Commit 721255b5 authored by Christian König's avatar Christian König
Browse files

drm/syncobj: flatten dma_fence_chains on transfer 



It is illegal to add a dma_fence_chain as timeline point. Flatten out
the fences into a dma_fence_array instead.

Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
Reviewed-by: default avatarNirmoy Das <nirmoy.das@linux.intel.com>
Cc: <stable@vger.kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209182600.434803-1-christian.koenig@amd.com
parent 15280383

drivers/gpu/drm/drm_syncobj.c

+56 −5
Original line number Diff line number Diff line
@@ -853,12 +853,57 @@ drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data, 
					&args->handle);

}





/*

 * Try to flatten a dma_fence_chain into a dma_fence_array so that it can be

 * added as timeline fence to a chain again.

 */

static int drm_syncobj_flatten_chain(struct dma_fence **f)

{

	struct dma_fence_chain *chain = to_dma_fence_chain(*f);

	struct dma_fence *tmp, **fences;

	struct dma_fence_array *array;

	unsigned int count;



	if (!chain)

		return 0;



	count = 0;

	dma_fence_chain_for_each(tmp, &chain->base)

		++count;



	fences = kmalloc_array(count, sizeof(*fences), GFP_KERNEL);

	if (!fences)

		return -ENOMEM;



	count = 0;

	dma_fence_chain_for_each(tmp, &chain->base)

		fences[count++] = dma_fence_get(tmp);



	array = dma_fence_array_create(count, fences,

				       dma_fence_context_alloc(1),

				       1, false);

	if (!array)

		goto free_fences;



	dma_fence_put(*f);

	*f = &array->base;

	return 0;



free_fences:

	while (count--)

		dma_fence_put(fences[count]);



	kfree(fences);

	return -ENOMEM;

}



static int drm_syncobj_transfer_to_timeline(struct drm_file *file_private,

					    struct drm_syncobj_transfer *args)

{

	struct drm_syncobj *timeline_syncobj = NULL;

	struct dma_fence *fence;

	struct dma_fence_chain *chain;

	struct dma_fence *fence;

	int ret;



	timeline_syncobj = drm_syncobj_find(file_private, args->dst_handle);
@@ -869,16 +914,22 @@ static int drm_syncobj_transfer_to_timeline(struct drm_file *file_private, 
				     args->src_point, args->flags,

				     &fence);

	if (ret)

		goto err;

		goto err_put_timeline;



	ret = drm_syncobj_flatten_chain(&fence);

	if (ret)

		goto err_free_fence;



	chain = dma_fence_chain_alloc();

	if (!chain) {

		ret = -ENOMEM;

		goto err1;

		goto err_free_fence;

	}



	drm_syncobj_add_point(timeline_syncobj, chain, fence, args->dst_point);

err1:

err_free_fence:

	dma_fence_put(fence);

err:

err_put_timeline:

	drm_syncobj_put(timeline_syncobj);



	return ret;