// SPDX-License-Identifier: GPL-2.0-only #include <linux/export.h>#include <linux/limits.h>#include <linux/math64.h>#include <linux/minmax.h>#include <linux/screen_info.h> #include <drm/drm_fourcc.h>#include <drm/drm_print.h> #include "drm_sysfb_helper.h" static s64 drm_sysfb_get_validated_size0(struct drm_device *dev, const char *name,					 u64 value, u64 max){	if (!value) {		drm_warn(dev, "%s of 0 not allowed\n", name);		return -EINVAL;	} else if (value > min(max, S64_MAX)) {		drm_warn(dev, "%s of %llu exceeds maximum of %llu\n", name, value, max);		return -EINVAL;	}	return value;} int drm_sysfb_get_width_si(struct drm_device *dev, const struct screen_info *si){	return drm_sysfb_get_validated_int0(dev, "width", si->lfb_width, U16_MAX);}EXPORT_SYMBOL(drm_sysfb_get_width_si); int drm_sysfb_get_height_si(struct drm_device *dev, const struct screen_info *si){	return drm_sysfb_get_validated_int0(dev, "height", si->lfb_height, U16_MAX);}EXPORT_SYMBOL(drm_sysfb_get_height_si); struct resource *drm_sysfb_get_memory_si(struct drm_device *dev,					 const struct screen_info *si,					 struct resource *res){	ssize_t	num; 	num = screen_info_resources(si, res, 1);	if (!num) {		drm_warn(dev, "memory resource not found\n");		return NULL;	} 	return res;}EXPORT_SYMBOL(drm_sysfb_get_memory_si); int drm_sysfb_get_stride_si(struct drm_device *dev, const struct screen_info *si,			    const struct drm_format_info *format,			    unsigned int width, unsigned int height, u64 size){	u64 lfb_linelength = si->lfb_linelength;	s64 stride; 	if (!lfb_linelength)		lfb_linelength = drm_format_info_min_pitch(format, 0, width); 	stride = drm_sysfb_get_validated_size0(dev, "stride", lfb_linelength,					       div64_u64(size, height));	if (stride < INT_MIN || stride > INT_MAX)		return -EINVAL; 	return (int)stride; /* stride or negative errno code */}EXPORT_SYMBOL(drm_sysfb_get_stride_si); s64 drm_sysfb_get_visible_size_si(struct drm_device *dev, const struct screen_info *si,				  unsigned int height, unsigned int stride, u64 size){	u64 vsize = mul_u32_u32(height, stride); 	return drm_sysfb_get_validated_size0(dev, "visible size", vsize, size);}EXPORT_SYMBOL(drm_sysfb_get_visible_size_si);