net: ethtool: ts: Let the active time stamping layer be selectable

Now that the current timestamp is saved in a variable lets add the
ETHTOOL_MSG_TS_SET ethtool netlink socket to make it selectable.
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/ethtool-netlink.rst

@@ -227,6 +227,7 @@ Userspace to kernel:
   ``ETHTOOL_MSG_MM_SET``                set MAC merge layer parameters
   ``ETHTOOL_MSG_TS_GET``                get current timestamping
   ``ETHTOOL_MSG_TS_LIST_GET``           list available timestampings
+  ``ETHTOOL_MSG_TS_SET``                set current timestamping
   ===================================== =================================
 
 Kernel to userspace:
@@ -2038,6 +2039,21 @@ Kernel response contents:
 
 This command lists all the possible timestamp layer available.
 
+TS_SET
+======
+
+Modify the selected timestamping.
+
+Request contents:
+
+  =======================  ======  ===================
+  ``ETHTOOL_A_TS_HEADER``  nested  reply header
+  ``ETHTOOL_A_TS_LAYER``   u32     timestamping
+  =======================  ======  ===================
+
+This command set the timestamping with one that should be listed by the
+TSLIST_GET command.
+
 Request translation
 ===================
 
@@ -2146,4 +2162,5 @@ are netlink only.
   n/a                                 ``ETHTOOL_MSG_MM_SET``
   n/a                                 ``ETHTOOL_MSG_TS_GET``
   n/a                                 ``ETHTOOL_MSG_TS_LIST_GET``
+  n/a                                 ``ETHTOOL_MSG_TS_SET``
   =================================== =====================================

include/uapi/linux/ethtool_netlink.h

@@ -59,6 +59,7 @@ enum {
 	ETHTOOL_MSG_MM_SET,
 	ETHTOOL_MSG_TS_GET,
 	ETHTOOL_MSG_TS_LIST_GET,
+	ETHTOOL_MSG_TS_SET,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_USER_CNT,

net/ethtool/netlink.c

@@ -308,6 +308,7 @@ ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
 	[ETHTOOL_MSG_MM_SET]		= &ethnl_mm_request_ops,
 	[ETHTOOL_MSG_TS_GET]		= &ethnl_ts_request_ops,
 	[ETHTOOL_MSG_TS_LIST_GET]	= &ethnl_ts_list_request_ops,
+	[ETHTOOL_MSG_TS_SET]		= &ethnl_ts_request_ops,
 };
 
 static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
@@ -1148,6 +1149,13 @@ static const struct genl_ops ethtool_genl_ops[] = {
 		.policy = ethnl_ts_get_policy,
 		.maxattr = ARRAY_SIZE(ethnl_ts_get_policy) - 1,
 	},
+	{
+		.cmd	= ETHTOOL_MSG_TS_SET,
+		.flags	= GENL_UNS_ADMIN_PERM,
+		.doit	= ethnl_default_set_doit,
+		.policy = ethnl_ts_set_policy,
+		.maxattr = ARRAY_SIZE(ethnl_ts_set_policy) - 1,
+	},
 };
 
 static const struct genl_multicast_group ethtool_nl_mcgrps[] = {

net/ethtool/netlink.h

@@ -444,6 +444,7 @@ extern const struct nla_policy ethnl_plca_get_status_policy[ETHTOOL_A_PLCA_HEADE
 extern const struct nla_policy ethnl_mm_get_policy[ETHTOOL_A_MM_HEADER + 1];
 extern const struct nla_policy ethnl_mm_set_policy[ETHTOOL_A_MM_MAX + 1];
 extern const struct nla_policy ethnl_ts_get_policy[ETHTOOL_A_TS_HEADER + 1];
+extern const struct nla_policy ethnl_ts_set_policy[ETHTOOL_A_TS_MAX + 1];
 
 int ethnl_set_features(struct sk_buff *skb, struct genl_info *info);
 int ethnl_act_cable_test(struct sk_buff *skb, struct genl_info *info);

net/ethtool/ts.c

@@ -59,6 +59,102 @@ static int ts_fill_reply(struct sk_buff *skb,
 	return nla_put_u32(skb, ETHTOOL_A_TS_LAYER, data->ts_layer);
 }
 
+/* TS_SET */
+const struct nla_policy ethnl_ts_set_policy[] = {
+	[ETHTOOL_A_TS_HEADER]	= NLA_POLICY_NESTED(ethnl_header_policy),
+	[ETHTOOL_A_TS_LAYER]	= NLA_POLICY_RANGE(NLA_U32, 0,
+						   __TIMESTAMPING_COUNT - 1)
+};
+
+static int ethnl_set_ts_validate(struct ethnl_req_info *req_info,
+				 struct genl_info *info)
+{
+	struct nlattr **tb = info->attrs;
+	const struct net_device_ops *ops = req_info->dev->netdev_ops;
+
+	if (!ops->ndo_hwtstamp_set)
+		return -EOPNOTSUPP;
+
+	if (!tb[ETHTOOL_A_TS_LAYER])
+		return 0;
+
+	return 1;
+}
+
+static int ethnl_set_ts(struct ethnl_req_info *req_info, struct genl_info *info)
+{
+	struct net_device *dev = req_info->dev;
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct kernel_hwtstamp_config config = {0};
+	struct nlattr **tb = info->attrs;
+	enum timestamping_layer ts_layer;
+	bool mod = false;
+	int ret;
+
+	ts_layer = dev->ts_layer;
+	ethnl_update_u32(&ts_layer, tb[ETHTOOL_A_TS_LAYER], &mod);
+
+	if (!mod)
+		return 0;
+
+	if (ts_layer == SOFTWARE_TIMESTAMPING) {
+		struct ethtool_ts_info ts_info = {0};
+
+		if (!ops->get_ts_info) {
+			NL_SET_ERR_MSG_ATTR(info->extack,
+					    tb[ETHTOOL_A_TS_LAYER],
+					    "this net device cannot support timestamping");
+			return -EINVAL;
+		}
+
+		ops->get_ts_info(dev, &ts_info);
+		if ((ts_info.so_timestamping &
+		    SOF_TIMESTAMPING_SOFTWARE_MASK) !=
+		    SOF_TIMESTAMPING_SOFTWARE_MASK) {
+			NL_SET_ERR_MSG_ATTR(info->extack,
+					    tb[ETHTOOL_A_TS_LAYER],
+					    "this net device cannot support software timestamping");
+			return -EINVAL;
+		}
+	} else if (ts_layer == MAC_TIMESTAMPING) {
+		struct ethtool_ts_info ts_info = {0};
+
+		if (!ops->get_ts_info) {
+			NL_SET_ERR_MSG_ATTR(info->extack,
+					    tb[ETHTOOL_A_TS_LAYER],
+					    "this net device cannot support timestamping");
+			return -EINVAL;
+		}
+
+		ops->get_ts_info(dev, &ts_info);
+		if ((ts_info.so_timestamping &
+		    SOF_TIMESTAMPING_HARDWARE_MASK) !=
+		    SOF_TIMESTAMPING_HARDWARE_MASK) {
+			NL_SET_ERR_MSG_ATTR(info->extack,
+					    tb[ETHTOOL_A_TS_LAYER],
+					    "this net device cannot support hardware timestamping");
+			return -EINVAL;
+		}
+	} else if (ts_layer == PHY_TIMESTAMPING && !phy_has_tsinfo(dev->phydev)) {
+		NL_SET_ERR_MSG_ATTR(info->extack, tb[ETHTOOL_A_TS_LAYER],
+				    "this phy device cannot support timestamping");
+		return -EINVAL;
+	}
+
+	/* Disable time stamping in the current layer. */
+	if (netif_device_present(dev) &&
+	    (dev->ts_layer == PHY_TIMESTAMPING ||
+	    dev->ts_layer == MAC_TIMESTAMPING)) {
+		ret = dev_set_hwtstamp_phylib(dev, &config, info->extack);
+		if (ret < 0)
+			return ret;
+	}
+
+	dev->ts_layer = ts_layer;
+
+	return 1;
+}
+
 const struct ethnl_request_ops ethnl_ts_request_ops = {
 	.request_cmd		= ETHTOOL_MSG_TS_GET,
 	.reply_cmd		= ETHTOOL_MSG_TS_GET_REPLY,
@@ -69,6 +165,9 @@ const struct ethnl_request_ops ethnl_ts_request_ops = {
 	.prepare_data		= ts_prepare_data,
 	.reply_size		= ts_reply_size,
 	.fill_reply		= ts_fill_reply,
+
+	.set_validate		= ethnl_set_ts_validate,
+	.set			= ethnl_set_ts,
 };
 
 /* TS_LIST_GET */