[Intel-gfx] [RFC 3/7] drm/i915: Move all runtime modified device info fields into runtime info

[Chris Wilson]

Quoting Tvrtko Ursulin (2018-11-13 09:13:47)
> 
> On 12/11/2018 17:24, Chris Wilson wrote:
> > Quoting Tvrtko Ursulin (2018-11-12 17:12:38)
> >>   struct intel_device_info {
> >> -       u16 device_id;
> >>          u16 gen_mask;
> >>   
> >> -       u8 gen;
> >> +       u8 __gen;
> >>          u8 gt; /* GT number, 0 if undefined */
> >> -       intel_ring_mask_t ring_mask; /* Rings supported by the HW */
> >> -       u8 num_pipes;
> >> +       intel_ring_mask_t __ring_mask; /* Rings supported by the HW */
> >> +       u8 __num_pipes;
> >>   
> >>          enum intel_platform platform;
> >>          u32 platform_mask;
> >>   
> >> -       enum intel_ppgtt ppgtt;
> >> -       unsigned int page_sizes; /* page sizes supported by the HW */
> >> +       enum intel_ppgtt __ppgtt;
> > 
> > ppgtt mode is static.
> 
> What about:
> 
> @@ -868,7 +867,7 @@ void intel_device_info_runtime_init(struct 
> drm_i915_private *dev_priv)
> 
>          if (IS_GEN6(dev_priv) && intel_vtd_active()) {
>                  DRM_INFO("Disabling ppGTT for VT-d support\n");
> -               info->ppgtt = INTEL_PPGTT_NONE;
> +               runtime_info->ppgtt = INTEL_PPGTT_NONE;

Cunning, you see I grepped the patch for the wrong thing (thinking it
was just the markup). We could make it static, but that would devalue the
information stored by ppgtt.

The alternative plan:
- move the disabling ppgtt into aliasing setup
- tag the PD offsets in the error state with [none, aliasing, full]

Advantage: we don't need to worry about runtime_info.pggtt
Disadvantage: extra code to generate equiv of runtime_info.ppgtt for
debugging.

>          }
> 
>          /* Initialize command stream timestamp frequency */
> 
> And:
> 
> @@ -1711,7 +1711,7 @@ int i915_gem_huge_page_mock_selftests(void)
>                  return -ENOMEM;
> 
>          /* Pretend to be a device which supports the 48b PPGTT */
> -       mkwrite_device_info(dev_priv)->ppgtt = INTEL_PPGTT_FULL_4LVL;
> +       dev_priv->runtime_info.ppgtt = INTEL_PPGTT_FULL_4LVL;

That can be made static, but drops out later anyway. And when we have
separate ppgtt mode and size, I think it should be static (certainly we
are unlikely to change the ppgtt_size at runtime).
-Chris