Commit e8c08688 authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

drm/sysfb: Share helpers for screen_info validation 



Share efidrm's and vesadrm's validation of struct screen_info in
shared helpers. Update the drivers.

Most validation helpers test individual values against limits and
can be shared as they are. For color formats, a common helper looks
up the correct DRM format info from a driver-provided list of color
formats.

These screen_info helpers are only available if CONFIG_SCREEN_INFO
has been selected, as done by efidrm and vesadrm.

Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarJavier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250410083834.10810-4-tzimmermann@suse.de
parent 6046b49b

drivers/gpu/drm/sysfb/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
drm_sysfb_helper-y := \

	drm_sysfb.o \

	drm_sysfb_modeset.o

drm_sysfb_helper-$(CONFIG_SCREEN_INFO) += drm_sysfb_screen_info.o

obj-$(CONFIG_DRM_SYSFB_HELPER)	+= drm_sysfb_helper.o



obj-$(CONFIG_DRM_EFIDRM)	+= efidrm.o

drivers/gpu/drm/sysfb/drm_sysfb_helper.h

+34 −0
Original line number Diff line number Diff line
@@ -6,12 +6,46 @@ 
#include <linux/container_of.h>

#include <linux/iosys-map.h>



#include <video/pixel_format.h>



#include <drm/drm_crtc.h>

#include <drm/drm_device.h>

#include <drm/drm_modes.h>



struct drm_format_info;

struct drm_scanout_buffer;

struct screen_info;



/*

 * Input parsing

 */



struct drm_sysfb_format {

	struct pixel_format pixel;

	u32 fourcc;

};



int drm_sysfb_get_validated_int(struct drm_device *dev, const char *name,

				u64 value, u32 max);

int drm_sysfb_get_validated_int0(struct drm_device *dev, const char *name,

				 u64 value, u32 max);



#if defined(CONFIG_SCREEN_INFO)

int drm_sysfb_get_width_si(struct drm_device *dev, const struct screen_info *si);

int drm_sysfb_get_height_si(struct drm_device *dev, const struct screen_info *si);

struct resource *drm_sysfb_get_memory_si(struct drm_device *dev,

					 const struct screen_info *si,

					 struct resource *res);

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 drm_sysfb_get_visible_size_si(struct drm_device *dev, const struct screen_info *si,

				  unsigned int height, unsigned int stride, u64 size);

const struct drm_format_info *drm_sysfb_get_format_si(struct drm_device *dev,

						      const struct drm_sysfb_format *formats,

						      size_t nformats,

						      const struct screen_info *si);

#endif



/*

 * Input parsing

drivers/gpu/drm/sysfb/drm_sysfb_screen_info.c

0 → 100644
+107 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only



#include <linux/export.h>

#include <linux/limits.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;



	if (!lfb_linelength)

		lfb_linelength = drm_format_info_min_pitch(format, 0, width);



	return drm_sysfb_get_validated_int0(dev, "stride", lfb_linelength, div64_u64(size, height));

}

EXPORT_SYMBOL(drm_sysfb_get_stride_si);



u64 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 = PAGE_ALIGN(height * stride);



	return drm_sysfb_get_validated_size0(dev, "visible size", vsize, size);

}

EXPORT_SYMBOL(drm_sysfb_get_visible_size_si);



const struct drm_format_info *drm_sysfb_get_format_si(struct drm_device *dev,

						      const struct drm_sysfb_format *formats,

						      size_t nformats,

						      const struct screen_info *si)

{

	const struct drm_format_info *format = NULL;

	u32 bits_per_pixel;

	size_t i;



	bits_per_pixel = __screen_info_lfb_bits_per_pixel(si);



	for (i = 0; i < nformats; ++i) {

		const struct pixel_format *f = &formats[i].pixel;



		if (bits_per_pixel == f->bits_per_pixel &&

		    si->red_size == f->red.length &&

		    si->red_pos == f->red.offset &&

		    si->green_size == f->green.length &&

		    si->green_pos == f->green.offset &&

		    si->blue_size == f->blue.length &&

		    si->blue_pos == f->blue.offset) {

			format = drm_format_info(formats[i].fourcc);

			break;

		}

	}



	if (!format)

		drm_warn(dev, "No compatible color format found\n");



	return format;

}

EXPORT_SYMBOL(drm_sysfb_get_format_si);

drivers/gpu/drm/sysfb/efidrm.c

+9 −96
Original line number Diff line number Diff line
@@ -33,72 +33,10 @@ 
#define DRIVER_MAJOR	1

#define DRIVER_MINOR	0



static s64 efidrm_get_validated_size0(struct drm_device *dev, const char *name,

				      u64 value, u64 max)

{

	if (!value) {

		drm_err(dev, "%s of 0 not allowed\n", name);

		return -EINVAL;

	} else if (value > max) {

		drm_err(dev, "%s of %llu exceeds maximum of %llu\n", name, value, max);

		return -EINVAL;

	}

	return value;

}



static int efidrm_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);

}



static int efidrm_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);

}



static struct resource *efidrm_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_err(dev, "memory resource not found\n");

		return NULL;

	}



	return res;

}



static int efidrm_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;



	if (!lfb_linelength)

		lfb_linelength = drm_format_info_min_pitch(format, 0, width);



	return drm_sysfb_get_validated_int0(dev, "stride", lfb_linelength,

					    div64_u64(size, height));

}



static u64 efidrm_get_visible_size_si(struct drm_device *dev, const struct screen_info *si,

				      unsigned int height, unsigned int stride, u64 size)

{

	u64 vsize = PAGE_ALIGN(height * stride);



	return efidrm_get_validated_size0(dev, "visible size", vsize, size);

}



static const struct drm_format_info *efidrm_get_format_si(struct drm_device *dev,

							  const struct screen_info *si)

{

	static const struct {

		struct pixel_format pixel;

		u32 fourcc;

	} efi_formats[] = {

	static const struct drm_sysfb_format formats[] = {

		{ PIXEL_FORMAT_XRGB1555, DRM_FORMAT_XRGB1555, },

		{ PIXEL_FORMAT_RGB565, DRM_FORMAT_RGB565, },

		{ PIXEL_FORMAT_RGB888, DRM_FORMAT_RGB888, },
@@ -106,33 +44,8 @@ static const struct drm_format_info *efidrm_get_format_si(struct drm_device *dev 
		{ PIXEL_FORMAT_XBGR8888, DRM_FORMAT_XBGR8888, },

		{ PIXEL_FORMAT_XRGB2101010, DRM_FORMAT_XRGB2101010, },

	};

	const struct drm_format_info *format = NULL;

	u32 bits_per_pixel;

	size_t i;



	bits_per_pixel = __screen_info_lfb_bits_per_pixel(si);



	for (i = 0; i < ARRAY_SIZE(efi_formats); ++i) {

		const struct pixel_format *f = &efi_formats[i].pixel;



		if (bits_per_pixel == f->bits_per_pixel &&

		    si->red_size == f->red.length &&

		    si->red_pos == f->red.offset &&

		    si->green_size == f->green.length &&

		    si->green_pos == f->green.offset &&

		    si->blue_size == f->blue.length &&

		    si->blue_pos == f->blue.offset) {

			format = drm_format_info(efi_formats[i].fourcc);

			break;

		}

	}



	if (!format)

		return ERR_PTR(-EINVAL);

	if (format->is_color_indexed)

		return ERR_PTR(-EINVAL);



	return format;

	return drm_sysfb_get_format_si(dev, formats, ARRAY_SIZE(formats), si);

}



static u64 efidrm_get_mem_flags(struct drm_device *dev, resource_size_t start,
@@ -268,21 +181,21 @@ static struct efidrm_device *efidrm_device_create(struct drm_driver *drv, 
	 */



	format = efidrm_get_format_si(dev, si);

	if (IS_ERR(format))

		return ERR_CAST(format);

	width = efidrm_get_width_si(dev, si);

	if (!format)

		return ERR_PTR(-EINVAL);

	width = drm_sysfb_get_width_si(dev, si);

	if (width < 0)

		return ERR_PTR(width);

	height = efidrm_get_height_si(dev, si);

	height = drm_sysfb_get_height_si(dev, si);

	if (height < 0)

		return ERR_PTR(height);

	res = efidrm_get_memory_si(dev, si, &resbuf);

	res = drm_sysfb_get_memory_si(dev, si, &resbuf);

	if (!res)

		return ERR_PTR(-EINVAL);

	stride = efidrm_get_stride_si(dev, si, format, width, height, resource_size(res));

	stride = drm_sysfb_get_stride_si(dev, si, format, width, height, resource_size(res));

	if (stride < 0)

		return ERR_PTR(stride);

	vsize = efidrm_get_visible_size_si(dev, si, height, stride, resource_size(res));

	vsize = drm_sysfb_get_visible_size_si(dev, si, height, stride, resource_size(res));

	if (!vsize)

		return ERR_PTR(-EINVAL);

drivers/gpu/drm/sysfb/vesadrm.c

+9 −96
Original line number Diff line number Diff line
@@ -36,105 +36,18 @@ 


#define VESADRM_GAMMA_LUT_SIZE 256



static s64 vesadrm_get_validated_size0(struct drm_device *dev, const char *name,

				       u64 value, u64 max)

{

	if (!value) {

		drm_err(dev, "vesadrm: %s of 0 not allowed\n", name);

		return -EINVAL;

	} else if (value > max) {

		drm_err(dev, "vesadrm: %s of %llu exceeds maximum of %llu\n", name, value, max);

		return -EINVAL;

	}

	return value;

}



static int vesadrm_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);

}



static int vesadrm_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);

}



static struct resource *vesadrm_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_err(dev, "vesadrm: memory resource not found\n");

		return NULL;

	}



	return res;

}



static int vesadrm_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;



	if (!lfb_linelength)

		lfb_linelength = drm_format_info_min_pitch(format, 0, width);



	return drm_sysfb_get_validated_int0(dev, "stride", lfb_linelength,

					    div64_u64(size, height));

}



static u64 vesadrm_get_visible_size_si(struct drm_device *dev, const struct screen_info *si,

				       unsigned int height, unsigned int stride, u64 size)

{

	u64 vsize = PAGE_ALIGN(height * stride);



	return vesadrm_get_validated_size0(dev, "visible size", vsize, size);

}



static const struct drm_format_info *vesadrm_get_format_si(struct drm_device *dev,

							   const struct screen_info *si)

{

	static const struct {

		struct pixel_format pixel;

		u32 fourcc;

	} vesa_formats[] = {

	static const struct drm_sysfb_format formats[] = {

		{ PIXEL_FORMAT_XRGB1555, DRM_FORMAT_XRGB1555, },

		{ PIXEL_FORMAT_RGB565, DRM_FORMAT_RGB565, },

		{ PIXEL_FORMAT_RGB888, DRM_FORMAT_RGB888, },

		{ PIXEL_FORMAT_XRGB8888, DRM_FORMAT_XRGB8888, },

		{ PIXEL_FORMAT_XBGR8888, DRM_FORMAT_XBGR8888, },

	};

	const struct drm_format_info *format = NULL;

	u32 bits_per_pixel;

	size_t i;



	bits_per_pixel = __screen_info_lfb_bits_per_pixel(si);



	for (i = 0; i < ARRAY_SIZE(vesa_formats); ++i) {

		const struct pixel_format *f = &vesa_formats[i].pixel;



		if (bits_per_pixel == f->bits_per_pixel &&

		    si->red_size == f->red.length &&

		    si->red_pos == f->red.offset &&

		    si->green_size == f->green.length &&

		    si->green_pos == f->green.offset &&

		    si->blue_size == f->blue.length &&

		    si->blue_pos == f->blue.offset) {

			format = drm_format_info(vesa_formats[i].fourcc);

			break;

		}

	}



	if (!format)

		return ERR_PTR(-EINVAL);

	if (format->is_color_indexed)

		return ERR_PTR(-EINVAL);



	return format;

	return drm_sysfb_get_format_si(dev, formats, ARRAY_SIZE(formats), si);

}



/*
@@ -426,21 +339,21 @@ static struct vesadrm_device *vesadrm_device_create(struct drm_driver *drv, 
	 */



	format = vesadrm_get_format_si(dev, si);

	if (IS_ERR(format))

		return ERR_CAST(format);

	width = vesadrm_get_width_si(dev, si);

	if (!format)

		return ERR_PTR(-EINVAL);

	width = drm_sysfb_get_width_si(dev, si);

	if (width < 0)

		return ERR_PTR(width);

	height = vesadrm_get_height_si(dev, si);

	height = drm_sysfb_get_height_si(dev, si);

	if (height < 0)

		return ERR_PTR(height);

	res = vesadrm_get_memory_si(dev, si, &resbuf);

	res = drm_sysfb_get_memory_si(dev, si, &resbuf);

	if (!res)

		return ERR_PTR(-EINVAL);

	stride = vesadrm_get_stride_si(dev, si, format, width, height, resource_size(res));

	stride = drm_sysfb_get_stride_si(dev, si, format, width, height, resource_size(res));

	if (stride < 0)

		return ERR_PTR(stride);

	vsize = vesadrm_get_visible_size_si(dev, si, height, stride, resource_size(res));

	vsize = drm_sysfb_get_visible_size_si(dev, si, height, stride, resource_size(res));

	if (!vsize)

		return ERR_PTR(-EINVAL);