diff options
Diffstat (limited to 'drivers/char/drm/drm_lock.c')
| -rw-r--r-- | drivers/char/drm/drm_lock.c | 391 |
1 files changed, 0 insertions, 391 deletions
diff --git a/drivers/char/drm/drm_lock.c b/drivers/char/drm/drm_lock.c deleted file mode 100644 index 0998723cde7..00000000000 --- a/drivers/char/drm/drm_lock.c +++ /dev/null @@ -1,391 +0,0 @@ -/** - * \file drm_lock.c - * IOCTLs for locking - * - * \author Rickard E. (Rik) Faith <faith@valinux.com> - * \author Gareth Hughes <gareth@valinux.com> - */ - -/* - * Created: Tue Feb 2 08:37:54 1999 by faith@valinux.com - * - * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas. - * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. - * All Rights Reserved. - * - * Permission is hereby granted, free of charge, to any person obtaining a - * copy of this software and associated documentation files (the "Software"), - * to deal in the Software without restriction, including without limitation - * the rights to use, copy, modify, merge, publish, distribute, sublicense, - * and/or sell copies of the Software, and to permit persons to whom the - * Software is furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice (including the next - * paragraph) shall be included in all copies or substantial portions of the - * Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL - * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR - * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, - * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR - * OTHER DEALINGS IN THE SOFTWARE. - */ - -#include "drmP.h" - -static int drm_notifier(void *priv); - -/** - * Lock ioctl. - * - * \param inode device inode. - * \param file_priv DRM file private. - * \param cmd command. - * \param arg user argument, pointing to a drm_lock structure. - * \return zero on success or negative number on failure. - * - * Add the current task to the lock wait queue, and attempt to take to lock. - */ -int drm_lock(struct drm_device *dev, void *data, struct drm_file *file_priv) -{ - DECLARE_WAITQUEUE(entry, current); - struct drm_lock *lock = data; - int ret = 0; - - ++file_priv->lock_count; - - if (lock->context == DRM_KERNEL_CONTEXT) { - DRM_ERROR("Process %d using kernel context %d\n", - task_pid_nr(current), lock->context); - return -EINVAL; - } - - DRM_DEBUG("%d (pid %d) requests lock (0x%08x), flags = 0x%08x\n", - lock->context, task_pid_nr(current), - dev->lock.hw_lock->lock, lock->flags); - - if (drm_core_check_feature(dev, DRIVER_DMA_QUEUE)) - if (lock->context < 0) - return -EINVAL; - - add_wait_queue(&dev->lock.lock_queue, &entry); - spin_lock_bh(&dev->lock.spinlock); - dev->lock.user_waiters++; - spin_unlock_bh(&dev->lock.spinlock); - for (;;) { - __set_current_state(TASK_INTERRUPTIBLE); - if (!dev->lock.hw_lock) { - /* Device has been unregistered */ - ret = -EINTR; - break; - } - if (drm_lock_take(&dev->lock, lock->context)) { - dev->lock.file_priv = file_priv; - dev->lock.lock_time = jiffies; - atomic_inc(&dev->counts[_DRM_STAT_LOCKS]); - break; /* Got lock */ - } - - /* Contention */ - schedule(); - if (signal_pending(current)) { - ret = -ERESTARTSYS; - break; - } - } - spin_lock_bh(&dev->lock.spinlock); - dev->lock.user_waiters--; - spin_unlock_bh(&dev->lock.spinlock); - __set_current_state(TASK_RUNNING); - remove_wait_queue(&dev->lock.lock_queue, &entry); - - DRM_DEBUG("%d %s\n", lock->context, - ret ? "interrupted" : "has lock"); - if (ret) return ret; - - sigemptyset(&dev->sigmask); - sigaddset(&dev->sigmask, SIGSTOP); - sigaddset(&dev->sigmask, SIGTSTP); - sigaddset(&dev->sigmask, SIGTTIN); - sigaddset(&dev->sigmask, SIGTTOU); - dev->sigdata.context = lock->context; - dev->sigdata.lock = dev->lock.hw_lock; - block_all_signals(drm_notifier, &dev->sigdata, &dev->sigmask); - - if (dev->driver->dma_ready && (lock->flags & _DRM_LOCK_READY)) - dev->driver->dma_ready(dev); - - if (dev->driver->dma_quiescent && (lock->flags & _DRM_LOCK_QUIESCENT)) - { - if (dev->driver->dma_quiescent(dev)) { - DRM_DEBUG("%d waiting for DMA quiescent\n", - lock->context); - return -EBUSY; - } - } - - if (dev->driver->kernel_context_switch && - dev->last_context != lock->context) { - dev->driver->kernel_context_switch(dev, dev->last_context, - lock->context); - } - - return 0; -} - -/** - * Unlock ioctl. - * - * \param inode device inode. - * \param file_priv DRM file private. - * \param cmd command. - * \param arg user argument, pointing to a drm_lock structure. - * \return zero on success or negative number on failure. - * - * Transfer and free the lock. - */ -int drm_unlock(struct drm_device *dev, void *data, struct drm_file *file_priv) -{ - struct drm_lock *lock = data; - unsigned long irqflags; - - if (lock->context == DRM_KERNEL_CONTEXT) { - DRM_ERROR("Process %d using kernel context %d\n", - task_pid_nr(current), lock->context); - return -EINVAL; - } - - spin_lock_irqsave(&dev->tasklet_lock, irqflags); - - if (dev->locked_tasklet_func) { - dev->locked_tasklet_func(dev); - - dev->locked_tasklet_func = NULL; - } - - spin_unlock_irqrestore(&dev->tasklet_lock, irqflags); - - atomic_inc(&dev->counts[_DRM_STAT_UNLOCKS]); - - /* kernel_context_switch isn't used by any of the x86 drm - * modules but is required by the Sparc driver. - */ - if (dev->driver->kernel_context_switch_unlock) - dev->driver->kernel_context_switch_unlock(dev); - else { - if (drm_lock_free(&dev->lock,lock->context)) { - /* FIXME: Should really bail out here. */ - } - } - - unblock_all_signals(); - return 0; -} - -/** - * Take the heavyweight lock. - * - * \param lock lock pointer. - * \param context locking context. - * \return one if the lock is held, or zero otherwise. - * - * Attempt to mark the lock as held by the given context, via the \p cmpxchg instruction. - */ -int drm_lock_take(struct drm_lock_data *lock_data, - unsigned int context) -{ - unsigned int old, new, prev; - volatile unsigned int *lock = &lock_data->hw_lock->lock; - - spin_lock_bh(&lock_data->spinlock); - do { - old = *lock; - if (old & _DRM_LOCK_HELD) - new = old | _DRM_LOCK_CONT; - else { - new = context | _DRM_LOCK_HELD | - ((lock_data->user_waiters + lock_data->kernel_waiters > 1) ? - _DRM_LOCK_CONT : 0); - } - prev = cmpxchg(lock, old, new); - } while (prev != old); - spin_unlock_bh(&lock_data->spinlock); - - if (_DRM_LOCKING_CONTEXT(old) == context) { - if (old & _DRM_LOCK_HELD) { - if (context != DRM_KERNEL_CONTEXT) { - DRM_ERROR("%d holds heavyweight lock\n", - context); - } - return 0; - } - } - - if ((_DRM_LOCKING_CONTEXT(new)) == context && (new & _DRM_LOCK_HELD)) { - /* Have lock */ - return 1; - } - return 0; -} - -/** - * This takes a lock forcibly and hands it to context. Should ONLY be used - * inside *_unlock to give lock to kernel before calling *_dma_schedule. - * - * \param dev DRM device. - * \param lock lock pointer. - * \param context locking context. - * \return always one. - * - * Resets the lock file pointer. - * Marks the lock as held by the given context, via the \p cmpxchg instruction. - */ -static int drm_lock_transfer(struct drm_lock_data *lock_data, - unsigned int context) -{ - unsigned int old, new, prev; - volatile unsigned int *lock = &lock_data->hw_lock->lock; - - lock_data->file_priv = NULL; - do { - old = *lock; - new = context | _DRM_LOCK_HELD; - prev = cmpxchg(lock, old, new); - } while (prev != old); - return 1; -} - -/** - * Free lock. - * - * \param dev DRM device. - * \param lock lock. - * \param context context. - * - * Resets the lock file pointer. - * Marks the lock as not held, via the \p cmpxchg instruction. Wakes any task - * waiting on the lock queue. - */ -int drm_lock_free(struct drm_lock_data *lock_data, unsigned int context) -{ - unsigned int old, new, prev; - volatile unsigned int *lock = &lock_data->hw_lock->lock; - - spin_lock_bh(&lock_data->spinlock); - if (lock_data->kernel_waiters != 0) { - drm_lock_transfer(lock_data, 0); - lock_data->idle_has_lock = 1; - spin_unlock_bh(&lock_data->spinlock); - return 1; - } - spin_unlock_bh(&lock_data->spinlock); - - do { - old = *lock; - new = _DRM_LOCKING_CONTEXT(old); - prev = cmpxchg(lock, old, new); - } while (prev != old); - - if (_DRM_LOCK_IS_HELD(old) && _DRM_LOCKING_CONTEXT(old) != context) { - DRM_ERROR("%d freed heavyweight lock held by %d\n", - context, _DRM_LOCKING_CONTEXT(old)); - return 1; - } - wake_up_interruptible(&lock_data->lock_queue); - return 0; -} - -/** - * If we get here, it means that the process has called DRM_IOCTL_LOCK - * without calling DRM_IOCTL_UNLOCK. - * - * If the lock is not held, then let the signal proceed as usual. If the lock - * is held, then set the contended flag and keep the signal blocked. - * - * \param priv pointer to a drm_sigdata structure. - * \return one if the signal should be delivered normally, or zero if the - * signal should be blocked. - */ -static int drm_notifier(void *priv) -{ - struct drm_sigdata *s = (struct drm_sigdata *) priv; - unsigned int old, new, prev; - - /* Allow signal delivery if lock isn't held */ - if (!s->lock || !_DRM_LOCK_IS_HELD(s->lock->lock) - || _DRM_LOCKING_CONTEXT(s->lock->lock) != s->context) - return 1; - - /* Otherwise, set flag to force call to - drmUnlock */ - do { - old = s->lock->lock; - new = old | _DRM_LOCK_CONT; - prev = cmpxchg(&s->lock->lock, old, new); - } while (prev != old); - return 0; -} - -/** - * This function returns immediately and takes the hw lock - * with the kernel context if it is free, otherwise it gets the highest priority when and if - * it is eventually released. - * - * This guarantees that the kernel will _eventually_ have the lock _unless_ it is held - * by a blocked process. (In the latter case an explicit wait for the hardware lock would cause - * a deadlock, which is why the "idlelock" was invented). - * - * This should be sufficient to wait for GPU idle without - * having to worry about starvation. - */ - -void drm_idlelock_take(struct drm_lock_data *lock_data) -{ - int ret = 0; - - spin_lock_bh(&lock_data->spinlock); - lock_data->kernel_waiters++; - if (!lock_data->idle_has_lock) { - - spin_unlock_bh(&lock_data->spinlock); - ret = drm_lock_take(lock_data, DRM_KERNEL_CONTEXT); - spin_lock_bh(&lock_data->spinlock); - - if (ret == 1) - lock_data->idle_has_lock = 1; - } - spin_unlock_bh(&lock_data->spinlock); -} -EXPORT_SYMBOL(drm_idlelock_take); - -void drm_idlelock_release(struct drm_lock_data *lock_data) -{ - unsigned int old, prev; - volatile unsigned int *lock = &lock_data->hw_lock->lock; - - spin_lock_bh(&lock_data->spinlock); - if (--lock_data->kernel_waiters == 0) { - if (lock_data->idle_has_lock) { - do { - old = *lock; - prev = cmpxchg(lock, old, DRM_KERNEL_CONTEXT); - } while (prev != old); - wake_up_interruptible(&lock_data->lock_queue); - lock_data->idle_has_lock = 0; - } - } - spin_unlock_bh(&lock_data->spinlock); -} -EXPORT_SYMBOL(drm_idlelock_release); - - -int drm_i_have_hw_lock(struct drm_device *dev, struct drm_file *file_priv) -{ - return (file_priv->lock_count && dev->lock.hw_lock && - _DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock) && - dev->lock.file_priv == file_priv); -} - -EXPORT_SYMBOL(drm_i_have_hw_lock); |