BSD: change drm_locked_task*() to use the same scheme as linux.

The current code can sleep in an interrupt handler, that is bad. So
instead if we can't grab the lock, flag it and run the tasklet on
unlock.

Signed-off-by: Robert Noland <rnoland@2hip.net>

diff --git a/bsd-core/drmP.h b/bsd-core/drmP.h
index 88ea4e6..65d7fae 100644 (file)
--- a/bsd-core/drmP.h
+++ b/bsd-core/drmP.h
@@ -739,6 +739,7 @@ struct drm_device {
        struct mtx        dev_lock;     /* protects everything else */
 #endif
        DRM_SPINTYPE      drw_lock;
+       DRM_SPINTYPE      tsk_lock;
 
                                /* Usage Counters */
        int               open_count;   /* Outstanding files open          */

diff --git a/bsd-core/drm_drv.c b/bsd-core/drm_drv.c
index 740a8b5..9bd6079 100644 (file)
--- a/bsd-core/drm_drv.c
+++ b/bsd-core/drm_drv.c
@@ -206,6 +206,7 @@ int drm_attach(device_t nbdev, drm_pci_id_list_t *idlist)
        mtx_init(&dev->irq_lock, "drmirq", NULL, MTX_DEF);
        mtx_init(&dev->vbl_lock, "drmvbl", NULL, MTX_DEF);
        mtx_init(&dev->drw_lock, "drmdrw", NULL, MTX_DEF);
+       mtx_init(&dev->tsk_lock, "drmtsk", NULL, MTX_DEF);
 #endif
 
        id_entry = drm_find_description(pci_get_vendor(dev->device),

diff --git a/bsd-core/drm_irq.c b/bsd-core/drm_irq.c
index c3ecd28..a066cfc 100644 (file)
--- a/bsd-core/drm_irq.c
+++ b/bsd-core/drm_irq.c
@@ -578,41 +578,42 @@ static void drm_locked_task(void *context, int pending __unused)
 {
        struct drm_device *dev = context;
 
-       DRM_LOCK();
-       for (;;) {
-               int ret;
-
-               if (drm_lock_take(&dev->lock.hw_lock->lock,
-                   DRM_KERNEL_CONTEXT))
-               {
-                       dev->lock.file_priv = NULL; /* kernel owned */
-                       dev->lock.lock_time = jiffies;
-                       atomic_inc(&dev->counts[_DRM_STAT_LOCKS]);
-                       break;  /* Got lock */
-               }
+       DRM_SPINLOCK(&dev->tsk_lock);
 
-               /* Contention */
-#if defined(__FreeBSD__) && __FreeBSD_version > 500000
-               ret = mtx_sleep((void *)&dev->lock.lock_queue, &dev->dev_lock,
-                   PZERO | PCATCH, "drmlk2", 0);
-#else
-               ret = tsleep((void *)&dev->lock.lock_queue, PZERO | PCATCH,
-                   "drmlk2", 0);
-#endif
-               if (ret != 0)
-                       return;
+       DRM_LOCK(); /* XXX drm_lock_take() should do it's own locking */
+       if (dev->locked_task_call == NULL ||
+           drm_lock_take(&dev->lock.hw_lock->lock, DRM_KERNEL_CONTEXT) == 0) {
+               DRM_UNLOCK();
+               DRM_SPINUNLOCK(&dev->tsk_lock);
+               return;
        }
+
+       dev->lock.file_priv = NULL; /* kernel owned */
+       dev->lock.lock_time = jiffies;
+       atomic_inc(&dev->counts[_DRM_STAT_LOCKS]);
+
        DRM_UNLOCK();
 
        dev->locked_task_call(dev);
 
        drm_lock_free(dev, &dev->lock.hw_lock->lock, DRM_KERNEL_CONTEXT);
+
+       dev->locked_task_call = NULL;
+
+       DRM_SPINUNLOCK(&dev->tsk_lock);
 }
 
 void
 drm_locked_tasklet(struct drm_device *dev,
                   void (*tasklet)(struct drm_device *dev))
 {
+       DRM_SPINLOCK(&dev->tsk_lock);
+       if (dev->locked_task_call != NULL) {
+               DRM_SPINUNLOCK(&dev->tsk_lock);
+               return;
+       }
+
        dev->locked_task_call = tasklet;
+       DRM_SPINUNLOCK(&dev->tsk_lock);
        taskqueue_enqueue(taskqueue_swi, &dev->locked_task);
 }

diff --git a/bsd-core/drm_lock.c b/bsd-core/drm_lock.c
index 9101dec..80ebb71 100644 (file)
--- a/bsd-core/drm_lock.c
+++ b/bsd-core/drm_lock.c
@@ -180,6 +180,13 @@ int drm_unlock(struct drm_device *dev, void *data, struct drm_file *file_priv)
            _DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock) != lock->context)
                return EINVAL;
 
+       DRM_SPINLOCK(&dev->tsk_lock);
+       if (dev->locked_task_call != NULL) {
+               dev->locked_task_call(dev);
+               dev->locked_task_call = NULL;
+       }
+       DRM_SPINUNLOCK(&dev->tsk_lock);
+
        atomic_inc(&dev->counts[_DRM_STAT_UNLOCKS]);
 
        DRM_LOCK();