1 files changed, 96 insertions, 0 deletions
diff --git a/include/linux/eventfd.h b/include/linux/eventfd.h
new file mode 100644
index 000000000..b9d83652c
--- /dev/null
+++ b/include/linux/eventfd.h
@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  include/linux/eventfd.h
+ *
+ *  Copyright (C) 2007  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#ifndef _LINUX_EVENTFD_H
+#define _LINUX_EVENTFD_H
+
+#include <linux/wait.h>
+#include <linux/err.h>
+#include <linux/percpu-defs.h>
+#include <linux/percpu.h>
+#include <linux/sched.h>
+#include <uapi/linux/eventfd.h>
+
+/*
+ * CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining
+ * new flags, since they might collide with O_* ones. We want
+ * to re-use O_* flags that couldn't possibly have a meaning
+ * from eventfd, in order to leave a free define-space for
+ * shared O_* flags.
+ */
+#define EFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)
+#define EFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS | EFD_SEMAPHORE)
+
+struct eventfd_ctx;
+struct file;
+
+#ifdef CONFIG_EVENTFD
+
+void eventfd_ctx_put(struct eventfd_ctx *ctx);
+struct file *eventfd_fget(int fd);
+struct eventfd_ctx *eventfd_ctx_fdget(int fd);
+struct eventfd_ctx *eventfd_ctx_fileget(struct file *file);
+__u64 eventfd_signal(struct eventfd_ctx *ctx, __u64 n);
+__u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n, __poll_t mask);
+int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *wait,
+				  __u64 *cnt);
+void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt);
+
+static inline bool eventfd_signal_allowed(void)
+{
+	return !current->in_eventfd;
+}
+
+#else /* CONFIG_EVENTFD */
+
+/*
+ * Ugly ugly ugly error layer to support modules that uses eventfd but
+ * pretend to work in !CONFIG_EVENTFD configurations. Namely, AIO.
+ */
+
+static inline struct eventfd_ctx *eventfd_ctx_fdget(int fd)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+static inline int eventfd_signal(struct eventfd_ctx *ctx, __u64 n)
+{
+	return -ENOSYS;
+}
+
+static inline int eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n,
+				      unsigned mask)
+{
+	return -ENOSYS;
+}
+
+static inline void eventfd_ctx_put(struct eventfd_ctx *ctx)
+{
+
+}
+
+static inline int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx,
+						wait_queue_entry_t *wait, __u64 *cnt)
+{
+	return -ENOSYS;
+}
+
+static inline bool eventfd_signal_allowed(void)
+{
+	return true;
+}
+
+static inline void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt)
+{
+
+}
+
+#endif
+
+#endif /* _LINUX_EVENTFD_H */
+