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Viewing changes to include/linux/rwsem.h

  • Committer: Bazaar Package Importer
  • Author(s): Paolo Pisati
  • Date: 2011-06-29 15:23:51 UTC
  • mfrom: (26.1.1 natty-proposed)
  • Revision ID: james.westby@ubuntu.com-20110629152351-xs96tm303d95rpbk
Tags: 3.0.0-1200.2
* Rebased against 3.0.0-6.7
* BSP from TI based on 3.0.0

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include/linux/rwsem.h
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#include <linux/types.h>
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#include <linux/kernel.h>
 
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#include <linux/list.h>
 
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#include <linux/spinlock.h>
 
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#include <asm/system.h>
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#include <asm/atomic.h>
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#ifdef CONFIG_RWSEM_GENERIC_SPINLOCK
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#include <linux/rwsem-spinlock.h> /* use a generic implementation */
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#else
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#include <asm/rwsem.h> /* use an arch-specific implementation */
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#endif
 
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/* All arch specific implementations share the same struct */
 
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struct rw_semaphore {
 
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        long                    count;
 
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        spinlock_t              wait_lock;
 
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        struct list_head        wait_list;
 
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
 
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        struct lockdep_map      dep_map;
 
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#endif
 
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};
 
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extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
 
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extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
 
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extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *);
 
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extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
 
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/* Include the arch specific part */
 
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#include <asm/rwsem.h>
 
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/* In all implementations count != 0 means locked */
 
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static inline int rwsem_is_locked(struct rw_semaphore *sem)
 
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{
 
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        return sem->count != 0;
 
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}
 
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#endif
 
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/* Common initializer macros and functions */
 
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
 
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# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname }
 
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#else
 
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# define __RWSEM_DEP_MAP_INIT(lockname)
 
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#endif
 
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#define __RWSEM_INITIALIZER(name) \
 
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        { RWSEM_UNLOCKED_VALUE, __SPIN_LOCK_UNLOCKED(name.wait_lock),   \
 
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          LIST_HEAD_INIT((name).wait_list) __RWSEM_DEP_MAP_INIT(name) }
 
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#define DECLARE_RWSEM(name) \
 
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        struct rw_semaphore name = __RWSEM_INITIALIZER(name)
 
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extern void __init_rwsem(struct rw_semaphore *sem, const char *name,
 
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                         struct lock_class_key *key);
 
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#define init_rwsem(sem)                                         \
 
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do {                                                            \
 
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        static struct lock_class_key __key;                     \
 
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                                                                \
 
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        __init_rwsem((sem), #sem, &__key);                      \
 
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} while (0)
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/*
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 * lock for reading