1 /*
2 * linux/drivers/efi/runtime-map.c
3 * Copyright (C) 2013 Red Hat, Inc., Dave Young <dyoung@redhat.com>
4 *
5 * This file is released under the GPLv2.
6 */
7
8 #include <linux/string.h>
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/types.h>
12 #include <linux/efi.h>
13 #include <linux/slab.h>
14
15 #include <asm/setup.h>
16
17 static void *efi_runtime_map;
18 static int nr_efi_runtime_map;
19 static u32 efi_memdesc_size;
20
21 struct efi_runtime_map_entry {
22 efi_memory_desc_t md;
23 struct kobject kobj; /* kobject for each entry */
24 };
25
26 static struct efi_runtime_map_entry **map_entries;
27
28 struct map_attribute {
29 struct attribute attr;
30 ssize_t (*show)(struct efi_runtime_map_entry *entry, char *buf);
31 };
32
to_map_attr(struct attribute * attr)33 static inline struct map_attribute *to_map_attr(struct attribute *attr)
34 {
35 return container_of(attr, struct map_attribute, attr);
36 }
37
type_show(struct efi_runtime_map_entry * entry,char * buf)38 static ssize_t type_show(struct efi_runtime_map_entry *entry, char *buf)
39 {
40 return snprintf(buf, PAGE_SIZE, "0x%x\n", entry->md.type);
41 }
42
43 #define EFI_RUNTIME_FIELD(var) entry->md.var
44
45 #define EFI_RUNTIME_U64_ATTR_SHOW(name) \
46 static ssize_t name##_show(struct efi_runtime_map_entry *entry, char *buf) \
47 { \
48 return snprintf(buf, PAGE_SIZE, "0x%llx\n", EFI_RUNTIME_FIELD(name)); \
49 }
50
51 EFI_RUNTIME_U64_ATTR_SHOW(phys_addr);
52 EFI_RUNTIME_U64_ATTR_SHOW(virt_addr);
53 EFI_RUNTIME_U64_ATTR_SHOW(num_pages);
54 EFI_RUNTIME_U64_ATTR_SHOW(attribute);
55
to_map_entry(struct kobject * kobj)56 static inline struct efi_runtime_map_entry *to_map_entry(struct kobject *kobj)
57 {
58 return container_of(kobj, struct efi_runtime_map_entry, kobj);
59 }
60
map_attr_show(struct kobject * kobj,struct attribute * attr,char * buf)61 static ssize_t map_attr_show(struct kobject *kobj, struct attribute *attr,
62 char *buf)
63 {
64 struct efi_runtime_map_entry *entry = to_map_entry(kobj);
65 struct map_attribute *map_attr = to_map_attr(attr);
66
67 return map_attr->show(entry, buf);
68 }
69
70 static struct map_attribute map_type_attr = __ATTR_RO_MODE(type, 0400);
71 static struct map_attribute map_phys_addr_attr = __ATTR_RO_MODE(phys_addr, 0400);
72 static struct map_attribute map_virt_addr_attr = __ATTR_RO_MODE(virt_addr, 0400);
73 static struct map_attribute map_num_pages_attr = __ATTR_RO_MODE(num_pages, 0400);
74 static struct map_attribute map_attribute_attr = __ATTR_RO_MODE(attribute, 0400);
75
76 /*
77 * These are default attributes that are added for every memmap entry.
78 */
79 static struct attribute *def_attrs[] = {
80 &map_type_attr.attr,
81 &map_phys_addr_attr.attr,
82 &map_virt_addr_attr.attr,
83 &map_num_pages_attr.attr,
84 &map_attribute_attr.attr,
85 NULL
86 };
87
88 static const struct sysfs_ops map_attr_ops = {
89 .show = map_attr_show,
90 };
91
map_release(struct kobject * kobj)92 static void map_release(struct kobject *kobj)
93 {
94 struct efi_runtime_map_entry *entry;
95
96 entry = to_map_entry(kobj);
97 kfree(entry);
98 }
99
100 static struct kobj_type __refdata map_ktype = {
101 .sysfs_ops = &map_attr_ops,
102 .default_attrs = def_attrs,
103 .release = map_release,
104 };
105
106 static struct kset *map_kset;
107
108 static struct efi_runtime_map_entry *
add_sysfs_runtime_map_entry(struct kobject * kobj,int nr)109 add_sysfs_runtime_map_entry(struct kobject *kobj, int nr)
110 {
111 int ret;
112 struct efi_runtime_map_entry *entry;
113
114 if (!map_kset) {
115 map_kset = kset_create_and_add("runtime-map", NULL, kobj);
116 if (!map_kset)
117 return ERR_PTR(-ENOMEM);
118 }
119
120 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
121 if (!entry) {
122 kset_unregister(map_kset);
123 return entry;
124 }
125
126 memcpy(&entry->md, efi_runtime_map + nr * efi_memdesc_size,
127 sizeof(efi_memory_desc_t));
128
129 kobject_init(&entry->kobj, &map_ktype);
130 entry->kobj.kset = map_kset;
131 ret = kobject_add(&entry->kobj, NULL, "%d", nr);
132 if (ret) {
133 kobject_put(&entry->kobj);
134 kset_unregister(map_kset);
135 return ERR_PTR(ret);
136 }
137
138 return entry;
139 }
140
efi_get_runtime_map_size(void)141 int efi_get_runtime_map_size(void)
142 {
143 return nr_efi_runtime_map * efi_memdesc_size;
144 }
145
efi_get_runtime_map_desc_size(void)146 int efi_get_runtime_map_desc_size(void)
147 {
148 return efi_memdesc_size;
149 }
150
efi_runtime_map_copy(void * buf,size_t bufsz)151 int efi_runtime_map_copy(void *buf, size_t bufsz)
152 {
153 size_t sz = efi_get_runtime_map_size();
154
155 if (sz > bufsz)
156 sz = bufsz;
157
158 memcpy(buf, efi_runtime_map, sz);
159 return 0;
160 }
161
efi_runtime_map_setup(void * map,int nr_entries,u32 desc_size)162 void efi_runtime_map_setup(void *map, int nr_entries, u32 desc_size)
163 {
164 efi_runtime_map = map;
165 nr_efi_runtime_map = nr_entries;
166 efi_memdesc_size = desc_size;
167 }
168
efi_runtime_map_init(struct kobject * efi_kobj)169 int __init efi_runtime_map_init(struct kobject *efi_kobj)
170 {
171 int i, j, ret = 0;
172 struct efi_runtime_map_entry *entry;
173
174 if (!efi_runtime_map)
175 return 0;
176
177 map_entries = kzalloc(nr_efi_runtime_map * sizeof(entry), GFP_KERNEL);
178 if (!map_entries) {
179 ret = -ENOMEM;
180 goto out;
181 }
182
183 for (i = 0; i < nr_efi_runtime_map; i++) {
184 entry = add_sysfs_runtime_map_entry(efi_kobj, i);
185 if (IS_ERR(entry)) {
186 ret = PTR_ERR(entry);
187 goto out_add_entry;
188 }
189 *(map_entries + i) = entry;
190 }
191
192 return 0;
193 out_add_entry:
194 for (j = i - 1; j >= 0; j--) {
195 entry = *(map_entries + j);
196 kobject_put(&entry->kobj);
197 }
198 if (map_kset)
199 kset_unregister(map_kset);
200 out:
201 return ret;
202 }
203