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_MID_SCORE 2 79 #define FIND_CHILD_MAX_SCORE 3 80 81 static int match_any(struct acpi_device *adev, void *not_used) 82 { 83 return 1; 84 } 85 86 static bool acpi_dev_has_children(struct acpi_device *adev) 87 { 88 return acpi_dev_for_each_child(adev, match_any, NULL) > 0; 89 } 90 91 static int find_child_checks(struct acpi_device *adev, bool check_children) 92 { 93 unsigned long long sta; 94 acpi_status status; 95 96 if (check_children && !acpi_dev_has_children(adev)) 97 return -ENODEV; 98 99 status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta); 100 if (status == AE_NOT_FOUND) { 101 /* 102 * Special case: backlight device objects without _STA are 103 * preferred to other objects with the same _ADR value, because 104 * it is more likely that they are actually useful. 105 */ 106 if (adev->pnp.type.backlight) 107 return FIND_CHILD_MID_SCORE; 108 109 return FIND_CHILD_MIN_SCORE; 110 } 111 112 if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED)) 113 return -ENODEV; 114 115 /* 116 * If the device has a _HID returning a valid ACPI/PNP device ID, it is 117 * better to make it look less attractive here, so that the other device 118 * with the same _ADR value (that may not have a valid device ID) can be 119 * matched going forward. [This means a second spec violation in a row, 120 * so whatever we do here is best effort anyway.] 121 */ 122 if (adev->pnp.type.platform_id) 123 return FIND_CHILD_MIN_SCORE; 124 125 return FIND_CHILD_MAX_SCORE; 126 } 127 128 struct find_child_walk_data { 129 struct acpi_device *adev; 130 u64 address; 131 int score; 132 bool check_sta; 133 bool check_children; 134 }; 135 136 static int check_one_child(struct acpi_device *adev, void *data) 137 { 138 struct find_child_walk_data *wd = data; 139 int score; 140 141 if (!adev->pnp.type.bus_address || acpi_device_adr(adev) != wd->address) 142 return 0; 143 144 if (!wd->adev) { 145 /* 146 * This is the first matching object, so save it. If it is not 147 * necessary to look for any other matching objects, stop the 148 * search. 149 */ 150 wd->adev = adev; 151 return !(wd->check_sta || wd->check_children); 152 } 153 154 /* 155 * There is more than one matching device object with the same _ADR 156 * value. That really is unexpected, so we are kind of beyond the scope 157 * of the spec here. We have to choose which one to return, though. 158 * 159 * First, get the score for the previously found object and terminate 160 * the walk if it is maximum. 161 */ 162 if (!wd->score) { 163 score = find_child_checks(wd->adev, wd->check_children); 164 if (score == FIND_CHILD_MAX_SCORE) 165 return 1; 166 167 wd->score = score; 168 } 169 /* 170 * Second, if the object that has just been found has a better score, 171 * replace the previously found one with it and terminate the walk if 172 * the new score is maximum. 173 */ 174 score = find_child_checks(adev, wd->check_children); 175 if (score > wd->score) { 176 wd->adev = adev; 177 if (score == FIND_CHILD_MAX_SCORE) 178 return 1; 179 180 wd->score = score; 181 } 182 183 /* Continue, because there may be better matches. */ 184 return 0; 185 } 186 187 static struct acpi_device *acpi_find_child(struct acpi_device *parent, 188 u64 address, bool check_children, 189 bool check_sta) 190 { 191 struct find_child_walk_data wd = { 192 .address = address, 193 .check_children = check_children, 194 .check_sta = check_sta, 195 .adev = NULL, 196 .score = 0, 197 }; 198 199 if (parent) 200 acpi_dev_for_each_child(parent, check_one_child, &wd); 201 202 return wd.adev; 203 } 204 205 struct acpi_device *acpi_find_child_device(struct acpi_device *parent, 206 u64 address, bool check_children) 207 { 208 return acpi_find_child(parent, address, check_children, true); 209 } 210 EXPORT_SYMBOL_GPL(acpi_find_child_device); 211 212 struct acpi_device *acpi_find_child_by_adr(struct acpi_device *adev, 213 acpi_bus_address adr) 214 { 215 return acpi_find_child(adev, adr, false, false); 216 } 217 EXPORT_SYMBOL_GPL(acpi_find_child_by_adr); 218 219 static void acpi_physnode_link_name(char *buf, unsigned int node_id) 220 { 221 if (node_id > 0) 222 snprintf(buf, PHYSICAL_NODE_NAME_SIZE, 223 PHYSICAL_NODE_STRING "%u", node_id); 224 else 225 strcpy(buf, PHYSICAL_NODE_STRING); 226 } 227 228 int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev) 229 { 230 struct acpi_device_physical_node *physical_node, *pn; 231 char physical_node_name[PHYSICAL_NODE_NAME_SIZE]; 232 struct list_head *physnode_list; 233 unsigned int node_id; 234 int retval = -EINVAL; 235 236 if (has_acpi_companion(dev)) { 237 if (acpi_dev) { 238 dev_warn(dev, "ACPI companion already set\n"); 239 return -EINVAL; 240 } else { 241 acpi_dev = ACPI_COMPANION(dev); 242 } 243 } 244 if (!acpi_dev) 245 return -EINVAL; 246 247 acpi_dev_get(acpi_dev); 248 get_device(dev); 249 physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL); 250 if (!physical_node) { 251 retval = -ENOMEM; 252 goto err; 253 } 254 255 mutex_lock(&acpi_dev->physical_node_lock); 256 257 /* 258 * Keep the list sorted by node_id so that the IDs of removed nodes can 259 * be recycled easily. 260 */ 261 physnode_list = &acpi_dev->physical_node_list; 262 node_id = 0; 263 list_for_each_entry(pn, &acpi_dev->physical_node_list, node) { 264 /* Sanity check. */ 265 if (pn->dev == dev) { 266 mutex_unlock(&acpi_dev->physical_node_lock); 267 268 dev_warn(dev, "Already associated with ACPI node\n"); 269 kfree(physical_node); 270 if (ACPI_COMPANION(dev) != acpi_dev) 271 goto err; 272 273 put_device(dev); 274 acpi_dev_put(acpi_dev); 275 return 0; 276 } 277 if (pn->node_id == node_id) { 278 physnode_list = &pn->node; 279 node_id++; 280 } 281 } 282 283 physical_node->node_id = node_id; 284 physical_node->dev = dev; 285 list_add(&physical_node->node, physnode_list); 286 acpi_dev->physical_node_count++; 287 288 if (!has_acpi_companion(dev)) 289 ACPI_COMPANION_SET(dev, acpi_dev); 290 291 acpi_physnode_link_name(physical_node_name, node_id); 292 retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj, 293 physical_node_name); 294 if (retval) 295 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n", 296 physical_node_name, retval); 297 298 retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj, 299 "firmware_node"); 300 if (retval) 301 dev_err(dev, "Failed to create link firmware_node (%d)\n", 302 retval); 303 304 mutex_unlock(&acpi_dev->physical_node_lock); 305 306 if (acpi_dev->wakeup.flags.valid) 307 device_set_wakeup_capable(dev, true); 308 309 return 0; 310 311 err: 312 ACPI_COMPANION_SET(dev, NULL); 313 put_device(dev); 314 acpi_dev_put(acpi_dev); 315 return retval; 316 } 317 EXPORT_SYMBOL_GPL(acpi_bind_one); 318 319 int acpi_unbind_one(struct device *dev) 320 { 321 struct acpi_device *acpi_dev = ACPI_COMPANION(dev); 322 struct acpi_device_physical_node *entry; 323 324 if (!acpi_dev) 325 return 0; 326 327 mutex_lock(&acpi_dev->physical_node_lock); 328 329 list_for_each_entry(entry, &acpi_dev->physical_node_list, node) 330 if (entry->dev == dev) { 331 char physnode_name[PHYSICAL_NODE_NAME_SIZE]; 332 333 list_del(&entry->node); 334 acpi_dev->physical_node_count--; 335 336 acpi_physnode_link_name(physnode_name, entry->node_id); 337 sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name); 338 sysfs_remove_link(&dev->kobj, "firmware_node"); 339 ACPI_COMPANION_SET(dev, NULL); 340 /* Drop references taken by acpi_bind_one(). */ 341 put_device(dev); 342 acpi_dev_put(acpi_dev); 343 kfree(entry); 344 break; 345 } 346 347 mutex_unlock(&acpi_dev->physical_node_lock); 348 return 0; 349 } 350 EXPORT_SYMBOL_GPL(acpi_unbind_one); 351 352 void acpi_device_notify(struct device *dev) 353 { 354 struct acpi_device *adev; 355 int ret; 356 357 ret = acpi_bind_one(dev, NULL); 358 if (ret) { 359 struct acpi_bus_type *type = acpi_get_bus_type(dev); 360 361 if (!type) 362 goto err; 363 364 adev = type->find_companion(dev); 365 if (!adev) { 366 dev_dbg(dev, "ACPI companion not found\n"); 367 goto err; 368 } 369 ret = acpi_bind_one(dev, adev); 370 if (ret) 371 goto err; 372 373 if (type->setup) { 374 type->setup(dev); 375 goto done; 376 } 377 } else { 378 adev = ACPI_COMPANION(dev); 379 380 if (dev_is_pci(dev)) { 381 pci_acpi_setup(dev, adev); 382 goto done; 383 } else if (dev_is_platform(dev)) { 384 acpi_configure_pmsi_domain(dev); 385 } 386 } 387 388 if (adev->handler && adev->handler->bind) 389 adev->handler->bind(dev); 390 391 done: 392 acpi_handle_debug(ACPI_HANDLE(dev), "Bound to device %s\n", 393 dev_name(dev)); 394 395 return; 396 397 err: 398 dev_dbg(dev, "No ACPI support\n"); 399 } 400 401 void acpi_device_notify_remove(struct device *dev) 402 { 403 struct acpi_device *adev = ACPI_COMPANION(dev); 404 405 if (!adev) 406 return; 407 408 if (dev_is_pci(dev)) 409 pci_acpi_cleanup(dev, adev); 410 else if (adev->handler && adev->handler->unbind) 411 adev->handler->unbind(dev); 412 413 acpi_unbind_one(dev); 414 } 415