[RFC v6 0/3] Introduce KUnit tests for TTM subsystem

[RFC v6 0/3] Introduce KUnit tests for TTM subsystem

[Karolina Stolarek]

This series introduces KUnit[1] tests for TTM (Translation Table Manager)
subsystem, a memory manager used by graphics drivers to create and manage
memory buffers across different memory domains, such as system memory
or VRAM.

Unit tests implemented here cover two data structures:
  - ttm_device -- referred as a buffer object device, which stores
    resource managers and page pools
  - ttm_pool -- a struct of pools (ttm_pool_type) of different page
    orders and caching attributes, with pages that can be reused on
    the next buffer allocation

Use kunit_tool script to manually run the tests:

$ ./tools/testing/kunit/kunit.py run --kunitconfig=drivers/gpu/drm/ttm/tests

To build a kernel with TTM KUnit tests, first enable CONFIG_KUNIT, and then
CONFIG_DRM_TTM_KUNIT_TEST.

As for now, tests are architecture-agnostic (i.e. KUnit runner uses UML
kernel), which means that we have limited coverage in some places. For
example, we can't fully test the initialization of global page pools,
such as global_write_combined. It is to be decided if we want to stick
to UML or use CONFIG_X86 (at least to some extent).

These patches are just a beginning of the work to improve the test
coverage of TTM. Feel free to suggest changes, test cases or priorities.

Many thanks,
Karolina

v6:
  - Rebase the series on the top of drm-misc-next (Christian)
  - Remove drm_dev_put() call from ttm_test_devices_put, the drm device is 
    already freed in drm_kunit_helper_free_device()
  - Remove an unnecessary priv assignment in ttm_test_devices_all()
  - Delete ttm_bo_put() from ttm_pool_test_fini() (as for now, we don't count
    krefs for dummy BOs)

v5:
  - Drop unnecessary brackets in 2/3
  - Rebase KConfig file on the top of drm-tip

v4:
  - Test helpers have been changed to make the creation of init/fini
    functions for each test suite easier:
    + Decouple device creation from test initialization by adding 
      helpers that initialize ttm_test_devices, a struct which stores
      DRM/TTM devices, and can be used in test-specific init/finis
      (see ttm_pool_tests.c for an example)
    + Introduce generic init/fini functions for tests that only need
      devices
    + Add ttm_device field to ttm_test_devices (previously
      ttm_test_devices_priv)
  - Make TTM buffer object outlive its TT (Christian)
  - Add a dedicated struct for ttm_pool_test (struct ttm_pool_test_priv)
  - Rename functions and structs:
    + struct ttm_test_devices_priv   --> struct ttm_test_devices
    + ttm_kunit_helper_init_device() --> ttm_device_kunit_init()
    + ttm_kunit_helper_ttm_bo_init() --> ttm_bo_kunit_init()
  - Split ttm_kunit_helper_init() into full config (with ttm_device
    init) and basic (init only with device/drm_device) initialization
    functions

v3:
  - Rename ttm_kunit_helper_alloc_device() to ttm_kunit_helper_init_device()
    (Christian)
  - Don't leak a full-blown drm_gem_object in ttm_kunit_helper_ttm_bo_init().
    (Christian). Create a small mock object just to get ttm_tt_init_fields()
    to init the right number of pages
  - As a follow up to the change above, delete ttm_kunit_helper_ttm_bo_fini()
    and just use ttm_bo_put()

v2:
  - Add missing symbol exports in ttm_kunit_helpers.c
  - Update helpers include to fix compilation issues (didn't catch it as
    KUnit tests weren't enabled in the kernel I tested, an oversight
    on my part)
  - Add checks for ttm_pool fields in ttm_pool_alloc_basic(), including the
    one for NUMA node id
  - Rebase the changes on the top of drm-tip

--------------------------------
[1] - https://www.kernel.org/doc/html/latest/dev-tools/kunit/index.html

Karolina Stolarek (3):
  drm/ttm: Introduce KUnit test
  drm/ttm/tests: Add tests for ttm_device
  drm/ttm/tests: Add tests for ttm_pool

 drivers/gpu/drm/Kconfig                       |  15 +
 drivers/gpu/drm/ttm/Makefile                  |   1 +
 drivers/gpu/drm/ttm/tests/.kunitconfig        |   4 +
 drivers/gpu/drm/ttm/tests/Makefile            |   6 +
 drivers/gpu/drm/ttm/tests/ttm_device_test.c   | 212 +++++++++
 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c | 113 +++++
 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h |  41 ++
 drivers/gpu/drm/ttm/tests/ttm_pool_test.c     | 437 ++++++++++++++++++
 8 files changed, 829 insertions(+)
 create mode 100644 drivers/gpu/drm/ttm/tests/.kunitconfig
 create mode 100644 drivers/gpu/drm/ttm/tests/Makefile
 create mode 100644 drivers/gpu/drm/ttm/tests/ttm_device_test.c
 create mode 100644 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
 create mode 100644 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h
 create mode 100644 drivers/gpu/drm/ttm/tests/ttm_pool_test.c

-- 
2.25.1

[RFC v6 1/3] drm/ttm: Introduce KUnit test

[Karolina Stolarek]

Add the initial version of unit tests for ttm_device struct, together
with helper functions.

Signed-off-by: Karolina Stolarek <karolina.stolarek@intel.com>
---
 drivers/gpu/drm/Kconfig                       | 15 +++
 drivers/gpu/drm/ttm/Makefile                  |  1 +
 drivers/gpu/drm/ttm/tests/.kunitconfig        |  4 +
 drivers/gpu/drm/ttm/tests/Makefile            |  5 +
 drivers/gpu/drm/ttm/tests/ttm_device_test.c   | 54 +++++++++++
 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c | 96 +++++++++++++++++++
 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h | 37 +++++++
 7 files changed, 212 insertions(+)
 create mode 100644 drivers/gpu/drm/ttm/tests/.kunitconfig
 create mode 100644 drivers/gpu/drm/ttm/tests/Makefile
 create mode 100644 drivers/gpu/drm/ttm/tests/ttm_device_test.c
 create mode 100644 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
 create mode 100644 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 2a44b9419d4d..9d1f0e04fd56 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -195,6 +195,21 @@ config DRM_TTM
 	  GPU memory types. Will be enabled automatically if a device driver
 	  uses it.
 
+config DRM_TTM_KUNIT_TEST
+        tristate "KUnit tests for TTM" if !KUNIT_ALL_TESTS
+        default n
+        depends on DRM && KUNIT
+        select DRM_TTM
+        select DRM_EXPORT_FOR_TESTS if m
+        select DRM_KUNIT_TEST_HELPERS
+        default KUNIT_ALL_TESTS
+        help
+          Enables unit tests for TTM, a GPU memory manager subsystem used
+          to manage memory buffers. This option is mostly useful for kernel
+          developers.
+
+          If in doubt, say "N".
+
 config DRM_EXEC
 	tristate
 	depends on DRM
diff --git a/drivers/gpu/drm/ttm/Makefile b/drivers/gpu/drm/ttm/Makefile
index f906b22959cf..dad298127226 100644
--- a/drivers/gpu/drm/ttm/Makefile
+++ b/drivers/gpu/drm/ttm/Makefile
@@ -8,3 +8,4 @@ ttm-y := ttm_tt.o ttm_bo.o ttm_bo_util.o ttm_bo_vm.o ttm_module.o \
 ttm-$(CONFIG_AGP) += ttm_agp_backend.o
 
 obj-$(CONFIG_DRM_TTM) += ttm.o
+obj-$(CONFIG_DRM_TTM_KUNIT_TEST) += tests/
diff --git a/drivers/gpu/drm/ttm/tests/.kunitconfig b/drivers/gpu/drm/ttm/tests/.kunitconfig
new file mode 100644
index 000000000000..75fdce0cd98e
--- /dev/null
+++ b/drivers/gpu/drm/ttm/tests/.kunitconfig
@@ -0,0 +1,4 @@
+CONFIG_KUNIT=y
+CONFIG_DRM=y
+CONFIG_DRM_KUNIT_TEST_HELPERS=y
+CONFIG_DRM_TTM_KUNIT_TEST=y
diff --git a/drivers/gpu/drm/ttm/tests/Makefile b/drivers/gpu/drm/ttm/tests/Makefile
new file mode 100644
index 000000000000..7917805f37af
--- /dev/null
+++ b/drivers/gpu/drm/ttm/tests/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0 AND MIT
+
+obj-$(CONFIG_DRM_TTM_KUNIT_TEST) += \
+        ttm_device_test.o \
+        ttm_kunit_helpers.o
diff --git a/drivers/gpu/drm/ttm/tests/ttm_device_test.c b/drivers/gpu/drm/ttm/tests/ttm_device_test.c
new file mode 100644
index 000000000000..76d927d07501
--- /dev/null
+++ b/drivers/gpu/drm/ttm/tests/ttm_device_test.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0 AND MIT
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+#include <drm/ttm/ttm_resource.h>
+#include <drm/ttm/ttm_device.h>
+#include <drm/ttm/ttm_placement.h>
+
+#include "ttm_kunit_helpers.h"
+
+static void ttm_device_init_basic(struct kunit *test)
+{
+	struct ttm_test_devices *priv = test->priv;
+	struct ttm_device *ttm_dev;
+	struct ttm_resource_manager *ttm_sys_man;
+	int err;
+
+	ttm_dev = kunit_kzalloc(test, sizeof(*ttm_dev), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, ttm_dev);
+
+	err = ttm_device_kunit_init(priv, ttm_dev, false, false);
+	KUNIT_ASSERT_EQ(test, err, 0);
+
+	KUNIT_EXPECT_PTR_EQ(test, ttm_dev->funcs, &ttm_dev_funcs);
+	KUNIT_ASSERT_NOT_NULL(test, ttm_dev->wq);
+	KUNIT_ASSERT_NOT_NULL(test, ttm_dev->man_drv[TTM_PL_SYSTEM]);
+
+	ttm_sys_man = &ttm_dev->sysman;
+	KUNIT_ASSERT_NOT_NULL(test, ttm_sys_man);
+	KUNIT_EXPECT_TRUE(test, ttm_sys_man->use_tt);
+	KUNIT_EXPECT_TRUE(test, ttm_sys_man->use_type);
+	KUNIT_ASSERT_NOT_NULL(test, ttm_sys_man->func);
+
+	KUNIT_EXPECT_PTR_EQ(test, ttm_dev->dev_mapping,
+			    priv->drm->anon_inode->i_mapping);
+
+	ttm_device_fini(ttm_dev);
+}
+
+static struct kunit_case ttm_device_test_cases[] = {
+	KUNIT_CASE(ttm_device_init_basic),
+	{}
+};
+
+static struct kunit_suite ttm_device_test_suite = {
+	.name = "ttm_device",
+	.init = ttm_test_devices_init,
+	.exit = ttm_test_devices_fini,
+	.test_cases = ttm_device_test_cases,
+};
+
+kunit_test_suites(&ttm_device_test_suite);
+
+MODULE_LICENSE("GPL");
diff --git a/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
new file mode 100644
index 000000000000..dedc1857734b
--- /dev/null
+++ b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0 AND MIT
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+#include "ttm_kunit_helpers.h"
+
+struct ttm_device_funcs ttm_dev_funcs = {
+};
+EXPORT_SYMBOL_GPL(ttm_dev_funcs);
+
+int ttm_device_kunit_init(struct ttm_test_devices *priv,
+			  struct ttm_device *ttm,
+			  bool use_dma_alloc,
+			  bool use_dma32)
+{
+	struct drm_device *drm = priv->drm;
+	int err;
+
+	err = ttm_device_init(ttm, &ttm_dev_funcs, drm->dev,
+			      drm->anon_inode->i_mapping,
+			      drm->vma_offset_manager,
+			      use_dma_alloc, use_dma32);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(ttm_device_kunit_init);
+
+struct ttm_test_devices *ttm_test_devices_basic(struct kunit *test)
+{
+	struct ttm_test_devices *devs;
+
+	devs = kunit_kzalloc(test, sizeof(*devs), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, devs);
+
+	devs->dev = drm_kunit_helper_alloc_device(test);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, devs->dev);
+
+	devs->drm = __drm_kunit_helper_alloc_drm_device(test, devs->dev,
+							sizeof(*devs->drm), 0,
+							DRIVER_GEM);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, devs->drm);
+
+	return devs;
+}
+EXPORT_SYMBOL_GPL(ttm_test_devices_basic);
+
+struct ttm_test_devices *ttm_test_devices_all(struct kunit *test)
+{
+	struct ttm_test_devices *devs;
+	struct ttm_device *ttm_dev;
+	int err;
+
+	devs = ttm_test_devices_basic(test);
+
+	ttm_dev = kunit_kzalloc(test, sizeof(*ttm_dev), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, ttm_dev);
+
+	err = ttm_device_kunit_init(devs, ttm_dev, false, false);
+	KUNIT_ASSERT_EQ(test, err, 0);
+
+	devs->ttm_dev = ttm_dev;
+
+	return devs;
+}
+EXPORT_SYMBOL_GPL(ttm_test_devices_all);
+
+void ttm_test_devices_put(struct kunit *test, struct ttm_test_devices *devs)
+{
+	if (devs->ttm_dev)
+		ttm_device_fini(devs->ttm_dev);
+
+	drm_kunit_helper_free_device(test, devs->dev);
+}
+EXPORT_SYMBOL_GPL(ttm_test_devices_put);
+
+int ttm_test_devices_init(struct kunit *test)
+{
+	struct ttm_test_devices *priv;
+
+	priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, priv);
+
+	priv = ttm_test_devices_basic(test);
+	test->priv = priv;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ttm_test_devices_init);
+
+void ttm_test_devices_fini(struct kunit *test)
+{
+	ttm_test_devices_put(test, test->priv);
+}
+EXPORT_SYMBOL_GPL(ttm_test_devices_fini);
+
+MODULE_LICENSE("GPL");
diff --git a/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h
new file mode 100644
index 000000000000..f9f5bc03e93a
--- /dev/null
+++ b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 AND MIT */
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+#ifndef TTM_KUNIT_HELPERS_H
+#define TTM_KUNIT_HELPERS_H
+
+#include <drm/drm_drv.h>
+#include <drm/ttm/ttm_device.h>
+
+#include <drm/drm_kunit_helpers.h>
+#include <kunit/test.h>
+
+extern struct ttm_device_funcs ttm_dev_funcs;
+
+struct ttm_test_devices {
+	struct drm_device *drm;
+	struct device *dev;
+	struct ttm_device *ttm_dev;
+};
+
+/* Building blocks for test-specific init functions */
+int ttm_device_kunit_init(struct ttm_test_devices *priv,
+			  struct ttm_device *ttm,
+			  bool use_dma_alloc,
+			  bool use_dma32);
+
+struct ttm_test_devices *ttm_test_devices_basic(struct kunit *test);
+struct ttm_test_devices *ttm_test_devices_all(struct kunit *test);
+
+void ttm_test_devices_put(struct kunit *test, struct ttm_test_devices *devs);
+
+/* Generic init/fini for tests that only need DRM/TTM devices */
+int ttm_test_devices_init(struct kunit *test);
+void ttm_test_devices_fini(struct kunit *test);
+
+#endif // TTM_KUNIT_HELPERS_H
-- 
2.25.1

[RFC v6 2/3] drm/ttm/tests: Add tests for ttm_device

[Karolina Stolarek]

Test initialization and cleanup of the ttm_device struct, including
some error paths. Verify the creation of page pools if use_dma_alloc
param is true.

Signed-off-by: Karolina Stolarek <karolina.stolarek@intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/ttm/tests/ttm_device_test.c | 158 ++++++++++++++++++++
 1 file changed, 158 insertions(+)

diff --git a/drivers/gpu/drm/ttm/tests/ttm_device_test.c b/drivers/gpu/drm/ttm/tests/ttm_device_test.c
index 76d927d07501..b1b423b68cdf 100644
--- a/drivers/gpu/drm/ttm/tests/ttm_device_test.c
+++ b/drivers/gpu/drm/ttm/tests/ttm_device_test.c
@@ -8,6 +8,13 @@
 
 #include "ttm_kunit_helpers.h"
 
+struct ttm_device_test_case {
+	const char *description;
+	bool use_dma_alloc;
+	bool use_dma32;
+	bool pools_init_expected;
+};
+
 static void ttm_device_init_basic(struct kunit *test)
 {
 	struct ttm_test_devices *priv = test->priv;
@@ -37,8 +44,159 @@ static void ttm_device_init_basic(struct kunit *test)
 	ttm_device_fini(ttm_dev);
 }
 
+static void ttm_device_init_multiple(struct kunit *test)
+{
+	struct ttm_test_devices *priv = test->priv;
+	struct ttm_device *ttm_devs;
+	unsigned int i, num_dev = 3;
+	int err;
+
+	ttm_devs = kunit_kcalloc(test, num_dev, sizeof(*ttm_devs), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, ttm_devs);
+
+	for (i = 0; i < num_dev; i++) {
+		err = ttm_device_kunit_init(priv, &ttm_devs[i], false, false);
+		KUNIT_ASSERT_EQ(test, err, 0);
+
+		KUNIT_EXPECT_PTR_EQ(test, ttm_devs[i].dev_mapping,
+				    priv->drm->anon_inode->i_mapping);
+		KUNIT_ASSERT_NOT_NULL(test, ttm_devs[i].wq);
+		KUNIT_EXPECT_PTR_EQ(test, ttm_devs[i].funcs, &ttm_dev_funcs);
+		KUNIT_ASSERT_NOT_NULL(test, ttm_devs[i].man_drv[TTM_PL_SYSTEM]);
+	}
+
+	KUNIT_ASSERT_EQ(test, list_count_nodes(&ttm_devs[0].device_list), num_dev);
+
+	for (i = 0; i < num_dev; i++)
+		ttm_device_fini(&ttm_devs[i]);
+}
+
+static void ttm_device_fini_basic(struct kunit *test)
+{
+	struct ttm_test_devices *priv = test->priv;
+	struct ttm_device *ttm_dev;
+	struct ttm_resource_manager *man;
+	int err;
+
+	ttm_dev = kunit_kzalloc(test, sizeof(*ttm_dev), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, ttm_dev);
+
+	err = ttm_device_kunit_init(priv, ttm_dev, false, false);
+	KUNIT_ASSERT_EQ(test, err, 0);
+
+	man = ttm_manager_type(ttm_dev, TTM_PL_SYSTEM);
+	KUNIT_ASSERT_NOT_NULL(test, man);
+
+	ttm_device_fini(ttm_dev);
+
+	KUNIT_ASSERT_FALSE(test, man->use_type);
+	KUNIT_ASSERT_TRUE(test, list_empty(&man->lru[0]));
+	KUNIT_ASSERT_NULL(test, ttm_dev->man_drv[TTM_PL_SYSTEM]);
+}
+
+static void ttm_device_init_no_vma_man(struct kunit *test)
+{
+	struct ttm_test_devices *priv = test->priv;
+	struct drm_device *drm = priv->drm;
+	struct ttm_device *ttm_dev;
+	struct drm_vma_offset_manager *vma_man;
+	int err;
+
+	ttm_dev = kunit_kzalloc(test, sizeof(*ttm_dev), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, ttm_dev);
+
+	/* Let's pretend there's no VMA manager allocated */
+	vma_man = drm->vma_offset_manager;
+	drm->vma_offset_manager = NULL;
+
+	err = ttm_device_kunit_init(priv, ttm_dev, false, false);
+	KUNIT_EXPECT_EQ(test, err, -EINVAL);
+
+	/* Bring the manager back for a graceful cleanup */
+	drm->vma_offset_manager = vma_man;
+}
+
+static const struct ttm_device_test_case ttm_device_cases[] = {
+	{
+		.description = "No DMA allocations, no DMA32 required",
+		.use_dma_alloc = false,
+		.use_dma32 = false,
+		.pools_init_expected = false,
+	},
+	{
+		.description = "DMA allocations, DMA32 required",
+		.use_dma_alloc = true,
+		.use_dma32 = true,
+		.pools_init_expected = true,
+	},
+	{
+		.description = "No DMA allocations, DMA32 required",
+		.use_dma_alloc = false,
+		.use_dma32 = true,
+		.pools_init_expected = false,
+	},
+	{
+		.description = "DMA allocations, no DMA32 required",
+		.use_dma_alloc = true,
+		.use_dma32 = false,
+		.pools_init_expected = true,
+	},
+};
+
+static void ttm_device_case_desc(const struct ttm_device_test_case *t, char *desc)
+{
+	strscpy(desc, t->description, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(ttm_device, ttm_device_cases, ttm_device_case_desc);
+
+static void ttm_device_init_pools(struct kunit *test)
+{
+	struct ttm_test_devices *priv = test->priv;
+	const struct ttm_device_test_case *params = test->param_value;
+	struct ttm_device *ttm_dev;
+	struct ttm_pool *pool;
+	struct ttm_pool_type pt;
+	int err;
+
+	ttm_dev = kunit_kzalloc(test, sizeof(*ttm_dev), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, ttm_dev);
+
+	err = ttm_device_kunit_init(priv, ttm_dev,
+				    params->use_dma_alloc,
+				    params->use_dma32);
+	KUNIT_ASSERT_EQ(test, err, 0);
+
+	pool = &ttm_dev->pool;
+	KUNIT_ASSERT_NOT_NULL(test, pool);
+	KUNIT_EXPECT_PTR_EQ(test, pool->dev, priv->dev);
+	KUNIT_EXPECT_EQ(test, pool->use_dma_alloc, params->use_dma_alloc);
+	KUNIT_EXPECT_EQ(test, pool->use_dma32, params->use_dma32);
+
+	if (params->pools_init_expected) {
+		for (int i = 0; i < TTM_NUM_CACHING_TYPES; ++i) {
+			for (int j = 0; j <= MAX_ORDER; ++j) {
+				pt = pool->caching[i].orders[j];
+				KUNIT_EXPECT_PTR_EQ(test, pt.pool, pool);
+				KUNIT_EXPECT_EQ(test, pt.caching, i);
+				KUNIT_EXPECT_EQ(test, pt.order, j);
+
+				if (params->use_dma_alloc)
+					KUNIT_ASSERT_FALSE(test,
+							   list_empty(&pt.pages));
+			}
+		}
+	}
+
+	ttm_device_fini(ttm_dev);
+}
+
 static struct kunit_case ttm_device_test_cases[] = {
 	KUNIT_CASE(ttm_device_init_basic),
+	KUNIT_CASE(ttm_device_init_multiple),
+	KUNIT_CASE(ttm_device_fini_basic),
+	KUNIT_CASE(ttm_device_init_no_vma_man),
+	KUNIT_CASE_PARAM(ttm_device_init_pools, ttm_device_gen_params),
 	{}
 };
 
-- 
2.25.1

[RFC v6 3/3] drm/ttm/tests: Add tests for ttm_pool

[Karolina Stolarek]

Add KUnit tests that exercise page allocation using page pools
and freeing pages, either by returning them to the pool or
freeing them. Add a basic test for ttm_pool cleanup. Introduce
helpers to create a dummy ttm_buffer_object.

Signed-off-by: Karolina Stolarek <karolina.stolarek@intel.com>
---
 drivers/gpu/drm/ttm/tests/Makefile            |   1 +
 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c |  17 +
 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h |   4 +
 drivers/gpu/drm/ttm/tests/ttm_pool_test.c     | 437 ++++++++++++++++++
 4 files changed, 459 insertions(+)
 create mode 100644 drivers/gpu/drm/ttm/tests/ttm_pool_test.c

diff --git a/drivers/gpu/drm/ttm/tests/Makefile b/drivers/gpu/drm/ttm/tests/Makefile
index 7917805f37af..ec87c4fc1ad5 100644
--- a/drivers/gpu/drm/ttm/tests/Makefile
+++ b/drivers/gpu/drm/ttm/tests/Makefile
@@ -2,4 +2,5 @@
 
 obj-$(CONFIG_DRM_TTM_KUNIT_TEST) += \
         ttm_device_test.o \
+        ttm_pool_test.o \
         ttm_kunit_helpers.o
diff --git a/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
index dedc1857734b..81661d8827aa 100644
--- a/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
+++ b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
@@ -25,6 +25,23 @@ int ttm_device_kunit_init(struct ttm_test_devices *priv,
 }
 EXPORT_SYMBOL_GPL(ttm_device_kunit_init);
 
+struct ttm_buffer_object *ttm_bo_kunit_init(struct kunit *test,
+					    struct ttm_test_devices *devs,
+					    size_t size)
+{
+	struct drm_gem_object gem_obj = { .size = size };
+	struct ttm_buffer_object *bo;
+
+	bo = kunit_kzalloc(test, sizeof(*bo), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, bo);
+
+	bo->base = gem_obj;
+	bo->bdev = devs->ttm_dev;
+
+	return bo;
+}
+EXPORT_SYMBOL_GPL(ttm_bo_kunit_init);
+
 struct ttm_test_devices *ttm_test_devices_basic(struct kunit *test)
 {
 	struct ttm_test_devices *devs;
diff --git a/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h
index f9f5bc03e93a..e261e3660d0b 100644
--- a/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h
+++ b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h
@@ -7,6 +7,7 @@
 
 #include <drm/drm_drv.h>
 #include <drm/ttm/ttm_device.h>
+#include <drm/ttm/ttm_bo.h>
 
 #include <drm/drm_kunit_helpers.h>
 #include <kunit/test.h>
@@ -24,6 +25,9 @@ int ttm_device_kunit_init(struct ttm_test_devices *priv,
 			  struct ttm_device *ttm,
 			  bool use_dma_alloc,
 			  bool use_dma32);
+struct ttm_buffer_object *ttm_bo_kunit_init(struct kunit *test,
+					    struct ttm_test_devices *devs,
+					    size_t size);
 
 struct ttm_test_devices *ttm_test_devices_basic(struct kunit *test);
 struct ttm_test_devices *ttm_test_devices_all(struct kunit *test);
diff --git a/drivers/gpu/drm/ttm/tests/ttm_pool_test.c b/drivers/gpu/drm/ttm/tests/ttm_pool_test.c
new file mode 100644
index 000000000000..8d90870fb199
--- /dev/null
+++ b/drivers/gpu/drm/ttm/tests/ttm_pool_test.c
@@ -0,0 +1,437 @@
+// SPDX-License-Identifier: GPL-2.0 AND MIT
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+#include <linux/mm.h>
+
+#include <drm/ttm/ttm_tt.h>
+#include <drm/ttm/ttm_pool.h>
+
+#include "ttm_kunit_helpers.h"
+
+struct ttm_pool_test_case {
+	const char *description;
+	unsigned int order;
+	bool use_dma_alloc;
+};
+
+struct ttm_pool_test_priv {
+	struct ttm_test_devices *devs;
+
+	/* Used to create mock ttm_tts */
+	struct ttm_buffer_object *mock_bo;
+};
+
+static struct ttm_operation_ctx simple_ctx = {
+	.interruptible = true,
+	.no_wait_gpu = false,
+};
+
+static int ttm_pool_test_init(struct kunit *test)
+{
+	struct ttm_pool_test_priv *priv;
+
+	priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, priv);
+
+	priv->devs = ttm_test_devices_basic(test);
+	test->priv = priv;
+
+	return 0;
+}
+
+static void ttm_pool_test_fini(struct kunit *test)
+{
+	struct ttm_pool_test_priv *priv = test->priv;
+
+	ttm_test_devices_put(test, priv->devs);
+}
+
+static struct ttm_tt *ttm_tt_kunit_init(struct kunit *test,
+					uint32_t page_flags,
+					enum ttm_caching caching,
+					size_t size)
+{
+	struct ttm_pool_test_priv *priv = test->priv;
+	struct ttm_buffer_object *bo;
+	struct ttm_tt *tt;
+	int err;
+
+	bo = ttm_bo_kunit_init(test, priv->devs, size);
+	KUNIT_ASSERT_NOT_NULL(test, bo);
+	priv->mock_bo = bo;
+
+	tt = kunit_kzalloc(test, sizeof(*tt), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, tt);
+
+	err = ttm_tt_init(tt, priv->mock_bo, page_flags, caching, 0);
+	KUNIT_ASSERT_EQ(test, err, 0);
+
+	return tt;
+}
+
+static struct ttm_pool *ttm_pool_pre_populated(struct kunit *test,
+					       size_t size,
+					       enum ttm_caching caching)
+{
+	struct ttm_pool_test_priv *priv = test->priv;
+	struct ttm_test_devices *devs = priv->devs;
+	struct ttm_pool *pool;
+	struct ttm_tt *tt;
+	unsigned long order = __fls(size / PAGE_SIZE);
+	int err;
+
+	tt = ttm_tt_kunit_init(test, order, caching, size);
+	KUNIT_ASSERT_NOT_NULL(test, tt);
+
+	pool = kunit_kzalloc(test, sizeof(*pool), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, pool);
+
+	ttm_pool_init(pool, devs->dev, NUMA_NO_NODE, true, false);
+
+	err = ttm_pool_alloc(pool, tt, &simple_ctx);
+	KUNIT_ASSERT_EQ(test, err, 0);
+
+	ttm_pool_free(pool, tt);
+	ttm_tt_fini(tt);
+
+	return pool;
+}
+
+static const struct ttm_pool_test_case ttm_pool_basic_cases[] = {
+	{
+		.description = "One page",
+		.order = 0,
+	},
+	{
+		.description = "More than one page",
+		.order = 2,
+	},
+	{
+		.description = "Above the allocation limit",
+		.order = MAX_ORDER + 1,
+	},
+	{
+		.description = "One page, with coherent DMA mappings enabled",
+		.order = 0,
+		.use_dma_alloc = true,
+	},
+	{
+		.description = "Above the allocation limit, with coherent DMA mappings enabled",
+		.order = MAX_ORDER + 1,
+		.use_dma_alloc = true,
+	},
+};
+
+static void ttm_pool_alloc_case_desc(const struct ttm_pool_test_case *t,
+				     char *desc)
+{
+	strscpy(desc, t->description, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(ttm_pool_alloc_basic, ttm_pool_basic_cases,
+		  ttm_pool_alloc_case_desc);
+
+static void ttm_pool_alloc_basic(struct kunit *test)
+{
+	struct ttm_pool_test_priv *priv = test->priv;
+	struct ttm_test_devices *devs = priv->devs;
+	const struct ttm_pool_test_case *params = test->param_value;
+	struct ttm_tt *tt;
+	struct ttm_pool *pool;
+	struct page *fst_page, *last_page;
+	enum ttm_caching caching = ttm_uncached;
+	unsigned int expected_num_pages = 1 << params->order;
+	size_t size = expected_num_pages * PAGE_SIZE;
+	int err;
+
+	tt = ttm_tt_kunit_init(test, 0, caching, size);
+	KUNIT_ASSERT_NOT_NULL(test, tt);
+
+	pool = kunit_kzalloc(test, sizeof(*pool), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, pool);
+
+	ttm_pool_init(pool, devs->dev, NUMA_NO_NODE, params->use_dma_alloc,
+		      false);
+
+	KUNIT_ASSERT_PTR_EQ(test, pool->dev, devs->dev);
+	KUNIT_ASSERT_EQ(test, pool->nid, NUMA_NO_NODE);
+	KUNIT_ASSERT_EQ(test, pool->use_dma_alloc, params->use_dma_alloc);
+
+	err = ttm_pool_alloc(pool, tt, &simple_ctx);
+	KUNIT_ASSERT_EQ(test, err, 0);
+	KUNIT_ASSERT_EQ(test, tt->num_pages, expected_num_pages);
+
+	fst_page = tt->pages[0];
+	last_page = tt->pages[tt->num_pages - 1];
+
+	if (params->order <= MAX_ORDER) {
+		if (params->use_dma_alloc) {
+			KUNIT_ASSERT_NOT_NULL(test, (void *)fst_page->private);
+			KUNIT_ASSERT_NOT_NULL(test, (void *)last_page->private);
+		} else {
+			KUNIT_ASSERT_EQ(test, fst_page->private, params->order);
+		}
+	} else {
+		if (params->use_dma_alloc) {
+			KUNIT_ASSERT_NOT_NULL(test, (void *)fst_page->private);
+			KUNIT_ASSERT_NULL(test, (void *)last_page->private);
+		} else {
+			/*
+			 * We expect to alloc one big block, followed by
+			 * order 0 blocks
+			 */
+			KUNIT_ASSERT_EQ(test, fst_page->private,
+					min_t(unsigned int, MAX_ORDER,
+					      params->order));
+			KUNIT_ASSERT_EQ(test, last_page->private, 0);
+		}
+	}
+
+	ttm_pool_free(pool, tt);
+	ttm_tt_fini(tt);
+	ttm_pool_fini(pool);
+}
+
+static void ttm_pool_alloc_basic_dma_addr(struct kunit *test)
+{
+	struct ttm_pool_test_priv *priv = test->priv;
+	struct ttm_test_devices *devs = priv->devs;
+	const struct ttm_pool_test_case *params = test->param_value;
+	struct ttm_tt *tt;
+	struct ttm_pool *pool;
+	struct ttm_buffer_object *bo;
+	dma_addr_t dma1, dma2;
+	enum ttm_caching caching = ttm_uncached;
+	unsigned int expected_num_pages = 1 << params->order;
+	size_t size = expected_num_pages * PAGE_SIZE;
+	int err;
+
+	tt = kunit_kzalloc(test, sizeof(*tt), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, tt);
+
+	bo = ttm_bo_kunit_init(test, devs, size);
+	KUNIT_ASSERT_NOT_NULL(test, bo);
+
+	err = ttm_sg_tt_init(tt, bo, 0, caching);
+	KUNIT_ASSERT_EQ(test, err, 0);
+
+	pool = kunit_kzalloc(test, sizeof(*pool), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, pool);
+
+	ttm_pool_init(pool, devs->dev, NUMA_NO_NODE, true, false);
+
+	err = ttm_pool_alloc(pool, tt, &simple_ctx);
+	KUNIT_ASSERT_EQ(test, err, 0);
+	KUNIT_ASSERT_EQ(test, tt->num_pages, expected_num_pages);
+
+	dma1 = tt->dma_address[0];
+	dma2 = tt->dma_address[tt->num_pages - 1];
+
+	KUNIT_ASSERT_NOT_NULL(test, (void *)dma1);
+	KUNIT_ASSERT_NOT_NULL(test, (void *)dma2);
+
+	ttm_pool_free(pool, tt);
+	ttm_tt_fini(tt);
+	ttm_pool_fini(pool);
+}
+
+static void ttm_pool_alloc_order_caching_match(struct kunit *test)
+{
+	struct ttm_tt *tt;
+	struct ttm_pool *pool;
+	struct ttm_pool_type *pt;
+	enum ttm_caching caching = ttm_uncached;
+	unsigned int order = 0;
+	size_t size = PAGE_SIZE;
+	int err;
+
+	pool = ttm_pool_pre_populated(test, size, caching);
+
+	pt = &pool->caching[caching].orders[order];
+	KUNIT_ASSERT_FALSE(test, list_empty(&pt->pages));
+
+	tt = ttm_tt_kunit_init(test, 0, caching, size);
+	KUNIT_ASSERT_NOT_NULL(test, tt);
+
+	err = ttm_pool_alloc(pool, tt, &simple_ctx);
+	KUNIT_ASSERT_EQ(test, err, 0);
+
+	KUNIT_ASSERT_TRUE(test, list_empty(&pt->pages));
+
+	ttm_pool_free(pool, tt);
+	ttm_tt_fini(tt);
+	ttm_pool_fini(pool);
+}
+
+static void ttm_pool_alloc_caching_mismatch(struct kunit *test)
+{
+	struct ttm_tt *tt;
+	struct ttm_pool *pool;
+	struct ttm_pool_type *pt_pool, *pt_tt;
+	enum ttm_caching tt_caching = ttm_uncached;
+	enum ttm_caching pool_caching = ttm_cached;
+	size_t size = PAGE_SIZE;
+	unsigned int order = 0;
+	int err;
+
+	pool = ttm_pool_pre_populated(test, size, pool_caching);
+
+	pt_pool = &pool->caching[pool_caching].orders[order];
+	pt_tt = &pool->caching[tt_caching].orders[order];
+
+	tt = ttm_tt_kunit_init(test, 0, tt_caching, size);
+	KUNIT_ASSERT_NOT_NULL(test, tt);
+
+	KUNIT_ASSERT_FALSE(test, list_empty(&pt_pool->pages));
+	KUNIT_ASSERT_TRUE(test, list_empty(&pt_tt->pages));
+
+	err = ttm_pool_alloc(pool, tt, &simple_ctx);
+	KUNIT_ASSERT_EQ(test, err, 0);
+
+	ttm_pool_free(pool, tt);
+	ttm_tt_fini(tt);
+
+	KUNIT_ASSERT_FALSE(test, list_empty(&pt_pool->pages));
+	KUNIT_ASSERT_FALSE(test, list_empty(&pt_tt->pages));
+
+	ttm_pool_fini(pool);
+}
+
+static void ttm_pool_alloc_order_mismatch(struct kunit *test)
+{
+	struct ttm_tt *tt;
+	struct ttm_pool *pool;
+	struct ttm_pool_type *pt_pool, *pt_tt;
+	enum ttm_caching caching = ttm_uncached;
+	unsigned int order = 2;
+	size_t fst_size = (1 << order) * PAGE_SIZE;
+	size_t snd_size = PAGE_SIZE;
+	int err;
+
+	pool = ttm_pool_pre_populated(test, fst_size, caching);
+
+	pt_pool = &pool->caching[caching].orders[order];
+	pt_tt = &pool->caching[caching].orders[0];
+
+	tt = ttm_tt_kunit_init(test, 0, caching, snd_size);
+	KUNIT_ASSERT_NOT_NULL(test, tt);
+
+	KUNIT_ASSERT_FALSE(test, list_empty(&pt_pool->pages));
+	KUNIT_ASSERT_TRUE(test, list_empty(&pt_tt->pages));
+
+	err = ttm_pool_alloc(pool, tt, &simple_ctx);
+	KUNIT_ASSERT_EQ(test, err, 0);
+
+	ttm_pool_free(pool, tt);
+	ttm_tt_fini(tt);
+
+	KUNIT_ASSERT_FALSE(test, list_empty(&pt_pool->pages));
+	KUNIT_ASSERT_FALSE(test, list_empty(&pt_tt->pages));
+
+	ttm_pool_fini(pool);
+}
+
+static void ttm_pool_free_dma_alloc(struct kunit *test)
+{
+	struct ttm_pool_test_priv *priv = test->priv;
+	struct ttm_test_devices *devs = priv->devs;
+	struct ttm_tt *tt;
+	struct ttm_pool *pool;
+	struct ttm_pool_type *pt;
+	enum ttm_caching caching = ttm_uncached;
+	unsigned int order = 2;
+	size_t size = (1 << order) * PAGE_SIZE;
+
+	tt = ttm_tt_kunit_init(test, 0, caching, size);
+	KUNIT_ASSERT_NOT_NULL(test, tt);
+
+	pool = kunit_kzalloc(test, sizeof(*pool), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, pool);
+
+	ttm_pool_init(pool, devs->dev, NUMA_NO_NODE, true, false);
+	ttm_pool_alloc(pool, tt, &simple_ctx);
+
+	pt = &pool->caching[caching].orders[order];
+	KUNIT_ASSERT_TRUE(test, list_empty(&pt->pages));
+
+	ttm_pool_free(pool, tt);
+	ttm_tt_fini(tt);
+
+	KUNIT_ASSERT_FALSE(test, list_empty(&pt->pages));
+
+	ttm_pool_fini(pool);
+}
+
+static void ttm_pool_free_no_dma_alloc(struct kunit *test)
+{
+	struct ttm_pool_test_priv *priv = test->priv;
+	struct ttm_test_devices *devs = priv->devs;
+	struct ttm_tt *tt;
+	struct ttm_pool *pool;
+	struct ttm_pool_type *pt;
+	enum ttm_caching caching = ttm_uncached;
+	unsigned int order = 2;
+	size_t size = (1 << order) * PAGE_SIZE;
+
+	tt = ttm_tt_kunit_init(test, 0, caching, size);
+	KUNIT_ASSERT_NOT_NULL(test, tt);
+
+	pool = kunit_kzalloc(test, sizeof(*pool), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, pool);
+
+	ttm_pool_init(pool, devs->dev, NUMA_NO_NODE, false, false);
+	ttm_pool_alloc(pool, tt, &simple_ctx);
+
+	pt = &pool->caching[caching].orders[order];
+	KUNIT_ASSERT_TRUE(test, list_is_singular(&pt->pages));
+
+	ttm_pool_free(pool, tt);
+	ttm_tt_fini(tt);
+
+	KUNIT_ASSERT_TRUE(test, list_is_singular(&pt->pages));
+
+	ttm_pool_fini(pool);
+}
+
+static void ttm_pool_fini_basic(struct kunit *test)
+{
+	struct ttm_pool *pool;
+	struct ttm_pool_type *pt;
+	enum ttm_caching caching = ttm_uncached;
+	unsigned int order = 0;
+	size_t size = PAGE_SIZE;
+
+	pool = ttm_pool_pre_populated(test, size, caching);
+	pt = &pool->caching[caching].orders[order];
+
+	KUNIT_ASSERT_FALSE(test, list_empty(&pt->pages));
+
+	ttm_pool_fini(pool);
+
+	KUNIT_ASSERT_TRUE(test, list_empty(&pt->pages));
+}
+
+static struct kunit_case ttm_pool_test_cases[] = {
+	KUNIT_CASE_PARAM(ttm_pool_alloc_basic, ttm_pool_alloc_basic_gen_params),
+	KUNIT_CASE_PARAM(ttm_pool_alloc_basic_dma_addr,
+			 ttm_pool_alloc_basic_gen_params),
+	KUNIT_CASE(ttm_pool_alloc_order_caching_match),
+	KUNIT_CASE(ttm_pool_alloc_caching_mismatch),
+	KUNIT_CASE(ttm_pool_alloc_order_mismatch),
+	KUNIT_CASE(ttm_pool_free_dma_alloc),
+	KUNIT_CASE(ttm_pool_free_no_dma_alloc),
+	KUNIT_CASE(ttm_pool_fini_basic),
+	{}
+};
+
+static struct kunit_suite ttm_pool_test_suite = {
+	.name = "ttm_pool",
+	.init = ttm_pool_test_init,
+	.exit = ttm_pool_test_fini,
+	.test_cases = ttm_pool_test_cases,
+};
+
+kunit_test_suites(&ttm_pool_test_suite);
+
+MODULE_LICENSE("GPL");
-- 
2.25.1

Re: [RFC v6 0/3] Introduce KUnit tests for TTM subsystem

[Christian König]

Am 08.08.23 um 11:51 schrieb Karolina Stolarek:
> This series introduces KUnit[1] tests for TTM (Translation Table Manager)
> subsystem, a memory manager used by graphics drivers to create and manage
> memory buffers across different memory domains, such as system memory
> or VRAM.
>
> Unit tests implemented here cover two data structures:
>    - ttm_device -- referred as a buffer object device, which stores
>      resource managers and page pools
>    - ttm_pool -- a struct of pools (ttm_pool_type) of different page
>      orders and caching attributes, with pages that can be reused on
>      the next buffer allocation
>
> Use kunit_tool script to manually run the tests:
>
> $ ./tools/testing/kunit/kunit.py run --kunitconfig=drivers/gpu/drm/ttm/tests
>
> To build a kernel with TTM KUnit tests, first enable CONFIG_KUNIT, and then
> CONFIG_DRM_TTM_KUNIT_TEST.
>
> As for now, tests are architecture-agnostic (i.e. KUnit runner uses UML
> kernel), which means that we have limited coverage in some places. For
> example, we can't fully test the initialization of global page pools,
> such as global_write_combined. It is to be decided if we want to stick
> to UML or use CONFIG_X86 (at least to some extent).
>
> These patches are just a beginning of the work to improve the test
> coverage of TTM. Feel free to suggest changes, test cases or priorities.

Couldn't find time for further testing, so I just reviewed and pushed 
this to drm-misc-next.

Thanks,
Christian.

>
> Many thanks,
> Karolina
>
> v6:
>    - Rebase the series on the top of drm-misc-next (Christian)
>    - Remove drm_dev_put() call from ttm_test_devices_put, the drm device is
>      already freed in drm_kunit_helper_free_device()
>    - Remove an unnecessary priv assignment in ttm_test_devices_all()
>    - Delete ttm_bo_put() from ttm_pool_test_fini() (as for now, we don't count
>      krefs for dummy BOs)
>
> v5:
>    - Drop unnecessary brackets in 2/3
>    - Rebase KConfig file on the top of drm-tip
>
> v4:
>    - Test helpers have been changed to make the creation of init/fini
>      functions for each test suite easier:
>      + Decouple device creation from test initialization by adding
>        helpers that initialize ttm_test_devices, a struct which stores
>        DRM/TTM devices, and can be used in test-specific init/finis
>        (see ttm_pool_tests.c for an example)
>      + Introduce generic init/fini functions for tests that only need
>        devices
>      + Add ttm_device field to ttm_test_devices (previously
>        ttm_test_devices_priv)
>    - Make TTM buffer object outlive its TT (Christian)
>    - Add a dedicated struct for ttm_pool_test (struct ttm_pool_test_priv)
>    - Rename functions and structs:
>      + struct ttm_test_devices_priv   --> struct ttm_test_devices
>      + ttm_kunit_helper_init_device() --> ttm_device_kunit_init()
>      + ttm_kunit_helper_ttm_bo_init() --> ttm_bo_kunit_init()
>    - Split ttm_kunit_helper_init() into full config (with ttm_device
>      init) and basic (init only with device/drm_device) initialization
>      functions
>
> v3:
>    - Rename ttm_kunit_helper_alloc_device() to ttm_kunit_helper_init_device()
>      (Christian)
>    - Don't leak a full-blown drm_gem_object in ttm_kunit_helper_ttm_bo_init().
>      (Christian). Create a small mock object just to get ttm_tt_init_fields()
>      to init the right number of pages
>    - As a follow up to the change above, delete ttm_kunit_helper_ttm_bo_fini()
>      and just use ttm_bo_put()
>
> v2:
>    - Add missing symbol exports in ttm_kunit_helpers.c
>    - Update helpers include to fix compilation issues (didn't catch it as
>      KUnit tests weren't enabled in the kernel I tested, an oversight
>      on my part)
>    - Add checks for ttm_pool fields in ttm_pool_alloc_basic(), including the
>      one for NUMA node id
>    - Rebase the changes on the top of drm-tip
>
> --------------------------------
> [1] - https://www.kernel.org/doc/html/latest/dev-tools/kunit/index.html
>
> Karolina Stolarek (3):
>    drm/ttm: Introduce KUnit test
>    drm/ttm/tests: Add tests for ttm_device
>    drm/ttm/tests: Add tests for ttm_pool
>
>   drivers/gpu/drm/Kconfig                       |  15 +
>   drivers/gpu/drm/ttm/Makefile                  |   1 +
>   drivers/gpu/drm/ttm/tests/.kunitconfig        |   4 +
>   drivers/gpu/drm/ttm/tests/Makefile            |   6 +
>   drivers/gpu/drm/ttm/tests/ttm_device_test.c   | 212 +++++++++
>   drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c | 113 +++++
>   drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h |  41 ++
>   drivers/gpu/drm/ttm/tests/ttm_pool_test.c     | 437 ++++++++++++++++++
>   8 files changed, 829 insertions(+)
>   create mode 100644 drivers/gpu/drm/ttm/tests/.kunitconfig
>   create mode 100644 drivers/gpu/drm/ttm/tests/Makefile
>   create mode 100644 drivers/gpu/drm/ttm/tests/ttm_device_test.c
>   create mode 100644 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
>   create mode 100644 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h
>   create mode 100644 drivers/gpu/drm/ttm/tests/ttm_pool_test.c
>

Re: [RFC v6 0/3] Introduce KUnit tests for TTM subsystem

[Karolina Stolarek]

On 10.08.2023 09:19, Christian König wrote:
> Am 08.08.23 um 11:51 schrieb Karolina Stolarek:
>> This series introduces KUnit[1] tests for TTM (Translation Table Manager)
>> subsystem, a memory manager used by graphics drivers to create and manage
>> memory buffers across different memory domains, such as system memory
>> or VRAM.
>>
>> Unit tests implemented here cover two data structures:
>>    - ttm_device -- referred as a buffer object device, which stores
>>      resource managers and page pools
>>    - ttm_pool -- a struct of pools (ttm_pool_type) of different page
>>      orders and caching attributes, with pages that can be reused on
>>      the next buffer allocation
>>
>> Use kunit_tool script to manually run the tests:
>>
>> $ ./tools/testing/kunit/kunit.py run 
>> --kunitconfig=drivers/gpu/drm/ttm/tests
>>
>> To build a kernel with TTM KUnit tests, first enable CONFIG_KUNIT, and 
>> then
>> CONFIG_DRM_TTM_KUNIT_TEST.
>>
>> As for now, tests are architecture-agnostic (i.e. KUnit runner uses UML
>> kernel), which means that we have limited coverage in some places. For
>> example, we can't fully test the initialization of global page pools,
>> such as global_write_combined. It is to be decided if we want to stick
>> to UML or use CONFIG_X86 (at least to some extent).
>>
>> These patches are just a beginning of the work to improve the test
>> coverage of TTM. Feel free to suggest changes, test cases or priorities.
> 
> Couldn't find time for further testing, so I just reviewed and pushed 
> this to drm-misc-next.
> 
> Thanks,
> Christian.

Thanks a lot for taking care of this, fingers crossed it's all working.

I'll rebase the upcoming tests on the top of drm-misc-next then.

All the best,
Karolina

> 
>>
>> Many thanks,
>> Karolina
>>
>> v6:
>>    - Rebase the series on the top of drm-misc-next (Christian)
>>    - Remove drm_dev_put() call from ttm_test_devices_put, the drm 
>> device is
>>      already freed in drm_kunit_helper_free_device()
>>    - Remove an unnecessary priv assignment in ttm_test_devices_all()
>>    - Delete ttm_bo_put() from ttm_pool_test_fini() (as for now, we 
>> don't count
>>      krefs for dummy BOs)
>>
>> v5:
>>    - Drop unnecessary brackets in 2/3
>>    - Rebase KConfig file on the top of drm-tip
>>
>> v4:
>>    - Test helpers have been changed to make the creation of init/fini
>>      functions for each test suite easier:
>>      + Decouple device creation from test initialization by adding
>>        helpers that initialize ttm_test_devices, a struct which stores
>>        DRM/TTM devices, and can be used in test-specific init/finis
>>        (see ttm_pool_tests.c for an example)
>>      + Introduce generic init/fini functions for tests that only need
>>        devices
>>      + Add ttm_device field to ttm_test_devices (previously
>>        ttm_test_devices_priv)
>>    - Make TTM buffer object outlive its TT (Christian)
>>    - Add a dedicated struct for ttm_pool_test (struct ttm_pool_test_priv)
>>    - Rename functions and structs:
>>      + struct ttm_test_devices_priv   --> struct ttm_test_devices
>>      + ttm_kunit_helper_init_device() --> ttm_device_kunit_init()
>>      + ttm_kunit_helper_ttm_bo_init() --> ttm_bo_kunit_init()
>>    - Split ttm_kunit_helper_init() into full config (with ttm_device
>>      init) and basic (init only with device/drm_device) initialization
>>      functions
>>
>> v3:
>>    - Rename ttm_kunit_helper_alloc_device() to 
>> ttm_kunit_helper_init_device()
>>      (Christian)
>>    - Don't leak a full-blown drm_gem_object in 
>> ttm_kunit_helper_ttm_bo_init().
>>      (Christian). Create a small mock object just to get 
>> ttm_tt_init_fields()
>>      to init the right number of pages
>>    - As a follow up to the change above, delete 
>> ttm_kunit_helper_ttm_bo_fini()
>>      and just use ttm_bo_put()
>>
>> v2:
>>    - Add missing symbol exports in ttm_kunit_helpers.c
>>    - Update helpers include to fix compilation issues (didn't catch it as
>>      KUnit tests weren't enabled in the kernel I tested, an oversight
>>      on my part)
>>    - Add checks for ttm_pool fields in ttm_pool_alloc_basic(), 
>> including the
>>      one for NUMA node id
>>    - Rebase the changes on the top of drm-tip
>>
>> --------------------------------
>> [1] - https://www.kernel.org/doc/html/latest/dev-tools/kunit/index.html
>>
>> Karolina Stolarek (3):
>>    drm/ttm: Introduce KUnit test
>>    drm/ttm/tests: Add tests for ttm_device
>>    drm/ttm/tests: Add tests for ttm_pool
>>
>>   drivers/gpu/drm/Kconfig                       |  15 +
>>   drivers/gpu/drm/ttm/Makefile                  |   1 +
>>   drivers/gpu/drm/ttm/tests/.kunitconfig        |   4 +
>>   drivers/gpu/drm/ttm/tests/Makefile            |   6 +
>>   drivers/gpu/drm/ttm/tests/ttm_device_test.c   | 212 +++++++++
>>   drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c | 113 +++++
>>   drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h |  41 ++
>>   drivers/gpu/drm/ttm/tests/ttm_pool_test.c     | 437 ++++++++++++++++++
>>   8 files changed, 829 insertions(+)
>>   create mode 100644 drivers/gpu/drm/ttm/tests/.kunitconfig
>>   create mode 100644 drivers/gpu/drm/ttm/tests/Makefile
>>   create mode 100644 drivers/gpu/drm/ttm/tests/ttm_device_test.c
>>   create mode 100644 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
>>   create mode 100644 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h
>>   create mode 100644 drivers/gpu/drm/ttm/tests/ttm_pool_test.c
>>
>