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From:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
To:     linux-bluetooth@vger.kernel.org
Subject: [RFC] Bluetooth: hci_sync: Add hci_cmd_sync_queue_once
Date:   Wed,  9 Aug 2023 14:39:16 -0700
Message-ID: <20230809213916.1636311-1-luiz.dentz@gmail.com>
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From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

This adds hci_cmd_sync_queue_once which can be used for callback that
shall be schedule only once.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
 include/net/bluetooth/hci_sync.h |  5 +++
 net/bluetooth/hci_sync.c         | 56 +++++++++++++++++++++++++++-----
 2 files changed, 53 insertions(+), 8 deletions(-)

diff --git a/include/net/bluetooth/hci_sync.h b/include/net/bluetooth/hci_sync.h
index 57eeb07aeb25..3d2ffcb6c461 100644
--- a/include/net/bluetooth/hci_sync.h
+++ b/include/net/bluetooth/hci_sync.h
@@ -48,6 +48,11 @@ 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);
+bool hci_cmd_sync_lookup(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
+			 void *data, hci_cmd_sync_work_destroy_t destroy,
+			 bool cancel);
+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);
 
 int hci_update_eir_sync(struct hci_dev *hdev);
 int hci_update_class_sync(struct hci_dev *hdev);
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index 5eb30ba21370..32fa9006f381 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -639,6 +639,17 @@ 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;
@@ -647,13 +658,8 @@ 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);
 }
 
@@ -740,6 +746,39 @@ int hci_cmd_sync_queue(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
 }
 EXPORT_SYMBOL(hci_cmd_sync_queue);
 
+bool hci_cmd_sync_lookup(struct hci_dev *hdev, hci_cmd_sync_work_func_t func,
+			 void *data, hci_cmd_sync_work_destroy_t destroy,
+			 bool cancel)
+{
+	struct hci_cmd_sync_work_entry *entry, *tmp;
+
+	mutex_lock(&hdev->cmd_sync_work_lock);
+	list_for_each_entry_safe(entry, tmp, &hdev->cmd_sync_work_list, list) {
+		if (entry->func == func && entry->data == data &&
+		    entry->destroy == destroy) {
+			if (cancel)
+				_hci_cmd_sync_cancel_entry(hdev, entry,
+							   -ECANCELED);
+			mutex_unlock(&hdev->cmd_sync_work_lock);
+			return true;
+		}
+	}
+	mutex_unlock(&hdev->cmd_sync_work_lock);
+
+	return false;
+}
+EXPORT_SYMBOL(hci_cmd_sync_pending);
+
+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(hdev, func, data, destroy, false))
+		return 0;
+
+	return hci_cmd_sync_queue(hdev, func, data, destroy);
+}
+EXPORT_SYMBOL(hci_cmd_sync_queue_once);
+
 int hci_update_eir_sync(struct hci_dev *hdev)
 {
 	struct hci_cp_write_eir cp;
@@ -2949,7 +2988,8 @@ 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)
-- 
2.41.0