Fix up buffer manager locking.

6 files changed, 41 insertions, 21 deletions

diff --git a/linux-core/drm_bo.c b/linux-core/drm_bo.c
index 144935d6..4ef697b5 100644
--- a/linux-core/drm_bo.c
+++ b/linux-core/drm_bo.c
@@ -1938,7 +1938,7 @@ int drm_bo_setstatus_ioctl(struct drm_device *dev,
 		return -EINVAL;
 	}
 
-	ret = drm_bo_read_lock(&dev->bm.bm_lock);
+	ret = drm_bo_read_lock(&dev->bm.bm_lock, 1);
 	if (ret)
 		return ret;
 
@@ -2449,7 +2449,7 @@ int drm_mm_init_ioctl(struct drm_device *dev, void *data, struct drm_file *file_
 		return -EINVAL;
 	}
 
-	ret = drm_bo_write_lock(&bm->bm_lock, file_priv);
+	ret = drm_bo_write_lock(&bm->bm_lock, 1, file_priv);
 	if (ret)
 		return ret;
 
@@ -2500,7 +2500,7 @@ int drm_mm_takedown_ioctl(struct drm_device *dev, void *data, struct drm_file *f
 		return -EINVAL;
 	}
 
-	ret = drm_bo_write_lock(&bm->bm_lock, file_priv);
+	ret = drm_bo_write_lock(&bm->bm_lock, 0, file_priv);
 	if (ret)
 		return ret;
 
@@ -2548,7 +2548,7 @@ int drm_mm_lock_ioctl(struct drm_device *dev, void *data, struct drm_file *file_
 	}
 
 	if (arg->lock_flags & DRM_BO_LOCK_UNLOCK_BM) {
-		ret = drm_bo_write_lock(&dev->bm.bm_lock, file_priv);
+		ret = drm_bo_write_lock(&dev->bm.bm_lock, 1, file_priv);
 		if (ret)
 			return ret;
 	}
diff --git a/linux-core/drm_bo_lock.c b/linux-core/drm_bo_lock.c
index 2795384e..32ebfbe2 100644
--- a/linux-core/drm_bo_lock.c
+++ b/linux-core/drm_bo_lock.c
@@ -49,7 +49,7 @@
  * unmappable regions to mappable. It's a bug to leave kernel space with the
  * read lock held.
  *
- * Both read- and write lock taking is interruptible for low signal-delivery
+ * Both read- and write lock taking may be interruptible for low signal-delivery
  * latency. The locking functions will return -EAGAIN if interrupted by a
  * signal.
  *
@@ -71,14 +71,20 @@ void drm_bo_read_unlock(struct drm_bo_lock *lock)
 	if (unlikely(atomic_add_negative(-1, &lock->readers)))
 		BUG();
 	if (atomic_read(&lock->readers) == 0)
-		wake_up_interruptible(&lock->queue);
+		wake_up_all(&lock->queue);
 }
 EXPORT_SYMBOL(drm_bo_read_unlock);
 
-int drm_bo_read_lock(struct drm_bo_lock *lock)
+int drm_bo_read_lock(struct drm_bo_lock *lock, int interruptible)
 {
 	while (unlikely(atomic_read(&lock->write_lock_pending) != 0)) {
 		int ret;
+
+		if (!interruptible) {
+			wait_event(lock->queue,
+				   atomic_read(&lock->write_lock_pending) == 0);
+			continue;
+		}
 		ret = wait_event_interruptible
 		    (lock->queue, atomic_read(&lock->write_lock_pending) == 0);
 		if (ret)
@@ -87,8 +93,14 @@ int drm_bo_read_lock(struct drm_bo_lock *lock)
 
 	while (unlikely(!atomic_add_unless(&lock->readers, 1, -1))) {
 		int ret;
+
+		if (!interruptible) {
+			wait_event(lock->queue,
+				   atomic_read(&lock->readers) != -1);
+			continue;
+		}
 		ret = wait_event_interruptible
-		    (lock->queue, atomic_add_unless(&lock->readers, 1, -1));
+			(lock->queue, atomic_read(&lock->readers) != -1);
 		if (ret)
 			return -EAGAIN;
 	}
@@ -100,9 +112,7 @@ static int __drm_bo_write_unlock(struct drm_bo_lock *lock)
 {
 	if (unlikely(atomic_cmpxchg(&lock->readers, -1, 0) != -1))
 		return -EINVAL;
-	if (unlikely(atomic_cmpxchg(&lock->write_lock_pending, 1, 0) != 1))
-		return -EINVAL;
-	wake_up_interruptible(&lock->queue);
+	wake_up_all(&lock->queue);
 	return 0;
 }
 
@@ -116,21 +126,26 @@ static void drm_bo_write_lock_remove(struct drm_file *file_priv,
 	BUG_ON(ret);
 }
 
-int drm_bo_write_lock(struct drm_bo_lock *lock, struct drm_file *file_priv)
+int drm_bo_write_lock(struct drm_bo_lock *lock, int interruptible,
+		      struct drm_file *file_priv)
 {
 	int ret = 0;
 	struct drm_device *dev;
 
-	if (unlikely(atomic_cmpxchg(&lock->write_lock_pending, 0, 1) != 0))
-		return -EINVAL;
+	atomic_inc(&lock->write_lock_pending);
 
 	while (unlikely(atomic_cmpxchg(&lock->readers, 0, -1) != 0)) {
+		if (!interruptible) {
+			wait_event(lock->queue,
+				   atomic_read(&lock->readers) == 0);
+			continue;
+		}
 		ret = wait_event_interruptible
-		    (lock->queue, atomic_cmpxchg(&lock->readers, 0, -1) == 0);
+		    (lock->queue, atomic_read(&lock->readers) == 0);
 
 		if (ret) {
-			atomic_set(&lock->write_lock_pending, 0);
-			wake_up_interruptible(&lock->queue);
+			atomic_dec(&lock->write_lock_pending);
+			wake_up_all(&lock->queue);
 			return -EAGAIN;
 		}
 	}
@@ -141,6 +156,7 @@ int drm_bo_write_lock(struct drm_bo_lock *lock, struct drm_file *file_priv)
 	 * while holding it.
 	 */
 
+	atomic_dec(&lock->write_lock_pending);
 	dev = file_priv->minor->dev;
 	mutex_lock(&dev->struct_mutex);
 	ret = drm_add_user_object(file_priv, &lock->base, 0);
diff --git a/linux-core/drm_compat.c b/linux-core/drm_compat.c
index 5dabeaea..23e5028a 100644
--- a/linux-core/drm_compat.c
+++ b/linux-core/drm_compat.c
@@ -213,7 +213,7 @@ static struct page *drm_bo_vm_fault(struct vm_area_struct *vma,
 	unsigned long bus_size;
 
 	dev = bo->dev;
-	while(drm_bo_read_lock(&dev->bm.bm_lock));
+	drm_bo_read_lock(&dev->bm.bm_lock, 0);
 
 	mutex_lock(&bo->mutex);
 
diff --git a/linux-core/drm_objects.h b/linux-core/drm_objects.h
index c32edacd..a1f3a18d 100644
--- a/linux-core/drm_objects.h
+++ b/linux-core/drm_objects.h
@@ -320,6 +320,8 @@ struct drm_ttm {
 	int destroy;
 	uint32_t mapping_offset;
 	struct drm_ttm_backend *be;
+	unsigned long highest_lomem_entry;
+	unsigned long lowest_himem_entry;
 	enum {
 		ttm_bound,
 		ttm_evicted,
@@ -798,8 +800,10 @@ extern void drm_regs_init(struct drm_reg_manager *manager,
 
 extern void drm_bo_init_lock(struct drm_bo_lock *lock);
 extern void drm_bo_read_unlock(struct drm_bo_lock *lock);
-extern int drm_bo_read_lock(struct drm_bo_lock *lock);
+extern int drm_bo_read_lock(struct drm_bo_lock *lock,
+			    int interruptible);
 extern int drm_bo_write_lock(struct drm_bo_lock *lock,
+			     int interruptible,
 			     struct drm_file *file_priv);
 
 extern int drm_bo_write_unlock(struct drm_bo_lock *lock,
diff --git a/linux-core/drm_vm.c b/linux-core/drm_vm.c
index ffda8284..a09bcddb 100644
--- a/linux-core/drm_vm.c
+++ b/linux-core/drm_vm.c
@@ -738,7 +738,7 @@ static unsigned long drm_bo_vm_nopfn(struct vm_area_struct *vma,
 		return NOPFN_SIGBUS;
 
 	dev = bo->dev;
-	err = drm_bo_read_lock(&dev->bm.bm_lock);
+	err = drm_bo_read_lock(&dev->bm.bm_lock, 1);
 	if (err)
 		return NOPFN_REFAULT;
 
diff --git a/linux-core/i915_execbuf.c b/linux-core/i915_execbuf.c
index 729ee0c3..088a2693 100644
--- a/linux-core/i915_execbuf.c
+++ b/linux-core/i915_execbuf.c
@@ -845,7 +845,7 @@ int i915_execbuffer(struct drm_device *dev, void *data,
 	if (exec_buf->num_buffers > dev_priv->max_validate_buffers)
 		return -EINVAL;
 
-	ret = drm_bo_read_lock(&dev->bm.bm_lock);
+	ret = drm_bo_read_lock(&dev->bm.bm_lock, 1);
 	if (ret)
 		return ret;