[PATCH v15 05/23] drm/v3d: Replace open-coded drm_gem_shmem_free() with drm_gem_object_put()

From: Dmitry Osipenko
Date: Sun Aug 27 2023 - 14:12:15 EST


The drm_gem_shmem_free() doesn't put GEM's kref to zero, which becomes
important with addition of the shrinker support to drm-shmem that will
use kref=0 in order to prevent taking lock during special GEM-freeing
time in order to avoid spurious lockdep warning about locking ordering
vs fs_reclaim code paths.

Replace open-coded drm_gem_shmem_free() with drm_gem_object_put() that
drops kref to zero before freeing GEM.

Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
---
drivers/gpu/drm/v3d/v3d_bo.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/v3d/v3d_bo.c b/drivers/gpu/drm/v3d/v3d_bo.c
index 8b3229a37c6d..70c1095d6eec 100644
--- a/drivers/gpu/drm/v3d/v3d_bo.c
+++ b/drivers/gpu/drm/v3d/v3d_bo.c
@@ -33,16 +33,18 @@ void v3d_free_object(struct drm_gem_object *obj)
struct v3d_dev *v3d = to_v3d_dev(obj->dev);
struct v3d_bo *bo = to_v3d_bo(obj);

- v3d_mmu_remove_ptes(bo);
+ if (drm_mm_node_allocated(&bo->node)) {
+ v3d_mmu_remove_ptes(bo);

- mutex_lock(&v3d->bo_lock);
- v3d->bo_stats.num_allocated--;
- v3d->bo_stats.pages_allocated -= obj->size >> PAGE_SHIFT;
- mutex_unlock(&v3d->bo_lock);
+ mutex_lock(&v3d->bo_lock);
+ v3d->bo_stats.num_allocated--;
+ v3d->bo_stats.pages_allocated -= obj->size >> PAGE_SHIFT;
+ mutex_unlock(&v3d->bo_lock);

- spin_lock(&v3d->mm_lock);
- drm_mm_remove_node(&bo->node);
- spin_unlock(&v3d->mm_lock);
+ spin_lock(&v3d->mm_lock);
+ drm_mm_remove_node(&bo->node);
+ spin_unlock(&v3d->mm_lock);
+ }

/* GPU execution may have dirtied any pages in the BO. */
bo->base.pages_mark_dirty_on_put = true;
@@ -142,7 +144,7 @@ struct v3d_bo *v3d_bo_create(struct drm_device *dev, struct drm_file *file_priv,
return bo;

free_obj:
- drm_gem_shmem_free(shmem_obj);
+ drm_gem_object_put(&shmem_obj->base);
return ERR_PTR(ret);
}

@@ -160,7 +162,7 @@ v3d_prime_import_sg_table(struct drm_device *dev,

ret = v3d_bo_create_finish(obj);
if (ret) {
- drm_gem_shmem_free(&to_v3d_bo(obj)->base);
+ drm_gem_object_put(obj);
return ERR_PTR(ret);
}

--
2.41.0