Test reservation and release of TTM buffer objects. Add tests to check pin and unpin operations. Signed-off-by: Karolina Stolarek <karolina.stolarek@xxxxxxxxx> --- 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..f0c829fdb67b --- /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, BO_SIZE); + + 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, BO_SIZE); + + 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, BO_SIZE); + + 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, BO_SIZE); + + 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, BO_SIZE); + + 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, BO_SIZE); + + 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 76c94d6afef1..c993443d8f64 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; -- 2.25.1