1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2013 Red Hat, Inc., Dave Young <dyoung@redhat.com>
4 */
5
6 #include <linux/string.h>
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/types.h>
10 #include <linux/efi.h>
11 #include <linux/slab.h>
12
13 #include <asm/efi.h>
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
28 static inline struct map_attribute *to_map_attr(struct attribute *attr)
29 {
30 return container_of(attr, struct map_attribute, attr);
31 }
32
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
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
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 ATTRIBUTE_GROUPS(def);
83
84 static const struct sysfs_ops map_attr_ops = {
85 .show = map_attr_show,
86 };
87
88 static void map_release(struct kobject *kobj)
89 {
90 struct efi_runtime_map_entry *entry;
91
92 entry = to_map_entry(kobj);
93 kfree(entry);
94 }
95
96 static const struct kobj_type __refconst map_ktype = {
97 .sysfs_ops = &map_attr_ops,
98 .default_groups = def_groups,
99 .release = map_release,
100 };
101
102 static struct kset *map_kset;
103
104 static struct efi_runtime_map_entry *
105 add_sysfs_runtime_map_entry(struct kobject *kobj, int nr,
106 efi_memory_desc_t *md)
107 {
108 int ret;
109 struct efi_runtime_map_entry *entry;
110
111 if (!map_kset) {
112 map_kset = kset_create_and_add("runtime-map", NULL, kobj);
113 if (!map_kset)
114 return ERR_PTR(-ENOMEM);
115 }
116
117 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
118 if (!entry) {
119 kset_unregister(map_kset);
120 map_kset = NULL;
121 return ERR_PTR(-ENOMEM);
122 }
123
124 memcpy(&entry->md, md, sizeof(efi_memory_desc_t));
125
126 kobject_init(&entry->kobj, &map_ktype);
127 entry->kobj.kset = map_kset;
128 ret = kobject_add(&entry->kobj, NULL, "%d", nr);
129 if (ret) {
130 kobject_put(&entry->kobj);
131 kset_unregister(map_kset);
132 map_kset = NULL;
133 return ERR_PTR(ret);
134 }
135
136 return entry;
137 }
138
139 int efi_get_runtime_map_size(void)
140 {
141 return efi.memmap.nr_map * efi.memmap.desc_size;
142 }
143
144 int efi_get_runtime_map_desc_size(void)
145 {
146 return efi.memmap.desc_size;
147 }
148
149 int efi_runtime_map_copy(void *buf, size_t bufsz)
150 {
151 size_t sz = efi_get_runtime_map_size();
152
153 if (sz > bufsz)
154 sz = bufsz;
155
156 memcpy(buf, efi.memmap.map, sz);
157 return 0;
158 }
159
160 static int __init efi_runtime_map_init(void)
161 {
162 int i, j, ret = 0;
163 struct efi_runtime_map_entry *entry;
164 efi_memory_desc_t *md;
165
166 if (!efi_enabled(EFI_MEMMAP) || !efi_kobj)
167 return 0;
168
169 map_entries = kcalloc(efi.memmap.nr_map, sizeof(entry), GFP_KERNEL);
170 if (!map_entries) {
171 ret = -ENOMEM;
172 goto out;
173 }
174
175 i = 0;
176 for_each_efi_memory_desc(md) {
177 entry = add_sysfs_runtime_map_entry(efi_kobj, i, md);
178 if (IS_ERR(entry)) {
179 ret = PTR_ERR(entry);
180 goto out_add_entry;
181 }
182 *(map_entries + i++) = entry;
183 }
184
185 return 0;
186 out_add_entry:
187 for (j = i - 1; j >= 0; j--) {
188 entry = *(map_entries + j);
189 kobject_put(&entry->kobj);
190 }
191 out:
192 return ret;
193 }
194 subsys_initcall_sync(efi_runtime_map_init);
195
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