ttm_lock.h

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 *
 * Copyright (c) 2007-2009 VMware, Inc., Palo Alto, CA., USA
 * All Rights Reserved.
 *
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/*
 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
 */

#ifndef _TTM_LOCK_H_
#define _TTM_LOCK_H_

#include <ttm/ttm_object.h>
#include <linux/wait.h>
#include <linux/atomic.h>

struct ttm_lock {
    struct ttm_base_object base;
    wait_queue_head_t queue;
    spinlock_t lock;
    int32_t rw;
    uint32_t flags;
    bool kill_takers;
    int signal;
    struct ttm_object_file *vt_holder;
};


extern void ttm_lock_init(struct ttm_lock *lock);

extern void ttm_read_unlock(struct ttm_lock *lock);

extern int ttm_read_lock(struct ttm_lock *lock, bool interruptible);

extern int ttm_read_trylock(struct ttm_lock *lock, bool interruptible);

extern void ttm_write_unlock(struct ttm_lock *lock);

extern int ttm_write_lock(struct ttm_lock *lock, bool interruptible);

extern void ttm_lock_downgrade(struct ttm_lock *lock);

extern void ttm_suspend_lock(struct ttm_lock *lock);

extern void ttm_suspend_unlock(struct ttm_lock *lock);

extern int ttm_vt_lock(struct ttm_lock *lock, bool interruptible,
               struct ttm_object_file *tfile);

extern int ttm_vt_unlock(struct ttm_lock *lock);

extern void ttm_write_unlock(struct ttm_lock *lock);

extern int ttm_write_lock(struct ttm_lock *lock, bool interruptible);

static inline void ttm_lock_set_kill(struct ttm_lock *lock, bool val,
                     int signal)
{
    lock->kill_takers = val;
    if (val)
        lock->signal = signal;
}

#endif