1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* |
3 | * include/linux/eventfd.h |
4 | * |
5 | * Copyright (C) 2007 Davide Libenzi <davidel@xmailserver.org> |
6 | * |
7 | */ |
8 | |
9 | #ifndef _LINUX_EVENTFD_H |
10 | #define _LINUX_EVENTFD_H |
11 | |
12 | #include <linux/wait.h> |
13 | #include <linux/err.h> |
14 | #include <linux/percpu-defs.h> |
15 | #include <linux/percpu.h> |
16 | #include <linux/sched.h> |
17 | #include <uapi/linux/eventfd.h> |
18 | |
19 | /* |
20 | * CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining |
21 | * new flags, since they might collide with O_* ones. We want |
22 | * to re-use O_* flags that couldn't possibly have a meaning |
23 | * from eventfd, in order to leave a free define-space for |
24 | * shared O_* flags. |
25 | */ |
26 | #define EFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK) |
27 | #define EFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS | EFD_SEMAPHORE) |
28 | |
29 | struct eventfd_ctx; |
30 | struct file; |
31 | |
32 | #ifdef CONFIG_EVENTFD |
33 | |
34 | void eventfd_ctx_put(struct eventfd_ctx *ctx); |
35 | struct file *eventfd_fget(int fd); |
36 | struct eventfd_ctx *eventfd_ctx_fdget(int fd); |
37 | struct eventfd_ctx *eventfd_ctx_fileget(struct file *file); |
38 | __u64 eventfd_signal(struct eventfd_ctx *ctx, __u64 n); |
39 | __u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n, __poll_t mask); |
40 | int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *wait, |
41 | __u64 *cnt); |
42 | void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt); |
43 | |
44 | static inline bool eventfd_signal_allowed(void) |
45 | { |
46 | return !current->in_eventfd; |
47 | } |
48 | |
49 | #else /* CONFIG_EVENTFD */ |
50 | |
51 | /* |
52 | * Ugly ugly ugly error layer to support modules that uses eventfd but |
53 | * pretend to work in !CONFIG_EVENTFD configurations. Namely, AIO. |
54 | */ |
55 | |
56 | static inline struct eventfd_ctx *eventfd_ctx_fdget(int fd) |
57 | { |
58 | return ERR_PTR(-ENOSYS); |
59 | } |
60 | |
61 | static inline int eventfd_signal(struct eventfd_ctx *ctx, __u64 n) |
62 | { |
63 | return -ENOSYS; |
64 | } |
65 | |
66 | static inline int eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n, |
67 | unsigned mask) |
68 | { |
69 | return -ENOSYS; |
70 | } |
71 | |
72 | static inline void eventfd_ctx_put(struct eventfd_ctx *ctx) |
73 | { |
74 | |
75 | } |
76 | |
77 | static inline int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, |
78 | wait_queue_entry_t *wait, __u64 *cnt) |
79 | { |
80 | return -ENOSYS; |
81 | } |
82 | |
83 | static inline bool eventfd_signal_allowed(void) |
84 | { |
85 | return true; |
86 | } |
87 | |
88 | static inline void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt) |
89 | { |
90 | |
91 | } |
92 | |
93 | #endif |
94 | |
95 | #endif /* _LINUX_EVENTFD_H */ |
96 | |
97 | |