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