drm/xe: Fix kunit integration due to missing prototypes

In order to avoid  -Werror=missing-prototypes, add the prototypes
in a separate tests/<test-name>_test.h file that is included by both
the implementation (tests/xe_<testname>.c, injected in xe.ko) and the
kunit module (tests/xe_<testname>_test.c -> xe-<testname>-test.ko).

v2: Add header and don't add ifdef to files that are already not built
when not using kunit (Matt Auld)

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

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

@@ -5,6 +5,8 @@
 
 #include <kunit/test.h>
 
+#include "tests/xe_bo_test.h"
+
 #include "xe_bo_evict.h"
 #include "xe_pci.h"
 

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

@@ -3,10 +3,9 @@
  * Copyright © 2022 Intel Corporation
  */
 
-#include <kunit/test.h>
+#include "xe_bo_test.h"
 
-void xe_ccs_migrate_kunit(struct kunit *test);
-void xe_bo_evict_kunit(struct kunit *test);
+#include <kunit/test.h>
 
 static struct kunit_case xe_bo_tests[] = {
 	KUNIT_CASE(xe_ccs_migrate_kunit),

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

@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 AND MIT */
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#ifndef __XE_BO_TEST_H__
+#define __XE_BO_TEST_H__
+
+struct kunit;
+
+void xe_ccs_migrate_kunit(struct kunit *test);
+void xe_bo_evict_kunit(struct kunit *test);
+
+#endif

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

@@ -5,6 +5,8 @@
 
 #include <kunit/test.h>
 
+#include "tests/xe_dma_buf_test.h"
+
 #include "xe_pci.h"
 
 static bool p2p_enabled(struct dma_buf_test_params *params)

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

@@ -3,9 +3,9 @@
  * Copyright © 2022 Intel Corporation
  */
 
-#include <kunit/test.h>
+#include "xe_dma_buf_test.h"
 
-void xe_dma_buf_kunit(struct kunit *test);
+#include <kunit/test.h>
 
 static struct kunit_case xe_dma_buf_tests[] = {
 	KUNIT_CASE(xe_dma_buf_kunit),

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

@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 AND MIT */
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#ifndef __XE_DMA_BUF_TEST_H__
+#define __XE_DMA_BUF_TEST_H__
+
+struct kunit;
+
+void xe_dma_buf_kunit(struct kunit *test);
+
+#endif

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

@@ -5,6 +5,8 @@
 
 #include <kunit/test.h>
 
+#include "tests/xe_migrate_test.h"
+
 #include "xe_pci.h"
 
 static bool sanity_fence_failed(struct xe_device *xe, struct dma_fence *fence,

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

@@ -3,9 +3,9 @@
  * Copyright © 2022 Intel Corporation
  */
 
-#include <kunit/test.h>
+#include "xe_migrate_test.h"
 
-void xe_migrate_sanity_kunit(struct kunit *test);
+#include <kunit/test.h>
 
 static struct kunit_case xe_migrate_tests[] = {
 	KUNIT_CASE(xe_migrate_sanity_kunit),

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

@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 AND MIT */
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#ifndef __XE_MIGRATE_TEST_H__
+#define __XE_MIGRATE_TEST_H__
+
+struct kunit;
+
+void xe_migrate_sanity_kunit(struct kunit *test);
+
+#endif