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