1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/drivers/efi/runtime-map.c
4 * Copyright (C) 2013 Red Hat, Inc., Dave Young <dyoung@redhat.com>
5 */
6
7 #include <linux/string.h>
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/types.h>
11 #include <linux/efi.h>
12 #include <linux/slab.h>
13
14 #include <asm/setup.h>
15
16 struct efi_runtime_map_entry {
17 efi_memory_desc_t md;
18 struct kobject kobj; /* kobject for each entry */
19 };
20
21 static struct efi_runtime_map_entry **map_entries;
22
23 struct map_attribute {
24 struct attribute attr;
25 ssize_t (*show)(struct efi_runtime_map_entry *entry, char *buf);
26 };
27
to_map_attr(struct attribute * attr)28 static inline struct map_attribute *to_map_attr(struct attribute *attr)
29 {
30 return container_of(attr, struct map_attribute, attr);
31 }
32
type_show(struct efi_runtime_map_entry * entry,char * buf)33 static ssize_t type_show(struct efi_runtime_map_entry *entry, char *buf)
34 {
35 return snprintf(buf, PAGE_SIZE, "0x%x\n", entry->md.type);
36 }
37
38 #define EFI_RUNTIME_FIELD(var) entry->md.var
39
40 #define EFI_RUNTIME_U64_ATTR_SHOW(name) \
41 static ssize_t name##_show(struct efi_runtime_map_entry *entry, char *buf) \
42 { \
43 return snprintf(buf, PAGE_SIZE, "0x%llx\n", EFI_RUNTIME_FIELD(name)); \
44 }
45
46 EFI_RUNTIME_U64_ATTR_SHOW(phys_addr);
47 EFI_RUNTIME_U64_ATTR_SHOW(virt_addr);
48 EFI_RUNTIME_U64_ATTR_SHOW(num_pages);
49 EFI_RUNTIME_U64_ATTR_SHOW(attribute);
50
to_map_entry(struct kobject * kobj)51 static inline struct efi_runtime_map_entry *to_map_entry(struct kobject *kobj)
52 {
53 return container_of(kobj, struct efi_runtime_map_entry, kobj);
54 }
55
map_attr_show(struct kobject * kobj,struct attribute * attr,char * buf)56 static ssize_t map_attr_show(struct kobject *kobj, struct attribute *attr,
57 char *buf)
58 {
59 struct efi_runtime_map_entry *entry = to_map_entry(kobj);
60 struct map_attribute *map_attr = to_map_attr(attr);
61
62 return map_attr->show(entry, buf);
63 }
64
65 static struct map_attribute map_type_attr = __ATTR_RO_MODE(type, 0400);
66 static struct map_attribute map_phys_addr_attr = __ATTR_RO_MODE(phys_addr, 0400);
67 static struct map_attribute map_virt_addr_attr = __ATTR_RO_MODE(virt_addr, 0400);
68 static struct map_attribute map_num_pages_attr = __ATTR_RO_MODE(num_pages, 0400);
69 static struct map_attribute map_attribute_attr = __ATTR_RO_MODE(attribute, 0400);
70
71 /*
72 * These are default attributes that are added for every memmap entry.
73 */
74 static struct attribute *def_attrs[] = {
75 &map_type_attr.attr,
76 &map_phys_addr_attr.attr,
77 &map_virt_addr_attr.attr,
78 &map_num_pages_attr.attr,
79 &map_attribute_attr.attr,
80 NULL
81 };
82
83 static const struct sysfs_ops map_attr_ops = {
84 .show = map_attr_show,
85 };
86
map_release(struct kobject * kobj)87 static void map_release(struct kobject *kobj)
88 {
89 struct efi_runtime_map_entry *entry;
90
91 entry = to_map_entry(kobj);
92 kfree(entry);
93 }
94
95 static struct kobj_type __refdata map_ktype = {
96 .sysfs_ops = &map_attr_ops,
97 .default_attrs = def_attrs,
98 .release = map_release,
99 };
100
101 static struct kset *map_kset;
102
103 static struct efi_runtime_map_entry *
add_sysfs_runtime_map_entry(struct kobject * kobj,int nr,efi_memory_desc_t * md)104 add_sysfs_runtime_map_entry(struct kobject *kobj, int nr,
105 efi_memory_desc_t *md)
106 {
107 int ret;
108 struct efi_runtime_map_entry *entry;
109
110 if (!map_kset) {
111 map_kset = kset_create_and_add("runtime-map", NULL, kobj);
112 if (!map_kset)
113 return ERR_PTR(-ENOMEM);
114 }
115
116 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
117 if (!entry) {
118 kset_unregister(map_kset);
119 map_kset = NULL;
120 return ERR_PTR(-ENOMEM);
121 }
122
123 memcpy(&entry->md, md, sizeof(efi_memory_desc_t));
124
125 kobject_init(&entry->kobj, &map_ktype);
126 entry->kobj.kset = map_kset;
127 ret = kobject_add(&entry->kobj, NULL, "%d", nr);
128 if (ret) {
129 kobject_put(&entry->kobj);
130 kset_unregister(map_kset);
131 map_kset = NULL;
132 return ERR_PTR(ret);
133 }
134
135 return entry;
136 }
137
efi_get_runtime_map_size(void)138 int efi_get_runtime_map_size(void)
139 {
140 return efi.memmap.nr_map * efi.memmap.desc_size;
141 }
142
efi_get_runtime_map_desc_size(void)143 int efi_get_runtime_map_desc_size(void)
144 {
145 return efi.memmap.desc_size;
146 }
147
efi_runtime_map_copy(void * buf,size_t bufsz)148 int efi_runtime_map_copy(void *buf, size_t bufsz)
149 {
150 size_t sz = efi_get_runtime_map_size();
151
152 if (sz > bufsz)
153 sz = bufsz;
154
155 memcpy(buf, efi.memmap.map, sz);
156 return 0;
157 }
158
efi_runtime_map_init(struct kobject * efi_kobj)159 int __init efi_runtime_map_init(struct kobject *efi_kobj)
160 {
161 int i, j, ret = 0;
162 struct efi_runtime_map_entry *entry;
163 efi_memory_desc_t *md;
164
165 if (!efi_enabled(EFI_MEMMAP))
166 return 0;
167
168 map_entries = kcalloc(efi.memmap.nr_map, sizeof(entry), GFP_KERNEL);
169 if (!map_entries) {
170 ret = -ENOMEM;
171 goto out;
172 }
173
174 i = 0;
175 for_each_efi_memory_desc(md) {
176 entry = add_sysfs_runtime_map_entry(efi_kobj, i, md);
177 if (IS_ERR(entry)) {
178 ret = PTR_ERR(entry);
179 goto out_add_entry;
180 }
181 *(map_entries + i++) = entry;
182 }
183
184 return 0;
185 out_add_entry:
186 for (j = i - 1; j >= 0; j--) {
187 entry = *(map_entries + j);
188 kobject_put(&entry->kobj);
189 }
190 out:
191 return ret;
192 }
193