cfg80211: make wdev_list accessible to drivers

There's no harm in having drivers read the list, since they can
use RCU protection or RTNL locking; allow this to not require
each and every driver to also implement its own bookkeeping.

Signed-off-by: Johannes Berg <[e-mail]>

include/net/cfg80211.h

···
  * @vht_capa_mod_mask:  Specify what VHT capabilities can be over-ridden.
  *	If null, then none can be over-ridden.
  *
+ * @wdev_list: the list of associated (virtual) interfaces; this list must
+ *	not be modified by the driver, but can be read with RTNL/RCU protection.
+ *
  * @max_acl_mac_addrs: Maximum number of MAC addresses that the device
  *	supports for ACL.
  *
···
 
 	const struct ieee80211_ht_cap *ht_capa_mod_mask;
 	const struct ieee80211_vht_cap *vht_capa_mod_mask;
+
+	struct list_head wdev_list;
 
 	/* the network namespace this phy lives in currently */
 	possible_net_t _net;

net/wireless/chan.c

···
 	 * and thus fail the GO instantiation, consider only the interfaces of
 	 * the current registered device.
 	 */
-	list_for_each_entry(wdev, &rdev->wdev_list, list) {
+	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
 		struct ieee80211_channel *other_chan = NULL;
 		int r1, r2;
 

net/wireless/core.c

···
  *
  * Copyright 2006-2010		Johannes Berg <[e-mail]>
  * Copyright 2013-2014  Intel Mobile Communications GmbH
+ * Copyright 2015	Intel Deutschland GmbH
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
···
 	if (!(rdev->wiphy.flags & WIPHY_FLAG_NETNS_OK))
 		return -EOPNOTSUPP;
 
-	list_for_each_entry(wdev, &rdev->wdev_list, list) {
+	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
 		if (!wdev->netdev)
 			continue;
 		wdev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
···
 		/* failed -- clean up to old netns */
 		net = wiphy_net(&rdev->wiphy);
 
-		list_for_each_entry_continue_reverse(wdev, &rdev->wdev_list,
+		list_for_each_entry_continue_reverse(wdev,
+						     &rdev->wiphy.wdev_list,
 						     list) {
 			if (!wdev->netdev)
 				continue;
···
 
 	ASSERT_RTNL();
 
-	list_for_each_entry(wdev, &rdev->wdev_list, list) {
+	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
 		if (wdev->netdev) {
 			dev_close(wdev->netdev);
 			continue;
···
 		kfree(item);
 		spin_unlock_irq(&rdev->destroy_list_lock);
 
-		list_for_each_entry_safe(wdev, tmp, &rdev->wdev_list, list) {
+		list_for_each_entry_safe(wdev, tmp,
+					 &rdev->wiphy.wdev_list, list) {
 			if (nlportid == wdev->owner_nlportid)
 				rdev_del_virtual_intf(rdev, wdev);
 		}
···
 		dev_set_name(&rdev->wiphy.dev, PHY_NAME "%d", rdev->wiphy_idx);
 	}
 
-	INIT_LIST_HEAD(&rdev->wdev_list);
+	INIT_LIST_HEAD(&rdev->wiphy.wdev_list);
 	INIT_LIST_HEAD(&rdev->beacon_registrations);
 	spin_lock_init(&rdev->beacon_registrations_lock);
 	spin_lock_init(&rdev->bss_lock);
···
 	nl80211_notify_wiphy(rdev, NL80211_CMD_DEL_WIPHY);
 	rdev->wiphy.registered = false;
 
-	WARN_ON(!list_empty(&rdev->wdev_list));
+	WARN_ON(!list_empty(&rdev->wiphy.wdev_list));
 
 	/*
 	 * First remove the hardware from everywhere, this makes
···
 		spin_lock_init(&wdev->mgmt_registrations_lock);
 
 		wdev->identifier = ++rdev->wdev_id;
-		list_add_rcu(&wdev->list, &rdev->wdev_list);
+		list_add_rcu(&wdev->list, &rdev->wiphy.wdev_list);
 		rdev->devlist_generation++;
 		/* can only change netns with wiphy */
 		dev->features |= NETIF_F_NETNS_LOCAL;

net/wireless/core.h

···
 	/* wiphy index, internal only */
 	int wiphy_idx;
 
-	/* associated wireless interfaces, protected by rtnl or RCU */
-	struct list_head wdev_list;
+	/* protected by RTNL */
 	int devlist_generation, wdev_id;
 	int opencount;
 	wait_queue_head_t dev_wait;

net/wireless/nl80211.c

···
 		if (have_wdev_id && rdev->wiphy_idx != wiphy_idx)
 			continue;
 
-		list_for_each_entry(wdev, &rdev->wdev_list, list) {
+		list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
 			if (have_ifidx && wdev->netdev &&
 			    wdev->netdev->ifindex == ifidx) {
 				result = wdev;
···
 		tmp = cfg80211_rdev_by_wiphy_idx(wdev_id >> 32);
 		if (tmp) {
 			/* make sure wdev exists */
-			list_for_each_entry(wdev, &tmp->wdev_list, list) {
+			list_for_each_entry(wdev, &tmp->wiphy.wdev_list, list) {
 				if (wdev->identifier != (u32)wdev_id)
 					continue;
 				found = true;
···
 		*rdev = wiphy_to_rdev(wiphy);
 		*wdev = NULL;
 
-		list_for_each_entry(tmp, &(*rdev)->wdev_list, list) {
+		list_for_each_entry(tmp, &(*rdev)->wiphy.wdev_list, list) {
 			if (tmp->identifier == cb->args[1]) {
 				*wdev = tmp;
 				break;
···
 		}
 		if_idx = 0;
 
-		list_for_each_entry(wdev, &rdev->wdev_list, list) {
+		list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
 			if (if_idx < if_start) {
 				if_idx++;
 				continue;
···
 		spin_lock_init(&wdev->mgmt_registrations_lock);
 
 		wdev->identifier = ++rdev->wdev_id;
-		list_add_rcu(&wdev->list, &rdev->wdev_list);
+		list_add_rcu(&wdev->list, &rdev->wiphy.wdev_list);
 		rdev->devlist_generation++;
 		break;
 	default:
···
 	struct wireless_dev *wdev;
 	bool ret = false;
 
-	list_for_each_entry(wdev, &rdev->wdev_list, list) {
+	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
 		if (wdev->iftype != NL80211_IFTYPE_AP &&
 		    wdev->iftype != NL80211_IFTYPE_P2P_GO)
 			continue;
···
 		*wdev = NULL;
 
 		if (cb->args[1]) {
-			list_for_each_entry(tmp, &(*rdev)->wdev_list, list) {
+			list_for_each_entry(tmp, &wiphy->wdev_list, list) {
 				if (tmp->identifier == cb->args[1] - 1) {
 					*wdev = tmp;
 					break;
···
 		    sched_scan_req->owner_nlportid == notify->portid)
 			schedule_scan_stop = true;
 
-		list_for_each_entry_rcu(wdev, &rdev->wdev_list, list) {
+		list_for_each_entry_rcu(wdev, &rdev->wiphy.wdev_list, list) {
 			cfg80211_mlme_unregister_socket(wdev, notify->portid);
 
 			if (wdev->owner_nlportid == notify->portid)

net/wireless/reg.c

···
 
 	ASSERT_RTNL();
 
-	list_for_each_entry(wdev, &rdev->wdev_list, list)
+	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list)
 		if (!reg_wdev_chan_valid(wiphy, wdev))
 			cfg80211_leave(rdev, wdev);
 }

net/wireless/sme.c

···
 
 	rtnl_lock();
 
-	list_for_each_entry(wdev, &rdev->wdev_list, list) {
+	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
 		if (!wdev->netdev)
 			continue;
 
···
 	 * count as new regulatory hints.
 	 */
 	list_for_each_entry(rdev, &cfg80211_rdev_list, list) {
-		list_for_each_entry(wdev, &rdev->wdev_list, list) {
+		list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
 			wdev_lock(wdev);
 			if (wdev->conn || wdev->current_bss)
 				is_all_idle = false;

net/wireless/sysfs.c

···
 {
 	struct wireless_dev *wdev;
 
-	list_for_each_entry(wdev, &rdev->wdev_list, list)
+	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list)
 		cfg80211_leave(rdev, wdev);
 }
 

net/wireless/util.c

···
 
 	ASSERT_RTNL();
 
-	list_for_each_entry(wdev, &rdev->wdev_list, list)
+	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list)
 		cfg80211_process_wdev_events(wdev);
 }
 
···
 	if (!beacon_int)
 		return -EINVAL;
 
-	list_for_each_entry(wdev, &rdev->wdev_list, list) {
+	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
 		if (!wdev->beacon_interval)
 			continue;
 		if (wdev->beacon_interval != beacon_int) {