drivers/acpi/glue.c

   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 }