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