Re: [RFC v2 1/3] drm/ttm: Introduce KUnit tests

[Karolina Stolarek <karolina.stolarek@intel.com>]

Hi Christian,

I'm taking a second look at this, and I wonder what would be the benefit 
of combining the initialization of device and ttm_device. (drm_)device 
can be initialized indepedently from the test params, so we can utilize 
.init and .exit callbacks offered by KUnit[1] to prepare and release the 
device indepedently of our setup. If we were to change it so ttm_device 
is also initialized there, we'd have to manually call init/fini in every 
single test. What's more, ttm_pool tests don't depend on ttm_device, and 
I can imagine that some structs can be tested in a similar way.

Would it be fine with you to rename ttm_kunit_helper_alloc_device(), but 
leave its definition as it is?

All the best,
Karolina
-------------------------------------------------------------------
[1] - https://kunit.dev/third_party/kernel/docs/api/test.html#c.kunit_suite

On 29.06.2023 12:05, Karolina Stolarek wrote:
> Hi Christian,
> 
> Thanks a lot for taking a look at my patches.
> 
> On 29.06.2023 09:50, Christian König wrote:
>> Am 27.06.23 um 10:32 schrieb 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 | 59 +++++++++++++++++++
>>>   drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h | 29 +++++++++
>>>   7 files changed, 167 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 afb3b2f5f425..53024e44a2d5 100644
>>> --- a/drivers/gpu/drm/Kconfig
>>> +++ b/drivers/gpu/drm/Kconfig
>>> @@ -194,6 +194,21 @@ 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_BUDDY
>>>       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..08d7314b1e35
>>> --- /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 *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_kunit_helper_alloc_device(test, 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..d03db0405484
>>> --- /dev/null
>>> +++ b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
>>> @@ -0,0 +1,59 @@
>>> +// 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_kunit_helper_alloc_device(struct kunit *test,
>>
>> Since this function is only initializing the ttm device I think we 
>> should name it ttm_kunit_helper_init_device().
>>
>> On the other hand I don't see a good reason why it can't also allocate 
>> the device.
> 
> I believe that's a leftover from times when I thought I'll reuse DRM 
> device between the tests. No problem, I can put them into one function.
> 
> All the best,
> Karolina
> 
>>
>> Apart from that looks like a good start,
>> Christian.
>>
>>> +                  struct ttm_device *ttm,
>>> +                  bool use_dma_alloc,
>>> +                  bool use_dma32)
>>> +{
>>> +    struct ttm_test_devices_priv *priv = test->priv;
>>> +    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_kunit_helper_alloc_device);
>>> +
>>> +int ttm_test_devices_init(struct kunit *test)
>>> +{
>>> +    struct ttm_test_devices_priv *priv;
>>> +
>>> +    priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL);
>>> +    KUNIT_ASSERT_NOT_NULL(test, priv);
>>> +
>>> +    test->priv = priv;
>>> +
>>> +    priv->dev = drm_kunit_helper_alloc_device(test);
>>> +    KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->dev);
>>> +
>>> +    priv->drm = __drm_kunit_helper_alloc_drm_device(test, priv->dev,
>>> +                            sizeof(*priv->drm), 0,
>>> +                            DRIVER_GEM);
>>> +    KUNIT_ASSERT_NOT_ERR_OR_NULL(test, priv->drm);
>>> +
>>> +    return 0;
>>> +}
>>> +EXPORT_SYMBOL_GPL(ttm_test_devices_init);
>>> +
>>> +void ttm_test_devices_fini(struct kunit *test)
>>> +{
>>> +    struct ttm_test_devices_priv *priv = test->priv;
>>> +
>>> +    drm_kunit_helper_free_device(test, priv->dev);
>>> +    drm_dev_put(priv->drm);
>>> +}
>>> +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..69fb03b9c4d2
>>> --- /dev/null
>>> +++ b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h
>>> @@ -0,0 +1,29 @@
>>> +/* 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_priv {
>>> +    struct drm_device *drm;
>>> +    struct device *dev;
>>> +};
>>> +
>>> +int ttm_kunit_helper_alloc_device(struct kunit *test,
>>> +                  struct ttm_device *ttm,
>>> +                  bool use_dma_alloc,
>>> +                  bool use_dma32);
>>> +
>>> +int ttm_test_devices_init(struct kunit *test);
>>> +void ttm_test_devices_fini(struct kunit *test);
>>> +
>>> +#endif // TTM_KUNIT_HELPERS_H
>>