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> |
b5e683d5 JA |
15 | #include <linux/percpu-defs.h> |
16 | #include <linux/percpu.h> | |
b542e383 | 17 | #include <linux/sched.h> |
b087498e | 18 | |
bcd0b235 | 19 | /* |
1d730c49 | 20 | * CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining |
bcd0b235 DL |
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_SEMAPHORE (1 << 0) | |
b087498e | 27 | #define EFD_CLOEXEC O_CLOEXEC |
e7d476df | 28 | #define EFD_NONBLOCK O_NONBLOCK |
b087498e | 29 | |
bcd0b235 DL |
30 | #define EFD_SHARED_FCNTL_FLAGS (O_CLOEXEC | O_NONBLOCK) |
31 | #define EFD_FLAGS_SET (EFD_SHARED_FCNTL_FLAGS | EFD_SEMAPHORE) | |
32 | ||
105f2b70 | 33 | struct eventfd_ctx; |
4e10f3c9 AV |
34 | struct file; |
35 | ||
13389010 DL |
36 | #ifdef CONFIG_EVENTFD |
37 | ||
13389010 | 38 | void eventfd_ctx_put(struct eventfd_ctx *ctx); |
e1ad7468 | 39 | struct file *eventfd_fget(int fd); |
13389010 DL |
40 | struct eventfd_ctx *eventfd_ctx_fdget(int fd); |
41 | struct eventfd_ctx *eventfd_ctx_fileget(struct file *file); | |
ee62c6b2 | 42 | __u64 eventfd_signal(struct eventfd_ctx *ctx, __u64 n); |
03e02acd | 43 | __u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n, unsigned mask); |
ac6424b9 | 44 | int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *wait, |
cb289d62 | 45 | __u64 *cnt); |
28f13267 | 46 | void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt); |
e1ad7468 | 47 | |
b542e383 | 48 | static inline bool eventfd_signal_allowed(void) |
b5e683d5 | 49 | { |
9f0deaa1 | 50 | return !current->in_eventfd; |
b5e683d5 JA |
51 | } |
52 | ||
e1ad7468 DL |
53 | #else /* CONFIG_EVENTFD */ |
54 | ||
13389010 DL |
55 | /* |
56 | * Ugly ugly ugly error layer to support modules that uses eventfd but | |
57 | * pretend to work in !CONFIG_EVENTFD configurations. Namely, AIO. | |
58 | */ | |
562787a5 | 59 | |
13389010 DL |
60 | static inline struct eventfd_ctx *eventfd_ctx_fdget(int fd) |
61 | { | |
62 | return ERR_PTR(-ENOSYS); | |
63 | } | |
64 | ||
fd4e60bf | 65 | static inline int eventfd_signal(struct eventfd_ctx *ctx, __u64 n) |
13389010 DL |
66 | { |
67 | return -ENOSYS; | |
68 | } | |
69 | ||
03e02acd JA |
70 | static inline int eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n, |
71 | unsigned mask) | |
72 | { | |
73 | return -ENOSYS; | |
74 | } | |
75 | ||
13389010 DL |
76 | static inline void eventfd_ctx_put(struct eventfd_ctx *ctx) |
77 | { | |
78 | ||
79 | } | |
e1ad7468 | 80 | |
cb289d62 | 81 | static inline int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, |
ac6424b9 | 82 | wait_queue_entry_t *wait, __u64 *cnt) |
cb289d62 DL |
83 | { |
84 | return -ENOSYS; | |
85 | } | |
86 | ||
b542e383 | 87 | static inline bool eventfd_signal_allowed(void) |
b5e683d5 | 88 | { |
b542e383 | 89 | return true; |
b5e683d5 JA |
90 | } |
91 | ||
28f13267 DW |
92 | static inline void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt) |
93 | { | |
94 | ||
95 | } | |
96 | ||
13389010 | 97 | #endif |
e1ad7468 | 98 | |
e1ad7468 DL |
99 | #endif /* _LINUX_EVENTFD_H */ |
100 |