Bluetooth: prioritizing data over HCI

This implement priority based scheduler using skbuffer priority set via
SO_PRIORITY socket option.

It introduces hci_chan_hash (list of HCI Channel/hci_chan) per connection,
each item in this list refer to a L2CAP connection and it is used to
queue the data for transmission.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 5a9db9a..f97792c 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -67,6 +67,12 @@
 	unsigned int     le_num;
 };
 
+struct hci_chan_hash {
+	struct list_head list;
+	spinlock_t       lock;
+	unsigned int     num;
+};
+
 struct bdaddr_list {
 	struct list_head list;
 	bdaddr_t bdaddr;
@@ -287,6 +293,7 @@
 	unsigned int	sent;
 
 	struct sk_buff_head data_q;
+	struct hci_chan_hash chan_hash;
 
 	struct timer_list disc_timer;
 	struct timer_list idle_timer;
@@ -309,6 +316,14 @@
 	void (*disconn_cfm_cb)	(struct hci_conn *conn, u8 reason);
 };
 
+struct hci_chan {
+	struct list_head list;
+
+	struct hci_conn *conn;
+	struct sk_buff_head data_q;
+	unsigned int	sent;
+};
+
 extern struct hci_proto *hci_proto[];
 extern struct list_head hci_dev_list;
 extern struct list_head hci_cb_list;
@@ -469,6 +484,28 @@
 	return NULL;
 }
 
+static inline void hci_chan_hash_init(struct hci_conn *c)
+{
+	struct hci_chan_hash *h = &c->chan_hash;
+	INIT_LIST_HEAD(&h->list);
+	spin_lock_init(&h->lock);
+	h->num = 0;
+}
+
+static inline void hci_chan_hash_add(struct hci_conn *c, struct hci_chan *chan)
+{
+	struct hci_chan_hash *h = &c->chan_hash;
+	list_add(&chan->list, &h->list);
+	h->num++;
+}
+
+static inline void hci_chan_hash_del(struct hci_conn *c, struct hci_chan *chan)
+{
+	struct hci_chan_hash *h = &c->chan_hash;
+	list_del(&chan->list);
+	h->num--;
+}
+
 void hci_acl_connect(struct hci_conn *conn);
 void hci_acl_disconn(struct hci_conn *conn, __u8 reason);
 void hci_add_sco(struct hci_conn *conn, __u16 handle);
@@ -480,6 +517,10 @@
 void hci_conn_hash_flush(struct hci_dev *hdev);
 void hci_conn_check_pending(struct hci_dev *hdev);
 
+struct hci_chan *hci_chan_create(struct hci_conn *conn);
+int hci_chan_del(struct hci_chan *chan);
+void hci_chan_hash_flush(struct hci_conn *conn);
+
 struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst,
 						__u8 sec_level, __u8 auth_type);
 int hci_conn_check_link_mode(struct hci_conn *conn);
@@ -849,7 +890,7 @@
 int hci_unregister_notifier(struct notifier_block *nb);
 
 int hci_send_cmd(struct hci_dev *hdev, __u16 opcode, __u32 plen, void *param);
-void hci_send_acl(struct hci_conn *conn, struct sk_buff *skb, __u16 flags);
+void hci_send_acl(struct hci_chan *chan, struct sk_buff *skb, __u16 flags);
 void hci_send_sco(struct hci_conn *conn, struct sk_buff *skb);
 
 void *hci_sent_cmd_data(struct hci_dev *hdev, __u16 opcode);
diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index c10bf1d..6ae9492 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -451,6 +451,7 @@
 
 struct l2cap_conn {
 	struct hci_conn	*hcon;
+	struct hci_chan	*hchan;
 
 	bdaddr_t	*dst;
 	bdaddr_t	*src;