drm: add unpin function to prime helpers

Prevents buffers from being pinned forever.

Change-Id: Ifee56b3eb72bf4c5e349e0daf5ebf3156c096247
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 5b7b911..49168be 100644 (file)
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -92,10 +92,13 @@ static void drm_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
 static void drm_gem_dmabuf_release(struct dma_buf *dma_buf)
 {
        struct drm_gem_object *obj = dma_buf->priv;
+       struct drm_device *dev = obj->dev;
 
        if (obj->export_dma_buf == dma_buf) {
                /* drop the reference on the export fd holds */
                obj->export_dma_buf = NULL;
+               if (dev->driver->gem_prime_unpin)
+                       dev->driver->gem_prime_unpin(obj);
                drm_gem_object_unreference_unlocked(obj);
        }
 }
@@ -185,12 +188,18 @@ static const struct dma_buf_ops drm_gem_prime_dmabuf_ops =  {
 struct dma_buf *drm_gem_prime_export(struct drm_device *dev,
                                     struct drm_gem_object *obj, int flags)
 {
+       struct dma_buf *buf;
+
        if (dev->driver->gem_prime_pin) {
                int ret = dev->driver->gem_prime_pin(obj);
                if (ret)
                        return ERR_PTR(ret);
        }
-       return dma_buf_export(obj, &drm_gem_prime_dmabuf_ops, obj->size, flags);
+       buf = dma_buf_export(obj, &drm_gem_prime_dmabuf_ops, obj->size, flags);
+
+       if (IS_ERR(buf) && dev->driver->gem_prime_unpin)
+               dev->driver->gem_prime_unpin(obj);
+       return buf;
 }
 EXPORT_SYMBOL(drm_gem_prime_export);
 

diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index af24599..9b9e0f2 100644 (file)
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -943,6 +943,7 @@ struct drm_driver {
                                struct dma_buf *dma_buf);
        /* low-level interface used by drm_gem_prime_{import,export} */
        int (*gem_prime_pin)(struct drm_gem_object *obj);
+       void (*gem_prime_unpin)(struct drm_gem_object *obj);
        struct sg_table *(*gem_prime_get_sg_table)(struct drm_gem_object *obj);
        struct drm_gem_object *(*gem_prime_import_sg_table)(
                                struct drm_device *dev, size_t size,