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/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;
 	}