Tools: Testbench: Fix notification pool memory leak

In capture direction testbench runs, pipeline_comp_copy() triggers
send_process_data_error_notif_msg() which allocates a notification
from the pool and queues it to the IPC message list via ipc_msg_send().
On Zephyr targets a work handler calls ipc_send_queued_msg() to process
the queue and invoke the free callback. In the testbench no such
handler exists, so queued notifications are never freed.

Add ipc_notification_pool_free() to notification_pool.c to release
all pool items. In tb_free(), drain the IPC message queue by calling
ipc_send_queued_msg() in a loop, then call ipc_notification_pool_free()
to free the pool before releasing IPC resources.

Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>

Author: singalsu

src/include/sof/ipc/notification_pool.h

@@ -23,4 +23,15 @@
  */
 struct ipc_msg *ipc_notification_pool_get(size_t size);
 
+#if CONFIG_LIBRARY
+/**
+ * @brief Frees all IPC notification messages in the pool.
+ *
+ * This function frees all notification messages currently held in
+ * the pool free list and resets the pool depth counter. It is
+ * required only in library (testbench) build.
+ */
+void ipc_notification_pool_free(void);
+#endif /* CONFIG_LIBRARY */
+
 #endif /* __SOF_IPC_NOTIFICATION_POOL_H__ */

src/ipc/notification_pool.c

@@ -100,3 +100,22 @@ struct ipc_msg *ipc_notification_pool_get(size_t size)
 	item->msg.tx_size = size;
 	return &item->msg;
 }
+
+#if CONFIG_LIBRARY
+void ipc_notification_pool_free(void)
+{
+	struct ipc_notif_pool_item *item;
+	k_spinlock_key_t key;
+
+	key = k_spin_lock(&pool_free_list_lock);
+	while (!list_is_empty(&pool_free_list)) {
+		item = list_first_item(&pool_free_list, struct ipc_notif_pool_item, msg.list);
+		list_item_del(&item->msg.list);
+		--pool_depth;
+		k_spin_unlock(&pool_free_list_lock, key);
+		rfree(item);
+		key = k_spin_lock(&pool_free_list_lock);
+	}
+	k_spin_unlock(&pool_free_list_lock, key);
+}
+#endif /* CONFIG_LIBRARY */

tools/testbench/utils.c

@@ -6,6 +6,8 @@
 #include <platform/lib/ll_schedule.h>
 #include <sof/audio/component.h>
 #include <sof/ipc/topology.h>
+#include <sof/ipc/msg.h>
+#include <sof/ipc/notification_pool.h>
 #include <sof/lib/notifier.h>
 
 #include <ctype.h>
@@ -211,6 +213,13 @@ void tb_free(struct sof *sof)
 	}
 	free(*arch_schedulers_get());
 
+	/* Drain IPC message queue to free queued notifications */
+	while (!list_is_empty(&sof->ipc->msg_list))
+		ipc_send_queued_msg();
+
+	/* Free notification pool items */
+	ipc_notification_pool_free();
+
 	/* free IPC data */
 	iipc = sof->ipc->private;
 	free(sof->ipc->comp_data);