ethtool: provide timestamping information with TSINFO_GET request

Implement TSINFO_GET request to get timestamping information for a network
device. This is traditionally available via ETHTOOL_GET_TS_INFO ioctl
request.

Move part of ethtool_get_ts_info() into common.c so that ioctl and netlink
code use the same logic to get timestamping information from the device.

v3: use "TSINFO" rather than "TIMESTAMP", suggested by Richard Cochran

Signed-off-by: Michal Kubecek <[e-mail]>
Acked-by: Richard Cochran <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

Documentation/networking/ethtool-netlink.rst

···
   ``ETHTOOL_MSG_PAUSE_SET``             set pause parameters
   ``ETHTOOL_MSG_EEE_GET``               get EEE settings
   ``ETHTOOL_MSG_EEE_SET``               set EEE settings
+  ``ETHTOOL_MSG_TSINFO_GET``		get timestamping info
   ===================================== ================================
 
 Kernel to userspace:
···
   ``ETHTOOL_MSG_PAUSE_NTF``             pause parameters
   ``ETHTOOL_MSG_EEE_GET_REPLY``         EEE settings
   ``ETHTOOL_MSG_EEE_NTF``               EEE settings
+  ``ETHTOOL_MSG_TSINFO_GET_REPLY``	timestamping info
   ===================================== =================================
 
 ``GET`` requests are sent by userspace applications to retrieve device
···
 callback supports.
 
 
+TSINFO_GET
+==========
+
+Gets timestamping information like ``ETHTOOL_GET_TS_INFO`` ioctl request.
+
+Request contents:
+
+  =====================================  ======  ==========================
+  ``ETHTOOL_A_TSINFO_HEADER``            nested  request header
+  =====================================  ======  ==========================
+
+Kernel response contents:
+
+  =====================================  ======  ==========================
+  ``ETHTOOL_A_TSINFO_HEADER``            nested  request header
+  ``ETHTOOL_A_TSINFO_TIMESTAMPING``      bitset  SO_TIMESTAMPING flags
+  ``ETHTOOL_A_TSINFO_TX_TYPES``          bitset  supported Tx types
+  ``ETHTOOL_A_TSINFO_RX_FILTERS``        bitset  supported Rx filters
+  ``ETHTOOL_A_TSINFO_PHC_INDEX``         u32     PTP hw clock index
+  =====================================  ======  ==========================
+
+``ETHTOOL_A_TSINFO_PHC_INDEX`` is absent if there is no associated PHC (there
+is no special value for this case). The bitset attributes are omitted if they
+would be empty (no bit set).
+
+
 Request translation
 ===================
 
···
   ``ETHTOOL_SET_DUMP``                n/a
   ``ETHTOOL_GET_DUMP_FLAG``           n/a
   ``ETHTOOL_GET_DUMP_DATA``           n/a
-  ``ETHTOOL_GET_TS_INFO``             n/a
+  ``ETHTOOL_GET_TS_INFO``             ``ETHTOOL_MSG_TSINFO_GET``
   ``ETHTOOL_GMODULEINFO``             n/a
   ``ETHTOOL_GMODULEEEPROM``           n/a
   ``ETHTOOL_GEEE``                    ``ETHTOOL_MSG_EEE_GET``

include/uapi/linux/ethtool_netlink.h

···
 	ETHTOOL_MSG_PAUSE_SET,
 	ETHTOOL_MSG_EEE_GET,
 	ETHTOOL_MSG_EEE_SET,
+	ETHTOOL_MSG_TSINFO_GET,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_USER_CNT,
···
 	ETHTOOL_MSG_PAUSE_NTF,
 	ETHTOOL_MSG_EEE_GET_REPLY,
 	ETHTOOL_MSG_EEE_NTF,
+	ETHTOOL_MSG_TSINFO_GET_REPLY,
 
 	/* add new constants above here */
 	__ETHTOOL_MSG_KERNEL_CNT,
···
 	/* add new constants above here */
 	__ETHTOOL_A_EEE_CNT,
 	ETHTOOL_A_EEE_MAX = (__ETHTOOL_A_EEE_CNT - 1)
+};
+
+/* TSINFO */
+
+enum {
+	ETHTOOL_A_TSINFO_UNSPEC,
+	ETHTOOL_A_TSINFO_HEADER,			/* nest - _A_HEADER_* */
+	ETHTOOL_A_TSINFO_TIMESTAMPING,			/* bitset */
+	ETHTOOL_A_TSINFO_TX_TYPES,			/* bitset */
+	ETHTOOL_A_TSINFO_RX_FILTERS,			/* bitset */
+	ETHTOOL_A_TSINFO_PHC_INDEX,			/* u32 */
+
+	/* add new constants above here */
+	__ETHTOOL_A_TSINFO_CNT,
+	ETHTOOL_A_TSINFO_MAX = (__ETHTOOL_A_TSINFO_CNT - 1)
 };
 
 /* generic netlink info */

net/ethtool/Makefile

···
 
 ethtool_nl-y	:= netlink.o bitset.o strset.o linkinfo.o linkmodes.o \
 		   linkstate.o debug.o wol.o features.o privflags.o rings.o \
-		   channels.o coalesce.o pause.o eee.o
+		   channels.o coalesce.o pause.o eee.o tsinfo.o

net/ethtool/common.c

···
 // SPDX-License-Identifier: GPL-2.0-only
 
 #include <linux/net_tstamp.h>
+#include <linux/phy.h>
 
 #include "common.h"
 
···
 	 * the fact that ops are checked at registration time does not
 	 * mean the ops attached to a netdev later on are sane.
 	 */
+	return 0;
+}
+
+int __ethtool_get_ts_info(struct net_device *dev, struct ethtool_ts_info *info)
+{
+	const struct ethtool_ops *ops = dev->ethtool_ops;
+	struct phy_device *phydev = dev->phydev;
+
+	memset(info, 0, sizeof(*info));
+	info->cmd = ETHTOOL_GET_TS_INFO;
+
+	if (phy_has_tsinfo(phydev))
+		return phy_ts_info(phydev, info);
+	if (ops->get_ts_info)
+		return ops->get_ts_info(dev, info);
+
+	info->so_timestamping = SOF_TIMESTAMPING_RX_SOFTWARE |
+				SOF_TIMESTAMPING_SOFTWARE;
+	info->phc_index = -1;
+
 	return 0;
 }

net/ethtool/common.h

···
 	struct ethtool_link_ksettings *link_ksettings,
 	const struct ethtool_cmd *legacy_settings);
 int ethtool_get_max_rxfh_channel(struct net_device *dev, u32 *max);
+int __ethtool_get_ts_info(struct net_device *dev, struct ethtool_ts_info *info);
 
 #endif /* _ETHTOOL_COMMON_H */

net/ethtool/ioctl.c

···
 
 static int ethtool_get_ts_info(struct net_device *dev, void __user *useraddr)
 {
-	int err = 0;
 	struct ethtool_ts_info info;
-	const struct ethtool_ops *ops = dev->ethtool_ops;
-	struct phy_device *phydev = dev->phydev;
+	int err;
 
-	memset(&info, 0, sizeof(info));
-	info.cmd = ETHTOOL_GET_TS_INFO;
-
-	if (phy_has_tsinfo(phydev)) {
-		err = phy_ts_info(phydev, &info);
-	} else if (ops->get_ts_info) {
-		err = ops->get_ts_info(dev, &info);
-	} else {
-		info.so_timestamping =
-			SOF_TIMESTAMPING_RX_SOFTWARE |
-			SOF_TIMESTAMPING_SOFTWARE;
-		info.phc_index = -1;
-	}
-
+	err = __ethtool_get_ts_info(dev, &info);
 	if (err)
 		return err;
 
 	if (copy_to_user(useraddr, &info, sizeof(info)))
-		err = -EFAULT;
+		return -EFAULT;
 
-	return err;
+	return 0;
 }
 
 static int __ethtool_get_module_info(struct net_device *dev,

net/ethtool/netlink.c

···
 	[ETHTOOL_MSG_COALESCE_GET]	= &ethnl_coalesce_request_ops,
 	[ETHTOOL_MSG_PAUSE_GET]		= &ethnl_pause_request_ops,
 	[ETHTOOL_MSG_EEE_GET]		= &ethnl_eee_request_ops,
+	[ETHTOOL_MSG_TSINFO_GET]	= &ethnl_tsinfo_request_ops,
 };
 
 static struct ethnl_dump_ctx *ethnl_dump_context(struct netlink_callback *cb)
···
 		.cmd	= ETHTOOL_MSG_EEE_SET,
 		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= ethnl_set_eee,
+	},
+	{
+		.cmd	= ETHTOOL_MSG_TSINFO_GET,
+		.doit	= ethnl_default_doit,
+		.start	= ethnl_default_start,
+		.dumpit	= ethnl_default_dumpit,
+		.done	= ethnl_default_done,
 	},
 };
 

net/ethtool/netlink.h

···
 extern const struct ethnl_request_ops ethnl_coalesce_request_ops;
 extern const struct ethnl_request_ops ethnl_pause_request_ops;
 extern const struct ethnl_request_ops ethnl_eee_request_ops;
+extern const struct ethnl_request_ops ethnl_tsinfo_request_ops;
 
 int ethnl_set_linkinfo(struct sk_buff *skb, struct genl_info *info);
 int ethnl_set_linkmodes(struct sk_buff *skb, struct genl_info *info);

net/ethtool/tsinfo.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/net_tstamp.h>
+
+#include "netlink.h"
+#include "common.h"
+#include "bitset.h"
+
+struct tsinfo_req_info {
+	struct ethnl_req_info		base;
+};
+
+struct tsinfo_reply_data {
+	struct ethnl_reply_data		base;
+	struct ethtool_ts_info		ts_info;
+};
+
+#define TSINFO_REPDATA(__reply_base) \
+	container_of(__reply_base, struct tsinfo_reply_data, base)
+
+static const struct nla_policy
+tsinfo_get_policy[ETHTOOL_A_TSINFO_MAX + 1] = {
+	[ETHTOOL_A_TSINFO_UNSPEC]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_TSINFO_HEADER]		= { .type = NLA_NESTED },
+	[ETHTOOL_A_TSINFO_TIMESTAMPING]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_TSINFO_TX_TYPES]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_TSINFO_RX_FILTERS]		= { .type = NLA_REJECT },
+	[ETHTOOL_A_TSINFO_PHC_INDEX]		= { .type = NLA_REJECT },
+};
+
+static int tsinfo_prepare_data(const struct ethnl_req_info *req_base,
+			       struct ethnl_reply_data *reply_base,
+			       struct genl_info *info)
+{
+	struct tsinfo_reply_data *data = TSINFO_REPDATA(reply_base);
+	struct net_device *dev = reply_base->dev;
+	int ret;
+
+	ret = ethnl_ops_begin(dev);
+	if (ret < 0)
+		return ret;
+	ret = __ethtool_get_ts_info(dev, &data->ts_info);
+	ethnl_ops_complete(dev);
+
+	return ret;
+}
+
+static int tsinfo_reply_size(const struct ethnl_req_info *req_base,
+			     const struct ethnl_reply_data *reply_base)
+{
+	const struct tsinfo_reply_data *data = TSINFO_REPDATA(reply_base);
+	bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
+	const struct ethtool_ts_info *ts_info = &data->ts_info;
+	int len = 0;
+	int ret;
+
+	BUILD_BUG_ON(__SOF_TIMESTAMPING_CNT > 32);
+	BUILD_BUG_ON(__HWTSTAMP_TX_CNT > 32);
+	BUILD_BUG_ON(__HWTSTAMP_FILTER_CNT > 32);
+
+	if (ts_info->so_timestamping) {
+		ret = ethnl_bitset32_size(&ts_info->so_timestamping, NULL,
+					  __SOF_TIMESTAMPING_CNT,
+					  sof_timestamping_names, compact);
+		if (ret < 0)
+			return ret;
+		len += ret;	/* _TSINFO_TIMESTAMPING */
+	}
+	if (ts_info->tx_types) {
+		ret = ethnl_bitset32_size(&ts_info->tx_types, NULL,
+					  __HWTSTAMP_TX_CNT,
+					  ts_tx_type_names, compact);
+		if (ret < 0)
+			return ret;
+		len += ret;	/* _TSINFO_TX_TYPES */
+	}
+	if (ts_info->rx_filters) {
+		ret = ethnl_bitset32_size(&ts_info->rx_filters, NULL,
+					  __HWTSTAMP_FILTER_CNT,
+					  ts_rx_filter_names, compact);
+		if (ret < 0)
+			return ret;
+		len += ret;	/* _TSINFO_RX_FILTERS */
+	}
+	if (ts_info->phc_index >= 0)
+		len += nla_total_size(sizeof(u32));	/* _TSINFO_PHC_INDEX */
+
+	return len;
+}
+
+static int tsinfo_fill_reply(struct sk_buff *skb,
+			     const struct ethnl_req_info *req_base,
+			     const struct ethnl_reply_data *reply_base)
+{
+	const struct tsinfo_reply_data *data = TSINFO_REPDATA(reply_base);
+	bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
+	const struct ethtool_ts_info *ts_info = &data->ts_info;
+	int ret;
+
+	if (ts_info->so_timestamping) {
+		ret = ethnl_put_bitset32(skb, ETHTOOL_A_TSINFO_TIMESTAMPING,
+					 &ts_info->so_timestamping, NULL,
+					 __SOF_TIMESTAMPING_CNT,
+					 sof_timestamping_names, compact);
+		if (ret < 0)
+			return ret;
+	}
+	if (ts_info->tx_types) {
+		ret = ethnl_put_bitset32(skb, ETHTOOL_A_TSINFO_TX_TYPES,
+					 &ts_info->tx_types, NULL,
+					 __HWTSTAMP_TX_CNT,
+					 ts_tx_type_names, compact);
+		if (ret < 0)
+			return ret;
+	}
+	if (ts_info->rx_filters) {
+		ret = ethnl_put_bitset32(skb, ETHTOOL_A_TSINFO_RX_FILTERS,
+					 &ts_info->rx_filters, NULL,
+					 __HWTSTAMP_FILTER_CNT,
+					 ts_rx_filter_names, compact);
+		if (ret < 0)
+			return ret;
+	}
+	if (ts_info->phc_index >= 0 &&
+	    nla_put_u32(skb, ETHTOOL_A_TSINFO_PHC_INDEX, ts_info->phc_index))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+const struct ethnl_request_ops ethnl_tsinfo_request_ops = {
+	.request_cmd		= ETHTOOL_MSG_TSINFO_GET,
+	.reply_cmd		= ETHTOOL_MSG_TSINFO_GET_REPLY,
+	.hdr_attr		= ETHTOOL_A_TSINFO_HEADER,
+	.max_attr		= ETHTOOL_A_TSINFO_MAX,
+	.req_info_size		= sizeof(struct tsinfo_req_info),
+	.reply_data_size	= sizeof(struct tsinfo_reply_data),
+	.request_policy		= tsinfo_get_policy,
+
+	.prepare_data		= tsinfo_prepare_data,
+	.reply_size		= tsinfo_reply_size,
+	.fill_reply		= tsinfo_fill_reply,
+};