// SPDX-License-Identifier: GPL-2.0-or-later #include <linux/export.h>#include <linux/fb.h>#include <linux/mutex.h>#include <linux/slab.h> /** * framebuffer_alloc - creates a new frame buffer info structure * * @size: size of driver private data, can be zero * @dev: pointer to the device for this fb, this can be NULL * * Creates a new frame buffer info structure. Also reserves @size bytes * for driver private data (info->par). info->par (if any) will be * aligned to sizeof(long). The new instances of struct fb_info and * the driver private data are both cleared to zero. * * Returns the new structure, or NULL if an error occurred. * */struct fb_info *framebuffer_alloc(size_t size, struct device *dev){#define BYTES_PER_LONG (BITS_PER_LONG/8)#define PADDING (BYTES_PER_LONG - (sizeof(struct fb_info) % BYTES_PER_LONG))	int fb_info_size = sizeof(struct fb_info);	struct fb_info *info;	char *p; 	if (size)		fb_info_size += PADDING; 	p = kzalloc(fb_info_size + size, GFP_KERNEL); 	if (!p)		return NULL; 	info = (struct fb_info *) p; 	if (size)		info->par = p + fb_info_size; 	info->device = dev;	info->fbcon_rotate_hint = -1;	info->blank = FB_BLANK_UNBLANK; #if IS_ENABLED(CONFIG_FB_BACKLIGHT)	mutex_init(&info->bl_curve_mutex);#endif 	return info;#undef PADDING#undef BYTES_PER_LONG}EXPORT_SYMBOL(framebuffer_alloc); /** * framebuffer_release - marks the structure available for freeing * * @info: frame buffer info structure * * Drop the reference count of the device embedded in the * framebuffer info structure. * */void framebuffer_release(struct fb_info *info){	if (!info)		return; 	if (WARN_ON(refcount_read(&info->count)))		return; #if IS_ENABLED(CONFIG_FB_BACKLIGHT)	mutex_destroy(&info->bl_curve_mutex);#endif 	kfree(info);}EXPORT_SYMBOL(framebuffer_release);