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 file *eventfd_file_create(unsigned int count, int flags); 31 struct eventfd_ctx *eventfd_ctx_get(struct eventfd_ctx *ctx); 32 void eventfd_ctx_put(struct eventfd_ctx *ctx); 33 struct file *eventfd_fget(int fd); 34 struct eventfd_ctx *eventfd_ctx_fdget(int fd); 35 struct eventfd_ctx *eventfd_ctx_fileget(struct file *file); 36 int eventfd_signal(struct eventfd_ctx *ctx, int n); 37 38 #else /* CONFIG_EVENTFD */ 39 40 /* 41 * Ugly ugly ugly error layer to support modules that uses eventfd but 42 * pretend to work in !CONFIG_EVENTFD configurations. Namely, AIO. 43 */ 44 static inline struct file *eventfd_file_create(unsigned int count, int flags) 45 { 46 return ERR_PTR(-ENOSYS); 47 } 48 49 static inline struct eventfd_ctx *eventfd_ctx_fdget(int fd) 50 { 51 return ERR_PTR(-ENOSYS); 52 } 53 54 static inline int eventfd_signal(struct eventfd_ctx *ctx, int n) 55 { 56 return -ENOSYS; 57 } 58 59 static inline void eventfd_ctx_put(struct eventfd_ctx *ctx) 60 { 61 62 } 63 64 #endif 65 66 #endif /* _LINUX_EVENTFD_H */ 67 68