Re: [PATCH] drm/gpuvm: Rename 'map' to 'op' in drm_gpuvm_map_req

["Ghimiray, Himal Prasad" <himal.prasad.ghimiray@intel.com>]

On 21-08-2025 19:05, Danilo Krummrich wrote:
> On Thu Aug 21, 2025 at 3:01 PM CEST, Boris Brezillon wrote:
>> On Thu, 21 Aug 2025 14:55:06 +0200
>> "Danilo Krummrich" <dakr@kernel.org> wrote:
>>
>>> On Thu Aug 21, 2025 at 1:25 PM CEST, Boris Brezillon wrote:
>>>> On Thu, 21 Aug 2025 13:01:46 +0200
>>>> Boris Brezillon <boris.brezillon@collabora.com> wrote:
>>>>> On a second thought, I'm now wondering why we need drm_gpuvm_map_req in
>>>>> the first place. It would kinda make sense if it was containing an
>>>>>
>>>>> 	bool madvise;
>>>>>
>>>>> field, so you don't have to pass it around, but even then, I'm
>>>>> wondering if we wouldn't be better off adding this field to
>>>>> drm_gpuva_op_map instead and passing an drm_gpuva_op_map object to
>>>>> the various map helpers (like Danilo suggested in his review of the
>>>>> REPEATED mode series Caterina sent).
>>>>
>>>> More on that: the very reason I introduced drm_gpuvm_map_req in the
>>>> first place is so we have a clear differentiation between an overall
>>>> map request and the sub-operations that are created to fulfill it.
>>>> Looks like this was not a concern for Danilo and he was happy with us
>>>> using _op_map for this.
>>>>
>>>> The other reason we might want to add drm_gpuvm_map_req is so that
>>>> information we only need while splitting a req don't pollute
>>>> drm_gpuva_op_map. Given I was going to pass the flags to the driver's
>>>> callback anyway (meaning it's needed at the op_map level), and given
>>>> you're passing madvise as a separate bool argument to various helpers
>>>> (_map_req just contains the op, not the madvise bool), I don't think
>>>> this aspect matters.
>>>
>>> Good catch! Indeed, when Himal picked up your struct drm_gpuvm_map_req patch,
>>> there were additional flags included in the structure. Now that it is
>>> essentially a transparent wrapper, I prefer to use struct drm_gpuva_op_map
>>> directly.
>>>
>>> However, given that you still have patches in flight that will add a flags field
>>> to struct drm_gpuvm_map_req I think it's probably fine to introduce it right
>>> away. Or did you drop this plan of adding those flags?
>>
>> I need the flags field in the op_map too (so I can propagate it to the
>> drm_gpuva object), so I'd rather go with an op_map object directly and
>> kill drm_gpuvm_map_req now.
> 
> In this case I agree, let's use struct drm_gpuva_op_map directly.

According to the kernel documentation for the drm_gpuva_op_map 
structure, it is intended to represent a single map operation generated 
as the output of ops_create or the GPU VA manager. Using it as a direct 
input to ops_create contradicts this definition.

For drm_gpuvm_sm_map_ops_create, the values align with those in 
drm_gpuvm_map_req. However, this is not the case for 
drm_gpuvm_madvise_ops_create.

If we plan to proceed with deprecating drm_gpuvm_map_req, we need to 
clarify the fundamental definition of drm_gpuva_op_map:
Should it represent a user-requested map, or an operation generated by 
the GPU VA manager?