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
  17 #include "internal.h"
  18
  19 #define ACPI_GLUE_DEBUG 0
  20 #if ACPI_GLUE_DEBUG
  21 #define DBG(fmt, ...)                                           \
  22         printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__)
  23 #else
  24 #define DBG(fmt, ...)                                           \
  25 do {                                                            \
  26         if (0)                                                  \
  27                 printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__);   \
  28 } while (0)
  29 #endif
  30 static LIST_HEAD(bus_type_list);
  31 static DECLARE_RWSEM(bus_type_sem);
  32
  33 #define PHYSICAL_NODE_STRING "physical_node"
  34 #define PHYSICAL_NODE_NAME_SIZE (sizeof(PHYSICAL_NODE_STRING) + 10)
  35
  36 int register_acpi_bus_type(struct acpi_bus_type *type)
  37 {
  38         if (acpi_disabled)
  39                 return -ENODEV;
  40         if (type && type->match && type->find_device) {
  41                 down_write(&bus_type_sem);
  42                 list_add_tail(&type->list, &bus_type_list);
  43                 up_write(&bus_type_sem);
  44                 printk(KERN_INFO PREFIX "bus type %s registered\n", type->name);
  45                 return 0;
  46         }
  47         return -ENODEV;
  48 }
  49 EXPORT_SYMBOL_GPL(register_acpi_bus_type);
  50
  51 int unregister_acpi_bus_type(struct acpi_bus_type *type)
  52 {
  53         if (acpi_disabled)
  54                 return 0;
  55         if (type) {
  56                 down_write(&bus_type_sem);
  57                 list_del_init(&type->list);
  58                 up_write(&bus_type_sem);
  59                 printk(KERN_INFO PREFIX "bus type %s unregistered\n",
  60                        type->name);
  61                 return 0;
  62         }
  63         return -ENODEV;
  64 }
  65 EXPORT_SYMBOL_GPL(unregister_acpi_bus_type);
  66
  67 static struct acpi_bus_type *acpi_get_bus_type(struct device *dev)
  68 {
  69         struct acpi_bus_type *tmp, *ret = NULL;
  70
  71         down_read(&bus_type_sem);
  72         list_for_each_entry(tmp, &bus_type_list, list) {
  73                 if (tmp->match(dev)) {
  74                         ret = tmp;
  75                         break;
  76                 }
  77         }
  78         up_read(&bus_type_sem);
  79         return ret;
  80 }
  81
  82 #define FIND_CHILD_MIN_SCORE    1
  83 #define FIND_CHILD_MAX_SCORE    2
  84
  85 static acpi_status acpi_dev_present(acpi_handle handle, u32 lvl_not_used,
  86                                   void *not_used, void **ret_p)
  87 {
  88         struct acpi_device *adev = NULL;
  89
  90         acpi_bus_get_device(handle, &adev);
  91         if (adev) {
  92                 *ret_p = handle;
  93                 return AE_CTRL_TERMINATE;
  94         }
  95         return AE_OK;
  96 }
  97
  98 static int do_find_child_checks(acpi_handle handle, bool is_bridge)
  99 {
 100         bool sta_present = true;
 101         unsigned long long sta;
 102         acpi_status status;
 103
 104         status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 105         if (status == AE_NOT_FOUND)
 106                 sta_present = false;
 107         else if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED))
 108                 return -ENODEV;
 109
 110         if (is_bridge) {
 111                 void *test = NULL;
 112
 113                 /* Check if this object has at least one child device. */
 114                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
 115                                     acpi_dev_present, NULL, NULL, &test);
 116                 if (!test)
 117                         return -ENODEV;
 118         }
 119         return sta_present ? FIND_CHILD_MAX_SCORE : FIND_CHILD_MIN_SCORE;
 120 }
 121
 122 struct find_child_context {
 123         u64 addr;
 124         bool is_bridge;
 125         acpi_handle ret;
 126         int ret_score;
 127 };
 128
 129 static acpi_status do_find_child(acpi_handle handle, u32 lvl_not_used,
 130                                  void *data, void **not_used)
 131 {
 132         struct find_child_context *context = data;
 133         unsigned long long addr;
 134         acpi_status status;
 135         int score;
 136
 137         status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &addr);
 138         if (ACPI_FAILURE(status) || addr != context->addr)
 139                 return AE_OK;
 140
 141         if (!context->ret) {
 142                 /* This is the first matching object.  Save its handle. */
 143                 context->ret = handle;
 144                 return AE_OK;
 145         }
 146         /*
 147          * There is more than one matching object with the same _ADR value.
 148          * That really is unexpected, so we are kind of beyond the scope of the
 149          * spec here.  We have to choose which one to return, though.
 150          *
 151          * First, check if the previously found object is good enough and return
 152          * its handle if so.  Second, check the same for the object that we've
 153          * just found.
 154          */
 155         if (!context->ret_score) {
 156                 score = do_find_child_checks(context->ret, context->is_bridge);
 157                 if (score == FIND_CHILD_MAX_SCORE)
 158                         return AE_CTRL_TERMINATE;
 159                 else
 160                         context->ret_score = score;
 161         }
 162         score = do_find_child_checks(handle, context->is_bridge);
 163         if (score == FIND_CHILD_MAX_SCORE) {
 164                 context->ret = handle;
 165                 return AE_CTRL_TERMINATE;
 166         } else if (score > context->ret_score) {
 167                 context->ret = handle;
 168                 context->ret_score = score;
 169         }
 170         return AE_OK;
 171 }
 172
 173 acpi_handle acpi_find_child(acpi_handle parent, u64 addr, bool is_bridge)
 174 {
 175         if (parent) {
 176                 struct find_child_context context = {
 177                         .addr = addr,
 178                         .is_bridge = is_bridge,
 179                 };
 180
 181                 acpi_walk_namespace(ACPI_TYPE_DEVICE, parent, 1, do_find_child,
 182                                     NULL, &context, NULL);
 183                 return context.ret;
 184         }
 185         return NULL;
 186 }
 187 EXPORT_SYMBOL_GPL(acpi_find_child);
 188
 189 static void acpi_physnode_link_name(char *buf, unsigned int node_id)
 190 {
 191         if (node_id > 0)
 192                 snprintf(buf, PHYSICAL_NODE_NAME_SIZE,
 193                          PHYSICAL_NODE_STRING "%u", node_id);
 194         else
 195                 strcpy(buf, PHYSICAL_NODE_STRING);
 196 }
 197
 198 int acpi_bind_one(struct device *dev, acpi_handle handle)
 199 {
 200         struct acpi_device *acpi_dev;
 201         acpi_status status;
 202         struct acpi_device_physical_node *physical_node, *pn;
 203         char physical_node_name[PHYSICAL_NODE_NAME_SIZE];
 204         struct list_head *physnode_list;
 205         unsigned int node_id;
 206         int retval = -EINVAL;
 207
 208         if (ACPI_HANDLE(dev)) {
 209                 if (handle) {
 210                         dev_warn(dev, "ACPI handle is already set\n");
 211                         return -EINVAL;
 212                 } else {
 213                         handle = ACPI_HANDLE(dev);
 214                 }
 215         }
 216         if (!handle)
 217                 return -EINVAL;
 218
 219         get_device(dev);
 220         status = acpi_bus_get_device(handle, &acpi_dev);
 221         if (ACPI_FAILURE(status))
 222                 goto err;
 223
 224         physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
 225         if (!physical_node) {
 226                 retval = -ENOMEM;
 227                 goto err;
 228         }
 229
 230         mutex_lock(&acpi_dev->physical_node_lock);
 231
 232         /*
 233          * Keep the list sorted by node_id so that the IDs of removed nodes can
 234          * be recycled easily.
 235          */
 236         physnode_list = &acpi_dev->physical_node_list;
 237         node_id = 0;
 238         list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
 239                 /* Sanity check. */
 240                 if (pn->dev == dev) {
 241                         mutex_unlock(&acpi_dev->physical_node_lock);
 242
 243                         dev_warn(dev, "Already associated with ACPI node\n");
 244                         kfree(physical_node);
 245                         if (ACPI_HANDLE(dev) != handle)
 246                                 goto err;
 247
 248                         put_device(dev);
 249                         return 0;
 250                 }
 251                 if (pn->node_id == node_id) {
 252                         physnode_list = &pn->node;
 253                         node_id++;
 254                 }
 255         }
 256
 257         physical_node->node_id = node_id;
 258         physical_node->dev = dev;
 259         list_add(&physical_node->node, physnode_list);
 260         acpi_dev->physical_node_count++;
 261
 262         if (!ACPI_HANDLE(dev))
 263                 ACPI_HANDLE_SET(dev, acpi_dev->handle);
 264
 265         acpi_physnode_link_name(physical_node_name, node_id);
 266         retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 267                                    physical_node_name);
 268         if (retval)
 269                 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
 270                         physical_node_name, retval);
 271
 272         retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 273                                    "firmware_node");
 274         if (retval)
 275                 dev_err(dev, "Failed to create link firmware_node (%d)\n",
 276                         retval);
 277
 278         mutex_unlock(&acpi_dev->physical_node_lock);
 279
 280         if (acpi_dev->wakeup.flags.valid)
 281                 device_set_wakeup_capable(dev, true);
 282
 283         return 0;
 284
 285  err:
 286         ACPI_HANDLE_SET(dev, NULL);
 287         put_device(dev);
 288         return retval;
 289 }
 290 EXPORT_SYMBOL_GPL(acpi_bind_one);
 291
 292 int acpi_unbind_one(struct device *dev)
 293 {
 294         struct acpi_device_physical_node *entry;
 295         struct acpi_device *acpi_dev;
 296         acpi_status status;
 297
 298         if (!ACPI_HANDLE(dev))
 299                 return 0;
 300
 301         status = acpi_bus_get_device(ACPI_HANDLE(dev), &acpi_dev);
 302         if (ACPI_FAILURE(status)) {
 303                 dev_err(dev, "Oops, ACPI handle corrupt in %s()\n", __func__);
 304                 return -EINVAL;
 305         }
 306
 307         mutex_lock(&acpi_dev->physical_node_lock);
 308
 309         list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
 310                 if (entry->dev == dev) {
 311                         char physnode_name[PHYSICAL_NODE_NAME_SIZE];
 312
 313                         list_del(&entry->node);
 314                         acpi_dev->physical_node_count--;
 315
 316                         acpi_physnode_link_name(physnode_name, entry->node_id);
 317                         sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
 318                         sysfs_remove_link(&dev->kobj, "firmware_node");
 319                         ACPI_HANDLE_SET(dev, NULL);
 320                         /* acpi_bind_one() increase refcnt by one. */
 321                         put_device(dev);
 322                         kfree(entry);
 323                         break;
 324                 }
 325
 326         mutex_unlock(&acpi_dev->physical_node_lock);
 327         return 0;
 328 }
 329 EXPORT_SYMBOL_GPL(acpi_unbind_one);
 330
 331 static int acpi_platform_notify(struct device *dev)
 332 {
 333         struct acpi_bus_type *type = acpi_get_bus_type(dev);
 334         acpi_handle handle;
 335         int ret;
 336
 337         ret = acpi_bind_one(dev, NULL);
 338         if (ret && type) {
 339                 ret = type->find_device(dev, &handle);
 340                 if (ret) {
 341                         DBG("Unable to get handle for %s\n", dev_name(dev));
 342                         goto out;
 343                 }
 344                 ret = acpi_bind_one(dev, handle);
 345                 if (ret)
 346                         goto out;
 347         }
 348
 349         if (type && type->setup)
 350                 type->setup(dev);
 351
 352  out:
 353 #if ACPI_GLUE_DEBUG
 354         if (!ret) {
 355                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 356
 357                 acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer);
 358                 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
 359                 kfree(buffer.pointer);
 360         } else
 361                 DBG("Device %s -> No ACPI support\n", dev_name(dev));
 362 #endif
 363
 364         return ret;
 365 }
 366
 367 static int acpi_platform_notify_remove(struct device *dev)
 368 {
 369         struct acpi_bus_type *type;
 370
 371         type = acpi_get_bus_type(dev);
 372         if (type && type->cleanup)
 373                 type->cleanup(dev);
 374
 375         acpi_unbind_one(dev);
 376         return 0;
 377 }
 378
 379 int __init init_acpi_device_notify(void)
 380 {
 381         if (platform_notify || platform_notify_remove) {
 382                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
 383                 return 0;
 384         }
 385         platform_notify = acpi_platform_notify;
 386         platform_notify_remove = acpi_platform_notify_remove;
 387         return 0;
 388 }