1 // SPDX-License-Identifier: GPL-2.0-or-later
12 #include <linux/dma-buf.h>
13 #include <linux/dma-mapping.h>
31  * for devices that do not support scatter-gather DMA (either directly or
35  * the buffer objects are allocated using a traditional page-based
58  * __drm_gem_dma_create - Create a GEM DMA object without allocating memory
67  * A struct drm_gem_dma_object * on success or an ERR_PTR()-encoded negative
77 	if (drm->driver->gem_create_object) {  in __drm_gem_dma_create()
78 		gem_obj = drm->driver->gem_create_object(drm, size);  in __drm_gem_dma_create()
85 			return ERR_PTR(-ENOMEM);  in __drm_gem_dma_create()
86 		gem_obj = &dma_obj->base;  in __drm_gem_dma_create()
89 	if (!gem_obj->funcs)  in __drm_gem_dma_create()
90 		gem_obj->funcs = &drm_gem_dma_default_funcs;  in __drm_gem_dma_create()
95 		/* Always use writecombine for dma-buf mappings */  in __drm_gem_dma_create()
96 		dma_obj->map_noncoherent = false;  in __drm_gem_dma_create()
117  * drm_gem_dma_create - allocate an object with the given size
131  * A struct drm_gem_dma_object * on success or an ERR_PTR()-encoded negative
146 	if (dma_obj->map_noncoherent) {  in drm_gem_dma_create()
147 		dma_obj->vaddr = dma_alloc_noncoherent(drm->dev, size,  in drm_gem_dma_create()
148 						       &dma_obj->dma_addr,  in drm_gem_dma_create()
152 		dma_obj->vaddr = dma_alloc_wc(drm->dev, size,  in drm_gem_dma_create()
153 					      &dma_obj->dma_addr,  in drm_gem_dma_create()
156 	if (!dma_obj->vaddr) {  in drm_gem_dma_create()
159 		ret = -ENOMEM;  in drm_gem_dma_create()
166 	drm_gem_object_put(&dma_obj->base);  in drm_gem_dma_create()
172  * drm_gem_dma_create_with_handle - allocate an object with the given size and
174  * @file_priv: DRM file-private structure to register the handle for
187  * A struct drm_gem_dma_object * on success or an ERR_PTR()-encoded negative
203 	gem_obj = &dma_obj->base;  in drm_gem_dma_create_with_handle()
210 	/* drop reference from allocate - handle holds it now. */  in drm_gem_dma_create_with_handle()
219  * drm_gem_dma_free - free resources associated with a DMA GEM object
228 	struct drm_gem_object *gem_obj = &dma_obj->base;  in drm_gem_dma_free()
229 	struct iosys_map map = IOSYS_MAP_INIT_VADDR(dma_obj->vaddr);  in drm_gem_dma_free()
231 	if (gem_obj->import_attach) {  in drm_gem_dma_free()
232 		if (dma_obj->vaddr)  in drm_gem_dma_free()
233 			dma_buf_vunmap_unlocked(gem_obj->import_attach->dmabuf, &map);  in drm_gem_dma_free()
234 		drm_prime_gem_destroy(gem_obj, dma_obj->sgt);  in drm_gem_dma_free()
235 	} else if (dma_obj->vaddr) {  in drm_gem_dma_free()
236 		if (dma_obj->map_noncoherent)  in drm_gem_dma_free()
237 			dma_free_noncoherent(gem_obj->dev->dev, dma_obj->base.size,  in drm_gem_dma_free()
238 					     dma_obj->vaddr, dma_obj->dma_addr,  in drm_gem_dma_free()
241 			dma_free_wc(gem_obj->dev->dev, dma_obj->base.size,  in drm_gem_dma_free()
242 				    dma_obj->vaddr, dma_obj->dma_addr);  in drm_gem_dma_free()
252  * drm_gem_dma_dumb_create_internal - create a dumb buffer object
253  * @file_priv: DRM file-private structure to create the dumb buffer for
269 	unsigned int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);  in drm_gem_dma_dumb_create_internal()
272 	if (args->pitch < min_pitch)  in drm_gem_dma_dumb_create_internal()
273 		args->pitch = min_pitch;  in drm_gem_dma_dumb_create_internal()
275 	if (args->size < args->pitch * args->height)  in drm_gem_dma_dumb_create_internal()
276 		args->size = args->pitch * args->height;  in drm_gem_dma_dumb_create_internal()
278 	dma_obj = drm_gem_dma_create_with_handle(file_priv, drm, args->size,  in drm_gem_dma_dumb_create_internal()
279 						 &args->handle);  in drm_gem_dma_dumb_create_internal()
285  * drm_gem_dma_dumb_create - create a dumb buffer object
286  * @file_priv: DRM file-private structure to create the dumb buffer for
308 	args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);  in drm_gem_dma_dumb_create()
309 	args->size = args->pitch * args->height;  in drm_gem_dma_dumb_create()
311 	dma_obj = drm_gem_dma_create_with_handle(file_priv, drm, args->size,  in drm_gem_dma_dumb_create()
312 						 &args->handle);  in drm_gem_dma_dumb_create()
325  * drm_gem_dma_get_unmapped_area - propose address for mapping in noMMU cases
348 	struct drm_file *priv = filp->private_data;  in drm_gem_dma_get_unmapped_area()
349 	struct drm_device *dev = priv->minor->dev;  in drm_gem_dma_get_unmapped_area()
353 		return -ENODEV;  in drm_gem_dma_get_unmapped_area()
355 	drm_vma_offset_lock_lookup(dev->vma_offset_manager);  in drm_gem_dma_get_unmapped_area()
356 	node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager,  in drm_gem_dma_get_unmapped_area()
362 		 * When the object is being freed, after it hits 0-refcnt it  in drm_gem_dma_get_unmapped_area()
365 		 * mgr->vm_lock.  Therefore if we find an object with a 0-refcnt  in drm_gem_dma_get_unmapped_area()
367 		 * destroyed and will be freed as soon as we release the lock -  in drm_gem_dma_get_unmapped_area()
368 		 * so we have to check for the 0-refcnted object and treat it as  in drm_gem_dma_get_unmapped_area()
371 		if (!kref_get_unless_zero(&obj->refcount))  in drm_gem_dma_get_unmapped_area()
375 	drm_vma_offset_unlock_lookup(dev->vma_offset_manager);  in drm_gem_dma_get_unmapped_area()
378 		return -EINVAL;  in drm_gem_dma_get_unmapped_area()
382 		return -EACCES;  in drm_gem_dma_get_unmapped_area()
389 	return dma_obj->vaddr ? (unsigned long)dma_obj->vaddr : -EINVAL;  in drm_gem_dma_get_unmapped_area()
395  * drm_gem_dma_print_info() - Print &drm_gem_dma_object info for debugfs
405 	drm_printf_indent(p, indent, "dma_addr=%pad\n", &dma_obj->dma_addr);  in drm_gem_dma_print_info()
406 	drm_printf_indent(p, indent, "vaddr=%p\n", dma_obj->vaddr);  in drm_gem_dma_print_info()
411  * drm_gem_dma_get_sg_table - provide a scatter/gather table of pinned
415  * This function exports a scatter/gather table by calling the standard
419  * A pointer to the scatter/gather table of pinned pages or NULL on failure.
423 	struct drm_gem_object *obj = &dma_obj->base;  in drm_gem_dma_get_sg_table()
429 		return ERR_PTR(-ENOMEM);  in drm_gem_dma_get_sg_table()
431 	ret = dma_get_sgtable(obj->dev->dev, sgt, dma_obj->vaddr,  in drm_gem_dma_get_sg_table()
432 			      dma_obj->dma_addr, obj->size);  in drm_gem_dma_get_sg_table()
445  * drm_gem_dma_prime_import_sg_table - produce a DMA GEM object from another
446  *     driver's scatter/gather table of pinned pages
448  * @attach: DMA-BUF attachment
449  * @sgt: scatter/gather table of pinned pages
451  * This function imports a scatter/gather table exported via DMA-BUF by
453  * (i.e. the scatter/gather table must contain a single entry). Drivers that
458  * A pointer to a newly created GEM object or an ERR_PTR-encoded negative
469 	if (drm_prime_get_contiguous_size(sgt) < attach->dmabuf->size)  in drm_gem_dma_prime_import_sg_table()
470 		return ERR_PTR(-EINVAL);  in drm_gem_dma_prime_import_sg_table()
473 	dma_obj = __drm_gem_dma_create(dev, attach->dmabuf->size, true);  in drm_gem_dma_prime_import_sg_table()
477 	dma_obj->dma_addr = sg_dma_address(sgt->sgl);  in drm_gem_dma_prime_import_sg_table()
478 	dma_obj->sgt = sgt;  in drm_gem_dma_prime_import_sg_table()
480 	drm_dbg_prime(dev, "dma_addr = %pad, size = %zu\n", &dma_obj->dma_addr,  in drm_gem_dma_prime_import_sg_table()
481 		      attach->dmabuf->size);  in drm_gem_dma_prime_import_sg_table()
483 	return &dma_obj->base;  in drm_gem_dma_prime_import_sg_table()
488  * drm_gem_dma_vmap - map a DMA GEM object into the kernel's virtual
504 	iosys_map_set_vaddr(map, dma_obj->vaddr);  in drm_gem_dma_vmap()
511  * drm_gem_dma_mmap - memory-map an exported DMA GEM object
517  * object instead of using on-demand faulting.
524 	struct drm_gem_object *obj = &dma_obj->base;  in drm_gem_dma_mmap()
532 	vma->vm_pgoff -= drm_vma_node_start(&obj->vma_node);  in drm_gem_dma_mmap()
535 	if (dma_obj->map_noncoherent) {  in drm_gem_dma_mmap()
536 		vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);  in drm_gem_dma_mmap()
538 		ret = dma_mmap_pages(dma_obj->base.dev->dev,  in drm_gem_dma_mmap()
539 				     vma, vma->vm_end - vma->vm_start,  in drm_gem_dma_mmap()
540 				     virt_to_page(dma_obj->vaddr));  in drm_gem_dma_mmap()
542 		ret = dma_mmap_wc(dma_obj->base.dev->dev, vma, dma_obj->vaddr,  in drm_gem_dma_mmap()
543 				  dma_obj->dma_addr,  in drm_gem_dma_mmap()
544 				  vma->vm_end - vma->vm_start);  in drm_gem_dma_mmap()
554  * drm_gem_dma_prime_import_sg_table_vmap - PRIME import another driver's
555  *	scatter/gather table and get the virtual address of the buffer
557  * @attach: DMA-BUF attachment
558  * @sgt: Scatter/gather table of pinned pages
560  * This function imports a scatter/gather table using
570  * A pointer to a newly created GEM object or an ERR_PTR-encoded negative
583 	ret = dma_buf_vmap_unlocked(attach->dmabuf, &map);  in drm_gem_dma_prime_import_sg_table_vmap()
591 		dma_buf_vunmap_unlocked(attach->dmabuf, &map);  in drm_gem_dma_prime_import_sg_table_vmap()
596 	dma_obj->vaddr = map.vaddr;  in drm_gem_dma_prime_import_sg_table_vmap()
602 MODULE_DESCRIPTION("DRM DMA memory-management helpers");