[PATCH v4 6/7] drm/panthor: Support GPU_CONTROL cache flush based on feature bit

[Chia-I Wu]

On Mon, Jun 2, 2025 at 7:42 AM Karunika Choo <karunika.choo at arm.com> wrote:
>
> As the FLUSH_MEM and FLUSH_PT commands are deprecated in GPUs from
> Mali-Gx20 onwards, this patch adds support for performing cache
> maintenance via the FLUSH_CACHES command in GPU_CONTROL, in place of
> FLUSH_MEM and FLUSH_PT based on PANTHOR_HW_FEATURE_GPU_CTRL_CACHE_FLUSH
> feature bit.
>
> This patch also enables cache maintenance via GPU_CONTROL for Mali-Gx10
> and Mali-Gx15 GPUs for consistency.
>
> Signed-off-by: Karunika Choo <karunika.choo at arm.com>
> ---
>  drivers/gpu/drm/panthor/panthor_hw.c  |  6 +++++
>  drivers/gpu/drm/panthor/panthor_hw.h  |  6 +++++
>  drivers/gpu/drm/panthor/panthor_mmu.c | 35 +++++++++++++++++++++++++++
>  3 files changed, 47 insertions(+)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_hw.c b/drivers/gpu/drm/panthor/panthor_hw.c
> index f5127a4b02dc..5ec9d7f28368 100644
> --- a/drivers/gpu/drm/panthor/panthor_hw.c
> +++ b/drivers/gpu/drm/panthor/panthor_hw.c
> @@ -99,9 +99,15 @@ static void panthor_hw_info_init(struct panthor_device *ptdev)
>  static struct panthor_hw panthor_hw_devices[] = {
>         {
>                 .arch_major = 10,
> +               .features = {
> +                       BIT(PANTHOR_HW_FEATURE_GPU_CTRL_CACHE_FLUSH)
> +               },
>         },
>         {
>                 .arch_major = 11,
> +               .features = {
> +                       BIT(PANTHOR_HW_FEATURE_GPU_CTRL_CACHE_FLUSH)
> +               },
>         },
>  };
Are there going to be major archs which do not support
PANTHOR_HW_FEATURE_GPU_CTRL_CACHE_FLUSH?  If not, we don't need the
feature bit.