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https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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e8c086880b
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
108 lines
2.9 KiB
C
108 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/export.h>
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#include <linux/limits.h>
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#include <linux/minmax.h>
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#include <linux/screen_info.h>
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#include <drm/drm_fourcc.h>
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#include <drm/drm_print.h>
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#include "drm_sysfb_helper.h"
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static s64 drm_sysfb_get_validated_size0(struct drm_device *dev, const char *name,
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u64 value, u64 max)
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{
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if (!value) {
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drm_warn(dev, "%s of 0 not allowed\n", name);
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return -EINVAL;
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} else if (value > min(max, S64_MAX)) {
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drm_warn(dev, "%s of %llu exceeds maximum of %llu\n", name, value, max);
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return -EINVAL;
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}
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return value;
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}
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int drm_sysfb_get_width_si(struct drm_device *dev, const struct screen_info *si)
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{
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return drm_sysfb_get_validated_int0(dev, "width", si->lfb_width, U16_MAX);
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}
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EXPORT_SYMBOL(drm_sysfb_get_width_si);
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int drm_sysfb_get_height_si(struct drm_device *dev, const struct screen_info *si)
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{
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return drm_sysfb_get_validated_int0(dev, "height", si->lfb_height, U16_MAX);
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}
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EXPORT_SYMBOL(drm_sysfb_get_height_si);
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struct resource *drm_sysfb_get_memory_si(struct drm_device *dev,
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const struct screen_info *si,
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struct resource *res)
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{
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ssize_t num;
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num = screen_info_resources(si, res, 1);
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if (!num) {
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drm_warn(dev, "memory resource not found\n");
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return NULL;
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}
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return res;
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}
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EXPORT_SYMBOL(drm_sysfb_get_memory_si);
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int drm_sysfb_get_stride_si(struct drm_device *dev, const struct screen_info *si,
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const struct drm_format_info *format,
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unsigned int width, unsigned int height, u64 size)
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{
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u64 lfb_linelength = si->lfb_linelength;
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if (!lfb_linelength)
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lfb_linelength = drm_format_info_min_pitch(format, 0, width);
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return drm_sysfb_get_validated_int0(dev, "stride", lfb_linelength, div64_u64(size, height));
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}
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EXPORT_SYMBOL(drm_sysfb_get_stride_si);
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u64 drm_sysfb_get_visible_size_si(struct drm_device *dev, const struct screen_info *si,
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unsigned int height, unsigned int stride, u64 size)
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{
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u64 vsize = PAGE_ALIGN(height * stride);
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return drm_sysfb_get_validated_size0(dev, "visible size", vsize, size);
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}
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EXPORT_SYMBOL(drm_sysfb_get_visible_size_si);
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const struct drm_format_info *drm_sysfb_get_format_si(struct drm_device *dev,
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const struct drm_sysfb_format *formats,
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size_t nformats,
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const struct screen_info *si)
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{
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const struct drm_format_info *format = NULL;
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u32 bits_per_pixel;
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size_t i;
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bits_per_pixel = __screen_info_lfb_bits_per_pixel(si);
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for (i = 0; i < nformats; ++i) {
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const struct pixel_format *f = &formats[i].pixel;
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if (bits_per_pixel == f->bits_per_pixel &&
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si->red_size == f->red.length &&
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si->red_pos == f->red.offset &&
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si->green_size == f->green.length &&
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si->green_pos == f->green.offset &&
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si->blue_size == f->blue.length &&
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si->blue_pos == f->blue.offset) {
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format = drm_format_info(formats[i].fourcc);
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break;
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}
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}
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if (!format)
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drm_warn(dev, "No compatible color format found\n");
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return format;
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}
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EXPORT_SYMBOL(drm_sysfb_get_format_si);
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