On Fri, Mar 11, 2022 at 12:43:40PM -0800, Matt Roper wrote:
On Fri, Mar 11, 2022 at 12:38:17PM -0800, Matt Roper wrote:On Fri, Mar 11, 2022 at 11:00:09AM -0800, Lucas De Marchi wrote: > On Thu, Mar 10, 2022 at 10:15:42PM -0800, Matt Roper wrote: > > Xe_HP removed "slice" as a first-class unit in the hardware design. > > Instead we now have a single pool of subslices (which are now referred > > to as "DSS") that different hardware units have different ways of > > grouping ("compute slices," "geometry slices," etc.). For the purposes > > of topology representation, we treat Xe_HP-based platforms as having a > > single slice that contains all of the platform's DSS. There's no need > > to allocate storage space for (max legacy slices * max dss); let's > > update some of our macros to minimize the storage requirement for sseu > > topology. We'll also document some of the constants to make it a little > > bit more clear what they represent. > > > > Signed-off-by: Matt Roper <matthew.d.roper@xxxxxxxxx> > > --- > > drivers/gpu/drm/i915/gt/intel_engine_types.h | 2 +- > > drivers/gpu/drm/i915/gt/intel_sseu.h | 47 +++++++++++++++----- > > 2 files changed, 36 insertions(+), 13 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h > > index 4fbf45a74ec0..f9e246004bc0 100644 > > --- a/drivers/gpu/drm/i915/gt/intel_engine_types.h > > +++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h > > @@ -645,7 +645,7 @@ intel_engine_has_relative_mmio(const struct intel_engine_cs * const engine) > > > > #define for_each_instdone_gslice_dss_xehp(dev_priv_, sseu_, iter_, gslice_, dss_) \ > > for ((iter_) = 0, (gslice_) = 0, (dss_) = 0; \ > > - (iter_) < GEN_MAX_SUBSLICES; \ > > + (iter_) < GEN_SS_MASK_SIZE; \ > > (iter_)++, (gslice_) = (iter_) / GEN_DSS_PER_GSLICE, \ > > (dss_) = (iter_) % GEN_DSS_PER_GSLICE) \ > > for_each_if(intel_sseu_has_subslice((sseu_), 0, (iter_))) > > diff --git a/drivers/gpu/drm/i915/gt/intel_sseu.h b/drivers/gpu/drm/i915/gt/intel_sseu.h > > index 8a79cd8eaab4..4f59eadbb61a 100644 > > --- a/drivers/gpu/drm/i915/gt/intel_sseu.h > > +++ b/drivers/gpu/drm/i915/gt/intel_sseu.h > > @@ -15,26 +15,49 @@ struct drm_i915_private; > > struct intel_gt; > > struct drm_printer; > > > > -#define GEN_MAX_SLICES (3) /* SKL upper bound */ > > -#define GEN_MAX_SUBSLICES (32) /* XEHPSDV upper bound */ > > -#define GEN_SSEU_STRIDE(max_entries) DIV_ROUND_UP(max_entries, BITS_PER_BYTE) > > -#define GEN_MAX_SUBSLICE_STRIDE GEN_SSEU_STRIDE(GEN_MAX_SUBSLICES) > > -#define GEN_MAX_EUS (16) /* TGL upper bound */ > > -#define GEN_MAX_EU_STRIDE GEN_SSEU_STRIDE(GEN_MAX_EUS) > > +/* > > + * Maximum number of legacy slices. Legacy slices no longer exist starting on > > + * Xe_HP ("gslices," "cslices," etc. on Xe_HP and beyond are a different > > + * concept and are not expressed through fusing). > > + */ > > +#define GEN_MAX_LEGACY_SLICES 3 > > + > > +/* > > + * Maximum number of subslices that can exist within a legacy slice. This is > > + * only relevant to pre-Xe_HP platforms (Xe_HP and beyond use the GEN_MAX_DSS > > + * value below). > > + */ > > +#define GEN_MAX_LEGACY_SUBSLICES 6 > > instead of calling the old legacy, maybe just add the XEHP_ prefix to > the new ones? Maybe a "HSW_" prefix on the old ones would be better? People still use the termm 'subslice' in casual discussion when talking about DSS, so I want to somehow distinguish that what we're talking about here is a different, older design than we have on modern platforms.Hmm, or maybe just "GEN_MAX_SUBSLICES_PER_LEGACY_SLICE" to tie it into the slice definition above?
I'm not too fond of calling it "legacy" when everywhere else in the driver we just use the platform as prefix/suffix. Some may see legacy as < ver 12, others as 12.50, etc. Well... but I will leave that up to you if you are convinced one is better than the other. thanks Lucas De Marchi
