTIMETERS);
+}
+
+static int marvell_vct7_distance_to_length(int distance, bool meter)
+{
+	if (meter)
+		distance *= 100;
+
+	return distance;
+}
+
+static bool marvell_vct7_distance_valid(int result)
+{
+	switch (result) {
+	case MII_VCT7_RESULTS_OPEN:
+	case MII_VCT7_RESULTS_SAME_SHORT:
+	case MII_VCT7_RESULTS_CROSS_SHORT:
+		return true;
+	}
+	return false;
+}
+
+static int marvell_vct7_report_length(struct phy_device *phydev,
+				      int pair, bool meter)
+{
+	int length;
+	int ret;
+
+	ret = phy_read_paged(phydev, MII_MARVELL_VCT7_PAGE,
+			     MII_VCT7_PAIR_0_DISTANCE + pair);
+	if (ret < 0)
+		return ret;
+
+	length = marvell_vct7_distance_to_length(ret, meter);
+
+	ethnl_cable_test_fault_length(phydev, pair, length);
+
+	return 0;
+}
+
+static int marvell_vct7_cable_test_report_trans(int result)
+{
+	switch (result) {
+	case MII_VCT7_RESULTS_OK:
+		return ETHTOOL_A_CABLE_RESULT_CODE_OK;
+	case MII_VCT7_RESULTS_OPEN:
+		return ETHTOOL_A_CABLE_RESULT_CODE_OPEN;
+	case MII_VCT7_RESULTS_SAME_SHORT:
+		return ETHTOOL_A_CABLE_RESULT_CODE_SAME_SHORT;
+	case MII_VCT7_RESULTS_CROSS_SHORT:
+		return ETHTOOL_A_CABLE_RESULT_CODE_CROSS_SHORT;
+	default:
+		return ETHTOOL_A_CABLE_RESULT_CODE_UNSPEC;
+	}
+}
+
+static int marvell_vct7_cable_test_report(struct phy_device *phydev)
+{
+	int pair0, pair1, pair2, pair3;
+	bool meter;
+	int ret;
+
+	ret = phy_read_paged(phydev, MII_MARVELL_VCT7_PAGE,
+			     MII_VCT7_RESULTS);
+	if (ret < 0)
+		return ret;
+
+	pair3 = (ret & MII_VCT7_RESULTS_PAIR3_MASK) >>
+		MII_VCT7_RESULTS_PAIR3_SHIFT;
+	pair2 = (ret & MII_VCT7_RESULTS_PAIR2_MASK) >>
+		MII_VCT7_RESULTS_PAIR2_SHIFT;
+	pair1 = (ret & MII_VCT7_RESULTS_PAIR1_MASK) >>
+		MII_VCT7_RESULTS_PAIR1_SHIFT;
+	pair0 = (ret & MII_VCT7_RESULTS_PAIR0_MASK) >>
+		MII_VCT7_RESULTS_PAIR0_SHIFT;
+
+	ethnl_cable_test_result(phydev, ETHTOOL_A_CABLE_PAIR_A,
+				marvell_vct7_cable_test_report_trans(pair0));
+	ethnl_cable_test_result(phydev, ETHTOOL_A_CABLE_PAIR_B,
+				marvell_vct7_cable_test_report_trans(pair1));
+	ethnl_cable_test_result(phydev, ETHTOOL_A_CABLE_PAIR_C,
+				marvell_vct7_cable_test_report_trans(pair2));
+	ethnl_cable_test_result(phydev, ETHTOOL_A_CABLE_PAIR_D,
+				marvell_vct7_cable_test_report_trans(pair3));
+
+	ret = phy_read_paged(phydev, MII_MARVELL_VCT7_PAGE, MII_VCT7_CTRL);
+	if (ret < 0)
+		return ret;
+
+	meter = ret & MII_VCT7_CTRL_METERS;
+
+	if (marvell_vct7_distance_valid(pair0))
+		marvell_vct7_report_length(phydev, 0, meter);
+	if (marvell_vct7_distance_valid(pair1))
+		marvell_vct7_report_length(phydev, 1, meter);
+	if (marvell_vct7_distance_valid(pair2))
+		marvell_vct7_report_length(phydev, 2, meter);
+	if (marvell_vct7_distance_valid(pair3))
+		marvell_vct7_report_length(phydev, 3, meter);
+
+	return 0;
+}
+
+static int marvell_vct7_cable_test_get_status(struct phy_device *phydev,
+					      bool *finished)
+{
+	int ret;
+
+	*finished = false;
+
+	ret = phy_read_paged(phydev, MII_MARVELL_VCT7_PAGE,
+			     MII_VCT7_CTRL);
+
+	if (ret < 0)
+		return ret;
+
+	if (!(ret & MII_VCT7_CTRL_IN_PROGRESS)) {
+		*finished = true;
+
+		return marvell_vct7_cable_test_report(phydev);
+	}
+
+	return 0;
+}
+
 #ifdef CONFIG_HWMON
 static int m88e1121_get_temp(struct phy_device *phydev, long *temp)
 {
@@ -2353,6 +2542,7 @@ static struct phy_driver marvell_drivers[] = {
 		.phy_id_mask = MARVELL_PHY_ID_MASK,
 		.name = "Marvell 88E1510",
 		.features = PHY_GBIT_FIBRE_FEATURES,
+		.flags = PHY_POLL_CABLE_TEST,
 		.probe = &m88e1510_probe,
 		.config_init = &m88e1510_config_init,
 		.config_aneg = &m88e1510_config_aneg,
@@ -2372,12 +2562,15 @@ static struct phy_driver marvell_drivers[] = {
 		.set_loopback = genphy_loopback,
 		.get_tunable = m88e1011_get_tunable,
 		.set_tunable = m88e1011_set_tunable,
+		.cable_test_start = marvell_vct7_cable_test_start,
+		.cable_test_get_status = marvell_vct7_cable_test_get_status,
 	},
 	{
 		.phy_id = MARVELL_PHY_ID_88E1540,
 		.phy_id_mask = MARVELL_PHY_ID_MASK,
 		.name = "Marvell 88E1540",
 		/* PHY_GBIT_FEATURES */
+		.flags = PHY_POLL_CABLE_TEST,
 		.probe = m88e1510_probe,
 		.config_init = &marvell_config_init,
 		.config_aneg = &m88e1510_config_aneg,
@@ -2394,13 +2587,16 @@ static struct phy_driver marvell_drivers[] = {
 		.get_stats = marvell_get_stats,
 		.get_tunable = m88e1540_get_tunable,
 		.set_tunable = m88e1540_set_tunable,
+		.cable_test_start = marvell_vct7_cable_test_start,
+		.cable_test_get_status = marvell_vct7_cable_test_get_status,
 	},
 	{
 		.phy_id = MARVELL_PHY_ID_88E1545,
 		.phy_id_mask = MARVELL_PHY_ID_MASK,
 		.name = "Marvell 88E1545",
 		.probe = m88e1510_probe,
 		/* PHY_GBIT_FEATURES */
+		.flags = PHY_POLL_CABLE_TEST,
 		.config_init = &marvell_config_init,
 		.config_aneg = &m88e1510_config_aneg,
 		.read_status = &marvell_read_status,
@@ -2416,6 +2612,8 @@ static struct phy_driver marvell_drivers[] = {
 		.get_stats = marvell_get_stats,
 		.get_tunable = m88e1540_get_tunable,
 		.set_tunable = m88e1540_set_tunable,
+		.cable_test_start = marvell_vct7_cable_test_start,
+		.cable_test_get_status = marvell_vct7_cable_test_get_status,
 	},
 	{
 		.phy_id = MARVELL_PHY_ID_88E3016,
@@ -2442,6 +2640,7 @@ static struct phy_driver marvell_drivers[] = {
 		.phy_id_mask = MARVELL_PHY_ID_MASK,
 		.name = "Marvell 88E6390",
 		/* PHY_GBIT_FEATURES */
+		.flags = PHY_POLL_CABLE_TEST,
 		.probe = m88e6390_probe,
 		.config_init = &marvell_config_init,
 		.config_aneg = &m88e6390_config_aneg,
@@ -2458,6 +2657,8 @@ static struct phy_driver marvell_drivers[] = {
 		.get_stats = marvell_get_stats,
 		.get_tunable = m88e1540_get_tunable,
 		.set_tunable = m88e1540_set_tunable,
+		.cable_test_start = marvell_vct7_cable_test_start,
+		.cable_test_get_status = marvell_vct7_cable_test_get_status,
 	},
 };