brcmfmac: make use of cfg80211_check_combinations()

Use cfg80211_check_combinations() so we can bail out early when an
interface add or change results in an invalid combination.
Reviewed-by: NHante Meuleman <meuleman@broadcom.com>
Reviewed-by: NFranky (Zhenhui) Lin <frankyl@broadcom.com>
Reviewed-by: NPieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: NArend van Spriel <arend@broadcom.com>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c

@@ -469,6 +469,36 @@ brcmf_find_wpsie(const u8 *parse, u32 len)
 	return NULL;
 }
 
+static int brcmf_vif_change_validate(struct brcmf_cfg80211_info *cfg,
+				     struct brcmf_cfg80211_vif *vif,
+				     enum nl80211_iftype new_type)
+{
+	int iftype_num[NUM_NL80211_IFTYPES];
+	struct brcmf_cfg80211_vif *pos;
+
+	memset(&iftype_num[0], 0, sizeof(iftype_num));
+	list_for_each_entry(pos, &cfg->vif_list, list)
+		if (pos == vif)
+			iftype_num[new_type]++;
+		else
+			iftype_num[pos->wdev.iftype]++;
+
+	return cfg80211_check_combinations(cfg->wiphy, 1, 0, iftype_num);
+}
+
+static int brcmf_vif_add_validate(struct brcmf_cfg80211_info *cfg,
+				  enum nl80211_iftype new_type)
+{
+	int iftype_num[NUM_NL80211_IFTYPES];
+	struct brcmf_cfg80211_vif *pos;
+
+	memset(&iftype_num[0], 0, sizeof(iftype_num));
+	list_for_each_entry(pos, &cfg->vif_list, list)
+		iftype_num[pos->wdev.iftype]++;
+
+	iftype_num[new_type]++;
+	return cfg80211_check_combinations(cfg->wiphy, 1, 0, iftype_num);
+}
 
 static void convert_key_from_CPU(struct brcmf_wsec_key *key,
 				 struct brcmf_wsec_key_le *key_le)
@@ -663,8 +693,14 @@ static struct wireless_dev *brcmf_cfg80211_add_iface(struct wiphy *wiphy,
 						     struct vif_params *params)
 {
 	struct wireless_dev *wdev;
+	int err;
 
 	brcmf_dbg(TRACE, "enter: %s type %d\n", name, type);
+	err = brcmf_vif_add_validate(wiphy_to_cfg(wiphy), type);
+	if (err) {
+		brcmf_err("iface validation failed: err=%d\n", err);
+		return ERR_PTR(err);
+	}
 	switch (type) {
 	case NL80211_IFTYPE_ADHOC:
 	case NL80211_IFTYPE_STATION:
@@ -823,8 +859,12 @@ brcmf_cfg80211_change_iface(struct wiphy *wiphy, struct net_device *ndev,
 	s32 ap = 0;
 	s32 err = 0;
 
-	brcmf_dbg(TRACE, "Enter, ndev=%p, type=%d\n", ndev, type);
-
+	brcmf_dbg(TRACE, "Enter, idx=%d, type=%d\n", ifp->bssidx, type);
+	err = brcmf_vif_change_validate(wiphy_to_cfg(wiphy), vif, type);
+	if (err) {
+		brcmf_err("iface validation failed: err=%d\n", err);
+		return err;
+	}
 	switch (type) {
 	case NL80211_IFTYPE_MONITOR:
 	case NL80211_IFTYPE_WDS: