static int init_status_page(struct intel_engine_cs *engine)
{
	struct drm_i915_gem_object *obj;
	struct i915_vma *vma;
	void *vaddr;
	int ret;

	/*
	 * Though the HWS register does support 36bit addresses, historically
	 * we have had hangs and corruption reported due to wild writes if
	 * the HWS is placed above 4G. We only allow objects to be allocated
	 * in GFP_DMA32 for i965, and no earlier physical address users had
	 * access to more than 4G.
	 */
	obj = i915_gem_object_create_internal(engine->i915, PAGE_SIZE);
	if (IS_ERR(obj)) {
		drm_err(&engine->i915->drm,
			"Failed to allocate status page\n");
		return PTR_ERR(obj);
	}

	i915_gem_object_set_cache_coherency(obj, I915_CACHE_LLC);

	vma = i915_vma_instance(obj, &engine->gt->ggtt->vm, NULL);
	if (IS_ERR(vma)) {
		ret = PTR_ERR(vma);
		goto err;
	}

	vaddr = i915_gem_object_pin_map(obj, I915_MAP_WB);
	if (IS_ERR(vaddr)) {
		ret = PTR_ERR(vaddr);
		goto err;
	}

	engine->status_page.addr = memset(vaddr, 0, PAGE_SIZE);
	engine->status_page.vma = vma;

	if (!HWS_NEEDS_PHYSICAL(engine->i915)) {
		ret = pin_ggtt_status_page(engine, vma);
		if (ret)
			goto err_unpin;
	}

	return 0;

err_unpin:
	i915_gem_object_unpin_map(obj);
err:
	i915_gem_object_put(obj);
	return ret;
}
static int init_status_page(struct intel_engine_cs *engine)
{
	struct drm_i915_gem_object *obj;
	struct i915_vma *vma;
	void *vaddr;
	int ret;

	 
	obj = i915_gem_object_create_internal(engine->i915, PAGE_SIZE);
	if (IS_ERR(obj)) {
		drm_err(&engine->i915->drm,
			"Failed to allocate status page\n");
		return PTR_ERR(obj);
	}

	i915_gem_object_set_cache_coherency(obj, I915_CACHE_LLC);

	vma = i915_vma_instance(obj, &engine->gt->ggtt->vm, NULL);
	if (IS_ERR(vma)) {
		ret = PTR_ERR(vma);
		goto err;
	}

	vaddr = i915_gem_object_pin_map(obj, I915_MAP_WB);
	if (IS_ERR(vaddr)) {
		ret = PTR_ERR(vaddr);
		goto err;
	}

	engine->status_page.addr = memset(vaddr, 0, PAGE_SIZE);
	engine->status_page.vma = vma;

	if (!HWS_NEEDS_PHYSICAL(engine->i915)) {
		ret = pin_ggtt_status_page(engine, vma);
		if (ret)
			goto err_unpin;
	}

	return 0;

err_unpin:
	i915_gem_object_unpin_map(obj);
err:
	i915_gem_object_put(obj);
	return ret;
}