Re: [PATCH v8 07/18] drm/virtio: add virtio_gpu_object_array & helpers

[Chia-I Wu]

On Fri, Aug 23, 2019 at 2:55 AM Gerd Hoffmann <kraxel@xxxxxxxxxx> wrote:
>
> Some helper functions to manage an array of gem objects.
>
> v6:
>  - add ticket to struct virtio_gpu_object_array.
>  - add virtio_gpu_array_{lock,unlock}_resv helpers.
>  - add virtio_gpu_array_add_fence helper.
> v5: some small optimizations (Chia-I Wu).
> v4: make them virtio-private instead of generic helpers.
>
> Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
> ---
>  drivers/gpu/drm/virtio/virtgpu_drv.h | 17 +++++
>  drivers/gpu/drm/virtio/virtgpu_gem.c | 93 ++++++++++++++++++++++++++++
>  2 files changed, 110 insertions(+)
>
> diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
> index db57bbb36216..b6bd2b1141fb 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_drv.h
> +++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
> @@ -84,6 +84,12 @@ struct virtio_gpu_object {
>  #define gem_to_virtio_gpu_obj(gobj) \
>         container_of((gobj), struct virtio_gpu_object, gem_base)
>
> +struct virtio_gpu_object_array {
> +       struct ww_acquire_ctx ticket;
> +       u32 nents, total;
> +       struct drm_gem_object *objs[];
> +};
> +
>  struct virtio_gpu_vbuffer;
>  struct virtio_gpu_device;
>
> @@ -251,6 +257,17 @@ int virtio_gpu_mode_dumb_mmap(struct drm_file *file_priv,
>                               struct drm_device *dev,
>                               uint32_t handle, uint64_t *offset_p);
>
> +struct virtio_gpu_object_array *virtio_gpu_array_alloc(u32 nents);
> +struct virtio_gpu_object_array*
> +virtio_gpu_array_from_handles(struct drm_file *drm_file, u32 *handles, u32 nents);
> +void virtio_gpu_array_add_obj(struct virtio_gpu_object_array *objs,
> +                             struct drm_gem_object *obj);
> +int virtio_gpu_array_lock_resv(struct virtio_gpu_object_array *objs);
> +void virtio_gpu_array_unlock_resv(struct virtio_gpu_object_array *objs);
> +void virtio_gpu_array_add_fence(struct virtio_gpu_object_array *objs,
> +                               struct dma_fence *fence);
> +void virtio_gpu_array_put_free(struct virtio_gpu_object_array *objs);
> +
>  /* virtio vg */
>  int virtio_gpu_alloc_vbufs(struct virtio_gpu_device *vgdev);
>  void virtio_gpu_free_vbufs(struct virtio_gpu_device *vgdev);
> diff --git a/drivers/gpu/drm/virtio/virtgpu_gem.c b/drivers/gpu/drm/virtio/virtgpu_gem.c
> index 6fe6f72f64d1..f3799f2e97cb 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_gem.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_gem.c
> @@ -171,3 +171,96 @@ void virtio_gpu_gem_object_close(struct drm_gem_object *obj,
>                                                 qobj->hw_res_handle);
>         virtio_gpu_object_unreserve(qobj);
>  }
> +
> +struct virtio_gpu_object_array *virtio_gpu_array_alloc(u32 nents)
> +{
> +       struct virtio_gpu_object_array *objs;
> +       size_t size = sizeof(*objs) + sizeof(objs->objs[0]) * nents;
> +
> +       objs = kmalloc(size, GFP_KERNEL);
> +       if (!objs)
> +               return NULL;
> +
> +       objs->nents = 0;
> +       objs->total = nents;
> +       return objs;
> +}
> +
> +static void virtio_gpu_array_free(struct virtio_gpu_object_array *objs)
> +{
> +       kfree(objs);
> +}
> +
> +struct virtio_gpu_object_array*
> +virtio_gpu_array_from_handles(struct drm_file *drm_file, u32 *handles, u32 nents)
> +{
> +       struct virtio_gpu_object_array *objs;
> +       u32 i;
> +
> +       objs = virtio_gpu_array_alloc(nents);
> +       if (!objs)
> +               return NULL;
> +
> +       for (i = 0; i < nents; i++) {
> +               objs->objs[i] = drm_gem_object_lookup(drm_file, handles[i]);
> +               if (!objs->objs[i]) {
> +                       objs->nents = i;
> +                       virtio_gpu_array_put_free(objs);
> +                       return NULL;
> +               }
> +       }
> +       objs->nents = i;
> +       return objs;
> +}
> +
> +void virtio_gpu_array_add_obj(struct virtio_gpu_object_array *objs,
> +                             struct drm_gem_object *obj)
> +{
> +       if (WARN_ON_ONCE(objs->nents == objs->total))
> +               return;
> +
> +       drm_gem_object_get(obj);
> +       objs->objs[objs->nents] = obj;
> +       objs->nents++;
> +}
> +
> +int virtio_gpu_array_lock_resv(struct virtio_gpu_object_array *objs)
> +{
> +       int ret;
> +
> +       if (objs->nents == 1) {
> +               ret = dma_resv_lock(objs->objs[0]->resv, NULL);
dma_resv_lock_interruptible to match what drm_gem_lock_reservations uses.
> +       } else {
> +               ret = drm_gem_lock_reservations(objs->objs, objs->nents,
> +                                               &objs->ticket);
> +       }
> +       return ret;
> +}
> +
> +void virtio_gpu_array_unlock_resv(struct virtio_gpu_object_array *objs)
> +{
> +       if (objs->nents == 1) {
> +               dma_resv_unlock(objs->objs[0]->resv);
> +       } else {
> +               drm_gem_unlock_reservations(objs->objs, objs->nents,
> +                                           &objs->ticket);
> +       }
> +}
> +
> +void virtio_gpu_array_add_fence(struct virtio_gpu_object_array *objs,
> +                               struct dma_fence *fence)
> +{
> +       int i;
> +
> +       for (i = 0; i < objs->nents; i++)
> +               dma_resv_add_excl_fence(objs->objs[i]->resv, fence);
> +}
> +
> +void virtio_gpu_array_put_free(struct virtio_gpu_object_array *objs)
> +{
> +       u32 i;
> +
> +       for (i = 0; i < objs->nents; i++)
> +               drm_gem_object_put_unlocked(objs->objs[i]);
> +       virtio_gpu_array_free(objs);
> +}
> --
> 2.18.1
>