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 <linux/dmi.h>
  39 #include <acpi/apei.h>  /* for acpi_hest_init() */
  40
  41 #include "internal.h"
  42
  43 #define _COMPONENT              ACPI_PCI_COMPONENT
  44 ACPI_MODULE_NAME("pci_root");
  45 #define ACPI_PCI_ROOT_CLASS             "pci_bridge"
  46 #define ACPI_PCI_ROOT_DEVICE_NAME       "PCI Root Bridge"
  47 static int acpi_pci_root_add(struct acpi_device *device,
  48                              const struct acpi_device_id *not_used);
  49 static void acpi_pci_root_remove(struct acpi_device *device);
  50
  51 static int acpi_pci_root_scan_dependent(struct acpi_device *adev)
  52 {
  53         acpiphp_check_host_bridge(adev);
  54         return 0;
  55 }
  56
  57 #define ACPI_PCIE_REQ_SUPPORT (OSC_PCI_EXT_CONFIG_SUPPORT \
  58                                 | OSC_PCI_ASPM_SUPPORT \
  59                                 | OSC_PCI_CLOCK_PM_SUPPORT \
  60                                 | OSC_PCI_MSI_SUPPORT)
  61
  62 static const struct acpi_device_id root_device_ids[] = {
  63         {"PNP0A03", 0},
  64         {"", 0},
  65 };
  66
  67 static struct acpi_scan_handler pci_root_handler = {
  68         .ids = root_device_ids,
  69         .attach = acpi_pci_root_add,
  70         .detach = acpi_pci_root_remove,
  71         .hotplug = {
  72                 .enabled = true,
  73                 .scan_dependent = acpi_pci_root_scan_dependent,
  74         },
  75 };
  76
  77 static DEFINE_MUTEX(osc_lock);
  78
  79 /**
  80  * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
  81  * @handle - the ACPI CA node in question.
  82  *
  83  * Note: we could make this API take a struct acpi_device * instead, but
  84  * for now, it's more convenient to operate on an acpi_handle.
  85  */
  86 int acpi_is_root_bridge(acpi_handle handle)
  87 {
  88         int ret;
  89         struct acpi_device *device;
  90
  91         ret = acpi_bus_get_device(handle, &device);
  92         if (ret)
  93                 return 0;
  94
  95         ret = acpi_match_device_ids(device, root_device_ids);
  96         if (ret)
  97                 return 0;
  98         else
  99                 return 1;
 100 }
 101 EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
 102
 103 static acpi_status
 104 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
 105 {
 106         struct resource *res = data;
 107         struct acpi_resource_address64 address;
 108         acpi_status status;
 109
 110         status = acpi_resource_to_address64(resource, &address);
 111         if (ACPI_FAILURE(status))
 112                 return AE_OK;
 113
 114         if ((address.address_length > 0) &&
 115             (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
 116                 res->start = address.minimum;
 117                 res->end = address.minimum + address.address_length - 1;
 118         }
 119
 120         return AE_OK;
 121 }
 122
 123 static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
 124                                              struct resource *res)
 125 {
 126         acpi_status status;
 127
 128         res->start = -1;
 129         status =
 130             acpi_walk_resources(handle, METHOD_NAME__CRS,
 131                                 get_root_bridge_busnr_callback, res);
 132         if (ACPI_FAILURE(status))
 133                 return status;
 134         if (res->start == -1)
 135                 return AE_ERROR;
 136         return AE_OK;
 137 }
 138
 139 struct pci_osc_bit_struct {
 140         u32 bit;
 141         char *desc;
 142 };
 143
 144 static struct pci_osc_bit_struct pci_osc_support_bit[] = {
 145         { OSC_PCI_EXT_CONFIG_SUPPORT, "ExtendedConfig" },
 146         { OSC_PCI_ASPM_SUPPORT, "ASPM" },
 147         { OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" },
 148         { OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" },
 149         { OSC_PCI_MSI_SUPPORT, "MSI" },
 150 };
 151
 152 static struct pci_osc_bit_struct pci_osc_control_bit[] = {
 153         { OSC_PCI_EXPRESS_NATIVE_HP_CONTROL, "PCIeHotplug" },
 154         { OSC_PCI_SHPC_NATIVE_HP_CONTROL, "SHPCHotplug" },
 155         { OSC_PCI_EXPRESS_PME_CONTROL, "PME" },
 156         { OSC_PCI_EXPRESS_AER_CONTROL, "AER" },
 157         { OSC_PCI_EXPRESS_CAPABILITY_CONTROL, "PCIeCapability" },
 158 };
 159
 160 static void decode_osc_bits(struct acpi_pci_root *root, char *msg, u32 word,
 161                             struct pci_osc_bit_struct *table, int size)
 162 {
 163         char buf[80];
 164         int i, len = 0;
 165         struct pci_osc_bit_struct *entry;
 166
 167         buf[0] = '\0';
 168         for (i = 0, entry = table; i < size; i++, entry++)
 169                 if (word & entry->bit)
 170                         len += snprintf(buf + len, sizeof(buf) - len, "%s%s",
 171                                         len ? " " : "", entry->desc);
 172
 173         dev_info(&root->device->dev, "_OSC: %s [%s]\n", msg, buf);
 174 }
 175
 176 static void decode_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
 177 {
 178         decode_osc_bits(root, msg, word, pci_osc_support_bit,
 179                         ARRAY_SIZE(pci_osc_support_bit));
 180 }
 181
 182 static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
 183 {
 184         decode_osc_bits(root, msg, word, pci_osc_control_bit,
 185                         ARRAY_SIZE(pci_osc_control_bit));
 186 }
 187
 188 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
 189
 190 static acpi_status acpi_pci_run_osc(acpi_handle handle,
 191                                     const u32 *capbuf, u32 *retval)
 192 {
 193         struct acpi_osc_context context = {
 194                 .uuid_str = pci_osc_uuid_str,
 195                 .rev = 1,
 196                 .cap.length = 12,
 197                 .cap.pointer = (void *)capbuf,
 198         };
 199         acpi_status status;
 200
 201         status = acpi_run_osc(handle, &context);
 202         if (ACPI_SUCCESS(status)) {
 203                 *retval = *((u32 *)(context.ret.pointer + 8));
 204                 kfree(context.ret.pointer);
 205         }
 206         return status;
 207 }
 208
 209 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
 210                                         u32 support,
 211                                         u32 *control)
 212 {
 213         acpi_status status;
 214         u32 result, capbuf[3];
 215
 216         support &= OSC_PCI_SUPPORT_MASKS;
 217         support |= root->osc_support_set;
 218
 219         capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
 220         capbuf[OSC_SUPPORT_DWORD] = support;
 221         if (control) {
 222                 *control &= OSC_PCI_CONTROL_MASKS;
 223                 capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
 224         } else {
 225                 /* Run _OSC query only with existing controls. */
 226                 capbuf[OSC_CONTROL_DWORD] = root->osc_control_set;
 227         }
 228
 229         status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
 230         if (ACPI_SUCCESS(status)) {
 231                 root->osc_support_set = support;
 232                 if (control)
 233                         *control = result;
 234         }
 235         return status;
 236 }
 237
 238 static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
 239 {
 240         acpi_status status;
 241
 242         mutex_lock(&osc_lock);
 243         status = acpi_pci_query_osc(root, flags, NULL);
 244         mutex_unlock(&osc_lock);
 245         return status;
 246 }
 247
 248 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
 249 {
 250         struct acpi_pci_root *root;
 251         struct acpi_device *device;
 252
 253         if (acpi_bus_get_device(handle, &device) ||
 254             acpi_match_device_ids(device, root_device_ids))
 255                 return NULL;
 256
 257         root = acpi_driver_data(device);
 258
 259         return root;
 260 }
 261 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
 262
 263 struct acpi_handle_node {
 264         struct list_head node;
 265         acpi_handle handle;
 266 };
 267
 268 /**
 269  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
 270  * @handle: the handle in question
 271  *
 272  * Given an ACPI CA handle, the desired PCI device is located in the
 273  * list of PCI devices.
 274  *
 275  * If the device is found, its reference count is increased and this
 276  * function returns a pointer to its data structure.  The caller must
 277  * decrement the reference count by calling pci_dev_put().
 278  * If no device is found, %NULL is returned.
 279  */
 280 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
 281 {
 282         int dev, fn;
 283         unsigned long long adr;
 284         acpi_status status;
 285         acpi_handle phandle;
 286         struct pci_bus *pbus;
 287         struct pci_dev *pdev = NULL;
 288         struct acpi_handle_node *node, *tmp;
 289         struct acpi_pci_root *root;
 290         LIST_HEAD(device_list);
 291
 292         /*
 293          * Walk up the ACPI CA namespace until we reach a PCI root bridge.
 294          */
 295         phandle = handle;
 296         while (!acpi_is_root_bridge(phandle)) {
 297                 node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
 298                 if (!node)
 299                         goto out;
 300
 301                 INIT_LIST_HEAD(&node->node);
 302                 node->handle = phandle;
 303                 list_add(&node->node, &device_list);
 304
 305                 status = acpi_get_parent(phandle, &phandle);
 306                 if (ACPI_FAILURE(status))
 307                         goto out;
 308         }
 309
 310         root = acpi_pci_find_root(phandle);
 311         if (!root)
 312                 goto out;
 313
 314         pbus = root->bus;
 315
 316         /*
 317          * Now, walk back down the PCI device tree until we return to our
 318          * original handle. Assumes that everything between the PCI root
 319          * bridge and the device we're looking for must be a P2P bridge.
 320          */
 321         list_for_each_entry(node, &device_list, node) {
 322                 acpi_handle hnd = node->handle;
 323                 status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
 324                 if (ACPI_FAILURE(status))
 325                         goto out;
 326                 dev = (adr >> 16) & 0xffff;
 327                 fn  = adr & 0xffff;
 328
 329                 pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
 330                 if (!pdev || hnd == handle)
 331                         break;
 332
 333                 pbus = pdev->subordinate;
 334                 pci_dev_put(pdev);
 335
 336                 /*
 337                  * This function may be called for a non-PCI device that has a
 338                  * PCI parent (eg. a disk under a PCI SATA controller).  In that
 339                  * case pdev->subordinate will be NULL for the parent.
 340                  */
 341                 if (!pbus) {
 342                         dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
 343                         pdev = NULL;
 344                         break;
 345                 }
 346         }
 347 out:
 348         list_for_each_entry_safe(node, tmp, &device_list, node)
 349                 kfree(node);
 350
 351         return pdev;
 352 }
 353 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
 354
 355 /**
 356  * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
 357  * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
 358  * @mask: Mask of _OSC bits to request control of, place to store control mask.
 359  * @req: Mask of _OSC bits the control of is essential to the caller.
 360  *
 361  * Run _OSC query for @mask and if that is successful, compare the returned
 362  * mask of control bits with @req.  If all of the @req bits are set in the
 363  * returned mask, run _OSC request for it.
 364  *
 365  * The variable at the @mask address may be modified regardless of whether or
 366  * not the function returns success.  On success it will contain the mask of
 367  * _OSC bits the BIOS has granted control of, but its contents are meaningless
 368  * on failure.
 369  **/
 370 acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
 371 {
 372         struct acpi_pci_root *root;
 373         acpi_status status = AE_OK;
 374         u32 ctrl, capbuf[3];
 375
 376         if (!mask)
 377                 return AE_BAD_PARAMETER;
 378
 379         ctrl = *mask & OSC_PCI_CONTROL_MASKS;
 380         if ((ctrl & req) != req)
 381                 return AE_TYPE;
 382
 383         root = acpi_pci_find_root(handle);
 384         if (!root)
 385                 return AE_NOT_EXIST;
 386
 387         mutex_lock(&osc_lock);
 388
 389         *mask = ctrl | root->osc_control_set;
 390         /* No need to evaluate _OSC if the control was already granted. */
 391         if ((root->osc_control_set & ctrl) == ctrl)
 392                 goto out;
 393
 394         /* Need to check the available controls bits before requesting them. */
 395         while (*mask) {
 396                 status = acpi_pci_query_osc(root, root->osc_support_set, mask);
 397                 if (ACPI_FAILURE(status))
 398                         goto out;
 399                 if (ctrl == *mask)
 400                         break;
 401                 decode_osc_control(root, "platform does not support",
 402                                    ctrl & ~(*mask));
 403                 ctrl = *mask;
 404         }
 405
 406         if ((ctrl & req) != req) {
 407                 decode_osc_control(root, "not requesting control; platform does not support",
 408                                    req & ~(ctrl));
 409                 status = AE_SUPPORT;
 410                 goto out;
 411         }
 412
 413         capbuf[OSC_QUERY_DWORD] = 0;
 414         capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set;
 415         capbuf[OSC_CONTROL_DWORD] = ctrl;
 416         status = acpi_pci_run_osc(handle, capbuf, mask);
 417         if (ACPI_SUCCESS(status))
 418                 root->osc_control_set = *mask;
 419 out:
 420         mutex_unlock(&osc_lock);
 421         return status;
 422 }
 423 EXPORT_SYMBOL(acpi_pci_osc_control_set);
 424
 425 static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
 426                                  int *clear_aspm)
 427 {
 428         u32 support, control, requested;
 429         acpi_status status;
 430         struct acpi_device *device = root->device;
 431         acpi_handle handle = device->handle;
 432
 433         /*
 434          * Apple always return failure on _OSC calls when _OSI("Darwin") has
 435          * been called successfully. We know the feature set supported by the
 436          * platform, so avoid calling _OSC at all
 437          */
 438
 439         if (dmi_match(DMI_SYS_VENDOR, "Apple Inc.")) {
 440                 root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;
 441                 decode_osc_control(root, "OS assumes control of",
 442                                    root->osc_control_set);
 443                 return;
 444         }
 445
 446         /*
 447          * All supported architectures that use ACPI have support for
 448          * PCI domains, so we indicate this in _OSC support capabilities.
 449          */
 450         support = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
 451         if (pci_ext_cfg_avail())
 452                 support |= OSC_PCI_EXT_CONFIG_SUPPORT;
 453         if (pcie_aspm_support_enabled())
 454                 support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
 455         if (pci_msi_enabled())
 456                 support |= OSC_PCI_MSI_SUPPORT;
 457
 458         decode_osc_support(root, "OS supports", support);
 459         status = acpi_pci_osc_support(root, support);
 460         if (ACPI_FAILURE(status)) {
 461                 dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
 462                          acpi_format_exception(status));
 463                 *no_aspm = 1;
 464                 return;
 465         }
 466
 467         if (pcie_ports_disabled) {
 468                 dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
 469                 return;
 470         }
 471
 472         if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
 473                 decode_osc_support(root, "not requesting OS control; OS requires",
 474                                    ACPI_PCIE_REQ_SUPPORT);
 475                 return;
 476         }
 477
 478         control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
 479                 | OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
 480                 | OSC_PCI_EXPRESS_PME_CONTROL;
 481
 482         if (pci_aer_available()) {
 483                 if (aer_acpi_firmware_first())
 484                         dev_info(&device->dev,
 485                                  "PCIe AER handled by firmware\n");
 486                 else
 487                         control |= OSC_PCI_EXPRESS_AER_CONTROL;
 488         }
 489
 490         requested = control;
 491         status = acpi_pci_osc_control_set(handle, &control,
 492                                           OSC_PCI_EXPRESS_CAPABILITY_CONTROL);
 493         if (ACPI_SUCCESS(status)) {
 494                 decode_osc_control(root, "OS now controls", control);
 495                 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 496                         /*
 497                          * We have ASPM control, but the FADT indicates
 498                          * that it's unsupported. Clear it.
 499                          */
 500                         *clear_aspm = 1;
 501                 }
 502         } else {
 503                 decode_osc_control(root, "OS requested", requested);
 504                 decode_osc_control(root, "platform willing to grant", control);
 505                 dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
 506                         acpi_format_exception(status));
 507
 508                 /*
 509                  * We want to disable ASPM here, but aspm_disabled
 510                  * needs to remain in its state from boot so that we
 511                  * properly handle PCIe 1.1 devices.  So we set this
 512                  * flag here, to defer the action until after the ACPI
 513                  * root scan.
 514                  */
 515                 *no_aspm = 1;
 516         }
 517 }
 518
 519 static int acpi_pci_root_add(struct acpi_device *device,
 520                              const struct acpi_device_id *not_used)
 521 {
 522         unsigned long long segment, bus;
 523         acpi_status status;
 524         int result;
 525         struct acpi_pci_root *root;
 526         acpi_handle handle = device->handle;
 527         int no_aspm = 0, clear_aspm = 0;
 528
 529         root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 530         if (!root)
 531                 return -ENOMEM;
 532
 533         segment = 0;
 534         status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL,
 535                                        &segment);
 536         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 537                 dev_err(&device->dev,  "can't evaluate _SEG\n");
 538                 result = -ENODEV;
 539                 goto end;
 540         }
 541
 542         /* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
 543         root->secondary.flags = IORESOURCE_BUS;
 544         status = try_get_root_bridge_busnr(handle, &root->secondary);
 545         if (ACPI_FAILURE(status)) {
 546                 /*
 547                  * We need both the start and end of the downstream bus range
 548                  * to interpret _CBA (MMCONFIG base address), so it really is
 549                  * supposed to be in _CRS.  If we don't find it there, all we
 550                  * can do is assume [_BBN-0xFF] or [0-0xFF].
 551                  */
 552                 root->secondary.end = 0xFF;
 553                 dev_warn(&device->dev,
 554                          FW_BUG "no secondary bus range in _CRS\n");
 555                 status = acpi_evaluate_integer(handle, METHOD_NAME__BBN,
 556                                                NULL, &bus);
 557                 if (ACPI_SUCCESS(status))
 558                         root->secondary.start = bus;
 559                 else if (status == AE_NOT_FOUND)
 560                         root->secondary.start = 0;
 561                 else {
 562                         dev_err(&device->dev, "can't evaluate _BBN\n");
 563                         result = -ENODEV;
 564                         goto end;
 565                 }
 566         }
 567
 568         root->device = device;
 569         root->segment = segment & 0xFFFF;
 570         strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
 571         strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 572         device->driver_data = root;
 573
 574         pr_info(PREFIX "%s [%s] (domain %04x %pR)\n",
 575                acpi_device_name(device), acpi_device_bid(device),
 576                root->segment, &root->secondary);
 577
 578         root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
 579
 580         negotiate_os_control(root, &no_aspm, &clear_aspm);
 581
 582         /*
 583          * TBD: Need PCI interface for enumeration/configuration of roots.
 584          */
 585
 586         /*
 587          * Scan the Root Bridge
 588          * --------------------
 589          * Must do this prior to any attempt to bind the root device, as the
 590          * PCI namespace does not get created until this call is made (and
 591          * thus the root bridge's pci_dev does not exist).
 592          */
 593         root->bus = pci_acpi_scan_root(root);
 594         if (!root->bus) {
 595                 dev_err(&device->dev,
 596                         "Bus %04x:%02x not present in PCI namespace\n",
 597                         root->segment, (unsigned int)root->secondary.start);
 598                 device->driver_data = NULL;
 599                 result = -ENODEV;
 600                 goto end;
 601         }
 602
 603         if (clear_aspm) {
 604                 dev_info(&device->dev, "Disabling ASPM (FADT indicates it is unsupported)\n");
 605                 pcie_clear_aspm(root->bus);
 606         }
 607         if (no_aspm)
 608                 pcie_no_aspm();
 609
 610         pci_acpi_add_bus_pm_notifier(device);
 611         if (device->wakeup.flags.run_wake)
 612                 device_set_run_wake(root->bus->bridge, true);
 613
 614         if (system_state != SYSTEM_BOOTING) {
 615                 pcibios_resource_survey_bus(root->bus);
 616                 pci_assign_unassigned_root_bus_resources(root->bus);
 617         }
 618
 619         pci_lock_rescan_remove();
 620         pci_bus_add_devices(root->bus);
 621         pci_unlock_rescan_remove();
 622         return 1;
 623
 624 end:
 625         kfree(root);
 626         return result;
 627 }
 628
 629 static void acpi_pci_root_remove(struct acpi_device *device)
 630 {
 631         struct acpi_pci_root *root = acpi_driver_data(device);
 632
 633         pci_lock_rescan_remove();
 634
 635         pci_stop_root_bus(root->bus);
 636
 637         device_set_run_wake(root->bus->bridge, false);
 638         pci_acpi_remove_bus_pm_notifier(device);
 639
 640         pci_remove_root_bus(root->bus);
 641
 642         pci_unlock_rescan_remove();
 643
 644         kfree(root);
 645 }
 646
 647 void __init acpi_pci_root_init(void)
 648 {
 649         acpi_hest_init();
 650         if (acpi_pci_disabled)
 651                 return;
 652
 653         pci_acpi_crs_quirks();
 654         acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root");
 655 }