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/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 }