tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * BGRT boot graphic support
4 * Authors: Matthew Garrett, Josh Triplett <josh@joshtriplett.org>
5 * Copyright 2012 Red Hat, Inc <mjg@redhat.com>
6 * Copyright 2012 Intel Corporation
7 */
8
9#include <linux/kernel.h>
10#include <linux/init.h>
11#include <linux/device.h>
12#include <linux/sysfs.h>
13#include <linux/efi-bgrt.h>
14
15static void *bgrt_image;
16static struct kobject *bgrt_kobj;
17
18static ssize_t version_show(struct device *dev,
19 struct device_attribute *attr, char *buf)
20{
21 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.version);
22}
23static DEVICE_ATTR_RO(version);
24
25static ssize_t status_show(struct device *dev,
26 struct device_attribute *attr, char *buf)
27{
28 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.status);
29}
30static DEVICE_ATTR_RO(status);
31
32static ssize_t type_show(struct device *dev,
33 struct device_attribute *attr, char *buf)
34{
35 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_type);
36}
37static DEVICE_ATTR_RO(type);
38
39static ssize_t xoffset_show(struct device *dev,
40 struct device_attribute *attr, char *buf)
41{
42 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_offset_x);
43}
44static DEVICE_ATTR_RO(xoffset);
45
46static ssize_t yoffset_show(struct device *dev,
47 struct device_attribute *attr, char *buf)
48{
49 return snprintf(buf, PAGE_SIZE, "%d\n", bgrt_tab.image_offset_y);
50}
51static DEVICE_ATTR_RO(yoffset);
52
53static ssize_t image_read(struct file *file, struct kobject *kobj,
54 struct bin_attribute *attr, char *buf, loff_t off, size_t count)
55{
56 memcpy(buf, attr->private + off, count);
57 return count;
58}
59
60static BIN_ATTR_RO(image, 0); /* size gets filled in later */
61
62static struct attribute *bgrt_attributes[] = {
63 &dev_attr_version.attr,
64 &dev_attr_status.attr,
65 &dev_attr_type.attr,
66 &dev_attr_xoffset.attr,
67 &dev_attr_yoffset.attr,
68 NULL,
69};
70
71static struct bin_attribute *bgrt_bin_attributes[] = {
72 &bin_attr_image,
73 NULL,
74};
75
76static const struct attribute_group bgrt_attribute_group = {
77 .attrs = bgrt_attributes,
78 .bin_attrs = bgrt_bin_attributes,
79};
80
81int __init acpi_parse_bgrt(struct acpi_table_header *table)
82{
83 efi_bgrt_init(table);
84 return 0;
85}
86
87static int __init bgrt_init(void)
88{
89 int ret;
90
91 if (!bgrt_tab.image_address)
92 return -ENODEV;
93
94 bgrt_image = memremap(bgrt_tab.image_address, bgrt_image_size,
95 MEMREMAP_WB);
96 if (!bgrt_image) {
97 pr_notice("Ignoring BGRT: failed to map image memory\n");
98 return -ENOMEM;
99 }
100
101 bin_attr_image.private = bgrt_image;
102 bin_attr_image.size = bgrt_image_size;
103
104 bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj);
105 if (!bgrt_kobj) {
106 ret = -EINVAL;
107 goto out_memmap;
108 }
109
110 ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group);
111 if (ret)
112 goto out_kobject;
113
114 return 0;
115
116out_kobject:
117 kobject_put(bgrt_kobj);
118out_memmap:
119 memunmap(bgrt_image);
120 return ret;
121}
122device_initcall(bgrt_init);