ath11k: Add support for STA to handle beacon miss

When AP goes down without any indication to STA, firmware detects
missing beacon, and sends wmi roam event with reason BEACON_MISS
to the host.

Added support for STA mode to trigger disassociation from AP,
on receiving this event from firmware.

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.4.0.1-01717-QCAHKSWPL_SILICONZ-1
Tested-on: QCA6390 hw2.0 PCI WLAN.HST.1.0.1-01740-QCAHSTSWPLZ_V2_TO_X86-1

Signed-off-by: Lavanya Suresh <lavaks@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1614340859-28867-1-git-send-email-lavaks@codeaurora.org

drivers/net/wireless/ath/ath11k/core.h

@@ -34,6 +34,7 @@
 #define ATH11K_PRB_RSP_DROP_THRESHOLD ((ATH11K_TX_MGMT_TARGET_MAX_SUPPORT_WMI * 3) / 4)
 
 #define ATH11K_INVALID_HW_MAC_ID	0xFF
+#define ATH11K_CONNECTION_LOSS_HZ	(3 * HZ)
 
 extern unsigned int ath11k_frame_mode;
 
@@ -235,6 +236,7 @@ struct ath11k_vif {
 	u32 aid;
 	u8 bssid[ETH_ALEN];
 	struct cfg80211_bitrate_mask bitrate_mask;
+	struct delayed_work connection_loss_work;
 	int num_legacy_stations;
 	int rtscts_prot_mode;
 	int txpower;

drivers/net/wireless/ath/ath11k/mac.c

@@ -829,6 +829,75 @@ static void ath11k_control_beaconing(struct ath11k_vif *arvif,
 	ath11k_dbg(ar->ab, ATH11K_DBG_MAC, "mac vdev %d up\n", arvif->vdev_id);
 }
 
+static void ath11k_mac_handle_beacon_iter(void *data, u8 *mac,
+					  struct ieee80211_vif *vif)
+{
+	struct sk_buff *skb = data;
+	struct ieee80211_mgmt *mgmt = (void *)skb->data;
+	struct ath11k_vif *arvif = (void *)vif->drv_priv;
+
+	if (vif->type != NL80211_IFTYPE_STATION)
+		return;
+
+	if (!ether_addr_equal(mgmt->bssid, vif->bss_conf.bssid))
+		return;
+
+	cancel_delayed_work(&arvif->connection_loss_work);
+}
+
+void ath11k_mac_handle_beacon(struct ath11k *ar, struct sk_buff *skb)
+{
+	ieee80211_iterate_active_interfaces_atomic(ar->hw,
+						   IEEE80211_IFACE_ITER_NORMAL,
+						   ath11k_mac_handle_beacon_iter,
+						   skb);
+}
+
+static void ath11k_mac_handle_beacon_miss_iter(void *data, u8 *mac,
+					       struct ieee80211_vif *vif)
+{
+	u32 *vdev_id = data;
+	struct ath11k_vif *arvif = (void *)vif->drv_priv;
+	struct ath11k *ar = arvif->ar;
+	struct ieee80211_hw *hw = ar->hw;
+
+	if (arvif->vdev_id != *vdev_id)
+		return;
+
+	if (!arvif->is_up)
+		return;
+
+	ieee80211_beacon_loss(vif);
+
+	/* Firmware doesn't report beacon loss events repeatedly. If AP probe
+	 * (done by mac80211) succeeds but beacons do not resume then it
+	 * doesn't make sense to continue operation. Queue connection loss work
+	 * which can be cancelled when beacon is received.
+	 */
+	ieee80211_queue_delayed_work(hw, &arvif->connection_loss_work,
+				     ATH11K_CONNECTION_LOSS_HZ);
+}
+
+void ath11k_mac_handle_beacon_miss(struct ath11k *ar, u32 vdev_id)
+{
+	ieee80211_iterate_active_interfaces_atomic(ar->hw,
+						   IEEE80211_IFACE_ITER_NORMAL,
+						   ath11k_mac_handle_beacon_miss_iter,
+						   &vdev_id);
+}
+
+static void ath11k_mac_vif_sta_connection_loss_work(struct work_struct *work)
+{
+	struct ath11k_vif *arvif = container_of(work, struct ath11k_vif,
+						connection_loss_work.work);
+	struct ieee80211_vif *vif = arvif->vif;
+
+	if (!arvif->is_up)
+		return;
+
+	ieee80211_connection_loss(vif);
+}
+
 static void ath11k_peer_assoc_h_basic(struct ath11k *ar,
 				      struct ieee80211_vif *vif,
 				      struct ieee80211_sta *sta,
@@ -1760,7 +1829,7 @@ static void ath11k_bss_disassoc(struct ieee80211_hw *hw,
 
 	arvif->is_up = false;
 
-	/* TODO: cancel connection_loss_work */
+	cancel_delayed_work_sync(&arvif->connection_loss_work);
 }
 
 static u32 ath11k_mac_get_rate_hw_value(int bitrate)
@@ -4615,10 +4684,8 @@ static int ath11k_mac_op_add_interface(struct ieee80211_hw *hw,
 	arvif->vif = vif;
 
 	INIT_LIST_HEAD(&arvif->list);
-
-	/* Should we initialize any worker to handle connection loss indication
-	 * from firmware in sta mode?
-	 */
+	INIT_DELAYED_WORK(&arvif->connection_loss_work,
+			  ath11k_mac_vif_sta_connection_loss_work);
 
 	for (i = 0; i < ARRAY_SIZE(arvif->bitrate_mask.control); i++) {
 		arvif->bitrate_mask.control[i].legacy = 0xffffffff;
@@ -4827,6 +4894,8 @@ static void ath11k_mac_op_remove_interface(struct ieee80211_hw *hw,
 	int ret;
 	int i;
 
+	cancel_delayed_work_sync(&arvif->connection_loss_work);
+
 	mutex_lock(&ar->conf_mutex);
 
 	ath11k_dbg(ab, ATH11K_DBG_MAC, "mac remove interface (vdev %d)\n",

drivers/net/wireless/ath/ath11k/mac.h

@@ -150,4 +150,6 @@ int ath11k_mac_tx_mgmt_pending_free(int buf_id, void *skb, void *ctx);
 u8 ath11k_mac_bw_to_mac80211_bw(u8 bw);
 enum ath11k_supported_bw ath11k_mac_mac80211_bw_to_ath11k_bw(enum rate_info_bw bw);
 enum hal_encrypt_type ath11k_dp_tx_get_encrypt_type(u32 cipher);
+void ath11k_mac_handle_beacon(struct ath11k *ar, struct sk_buff *skb);
+void ath11k_mac_handle_beacon_miss(struct ath11k *ar, u32 vdev_id);
 #endif

drivers/net/wireless/ath/ath11k/wmi.c

@@ -6171,10 +6171,8 @@ static void ath11k_mgmt_rx_event(struct ath11k_base *ab, struct sk_buff *skb)
 		}
 	}
 
-	/* TODO: Pending handle beacon implementation
-	 *if (ieee80211_is_beacon(hdr->frame_control))
-	 *	ath11k_mac_handle_beacon(ar, skb);
-	 */
+	if (ieee80211_is_beacon(hdr->frame_control))
+		ath11k_mac_handle_beacon(ar, skb);
 
 	ath11k_dbg(ab, ATH11K_DBG_MGMT,
 		   "event mgmt rx skb %pK len %d ftype %02x stype %02x\n",
@@ -6393,10 +6391,7 @@ static void ath11k_roam_event(struct ath11k_base *ab, struct sk_buff *skb)
 
 	switch (roam_ev.reason) {
 	case WMI_ROAM_REASON_BEACON_MISS:
-		/* TODO: Pending beacon miss and connection_loss_work
-		 * implementation
-		 * ath11k_mac_handle_beacon_miss(ar, vdev_id);
-		 */
+		ath11k_mac_handle_beacon_miss(ar, roam_ev.vdev_id);
 		break;
 	case WMI_ROAM_REASON_BETTER_AP:
 	case WMI_ROAM_REASON_LOW_RSSI: