drivers/acpi/glue.c

   1 /*
   2  * Link physical devices with ACPI devices support
   3  *
   4  * Copyright (c) 2005 David Shaohua Li <shaohua.li@intel.com>
   5  * Copyright (c) 2005 Intel Corp.
   6  *
   7  * This file is released under the GPLv2.
   8  */
   9
  10 #include <linux/acpi_iort.h>
  11 #include <linux/export.h>
  12 #include <linux/init.h>
  13 #include <linux/list.h>
  14 #include <linux/device.h>
  15 #include <linux/slab.h>
  16 #include <linux/rwsem.h>
  17 #include <linux/acpi.h>
  18 #include <linux/dma-mapping.h>
  19 #include <linux/platform_device.h>
  20
  21 #include "internal.h"
  22
  23 #define ACPI_GLUE_DEBUG 0
  24 #if ACPI_GLUE_DEBUG
  25 #define DBG(fmt, ...)                                           \
  26         printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__)
  27 #else
  28 #define DBG(fmt, ...)                                           \
  29 do {                                                            \
  30         if (0)                                                  \
  31                 printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__);   \
  32 } while (0)
  33 #endif
  34 static LIST_HEAD(bus_type_list);
  35 static DECLARE_RWSEM(bus_type_sem);
  36
  37 #define PHYSICAL_NODE_STRING "physical_node"
  38 #define PHYSICAL_NODE_NAME_SIZE (sizeof(PHYSICAL_NODE_STRING) + 10)
  39
  40 int register_acpi_bus_type(struct acpi_bus_type *type)
  41 {
  42         if (acpi_disabled)
  43                 return -ENODEV;
  44         if (type && type->match && type->find_companion) {
  45                 down_write(&bus_type_sem);
  46                 list_add_tail(&type->list, &bus_type_list);
  47                 up_write(&bus_type_sem);
  48                 printk(KERN_INFO PREFIX "bus type %s registered\n", type->name);
  49                 return 0;
  50         }
  51         return -ENODEV;
  52 }
  53 EXPORT_SYMBOL_GPL(register_acpi_bus_type);
  54
  55 int unregister_acpi_bus_type(struct acpi_bus_type *type)
  56 {
  57         if (acpi_disabled)
  58                 return 0;
  59         if (type) {
  60                 down_write(&bus_type_sem);
  61                 list_del_init(&type->list);
  62                 up_write(&bus_type_sem);
  63                 printk(KERN_INFO PREFIX "bus type %s unregistered\n",
  64                        type->name);
  65                 return 0;
  66         }
  67         return -ENODEV;
  68 }
  69 EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
  70
  71 static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
  72 {
  73         struct acpi_bus_type *tmp, *ret = NULL;
  74
  75         down_read(&bus_type_sem);
  76         list_for_each_entry(tmp, &bus_type_list, list) {
  77                 if (tmp->match(dev)) {
  78                         ret = tmp;
  79                         break;
  80                 }
  81         }
  82         up_read(&bus_type_sem);
  83         return ret;
  84 }
  85
  86 #define FIND_CHILD_MIN_SCORE    1
  87 #define FIND_CHILD_MAX_SCORE    2
  88
  89 static int find_child_checks(struct acpi_device *adev, bool check_children)
  90 {
  91         bool sta_present = true;
  92         unsigned long long sta;
  93         acpi_status status;
  94
  95         status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
  96         if (status == AE_NOT_FOUND)
  97                 sta_present = false;
  98         else if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
  99                 return -ENODEV;
 100
 101         if (check_children && list_empty(&adev->children))
 102                 return -ENODEV;
 103
 104         /*
 105          * If the device has a _HID returning a valid ACPI/PNP device ID, it is
 106          * better to make it look less attractive here, so that the other device
 107          * with the same _ADR value (that may not have a valid device ID) can be
 108          * matched going forward.  [This means a second spec violation in a row,
 109          * so whatever we do here is best effort anyway.]
 110          */
 111         return sta_present && !adev->pnp.type.platform_id ?
 112                         FIND_CHILD_MAX_SCORE : FIND_CHILD_MIN_SCORE;
 113 }
 114
 115 struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
 116                                            u64 address, bool check_children)
 117 {
 118         struct acpi_device *adev, *ret = NULL;
 119         int ret_score = 0;
 120
 121         if (!parent)
 122                 return NULL;
 123
 124         list_for_each_entry(adev, &parent->children, node) {
 125                 unsigned long long addr;
 126                 acpi_status status;
 127                 int score;
 128
 129                 status = acpi_evaluate_integer(adev->handle, METHOD_NAME__ADR,
 130                                                NULL, &addr);
 131                 if (ACPI_FAILURE(status) || addr != address)
 132                         continue;
 133
 134                 if (!ret) {
 135                         /* This is the first matching object.  Save it. */
 136                         ret = adev;
 137                         continue;
 138                 }
 139                 /*
 140                  * There is more than one matching device object with the same
 141                  * _ADR value.  That really is unexpected, so we are kind of
 142                  * beyond the scope of the spec here.  We have to choose which
 143                  * one to return, though.
 144                  *
 145                  * First, check if the previously found object is good enough
 146                  * and return it if so.  Second, do the same for the object that
 147                  * we've just found.
 148                  */
 149                 if (!ret_score) {
 150                         ret_score = find_child_checks(ret, check_children);
 151                         if (ret_score == FIND_CHILD_MAX_SCORE)
 152                                 return ret;
 153                 }
 154                 score = find_child_checks(adev, check_children);
 155                 if (score == FIND_CHILD_MAX_SCORE) {
 156                         return adev;
 157                 } else if (score > ret_score) {
 158                         ret = adev;
 159                         ret_score = score;
 160                 }
 161         }
 162         return ret;
 163 }
 164 EXPORT_SYMBOL_GPL(acpi_find_child_device);
 165
 166 static void acpi_physnode_link_name(char *buf, unsigned int node_id)
 167 {
 168         if (node_id > 0)
 169                 snprintf(buf, PHYSICAL_NODE_NAME_SIZE,
 170                          PHYSICAL_NODE_STRING "%u", node_id);
 171         else
 172                 strcpy(buf, PHYSICAL_NODE_STRING);
 173 }
 174
 175 int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
 176 {
 177         struct acpi_device_physical_node *physical_node, *pn;
 178         char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
 179         struct list_head *physnode_list;
 180         unsigned int node_id;
 181         int retval = -EINVAL;
 182
 183         if (has_acpi_companion(dev)) {
 184                 if (acpi_dev) {
 185                         dev_warn(dev, "ACPI companion already set\n");
 186                         return -EINVAL;
 187                 } else {
 188                         acpi_dev = ACPI_COMPANION(dev);
 189                 }
 190         }
 191         if (!acpi_dev)
 192                 return -EINVAL;
 193
 194         get_device(&acpi_dev->dev);
 195         get_device(dev);
 196         physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
 197         if (!physical_node) {
 198                 retval = -ENOMEM;
 199                 goto err;
 200         }
 201
 202         mutex_lock(&acpi_dev->physical_node_lock);
 203
 204         /*
 205          * Keep the list sorted by node_id so that the IDs of removed nodes can
 206          * be recycled easily.
 207          */
 208         physnode_list = &acpi_dev->physical_node_list;
 209         node_id = 0;
 210         list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
 211                 /* Sanity check. */
 212                 if (pn->dev == dev) {
 213                         mutex_unlock(&acpi_dev->physical_node_lock);
 214
 215                         dev_warn(dev, "Already associated with ACPI node\n");
 216                         kfree(physical_node);
 217                         if (ACPI_COMPANION(dev) != acpi_dev)
 218                                 goto err;
 219
 220                         put_device(dev);
 221                         put_device(&acpi_dev->dev);
 222                         return 0;
 223                 }
 224                 if (pn->node_id == node_id) {
 225                         physnode_list = &pn->node;
 226                         node_id++;
 227                 }
 228         }
 229
 230         physical_node->node_id = node_id;
 231         physical_node->dev = dev;
 232         list_add(&physical_node->node, physnode_list);
 233         acpi_dev->physical_node_count++;
 234
 235         if (!has_acpi_companion(dev))
 236                 ACPI_COMPANION_SET(dev, acpi_dev);
 237
 238         acpi_physnode_link_name(physical_node_name, node_id);
 239         retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 240                                    physical_node_name);
 241         if (retval)
 242                 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
 243                         physical_node_name, retval);
 244
 245         retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 246                                    "firmware_node");
 247         if (retval)
 248                 dev_err(dev, "Failed to create link firmware_node (%d)\n",
 249                         retval);
 250
 251         mutex_unlock(&acpi_dev->physical_node_lock);
 252
 253         if (acpi_dev->wakeup.flags.valid)
 254                 device_set_wakeup_capable(dev, true);
 255
 256         return 0;
 257
 258  err:
 259         ACPI_COMPANION_SET(dev, NULL);
 260         put_device(dev);
 261         put_device(&acpi_dev->dev);
 262         return retval;
 263 }
 264 EXPORT_SYMBOL_GPL(acpi_bind_one);
 265
 266 int acpi_unbind_one(struct device *dev)
 267 {
 268         struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
 269         struct acpi_device_physical_node *entry;
 270
 271         if (!acpi_dev)
 272                 return 0;
 273
 274         mutex_lock(&acpi_dev->physical_node_lock);
 275
 276         list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
 277                 if (entry->dev == dev) {
 278                         char physnode_name[PHYSICAL_NODE_NAME_SIZE];
 279
 280                         list_del(&entry->node);
 281                         acpi_dev->physical_node_count--;
 282
 283                         acpi_physnode_link_name(physnode_name, entry->node_id);
 284                         sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
 285                         sysfs_remove_link(&dev->kobj, "firmware_node");
 286                         ACPI_COMPANION_SET(dev, NULL);
 287                         /* Drop references taken by acpi_bind_one(). */
 288                         put_device(dev);
 289                         put_device(&acpi_dev->dev);
 290                         kfree(entry);
 291                         break;
 292                 }
 293
 294         mutex_unlock(&acpi_dev->physical_node_lock);
 295         return 0;
 296 }
 297 EXPORT_SYMBOL_GPL(acpi_unbind_one);
 298
 299 static int acpi_platform_notify(struct device *dev)
 300 {
 301         struct acpi_bus_type *type = acpi_get_bus_type(dev);
 302         struct acpi_device *adev;
 303         int ret;
 304
 305         ret = acpi_bind_one(dev, NULL);
 306         if (ret && type) {
 307                 struct acpi_device *adev;
 308
 309                 adev = type->find_companion(dev);
 310                 if (!adev) {
 311                         DBG("Unable to get handle for %s\n", dev_name(dev));
 312                         ret = -ENODEV;
 313                         goto out;
 314                 }
 315                 ret = acpi_bind_one(dev, adev);
 316                 if (ret)
 317                         goto out;
 318         }
 319         adev = ACPI_COMPANION(dev);
 320         if (!adev)
 321                 goto out;
 322
 323         if (dev_is_platform(dev))
 324                 acpi_configure_pmsi_domain(dev);
 325
 326         if (type && type->setup)
 327                 type->setup(dev);
 328         else if (adev->handler && adev->handler->bind)
 329                 adev->handler->bind(dev);
 330
 331  out:
 332 #if ACPI_GLUE_DEBUG
 333         if (!ret) {
 334                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 335
 336                 acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer);
 337                 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
 338                 kfree(buffer.pointer);
 339         } else
 340                 DBG("Device %s -> No ACPI support\n", dev_name(dev));
 341 #endif
 342
 343         return ret;
 344 }
 345
 346 static int acpi_platform_notify_remove(struct device *dev)
 347 {
 348         struct acpi_device *adev = ACPI_COMPANION(dev);
 349         struct acpi_bus_type *type;
 350
 351         if (!adev)
 352                 return 0;
 353
 354         type = acpi_get_bus_type(dev);
 355         if (type && type->cleanup)
 356                 type->cleanup(dev);
 357         else if (adev->handler && adev->handler->unbind)
 358                 adev->handler->unbind(dev);
 359
 360         acpi_unbind_one(dev);
 361         return 0;
 362 }
 363
 364 void __init init_acpi_device_notify(void)
 365 {
 366         if (platform_notify || platform_notify_remove) {
 367                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
 368                 return;
 369         }
 370         platform_notify = acpi_platform_notify;
 371         platform_notify_remove = acpi_platform_notify_remove;
 372 }