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 find_child_checks(struct acpi_device *adev, bool check_children) 81 { 82 bool sta_present = true; 83 unsigned long long sta; 84 acpi_status status; 85 86 status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta); 87 if (status == AE_NOT_FOUND) 88 sta_present = false; 89 else if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED)) 90 return -ENODEV; 91 92 if (check_children && list_empty(&adev->children)) 93 return -ENODEV; 94 95 /* 96 * If the device has a _HID returning a valid ACPI/PNP device ID, it is 97 * better to make it look less attractive here, so that the other device 98 * with the same _ADR value (that may not have a valid device ID) can be 99 * matched going forward. [This means a second spec violation in a row, 100 * so whatever we do here is best effort anyway.] 101 */ 102 return sta_present && !adev->pnp.type.platform_id ? 103 FIND_CHILD_MAX_SCORE : FIND_CHILD_MIN_SCORE; 104 } 105 106 struct acpi_device *acpi_find_child_device(struct acpi_device *parent, 107 u64 address, bool check_children) 108 { 109 struct acpi_device *adev, *ret = NULL; 110 int ret_score = 0; 111 112 if (!parent) 113 return NULL; 114 115 list_for_each_entry(adev, &parent->children, node) { 116 acpi_bus_address addr = acpi_device_adr(adev); 117 int score; 118 119 if (!adev->pnp.type.bus_address || addr != address) 120 continue; 121 122 if (!ret) { 123 /* This is the first matching object. Save it. */ 124 ret = adev; 125 continue; 126 } 127 /* 128 * There is more than one matching device object with the same 129 * _ADR value. That really is unexpected, so we are kind of 130 * beyond the scope of the spec here. We have to choose which 131 * one to return, though. 132 * 133 * First, check if the previously found object is good enough 134 * and return it if so. Second, do the same for the object that 135 * we've just found. 136 */ 137 if (!ret_score) { 138 ret_score = find_child_checks(ret, check_children); 139 if (ret_score == FIND_CHILD_MAX_SCORE) 140 return ret; 141 } 142 score = find_child_checks(adev, check_children); 143 if (score == FIND_CHILD_MAX_SCORE) { 144 return adev; 145 } else if (score > ret_score) { 146 ret = adev; 147 ret_score = score; 148 } 149 } 150 return ret; 151 } 152 EXPORT_SYMBOL_GPL(acpi_find_child_device); 153 154 static void acpi_physnode_link_name(char *buf, unsigned int node_id) 155 { 156 if (node_id > 0) 157 snprintf(buf, PHYSICAL_NODE_NAME_SIZE, 158 PHYSICAL_NODE_STRING "%u", node_id); 159 else 160 strcpy(buf, PHYSICAL_NODE_STRING); 161 } 162 163 int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev) 164 { 165 struct acpi_device_physical_node *physical_node, *pn; 166 char physical_node_name[PHYSICAL_NODE_NAME_SIZE]; 167 struct list_head *physnode_list; 168 unsigned int node_id; 169 int retval = -EINVAL; 170 171 if (has_acpi_companion(dev)) { 172 if (acpi_dev) { 173 dev_warn(dev, "ACPI companion already set\n"); 174 return -EINVAL; 175 } else { 176 acpi_dev = ACPI_COMPANION(dev); 177 } 178 } 179 if (!acpi_dev) 180 return -EINVAL; 181 182 acpi_dev_get(acpi_dev); 183 get_device(dev); 184 physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL); 185 if (!physical_node) { 186 retval = -ENOMEM; 187 goto err; 188 } 189 190 mutex_lock(&acpi_dev->physical_node_lock); 191 192 /* 193 * Keep the list sorted by node_id so that the IDs of removed nodes can 194 * be recycled easily. 195 */ 196 physnode_list = &acpi_dev->physical_node_list; 197 node_id = 0; 198 list_for_each_entry(pn, &acpi_dev->physical_node_list, node) { 199 /* Sanity check. */ 200 if (pn->dev == dev) { 201 mutex_unlock(&acpi_dev->physical_node_lock); 202 203 dev_warn(dev, "Already associated with ACPI node\n"); 204 kfree(physical_node); 205 if (ACPI_COMPANION(dev) != acpi_dev) 206 goto err; 207 208 put_device(dev); 209 acpi_dev_put(acpi_dev); 210 return 0; 211 } 212 if (pn->node_id == node_id) { 213 physnode_list = &pn->node; 214 node_id++; 215 } 216 } 217 218 physical_node->node_id = node_id; 219 physical_node->dev = dev; 220 list_add(&physical_node->node, physnode_list); 221 acpi_dev->physical_node_count++; 222 223 if (!has_acpi_companion(dev)) 224 ACPI_COMPANION_SET(dev, acpi_dev); 225 226 acpi_physnode_link_name(physical_node_name, node_id); 227 retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj, 228 physical_node_name); 229 if (retval) 230 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n", 231 physical_node_name, retval); 232 233 retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj, 234 "firmware_node"); 235 if (retval) 236 dev_err(dev, "Failed to create link firmware_node (%d)\n", 237 retval); 238 239 mutex_unlock(&acpi_dev->physical_node_lock); 240 241 if (acpi_dev->wakeup.flags.valid) 242 device_set_wakeup_capable(dev, true); 243 244 return 0; 245 246 err: 247 ACPI_COMPANION_SET(dev, NULL); 248 put_device(dev); 249 acpi_dev_put(acpi_dev); 250 return retval; 251 } 252 EXPORT_SYMBOL_GPL(acpi_bind_one); 253 254 int acpi_unbind_one(struct device *dev) 255 { 256 struct acpi_device *acpi_dev = ACPI_COMPANION(dev); 257 struct acpi_device_physical_node *entry; 258 259 if (!acpi_dev) 260 return 0; 261 262 mutex_lock(&acpi_dev->physical_node_lock); 263 264 list_for_each_entry(entry, &acpi_dev->physical_node_list, node) 265 if (entry->dev == dev) { 266 char physnode_name[PHYSICAL_NODE_NAME_SIZE]; 267 268 list_del(&entry->node); 269 acpi_dev->physical_node_count--; 270 271 acpi_physnode_link_name(physnode_name, entry->node_id); 272 sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name); 273 sysfs_remove_link(&dev->kobj, "firmware_node"); 274 ACPI_COMPANION_SET(dev, NULL); 275 /* Drop references taken by acpi_bind_one(). */ 276 put_device(dev); 277 acpi_dev_put(acpi_dev); 278 kfree(entry); 279 break; 280 } 281 282 mutex_unlock(&acpi_dev->physical_node_lock); 283 return 0; 284 } 285 EXPORT_SYMBOL_GPL(acpi_unbind_one); 286 287 void acpi_device_notify(struct device *dev) 288 { 289 struct acpi_device *adev; 290 int ret; 291 292 ret = acpi_bind_one(dev, NULL); 293 if (ret) { 294 struct acpi_bus_type *type = acpi_get_bus_type(dev); 295 296 if (!type) 297 goto err; 298 299 adev = type->find_companion(dev); 300 if (!adev) { 301 dev_dbg(dev, "ACPI companion not found\n"); 302 goto err; 303 } 304 ret = acpi_bind_one(dev, adev); 305 if (ret) 306 goto err; 307 308 if (type->setup) { 309 type->setup(dev); 310 goto done; 311 } 312 } else { 313 adev = ACPI_COMPANION(dev); 314 315 if (dev_is_pci(dev)) { 316 pci_acpi_setup(dev, adev); 317 goto done; 318 } else if (dev_is_platform(dev)) { 319 acpi_configure_pmsi_domain(dev); 320 } 321 } 322 323 if (adev->handler && adev->handler->bind) 324 adev->handler->bind(dev); 325 326 done: 327 acpi_handle_debug(ACPI_HANDLE(dev), "Bound to device %s\n", 328 dev_name(dev)); 329 330 return; 331 332 err: 333 dev_dbg(dev, "No ACPI support\n"); 334 } 335 336 void acpi_device_notify_remove(struct device *dev) 337 { 338 struct acpi_device *adev = ACPI_COMPANION(dev); 339 340 if (!adev) 341 return; 342 343 if (dev_is_pci(dev)) 344 pci_acpi_cleanup(dev, adev); 345 else if (adev->handler && adev->handler->unbind) 346 adev->handler->unbind(dev); 347 348 acpi_unbind_one(dev); 349 } 350