drm/xe/kunit: Add test for LMTT operations

The LMTT variants are abstracted with xe_lmtt_ops. Make sure that
both 2L and ML ops implementations are correct.
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com>
Link: https://lore.kernel.org/r/20231128151507.1015-6-michal.wajdeczko@intel.comSigned-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

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

+// SPDX-License-Identifier: GPL-2.0 AND MIT
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#include <kunit/test.h>
+
+static const struct lmtt_ops_param {
+	const char *desc;
+	const struct xe_lmtt_ops *ops;
+} lmtt_ops_params[] = {
+	{ "2-level", &lmtt_2l_ops, },
+	{ "multi-level", &lmtt_ml_ops, },
+};
+
+static void lmtt_ops_param_get_desc(const struct lmtt_ops_param *p, char *desc)
+{
+	snprintf(desc, KUNIT_PARAM_DESC_SIZE, "%s", p->desc);
+}
+
+KUNIT_ARRAY_PARAM(lmtt_ops, lmtt_ops_params, lmtt_ops_param_get_desc);
+
+static void test_ops(struct kunit *test)
+{
+	const struct lmtt_ops_param *p = test->param_value;
+	const struct xe_lmtt_ops *ops = p->ops;
+	unsigned int n;
+
+	KUNIT_ASSERT_NOT_NULL(test, ops->lmtt_root_pd_level);
+	KUNIT_ASSERT_NOT_NULL(test, ops->lmtt_pte_num);
+	KUNIT_ASSERT_NOT_NULL(test, ops->lmtt_pte_size);
+	KUNIT_ASSERT_NOT_NULL(test, ops->lmtt_pte_shift);
+	KUNIT_ASSERT_NOT_NULL(test, ops->lmtt_pte_index);
+	KUNIT_ASSERT_NOT_NULL(test, ops->lmtt_pte_encode);
+
+	KUNIT_EXPECT_NE(test, ops->lmtt_root_pd_level(), 0);
+
+	for (n = 0; n <= ops->lmtt_root_pd_level(); n++) {
+		KUNIT_EXPECT_NE_MSG(test, ops->lmtt_pte_num(n), 0,
+				    "level=%u", n);
+		KUNIT_EXPECT_NE_MSG(test, ops->lmtt_pte_size(n), 0,
+				    "level=%u", n);
+		KUNIT_EXPECT_NE_MSG(test, ops->lmtt_pte_encode(0, n), LMTT_PTE_INVALID,
+				    "level=%u", n);
+	}
+
+	for (n = 0; n < ops->lmtt_root_pd_level(); n++) {
+		u64 addr = BIT_ULL(ops->lmtt_pte_shift(n));
+
+		KUNIT_EXPECT_NE_MSG(test, ops->lmtt_pte_shift(n), 0,
+				    "level=%u", n);
+		KUNIT_EXPECT_EQ_MSG(test, ops->lmtt_pte_index(addr - 1, n), 0,
+				    "addr=%#llx level=%u", addr, n);
+		KUNIT_EXPECT_EQ_MSG(test, ops->lmtt_pte_index(addr + 1, n), 1,
+				    "addr=%#llx level=%u", addr, n);
+		KUNIT_EXPECT_EQ_MSG(test, ops->lmtt_pte_index(addr * 2 - 1, n), 1,
+				    "addr=%#llx level=%u", addr, n);
+		KUNIT_EXPECT_EQ_MSG(test, ops->lmtt_pte_index(addr * 2, n), 2,
+				    "addr=%#llx level=%u", addr, n);
+	}
+}
+
+static struct kunit_case lmtt_test_cases[] = {
+	KUNIT_CASE_PARAM(test_ops, lmtt_ops_gen_params),
+	{}
+};
+
+static struct kunit_suite lmtt_suite = {
+	.name = "lmtt",
+	.test_cases = lmtt_test_cases,
+};
+
+kunit_test_suites(&lmtt_suite);

drivers/gpu/drm/xe/xe_lmtt.c

@@ -500,3 +500,7 @@ u64 xe_lmtt_estimate_pt_size(struct xe_lmtt *lmtt, u64 size)
 
 	return pt_size;
 }
+
+#if IS_BUILTIN(CONFIG_DRM_XE_KUNIT_TEST)
+#include "tests/xe_lmtt_test.c"
+#endif