[PATCH v3 09/12] drm/xe/pxp: Add API to mark a BO as using PXP

[Jani Nikula]

On Thu, 21 Nov 2024, Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com> wrote:
> On 11/21/2024 12:03 PM, Jani Nikula wrote:
>> On Thu, 21 Nov 2024, Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com> wrote:
>>> On 11/21/2024 1:57 AM, Jani Nikula wrote:
>>>> On Wed, 20 Nov 2024, Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com> wrote:
>>>>> diff --git a/drivers/gpu/drm/xe/compat-i915-headers/pxp/intel_pxp.h b/drivers/gpu/drm/xe/compat-i915-headers/pxp/intel_pxp.h
>>>>> index 419e8e926f00..533bc82255b6 100644
>>>>> --- a/drivers/gpu/drm/xe/compat-i915-headers/pxp/intel_pxp.h
>>>>> +++ b/drivers/gpu/drm/xe/compat-i915-headers/pxp/intel_pxp.h
>>>>> @@ -9,6 +9,9 @@
>>>>>    #include <linux/errno.h>
>>>>>    #include <linux/types.h>
>>>>>    
>>>>> +#include "xe_bo.h"
>>>>> +#include "xe_pxp.h"
>>>>> +
>>>> Can't have this. This will include xe_bo.h and xe_pxp.h from i915
>>>> display.
>>>>
>>>> Basically you can't use gem_to_xe_bo() in static inlines in headers that
>>>> get included to i915 display. It all needs to stay opaque.
>>> Why would this be included to i915 display? This is the copy of the
>>> header used for building the display code with Xe, i915 should use it's
>>> own copy (i915/pxp/intel_pxp.h). Several other headers in the
>>> compat-i915-headers subfolder include Xe headers. Or is the problem
>>> specifically with the BO part of it? Because I can move the code to
>>> xe_pxp.c, but I'd still have to include at least xe_pxp.h.
>> With "i915 display", I refer to the display code that gets built for
>> both i915 and xe. And regardless of which module the code is being built
>> for, it should not include details like this. The goal is to make it
>> more and more independent from the two, eventually spawning into a
>> dedicated module. So we want to axe includes that lead from i915 display
>> to either i915 or xe core headers.
>
> Ok that makes sense, but I'm not sure if it can be easily avoided here. 
> The PXP key is managed outside of the display code, so we do need a 
> callback into Xe or i915 to get that info. The only way I can see that 
> being doable without the different headers is if we pass a function 
> pointer at display init time and keep that stored inside the 
> intel_display structure. That to me sounds like something that should be 
> introduced more structurally for multiple callbacks into i915/xe instead 
> of just for PXP, but I can do it if that's the preference.

Why not make xe_pxp_key_check() accept struct drm_gem_object * instead
of struct xe_bo *? Basically all the interfaces to/from display will
need to use i915/xe independent types anyway.

See ad36a322619c ("drm/i915/display: convert skl_universal_plane.c to
struct drm_gem_object") which converts i915 pxp. And i915 display gets
to use either opaque types or generic drm types.

BR,
Jani.



>
> thanks,
> Daniele
>
>>
>> BR,
>> Jani.
>>
>>
>>
>>> Daniele
>>>
>>>> BR,
>>>> Jani.
>>>>
>>>>>    struct drm_gem_object;
>>>>>    struct xe_pxp;
>>>>>    
>>>>> @@ -16,7 +19,15 @@ static inline int intel_pxp_key_check(struct xe_pxp *pxp,
>>>>>    				      struct drm_gem_object *obj,
>>>>>    				      bool assign)
>>>>>    {
>>>>> -	return -ENODEV;
>>>>> +	/*
>>>>> +	 * The assign variable is used in i915 to assign the key to the BO at
>>>>> +	 * first submission time. In Xe the key is instead assigned at BO
>>>>> +	 * creation time, so the assign variable must always be false.
>>>>> +	 */
>>>>> +	if (assign)
>>>>> +		return -EINVAL;
>>>>> +
>>>>> +	return xe_pxp_key_check(pxp, gem_to_xe_bo(obj));
>>>>>    }
>>>>>    
>>>>>    #endif
>

-- 
Jani Nikula, Intel