diff mbox series

[v10,3/9] drm/ttm/tests: Test simple BO creation and validation

Message ID 7c1f626ac0423ee43e0e7602a063e7f9a4e163b9.1711117249.git.karolina.stolarek@intel.com (mailing list archive)
State New, archived
Headers show
Series Improve test coverage of TTM | expand

Commit Message

Karolina Stolarek March 22, 2024, 2:29 p.m. UTC 
Add tests for ttm_bo_init_reserved() and ttm_bo_validate() that use
sys manager. Define a simple move function in ttm_device_funcs. Expose
destroy callback of the buffer object to make testing of
ttm_bo_init_reserved() behaviour easier.

Signed-off-by: Karolina Stolarek <karolina.stolarek@intel.com>
---
 drivers/gpu/drm/ttm/tests/Makefile            |   1 +
 .../gpu/drm/ttm/tests/ttm_bo_validate_test.c  | 207 ++++++++++++++++++
 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c |  14 +-
 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h |   1 +
 4 files changed, 222 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/ttm/tests/ttm_bo_validate_test.c

Comments

Matthew Auld April 10, 2024, 2:01 p.m. UTC | #1 
On 22/03/2024 14:29, Karolina Stolarek wrote:
> Add tests for ttm_bo_init_reserved() and ttm_bo_validate() that use
> sys manager. Define a simple move function in ttm_device_funcs. Expose
> destroy callback of the buffer object to make testing of
> ttm_bo_init_reserved() behaviour easier.
> 
> Signed-off-by: Karolina Stolarek <karolina.stolarek@intel.com>
> ---
>   drivers/gpu/drm/ttm/tests/Makefile            |   1 +
>   .../gpu/drm/ttm/tests/ttm_bo_validate_test.c  | 207 ++++++++++++++++++
>   drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c |  14 +-
>   drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h |   1 +
>   4 files changed, 222 insertions(+), 1 deletion(-)
>   create mode 100644 drivers/gpu/drm/ttm/tests/ttm_bo_validate_test.c
> 
> diff --git a/drivers/gpu/drm/ttm/tests/Makefile b/drivers/gpu/drm/ttm/tests/Makefile
> index 468535f7eed2..2e5ed63fb414 100644
> --- a/drivers/gpu/drm/ttm/tests/Makefile
> +++ b/drivers/gpu/drm/ttm/tests/Makefile
> @@ -6,4 +6,5 @@ obj-$(CONFIG_DRM_TTM_KUNIT_TEST) += \
>           ttm_resource_test.o \
>           ttm_tt_test.o \
>           ttm_bo_test.o \
> +        ttm_bo_validate_test.o \
>           ttm_kunit_helpers.o
> diff --git a/drivers/gpu/drm/ttm/tests/ttm_bo_validate_test.c b/drivers/gpu/drm/ttm/tests/ttm_bo_validate_test.c
> new file mode 100644
> index 000000000000..8229bb31d747
> --- /dev/null
> +++ b/drivers/gpu/drm/ttm/tests/ttm_bo_validate_test.c
> @@ -0,0 +1,207 @@
> +// SPDX-License-Identifier: GPL-2.0 AND MIT
> +/*
> + * Copyright © 2023 Intel Corporation
> + */
> +
> +#include <drm/ttm/ttm_resource.h>
> +#include <drm/ttm/ttm_placement.h>
> +#include <drm/ttm/ttm_tt.h>
> +
> +#include "ttm_kunit_helpers.h"
> +
> +#define BO_SIZE		SZ_4K
> +
> +struct ttm_bo_validate_test_case {
> +	const char *description;
> +	enum ttm_bo_type bo_type;
> +	bool with_ttm;
> +};
> +
> +static struct ttm_placement *ttm_placement_kunit_init(struct kunit *test,
> +						      struct ttm_place *places,
> +						      unsigned int num_places)
> +{
> +	struct ttm_placement *placement;
> +
> +	placement = kunit_kzalloc(test, sizeof(*placement), GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_NULL(test, placement);
> +
> +	placement->num_placement = num_places;
> +	placement->placement = places;
> +
> +	return placement;
> +}
> +
> +static void ttm_bo_validate_case_desc(const struct ttm_bo_validate_test_case *t,
> +				      char *desc)
> +{
> +	strscpy(desc, t->description, KUNIT_PARAM_DESC_SIZE);
> +}
> +
> +static const struct ttm_bo_validate_test_case ttm_bo_type_cases[] = {
> +	{
> +		.description = "Buffer object for userspace",
> +		.bo_type = ttm_bo_type_device,
> +	},
> +	{
> +		.description = "Kernel buffer object",
> +		.bo_type = ttm_bo_type_kernel,
> +	},
> +	{
> +		.description = "Shared buffer object",
> +		.bo_type = ttm_bo_type_sg,
> +	},
> +};
> +
> +KUNIT_ARRAY_PARAM(ttm_bo_types, ttm_bo_type_cases,
> +		  ttm_bo_validate_case_desc);
> +
> +static void ttm_bo_init_reserved_sys_man(struct kunit *test)
> +{
> +	const struct ttm_bo_validate_test_case *params = test->param_value;
> +	struct ttm_test_devices *priv = test->priv;
> +	enum ttm_bo_type bo_type = params->bo_type;
> +	uint32_t size = ALIGN(BO_SIZE, PAGE_SIZE);
> +	struct ttm_operation_ctx ctx = { };
> +	struct ttm_placement *placement;
> +	struct ttm_buffer_object *bo;
> +	struct ttm_place *place;
> +	int err;
> +
> +	bo = kunit_kzalloc(test, sizeof(*bo), GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_NULL(test, bo);
> +
> +	place = ttm_place_kunit_init(test, TTM_PL_SYSTEM, 0);
> +	placement = ttm_placement_kunit_init(test, place, 1);
> +
> +	drm_gem_private_object_init(priv->drm, &bo->base, size);
> +
> +	err = ttm_bo_init_reserved(priv->ttm_dev, bo, bo_type, placement,
> +				   PAGE_SIZE, &ctx, NULL, NULL,
> +				   &dummy_ttm_bo_destroy);
> +	dma_resv_unlock(bo->base.resv);
> +
> +	KUNIT_EXPECT_EQ(test, err, 0);
> +	KUNIT_EXPECT_EQ(test, kref_read(&bo->kref), 1);
> +	KUNIT_EXPECT_PTR_EQ(test, bo->bdev, priv->ttm_dev);
> +	KUNIT_EXPECT_EQ(test, bo->type, bo_type);
> +	KUNIT_EXPECT_EQ(test, bo->page_alignment, PAGE_SIZE);
> +	KUNIT_EXPECT_PTR_EQ(test, bo->destroy, &dummy_ttm_bo_destroy);
> +	KUNIT_EXPECT_EQ(test, bo->pin_count, 0);
> +	KUNIT_EXPECT_NULL(test, bo->bulk_move);
> +	KUNIT_EXPECT_NOT_NULL(test, bo->ttm);
> +	KUNIT_EXPECT_FALSE(test, ttm_tt_is_populated(bo->ttm));
> +	KUNIT_EXPECT_NOT_NULL(test, (void *)bo->base.resv->fences);
> +	KUNIT_EXPECT_EQ(test, ctx.bytes_moved, size);
> +
> +	if (bo_type != ttm_bo_type_kernel)
> +		KUNIT_EXPECT_TRUE(test,
> +				  drm_mm_node_allocated(&bo->base.vma_node.vm_node));
> +
> +	ttm_resource_free(bo, &bo->resource);
> +	ttm_bo_put(bo);
> +}
> +
> +static void ttm_bo_init_reserved_resv(struct kunit *test)
> +{
> +	enum ttm_bo_type bo_type = ttm_bo_type_device;
> +	struct ttm_test_devices *priv = test->priv;
> +	uint32_t size = ALIGN(BO_SIZE, PAGE_SIZE);
> +	struct ttm_operation_ctx ctx = { };
> +	struct ttm_placement *placement;
> +	struct ttm_buffer_object *bo;
> +	struct ttm_place *place;
> +	struct dma_resv resv;
> +	int err;
> +
> +	bo = kunit_kzalloc(test, sizeof(*bo), GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_NULL(test, bo);
> +
> +	place = ttm_place_kunit_init(test, TTM_PL_SYSTEM, 0);
> +	placement = ttm_placement_kunit_init(test, place, 1);
> +
> +	drm_gem_private_object_init(priv->drm, &bo->base, size);
> +	dma_resv_init(&resv);
> +	dma_resv_lock(&resv, NULL);
> +
> +	err = ttm_bo_init_reserved(priv->ttm_dev, bo, bo_type, placement,
> +				   PAGE_SIZE, &ctx, NULL, &resv,
> +				   &dummy_ttm_bo_destroy);
> +	dma_resv_unlock(bo->base.resv);
> +
> +	KUNIT_EXPECT_EQ(test, err, 0);
> +	KUNIT_EXPECT_PTR_EQ(test, bo->base.resv, &resv);
> +
> +	ttm_resource_free(bo, &bo->resource);
> +	ttm_bo_put(bo);
> +}
> +
> +static void ttm_bo_validate_invalid_placement(struct kunit *test)
> +{
> +	enum ttm_bo_type bo_type = ttm_bo_type_device;
> +	uint32_t unknown_mem_type = TTM_PL_PRIV + 1;
> +	uint32_t size = ALIGN(BO_SIZE, PAGE_SIZE);
> +	struct ttm_operation_ctx ctx = { };
> +	struct ttm_placement *placement;
> +	struct ttm_buffer_object *bo;
> +	struct ttm_place *place;
> +	int err;
> +
> +	place = ttm_place_kunit_init(test, unknown_mem_type, 0);
> +	placement = ttm_placement_kunit_init(test, place, 1);
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, size);
> +	bo->type = bo_type;
> +
> +	ttm_bo_reserve(bo, false, false, NULL);
> +	err = ttm_bo_validate(bo, placement, &ctx);
> +	dma_resv_unlock(bo->base.resv);
> +
> +	KUNIT_EXPECT_EQ(test, err, -ENOMEM);
> +
> +	ttm_bo_put(bo);
> +}
> +
> +static void ttm_bo_validate_pinned(struct kunit *test)
> +{
> +	enum ttm_bo_type bo_type = ttm_bo_type_device;
> +	uint32_t size = ALIGN(BO_SIZE, PAGE_SIZE);
> +	struct ttm_operation_ctx ctx = { };
> +	uint32_t mem_type = TTM_PL_SYSTEM;
> +	struct ttm_placement *placement;
> +	struct ttm_buffer_object *bo;
> +	struct ttm_place *place;
> +	int err;
> +
> +	place = ttm_place_kunit_init(test, mem_type, 0);
> +	placement = ttm_placement_kunit_init(test, place, 1);
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, size);
> +	bo->type = bo_type;
> +
> +	ttm_bo_reserve(bo, false, false, NULL);
> +	ttm_bo_pin(bo);
> +	err = ttm_bo_validate(bo, placement, &ctx);
> +	dma_resv_unlock(bo->base.resv);
> +
> +	KUNIT_EXPECT_EQ(test, err, -EINVAL);

ttm_bo_put(bo) ?

Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Karolina Stolarek April 11, 2024, 12:20 p.m. UTC | #2 
On 10.04.2024 16:01, Matthew Auld wrote:
> On 22/03/2024 14:29, Karolina Stolarek wrote:
>> +static void ttm_bo_validate_pinned(struct kunit *test)
>> +{
>> +    enum ttm_bo_type bo_type = ttm_bo_type_device;
>> +    uint32_t size = ALIGN(BO_SIZE, PAGE_SIZE);
>> +    struct ttm_operation_ctx ctx = { };
>> +    uint32_t mem_type = TTM_PL_SYSTEM;
>> +    struct ttm_placement *placement;
>> +    struct ttm_buffer_object *bo;
>> +    struct ttm_place *place;
>> +    int err;
>> +
>> +    place = ttm_place_kunit_init(test, mem_type, 0);
>> +    placement = ttm_placement_kunit_init(test, place, 1);
>> +
>> +    bo = ttm_bo_kunit_init(test, test->priv, size);
>> +    bo->type = bo_type;
>> +
>> +    ttm_bo_reserve(bo, false, false, NULL);
>> +    ttm_bo_pin(bo);
>> +    err = ttm_bo_validate(bo, placement, &ctx);
>> +    dma_resv_unlock(bo->base.resv);
>> +
>> +    KUNIT_EXPECT_EQ(test, err, -EINVAL);
> 
> ttm_bo_put(bo) ?

Good catch, I'll unpin the buffer and release it, thanks!

All the best,
Karolina

> 
> Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Somalapuram, Amaranath April 16, 2024, 12:20 p.m. UTC | #3 
On 3/22/2024 7:59 PM, Karolina Stolarek wrote:
> Add tests for ttm_bo_init_reserved() and ttm_bo_validate() that use
> sys manager. Define a simple move function in ttm_device_funcs. Expose
> destroy callback of the buffer object to make testing of
> ttm_bo_init_reserved() behaviour easier.
>
> Signed-off-by: Karolina Stolarek <karolina.stolarek@intel.com>
> ---
Reviewed-by: Somalapuram, Amaranath <asomalap@amd.com>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/ttm/tests/Makefile b/drivers/gpu/drm/ttm/tests/Makefile
index 468535f7eed2..2e5ed63fb414 100644
--- a/drivers/gpu/drm/ttm/tests/Makefile
+++ b/drivers/gpu/drm/ttm/tests/Makefile
@@ -6,4 +6,5 @@  obj-$(CONFIG_DRM_TTM_KUNIT_TEST) += \
         ttm_resource_test.o \
         ttm_tt_test.o \
         ttm_bo_test.o \
+        ttm_bo_validate_test.o \
         ttm_kunit_helpers.o
diff --git a/drivers/gpu/drm/ttm/tests/ttm_bo_validate_test.c b/drivers/gpu/drm/ttm/tests/ttm_bo_validate_test.c
new file mode 100644
index 000000000000..8229bb31d747
--- /dev/null
+++ b/drivers/gpu/drm/ttm/tests/ttm_bo_validate_test.c
@@ -0,0 +1,207 @@ 
+// SPDX-License-Identifier: GPL-2.0 AND MIT
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#include <drm/ttm/ttm_resource.h>
+#include <drm/ttm/ttm_placement.h>
+#include <drm/ttm/ttm_tt.h>
+
+#include "ttm_kunit_helpers.h"
+
+#define BO_SIZE		SZ_4K
+
+struct ttm_bo_validate_test_case {
+	const char *description;
+	enum ttm_bo_type bo_type;
+	bool with_ttm;
+};
+
+static struct ttm_placement *ttm_placement_kunit_init(struct kunit *test,
+						      struct ttm_place *places,
+						      unsigned int num_places)
+{
+	struct ttm_placement *placement;
+
+	placement = kunit_kzalloc(test, sizeof(*placement), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, placement);
+
+	placement->num_placement = num_places;
+	placement->placement = places;
+
+	return placement;
+}
+
+static void ttm_bo_validate_case_desc(const struct ttm_bo_validate_test_case *t,
+				      char *desc)
+{
+	strscpy(desc, t->description, KUNIT_PARAM_DESC_SIZE);
+}
+
+static const struct ttm_bo_validate_test_case ttm_bo_type_cases[] = {
+	{
+		.description = "Buffer object for userspace",
+		.bo_type = ttm_bo_type_device,
+	},
+	{
+		.description = "Kernel buffer object",
+		.bo_type = ttm_bo_type_kernel,
+	},
+	{
+		.description = "Shared buffer object",
+		.bo_type = ttm_bo_type_sg,
+	},
+};
+
+KUNIT_ARRAY_PARAM(ttm_bo_types, ttm_bo_type_cases,
+		  ttm_bo_validate_case_desc);
+
+static void ttm_bo_init_reserved_sys_man(struct kunit *test)
+{
+	const struct ttm_bo_validate_test_case *params = test->param_value;
+	struct ttm_test_devices *priv = test->priv;
+	enum ttm_bo_type bo_type = params->bo_type;
+	uint32_t size = ALIGN(BO_SIZE, PAGE_SIZE);
+	struct ttm_operation_ctx ctx = { };
+	struct ttm_placement *placement;
+	struct ttm_buffer_object *bo;
+	struct ttm_place *place;
+	int err;
+
+	bo = kunit_kzalloc(test, sizeof(*bo), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, bo);
+
+	place = ttm_place_kunit_init(test, TTM_PL_SYSTEM, 0);
+	placement = ttm_placement_kunit_init(test, place, 1);
+
+	drm_gem_private_object_init(priv->drm, &bo->base, size);
+
+	err = ttm_bo_init_reserved(priv->ttm_dev, bo, bo_type, placement,
+				   PAGE_SIZE, &ctx, NULL, NULL,
+				   &dummy_ttm_bo_destroy);
+	dma_resv_unlock(bo->base.resv);
+
+	KUNIT_EXPECT_EQ(test, err, 0);
+	KUNIT_EXPECT_EQ(test, kref_read(&bo->kref), 1);
+	KUNIT_EXPECT_PTR_EQ(test, bo->bdev, priv->ttm_dev);
+	KUNIT_EXPECT_EQ(test, bo->type, bo_type);
+	KUNIT_EXPECT_EQ(test, bo->page_alignment, PAGE_SIZE);
+	KUNIT_EXPECT_PTR_EQ(test, bo->destroy, &dummy_ttm_bo_destroy);
+	KUNIT_EXPECT_EQ(test, bo->pin_count, 0);
+	KUNIT_EXPECT_NULL(test, bo->bulk_move);
+	KUNIT_EXPECT_NOT_NULL(test, bo->ttm);
+	KUNIT_EXPECT_FALSE(test, ttm_tt_is_populated(bo->ttm));
+	KUNIT_EXPECT_NOT_NULL(test, (void *)bo->base.resv->fences);
+	KUNIT_EXPECT_EQ(test, ctx.bytes_moved, size);
+
+	if (bo_type != ttm_bo_type_kernel)
+		KUNIT_EXPECT_TRUE(test,
+				  drm_mm_node_allocated(&bo->base.vma_node.vm_node));
+
+	ttm_resource_free(bo, &bo->resource);
+	ttm_bo_put(bo);
+}
+
+static void ttm_bo_init_reserved_resv(struct kunit *test)
+{
+	enum ttm_bo_type bo_type = ttm_bo_type_device;
+	struct ttm_test_devices *priv = test->priv;
+	uint32_t size = ALIGN(BO_SIZE, PAGE_SIZE);
+	struct ttm_operation_ctx ctx = { };
+	struct ttm_placement *placement;
+	struct ttm_buffer_object *bo;
+	struct ttm_place *place;
+	struct dma_resv resv;
+	int err;
+
+	bo = kunit_kzalloc(test, sizeof(*bo), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_NULL(test, bo);
+
+	place = ttm_place_kunit_init(test, TTM_PL_SYSTEM, 0);
+	placement = ttm_placement_kunit_init(test, place, 1);
+
+	drm_gem_private_object_init(priv->drm, &bo->base, size);
+	dma_resv_init(&resv);
+	dma_resv_lock(&resv, NULL);
+
+	err = ttm_bo_init_reserved(priv->ttm_dev, bo, bo_type, placement,
+				   PAGE_SIZE, &ctx, NULL, &resv,
+				   &dummy_ttm_bo_destroy);
+	dma_resv_unlock(bo->base.resv);
+
+	KUNIT_EXPECT_EQ(test, err, 0);
+	KUNIT_EXPECT_PTR_EQ(test, bo->base.resv, &resv);
+
+	ttm_resource_free(bo, &bo->resource);
+	ttm_bo_put(bo);
+}
+
+static void ttm_bo_validate_invalid_placement(struct kunit *test)
+{
+	enum ttm_bo_type bo_type = ttm_bo_type_device;
+	uint32_t unknown_mem_type = TTM_PL_PRIV + 1;
+	uint32_t size = ALIGN(BO_SIZE, PAGE_SIZE);
+	struct ttm_operation_ctx ctx = { };
+	struct ttm_placement *placement;
+	struct ttm_buffer_object *bo;
+	struct ttm_place *place;
+	int err;
+
+	place = ttm_place_kunit_init(test, unknown_mem_type, 0);
+	placement = ttm_placement_kunit_init(test, place, 1);
+
+	bo = ttm_bo_kunit_init(test, test->priv, size);
+	bo->type = bo_type;
+
+	ttm_bo_reserve(bo, false, false, NULL);
+	err = ttm_bo_validate(bo, placement, &ctx);
+	dma_resv_unlock(bo->base.resv);
+
+	KUNIT_EXPECT_EQ(test, err, -ENOMEM);
+
+	ttm_bo_put(bo);
+}
+
+static void ttm_bo_validate_pinned(struct kunit *test)
+{
+	enum ttm_bo_type bo_type = ttm_bo_type_device;
+	uint32_t size = ALIGN(BO_SIZE, PAGE_SIZE);
+	struct ttm_operation_ctx ctx = { };
+	uint32_t mem_type = TTM_PL_SYSTEM;
+	struct ttm_placement *placement;
+	struct ttm_buffer_object *bo;
+	struct ttm_place *place;
+	int err;
+
+	place = ttm_place_kunit_init(test, mem_type, 0);
+	placement = ttm_placement_kunit_init(test, place, 1);
+
+	bo = ttm_bo_kunit_init(test, test->priv, size);
+	bo->type = bo_type;
+
+	ttm_bo_reserve(bo, false, false, NULL);
+	ttm_bo_pin(bo);
+	err = ttm_bo_validate(bo, placement, &ctx);
+	dma_resv_unlock(bo->base.resv);
+
+	KUNIT_EXPECT_EQ(test, err, -EINVAL);
+}
+
+static struct kunit_case ttm_bo_validate_test_cases[] = {
+	KUNIT_CASE_PARAM(ttm_bo_init_reserved_sys_man, ttm_bo_types_gen_params),
+	KUNIT_CASE(ttm_bo_init_reserved_resv),
+	KUNIT_CASE(ttm_bo_validate_invalid_placement),
+	KUNIT_CASE(ttm_bo_validate_pinned),
+	{}
+};
+
+static struct kunit_suite ttm_bo_validate_test_suite = {
+	.name = "ttm_bo_validate",
+	.init = ttm_test_devices_all_init,
+	.exit = ttm_test_devices_fini,
+	.test_cases = ttm_bo_validate_test_cases,
+};
+
+kunit_test_suites(&ttm_bo_validate_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
index 2fe0c66f31a9..c75de24de783 100644
--- a/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
+++ b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
@@ -22,13 +22,19 @@  static void ttm_tt_simple_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
 	kfree(ttm);
 }
 
-static void dummy_ttm_bo_destroy(struct ttm_buffer_object *bo)
+static int mock_move(struct ttm_buffer_object *bo, bool evict,
+		     struct ttm_operation_ctx *ctx,
+		     struct ttm_resource *new_mem,
+		     struct ttm_place *hop)
 {
+	bo->resource = new_mem;
+	return 0;
 }
 
 struct ttm_device_funcs ttm_dev_funcs = {
 	.ttm_tt_create = ttm_tt_simple_create,
 	.ttm_tt_destroy = ttm_tt_simple_destroy,
+	.move = mock_move,
 };
 EXPORT_SYMBOL_GPL(ttm_dev_funcs);
 
@@ -88,6 +94,12 @@  struct ttm_place *ttm_place_kunit_init(struct kunit *test,
 }
 EXPORT_SYMBOL_GPL(ttm_place_kunit_init);
 
+void dummy_ttm_bo_destroy(struct ttm_buffer_object *bo)
+{
+	drm_gem_object_release(&bo->base);
+}
+EXPORT_SYMBOL_GPL(dummy_ttm_bo_destroy);
+
 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 53bb5834939f..3e5fe272c54c 100644
--- a/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h
+++ b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h
@@ -31,6 +31,7 @@  struct ttm_buffer_object *ttm_bo_kunit_init(struct kunit *test,
 					    size_t size);
 struct ttm_place *ttm_place_kunit_init(struct kunit *test,
 				       uint32_t mem_type, uint32_t flags);
+void dummy_ttm_bo_destroy(struct ttm_buffer_object *bo);
 
 struct ttm_test_devices *ttm_test_devices_basic(struct kunit *test);
 struct ttm_test_devices *ttm_test_devices_all(struct kunit *test);