rtw88: handle and recover when firmware crash

This handles the situation when firmware crashes.
When firmware crashes, it will send an interrupt, and driver will queue
a work for recovery.
In the work, driver will reset it's internal association state, which
includes removing associated sta's macid, resetting vifs' states
and removing keys. After resetting the driver's state, driver will call
rtw_enter_ips() to force the chipset power off to reset the chip.
Finally, driver calls ieee80211_restart_hw() to inform mac80211 stack
to restart.
Since only 8822c firmware supports this feature, the interrupt will only
be triggered when 8822c chipset is loaded.

Signed-off-by: Tzu-En Huang <tehuang@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200925061219.23754-3-tehuang@realtek.com

1 files changed, 132 insertions, 0 deletions

diff --git a/drivers/net/wireless/realtek/rtw88/main.c b/drivers/net/wireless/realtek/rtw88/main.c
index cc82c80f0433..420853eaf270 100644
--- a/drivers/net/wireless/realtek/rtw88/main.c
+++ b/drivers/net/wireless/realtek/rtw88/main.c
@@ -259,6 +259,137 @@ static void rtw_c2h_work(struct work_struct *work)
 	}
 }
 
+static u8 rtw_acquire_macid(struct rtw_dev *rtwdev)
+{
+	unsigned long mac_id;
+
+	mac_id = find_first_zero_bit(rtwdev->mac_id_map, RTW_MAX_MAC_ID_NUM);
+	if (mac_id < RTW_MAX_MAC_ID_NUM)
+		set_bit(mac_id, rtwdev->mac_id_map);
+
+	return mac_id;
+}
+
+int rtw_sta_add(struct rtw_dev *rtwdev, struct ieee80211_sta *sta,
+		struct ieee80211_vif *vif)
+{
+	struct rtw_sta_info *si = (struct rtw_sta_info *)sta->drv_priv;
+	int i;
+
+	si->mac_id = rtw_acquire_macid(rtwdev);
+	if (si->mac_id >= RTW_MAX_MAC_ID_NUM)
+		return -ENOSPC;
+
+	si->sta = sta;
+	si->vif = vif;
+	si->init_ra_lv = 1;
+	ewma_rssi_init(&si->avg_rssi);
+	for (i = 0; i < ARRAY_SIZE(sta->txq); i++)
+		rtw_txq_init(rtwdev, sta->txq[i]);
+
+	rtw_update_sta_info(rtwdev, si);
+	rtw_fw_media_status_report(rtwdev, si->mac_id, true);
+
+	rtwdev->sta_cnt++;
+	rtw_info(rtwdev, "sta %pM joined with macid %d\n",
+		 sta->addr, si->mac_id);
+
+	return 0;
+}
+
+void rtw_sta_remove(struct rtw_dev *rtwdev, struct ieee80211_sta *sta,
+		    bool fw_exist)
+{
+	struct rtw_sta_info *si = (struct rtw_sta_info *)sta->drv_priv;
+	int i;
+
+	rtw_release_macid(rtwdev, si->mac_id);
+	if (fw_exist)
+		rtw_fw_media_status_report(rtwdev, si->mac_id, false);
+
+	for (i = 0; i < ARRAY_SIZE(sta->txq); i++)
+		rtw_txq_cleanup(rtwdev, sta->txq[i]);
+
+	kfree(si->mask);
+
+	rtwdev->sta_cnt--;
+	rtw_info(rtwdev, "sta %pM with macid %d left\n",
+		 sta->addr, si->mac_id);
+}
+
+void rtw_vif_assoc_changed(struct rtw_vif *rtwvif,
+			   struct ieee80211_bss_conf *conf)
+{
+	if (conf && conf->assoc) {
+		rtwvif->aid = conf->aid;
+		rtwvif->net_type = RTW_NET_MGD_LINKED;
+	} else {
+		rtwvif->aid = 0;
+		rtwvif->net_type = RTW_NET_NO_LINK;
+	}
+}
+
+static void rtw_reset_key_iter(struct ieee80211_hw *hw,
+			       struct ieee80211_vif *vif,
+			       struct ieee80211_sta *sta,
+			       struct ieee80211_key_conf *key,
+			       void *data)
+{
+	struct rtw_dev *rtwdev = (struct rtw_dev *)data;
+	struct rtw_sec_desc *sec = &rtwdev->sec;
+
+	rtw_sec_clear_cam(rtwdev, sec, key->hw_key_idx);
+}
+
+static void rtw_reset_sta_iter(void *data, struct ieee80211_sta *sta)
+{
+	struct rtw_dev *rtwdev = (struct rtw_dev *)data;
+
+	if (rtwdev->sta_cnt == 0) {
+		rtw_warn(rtwdev, "sta count before reset should not be 0\n");
+		return;
+	}
+	rtw_sta_remove(rtwdev, sta, false);
+}
+
+static void rtw_reset_vif_iter(void *data, u8 *mac, struct ieee80211_vif *vif)
+{
+	struct rtw_dev *rtwdev = (struct rtw_dev *)data;
+	struct rtw_vif *rtwvif = (struct rtw_vif *)vif->drv_priv;
+
+	rtw_bf_disassoc(rtwdev, vif, NULL);
+	rtw_vif_assoc_changed(rtwvif, NULL);
+	rtw_txq_cleanup(rtwdev, vif->txq);
+}
+
+void rtw_fw_recovery(struct rtw_dev *rtwdev)
+{
+	if (!test_bit(RTW_FLAG_RESTARTING, rtwdev->flags))
+		ieee80211_queue_work(rtwdev->hw, &rtwdev->fw_recovery_work);
+}
+
+static void rtw_fw_recovery_work(struct work_struct *work)
+{
+	struct rtw_dev *rtwdev = container_of(work, struct rtw_dev,
+					      fw_recovery_work);
+
+	WARN(1, "firmware crash, start reset and recover\n");
+
+	mutex_lock(&rtwdev->mutex);
+
+	set_bit(RTW_FLAG_RESTARTING, rtwdev->flags);
+	rcu_read_lock();
+	rtw_iterate_keys_rcu(rtwdev, NULL, rtw_reset_key_iter, rtwdev);
+	rcu_read_unlock();
+	rtw_iterate_stas_atomic(rtwdev, rtw_reset_sta_iter, rtwdev);
+	rtw_iterate_vifs_atomic(rtwdev, rtw_reset_vif_iter, rtwdev);
+	rtw_enter_ips(rtwdev);
+
+	mutex_unlock(&rtwdev->mutex);
+
+	ieee80211_restart_hw(rtwdev->hw);
+}
+
 struct rtw_txq_ba_iter_data {
 };
 
@@ -1431,6 +1562,7 @@ int rtw_core_init(struct rtw_dev *rtwdev)
 	INIT_DELAYED_WORK(&coex->wl_remain_work, rtw_coex_wl_remain_work);
 	INIT_DELAYED_WORK(&coex->bt_remain_work, rtw_coex_bt_remain_work);
 	INIT_WORK(&rtwdev->c2h_work, rtw_c2h_work);
+	INIT_WORK(&rtwdev->fw_recovery_work, rtw_fw_recovery_work);
 	INIT_WORK(&rtwdev->ba_work, rtw_txq_ba_work);
 	skb_queue_head_init(&rtwdev->c2h_queue);
 	skb_queue_head_init(&rtwdev->coex.queue);