// SPDX-License-Identifier: MIT #include <linux/moduleparam.h>#include <linux/vmalloc.h> #include <drm/drm_crtc_helper.h>#include <drm/drm_drv.h>#include <drm/drm_fb_helper.h>#include <drm/drm_framebuffer.h>#include <drm/drm_gem.h>#include <drm/drm_print.h> #include <drm/drm_fbdev_generic.h> /* @user: 1=userspace, 0=fbcon */static int drm_fbdev_generic_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_generic_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_generic,				   drm_fb_helper_damage_range,				   drm_fb_helper_damage_area); static void drm_fbdev_generic_fb_destroy(struct fb_info *info){	struct drm_fb_helper *fb_helper = info->par;	void *shadow = info->screen_buffer; 	if (!fb_helper->dev)		return; 	fb_deferred_io_cleanup(info);	drm_fb_helper_fini(fb_helper);	vfree(shadow);	drm_client_framebuffer_delete(fb_helper->buffer); 	drm_client_release(&fb_helper->client);	drm_fb_helper_unprepare(fb_helper);	kfree(fb_helper);} static const struct fb_ops drm_fbdev_generic_fb_ops = {	.owner		= THIS_MODULE,	.fb_open	= drm_fbdev_generic_fb_open,	.fb_release	= drm_fbdev_generic_fb_release,	FB_DEFAULT_DEFERRED_OPS(drm_fbdev_generic),	DRM_FB_HELPER_DEFAULT_OPS,	.fb_destroy	= drm_fbdev_generic_fb_destroy,}; /* * This function uses the client API to create a framebuffer backed by a dumb buffer. */static int drm_fbdev_generic_helper_fb_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 drm_client_buffer *buffer;	struct fb_info *info;	size_t screen_size;	void *screen_buffer;	u32 format;	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_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);	buffer = drm_client_framebuffer_create(client, sizes->surface_width,					       sizes->surface_height, format);	if (IS_ERR(buffer))		return PTR_ERR(buffer); 	fb_helper->buffer = buffer;	fb_helper->fb = buffer->fb; 	screen_size = buffer->gem->size;	screen_buffer = vzalloc(screen_size);	if (!screen_buffer) {		ret = -ENOMEM;		goto err_drm_client_framebuffer_delete;	} 	info = drm_fb_helper_alloc_info(fb_helper);	if (IS_ERR(info)) {		ret = PTR_ERR(info);		goto err_vfree;	} 	drm_fb_helper_fill_info(info, fb_helper, sizes); 	info->fbops = &drm_fbdev_generic_fb_ops; 	/* screen */	info->flags |= FBINFO_VIRTFB | FBINFO_READS_FAST;	info->screen_buffer = screen_buffer;	info->fix.smem_start = page_to_phys(vmalloc_to_page(info->screen_buffer));	info->fix.smem_len = screen_size; 	/* deferred I/O */	fb_helper->fbdefio.delay = HZ / 20;	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_fb_helper_release_info; 	return 0; err_drm_fb_helper_release_info:	drm_fb_helper_release_info(fb_helper);err_vfree:	vfree(screen_buffer);err_drm_client_framebuffer_delete:	fb_helper->fb = NULL;	fb_helper->buffer = NULL;	drm_client_framebuffer_delete(buffer);	return ret;} static void drm_fbdev_generic_damage_blit_real(struct drm_fb_helper *fb_helper,					       struct drm_clip_rect *clip,					       struct iosys_map *dst){	struct drm_framebuffer *fb = fb_helper->fb;	size_t offset = clip->y1 * fb->pitches[0];	size_t len = clip->x2 - clip->x1;	unsigned int y;	void *src; 	switch (drm_format_info_bpp(fb->format, 0)) {	case 1:		offset += clip->x1 / 8;		len = DIV_ROUND_UP(len + clip->x1 % 8, 8);		break;	case 2:		offset += clip->x1 / 4;		len = DIV_ROUND_UP(len + clip->x1 % 4, 4);		break;	case 4:		offset += clip->x1 / 2;		len = DIV_ROUND_UP(len + clip->x1 % 2, 2);		break;	default:		offset += clip->x1 * fb->format->cpp[0];		len *= fb->format->cpp[0];		break;	} 	src = fb_helper->info->screen_buffer + offset;	iosys_map_incr(dst, offset); /* go to first pixel within clip rect */ 	for (y = clip->y1; y < clip->y2; y++) {		iosys_map_memcpy_to(dst, 0, src, len);		iosys_map_incr(dst, fb->pitches[0]);		src += fb->pitches[0];	}} static int drm_fbdev_generic_damage_blit(struct drm_fb_helper *fb_helper,					 struct drm_clip_rect *clip){	struct drm_client_buffer *buffer = fb_helper->buffer;	struct iosys_map map, dst;	int ret; 	/*	 * We have to pin the client buffer to its current location while	 * flushing the shadow buffer. In the general case, concurrent	 * modesetting operations could try to move the buffer and would	 * fail. The modeset has to be serialized by acquiring the reservation	 * object of the underlying BO here.	 *	 * For fbdev emulation, we only have to protect against fbdev modeset	 * operations. Nothing else will involve the client buffer's BO. So it	 * is sufficient to acquire struct drm_fb_helper.lock here.	 */	mutex_lock(&fb_helper->lock); 	ret = drm_client_buffer_vmap(buffer, &map);	if (ret)		goto out; 	dst = map;	drm_fbdev_generic_damage_blit_real(fb_helper, clip, &dst); 	drm_client_buffer_vunmap(buffer); out:	mutex_unlock(&fb_helper->lock); 	return ret;} static int drm_fbdev_generic_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; 	ret = drm_fbdev_generic_damage_blit(helper, clip);	if (drm_WARN_ONCE(dev, ret, "Damage blitter failed: ret=%d\n", ret))		return ret; 	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_generic_helper_funcs = {	.fb_probe = drm_fbdev_generic_helper_fb_probe,	.fb_dirty = drm_fbdev_generic_helper_fb_dirty,}; static void drm_fbdev_generic_client_unregister(struct drm_client_dev *client){	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); 	if (fb_helper->info) {		drm_fb_helper_unregister_info(fb_helper);	} else {		drm_client_release(&fb_helper->client);		drm_fb_helper_unprepare(fb_helper);		kfree(fb_helper);	}} static int drm_fbdev_generic_client_restore(struct drm_client_dev *client){	drm_fb_helper_lastclose(client->dev); 	return 0;} static int drm_fbdev_generic_client_hotplug(struct drm_client_dev *client){	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);	struct drm_device *dev = client->dev;	int ret; 	if (dev->fb_helper)		return drm_fb_helper_hotplug_event(dev->fb_helper); 	ret = drm_fb_helper_init(dev, fb_helper);	if (ret)		goto err_drm_err; 	if (!drm_drv_uses_atomic_modeset(dev))		drm_helper_disable_unused_functions(dev); 	ret = drm_fb_helper_initial_config(fb_helper);	if (ret)		goto err_drm_fb_helper_fini; 	return 0; err_drm_fb_helper_fini:	drm_fb_helper_fini(fb_helper);err_drm_err:	drm_err(dev, "fbdev: Failed to setup generic emulation (ret=%d)\n", ret);	return ret;} static const struct drm_client_funcs drm_fbdev_generic_client_funcs = {	.owner		= THIS_MODULE,	.unregister	= drm_fbdev_generic_client_unregister,	.restore	= drm_fbdev_generic_client_restore,	.hotplug	= drm_fbdev_generic_client_hotplug,}; /** * drm_fbdev_generic_setup() - Setup generic fbdev emulation * @dev: DRM device * @preferred_bpp: Preferred bits per pixel for the device. * * This function sets up generic fbdev emulation for drivers that supports * dumb buffers with a virtual address and that can be mmap'ed. * drm_fbdev_generic_setup() shall be called after the DRM driver registered * the new DRM device with drm_dev_register(). * * Restore, hotplug events and teardown are all taken care of. Drivers that do * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves. * Simple drivers might use drm_mode_config_helper_suspend(). * * In order to provide fixed mmap-able memory ranges, generic fbdev emulation * uses a shadow buffer in system memory. The implementation blits the shadow * fbdev buffer onto the real buffer in regular intervals. * * This function is safe to call even when there are no connectors present. * Setup will be retried on the next hotplug event. * * The fbdev is destroyed by drm_dev_unregister(). */void drm_fbdev_generic_setup(struct drm_device *dev, unsigned int preferred_bpp){	struct drm_fb_helper *fb_helper;	int ret; 	drm_WARN(dev, !dev->registered, "Device has not been registered.\n");	drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n"); 	fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);	if (!fb_helper)		return;	drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_generic_helper_funcs); 	ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_generic_client_funcs);	if (ret) {		drm_err(dev, "Failed to register client: %d\n", ret);		goto err_drm_client_init;	} 	drm_client_register(&fb_helper->client); 	return; err_drm_client_init:	drm_fb_helper_unprepare(fb_helper);	kfree(fb_helper);	return;}EXPORT_SYMBOL(drm_fbdev_generic_setup);