drm/i915/gt: Cleanup interface for MCR operations

Let's replace the assortment of intel_gt_* and intel_uncore_* functions
that operate on MCR registers with a cleaner set of interfaces:

  * intel_gt_mcr_read -- unicast read from specific instance
  * intel_gt_mcr_read_any[_fw] -- unicast read from any non-terminated
    instance
  * intel_gt_mcr_unicast_write -- unicast write to specific instance
  * intel_gt_mcr_multicast_write[_fw] -- multicast write to all instances

We'll also replace the historic "slice" and "subslice" terminology with
"group" and "instance" to match the documentation for more recent
platforms; these days MCR steering applies to more types of replication
than just slice/subslice.

v2:
 - Reference the new kerneldoc from i915.rst.  (Jani)
 - Tweak the wording of the documentation for a couple functions to
   clarify the difference between "_fw" and non-"_fw" forms.

v3:
 - s/read/write/ to fix copy-paste mistake in a couple comments.
   (Harish)

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Acked-by: Jani Nikula <jani.nikula@linux.intel.com>
Reviewed-by: Harish Chegondi <harish.chegondi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220615001019.1821989-3-matthew.d.roper@intel.com

1 files changed, 15 insertions, 18 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index 244af1bdb7db..136cc44c3deb 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -1428,14 +1428,6 @@ void intel_engine_cancel_stop_cs(struct intel_engine_cs *engine)
 	ENGINE_WRITE_FW(engine, RING_MI_MODE, _MASKED_BIT_DISABLE(STOP_RING));
 }
 
-static u32
-read_subslice_reg(const struct intel_engine_cs *engine,
-		  int slice, int subslice, i915_reg_t reg)
-{
-	return intel_uncore_read_with_mcr_steering(engine->uncore, reg,
-						   slice, subslice);
-}
-
 /* NB: please notice the memset */
 void intel_engine_get_instdone(const struct intel_engine_cs *engine,
 			       struct intel_instdone *instdone)
@@ -1469,28 +1461,33 @@ void intel_engine_get_instdone(const struct intel_engine_cs *engine,
 		if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 50)) {
 			for_each_instdone_gslice_dss_xehp(i915, sseu, iter, slice, subslice) {
 				instdone->sampler[slice][subslice] =
-					read_subslice_reg(engine, slice, subslice,
-							  GEN7_SAMPLER_INSTDONE);
+					intel_gt_mcr_read(engine->gt,
+							  GEN7_SAMPLER_INSTDONE,
+							  slice, subslice);
 				instdone->row[slice][subslice] =
-					read_subslice_reg(engine, slice, subslice,
-							  GEN7_ROW_INSTDONE);
+					intel_gt_mcr_read(engine->gt,
+							  GEN7_ROW_INSTDONE,
+							  slice, subslice);
 			}
 		} else {
 			for_each_instdone_slice_subslice(i915, sseu, slice, subslice) {
 				instdone->sampler[slice][subslice] =
-					read_subslice_reg(engine, slice, subslice,
-							  GEN7_SAMPLER_INSTDONE);
+					intel_gt_mcr_read(engine->gt,
+							  GEN7_SAMPLER_INSTDONE,
+							  slice, subslice);
 				instdone->row[slice][subslice] =
-					read_subslice_reg(engine, slice, subslice,
-							  GEN7_ROW_INSTDONE);
+					intel_gt_mcr_read(engine->gt,
+							  GEN7_ROW_INSTDONE,
+							  slice, subslice);
 			}
 		}
 
 		if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 55)) {
 			for_each_instdone_gslice_dss_xehp(i915, sseu, iter, slice, subslice)
 				instdone->geom_svg[slice][subslice] =
-					read_subslice_reg(engine, slice, subslice,
-							  XEHPG_INSTDONE_GEOM_SVG);
+					intel_gt_mcr_read(engine->gt,
+							  XEHPG_INSTDONE_GEOM_SVG,
+							  slice, subslice);
 		}
 	} else if (GRAPHICS_VER(i915) >= 7) {
 		instdone->instdone =