Re: [PATCH v5 2/4] drm/ttm/tests: Add tests for ttm_tt

[Christian König <christian.koenig@xxxxxxx>]

Am 16.10.23 um 10:52 schrieb Karolina Stolarek:
> Test initialization, creation and destruction of ttm_tt instances.
> Export ttm_tt_destroy and ttm_tt_create symbols for testing purposes.
>
> Signed-off-by: Karolina Stolarek <karolina.stolarek@xxxxxxxxx>

At least of hand I can't see anything obviously wrong, but I also 
haven't spend to much time on reading though this.

Feel free to add Reviewed-by: Christian König <christian.koenig@xxxxxxx>

Regards,
Christian.

> ---
>   drivers/gpu/drm/ttm/tests/Makefile            |   1 +
>   drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c |  20 ++
>   drivers/gpu/drm/ttm/tests/ttm_tt_test.c       | 295 ++++++++++++++++++
>   drivers/gpu/drm/ttm/ttm_tt.c                  |   3 +
>   4 files changed, 319 insertions(+)
>   create mode 100644 drivers/gpu/drm/ttm/tests/ttm_tt_test.c
>
> diff --git a/drivers/gpu/drm/ttm/tests/Makefile b/drivers/gpu/drm/ttm/tests/Makefile
> index c92fe2052ef6..f570530bbb60 100644
> --- a/drivers/gpu/drm/ttm/tests/Makefile
> +++ b/drivers/gpu/drm/ttm/tests/Makefile
> @@ -4,4 +4,5 @@ obj-$(CONFIG_DRM_TTM_KUNIT_TEST) += \
>           ttm_device_test.o \
>           ttm_pool_test.o \
>           ttm_resource_test.o \
> +        ttm_tt_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 c605f010ea08..5aa9d1d2fca3 100644
> --- a/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
> +++ b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
> @@ -2,9 +2,29 @@
>   /*
>    * Copyright © 2023 Intel Corporation
>    */
> +#include <drm/ttm/ttm_tt.h>
> +
>   #include "ttm_kunit_helpers.h"
>   
> +static struct ttm_tt *ttm_tt_simple_create(struct ttm_buffer_object *bo,
> +					   uint32_t page_flags)
> +{
> +	struct ttm_tt *tt;
> +
> +	tt = kzalloc(sizeof(*tt), GFP_KERNEL);
> +	ttm_tt_init(tt, bo, page_flags, ttm_cached, 0);
> +
> +	return tt;
> +}
> +
> +static void ttm_tt_simple_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
> +{
> +	kfree(ttm);
> +}
> +
>   struct ttm_device_funcs ttm_dev_funcs = {
> +	.ttm_tt_create = ttm_tt_simple_create,
> +	.ttm_tt_destroy = ttm_tt_simple_destroy,
>   };
>   EXPORT_SYMBOL_GPL(ttm_dev_funcs);
>   
> diff --git a/drivers/gpu/drm/ttm/tests/ttm_tt_test.c b/drivers/gpu/drm/ttm/tests/ttm_tt_test.c
> new file mode 100644
> index 000000000000..4f5fc4d460b4
> --- /dev/null
> +++ b/drivers/gpu/drm/ttm/tests/ttm_tt_test.c
> @@ -0,0 +1,295 @@
> +// SPDX-License-Identifier: GPL-2.0 AND MIT
> +/*
> + * Copyright © 2023 Intel Corporation
> + */
> +#include <linux/shmem_fs.h>
> +#include <drm/ttm/ttm_tt.h>
> +
> +#include "ttm_kunit_helpers.h"
> +
> +#define BO_SIZE		SZ_4K
> +
> +struct ttm_tt_test_case {
> +	const char *description;
> +	uint32_t size;
> +	uint32_t extra_pages_num;
> +};
> +
> +static int ttm_tt_test_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_all(test);
> +	test->priv = priv;
> +
> +	return 0;
> +}
> +
> +static const struct ttm_tt_test_case ttm_tt_init_basic_cases[] = {
> +	{
> +		.description = "Page-aligned size",
> +		.size = SZ_4K,
> +	},
> +	{
> +		.description = "Extra pages requested",
> +		.size = SZ_4K,
> +		.extra_pages_num = 1,
> +	},
> +};
> +
> +static void ttm_tt_init_case_desc(const struct ttm_tt_test_case *t,
> +				  char *desc)
> +{
> +	strscpy(desc, t->description, KUNIT_PARAM_DESC_SIZE);
> +}
> +
> +KUNIT_ARRAY_PARAM(ttm_tt_init_basic, ttm_tt_init_basic_cases,
> +		  ttm_tt_init_case_desc);
> +
> +static void ttm_tt_init_basic(struct kunit *test)
> +{
> +	const struct ttm_tt_test_case *params = test->param_value;
> +	struct ttm_buffer_object *bo;
> +	struct ttm_tt *tt;
> +	uint32_t page_flags = TTM_TT_FLAG_ZERO_ALLOC;
> +	enum ttm_caching caching = ttm_cached;
> +	uint32_t extra_pages = params->extra_pages_num;
> +	int num_pages = params->size >> PAGE_SHIFT;
> +	int err;
> +
> +	tt = kunit_kzalloc(test, sizeof(*tt), GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_NULL(test, tt);
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, params->size);
> +
> +	err = ttm_tt_init(tt, bo, page_flags, caching, extra_pages);
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +
> +	KUNIT_ASSERT_EQ(test, tt->num_pages, num_pages + extra_pages);
> +
> +	KUNIT_ASSERT_EQ(test, tt->page_flags, page_flags);
> +	KUNIT_ASSERT_EQ(test, tt->caching, caching);
> +
> +	KUNIT_ASSERT_NULL(test, tt->dma_address);
> +	KUNIT_ASSERT_NULL(test, tt->swap_storage);
> +}
> +
> +static void ttm_tt_init_misaligned(struct kunit *test)
> +{
> +	struct ttm_buffer_object *bo;
> +	struct ttm_tt *tt;
> +	enum ttm_caching caching = ttm_cached;
> +	uint32_t size = SZ_8K;
> +	int num_pages = (size + SZ_4K) >> PAGE_SHIFT;
> +	int err;
> +
> +	tt = kunit_kzalloc(test, sizeof(*tt), GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_NULL(test, tt);
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, size);
> +
> +	/* Make the object size misaligned */
> +	bo->base.size += 1;
> +
> +	err = ttm_tt_init(tt, bo, 0, caching, 0);
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +
> +	KUNIT_ASSERT_EQ(test, tt->num_pages, num_pages);
> +}
> +
> +static void ttm_tt_fini_basic(struct kunit *test)
> +{
> +	struct ttm_buffer_object *bo;
> +	struct ttm_tt *tt;
> +	enum ttm_caching caching = ttm_cached;
> +	int err;
> +
> +	tt = kunit_kzalloc(test, sizeof(*tt), GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_NULL(test, tt);
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +
> +	err = ttm_tt_init(tt, bo, 0, caching, 0);
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +	KUNIT_ASSERT_NOT_NULL(test, tt->pages);
> +
> +	ttm_tt_fini(tt);
> +	KUNIT_ASSERT_NULL(test, tt->pages);
> +}
> +
> +static void ttm_tt_fini_sg(struct kunit *test)
> +{
> +	struct ttm_buffer_object *bo;
> +	struct ttm_tt *tt;
> +	enum ttm_caching caching = ttm_cached;
> +	int err;
> +
> +	tt = kunit_kzalloc(test, sizeof(*tt), GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_NULL(test, tt);
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +
> +	err = ttm_sg_tt_init(tt, bo, 0, caching);
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +	KUNIT_ASSERT_NOT_NULL(test, tt->dma_address);
> +
> +	ttm_tt_fini(tt);
> +	KUNIT_ASSERT_NULL(test, tt->dma_address);
> +}
> +
> +static void ttm_tt_fini_shmem(struct kunit *test)
> +{
> +	struct ttm_buffer_object *bo;
> +	struct ttm_tt *tt;
> +	struct file *shmem;
> +	enum ttm_caching caching = ttm_cached;
> +	int err;
> +
> +	tt = kunit_kzalloc(test, sizeof(*tt), GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_NULL(test, tt);
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +
> +	err = ttm_tt_init(tt, bo, 0, caching, 0);
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +
> +	shmem = shmem_file_setup("ttm swap", BO_SIZE, 0);
> +	tt->swap_storage = shmem;
> +
> +	ttm_tt_fini(tt);
> +	KUNIT_ASSERT_NULL(test, tt->swap_storage);
> +}
> +
> +static void ttm_tt_create_basic(struct kunit *test)
> +{
> +	struct ttm_buffer_object *bo;
> +	int err;
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +	bo->type = ttm_bo_type_device;
> +
> +	dma_resv_lock(bo->base.resv, NULL);
> +	err = ttm_tt_create(bo, false);
> +	dma_resv_unlock(bo->base.resv);
> +
> +	KUNIT_EXPECT_EQ(test, err, 0);
> +	KUNIT_EXPECT_NOT_NULL(test, bo->ttm);
> +
> +	/* Free manually, as it was allocated outside of KUnit */
> +	kfree(bo->ttm);
> +}
> +
> +static void ttm_tt_create_invalid_bo_type(struct kunit *test)
> +{
> +	struct ttm_buffer_object *bo;
> +	int err;
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +	bo->type = ttm_bo_type_sg + 1;
> +
> +	dma_resv_lock(bo->base.resv, NULL);
> +	err = ttm_tt_create(bo, false);
> +	dma_resv_unlock(bo->base.resv);
> +
> +	KUNIT_EXPECT_EQ(test, err, -EINVAL);
> +	KUNIT_EXPECT_NULL(test, bo->ttm);
> +}
> +
> +static void ttm_tt_create_ttm_exists(struct kunit *test)
> +{
> +	struct ttm_buffer_object *bo;
> +	struct ttm_tt *tt;
> +	enum ttm_caching caching = ttm_cached;
> +	int err;
> +
> +	tt = kunit_kzalloc(test, sizeof(*tt), GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_NULL(test, tt);
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +
> +	err = ttm_tt_init(tt, bo, 0, caching, 0);
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +	bo->ttm = tt;
> +
> +	dma_resv_lock(bo->base.resv, NULL);
> +	err = ttm_tt_create(bo, false);
> +	dma_resv_unlock(bo->base.resv);
> +
> +	/* Expect to keep the previous TTM */
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +	KUNIT_ASSERT_PTR_EQ(test, tt, bo->ttm);
> +}
> +
> +static struct ttm_tt *ttm_tt_null_create(struct ttm_buffer_object *bo,
> +					 uint32_t page_flags)
> +{
> +	return NULL;
> +}
> +
> +struct ttm_device_funcs ttm_dev_empty_funcs = {
> +	.ttm_tt_create = ttm_tt_null_create,
> +};
> +
> +static void ttm_tt_create_failed(struct kunit *test)
> +{
> +	const struct ttm_test_devices *devs = test->priv;
> +	struct ttm_buffer_object *bo;
> +	int err;
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +
> +	/* Update ttm_device_funcs so we don't alloc ttm_tt */
> +	devs->ttm_dev->funcs = &ttm_dev_empty_funcs;
> +
> +	dma_resv_lock(bo->base.resv, NULL);
> +	err = ttm_tt_create(bo, false);
> +	dma_resv_unlock(bo->base.resv);
> +
> +	KUNIT_ASSERT_EQ(test, err, -ENOMEM);
> +}
> +
> +static void ttm_tt_destroy_basic(struct kunit *test)
> +{
> +	const struct ttm_test_devices *devs = test->priv;
> +	struct ttm_buffer_object *bo;
> +	int err;
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +
> +	dma_resv_lock(bo->base.resv, NULL);
> +	err = ttm_tt_create(bo, false);
> +	dma_resv_unlock(bo->base.resv);
> +
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +	KUNIT_ASSERT_NOT_NULL(test, bo->ttm);
> +
> +	ttm_tt_destroy(devs->ttm_dev, bo->ttm);
> +}
> +
> +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),
> +	KUNIT_CASE(ttm_tt_fini_basic),
> +	KUNIT_CASE(ttm_tt_fini_sg),
> +	KUNIT_CASE(ttm_tt_fini_shmem),
> +	KUNIT_CASE(ttm_tt_create_basic),
> +	KUNIT_CASE(ttm_tt_create_invalid_bo_type),
> +	KUNIT_CASE(ttm_tt_create_ttm_exists),
> +	KUNIT_CASE(ttm_tt_create_failed),
> +	KUNIT_CASE(ttm_tt_destroy_basic),
> +	{}
> +};
> +
> +static struct kunit_suite ttm_tt_test_suite = {
> +	.name = "ttm_tt",
> +	.init = ttm_tt_test_init,
> +	.exit = ttm_test_devices_fini,
> +	.test_cases = ttm_tt_test_cases,
> +};
> +
> +kunit_test_suites(&ttm_tt_test_suite);
> +
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
> index e0a77671edd6..d978dc539a9b 100644
> --- a/drivers/gpu/drm/ttm/ttm_tt.c
> +++ b/drivers/gpu/drm/ttm/ttm_tt.c
> @@ -36,6 +36,7 @@
>   #include <linux/file.h>
>   #include <linux/module.h>
>   #include <drm/drm_cache.h>
> +#include <drm/drm_util.h>
>   #include <drm/ttm/ttm_bo.h>
>   #include <drm/ttm/ttm_tt.h>
>   
> @@ -91,6 +92,7 @@ int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc)
>   
>   	return 0;
>   }
> +EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_create);
>   
>   /*
>    * Allocates storage for pointers to the pages that back the ttm.
> @@ -129,6 +131,7 @@ void ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
>   {
>   	bdev->funcs->ttm_tt_destroy(bdev, ttm);
>   }
> +EXPORT_SYMBOL_FOR_TESTS_ONLY(ttm_tt_destroy);
>   
>   static void ttm_tt_init_fields(struct ttm_tt *ttm,
>   			       struct ttm_buffer_object *bo,