drm/ttm/tests: Add tests for ttm_tt_populate

Add tests for functions that add and release pages to TTs. Test the
swapin operation. Export ttm_tt_unpopulate, ttm_tt_swapin and
ttm_tt_swapout symbols for testing purposes.

Signed-off-by: Karolina Stolarek <karolina.stolarek@intel.com>
Reviewed-by: Somalapuram, Amaranath <asomalap@amd.com>
Tested-by: Somalapuram, Amaranath <asomalap@amd.com>
Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/ee42d83a472ba6bca22b4bce58f332f800891186.1718192625.git.karolina.stolarek@intel.com

2 files changed, 122 insertions, 0 deletions

diff --git a/drivers/gpu/drm/ttm/tests/ttm_tt_test.c b/drivers/gpu/drm/ttm/tests/ttm_tt_test.c
index 17988fa99fa6..a9d75a33acaf 100644
--- a/drivers/gpu/drm/ttm/tests/ttm_tt_test.c
+++ b/drivers/gpu/drm/ttm/tests/ttm_tt_test.c
@@ -256,6 +256,120 @@ static void ttm_tt_destroy_basic(struct kunit *test)
 	ttm_tt_destroy(devs->ttm_dev, bo->ttm);
 }
 
+static void ttm_tt_populate_null_ttm(struct kunit *test)
+{
+	const struct ttm_test_devices *devs = test->priv;
+	struct ttm_operation_ctx ctx = { };
+	int err;
+
+	err = ttm_tt_populate(devs->ttm_dev, NULL, &ctx);
+	KUNIT_ASSERT_EQ(test, err, -EINVAL);
+}
+
+static void ttm_tt_populate_populated_ttm(struct kunit *test)
+{
+	const struct ttm_test_devices *devs = test->priv;
+	struct ttm_operation_ctx ctx = { };
+	struct ttm_buffer_object *bo;
+	struct ttm_tt *tt;
+	struct page *populated_page;
+	int err;
+
+	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE, NULL);
+
+	tt = kunit_kzalloc(test, sizeof(*tt), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, tt);
+
+	err = ttm_tt_init(tt, bo, 0, ttm_cached, 0);
+	KUNIT_ASSERT_EQ(test, err, 0);
+
+	err = ttm_tt_populate(devs->ttm_dev, tt, &ctx);
+	KUNIT_ASSERT_EQ(test, err, 0);
+	populated_page = *tt->pages;
+
+	err = ttm_tt_populate(devs->ttm_dev, tt, &ctx);
+	KUNIT_ASSERT_PTR_EQ(test, populated_page, *tt->pages);
+}
+
+static void ttm_tt_unpopulate_basic(struct kunit *test)
+{
+	const struct ttm_test_devices *devs = test->priv;
+	struct ttm_operation_ctx ctx = { };
+	struct ttm_buffer_object *bo;
+	struct ttm_tt *tt;
+	int err;
+
+	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE, NULL);
+
+	tt = kunit_kzalloc(test, sizeof(*tt), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, tt);
+
+	err = ttm_tt_init(tt, bo, 0, ttm_cached, 0);
+	KUNIT_ASSERT_EQ(test, err, 0);
+
+	err = ttm_tt_populate(devs->ttm_dev, tt, &ctx);
+	KUNIT_ASSERT_EQ(test, err, 0);
+	KUNIT_ASSERT_TRUE(test, ttm_tt_is_populated(tt));
+
+	ttm_tt_unpopulate(devs->ttm_dev, tt);
+	KUNIT_ASSERT_FALSE(test, ttm_tt_is_populated(tt));
+}
+
+static void ttm_tt_unpopulate_empty_ttm(struct kunit *test)
+{
+	const struct ttm_test_devices *devs = test->priv;
+	struct ttm_buffer_object *bo;
+	struct ttm_tt *tt;
+	int err;
+
+	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE, NULL);
+
+	tt = kunit_kzalloc(test, sizeof(*tt), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, tt);
+
+	err = ttm_tt_init(tt, bo, 0, ttm_cached, 0);
+	KUNIT_ASSERT_EQ(test, err, 0);
+
+	ttm_tt_unpopulate(devs->ttm_dev, tt);
+	/* Expect graceful handling of unpopulated TTs */
+}
+
+static void ttm_tt_swapin_basic(struct kunit *test)
+{
+	const struct ttm_test_devices *devs = test->priv;
+	int expected_num_pages = BO_SIZE >> PAGE_SHIFT;
+	struct ttm_operation_ctx ctx = { };
+	struct ttm_buffer_object *bo;
+	struct ttm_tt *tt;
+	int err, num_pages;
+
+	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE, NULL);
+
+	tt = kunit_kzalloc(test, sizeof(*tt), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, tt);
+
+	err = ttm_tt_init(tt, bo, 0, ttm_cached, 0);
+	KUNIT_ASSERT_EQ(test, err, 0);
+
+	err = ttm_tt_populate(devs->ttm_dev, tt, &ctx);
+	KUNIT_ASSERT_EQ(test, err, 0);
+	KUNIT_ASSERT_TRUE(test, ttm_tt_is_populated(tt));
+
+	num_pages = ttm_tt_swapout(devs->ttm_dev, tt, GFP_KERNEL);
+	KUNIT_ASSERT_EQ(test, num_pages, expected_num_pages);
+	KUNIT_ASSERT_NOT_NULL(test, tt->swap_storage);
+	KUNIT_ASSERT_TRUE(test, tt->page_flags & TTM_TT_FLAG_SWAPPED);
+
+	/* Swapout depopulates TT, allocate pages and then swap them in */
+	err = ttm_pool_alloc(&devs->ttm_dev->pool, tt, &ctx);
+	KUNIT_ASSERT_EQ(test, err, 0);
+
+	err = ttm_tt_swapin(tt);
+	KUNIT_ASSERT_EQ(test, err, 0);
+	KUNIT_ASSERT_NULL(test, tt->swap_storage);
+	KUNIT_ASSERT_FALSE(test, tt->page_flags & TTM_TT_FLAG_SWAPPED);
+}
+
 static struct kunit_case ttm_tt_test_cases[] = {
 	KUNIT_CASE_PARAM(ttm_tt_init_basic, ttm_tt_init_basic_gen_params),
 	KUNIT_CASE(ttm_tt_init_misaligned),
@@ -267,6 +381,11 @@ static struct kunit_case ttm_tt_test_cases[] = {
 	KUNIT_CASE(ttm_tt_create_ttm_exists),
 	KUNIT_CASE(ttm_tt_create_failed),
 	KUNIT_CASE(ttm_tt_destroy_basic),
+	KUNIT_CASE(ttm_tt_populate_null_ttm),
+	KUNIT_CASE(ttm_tt_populate_populated_ttm),
+	KUNIT_CASE(ttm_tt_unpopulate_basic),
+	KUNIT_CASE(ttm_tt_unpopulate_empty_ttm),
+	KUNIT_CASE(ttm_tt_swapin_basic),
 	{}
 };
 
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index 7b00ddf0ce49..4b51b9023126 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -251,6 +251,7 @@ int ttm_tt_swapin(struct ttm_tt *ttm)
 out_err:
 	return ret;
 }
+EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_swapin);
 
 /**
  * ttm_tt_swapout - swap out tt object
@@ -308,6 +309,7 @@ out_err:
 
 	return ret;
 }
+EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_swapout);
 
 int ttm_tt_populate(struct ttm_device *bdev,
 		    struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
@@ -386,6 +388,7 @@ void ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm)
 
 	ttm->page_flags &= ~TTM_TT_FLAG_PRIV_POPULATED;
 }
+EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_unpopulate);
 
 #ifdef CONFIG_DEBUG_FS