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         enum dev_dma_attr attr;
 183
 184         if (has_acpi_companion(dev)) {
 185                 if (acpi_dev) {
 186                         dev_warn(dev, "ACPI companion already set\n");
 187                         return -EINVAL;
 188                 } else {
 189                         acpi_dev = ACPI_COMPANION(dev);
 190                 }
 191         }
 192         if (!acpi_dev)
 193                 return -EINVAL;
 194
 195         get_device(&acpi_dev->dev);
 196         get_device(dev);
 197         physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL);
 198         if (!physical_node) {
 199                 retval = -ENOMEM;
 200                 goto err;
 201         }
 202
 203         mutex_lock(&acpi_dev->physical_node_lock);
 204
 205         /*
 206          * Keep the list sorted by node_id so that the IDs of removed nodes can
 207          * be recycled easily.
 208          */
 209         physnode_list = &acpi_dev->physical_node_list;
 210         node_id = 0;
 211         list_for_each_entry(pn, &acpi_dev->physical_node_list, node) {
 212                 /* Sanity check. */
 213                 if (pn->dev == dev) {
 214                         mutex_unlock(&acpi_dev->physical_node_lock);
 215
 216                         dev_warn(dev, "Already associated with ACPI node\n");
 217                         kfree(physical_node);
 218                         if (ACPI_COMPANION(dev) != acpi_dev)
 219                                 goto err;
 220
 221                         put_device(dev);
 222                         put_device(&acpi_dev->dev);
 223                         return 0;
 224                 }
 225                 if (pn->node_id == node_id) {
 226                         physnode_list = &pn->node;
 227                         node_id++;
 228                 }
 229         }
 230
 231         physical_node->node_id = node_id;
 232         physical_node->dev = dev;
 233         list_add(&physical_node->node, physnode_list);
 234         acpi_dev->physical_node_count++;
 235
 236         if (!has_acpi_companion(dev))
 237                 ACPI_COMPANION_SET(dev, acpi_dev);
 238
 239         attr = acpi_get_dma_attr(acpi_dev);
 240         if (attr != DEV_DMA_NOT_SUPPORTED)
 241                 acpi_dma_configure(dev, attr);
 242
 243         acpi_physnode_link_name(physical_node_name, node_id);
 244         retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 245                                    physical_node_name);
 246         if (retval)
 247                 dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n",
 248                         physical_node_name, retval);
 249
 250         retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj,
 251                                    "firmware_node");
 252         if (retval)
 253                 dev_err(dev, "Failed to create link firmware_node (%d)\n",
 254                         retval);
 255
 256         mutex_unlock(&acpi_dev->physical_node_lock);
 257
 258         if (acpi_dev->wakeup.flags.valid)
 259                 device_set_wakeup_capable(dev, true);
 260
 261         return 0;
 262
 263  err:
 264         ACPI_COMPANION_SET(dev, NULL);
 265         put_device(dev);
 266         put_device(&acpi_dev->dev);
 267         return retval;
 268 }
 269 EXPORT_SYMBOL_GPL(acpi_bind_one);
 270
 271 int acpi_unbind_one(struct device *dev)
 272 {
 273         struct acpi_device *acpi_dev = ACPI_COMPANION(dev);
 274         struct acpi_device_physical_node *entry;
 275
 276         if (!acpi_dev)
 277                 return 0;
 278
 279         mutex_lock(&acpi_dev->physical_node_lock);
 280
 281         list_for_each_entry(entry, &acpi_dev->physical_node_list, node)
 282                 if (entry->dev == dev) {
 283                         char physnode_name[PHYSICAL_NODE_NAME_SIZE];
 284
 285                         list_del(&entry->node);
 286                         acpi_dev->physical_node_count--;
 287
 288                         acpi_physnode_link_name(physnode_name, entry->node_id);
 289                         sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name);
 290                         sysfs_remove_link(&dev->kobj, "firmware_node");
 291                         ACPI_COMPANION_SET(dev, NULL);
 292                         /* Drop references taken by acpi_bind_one(). */
 293                         put_device(dev);
 294                         put_device(&acpi_dev->dev);
 295                         kfree(entry);
 296                         break;
 297                 }
 298
 299         mutex_unlock(&acpi_dev->physical_node_lock);
 300         return 0;
 301 }
 302 EXPORT_SYMBOL_GPL(acpi_unbind_one);
 303
 304 static int acpi_platform_notify(struct device *dev)
 305 {
 306         struct acpi_bus_type *type = acpi_get_bus_type(dev);
 307         struct acpi_device *adev;
 308         int ret;
 309
 310         ret = acpi_bind_one(dev, NULL);
 311         if (ret && type) {
 312                 struct acpi_device *adev;
 313
 314                 adev = type->find_companion(dev);
 315                 if (!adev) {
 316                         DBG("Unable to get handle for %s\n", dev_name(dev));
 317                         ret = -ENODEV;
 318                         goto out;
 319                 }
 320                 ret = acpi_bind_one(dev, adev);
 321                 if (ret)
 322                         goto out;
 323         }
 324         adev = ACPI_COMPANION(dev);
 325         if (!adev)
 326                 goto out;
 327
 328         if (dev->bus == &platform_bus_type)
 329                 acpi_configure_pmsi_domain(dev);
 330
 331         if (type && type->setup)
 332                 type->setup(dev);
 333         else if (adev->handler && adev->handler->bind)
 334                 adev->handler->bind(dev);
 335
 336  out:
 337 #if ACPI_GLUE_DEBUG
 338         if (!ret) {
 339                 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 340
 341                 acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer);
 342                 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer);
 343                 kfree(buffer.pointer);
 344         } else
 345                 DBG("Device %s -> No ACPI support\n", dev_name(dev));
 346 #endif
 347
 348         return ret;
 349 }
 350
 351 static int acpi_platform_notify_remove(struct device *dev)
 352 {
 353         struct acpi_device *adev = ACPI_COMPANION(dev);
 354         struct acpi_bus_type *type;
 355
 356         if (!adev)
 357                 return 0;
 358
 359         type = acpi_get_bus_type(dev);
 360         if (type && type->cleanup)
 361                 type->cleanup(dev);
 362         else if (adev->handler && adev->handler->unbind)
 363                 adev->handler->unbind(dev);
 364
 365         acpi_unbind_one(dev);
 366         return 0;
 367 }
 368
 369 void __init init_acpi_device_notify(void)
 370 {
 371         if (platform_notify || platform_notify_remove) {
 372                 printk(KERN_ERR PREFIX "Can't use platform_notify\n");
 373                 return;
 374         }
 375         platform_notify = acpi_platform_notify;
 376         platform_notify_remove = acpi_platform_notify_remove;
 377 }