drm/i915/selftests: Move local mock_ggtt allocations to the heap

This struct appears quite large and pushes our stack frame over
1024 bytes -- too high for conservative setups. So move the mock_ggtt
struct to the heap.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190217202518.24730-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/selftests/i915_gem_gtt.c

@@ -1681,25 +1681,31 @@ int i915_gem_gtt_mock_selftests(void)
 		SUBTEST(igt_gtt_insert),
 	};
 	struct drm_i915_private *i915;
-	struct i915_ggtt ggtt;
+	struct i915_ggtt *ggtt;
 	int err;
 
 	i915 = mock_gem_device();
 	if (!i915)
 		return -ENOMEM;
 
-	mock_init_ggtt(i915, &ggtt);
+	ggtt = kmalloc(sizeof(*ggtt), GFP_KERNEL);
+	if (!ggtt) {
+		err = -ENOMEM;
+		goto out_put;
+	}
+	mock_init_ggtt(i915, ggtt);
 
 	mutex_lock(&i915->drm.struct_mutex);
-	err = i915_subtests(tests, &ggtt);
+	err = i915_subtests(tests, ggtt);
 	mock_device_flush(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 
 	i915_gem_drain_freed_objects(i915);
 
-	mock_fini_ggtt(&ggtt);
+	mock_fini_ggtt(ggtt);
+	kfree(ggtt);
+out_put:
 	drm_dev_put(&i915->drm);
-
 	return err;
 }
 

drivers/gpu/drm/i915/selftests/i915_vma.c

@@ -725,24 +725,30 @@ int i915_vma_mock_selftests(void)
 		SUBTEST(igt_vma_partial),
 	};
 	struct drm_i915_private *i915;
-	struct i915_ggtt ggtt;
+	struct i915_ggtt *ggtt;
 	int err;
 
 	i915 = mock_gem_device();
 	if (!i915)
 		return -ENOMEM;
 
-	mock_init_ggtt(i915, &ggtt);
+	ggtt = kmalloc(sizeof(*ggtt), GFP_KERNEL);
+	if (!ggtt) {
+		err = -ENOMEM;
+		goto out_put;
+	}
+	mock_init_ggtt(i915, ggtt);
 
 	mutex_lock(&i915->drm.struct_mutex);
-	err = i915_subtests(tests, &ggtt);
+	err = i915_subtests(tests, ggtt);
 	mock_device_flush(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 
 	i915_gem_drain_freed_objects(i915);
 
-	mock_fini_ggtt(&ggtt);
+	mock_fini_ggtt(ggtt);
+	kfree(ggtt);
+out_put:
 	drm_dev_put(&i915->drm);
-
 	return err;
 }