#include "drmP.h"
-static int drm_lock_transfer(drm_device_t * dev,
- __volatile__ unsigned int *lock,
- unsigned int context);
static int drm_notifier(void *priv);
/**
return -EINVAL;
add_wait_queue(&dev->lock.lock_queue, &entry);
+ spin_lock(&dev->lock.spinlock);
+ dev->lock.user_waiters++;
+ spin_unlock(&dev->lock.spinlock);
for (;;) {
__set_current_state(TASK_INTERRUPTIBLE);
if (!dev->lock.hw_lock) {
ret = -EINTR;
break;
}
- if (drm_lock_take(&dev->lock.hw_lock->lock, lock.context)) {
+ if (drm_lock_take(&dev->lock, lock.context)) {
dev->lock.filp = filp;
dev->lock.lock_time = jiffies;
atomic_inc(&dev->counts[_DRM_STAT_LOCKS]);
break;
}
}
+ spin_lock(&dev->lock.spinlock);
+ dev->lock.user_waiters--;
+ spin_unlock(&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);
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))
- return dev->driver->dma_quiescent(dev);
-
- /* dev->driver->kernel_context_switch isn't used by any of the x86
- * drivers but is used by the Sparc driver.
- */
+ 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 DRM_ERR(EBUSY);
+ }
+ }
if (dev->driver->kernel_context_switch &&
dev->last_context != lock.context) {
dev->driver->kernel_context_switch(dev, dev->last_context,
lock.context);
}
- DRM_DEBUG("%d %s\n", lock.context, ret ? "interrupted" : "has lock");
- return ret;
+ return 0;
}
/**
drm_file_t *priv = filp->private_data;
drm_device_t *dev = priv->head->dev;
drm_lock_t lock;
+ unsigned long irqflags;
if (copy_from_user(&lock, (drm_lock_t __user *) arg, sizeof(lock)))
return -EFAULT;
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, &lock);
+ dev->driver->kernel_context_switch_unlock(dev);
else {
- drm_lock_transfer(dev, &dev->lock.hw_lock->lock,
- DRM_KERNEL_CONTEXT);
-
- if (drm_lock_free(dev, &dev->lock.hw_lock->lock,
- DRM_KERNEL_CONTEXT)) {
- DRM_ERROR("\n");
+ if (drm_lock_free(&dev->lock,lock.context)) {
+ /* FIXME: Should really bail out here. */
}
}
*
* Attempt to mark the lock as held by the given context, via the \p cmpxchg instruction.
*/
-int drm_lock_take(__volatile__ unsigned int *lock, unsigned int context)
+int drm_lock_take(drm_lock_data_t *lock_data,
+ unsigned int context)
{
unsigned int old, new, prev;
+ volatile unsigned int *lock = &lock_data->hw_lock->lock;
+ spin_lock(&lock_data->spinlock);
do {
old = *lock;
if (old & _DRM_LOCK_HELD)
new = old | _DRM_LOCK_CONT;
- else
- new = context | _DRM_LOCK_HELD;
+ 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(&lock_data->spinlock);
+
if (_DRM_LOCKING_CONTEXT(old) == context) {
if (old & _DRM_LOCK_HELD) {
if (context != DRM_KERNEL_CONTEXT) {
return 0;
}
}
- if (new == (context | _DRM_LOCK_HELD)) {
+
+ if ((_DRM_LOCKING_CONTEXT(new)) == context && (new & _DRM_LOCK_HELD)) {
/* Have lock */
return 1;
}
* Resets the lock file pointer.
* Marks the lock as held by the given context, via the \p cmpxchg instruction.
*/
-static int drm_lock_transfer(drm_device_t * dev,
- __volatile__ unsigned int *lock,
+static int drm_lock_transfer(drm_lock_data_t *lock_data,
unsigned int context)
{
unsigned int old, new, prev;
+ volatile unsigned int *lock = &lock_data->hw_lock->lock;
- dev->lock.filp = NULL;
+ lock_data->filp = NULL;
do {
old = *lock;
new = context | _DRM_LOCK_HELD;
* Marks the lock as not held, via the \p cmpxchg instruction. Wakes any task
* waiting on the lock queue.
*/
-int drm_lock_free(drm_device_t * dev,
- __volatile__ unsigned int *lock, unsigned int context)
+int drm_lock_free(drm_lock_data_t *lock_data, unsigned int context)
{
unsigned int old, new, prev;
+ volatile unsigned int *lock = &lock_data->hw_lock->lock;
+
+ spin_lock(&lock_data->spinlock);
+ if (lock_data->kernel_waiters != 0) {
+ drm_lock_transfer(lock_data, 0);
+ lock_data->idle_has_lock = 1;
+ spin_unlock(&lock_data->spinlock);
+ return 1;
+ }
+ spin_unlock(&lock_data->spinlock);
- dev->lock.filp = NULL;
do {
old = *lock;
- new = 0;
+ 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(&dev->lock.lock_queue);
+ wake_up_interruptible(&lock_data->lock_queue);
return 0;
}
} 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(drm_lock_data_t *lock_data)
+{
+ int ret = 0;
+
+ spin_lock(&lock_data->spinlock);
+ lock_data->kernel_waiters++;
+ if (!lock_data->idle_has_lock) {
+
+ spin_unlock(&lock_data->spinlock);
+ ret = drm_lock_take(lock_data, DRM_KERNEL_CONTEXT);
+ spin_lock(&lock_data->spinlock);
+
+ if (ret == 1)
+ lock_data->idle_has_lock = 1;
+ }
+ spin_unlock(&lock_data->spinlock);
+}
+EXPORT_SYMBOL(drm_idlelock_take);
+
+void drm_idlelock_release(drm_lock_data_t *lock_data)
+{
+ unsigned int old, prev;
+ volatile unsigned int *lock = &lock_data->hw_lock->lock;
+
+ spin_lock(&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(&lock_data->spinlock);
+}
+EXPORT_SYMBOL(drm_idlelock_release);
+
+
+int drm_i_have_hw_lock(struct file *filp)
+{
+ DRM_DEVICE;
+
+ return (priv->lock_count && dev->lock.hw_lock &&
+ _DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock) &&
+ dev->lock.filp == filp);
+}
+
+EXPORT_SYMBOL(drm_i_have_hw_lock);
projects / linux-drm-fsl-dcu.git / blobdiff