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_device *acpi_companion_lookup(struct device *dev) 63 { 64 struct acpi_bus_type *type; 65 66 if (!dev->type) 67 return NULL; 68 69 guard(rwsem_read)(&bus_type_sem); 70 71 list_for_each_entry(type, &bus_type_list, list) { 72 struct acpi_device *adev; 73 74 if (!type->match(dev)) 75 continue; 76 77 adev = type->find_companion(dev); 78 if (!adev) { 79 dev_dbg(dev, "ACPI companion not found\n"); 80 return NULL; 81 } 82 if (acpi_bind_one(dev, adev)) { 83 dev_dbg(dev, "Binding to ACPI companion failed\n"); 84 return NULL; 85 } 86 if (type->setup) 87 type->setup(dev); 88 89 return adev; 90 } 91 92 return NULL; 93 } 94 95 #define FIND_CHILD_MIN_SCORE 1 96 #define FIND_CHILD_MID_SCORE 2 97 #define FIND_CHILD_MAX_SCORE 3 98 99 static int match_any(struct acpi_device *adev, void *not_used) 100 { 101 return 1; 102 } 103 104 static bool acpi_dev_has_children(struct acpi_device *adev) 105 { 106 return acpi_dev_for_each_child(adev, match_any, NULL) > 0; 107 } 108 109 static int find_child_checks(struct acpi_device *adev, bool check_children) 110 { 111 unsigned long long sta; 112 acpi_status status; 113 114 if (check_children && !acpi_dev_has_children(adev)) 115 return -ENODEV; 116 117 status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta); 118 if (status == AE_NOT_FOUND) { 119 /* 120 * Special case: backlight device objects without _STA are 121 * preferred to other objects with the same _ADR value, because 122 * it is more likely that they are actually useful. 123 */ 124 if (adev->pnp.type.backlight) 125 return FIND_CHILD_MID_SCORE; 126 127 return FIND_CHILD_MIN_SCORE; 128 } 129 130 if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED)) 131 return -ENODEV; 132 133 /* 134 * If the device has a _HID returning a valid ACPI/PNP device ID, it is 135 * better to make it look less attractive here, so that the other device 136 * with the same _ADR value (that may not have a valid device ID) can be 137 * matched going forward. [This means a second spec violation in a row, 138 * so whatever we do here is best effort anyway.] 139 */ 140 if (adev->pnp.type.platform_id) 141 return FIND_CHILD_MIN_SCORE; 142 143 return FIND_CHILD_MAX_SCORE; 144 } 145 146 struct find_child_walk_data { 147 struct acpi_device *adev; 148 u64 address; 149 int score; 150 bool check_sta; 151 bool check_children; 152 }; 153 154 static int check_one_child(struct acpi_device *adev, void *data) 155 { 156 struct find_child_walk_data *wd = data; 157 int score; 158 159 if (!adev->pnp.type.bus_address || acpi_device_adr(adev) != wd->address) 160 return 0; 161 162 if (!wd->adev) { 163 /* 164 * This is the first matching object, so save it. If it is not 165 * necessary to look for any other matching objects, stop the 166 * search. 167 */ 168 wd->adev = adev; 169 return !(wd->check_sta || wd->check_children); 170 } 171 172 /* 173 * There is more than one matching device object with the same _ADR 174 * value. That really is unexpected, so we are kind of beyond the scope 175 * of the spec here. We have to choose which one to return, though. 176 * 177 * First, get the score for the previously found object and terminate 178 * the walk if it is maximum. 179 */ 180 if (!wd->score) { 181 score = find_child_checks(wd->adev, wd->check_children); 182 if (score == FIND_CHILD_MAX_SCORE) 183 return 1; 184 185 wd->score = score; 186 } 187 /* 188 * Second, if the object that has just been found has a better score, 189 * replace the previously found one with it and terminate the walk if 190 * the new score is maximum. 191 */ 192 score = find_child_checks(adev, wd->check_children); 193 if (score > wd->score) { 194 wd->adev = adev; 195 if (score == FIND_CHILD_MAX_SCORE) 196 return 1; 197 198 wd->score = score; 199 } 200 201 /* Continue, because there may be better matches. */ 202 return 0; 203 } 204 205 static struct acpi_device *acpi_find_child(struct acpi_device *parent, 206 u64 address, bool check_children, 207 bool check_sta) 208 { 209 struct find_child_walk_data wd = { 210 .address = address, 211 .check_children = check_children, 212 .check_sta = check_sta, 213 .adev = NULL, 214 .score = 0, 215 }; 216 217 if (parent) 218 acpi_dev_for_each_child(parent, check_one_child, &wd); 219 220 return wd.adev; 221 } 222 223 struct acpi_device *acpi_find_child_device(struct acpi_device *parent, 224 u64 address, bool check_children) 225 { 226 return acpi_find_child(parent, address, check_children, true); 227 } 228 EXPORT_SYMBOL_GPL(acpi_find_child_device); 229 230 struct acpi_device *acpi_find_child_by_adr(struct acpi_device *adev, 231 acpi_bus_address adr) 232 { 233 return acpi_find_child(adev, adr, false, false); 234 } 235 EXPORT_SYMBOL_GPL(acpi_find_child_by_adr); 236 237 static void acpi_physnode_link_name(char *buf, unsigned int node_id) 238 { 239 if (node_id > 0) 240 snprintf(buf, PHYSICAL_NODE_NAME_SIZE, 241 PHYSICAL_NODE_STRING "%u", node_id); 242 else 243 strcpy(buf, PHYSICAL_NODE_STRING); 244 } 245 246 int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev) 247 { 248 struct acpi_device_physical_node *physical_node, *pn; 249 struct acpi_device *comp_dev = ACPI_COMPANION(dev); 250 char physical_node_name[PHYSICAL_NODE_NAME_SIZE]; 251 struct list_head *physnode_list; 252 unsigned int node_id; 253 int retval = -EINVAL; 254 255 if (!acpi_dev) { 256 if (!comp_dev) 257 return -EINVAL; 258 259 /* If the companion has been set upfront, pick it up. */ 260 acpi_dev = comp_dev; 261 } else if (comp_dev && acpi_dev != comp_dev) { 262 dev_warn(dev, "ACPI companion already set to %s which is not %s\n", 263 acpi_dev_name(comp_dev), acpi_dev_name(acpi_dev)); 264 return -EEXIST; 265 } 266 267 guard(mutex)(&acpi_dev->physical_node_lock); 268 269 /* 270 * Keep the list sorted by node_id so that the IDs of removed nodes can 271 * be recycled easily. 272 */ 273 physnode_list = &acpi_dev->physical_node_list; 274 node_id = 0; 275 list_for_each_entry(pn, &acpi_dev->physical_node_list, node) { 276 /* Sanity check. */ 277 if (pn->dev == dev) { 278 if (!comp_dev) { 279 /* Really unexpected. */ 280 ACPI_COMPANION_SET(dev, acpi_dev); 281 dev_warn(&acpi_dev->dev, 282 "Physical device list corruption fixed up\n"); 283 } 284 return 0; 285 } 286 if (pn->node_id == node_id) { 287 physnode_list = &pn->node; 288 node_id++; 289 } 290 } 291 292 physical_node = kzalloc_obj(*physical_node); 293 if (!physical_node) 294 return -ENOMEM; 295 296 acpi_dev_get(acpi_dev); 297 get_device(dev); 298 299 physical_node->node_id = node_id; 300 physical_node->dev = dev; 301 list_add(&physical_node->node, physnode_list); 302 acpi_dev->physical_node_count++; 303 304 if (!comp_dev) 305 ACPI_COMPANION_SET(dev, acpi_dev); 306 307 acpi_physnode_link_name(physical_node_name, node_id); 308 retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj, 309 physical_node_name); 310 if (retval) 311 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n", 312 physical_node_name, retval); 313 314 retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj, 315 "firmware_node"); 316 if (retval) 317 dev_err(dev, "Failed to create link firmware_node (%d)\n", 318 retval); 319 320 if (acpi_dev->wakeup.flags.valid) 321 device_set_wakeup_capable(dev, true); 322 323 return 0; 324 } 325 EXPORT_SYMBOL_GPL(acpi_bind_one); 326 327 void acpi_unbind_one(struct device *dev) 328 { 329 struct acpi_device *acpi_dev = ACPI_COMPANION(dev); 330 struct acpi_device_physical_node *entry; 331 332 if (!acpi_dev) 333 return; 334 335 mutex_lock(&acpi_dev->physical_node_lock); 336 337 list_for_each_entry(entry, &acpi_dev->physical_node_list, node) 338 if (entry->dev == dev) { 339 char physnode_name[PHYSICAL_NODE_NAME_SIZE]; 340 341 list_del(&entry->node); 342 acpi_dev->physical_node_count--; 343 344 acpi_physnode_link_name(physnode_name, entry->node_id); 345 sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name); 346 sysfs_remove_link(&dev->kobj, "firmware_node"); 347 ACPI_COMPANION_SET(dev, NULL); 348 349 mutex_unlock(&acpi_dev->physical_node_lock); 350 351 /* Drop references taken by acpi_bind_one(). */ 352 put_device(dev); 353 acpi_dev_put(acpi_dev); 354 kfree(entry); 355 return; 356 } 357 358 mutex_unlock(&acpi_dev->physical_node_lock); 359 } 360 EXPORT_SYMBOL_GPL(acpi_unbind_one); 361 362 void acpi_device_notify(struct device *dev) 363 { 364 struct acpi_device *adev; 365 int ret; 366 367 /* ACPI devices have no ACPI companions. */ 368 if (dev->bus == &acpi_bus_type) 369 return; 370 371 ret = acpi_bind_one(dev, NULL); 372 if (ret) { 373 adev = acpi_companion_lookup(dev); 374 if (!adev) 375 return; 376 } else { 377 adev = ACPI_COMPANION(dev); 378 379 if (dev_is_pci(dev)) { 380 pci_acpi_setup(dev, adev); 381 } else if (dev_is_platform(dev)) { 382 acpi_configure_pmsi_domain(dev); 383 384 if (adev->handler && adev->handler->bind) 385 adev->handler->bind(dev); 386 } 387 } 388 389 dev_dbg(dev, "Bound to ACPI device %s\n", acpi_dev_name(adev)); 390 } 391 392 void acpi_device_notify_remove(struct device *dev) 393 { 394 struct acpi_device *adev = ACPI_COMPANION(dev); 395 396 if (!adev) 397 return; 398 399 if (dev_is_pci(dev)) 400 pci_acpi_cleanup(dev, adev); 401 else if (adev->handler && adev->handler->unbind) 402 adev->handler->unbind(dev); 403 404 acpi_unbind_one(dev); 405 } 406