diff --git a/Documentation/DocBook/80211.tmpl b/Documentation/DocBook/80211.tmpl
index 044b764..d9b9416 100644
--- a/Documentation/DocBook/80211.tmpl
+++ b/Documentation/DocBook/80211.tmpl
@@ -100,6 +100,7 @@
 !Finclude/net/cfg80211.h wdev_priv
 !Finclude/net/cfg80211.h ieee80211_iface_limit
 !Finclude/net/cfg80211.h ieee80211_iface_combination
+!Finclude/net/cfg80211.h cfg80211_check_combinations
       </chapter>
       <chapter>
       <title>Actions and configuration</title>
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index ff3af16..768fcc0 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -4682,6 +4682,28 @@ void cfg80211_crit_proto_stopped(struct wireless_dev *wdev, gfp_t gfp);
  */
 unsigned int ieee80211_get_num_supported_channels(struct wiphy *wiphy);
 
+/**
+ * cfg80211_check_combinations - check interface combinations
+ *
+ * @wiphy: the wiphy
+ * @num_different_channels: the number of different channels we want
+ *	to use for verification
+ * @radar_detect: a bitmap where each bit corresponds to a channel
+ *	width where radar detection is needed, as in the definition of
+ *	&struct ieee80211_iface_combination.@radar_detect_widths
+ * @iftype_num: array with the numbers of interfaces of each interface
+ *	type.  The index is the interface type as specified in &enum
+ *	nl80211_iftype.
+ *
+ * This function can be called by the driver to check whether a
+ * combination of interfaces and their types are allowed according to
+ * the interface combinations.
+ */
+int cfg80211_check_combinations(struct wiphy *wiphy,
+				const int num_different_channels,
+				const u8 radar_detect,
+				const int iftype_num[NUM_NL80211_IFTYPES]);
+
 /* Logging, debugging and troubleshooting/diagnostic helpers. */
 
 /* wiphy_printk helpers, similar to dev_printk */
diff --git a/net/wireless/util.c b/net/wireless/util.c
index dadc934..7ecc0ef 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -1253,6 +1253,75 @@ int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
 	return res;
 }
 
+int cfg80211_check_combinations(struct wiphy *wiphy,
+				const int num_different_channels,
+				const u8 radar_detect,
+				const int iftype_num[NUM_NL80211_IFTYPES])
+{
+	int i, j, iftype;
+	int num_interfaces = 0;
+	u32 used_iftypes = 0;
+
+	for (iftype = 0; iftype < NUM_NL80211_IFTYPES; iftype++) {
+		num_interfaces += iftype_num[iftype];
+		if (iftype_num[iftype] > 0)
+			used_iftypes |= BIT(iftype);
+	}
+
+	for (i = 0; i < wiphy->n_iface_combinations; i++) {
+		const struct ieee80211_iface_combination *c;
+		struct ieee80211_iface_limit *limits;
+		u32 all_iftypes = 0;
+
+		c = &wiphy->iface_combinations[i];
+
+		if (num_interfaces > c->max_interfaces)
+			continue;
+		if (num_different_channels > c->num_different_channels)
+			continue;
+
+		limits = kmemdup(c->limits, sizeof(limits[0]) * c->n_limits,
+				 GFP_KERNEL);
+		if (!limits)
+			return -ENOMEM;
+
+		for (iftype = 0; iftype < NUM_NL80211_IFTYPES; iftype++) {
+			if (wiphy->software_iftypes & BIT(iftype))
+				continue;
+			for (j = 0; j < c->n_limits; j++) {
+				all_iftypes |= limits[j].types;
+				if (!(limits[j].types & BIT(iftype)))
+					continue;
+				if (limits[j].max < iftype_num[iftype])
+					goto cont;
+				limits[j].max -= iftype_num[iftype];
+			}
+		}
+
+		if (radar_detect && !(c->radar_detect_widths & radar_detect))
+			goto cont;
+
+		/* Finally check that all iftypes that we're currently
+		 * using are actually part of this combination. If they
+		 * aren't then we can't use this combination and have
+		 * to continue to the next.
+		 */
+		if ((all_iftypes & used_iftypes) != used_iftypes)
+			goto cont;
+
+		/* This combination covered all interface types and
+		 * supported the requested numbers, so we're good.
+		 */
+		kfree(limits);
+		return 0;
+ cont:
+		kfree(limits);
+	}
+
+	return -EBUSY;
+}
+EXPORT_SYMBOL(cfg80211_check_combinations);
+
 int cfg80211_can_use_iftype_chan(struct cfg80211_registered_device *rdev,
 				 struct wireless_dev *wdev,
 				 enum nl80211_iftype iftype,
@@ -1261,7 +1330,6 @@ int cfg80211_can_use_iftype_chan(struct cfg80211_registered_device *rdev,
 				 u8 radar_detect)
 {
 	struct wireless_dev *wdev_iter;
-	u32 used_iftypes = BIT(iftype);
 	int num[NUM_NL80211_IFTYPES];
 	struct ieee80211_channel
 			*used_channels[CFG80211_MAX_NUM_DIFFERENT_CHANNELS];
@@ -1269,7 +1337,7 @@ int cfg80211_can_use_iftype_chan(struct cfg80211_registered_device *rdev,
 	enum cfg80211_chan_mode chmode;
 	int num_different_channels = 0;
 	int total = 1;
-	int i, j;
+	int i;
 
 	ASSERT_RTNL();
 
@@ -1354,65 +1422,13 @@ int cfg80211_can_use_iftype_chan(struct cfg80211_registered_device *rdev,
 
 		num[wdev_iter->iftype]++;
 		total++;
-		used_iftypes |= BIT(wdev_iter->iftype);
 	}
 
 	if (total == 1 && !radar_detect)
 		return 0;
 
-	for (i = 0; i < rdev->wiphy.n_iface_combinations; i++) {
-		const struct ieee80211_iface_combination *c;
-		struct ieee80211_iface_limit *limits;
-		u32 all_iftypes = 0;
-
-		c = &rdev->wiphy.iface_combinations[i];
-
-		if (total > c->max_interfaces)
-			continue;
-		if (num_different_channels > c->num_different_channels)
-			continue;
-
-		limits = kmemdup(c->limits, sizeof(limits[0]) * c->n_limits,
-				 GFP_KERNEL);
-		if (!limits)
-			return -ENOMEM;
-
-		for (iftype = 0; iftype < NUM_NL80211_IFTYPES; iftype++) {
-			if (rdev->wiphy.software_iftypes & BIT(iftype))
-				continue;
-			for (j = 0; j < c->n_limits; j++) {
-				all_iftypes |= limits[j].types;
-				if (!(limits[j].types & BIT(iftype)))
-					continue;
-				if (limits[j].max < num[iftype])
-					goto cont;
-				limits[j].max -= num[iftype];
-			}
-		}
-
-		if (radar_detect && !(c->radar_detect_widths & radar_detect))
-			goto cont;
-
-		/*
-		 * Finally check that all iftypes that we're currently
-		 * using are actually part of this combination. If they
-		 * aren't then we can't use this combination and have
-		 * to continue to the next.
-		 */
-		if ((all_iftypes & used_iftypes) != used_iftypes)
-			goto cont;
-
-		/*
-		 * This combination covered all interface types and
-		 * supported the requested numbers, so we're good.
-		 */
-		kfree(limits);
-		return 0;
- cont:
-		kfree(limits);
-	}
-
-	return -EBUSY;
+	return cfg80211_check_combinations(&rdev->wiphy, num_different_channels,
+					   radar_detect, num);
 }
 
 int ieee80211_get_ratemask(struct ieee80211_supported_band *sband,
