1 /* 2 * include/linux/eventfd.h 3 * 4 * Copyright (C) 2007 Davide Libenzi <[email protected]> 5 * 6 */ 7 8 #ifndef _LINUX_EVENTFD_H 9 #define _LINUX_EVENTFD_H 10 11 #include <linux/fcntl.h> 12 #include <linux/file.h> 13 14 /* 15 * CAREFUL: Check include/asm-generic/fcntl.h when defining 16 * new flags, since they might collide with O_* ones. We want 17 * to re-use O_* flags that couldn't possibly have a meaning 18 * from eventfd, in order to leave a free define-space for 19 * shared O_* flags. 20 */ 21 #define EFD_SEMAPHORE (1 << 0) 22 #define EFD_CLOEXEC O_CLOEXEC 23 #define EFD_NONBLOCK O_NONBLOCK 24 25 #define EFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK) 26 #define EFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS | EFD_SEMAPHORE) 27 28 #ifdef CONFIG_EVENTFD 29 30 struct eventfd_ctx *eventfd_ctx_get(struct eventfd_ctx *ctx); 31 void eventfd_ctx_put(struct eventfd_ctx *ctx); 32 struct file *eventfd_fget(int fd); 33 struct eventfd_ctx *eventfd_ctx_fdget(int fd); 34 struct eventfd_ctx *eventfd_ctx_fileget(struct file *file); 35 int eventfd_signal(struct eventfd_ctx *ctx, int n); 36 37 #else /* CONFIG_EVENTFD */ 38 39 /* 40 * Ugly ugly ugly error layer to support modules that uses eventfd but 41 * pretend to work in !CONFIG_EVENTFD configurations. Namely, AIO. 42 */ 43 static inline struct eventfd_ctx *eventfd_ctx_fdget(int fd) 44 { 45 return ERR_PTR(-ENOSYS); 46 } 47 48 static inline int eventfd_signal(struct eventfd_ctx *ctx, int n) 49 { 50 return -ENOSYS; 51 } 52 53 static inline void eventfd_ctx_put(struct eventfd_ctx *ctx) 54 { 55 56 } 57 58 #endif 59 60 #endif /* _LINUX_EVENTFD_H */ 61 62