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11#define pr_fmt(fmt) "ACPI configfs: " fmt
12
13#include <linux/init.h>
14#include <linux/module.h>
15#include <linux/configfs.h>
16#include <linux/acpi.h>
17#include <linux/kernel.h>
18
19static struct config_group *acpi_table_group;
20
21struct acpi_table {
22 struct config_item cfg;
23 struct acpi_table_header *header;
24 u32 index;
25};
26
27static ssize_t acpi_table_aml_write(struct config_item *cfg,
28 const void *data, size_t size)
29{
30 const struct acpi_table_header *header = data;
31 struct acpi_table *table;
32 int ret = kernel_is_locked_down("Modifying ACPI tables");
33
34 if (ret)
35 return ret;
36
37 table = container_of(cfg, struct acpi_table, cfg);
38
39 if (table->header) {
40 pr_err("table already loaded\n");
41 return -EBUSY;
42 }
43
44 if (header->length != size) {
45 pr_err("invalid table length\n");
46 return -EINVAL;
47 }
48
49 if (memcmp(header->signature, ACPI_SIG_SSDT, 4)) {
50 pr_err("invalid table signature\n");
51 return -EINVAL;
52 }
53
54 table = container_of(cfg, struct acpi_table, cfg);
55
56 table->header = kmemdup(header, header->length, GFP_KERNEL);
57 if (!table->header)
58 return -ENOMEM;
59
60 ret = acpi_load_table(table->header, &table->index);
61 if (ret) {
62 kfree(table->header);
63 table->header = NULL;
64 }
65
66 return ret;
67}
68
69static inline struct acpi_table_header *get_header(struct config_item *cfg)
70{
71 struct acpi_table *table = container_of(cfg, struct acpi_table, cfg);
72
73 if (!table->header)
74 pr_err("table not loaded\n");
75
76 return table->header;
77}
78
79static ssize_t acpi_table_aml_read(struct config_item *cfg,
80 void *data, size_t size)
81{
82 struct acpi_table_header *h = get_header(cfg);
83
84 if (!h)
85 return -EINVAL;
86
87 if (data)
88 memcpy(data, h, h->length);
89
90 return h->length;
91}
92
93#define MAX_ACPI_TABLE_SIZE (128 * 1024)
94
95CONFIGFS_BIN_ATTR(acpi_table_, aml, NULL, MAX_ACPI_TABLE_SIZE);
96
97static struct configfs_bin_attribute *acpi_table_bin_attrs[] = {
98 &acpi_table_attr_aml,
99 NULL,
100};
101
102static ssize_t acpi_table_signature_show(struct config_item *cfg, char *str)
103{
104 struct acpi_table_header *h = get_header(cfg);
105
106 if (!h)
107 return -EINVAL;
108
109 return sprintf(str, "%.*s\n", ACPI_NAMESEG_SIZE, h->signature);
110}
111
112static ssize_t acpi_table_length_show(struct config_item *cfg, char *str)
113{
114 struct acpi_table_header *h = get_header(cfg);
115
116 if (!h)
117 return -EINVAL;
118
119 return sprintf(str, "%d\n", h->length);
120}
121
122static ssize_t acpi_table_revision_show(struct config_item *cfg, char *str)
123{
124 struct acpi_table_header *h = get_header(cfg);
125
126 if (!h)
127 return -EINVAL;
128
129 return sprintf(str, "%d\n", h->revision);
130}
131
132static ssize_t acpi_table_oem_id_show(struct config_item *cfg, char *str)
133{
134 struct acpi_table_header *h = get_header(cfg);
135
136 if (!h)
137 return -EINVAL;
138
139 return sprintf(str, "%.*s\n", ACPI_OEM_ID_SIZE, h->oem_id);
140}
141
142static ssize_t acpi_table_oem_table_id_show(struct config_item *cfg, char *str)
143{
144 struct acpi_table_header *h = get_header(cfg);
145
146 if (!h)
147 return -EINVAL;
148
149 return sprintf(str, "%.*s\n", ACPI_OEM_TABLE_ID_SIZE, h->oem_table_id);
150}
151
152static ssize_t acpi_table_oem_revision_show(struct config_item *cfg, char *str)
153{
154 struct acpi_table_header *h = get_header(cfg);
155
156 if (!h)
157 return -EINVAL;
158
159 return sprintf(str, "%d\n", h->oem_revision);
160}
161
162static ssize_t acpi_table_asl_compiler_id_show(struct config_item *cfg,
163 char *str)
164{
165 struct acpi_table_header *h = get_header(cfg);
166
167 if (!h)
168 return -EINVAL;
169
170 return sprintf(str, "%.*s\n", ACPI_NAMESEG_SIZE, h->asl_compiler_id);
171}
172
173static ssize_t acpi_table_asl_compiler_revision_show(struct config_item *cfg,
174 char *str)
175{
176 struct acpi_table_header *h = get_header(cfg);
177
178 if (!h)
179 return -EINVAL;
180
181 return sprintf(str, "%d\n", h->asl_compiler_revision);
182}
183
184CONFIGFS_ATTR_RO(acpi_table_, signature);
185CONFIGFS_ATTR_RO(acpi_table_, length);
186CONFIGFS_ATTR_RO(acpi_table_, revision);
187CONFIGFS_ATTR_RO(acpi_table_, oem_id);
188CONFIGFS_ATTR_RO(acpi_table_, oem_table_id);
189CONFIGFS_ATTR_RO(acpi_table_, oem_revision);
190CONFIGFS_ATTR_RO(acpi_table_, asl_compiler_id);
191CONFIGFS_ATTR_RO(acpi_table_, asl_compiler_revision);
192
193static struct configfs_attribute *acpi_table_attrs[] = {
194 &acpi_table_attr_signature,
195 &acpi_table_attr_length,
196 &acpi_table_attr_revision,
197 &acpi_table_attr_oem_id,
198 &acpi_table_attr_oem_table_id,
199 &acpi_table_attr_oem_revision,
200 &acpi_table_attr_asl_compiler_id,
201 &acpi_table_attr_asl_compiler_revision,
202 NULL,
203};
204
205static const struct config_item_type acpi_table_type = {
206 .ct_owner = THIS_MODULE,
207 .ct_bin_attrs = acpi_table_bin_attrs,
208 .ct_attrs = acpi_table_attrs,
209};
210
211static struct config_item *acpi_table_make_item(struct config_group *group,
212 const char *name)
213{
214 struct acpi_table *table;
215
216 table = kzalloc(sizeof(*table), GFP_KERNEL);
217 if (!table)
218 return ERR_PTR(-ENOMEM);
219
220 config_item_init_type_name(&table->cfg, name, &acpi_table_type);
221 return &table->cfg;
222}
223
224static void acpi_table_drop_item(struct config_group *group,
225 struct config_item *cfg)
226{
227 struct acpi_table *table = container_of(cfg, struct acpi_table, cfg);
228
229 pr_debug("Host-directed Dynamic ACPI Table Unload\n");
230 acpi_unload_table(table->index);
231 config_item_put(cfg);
232}
233
234static struct configfs_group_operations acpi_table_group_ops = {
235 .make_item = acpi_table_make_item,
236 .drop_item = acpi_table_drop_item,
237};
238
239static const struct config_item_type acpi_tables_type = {
240 .ct_owner = THIS_MODULE,
241 .ct_group_ops = &acpi_table_group_ops,
242};
243
244static const struct config_item_type acpi_root_group_type = {
245 .ct_owner = THIS_MODULE,
246};
247
248static struct configfs_subsystem acpi_configfs = {
249 .su_group = {
250 .cg_item = {
251 .ci_namebuf = "acpi",
252 .ci_type = &acpi_root_group_type,
253 },
254 },
255 .su_mutex = __MUTEX_INITIALIZER(acpi_configfs.su_mutex),
256};
257
258static int __init acpi_configfs_init(void)
259{
260 int ret;
261 struct config_group *root = &acpi_configfs.su_group;
262
263 config_group_init(root);
264
265 ret = configfs_register_subsystem(&acpi_configfs);
266 if (ret)
267 return ret;
268
269 acpi_table_group = configfs_register_default_group(root, "table",
270 &acpi_tables_type);
271 if (IS_ERR(acpi_table_group)) {
272 configfs_unregister_subsystem(&acpi_configfs);
273 return PTR_ERR(acpi_table_group);
274 }
275
276 return 0;
277}
278module_init(acpi_configfs_init);
279
280static void __exit acpi_configfs_exit(void)
281{
282 configfs_unregister_default_group(acpi_table_group);
283 configfs_unregister_subsystem(&acpi_configfs);
284}
285module_exit(acpi_configfs_exit);
286
287MODULE_AUTHOR("Octavian Purdila <octavian.purdila@intel.com>");
288MODULE_DESCRIPTION("ACPI configfs support");
289MODULE_LICENSE("GPL v2");
290
