diff options
| author | Davide Libenzi <davidel@xmailserver.org> | 2010-01-13 09:34:36 -0800 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2010-01-25 12:26:38 -0200 |
| commit | cb289d6244a37cf932c571d6deb0daa8030f931b (patch) | |
| tree | 05bea15a25c9d9a4dcc0658a6a8bf845daca535a /include/linux | |
| parent | a6085fbaf65ab09bfb5ec8d902d6d21680fe1895 (diff) | |
eventfd - allow atomic read and waitqueue remove
KVM needs a wait to atomically remove themselves from the eventfd ->poll()
wait queue head, in order to handle correctly their IRQfd deassign
operation.
This patch introduces such API, plus a way to read an eventfd from its
context.
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/eventfd.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/include/linux/eventfd.h b/include/linux/eventfd.h index 94dd10366a7..91bb4f27238 100644 --- a/include/linux/eventfd.h +++ b/include/linux/eventfd.h @@ -10,6 +10,7 @@ #include <linux/fcntl.h> #include <linux/file.h> +#include <linux/wait.h> /* * CAREFUL: Check include/asm-generic/fcntl.h when defining @@ -34,6 +35,9 @@ struct file *eventfd_fget(int fd); struct eventfd_ctx *eventfd_ctx_fdget(int fd); struct eventfd_ctx *eventfd_ctx_fileget(struct file *file); int eventfd_signal(struct eventfd_ctx *ctx, int n); +ssize_t eventfd_ctx_read(struct eventfd_ctx *ctx, int no_wait, __u64 *cnt); +int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_t *wait, + __u64 *cnt); #else /* CONFIG_EVENTFD */ @@ -61,6 +65,18 @@ static inline void eventfd_ctx_put(struct eventfd_ctx *ctx) } +static inline ssize_t eventfd_ctx_read(struct eventfd_ctx *ctx, int no_wait, + __u64 *cnt) +{ + return -ENOSYS; +} + +static inline int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, + wait_queue_t *wait, __u64 *cnt) +{ + return -ENOSYS; +} + #endif #endif /* _LINUX_EVENTFD_H */ |