Commit 7d2cd72a authored by Daniel Vetter's avatar Daniel Vetter
Browse files

drm/shmem-helpers: Simplify dma-buf importing 



- Ditch the ->pages array
- Make it a private gem bo, which means no shmem object, which means
  fireworks if anyone calls drm_gem_object_get_pages. But we've just
  made sure that's all covered.

v2: Rebase

v3: I forgot to remove the page_count mangling from the free path too.
Noticed by Boris while testing.

Cc: Boris Brezillon <boris.brezillon@collabora.com>
Tested-by: default avatarBoris Brezillon <boris.brezillon@collabora.com>
Acked-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200529140542.2103713-1-daniel.vetter@ffwll.ch
parent 52640835

drivers/gpu/drm/drm_gem_shmem_helper.c

+23 −37
Original line number Diff line number Diff line
@@ -35,22 +35,12 @@ static const struct drm_gem_object_funcs drm_gem_shmem_funcs = { 
	.mmap = drm_gem_shmem_mmap,

};



/**

 * drm_gem_shmem_create - Allocate an object with the given size

 * @dev: DRM device

 * @size: Size of the object to allocate

 *

 * This function creates a shmem GEM object.

 *

 * Returns:

 * A struct drm_gem_shmem_object * on success or an ERR_PTR()-encoded negative

 * error code on failure.

 */

struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size)

static struct drm_gem_shmem_object *

__drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private)

{

	struct drm_gem_shmem_object *shmem;

	struct drm_gem_object *obj;

	int ret;

	int ret = 0;



	size = PAGE_ALIGN(size);
@@ -64,6 +54,9 @@ struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t 
	if (!obj->funcs)

		obj->funcs = &drm_gem_shmem_funcs;



	if (private)

		drm_gem_private_object_init(dev, obj, size);

	else

		ret = drm_gem_object_init(dev, obj, size);

	if (ret)

		goto err_free;
@@ -96,6 +89,21 @@ struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t 


	return ERR_PTR(ret);

}

/**

 * drm_gem_shmem_create - Allocate an object with the given size

 * @dev: DRM device

 * @size: Size of the object to allocate

 *

 * This function creates a shmem GEM object.

 *

 * Returns:

 * A struct drm_gem_shmem_object * on success or an ERR_PTR()-encoded negative

 * error code on failure.

 */

struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size)

{

	return __drm_gem_shmem_create(dev, size, false);

}

EXPORT_SYMBOL_GPL(drm_gem_shmem_create);



/**
@@ -113,9 +121,7 @@ void drm_gem_shmem_free_object(struct drm_gem_object *obj) 
	WARN_ON(shmem->vmap_use_count);



	if (obj->import_attach) {

		shmem->pages_use_count--;

		drm_prime_gem_destroy(obj, shmem->sgt);

		kvfree(shmem->pages);

	} else {

		if (shmem->sgt) {

			dma_unmap_sg(obj->dev->dev, shmem->sgt->sgl,
@@ -371,7 +377,7 @@ drm_gem_shmem_create_with_handle(struct drm_file *file_priv, 
	struct drm_gem_shmem_object *shmem;

	int ret;



	shmem = drm_gem_shmem_create(dev, size);

	shmem = __drm_gem_shmem_create(dev, size, true);

	if (IS_ERR(shmem))

		return shmem;
@@ -695,36 +701,16 @@ drm_gem_shmem_prime_import_sg_table(struct drm_device *dev, 
				    struct sg_table *sgt)

{

	size_t size = PAGE_ALIGN(attach->dmabuf->size);

	size_t npages = size >> PAGE_SHIFT;

	struct drm_gem_shmem_object *shmem;

	int ret;



	shmem = drm_gem_shmem_create(dev, size);

	if (IS_ERR(shmem))

		return ERR_CAST(shmem);



	shmem->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);

	if (!shmem->pages) {

		ret = -ENOMEM;

		goto err_free_gem;

	}



	ret = drm_prime_sg_to_page_addr_arrays(sgt, shmem->pages, NULL, npages);

	if (ret < 0)

		goto err_free_array;



	shmem->sgt = sgt;

	shmem->pages_use_count = 1; /* Permanently pinned from our point of view */



	DRM_DEBUG_PRIME("size = %zu\n", size);



	return &shmem->base;



err_free_array:

	kvfree(shmem->pages);

err_free_gem:

	drm_gem_object_put(&shmem->base);



	return ERR_PTR(ret);

}

EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_import_sg_table);