Quelle  bgrt.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
 * BGRT boot graphic support
 * Authors: Matthew Garrett, Josh Triplett <josh@joshtriplett.org>
 * Copyright 2012 Red Hat, Inc <mjg@redhat.com>
 * Copyright 2012 Intel Corporation
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/sysfs.h>
#include <linux/efi-bgrt.h>

static void *bgrt_image;
static struct kobject *bgrt_kobj;

#define BGRT_SHOW(_name, _member) \
 static ssize_t _name##_show(struct kobject *kobj,   \
        struct kobj_attribute *attr, char *buf) \
 {         \
  return sysfs_emit(buf, "%d\n", bgrt_tab._member);  \
 }         \
 static struct kobj_attribute bgrt_attr_##_name = __ATTR_RO(_name)

BGRT_SHOW(version, version);
BGRT_SHOW(status, status);
BGRT_SHOW(type, image_type);
BGRT_SHOW(xoffset, image_offset_x);
BGRT_SHOW(yoffset, image_offset_y);

static __ro_after_init BIN_ATTR_SIMPLE_RO(image);

static struct attribute *bgrt_attributes[] = {
 &bgrt_attr_version.attr,
 &bgrt_attr_status.attr,
 &bgrt_attr_type.attr,
 &bgrt_attr_xoffset.attr,
 &bgrt_attr_yoffset.attr,
 NULL,
};

static const struct bin_attribute *const bgrt_bin_attributes[] = {
 &bin_attr_image,
 NULL,
};

static const struct attribute_group bgrt_attribute_group = {
 .attrs = bgrt_attributes,
 .bin_attrs = bgrt_bin_attributes,
};

int __init acpi_parse_bgrt(struct acpi_table_header *table)
{
 efi_bgrt_init(table);
 return 0;
}

static int __init bgrt_init(void)
{
 int ret;

 if (!bgrt_tab.image_address)
  return -ENODEV;

 bgrt_image = memremap(bgrt_tab.image_address, bgrt_image_size,
         MEMREMAP_WB);
 if (!bgrt_image) {
  pr_notice("Ignoring BGRT: failed to map image memory\n");
  return -ENOMEM;
 }

 bin_attr_image.private = bgrt_image;
 bin_attr_image.size = bgrt_image_size;

 bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj);
 if (!bgrt_kobj) {
  ret = -EINVAL;
  goto out_memmap;
 }

 ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group);
 if (ret)
  goto out_kobject;

 return 0;

out_kobject:
 kobject_put(bgrt_kobj);
out_memmap:
 memunmap(bgrt_image);
 return ret;
}
device_initcall(bgrt_init);