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