1 files changed, 59 insertions, 0 deletions
diff --git a/sound/core/seq/seq_fifo.h b/sound/core/seq/seq_fifo.h
new file mode 100644
index 000000000..b56a7b897
--- /dev/null
+++ b/sound/core/seq/seq_fifo.h
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *   ALSA sequencer FIFO
+ *   Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
+ */
+#ifndef __SND_SEQ_FIFO_H
+#define __SND_SEQ_FIFO_H
+
+#include "seq_memory.h"
+#include "seq_lock.h"
+
+
+/* === FIFO === */
+
+struct snd_seq_fifo {
+	struct snd_seq_pool *pool;		/* FIFO pool */
+	struct snd_seq_event_cell *head;    	/* pointer to head of fifo */
+	struct snd_seq_event_cell *tail;    	/* pointer to tail of fifo */
+	int cells;
+	spinlock_t lock;
+	snd_use_lock_t use_lock;
+	wait_queue_head_t input_sleep;
+	atomic_t overflow;
+
+};
+
+/* create new fifo (constructor) */
+struct snd_seq_fifo *snd_seq_fifo_new(int poolsize);
+
+/* delete fifo (destructor) */
+void snd_seq_fifo_delete(struct snd_seq_fifo **f);
+
+
+/* enqueue event to fifo */
+int snd_seq_fifo_event_in(struct snd_seq_fifo *f, struct snd_seq_event *event);
+
+/* lock fifo from release */
+#define snd_seq_fifo_lock(fifo)		snd_use_lock_use(&(fifo)->use_lock)
+#define snd_seq_fifo_unlock(fifo)	snd_use_lock_free(&(fifo)->use_lock)
+
+/* get a cell from fifo - fifo should be locked */
+int snd_seq_fifo_cell_out(struct snd_seq_fifo *f, struct snd_seq_event_cell **cellp, int nonblock);
+
+/* free dequeued cell - fifo should be locked */
+void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f, struct snd_seq_event_cell *cell);
+
+/* clean up queue */
+void snd_seq_fifo_clear(struct snd_seq_fifo *f);
+
+/* polling */
+int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file, poll_table *wait);
+
+/* resize pool in fifo */
+int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize);
+
+/* get the number of unused cells safely */
+int snd_seq_fifo_unused_cells(struct snd_seq_fifo *f);
+
+#endif