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Viewing changes to arch/xtensa/include/asm/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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arch/xtensa/include/asm/rwsem.h
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#error "Please don't include <asm/rwsem.h> directly, use <linux/rwsem.h> instead."
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#endif
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#include <linux/list.h>
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#include <linux/spinlock.h>
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#include <asm/atomic.h>
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#include <asm/system.h>
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/*
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 * the semaphore definition
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 */
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struct rw_semaphore {
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        signed long             count;
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#define RWSEM_UNLOCKED_VALUE            0x00000000
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#define RWSEM_ACTIVE_BIAS               0x00000001
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#define RWSEM_ACTIVE_MASK               0x0000ffff
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#define RWSEM_WAITING_BIAS              (-0x00010000)
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#define RWSEM_ACTIVE_READ_BIAS          RWSEM_ACTIVE_BIAS
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#define RWSEM_ACTIVE_WRITE_BIAS         (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
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        spinlock_t              wait_lock;
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        struct list_head        wait_list;
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};
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#define __RWSEM_INITIALIZER(name) \
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        { RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, \
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          LIST_HEAD_INIT((name).wait_list) }
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#define DECLARE_RWSEM(name)             \
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        struct rw_semaphore name = __RWSEM_INITIALIZER(name)
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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 *sem);
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extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
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static inline void init_rwsem(struct rw_semaphore *sem)
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{
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        sem->count = RWSEM_UNLOCKED_VALUE;
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        spin_lock_init(&sem->wait_lock);
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        INIT_LIST_HEAD(&sem->wait_list);
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}
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/*
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 * lock for reading
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        return atomic_add_return(delta, (atomic_t *)(&sem->count));
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}
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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  /* _XTENSA_RWSEM_H */