Re: [PATCH v3 4/7] drm: nova: Add GETPARAM parameter to read the GPU chipid

From: Danilo Krummrich

Date: Sat Jul 25 2026 - 11:24:27 EST


On Thu Jul 23, 2026 at 8:30 AM CEST, Alistair Popple wrote:
> diff --git a/drivers/gpu/drm/nova/file.rs b/drivers/gpu/drm/nova/file.rs
> index 1156df51c533..855f23877734 100644
> --- a/drivers/gpu/drm/nova/file.rs
> +++ b/drivers/gpu/drm/nova/file.rs
> @@ -34,7 +34,7 @@ impl File {
> /// IOCTL: get_param: Query GPU / driver metadata.
> pub(crate) fn get_param(
> dev: &NovaDevice<Registered>,
> - _reg_data: &DrmRegData<'_>,
> + reg_data: &DrmRegData<'_>,
> getparam: &mut uapi::drm_nova_getparam,
> _file: &drm::File<File>,
> ) -> Result<u32> {
> @@ -43,6 +43,7 @@ pub(crate) fn get_param(
>
> let value = match getparam.param as u32 {
> uapi::NOVA_GETPARAM_VRAM_BAR_SIZE => pdev.resource_len(1)?,
> + uapi::NOVA_GETPARAM_GPU_CHIPID => reg_data.api.chipset() as u64,

NIT: Given the subsequent changes I'd create a temporary

let api = reg_data.api;

for this.

> +/*
> + * NOVA_GETPARAM_GPU_CHIPID
> + *
> + * Query the GPU chipid (architecture/implementation).
> + */
> +#define NOVA_GETPARAM_GPU_CHIPID 0x2

As mentioned in the previous reply, do we want userspace to extract additional
information from the chipid directly? Defining it as opaque value would make
things easier if the encoding details of the chipid ever change.