drivers/acpi/pci_root.c

   1 /*
   2  *  pci_root.c - ACPI PCI Root Bridge Driver ($Revision: 40 $)
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *
   7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or (at
  12  *  your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful, but
  15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *  General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License along
  20  *  with this program; if not, write to the Free Software Foundation, Inc.,
  21  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  22  *
  23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/module.h>
  28 #include <linux/init.h>
  29 #include <linux/types.h>
  30 #include <linux/mutex.h>
  31 #include <linux/pm.h>
  32 #include <linux/pm_runtime.h>
  33 #include <linux/pci.h>
  34 #include <linux/pci-acpi.h>
  35 #include <linux/pci-aspm.h>
  36 #include <linux/acpi.h>
  37 #include <linux/slab.h>
  38 #include <acpi/acpi_bus.h>
  39 #include <acpi/acpi_drivers.h>
  40 #include <acpi/apei.h>
  41
  42 #define PREFIX "ACPI: "
  43
  44 #define _COMPONENT              ACPI_PCI_COMPONENT
  45 ACPI_MODULE_NAME("pci_root");
  46 #define ACPI_PCI_ROOT_CLASS             "pci_bridge"
  47 #define ACPI_PCI_ROOT_DEVICE_NAME       "PCI Root Bridge"
  48 static int acpi_pci_root_add(struct acpi_device *device,
  49                              const struct acpi_device_id *not_used);
  50 static void acpi_pci_root_remove(struct acpi_device *device);
  51
  52 #define ACPI_PCIE_REQ_SUPPORT (OSC_EXT_PCI_CONFIG_SUPPORT \
  53                                 | OSC_ACTIVE_STATE_PWR_SUPPORT \
  54                                 | OSC_CLOCK_PWR_CAPABILITY_SUPPORT \
  55                                 | OSC_MSI_SUPPORT)
  56
  57 static const struct acpi_device_id root_device_ids[] = {
  58         {"PNP0A03", 0},
  59         {"", 0},
  60 };
  61
  62 static struct acpi_scan_handler pci_root_handler = {
  63         .ids = root_device_ids,
  64         .attach = acpi_pci_root_add,
  65         .detach = acpi_pci_root_remove,
  66 };
  67
  68 /* Lock to protect both acpi_pci_roots and acpi_pci_drivers lists */
  69 static DEFINE_MUTEX(acpi_pci_root_lock);
  70 static LIST_HEAD(acpi_pci_roots);
  71 static LIST_HEAD(acpi_pci_drivers);
  72
  73 static DEFINE_MUTEX(osc_lock);
  74
  75 int acpi_pci_register_driver(struct acpi_pci_driver *driver)
  76 {
  77         int n = 0;
  78         struct acpi_pci_root *root;
  79
  80         mutex_lock(&acpi_pci_root_lock);
  81         list_add_tail(&driver->node, &acpi_pci_drivers);
  82         if (driver->add)
  83                 list_for_each_entry(root, &acpi_pci_roots, node) {
  84                         driver->add(root);
  85                         n++;
  86                 }
  87         mutex_unlock(&acpi_pci_root_lock);
  88
  89         return n;
  90 }
  91 EXPORT_SYMBOL(acpi_pci_register_driver);
  92
  93 void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
  94 {
  95         struct acpi_pci_root *root;
  96
  97         mutex_lock(&acpi_pci_root_lock);
  98         list_del(&driver->node);
  99         if (driver->remove)
 100                 list_for_each_entry(root, &acpi_pci_roots, node)
 101                         driver->remove(root);
 102         mutex_unlock(&acpi_pci_root_lock);
 103 }
 104 EXPORT_SYMBOL(acpi_pci_unregister_driver);
 105
 106 /**
 107  * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
 108  * @handle - the ACPI CA node in question.
 109  *
 110  * Note: we could make this API take a struct acpi_device * instead, but
 111  * for now, it's more convenient to operate on an acpi_handle.
 112  */
 113 int acpi_is_root_bridge(acpi_handle handle)
 114 {
 115         int ret;
 116         struct acpi_device *device;
 117
 118         ret = acpi_bus_get_device(handle, &device);
 119         if (ret)
 120                 return 0;
 121
 122         ret = acpi_match_device_ids(device, root_device_ids);
 123         if (ret)
 124                 return 0;
 125         else
 126                 return 1;
 127 }
 128 EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
 129
 130 static acpi_status
 131 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
 132 {
 133         struct resource *res = data;
 134         struct acpi_resource_address64 address;
 135
 136         if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
 137             resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
 138             resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
 139                 return AE_OK;
 140
 141         acpi_resource_to_address64(resource, &address);
 142         if ((address.address_length > 0) &&
 143             (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
 144                 res->start = address.minimum;
 145                 res->end = address.minimum + address.address_length - 1;
 146         }
 147
 148         return AE_OK;
 149 }
 150
 151 static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
 152                                              struct resource *res)
 153 {
 154         acpi_status status;
 155
 156         res->start = -1;
 157         status =
 158             acpi_walk_resources(handle, METHOD_NAME__CRS,
 159                                 get_root_bridge_busnr_callback, res);
 160         if (ACPI_FAILURE(status))
 161                 return status;
 162         if (res->start == -1)
 163                 return AE_ERROR;
 164         return AE_OK;
 165 }
 166
 167 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
 168
 169 static acpi_status acpi_pci_run_osc(acpi_handle handle,
 170                                     const u32 *capbuf, u32 *retval)
 171 {
 172         struct acpi_osc_context context = {
 173                 .uuid_str = pci_osc_uuid_str,
 174                 .rev = 1,
 175                 .cap.length = 12,
 176                 .cap.pointer = (void *)capbuf,
 177         };
 178         acpi_status status;
 179
 180         status = acpi_run_osc(handle, &context);
 181         if (ACPI_SUCCESS(status)) {
 182                 *retval = *((u32 *)(context.ret.pointer + 8));
 183                 kfree(context.ret.pointer);
 184         }
 185         return status;
 186 }
 187
 188 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
 189                                         u32 support,
 190                                         u32 *control)
 191 {
 192         acpi_status status;
 193         u32 result, capbuf[3];
 194
 195         support &= OSC_PCI_SUPPORT_MASKS;
 196         support |= root->osc_support_set;
 197
 198         capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
 199         capbuf[OSC_SUPPORT_TYPE] = support;
 200         if (control) {
 201                 *control &= OSC_PCI_CONTROL_MASKS;
 202                 capbuf[OSC_CONTROL_TYPE] = *control | root->osc_control_set;
 203         } else {
 204                 /* Run _OSC query for all possible controls. */
 205                 capbuf[OSC_CONTROL_TYPE] = OSC_PCI_CONTROL_MASKS;
 206         }
 207
 208         status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
 209         if (ACPI_SUCCESS(status)) {
 210                 root->osc_support_set = support;
 211                 if (control)
 212                         *control = result;
 213         }
 214         return status;
 215 }
 216
 217 static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
 218 {
 219         acpi_status status;
 220         acpi_handle tmp;
 221
 222         status = acpi_get_handle(root->device->handle, "_OSC", &tmp);
 223         if (ACPI_FAILURE(status))
 224                 return status;
 225         mutex_lock(&osc_lock);
 226         status = acpi_pci_query_osc(root, flags, NULL);
 227         mutex_unlock(&osc_lock);
 228         return status;
 229 }
 230
 231 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
 232 {
 233         struct acpi_pci_root *root;
 234         struct acpi_device *device;
 235
 236         if (acpi_bus_get_device(handle, &device) ||
 237             acpi_match_device_ids(device, root_device_ids))
 238                 return NULL;
 239
 240         root = acpi_driver_data(device);
 241
 242         return root;
 243 }
 244 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
 245
 246 struct acpi_handle_node {
 247         struct list_head node;
 248         acpi_handle handle;
 249 };
 250
 251 /**
 252  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
 253  * @handle: the handle in question
 254  *
 255  * Given an ACPI CA handle, the desired PCI device is located in the
 256  * list of PCI devices.
 257  *
 258  * If the device is found, its reference count is increased and this
 259  * function returns a pointer to its data structure.  The caller must
 260  * decrement the reference count by calling pci_dev_put().
 261  * If no device is found, %NULL is returned.
 262  */
 263 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
 264 {
 265         int dev, fn;
 266         unsigned long long adr;
 267         acpi_status status;
 268         acpi_handle phandle;
 269         struct pci_bus *pbus;
 270         struct pci_dev *pdev = NULL;
 271         struct acpi_handle_node *node, *tmp;
 272         struct acpi_pci_root *root;
 273         LIST_HEAD(device_list);
 274
 275         /*
 276          * Walk up the ACPI CA namespace until we reach a PCI root bridge.
 277          */
 278         phandle = handle;
 279         while (!acpi_is_root_bridge(phandle)) {
 280                 node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
 281                 if (!node)
 282                         goto out;
 283
 284                 INIT_LIST_HEAD(&node->node);
 285                 node->handle = phandle;
 286                 list_add(&node->node, &device_list);
 287
 288                 status = acpi_get_parent(phandle, &phandle);
 289                 if (ACPI_FAILURE(status))
 290                         goto out;
 291         }
 292
 293         root = acpi_pci_find_root(phandle);
 294         if (!root)
 295                 goto out;
 296
 297         pbus = root->bus;
 298
 299         /*
 300          * Now, walk back down the PCI device tree until we return to our
 301          * original handle. Assumes that everything between the PCI root
 302          * bridge and the device we're looking for must be a P2P bridge.
 303          */
 304         list_for_each_entry(node, &device_list, node) {
 305                 acpi_handle hnd = node->handle;
 306                 status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
 307                 if (ACPI_FAILURE(status))
 308                         goto out;
 309                 dev = (adr >> 16) & 0xffff;
 310                 fn  = adr & 0xffff;
 311
 312                 pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
 313                 if (!pdev || hnd == handle)
 314                         break;
 315
 316                 pbus = pdev->subordinate;
 317                 pci_dev_put(pdev);
 318
 319                 /*
 320                  * This function may be called for a non-PCI device that has a
 321                  * PCI parent (eg. a disk under a PCI SATA controller).  In that
 322                  * case pdev->subordinate will be NULL for the parent.
 323                  */
 324                 if (!pbus) {
 325                         dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
 326                         pdev = NULL;
 327                         break;
 328                 }
 329         }
 330 out:
 331         list_for_each_entry_safe(node, tmp, &device_list, node)
 332                 kfree(node);
 333
 334         return pdev;
 335 }
 336 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
 337
 338 /**
 339  * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
 340  * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
 341  * @mask: Mask of _OSC bits to request control of, place to store control mask.
 342  * @req: Mask of _OSC bits the control of is essential to the caller.
 343  *
 344  * Run _OSC query for @mask and if that is successful, compare the returned
 345  * mask of control bits with @req.  If all of the @req bits are set in the
 346  * returned mask, run _OSC request for it.
 347  *
 348  * The variable at the @mask address may be modified regardless of whether or
 349  * not the function returns success.  On success it will contain the mask of
 350  * _OSC bits the BIOS has granted control of, but its contents are meaningless
 351  * on failure.
 352  **/
 353 acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
 354 {
 355         struct acpi_pci_root *root;
 356         acpi_status status;
 357         u32 ctrl, capbuf[3];
 358         acpi_handle tmp;
 359
 360         if (!mask)
 361                 return AE_BAD_PARAMETER;
 362
 363         ctrl = *mask & OSC_PCI_CONTROL_MASKS;
 364         if ((ctrl & req) != req)
 365                 return AE_TYPE;
 366
 367         root = acpi_pci_find_root(handle);
 368         if (!root)
 369                 return AE_NOT_EXIST;
 370
 371         status = acpi_get_handle(handle, "_OSC", &tmp);
 372         if (ACPI_FAILURE(status))
 373                 return status;
 374
 375         mutex_lock(&osc_lock);
 376
 377         *mask = ctrl | root->osc_control_set;
 378         /* No need to evaluate _OSC if the control was already granted. */
 379         if ((root->osc_control_set & ctrl) == ctrl)
 380                 goto out;
 381
 382         /* Need to check the available controls bits before requesting them. */
 383         while (*mask) {
 384                 status = acpi_pci_query_osc(root, root->osc_support_set, mask);
 385                 if (ACPI_FAILURE(status))
 386                         goto out;
 387                 if (ctrl == *mask)
 388                         break;
 389                 ctrl = *mask;
 390         }
 391
 392         if ((ctrl & req) != req) {
 393                 status = AE_SUPPORT;
 394                 goto out;
 395         }
 396
 397         capbuf[OSC_QUERY_TYPE] = 0;
 398         capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set;
 399         capbuf[OSC_CONTROL_TYPE] = ctrl;
 400         status = acpi_pci_run_osc(handle, capbuf, mask);
 401         if (ACPI_SUCCESS(status))
 402                 root->osc_control_set = *mask;
 403 out:
 404         mutex_unlock(&osc_lock);
 405         return status;
 406 }
 407 EXPORT_SYMBOL(acpi_pci_osc_control_set);
 408
 409 static int acpi_pci_root_add(struct acpi_device *device,
 410                              const struct acpi_device_id *not_used)
 411 {
 412         unsigned long long segment, bus;
 413         acpi_status status;
 414         int result;
 415         struct acpi_pci_root *root;
 416         struct acpi_pci_driver *driver;
 417         u32 flags, base_flags;
 418
 419         root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 420         if (!root)
 421                 return -ENOMEM;
 422
 423         segment = 0;
 424         status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
 425                                        &segment);
 426         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 427                 printk(KERN_ERR PREFIX "can't evaluate _SEG\n");
 428                 result = -ENODEV;
 429                 goto end;
 430         }
 431
 432         /* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
 433         root->secondary.flags = IORESOURCE_BUS;
 434         status = try_get_root_bridge_busnr(device->handle, &root->secondary);
 435         if (ACPI_FAILURE(status)) {
 436                 /*
 437                  * We need both the start and end of the downstream bus range
 438                  * to interpret _CBA (MMCONFIG base address), so it really is
 439                  * supposed to be in _CRS.  If we don't find it there, all we
 440                  * can do is assume [_BBN-0xFF] or [0-0xFF].
 441                  */
 442                 root->secondary.end = 0xFF;
 443                 printk(KERN_WARNING FW_BUG PREFIX
 444                        "no secondary bus range in _CRS\n");
 445                 status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN,
 446                                                NULL, &bus);
 447                 if (ACPI_SUCCESS(status))
 448                         root->secondary.start = bus;
 449                 else if (status == AE_NOT_FOUND)
 450                         root->secondary.start = 0;
 451                 else {
 452                         printk(KERN_ERR PREFIX "can't evaluate _BBN\n");
 453                         result = -ENODEV;
 454                         goto end;
 455                 }
 456         }
 457
 458         INIT_LIST_HEAD(&root->node);
 459         root->device = device;
 460         root->segment = segment & 0xFFFF;
 461         strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
 462         strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 463         device->driver_data = root;
 464
 465         printk(KERN_INFO PREFIX "%s [%s] (domain %04x %pR)\n",
 466                acpi_device_name(device), acpi_device_bid(device),
 467                root->segment, &root->secondary);
 468
 469         root->mcfg_addr = acpi_pci_root_get_mcfg_addr(device->handle);
 470
 471         /*
 472          * All supported architectures that use ACPI have support for
 473          * PCI domains, so we indicate this in _OSC support capabilities.
 474          */
 475         flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
 476         acpi_pci_osc_support(root, flags);
 477
 478         /*
 479          * TBD: Need PCI interface for enumeration/configuration of roots.
 480          */
 481
 482         mutex_lock(&acpi_pci_root_lock);
 483         list_add_tail(&root->node, &acpi_pci_roots);
 484         mutex_unlock(&acpi_pci_root_lock);
 485
 486         /*
 487          * Scan the Root Bridge
 488          * --------------------
 489          * Must do this prior to any attempt to bind the root device, as the
 490          * PCI namespace does not get created until this call is made (and
 491          * thus the root bridge's pci_dev does not exist).
 492          */
 493         root->bus = pci_acpi_scan_root(root);
 494         if (!root->bus) {
 495                 printk(KERN_ERR PREFIX
 496                             "Bus %04x:%02x not present in PCI namespace\n",
 497                             root->segment, (unsigned int)root->secondary.start);
 498                 result = -ENODEV;
 499                 goto out_del_root;
 500         }
 501
 502         /* Indicate support for various _OSC capabilities. */
 503         if (pci_ext_cfg_avail())
 504                 flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
 505         if (pcie_aspm_support_enabled()) {
 506                 flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
 507                 OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
 508         }
 509         if (pci_msi_enabled())
 510                 flags |= OSC_MSI_SUPPORT;
 511         if (flags != base_flags) {
 512                 status = acpi_pci_osc_support(root, flags);
 513                 if (ACPI_FAILURE(status)) {
 514                         dev_info(&device->dev, "ACPI _OSC support "
 515                                 "notification failed, disabling PCIe ASPM\n");
 516                         pcie_no_aspm();
 517                         flags = base_flags;
 518                 }
 519         }
 520
 521         if (!pcie_ports_disabled
 522             && (flags & ACPI_PCIE_REQ_SUPPORT) == ACPI_PCIE_REQ_SUPPORT) {
 523                 flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL
 524                         | OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
 525                         | OSC_PCI_EXPRESS_PME_CONTROL;
 526
 527                 if (pci_aer_available()) {
 528                         if (aer_acpi_firmware_first())
 529                                 dev_dbg(&device->dev,
 530                                         "PCIe errors handled by BIOS.\n");
 531                         else
 532                                 flags |= OSC_PCI_EXPRESS_AER_CONTROL;
 533                 }
 534
 535                 dev_info(&device->dev,
 536                         "Requesting ACPI _OSC control (0x%02x)\n", flags);
 537
 538                 status = acpi_pci_osc_control_set(device->handle, &flags,
 539                                        OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
 540                 if (ACPI_SUCCESS(status)) {
 541                         dev_info(&device->dev,
 542                                 "ACPI _OSC control (0x%02x) granted\n", flags);
 543                         if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 544                                 /*
 545                                  * We have ASPM control, but the FADT indicates
 546                                  * that it's unsupported. Clear it.
 547                                  */
 548                                 pcie_clear_aspm(root->bus);
 549                         }
 550                 } else {
 551                         dev_info(&device->dev,
 552                                 "ACPI _OSC request failed (%s), "
 553                                 "returned control mask: 0x%02x\n",
 554                                 acpi_format_exception(status), flags);
 555                         pr_info("ACPI _OSC control for PCIe not granted, "
 556                                 "disabling ASPM\n");
 557                         pcie_no_aspm();
 558                 }
 559         } else {
 560                 dev_info(&device->dev,
 561                          "Unable to request _OSC control "
 562                          "(_OSC support mask: 0x%02x)\n", flags);
 563         }
 564
 565         pci_acpi_add_bus_pm_notifier(device, root->bus);
 566         if (device->wakeup.flags.run_wake)
 567                 device_set_run_wake(root->bus->bridge, true);
 568
 569         if (system_state != SYSTEM_BOOTING) {
 570                 pcibios_resource_survey_bus(root->bus);
 571                 pci_assign_unassigned_bus_resources(root->bus);
 572         }
 573
 574         mutex_lock(&acpi_pci_root_lock);
 575         list_for_each_entry(driver, &acpi_pci_drivers, node)
 576                 if (driver->add)
 577                         driver->add(root);
 578         mutex_unlock(&acpi_pci_root_lock);
 579
 580         /* need to after hot-added ioapic is registered */
 581         if (system_state != SYSTEM_BOOTING)
 582                 pci_enable_bridges(root->bus);
 583
 584         pci_bus_add_devices(root->bus);
 585         return 1;
 586
 587 out_del_root:
 588         mutex_lock(&acpi_pci_root_lock);
 589         list_del(&root->node);
 590         mutex_unlock(&acpi_pci_root_lock);
 591
 592 end:
 593         kfree(root);
 594         return result;
 595 }
 596
 597 static void acpi_pci_root_remove(struct acpi_device *device)
 598 {
 599         struct acpi_pci_root *root = acpi_driver_data(device);
 600         struct acpi_pci_driver *driver;
 601
 602         pci_stop_root_bus(root->bus);
 603
 604         mutex_lock(&acpi_pci_root_lock);
 605         list_for_each_entry_reverse(driver, &acpi_pci_drivers, node)
 606                 if (driver->remove)
 607                         driver->remove(root);
 608         mutex_unlock(&acpi_pci_root_lock);
 609
 610         device_set_run_wake(root->bus->bridge, false);
 611         pci_acpi_remove_bus_pm_notifier(device);
 612
 613         pci_remove_root_bus(root->bus);
 614
 615         mutex_lock(&acpi_pci_root_lock);
 616         list_del(&root->node);
 617         mutex_unlock(&acpi_pci_root_lock);
 618         kfree(root);
 619 }
 620
 621 void __init acpi_pci_root_init(void)
 622 {
 623         acpi_hest_init();
 624
 625         if (!acpi_pci_disabled) {
 626                 pci_acpi_crs_quirks();
 627                 acpi_scan_add_handler(&pci_root_handler);
 628         }
 629 }
 630 /* Support root bridge hotplug */
 631
 632 static void handle_root_bridge_insertion(acpi_handle handle)
 633 {
 634         struct acpi_device *device;
 635
 636         if (!acpi_bus_get_device(handle, &device)) {
 637                 printk(KERN_DEBUG "acpi device exists...\n");
 638                 return;
 639         }
 640
 641         if (acpi_bus_scan(handle))
 642                 printk(KERN_ERR "cannot add bridge to acpi list\n");
 643 }
 644
 645 static void handle_root_bridge_removal(struct acpi_device *device)
 646 {
 647         acpi_status status;
 648         struct acpi_eject_event *ej_event;
 649
 650         ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
 651         if (!ej_event) {
 652                 /* Inform firmware the hot-remove operation has error */
 653                 (void) acpi_evaluate_hotplug_ost(device->handle,
 654                                         ACPI_NOTIFY_EJECT_REQUEST,
 655                                         ACPI_OST_SC_NON_SPECIFIC_FAILURE,
 656                                         NULL);
 657                 return;
 658         }
 659
 660         ej_event->device = device;
 661         ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
 662
 663         status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device, ej_event);
 664         if (ACPI_FAILURE(status))
 665                 kfree(ej_event);
 666 }
 667
 668 static void _handle_hotplug_event_root(struct work_struct *work)
 669 {
 670         struct acpi_pci_root *root;
 671         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER };
 672         struct acpi_hp_work *hp_work;
 673         acpi_handle handle;
 674         u32 type;
 675
 676         hp_work = container_of(work, struct acpi_hp_work, work);
 677         handle = hp_work->handle;
 678         type = hp_work->type;
 679
 680         acpi_scan_lock_acquire();
 681
 682         root = acpi_pci_find_root(handle);
 683         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 684
 685         switch (type) {
 686         case ACPI_NOTIFY_BUS_CHECK:
 687                 /* bus enumerate */
 688                 printk(KERN_DEBUG "%s: Bus check notify on %s\n", __func__,
 689                                  (char *)buffer.pointer);
 690                 if (!root)
 691                         handle_root_bridge_insertion(handle);
 692
 693                 break;
 694
 695         case ACPI_NOTIFY_DEVICE_CHECK:
 696                 /* device check */
 697                 printk(KERN_DEBUG "%s: Device check notify on %s\n", __func__,
 698                                  (char *)buffer.pointer);
 699                 if (!root)
 700                         handle_root_bridge_insertion(handle);
 701                 break;
 702
 703         case ACPI_NOTIFY_EJECT_REQUEST:
 704                 /* request device eject */
 705                 printk(KERN_DEBUG "%s: Device eject notify on %s\n", __func__,
 706                                  (char *)buffer.pointer);
 707                 if (root)
 708                         handle_root_bridge_removal(root->device);
 709                 break;
 710         default:
 711                 printk(KERN_WARNING "notify_handler: unknown event type 0x%x for %s\n",
 712                                  type, (char *)buffer.pointer);
 713                 break;
 714         }
 715
 716         acpi_scan_lock_release();
 717         kfree(hp_work); /* allocated in handle_hotplug_event_bridge */
 718         kfree(buffer.pointer);
 719 }
 720
 721 static void handle_hotplug_event_root(acpi_handle handle, u32 type,
 722                                         void *context)
 723 {
 724         alloc_acpi_hp_work(handle, type, context,
 725                                 _handle_hotplug_event_root);
 726 }
 727
 728 static acpi_status __init
 729 find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
 730 {
 731         acpi_status status;
 732         char objname[64];
 733         struct acpi_buffer buffer = { .length = sizeof(objname),
 734                                       .pointer = objname };
 735         int *count = (int *)context;
 736
 737         if (!acpi_is_root_bridge(handle))
 738                 return AE_OK;
 739
 740         (*count)++;
 741
 742         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 743
 744         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 745                                         handle_hotplug_event_root, NULL);
 746         if (ACPI_FAILURE(status))
 747                 printk(KERN_DEBUG "acpi root: %s notify handler is not installed, exit status: %u\n",
 748                                   objname, (unsigned int)status);
 749         else
 750                 printk(KERN_DEBUG "acpi root: %s notify handler is installed\n",
 751                                  objname);
 752
 753         return AE_OK;
 754 }
 755
 756 void __init acpi_pci_root_hp_init(void)
 757 {
 758         int num = 0;
 759
 760         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 761                 ACPI_UINT32_MAX, find_root_bridges, NULL, &num, NULL);
 762
 763         printk(KERN_DEBUG "Found %d acpi root devices\n", num);
 764 }