[PATCH v7 3/8] drm/ttm/tests: Add tests for ttm_bo functions

[Christian König]

Am 17.11.23 um 09:49 schrieb Karolina Stolarek:
> Test reservation and release of TTM buffer objects. Add tests to check
> pin and unpin operations.
>
> Signed-off-by: Karolina Stolarek <karolina.stolarek at intel.com>
> Tested-by: Amaranath Somalapuram <Amaranath.Somalapuram at amd.com>

 From the TTM side it looks good, but I can't judge if the lockdep hack 
in the deadlock test is valid or not.

Feel free to add Acked-by: Christian König <christian.koenig at amd.com>.

Regards,
Christian.

> ---
>   drivers/gpu/drm/ttm/tests/Makefile            |   1 +
>   drivers/gpu/drm/ttm/tests/ttm_bo_test.c       | 619 ++++++++++++++++++
>   drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c |   6 +
>   3 files changed, 626 insertions(+)
>   create mode 100644 drivers/gpu/drm/ttm/tests/ttm_bo_test.c
>
> diff --git a/drivers/gpu/drm/ttm/tests/Makefile b/drivers/gpu/drm/ttm/tests/Makefile
> index f570530bbb60..468535f7eed2 100644
> --- a/drivers/gpu/drm/ttm/tests/Makefile
> +++ b/drivers/gpu/drm/ttm/tests/Makefile
> @@ -5,4 +5,5 @@ obj-$(CONFIG_DRM_TTM_KUNIT_TEST) += \
>           ttm_pool_test.o \
>           ttm_resource_test.o \
>           ttm_tt_test.o \
> +        ttm_bo_test.o \
>           ttm_kunit_helpers.o
> diff --git a/drivers/gpu/drm/ttm/tests/ttm_bo_test.c b/drivers/gpu/drm/ttm/tests/ttm_bo_test.c
> new file mode 100644
> index 000000000000..71bca47205ed
> --- /dev/null
> +++ b/drivers/gpu/drm/ttm/tests/ttm_bo_test.c
> @@ -0,0 +1,619 @@
> +// SPDX-License-Identifier: GPL-2.0 AND MIT
> +/*
> + * Copyright © 2023 Intel Corporation
> + */
> +#include <linux/dma-resv.h>
> +#include <linux/kthread.h>
> +#include <linux/delay.h>
> +#include <linux/timer.h>
> +#include <linux/jiffies.h>
> +#include <linux/mutex.h>
> +#include <linux/ww_mutex.h>
> +
> +#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_8K
> +
> +struct ttm_bo_test_case {
> +	const char *description;
> +	bool interruptible;
> +	bool no_wait;
> +};
> +
> +static const struct ttm_bo_test_case ttm_bo_reserved_cases[] = {
> +	{
> +		.description = "Cannot be interrupted and sleeps",
> +		.interruptible = false,
> +		.no_wait = false,
> +	},
> +	{
> +		.description = "Cannot be interrupted, locks straight away",
> +		.interruptible = false,
> +		.no_wait = true,
> +	},
> +	{
> +		.description = "Can be interrupted, sleeps",
> +		.interruptible = true,
> +		.no_wait = false,
> +	},
> +};
> +
> +static void ttm_bo_init_case_desc(const struct ttm_bo_test_case *t,
> +				  char *desc)
> +{
> +	strscpy(desc, t->description, KUNIT_PARAM_DESC_SIZE);
> +}
> +
> +KUNIT_ARRAY_PARAM(ttm_bo_reserve, ttm_bo_reserved_cases, ttm_bo_init_case_desc);
> +
> +static void ttm_bo_reserve_optimistic_no_ticket(struct kunit *test)
> +{
> +	const struct ttm_bo_test_case *params = test->param_value;
> +	struct ttm_buffer_object *bo;
> +	int err;
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +
> +	err = ttm_bo_reserve(bo, params->interruptible, params->no_wait, NULL);
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +
> +	dma_resv_unlock(bo->base.resv);
> +}
> +
> +static void ttm_bo_reserve_locked_no_sleep(struct kunit *test)
> +{
> +	struct ttm_buffer_object *bo;
> +	bool interruptible = false;
> +	bool no_wait = true;
> +	int err;
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +
> +	/* Let's lock it beforehand */
> +	dma_resv_lock(bo->base.resv, NULL);
> +
> +	err = ttm_bo_reserve(bo, interruptible, no_wait, NULL);
> +	dma_resv_unlock(bo->base.resv);
> +
> +	KUNIT_ASSERT_EQ(test, err, -EBUSY);
> +}
> +
> +static void ttm_bo_reserve_no_wait_ticket(struct kunit *test)
> +{
> +	struct ttm_buffer_object *bo;
> +	struct ww_acquire_ctx ctx;
> +	bool interruptible = false;
> +	bool no_wait = true;
> +	int err;
> +
> +	ww_acquire_init(&ctx, &reservation_ww_class);
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +
> +	err = ttm_bo_reserve(bo, interruptible, no_wait, &ctx);
> +	KUNIT_ASSERT_EQ(test, err, -EBUSY);
> +
> +	ww_acquire_fini(&ctx);
> +}
> +
> +static void ttm_bo_reserve_double_resv(struct kunit *test)
> +{
> +	struct ttm_buffer_object *bo;
> +	struct ww_acquire_ctx ctx;
> +	bool interruptible = false;
> +	bool no_wait = false;
> +	int err;
> +
> +	ww_acquire_init(&ctx, &reservation_ww_class);
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +
> +	err = ttm_bo_reserve(bo, interruptible, no_wait, &ctx);
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +
> +	err = ttm_bo_reserve(bo, interruptible, no_wait, &ctx);
> +
> +	dma_resv_unlock(bo->base.resv);
> +	ww_acquire_fini(&ctx);
> +
> +	KUNIT_ASSERT_EQ(test, err, -EALREADY);
> +}
> +
> +/*
> + * A test case heavily inspired by ww_test_edeadlk_normal(). Checks
> + * if -EDEADLK is properly propagated by ttm_bo_reserve()
> + */
> +static void ttm_bo_reserve_deadlock(struct kunit *test)
> +{
> +	struct ttm_buffer_object *bo1, *bo2;
> +	struct ww_acquire_ctx ctx1, ctx2;
> +	bool interruptible = false;
> +	bool no_wait = false;
> +	int err;
> +
> +	bo1 = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +	bo2 = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +
> +	ww_acquire_init(&ctx1, &reservation_ww_class);
> +	mutex_lock(&bo2->base.resv->lock.base);
> +
> +	/* The deadlock will be caught by WW mutex, don't warn about it */
> +	lock_release(&bo2->base.resv->lock.base.dep_map, 1);
> +
> +	bo2->base.resv->lock.ctx = &ctx2;
> +	ctx2 = ctx1;
> +	ctx2.stamp--; /* Make the context holding the lock younger */
> +
> +	err = ttm_bo_reserve(bo1, interruptible, no_wait, &ctx1);
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +
> +	err = ttm_bo_reserve(bo2, interruptible, no_wait, &ctx1);
> +	KUNIT_ASSERT_EQ(test, err, -EDEADLK);
> +
> +	dma_resv_unlock(bo1->base.resv);
> +	ww_acquire_fini(&ctx1);
> +}
> +
> +#if IS_BUILTIN(CONFIG_DRM_TTM_KUNIT_TEST)
> +struct signal_timer {
> +	struct timer_list timer;
> +	struct ww_acquire_ctx *ctx;
> +};
> +
> +static void signal_for_ttm_bo_reserve(struct timer_list *t)
> +{
> +	struct signal_timer *s_timer = from_timer(s_timer, t, timer);
> +	struct task_struct *task = s_timer->ctx->task;
> +
> +	do_send_sig_info(SIGTERM, SEND_SIG_PRIV, task, PIDTYPE_PID);
> +}
> +
> +static int threaded_ttm_bo_reserve(void *arg)
> +{
> +	struct ttm_buffer_object *bo = arg;
> +	struct signal_timer s_timer;
> +	struct ww_acquire_ctx ctx;
> +	bool interruptible = true;
> +	bool no_wait = false;
> +	int err;
> +
> +	ww_acquire_init(&ctx, &reservation_ww_class);
> +
> +	/* Prepare a signal that will interrupt the reservation attempt */
> +	timer_setup_on_stack(&s_timer.timer, &signal_for_ttm_bo_reserve, 0);
> +	s_timer.ctx = &ctx;
> +
> +	mod_timer(&s_timer.timer, msecs_to_jiffies(100));
> +
> +	err = ttm_bo_reserve(bo, interruptible, no_wait, &ctx);
> +
> +	timer_delete_sync(&s_timer.timer);
> +	destroy_timer_on_stack(&s_timer.timer);
> +
> +	ww_acquire_fini(&ctx);
> +
> +	return err;
> +}
> +
> +static void ttm_bo_reserve_interrupted(struct kunit *test)
> +{
> +	struct ttm_buffer_object *bo;
> +	struct task_struct *task;
> +	int err;
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +
> +	task = kthread_create(threaded_ttm_bo_reserve, bo, "ttm-bo-reserve");
> +
> +	if (IS_ERR(task))
> +		KUNIT_FAIL(test, "Couldn't create ttm bo reserve task\n");
> +
> +	/* Take a lock so the threaded reserve has to wait */
> +	mutex_lock(&bo->base.resv->lock.base);
> +
> +	wake_up_process(task);
> +	msleep(20);
> +	err = kthread_stop(task);
> +
> +	mutex_unlock(&bo->base.resv->lock.base);
> +
> +	KUNIT_ASSERT_EQ(test, err, -ERESTARTSYS);
> +}
> +#endif /* IS_BUILTIN(CONFIG_DRM_TTM_KUNIT_TEST) */
> +
> +static void ttm_bo_unreserve_basic(struct kunit *test)
> +{
> +	struct ttm_test_devices *priv = test->priv;
> +	struct ttm_buffer_object *bo;
> +	struct ttm_device *ttm_dev;
> +	struct ttm_resource *res1, *res2;
> +	struct ttm_place *place;
> +	struct ttm_resource_manager *man;
> +	unsigned int bo_prio = TTM_MAX_BO_PRIORITY - 1;
> +	uint32_t mem_type = TTM_PL_SYSTEM;
> +	int err;
> +
> +	place = ttm_place_kunit_init(test, mem_type, 0);
> +
> +	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);
> +	priv->ttm_dev = ttm_dev;
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +	bo->priority = bo_prio;
> +
> +	err = ttm_resource_alloc(bo, place, &res1);
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +
> +	bo->resource = res1;
> +
> +	/* Add a dummy resource to populate LRU */
> +	ttm_resource_alloc(bo, place, &res2);
> +
> +	dma_resv_lock(bo->base.resv, NULL);
> +	ttm_bo_unreserve(bo);
> +
> +	man = ttm_manager_type(priv->ttm_dev, mem_type);
> +	KUNIT_ASSERT_EQ(test,
> +			list_is_last(&res1->lru, &man->lru[bo->priority]), 1);
> +
> +	ttm_resource_free(bo, &res2);
> +	ttm_resource_free(bo, &res1);
> +}
> +
> +static void ttm_bo_unreserve_pinned(struct kunit *test)
> +{
> +	struct ttm_test_devices *priv = test->priv;
> +	struct ttm_buffer_object *bo;
> +	struct ttm_device *ttm_dev;
> +	struct ttm_resource *res1, *res2;
> +	struct ttm_place *place;
> +	uint32_t mem_type = TTM_PL_SYSTEM;
> +	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);
> +	priv->ttm_dev = ttm_dev;
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +	place = ttm_place_kunit_init(test, mem_type, 0);
> +
> +	dma_resv_lock(bo->base.resv, NULL);
> +	ttm_bo_pin(bo);
> +
> +	err = ttm_resource_alloc(bo, place, &res1);
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +	bo->resource = res1;
> +
> +	/* Add a dummy resource to the pinned list */
> +	err = ttm_resource_alloc(bo, place, &res2);
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +	KUNIT_ASSERT_EQ(test,
> +			list_is_last(&res2->lru, &priv->ttm_dev->pinned), 1);
> +
> +	ttm_bo_unreserve(bo);
> +	KUNIT_ASSERT_EQ(test,
> +			list_is_last(&res1->lru, &priv->ttm_dev->pinned), 1);
> +
> +	ttm_resource_free(bo, &res1);
> +	ttm_resource_free(bo, &res2);
> +}
> +
> +static void ttm_bo_unreserve_bulk(struct kunit *test)
> +{
> +	struct ttm_test_devices *priv = test->priv;
> +	struct ttm_lru_bulk_move lru_bulk_move;
> +	struct ttm_lru_bulk_move_pos *pos;
> +	struct ttm_buffer_object *bo1, *bo2;
> +	struct ttm_resource *res1, *res2;
> +	struct ttm_device *ttm_dev;
> +	struct ttm_place *place;
> +	uint32_t mem_type = TTM_PL_SYSTEM;
> +	unsigned int bo_priority = 0;
> +	int err;
> +
> +	ttm_lru_bulk_move_init(&lru_bulk_move);
> +
> +	place = ttm_place_kunit_init(test, mem_type, 0);
> +
> +	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);
> +	priv->ttm_dev = ttm_dev;
> +
> +	bo1 = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +	bo2 = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +
> +	dma_resv_lock(bo1->base.resv, NULL);
> +	ttm_bo_set_bulk_move(bo1, &lru_bulk_move);
> +	dma_resv_unlock(bo1->base.resv);
> +
> +	err = ttm_resource_alloc(bo1, place, &res1);
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +	bo1->resource = res1;
> +
> +	dma_resv_lock(bo2->base.resv, NULL);
> +	ttm_bo_set_bulk_move(bo2, &lru_bulk_move);
> +	dma_resv_unlock(bo2->base.resv);
> +
> +	err = ttm_resource_alloc(bo2, place, &res2);
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +	bo2->resource = res2;
> +
> +	ttm_bo_reserve(bo1, false, false, NULL);
> +	ttm_bo_unreserve(bo1);
> +
> +	pos = &lru_bulk_move.pos[mem_type][bo_priority];
> +	KUNIT_ASSERT_PTR_EQ(test, res1, pos->last);
> +
> +	ttm_resource_free(bo1, &res1);
> +	ttm_resource_free(bo2, &res2);
> +}
> +
> +static void ttm_bo_put_basic(struct kunit *test)
> +{
> +	struct ttm_test_devices *priv = test->priv;
> +	struct ttm_buffer_object *bo;
> +	struct ttm_resource *res;
> +	struct ttm_device *ttm_dev;
> +	struct ttm_place *place;
> +	uint32_t mem_type = TTM_PL_SYSTEM;
> +	int err;
> +
> +	place = ttm_place_kunit_init(test, mem_type, 0);
> +
> +	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);
> +	priv->ttm_dev = ttm_dev;
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +	bo->type = ttm_bo_type_device;
> +
> +	err = ttm_resource_alloc(bo, place, &res);
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +	bo->resource = res;
> +
> +	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);
> +
> +	ttm_bo_put(bo);
> +}
> +
> +static const char *mock_name(struct dma_fence *f)
> +{
> +	return "kunit-ttm-bo-put";
> +}
> +
> +static const struct dma_fence_ops mock_fence_ops = {
> +	.get_driver_name = mock_name,
> +	.get_timeline_name = mock_name,
> +};
> +
> +static void ttm_bo_put_shared_resv(struct kunit *test)
> +{
> +	struct ttm_test_devices *priv = test->priv;
> +	struct ttm_buffer_object *bo;
> +	struct dma_resv *external_resv;
> +	struct dma_fence *fence;
> +	/* A dummy DMA fence lock */
> +	spinlock_t fence_lock;
> +	struct ttm_device *ttm_dev;
> +	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);
> +	priv->ttm_dev = ttm_dev;
> +
> +	external_resv = kunit_kzalloc(test, sizeof(*ttm_dev), GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_NULL(test, external_resv);
> +
> +	dma_resv_init(external_resv);
> +
> +	fence = kunit_kzalloc(test, sizeof(*fence), GFP_KERNEL);
> +	KUNIT_ASSERT_NOT_NULL(test, fence);
> +
> +	spin_lock_init(&fence_lock);
> +	dma_fence_init(fence, &mock_fence_ops, &fence_lock, 0, 0);
> +
> +	dma_resv_lock(external_resv, NULL);
> +	dma_resv_reserve_fences(external_resv, 1);
> +	dma_resv_add_fence(external_resv, fence, DMA_RESV_USAGE_BOOKKEEP);
> +	dma_resv_unlock(external_resv);
> +
> +	dma_fence_signal(fence);
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +	bo->type = ttm_bo_type_device;
> +	bo->base.resv = external_resv;
> +
> +	ttm_bo_put(bo);
> +}
> +
> +static void ttm_bo_pin_basic(struct kunit *test)
> +{
> +	struct ttm_test_devices *priv = test->priv;
> +	struct ttm_buffer_object *bo;
> +	struct ttm_device *ttm_dev;
> +	unsigned int no_pins = 3;
> +	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);
> +	priv->ttm_dev = ttm_dev;
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +
> +	for (int i = 0; i < no_pins; i++) {
> +		dma_resv_lock(bo->base.resv, NULL);
> +		ttm_bo_pin(bo);
> +		dma_resv_unlock(bo->base.resv);
> +	}
> +
> +	KUNIT_ASSERT_EQ(test, bo->pin_count, no_pins);
> +}
> +
> +static void ttm_bo_pin_unpin_resource(struct kunit *test)
> +{
> +	struct ttm_test_devices *priv = test->priv;
> +	struct ttm_lru_bulk_move lru_bulk_move;
> +	struct ttm_lru_bulk_move_pos *pos;
> +	struct ttm_buffer_object *bo;
> +	struct ttm_resource *res;
> +	struct ttm_device *ttm_dev;
> +	struct ttm_place *place;
> +	uint32_t mem_type = TTM_PL_SYSTEM;
> +	unsigned int bo_priority = 0;
> +	int err;
> +
> +	ttm_lru_bulk_move_init(&lru_bulk_move);
> +
> +	place = ttm_place_kunit_init(test, mem_type, 0);
> +
> +	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);
> +	priv->ttm_dev = ttm_dev;
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +
> +	err = ttm_resource_alloc(bo, place, &res);
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +	bo->resource = res;
> +
> +	dma_resv_lock(bo->base.resv, NULL);
> +	ttm_bo_set_bulk_move(bo, &lru_bulk_move);
> +	ttm_bo_pin(bo);
> +	dma_resv_unlock(bo->base.resv);
> +
> +	pos = &lru_bulk_move.pos[mem_type][bo_priority];
> +
> +	KUNIT_ASSERT_EQ(test, bo->pin_count, 1);
> +	KUNIT_ASSERT_NULL(test, pos->first);
> +	KUNIT_ASSERT_NULL(test, pos->last);
> +
> +	dma_resv_lock(bo->base.resv, NULL);
> +	ttm_bo_unpin(bo);
> +	dma_resv_unlock(bo->base.resv);
> +
> +	KUNIT_ASSERT_PTR_EQ(test, res, pos->last);
> +	KUNIT_ASSERT_EQ(test, bo->pin_count, 0);
> +
> +	ttm_resource_free(bo, &res);
> +}
> +
> +static void ttm_bo_multiple_pin_one_unpin(struct kunit *test)
> +{
> +	struct ttm_test_devices *priv = test->priv;
> +	struct ttm_lru_bulk_move lru_bulk_move;
> +	struct ttm_lru_bulk_move_pos *pos;
> +	struct ttm_buffer_object *bo;
> +	struct ttm_resource *res;
> +	struct ttm_device *ttm_dev;
> +	struct ttm_place *place;
> +	uint32_t mem_type = TTM_PL_SYSTEM;
> +	unsigned int bo_priority = 0;
> +	int err;
> +
> +	ttm_lru_bulk_move_init(&lru_bulk_move);
> +
> +	place = ttm_place_kunit_init(test, mem_type, 0);
> +
> +	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);
> +	priv->ttm_dev = ttm_dev;
> +
> +	bo = ttm_bo_kunit_init(test, test->priv, BO_SIZE);
> +
> +	err = ttm_resource_alloc(bo, place, &res);
> +	KUNIT_ASSERT_EQ(test, err, 0);
> +	bo->resource = res;
> +
> +	dma_resv_lock(bo->base.resv, NULL);
> +	ttm_bo_set_bulk_move(bo, &lru_bulk_move);
> +
> +	/* Multiple pins */
> +	ttm_bo_pin(bo);
> +	ttm_bo_pin(bo);
> +
> +	dma_resv_unlock(bo->base.resv);
> +
> +	pos = &lru_bulk_move.pos[mem_type][bo_priority];
> +
> +	KUNIT_ASSERT_EQ(test, bo->pin_count, 2);
> +	KUNIT_ASSERT_NULL(test, pos->first);
> +	KUNIT_ASSERT_NULL(test, pos->last);
> +
> +	dma_resv_lock(bo->base.resv, NULL);
> +	ttm_bo_unpin(bo);
> +	dma_resv_unlock(bo->base.resv);
> +
> +	KUNIT_ASSERT_EQ(test, bo->pin_count, 1);
> +	KUNIT_ASSERT_NULL(test, pos->first);
> +	KUNIT_ASSERT_NULL(test, pos->last);
> +
> +	dma_resv_lock(bo->base.resv, NULL);
> +	ttm_bo_unpin(bo);
> +	dma_resv_unlock(bo->base.resv);
> +
> +	ttm_resource_free(bo, &res);
> +}
> +
> +static struct kunit_case ttm_bo_test_cases[] = {
> +	KUNIT_CASE_PARAM(ttm_bo_reserve_optimistic_no_ticket,
> +			 ttm_bo_reserve_gen_params),
> +	KUNIT_CASE(ttm_bo_reserve_locked_no_sleep),
> +	KUNIT_CASE(ttm_bo_reserve_no_wait_ticket),
> +	KUNIT_CASE(ttm_bo_reserve_double_resv),
> +#if IS_BUILTIN(CONFIG_DRM_TTM_KUNIT_TEST)
> +	KUNIT_CASE(ttm_bo_reserve_interrupted),
> +#endif
> +	KUNIT_CASE(ttm_bo_reserve_deadlock),
> +	KUNIT_CASE(ttm_bo_unreserve_basic),
> +	KUNIT_CASE(ttm_bo_unreserve_pinned),
> +	KUNIT_CASE(ttm_bo_unreserve_bulk),
> +	KUNIT_CASE(ttm_bo_put_basic),
> +	KUNIT_CASE(ttm_bo_put_shared_resv),
> +	KUNIT_CASE(ttm_bo_pin_basic),
> +	KUNIT_CASE(ttm_bo_pin_unpin_resource),
> +	KUNIT_CASE(ttm_bo_multiple_pin_one_unpin),
> +	{}
> +};
> +
> +static struct kunit_suite ttm_bo_test_suite = {
> +	.name = "ttm_bo",
> +	.init = ttm_test_devices_init,
> +	.exit = ttm_test_devices_fini,
> +	.test_cases = ttm_bo_test_cases,
> +};
> +
> +kunit_test_suites(&ttm_bo_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 ba4e5c689164..7b7c1fa805fc 100644
> --- a/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
> +++ b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
> @@ -22,6 +22,10 @@ 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)
> +{
> +}
> +
>   struct ttm_device_funcs ttm_dev_funcs = {
>   	.ttm_tt_create = ttm_tt_simple_create,
>   	.ttm_tt_destroy = ttm_tt_simple_destroy,
> @@ -61,6 +65,8 @@ struct ttm_buffer_object *ttm_bo_kunit_init(struct kunit *test,
>   	KUNIT_ASSERT_EQ(test, err, 0);
>   
>   	bo->bdev = devs->ttm_dev;
> +	bo->destroy = dummy_ttm_bo_destroy;
> +
>   	kref_init(&bo->kref);
>   
>   	return bo;