ath10k: track number of existing peers

To not exceed number of allowed clients (AP mode), make sure to
check how many of them are already on the peers list.

10.X firmware support up to 127 peers, non-AP centric firmwares 16.

Signed-off-by: Bartosz Markowski <bartosz.markowski@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
diff --git a/drivers/net/wireless/ath/ath10k/core.h b/drivers/net/wireless/ath/ath10k/core.h
index 035cbf6..9d8fc29 100644
--- a/drivers/net/wireless/ath/ath10k/core.h
+++ b/drivers/net/wireless/ath/ath10k/core.h
@@ -432,6 +432,9 @@
 	struct list_head peers;
 	wait_queue_head_t peer_mapping_wq;
 
+	/* number of created peers; protected by data_lock */
+	int num_peers;
+
 	struct work_struct offchan_tx_work;
 	struct sk_buff_head offchan_tx_queue;
 	struct completion offchan_tx_completed;
diff --git a/drivers/net/wireless/ath/ath10k/hw.h b/drivers/net/wireless/ath/ath10k/hw.h
index 9535eaa..f1505a2 100644
--- a/drivers/net/wireless/ath/ath10k/hw.h
+++ b/drivers/net/wireless/ath/ath10k/hw.h
@@ -115,6 +115,7 @@
 #define TARGET_10X_MAC_AGGR_DELIM		0
 #define TARGET_10X_AST_SKID_LIMIT		16
 #define TARGET_10X_NUM_PEERS			(128 + (TARGET_10X_NUM_VDEVS))
+#define TARGET_10X_NUM_PEERS_MAX		128
 #define TARGET_10X_NUM_OFFLOAD_PEERS		0
 #define TARGET_10X_NUM_OFFLOAD_REORDER_BUFS	0
 #define TARGET_10X_NUM_PEER_KEYS		2
diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index 2a4e7aa..ce0f1db 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -332,6 +332,9 @@
 		ath10k_warn("Failed to wait for created wmi peer: %i\n", ret);
 		return ret;
 	}
+	spin_lock_bh(&ar->data_lock);
+	ar->num_peers++;
+	spin_unlock_bh(&ar->data_lock);
 
 	return 0;
 }
@@ -377,6 +380,10 @@
 	if (ret)
 		return ret;
 
+	spin_lock_bh(&ar->data_lock);
+	ar->num_peers--;
+	spin_unlock_bh(&ar->data_lock);
+
 	return 0;
 }
 
@@ -396,6 +403,7 @@
 
 		list_del(&peer->list);
 		kfree(peer);
+		ar->num_peers--;
 	}
 	spin_unlock_bh(&ar->data_lock);
 }
@@ -411,6 +419,7 @@
 		list_del(&peer->list);
 		kfree(peer);
 	}
+	ar->num_peers = 0;
 	spin_unlock_bh(&ar->data_lock);
 }
 
@@ -2849,6 +2858,7 @@
 {
 	struct ath10k *ar = hw->priv;
 	struct ath10k_vif *arvif = ath10k_vif_to_arvif(vif);
+	int max_num_peers;
 	int ret = 0;
 
 	mutex_lock(&ar->conf_mutex);
@@ -2859,9 +2869,21 @@
 		/*
 		 * New station addition.
 		 */
+		if (test_bit(ATH10K_FW_FEATURE_WMI_10X, ar->fw_features))
+			max_num_peers = TARGET_10X_NUM_PEERS_MAX - 1;
+		else
+			max_num_peers = TARGET_NUM_PEERS;
+
+		if (ar->num_peers >= max_num_peers) {
+			ath10k_warn("Number of peers exceeded: peers number %d (max peers %d)\n",
+				    ar->num_peers, max_num_peers);
+			ret = -ENOBUFS;
+			goto exit;
+		}
+
 		ath10k_dbg(ATH10K_DBG_MAC,
-			   "mac vdev %d peer create %pM (new sta)\n",
-			   arvif->vdev_id, sta->addr);
+			   "mac vdev %d peer create %pM (new sta) num_peers %d\n",
+			   arvif->vdev_id, sta->addr, ar->num_peers);
 
 		ret = ath10k_peer_create(ar, arvif->vdev_id, sta->addr);
 		if (ret)
@@ -2911,7 +2933,7 @@
 			ath10k_warn("Failed to disassociate station: %pM\n",
 				    sta->addr);
 	}
-
+exit:
 	mutex_unlock(&ar->conf_mutex);
 	return ret;
 }