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         bool is_osc_granted = false;
 419
 420         root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 421         if (!root)
 422                 return -ENOMEM;
 423
 424         segment = 0;
 425         status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
 426                                        &segment);
 427         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 428                 printk(KERN_ERR PREFIX "can't evaluate _SEG\n");
 429                 result = -ENODEV;
 430                 goto end;
 431         }
 432
 433         /* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
 434         root->secondary.flags = IORESOURCE_BUS;
 435         status = try_get_root_bridge_busnr(device->handle, &root->secondary);
 436         if (ACPI_FAILURE(status)) {
 437                 /*
 438                  * We need both the start and end of the downstream bus range
 439                  * to interpret _CBA (MMCONFIG base address), so it really is
 440                  * supposed to be in _CRS.  If we don't find it there, all we
 441                  * can do is assume [_BBN-0xFF] or [0-0xFF].
 442                  */
 443                 root->secondary.end = 0xFF;
 444                 printk(KERN_WARNING FW_BUG PREFIX
 445                        "no secondary bus range in _CRS\n");
 446                 status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN,
 447                                                NULL, &bus);
 448                 if (ACPI_SUCCESS(status))
 449                         root->secondary.start = bus;
 450                 else if (status == AE_NOT_FOUND)
 451                         root->secondary.start = 0;
 452                 else {
 453                         printk(KERN_ERR PREFIX "can't evaluate _BBN\n");
 454                         result = -ENODEV;
 455                         goto end;
 456                 }
 457         }
 458
 459         INIT_LIST_HEAD(&root->node);
 460         root->device = device;
 461         root->segment = segment & 0xFFFF;
 462         strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
 463         strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 464         device->driver_data = root;
 465
 466         printk(KERN_INFO PREFIX "%s [%s] (domain %04x %pR)\n",
 467                acpi_device_name(device), acpi_device_bid(device),
 468                root->segment, &root->secondary);
 469
 470         root->mcfg_addr = acpi_pci_root_get_mcfg_addr(device->handle);
 471
 472         /*
 473          * All supported architectures that use ACPI have support for
 474          * PCI domains, so we indicate this in _OSC support capabilities.
 475          */
 476         flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
 477         acpi_pci_osc_support(root, flags);
 478
 479         /* Indicate support for various _OSC capabilities. */
 480         if (pci_ext_cfg_avail())
 481                 flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
 482         if (pcie_aspm_support_enabled()) {
 483                 flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
 484                 OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
 485         }
 486         if (pci_msi_enabled())
 487                 flags |= OSC_MSI_SUPPORT;
 488         if (flags != base_flags) {
 489                 status = acpi_pci_osc_support(root, flags);
 490                 if (ACPI_FAILURE(status)) {
 491                         dev_info(&device->dev, "ACPI _OSC support "
 492                                 "notification failed, disabling PCIe ASPM\n");
 493                         pcie_no_aspm();
 494                         flags = base_flags;
 495                 }
 496         }
 497         if (!pcie_ports_disabled
 498             && (flags & ACPI_PCIE_REQ_SUPPORT) == ACPI_PCIE_REQ_SUPPORT) {
 499                 flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL
 500                         | OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
 501                         | OSC_PCI_EXPRESS_PME_CONTROL;
 502
 503                 if (pci_aer_available()) {
 504                         if (aer_acpi_firmware_first())
 505                                 dev_dbg(&device->dev,
 506                                         "PCIe errors handled by BIOS.\n");
 507                         else
 508                                 flags |= OSC_PCI_EXPRESS_AER_CONTROL;
 509                 }
 510
 511                 dev_info(&device->dev,
 512                         "Requesting ACPI _OSC control (0x%02x)\n", flags);
 513
 514                 status = acpi_pci_osc_control_set(device->handle, &flags,
 515                                        OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
 516                 if (ACPI_SUCCESS(status)) {
 517                         is_osc_granted = true;
 518                         dev_info(&device->dev,
 519                                 "ACPI _OSC control (0x%02x) granted\n", flags);
 520                 } else {
 521                         is_osc_granted = false;
 522                         dev_info(&device->dev,
 523                                 "ACPI _OSC request failed (%s), "
 524                                 "returned control mask: 0x%02x\n",
 525                                 acpi_format_exception(status), flags);
 526                 }
 527         } else {
 528                 dev_info(&device->dev,
 529                         "Unable to request _OSC control "
 530                         "(_OSC support mask: 0x%02x)\n", flags);
 531         }
 532
 533         /*
 534          * TBD: Need PCI interface for enumeration/configuration of roots.
 535          */
 536
 537         mutex_lock(&acpi_pci_root_lock);
 538         list_add_tail(&root->node, &acpi_pci_roots);
 539         mutex_unlock(&acpi_pci_root_lock);
 540
 541         /*
 542          * Scan the Root Bridge
 543          * --------------------
 544          * Must do this prior to any attempt to bind the root device, as the
 545          * PCI namespace does not get created until this call is made (and
 546          * thus the root bridge's pci_dev does not exist).
 547          */
 548         root->bus = pci_acpi_scan_root(root);
 549         if (!root->bus) {
 550                 printk(KERN_ERR PREFIX
 551                             "Bus %04x:%02x not present in PCI namespace\n",
 552                             root->segment, (unsigned int)root->secondary.start);
 553                 result = -ENODEV;
 554                 goto out_del_root;
 555         }
 556
 557         /* ASPM setting */
 558         if (is_osc_granted) {
 559                 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM)
 560                         pcie_clear_aspm(root->bus);
 561         } else {
 562                 pr_info("ACPI _OSC control for PCIe not granted, "
 563                         "disabling ASPM\n");
 564                 pcie_no_aspm();
 565         }
 566
 567         pci_acpi_add_bus_pm_notifier(device, root->bus);
 568         if (device->wakeup.flags.run_wake)
 569                 device_set_run_wake(root->bus->bridge, true);
 570
 571         if (system_state != SYSTEM_BOOTING) {
 572                 pcibios_resource_survey_bus(root->bus);
 573                 pci_assign_unassigned_bus_resources(root->bus);
 574         }
 575
 576         mutex_lock(&acpi_pci_root_lock);
 577         list_for_each_entry(driver, &acpi_pci_drivers, node)
 578                 if (driver->add)
 579                         driver->add(root);
 580         mutex_unlock(&acpi_pci_root_lock);
 581
 582         /* need to after hot-added ioapic is registered */
 583         if (system_state != SYSTEM_BOOTING)
 584                 pci_enable_bridges(root->bus);
 585
 586         pci_bus_add_devices(root->bus);
 587         return 1;
 588
 589 out_del_root:
 590         mutex_lock(&acpi_pci_root_lock);
 591         list_del(&root->node);
 592         mutex_unlock(&acpi_pci_root_lock);
 593
 594 end:
 595         kfree(root);
 596         return result;
 597 }
 598
 599 static void acpi_pci_root_remove(struct acpi_device *device)
 600 {
 601         struct acpi_pci_root *root = acpi_driver_data(device);
 602         struct acpi_pci_driver *driver;
 603
 604         pci_stop_root_bus(root->bus);
 605
 606         mutex_lock(&acpi_pci_root_lock);
 607         list_for_each_entry_reverse(driver, &acpi_pci_drivers, node)
 608                 if (driver->remove)
 609                         driver->remove(root);
 610         mutex_unlock(&acpi_pci_root_lock);
 611
 612         device_set_run_wake(root->bus->bridge, false);
 613         pci_acpi_remove_bus_pm_notifier(device);
 614
 615         pci_remove_root_bus(root->bus);
 616
 617         mutex_lock(&acpi_pci_root_lock);
 618         list_del(&root->node);
 619         mutex_unlock(&acpi_pci_root_lock);
 620         kfree(root);
 621 }
 622
 623 void __init acpi_pci_root_init(void)
 624 {
 625         acpi_hest_init();
 626
 627         if (!acpi_pci_disabled) {
 628                 pci_acpi_crs_quirks();
 629                 acpi_scan_add_handler(&pci_root_handler);
 630         }
 631 }
 632 /* Support root bridge hotplug */
 633
 634 static void handle_root_bridge_insertion(acpi_handle handle)
 635 {
 636         struct acpi_device *device;
 637
 638         if (!acpi_bus_get_device(handle, &device)) {
 639                 printk(KERN_DEBUG "acpi device exists...\n");
 640                 return;
 641         }
 642
 643         if (acpi_bus_scan(handle))
 644                 printk(KERN_ERR "cannot add bridge to acpi list\n");
 645 }
 646
 647 static void handle_root_bridge_removal(struct acpi_device *device)
 648 {
 649         struct acpi_eject_event *ej_event;
 650
 651         ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
 652         if (!ej_event) {
 653                 /* Inform firmware the hot-remove operation has error */
 654                 (void) acpi_evaluate_hotplug_ost(device->handle,
 655                                         ACPI_NOTIFY_EJECT_REQUEST,
 656                                         ACPI_OST_SC_NON_SPECIFIC_FAILURE,
 657                                         NULL);
 658                 return;
 659         }
 660
 661         ej_event->device = device;
 662         ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
 663
 664         acpi_bus_hot_remove_device(ej_event);
 665 }
 666
 667 static void _handle_hotplug_event_root(struct work_struct *work)
 668 {
 669         struct acpi_pci_root *root;
 670         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER };
 671         struct acpi_hp_work *hp_work;
 672         acpi_handle handle;
 673         u32 type;
 674
 675         hp_work = container_of(work, struct acpi_hp_work, work);
 676         handle = hp_work->handle;
 677         type = hp_work->type;
 678
 679         root = acpi_pci_find_root(handle);
 680
 681         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 682
 683         switch (type) {
 684         case ACPI_NOTIFY_BUS_CHECK:
 685                 /* bus enumerate */
 686                 printk(KERN_DEBUG "%s: Bus check notify on %s\n", __func__,
 687                                  (char *)buffer.pointer);
 688                 if (!root)
 689                         handle_root_bridge_insertion(handle);
 690
 691                 break;
 692
 693         case ACPI_NOTIFY_DEVICE_CHECK:
 694                 /* device check */
 695                 printk(KERN_DEBUG "%s: Device check notify on %s\n", __func__,
 696                                  (char *)buffer.pointer);
 697                 if (!root)
 698                         handle_root_bridge_insertion(handle);
 699                 break;
 700
 701         case ACPI_NOTIFY_EJECT_REQUEST:
 702                 /* request device eject */
 703                 printk(KERN_DEBUG "%s: Device eject notify on %s\n", __func__,
 704                                  (char *)buffer.pointer);
 705                 if (root)
 706                         handle_root_bridge_removal(root->device);
 707                 break;
 708         default:
 709                 printk(KERN_WARNING "notify_handler: unknown event type 0x%x for %s\n",
 710                                  type, (char *)buffer.pointer);
 711                 break;
 712         }
 713
 714         kfree(hp_work); /* allocated in handle_hotplug_event_bridge */
 715         kfree(buffer.pointer);
 716 }
 717
 718 static void handle_hotplug_event_root(acpi_handle handle, u32 type,
 719                                         void *context)
 720 {
 721         alloc_acpi_hp_work(handle, type, context,
 722                                 _handle_hotplug_event_root);
 723 }
 724
 725 static acpi_status __init
 726 find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
 727 {
 728         acpi_status status;
 729         char objname[64];
 730         struct acpi_buffer buffer = { .length = sizeof(objname),
 731                                       .pointer = objname };
 732         int *count = (int *)context;
 733
 734         if (!acpi_is_root_bridge(handle))
 735                 return AE_OK;
 736
 737         (*count)++;
 738
 739         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 740
 741         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 742                                         handle_hotplug_event_root, NULL);
 743         if (ACPI_FAILURE(status))
 744                 printk(KERN_DEBUG "acpi root: %s notify handler is not installed, exit status: %u\n",
 745                                   objname, (unsigned int)status);
 746         else
 747                 printk(KERN_DEBUG "acpi root: %s notify handler is installed\n",
 748                                  objname);
 749
 750         return AE_OK;
 751 }
 752
 753 void __init acpi_pci_root_hp_init(void)
 754 {
 755         int num = 0;
 756
 757         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 758                 ACPI_UINT32_MAX, find_root_bridges, NULL, &num, NULL);
 759
 760         printk(KERN_DEBUG "Found %d acpi root devices\n", num);
 761 }