On 17/05/2022 06:20, Matt Roper wrote:
Slice/subslice/EU information should be obtained via the topology queries provided by the I915_QUERY interface; let's turn off support for the old GETPARAM lookups on Xe_HP and beyond where we can't return meaningful values. The slice mask lookup is meaningless since Xe_HP doesn't support traditional slices (and we make no attempt to return the various new units like gslices, cslices, mslices, etc.) here. The subslice mask lookup is even more problematic; given the distinct masks for geometry vs compute purposes, the combined mask returned here is likely not what userspace would want to act upon anyway. The value is also limited to 32-bits by the nature of the GETPARAM ioctl which is sufficient for the initial Xe_HP platforms, but is unable to convey the larger masks that will be needed on other upcoming platforms. Finally, the value returned here becomes even less meaningful when used on multi-tile platforms where each tile will have its own masks. Signed-off-by: Matt Roper <matthew.d.roper@xxxxxxxxx>
Sounds fair. We've been relying on the topology query in Mesa since it's available and it's a requirement for Gfx10+.
FYI, we're also not using I915_PARAM_EU_TOTAL on Gfx10+ for the same reason. Acked-by: Lionel Landwerlin <lionel.g.landwerlin@xxxxxxxxx>
--- drivers/gpu/drm/i915/i915_getparam.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_getparam.c b/drivers/gpu/drm/i915/i915_getparam.c index c12a0adefda5..ac9767c56619 100644 --- a/drivers/gpu/drm/i915/i915_getparam.c +++ b/drivers/gpu/drm/i915/i915_getparam.c @@ -148,11 +148,19 @@ int i915_getparam_ioctl(struct drm_device *dev, void *data, value = intel_engines_has_context_isolation(i915); break; case I915_PARAM_SLICE_MASK: + /* Not supported from Xe_HP onward; use topology queries */ + if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 50)) + return -EINVAL; + value = sseu->slice_mask; if (!value) return -ENODEV; break; case I915_PARAM_SUBSLICE_MASK: + /* Not supported from Xe_HP onward; use topology queries */ + if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 50)) + return -EINVAL; + /* Only copy bits from the first slice */ memcpy(&value, sseu->subslice_mask, min(sseu->ss_stride, (u8)sizeof(value)));
