[Copybara Auto Merge] Merge branch 'zuma' into 'android13-gs-pixel-5.15'

Initial commit for porting Zuma GXP drivers.

Bug: 239766974
GitOrigin-RevId: c3436b0c942dd009060c865c9b11d21b24de8d1b
Change-Id: Icf7b5fea1929c1786d2ed979460d5290c3a11f13

1 files changed, 53 insertions, 0 deletions

diff --git a/gxp-eventfd.h b/gxp-eventfd.h
new file mode 100644
index 0000000..6a23200
--- /dev/null
+++ b/gxp-eventfd.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * GXP eventfd
+ *
+ * Copyright (C) 2022 Google LLC
+ */
+#ifndef __GXP_EVENTFD_H__
+#define __GXP_EVENTFD_H__
+
+#include "gxp-internal.h"
+
+struct gxp_eventfd;
+
+/**
+ * gxp_eventfd_create() - Open and initialize an eventfd
+ * @fd: A file descriptor from user-space describing an eventfd
+ *
+ * If successful, the gxp_eventfd will be returned with a reference count of 1.
+ *
+ * Return: A pointer to the new gxp_eventfd or an ERR_PTR on failure
+ * * -ENOMEM: Insufficient memory to create the gxp_eventfd
+ * * other: Failed to obtain an eventfd from @fd
+ */
+struct gxp_eventfd *gxp_eventfd_create(int fd);
+
+/**
+ * gxp_eventfd_get() - Increment an existing gxp_eventfd's reference count
+ * @eventfd: The gxp_eventfd to get a reference to
+ *
+ * Return: true on success, false if the eventfd's reference count was already 0
+ */
+bool gxp_eventfd_get(struct gxp_eventfd *eventfd);
+
+/**
+ * gxp_eventfd_put() - Decrement an eventfd's reference count
+ * @eventfd: The gxp_eventfd to close a reference to, and potentially free
+ *
+ * If the reference count drops to 0, the @eventfd will be freed.
+ *
+ * Return: true if the reference count dropped to 0 and the gxp_eventfd was
+ *         released, otherwise false
+ */
+bool gxp_eventfd_put(struct gxp_eventfd *eventfd);
+
+/**
+ * gxp_eventfd_signal() - Signal an eventfd.
+ * @eventfd: The gxp_eventfd to signal
+ *
+ * Return: true on success, false if the gxp_eventfd had a reference count of 0
+ */
+bool gxp_eventfd_signal(struct gxp_eventfd *eventfd);
+
+#endif /* __GXP_EVENTFD_H__ */