[PATCH v2 2/4] drm/prime: add support for virtio exported objects

[David Stevens <stevensd@chromium.org>]

This change exposes dma-buf's get_uuid callback to PRIME drivers.

Signed-off-by: David Stevens <stevensd@chromium.org>
---
 drivers/gpu/drm/drm_prime.c | 27 +++++++++++++++++++++++++++
 include/drm/drm_drv.h       | 15 +++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 86d9b0e45c8c..fc6e932a4fa6 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -779,6 +779,30 @@ int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 }
 EXPORT_SYMBOL(drm_gem_dmabuf_mmap);
 
+#ifdef CONFIG_VIRTIO
+/**
+ * drm_gem_dmabuf_get_uuid - dma_buf get_uuid implementation for GEM
+ * @dma_buf: buffer to query
+ * @uuid: uuid outparam
+ *
+ * Queries the buffer's virtio UUID. This can be used as the
+ * &dma_buf_ops.get_uuid callback. Calls into &drm_driver.gem_prime_get_uuid.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int drm_gem_dmabuf_get_uuid(struct dma_buf *dma_buf, uuid_t *uuid)
+{
+	struct drm_gem_object *obj = dma_buf->priv;
+	struct drm_device *dev = obj->dev;
+
+	if (!dev->driver->gem_prime_get_uuid)
+		return -ENODEV;
+
+	return dev->driver->gem_prime_get_uuid(obj, uuid);
+}
+EXPORT_SYMBOL(drm_gem_dmabuf_get_uuid);
+#endif
+
 static const struct dma_buf_ops drm_gem_prime_dmabuf_ops =  {
 	.cache_sgt_mapping = true,
 	.attach = drm_gem_map_attach,
@@ -789,6 +813,9 @@ static const struct dma_buf_ops drm_gem_prime_dmabuf_ops =  {
 	.mmap = drm_gem_dmabuf_mmap,
 	.vmap = drm_gem_dmabuf_vmap,
 	.vunmap = drm_gem_dmabuf_vunmap,
+#ifdef CONFIG_VIRTIO
+	.get_uuid = drm_gem_dmabuf_get_uuid,
+#endif
 };
 
 /**
diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
index 77685ed7aa65..3cbe9aa6b44a 100644
--- a/include/drm/drm_drv.h
+++ b/include/drm/drm_drv.h
@@ -32,6 +32,10 @@
 
 #include <drm/drm_device.h>
 
+#ifdef CONFIG_VIRTIO
+#include <linux/uuid.h>
+#endif
+
 struct drm_file;
 struct drm_gem_object;
 struct drm_master;
@@ -639,6 +643,17 @@ struct drm_driver {
 	int (*gem_prime_mmap)(struct drm_gem_object *obj,
 				struct vm_area_struct *vma);
 
+#ifdef CONFIG_VIRTIO
+	/**
+	 * @gem_prime_get_uuid
+	 *
+	 * get_uuid hook for GEM drivers. Retrieves the virtio uuid of the
+	 * given GEM buffer.
+	 */
+	int (*gem_prime_get_uuid)(struct drm_gem_object *obj,
+				  uuid_t *uuid);
+#endif
+
 	/**
 	 * @dumb_create:
 	 *
-- 
2.25.0.265.gbab2e86ba0-goog