drm: rename dev->count_lock to dev->buf_lock

Since really that's all it protects - legacy horror stories in
drm_bufs.c. Since I don't want to waste any more time on this I didn't
bother to actually look at what it protects in there, but it's at
least contained now.

v2: Move the spurious hunk to the right patch (Thierry).

Cc: Thierry Reding <thierry.reding@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_bufs.c

@@ -656,13 +656,13 @@ int drm_addbufs_agp(struct drm_device * dev, struct drm_buf_desc * request)
 		DRM_DEBUG("zone invalid\n");
 		return -EINVAL;
 	}
-	spin_lock(&dev->count_lock);
+	spin_lock(&dev->buf_lock);
 	if (dev->buf_use) {
-		spin_unlock(&dev->count_lock);
+		spin_unlock(&dev->buf_lock);
 		return -EBUSY;
 	}
 	atomic_inc(&dev->buf_alloc);
-	spin_unlock(&dev->count_lock);
+	spin_unlock(&dev->buf_lock);
 
 	mutex_lock(&dev->struct_mutex);
 	entry = &dma->bufs[order];
@@ -805,13 +805,13 @@ int drm_addbufs_pci(struct drm_device * dev, struct drm_buf_desc * request)
 	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
 	total = PAGE_SIZE << page_order;
 
-	spin_lock(&dev->count_lock);
+	spin_lock(&dev->buf_lock);
 	if (dev->buf_use) {
-		spin_unlock(&dev->count_lock);
+		spin_unlock(&dev->buf_lock);
 		return -EBUSY;
 	}
 	atomic_inc(&dev->buf_alloc);
-	spin_unlock(&dev->count_lock);
+	spin_unlock(&dev->buf_lock);
 
 	mutex_lock(&dev->struct_mutex);
 	entry = &dma->bufs[order];
@@ -1015,13 +1015,13 @@ static int drm_addbufs_sg(struct drm_device * dev, struct drm_buf_desc * request
 	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER)
 		return -EINVAL;
 
-	spin_lock(&dev->count_lock);
+	spin_lock(&dev->buf_lock);
 	if (dev->buf_use) {
-		spin_unlock(&dev->count_lock);
+		spin_unlock(&dev->buf_lock);
 		return -EBUSY;
 	}
 	atomic_inc(&dev->buf_alloc);
-	spin_unlock(&dev->count_lock);
+	spin_unlock(&dev->buf_lock);
 
 	mutex_lock(&dev->struct_mutex);
 	entry = &dma->bufs[order];
@@ -1175,7 +1175,7 @@ int drm_addbufs(struct drm_device *dev, void *data,
  * \param arg pointer to a drm_buf_info structure.
  * \return zero on success or a negative number on failure.
  *
- * Increments drm_device::buf_use while holding the drm_device::count_lock
+ * Increments drm_device::buf_use while holding the drm_device::buf_lock
  * lock, preventing of allocating more buffers after this call. Information
  * about each requested buffer is then copied into user space.
  */
@@ -1196,13 +1196,13 @@ int drm_infobufs(struct drm_device *dev, void *data,
 	if (!dma)
 		return -EINVAL;
 
-	spin_lock(&dev->count_lock);
+	spin_lock(&dev->buf_lock);
 	if (atomic_read(&dev->buf_alloc)) {
-		spin_unlock(&dev->count_lock);
+		spin_unlock(&dev->buf_lock);
 		return -EBUSY;
 	}
 	++dev->buf_use;		/* Can't allocate more after this call */
-	spin_unlock(&dev->count_lock);
+	spin_unlock(&dev->buf_lock);
 
 	for (i = 0, count = 0; i < DRM_MAX_ORDER + 1; i++) {
 		if (dma->bufs[i].buf_count)
@@ -1381,13 +1381,13 @@ int drm_mapbufs(struct drm_device *dev, void *data,
 	if (!dma)
 		return -EINVAL;
 
-	spin_lock(&dev->count_lock);
+	spin_lock(&dev->buf_lock);
 	if (atomic_read(&dev->buf_alloc)) {
-		spin_unlock(&dev->count_lock);
+		spin_unlock(&dev->buf_lock);
 		return -EBUSY;
 	}
 	dev->buf_use++;		/* Can't allocate more after this call */
-	spin_unlock(&dev->count_lock);
+	spin_unlock(&dev->buf_lock);
 
 	if (request->count >= dma->buf_count) {
 		if ((dev->agp && (dma->flags & _DRM_DMA_USE_AGP))

drivers/gpu/drm/drm_stub.c

@@ -569,7 +569,7 @@ struct drm_device *drm_dev_alloc(struct drm_driver *driver,
 	INIT_LIST_HEAD(&dev->maplist);
 	INIT_LIST_HEAD(&dev->vblank_event_list);
 
-	spin_lock_init(&dev->count_lock);
+	spin_lock_init(&dev->buf_lock);
 	spin_lock_init(&dev->event_lock);
 	mutex_init(&dev->struct_mutex);
 	mutex_init(&dev->ctxlist_mutex);

include/drm/drmP.h

@@ -1069,7 +1069,6 @@ struct drm_device {
 
 	/** \name Locks */
 	/*@{ */
-	spinlock_t count_lock;		/**< For inuse, drm_device::open_count, drm_device::buf_use */
 	struct mutex struct_mutex;	/**< For others */
 	struct mutex master_mutex;      /**< For drm_minor::master and drm_file::is_master */
 	/*@} */
@@ -1077,6 +1076,7 @@ struct drm_device {
 	/** \name Usage Counters */
 	/*@{ */
 	int open_count;			/**< Outstanding files open, protected by drm_global_mutex. */
+	spinlock_t buf_lock;		/**< For drm_device::buf_use and a few other things. */
 	int buf_use;			/**< Buffers in use -- cannot alloc */
 	atomic_t buf_alloc;		/**< Buffer allocation in progress */
 	/*@} */