Commit | Line | Data |
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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
e1ad7468 DL |
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 | ||
b087498e | 12 | #include <linux/fcntl.h> |
cb289d62 | 13 | #include <linux/wait.h> |
fa3fc2ad | 14 | #include <linux/err.h> |
b087498e | 15 | |
bcd0b235 | 16 | /* |
1d730c49 | 17 | * CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining |
bcd0b235 DL |
18 | * new flags, since they might collide with O_* ones. We want |
19 | * to re-use O_* flags that couldn't possibly have a meaning | |
20 | * from eventfd, in order to leave a free define-space for | |
21 | * shared O_* flags. | |
22 | */ | |
23 | #define EFD_SEMAPHORE (1 << 0) | |
b087498e | 24 | #define EFD_CLOEXEC O_CLOEXEC |
e7d476df | 25 | #define EFD_NONBLOCK O_NONBLOCK |
b087498e | 26 | |
bcd0b235 DL |
27 | #define EFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK) |
28 | #define EFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS | EFD_SEMAPHORE) | |
29 | ||
105f2b70 | 30 | struct eventfd_ctx; |
4e10f3c9 AV |
31 | struct file; |
32 | ||
13389010 DL |
33 | #ifdef CONFIG_EVENTFD |
34 | ||
13389010 | 35 | void eventfd_ctx_put(struct eventfd_ctx *ctx); |
e1ad7468 | 36 | struct file *eventfd_fget(int fd); |
13389010 DL |
37 | struct eventfd_ctx *eventfd_ctx_fdget(int fd); |
38 | struct eventfd_ctx *eventfd_ctx_fileget(struct file *file); | |
ee62c6b2 | 39 | __u64 eventfd_signal(struct eventfd_ctx *ctx, __u64 n); |
ac6424b9 | 40 | int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *wait, |
cb289d62 | 41 | __u64 *cnt); |
e1ad7468 DL |
42 | |
43 | #else /* CONFIG_EVENTFD */ | |
44 | ||
13389010 DL |
45 | /* |
46 | * Ugly ugly ugly error layer to support modules that uses eventfd but | |
47 | * pretend to work in !CONFIG_EVENTFD configurations. Namely, AIO. | |
48 | */ | |
562787a5 | 49 | |
13389010 DL |
50 | static inline struct eventfd_ctx *eventfd_ctx_fdget(int fd) |
51 | { | |
52 | return ERR_PTR(-ENOSYS); | |
53 | } | |
54 | ||
55 | static inline int eventfd_signal(struct eventfd_ctx *ctx, int n) | |
56 | { | |
57 | return -ENOSYS; | |
58 | } | |
59 | ||
60 | static inline void eventfd_ctx_put(struct eventfd_ctx *ctx) | |
61 | { | |
62 | ||
63 | } | |
e1ad7468 | 64 | |
cb289d62 | 65 | static inline int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, |
ac6424b9 | 66 | wait_queue_entry_t *wait, __u64 *cnt) |
cb289d62 DL |
67 | { |
68 | return -ENOSYS; | |
69 | } | |
70 | ||
13389010 | 71 | #endif |
e1ad7468 | 72 | |
e1ad7468 DL |
73 | #endif /* _LINUX_EVENTFD_H */ |
74 |