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/**************************************************************************
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* Copyright (c) 2007-2009 VMware, Inc., Palo Alto, CA., USA
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sub license, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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* The above copyright notice and this permission notice (including the
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* next paragraph) shall be included in all copies or substantial portions
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
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* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
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* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
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* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
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* USE OR OTHER DEALINGS IN THE SOFTWARE.
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**************************************************************************/
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* Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
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#include "ttm/ttm_lock.h"
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#include "ttm/ttm_module.h"
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#include <asm/atomic.h>
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#include <linux/errno.h>
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#include <linux/wait.h>
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#include <linux/sched.h>
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#include <linux/module.h>
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#define TTM_WRITE_LOCK_PENDING (1 << 0)
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#define TTM_VT_LOCK_PENDING (1 << 1)
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#define TTM_SUSPEND_LOCK_PENDING (1 << 2)
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#define TTM_VT_LOCK (1 << 3)
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#define TTM_SUSPEND_LOCK (1 << 4)
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void ttm_lock_init(struct ttm_lock *lock)
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spin_lock_init(&lock->lock);
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init_waitqueue_head(&lock->queue);
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lock->kill_takers = false;
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lock->signal = SIGKILL;
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EXPORT_SYMBOL(ttm_lock_init);
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void ttm_read_unlock(struct ttm_lock *lock)
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spin_lock(&lock->lock);
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wake_up_all(&lock->queue);
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spin_unlock(&lock->lock);
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EXPORT_SYMBOL(ttm_read_unlock);
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static bool __ttm_read_lock(struct ttm_lock *lock)
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spin_lock(&lock->lock);
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if (unlikely(lock->kill_takers)) {
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send_sig(lock->signal, current, 0);
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spin_unlock(&lock->lock);
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if (lock->rw >= 0 && lock->flags == 0) {
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spin_unlock(&lock->lock);
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int ttm_read_lock(struct ttm_lock *lock, bool interruptible)
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ret = wait_event_interruptible(lock->queue,
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__ttm_read_lock(lock));
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wait_event(lock->queue, __ttm_read_lock(lock));
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EXPORT_SYMBOL(ttm_read_lock);
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static bool __ttm_read_trylock(struct ttm_lock *lock, bool *locked)
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spin_lock(&lock->lock);
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if (unlikely(lock->kill_takers)) {
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send_sig(lock->signal, current, 0);
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spin_unlock(&lock->lock);
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if (lock->rw >= 0 && lock->flags == 0) {
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} else if (lock->flags == 0) {
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spin_unlock(&lock->lock);
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int ttm_read_trylock(struct ttm_lock *lock, bool interruptible)
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ret = wait_event_interruptible
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(lock->queue, __ttm_read_trylock(lock, &locked));
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wait_event(lock->queue, __ttm_read_trylock(lock, &locked));
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if (unlikely(ret != 0)) {
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return (locked) ? 0 : -EBUSY;
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void ttm_write_unlock(struct ttm_lock *lock)
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spin_lock(&lock->lock);
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wake_up_all(&lock->queue);
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spin_unlock(&lock->lock);
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EXPORT_SYMBOL(ttm_write_unlock);
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static bool __ttm_write_lock(struct ttm_lock *lock)
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spin_lock(&lock->lock);
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if (unlikely(lock->kill_takers)) {
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send_sig(lock->signal, current, 0);
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spin_unlock(&lock->lock);
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if (lock->rw == 0 && ((lock->flags & ~TTM_WRITE_LOCK_PENDING) == 0)) {
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lock->flags &= ~TTM_WRITE_LOCK_PENDING;
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lock->flags |= TTM_WRITE_LOCK_PENDING;
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spin_unlock(&lock->lock);
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int ttm_write_lock(struct ttm_lock *lock, bool interruptible)
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ret = wait_event_interruptible(lock->queue,
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__ttm_write_lock(lock));
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if (unlikely(ret != 0)) {
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spin_lock(&lock->lock);
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lock->flags &= ~TTM_WRITE_LOCK_PENDING;
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wake_up_all(&lock->queue);
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spin_unlock(&lock->lock);
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wait_event(lock->queue, __ttm_read_lock(lock));
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EXPORT_SYMBOL(ttm_write_lock);
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void ttm_write_lock_downgrade(struct ttm_lock *lock)
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spin_lock(&lock->lock);
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wake_up_all(&lock->queue);
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spin_unlock(&lock->lock);
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static int __ttm_vt_unlock(struct ttm_lock *lock)
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spin_lock(&lock->lock);
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if (unlikely(!(lock->flags & TTM_VT_LOCK)))
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lock->flags &= ~TTM_VT_LOCK;
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wake_up_all(&lock->queue);
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spin_unlock(&lock->lock);
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printk(KERN_INFO TTM_PFX "vt unlock.\n");
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static void ttm_vt_lock_remove(struct ttm_base_object **p_base)
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struct ttm_base_object *base = *p_base;
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struct ttm_lock *lock = container_of(base, struct ttm_lock, base);
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ret = __ttm_vt_unlock(lock);
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static bool __ttm_vt_lock(struct ttm_lock *lock)
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spin_lock(&lock->lock);
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lock->flags &= ~TTM_VT_LOCK_PENDING;
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lock->flags |= TTM_VT_LOCK;
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lock->flags |= TTM_VT_LOCK_PENDING;
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spin_unlock(&lock->lock);
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int ttm_vt_lock(struct ttm_lock *lock,
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struct ttm_object_file *tfile)
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ret = wait_event_interruptible(lock->queue,
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__ttm_vt_lock(lock));
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if (unlikely(ret != 0)) {
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spin_lock(&lock->lock);
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lock->flags &= ~TTM_VT_LOCK_PENDING;
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wake_up_all(&lock->queue);
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spin_unlock(&lock->lock);
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wait_event(lock->queue, __ttm_vt_lock(lock));
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* Add a base-object, the destructor of which will
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* make sure the lock is released if the client dies
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ret = ttm_base_object_init(tfile, &lock->base, false,
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ttm_lock_type, &ttm_vt_lock_remove, NULL);
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(void)__ttm_vt_unlock(lock);
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lock->vt_holder = tfile;
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printk(KERN_INFO TTM_PFX "vt lock.\n");
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EXPORT_SYMBOL(ttm_vt_lock);
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int ttm_vt_unlock(struct ttm_lock *lock)
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return ttm_ref_object_base_unref(lock->vt_holder,
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lock->base.hash.key, TTM_REF_USAGE);
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EXPORT_SYMBOL(ttm_vt_unlock);
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void ttm_suspend_unlock(struct ttm_lock *lock)
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spin_lock(&lock->lock);
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lock->flags &= ~TTM_SUSPEND_LOCK;
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wake_up_all(&lock->queue);
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spin_unlock(&lock->lock);
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EXPORT_SYMBOL(ttm_suspend_unlock);
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static bool __ttm_suspend_lock(struct ttm_lock *lock)
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spin_lock(&lock->lock);
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lock->flags &= ~TTM_SUSPEND_LOCK_PENDING;
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lock->flags |= TTM_SUSPEND_LOCK;
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lock->flags |= TTM_SUSPEND_LOCK_PENDING;
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spin_unlock(&lock->lock);
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void ttm_suspend_lock(struct ttm_lock *lock)
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wait_event(lock->queue, __ttm_suspend_lock(lock));
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EXPORT_SYMBOL(ttm_suspend_lock);
added
removed
updates/nouveau/ttm/ttm_lock.c
