wifi: nl80211: add a command to enable/disable HW timestamping

Add a command to enable and disable HW timestamping of TM and FTM
frames. HW timestamping can be enabled for a specific mac address
or for all addresses.

The low level driver will indicate how many peers HW timestamping
can be enabled concurrently, and this information will be passed
to userspace.

Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230301115906.05678d7b1c17.Iccc08869ea8156f1c71a3111a47f86dd56234bd0@changeid
[switch to needing netdev UP, minor edits]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -827,6 +827,18 @@ struct cfg80211_fils_aad {
 	const u8 *anonce;
 };
 
+/**
+ * struct cfg80211_set_hw_timestamp - enable/disable HW timestamping
+ * @macaddr: peer MAC address. NULL to enable/disable HW timestamping for all
+ *	addresses.
+ * @enable: if set, enable HW timestamping for the specified MAC address.
+ *	Otherwise disable HW timestamping for the specified MAC address.
+ */
+struct cfg80211_set_hw_timestamp {
+	const u8 *macaddr;
+	bool enable;
+};
+
 /**
  * cfg80211_get_chandef_type - return old channel type from chandef
  * @chandef: the channel definition
@@ -4330,6 +4342,8 @@ struct mgmt_frame_regs {
  * @add_link_station: Add a link to a station.
  * @mod_link_station: Modify a link of a station.
  * @del_link_station: Remove a link of a station.
+ *
+ * @set_hw_timestamp: Enable/disable HW timestamping of TM/FTM frames.
  */
 struct cfg80211_ops {
 	int	(*suspend)(struct wiphy *wiphy, struct cfg80211_wowlan *wow);
@@ -4683,6 +4697,8 @@ struct cfg80211_ops {
 				    struct link_station_parameters *params);
 	int	(*del_link_station)(struct wiphy *wiphy, struct net_device *dev,
 				    struct link_station_del_parameters *params);
+	int	(*set_hw_timestamp)(struct wiphy *wiphy, struct net_device *dev,
+				    struct cfg80211_set_hw_timestamp *hwts);
 };
 
 /*
@@ -5139,6 +5155,8 @@ struct wiphy_iftype_akm_suites {
 	int n_akm_suites;
 };
 
+#define CFG80211_HW_TIMESTAMP_ALL_PEERS	0xffff
+
 /**
  * struct wiphy - wireless hardware description
  * @mtx: mutex for the data (structures) of this device
@@ -5348,6 +5366,13 @@ struct wiphy_iftype_akm_suites {
  *	NL80211_MAX_NR_AKM_SUITES in order to avoid compatibility issues with
  *	legacy userspace and maximum allowed value is
  *	CFG80211_MAX_NUM_AKM_SUITES.
+ *
+ * @hw_timestamp_max_peers: maximum number of peers that the driver supports
+ *	enabling HW timestamping for concurrently. Setting this field to a
+ *	non-zero value indicates that the driver supports HW timestamping.
+ *	A value of %CFG80211_HW_TIMESTAMP_ALL_PEERS indicates the driver
+ *	supports enabling HW timestamping for all peers (i.e. no need to
+ *	specify a mac address).
  */
 struct wiphy {
 	struct mutex mtx;
@@ -5496,6 +5521,8 @@ struct wiphy {
 	u8 ema_max_profile_periodicity;
 	u16 max_num_akm_suites;
 
+	u16 hw_timestamp_max_peers;
+
 	char priv[] __aligned(NETDEV_ALIGN);
 };
 

include/uapi/linux/nl80211.h

@@ -1299,6 +1299,16 @@
  * @NL80211_CMD_MODIFY_LINK_STA: Modify a link of an MLD station
  * @NL80211_CMD_REMOVE_LINK_STA: Remove a link of an MLD station
  *
+ * @NL80211_CMD_SET_HW_TIMESTAMP: Enable/disable HW timestamping of Timing
+ *	measurement and Fine timing measurement frames. If %NL80211_ATTR_MAC
+ *	is included, enable/disable HW timestamping only for frames to/from the
+ *	specified MAC address. Otherwise enable/disable HW timestamping for
+ *	all TM/FTM frames (including ones that were enabled with specific MAC
+ *	address). If %NL80211_ATTR_HW_TIMESTAMP_ENABLED is not included, disable
+ *	HW timestamping.
+ *	The number of peers that HW timestamping can be enabled for concurrently
+ *	is indicated by %NL80211_ATTR_MAX_HW_TIMESTAMP_PEERS.
+ *
  * @NL80211_CMD_MAX: highest used command number
  * @__NL80211_CMD_AFTER_LAST: internal use
  */
@@ -1550,6 +1560,8 @@ enum nl80211_commands {
 	NL80211_CMD_MODIFY_LINK_STA,
 	NL80211_CMD_REMOVE_LINK_STA,
 
+	NL80211_CMD_SET_HW_TIMESTAMP,
+
 	/* add new commands above here */
 
 	/* used to define NL80211_CMD_MAX below */
@@ -2775,6 +2787,13 @@ enum nl80211_commands {
  *	indicates that the sub-channel is punctured. Higher 16 bits are
  *	reserved.
  *
+ * @NL80211_ATTR_MAX_HW_TIMESTAMP_PEERS: Maximum number of peers that HW
+ *	timestamping can be enabled for concurrently (u16), a wiphy attribute.
+ *	A value of 0xffff indicates setting for all peers (i.e. not specifying
+ *	an address with %NL80211_CMD_SET_HW_TIMESTAMP) is supported.
+ * @NL80211_ATTR_HW_TIMESTAMP_ENABLED: Indicates whether HW timestamping should
+ *	be enabled or not (flag attribute).
+ *
  * @NUM_NL80211_ATTR: total number of nl80211_attrs available
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
@@ -3306,6 +3325,9 @@ enum nl80211_attrs {
 
 	NL80211_ATTR_PUNCT_BITMAP,
 
+	NL80211_ATTR_MAX_HW_TIMESTAMP_PEERS,
+	NL80211_ATTR_HW_TIMESTAMP_ENABLED,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,

net/wireless/nl80211.c

@@ -806,6 +806,9 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 	[NL80211_ATTR_MLO_SUPPORT] = { .type = NLA_FLAG },
 	[NL80211_ATTR_MAX_NUM_AKM_SUITES] = { .type = NLA_REJECT },
 	[NL80211_ATTR_PUNCT_BITMAP] = NLA_POLICY_RANGE(NLA_U8, 0, 0xffff),
+
+	[NL80211_ATTR_MAX_HW_TIMESTAMP_PEERS] = { .type = NLA_U16 },
+	[NL80211_ATTR_HW_TIMESTAMP_ENABLED] = { .type = NLA_FLAG },
 };
 
 /* policy for the key attributes */
@@ -2964,6 +2967,11 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev,
 		if (rdev->wiphy.flags & WIPHY_FLAG_SUPPORTS_MLO)
 			nla_put_flag(msg, NL80211_ATTR_MLO_SUPPORT);
 
+		if (rdev->wiphy.hw_timestamp_max_peers &&
+		    nla_put_u16(msg, NL80211_ATTR_MAX_HW_TIMESTAMP_PEERS,
+				rdev->wiphy.hw_timestamp_max_peers))
+			goto nla_put_failure;
+
 		/* done */
 		state->split_start = 0;
 		break;
@@ -16162,6 +16170,29 @@ nl80211_remove_link_station(struct sk_buff *skb, struct genl_info *info)
 	return ret;
 }
 
+static int nl80211_set_hw_timestamp(struct sk_buff *skb,
+				    struct genl_info *info)
+{
+	struct cfg80211_registered_device *rdev = info->user_ptr[0];
+	struct net_device *dev = info->user_ptr[1];
+	struct cfg80211_set_hw_timestamp hwts = {};
+
+	if (!rdev->wiphy.hw_timestamp_max_peers)
+		return -EOPNOTSUPP;
+
+	if (!info->attrs[NL80211_ATTR_MAC] &&
+	    rdev->wiphy.hw_timestamp_max_peers != CFG80211_HW_TIMESTAMP_ALL_PEERS)
+		return -EOPNOTSUPP;
+
+	if (info->attrs[NL80211_ATTR_MAC])
+		hwts.macaddr = nla_data(info->attrs[NL80211_ATTR_MAC]);
+
+	hwts.enable =
+		nla_get_flag(info->attrs[NL80211_ATTR_HW_TIMESTAMP_ENABLED]);
+
+	return rdev_set_hw_timestamp(rdev, dev, &hwts);
+}
+
 #define NL80211_FLAG_NEED_WIPHY		0x01
 #define NL80211_FLAG_NEED_NETDEV	0x02
 #define NL80211_FLAG_NEED_RTNL		0x04
@@ -17336,6 +17367,12 @@ static const struct genl_small_ops nl80211_small_ops[] = {
 		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV_UP |
 					 NL80211_FLAG_MLO_VALID_LINK_ID),
 	},
+	{
+		.cmd = NL80211_CMD_SET_HW_TIMESTAMP,
+		.doit = nl80211_set_hw_timestamp,
+		.flags = GENL_UNS_ADMIN_PERM,
+		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV_UP),
+	},
 };
 
 static struct genl_family nl80211_fam __ro_after_init = {

net/wireless/rdev-ops.h

@@ -1494,4 +1494,21 @@ rdev_del_link_station(struct cfg80211_registered_device *rdev,
 	return ret;
 }
 
+static inline int
+rdev_set_hw_timestamp(struct cfg80211_registered_device *rdev,
+		      struct net_device *dev,
+		      struct cfg80211_set_hw_timestamp *hwts)
+{
+	struct wiphy *wiphy = &rdev->wiphy;
+	int ret;
+
+	if (!rdev->ops->set_hw_timestamp)
+		return -EOPNOTSUPP;
+
+	trace_rdev_set_hw_timestamp(wiphy, dev, hwts);
+	ret = rdev->ops->set_hw_timestamp(wiphy, dev, hwts);
+	trace_rdev_return_int(wiphy, ret);
+
+	return ret;
+}
 #endif /* __CFG80211_RDEV_OPS */

net/wireless/trace.h

@@ -3918,6 +3918,31 @@ TRACE_EVENT(rdev_del_link_station,
 		  __entry->link_id)
 );
 
+TRACE_EVENT(rdev_set_hw_timestamp,
+	TP_PROTO(struct wiphy *wiphy, struct net_device *netdev,
+		 struct cfg80211_set_hw_timestamp *hwts),
+
+	TP_ARGS(wiphy, netdev, hwts),
+
+	TP_STRUCT__entry(
+		WIPHY_ENTRY
+		NETDEV_ENTRY
+		MAC_ENTRY(macaddr)
+		__field(bool, enable)
+	),
+
+	TP_fast_assign(
+		WIPHY_ASSIGN;
+		NETDEV_ASSIGN;
+		MAC_ASSIGN(macaddr, hwts->macaddr);
+		__entry->enable = hwts->enable;
+	),
+
+	TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", mac %pM, enable: %u",
+		  WIPHY_PR_ARG, NETDEV_PR_ARG, __entry->macaddr,
+		  __entry->enable)
+);
+
 #endif /* !__RDEV_OPS_TRACE || TRACE_HEADER_MULTI_READ */
 
 #undef TRACE_INCLUDE_PATH