// SPDX-License-Identifier: MIT #include <linux/export.h>#include <linux/fb.h> #include <drm/drm_drv.h>#include <drm/drm_fbdev_shmem.h>#include <drm/drm_fb_helper.h>#include <drm/drm_framebuffer.h>#include <drm/drm_gem_framebuffer_helper.h>#include <drm/drm_gem_shmem_helper.h>#include <drm/drm_print.h> /* * struct fb_ops */ static int drm_fbdev_shmem_fb_open(struct fb_info *info, int user){	struct drm_fb_helper *fb_helper = info->par; 	/* No need to take a ref for fbcon because it unbinds on unregister */	if (user && !try_module_get(fb_helper->dev->driver->fops->owner))		return -ENODEV; 	return 0;} static int drm_fbdev_shmem_fb_release(struct fb_info *info, int user){	struct drm_fb_helper *fb_helper = info->par; 	if (user)		module_put(fb_helper->dev->driver->fops->owner); 	return 0;} FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(drm_fbdev_shmem,				   drm_fb_helper_damage_range,				   drm_fb_helper_damage_area); static int drm_fbdev_shmem_fb_mmap(struct fb_info *info, struct vm_area_struct *vma){	struct drm_fb_helper *fb_helper = info->par;	struct drm_framebuffer *fb = fb_helper->fb;	struct drm_gem_object *obj = drm_gem_fb_get_obj(fb, 0);	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); 	if (shmem->map_wc)		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); 	return fb_deferred_io_mmap(info, vma);} static void drm_fbdev_shmem_fb_destroy(struct fb_info *info){	struct drm_fb_helper *fb_helper = info->par; 	if (!fb_helper->dev)		return; 	fb_deferred_io_cleanup(info);	drm_fb_helper_fini(fb_helper); 	drm_client_buffer_vunmap(fb_helper->buffer);	drm_client_buffer_delete(fb_helper->buffer);	drm_client_release(&fb_helper->client);} static const struct fb_ops drm_fbdev_shmem_fb_ops = {	.owner = THIS_MODULE,	.fb_open = drm_fbdev_shmem_fb_open,	.fb_release = drm_fbdev_shmem_fb_release,	__FB_DEFAULT_DEFERRED_OPS_RDWR(drm_fbdev_shmem),	DRM_FB_HELPER_DEFAULT_OPS,	__FB_DEFAULT_DEFERRED_OPS_DRAW(drm_fbdev_shmem),	.fb_mmap = drm_fbdev_shmem_fb_mmap,	.fb_destroy = drm_fbdev_shmem_fb_destroy,}; static struct page *drm_fbdev_shmem_get_page(struct fb_info *info, unsigned long offset){	struct drm_fb_helper *fb_helper = info->par;	struct drm_framebuffer *fb = fb_helper->fb;	struct drm_gem_object *obj = drm_gem_fb_get_obj(fb, 0);	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);	unsigned int i = offset >> PAGE_SHIFT;	struct page *page; 	if (fb_WARN_ON_ONCE(info, offset > obj->size))		return NULL; 	page = shmem->pages[i]; // protected by active vmap	if (page)		get_page(page);	fb_WARN_ON_ONCE(info, !page); 	return page;} /* * struct drm_fb_helper */ static int drm_fbdev_shmem_helper_fb_dirty(struct drm_fb_helper *helper,					   struct drm_clip_rect *clip){	struct drm_device *dev = helper->dev;	int ret; 	/* Call damage handlers only if necessary */	if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))		return 0; 	if (helper->fb->funcs->dirty) {		ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);		if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret))			return ret;	} 	return 0;} static const struct drm_fb_helper_funcs drm_fbdev_shmem_helper_funcs = {	.fb_dirty = drm_fbdev_shmem_helper_fb_dirty,}; /* * struct drm_driver */ int drm_fbdev_shmem_driver_fbdev_probe(struct drm_fb_helper *fb_helper,				       struct drm_fb_helper_surface_size *sizes){	struct drm_client_dev *client = &fb_helper->client;	struct drm_device *dev = fb_helper->dev;	struct fb_info *info = fb_helper->info;	struct drm_client_buffer *buffer;	struct drm_gem_shmem_object *shmem;	struct drm_framebuffer *fb;	u32 format;	struct iosys_map map;	int ret; 	drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n",		    sizes->surface_width, sizes->surface_height,		    sizes->surface_bpp); 	format = drm_driver_legacy_fb_format(dev, sizes->surface_bpp, sizes->surface_depth);	buffer = drm_client_buffer_create_dumb(client, sizes->surface_width,					       sizes->surface_height, format);	if (IS_ERR(buffer))		return PTR_ERR(buffer);	shmem = to_drm_gem_shmem_obj(buffer->gem); 	fb = buffer->fb; 	ret = drm_client_buffer_vmap(buffer, &map);	if (ret) {		goto err_drm_client_buffer_delete;	} else if (drm_WARN_ON(dev, map.is_iomem)) {		ret = -ENODEV; /* I/O memory not supported; use generic emulation */		goto err_drm_client_buffer_delete;	} 	fb_helper->funcs = &drm_fbdev_shmem_helper_funcs;	fb_helper->buffer = buffer;	fb_helper->fb = fb; 	drm_fb_helper_fill_info(info, fb_helper, sizes); 	info->fbops = &drm_fbdev_shmem_fb_ops; 	/* screen */	info->flags |= FBINFO_VIRTFB; /* system memory */	if (!shmem->map_wc)		info->flags |= FBINFO_READS_FAST; /* signal caching */	info->screen_size = sizes->surface_height * fb->pitches[0];	info->screen_buffer = map.vaddr;	info->fix.smem_len = info->screen_size; 	/* deferred I/O */	fb_helper->fbdefio.delay = HZ / 20;	fb_helper->fbdefio.get_page = drm_fbdev_shmem_get_page;	fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io; 	info->fbdefio = &fb_helper->fbdefio;	ret = fb_deferred_io_init(info);	if (ret)		goto err_drm_client_buffer_vunmap; 	return 0; err_drm_client_buffer_vunmap:	fb_helper->fb = NULL;	fb_helper->buffer = NULL;	drm_client_buffer_vunmap(buffer);err_drm_client_buffer_delete:	drm_client_buffer_delete(buffer);	return ret;}EXPORT_SYMBOL(drm_fbdev_shmem_driver_fbdev_probe);