Bluetooth: hci_sync: Add helper functions to manipulate cmd_sync queue

This adds functions to queue, dequeue and lookup into the cmd_sync
list.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

include/net/bluetooth/hci_sync.h

@@ -48,6 +48,18 @@ int hci_cmd_sync_submit(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
 			void *data, hci_cmd_sync_work_destroy_t destroy);
 int hci_cmd_sync_queue(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
 		       void *data, hci_cmd_sync_work_destroy_t destroy);
+struct hci_cmd_sync_work_entry *
+hci_cmd_sync_lookup_entry(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
+			  void *data, hci_cmd_sync_work_destroy_t destroy);
+int hci_cmd_sync_queue_once(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
+			    void *data, hci_cmd_sync_work_destroy_t destroy);
+void hci_cmd_sync_cancel_entry(struct hci_dev *hdev,
+			       struct hci_cmd_sync_work_entry *entry);
+bool hci_cmd_sync_dequeue(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
+			  void *data, hci_cmd_sync_work_destroy_t destroy);
+bool hci_cmd_sync_dequeue_once(struct hci_dev *hdev,
+			      hci_cmd_sync_work_func_t func, void *data,
+			      hci_cmd_sync_work_destroy_t destroy);
 
 int hci_update_eir_sync(struct hci_dev *hdev);
 int hci_update_class_sync(struct hci_dev *hdev);

net/bluetooth/hci_sync.c

@@ -566,6 +566,17 @@ void hci_cmd_sync_init(struct hci_dev *hdev)
 	INIT_DELAYED_WORK(&hdev->adv_instance_expire, adv_timeout_expire);
 }
 
+static void _hci_cmd_sync_cancel_entry(struct hci_dev *hdev,
+				       struct hci_cmd_sync_work_entry *entry,
+				       int err)
+{
+	if (entry->destroy)
+		entry->destroy(hdev, entry->data, err);
+
+	list_del(&entry->list);
+	kfree(entry);
+}
+
 void hci_cmd_sync_clear(struct hci_dev *hdev)
 {
 	struct hci_cmd_sync_work_entry *entry, *tmp;
@@ -574,13 +585,8 @@ void hci_cmd_sync_clear(struct hci_dev *hdev)
 	cancel_work_sync(&hdev->reenable_adv_work);
 
 	mutex_lock(&hdev->cmd_sync_work_lock);
-	list_for_each_entry_safe(entry, tmp, &hdev->cmd_sync_work_list, list) {
-		if (entry->destroy)
-			entry->destroy(hdev, entry->data, -ECANCELED);
-
-		list_del(&entry->list);
-		kfree(entry);
-	}
+	list_for_each_entry_safe(entry, tmp, &hdev->cmd_sync_work_list, list)
+		_hci_cmd_sync_cancel_entry(hdev, entry, -ECANCELED);
 	mutex_unlock(&hdev->cmd_sync_work_lock);
 }
 
@@ -669,6 +675,115 @@ int hci_cmd_sync_queue(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
 }
 EXPORT_SYMBOL(hci_cmd_sync_queue);
 
+static struct hci_cmd_sync_work_entry *
+_hci_cmd_sync_lookup_entry(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
+			   void *data, hci_cmd_sync_work_destroy_t destroy)
+{
+	struct hci_cmd_sync_work_entry *entry, *tmp;
+
+	list_for_each_entry_safe(entry, tmp, &hdev->cmd_sync_work_list, list) {
+		if (func && entry->func != func)
+			continue;
+
+		if (data && entry->data != data)
+			continue;
+
+		if (destroy && entry->destroy != destroy)
+			continue;
+
+		return entry;
+	}
+
+	return NULL;
+}
+
+/* Queue HCI command entry once:
+ *
+ * - Lookup if an entry already exist and only if it doesn't creates a new entry
+ *   and queue it.
+ */
+int hci_cmd_sync_queue_once(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
+			    void *data, hci_cmd_sync_work_destroy_t destroy)
+{
+	if (hci_cmd_sync_lookup_entry(hdev, func, data, destroy))
+		return 0;
+
+	return hci_cmd_sync_queue(hdev, func, data, destroy);
+}
+EXPORT_SYMBOL(hci_cmd_sync_queue_once);
+
+/* Lookup HCI command entry:
+ *
+ * - Return first entry that matches by function callback or data or
+ *   destroy callback.
+ */
+struct hci_cmd_sync_work_entry *
+hci_cmd_sync_lookup_entry(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
+			  void *data, hci_cmd_sync_work_destroy_t destroy)
+{
+	struct hci_cmd_sync_work_entry *entry;
+
+	mutex_lock(&hdev->cmd_sync_work_lock);
+	entry = _hci_cmd_sync_lookup_entry(hdev, func, data, destroy);
+	mutex_unlock(&hdev->cmd_sync_work_lock);
+
+	return entry;
+}
+EXPORT_SYMBOL(hci_cmd_sync_lookup_entry);
+
+/* Cancel HCI command entry */
+void hci_cmd_sync_cancel_entry(struct hci_dev *hdev,
+			       struct hci_cmd_sync_work_entry *entry)
+{
+	mutex_lock(&hdev->cmd_sync_work_lock);
+	_hci_cmd_sync_cancel_entry(hdev, entry, -ECANCELED);
+	mutex_unlock(&hdev->cmd_sync_work_lock);
+}
+EXPORT_SYMBOL(hci_cmd_sync_cancel_entry);
+
+/* Dequeue one HCI command entry:
+ *
+ * - Lookup and cancel first entry that matches.
+ */
+bool hci_cmd_sync_dequeue_once(struct hci_dev *hdev,
+			       hci_cmd_sync_work_func_t func,
+			       void *data, hci_cmd_sync_work_destroy_t destroy)
+{
+	struct hci_cmd_sync_work_entry *entry;
+
+	entry = hci_cmd_sync_lookup_entry(hdev, func, data, destroy);
+	if (!entry)
+		return false;
+
+	hci_cmd_sync_cancel_entry(hdev, entry);
+
+	return true;
+}
+EXPORT_SYMBOL(hci_cmd_sync_dequeue_once);
+
+/* Dequeue HCI command entry:
+ *
+ * - Lookup and cancel any entry that matches by function callback or data or
+ *   destroy callback.
+ */
+bool hci_cmd_sync_dequeue(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
+			  void *data, hci_cmd_sync_work_destroy_t destroy)
+{
+	struct hci_cmd_sync_work_entry *entry;
+	bool ret = false;
+
+	mutex_lock(&hdev->cmd_sync_work_lock);
+	while ((entry = _hci_cmd_sync_lookup_entry(hdev, func, data,
+						   destroy))) {
+		_hci_cmd_sync_cancel_entry(hdev, entry, -ECANCELED);
+		ret = true;
+	}
+	mutex_unlock(&hdev->cmd_sync_work_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(hci_cmd_sync_dequeue);
+
 int hci_update_eir_sync(struct hci_dev *hdev)
 {
 	struct hci_cp_write_eir cp;
@@ -2881,7 +2996,8 @@ int hci_update_passive_scan(struct hci_dev *hdev)
 	    hci_dev_test_flag(hdev, HCI_UNREGISTER))
 		return 0;
 
-	return hci_cmd_sync_queue(hdev, update_passive_scan_sync, NULL, NULL);
+	return hci_cmd_sync_queue_once(hdev, update_passive_scan_sync, NULL,
+				       NULL);
 }
 
 int hci_write_sc_support_sync(struct hci_dev *hdev, u8 val)