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: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20250410083834.10810-4-tzimmermann@suse.de
This commit is contained in:
Thomas Zimmermann
2025-04-10 10:37:25 +02:00
parent 6046b49baf
commit e8c086880b
5 changed files with 160 additions and 192 deletions

View File

@@ -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

View File

@@ -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

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@@ -0,0 +1,107 @@
// 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);

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@@ -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);

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@@ -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);