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 static int acpi_pci_root_remove(struct acpi_device *device, int type);
  50 static int acpi_pci_root_start(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 MODULE_DEVICE_TABLE(acpi, root_device_ids);
  62
  63 static struct acpi_driver acpi_pci_root_driver = {
  64         .name = "pci_root",
  65         .class = ACPI_PCI_ROOT_CLASS,
  66         .ids = root_device_ids,
  67         .ops = {
  68                 .add = acpi_pci_root_add,
  69                 .remove = acpi_pci_root_remove,
  70                 .start = acpi_pci_root_start,
  71                 },
  72 };
  73
  74 /* Lock to protect both acpi_pci_roots and acpi_pci_drivers lists */
  75 static DEFINE_MUTEX(acpi_pci_root_lock);
  76 static LIST_HEAD(acpi_pci_roots);
  77 static LIST_HEAD(acpi_pci_drivers);
  78
  79 static DEFINE_MUTEX(osc_lock);
  80
  81 int acpi_pci_register_driver(struct acpi_pci_driver *driver)
  82 {
  83         int n = 0;
  84         struct acpi_pci_root *root;
  85
  86         mutex_lock(&acpi_pci_root_lock);
  87         list_add_tail(&driver->node, &acpi_pci_drivers);
  88         if (driver->add)
  89                 list_for_each_entry(root, &acpi_pci_roots, node) {
  90                         driver->add(root);
  91                         n++;
  92                 }
  93         mutex_unlock(&acpi_pci_root_lock);
  94
  95         return n;
  96 }
  97 EXPORT_SYMBOL(acpi_pci_register_driver);
  98
  99 void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
 100 {
 101         struct acpi_pci_root *root;
 102
 103         mutex_lock(&acpi_pci_root_lock);
 104         list_del(&driver->node);
 105         if (driver->remove)
 106                 list_for_each_entry(root, &acpi_pci_roots, node)
 107                         driver->remove(root);
 108         mutex_unlock(&acpi_pci_root_lock);
 109 }
 110 EXPORT_SYMBOL(acpi_pci_unregister_driver);
 111
 112 acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
 113 {
 114         struct acpi_pci_root *root;
 115         acpi_handle handle = NULL;
 116
 117         mutex_lock(&acpi_pci_root_lock);
 118         list_for_each_entry(root, &acpi_pci_roots, node)
 119                 if ((root->segment == (u16) seg) &&
 120                     (root->secondary.start == (u16) bus)) {
 121                         handle = root->device->handle;
 122                         break;
 123                 }
 124         mutex_unlock(&acpi_pci_root_lock);
 125         return handle;
 126 }
 127
 128 EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
 129
 130 /**
 131  * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
 132  * @handle - the ACPI CA node in question.
 133  *
 134  * Note: we could make this API take a struct acpi_device * instead, but
 135  * for now, it's more convenient to operate on an acpi_handle.
 136  */
 137 int acpi_is_root_bridge(acpi_handle handle)
 138 {
 139         int ret;
 140         struct acpi_device *device;
 141
 142         ret = acpi_bus_get_device(handle, &device);
 143         if (ret)
 144                 return 0;
 145
 146         ret = acpi_match_device_ids(device, root_device_ids);
 147         if (ret)
 148                 return 0;
 149         else
 150                 return 1;
 151 }
 152 EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
 153
 154 static acpi_status
 155 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
 156 {
 157         struct resource *res = data;
 158         struct acpi_resource_address64 address;
 159
 160         if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
 161             resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
 162             resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
 163                 return AE_OK;
 164
 165         acpi_resource_to_address64(resource, &address);
 166         if ((address.address_length > 0) &&
 167             (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
 168                 res->start = address.minimum;
 169                 res->end = address.minimum + address.address_length - 1;
 170         }
 171
 172         return AE_OK;
 173 }
 174
 175 static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
 176                                              struct resource *res)
 177 {
 178         acpi_status status;
 179
 180         res->start = -1;
 181         status =
 182             acpi_walk_resources(handle, METHOD_NAME__CRS,
 183                                 get_root_bridge_busnr_callback, res);
 184         if (ACPI_FAILURE(status))
 185                 return status;
 186         if (res->start == -1)
 187                 return AE_ERROR;
 188         return AE_OK;
 189 }
 190
 191 static void acpi_pci_bridge_scan(struct acpi_device *device)
 192 {
 193         int status;
 194         struct acpi_device *child = NULL;
 195
 196         if (device->flags.bus_address)
 197                 if (device->parent && device->parent->ops.bind) {
 198                         status = device->parent->ops.bind(device);
 199                         if (!status) {
 200                                 list_for_each_entry(child, &device->children, node)
 201                                         acpi_pci_bridge_scan(child);
 202                         }
 203                 }
 204 }
 205
 206 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
 207
 208 static acpi_status acpi_pci_run_osc(acpi_handle handle,
 209                                     const u32 *capbuf, u32 *retval)
 210 {
 211         struct acpi_osc_context context = {
 212                 .uuid_str = pci_osc_uuid_str,
 213                 .rev = 1,
 214                 .cap.length = 12,
 215                 .cap.pointer = (void *)capbuf,
 216         };
 217         acpi_status status;
 218
 219         status = acpi_run_osc(handle, &context);
 220         if (ACPI_SUCCESS(status)) {
 221                 *retval = *((u32 *)(context.ret.pointer + 8));
 222                 kfree(context.ret.pointer);
 223         }
 224         return status;
 225 }
 226
 227 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
 228                                         u32 support,
 229                                         u32 *control)
 230 {
 231         acpi_status status;
 232         u32 result, capbuf[3];
 233
 234         support &= OSC_PCI_SUPPORT_MASKS;
 235         support |= root->osc_support_set;
 236
 237         capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
 238         capbuf[OSC_SUPPORT_TYPE] = support;
 239         if (control) {
 240                 *control &= OSC_PCI_CONTROL_MASKS;
 241                 capbuf[OSC_CONTROL_TYPE] = *control | root->osc_control_set;
 242         } else {
 243                 /* Run _OSC query for all possible controls. */
 244                 capbuf[OSC_CONTROL_TYPE] = OSC_PCI_CONTROL_MASKS;
 245         }
 246
 247         status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
 248         if (ACPI_SUCCESS(status)) {
 249                 root->osc_support_set = support;
 250                 if (control)
 251                         *control = result;
 252         }
 253         return status;
 254 }
 255
 256 static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
 257 {
 258         acpi_status status;
 259         acpi_handle tmp;
 260
 261         status = acpi_get_handle(root->device->handle, "_OSC", &tmp);
 262         if (ACPI_FAILURE(status))
 263                 return status;
 264         mutex_lock(&osc_lock);
 265         status = acpi_pci_query_osc(root, flags, NULL);
 266         mutex_unlock(&osc_lock);
 267         return status;
 268 }
 269
 270 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
 271 {
 272         struct acpi_pci_root *root;
 273         struct acpi_device *device;
 274
 275         if (acpi_bus_get_device(handle, &device) ||
 276             acpi_match_device_ids(device, root_device_ids))
 277                 return NULL;
 278
 279         root = acpi_driver_data(device);
 280
 281         return root;
 282 }
 283 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
 284
 285 struct acpi_handle_node {
 286         struct list_head node;
 287         acpi_handle handle;
 288 };
 289
 290 /**
 291  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
 292  * @handle: the handle in question
 293  *
 294  * Given an ACPI CA handle, the desired PCI device is located in the
 295  * list of PCI devices.
 296  *
 297  * If the device is found, its reference count is increased and this
 298  * function returns a pointer to its data structure.  The caller must
 299  * decrement the reference count by calling pci_dev_put().
 300  * If no device is found, %NULL is returned.
 301  */
 302 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
 303 {
 304         int dev, fn;
 305         unsigned long long adr;
 306         acpi_status status;
 307         acpi_handle phandle;
 308         struct pci_bus *pbus;
 309         struct pci_dev *pdev = NULL;
 310         struct acpi_handle_node *node, *tmp;
 311         struct acpi_pci_root *root;
 312         LIST_HEAD(device_list);
 313
 314         /*
 315          * Walk up the ACPI CA namespace until we reach a PCI root bridge.
 316          */
 317         phandle = handle;
 318         while (!acpi_is_root_bridge(phandle)) {
 319                 node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
 320                 if (!node)
 321                         goto out;
 322
 323                 INIT_LIST_HEAD(&node->node);
 324                 node->handle = phandle;
 325                 list_add(&node->node, &device_list);
 326
 327                 status = acpi_get_parent(phandle, &phandle);
 328                 if (ACPI_FAILURE(status))
 329                         goto out;
 330         }
 331
 332         root = acpi_pci_find_root(phandle);
 333         if (!root)
 334                 goto out;
 335
 336         pbus = root->bus;
 337
 338         /*
 339          * Now, walk back down the PCI device tree until we return to our
 340          * original handle. Assumes that everything between the PCI root
 341          * bridge and the device we're looking for must be a P2P bridge.
 342          */
 343         list_for_each_entry(node, &device_list, node) {
 344                 acpi_handle hnd = node->handle;
 345                 status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
 346                 if (ACPI_FAILURE(status))
 347                         goto out;
 348                 dev = (adr >> 16) & 0xffff;
 349                 fn  = adr & 0xffff;
 350
 351                 pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
 352                 if (!pdev || hnd == handle)
 353                         break;
 354
 355                 pbus = pdev->subordinate;
 356                 pci_dev_put(pdev);
 357
 358                 /*
 359                  * This function may be called for a non-PCI device that has a
 360                  * PCI parent (eg. a disk under a PCI SATA controller).  In that
 361                  * case pdev->subordinate will be NULL for the parent.
 362                  */
 363                 if (!pbus) {
 364                         dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
 365                         pdev = NULL;
 366                         break;
 367                 }
 368         }
 369 out:
 370         list_for_each_entry_safe(node, tmp, &device_list, node)
 371                 kfree(node);
 372
 373         return pdev;
 374 }
 375 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
 376
 377 /**
 378  * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
 379  * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
 380  * @mask: Mask of _OSC bits to request control of, place to store control mask.
 381  * @req: Mask of _OSC bits the control of is essential to the caller.
 382  *
 383  * Run _OSC query for @mask and if that is successful, compare the returned
 384  * mask of control bits with @req.  If all of the @req bits are set in the
 385  * returned mask, run _OSC request for it.
 386  *
 387  * The variable at the @mask address may be modified regardless of whether or
 388  * not the function returns success.  On success it will contain the mask of
 389  * _OSC bits the BIOS has granted control of, but its contents are meaningless
 390  * on failure.
 391  **/
 392 acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
 393 {
 394         struct acpi_pci_root *root;
 395         acpi_status status;
 396         u32 ctrl, capbuf[3];
 397         acpi_handle tmp;
 398
 399         if (!mask)
 400                 return AE_BAD_PARAMETER;
 401
 402         ctrl = *mask & OSC_PCI_CONTROL_MASKS;
 403         if ((ctrl & req) != req)
 404                 return AE_TYPE;
 405
 406         root = acpi_pci_find_root(handle);
 407         if (!root)
 408                 return AE_NOT_EXIST;
 409
 410         status = acpi_get_handle(handle, "_OSC", &tmp);
 411         if (ACPI_FAILURE(status))
 412                 return status;
 413
 414         mutex_lock(&osc_lock);
 415
 416         *mask = ctrl | root->osc_control_set;
 417         /* No need to evaluate _OSC if the control was already granted. */
 418         if ((root->osc_control_set & ctrl) == ctrl)
 419                 goto out;
 420
 421         /* Need to check the available controls bits before requesting them. */
 422         while (*mask) {
 423                 status = acpi_pci_query_osc(root, root->osc_support_set, mask);
 424                 if (ACPI_FAILURE(status))
 425                         goto out;
 426                 if (ctrl == *mask)
 427                         break;
 428                 ctrl = *mask;
 429         }
 430
 431         if ((ctrl & req) != req) {
 432                 status = AE_SUPPORT;
 433                 goto out;
 434         }
 435
 436         capbuf[OSC_QUERY_TYPE] = 0;
 437         capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set;
 438         capbuf[OSC_CONTROL_TYPE] = ctrl;
 439         status = acpi_pci_run_osc(handle, capbuf, mask);
 440         if (ACPI_SUCCESS(status))
 441                 root->osc_control_set = *mask;
 442 out:
 443         mutex_unlock(&osc_lock);
 444         return status;
 445 }
 446 EXPORT_SYMBOL(acpi_pci_osc_control_set);
 447
 448 static int acpi_pci_root_add(struct acpi_device *device)
 449 {
 450         unsigned long long segment, bus;
 451         acpi_status status;
 452         int result;
 453         struct acpi_pci_root *root;
 454         acpi_handle handle;
 455         struct acpi_device *child;
 456         u32 flags, base_flags;
 457         bool is_osc_granted = false;
 458
 459         root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 460         if (!root)
 461                 return -ENOMEM;
 462
 463         segment = 0;
 464         status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
 465                                        &segment);
 466         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 467                 printk(KERN_ERR PREFIX "can't evaluate _SEG\n");
 468                 result = -ENODEV;
 469                 goto end;
 470         }
 471
 472         /* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
 473         root->secondary.flags = IORESOURCE_BUS;
 474         status = try_get_root_bridge_busnr(device->handle, &root->secondary);
 475         if (ACPI_FAILURE(status)) {
 476                 /*
 477                  * We need both the start and end of the downstream bus range
 478                  * to interpret _CBA (MMCONFIG base address), so it really is
 479                  * supposed to be in _CRS.  If we don't find it there, all we
 480                  * can do is assume [_BBN-0xFF] or [0-0xFF].
 481                  */
 482                 root->secondary.end = 0xFF;
 483                 printk(KERN_WARNING FW_BUG PREFIX
 484                        "no secondary bus range in _CRS\n");
 485                 status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN,
 486                                                NULL, &bus);
 487                 if (ACPI_SUCCESS(status))
 488                         root->secondary.start = bus;
 489                 else if (status == AE_NOT_FOUND)
 490                         root->secondary.start = 0;
 491                 else {
 492                         printk(KERN_ERR PREFIX "can't evaluate _BBN\n");
 493                         result = -ENODEV;
 494                         goto end;
 495                 }
 496         }
 497
 498         INIT_LIST_HEAD(&root->node);
 499         root->device = device;
 500         root->segment = segment & 0xFFFF;
 501         strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
 502         strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 503         device->driver_data = root;
 504
 505         printk(KERN_INFO PREFIX "%s [%s] (domain %04x %pR)\n",
 506                acpi_device_name(device), acpi_device_bid(device),
 507                root->segment, &root->secondary);
 508
 509         /*
 510          * PCI Routing Table
 511          * -----------------
 512          * Evaluate and parse _PRT, if exists.
 513          */
 514         status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
 515         if (ACPI_SUCCESS(status))
 516                 result = acpi_pci_irq_add_prt(device->handle, root->segment,
 517                                               root->secondary.start);
 518
 519         root->mcfg_addr = acpi_pci_root_get_mcfg_addr(device->handle);
 520
 521         /*
 522          * All supported architectures that use ACPI have support for
 523          * PCI domains, so we indicate this in _OSC support capabilities.
 524          */
 525         flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
 526         acpi_pci_osc_support(root, flags);
 527
 528         /* Indicate support for various _OSC capabilities. */
 529         if (pci_ext_cfg_avail())
 530                 flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
 531         if (pcie_aspm_support_enabled()) {
 532                 flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
 533                 OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
 534         }
 535         if (pci_msi_enabled())
 536                 flags |= OSC_MSI_SUPPORT;
 537         if (flags != base_flags) {
 538                 status = acpi_pci_osc_support(root, flags);
 539                 if (ACPI_FAILURE(status)) {
 540                         dev_info(&device->dev, "ACPI _OSC support "
 541                                 "notification failed, disabling PCIe ASPM\n");
 542                         pcie_no_aspm();
 543                         flags = base_flags;
 544                 }
 545         }
 546         if (!pcie_ports_disabled
 547             && (flags & ACPI_PCIE_REQ_SUPPORT) == ACPI_PCIE_REQ_SUPPORT) {
 548                 flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL
 549                         | OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
 550                         | OSC_PCI_EXPRESS_PME_CONTROL;
 551
 552                 if (pci_aer_available()) {
 553                         if (aer_acpi_firmware_first())
 554                                 dev_dbg(&device->dev,
 555                                         "PCIe errors handled by BIOS.\n");
 556                         else
 557                                 flags |= OSC_PCI_EXPRESS_AER_CONTROL;
 558                 }
 559
 560                 dev_info(&device->dev,
 561                         "Requesting ACPI _OSC control (0x%02x)\n", flags);
 562
 563                 status = acpi_pci_osc_control_set(device->handle, &flags,
 564                                        OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
 565                 if (ACPI_SUCCESS(status)) {
 566                         is_osc_granted = true;
 567                         dev_info(&device->dev,
 568                                 "ACPI _OSC control (0x%02x) granted\n", flags);
 569                 } else {
 570                         is_osc_granted = false;
 571                         dev_info(&device->dev,
 572                                 "ACPI _OSC request failed (%s), "
 573                                 "returned control mask: 0x%02x\n",
 574                                 acpi_format_exception(status), flags);
 575                 }
 576         } else {
 577                 dev_info(&device->dev,
 578                         "Unable to request _OSC control "
 579                         "(_OSC support mask: 0x%02x)\n", flags);
 580         }
 581
 582         /*
 583          * TBD: Need PCI interface for enumeration/configuration of roots.
 584          */
 585
 586         mutex_lock(&acpi_pci_root_lock);
 587         list_add_tail(&root->node, &acpi_pci_roots);
 588         mutex_unlock(&acpi_pci_root_lock);
 589
 590         /*
 591          * Scan the Root Bridge
 592          * --------------------
 593          * Must do this prior to any attempt to bind the root device, as the
 594          * PCI namespace does not get created until this call is made (and
 595          * thus the root bridge's pci_dev does not exist).
 596          */
 597         root->bus = pci_acpi_scan_root(root);
 598         if (!root->bus) {
 599                 printk(KERN_ERR PREFIX
 600                             "Bus %04x:%02x not present in PCI namespace\n",
 601                             root->segment, (unsigned int)root->secondary.start);
 602                 result = -ENODEV;
 603                 goto out_del_root;
 604         }
 605
 606         /*
 607          * Attach ACPI-PCI Context
 608          * -----------------------
 609          * Thus binding the ACPI and PCI devices.
 610          */
 611         result = acpi_pci_bind_root(device);
 612         if (result)
 613                 goto out_del_root;
 614
 615         /*
 616          * Scan and bind all _ADR-Based Devices
 617          */
 618         list_for_each_entry(child, &device->children, node)
 619                 acpi_pci_bridge_scan(child);
 620
 621         /* ASPM setting */
 622         if (is_osc_granted) {
 623                 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM)
 624                         pcie_clear_aspm(root->bus);
 625         } else {
 626                 pr_info("ACPI _OSC control for PCIe not granted, "
 627                         "disabling ASPM\n");
 628                 pcie_no_aspm();
 629         }
 630
 631         pci_acpi_add_bus_pm_notifier(device, root->bus);
 632         if (device->wakeup.flags.run_wake)
 633                 device_set_run_wake(root->bus->bridge, true);
 634
 635         return 0;
 636
 637 out_del_root:
 638         mutex_lock(&acpi_pci_root_lock);
 639         list_del(&root->node);
 640         mutex_unlock(&acpi_pci_root_lock);
 641
 642         acpi_pci_irq_del_prt(root->segment, root->secondary.start);
 643 end:
 644         kfree(root);
 645         return result;
 646 }
 647
 648 static int acpi_pci_root_start(struct acpi_device *device)
 649 {
 650         struct acpi_pci_root *root = acpi_driver_data(device);
 651         struct acpi_pci_driver *driver;
 652
 653         if (system_state != SYSTEM_BOOTING)
 654                 pci_assign_unassigned_bus_resources(root->bus);
 655
 656         mutex_lock(&acpi_pci_root_lock);
 657         list_for_each_entry(driver, &acpi_pci_drivers, node)
 658                 if (driver->add)
 659                         driver->add(root);
 660         mutex_unlock(&acpi_pci_root_lock);
 661
 662         /* need to after hot-added ioapic is registered */
 663         if (system_state != SYSTEM_BOOTING)
 664                 pci_enable_bridges(root->bus);
 665
 666         pci_bus_add_devices(root->bus);
 667
 668         return 0;
 669 }
 670
 671 static int acpi_pci_root_remove(struct acpi_device *device, int type)
 672 {
 673         acpi_status status;
 674         acpi_handle handle;
 675         struct acpi_pci_root *root = acpi_driver_data(device);
 676         struct acpi_pci_driver *driver;
 677
 678         pci_stop_root_bus(root->bus);
 679
 680         mutex_lock(&acpi_pci_root_lock);
 681         list_for_each_entry_reverse(driver, &acpi_pci_drivers, node)
 682                 if (driver->remove)
 683                         driver->remove(root);
 684         mutex_unlock(&acpi_pci_root_lock);
 685
 686         device_set_run_wake(root->bus->bridge, false);
 687         pci_acpi_remove_bus_pm_notifier(device);
 688
 689         status = acpi_get_handle(device->handle, METHOD_NAME__PRT, &handle);
 690         if (ACPI_SUCCESS(status))
 691                 acpi_pci_irq_del_prt(root->segment, root->secondary.start);
 692
 693         pci_remove_root_bus(root->bus);
 694
 695         mutex_lock(&acpi_pci_root_lock);
 696         list_del(&root->node);
 697         mutex_unlock(&acpi_pci_root_lock);
 698         kfree(root);
 699         return 0;
 700 }
 701
 702 static int __init acpi_pci_root_init(void)
 703 {
 704         acpi_hest_init();
 705
 706         if (acpi_pci_disabled)
 707                 return 0;
 708
 709         pci_acpi_crs_quirks();
 710         if (acpi_bus_register_driver(&acpi_pci_root_driver) < 0)
 711                 return -ENODEV;
 712
 713         return 0;
 714 }
 715
 716 subsys_initcall(acpi_pci_root_init);