drm/xe/kunit: Define helper functions to allocate fake xe device

There will be more KUnit tests added that will require fake device.
Define generic helper functions to avoid code duplications.

Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20231218190629.502-6-michal.wajdeczko@intel.comSigned-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>

drivers/gpu/drm/xe/Makefile

@@ -156,6 +156,9 @@ xe-$(CONFIG_PCI_IOV) += \
 	xe_lmtt_2l.o \
 	xe_lmtt_ml.o
 
+xe-$(CONFIG_DRM_XE_KUNIT_TEST) += \
+	tests/xe_kunit_helpers.o
+
 # i915 Display compat #defines and #includes
 subdir-ccflags-$(CONFIG_DRM_XE_DISPLAY) += \
 	-I$(srctree)/$(src)/display/ext \

drivers/gpu/drm/xe/tests/xe_kunit_helpers.c

+// SPDX-License-Identifier: GPL-2.0 AND MIT
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#include <kunit/test.h>
+#include <kunit/static_stub.h>
+#include <kunit/visibility.h>
+
+#include <drm/drm_drv.h>
+#include <drm/drm_kunit_helpers.h>
+
+#include "tests/xe_kunit_helpers.h"
+#include "tests/xe_pci_test.h"
+#include "xe_device_types.h"
+
+/**
+ * xe_kunit_helper_alloc_xe_device - Allocate a &xe_device for a KUnit test.
+ * @test: the &kunit where this &xe_device will be used
+ * @dev: The parent device object
+ *
+ * This function allocates xe_device using drm_kunit_helper_alloc_device().
+ * The xe_device allocation is managed by the test.
+ *
+ * @dev should be allocated using drm_kunit_helper_alloc_device().
+ *
+ * This function uses KUNIT_ASSERT to detect any allocation failures.
+ *
+ * Return: A pointer to the new &xe_device.
+ */
+struct xe_device *xe_kunit_helper_alloc_xe_device(struct kunit *test,
+						  struct device *dev)
+{
+	struct xe_device *xe;
+
+	xe = drm_kunit_helper_alloc_drm_device(test, dev,
+					       struct xe_device,
+					       drm, DRIVER_GEM);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, xe);
+	return xe;
+}
+EXPORT_SYMBOL_IF_KUNIT(xe_kunit_helper_alloc_xe_device);
+
+/**
+ * xe_kunit_helper_xe_device_test_init - Prepare a &xe_device for a KUnit test.
+ * @test: the &kunit where this fake &xe_device will be used
+ *
+ * This function allocates and initializes a fake &xe_device and stores its
+ * pointer as &kunit.priv to allow the test code to access it.
+ *
+ * This function can be directly used as custom implementation of
+ * &kunit_suite.init.
+ *
+ * It is possible to prepare specific variant of the fake &xe_device by passing
+ * in &kunit.priv pointer to the struct xe_pci_fake_data supplemented with
+ * desired parameters prior to calling this function.
+ *
+ * This function uses KUNIT_ASSERT to detect any failures.
+ *
+ * Return: Always 0.
+ */
+int xe_kunit_helper_xe_device_test_init(struct kunit *test)
+{
+	struct xe_device *xe;
+	struct device *dev;
+	int err;
+
+	dev = drm_kunit_helper_alloc_device(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev);
+
+	xe = xe_kunit_helper_alloc_xe_device(test, dev);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, xe);
+
+	err = xe_pci_fake_device_init(xe);
+	KUNIT_ASSERT_EQ(test, err, 0);
+
+	test->priv = xe;
+	return 0;
+}
+EXPORT_SYMBOL_IF_KUNIT(xe_kunit_helper_xe_device_test_init);

drivers/gpu/drm/xe/tests/xe_kunit_helpers.h

+/* SPDX-License-Identifier: GPL-2.0 AND MIT */
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#ifndef _XE_KUNIT_HELPERS_H_
+#define _XE_KUNIT_HELPERS_H_
+
+struct device;
+struct kunit;
+struct xe_device;
+
+struct xe_device *xe_kunit_helper_alloc_xe_device(struct kunit *test,
+						  struct device *dev);
+int xe_kunit_helper_xe_device_test_init(struct kunit *test);
+
+#endif