diff options
Diffstat (limited to 'include/linux/tty_ldisc.h')
| -rw-r--r-- | include/linux/tty_ldisc.h | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h index 58390c73df8b..7b24bbd85ea8 100644 --- a/include/linux/tty_ldisc.h +++ b/include/linux/tty_ldisc.h @@ -110,6 +110,52 @@ #include <linux/wait.h> #include <linux/wait.h> + +/* + * the semaphore definition + */ +struct ld_semaphore { + long count; + raw_spinlock_t wait_lock; + unsigned int wait_readers; + struct list_head read_wait; + struct list_head write_wait; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif +}; + +extern void __init_ldsem(struct ld_semaphore *sem, const char *name, + struct lock_class_key *key); + +#define init_ldsem(sem) \ +do { \ + static struct lock_class_key __key; \ + \ + __init_ldsem((sem), #sem, &__key); \ +} while (0) + + +extern int ldsem_down_read(struct ld_semaphore *sem, long timeout); +extern int ldsem_down_read_trylock(struct ld_semaphore *sem); +extern int ldsem_down_write(struct ld_semaphore *sem, long timeout); +extern int ldsem_down_write_trylock(struct ld_semaphore *sem); +extern void ldsem_up_read(struct ld_semaphore *sem); +extern void ldsem_up_write(struct ld_semaphore *sem); + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +extern int ldsem_down_read_nested(struct ld_semaphore *sem, int subclass, + long timeout); +extern int ldsem_down_write_nested(struct ld_semaphore *sem, int subclass, + long timeout); +#else +# define ldsem_down_read_nested(sem, subclass, timeout) \ + ldsem_down_read(sem, timeout) +# define ldsem_down_write_nested(sem, subclass, timeout) \ + ldsem_down_write(sem, timeout) +#endif + + struct tty_ldisc_ops { int magic; char *name; |