1
2
3
4
5
6
7
8#define pr_fmt(fmt) "ACPI configfs: " fmt
9
10#include <linux/init.h>
11#include <linux/module.h>
12#include <linux/configfs.h>
13#include <linux/acpi.h>
14#include <linux/security.h>
15
16static struct config_group *acpi_table_group;
17
18struct acpi_table {
19 struct config_item cfg;
20 struct acpi_table_header *header;
21 u32 index;
22};
23
24static ssize_t acpi_table_aml_write(struct config_item *cfg,
25 const void *data, size_t size)
26{
27 const struct acpi_table_header *header = data;
28 struct acpi_table *table;
29 int ret = security_locked_down(LOCKDOWN_ACPI_TABLES);
30
31 if (ret)
32 return ret;
33
34 table = container_of(cfg, struct acpi_table, cfg);
35
36 if (table->header) {
37 pr_err("table already loaded\n");
38 return -EBUSY;
39 }
40
41 if (header->length != size) {
42 pr_err("invalid table length\n");
43 return -EINVAL;
44 }
45
46 if (memcmp(header->signature, ACPI_SIG_SSDT, 4)) {
47 pr_err("invalid table signature\n");
48 return -EINVAL;
49 }
50
51 table = container_of(cfg, struct acpi_table, cfg);
52
53 table->header = kmemdup(header, header->length, GFP_KERNEL);
54 if (!table->header)
55 return -ENOMEM;
56
57 ret = acpi_load_table(table->header, &table->index);
58 if (ret) {
59 kfree(table->header);
60 table->header = NULL;
61 }
62
63 return ret;
64}
65
66static inline struct acpi_table_header *get_header(struct config_item *cfg)
67{
68 struct acpi_table *table = container_of(cfg, struct acpi_table, cfg);
69
70 if (!table->header)
71 pr_err("table not loaded\n");
72
73 return table->header ?: ERR_PTR(-EINVAL);
74}
75
76static ssize_t acpi_table_aml_read(struct config_item *cfg,
77 void *data, size_t size)
78{
79 struct acpi_table_header *h = get_header(cfg);
80
81 if (IS_ERR(h))
82 return PTR_ERR(h);
83
84 if (data)
85 memcpy(data, h, h->length);
86
87 return h->length;
88}
89
90#define MAX_ACPI_TABLE_SIZE (128 * 1024)
91
92CONFIGFS_BIN_ATTR(acpi_table_, aml, NULL, MAX_ACPI_TABLE_SIZE);
93
94static struct configfs_bin_attribute *acpi_table_bin_attrs[] = {
95 &acpi_table_attr_aml,
96 NULL,
97};
98
99static ssize_t acpi_table_signature_show(struct config_item *cfg, char *str)
100{
101 struct acpi_table_header *h = get_header(cfg);
102
103 if (IS_ERR(h))
104 return PTR_ERR(h);
105
106 return sysfs_emit(str, "%.*s\n", ACPI_NAMESEG_SIZE, h->signature);
107}
108
109static ssize_t acpi_table_length_show(struct config_item *cfg, char *str)
110{
111 struct acpi_table_header *h = get_header(cfg);
112
113 if (IS_ERR(h))
114 return PTR_ERR(h);
115
116 return sysfs_emit(str, "%d\n", h->length);
117}
118
119static ssize_t acpi_table_revision_show(struct config_item *cfg, char *str)
120{
121 struct acpi_table_header *h = get_header(cfg);
122
123 if (IS_ERR(h))
124 return PTR_ERR(h);
125
126 return sysfs_emit(str, "%d\n", h->revision);
127}
128
129static ssize_t acpi_table_oem_id_show(struct config_item *cfg, char *str)
130{
131 struct acpi_table_header *h = get_header(cfg);
132
133 if (IS_ERR(h))
134 return PTR_ERR(h);
135
136 return sysfs_emit(str, "%.*s\n", ACPI_OEM_ID_SIZE, h->oem_id);
137}
138
139static ssize_t acpi_table_oem_table_id_show(struct config_item *cfg, char *str)
140{
141 struct acpi_table_header *h = get_header(cfg);
142
143 if (IS_ERR(h))
144 return PTR_ERR(h);
145
146 return sysfs_emit(str, "%.*s\n", ACPI_OEM_TABLE_ID_SIZE, h->oem_table_id);
147}
148
149static ssize_t acpi_table_oem_revision_show(struct config_item *cfg, char *str)
150{
151 struct acpi_table_header *h = get_header(cfg);
152
153 if (IS_ERR(h))
154 return PTR_ERR(h);
155
156 return sysfs_emit(str, "%d\n", h->oem_revision);
157}
158
159static ssize_t acpi_table_asl_compiler_id_show(struct config_item *cfg,
160 char *str)
161{
162 struct acpi_table_header *h = get_header(cfg);
163
164 if (IS_ERR(h))
165 return PTR_ERR(h);
166
167 return sysfs_emit(str, "%.*s\n", ACPI_NAMESEG_SIZE, h->asl_compiler_id);
168}
169
170static ssize_t acpi_table_asl_compiler_revision_show(struct config_item *cfg,
171 char *str)
172{
173 struct acpi_table_header *h = get_header(cfg);
174
175 if (IS_ERR(h))
176 return PTR_ERR(h);
177
178 return sysfs_emit(str, "%d\n", h->asl_compiler_revision);
179}
180
181CONFIGFS_ATTR_RO(acpi_table_, signature);
182CONFIGFS_ATTR_RO(acpi_table_, length);
183CONFIGFS_ATTR_RO(acpi_table_, revision);
184CONFIGFS_ATTR_RO(acpi_table_, oem_id);
185CONFIGFS_ATTR_RO(acpi_table_, oem_table_id);
186CONFIGFS_ATTR_RO(acpi_table_, oem_revision);
187CONFIGFS_ATTR_RO(acpi_table_, asl_compiler_id);
188CONFIGFS_ATTR_RO(acpi_table_, asl_compiler_revision);
189
190static struct configfs_attribute *acpi_table_attrs[] = {
191 &acpi_table_attr_signature,
192 &acpi_table_attr_length,
193 &acpi_table_attr_revision,
194 &acpi_table_attr_oem_id,
195 &acpi_table_attr_oem_table_id,
196 &acpi_table_attr_oem_revision,
197 &acpi_table_attr_asl_compiler_id,
198 &acpi_table_attr_asl_compiler_revision,
199 NULL,
200};
201
202static const struct config_item_type acpi_table_type = {
203 .ct_owner = THIS_MODULE,
204 .ct_bin_attrs = acpi_table_bin_attrs,
205 .ct_attrs = acpi_table_attrs,
206};
207
208static struct config_item *acpi_table_make_item(struct config_group *group,
209 const char *name)
210{
211 struct acpi_table *table;
212
213 table = kzalloc(sizeof(*table), GFP_KERNEL);
214 if (!table)
215 return ERR_PTR(-ENOMEM);
216
217 config_item_init_type_name(&table->cfg, name, &acpi_table_type);
218 return &table->cfg;
219}
220
221static void acpi_table_drop_item(struct config_group *group,
222 struct config_item *cfg)
223{
224 struct acpi_table *table = container_of(cfg, struct acpi_table, cfg);
225
226 pr_debug("Host-directed Dynamic ACPI Table Unload\n");
227 acpi_unload_table(table->index);
228 config_item_put(cfg);
229}
230
231static struct configfs_group_operations acpi_table_group_ops = {
232 .make_item = acpi_table_make_item,
233 .drop_item = acpi_table_drop_item,
234};
235
236static const struct config_item_type acpi_tables_type = {
237 .ct_owner = THIS_MODULE,
238 .ct_group_ops = &acpi_table_group_ops,
239};
240
241static const struct config_item_type acpi_root_group_type = {
242 .ct_owner = THIS_MODULE,
243};
244
245static struct configfs_subsystem acpi_configfs = {
246 .su_group = {
247 .cg_item = {
248 .ci_namebuf = "acpi",
249 .ci_type = &acpi_root_group_type,
250 },
251 },
252 .su_mutex = __MUTEX_INITIALIZER(acpi_configfs.su_mutex),
253};
254
255static int __init acpi_configfs_init(void)
256{
257 int ret;
258 struct config_group *root = &acpi_configfs.su_group;
259
260 config_group_init(root);
261
262 ret = configfs_register_subsystem(&acpi_configfs);
263 if (ret)
264 return ret;
265
266 acpi_table_group = configfs_register_default_group(root, "table",
267 &acpi_tables_type);
268 if (IS_ERR(acpi_table_group)) {
269 configfs_unregister_subsystem(&acpi_configfs);
270 return PTR_ERR(acpi_table_group);
271 }
272
273 return 0;
274}
275module_init(acpi_configfs_init);
276
277static void __exit acpi_configfs_exit(void)
278{
279 configfs_unregister_default_group(acpi_table_group);
280 configfs_unregister_subsystem(&acpi_configfs);
281}
282module_exit(acpi_configfs_exit);
283
284MODULE_AUTHOR("Octavian Purdila <octavian.purdila@intel.com>");
285MODULE_DESCRIPTION("ACPI configfs support");
286MODULE_LICENSE("GPL v2");
287
