From 05b1de51df077a2089e3d8ceec68aa687cff15db Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Mon, 15 Nov 2021 13:01:47 +0100 Subject: drm/cma-helper: Export dedicated wrappers for GEM object functions Wrap GEM CMA functions for struct drm_gem_object_funcs and update all callers. This will allow for an update of the public interfaces of the GEM CMA helper library. Signed-off-by: Thomas Zimmermann Reviewed-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20211115120148.21766-3-tzimmermann@suse.de --- drivers/gpu/drm/drm_gem_cma_helper.c | 23 +++++++++-------------- 1 file changed, 9 insertions(+), 14 deletions(-) (limited to 'drivers/gpu/drm/drm_gem_cma_helper.c') diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c index 2a34241fee02..fcd7d2eb90ab 100644 --- a/drivers/gpu/drm/drm_gem_cma_helper.c +++ b/drivers/gpu/drm/drm_gem_cma_helper.c @@ -35,11 +35,11 @@ */ static const struct drm_gem_object_funcs drm_gem_cma_default_funcs = { - .free = drm_gem_cma_free_object, - .print_info = drm_gem_cma_print_info, - .get_sg_table = drm_gem_cma_get_sg_table, - .vmap = drm_gem_cma_vmap, - .mmap = drm_gem_cma_mmap, + .free = drm_gem_cma_object_free, + .print_info = drm_gem_cma_object_print_info, + .get_sg_table = drm_gem_cma_object_get_sg_table, + .vmap = drm_gem_cma_object_vmap, + .mmap = drm_gem_cma_object_mmap, .vm_ops = &drm_gem_cma_vm_ops, }; @@ -198,8 +198,6 @@ drm_gem_cma_create_with_handle(struct drm_file *file_priv, * This function frees the backing memory of the CMA GEM object, cleans up the * GEM object state and frees the memory used to store the object itself. * If the buffer is imported and the virtual address is set, it is released. - * Drivers using the CMA helpers should set this as their - * &drm_gem_object_funcs.free callback. */ void drm_gem_cma_free_object(struct drm_gem_object *gem_obj) { @@ -388,9 +386,8 @@ EXPORT_SYMBOL(drm_gem_cma_print_info); * pages for a CMA GEM object * @obj: GEM object * - * This function exports a scatter/gather table by - * calling the standard DMA mapping API. Drivers using the CMA helpers should - * set this as their &drm_gem_object_funcs.get_sg_table callback. + * This function exports a scatter/gather table by calling the standard + * DMA mapping API. * * Returns: * A pointer to the scatter/gather table of pinned pages or NULL on failure. @@ -470,8 +467,7 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_prime_import_sg_table); * This function maps a buffer into the kernel's * virtual address space. Since the CMA buffers are already mapped into the * kernel virtual address space this simply returns the cached virtual - * address. Drivers using the CMA helpers should set this as their DRM - * driver's &drm_gem_object_funcs.vmap callback. + * address. * * Returns: * 0 on success, or a negative error code otherwise. @@ -493,8 +489,7 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_vmap); * * This function maps a buffer into a userspace process's address space. * In addition to the usual GEM VMA setup it immediately faults in the entire - * object instead of using on-demand faulting. Drivers that use the CMA - * helpers should set this as their &drm_gem_object_funcs.mmap callback. + * object instead of using on-demand faulting. * * Returns: * 0 on success or a negative error code on failure. -- cgit v1.2.3 From e580ea25c08d9e89593bcf80640e29108f0542cb Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Mon, 15 Nov 2021 13:01:48 +0100 Subject: drm/cma-helper: Pass GEM CMA object in public interfaces Change all GEM CMA object functions that receive a GEM object of type struct drm_gem_object to expect an object of type struct drm_gem_cma_object instead. This change reduces the number of upcasts from struct drm_gem_object by moving them into callers. The C compiler can now verify that the GEM CMA functions are called with the correct type. For consistency, the patch also renames drm_gem_cma_free_object to drm_gem_cma_free. It further updates documentation for a number of functions. Signed-off-by: Thomas Zimmermann Reviewed-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20211115120148.21766-4-tzimmermann@suse.de --- drivers/gpu/drm/drm_gem_cma_helper.c | 52 +++++++++++++++++------------------- drivers/gpu/drm/vc4/vc4_bo.c | 4 +-- include/drm/drm_gem_cma_helper.h | 39 +++++++++++++++------------ 3 files changed, 48 insertions(+), 47 deletions(-) (limited to 'drivers/gpu/drm/drm_gem_cma_helper.c') diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c index fcd7d2eb90ab..5f42e44b2ab3 100644 --- a/drivers/gpu/drm/drm_gem_cma_helper.c +++ b/drivers/gpu/drm/drm_gem_cma_helper.c @@ -32,6 +32,10 @@ * The DRM GEM/CMA helpers use this allocator as a means to provide buffer * objects that are physically contiguous in memory. This is useful for * display drivers that are unable to map scattered buffers via an IOMMU. + * + * For GEM callback helpers in struct &drm_gem_object functions, see likewise + * named functions with an _object_ infix (e.g., drm_gem_cma_object_vmap() wraps + * drm_gem_cma_vmap()). These helpers perform the necessary type conversion. */ static const struct drm_gem_object_funcs drm_gem_cma_default_funcs = { @@ -192,16 +196,16 @@ drm_gem_cma_create_with_handle(struct drm_file *file_priv, } /** - * drm_gem_cma_free_object - free resources associated with a CMA GEM object - * @gem_obj: GEM object to free + * drm_gem_cma_free - free resources associated with a CMA GEM object + * @cma_obj: CMA GEM object to free * * This function frees the backing memory of the CMA GEM object, cleans up the * GEM object state and frees the memory used to store the object itself. * If the buffer is imported and the virtual address is set, it is released. */ -void drm_gem_cma_free_object(struct drm_gem_object *gem_obj) +void drm_gem_cma_free(struct drm_gem_cma_object *cma_obj) { - struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(gem_obj); + struct drm_gem_object *gem_obj = &cma_obj->base; struct dma_buf_map map = DMA_BUF_MAP_INIT_VADDR(cma_obj->vaddr); if (gem_obj->import_attach) { @@ -217,7 +221,7 @@ void drm_gem_cma_free_object(struct drm_gem_object *gem_obj) kfree(cma_obj); } -EXPORT_SYMBOL_GPL(drm_gem_cma_free_object); +EXPORT_SYMBOL_GPL(drm_gem_cma_free); /** * drm_gem_cma_dumb_create_internal - create a dumb buffer object @@ -364,18 +368,15 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_get_unmapped_area); /** * drm_gem_cma_print_info() - Print &drm_gem_cma_object info for debugfs + * @cma_obj: CMA GEM object * @p: DRM printer * @indent: Tab indentation level - * @obj: GEM object * - * This function can be used as the &drm_driver->gem_print_info callback. - * It prints paddr and vaddr for use in e.g. debugfs output. + * This function prints paddr and vaddr for use in e.g. debugfs output. */ -void drm_gem_cma_print_info(struct drm_printer *p, unsigned int indent, - const struct drm_gem_object *obj) +void drm_gem_cma_print_info(const struct drm_gem_cma_object *cma_obj, + struct drm_printer *p, unsigned int indent) { - const struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj); - drm_printf_indent(p, indent, "paddr=%pad\n", &cma_obj->paddr); drm_printf_indent(p, indent, "vaddr=%p\n", cma_obj->vaddr); } @@ -384,7 +385,7 @@ EXPORT_SYMBOL(drm_gem_cma_print_info); /** * drm_gem_cma_get_sg_table - provide a scatter/gather table of pinned * pages for a CMA GEM object - * @obj: GEM object + * @cma_obj: CMA GEM object * * This function exports a scatter/gather table by calling the standard * DMA mapping API. @@ -392,9 +393,9 @@ EXPORT_SYMBOL(drm_gem_cma_print_info); * Returns: * A pointer to the scatter/gather table of pinned pages or NULL on failure. */ -struct sg_table *drm_gem_cma_get_sg_table(struct drm_gem_object *obj) +struct sg_table *drm_gem_cma_get_sg_table(struct drm_gem_cma_object *cma_obj) { - struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj); + struct drm_gem_object *obj = &cma_obj->base; struct sg_table *sgt; int ret; @@ -460,22 +461,19 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_prime_import_sg_table); /** * drm_gem_cma_vmap - map a CMA GEM object into the kernel's virtual * address space - * @obj: GEM object + * @cma_obj: CMA GEM object * @map: Returns the kernel virtual address of the CMA GEM object's backing * store. * - * This function maps a buffer into the kernel's - * virtual address space. Since the CMA buffers are already mapped into the - * kernel virtual address space this simply returns the cached virtual - * address. + * This function maps a buffer into the kernel's virtual address space. + * Since the CMA buffers are already mapped into the kernel virtual address + * space this simply returns the cached virtual address. * * Returns: * 0 on success, or a negative error code otherwise. */ -int drm_gem_cma_vmap(struct drm_gem_object *obj, struct dma_buf_map *map) +int drm_gem_cma_vmap(struct drm_gem_cma_object *cma_obj, struct dma_buf_map *map) { - struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj); - dma_buf_map_set_vaddr(map, cma_obj->vaddr); return 0; @@ -484,7 +482,7 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_vmap); /** * drm_gem_cma_mmap - memory-map an exported CMA GEM object - * @obj: GEM object + * @cma_obj: CMA GEM object * @vma: VMA for the area to be mapped * * This function maps a buffer into a userspace process's address space. @@ -494,9 +492,9 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_vmap); * Returns: * 0 on success or a negative error code on failure. */ -int drm_gem_cma_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) +int drm_gem_cma_mmap(struct drm_gem_cma_object *cma_obj, struct vm_area_struct *vma) { - struct drm_gem_cma_object *cma_obj; + struct drm_gem_object *obj = &cma_obj->base; int ret; /* @@ -507,8 +505,6 @@ int drm_gem_cma_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) vma->vm_pgoff -= drm_vma_node_start(&obj->vma_node); vma->vm_flags &= ~VM_PFNMAP; - cma_obj = to_drm_gem_cma_obj(obj); - if (cma_obj->map_noncoherent) { vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); diff --git a/drivers/gpu/drm/vc4/vc4_bo.c b/drivers/gpu/drm/vc4/vc4_bo.c index 830756b3159e..6d1281a343e9 100644 --- a/drivers/gpu/drm/vc4/vc4_bo.c +++ b/drivers/gpu/drm/vc4/vc4_bo.c @@ -177,7 +177,7 @@ static void vc4_bo_destroy(struct vc4_bo *bo) bo->validated_shader = NULL; } - drm_gem_cma_free_object(obj); + drm_gem_cma_free(&bo->base); } static void vc4_bo_remove_from_cache(struct vc4_bo *bo) @@ -720,7 +720,7 @@ static int vc4_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct return -EINVAL; } - return drm_gem_cma_mmap(obj, vma); + return drm_gem_cma_mmap(&bo->base, vma); } static const struct vm_operations_struct vc4_vm_ops = { diff --git a/include/drm/drm_gem_cma_helper.h b/include/drm/drm_gem_cma_helper.h index 56d2f9fdf9ac..adb507a9dbf0 100644 --- a/include/drm/drm_gem_cma_helper.h +++ b/include/drm/drm_gem_cma_helper.h @@ -32,28 +32,23 @@ struct drm_gem_cma_object { #define to_drm_gem_cma_obj(gem_obj) \ container_of(gem_obj, struct drm_gem_cma_object, base) -/* free GEM object */ -void drm_gem_cma_free_object(struct drm_gem_object *gem_obj); - -/* allocate physical memory */ struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm, size_t size); +void drm_gem_cma_free(struct drm_gem_cma_object *cma_obj); +void drm_gem_cma_print_info(const struct drm_gem_cma_object *cma_obj, + struct drm_printer *p, unsigned int indent); +struct sg_table *drm_gem_cma_get_sg_table(struct drm_gem_cma_object *cma_obj); +int drm_gem_cma_vmap(struct drm_gem_cma_object *cma_obj, struct dma_buf_map *map); +int drm_gem_cma_mmap(struct drm_gem_cma_object *cma_obj, struct vm_area_struct *vma); extern const struct vm_operations_struct drm_gem_cma_vm_ops; -void drm_gem_cma_print_info(struct drm_printer *p, unsigned int indent, - const struct drm_gem_object *obj); - -struct sg_table *drm_gem_cma_get_sg_table(struct drm_gem_object *obj); -int drm_gem_cma_vmap(struct drm_gem_object *obj, struct dma_buf_map *map); -int drm_gem_cma_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma); - /* * GEM object functions */ /** - * drm_gem_cma_object_free - GEM object function for drm_gem_cma_free_object() + * drm_gem_cma_object_free - GEM object function for drm_gem_cma_free() * @obj: GEM object to free * * This function wraps drm_gem_cma_free_object(). Drivers that employ the CMA helpers @@ -61,7 +56,9 @@ int drm_gem_cma_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma); */ static inline void drm_gem_cma_object_free(struct drm_gem_object *obj) { - drm_gem_cma_free_object(obj); + struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj); + + drm_gem_cma_free(cma_obj); } /** @@ -76,7 +73,9 @@ static inline void drm_gem_cma_object_free(struct drm_gem_object *obj) static inline void drm_gem_cma_object_print_info(struct drm_printer *p, unsigned int indent, const struct drm_gem_object *obj) { - drm_gem_cma_print_info(p, indent, obj); + const struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj); + + drm_gem_cma_print_info(cma_obj, p, indent); } /** @@ -91,7 +90,9 @@ static inline void drm_gem_cma_object_print_info(struct drm_printer *p, unsigned */ static inline struct sg_table *drm_gem_cma_object_get_sg_table(struct drm_gem_object *obj) { - return drm_gem_cma_get_sg_table(obj); + struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj); + + return drm_gem_cma_get_sg_table(cma_obj); } /* @@ -107,7 +108,9 @@ static inline struct sg_table *drm_gem_cma_object_get_sg_table(struct drm_gem_ob */ static inline int drm_gem_cma_object_vmap(struct drm_gem_object *obj, struct dma_buf_map *map) { - return drm_gem_cma_vmap(obj, map); + struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj); + + return drm_gem_cma_vmap(cma_obj, map); } /** @@ -123,7 +126,9 @@ static inline int drm_gem_cma_object_vmap(struct drm_gem_object *obj, struct dma */ static inline int drm_gem_cma_object_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) { - return drm_gem_cma_mmap(obj, vma); + struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj); + + return drm_gem_cma_mmap(cma_obj, vma); } /* -- cgit v1.2.3 From 4ff22f487f8c26b99cbe1678344595734c001a39 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Tue, 30 Nov 2021 10:52:55 +0100 Subject: drm: Return error codes from struct drm_driver.gem_create_object 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 Reviewed-by: Steven Price Acked-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20211130095255.26710-1-tzimmermann@suse.de --- 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/vgem/vgem_drv.c | 2 +- drivers/gpu/drm/virtio/virtgpu_object.c | 2 +- include/drm/drm_drv.h | 5 +++-- 9 files changed, 31 insertions(+), 24 deletions(-) (limited to 'drivers/gpu/drm/drm_gem_cma_helper.c') diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c index 5f42e44b2ab3..6f18f143dd30 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/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); -- cgit v1.2.3