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_PCI_EXT_CONFIG_SUPPORT \
  53                                 | OSC_PCI_ASPM_SUPPORT \
  54                                 | OSC_PCI_CLOCK_PM_SUPPORT \
  55                                 | OSC_PCI_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 static DEFINE_MUTEX(osc_lock);
  69
  70 /**
  71  * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
  72  * @handle - the ACPI CA node in question.
  73  *
  74  * Note: we could make this API take a struct acpi_device * instead, but
  75  * for now, it's more convenient to operate on an acpi_handle.
  76  */
  77 int acpi_is_root_bridge(acpi_handle handle)
  78 {
  79         int ret;
  80         struct acpi_device *device;
  81
  82         ret = acpi_bus_get_device(handle, &device);
  83         if (ret)
  84                 return 0;
  85
  86         ret = acpi_match_device_ids(device, root_device_ids);
  87         if (ret)
  88                 return 0;
  89         else
  90                 return 1;
  91 }
  92 EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
  93
  94 static acpi_status
  95 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
  96 {
  97         struct resource *res = data;
  98         struct acpi_resource_address64 address;
  99         acpi_status status;
 100
 101         status = acpi_resource_to_address64(resource, &address);
 102         if (ACPI_FAILURE(status))
 103                 return AE_OK;
 104
 105         if ((address.address_length > 0) &&
 106             (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
 107                 res->start = address.minimum;
 108                 res->end = address.minimum + address.address_length - 1;
 109         }
 110
 111         return AE_OK;
 112 }
 113
 114 static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
 115                                              struct resource *res)
 116 {
 117         acpi_status status;
 118
 119         res->start = -1;
 120         status =
 121             acpi_walk_resources(handle, METHOD_NAME__CRS,
 122                                 get_root_bridge_busnr_callback, res);
 123         if (ACPI_FAILURE(status))
 124                 return status;
 125         if (res->start == -1)
 126                 return AE_ERROR;
 127         return AE_OK;
 128 }
 129
 130 struct pci_osc_bit_struct {
 131         u32 bit;
 132         char *desc;
 133 };
 134
 135 static struct pci_osc_bit_struct pci_osc_support_bit[] = {
 136         { OSC_PCI_EXT_CONFIG_SUPPORT, "ExtendedConfig" },
 137         { OSC_PCI_ASPM_SUPPORT, "ASPM" },
 138         { OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" },
 139         { OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" },
 140         { OSC_PCI_MSI_SUPPORT, "MSI" },
 141 };
 142
 143 static struct pci_osc_bit_struct pci_osc_control_bit[] = {
 144         { OSC_PCI_EXPRESS_NATIVE_HP_CONTROL, "PCIeHotplug" },
 145         { OSC_PCI_SHPC_NATIVE_HP_CONTROL, "SHPCHotplug" },
 146         { OSC_PCI_EXPRESS_PME_CONTROL, "PME" },
 147         { OSC_PCI_EXPRESS_AER_CONTROL, "AER" },
 148         { OSC_PCI_EXPRESS_CAPABILITY_CONTROL, "PCIeCapability" },
 149 };
 150
 151 static void decode_osc_bits(struct acpi_pci_root *root, char *msg, u32 word,
 152                             struct pci_osc_bit_struct *table, int size)
 153 {
 154         char buf[80];
 155         int i, len = 0;
 156         struct pci_osc_bit_struct *entry;
 157
 158         buf[0] = '\0';
 159         for (i = 0, entry = table; i < size; i++, entry++)
 160                 if (word & entry->bit)
 161                         len += snprintf(buf + len, sizeof(buf) - len, "%s%s",
 162                                         len ? " " : "", entry->desc);
 163
 164         dev_info(&root->device->dev, "_OSC: %s [%s]\n", msg, buf);
 165 }
 166
 167 static void decode_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
 168 {
 169         decode_osc_bits(root, msg, word, pci_osc_support_bit,
 170                         ARRAY_SIZE(pci_osc_support_bit));
 171 }
 172
 173 static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
 174 {
 175         decode_osc_bits(root, msg, word, pci_osc_control_bit,
 176                         ARRAY_SIZE(pci_osc_control_bit));
 177 }
 178
 179 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
 180
 181 static acpi_status acpi_pci_run_osc(acpi_handle handle,
 182                                     const u32 *capbuf, u32 *retval)
 183 {
 184         struct acpi_osc_context context = {
 185                 .uuid_str = pci_osc_uuid_str,
 186                 .rev = 1,
 187                 .cap.length = 12,
 188                 .cap.pointer = (void *)capbuf,
 189         };
 190         acpi_status status;
 191
 192         status = acpi_run_osc(handle, &context);
 193         if (ACPI_SUCCESS(status)) {
 194                 *retval = *((u32 *)(context.ret.pointer + 8));
 195                 kfree(context.ret.pointer);
 196         }
 197         return status;
 198 }
 199
 200 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
 201                                         u32 support,
 202                                         u32 *control)
 203 {
 204         acpi_status status;
 205         u32 result, capbuf[3];
 206
 207         support &= OSC_PCI_SUPPORT_MASKS;
 208         support |= root->osc_support_set;
 209
 210         capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
 211         capbuf[OSC_SUPPORT_DWORD] = support;
 212         if (control) {
 213                 *control &= OSC_PCI_CONTROL_MASKS;
 214                 capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
 215         } else {
 216                 /* Run _OSC query only with existing controls. */
 217                 capbuf[OSC_CONTROL_DWORD] = root->osc_control_set;
 218         }
 219
 220         status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
 221         if (ACPI_SUCCESS(status)) {
 222                 root->osc_support_set = support;
 223                 if (control)
 224                         *control = result;
 225         }
 226         return status;
 227 }
 228
 229 static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
 230 {
 231         acpi_status status;
 232
 233         mutex_lock(&osc_lock);
 234         status = acpi_pci_query_osc(root, flags, NULL);
 235         mutex_unlock(&osc_lock);
 236         return status;
 237 }
 238
 239 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
 240 {
 241         struct acpi_pci_root *root;
 242         struct acpi_device *device;
 243
 244         if (acpi_bus_get_device(handle, &device) ||
 245             acpi_match_device_ids(device, root_device_ids))
 246                 return NULL;
 247
 248         root = acpi_driver_data(device);
 249
 250         return root;
 251 }
 252 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
 253
 254 struct acpi_handle_node {
 255         struct list_head node;
 256         acpi_handle handle;
 257 };
 258
 259 /**
 260  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
 261  * @handle: the handle in question
 262  *
 263  * Given an ACPI CA handle, the desired PCI device is located in the
 264  * list of PCI devices.
 265  *
 266  * If the device is found, its reference count is increased and this
 267  * function returns a pointer to its data structure.  The caller must
 268  * decrement the reference count by calling pci_dev_put().
 269  * If no device is found, %NULL is returned.
 270  */
 271 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
 272 {
 273         int dev, fn;
 274         unsigned long long adr;
 275         acpi_status status;
 276         acpi_handle phandle;
 277         struct pci_bus *pbus;
 278         struct pci_dev *pdev = NULL;
 279         struct acpi_handle_node *node, *tmp;
 280         struct acpi_pci_root *root;
 281         LIST_HEAD(device_list);
 282
 283         /*
 284          * Walk up the ACPI CA namespace until we reach a PCI root bridge.
 285          */
 286         phandle = handle;
 287         while (!acpi_is_root_bridge(phandle)) {
 288                 node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
 289                 if (!node)
 290                         goto out;
 291
 292                 INIT_LIST_HEAD(&node->node);
 293                 node->handle = phandle;
 294                 list_add(&node->node, &device_list);
 295
 296                 status = acpi_get_parent(phandle, &phandle);
 297                 if (ACPI_FAILURE(status))
 298                         goto out;
 299         }
 300
 301         root = acpi_pci_find_root(phandle);
 302         if (!root)
 303                 goto out;
 304
 305         pbus = root->bus;
 306
 307         /*
 308          * Now, walk back down the PCI device tree until we return to our
 309          * original handle. Assumes that everything between the PCI root
 310          * bridge and the device we're looking for must be a P2P bridge.
 311          */
 312         list_for_each_entry(node, &device_list, node) {
 313                 acpi_handle hnd = node->handle;
 314                 status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
 315                 if (ACPI_FAILURE(status))
 316                         goto out;
 317                 dev = (adr >> 16) & 0xffff;
 318                 fn  = adr & 0xffff;
 319
 320                 pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
 321                 if (!pdev || hnd == handle)
 322                         break;
 323
 324                 pbus = pdev->subordinate;
 325                 pci_dev_put(pdev);
 326
 327                 /*
 328                  * This function may be called for a non-PCI device that has a
 329                  * PCI parent (eg. a disk under a PCI SATA controller).  In that
 330                  * case pdev->subordinate will be NULL for the parent.
 331                  */
 332                 if (!pbus) {
 333                         dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
 334                         pdev = NULL;
 335                         break;
 336                 }
 337         }
 338 out:
 339         list_for_each_entry_safe(node, tmp, &device_list, node)
 340                 kfree(node);
 341
 342         return pdev;
 343 }
 344 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
 345
 346 /**
 347  * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
 348  * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
 349  * @mask: Mask of _OSC bits to request control of, place to store control mask.
 350  * @req: Mask of _OSC bits the control of is essential to the caller.
 351  *
 352  * Run _OSC query for @mask and if that is successful, compare the returned
 353  * mask of control bits with @req.  If all of the @req bits are set in the
 354  * returned mask, run _OSC request for it.
 355  *
 356  * The variable at the @mask address may be modified regardless of whether or
 357  * not the function returns success.  On success it will contain the mask of
 358  * _OSC bits the BIOS has granted control of, but its contents are meaningless
 359  * on failure.
 360  **/
 361 acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
 362 {
 363         struct acpi_pci_root *root;
 364         acpi_status status = AE_OK;
 365         u32 ctrl, capbuf[3];
 366
 367         if (!mask)
 368                 return AE_BAD_PARAMETER;
 369
 370         ctrl = *mask & OSC_PCI_CONTROL_MASKS;
 371         if ((ctrl & req) != req)
 372                 return AE_TYPE;
 373
 374         root = acpi_pci_find_root(handle);
 375         if (!root)
 376                 return AE_NOT_EXIST;
 377
 378         mutex_lock(&osc_lock);
 379
 380         *mask = ctrl | root->osc_control_set;
 381         /* No need to evaluate _OSC if the control was already granted. */
 382         if ((root->osc_control_set & ctrl) == ctrl)
 383                 goto out;
 384
 385         /* Need to check the available controls bits before requesting them. */
 386         while (*mask) {
 387                 status = acpi_pci_query_osc(root, root->osc_support_set, mask);
 388                 if (ACPI_FAILURE(status))
 389                         goto out;
 390                 if (ctrl == *mask)
 391                         break;
 392                 decode_osc_control(root, "platform does not support",
 393                                    ctrl & ~(*mask));
 394                 ctrl = *mask;
 395         }
 396
 397         if ((ctrl & req) != req) {
 398                 decode_osc_control(root, "not requesting control; platform does not support",
 399                                    req & ~(ctrl));
 400                 status = AE_SUPPORT;
 401                 goto out;
 402         }
 403
 404         capbuf[OSC_QUERY_DWORD] = 0;
 405         capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set;
 406         capbuf[OSC_CONTROL_DWORD] = ctrl;
 407         status = acpi_pci_run_osc(handle, capbuf, mask);
 408         if (ACPI_SUCCESS(status))
 409                 root->osc_control_set = *mask;
 410 out:
 411         mutex_unlock(&osc_lock);
 412         return status;
 413 }
 414 EXPORT_SYMBOL(acpi_pci_osc_control_set);
 415
 416 static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
 417                                  int *clear_aspm)
 418 {
 419         u32 support, control, requested;
 420         acpi_status status;
 421         struct acpi_device *device = root->device;
 422         acpi_handle handle = device->handle;
 423
 424         /*
 425          * All supported architectures that use ACPI have support for
 426          * PCI domains, so we indicate this in _OSC support capabilities.
 427          */
 428         support = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
 429         if (pci_ext_cfg_avail())
 430                 support |= OSC_PCI_EXT_CONFIG_SUPPORT;
 431         if (pcie_aspm_support_enabled())
 432                 support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
 433         if (pci_msi_enabled())
 434                 support |= OSC_PCI_MSI_SUPPORT;
 435
 436         decode_osc_support(root, "OS supports", support);
 437         status = acpi_pci_osc_support(root, support);
 438         if (ACPI_FAILURE(status)) {
 439                 dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
 440                          acpi_format_exception(status));
 441                 *no_aspm = 1;
 442                 return;
 443         }
 444
 445         if (pcie_ports_disabled) {
 446                 dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
 447                 return;
 448         }
 449
 450         if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
 451                 decode_osc_support(root, "not requesting OS control; OS requires",
 452                                    ACPI_PCIE_REQ_SUPPORT);
 453                 return;
 454         }
 455
 456         control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
 457                 | OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
 458                 | OSC_PCI_EXPRESS_PME_CONTROL;
 459
 460         if (pci_aer_available()) {
 461                 if (aer_acpi_firmware_first())
 462                         dev_info(&device->dev,
 463                                  "PCIe AER handled by firmware\n");
 464                 else
 465                         control |= OSC_PCI_EXPRESS_AER_CONTROL;
 466         }
 467
 468         requested = control;
 469         status = acpi_pci_osc_control_set(handle, &control,
 470                                           OSC_PCI_EXPRESS_CAPABILITY_CONTROL);
 471         if (ACPI_SUCCESS(status)) {
 472                 decode_osc_control(root, "OS now controls", control);
 473                 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 474                         /*
 475                          * We have ASPM control, but the FADT indicates
 476                          * that it's unsupported. Clear it.
 477                          */
 478                         *clear_aspm = 1;
 479                 }
 480         } else {
 481                 decode_osc_control(root, "OS requested", requested);
 482                 decode_osc_control(root, "platform willing to grant", control);
 483                 dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
 484                         acpi_format_exception(status));
 485
 486                 /*
 487                  * We want to disable ASPM here, but aspm_disabled
 488                  * needs to remain in its state from boot so that we
 489                  * properly handle PCIe 1.1 devices.  So we set this
 490                  * flag here, to defer the action until after the ACPI
 491                  * root scan.
 492                  */
 493                 *no_aspm = 1;
 494         }
 495 }
 496
 497 static int acpi_pci_root_add(struct acpi_device *device,
 498                              const struct acpi_device_id *not_used)
 499 {
 500         unsigned long long segment, bus;
 501         acpi_status status;
 502         int result;
 503         struct acpi_pci_root *root;
 504         acpi_handle handle = device->handle;
 505         int no_aspm = 0, clear_aspm = 0;
 506
 507         root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 508         if (!root)
 509                 return -ENOMEM;
 510
 511         segment = 0;
 512         status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL,
 513                                        &segment);
 514         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 515                 dev_err(&device->dev,  "can't evaluate _SEG\n");
 516                 result = -ENODEV;
 517                 goto end;
 518         }
 519
 520         /* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
 521         root->secondary.flags = IORESOURCE_BUS;
 522         status = try_get_root_bridge_busnr(handle, &root->secondary);
 523         if (ACPI_FAILURE(status)) {
 524                 /*
 525                  * We need both the start and end of the downstream bus range
 526                  * to interpret _CBA (MMCONFIG base address), so it really is
 527                  * supposed to be in _CRS.  If we don't find it there, all we
 528                  * can do is assume [_BBN-0xFF] or [0-0xFF].
 529                  */
 530                 root->secondary.end = 0xFF;
 531                 dev_warn(&device->dev,
 532                          FW_BUG "no secondary bus range in _CRS\n");
 533                 status = acpi_evaluate_integer(handle, METHOD_NAME__BBN,
 534                                                NULL, &bus);
 535                 if (ACPI_SUCCESS(status))
 536                         root->secondary.start = bus;
 537                 else if (status == AE_NOT_FOUND)
 538                         root->secondary.start = 0;
 539                 else {
 540                         dev_err(&device->dev, "can't evaluate _BBN\n");
 541                         result = -ENODEV;
 542                         goto end;
 543                 }
 544         }
 545
 546         root->device = device;
 547         root->segment = segment & 0xFFFF;
 548         strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
 549         strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 550         device->driver_data = root;
 551
 552         pr_info(PREFIX "%s [%s] (domain %04x %pR)\n",
 553                acpi_device_name(device), acpi_device_bid(device),
 554                root->segment, &root->secondary);
 555
 556         root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
 557
 558         negotiate_os_control(root, &no_aspm, &clear_aspm);
 559
 560         /*
 561          * TBD: Need PCI interface for enumeration/configuration of roots.
 562          */
 563
 564         /*
 565          * Scan the Root Bridge
 566          * --------------------
 567          * Must do this prior to any attempt to bind the root device, as the
 568          * PCI namespace does not get created until this call is made (and
 569          * thus the root bridge's pci_dev does not exist).
 570          */
 571         root->bus = pci_acpi_scan_root(root);
 572         if (!root->bus) {
 573                 dev_err(&device->dev,
 574                         "Bus %04x:%02x not present in PCI namespace\n",
 575                         root->segment, (unsigned int)root->secondary.start);
 576                 result = -ENODEV;
 577                 goto end;
 578         }
 579
 580         if (clear_aspm) {
 581                 dev_info(&device->dev, "Disabling ASPM (FADT indicates it is unsupported)\n");
 582                 pcie_clear_aspm(root->bus);
 583         }
 584         if (no_aspm)
 585                 pcie_no_aspm();
 586
 587         pci_acpi_add_bus_pm_notifier(device, root->bus);
 588         if (device->wakeup.flags.run_wake)
 589                 device_set_run_wake(root->bus->bridge, true);
 590
 591         if (system_state != SYSTEM_BOOTING) {
 592                 pcibios_resource_survey_bus(root->bus);
 593                 pci_assign_unassigned_root_bus_resources(root->bus);
 594         }
 595
 596         pci_bus_add_devices(root->bus);
 597         return 1;
 598
 599 end:
 600         kfree(root);
 601         return result;
 602 }
 603
 604 static void acpi_pci_root_remove(struct acpi_device *device)
 605 {
 606         struct acpi_pci_root *root = acpi_driver_data(device);
 607
 608         pci_stop_root_bus(root->bus);
 609
 610         device_set_run_wake(root->bus->bridge, false);
 611         pci_acpi_remove_bus_pm_notifier(device);
 612
 613         pci_remove_root_bus(root->bus);
 614
 615         kfree(root);
 616 }
 617
 618 void __init acpi_pci_root_init(void)
 619 {
 620         acpi_hest_init();
 621
 622         if (!acpi_pci_disabled) {
 623                 pci_acpi_crs_quirks();
 624                 acpi_scan_add_handler(&pci_root_handler);
 625         }
 626 }
 627 /* Support root bridge hotplug */
 628
 629 static void handle_root_bridge_insertion(acpi_handle handle)
 630 {
 631         struct acpi_device *device;
 632
 633         if (!acpi_bus_get_device(handle, &device)) {
 634                 dev_printk(KERN_DEBUG, &device->dev,
 635                            "acpi device already exists; ignoring notify\n");
 636                 return;
 637         }
 638
 639         if (acpi_bus_scan(handle))
 640                 acpi_handle_err(handle, "cannot add bridge to acpi list\n");
 641 }
 642
 643 static void handle_root_bridge_removal(struct acpi_device *device)
 644 {
 645         acpi_status status;
 646         struct acpi_eject_event *ej_event;
 647
 648         ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
 649         if (!ej_event) {
 650                 /* Inform firmware the hot-remove operation has error */
 651                 (void) acpi_evaluate_hotplug_ost(device->handle,
 652                                         ACPI_NOTIFY_EJECT_REQUEST,
 653                                         ACPI_OST_SC_NON_SPECIFIC_FAILURE,
 654                                         NULL);
 655                 return;
 656         }
 657
 658         ej_event->device = device;
 659         ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
 660
 661         status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device, ej_event);
 662         if (ACPI_FAILURE(status))
 663                 kfree(ej_event);
 664 }
 665
 666 static void _handle_hotplug_event_root(struct work_struct *work)
 667 {
 668         struct acpi_pci_root *root;
 669         struct acpi_hp_work *hp_work;
 670         acpi_handle handle;
 671         u32 type;
 672
 673         hp_work = container_of(work, struct acpi_hp_work, work);
 674         handle = hp_work->handle;
 675         type = hp_work->type;
 676
 677         acpi_scan_lock_acquire();
 678
 679         root = acpi_pci_find_root(handle);
 680
 681         switch (type) {
 682         case ACPI_NOTIFY_BUS_CHECK:
 683                 /* bus enumerate */
 684                 acpi_handle_printk(KERN_DEBUG, handle,
 685                                    "Bus check notify on %s\n", __func__);
 686                 if (root)
 687                         acpiphp_check_host_bridge(handle);
 688                 else
 689                         handle_root_bridge_insertion(handle);
 690
 691                 break;
 692
 693         case ACPI_NOTIFY_DEVICE_CHECK:
 694                 /* device check */
 695                 acpi_handle_printk(KERN_DEBUG, handle,
 696                                    "Device check notify on %s\n", __func__);
 697                 if (!root)
 698                         handle_root_bridge_insertion(handle);
 699                 break;
 700
 701         case ACPI_NOTIFY_EJECT_REQUEST:
 702                 /* request device eject */
 703                 acpi_handle_printk(KERN_DEBUG, handle,
 704                                    "Device eject notify on %s\n", __func__);
 705                 if (root)
 706                         handle_root_bridge_removal(root->device);
 707                 break;
 708         default:
 709                 acpi_handle_warn(handle,
 710                                  "notify_handler: unknown event type 0x%x\n",
 711                                  type);
 712                 break;
 713         }
 714
 715         acpi_scan_lock_release();
 716         kfree(hp_work); /* allocated in handle_hotplug_event_bridge */
 717 }
 718
 719 static void handle_hotplug_event_root(acpi_handle handle, u32 type,
 720                                         void *context)
 721 {
 722         alloc_acpi_hp_work(handle, type, context,
 723                                 _handle_hotplug_event_root);
 724 }
 725
 726 static acpi_status __init
 727 find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
 728 {
 729         acpi_status status;
 730         int *count = (int *)context;
 731
 732         if (!acpi_is_root_bridge(handle))
 733                 return AE_OK;
 734
 735         (*count)++;
 736
 737         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 738                                         handle_hotplug_event_root, NULL);
 739         if (ACPI_FAILURE(status))
 740                 acpi_handle_printk(KERN_DEBUG, handle,
 741                         "notify handler is not installed, exit status: %u\n",
 742                          (unsigned int)status);
 743         else
 744                 acpi_handle_printk(KERN_DEBUG, handle,
 745                                    "notify handler is installed\n");
 746
 747         return AE_OK;
 748 }
 749
 750 void __init acpi_pci_root_hp_init(void)
 751 {
 752         int num = 0;
 753
 754         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 755                 ACPI_UINT32_MAX, find_root_bridges, NULL, &num, NULL);
 756
 757         printk(KERN_DEBUG "Found %d acpi root devices\n", num);
 758 }