wifi: cfg80211: handle DFS per link

Currently, during starting a radar detection, no link id information is
parsed and passed down. In order to support starting radar detection
during Multi Link Operation, it is required to pass link id as well.

Add changes to first parse and then pass link id in the start radar
detection path.

Additionally, update notification APIs to allow drivers/mac80211 to
pass the link ID.

However, everything is handled at link 0 only until all API's are ready to
handle it per link.

Signed-off-by: Aditya Kumar Singh <quic_adisi@quicinc.com>
Link: https://patch.msgid.link/20240906064426.2101315-6-quic_adisi@quicinc.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

9 files changed, 68 insertions, 40 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 5725ab6f495f..67dd780530fb 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1667,7 +1667,7 @@ static int ieee80211_stop_ap(struct wiphy *wiphy, struct net_device *dev,
 		wiphy_delayed_work_cancel(wiphy, &link->dfs_cac_timer_work);
 		cfg80211_cac_event(sdata->dev, &chandef,
 				   NL80211_RADAR_CAC_ABORTED,
-				   GFP_KERNEL);
+				   GFP_KERNEL, 0);
 	}
 
 	drv_stop_ap(sdata->local, sdata, link_conf);
@@ -3462,7 +3462,7 @@ static int ieee80211_set_bitrate_mask(struct wiphy *wiphy,
 static int ieee80211_start_radar_detection(struct wiphy *wiphy,
 					   struct net_device *dev,
 					   struct cfg80211_chan_def *chandef,
-					   u32 cac_time_ms)
+					   u32 cac_time_ms, int link_id)
 {
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 	struct ieee80211_chan_req chanreq = { .oper = *chandef };
@@ -3490,7 +3490,7 @@ static int ieee80211_start_radar_detection(struct wiphy *wiphy,
 }
 
 static void ieee80211_end_cac(struct wiphy *wiphy,
-			      struct net_device *dev)
+			      struct net_device *dev, unsigned int link_id)
 {
 	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 	struct ieee80211_local *local = sdata->local;
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index bdaf8e215965..e074de893ed6 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -558,7 +558,7 @@ static void ieee80211_do_stop(struct ieee80211_sub_if_data *sdata, bool going_do
 		ieee80211_link_release_channel(&sdata->deflink);
 		cfg80211_cac_event(sdata->dev, &chandef,
 				   NL80211_RADAR_CAC_ABORTED,
-				   GFP_KERNEL);
+				   GFP_KERNEL, 0);
 	}
 
 	if (sdata->vif.type == NL80211_IFTYPE_AP) {
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 79579c89e281..715709860fdd 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -3043,7 +3043,7 @@ void ieee80211_dfs_cac_timer_work(struct wiphy *wiphy, struct wiphy_work *work)
 		ieee80211_link_release_channel(link);
 		cfg80211_cac_event(sdata->dev, &chandef,
 				   NL80211_RADAR_CAC_FINISHED,
-				   GFP_KERNEL);
+				   GFP_KERNEL, 0);
 	}
 }
 
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index ab17361dba97..c4fd60fbcfd4 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -3484,7 +3484,7 @@ void ieee80211_dfs_cac_cancel(struct ieee80211_local *local)
 			cfg80211_cac_event(sdata->dev,
 					   &chandef,
 					   NL80211_RADAR_CAC_ABORTED,
-					   GFP_KERNEL);
+					   GFP_KERNEL, 0);
 		}
 	}
 }
diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index fddd6a62b942..115c8cd28aaf 100644
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -1110,18 +1110,19 @@ EXPORT_SYMBOL(__cfg80211_radar_event);
 
 void cfg80211_cac_event(struct net_device *netdev,
 			const struct cfg80211_chan_def *chandef,
-			enum nl80211_radar_event event, gfp_t gfp)
+			enum nl80211_radar_event event, gfp_t gfp,
+			unsigned int link_id)
 {
 	struct wireless_dev *wdev = netdev->ieee80211_ptr;
 	struct wiphy *wiphy = wdev->wiphy;
 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 	unsigned long timeout;
 
-	/* not yet supported */
-	if (wdev->valid_links)
+	if (WARN_ON(wdev->valid_links &&
+		    !(wdev->valid_links & BIT(link_id))))
 		return;
 
-	trace_cfg80211_cac_event(netdev, event);
+	trace_cfg80211_cac_event(netdev, event, link_id);
 
 	if (WARN_ON(!wdev->links[0].cac_started &&
 		    event != NL80211_RADAR_CAC_STARTED))
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index f4fdf32d5d07..7d9264304a8a 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -10121,7 +10121,20 @@ static int nl80211_start_radar_detection(struct sk_buff *skb,
 		goto unlock;
 	}
 
-	if (cfg80211_beaconing_iface_active(wdev) || wdev->links[0].cac_started) {
+	if (cfg80211_beaconing_iface_active(wdev)) {
+		/* During MLO other link(s) can beacon, only the current link
+		 * can not already beacon
+		 */
+		if (wdev->valid_links &&
+		    !wdev->links[0].ap.beacon_interval) {
+			/* nothing */
+		} else {
+			err = -EBUSY;
+			goto unlock;
+		}
+	}
+
+	if (wdev->links[0].cac_started) {
 		err = -EBUSY;
 		goto unlock;
 	}
@@ -10141,7 +10154,8 @@ static int nl80211_start_radar_detection(struct sk_buff *skb,
 	if (WARN_ON(!cac_time_ms))
 		cac_time_ms = IEEE80211_DFS_MIN_CAC_TIME_MS;
 
-	err = rdev_start_radar_detection(rdev, dev, &chandef, cac_time_ms);
+	err = rdev_start_radar_detection(rdev, dev, &chandef, cac_time_ms,
+					 0);
 	if (!err) {
 		switch (wdev->iftype) {
 		case NL80211_IFTYPE_AP:
@@ -16515,10 +16529,10 @@ nl80211_set_ttlm(struct sk_buff *skb, struct genl_info *info)
 	SELECTOR(__sel, NETDEV_UP_NOTMX,		\
 		 NL80211_FLAG_NEED_NETDEV_UP |		\
 		 NL80211_FLAG_NO_WIPHY_MTX)		\
-	SELECTOR(__sel, NETDEV_UP_NOTMX_NOMLO,		\
+	SELECTOR(__sel, NETDEV_UP_NOTMX_MLO,		\
 		 NL80211_FLAG_NEED_NETDEV_UP |		\
 		 NL80211_FLAG_NO_WIPHY_MTX |		\
-		 NL80211_FLAG_MLO_UNSUPPORTED)		\
+		 NL80211_FLAG_MLO_VALID_LINK_ID)	\
 	SELECTOR(__sel, NETDEV_UP_CLEAR,		\
 		 NL80211_FLAG_NEED_NETDEV_UP |		\
 		 NL80211_FLAG_CLEAR_SKB)		\
@@ -17413,7 +17427,7 @@ static const struct genl_small_ops nl80211_small_ops[] = {
 		.flags = GENL_UNS_ADMIN_PERM,
 		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV_UP |
 					 NL80211_FLAG_NO_WIPHY_MTX |
-					 NL80211_FLAG_MLO_UNSUPPORTED),
+					 NL80211_FLAG_MLO_VALID_LINK_ID),
 	},
 	{
 		.cmd = NL80211_CMD_GET_PROTOCOL_FEATURES,
diff --git a/net/wireless/rdev-ops.h b/net/wireless/rdev-ops.h
index ec3f4aa1c807..f5adbf6b5c84 100644
--- a/net/wireless/rdev-ops.h
+++ b/net/wireless/rdev-ops.h
@@ -1200,26 +1200,27 @@ static inline int
 rdev_start_radar_detection(struct cfg80211_registered_device *rdev,
 			   struct net_device *dev,
 			   struct cfg80211_chan_def *chandef,
-			   u32 cac_time_ms)
+			   u32 cac_time_ms, int link_id)
 {
 	int ret = -EOPNOTSUPP;
 
 	trace_rdev_start_radar_detection(&rdev->wiphy, dev, chandef,
-					 cac_time_ms);
+					 cac_time_ms, link_id);
 	if (rdev->ops->start_radar_detection)
 		ret = rdev->ops->start_radar_detection(&rdev->wiphy, dev,
-						       chandef, cac_time_ms);
+						       chandef, cac_time_ms,
+						       link_id);
 	trace_rdev_return_int(&rdev->wiphy, ret);
 	return ret;
 }
 
 static inline void
 rdev_end_cac(struct cfg80211_registered_device *rdev,
-	     struct net_device *dev)
+	     struct net_device *dev, unsigned int link_id)
 {
-	trace_rdev_end_cac(&rdev->wiphy, dev);
+	trace_rdev_end_cac(&rdev->wiphy, dev, link_id);
 	if (rdev->ops->end_cac)
-		rdev->ops->end_cac(&rdev->wiphy, dev);
+		rdev->ops->end_cac(&rdev->wiphy, dev, link_id);
 	trace_rdev_return_void(&rdev->wiphy);
 }
 
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 898abc6d0609..6489ba943a63 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -4229,6 +4229,8 @@ EXPORT_SYMBOL(regulatory_pre_cac_allowed);
 static void cfg80211_check_and_end_cac(struct cfg80211_registered_device *rdev)
 {
 	struct wireless_dev *wdev;
+	unsigned int link_id;
+
 	/* If we finished CAC or received radar, we should end any
 	 * CAC running on the same channels.
 	 * the check !cfg80211_chandef_dfs_usable contain 2 options:
@@ -4241,16 +4243,17 @@ static void cfg80211_check_and_end_cac(struct cfg80211_registered_device *rdev)
 	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
 		struct cfg80211_chan_def *chandef;
 
-		if (!wdev->links[0].cac_started)
-			continue;
+		for_each_valid_link(wdev, link_id) {
+			if (!wdev->links[link_id].cac_started)
+				continue;
 
-		/* FIXME: radar detection is tied to link 0 for now */
-		chandef = wdev_chandef(wdev, 0);
-		if (!chandef)
-			continue;
+			chandef = wdev_chandef(wdev, link_id);
+			if (!chandef)
+				continue;
 
-		if (!cfg80211_chandef_dfs_usable(&rdev->wiphy, chandef))
-			rdev_end_cac(rdev, wdev->netdev);
+			if (!cfg80211_chandef_dfs_usable(&rdev->wiphy, chandef))
+				rdev_end_cac(rdev, wdev->netdev, link_id);
+		}
 	}
 }
 
diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index 7fc7de9bcc34..97c21b627791 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -806,17 +806,21 @@ DEFINE_EVENT(wiphy_netdev_evt, rdev_flush_pmksa,
 );
 
 TRACE_EVENT(rdev_end_cac,
-	TP_PROTO(struct wiphy *wiphy, struct net_device *netdev),
-	TP_ARGS(wiphy, netdev),
+	TP_PROTO(struct wiphy *wiphy, struct net_device *netdev,
+		 unsigned int link_id),
+	TP_ARGS(wiphy, netdev, link_id),
 	TP_STRUCT__entry(
 		WIPHY_ENTRY
 		NETDEV_ENTRY
+		__field(unsigned int, link_id)
 	),
 	TP_fast_assign(
 		WIPHY_ASSIGN;
 		NETDEV_ASSIGN;
+		__entry->link_id = link_id;
 	),
-	TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT, WIPHY_PR_ARG, NETDEV_PR_ARG)
+	TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", link_id: %d",
+		  WIPHY_PR_ARG, NETDEV_PR_ARG, __entry->link_id)
 );
 
 DECLARE_EVENT_CLASS(station_add_change,
@@ -2661,24 +2665,26 @@ TRACE_EVENT(rdev_external_auth,
 TRACE_EVENT(rdev_start_radar_detection,
 	TP_PROTO(struct wiphy *wiphy, struct net_device *netdev,
 		 struct cfg80211_chan_def *chandef,
-		 u32 cac_time_ms),
-	TP_ARGS(wiphy, netdev, chandef, cac_time_ms),
+		 u32 cac_time_ms, int link_id),
+	TP_ARGS(wiphy, netdev, chandef, cac_time_ms, link_id),
 	TP_STRUCT__entry(
 		WIPHY_ENTRY
 		NETDEV_ENTRY
 		CHAN_DEF_ENTRY
 		__field(u32, cac_time_ms)
+		__field(int, link_id)
 	),
 	TP_fast_assign(
 		WIPHY_ASSIGN;
 		NETDEV_ASSIGN;
 		CHAN_DEF_ASSIGN(chandef);
 		__entry->cac_time_ms = cac_time_ms;
+		__entry->link_id = link_id;
 	),
 	TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", " CHAN_DEF_PR_FMT
-		  ", cac_time_ms=%u",
+		  ", cac_time_ms=%u, link_id=%d",
 		  WIPHY_PR_ARG, NETDEV_PR_ARG, CHAN_DEF_PR_ARG,
-		  __entry->cac_time_ms)
+		  __entry->cac_time_ms, __entry->link_id)
 );
 
 TRACE_EVENT(rdev_set_mcast_rate,
@@ -3492,18 +3498,21 @@ TRACE_EVENT(cfg80211_radar_event,
 );
 
 TRACE_EVENT(cfg80211_cac_event,
-	TP_PROTO(struct net_device *netdev, enum nl80211_radar_event evt),
-	TP_ARGS(netdev, evt),
+	TP_PROTO(struct net_device *netdev, enum nl80211_radar_event evt,
+		 unsigned int link_id),
+	TP_ARGS(netdev, evt, link_id),
 	TP_STRUCT__entry(
 		NETDEV_ENTRY
 		__field(enum nl80211_radar_event, evt)
+		__field(unsigned int, link_id)
 	),
 	TP_fast_assign(
 		NETDEV_ASSIGN;
 		__entry->evt = evt;
+		__entry->link_id = link_id;
 	),
-	TP_printk(NETDEV_PR_FMT ",  event: %d",
-		  NETDEV_PR_ARG, __entry->evt)
+	TP_printk(NETDEV_PR_FMT ",  event: %d, link_id=%u",
+		  NETDEV_PR_ARG, __entry->evt, __entry->link_id)
 );
 
 DECLARE_EVENT_CLASS(cfg80211_rx_evt,