net: ethtool: Add a command to list available time stamping layers

Introduce a new netlink message that lists all available time stamping
layers on a given interface.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: kmaincent

Documentation/networking/ethtool-netlink.rst

@@ -226,6 +226,7 @@ Userspace to kernel:
   ``ETHTOOL_MSG_MM_GET``                get MAC merge layer state
   ``ETHTOOL_MSG_MM_SET``                set MAC merge layer parameters
   ``ETHTOOL_MSG_TS_GET``                get current timestamping
+  ``ETHTOOL_MSG_TS_LIST_GET``           list available timestampings
   ===================================== =================================
 
 Kernel to userspace:
@@ -270,6 +271,7 @@ Kernel to userspace:
   ``ETHTOOL_MSG_RSS_GET_REPLY``            RSS settings
   ``ETHTOOL_MSG_MM_GET_REPLY``             MAC merge layer status
   ``ETHTOOL_MSG_TS_GET_REPLY``             current timestamping
+  ``ETHTOOL_MSG_TS_LIST_GET_REPLY``        available timestampings
   ======================================== =================================
 
 ``GET`` requests are sent by userspace applications to retrieve device
@@ -2016,6 +2018,26 @@ Kernel response contents:
 
 This command get the current timestamp layer.
 
+TS_LIST_GET
+===========
+
+Get the list of available timestampings.
+
+Request contents:
+
+  =================================  ======  ====================
+  ``ETHTOOL_A_TS_HEADER``            nested  request header
+  =================================  ======  ====================
+
+Kernel response contents:
+
+  ===========================  ======  ==============================
+  ``ETHTOOL_A_TS_HEADER``      nested  reply header
+  ``ETHTOOL_A_TS_LIST_LAYER``  binary  available timestampings
+  ===========================  ======  ==============================
+
+This command lists all the possible timestamp layer available.
+
 Request translation
 ===================
 
@@ -2123,4 +2145,5 @@ are netlink only.
   n/a                                 ``ETHTOOL_MSG_MM_GET``
   n/a                                 ``ETHTOOL_MSG_MM_SET``
   n/a                                 ``ETHTOOL_MSG_TS_GET``
+  n/a                                 ``ETHTOOL_MSG_TS_LIST_GET``
   =================================== =====================================

include/uapi/linux/ethtool_netlink.h

@@ -58,6 +58,7 @@ enum {
 	ETHTOOL_MSG_MM_GET,
 	ETHTOOL_MSG_MM_SET,
 	ETHTOOL_MSG_TS_GET,
+	ETHTOOL_MSG_TS_LIST_GET,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_USER_CNT,
@@ -111,6 +112,7 @@ enum {
 	ETHTOOL_MSG_MM_GET_REPLY,
 	ETHTOOL_MSG_MM_NTF,
 	ETHTOOL_MSG_TS_GET_REPLY,
+	ETHTOOL_MSG_TS_LIST_GET_REPLY,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_KERNEL_CNT,
@@ -989,6 +991,18 @@ enum {
 	ETHTOOL_A_TS_MAX = (__ETHTOOL_A_TS_CNT - 1)
 };
 
+/* TS LIST LAYER */
+
+enum {
+	ETHTOOL_A_TS_LIST_UNSPEC,
+	ETHTOOL_A_TS_LIST_HEADER,			/* nest - _A_HEADER_* */
+	ETHTOOL_A_TS_LIST_LAYER,		/* array, u32 */
+
+	/* add new constants above here */
+	__ETHTOOL_A_TS_LIST_CNT,
+	ETHTOOL_A_TS_LIST_MAX = (__ETHTOOL_A_TS_LIST_CNT - 1)
+};
+
 /* generic netlink info */
 #define ETHTOOL_GENL_NAME "ethtool"
 #define ETHTOOL_GENL_VERSION 1

net/ethtool/netlink.c

@@ -307,6 +307,7 @@ ethnl_default_requests[__ETHTOOL_MSG_USER_CNT] = {
 	[ETHTOOL_MSG_MM_GET]		= &ethnl_mm_request_ops,
 	[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,
 };
 
 static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
@@ -1138,6 +1139,15 @@ 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_LIST_GET,
+		.doit	= ethnl_default_doit,
+		.start	= ethnl_default_start,
+		.dumpit	= ethnl_default_dumpit,
+		.done	= ethnl_default_done,
+		.policy = ethnl_ts_get_policy,
+		.maxattr = ARRAY_SIZE(ethnl_ts_get_policy) - 1,
+	},
 };
 
 static const struct genl_multicast_group ethtool_nl_mcgrps[] = {

net/ethtool/netlink.h

@@ -396,6 +396,7 @@ extern const struct ethnl_request_ops ethnl_plca_cfg_request_ops;
 extern const struct ethnl_request_ops ethnl_plca_status_request_ops;
 extern const struct ethnl_request_ops ethnl_mm_request_ops;
 extern const struct ethnl_request_ops ethnl_ts_request_ops;
+extern const struct ethnl_request_ops ethnl_ts_list_request_ops;
 
 extern const struct nla_policy ethnl_header_policy[ETHTOOL_A_HEADER_FLAGS + 1];
 extern const struct nla_policy ethnl_header_policy_stats[ETHTOOL_A_HEADER_FLAGS + 1];

net/ethtool/ts.c

@@ -86,3 +86,76 @@ const struct ethnl_request_ops ethnl_ts_request_ops = {
 	.reply_size		= ts_reply_size,
 	.fill_reply		= ts_fill_reply,
 };
+
+/* TS_LIST_GET */
+struct ts_list_reply_data {
+	struct ethnl_reply_data		base;
+	enum timestamping_layer		ts_layer[__TIMESTAMPING_COUNT];
+	u8				num_ts;
+};
+
+#define TS_LIST_REPDATA(__reply_base) \
+	container_of(__reply_base, struct ts_list_reply_data, base)
+
+static int ts_list_prepare_data(const struct ethnl_req_info *req_base,
+				struct ethnl_reply_data *reply_base,
+				const struct genl_info *info)
+{
+	struct ts_list_reply_data *data = TS_LIST_REPDATA(reply_base);
+	struct net_device *dev = reply_base->dev;
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	int ret, i = 0;
+
+	ret = ethnl_ops_begin(dev);
+	if (ret < 0)
+		return ret;
+
+	if (phy_has_tsinfo(dev->phydev))
+		data->ts_layer[i++] = PHY_TIMESTAMPING;
+	if (ops->get_ts_info) {
+		struct ethtool_ts_info ts_info = {0};
+
+		ops->get_ts_info(dev, &ts_info);
+		if (ts_info.so_timestamping &
+		    SOF_TIMESTAMPING_HARDWARE_MASK)
+			data->ts_layer[i++] = MAC_TIMESTAMPING;
+
+		if (ts_info.so_timestamping &
+		    SOF_TIMESTAMPING_SOFTWARE_MASK)
+			data->ts_layer[i++] = SOFTWARE_TIMESTAMPING;
+	}
+
+	data->num_ts = i;
+	ethnl_ops_complete(dev);
+
+	return ret;
+}
+
+static int ts_list_reply_size(const struct ethnl_req_info *req_base,
+			      const struct ethnl_reply_data *reply_base)
+{
+	struct ts_list_reply_data *data = TS_LIST_REPDATA(reply_base);
+
+	return nla_total_size(sizeof(u32)) * data->num_ts;
+}
+
+static int ts_list_fill_reply(struct sk_buff *skb,
+			      const struct ethnl_req_info *req_base,
+			 const struct ethnl_reply_data *reply_base)
+{
+	struct ts_list_reply_data *data = TS_LIST_REPDATA(reply_base);
+
+	return nla_put(skb, ETHTOOL_A_TS_LIST_LAYER, sizeof(u32) * data->num_ts, data->ts_layer);
+}
+
+const struct ethnl_request_ops ethnl_ts_list_request_ops = {
+	.request_cmd		= ETHTOOL_MSG_TS_LIST_GET,
+	.reply_cmd		= ETHTOOL_MSG_TS_LIST_GET_REPLY,
+	.hdr_attr		= ETHTOOL_A_TS_HEADER,
+	.req_info_size		= sizeof(struct ts_req_info),
+	.reply_data_size	= sizeof(struct ts_list_reply_data),
+
+	.prepare_data		= ts_list_prepare_data,
+	.reply_size		= ts_list_reply_size,
+	.fill_reply		= ts_list_fill_reply,
+};