drm/i915/selftests: Check for hangs mid context execution tests

Use the live_test struct to record the reset count before and compare it
at the end of the test to assert that no mystery hang occurred during the
test.

v2: Check per-engine resets as well
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181012122404.10874-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/selftests/i915_gem_context.c

@@ -39,7 +39,8 @@ struct live_test {
 	const char *func;
 	const char *name;
 
-	unsigned int reset_count;
+	unsigned int reset_global;
+	unsigned int reset_engine[I915_NUM_ENGINES];
 };
 
 static int begin_live_test(struct live_test *t,
@@ -47,6 +48,8 @@ static int begin_live_test(struct live_test *t,
 			   const char *func,
 			   const char *name)
 {
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
 	int err;
 
 	t->i915 = i915;
@@ -63,7 +66,11 @@ static int begin_live_test(struct live_test *t,
 	}
 
 	i915->gpu_error.missed_irq_rings = 0;
-	t->reset_count = i915_reset_count(&i915->gpu_error);
+	t->reset_global = i915_reset_count(&i915->gpu_error);
+
+	for_each_engine(engine, i915, id)
+		t->reset_engine[id] =
+			i915_reset_engine_count(&i915->gpu_error, engine);
 
 	return 0;
 }
@@ -71,14 +78,28 @@ static int begin_live_test(struct live_test *t,
 static int end_live_test(struct live_test *t)
 {
 	struct drm_i915_private *i915 = t->i915;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
 
 	if (igt_flush_test(i915, I915_WAIT_LOCKED))
 		return -EIO;
 
-	if (t->reset_count != i915_reset_count(&i915->gpu_error)) {
+	if (t->reset_global != i915_reset_count(&i915->gpu_error)) {
 		pr_err("%s(%s): GPU was reset %d times!\n",
 		       t->func, t->name,
-		       i915_reset_count(&i915->gpu_error) - t->reset_count);
+		       i915_reset_count(&i915->gpu_error) - t->reset_global);
+		return -EIO;
+	}
+
+	for_each_engine(engine, i915, id) {
+		if (t->reset_engine[id] ==
+		    i915_reset_engine_count(&i915->gpu_error, engine))
+			continue;
+
+		pr_err("%s(%s): engine '%s' was reset %d times!\n",
+		       t->func, t->name, engine->name,
+		       i915_reset_engine_count(&i915->gpu_error, engine) -
+		       t->reset_engine[id]);
 		return -EIO;
 	}
 
@@ -531,10 +552,11 @@ static int igt_ctx_exec(void *arg)
 {
 	struct drm_i915_private *i915 = arg;
 	struct drm_i915_gem_object *obj = NULL;
+	unsigned long ncontexts, ndwords, dw;
 	struct drm_file *file;
 	IGT_TIMEOUT(end_time);
 	LIST_HEAD(objects);
-	unsigned long ncontexts, ndwords, dw;
+	struct live_test t;
 	int err = -ENODEV;
 
 	/*
@@ -552,6 +574,10 @@ static int igt_ctx_exec(void *arg)
 
 	mutex_lock(&i915->drm.struct_mutex);
 
+	err = begin_live_test(&t, i915, __func__, "");
+	if (err)
+		goto out_unlock;
+
 	ncontexts = 0;
 	ndwords = 0;
 	dw = 0;
@@ -616,7 +642,7 @@ static int igt_ctx_exec(void *arg)
 	}
 
 out_unlock:
-	if (igt_flush_test(i915, I915_WAIT_LOCKED))
+	if (end_live_test(&t))
 		err = -EIO;
 	mutex_unlock(&i915->drm.struct_mutex);
 
@@ -628,13 +654,14 @@ static int igt_ctx_readonly(void *arg)
 {
 	struct drm_i915_private *i915 = arg;
 	struct drm_i915_gem_object *obj = NULL;
+	struct i915_gem_context *ctx;
+	struct i915_hw_ppgtt *ppgtt;
+	unsigned long ndwords, dw;
 	struct drm_file *file;
 	I915_RND_STATE(prng);
 	IGT_TIMEOUT(end_time);
 	LIST_HEAD(objects);
-	struct i915_gem_context *ctx;
-	struct i915_hw_ppgtt *ppgtt;
-	unsigned long ndwords, dw;
+	struct live_test t;
 	int err = -ENODEV;
 
 	/*
@@ -649,6 +676,10 @@ static int igt_ctx_readonly(void *arg)
 
 	mutex_lock(&i915->drm.struct_mutex);
 
+	err = begin_live_test(&t, i915, __func__, "");
+	if (err)
+		goto out_unlock;
+
 	ctx = i915_gem_create_context(i915, file->driver_priv);
 	if (IS_ERR(ctx)) {
 		err = PTR_ERR(ctx);
@@ -721,7 +752,7 @@ static int igt_ctx_readonly(void *arg)
 	}
 
 out_unlock:
-	if (igt_flush_test(i915, I915_WAIT_LOCKED))
+	if (end_live_test(&t))
 		err = -EIO;
 	mutex_unlock(&i915->drm.struct_mutex);