drm/i915/tgl: Tigerlake only has global MOCS registers

Until Icelake, each engine had its own set of 64 MOCS registers. In
order to simplify, Tigerlake moves to only 64 Global MOCS registers,
which are no longer part of the engine context. Since these registers
are now global, they also only need to be initialized once.

>From Gen12 onwards, MOCS must specify the target cache (3:2) and LRU
management (5:4) fields and cannot be programmed to 'use the value from
Private PAT', because these fields are no longer part of the PPAT. Also
cacheability control (1:0) field has changed, 00 no longer means 'use
controls from page table', but uncacheable (UC).

v2 (Lucas):
    - Move the changes to the fault registers to a separate commit - the
      old ones overlap with the range used by the new global MOCS
      (requested by Daniele)
v3 (Lucas):
    - Clarify comment about setting the unused entries to the same value
      of index 0, that is the invalid entry (requested by Daniele)
    - Move changes to DONE_REG and ERROR_GEN6 to a separate commit
      (requested by Daniele)

Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Michel Thierry <michel.thierry@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Tomasz Lis <tomasz.lis@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190730180407.5993-5-lucas.demarchi@intel.com

1 files changed, 43 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_mocs.c b/drivers/gpu/drm/i915/gt/intel_mocs.c
index d93301310dc7..764e47131c06 100644
--- a/drivers/gpu/drm/i915/gt/intel_mocs.c
+++ b/drivers/gpu/drm/i915/gt/intel_mocs.c
@@ -392,6 +392,10 @@ void intel_mocs_init_engine(struct intel_engine_cs *engine)
 	unsigned int index;
 	u32 unused_value;
 
+	/* Platforms with global MOCS do not need per-engine initialization. */
+	if (HAS_GLOBAL_MOCS_REGISTERS(gt->i915))
+		return;
+
 	/* Called under a blanket forcewake */
 	assert_forcewakes_active(uncore, FORCEWAKE_ALL);
 
@@ -417,6 +421,43 @@ void intel_mocs_init_engine(struct intel_engine_cs *engine)
 }
 
 /**
+ * intel_mocs_init_global() - program the global mocs registers
+ * gt:      pointer to struct intel_gt
+ *
+ * This function initializes the MOCS global registers.
+ */
+void intel_mocs_init_global(struct intel_gt *gt)
+{
+	struct intel_uncore *uncore = gt->uncore;
+	struct drm_i915_mocs_table table;
+	unsigned int index;
+
+	if (!HAS_GLOBAL_MOCS_REGISTERS(gt->i915))
+		return;
+
+	if (!get_mocs_settings(gt, &table))
+		return;
+
+	if (GEM_DEBUG_WARN_ON(table.size > table.n_entries))
+		return;
+
+	for (index = 0; index < table.size; index++)
+		intel_uncore_write(uncore,
+				   GEN12_GLOBAL_MOCS(index),
+				   table.table[index].control_value);
+
+	/*
+	 * Ok, now set the unused entries to the invalid entry (index 0). These
+	 * entries are officially undefined and no contract for the contents and
+	 * settings is given for these entries.
+	 */
+	for (; index < table.n_entries; index++)
+		intel_uncore_write(uncore,
+				   GEN12_GLOBAL_MOCS(index),
+				   table.table[0].control_value);
+}
+
+/**
  * emit_mocs_control_table() - emit the mocs control table
  * @rq:	Request to set up the MOCS table for.
  * @table:	The values to program into the control regs.
@@ -619,7 +660,8 @@ int intel_mocs_emit(struct i915_request *rq)
 	struct drm_i915_mocs_table t;
 	int ret;
 
-	if (rq->engine->class != RENDER_CLASS)
+	if (HAS_GLOBAL_MOCS_REGISTERS(rq->i915) ||
+	    rq->engine->class != RENDER_CLASS)
 		return 0;
 
 	if (get_mocs_settings(rq->engine->gt, &t)) {