drm/selftests: Move i915 buddy selftests into drm

- move i915 buddy selftests into drm selftests folder
- add Makefile and Kconfig support
- add sanitycheck testcase

Prerequisites
- These series of selftests patches are created on top of
  drm buddy series
- Enable kselftests for DRM as a module in .config
Signed-off-by: Arunpravin <Arunpravin.PaneerSelvam@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220222174845.2175-1-Arunpravin.PaneerSelvam@amd.comSigned-off-by: Christian König <christian.koenig@amd.com>

drivers/gpu/drm/Kconfig

@@ -71,6 +71,7 @@ config DRM_DEBUG_SELFTEST
 	select DRM_DP_HELPER
 	select DRM_LIB_RANDOM
 	select DRM_KMS_HELPER
+	select DRM_BUDDY
 	select DRM_EXPORT_FOR_TESTS if m
 	default n
 	help

drivers/gpu/drm/selftests/Makefile

@@ -4,4 +4,5 @@ test-drm_modeset-y := test-drm_modeset_common.o test-drm_plane_helper.o \
 		      test-drm_damage_helper.o test-drm_dp_mst_helper.o \
 		      test-drm_rect.o
 
-obj-$(CONFIG_DRM_DEBUG_SELFTEST) += test-drm_mm.o test-drm_modeset.o test-drm_cmdline_parser.o
+obj-$(CONFIG_DRM_DEBUG_SELFTEST) += test-drm_mm.o test-drm_modeset.o test-drm_cmdline_parser.o \
+				    test-drm_buddy.o

drivers/gpu/drm/selftests/drm_buddy_selftests.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/* List each unit test as selftest(name, function)
+ *
+ * The name is used as both an enum and expanded as igt__name to create
+ * a module parameter. It must be unique and legal for a C identifier.
+ *
+ * Tests are executed in order by igt/drm_buddy
+ */
+selftest(sanitycheck, igt_sanitycheck) /* keep first (selfcheck for igt) */

drivers/gpu/drm/selftests/test-drm_buddy.c

+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2019 Intel Corporation
+ */
+
+#define pr_fmt(fmt) "drm_buddy: " fmt
+
+#include <linux/module.h>
+
+#include <drm/drm_buddy.h>
+
+#include "../lib/drm_random.h"
+
+#define TESTS "drm_buddy_selftests.h"
+#include "drm_selftest.h"
+
+static unsigned int random_seed;
+
+static int igt_sanitycheck(void *ignored)
+{
+	pr_info("%s - ok!\n", __func__);
+	return 0;
+}
+
+#include "drm_selftest.c"
+
+static int __init test_drm_buddy_init(void)
+{
+	int err;
+
+	while (!random_seed)
+		random_seed = get_random_int();
+
+	pr_info("Testing DRM buddy manager (struct drm_buddy), with random_seed=0x%x\n",
+		random_seed);
+	err = run_selftests(selftests, ARRAY_SIZE(selftests), NULL);
+
+	return err > 0 ? 0 : err;
+}
+
+static void __exit test_drm_buddy_exit(void)
+{
+}
+
+module_init(test_drm_buddy_init);
+module_exit(test_drm_buddy_exit);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL");