diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 313aabb2d511..934c58d042b0 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -4399,4 +4399,7 @@ enum ieee80211_range_params_max_total_ltf {
 	IEEE80211_RANGE_PARAMS_MAX_TOTAL_LTF_UNSPECIFIED,
 };
 
+/* multi-link device */
+#define IEEE80211_MLD_MAX_NUM_LINKS	15
+
 #endif /* LINUX_IEEE80211_H */
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 1d9e240e1a69..32e4848b5749 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -5600,6 +5600,7 @@ struct wireless_dev {
 	u8 address[ETH_ALEN] __aligned(sizeof(u16));
 
 	/* currently used for IBSS and SME - might be rearranged later */
+	// FIXME: move SSID to link?
 	u8 ssid[IEEE80211_MAX_SSID_LEN];
 	u8 ssid_len, mesh_id_len, mesh_id_up_len;
 	struct cfg80211_conn *conn;
@@ -5613,20 +5614,18 @@ struct wireless_dev {
 	struct list_head event_list;
 	spinlock_t event_lock;
 
+	// FIXME: move to link, I think
 	struct cfg80211_internal_bss *current_bss; /* associated / joined */
-	struct cfg80211_chan_def preset_chandef;
-	struct cfg80211_chan_def chandef;
 
 	bool ps;
 	int ps_timeout;
 
-	int beacon_interval;
-
 	u32 ap_unexpected_nlportid;
 
 	u32 owner_nlportid;
 	bool nl_owner_dead;
 
+	// FIXME: move to link?
 	bool cac_started;
 	unsigned long cac_start_time;
 	unsigned int cac_time_ms;
@@ -5654,6 +5653,15 @@ struct wireless_dev {
 	struct work_struct pmsr_free_wk;
 
 	unsigned long unprot_beacon_reported;
+
+	struct {
+		u8 addr[ETH_ALEN];
+		int beacon_interval;
+		struct cfg80211_chan_def preset_chandef;
+		struct cfg80211_chan_def chandef;
+	} links[IEEE80211_MLD_MAX_NUM_LINKS];
+	u16 valid_links;
+	u16 active_links;
 };
 
 static inline const u8 *wdev_address(struct wireless_dev *wdev)
@@ -5682,6 +5690,33 @@ static inline void *wdev_priv(struct wireless_dev *wdev)
 	return wiphy_priv(wdev->wiphy);
 }
 
+static inline void WARN_INVALID_LINK_ID(struct wireless_dev *wdev,
+					unsigned int link_id)
+{
+	WARN_ON(link_id && !wdev->valid_links);
+	WARN_ON(wdev->valid_links &&
+		!(wdev->valid_links & BIT(link_id)));
+}
+
+#define for_each_valid_link(wdev, link_id)					\
+	for (unsigned int link_id = 0;						\
+	     link_id < ((wdev)->valid_links ? ARRAY_SIZE((wdev)->links) : 1);	\
+	     link_id++)								\
+		if (!(wdev)->valid_links ||					\
+		    ((wdev)->valid_links & BIT(link_id)))
+
+#define for_each_active_link(wdev, link_id)					\
+	for (unsigned int link_id = 0;						\
+	     link_id < ((wdev)->valid_links ? ARRAY_SIZE((wdev)->links) : 1);	\
+	     link_id++)								\
+		if (!(wdev)->valid_links ||					\
+		    ((wdev)->active_links & BIT(link_id)))
+
+static inline unsigned int wdev_num_active_links(struct wireless_dev *wdev)
+{
+	return wdev->active_links ? hweight16(wdev->active_links) : 1;
+}
+
 /**
  * DOC: Utility functions
  *
@@ -7996,12 +8031,14 @@ bool cfg80211_reg_can_beacon_relax(struct wiphy *wiphy,
  * cfg80211_ch_switch_notify - update wdev channel and notify userspace
  * @dev: the device which switched channels
  * @chandef: the new channel definition
+ * @link_id: the link ID for MLO, must be 0 for non-MLO
  *
  * Caller must acquire wdev_lock, therefore must only be called from sleepable
  * driver context!
  */
 void cfg80211_ch_switch_notify(struct net_device *dev,
-			       struct cfg80211_chan_def *chandef);
+			       struct cfg80211_chan_def *chandef,
+			       unsigned int link_id);
 
 /*
  * cfg80211_ch_switch_started_notify - notify channel switch start
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index f63f9fa80c30..06d93f298cf7 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -323,6 +323,17 @@
  * Once the association is done, the driver cleans the FILS AAD data.
  */
 
+/**
+ * DOC: Multi-Link Operation
+ *
+ * In Multi-Link Operation, a connection between to MLDs utilizes multiple
+ * links. To use this in nl80211, various commands and responses now need
+ * to or will include the new %NL80211_ATTR_MLO_LINKS attribute.
+ * Additionally, various commands that need to operate on a specific link
+ * now need to be given the %NL80211_ATTR_MLO_LINK_ID attribute, e.g. to
+ * use %NL80211_CMD_START_AP or similar functions.
+ */
+
 /**
  * enum nl80211_commands - supported nl80211 commands
  *
@@ -1244,6 +1255,12 @@
  *      to describe the BSSID address of the AP and %NL80211_ATTR_TIMEOUT to
  *      specify the timeout value.
  *
+ * @NL80211_CMD_ADD_LINK: Add a new link to an interface. The
+ *	%NL80211_ATTR_MLO_LINK_ID attribute is used for the new link.
+ * @NL80211_CMD_REMOVE_LINK: Remove a link from an interface. This may come
+ *	without %NL80211_ATTR_MLO_LINK_ID as an easy way to remove all links
+ *	in preparation for e.g. roaming to a regular (non-MLO) AP.
+ *
  * @NL80211_CMD_MAX: highest used command number
  * @__NL80211_CMD_AFTER_LAST: internal use
  */
@@ -1488,6 +1505,9 @@ enum nl80211_commands {
 
 	NL80211_CMD_ASSOC_COMEBACK,
 
+	NL80211_CMD_ADD_LINK,
+	NL80211_CMD_REMOVE_LINK,
+
 	/* let this always be before all commands we haven't upstreamed yet */
 	__NL80211_CMD_NONUPSTREAM_START,
 
@@ -3199,6 +3219,9 @@ enum nl80211_attrs {
 	NL80211_ATTR_TX_HW_TIMESTAMP,
 	NL80211_ATTR_RX_HW_TIMESTAMP,
 
+	NL80211_ATTR_MLO_LINKS,
+	NL80211_ATTR_MLO_LINK_ID,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 7303543c2741..9f0f4ed827fe 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -3293,7 +3293,7 @@ static int __ieee80211_csa_finalize(struct ieee80211_sub_if_data *sdata)
 	if (err)
 		return err;
 
-	cfg80211_ch_switch_notify(sdata->dev, &sdata->csa_chandef);
+	cfg80211_ch_switch_notify(sdata->dev, &sdata->csa_chandef, 0);
 
 	return 0;
 }
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index b75eb9c28791..18040109eefb 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1424,7 +1424,7 @@ static void ieee80211_chswitch_post_beacon(struct ieee80211_sub_if_data *sdata)
 		return;
 	}
 
-	cfg80211_ch_switch_notify(sdata->dev, &sdata->reserved_chandef);
+	cfg80211_ch_switch_notify(sdata->dev, &sdata->reserved_chandef, 0);
 }
 
 void ieee80211_chswitch_done(struct ieee80211_vif *vif, bool success)
diff --git a/net/wireless/ap.c b/net/wireless/ap.c
index 550ac9d827fe..7691395c1f84 100644
--- a/net/wireless/ap.c
+++ b/net/wireless/ap.c
@@ -1,4 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0
+/*
+ * Portions
+ * Copyright (C) 2022 Intel Corporation
+ */
 #include <linux/ieee80211.h>
 #include <linux/export.h>
 #include <net/cfg80211.h>
@@ -7,8 +11,9 @@
 #include "rdev-ops.h"
 
 
-int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
-		       struct net_device *dev, bool notify)
+static int ___cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
+			       struct net_device *dev, unsigned int link_id,
+			       bool notify)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	int err;
@@ -22,14 +27,16 @@ int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
 	    dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
 		return -EOPNOTSUPP;
 
-	if (!wdev->beacon_interval)
+	if (!wdev->links[link_id].beacon_interval)
 		return -ENOENT;
 
+	// FIXME - pass link id
 	err = rdev_stop_ap(rdev, dev);
 	if (!err) {
 		wdev->conn_owner_nlportid = 0;
-		wdev->beacon_interval = 0;
-		memset(&wdev->chandef, 0, sizeof(wdev->chandef));
+		wdev->links[link_id].beacon_interval = 0;
+		memset(&wdev->links[link_id].chandef, 0,
+		       sizeof(wdev->links[link_id].chandef));
 		wdev->ssid_len = 0;
 		rdev_set_qos_map(rdev, dev, NULL);
 		if (notify)
@@ -46,14 +53,35 @@ int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
 	return err;
 }
 
+int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
+		       struct net_device *dev, int link_id,
+		       bool notify)
+{
+	int ret;
+
+	if (link_id >= 0)
+		return ___cfg80211_stop_ap(rdev, dev, link_id, notify);
+
+	for_each_valid_link(dev->ieee80211_ptr, link) {
+		int ret1 = ___cfg80211_stop_ap(rdev, dev, link, notify);
+
+		if (ret1)
+			ret = ret1;
+		/* try the next one also if one errored */
+	}
+
+	return ret;
+}
+
 int cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
-		     struct net_device *dev, bool notify)
+		     struct net_device *dev, int link_id,
+		     bool notify)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	int err;
 
 	wdev_lock(wdev);
-	err = __cfg80211_stop_ap(rdev, dev, notify);
+	err = __cfg80211_stop_ap(rdev, dev, link_id, notify);
 	wdev_unlock(wdev);
 
 	return err;
diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index 3a5bce5e422a..3a176f3e415d 100644
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -704,40 +704,57 @@ bool cfg80211_is_sub_chan(struct cfg80211_chan_def *chandef,
 
 bool cfg80211_beaconing_iface_active(struct wireless_dev *wdev)
 {
-	bool active = false;
-
 	ASSERT_WDEV_LOCK(wdev);
 
-	if (!wdev->chandef.chan)
-		return false;
+	for_each_valid_link(wdev, link_id) {
+		if (!wdev->links[link_id].chandef.chan)
+			continue;
 
-	switch (wdev->iftype) {
-	case NL80211_IFTYPE_AP:
-	case NL80211_IFTYPE_P2P_GO:
-		active = wdev->beacon_interval != 0;
-		break;
-	case NL80211_IFTYPE_ADHOC:
-		active = wdev->ssid_len != 0;
-		break;
-	case NL80211_IFTYPE_MESH_POINT:
-		active = wdev->mesh_id_len != 0;
-		break;
-	case NL80211_IFTYPE_STATION:
-	case NL80211_IFTYPE_OCB:
-	case NL80211_IFTYPE_P2P_CLIENT:
-	case NL80211_IFTYPE_MONITOR:
-	case NL80211_IFTYPE_AP_VLAN:
-	case NL80211_IFTYPE_P2P_DEVICE:
-	/* Can NAN type be considered as beaconing interface? */
-	case NL80211_IFTYPE_NAN:
-		break;
-	case NL80211_IFTYPE_UNSPECIFIED:
-	case NL80211_IFTYPE_WDS:
-	case NUM_NL80211_IFTYPES:
-		WARN_ON(1);
+		switch (wdev->iftype) {
+		case NL80211_IFTYPE_AP:
+		case NL80211_IFTYPE_P2P_GO:
+			if (wdev->links[link_id].beacon_interval)
+				return true;
+			break;
+		case NL80211_IFTYPE_ADHOC:
+			if (wdev->ssid_len)
+				return true;
+			break;
+		case NL80211_IFTYPE_MESH_POINT:
+			if (wdev->mesh_id_len)
+				return true;
+			break;
+		case NL80211_IFTYPE_STATION:
+		case NL80211_IFTYPE_OCB:
+		case NL80211_IFTYPE_P2P_CLIENT:
+		case NL80211_IFTYPE_MONITOR:
+		case NL80211_IFTYPE_AP_VLAN:
+		case NL80211_IFTYPE_P2P_DEVICE:
+		/* Can NAN type be considered as beaconing interface? */
+		case NL80211_IFTYPE_NAN:
+			break;
+		case NL80211_IFTYPE_UNSPECIFIED:
+		case NL80211_IFTYPE_WDS:
+		case NUM_NL80211_IFTYPES:
+			WARN_ON(1);
+		}
 	}
 
-	return active;
+	return false;
+}
+
+static bool cfg80211_wdev_on_sub_chan(struct wireless_dev *wdev,
+				      struct ieee80211_channel *chan)
+{
+	for_each_valid_link(wdev, link_id) {
+		if (!wdev->links[link_id].chandef.chan)
+			continue;
+
+		if (cfg80211_is_sub_chan(&wdev->links[link_id].chandef, chan))
+			return true;
+	}
+
+	return false;
 }
 
 static bool cfg80211_is_wiphy_oper_chan(struct wiphy *wiphy,
@@ -752,7 +769,7 @@ static bool cfg80211_is_wiphy_oper_chan(struct wiphy *wiphy,
 			continue;
 		}
 
-		if (cfg80211_is_sub_chan(&wdev->chandef, chan)) {
+		if (cfg80211_wdev_on_sub_chan(wdev, chan)) {
 			wdev_unlock(wdev);
 			return true;
 		}
@@ -1189,6 +1206,7 @@ static bool cfg80211_ir_permissive_chan(struct wiphy *wiphy,
 					enum nl80211_iftype iftype,
 					struct ieee80211_channel *chan)
 {
+#if 0
 	struct wireless_dev *wdev;
 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 
@@ -1273,7 +1291,7 @@ static bool cfg80211_ir_permissive_chan(struct wiphy *wiphy,
 			return true;
 		}
 	}
-
+#endif
 	return false;
 }
 
diff --git a/net/wireless/core.c b/net/wireless/core.c
index cb3039fd8dbf..bc3e73f2a1be 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -1240,7 +1240,7 @@ void __cfg80211_leave(struct cfg80211_registered_device *rdev,
 		break;
 	case NL80211_IFTYPE_AP:
 	case NL80211_IFTYPE_P2P_GO:
-		__cfg80211_stop_ap(rdev, dev, true);
+		__cfg80211_stop_ap(rdev, dev, -1, true);
 		break;
 	case NL80211_IFTYPE_OCB:
 		__cfg80211_leave_ocb(rdev, dev);
diff --git a/net/wireless/core.h b/net/wireless/core.h
index b67179126a55..433db44e6a39 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -354,9 +354,11 @@ int cfg80211_leave_ocb(struct cfg80211_registered_device *rdev,
 
 /* AP */
 int __cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
-		       struct net_device *dev, bool notify);
+		       struct net_device *dev, int link_id,
+		       bool notify);
 int cfg80211_stop_ap(struct cfg80211_registered_device *rdev,
-		     struct net_device *dev, bool notify);
+		     struct net_device *dev, int link_id,
+		     bool notify);
 
 /* MLME */
 int cfg80211_mlme_auth(struct cfg80211_registered_device *rdev,
diff --git a/net/wireless/ibss.c b/net/wireless/ibss.c
index 02f45128049d..64c919860e08 100644
--- a/net/wireless/ibss.c
+++ b/net/wireless/ibss.c
@@ -131,7 +131,7 @@ int __cfg80211_join_ibss(struct cfg80211_registered_device *rdev,
 		kfree_sensitive(wdev->connect_keys);
 	wdev->connect_keys = connkeys;
 
-	wdev->chandef = params->chandef;
+	wdev->links[0].chandef = params->chandef;
 	if (connkeys) {
 		params->wep_keys = connkeys->params;
 		params->wep_tx_key = connkeys->def;
@@ -180,7 +180,7 @@ static void __cfg80211_clear_ibss(struct net_device *dev, bool nowext)
 
 	wdev->current_bss = NULL;
 	wdev->ssid_len = 0;
-	memset(&wdev->chandef, 0, sizeof(wdev->chandef));
+	memset(&wdev->links[0].chandef, 0, sizeof(wdev->links[0].chandef));
 #ifdef CPTCFG_CFG80211_WEXT
 	if (!nowext)
 		wdev->wext.ibss.ssid_len = 0;
diff --git a/net/wireless/mesh.c b/net/wireless/mesh.c
index e4e363138279..0df4fe633e64 100644
--- a/net/wireless/mesh.c
+++ b/net/wireless/mesh.c
@@ -1,4 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0
+/*
+ * Portions
+ * Copyright (C) 2022 Intel Corporation
+ */
 #include <linux/ieee80211.h>
 #include <linux/export.h>
 #include <net/cfg80211.h>
@@ -125,7 +129,7 @@ int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
 
 	if (!setup->chandef.chan) {
 		/* if no channel explicitly given, use preset channel */
-		setup->chandef = wdev->preset_chandef;
+		setup->chandef = wdev->links[0].preset_chandef;
 	}
 
 	if (!setup->chandef.chan) {
@@ -211,8 +215,8 @@ int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
 	if (!err) {
 		memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
 		wdev->mesh_id_len = setup->mesh_id_len;
-		wdev->chandef = setup->chandef;
-		wdev->beacon_interval = setup->beacon_interval;
+		wdev->links[0].chandef = setup->chandef;
+		wdev->links[0].beacon_interval = setup->beacon_interval;
 	}
 
 	return err;
@@ -241,7 +245,7 @@ int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
 		err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
 						     chandef->chan);
 		if (!err)
-			wdev->chandef = *chandef;
+			wdev->links[0].chandef = *chandef;
 
 		return err;
 	}
@@ -249,7 +253,7 @@ int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
 	if (wdev->mesh_id_len)
 		return -EBUSY;
 
-	wdev->preset_chandef = *chandef;
+	wdev->links[0].preset_chandef = *chandef;
 	return 0;
 }
 
@@ -274,8 +278,9 @@ int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
 	if (!err) {
 		wdev->conn_owner_nlportid = 0;
 		wdev->mesh_id_len = 0;
-		wdev->beacon_interval = 0;
-		memset(&wdev->chandef, 0, sizeof(wdev->chandef));
+		wdev->links[0].beacon_interval = 0;
+		memset(&wdev->links[0].chandef, 0,
+		       sizeof(wdev->links[0].chandef));
 		rdev_set_qos_map(rdev, dev, NULL);
 		cfg80211_sched_dfs_chan_update(rdev);
 	}
diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index 1d2e1af19ab8..1cde5207ed19 100644
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -944,8 +944,9 @@ void cfg80211_cac_event(struct net_device *netdev,
 	if (WARN_ON(!wdev->cac_started && event != NL80211_RADAR_CAC_STARTED))
 		return;
 
-	if (WARN_ON(!wdev->chandef.chan))
-		return;
+// FIXME - what was this for? not trusting drivers?
+//	if (WARN_ON(!wdev->chandef.chan))
+//		return;
 
 	switch (event) {
 	case NL80211_RADAR_CAC_FINISHED:
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index d782df482ee4..a812533c5506 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -809,6 +809,10 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 	[NL80211_ATTR_EHT_CAPABILITY] =
 		NLA_POLICY_BINARY_RANGE(NL80211_EHT_MIN_CAPABILITY_LEN,
 					NL80211_EHT_MAX_CAPABILITY_LEN),
+	[NL80211_ATTR_MLO_LINKS] =
+		NLA_POLICY_NESTED_ARRAY(nl80211_policy),
+	[NL80211_ATTR_MLO_LINK_ID] =
+		NLA_POLICY_RANGE(NLA_U8, 0, IEEE80211_MLD_MAX_NUM_LINKS),
 };
 
 /* policy for the key attributes */
@@ -1242,6 +1246,27 @@ static bool nl80211_put_txq_stats(struct sk_buff *msg,
 
 /* netlink command implementations */
 
+/**
+ * nl80211_link_id - return link ID
+ * @attrs: attributes to look at
+ *
+ * Returns: the link ID or 0 if not given
+ *
+ * Note this function doesn't do any validation of the link
+ * ID validity wrt. links that were actually added, so it must
+ * be called only from ops with %NL80211_FLAG_MLO_VALID_LINK_ID
+ * or if additional validation is done.
+ */
+static unsigned int nl80211_link_id(struct nlattr **attrs)
+{
+	struct nlattr *linkid = attrs[NL80211_ATTR_MLO_LINK_ID];
+
+	if (!linkid)
+		return 0;
+
+	return nla_get_u8(linkid);
+}
+
 struct key_parse {
 	struct key_params p;
 	int idx;
@@ -3240,7 +3265,8 @@ int nl80211_parse_chandef(struct cfg80211_registered_device *rdev,
 
 static int __nl80211_set_channel(struct cfg80211_registered_device *rdev,
 				 struct net_device *dev,
-				 struct genl_info *info)
+				 struct genl_info *info,
+				 int link_id)
 {
 	struct cfg80211_chan_def chandef;
 	int result;
@@ -3261,12 +3287,22 @@ static int __nl80211_set_channel(struct cfg80211_registered_device *rdev,
 	switch (iftype) {
 	case NL80211_IFTYPE_AP:
 	case NL80211_IFTYPE_P2P_GO:
+		if (link_id < 0) {
+			if (wdev->valid_links) {
+				result = -EINVAL;
+				break;
+			}
+			link_id = 0;
+		}
+
 		if (!cfg80211_reg_can_beacon_relax(&rdev->wiphy, &chandef,
 						   iftype)) {
 			result = -EINVAL;
 			break;
 		}
-		if (wdev->beacon_interval) {
+		if (wdev->links[link_id].beacon_interval) {
+			struct ieee80211_channel *preset_chan;
+
 			if (!dev || !rdev->ops->set_ap_chanwidth ||
 			    !(rdev->wiphy.features &
 			      NL80211_FEATURE_AP_MODE_CHAN_WIDTH_CHANGE)) {
@@ -3275,15 +3311,18 @@ static int __nl80211_set_channel(struct cfg80211_registered_device *rdev,
 			}
 
 			/* Only allow dynamic channel width changes */
-			if (chandef.chan != wdev->preset_chandef.chan) {
+			preset_chan = wdev->links[link_id].preset_chandef.chan;
+			if (chandef.chan != preset_chan) {
 				result = -EBUSY;
 				break;
 			}
+
+			// FIXME: pass link_id!!
 			result = rdev_set_ap_chanwidth(rdev, dev, &chandef);
 			if (result)
 				break;
 		}
-		wdev->preset_chandef = chandef;
+		wdev->links[link_id].preset_chandef = chandef;
 		result = 0;
 		break;
 	case NL80211_IFTYPE_MESH_POINT:
@@ -3302,9 +3341,10 @@ static int __nl80211_set_channel(struct cfg80211_registered_device *rdev,
 static int nl80211_set_channel(struct sk_buff *skb, struct genl_info *info)
 {
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
+	unsigned int link_id = nl80211_link_id(info->attrs);
 	struct net_device *netdev = info->user_ptr[1];
 
-	return __nl80211_set_channel(rdev, netdev, info);
+	return __nl80211_set_channel(rdev, netdev, info, link_id);
 }
 
 static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
@@ -3419,7 +3459,7 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 		result = __nl80211_set_channel(
 			rdev,
 			nl80211_can_set_dev_channel(wdev) ? netdev : NULL,
-			info);
+			info, -1);
 		if (result)
 			goto out;
 	}
@@ -4669,8 +4709,12 @@ static int nl80211_set_mac_acl(struct sk_buff *skb, struct genl_info *info)
 	    dev->ieee80211_ptr->iftype != NL80211_IFTYPE_P2P_GO)
 		return -EOPNOTSUPP;
 
-	if (!dev->ieee80211_ptr->beacon_interval)
-		return -EINVAL;
+// FIXME: do we consider this to be on the MLD? I guess so?
+//	  then what about legacy stations? or should we have
+//	  ACL on each link? seems odd ...
+//
+//	if (!dev->ieee80211_ptr->beacon_interval)
+//		return -EINVAL;
 
 	acl = parse_acl_data(&rdev->wiphy, info);
 	if (IS_ERR(acl))
@@ -4825,14 +4869,14 @@ static void he_build_mcs_mask(u16 he_mcs_map,
 	}
 }
 
-static u16 he_get_txmcsmap(struct genl_info *info,
+static u16 he_get_txmcsmap(struct genl_info *info, unsigned int link_id,
 			   const struct ieee80211_sta_he_cap *he_cap)
 {
 	struct net_device *dev = info->user_ptr[1];
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	__le16	tx_mcs;
 
-	switch (wdev->chandef.width) {
+	switch (wdev->links[link_id].chandef.width) {
 	case NL80211_CHAN_WIDTH_80P80:
 		tx_mcs = he_cap->he_mcs_nss_supp.tx_mcs_80p80;
 		break;
@@ -4850,7 +4894,8 @@ static bool he_set_mcs_mask(struct genl_info *info,
 			    struct wireless_dev *wdev,
 			    struct ieee80211_supported_band *sband,
 			    struct nl80211_txrate_he *txrate,
-			    u16 mcs[NL80211_HE_NSS_MAX])
+			    u16 mcs[NL80211_HE_NSS_MAX],
+			    unsigned int link_id)
 {
 	const struct ieee80211_sta_he_cap *he_cap;
 	u16 tx_mcs_mask[NL80211_HE_NSS_MAX] = {};
@@ -4863,7 +4908,7 @@ static bool he_set_mcs_mask(struct genl_info *info,
 
 	memset(mcs, 0, sizeof(u16) * NL80211_HE_NSS_MAX);
 
-	tx_mcs_map = he_get_txmcsmap(info, he_cap);
+	tx_mcs_map = he_get_txmcsmap(info, link_id, he_cap);
 
 	/* Build he_mcs_mask from HE capabilities */
 	he_build_mcs_mask(tx_mcs_map, tx_mcs_mask);
@@ -4883,7 +4928,8 @@ static int nl80211_parse_tx_bitrate_mask(struct genl_info *info,
 					 enum nl80211_attrs attr,
 					 struct cfg80211_bitrate_mask *mask,
 					 struct net_device *dev,
-					 bool default_all_enabled)
+					 bool default_all_enabled,
+					 unsigned int link_id)
 {
 	struct nlattr *tb[NL80211_TXRATE_MAX + 1];
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
@@ -4920,7 +4966,7 @@ static int nl80211_parse_tx_bitrate_mask(struct genl_info *info,
 		if (!he_cap)
 			continue;
 
-		he_tx_mcs_map = he_get_txmcsmap(info, he_cap);
+		he_tx_mcs_map = he_get_txmcsmap(info, link_id, he_cap);
 		he_build_mcs_mask(he_tx_mcs_map, mask->control[i].he_mcs);
 
 		mask->control[i].he_gi = 0xFF;
@@ -4985,7 +5031,8 @@ static int nl80211_parse_tx_bitrate_mask(struct genl_info *info,
 		if (tb[NL80211_TXRATE_HE] &&
 		    !he_set_mcs_mask(info, wdev, sband,
 				     nla_data(tb[NL80211_TXRATE_HE]),
-				     mask->control[band].he_mcs))
+				     mask->control[band].he_mcs,
+				     link_id))
 			return -EINVAL;
 
 		if (tb[NL80211_TXRATE_HE_GI])
@@ -5474,10 +5521,14 @@ static bool nl80211_get_ap_channel(struct cfg80211_registered_device *rdev,
 		    wdev->iftype != NL80211_IFTYPE_P2P_GO)
 			continue;
 
-		if (!wdev->preset_chandef.chan)
+		/* let this method only work for non-MLD */
+		if (wdev->valid_links)
+			continue;
+
+		if (!wdev->links[0].preset_chandef.chan)
 			continue;
 
-		params->chandef = wdev->preset_chandef;
+		params->chandef = wdev->links[0].preset_chandef;
 		ret = true;
 		break;
 	}
@@ -5540,6 +5591,7 @@ static bool nl80211_valid_auth_type(struct cfg80211_registered_device *rdev,
 static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 {
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
+	unsigned int link_id = nl80211_link_id(info->attrs);
 	struct net_device *dev = info->user_ptr[1];
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	struct cfg80211_ap_settings *params;
@@ -5552,7 +5604,7 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 	if (!rdev->ops->start_ap)
 		return -EOPNOTSUPP;
 
-	if (wdev->beacon_interval)
+	if (wdev->links[link_id].beacon_interval)
 		return -EALREADY;
 
 	/* these are required for START_AP */
@@ -5661,8 +5713,8 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 		err = nl80211_parse_chandef(rdev, info, &params->chandef);
 		if (err)
 			goto out;
-	} else if (wdev->preset_chandef.chan) {
-		params->chandef = wdev->preset_chandef;
+	} else if (wdev->links[link_id].preset_chandef.chan) {
+		params->chandef = wdev->links[link_id].preset_chandef;
 	} else if (!nl80211_get_ap_channel(rdev, params)) {
 		err = -EINVAL;
 		goto out;
@@ -5678,7 +5730,7 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 		err = nl80211_parse_tx_bitrate_mask(info, info->attrs,
 						    NL80211_ATTR_TX_RATES,
 						    &params->beacon_rate,
-						    dev, false);
+						    dev, false, link_id);
 		if (err)
 			goto out;
 
@@ -5785,12 +5837,18 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 	else if (info->attrs[NL80211_ATTR_EXTERNAL_AUTH_SUPPORT])
 		params->flags |= NL80211_AP_SETTINGS_EXTERNAL_AUTH_SUPPORT;
 
+	/* FIXME: check that SSID(len) didn't change!
+	 * or - ugh - can it? what about multi-BSSID
+	 * where the transmitting BSSID/SSID might be
+	 * different on different links?
+	 */
+
 	wdev_lock(wdev);
 	err = rdev_start_ap(rdev, dev, params);
 	if (!err) {
-		wdev->preset_chandef = params->chandef;
-		wdev->beacon_interval = params->beacon_interval;
-		wdev->chandef = params->chandef;
+		wdev->links[link_id].preset_chandef = params->chandef;
+		wdev->links[link_id].beacon_interval = params->beacon_interval;
+		wdev->links[link_id].chandef = params->chandef;
 		wdev->ssid_len = params->ssid_len;
 		memcpy(wdev->ssid, params->ssid, wdev->ssid_len);
 
@@ -5814,6 +5872,7 @@ out:
 static int nl80211_set_beacon(struct sk_buff *skb, struct genl_info *info)
 {
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
+	unsigned int link_id = nl80211_link_id(info->attrs);
 	struct net_device *dev = info->user_ptr[1];
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	struct cfg80211_beacon_data params;
@@ -5826,7 +5885,7 @@ static int nl80211_set_beacon(struct sk_buff *skb, struct genl_info *info)
 	if (!rdev->ops->change_beacon)
 		return -EOPNOTSUPP;
 
-	if (!wdev->beacon_interval)
+	if (!wdev->links[link_id].beacon_interval)
 		return -EINVAL;
 
 	err = nl80211_parse_beacon(rdev, info->attrs, &params);
@@ -5845,9 +5904,10 @@ out:
 static int nl80211_stop_ap(struct sk_buff *skb, struct genl_info *info)
 {
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
+	unsigned int link_id = nl80211_link_id(info->attrs);
 	struct net_device *dev = info->user_ptr[1];
 
-	return cfg80211_stop_ap(rdev, dev, false);
+	return cfg80211_stop_ap(rdev, dev, link_id, false);
 }
 
 static const struct nla_policy sta_flags_policy[NL80211_STA_FLAG_MAX + 1] = {
@@ -8471,16 +8531,49 @@ int nl80211_parse_random_mac(struct nlattr **attrs,
 	return 0;
 }
 
-static bool cfg80211_off_channel_oper_allowed(struct wireless_dev *wdev)
+static bool cfg80211_have_free_link(struct wiphy *wiphy,
+				    struct ieee80211_channel *target)
+{
+	// FIXME: use interface combinations data to check if we have the
+	//	  ability to use a separate HW resource for the given target
+	//	  channel, be it for scan, remain-on-channel, or operation
+	return false;
+}
+
+// FIXME: maybe rename to "on_same_resource" or something?
+static bool cfg80211_on_same_freq_range(struct wiphy *wiphy,
+					struct ieee80211_channel *chan1,
+					struct ieee80211_channel *chan2)
+{
+	// FIXME: use interface combinations data to check if the two
+	//	  channels are on the same hardware resource and can be
+	//	  (temporarily) committed to a new operation, or e.g.
+	//	  for channel switch
+
+	return true;
+}
+
+static bool cfg80211_off_channel_oper_allowed(struct wireless_dev *wdev,
+					      struct ieee80211_channel *chan)
 {
 	ASSERT_WDEV_LOCK(wdev);
 
 	if (!cfg80211_beaconing_iface_active(wdev))
 		return true;
 
-	if (!(wdev->chandef.chan->flags & IEEE80211_CHAN_RADAR))
+	if (cfg80211_have_free_link(wdev->wiphy, chan))
 		return true;
 
+	for_each_active_link(wdev, l) {
+		/* we cannot leave radar channels */
+		if (wdev->links[l].chandef.chan->flags & IEEE80211_CHAN_RADAR)
+			continue;
+
+		if (cfg80211_on_same_freq_range(wdev->wiphy, chan,
+						wdev->links[l].chandef.chan))
+			return true;
+	}
+
 	return regulatory_pre_cac_allowed(wdev->wiphy);
 }
 
@@ -8698,17 +8791,23 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
 	request->n_channels = i;
 
 	wdev_lock(wdev);
-	if (!cfg80211_off_channel_oper_allowed(wdev)) {
-		struct ieee80211_channel *chan;
+	for (i = 0; i < request->n_channels; i++) {
+		struct ieee80211_channel *chan = request->channels[i];
+		bool found = false;
 
-		if (request->n_channels != 1) {
-			wdev_unlock(wdev);
-			err = -EBUSY;
-			goto out_free;
+		/* if we can go off-channel to the target channel we're good */
+		if (cfg80211_off_channel_oper_allowed(wdev, chan))
+			continue;
+
+		/* otherwise see if we have a link on the target channel */
+		for_each_active_link(wdev, link_id) {
+			if (wdev->links[link_id].chandef.chan == chan) {
+				found = true;
+				break;
+			}
 		}
 
-		chan = request->channels[0];
-		if (chan->center_freq != wdev->chandef.chan->center_freq) {
+		if (!found) {
 			wdev_unlock(wdev);
 			err = -EBUSY;
 			goto out_free;
@@ -9453,7 +9552,8 @@ static int nl80211_start_radar_detection(struct sk_buff *skb,
 
 	err = rdev_start_radar_detection(rdev, dev, &chandef, cac_time_ms);
 	if (!err) {
-		wdev->chandef = chandef;
+// FIXME
+//		wdev->chandef = chandef;
 		wdev->cac_started = true;
 		wdev->cac_start_time = jiffies;
 		wdev->cac_time_ms = cac_time_ms;
@@ -9521,6 +9621,7 @@ static int nl80211_notify_radar_detection(struct sk_buff *skb,
 static int nl80211_channel_switch(struct sk_buff *skb, struct genl_info *info)
 {
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
+	unsigned int link_id = nl80211_link_id(info->attrs);
 	struct net_device *dev = info->user_ptr[1];
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	struct cfg80211_csa_settings params;
@@ -9547,7 +9648,7 @@ static int nl80211_channel_switch(struct sk_buff *skb, struct genl_info *info)
 		need_handle_dfs_flag = false;
 
 		/* useless if AP is not running */
-		if (!wdev->beacon_interval)
+		if (!wdev->links[link_id].beacon_interval)
 			return -ENOTCONN;
 		break;
 	case NL80211_IFTYPE_ADHOC:
@@ -11597,7 +11698,6 @@ static int nl80211_remain_on_channel(struct sk_buff *skb,
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
 	struct wireless_dev *wdev = info->user_ptr[1];
 	struct cfg80211_chan_def chandef;
-	const struct cfg80211_chan_def *compat_chandef;
 	struct sk_buff *msg;
 	void *hdr;
 	u64 cookie;
@@ -11627,11 +11727,29 @@ static int nl80211_remain_on_channel(struct sk_buff *skb,
 		return err;
 
 	wdev_lock(wdev);
-	if (!cfg80211_off_channel_oper_allowed(wdev) &&
-	    !cfg80211_chandef_identical(&wdev->chandef, &chandef)) {
-		compat_chandef = cfg80211_chandef_compatible(&wdev->chandef,
-							     &chandef);
-		if (compat_chandef != &chandef) {
+	if (!cfg80211_off_channel_oper_allowed(wdev, chandef.chan)) {
+		bool have_matching_link = false;
+
+		/* Check if there's a link (must be active!) that has
+		 * the right chandef - actually the notion of active is
+		 * a bit redundant here, since we only get here for a
+		 * beaconing interface, where mostly active == valid
+		 * links, except perhaps during the phase where a new
+		 * link is added.
+		 */
+		for_each_active_link(wdev, link_id) {
+			/* note: returns first one if identical chandefs */
+			const struct cfg80211_chan_def *compat_chandef =
+				cfg80211_chandef_compatible(&chandef,
+							    &wdev->links[0].chandef);
+
+			if (compat_chandef == &chandef) {
+				have_matching_link = true;
+				break;
+			}
+		}
+
+		if (!have_matching_link) {
 			wdev_unlock(wdev);
 			return -EBUSY;
 		}
@@ -11692,6 +11810,7 @@ static int nl80211_set_tx_bitrate_mask(struct sk_buff *skb,
 				       struct genl_info *info)
 {
 	struct cfg80211_bitrate_mask mask;
+	unsigned int link_id = nl80211_link_id(info->attrs);
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
 	struct net_device *dev = info->user_ptr[1];
 	int err;
@@ -11701,10 +11820,11 @@ static int nl80211_set_tx_bitrate_mask(struct sk_buff *skb,
 
 	err = nl80211_parse_tx_bitrate_mask(info, info->attrs,
 					    NL80211_ATTR_TX_RATES, &mask,
-					    dev, true);
+					    dev, true, link_id);
 	if (err)
 		return err;
 
+	// FIXME: pass link_id!
 	return rdev_set_bitrate_mask(rdev, dev, NULL, &mask);
 }
 
@@ -11827,7 +11947,8 @@ static int nl80211_tx_mgmt(struct sk_buff *skb, struct genl_info *info)
 		return -EINVAL;
 
 	wdev_lock(wdev);
-	if (params.offchan && !cfg80211_off_channel_oper_allowed(wdev)) {
+	if (params.offchan &&
+	    !cfg80211_off_channel_oper_allowed(wdev, chandef.chan)) {
 		wdev_unlock(wdev);
 		return -EBUSY;
 	}
@@ -12313,7 +12434,7 @@ static int nl80211_join_mesh(struct sk_buff *skb, struct genl_info *info)
 		err = nl80211_parse_tx_bitrate_mask(info, info->attrs,
 						    NL80211_ATTR_TX_RATES,
 						    &setup.beacon_rate,
-						    dev, false);
+						    dev, false, 0);
 		if (err)
 			return err;
 
@@ -14908,12 +15029,14 @@ static int nl80211_get_ftm_responder_stats(struct sk_buff *skb,
 	struct net_device *dev = info->user_ptr[1];
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	struct cfg80211_ftm_responder_stats ftm_stats = {};
+	unsigned int link_id = nl80211_link_id(info->attrs);
 	struct sk_buff *msg;
 	void *hdr;
 	struct nlattr *ftm_stats_attr;
 	int err;
 
-	if (wdev->iftype != NL80211_IFTYPE_AP || !wdev->beacon_interval)
+	if (wdev->iftype != NL80211_IFTYPE_AP ||
+	    !wdev->links[link_id].beacon_interval)
 		return -EOPNOTSUPP;
 
 	err = rdev_get_ftm_responder_stats(rdev, dev, &ftm_stats);
@@ -15043,7 +15166,8 @@ static int nl80211_probe_mesh_link(struct sk_buff *skb, struct genl_info *info)
 static int parse_tid_conf(struct cfg80211_registered_device *rdev,
 			  struct nlattr *attrs[], struct net_device *dev,
 			  struct cfg80211_tid_cfg *tid_conf,
-			  struct genl_info *info, const u8 *peer)
+			  struct genl_info *info, const u8 *peer,
+			  unsigned int link_id)
 {
 	struct netlink_ext_ack *extack = genl_info_extack(info);
 	u64 mask;
@@ -15118,7 +15242,7 @@ static int parse_tid_conf(struct cfg80211_registered_device *rdev,
 			attr = NL80211_TID_CONFIG_ATTR_TX_RATE;
 			err = nl80211_parse_tx_bitrate_mask(info, attrs, attr,
 						    &tid_conf->txrate_mask, dev,
-						    true);
+						    true, link_id);
 			if (err)
 				return err;
 
@@ -15145,6 +15269,7 @@ static int nl80211_set_tid_config(struct sk_buff *skb,
 {
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
 	struct nlattr *attrs[NL80211_TID_CONFIG_ATTR_MAX + 1];
+	unsigned int link_id = nl80211_link_id(info->attrs);
 	struct net_device *dev = info->user_ptr[1];
 	struct cfg80211_tid_config *tid_config;
 	struct nlattr *tid;
@@ -15182,7 +15307,7 @@ static int nl80211_set_tid_config(struct sk_buff *skb,
 
 		ret = parse_tid_conf(rdev, attrs, dev,
 				     &tid_config->tid_conf[conf_idx],
-				     info, tid_config->peer);
+				     info, tid_config->peer, link_id);
 		if (ret)
 			goto bad_tid_conf;
 
@@ -15333,6 +15458,7 @@ static int nl80211_set_fils_aad(struct sk_buff *skb,
 					 NL80211_FLAG_CHECK_NETDEV_UP)
 #define NL80211_FLAG_CLEAR_SKB		0x20
 #define NL80211_FLAG_NO_WIPHY_MTX	0x40
+#define NL80211_FLAG_MLO_VALID_LINK_ID	0x80
 
 #define INTERNAL_FLAG_SELECTORS(__sel)			\
 	SELECTOR(__sel, NONE, 0) /* must be first */	\
@@ -15342,6 +15468,9 @@ static int nl80211_set_fils_aad(struct sk_buff *skb,
 		 NL80211_FLAG_NEED_WDEV)		\
 	SELECTOR(__sel, NETDEV,				\
 		 NL80211_FLAG_NEED_NETDEV)		\
+	SELECTOR(__sel, NETDEV_LINK,			\
+		 NL80211_FLAG_NEED_NETDEV |		\
+		 NL80211_FLAG_MLO_VALID_LINK_ID)	\
 	SELECTOR(__sel, WIPHY_RTNL,			\
 		 NL80211_FLAG_NEED_WIPHY |		\
 		 NL80211_FLAG_NEED_RTNL)		\
@@ -15357,6 +15486,9 @@ static int nl80211_set_fils_aad(struct sk_buff *skb,
 		 NL80211_FLAG_NEED_RTNL)		\
 	SELECTOR(__sel, NETDEV_UP,			\
 		 NL80211_FLAG_NEED_NETDEV_UP)		\
+	SELECTOR(__sel, NETDEV_UP_LINK,			\
+		 NL80211_FLAG_NEED_NETDEV_UP |		\
+		 NL80211_FLAG_MLO_VALID_LINK_ID)	\
 	SELECTOR(__sel, NETDEV_UP_NOTMX,		\
 		 NL80211_FLAG_NEED_NETDEV_UP |		\
 		 NL80211_FLAG_NO_WIPHY_MTX)		\
@@ -15388,9 +15520,10 @@ static int nl80211_pre_doit(const struct genl_ops *ops, struct sk_buff *skb,
 			    struct genl_info *info)
 {
 	struct cfg80211_registered_device *rdev = NULL;
-	struct wireless_dev *wdev;
-	struct net_device *dev;
+	struct wireless_dev *wdev = NULL;
+	struct net_device *dev = NULL;
 	u32 internal_flags;
+	int err;
 
 	if (WARN_ON(ops->internal_flags >= ARRAY_SIZE(nl80211_internal_flags)))
 		return -EINVAL;
@@ -15406,8 +15539,8 @@ static int nl80211_pre_doit(const struct genl_ops *ops, struct sk_buff *skb,
 	if (internal_flags & NL80211_FLAG_NEED_WIPHY) {
 		rdev = cfg80211_get_dev_from_info(genl_info_net(info), info);
 		if (IS_ERR(rdev)) {
-			rtnl_unlock();
-			return PTR_ERR(rdev);
+			err = PTR_ERR(rdev);
+			goto out_unlock;
 		}
 		info->user_ptr[0] = rdev;
 	} else if (internal_flags & NL80211_FLAG_NEED_NETDEV ||
@@ -15415,8 +15548,8 @@ static int nl80211_pre_doit(const struct genl_ops *ops, struct sk_buff *skb,
 		wdev = __cfg80211_wdev_from_attrs(NULL, genl_info_net(info),
 						  info->attrs);
 		if (IS_ERR(wdev)) {
-			rtnl_unlock();
-			return PTR_ERR(wdev);
+			err = PTR_ERR(wdev);
+			goto out_unlock;
 		}
 
 		dev = wdev->netdev;
@@ -15424,8 +15557,8 @@ static int nl80211_pre_doit(const struct genl_ops *ops, struct sk_buff *skb,
 
 		if (internal_flags & NL80211_FLAG_NEED_NETDEV) {
 			if (!dev) {
-				rtnl_unlock();
-				return -EINVAL;
+				err = -EINVAL;
+				goto out_unlock;
 			}
 
 			info->user_ptr[1] = dev;
@@ -15435,14 +15568,37 @@ static int nl80211_pre_doit(const struct genl_ops *ops, struct sk_buff *skb,
 
 		if (internal_flags & NL80211_FLAG_CHECK_NETDEV_UP &&
 		    !wdev_running(wdev)) {
-			rtnl_unlock();
-			return -ENETDOWN;
+			err = -ENETDOWN;
+			goto out_unlock;
 		}
 
 		dev_hold(dev);
 		info->user_ptr[0] = rdev;
 	}
 
+	if (internal_flags & NL80211_FLAG_MLO_VALID_LINK_ID) {
+		struct nlattr *link_id = info->attrs[NL80211_ATTR_MLO_LINK_ID];
+
+		if (!wdev) {
+			err = -EINVAL;
+			goto out_unlock;
+		}
+
+		/* MLO -> require valid link ID */
+		if (wdev->valid_links &&
+		    (!link_id ||
+		     !(wdev->valid_links & BIT(nla_get_u16(link_id))))) {
+			err = -EINVAL;
+			goto out_unlock;
+		}
+
+		/* non-MLO -> no link ID attribute accepted */
+		if (!wdev->valid_links && link_id) {
+			err = -EINVAL;
+			goto out_unlock;
+		}
+	}
+
 	if (rdev && !(internal_flags & NL80211_FLAG_NO_WIPHY_MTX)) {
 		wiphy_lock(&rdev->wiphy);
 		/* we keep the mutex locked until post_doit */
@@ -15452,6 +15608,10 @@ static int nl80211_pre_doit(const struct genl_ops *ops, struct sk_buff *skb,
 		rtnl_unlock();
 
 	return 0;
+out_unlock:
+	rtnl_unlock();
+	dev_put(dev);
+	return err;
 }
 
 static void nl80211_post_doit(const struct genl_ops *ops, struct sk_buff *skb,
@@ -15669,6 +15829,7 @@ static const struct genl_small_ops nl80211_small_ops[] = {
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = nl80211_set_key,
 		.flags = GENL_UNS_ADMIN_PERM,
+		// cannot use NL80211_FLAG_MLO_VALID_LINK_ID, 
 		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV_UP |
 					 NL80211_FLAG_CLEAR_SKB),
 	},
@@ -15692,21 +15853,24 @@ static const struct genl_small_ops nl80211_small_ops[] = {
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.flags = GENL_UNS_ADMIN_PERM,
 		.doit = nl80211_set_beacon,
-		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV_UP),
+		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV_UP |
+					 NL80211_FLAG_MLO_VALID_LINK_ID),
 	},
 	{
 		.cmd = NL80211_CMD_START_AP,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.flags = GENL_UNS_ADMIN_PERM,
 		.doit = nl80211_start_ap,
-		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV_UP),
+		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV_UP |
+					 NL80211_FLAG_MLO_VALID_LINK_ID),
 	},
 	{
 		.cmd = NL80211_CMD_STOP_AP,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.flags = GENL_UNS_ADMIN_PERM,
 		.doit = nl80211_stop_ap,
-		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV_UP),
+		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV_UP |
+					 NL80211_FLAG_MLO_VALID_LINK_ID),
 	},
 	{
 		.cmd = NL80211_CMD_GET_STATION,
@@ -15986,7 +16150,8 @@ static const struct genl_small_ops nl80211_small_ops[] = {
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = nl80211_set_tx_bitrate_mask,
 		.flags = GENL_UNS_ADMIN_PERM,
-		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV),
+		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV |
+					 NL80211_FLAG_MLO_VALID_LINK_ID),
 	},
 	{
 		.cmd = NL80211_CMD_REGISTER_FRAME,
@@ -16035,7 +16200,8 @@ static const struct genl_small_ops nl80211_small_ops[] = {
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = nl80211_set_channel,
 		.flags = GENL_UNS_ADMIN_PERM,
-		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV),
+		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV |
+					 NL80211_FLAG_MLO_VALID_LINK_ID),
 	},
 	{
 		.cmd = NL80211_CMD_JOIN_MESH,
@@ -16250,7 +16416,8 @@ static const struct genl_small_ops nl80211_small_ops[] = {
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = nl80211_channel_switch,
 		.flags = GENL_UNS_ADMIN_PERM,
-		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV_UP),
+		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV_UP |
+					 NL80211_FLAG_MLO_VALID_LINK_ID),
 	},
 	{
 		.cmd = NL80211_CMD_VENDOR,
@@ -16334,7 +16501,8 @@ static const struct genl_small_ops nl80211_small_ops[] = {
 		.cmd = NL80211_CMD_GET_FTM_RESPONDER_STATS,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = nl80211_get_ftm_responder_stats,
-		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV),
+		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV |
+					 NL80211_FLAG_MLO_VALID_LINK_ID),
 	},
 	{
 		.cmd = NL80211_CMD_PEER_MEASUREMENT_START,
@@ -16366,7 +16534,8 @@ static const struct genl_small_ops nl80211_small_ops[] = {
 		.cmd = NL80211_CMD_SET_TID_CONFIG,
 		.doit = nl80211_set_tid_config,
 		.flags = GENL_UNS_ADMIN_PERM,
-		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV),
+		.internal_flags = IFLAGS(NL80211_FLAG_NEED_NETDEV |
+					 NL80211_FLAG_MLO_VALID_LINK_ID),
 	},
 	{
 		.cmd = NL80211_CMD_SET_SAR_SPECS,
@@ -18040,18 +18209,20 @@ static void nl80211_ch_switch_notify(struct cfg80211_registered_device *rdev,
 }
 
 void cfg80211_ch_switch_notify(struct net_device *dev,
-			       struct cfg80211_chan_def *chandef)
+			       struct cfg80211_chan_def *chandef,
+			       unsigned int link_id)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	struct wiphy *wiphy = wdev->wiphy;
 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 
 	ASSERT_WDEV_LOCK(wdev);
+	WARN_INVALID_LINK_ID(wdev, link_id);
 
-	trace_cfg80211_ch_switch_notify(dev, chandef);
+	trace_cfg80211_ch_switch_notify(dev, chandef, link_id);
 
-	wdev->chandef = *chandef;
-	wdev->preset_chandef = *chandef;
+	wdev->links[link_id].chandef = *chandef;
+	wdev->links[link_id].preset_chandef = *chandef;
 
 	if ((wdev->iftype == NL80211_IFTYPE_STATION ||
 	     wdev->iftype == NL80211_IFTYPE_P2P_CLIENT) &&
diff --git a/net/wireless/ocb.c b/net/wireless/ocb.c
index 2d26a6d980bf..30dbb7e93648 100644
--- a/net/wireless/ocb.c
+++ b/net/wireless/ocb.c
@@ -4,6 +4,7 @@
  *
  * Copyright: (c) 2014 Czech Technical University in Prague
  *            (c) 2014 Volkswagen Group Research
+ * Copyright (C) 2022 Intel Corporation
  * Author:    Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
  * Funded by: Volkswagen Group Research
  */
@@ -34,7 +35,7 @@ int __cfg80211_join_ocb(struct cfg80211_registered_device *rdev,
 
 	err = rdev_join_ocb(rdev, dev, setup);
 	if (!err)
-		wdev->chandef = setup->chandef;
+		wdev->links[0].chandef = setup->chandef;
 
 	return err;
 }
@@ -69,7 +70,7 @@ int __cfg80211_leave_ocb(struct cfg80211_registered_device *rdev,
 
 	err = rdev_leave_ocb(rdev, dev);
 	if (!err)
-		memset(&wdev->chandef, 0, sizeof(wdev->chandef));
+		memset(&wdev->links[0].chandef, 0, sizeof(wdev->links[0].chandef));
 
 	return err;
 }
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 8c4fed2ec225..945d1897c98a 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -5,7 +5,7 @@
  * Copyright 2008-2011	Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
  * Copyright 2013-2014  Intel Mobile Communications GmbH
  * Copyright      2017  Intel Deutschland GmbH
- * Copyright (C) 2018 - 2021 Intel Corporation
+ * Copyright (C) 2018 - 2022 Intel Corporation
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -2366,6 +2366,7 @@ static bool reg_wdev_chan_valid(struct wiphy *wiphy, struct wireless_dev *wdev)
 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
 	enum nl80211_iftype iftype;
 	bool ret;
+	int link;
 
 	wdev_lock(wdev);
 	iftype = wdev->iftype;
@@ -2374,62 +2375,80 @@ static bool reg_wdev_chan_valid(struct wiphy *wiphy, struct wireless_dev *wdev)
 	if (!wdev->netdev || !netif_running(wdev->netdev))
 		goto wdev_inactive_unlock;
 
-	switch (iftype) {
-	case NL80211_IFTYPE_AP:
-	case NL80211_IFTYPE_P2P_GO:
-	case NL80211_IFTYPE_MESH_POINT:
-		if (!wdev->beacon_interval)
-			goto wdev_inactive_unlock;
-		chandef = wdev->chandef;
-		break;
-	case NL80211_IFTYPE_ADHOC:
-		if (!wdev->ssid_len)
-			goto wdev_inactive_unlock;
-		chandef = wdev->chandef;
-		break;
-	case NL80211_IFTYPE_STATION:
-	case NL80211_IFTYPE_P2P_CLIENT:
-		if (!wdev->current_bss ||
-		    !wdev->current_bss->pub.channel)
-			goto wdev_inactive_unlock;
-
-		if (!rdev->ops->get_channel ||
-		    rdev_get_channel(rdev, wdev, &chandef))
-			cfg80211_chandef_create(&chandef,
-						wdev->current_bss->pub.channel,
-						NL80211_CHAN_NO_HT);
-		break;
-	case NL80211_IFTYPE_MONITOR:
-	case NL80211_IFTYPE_AP_VLAN:
-	case NL80211_IFTYPE_P2P_DEVICE:
-		/* no enforcement required */
-		break;
-	default:
-		/* others not implemented for now */
-		WARN_ON(1);
-		break;
-	}
+	for (link = 0; link < ARRAY_SIZE(wdev->links); link++) {
+		if (!wdev->valid_links && link > 0)
+			break;
+		if (!(wdev->valid_links & BIT(link)))
+			continue;
+		switch (iftype) {
+		case NL80211_IFTYPE_AP:
+		case NL80211_IFTYPE_P2P_GO:
+		case NL80211_IFTYPE_MESH_POINT:
+			if (!wdev->links[link].beacon_interval)
+				goto wdev_inactive_unlock;
+			chandef = wdev->links[link].chandef;
+			break;
+		case NL80211_IFTYPE_ADHOC:
+			if (!wdev->ssid_len)
+				goto wdev_inactive_unlock;
+			chandef = wdev->links[link].chandef;
+			break;
+		case NL80211_IFTYPE_STATION:
+		case NL80211_IFTYPE_P2P_CLIENT:
+			/* FIXME - get the right BSS? how do we do this? */
+			if (!wdev->current_bss ||
+			    !wdev->current_bss->pub.channel)
+				goto wdev_inactive_unlock;
+
+			/* FIXME - pass link ID to get_channel() */
+			if (!rdev->ops->get_channel ||
+			    rdev_get_channel(rdev, wdev, &chandef))
+				cfg80211_chandef_create(&chandef,
+							wdev->current_bss->pub.channel,
+							NL80211_CHAN_NO_HT);
+			break;
+		case NL80211_IFTYPE_MONITOR:
+		case NL80211_IFTYPE_AP_VLAN:
+		case NL80211_IFTYPE_P2P_DEVICE:
+			/* no enforcement required */
+			break;
+		default:
+			/* others not implemented for now */
+			WARN_ON(1);
+			break;
+		}
 
-	wdev_unlock(wdev);
+		wdev_unlock(wdev);
 
-	switch (iftype) {
-	case NL80211_IFTYPE_AP:
-	case NL80211_IFTYPE_P2P_GO:
-	case NL80211_IFTYPE_ADHOC:
-	case NL80211_IFTYPE_MESH_POINT:
-		wiphy_lock(wiphy);
-		ret = cfg80211_reg_can_beacon_relax(wiphy, &chandef, iftype);
-		wiphy_unlock(wiphy);
+		switch (iftype) {
+		case NL80211_IFTYPE_AP:
+		case NL80211_IFTYPE_P2P_GO:
+		case NL80211_IFTYPE_ADHOC:
+		case NL80211_IFTYPE_MESH_POINT:
+			wiphy_lock(wiphy);
+			ret = cfg80211_reg_can_beacon_relax(wiphy, &chandef,
+							    iftype);
+			wiphy_unlock(wiphy);
 
-		return ret;
-	case NL80211_IFTYPE_STATION:
-	case NL80211_IFTYPE_P2P_CLIENT:
-		return cfg80211_chandef_usable(wiphy, &chandef,
-					       IEEE80211_CHAN_DISABLED);
-	default:
-		break;
+			if (!ret)
+				return ret;
+			break;
+		case NL80211_IFTYPE_STATION:
+		case NL80211_IFTYPE_P2P_CLIENT:
+			ret = cfg80211_chandef_usable(wiphy, &chandef,
+						      IEEE80211_CHAN_DISABLED);
+			if (!ret)
+				return ret;
+			break;
+		default:
+			break;
+		}
+
+		wdev_lock(wdev);
 	}
 
+	wdev_unlock(wdev);
+
 	return true;
 
 wdev_inactive_unlock:
@@ -4210,8 +4229,8 @@ static void cfg80211_check_and_end_cac(struct cfg80211_registered_device *rdev)
 	 * In both cases we should end the CAC on the wdev.
 	 */
 	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
-		if (wdev->cac_started &&
-		    !cfg80211_chandef_dfs_usable(&rdev->wiphy, &wdev->chandef))
+		if (wdev->cac_started /* FIXME &&
+		    !cfg80211_chandef_dfs_usable(&rdev->wiphy, &wdev->chandef) */)
 			rdev_end_cac(rdev, wdev->netdev);
 	}
 }
diff --git a/net/wireless/sme.c b/net/wireless/sme.c
index ae825d5cf8db..f9f58dcfddf6 100644
--- a/net/wireless/sme.c
+++ b/net/wireless/sme.c
@@ -5,7 +5,7 @@
  * (for nl80211's connect() and wext)
  *
  * Copyright 2009	Johannes Berg <johannes@sipsolutions.net>
- * Copyright (C) 2009, 2020 Intel Corporation. All rights reserved.
+ * Copyright (C) 2009, 2020, 2022 Intel Corporation. All rights reserved.
  * Copyright 2017	Intel Deutschland GmbH
  */
 
@@ -1322,7 +1322,7 @@ void cfg80211_autodisconnect_wk(struct work_struct *work)
 			break;
 		case NL80211_IFTYPE_AP:
 		case NL80211_IFTYPE_P2P_GO:
-			__cfg80211_stop_ap(rdev, wdev->netdev, false);
+			__cfg80211_stop_ap(rdev, wdev->netdev, -1, false);
 			break;
 		case NL80211_IFTYPE_MESH_POINT:
 			__cfg80211_leave_mesh(rdev, wdev->netdev);
diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index 414a249440f6..107430e5b71c 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -3038,18 +3038,21 @@ TRACE_EVENT(cfg80211_chandef_dfs_required,
 
 TRACE_EVENT(cfg80211_ch_switch_notify,
 	TP_PROTO(struct net_device *netdev,
-		 struct cfg80211_chan_def *chandef),
-	TP_ARGS(netdev, chandef),
+		 struct cfg80211_chan_def *chandef,
+		 unsigned int link_id),
+	TP_ARGS(netdev, chandef, link_id),
 	TP_STRUCT__entry(
 		NETDEV_ENTRY
 		CHAN_DEF_ENTRY
+		__field(unsigned int, link_id)
 	),
 	TP_fast_assign(
 		NETDEV_ASSIGN;
 		CHAN_DEF_ASSIGN(chandef);
+		__entry->link_id = link_id;
 	),
-	TP_printk(NETDEV_PR_FMT ", " CHAN_DEF_PR_FMT,
-		  NETDEV_PR_ARG, CHAN_DEF_PR_ARG)
+	TP_printk(NETDEV_PR_FMT ", " CHAN_DEF_PR_FMT ", link:%d",
+		  NETDEV_PR_ARG, CHAN_DEF_PR_ARG, __entry->link_id)
 );
 
 TRACE_EVENT(cfg80211_ch_switch_started_notify,
diff --git a/net/wireless/util.c b/net/wireless/util.c
index a60d7d638e72..e968a66608f9 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -5,7 +5,7 @@
  * Copyright 2007-2009	Johannes Berg <johannes@sipsolutions.net>
  * Copyright 2013-2014  Intel Mobile Communications GmbH
  * Copyright 2017	Intel Deutschland GmbH
- * Copyright (C) 2018-2021 Intel Corporation
+ * Copyright (C) 2018-2022 Intel Corporation
  */
 #include <linux/export.h>
 #include <linux/bitops.h>
@@ -1049,7 +1049,7 @@ int cfg80211_change_iface(struct cfg80211_registered_device *rdev,
 		switch (otype) {
 		case NL80211_IFTYPE_AP:
 		case NL80211_IFTYPE_P2P_GO:
-			cfg80211_stop_ap(rdev, dev, true);
+			cfg80211_stop_ap(rdev, dev, -1, true);
 			break;
 		case NL80211_IFTYPE_ADHOC:
 			cfg80211_leave_ibss(rdev, dev, false);
@@ -1940,19 +1940,24 @@ static void cfg80211_calculate_bi_data(struct wiphy *wiphy, u32 new_beacon_int,
 	*beacon_int_different = false;
 
 	list_for_each_entry(wdev, &wiphy->wdev_list, list) {
-		if (!wdev->beacon_interval)
+		/* this feature isn't supported with MLO */
+		if (wdev->valid_links)
+			continue;
+
+		if (!wdev->links[0].beacon_interval)
 			continue;
 
 		if (!*beacon_int_gcd) {
-			*beacon_int_gcd = wdev->beacon_interval;
+			*beacon_int_gcd = wdev->links[0].beacon_interval;
 			continue;
 		}
 
-		if (wdev->beacon_interval == *beacon_int_gcd)
+		if (wdev->links[0].beacon_interval == *beacon_int_gcd)
 			continue;
 
 		*beacon_int_different = true;
-		*beacon_int_gcd = gcd(*beacon_int_gcd, wdev->beacon_interval);
+		*beacon_int_gcd = gcd(*beacon_int_gcd,
+				      wdev->links[0].beacon_interval);
 	}
 
 	if (new_beacon_int && *beacon_int_gcd != new_beacon_int) {
