[PATCH v2 06/17] drm/v3d: Decouple job allocation from job initiation

[Iago Toral]

El jue, 23-11-2023 a las 21:47 -0300, Maíra Canal escribió:
> We want to allow the IOCTLs to allocate the job without initiating
> it.
> This will be useful for the CPU job submission IOCTL, as the CPU job
> has
> the need to use information from the user extensions. Currently, the
> user extensions are parsed before the job allocation, making it
> impossible to fill the CPU job when parsing the user extensions.
> Therefore, decouple the job allocation from the job initiation.
> 
> Signed-off-by: Maíra Canal <mcanal at igalia.com>
> ---
>  drivers/gpu/drm/v3d/v3d_submit.c | 23 ++++++++++++++++++-----
>  1 file changed, 18 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/v3d/v3d_submit.c
> b/drivers/gpu/drm/v3d/v3d_submit.c
> index fe46dd316ca0..ed1a310bbd2f 100644
> --- a/drivers/gpu/drm/v3d/v3d_submit.c
> +++ b/drivers/gpu/drm/v3d/v3d_submit.c
> @@ -135,6 +135,21 @@ void v3d_job_put(struct v3d_job *job)
>         kref_put(&job->refcount, job->free);
>  }
>  
> +static int
> +v3d_job_allocate(void **container, size_t size)
> +{
> +       if (*container)
> +               return 0;

Mmm... is this really what we want? At least right now we expect
v3d_job_allocate to always allocate memory, is there any scenario in
which we would expect to call this with an already allocated container?

Iago

> +
> +       *container = kcalloc(1, size, GFP_KERNEL);
> +       if (!*container) {
> +               DRM_ERROR("Cannot allocate memory for V3D job.\n");
> +               return -ENOMEM;
> +       }
> +
> +       return 0;
> +}
> +
>  static int
>  v3d_job_init(struct v3d_dev *v3d, struct drm_file *file_priv,
>              void **container, size_t size, void (*free)(struct kref
> *ref),
> @@ -145,11 +160,9 @@ v3d_job_init(struct v3d_dev *v3d, struct
> drm_file *file_priv,
>         bool has_multisync = se && (se->flags &
> DRM_V3D_EXT_ID_MULTI_SYNC);
>         int ret, i;
>  
> -       *container = kcalloc(1, size, GFP_KERNEL);
> -       if (!*container) {
> -               DRM_ERROR("Cannot allocate memory for v3d job.");
> -               return -ENOMEM;
> -       }
> +       ret = v3d_job_allocate(container, size);
> +       if (ret)
> +               return ret;
>  
>         job = *container;
>         job->v3d = v3d;