/* 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/fcntl.h> #include <linux/wait.h> #include <linux/err.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 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); int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_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 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 int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *wait, __u64 *cnt) { return -ENOSYS; } #endif #endif /* _LINUX_EVENTFD_H */