drm/i915/guc: Support programming the EU priority in the GuC descriptor

In GuC submission mode the EU priority must be updated by the GuC rather
than the driver as the GuC owns the programming of the context descriptor.

Given that the GuC code uses the GuC priorities, we can't use a generic
function using i915 priorities for both execlists and GuC submission.
The existing function has therefore been pushed to the execlists
back-end while a new one has been added for GuC.

v2: correctly use the GuC prio.

Cc: John Harrison <john.c.harrison@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Aravind Iddamsetty <aravind.iddamsetty@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220504234636.2119794-1-daniele.ceraolospurio@intel.com

drivers/gpu/drm/i915/gt/intel_execlists_submission.c

@@ -661,6 +661,16 @@ static inline void execlists_schedule_out(struct i915_request *rq)
 	i915_request_put(rq);
 }
 
+static u32 map_i915_prio_to_lrc_desc_prio(int prio)
+{
+	if (prio > I915_PRIORITY_NORMAL)
+		return GEN12_CTX_PRIORITY_HIGH;
+	else if (prio < I915_PRIORITY_NORMAL)
+		return GEN12_CTX_PRIORITY_LOW;
+	else
+		return GEN12_CTX_PRIORITY_NORMAL;
+}
+
 static u64 execlists_update_context(struct i915_request *rq)
 {
 	struct intel_context *ce = rq->context;
@@ -669,7 +679,7 @@ static u64 execlists_update_context(struct i915_request *rq)
 
 	desc = ce->lrc.desc;
 	if (rq->engine->flags & I915_ENGINE_HAS_EU_PRIORITY)
-		desc |= lrc_desc_priority(rq_prio(rq));
+		desc |= map_i915_prio_to_lrc_desc_prio(rq_prio(rq));
 
 	/*
 	 * WaIdleLiteRestore:bdw,skl

drivers/gpu/drm/i915/gt/intel_lrc.h

@@ -111,16 +111,6 @@ enum {
 #define XEHP_SW_COUNTER_SHIFT			58
 #define XEHP_SW_COUNTER_WIDTH			6
 
-static inline u32 lrc_desc_priority(int prio)
-{
-	if (prio > I915_PRIORITY_NORMAL)
-		return GEN12_CTX_PRIORITY_HIGH;
-	else if (prio < I915_PRIORITY_NORMAL)
-		return GEN12_CTX_PRIORITY_LOW;
-	else
-		return GEN12_CTX_PRIORITY_NORMAL;
-}
-
 static inline void lrc_runtime_start(struct intel_context *ce)
 {
 	struct intel_context_stats *stats = &ce->stats;

drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c

@@ -2394,6 +2394,26 @@ static int guc_context_policy_init(struct intel_context *ce, bool loop)
 	return ret;
 }
 
+static u32 map_guc_prio_to_lrc_desc_prio(u8 prio)
+{
+	/*
+	 * this matches the mapping we do in map_i915_prio_to_guc_prio()
+	 * (e.g. prio < I915_PRIORITY_NORMAL maps to GUC_CLIENT_PRIORITY_NORMAL)
+	 */
+	switch (prio) {
+	default:
+		MISSING_CASE(prio);
+		fallthrough;
+	case GUC_CLIENT_PRIORITY_KMD_NORMAL:
+		return GEN12_CTX_PRIORITY_NORMAL;
+	case GUC_CLIENT_PRIORITY_NORMAL:
+		return GEN12_CTX_PRIORITY_LOW;
+	case GUC_CLIENT_PRIORITY_HIGH:
+	case GUC_CLIENT_PRIORITY_KMD_HIGH:
+		return GEN12_CTX_PRIORITY_HIGH;
+	}
+}
+
 static void prepare_context_registration_info(struct intel_context *ce,
 					      struct guc_ctxt_registration_info *info)
 {
@@ -2420,6 +2440,8 @@ static void prepare_context_registration_info(struct intel_context *ce,
 	 */
 	info->hwlrca_lo = lower_32_bits(ce->lrc.lrca);
 	info->hwlrca_hi = upper_32_bits(ce->lrc.lrca);
+	if (engine->flags & I915_ENGINE_HAS_EU_PRIORITY)
+		info->hwlrca_lo |= map_guc_prio_to_lrc_desc_prio(ce->guc_state.prio);
 	info->flags = CONTEXT_REGISTRATION_FLAG_KMD;
 
 	/*