rtw89: ser: fix CAM leaks occurring in L2 reset

The CAM, meaning address CAM and bssid CAM here, will get leaks during
SER (system error recover) L2 reset process and ieee80211_restart_hw()
which is called by L2 reset process eventually.

The normal flow would be like
-> add interface (acquire 1)
-> enter ips (release 1)
-> leave ips (acquire 1)
-> connection (occupy 1) <(A) 1 leak after L2 reset if non-sec connection>

The ieee80211_restart_hw() flow (under connection)
-> ieee80211 reconfig
-> add interface (acquire 1)
-> leave ips (acquire 1)
-> connection (occupy (A) + 2) <(B) 1 more leak>

Originally, CAM is released before HW restart only if connection is under
security. Now, release CAM whatever connection it is to fix leak in (A).
OTOH, check if CAM is already valid to avoid acquiring multiple times to
fix (B).

Besides, if AP mode, release address CAM of all stations before HW restart.
Signed-off-by: Zong-Zhe Yang <kevin_yang@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220314071250.40292-2-pkshih@realtek.com

drivers/net/wireless/realtek/rtw89/cam.c

@@ -421,10 +421,8 @@ static void rtw89_cam_reset_key_iter(struct ieee80211_hw *hw,
 				     void *data)
 {
 	struct rtw89_dev *rtwdev = (struct rtw89_dev *)data;
-	struct rtw89_vif *rtwvif = (struct rtw89_vif *)vif->drv_priv;
 
 	rtw89_cam_sec_key_del(rtwdev, vif, sta, key, false);
-	rtw89_cam_deinit(rtwdev, rtwvif);
 }
 
 void rtw89_cam_deinit_addr_cam(struct rtw89_dev *rtwdev,
@@ -480,6 +478,12 @@ int rtw89_cam_init_addr_cam(struct rtw89_dev *rtwdev,
 	int i;
 	int ret;
 
+	if (unlikely(addr_cam->valid)) {
+		rtw89_debug(rtwdev, RTW89_DBG_FW,
+			    "addr cam is already valid; skip init\n");
+		return 0;
+	}
+
 	ret = rtw89_cam_get_avail_addr_cam(rtwdev, &addr_cam_idx);
 	if (ret) {
 		rtw89_err(rtwdev, "failed to get available addr cam\n");
@@ -531,6 +535,12 @@ static int rtw89_cam_init_bssid_cam(struct rtw89_dev *rtwdev,
 	u8 bssid_cam_idx;
 	int ret;
 
+	if (unlikely(bssid_cam->valid)) {
+		rtw89_debug(rtwdev, RTW89_DBG_FW,
+			    "bssid cam is already valid; skip init\n");
+		return 0;
+	}
+
 	ret = rtw89_cam_get_avail_bssid_cam(rtwdev, &bssid_cam_idx);
 	if (ret) {
 		rtw89_err(rtwdev, "failed to get available bssid cam\n");

drivers/net/wireless/realtek/rtw89/ser.c

@@ -220,11 +220,32 @@ static void ser_reset_vif(struct rtw89_dev *rtwdev, struct rtw89_vif *rtwvif)
 	rtwvif->trigger = false;
 }
 
+static void ser_sta_deinit_addr_cam_iter(void *data, struct ieee80211_sta *sta)
+{
+	struct rtw89_dev *rtwdev = (struct rtw89_dev *)data;
+	struct rtw89_sta *rtwsta = (struct rtw89_sta *)sta->drv_priv;
+
+	rtw89_cam_deinit_addr_cam(rtwdev, &rtwsta->addr_cam);
+}
+
+static void ser_deinit_cam(struct rtw89_dev *rtwdev, struct rtw89_vif *rtwvif)
+{
+	if (rtwvif->net_type == RTW89_NET_TYPE_AP_MODE)
+		ieee80211_iterate_stations_atomic(rtwdev->hw,
+						  ser_sta_deinit_addr_cam_iter,
+						  rtwdev);
+
+	rtw89_cam_deinit(rtwdev, rtwvif);
+}
+
 static void ser_reset_mac_binding(struct rtw89_dev *rtwdev)
 {
 	struct rtw89_vif *rtwvif;
 
 	rtw89_cam_reset_keys(rtwdev);
+	rtw89_for_each_rtwvif(rtwdev, rtwvif)
+		ser_deinit_cam(rtwdev, rtwvif);
+
 	rtw89_core_release_all_bits_map(rtwdev->mac_id_map, RTW89_MAX_MAC_ID_NUM);
 	rtw89_for_each_rtwvif(rtwdev, rtwvif)
 		ser_reset_vif(rtwdev, rtwvif);