1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Link physical devices with ACPI devices support 4 * 5 * Copyright (c) 2005 David Shaohua Li <shaohua.li@intel.com> 6 * Copyright (c) 2005 Intel Corp. 7 */ 8 9 #define pr_fmt(fmt) "ACPI: " fmt 10 11 #include <linux/acpi_iort.h> 12 #include <linux/export.h> 13 #include <linux/init.h> 14 #include <linux/list.h> 15 #include <linux/device.h> 16 #include <linux/slab.h> 17 #include <linux/rwsem.h> 18 #include <linux/acpi.h> 19 #include <linux/dma-mapping.h> 20 #include <linux/pci.h> 21 #include <linux/pci-acpi.h> 22 #include <linux/platform_device.h> 23 24 #include "internal.h" 25 26 static LIST_HEAD(bus_type_list); 27 static DECLARE_RWSEM(bus_type_sem); 28 29 #define PHYSICAL_NODE_STRING "physical_node" 30 #define PHYSICAL_NODE_NAME_SIZE (sizeof(PHYSICAL_NODE_STRING) + 10) 31 32 int register_acpi_bus_type(struct acpi_bus_type *type) 33 { 34 if (acpi_disabled) 35 return -ENODEV; 36 if (type && type->match && type->find_companion) { 37 down_write(&bus_type_sem); 38 list_add_tail(&type->list, &bus_type_list); 39 up_write(&bus_type_sem); 40 pr_info("bus type %s registered\n", type->name); 41 return 0; 42 } 43 return -ENODEV; 44 } 45 EXPORT_SYMBOL_GPL(register_acpi_bus_type); 46 47 int unregister_acpi_bus_type(struct acpi_bus_type *type) 48 { 49 if (acpi_disabled) 50 return 0; 51 if (type) { 52 down_write(&bus_type_sem); 53 list_del_init(&type->list); 54 up_write(&bus_type_sem); 55 pr_info("bus type %s unregistered\n", type->name); 56 return 0; 57 } 58 return -ENODEV; 59 } 60 EXPORT_SYMBOL_GPL(unregister_acpi_bus_type); 61 62 static struct acpi_bus_type *acpi_get_bus_type(struct device *dev) 63 { 64 struct acpi_bus_type *tmp, *ret = NULL; 65 66 down_read(&bus_type_sem); 67 list_for_each_entry(tmp, &bus_type_list, list) { 68 if (tmp->match(dev)) { 69 ret = tmp; 70 break; 71 } 72 } 73 up_read(&bus_type_sem); 74 return ret; 75 } 76 77 #define FIND_CHILD_MIN_SCORE 1 78 #define FIND_CHILD_MAX_SCORE 2 79 80 static int match_any(struct acpi_device *adev, void *not_used) 81 { 82 return 1; 83 } 84 85 static bool acpi_dev_has_children(struct acpi_device *adev) 86 { 87 return acpi_dev_for_each_child(adev, match_any, NULL) > 0; 88 } 89 90 static int find_child_checks(struct acpi_device *adev, bool check_children) 91 { 92 unsigned long long sta; 93 acpi_status status; 94 95 if (check_children && !acpi_dev_has_children(adev)) 96 return -ENODEV; 97 98 status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta); 99 if (status == AE_NOT_FOUND) 100 return FIND_CHILD_MIN_SCORE; 101 102 if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED)) 103 return -ENODEV; 104 105 /* 106 * If the device has a _HID returning a valid ACPI/PNP device ID, it is 107 * better to make it look less attractive here, so that the other device 108 * with the same _ADR value (that may not have a valid device ID) can be 109 * matched going forward. [This means a second spec violation in a row, 110 * so whatever we do here is best effort anyway.] 111 */ 112 if (adev->pnp.type.platform_id) 113 return FIND_CHILD_MIN_SCORE; 114 115 return FIND_CHILD_MAX_SCORE; 116 } 117 118 struct find_child_walk_data { 119 struct acpi_device *adev; 120 u64 address; 121 int score; 122 bool check_sta; 123 bool check_children; 124 }; 125 126 static int check_one_child(struct acpi_device *adev, void *data) 127 { 128 struct find_child_walk_data *wd = data; 129 int score; 130 131 if (!adev->pnp.type.bus_address || acpi_device_adr(adev) != wd->address) 132 return 0; 133 134 if (!wd->adev) { 135 /* 136 * This is the first matching object, so save it. If it is not 137 * necessary to look for any other matching objects, stop the 138 * search. 139 */ 140 wd->adev = adev; 141 return !(wd->check_sta || wd->check_children); 142 } 143 144 /* 145 * There is more than one matching device object with the same _ADR 146 * value. That really is unexpected, so we are kind of beyond the scope 147 * of the spec here. We have to choose which one to return, though. 148 * 149 * First, get the score for the previously found object and terminate 150 * the walk if it is maximum. 151 */ 152 if (!wd->score) { 153 score = find_child_checks(wd->adev, wd->check_children); 154 if (score == FIND_CHILD_MAX_SCORE) 155 return 1; 156 157 wd->score = score; 158 } 159 /* 160 * Second, if the object that has just been found has a better score, 161 * replace the previously found one with it and terminate the walk if 162 * the new score is maximum. 163 */ 164 score = find_child_checks(adev, wd->check_children); 165 if (score > wd->score) { 166 wd->adev = adev; 167 if (score == FIND_CHILD_MAX_SCORE) 168 return 1; 169 170 wd->score = score; 171 } 172 173 /* Continue, because there may be better matches. */ 174 return 0; 175 } 176 177 static struct acpi_device *acpi_find_child(struct acpi_device *parent, 178 u64 address, bool check_children, 179 bool check_sta) 180 { 181 struct find_child_walk_data wd = { 182 .address = address, 183 .check_children = check_children, 184 .check_sta = check_sta, 185 .adev = NULL, 186 .score = 0, 187 }; 188 189 if (parent) 190 acpi_dev_for_each_child(parent, check_one_child, &wd); 191 192 return wd.adev; 193 } 194 195 struct acpi_device *acpi_find_child_device(struct acpi_device *parent, 196 u64 address, bool check_children) 197 { 198 return acpi_find_child(parent, address, check_children, true); 199 } 200 EXPORT_SYMBOL_GPL(acpi_find_child_device); 201 202 struct acpi_device *acpi_find_child_by_adr(struct acpi_device *adev, 203 acpi_bus_address adr) 204 { 205 return acpi_find_child(adev, adr, false, false); 206 } 207 EXPORT_SYMBOL_GPL(acpi_find_child_by_adr); 208 209 static void acpi_physnode_link_name(char *buf, unsigned int node_id) 210 { 211 if (node_id > 0) 212 snprintf(buf, PHYSICAL_NODE_NAME_SIZE, 213 PHYSICAL_NODE_STRING "%u", node_id); 214 else 215 strcpy(buf, PHYSICAL_NODE_STRING); 216 } 217 218 int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev) 219 { 220 struct acpi_device_physical_node *physical_node, *pn; 221 char physical_node_name[PHYSICAL_NODE_NAME_SIZE]; 222 struct list_head *physnode_list; 223 unsigned int node_id; 224 int retval = -EINVAL; 225 226 if (has_acpi_companion(dev)) { 227 if (acpi_dev) { 228 dev_warn(dev, "ACPI companion already set\n"); 229 return -EINVAL; 230 } else { 231 acpi_dev = ACPI_COMPANION(dev); 232 } 233 } 234 if (!acpi_dev) 235 return -EINVAL; 236 237 acpi_dev_get(acpi_dev); 238 get_device(dev); 239 physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL); 240 if (!physical_node) { 241 retval = -ENOMEM; 242 goto err; 243 } 244 245 mutex_lock(&acpi_dev->physical_node_lock); 246 247 /* 248 * Keep the list sorted by node_id so that the IDs of removed nodes can 249 * be recycled easily. 250 */ 251 physnode_list = &acpi_dev->physical_node_list; 252 node_id = 0; 253 list_for_each_entry(pn, &acpi_dev->physical_node_list, node) { 254 /* Sanity check. */ 255 if (pn->dev == dev) { 256 mutex_unlock(&acpi_dev->physical_node_lock); 257 258 dev_warn(dev, "Already associated with ACPI node\n"); 259 kfree(physical_node); 260 if (ACPI_COMPANION(dev) != acpi_dev) 261 goto err; 262 263 put_device(dev); 264 acpi_dev_put(acpi_dev); 265 return 0; 266 } 267 if (pn->node_id == node_id) { 268 physnode_list = &pn->node; 269 node_id++; 270 } 271 } 272 273 physical_node->node_id = node_id; 274 physical_node->dev = dev; 275 list_add(&physical_node->node, physnode_list); 276 acpi_dev->physical_node_count++; 277 278 if (!has_acpi_companion(dev)) 279 ACPI_COMPANION_SET(dev, acpi_dev); 280 281 acpi_physnode_link_name(physical_node_name, node_id); 282 retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj, 283 physical_node_name); 284 if (retval) 285 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n", 286 physical_node_name, retval); 287 288 retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj, 289 "firmware_node"); 290 if (retval) 291 dev_err(dev, "Failed to create link firmware_node (%d)\n", 292 retval); 293 294 mutex_unlock(&acpi_dev->physical_node_lock); 295 296 if (acpi_dev->wakeup.flags.valid) 297 device_set_wakeup_capable(dev, true); 298 299 return 0; 300 301 err: 302 ACPI_COMPANION_SET(dev, NULL); 303 put_device(dev); 304 acpi_dev_put(acpi_dev); 305 return retval; 306 } 307 EXPORT_SYMBOL_GPL(acpi_bind_one); 308 309 int acpi_unbind_one(struct device *dev) 310 { 311 struct acpi_device *acpi_dev = ACPI_COMPANION(dev); 312 struct acpi_device_physical_node *entry; 313 314 if (!acpi_dev) 315 return 0; 316 317 mutex_lock(&acpi_dev->physical_node_lock); 318 319 list_for_each_entry(entry, &acpi_dev->physical_node_list, node) 320 if (entry->dev == dev) { 321 char physnode_name[PHYSICAL_NODE_NAME_SIZE]; 322 323 list_del(&entry->node); 324 acpi_dev->physical_node_count--; 325 326 acpi_physnode_link_name(physnode_name, entry->node_id); 327 sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name); 328 sysfs_remove_link(&dev->kobj, "firmware_node"); 329 ACPI_COMPANION_SET(dev, NULL); 330 /* Drop references taken by acpi_bind_one(). */ 331 put_device(dev); 332 acpi_dev_put(acpi_dev); 333 kfree(entry); 334 break; 335 } 336 337 mutex_unlock(&acpi_dev->physical_node_lock); 338 return 0; 339 } 340 EXPORT_SYMBOL_GPL(acpi_unbind_one); 341 342 void acpi_device_notify(struct device *dev) 343 { 344 struct acpi_device *adev; 345 int ret; 346 347 ret = acpi_bind_one(dev, NULL); 348 if (ret) { 349 struct acpi_bus_type *type = acpi_get_bus_type(dev); 350 351 if (!type) 352 goto err; 353 354 adev = type->find_companion(dev); 355 if (!adev) { 356 dev_dbg(dev, "ACPI companion not found\n"); 357 goto err; 358 } 359 ret = acpi_bind_one(dev, adev); 360 if (ret) 361 goto err; 362 363 if (type->setup) { 364 type->setup(dev); 365 goto done; 366 } 367 } else { 368 adev = ACPI_COMPANION(dev); 369 370 if (dev_is_pci(dev)) { 371 pci_acpi_setup(dev, adev); 372 goto done; 373 } else if (dev_is_platform(dev)) { 374 acpi_configure_pmsi_domain(dev); 375 } 376 } 377 378 if (adev->handler && adev->handler->bind) 379 adev->handler->bind(dev); 380 381 done: 382 acpi_handle_debug(ACPI_HANDLE(dev), "Bound to device %s\n", 383 dev_name(dev)); 384 385 return; 386 387 err: 388 dev_dbg(dev, "No ACPI support\n"); 389 } 390 391 void acpi_device_notify_remove(struct device *dev) 392 { 393 struct acpi_device *adev = ACPI_COMPANION(dev); 394 395 if (!adev) 396 return; 397 398 if (dev_is_pci(dev)) 399 pci_acpi_cleanup(dev, adev); 400 else if (adev->handler && adev->handler->unbind) 401 adev->handler->unbind(dev); 402 403 acpi_unbind_one(dev); 404 } 405