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author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2008-08-07 09:55:03 +0100 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2008-08-07 09:55:03 +0100 |
commit | 4fb8af10d0fd09372d52966b76922b9e82bbc950 (patch) | |
tree | d240e4d40357583e3f3eb228dccf20122a5b31ed /arch/sparc/include/asm/rwsem.h | |
parent | f44f82e8a20b98558486eb14497b2f71c78fa325 (diff) | |
parent | 64a99d2a8c3ed5c4e39f3ae1cc682aa8fd3977fc (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes
Diffstat (limited to 'arch/sparc/include/asm/rwsem.h')
-rw-r--r-- | arch/sparc/include/asm/rwsem.h | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/arch/sparc/include/asm/rwsem.h b/arch/sparc/include/asm/rwsem.h new file mode 100644 index 00000000000..1dc129ac2fe --- /dev/null +++ b/arch/sparc/include/asm/rwsem.h @@ -0,0 +1,84 @@ +/* + * rwsem.h: R/W semaphores implemented using CAS + * + * Written by David S. Miller (davem@redhat.com), 2001. + * Derived from asm-i386/rwsem.h + */ +#ifndef _SPARC64_RWSEM_H +#define _SPARC64_RWSEM_H + +#ifndef _LINUX_RWSEM_H +#error "please don't include asm/rwsem.h directly, use linux/rwsem.h instead" +#endif + +#ifdef __KERNEL__ + +#include <linux/list.h> +#include <linux/spinlock.h> +#include <asm/rwsem-const.h> + +struct rwsem_waiter; + +struct rw_semaphore { + signed int count; + 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) \ +{ RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, 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 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 void __down_write_nested(struct rw_semaphore *sem, int subclass) +{ + __down_write(sem); +} + +static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem) +{ + return atomic_add_return(delta, (atomic_t *)(&sem->count)); +} + +static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem) +{ + atomic_add(delta, (atomic_t *)(&sem->count)); +} + +static inline int rwsem_is_locked(struct rw_semaphore *sem) +{ + return (sem->count != 0); +} + +#endif /* __KERNEL__ */ + +#endif /* _SPARC64_RWSEM_H */ |