1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * ACPI configfs support 4 * 5 * Copyright (c) 2016 Intel Corporation 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 16 #include "acpica/accommon.h" 17 #include "acpica/actables.h" 18 19 static struct config_group *acpi_table_group; 20 21 struct acpi_table { 22 struct config_item cfg; 23 struct acpi_table_header *header; 24 u32 index; 25 }; 26 27 static 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 = security_locked_down(LOCKDOWN_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 69 static 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 79 static 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 95 CONFIGFS_BIN_ATTR(acpi_table_, aml, NULL, MAX_ACPI_TABLE_SIZE); 96 97 static struct configfs_bin_attribute *acpi_table_bin_attrs[] = { 98 &acpi_table_attr_aml, 99 NULL, 100 }; 101 102 static 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 } 111 112 static 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 } 121 122 static 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 } 131 132 static 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 } 141 142 static 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 } 151 152 static 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 } 161 162 static 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 } 172 173 static 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 } 183 184 CONFIGFS_ATTR_RO(acpi_table_, signature); 185 CONFIGFS_ATTR_RO(acpi_table_, length); 186 CONFIGFS_ATTR_RO(acpi_table_, revision); 187 CONFIGFS_ATTR_RO(acpi_table_, oem_id); 188 CONFIGFS_ATTR_RO(acpi_table_, oem_table_id); 189 CONFIGFS_ATTR_RO(acpi_table_, oem_revision); 190 CONFIGFS_ATTR_RO(acpi_table_, asl_compiler_id); 191 CONFIGFS_ATTR_RO(acpi_table_, asl_compiler_revision); 192 193 static 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 }; 204 205 static 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 }; 210 211 static 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 } 223 224 static 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 ACPI_INFO(("Host-directed Dynamic ACPI Table Unload")); 230 acpi_unload_table(table->index); 231 config_item_put(cfg); 232 } 233 234 static struct configfs_group_operations acpi_table_group_ops = { 235 .make_item = acpi_table_make_item, 236 .drop_item = acpi_table_drop_item, 237 }; 238 239 static const struct config_item_type acpi_tables_type = { 240 .ct_owner = THIS_MODULE, 241 .ct_group_ops = &acpi_table_group_ops, 242 }; 243 244 static const struct config_item_type acpi_root_group_type = { 245 .ct_owner = THIS_MODULE, 246 }; 247 248 static 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 }; 257 258 static 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 return PTR_ERR_OR_ZERO(acpi_table_group); 272 } 273 module_init(acpi_configfs_init); 274 275 static void __exit acpi_configfs_exit(void) 276 { 277 configfs_unregister_default_group(acpi_table_group); 278 configfs_unregister_subsystem(&acpi_configfs); 279 } 280 module_exit(acpi_configfs_exit); 281 282 MODULE_AUTHOR("Octavian Purdila <octavian.purdila@intel.com>"); 283 MODULE_DESCRIPTION("ACPI configfs support"); 284 MODULE_LICENSE("GPL v2"); 285