Add drm_gem_prime_self_import() to detect and handle the case where a PRIME dma-buf being imported was exported by the same DRM device.
When the dma-buf originates from the importing device and uses the expected dma-buf ops, the helper returns the associated GEM object and takes an extra reference on it. This allows drivers to bypass the generic PRIME import path and avoid taking an additional reference on the dma-buf file. The helper simplifies self-import handling and avoids duplication of this pattern across DRM drivers. Signed-off-by: Farah Kassabri <[email protected]> --- drivers/gpu/drm/drm_prime.c | 48 ++++++++++++++++++++++++++++++------- include/drm/drm_prime.h | 5 +++- 2 files changed, 44 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 21809a82187b..6c9ad3957f42 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -974,15 +974,9 @@ struct drm_gem_object *drm_gem_prime_import_dev(struct drm_device *dev, struct drm_gem_object *obj; int ret; - if (drm_gem_is_prime_exported_dma_buf(dev, dma_buf)) { - /* - * Importing dmabuf exported from our own gem increases - * refcount on gem itself instead of f_count of dmabuf. - */ - obj = dma_buf->priv; - drm_gem_object_get(obj); + obj = drm_gem_prime_self_import(dev, dma_buf, &drm_gem_prime_dmabuf_ops); + if (obj) return obj; - } if (!dev->driver->gem_prime_import_sg_table) return ERR_PTR(-EINVAL); @@ -1116,3 +1110,41 @@ void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg) dma_buf_put(dma_buf); } EXPORT_SYMBOL(drm_prime_gem_destroy); + +/** + * drm_gem_prime_self_import - Attempt to import a dma-buf exported by this DRM device + * @dev: DRM device performing the import + * @dma_buf: dma-buf to import + * @expected_ops: dma-buf ops used by this driver + * + * If @dma_buf was exported by this DRM device using @expected_ops, return the + * corresponding GEM object and take an extra reference on it. In this case, + * the import avoids taking a reference on the dma-buf file and instead bumps + * the GEM object's refcount directly. + * + * Returns: + * A referenced GEM object on success, or %NULL if the dma-buf was not exported + * by this device or does not match @expected_ops. + */ +struct drm_gem_object *drm_gem_prime_self_import(struct drm_device *dev, + struct dma_buf *dma_buf, + const struct dma_buf_ops *expected_ops) +{ + struct drm_gem_object *obj; + + if (dma_buf->ops != expected_ops) + return NULL; + + obj = dma_buf->priv; + if (!obj || obj->dev != dev) + return NULL; + + /* + * Importing dmabuf exported from our own gem increases + * refcount on gem itself instead of f_count of dmabuf. + */ + drm_gem_object_get(obj); + + return obj; +} +EXPORT_SYMBOL(drm_gem_prime_self_import); diff --git a/include/drm/drm_prime.h b/include/drm/drm_prime.h index f50f862f0d8b..4cdb543b9eb7 100644 --- a/include/drm/drm_prime.h +++ b/include/drm/drm_prime.h @@ -54,6 +54,7 @@ struct device; struct dma_buf_export_info; struct dma_buf; struct dma_buf_attachment; +struct dma_buf_ops; struct iosys_map; enum dma_data_direction; @@ -108,6 +109,9 @@ struct drm_gem_object *drm_gem_prime_import_dev(struct drm_device *dev, struct device *attach_dev); struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev, struct dma_buf *dma_buf); +struct drm_gem_object *drm_gem_prime_self_import(struct drm_device *dev, + struct dma_buf *dma_buf, + const struct dma_buf_ops *expected_ops); void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg); @@ -115,5 +119,4 @@ int drm_prime_sg_to_page_array(struct sg_table *sgt, struct page **pages, int max_pages); int drm_prime_sg_to_dma_addr_array(struct sg_table *sgt, dma_addr_t *addrs, int max_pages); - #endif /* __DRM_PRIME_H__ */ -- 2.43.0 --------------------------------------------------------------------- Intel Israel (74) Limited This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies.
