diff options
author | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2013-07-27 22:15:01 +0000 |
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committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2013-07-27 22:15:01 +0000 |
commit | 7996a3d79d55b7f879dfd62e202bbfe2963718d3 (patch) | |
tree | 8d9f6759fec4099b9be503c11c7ed174f7204980 /libdde-linux26/contrib/include/linux/rwsem-spinlock.h | |
parent | 4fbe7358c7747a9165f776eb19addbb9baf7def2 (diff) |
really properly move files
Diffstat (limited to 'libdde-linux26/contrib/include/linux/rwsem-spinlock.h')
-rw-r--r-- | libdde-linux26/contrib/include/linux/rwsem-spinlock.h | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/libdde-linux26/contrib/include/linux/rwsem-spinlock.h b/libdde-linux26/contrib/include/linux/rwsem-spinlock.h new file mode 100644 index 00000000..6c3c0f6c --- /dev/null +++ b/libdde-linux26/contrib/include/linux/rwsem-spinlock.h @@ -0,0 +1,78 @@ +/* rwsem-spinlock.h: fallback C implementation + * + * Copyright (c) 2001 David Howells (dhowells@redhat.com). + * - Derived partially from ideas by Andrea Arcangeli <andrea@suse.de> + * - Derived also from comments by Linus + */ + +#ifndef _LINUX_RWSEM_SPINLOCK_H +#define _LINUX_RWSEM_SPINLOCK_H + +#ifndef _LINUX_RWSEM_H +#error "please don't include linux/rwsem-spinlock.h directly, use linux/rwsem.h instead" +#endif + +#include <linux/spinlock.h> +#include <linux/list.h> + +#ifdef __KERNEL__ + +#include <linux/types.h> + +struct rwsem_waiter; + +/* + * the rw-semaphore definition + * - if activity is 0 then there are no active readers or writers + * - if activity is +ve then that is the number of active readers + * - if activity is -1 then there is one active writer + * - if wait_list is not empty, then there are processes waiting for the semaphore + */ +struct rw_semaphore { + __s32 activity; + spinlock_t wait_lock; + struct list_head wait_list; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif +}; + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname } +#else +# define __RWSEM_DEP_MAP_INIT(lockname) +#endif + +#define __RWSEM_INITIALIZER(name) \ +{ 0, __SPIN_LOCK_UNLOCKED(name.wait_lock), LIST_HEAD_INIT((name).wait_list) \ + __RWSEM_DEP_MAP_INIT(name) } + +#define DECLARE_RWSEM(name) \ + struct rw_semaphore name = __RWSEM_INITIALIZER(name) + +extern void __init_rwsem(struct rw_semaphore *sem, const char *name, + struct lock_class_key *key); + +#define init_rwsem(sem) \ +do { \ + static struct lock_class_key __key; \ + \ + __init_rwsem((sem), #sem, &__key); \ +} while (0) + +extern void __down_read(struct rw_semaphore *sem); +extern int __down_read_trylock(struct rw_semaphore *sem); +extern void __down_write(struct rw_semaphore *sem); +extern void __down_write_nested(struct rw_semaphore *sem, int subclass); +extern int __down_write_trylock(struct rw_semaphore *sem); +extern void __up_read(struct rw_semaphore *sem); +extern void __up_write(struct rw_semaphore *sem); +extern void __downgrade_write(struct rw_semaphore *sem); + +static inline int rwsem_is_locked(struct rw_semaphore *sem) +{ + return (sem->activity != 0); +} + +#endif /* __KERNEL__ */ +#endif /* _LINUX_RWSEM_SPINLOCK_H */ |