Bluetooth: Track number of LE slave connections

Most (probably all) controllers can only deal with a single slave LE
connection at a time. This patch adds a counter for such connections so
that the number can be quickly looked up without iterating the
connections list.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/hci_core.h

@@ -83,6 +83,7 @@ struct hci_conn_hash {
 	unsigned int     amp_num;
 	unsigned int     sco_num;
 	unsigned int     le_num;
+	unsigned int     le_num_slave;
 };
 
 struct bdaddr_list {
@@ -575,6 +576,8 @@ static inline void hci_conn_hash_add(struct hci_dev *hdev, struct hci_conn *c)
 		break;
 	case LE_LINK:
 		h->le_num++;
+		if (c->role == HCI_ROLE_SLAVE)
+			h->le_num_slave++;
 		break;
 	case SCO_LINK:
 	case ESCO_LINK:
@@ -599,6 +602,8 @@ static inline void hci_conn_hash_del(struct hci_dev *hdev, struct hci_conn *c)
 		break;
 	case LE_LINK:
 		h->le_num--;
+		if (c->role == HCI_ROLE_SLAVE)
+			h->le_num_slave--;
 		break;
 	case SCO_LINK:
 	case ESCO_LINK: