wifi: mac80211: isolate driver from inactive links

In order to let the driver select active links and properly
make multi-link connections, as a first step isolate the
driver from inactive links, and set the active links to be
only the association link for client-side interfaces. For
AP side nothing changes since APs always have to have all
their links active.

To simplify things, update the for_each_sta_active_link()
API to include the appropriate vif pointer.

This also implies not allocating a chanctx for an inactive
link, which requires a few more changes.

Since we now no longer try to program multiple links to the
driver, remove the check in the MLME code.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -1799,6 +1799,9 @@ struct ieee80211_vif_cfg {
  * @link_conf: in case of MLD, the per-link BSS configuration,
  *	indexed by link ID
  * @valid_links: bitmap of valid links, or 0 for non-MLO.
+ * @active_links: The bitmap of active links, or 0 for non-MLO.
+ *	The driver shouldn't change this directly, but use the
+ *	API calls meant for that purpose.
  * @addr: address of this interface
  * @p2p: indicates whether this AP or STA interface is a p2p
  *	interface, i.e. a GO or p2p-sta respectively
@@ -1834,7 +1837,7 @@ struct ieee80211_vif {
 	struct ieee80211_vif_cfg cfg;
 	struct ieee80211_bss_conf bss_conf;
 	struct ieee80211_bss_conf __rcu *link_conf[IEEE80211_MLD_MAX_NUM_LINKS];
-	u16 valid_links;
+	u16 valid_links, active_links;
 	u8 addr[ETH_ALEN] __aligned(2);
 	bool p2p;
 
@@ -1861,12 +1864,11 @@ struct ieee80211_vif {
 	u8 drv_priv[] __aligned(sizeof(void *));
 };
 
-/* FIXME: for now loop over all the available links; later will be changed
- * to loop only over the active links.
- */
-#define for_each_vif_active_link(vif, link, link_id)			     \
-	for (link_id = 0; link_id < ARRAY_SIZE((vif)->link_conf); link_id++) \
-		if ((link = rcu_dereference((vif)->link_conf[link_id])))
+#define for_each_vif_active_link(vif, link, link_id)				\
+	for (link_id = 0; link_id < ARRAY_SIZE((vif)->link_conf); link_id++)	\
+		if ((!(vif)->active_links ||					\
+		     (vif)->active_links & BIT(link_id)) &&			\
+		    (link = rcu_dereference((vif)->link_conf[link_id])))
 
 static inline bool ieee80211_vif_is_mesh(struct ieee80211_vif *vif)
 {
@@ -2264,13 +2266,13 @@ struct ieee80211_sta {
 	u8 drv_priv[] __aligned(sizeof(void *));
 };
 
-/* FIXME: need to loop only over links which are active and check the actual
- * lock
- */
-#define for_each_sta_active_link(sta, link_sta, link_id)		         \
-	for (link_id = 0; link_id < ARRAY_SIZE((sta)->link); link_id++)	         \
-		if (((link_sta) = rcu_dereference_protected((sta)->link[link_id],\
-							    1)))	         \
+/* FIXME: check the locking correctly */
+#define for_each_sta_active_link(vif, sta, link_sta, link_id)			\
+	for (link_id = 0; link_id < ARRAY_SIZE((sta)->link); link_id++)		\
+		if ((!(vif)->active_links ||					\
+		     (vif)->active_links & BIT(link_id)) &&			\
+		    ((link_sta) = rcu_dereference_protected((sta)->link[link_id],\
+							    1)))
 
 /**
  * enum sta_notify_cmd - sta notify command

net/mac80211/chan.c

@@ -1799,6 +1799,12 @@ int ieee80211_link_use_channel(struct ieee80211_link_data *link,
 
 	lockdep_assert_held(&local->mtx);
 
+	if (sdata->vif.active_links &&
+	    !(sdata->vif.active_links & BIT(link->link_id))) {
+		ieee80211_link_update_chandef(link, chandef);
+		return 0;
+	}
+
 	mutex_lock(&local->chanctx_mtx);
 
 	ret = cfg80211_chandef_dfs_required(local->hw.wiphy,

net/mac80211/driver-ops.c

@@ -192,6 +192,10 @@ int drv_conf_tx(struct ieee80211_local *local,
 	if (!check_sdata_in_driver(sdata))
 		return -EIO;
 
+	if (sdata->vif.active_links &&
+	    !(sdata->vif.active_links & BIT(link->link_id)))
+		return 0;
+
 	if (params->cw_min == 0 || params->cw_min > params->cw_max) {
 		/*
 		 * If we can't configure hardware anyway, don't warn. We may
@@ -272,6 +276,60 @@ void drv_reset_tsf(struct ieee80211_local *local,
 	trace_drv_return_void(local);
 }
 
+int drv_assign_vif_chanctx(struct ieee80211_local *local,
+			   struct ieee80211_sub_if_data *sdata,
+			   struct ieee80211_bss_conf *link_conf,
+			   struct ieee80211_chanctx *ctx)
+{
+	int ret = 0;
+
+	drv_verify_link_exists(sdata, link_conf);
+	if (!check_sdata_in_driver(sdata))
+		return -EIO;
+
+	if (sdata->vif.active_links &&
+	    !(sdata->vif.active_links & BIT(link_conf->link_id)))
+		return 0;
+
+	trace_drv_assign_vif_chanctx(local, sdata, link_conf, ctx);
+	if (local->ops->assign_vif_chanctx) {
+		WARN_ON_ONCE(!ctx->driver_present);
+		ret = local->ops->assign_vif_chanctx(&local->hw,
+						     &sdata->vif,
+						     link_conf,
+						     &ctx->conf);
+	}
+	trace_drv_return_int(local, ret);
+
+	return ret;
+}
+
+void drv_unassign_vif_chanctx(struct ieee80211_local *local,
+			      struct ieee80211_sub_if_data *sdata,
+			      struct ieee80211_bss_conf *link_conf,
+			      struct ieee80211_chanctx *ctx)
+{
+	might_sleep();
+
+	drv_verify_link_exists(sdata, link_conf);
+	if (!check_sdata_in_driver(sdata))
+		return;
+
+	if (sdata->vif.active_links &&
+	    !(sdata->vif.active_links & BIT(link_conf->link_id)))
+		return;
+
+	trace_drv_unassign_vif_chanctx(local, sdata, link_conf, ctx);
+	if (local->ops->unassign_vif_chanctx) {
+		WARN_ON_ONCE(!ctx->driver_present);
+		local->ops->unassign_vif_chanctx(&local->hw,
+						 &sdata->vif,
+						 link_conf,
+						 &ctx->conf);
+	}
+	trace_drv_return_void(local);
+}
+
 int drv_switch_vif_chanctx(struct ieee80211_local *local,
 			   struct ieee80211_vif_chanctx_switch *vifs,
 			   int n_vifs, enum ieee80211_chanctx_switch_mode mode)
@@ -346,3 +404,117 @@ int drv_ampdu_action(struct ieee80211_local *local,
 
 	return ret;
 }
+
+void drv_link_info_changed(struct ieee80211_local *local,
+			   struct ieee80211_sub_if_data *sdata,
+			   struct ieee80211_bss_conf *info,
+			   int link_id, u64 changed)
+{
+	might_sleep();
+
+	if (WARN_ON_ONCE(changed & (BSS_CHANGED_BEACON |
+				    BSS_CHANGED_BEACON_ENABLED) &&
+			 sdata->vif.type != NL80211_IFTYPE_AP &&
+			 sdata->vif.type != NL80211_IFTYPE_ADHOC &&
+			 sdata->vif.type != NL80211_IFTYPE_MESH_POINT &&
+			 sdata->vif.type != NL80211_IFTYPE_OCB))
+		return;
+
+	if (WARN_ON_ONCE(sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE ||
+			 sdata->vif.type == NL80211_IFTYPE_NAN ||
+			 (sdata->vif.type == NL80211_IFTYPE_MONITOR &&
+			  !sdata->vif.bss_conf.mu_mimo_owner &&
+			  !(changed & BSS_CHANGED_TXPOWER))))
+		return;
+
+	if (!check_sdata_in_driver(sdata))
+		return;
+
+	if (sdata->vif.active_links &&
+	    !(sdata->vif.active_links & BIT(link_id)))
+		return;
+
+	trace_drv_link_info_changed(local, sdata, info, changed);
+	if (local->ops->link_info_changed)
+		local->ops->link_info_changed(&local->hw, &sdata->vif,
+					      info, changed);
+	else if (local->ops->bss_info_changed)
+		local->ops->bss_info_changed(&local->hw, &sdata->vif,
+					     info, changed);
+	trace_drv_return_void(local);
+}
+
+int drv_set_key(struct ieee80211_local *local,
+		enum set_key_cmd cmd,
+		struct ieee80211_sub_if_data *sdata,
+		struct ieee80211_sta *sta,
+		struct ieee80211_key_conf *key)
+{
+	int ret;
+
+	might_sleep();
+
+	sdata = get_bss_sdata(sdata);
+	if (!check_sdata_in_driver(sdata))
+		return -EIO;
+
+	if (WARN_ON(key->link_id >= 0 && sdata->vif.active_links &&
+		    !(sdata->vif.active_links & BIT(key->link_id))))
+		return -ENOLINK;
+
+	trace_drv_set_key(local, cmd, sdata, sta, key);
+	ret = local->ops->set_key(&local->hw, cmd, &sdata->vif, sta, key);
+	trace_drv_return_int(local, ret);
+	return ret;
+}
+
+int drv_change_vif_links(struct ieee80211_local *local,
+			 struct ieee80211_sub_if_data *sdata,
+			 u16 old_links, u16 new_links,
+			 struct ieee80211_bss_conf *old[IEEE80211_MLD_MAX_NUM_LINKS])
+{
+	int ret = -EOPNOTSUPP;
+
+	might_sleep();
+
+	if (!check_sdata_in_driver(sdata))
+		return -EIO;
+
+	if (old_links == new_links)
+		return 0;
+
+	trace_drv_change_vif_links(local, sdata, old_links, new_links);
+	if (local->ops->change_vif_links)
+		ret = local->ops->change_vif_links(&local->hw, &sdata->vif,
+						   old_links, new_links, old);
+	trace_drv_return_int(local, ret);
+
+	return ret;
+}
+
+int drv_change_sta_links(struct ieee80211_local *local,
+			 struct ieee80211_sub_if_data *sdata,
+			 struct ieee80211_sta *sta,
+			 u16 old_links, u16 new_links)
+{
+	int ret = -EOPNOTSUPP;
+
+	might_sleep();
+
+	if (!check_sdata_in_driver(sdata))
+		return -EIO;
+
+	old_links &= sdata->vif.active_links;
+	new_links &= sdata->vif.active_links;
+
+	if (old_links == new_links)
+		return 0;
+
+	trace_drv_change_sta_links(local, sdata, sta, old_links, new_links);
+	if (local->ops->change_sta_links)
+		ret = local->ops->change_sta_links(&local->hw, &sdata->vif, sta,
+						   old_links, new_links);
+	trace_drv_return_int(local, ret);
+
+	return ret;
+}