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 
15 static void *bgrt_image;
16 static struct kobject *bgrt_kobj;
17 
18 #define BGRT_SHOW(_name, _member) \
19 	static ssize_t _name##_show(struct kobject *kobj,			\
20 				    struct kobj_attribute *attr, char *buf)	\
21 	{									\
22 		return sysfs_emit(buf, "%d\n", bgrt_tab._member);		\
23 	}									\
24 	static struct kobj_attribute bgrt_attr_##_name = __ATTR_RO(_name)
25 
26 BGRT_SHOW(version, version);
27 BGRT_SHOW(status, status);
28 BGRT_SHOW(type, image_type);
29 BGRT_SHOW(xoffset, image_offset_x);
30 BGRT_SHOW(yoffset, image_offset_y);
31 
32 static BIN_ATTR_SIMPLE_RO(image);
33 
34 static struct attribute *bgrt_attributes[] = {
35 	&bgrt_attr_version.attr,
36 	&bgrt_attr_status.attr,
37 	&bgrt_attr_type.attr,
38 	&bgrt_attr_xoffset.attr,
39 	&bgrt_attr_yoffset.attr,
40 	NULL,
41 };
42 
43 static struct bin_attribute *bgrt_bin_attributes[] = {
44 	&bin_attr_image,
45 	NULL,
46 };
47 
48 static const struct attribute_group bgrt_attribute_group = {
49 	.attrs = bgrt_attributes,
50 	.bin_attrs = bgrt_bin_attributes,
51 };
52 
acpi_parse_bgrt(struct acpi_table_header * table)53 int __init acpi_parse_bgrt(struct acpi_table_header *table)
54 {
55 	efi_bgrt_init(table);
56 	return 0;
57 }
58 
bgrt_init(void)59 static int __init bgrt_init(void)
60 {
61 	int ret;
62 
63 	if (!bgrt_tab.image_address)
64 		return -ENODEV;
65 
66 	bgrt_image = memremap(bgrt_tab.image_address, bgrt_image_size,
67 			      MEMREMAP_WB);
68 	if (!bgrt_image) {
69 		pr_notice("Ignoring BGRT: failed to map image memory\n");
70 		return -ENOMEM;
71 	}
72 
73 	bin_attr_image.private = bgrt_image;
74 	bin_attr_image.size = bgrt_image_size;
75 
76 	bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj);
77 	if (!bgrt_kobj) {
78 		ret = -EINVAL;
79 		goto out_memmap;
80 	}
81 
82 	ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group);
83 	if (ret)
84 		goto out_kobject;
85 
86 	return 0;
87 
88 out_kobject:
89 	kobject_put(bgrt_kobj);
90 out_memmap:
91 	memunmap(bgrt_image);
92 	return ret;
93 }
94 device_initcall(bgrt_init);
95