1 files changed, 84 insertions, 0 deletions
diff --git a/kernel/include/linux/eventfd.h b/kernel/include/linux/eventfd.h
new file mode 100644
index 000000000..ff0b981f0
--- /dev/null
+++ b/kernel/include/linux/eventfd.h
@@ -0,0 +1,84 @@
+/*
+ *  include/linux/eventfd.h
+ *
+ *  Copyright (C) 2007  Davide Libenzi <davidel@xmailserver.org>
+ *
+ */
+
+#ifndef _LINUX_EVENTFD_H
+#define _LINUX_EVENTFD_H
+
+#include <linux/fcntl.h>
+#include <linux/wait.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_SEMAPHORE (1 << 0)
+#define EFD_CLOEXEC O_CLOEXEC
+#define EFD_NONBLOCK O_NONBLOCK
+
+#define EFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK)
+#define EFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS | EFD_SEMAPHORE)
+
+struct file;
+
+#ifdef CONFIG_EVENTFD
+
+struct file *eventfd_file_create(unsigned int count, int flags);
+struct eventfd_ctx *eventfd_ctx_get(struct eventfd_ctx *ctx);
+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);
+ssize_t eventfd_ctx_read(struct eventfd_ctx *ctx, int no_wait, __u64 *cnt);
+int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_t *wait,
+				  __u64 *cnt);
+
+#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 file *eventfd_file_create(unsigned int count, int flags)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+static inline struct eventfd_ctx *eventfd_ctx_fdget(int fd)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+static inline int eventfd_signal(struct eventfd_ctx *ctx, int n)
+{
+	return -ENOSYS;
+}
+
+static inline void eventfd_ctx_put(struct eventfd_ctx *ctx)
+{
+
+}
+
+static inline ssize_t eventfd_ctx_read(struct eventfd_ctx *ctx, int no_wait,
+				       __u64 *cnt)
+{
+	return -ENOSYS;
+}
+
+static inline int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx,
+						wait_queue_t *wait, __u64 *cnt)
+{
+	return -ENOSYS;
+}
+
+#endif
+
+#endif /* _LINUX_EVENTFD_H */
+