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 ssize_t image_read(struct file *file, struct kobject *kobj, 33 struct bin_attribute *attr, char *buf, loff_t off, size_t count) 34 { 35 memcpy(buf, attr->private + off, count); 36 return count; 37 } 38 39 static BIN_ATTR_RO(image, 0); /* size gets filled in later */ 40 41 static struct attribute *bgrt_attributes[] = { 42 &bgrt_attr_version.attr, 43 &bgrt_attr_status.attr, 44 &bgrt_attr_type.attr, 45 &bgrt_attr_xoffset.attr, 46 &bgrt_attr_yoffset.attr, 47 NULL, 48 }; 49 50 static struct bin_attribute *bgrt_bin_attributes[] = { 51 &bin_attr_image, 52 NULL, 53 }; 54 55 static const struct attribute_group bgrt_attribute_group = { 56 .attrs = bgrt_attributes, 57 .bin_attrs = bgrt_bin_attributes, 58 }; 59 60 int __init acpi_parse_bgrt(struct acpi_table_header *table) 61 { 62 efi_bgrt_init(table); 63 return 0; 64 } 65 66 static int __init bgrt_init(void) 67 { 68 int ret; 69 70 if (!bgrt_tab.image_address) 71 return -ENODEV; 72 73 bgrt_image = memremap(bgrt_tab.image_address, bgrt_image_size, 74 MEMREMAP_WB); 75 if (!bgrt_image) { 76 pr_notice("Ignoring BGRT: failed to map image memory\n"); 77 return -ENOMEM; 78 } 79 80 bin_attr_image.private = bgrt_image; 81 bin_attr_image.size = bgrt_image_size; 82 83 bgrt_kobj = kobject_create_and_add("bgrt", acpi_kobj); 84 if (!bgrt_kobj) { 85 ret = -EINVAL; 86 goto out_memmap; 87 } 88 89 ret = sysfs_create_group(bgrt_kobj, &bgrt_attribute_group); 90 if (ret) 91 goto out_kobject; 92 93 return 0; 94 95 out_kobject: 96 kobject_put(bgrt_kobj); 97 out_memmap: 98 memunmap(bgrt_image); 99 return ret; 100 } 101 device_initcall(bgrt_init); 102