On 30/11/2021 09:52, Thomas Zimmermann wrote: > GEM helper libraries use struct drm_driver.gem_create_object to let > drivers override GEM object allocation. On failure, the call returns > NULL. > > Change the semantics to make the calls return a pointer-encoded error. > This aligns the callback with its callers. Fixes the ingenic driver, > which already returns an error pointer. > > Also update the callers to handle the involved types more strictly. > > Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx> Reviewed-by: Steven Price <steven.price@xxxxxxx> > --- > There is an alternative patch at [1] that updates the value returned > by ingenics' gem_create_object to NULL. Fixing the interface to return > an errno code is more consistent with the rest of the GEM functions. > > [1] https://lore.kernel.org/dri-devel/20211118111522.GD1147@kili/ > --- > drivers/gpu/drm/drm_gem_cma_helper.c | 17 ++++++++++------- > drivers/gpu/drm/drm_gem_shmem_helper.c | 17 ++++++++++------- > drivers/gpu/drm/drm_gem_vram_helper.c | 4 ++-- > drivers/gpu/drm/lima/lima_gem.c | 2 +- > drivers/gpu/drm/panfrost/panfrost_gem.c | 2 +- > drivers/gpu/drm/v3d/v3d_bo.c | 4 ++-- > drivers/gpu/drm/vc4/vc4_bo.c | 2 +- > drivers/gpu/drm/vgem/vgem_drv.c | 2 +- > drivers/gpu/drm/virtio/virtgpu_object.c | 2 +- > include/drm/drm_drv.h | 5 +++-- > 10 files changed, 32 insertions(+), 25 deletions(-) > > diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c > index 7d4895de9e0d..cefd0cbf9deb 100644 > --- a/drivers/gpu/drm/drm_gem_cma_helper.c > +++ b/drivers/gpu/drm/drm_gem_cma_helper.c > @@ -67,18 +67,21 @@ __drm_gem_cma_create(struct drm_device *drm, size_t size, bool private) > struct drm_gem_object *gem_obj; > int ret = 0; > > - if (drm->driver->gem_create_object) > + if (drm->driver->gem_create_object) { > gem_obj = drm->driver->gem_create_object(drm, size); > - else > - gem_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL); > - if (!gem_obj) > - return ERR_PTR(-ENOMEM); > + if (IS_ERR(gem_obj)) > + return ERR_CAST(gem_obj); > + cma_obj = to_drm_gem_cma_obj(gem_obj); > + } else { > + cma_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL); > + if (!cma_obj) > + return ERR_PTR(-ENOMEM); > + gem_obj = &cma_obj->base; > + } > > if (!gem_obj->funcs) > gem_obj->funcs = &drm_gem_cma_default_funcs; > > - cma_obj = container_of(gem_obj, struct drm_gem_cma_object, base); > - > if (private) { > drm_gem_private_object_init(drm, gem_obj, size); > > diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c > index 0eeda1012364..7915047cb041 100644 > --- a/drivers/gpu/drm/drm_gem_shmem_helper.c > +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c > @@ -56,14 +56,17 @@ __drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private) > > size = PAGE_ALIGN(size); > > - if (dev->driver->gem_create_object) > + if (dev->driver->gem_create_object) { > obj = dev->driver->gem_create_object(dev, size); > - else > - obj = kzalloc(sizeof(*shmem), GFP_KERNEL); > - if (!obj) > - return ERR_PTR(-ENOMEM); > - > - shmem = to_drm_gem_shmem_obj(obj); > + if (IS_ERR(obj)) > + return ERR_CAST(obj); > + shmem = to_drm_gem_shmem_obj(obj); > + } else { > + shmem = kzalloc(sizeof(*shmem), GFP_KERNEL); > + if (!shmem) > + return ERR_PTR(-ENOMEM); > + obj = &shmem->base; > + } > > if (!obj->funcs) > obj->funcs = &drm_gem_shmem_funcs; > diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c b/drivers/gpu/drm/drm_gem_vram_helper.c > index bfa386b98134..3f00192215d1 100644 > --- a/drivers/gpu/drm/drm_gem_vram_helper.c > +++ b/drivers/gpu/drm/drm_gem_vram_helper.c > @@ -197,8 +197,8 @@ struct drm_gem_vram_object *drm_gem_vram_create(struct drm_device *dev, > > if (dev->driver->gem_create_object) { > gem = dev->driver->gem_create_object(dev, size); > - if (!gem) > - return ERR_PTR(-ENOMEM); > + if (IS_ERR(gem)) > + return ERR_CAST(gem); > gbo = drm_gem_vram_of_gem(gem); > } else { > gbo = kzalloc(sizeof(*gbo), GFP_KERNEL); > diff --git a/drivers/gpu/drm/lima/lima_gem.c b/drivers/gpu/drm/lima/lima_gem.c > index 2723d333c608..f9a9198ef198 100644 > --- a/drivers/gpu/drm/lima/lima_gem.c > +++ b/drivers/gpu/drm/lima/lima_gem.c > @@ -221,7 +221,7 @@ struct drm_gem_object *lima_gem_create_object(struct drm_device *dev, size_t siz > > bo = kzalloc(sizeof(*bo), GFP_KERNEL); > if (!bo) > - return NULL; > + return ERR_PTR(-ENOMEM); > > mutex_init(&bo->lock); > INIT_LIST_HEAD(&bo->va); > diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c > index 6d9bdb9180cb..ead65f5fa2bc 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_gem.c > +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c > @@ -223,7 +223,7 @@ struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t > > obj = kzalloc(sizeof(*obj), GFP_KERNEL); > if (!obj) > - return NULL; > + return ERR_PTR(-ENOMEM); > > INIT_LIST_HEAD(&obj->mappings.list); > mutex_init(&obj->mappings.lock); > diff --git a/drivers/gpu/drm/v3d/v3d_bo.c b/drivers/gpu/drm/v3d/v3d_bo.c > index 0d9af62f69ad..6e3113f419f4 100644 > --- a/drivers/gpu/drm/v3d/v3d_bo.c > +++ b/drivers/gpu/drm/v3d/v3d_bo.c > @@ -70,11 +70,11 @@ struct drm_gem_object *v3d_create_object(struct drm_device *dev, size_t size) > struct drm_gem_object *obj; > > if (size == 0) > - return NULL; > + return ERR_PTR(-EINVAL); > > bo = kzalloc(sizeof(*bo), GFP_KERNEL); > if (!bo) > - return NULL; > + return ERR_PTR(-ENOMEM); > obj = &bo->base.base; > > obj->funcs = &v3d_gem_funcs; > diff --git a/drivers/gpu/drm/vc4/vc4_bo.c b/drivers/gpu/drm/vc4/vc4_bo.c > index 8520e440dbd1..6d1281a343e9 100644 > --- a/drivers/gpu/drm/vc4/vc4_bo.c > +++ b/drivers/gpu/drm/vc4/vc4_bo.c > @@ -391,7 +391,7 @@ struct drm_gem_object *vc4_create_object(struct drm_device *dev, size_t size) > > bo = kzalloc(sizeof(*bo), GFP_KERNEL); > if (!bo) > - return NULL; > + return ERR_PTR(-ENOMEM); > > bo->madv = VC4_MADV_WILLNEED; > refcount_set(&bo->usecnt, 0); > diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c > index a87eafa89e9f..c5e3e5457737 100644 > --- a/drivers/gpu/drm/vgem/vgem_drv.c > +++ b/drivers/gpu/drm/vgem/vgem_drv.c > @@ -97,7 +97,7 @@ static struct drm_gem_object *vgem_gem_create_object(struct drm_device *dev, siz > > obj = kzalloc(sizeof(*obj), GFP_KERNEL); > if (!obj) > - return NULL; > + return ERR_PTR(-ENOMEM); > > /* > * vgem doesn't have any begin/end cpu access ioctls, therefore must use > diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c > index 187e10da2f17..baef2c5f2aaf 100644 > --- a/drivers/gpu/drm/virtio/virtgpu_object.c > +++ b/drivers/gpu/drm/virtio/virtgpu_object.c > @@ -139,7 +139,7 @@ struct drm_gem_object *virtio_gpu_create_object(struct drm_device *dev, > > shmem = kzalloc(sizeof(*shmem), GFP_KERNEL); > if (!shmem) > - return NULL; > + return ERR_PTR(-ENOMEM); > > dshmem = &shmem->base.base; > dshmem->base.funcs = &virtio_gpu_shmem_funcs; > diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h > index da0c836fe8e1..f6159acb8856 100644 > --- a/include/drm/drm_drv.h > +++ b/include/drm/drm_drv.h > @@ -291,8 +291,9 @@ struct drm_driver { > /** > * @gem_create_object: constructor for gem objects > * > - * Hook for allocating the GEM object struct, for use by the CMA and > - * SHMEM GEM helpers. > + * Hook for allocating the GEM object struct, for use by the CMA > + * and SHMEM GEM helpers. Returns a GEM object on success, or an > + * ERR_PTR()-encoded error code otherwise. > */ > struct drm_gem_object *(*gem_create_object)(struct drm_device *dev, > size_t size); > -- > 2.34.0 >
