Re: [PATCH v3 3/7] drm: nova: Add chipid enum to nova-drm UAPI

[John Hubbard]

On 7/28/26 2:29 PM, Danilo Krummrich wrote:
> On Tue Jul 28, 2026 at 10:00 AM CEST, Alistair Popple wrote:
>> On 2026-07-26 at 01:23 +1000, Danilo Krummrich <dakr@xxxxxxxxxx> wrote...
>>> On Thu Jul 23, 2026 at 8:30 AM CEST, Alistair Popple wrote:
...
>>> For instance, what's valid for userspace to extract from this? Given chipid is a
>>> composed value, is userspace e.g. allowed to make assumptions on extracting the
>>> architecture? Or is this something we want to expose separately and tell
>>> userspace that the chipid is an opaque value identifying a specific chip only?
>>
>> I _think_ it makes sense for this to just be an opaque value, but it's a good
>> question that I should probably try and get some internal feedback on as well.
>> Reading the arch would then be a separate parameter.
> 
> I'd prefer exposing it as an opaque value and provide other information
> separately; the kernel already does the work anyway, so why duplicate it in
> userspace. It would also remain much cleaner if encoding details ever change.
> 

Just to orient myself, I'm assuming that by "opaque values", you mean using
something that just counts up from, say, 1, instead of using real boot42
values below, right?

That seems like a good approach to me, too. Because I can't imagine anything
particularly good coming from providing unnecessary details to user space
here. :)

>>>> +	/* Turing */
>>>> +	NOVA_DRM_CHIPID_TU102 = 0x162,
>>>> +	NOVA_DRM_CHIPID_TU104 = 0x164,
>>>> +	NOVA_DRM_CHIPID_TU106 = 0x166,
>>>> +	NOVA_DRM_CHIPID_TU117 = 0x167,
>>>> +	NOVA_DRM_CHIPID_TU116 = 0x168,
>>>> +	/* Ampere */
>>>> +	NOVA_DRM_CHIPID_GA100 = 0x170,
>>>> +	NOVA_DRM_CHIPID_GA102 = 0x172,
>>>> +	NOVA_DRM_CHIPID_GA103 = 0x173,
>>>> +	NOVA_DRM_CHIPID_GA104 = 0x174,
>>>> +	NOVA_DRM_CHIPID_GA106 = 0x176,
>>>> +	NOVA_DRM_CHIPID_GA107 = 0x177,
>>>> +	/* Hopper */
>>>> +	NOVA_DRM_CHIPID_GH100 = 0x180,
>>>> +	/* Ada */
>>>> +	NOVA_DRM_CHIPID_AD102 = 0x192,
>>>> +	NOVA_DRM_CHIPID_AD103 = 0x193,
>>>> +	NOVA_DRM_CHIPID_AD104 = 0x194,
>>>> +	NOVA_DRM_CHIPID_AD106 = 0x196,
>>>> +	NOVA_DRM_CHIPID_AD107 = 0x197,
>>>> +	/* Blackwell GB10x */
>>>> +	NOVA_DRM_CHIPID_GB100 = 0x1a0,
>>>> +	NOVA_DRM_CHIPID_GB102 = 0x1a2,
>>>> +	/* Blackwell GB20x */
>>>> +	NOVA_DRM_CHIPID_GB202 = 0x1b2,
>>>> +	NOVA_DRM_CHIPID_GB203 = 0x1b3,
>>>> +	NOVA_DRM_CHIPID_GB205 = 0x1b5,
>>>> +	NOVA_DRM_CHIPID_GB206 = 0x1b6,
>>>> +	NOVA_DRM_CHIPID_GB207 = 0x1b7,
>>>> +};
> 

thanks,
-- 
John Hubbard