net: ethtool: add helpers for aggregate statistics

When a pMAC exists but the driver is unable to atomically query the
aggregate eMAC+pMAC statistics, the user should be given back at least
the sum of eMAC and pMAC counters queried separately.

This is a generic problem, so add helpers in ethtool to do this
operation, if the driver doesn't have a better way to report aggregate
stats. Do this in a way that does not require changes to these functions
when new stats are added (basically treat the structures as an array of
u64 values, except for the first element which is the stats source).

In include/linux/ethtool.h, there is already a section where helper
function prototypes should be placed. The trouble is, this section is
too early, before the definitions of struct ethtool_eth_mac_stats et.al.
Move that section at the end and append these new helpers to it.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 127 insertions, 0 deletions

diff --git a/net/ethtool/stats.c b/net/ethtool/stats.c
index 26a70320e01d..7294be5855d4 100644
--- a/net/ethtool/stats.c
+++ b/net/ethtool/stats.c
@@ -440,3 +440,130 @@ const struct ethnl_request_ops ethnl_stats_request_ops = {
 	.reply_size		= stats_reply_size,
 	.fill_reply		= stats_fill_reply,
 };
+
+static u64 ethtool_stats_sum(u64 a, u64 b)
+{
+	if (a == ETHTOOL_STAT_NOT_SET)
+		return b;
+	if (b == ETHTOOL_STAT_NOT_SET)
+		return a;
+	return a + b;
+}
+
+/* Avoid modifying the aggregation procedure every time a new counter is added
+ * by treating the structures as an array of u64 statistics.
+ */
+static void ethtool_aggregate_stats(void *aggr_stats, const void *emac_stats,
+				    const void *pmac_stats, size_t stats_size,
+				    size_t stats_offset)
+{
+	size_t num_stats = stats_size / sizeof(u64);
+	const u64 *s1 = emac_stats + stats_offset;
+	const u64 *s2 = pmac_stats + stats_offset;
+	u64 *s = aggr_stats + stats_offset;
+	int i;
+
+	for (i = 0; i < num_stats; i++)
+		s[i] = ethtool_stats_sum(s1[i], s2[i]);
+}
+
+void ethtool_aggregate_mac_stats(struct net_device *dev,
+				 struct ethtool_eth_mac_stats *mac_stats)
+{
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct ethtool_eth_mac_stats pmac, emac;
+
+	memset(&emac, 0xff, sizeof(emac));
+	memset(&pmac, 0xff, sizeof(pmac));
+	emac.src = ETHTOOL_MAC_STATS_SRC_EMAC;
+	pmac.src = ETHTOOL_MAC_STATS_SRC_PMAC;
+
+	ops->get_eth_mac_stats(dev, &emac);
+	ops->get_eth_mac_stats(dev, &pmac);
+
+	ethtool_aggregate_stats(mac_stats, &emac, &pmac,
+				sizeof(mac_stats->stats),
+				offsetof(struct ethtool_eth_mac_stats, stats));
+}
+EXPORT_SYMBOL(ethtool_aggregate_mac_stats);
+
+void ethtool_aggregate_phy_stats(struct net_device *dev,
+				 struct ethtool_eth_phy_stats *phy_stats)
+{
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct ethtool_eth_phy_stats pmac, emac;
+
+	memset(&emac, 0xff, sizeof(emac));
+	memset(&pmac, 0xff, sizeof(pmac));
+	emac.src = ETHTOOL_MAC_STATS_SRC_EMAC;
+	pmac.src = ETHTOOL_MAC_STATS_SRC_PMAC;
+
+	ops->get_eth_phy_stats(dev, &emac);
+	ops->get_eth_phy_stats(dev, &pmac);
+
+	ethtool_aggregate_stats(phy_stats, &emac, &pmac,
+				sizeof(phy_stats->stats),
+				offsetof(struct ethtool_eth_phy_stats, stats));
+}
+EXPORT_SYMBOL(ethtool_aggregate_phy_stats);
+
+void ethtool_aggregate_ctrl_stats(struct net_device *dev,
+				  struct ethtool_eth_ctrl_stats *ctrl_stats)
+{
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct ethtool_eth_ctrl_stats pmac, emac;
+
+	memset(&emac, 0xff, sizeof(emac));
+	memset(&pmac, 0xff, sizeof(pmac));
+	emac.src = ETHTOOL_MAC_STATS_SRC_EMAC;
+	pmac.src = ETHTOOL_MAC_STATS_SRC_PMAC;
+
+	ops->get_eth_ctrl_stats(dev, &emac);
+	ops->get_eth_ctrl_stats(dev, &pmac);
+
+	ethtool_aggregate_stats(ctrl_stats, &emac, &pmac,
+				sizeof(ctrl_stats->stats),
+				offsetof(struct ethtool_eth_ctrl_stats, stats));
+}
+EXPORT_SYMBOL(ethtool_aggregate_ctrl_stats);
+
+void ethtool_aggregate_pause_stats(struct net_device *dev,
+				   struct ethtool_pause_stats *pause_stats)
+{
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct ethtool_pause_stats pmac, emac;
+
+	memset(&emac, 0xff, sizeof(emac));
+	memset(&pmac, 0xff, sizeof(pmac));
+	emac.src = ETHTOOL_MAC_STATS_SRC_EMAC;
+	pmac.src = ETHTOOL_MAC_STATS_SRC_PMAC;
+
+	ops->get_pause_stats(dev, &emac);
+	ops->get_pause_stats(dev, &pmac);
+
+	ethtool_aggregate_stats(pause_stats, &emac, &pmac,
+				sizeof(pause_stats->stats),
+				offsetof(struct ethtool_pause_stats, stats));
+}
+EXPORT_SYMBOL(ethtool_aggregate_pause_stats);
+
+void ethtool_aggregate_rmon_stats(struct net_device *dev,
+				  struct ethtool_rmon_stats *rmon_stats)
+{
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	const struct ethtool_rmon_hist_range *dummy;
+	struct ethtool_rmon_stats pmac, emac;
+
+	memset(&emac, 0xff, sizeof(emac));
+	memset(&pmac, 0xff, sizeof(pmac));
+	emac.src = ETHTOOL_MAC_STATS_SRC_EMAC;
+	pmac.src = ETHTOOL_MAC_STATS_SRC_PMAC;
+
+	ops->get_rmon_stats(dev, &emac, &dummy);
+	ops->get_rmon_stats(dev, &pmac, &dummy);
+
+	ethtool_aggregate_stats(rmon_stats, &emac, &pmac,
+				sizeof(rmon_stats->stats),
+				offsetof(struct ethtool_rmon_stats, stats));
+}
+EXPORT_SYMBOL(ethtool_aggregate_rmon_stats);