[igt-dev] [PATCH i-g-t 1/2] i915/gem_engine_topology: Generate engine names based on class

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

With the introduction of dynamic subtests we got one step closer towards
eliminating the duality of static and dynamic engine enumeration.

This patch makes one more step in that direction by removing the
dependency on the static list when generating probed engine names.

v2:
 * Fix __for_each_static_engine iterator.
 * Prefix unknown engines with 'unknown'.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Cc: Andi Shyti <andi.shyti at intel.com>
Cc: Petri Latvala <petri.latvala at intel.com>
---
 lib/i915/gem_engine_topology.c | 39 +++++++++++++++++++---------------
 lib/i915/gem_engine_topology.h |  2 +-
 lib/igt_gt.h                   |  2 +-
 3 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/lib/i915/gem_engine_topology.c b/lib/i915/gem_engine_topology.c
index 790d455ff2ad..c3645eab8538 100644
--- a/lib/i915/gem_engine_topology.c
+++ b/lib/i915/gem_engine_topology.c
@@ -97,39 +97,43 @@ static void ctx_map_engines(int fd, struct intel_engine_data *ed,
 	gem_context_set_param(fd, param);
 }
 
+static const char *class_names[] = {
+	[I915_ENGINE_CLASS_RENDER]	  = "rcs",
+	[I915_ENGINE_CLASS_COPY]	  = "bcs",
+	[I915_ENGINE_CLASS_VIDEO]	  = "vcs",
+	[I915_ENGINE_CLASS_VIDEO_ENHANCE] = "vecs",
+};
+
 static void init_engine(struct intel_execution_engine2 *e2,
 			int class, int instance, uint64_t flags)
 {
-	const struct intel_execution_engine2 *__e2;
-	static const char *unknown_name = "unknown",
-			  *virtual_name = "virtual";
+	int ret;
 
 	e2->class    = class;
 	e2->instance = instance;
-	e2->flags    = flags;
 
 	/* engine is a virtual engine */
 	if (class == I915_ENGINE_CLASS_INVALID &&
 	    instance == I915_ENGINE_CLASS_INVALID_VIRTUAL) {
-		e2->name = virtual_name;
+		strcpy(e2->name, "virtual");
 		e2->is_virtual = true;
 		return;
+	} else {
+		e2->is_virtual = false;
 	}
 
-	__for_each_static_engine(__e2)
-		if (__e2->class == class && __e2->instance == instance)
-			break;
-
-	if (__e2->name) {
-		e2->name = __e2->name;
+	if (class < ARRAY_SIZE(class_names)) {
+		e2->flags = flags;
+		ret = snprintf(e2->name, sizeof(e2->name), "%s%u",
+			       class_names[class], instance);
 	} else {
 		igt_warn("found unknown engine (%d, %d)\n", class, instance);
-		e2->name = unknown_name;
 		e2->flags = -1;
+		ret = snprintf(e2->name, sizeof(e2->name), "unknown%u-%u",
+			       class, instance);
 	}
 
-	/* just to remark it */
-	e2->is_virtual = false;
+	igt_assert(ret < sizeof(e2->name));
 }
 
 static void query_engine_list(int fd, struct intel_engine_data *ed)
@@ -223,7 +227,7 @@ struct intel_engine_data intel_init_engine_list(int fd, uint32_t ctx_id)
 			struct intel_execution_engine2 *__e2 =
 				&engine_data.engines[engine_data.nengines];
 
-			__e2->name       = e2->name;
+			strcpy(__e2->name, e2->name);
 			__e2->instance   = e2->instance;
 			__e2->class      = e2->class;
 			__e2->flags      = e2->flags;
@@ -297,12 +301,11 @@ struct intel_execution_engine2 gem_eb_flags_to_engine(unsigned int flags)
 		.class = -1,
 		.instance = -1,
 		.flags = -1,
-		.name = "invalid"
 	};
 
 	if (ring == I915_EXEC_DEFAULT) {
 		e2__.flags = I915_EXEC_DEFAULT;
-		e2__.name = "default";
+		strcpy(e2__.name, "default");
 	} else {
 		const struct intel_execution_engine2 *e2;
 
@@ -310,6 +313,8 @@ struct intel_execution_engine2 gem_eb_flags_to_engine(unsigned int flags)
 			if (e2->flags == ring)
 				return *e2;
 		}
+
+		strcpy(e2__.name, "invalid");
 	}
 
 	return e2__;
diff --git a/lib/i915/gem_engine_topology.h b/lib/i915/gem_engine_topology.h
index d98773e06783..525741cc8a08 100644
--- a/lib/i915/gem_engine_topology.h
+++ b/lib/i915/gem_engine_topology.h
@@ -61,7 +61,7 @@ bool gem_engine_is_equal(const struct intel_execution_engine2 *e1,
 struct intel_execution_engine2 gem_eb_flags_to_engine(unsigned int flags);
 
 #define __for_each_static_engine(e__) \
-	for ((e__) = intel_execution_engines2; (e__)->name; (e__)++)
+	for ((e__) = intel_execution_engines2; (e__)->name[0]; (e__)++)
 
 #define for_each_context_engine(fd__, ctx__, e__) \
 	for (struct intel_engine_data i__ = intel_init_engine_list(fd__, ctx__); \
diff --git a/lib/igt_gt.h b/lib/igt_gt.h
index 66088d39176a..6a8eceb68817 100644
--- a/lib/igt_gt.h
+++ b/lib/igt_gt.h
@@ -95,7 +95,7 @@ bool gem_can_store_dword(int fd, unsigned int engine);
 bool gem_class_can_store_dword(int fd, int class);
 
 extern const struct intel_execution_engine2 {
-	const char *name;
+	char name[16];
 	int class;
 	int instance;
 	uint64_t flags;
-- 
2.20.1