drm/i915: Add logical engine mapping

Add logical engine mapping. This is required for split-frame, as
workloads need to be placed on engines in a logically contiguous manner.

v2:
 (Daniel Vetter)
  - Add kernel doc for new fields
v3:
 (Tvrtko)
  - Update comment for new logical_mask field
v4:
 (John Harrison)
  - Update comment for new logical_mask field

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211014172005.27155-6-matthew.brost@intel.com

1 files changed, 51 insertions, 9 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index 2ae57e4656a3..2eb798ad068b 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -290,7 +290,8 @@ static void nop_irq_handler(struct intel_engine_cs *engine, u16 iir)
 	GEM_DEBUG_WARN_ON(iir);
 }
 
-static int intel_engine_setup(struct intel_gt *gt, enum intel_engine_id id)
+static int intel_engine_setup(struct intel_gt *gt, enum intel_engine_id id,
+			      u8 logical_instance)
 {
 	const struct engine_info *info = &intel_engines[id];
 	struct drm_i915_private *i915 = gt->i915;
@@ -335,6 +336,7 @@ static int intel_engine_setup(struct intel_gt *gt, enum intel_engine_id id)
 
 	engine->class = info->class;
 	engine->instance = info->instance;
+	engine->logical_mask = BIT(logical_instance);
 	__sprint_engine_name(engine);
 
 	engine->props.heartbeat_interval_ms =
@@ -588,6 +590,37 @@ static intel_engine_mask_t init_engine_mask(struct intel_gt *gt)
 	return info->engine_mask;
 }
 
+static void populate_logical_ids(struct intel_gt *gt, u8 *logical_ids,
+				 u8 class, const u8 *map, u8 num_instances)
+{
+	int i, j;
+	u8 current_logical_id = 0;
+
+	for (j = 0; j < num_instances; ++j) {
+		for (i = 0; i < ARRAY_SIZE(intel_engines); ++i) {
+			if (!HAS_ENGINE(gt, i) ||
+			    intel_engines[i].class != class)
+				continue;
+
+			if (intel_engines[i].instance == map[j]) {
+				logical_ids[intel_engines[i].instance] =
+					current_logical_id++;
+				break;
+			}
+		}
+	}
+}
+
+static void setup_logical_ids(struct intel_gt *gt, u8 *logical_ids, u8 class)
+{
+	int i;
+	u8 map[MAX_ENGINE_INSTANCE + 1];
+
+	for (i = 0; i < MAX_ENGINE_INSTANCE + 1; ++i)
+		map[i] = i;
+	populate_logical_ids(gt, logical_ids, class, map, ARRAY_SIZE(map));
+}
+
 /**
  * intel_engines_init_mmio() - allocate and prepare the Engine Command Streamers
  * @gt: pointer to struct intel_gt
@@ -599,7 +632,8 @@ int intel_engines_init_mmio(struct intel_gt *gt)
 	struct drm_i915_private *i915 = gt->i915;
 	const unsigned int engine_mask = init_engine_mask(gt);
 	unsigned int mask = 0;
-	unsigned int i;
+	unsigned int i, class;
+	u8 logical_ids[MAX_ENGINE_INSTANCE + 1];
 	int err;
 
 	drm_WARN_ON(&i915->drm, engine_mask == 0);
@@ -609,15 +643,23 @@ int intel_engines_init_mmio(struct intel_gt *gt)
 	if (i915_inject_probe_failure(i915))
 		return -ENODEV;
 
-	for (i = 0; i < ARRAY_SIZE(intel_engines); i++) {
-		if (!HAS_ENGINE(gt, i))
-			continue;
+	for (class = 0; class < MAX_ENGINE_CLASS + 1; ++class) {
+		setup_logical_ids(gt, logical_ids, class);
 
-		err = intel_engine_setup(gt, i);
-		if (err)
-			goto cleanup;
+		for (i = 0; i < ARRAY_SIZE(intel_engines); ++i) {
+			u8 instance = intel_engines[i].instance;
+
+			if (intel_engines[i].class != class ||
+			    !HAS_ENGINE(gt, i))
+				continue;
 
-		mask |= BIT(i);
+			err = intel_engine_setup(gt, i,
+						 logical_ids[instance]);
+			if (err)
+				goto cleanup;
+
+			mask |= BIT(i);
+		}
 	}
 
 	/*