net: ethtool: netlink: retrieve stats from multiple sources (eMAC, pMAC)

IEEE 802.3-2018 clause 99 defines a MAC Merge sublayer which contains an
Express MAC and a Preemptible MAC. Both MACs are hidden to higher and
lower layers and visible as a single MAC (packet classification to eMAC
or pMAC on TX is done based on priority; classification on RX is done
based on SFD).

For devices which support a MAC Merge sublayer, it is desirable to
retrieve individual packet counters from the eMAC and the pMAC, as well
as aggregate statistics (their sum).

Introduce a new ETHTOOL_A_STATS_SRC attribute which is part of the
policy of ETHTOOL_MSG_STATS_GET and, and an ETHTOOL_A_PAUSE_STATS_SRC
which is part of the policy of ETHTOOL_MSG_PAUSE_GET (accepted when
ETHTOOL_FLAG_STATS is set in the common ethtool header). Both of these
take values from enum ethtool_mac_stats_src, defaulting to "aggregate"
in the absence of the attribute.

Existing drivers do not need to pay attention to this enum which was
added to all driver-facing structures, just the ones which report the
MAC merge layer as supported.

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

1 files changed, 48 insertions, 0 deletions

diff --git a/net/ethtool/pause.c b/net/ethtool/pause.c
index a8c113d244db..e2be9e89c9d9 100644
--- a/net/ethtool/pause.c
+++ b/net/ethtool/pause.c
@@ -5,8 +5,12 @@
 
 struct pause_req_info {
 	struct ethnl_req_info		base;
+	enum ethtool_mac_stats_src	src;
 };
 
+#define PAUSE_REQINFO(__req_base) \
+	container_of(__req_base, struct pause_req_info, base)
+
 struct pause_reply_data {
 	struct ethnl_reply_data		base;
 	struct ethtool_pauseparam	pauseparam;
@@ -19,13 +23,40 @@ struct pause_reply_data {
 const struct nla_policy ethnl_pause_get_policy[] = {
 	[ETHTOOL_A_PAUSE_HEADER]		=
 		NLA_POLICY_NESTED(ethnl_header_policy_stats),
+	[ETHTOOL_A_PAUSE_STATS_SRC]		=
+		NLA_POLICY_MAX(NLA_U32, ETHTOOL_MAC_STATS_SRC_PMAC),
 };
 
+static int pause_parse_request(struct ethnl_req_info *req_base,
+			       struct nlattr **tb,
+			       struct netlink_ext_ack *extack)
+{
+	enum ethtool_mac_stats_src src = ETHTOOL_MAC_STATS_SRC_AGGREGATE;
+	struct pause_req_info *req_info = PAUSE_REQINFO(req_base);
+
+	if (tb[ETHTOOL_A_PAUSE_STATS_SRC]) {
+		if (!(req_base->flags & ETHTOOL_FLAG_STATS)) {
+			NL_SET_ERR_MSG_MOD(extack,
+					   "ETHTOOL_FLAG_STATS must be set when requesting a source of stats");
+			return -EINVAL;
+		}
+
+		src = nla_get_u32(tb[ETHTOOL_A_PAUSE_STATS_SRC]);
+	}
+
+	req_info->src = src;
+
+	return 0;
+}
+
 static int pause_prepare_data(const struct ethnl_req_info *req_base,
 			      struct ethnl_reply_data *reply_base,
 			      struct genl_info *info)
 {
+	const struct pause_req_info *req_info = PAUSE_REQINFO(req_base);
 	struct pause_reply_data *data = PAUSE_REPDATA(reply_base);
+	enum ethtool_mac_stats_src src = req_info->src;
+	struct netlink_ext_ack *extack = info->extack;
 	struct net_device *dev = reply_base->dev;
 	int ret;
 
@@ -34,14 +65,26 @@ static int pause_prepare_data(const struct ethnl_req_info *req_base,
 
 	ethtool_stats_init((u64 *)&data->pausestat,
 			   sizeof(data->pausestat) / 8);
+	data->pausestat.src = src;
 
 	ret = ethnl_ops_begin(dev);
 	if (ret < 0)
 		return ret;
+
+	if ((src == ETHTOOL_MAC_STATS_SRC_EMAC ||
+	     src == ETHTOOL_MAC_STATS_SRC_PMAC) &&
+	    !__ethtool_dev_mm_supported(dev)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Device does not support MAC merge layer");
+		ethnl_ops_complete(dev);
+		return -EOPNOTSUPP;
+	}
+
 	dev->ethtool_ops->get_pauseparam(dev, &data->pauseparam);
 	if (req_base->flags & ETHTOOL_FLAG_STATS &&
 	    dev->ethtool_ops->get_pause_stats)
 		dev->ethtool_ops->get_pause_stats(dev, &data->pausestat);
+
 	ethnl_ops_complete(dev);
 
 	return 0;
@@ -56,6 +99,7 @@ static int pause_reply_size(const struct ethnl_req_info *req_base,
 
 	if (req_base->flags & ETHTOOL_FLAG_STATS)
 		n += nla_total_size(0) +	/* _PAUSE_STATS */
+		     nla_total_size(sizeof(u32)) + /* _PAUSE_STATS_SRC */
 		     nla_total_size_64bit(sizeof(u64)) * ETHTOOL_PAUSE_STAT_CNT;
 	return n;
 }
@@ -77,6 +121,9 @@ static int pause_put_stats(struct sk_buff *skb,
 	const u16 pad = ETHTOOL_A_PAUSE_STAT_PAD;
 	struct nlattr *nest;
 
+	if (nla_put_u32(skb, ETHTOOL_A_PAUSE_STATS_SRC, pause_stats->src))
+		return -EMSGSIZE;
+
 	nest = nla_nest_start(skb, ETHTOOL_A_PAUSE_STATS);
 	if (!nest)
 		return -EMSGSIZE;
@@ -121,6 +168,7 @@ const struct ethnl_request_ops ethnl_pause_request_ops = {
 	.req_info_size		= sizeof(struct pause_req_info),
 	.reply_data_size	= sizeof(struct pause_reply_data),
 
+	.parse_request		= pause_parse_request,
 	.prepare_data		= pause_prepare_data,
 	.reply_size		= pause_reply_size,
 	.fill_reply		= pause_fill_reply,