drm/i915/gt: Show engine properties in the pretty printer

When debugging the engine state, include the user properties that may,
or may not, have been adjusted by the user/test.

For example,
vecs0
	...
	Properties:
		heartbeat_interval_ms: 2500 [default 2500]
		max_busywait_duration_ns: 8000 [default 8000]
		preempt_timeout_ms: 640 [default 640]
		stop_timeout_ms: 100 [default 100]
		timeslice_duration_ms: 1 [default 1]
Suggested-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200916090059.3189-1-chris@chris-wilson.co.uk

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

@@ -1599,6 +1599,41 @@ static unsigned long list_count(struct list_head *list)
 	return count;
 }
 
+static unsigned long read_ul(void *p, size_t x)
+{
+	return *(unsigned long *)(p + x);
+}
+
+static void print_properties(struct intel_engine_cs *engine,
+			     struct drm_printer *m)
+{
+	static const struct pmap {
+		size_t offset;
+		const char *name;
+	} props[] = {
+#define P(x) { \
+	.offset = offsetof(typeof(engine->props), x), \
+	.name = #x \
+}
+		P(heartbeat_interval_ms),
+		P(max_busywait_duration_ns),
+		P(preempt_timeout_ms),
+		P(stop_timeout_ms),
+		P(timeslice_duration_ms),
+
+		{},
+#undef P
+	};
+	const struct pmap *p;
+
+	drm_printf(m, "\tProperties:\n");
+	for (p = props; p->name; p++)
+		drm_printf(m, "\t\t%s: %lu [default %lu]\n",
+			   p->name,
+			   read_ul(&engine->props, p->offset),
+			   read_ul(&engine->defaults, p->offset));
+}
+
 void intel_engine_dump(struct intel_engine_cs *engine,
 		       struct drm_printer *m,
 		       const char *header, ...)
@@ -1641,6 +1676,7 @@ void intel_engine_dump(struct intel_engine_cs *engine,
 	drm_printf(m, "\tReset count: %d (global %d)\n",
 		   i915_reset_engine_count(error, engine),
 		   i915_reset_count(error));
+	print_properties(engine, m);
 
 	drm_printf(m, "\tRequests:\n");