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