ethtool: Add phy statistics

Ethernet PHYs can maintain statistics, for example errors while idle
and receive errors. Add an ethtool mechanism to retrieve these
statistics, using the same model as MAC statistics.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 05fde31..a89cb0e 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -589,6 +589,12 @@
 	int (*module_eeprom)(struct phy_device *dev,
 			     struct ethtool_eeprom *ee, u8 *data);
 
+	/* Get statistics from the phy using ethtool */
+	int (*get_sset_count)(struct phy_device *dev);
+	void (*get_strings)(struct phy_device *dev, u8 *data);
+	void (*get_stats)(struct phy_device *dev,
+			  struct ethtool_stats *stats, u64 *data);
+
 	struct device_driver driver;
 };
 #define to_phy_driver(d) container_of(d, struct phy_driver, driver)
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index cd16291..57fa390 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -542,6 +542,7 @@
  *	now deprecated
  * @ETH_SS_FEATURES: Device feature names
  * @ETH_SS_RSS_HASH_FUNCS: RSS hush function names
+ * @ETH_SS_PHY_STATS: Statistic names, for use with %ETHTOOL_GPHYSTATS
  */
 enum ethtool_stringset {
 	ETH_SS_TEST		= 0,
@@ -551,6 +552,7 @@
 	ETH_SS_FEATURES,
 	ETH_SS_RSS_HASH_FUNCS,
 	ETH_SS_TUNABLES,
+	ETH_SS_PHY_STATS,
 };
 
 /**
@@ -1225,6 +1227,7 @@
 #define ETHTOOL_SRSSH		0x00000047 /* Set RX flow hash configuration */
 #define ETHTOOL_GTUNABLE	0x00000048 /* Get tunable configuration */
 #define ETHTOOL_STUNABLE	0x00000049 /* Set tunable configuration */
+#define ETHTOOL_GPHYSTATS	0x0000004a /* get PHY-specific statistics */
 
 /* compatibility with older code */
 #define SPARC_ETH_GSET		ETHTOOL_GSET
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 09948a7..daf0470 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -191,6 +191,23 @@
 	return ret;
 }
 
+static int phy_get_sset_count(struct phy_device *phydev)
+{
+	int ret;
+
+	if (phydev->drv->get_sset_count &&
+	    phydev->drv->get_strings &&
+	    phydev->drv->get_stats) {
+		mutex_lock(&phydev->lock);
+		ret = phydev->drv->get_sset_count(phydev);
+		mutex_unlock(&phydev->lock);
+
+		return ret;
+	}
+
+	return -EOPNOTSUPP;
+}
+
 static int __ethtool_get_sset_count(struct net_device *dev, int sset)
 {
 	const struct ethtool_ops *ops = dev->ethtool_ops;
@@ -204,6 +221,13 @@
 	if (sset == ETH_SS_TUNABLES)
 		return ARRAY_SIZE(tunable_strings);
 
+	if (sset == ETH_SS_PHY_STATS) {
+		if (dev->phydev)
+			return phy_get_sset_count(dev->phydev);
+		else
+			return -EOPNOTSUPP;
+	}
+
 	if (ops->get_sset_count && ops->get_strings)
 		return ops->get_sset_count(dev, sset);
 	else
@@ -223,7 +247,17 @@
 		       sizeof(rss_hash_func_strings));
 	else if (stringset == ETH_SS_TUNABLES)
 		memcpy(data, tunable_strings, sizeof(tunable_strings));
-	else
+	else if (stringset == ETH_SS_PHY_STATS) {
+		struct phy_device *phydev = dev->phydev;
+
+		if (phydev) {
+			mutex_lock(&phydev->lock);
+			phydev->drv->get_strings(phydev, data);
+			mutex_unlock(&phydev->lock);
+		} else {
+			return;
+		}
+	} else
 		/* ops->get_strings is valid because checked earlier */
 		ops->get_strings(dev, stringset, data);
 }
@@ -1401,6 +1435,47 @@
 	return ret;
 }
 
+static int ethtool_get_phy_stats(struct net_device *dev, void __user *useraddr)
+{
+	struct ethtool_stats stats;
+	struct phy_device *phydev = dev->phydev;
+	u64 *data;
+	int ret, n_stats;
+
+	if (!phydev)
+		return -EOPNOTSUPP;
+
+	n_stats = phy_get_sset_count(phydev);
+
+	if (n_stats < 0)
+		return n_stats;
+	WARN_ON(n_stats == 0);
+
+	if (copy_from_user(&stats, useraddr, sizeof(stats)))
+		return -EFAULT;
+
+	stats.n_stats = n_stats;
+	data = kmalloc_array(n_stats, sizeof(u64), GFP_USER);
+	if (!data)
+		return -ENOMEM;
+
+	mutex_lock(&phydev->lock);
+	phydev->drv->get_stats(phydev, &stats, data);
+	mutex_unlock(&phydev->lock);
+
+	ret = -EFAULT;
+	if (copy_to_user(useraddr, &stats, sizeof(stats)))
+		goto out;
+	useraddr += sizeof(stats);
+	if (copy_to_user(useraddr, data, stats.n_stats * sizeof(u64)))
+		goto out;
+	ret = 0;
+
+ out:
+	kfree(data);
+	return ret;
+}
+
 static int ethtool_get_perm_addr(struct net_device *dev, void __user *useraddr)
 {
 	struct ethtool_perm_addr epaddr;
@@ -1779,6 +1854,7 @@
 	case ETHTOOL_GSSET_INFO:
 	case ETHTOOL_GSTRINGS:
 	case ETHTOOL_GSTATS:
+	case ETHTOOL_GPHYSTATS:
 	case ETHTOOL_GTSO:
 	case ETHTOOL_GPERMADDR:
 	case ETHTOOL_GUFO:
@@ -1991,6 +2067,9 @@
 	case ETHTOOL_STUNABLE:
 		rc = ethtool_set_tunable(dev, useraddr);
 		break;
+	case ETHTOOL_GPHYSTATS:
+		rc = ethtool_get_phy_stats(dev, useraddr);
+		break;
 	default:
 		rc = -EOPNOTSUPP;
 	}