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 #include <linux/export.h>
  10 #include <linux/init.h>
  11 #include <linux/list.h>
  12 #include <linux/device.h>
  13 #include <linux/slab.h>
  14 #include <linux/rwsem.h>
  15 #include <linux/acpi.h>
  16 #include <linux/dma-mapping.h>
  17
  18 #include "internal.h"
  19
  20 #define ACPI_GLUE_DEBUG 0
  21 #if ACPI_GLUE_DEBUG
  22 #define DBG(fmt, ...)                                           \
  23         printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__)
  24 #else
  25 #define DBG(fmt, ...)                                           \
  26 do {                                                            \
  27         if (0)                                                  \
  28                 printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__);   \
  29 } while (0)
  30 #endif
  31 static LIST_HEAD(bus_type_list);
  32 static DECLARE_RWSEM(bus_type_sem);
  33
  34 #define PHYSICAL_NODE_STRING "physical_node"
  35 #define PHYSICAL_NODE_NAME_SIZE (sizeof(PHYSICAL_NODE_STRING) + 10)
  36
  37 int register_acpi_bus_type(struct acpi_bus_type *type)
  38 {
  39         if (acpi_disabled)
  40                 return -ENODEV;
  41         if (type && type->match && type->find_companion) {
  42                 down_write(&bus_type_sem);
  43                 list_add_tail(&type->list, &bus_type_list);
  44                 up_write(&bus_type_sem);
  45                 printk(KERN_INFO PREFIX "bus type %s registered\n", type->name);
  46                 return 0;
  47         }
  48         return -ENODEV;
  49 }
  50 EXPORT_SYMBOL_GPL(register_acpi_bus_type);
  51
  52 int unregister_acpi_bus_type(struct acpi_bus_type *type)
  53 {
  54         if (acpi_disabled)
  55                 return 0;
  56         if (type) {
  57                 down_write(&bus_type_sem);
  58                 list_del_init(&type->list);
  59                 up_write(&bus_type_sem);
  60                 printk(KERN_INFO PREFIX "bus type %s unregistered\n",
  61                        type->name);
  62                 return 0;
  63         }
  64         return -ENODEV;
  65 }
  66 EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
  67
  68 static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
  69 {
  70         struct acpi_bus_type *tmp, *ret = NULL;
  71
  72         down_read(&bus_type_sem);
  73         list_for_each_entry(tmp, &bus_type_list, list) {
  74                 if (tmp->match(dev)) {
  75                         ret = tmp;
  76                         break;
  77                 }
  78         }
  79         up_read(&bus_type_sem);
  80         return ret;
  81 }
  82
  83 #define FIND_CHILD_MIN_SCORE    1
  84 #define FIND_CHILD_MAX_SCORE    2
  85
  86 static int find_child_checks(struct acpi_device *adev, bool check_children)
  87 {
  88         bool sta_present = true;
  89         unsigned long long sta;
  90         acpi_status status;
  91
  92         status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
  93         if (status == AE_NOT_FOUND)
  94                 sta_present = false;
  95         else if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
  96                 return -ENODEV;
  97
  98         if (check_children && list_empty(&adev->children))
  99                 return -ENODEV;
 100
 101         return sta_present ? 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         enum dev_dma_attr attr;
 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         get_device(&acpi_dev->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                         put_device(&acpi_dev->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         attr = acpi_get_dma_attr(acpi_dev);
 229         if (attr != DEV_DMA_NOT_SUPPORTED)
 230                 arch_setup_dma_ops(dev, 0, 0, NULL,
 231                                    attr == DEV_DMA_COHERENT);
 232
 233         acpi_physnode_link_name(physical_node_name, node_id);
 234         retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 235                                    physical_node_name);
 236         if (retval)
 237                 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
 238                         physical_node_name, retval);
 239
 240         retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 241                                    "firmware_node");
 242         if (retval)
 243                 dev_err(dev, "Failed to create link firmware_node (%d)\n",
 244                         retval);
 245
 246         mutex_unlock(&acpi_dev->physical_node_lock);
 247
 248         if (acpi_dev->wakeup.flags.valid)
 249                 device_set_wakeup_capable(dev, true);
 250
 251         return 0;
 252
 253  err:
 254         ACPI_COMPANION_SET(dev, NULL);
 255         put_device(dev);
 256         put_device(&acpi_dev->dev);
 257         return retval;
 258 }
 259 EXPORT_SYMBOL_GPL(acpi_bind_one);
 260
 261 int acpi_unbind_one(struct device *dev)
 262 {
 263         struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
 264         struct acpi_device_physical_node *entry;
 265
 266         if (!acpi_dev)
 267                 return 0;
 268
 269         mutex_lock(&acpi_dev->physical_node_lock);
 270
 271         list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
 272                 if (entry->dev == dev) {
 273                         char physnode_name[PHYSICAL_NODE_NAME_SIZE];
 274
 275                         list_del(&entry->node);
 276                         acpi_dev->physical_node_count--;
 277
 278                         acpi_physnode_link_name(physnode_name, entry->node_id);
 279                         sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
 280                         sysfs_remove_link(&dev->kobj, "firmware_node");
 281                         ACPI_COMPANION_SET(dev, NULL);
 282                         /* Drop references taken by acpi_bind_one(). */
 283                         put_device(dev);
 284                         put_device(&acpi_dev->dev);
 285                         kfree(entry);
 286                         break;
 287                 }
 288
 289         mutex_unlock(&acpi_dev->physical_node_lock);
 290         return 0;
 291 }
 292 EXPORT_SYMBOL_GPL(acpi_unbind_one);
 293
 294 static int acpi_platform_notify(struct device *dev)
 295 {
 296         struct acpi_bus_type *type = acpi_get_bus_type(dev);
 297         struct acpi_device *adev;
 298         int ret;
 299
 300         ret = acpi_bind_one(dev, NULL);
 301         if (ret && type) {
 302                 struct acpi_device *adev;
 303
 304                 adev = type->find_companion(dev);
 305                 if (!adev) {
 306                         DBG("Unable to get handle for %s\n", dev_name(dev));
 307                         ret = -ENODEV;
 308                         goto out;
 309                 }
 310                 ret = acpi_bind_one(dev, adev);
 311                 if (ret)
 312                         goto out;
 313         }
 314         adev = ACPI_COMPANION(dev);
 315         if (!adev)
 316                 goto out;
 317
 318         if (type && type->setup)
 319                 type->setup(dev);
 320         else if (adev->handler && adev->handler->bind)
 321                 adev->handler->bind(dev);
 322
 323  out:
 324 #if ACPI_GLUE_DEBUG
 325         if (!ret) {
 326                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 327
 328                 acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer);
 329                 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
 330                 kfree(buffer.pointer);
 331         } else
 332                 DBG("Device %s -> No ACPI support\n", dev_name(dev));
 333 #endif
 334
 335         return ret;
 336 }
 337
 338 static int acpi_platform_notify_remove(struct device *dev)
 339 {
 340         struct acpi_device *adev = ACPI_COMPANION(dev);
 341         struct acpi_bus_type *type;
 342
 343         if (!adev)
 344                 return 0;
 345
 346         type = acpi_get_bus_type(dev);
 347         if (type && type->cleanup)
 348                 type->cleanup(dev);
 349         else if (adev->handler && adev->handler->unbind)
 350                 adev->handler->unbind(dev);
 351
 352         acpi_unbind_one(dev);
 353         return 0;
 354 }
 355
 356 void __init init_acpi_device_notify(void)
 357 {
 358         if (platform_notify || platform_notify_remove) {
 359                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
 360                 return;
 361         }
 362         platform_notify = acpi_platform_notify;
 363         platform_notify_remove = acpi_platform_notify_remove;
 364 }