Bluetooth: Add request cmd_complete and cmd_status functions

This patch introduces functions to process the HCI request state when
receiving HCI Command Status or Command Complete events. Some HCI
commands, like Inquiry do not result in a Command complete event so
special handling is needed for them. Inquiry is a particularly important
one since it is the only forseeable "non-cmd_complete" command that will
make good use of the request functionality, and its completion is either
indicated by an Inquiry Complete event of a successful Command Complete
for HCI_Inquiry_Cancel.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 4f8142b..0ada2ec 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3208,6 +3208,91 @@
 	kfree_skb(skb);
 }
 
+static bool hci_req_is_complete(struct hci_dev *hdev)
+{
+	struct sk_buff *skb;
+
+	skb = skb_peek(&hdev->cmd_q);
+	if (!skb)
+		return true;
+
+	return bt_cb(skb)->req.start;
+}
+
+void hci_req_cmd_complete(struct hci_dev *hdev, u16 opcode, u8 status)
+{
+	hci_req_complete_t req_complete = NULL;
+	struct sk_buff *skb;
+	unsigned long flags;
+
+	BT_DBG("opcode 0x%04x status 0x%02x", opcode, status);
+
+	/* Check that the completed command really matches the last one
+	 * that was sent.
+	 */
+	if (!hci_sent_cmd_data(hdev, opcode))
+		return;
+
+	/* If the command succeeded and there's still more commands in
+	 * this request the request is not yet complete.
+	 */
+	if (!status && !hci_req_is_complete(hdev))
+		return;
+
+	/* If this was the last command in a request the complete
+	 * callback would be found in hdev->sent_cmd instead of the
+	 * command queue (hdev->cmd_q).
+	 */
+	if (hdev->sent_cmd) {
+		req_complete = bt_cb(hdev->sent_cmd)->req.complete;
+		if (req_complete)
+			goto call_complete;
+	}
+
+	/* Remove all pending commands belonging to this request */
+	spin_lock_irqsave(&hdev->cmd_q.lock, flags);
+	while ((skb = __skb_dequeue(&hdev->cmd_q))) {
+		if (bt_cb(skb)->req.start) {
+			__skb_queue_head(&hdev->cmd_q, skb);
+			break;
+		}
+
+		req_complete = bt_cb(skb)->req.complete;
+		kfree_skb(skb);
+	}
+	spin_unlock_irqrestore(&hdev->cmd_q.lock, flags);
+
+call_complete:
+	if (req_complete)
+		req_complete(hdev, status);
+}
+
+void hci_req_cmd_status(struct hci_dev *hdev, u16 opcode, u8 status)
+{
+	hci_req_complete_t req_complete = NULL;
+
+	BT_DBG("opcode 0x%04x status 0x%02x", opcode, status);
+
+	if (status) {
+		hci_req_cmd_complete(hdev, opcode, status);
+		return;
+	}
+
+	/* No need to handle success status if there are more commands */
+	if (!hci_req_is_complete(hdev))
+		return;
+
+	if (hdev->sent_cmd)
+		req_complete = bt_cb(hdev->sent_cmd)->req.complete;
+
+	/* If the request doesn't have a complete callback or there
+	 * are other commands/requests in the hdev queue we consider
+	 * this request as completed.
+	 */
+	if (!req_complete || !skb_queue_empty(&hdev->cmd_q))
+		hci_req_cmd_complete(hdev, opcode, status);
+}
+
 static void hci_rx_work(struct work_struct *work)
 {
 	struct hci_dev *hdev = container_of(work, struct hci_dev, rx_work);