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         unsigned long long sta;
  83         acpi_status status;
  84
  85         if (check_children && list_empty(&adev->children))
  86                 return -ENODEV;
  87
  88         status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
  89         if (status == AE_NOT_FOUND)
  90                 return FIND_CHILD_MIN_SCORE;
  91
  92         if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
  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         if (adev->pnp.type.platform_id)
 103                 return FIND_CHILD_MIN_SCORE;
 104
 105         return FIND_CHILD_MAX_SCORE;
 106 }
 107
 108 struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
 109                                            u64 address, bool check_children)
 110 {
 111         struct acpi_device *adev, *ret = NULL;
 112         int ret_score = 0;
 113
 114         if (!parent)
 115                 return NULL;
 116
 117         list_for_each_entry(adev, &parent->children, node) {
 118                 acpi_bus_address addr = acpi_device_adr(adev);
 119                 int score;
 120
 121                 if (!adev->pnp.type.bus_address || addr != address)
 122                         continue;
 123
 124                 if (!ret) {
 125                         /* This is the first matching object.  Save it. */
 126                         ret = adev;
 127                         continue;
 128                 }
 129                 /*
 130                  * There is more than one matching device object with the same
 131                  * _ADR value.  That really is unexpected, so we are kind of
 132                  * beyond the scope of the spec here.  We have to choose which
 133                  * one to return, though.
 134                  *
 135                  * First, check if the previously found object is good enough
 136                  * and return it if so.  Second, do the same for the object that
 137                  * we've just found.
 138                  */
 139                 if (!ret_score) {
 140                         ret_score = find_child_checks(ret, check_children);
 141                         if (ret_score == FIND_CHILD_MAX_SCORE)
 142                                 return ret;
 143                 }
 144                 score = find_child_checks(adev, check_children);
 145                 if (score == FIND_CHILD_MAX_SCORE) {
 146                         return adev;
 147                 } else if (score > ret_score) {
 148                         ret = adev;
 149                         ret_score = score;
 150                 }
 151         }
 152         return ret;
 153 }
 154 EXPORT_SYMBOL_GPL(acpi_find_child_device);
 155
 156 static void acpi_physnode_link_name(char *buf, unsigned int node_id)
 157 {
 158         if (node_id > 0)
 159                 snprintf(buf, PHYSICAL_NODE_NAME_SIZE,
 160                          PHYSICAL_NODE_STRING "%u", node_id);
 161         else
 162                 strcpy(buf, PHYSICAL_NODE_STRING);
 163 }
 164
 165 int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
 166 {
 167         struct acpi_device_physical_node *physical_node, *pn;
 168         char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
 169         struct list_head *physnode_list;
 170         unsigned int node_id;
 171         int retval = -EINVAL;
 172
 173         if (has_acpi_companion(dev)) {
 174                 if (acpi_dev) {
 175                         dev_warn(dev, "ACPI companion already set\n");
 176                         return -EINVAL;
 177                 } else {
 178                         acpi_dev = ACPI_COMPANION(dev);
 179                 }
 180         }
 181         if (!acpi_dev)
 182                 return -EINVAL;
 183
 184         acpi_dev_get(acpi_dev);
 185         get_device(dev);
 186         physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
 187         if (!physical_node) {
 188                 retval = -ENOMEM;
 189                 goto err;
 190         }
 191
 192         mutex_lock(&acpi_dev->physical_node_lock);
 193
 194         /*
 195          * Keep the list sorted by node_id so that the IDs of removed nodes can
 196          * be recycled easily.
 197          */
 198         physnode_list = &acpi_dev->physical_node_list;
 199         node_id = 0;
 200         list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
 201                 /* Sanity check. */
 202                 if (pn->dev == dev) {
 203                         mutex_unlock(&acpi_dev->physical_node_lock);
 204
 205                         dev_warn(dev, "Already associated with ACPI node\n");
 206                         kfree(physical_node);
 207                         if (ACPI_COMPANION(dev) != acpi_dev)
 208                                 goto err;
 209
 210                         put_device(dev);
 211                         acpi_dev_put(acpi_dev);
 212                         return 0;
 213                 }
 214                 if (pn->node_id == node_id) {
 215                         physnode_list = &pn->node;
 216                         node_id++;
 217                 }
 218         }
 219
 220         physical_node->node_id = node_id;
 221         physical_node->dev = dev;
 222         list_add(&physical_node->node, physnode_list);
 223         acpi_dev->physical_node_count++;
 224
 225         if (!has_acpi_companion(dev))
 226                 ACPI_COMPANION_SET(dev, acpi_dev);
 227
 228         acpi_physnode_link_name(physical_node_name, node_id);
 229         retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 230                                    physical_node_name);
 231         if (retval)
 232                 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
 233                         physical_node_name, retval);
 234
 235         retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 236                                    "firmware_node");
 237         if (retval)
 238                 dev_err(dev, "Failed to create link firmware_node (%d)\n",
 239                         retval);
 240
 241         mutex_unlock(&acpi_dev->physical_node_lock);
 242
 243         if (acpi_dev->wakeup.flags.valid)
 244                 device_set_wakeup_capable(dev, true);
 245
 246         return 0;
 247
 248  err:
 249         ACPI_COMPANION_SET(dev, NULL);
 250         put_device(dev);
 251         acpi_dev_put(acpi_dev);
 252         return retval;
 253 }
 254 EXPORT_SYMBOL_GPL(acpi_bind_one);
 255
 256 int acpi_unbind_one(struct device *dev)
 257 {
 258         struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
 259         struct acpi_device_physical_node *entry;
 260
 261         if (!acpi_dev)
 262                 return 0;
 263
 264         mutex_lock(&acpi_dev->physical_node_lock);
 265
 266         list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
 267                 if (entry->dev == dev) {
 268                         char physnode_name[PHYSICAL_NODE_NAME_SIZE];
 269
 270                         list_del(&entry->node);
 271                         acpi_dev->physical_node_count--;
 272
 273                         acpi_physnode_link_name(physnode_name, entry->node_id);
 274                         sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
 275                         sysfs_remove_link(&dev->kobj, "firmware_node");
 276                         ACPI_COMPANION_SET(dev, NULL);
 277                         /* Drop references taken by acpi_bind_one(). */
 278                         put_device(dev);
 279                         acpi_dev_put(acpi_dev);
 280                         kfree(entry);
 281                         break;
 282                 }
 283
 284         mutex_unlock(&acpi_dev->physical_node_lock);
 285         return 0;
 286 }
 287 EXPORT_SYMBOL_GPL(acpi_unbind_one);
 288
 289 void acpi_device_notify(struct device *dev)
 290 {
 291         struct acpi_device *adev;
 292         int ret;
 293
 294         ret = acpi_bind_one(dev, NULL);
 295         if (ret) {
 296                 struct acpi_bus_type *type = acpi_get_bus_type(dev);
 297
 298                 if (!type)
 299                         goto err;
 300
 301                 adev = type->find_companion(dev);
 302                 if (!adev) {
 303                         dev_dbg(dev, "ACPI companion not found\n");
 304                         goto err;
 305                 }
 306                 ret = acpi_bind_one(dev, adev);
 307                 if (ret)
 308                         goto err;
 309
 310                 if (type->setup) {
 311                         type->setup(dev);
 312                         goto done;
 313                 }
 314         } else {
 315                 adev = ACPI_COMPANION(dev);
 316
 317                 if (dev_is_pci(dev)) {
 318                         pci_acpi_setup(dev, adev);
 319                         goto done;
 320                 } else if (dev_is_platform(dev)) {
 321                         acpi_configure_pmsi_domain(dev);
 322                 }
 323         }
 324
 325         if (adev->handler && adev->handler->bind)
 326                 adev->handler->bind(dev);
 327
 328 done:
 329         acpi_handle_debug(ACPI_HANDLE(dev), "Bound to device %s\n",
 330                           dev_name(dev));
 331
 332         return;
 333
 334 err:
 335         dev_dbg(dev, "No ACPI support\n");
 336 }
 337
 338 void acpi_device_notify_remove(struct device *dev)
 339 {
 340         struct acpi_device *adev = ACPI_COMPANION(dev);
 341
 342         if (!adev)
 343                 return;
 344
 345         if (dev_is_pci(dev))
 346                 pci_acpi_cleanup(dev, adev);
 347         else if (adev->handler && adev->handler->unbind)
 348                 adev->handler->unbind(dev);
 349
 350         acpi_unbind_one(dev);
 351 }