Hi Laurent Am 15.11.21 um 14:50 schrieb Laurent Pinchart:
Hi Thomas, Thank you for the patch. On Mon, Nov 15, 2021 at 01:01:48PM +0100, Thomas Zimmermann wrote: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.I'm not convinced to be honest. I won't block this series, but I don't really see what it brings us.
Type checking. It's much harder to accidentaly pass a wrong GEM object (SHMEM, VRAM, etc) to the functions now. I know that it's not been a super-huge problem so far, but still worth addressing IMHO.
Best regards Thomas
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx> --- 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(-) diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c index 27ccb71e3d66..7d4895de9e0d 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) {@@ -222,7 +226,7 @@ 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 @@ -369,18 +373,15 @@ 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); } @@ -389,7 +390,7 @@ 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. @@ -397,9 +398,9 @@ 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;@@ -465,22 +466,19 @@ 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;@@ -489,7 +487,7 @@ 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. @@ -499,9 +497,9 @@ 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;/*@@ -512,8 +510,6 @@ 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.cindex 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); }/*
-- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 Nürnberg, Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Ivo Totev
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