drivers/acpi/pci_root.c

   1 /*
   2  *  pci_root.c - ACPI PCI Root Bridge Driver ($Revision: 40 $)
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *
   7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or (at
  12  *  your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful, but
  15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *  General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License along
  20  *  with this program; if not, write to the Free Software Foundation, Inc.,
  21  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  22  *
  23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/module.h>
  28 #include <linux/init.h>
  29 #include <linux/types.h>
  30 #include <linux/mutex.h>
  31 #include <linux/pm.h>
  32 #include <linux/pm_runtime.h>
  33 #include <linux/pci.h>
  34 #include <linux/pci-acpi.h>
  35 #include <linux/pci-aspm.h>
  36 #include <linux/acpi.h>
  37 #include <linux/slab.h>
  38 #include <acpi/acpi_bus.h>
  39 #include <acpi/acpi_drivers.h>
  40 #include <acpi/apei.h>
  41
  42 #define PREFIX "ACPI: "
  43
  44 #define _COMPONENT              ACPI_PCI_COMPONENT
  45 ACPI_MODULE_NAME("pci_root");
  46 #define ACPI_PCI_ROOT_CLASS             "pci_bridge"
  47 #define ACPI_PCI_ROOT_DEVICE_NAME       "PCI Root Bridge"
  48 static int acpi_pci_root_add(struct acpi_device *device,
  49                              const struct acpi_device_id *not_used);
  50 static void acpi_pci_root_remove(struct acpi_device *device);
  51
  52 #define ACPI_PCIE_REQ_SUPPORT (OSC_EXT_PCI_CONFIG_SUPPORT \
  53                                 | OSC_ACTIVE_STATE_PWR_SUPPORT \
  54                                 | OSC_CLOCK_PWR_CAPABILITY_SUPPORT \
  55                                 | OSC_MSI_SUPPORT)
  56
  57 static const struct acpi_device_id root_device_ids[] = {
  58         {"PNP0A03", 0},
  59         {"", 0},
  60 };
  61
  62 static struct acpi_scan_handler pci_root_handler = {
  63         .ids = root_device_ids,
  64         .attach = acpi_pci_root_add,
  65         .detach = acpi_pci_root_remove,
  66 };
  67
  68 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 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
 131
 132 static acpi_status acpi_pci_run_osc(acpi_handle handle,
 133                                     const u32 *capbuf, u32 *retval)
 134 {
 135         struct acpi_osc_context context = {
 136                 .uuid_str = pci_osc_uuid_str,
 137                 .rev = 1,
 138                 .cap.length = 12,
 139                 .cap.pointer = (void *)capbuf,
 140         };
 141         acpi_status status;
 142
 143         status = acpi_run_osc(handle, &context);
 144         if (ACPI_SUCCESS(status)) {
 145                 *retval = *((u32 *)(context.ret.pointer + 8));
 146                 kfree(context.ret.pointer);
 147         }
 148         return status;
 149 }
 150
 151 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
 152                                         u32 support,
 153                                         u32 *control)
 154 {
 155         acpi_status status;
 156         u32 result, capbuf[3];
 157
 158         support &= OSC_PCI_SUPPORT_MASKS;
 159         support |= root->osc_support_set;
 160
 161         capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
 162         capbuf[OSC_SUPPORT_TYPE] = support;
 163         if (control) {
 164                 *control &= OSC_PCI_CONTROL_MASKS;
 165                 capbuf[OSC_CONTROL_TYPE] = *control | root->osc_control_set;
 166         } else {
 167                 /* Run _OSC query only with existing controls. */
 168                 capbuf[OSC_CONTROL_TYPE] = root->osc_control_set;
 169         }
 170
 171         status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
 172         if (ACPI_SUCCESS(status)) {
 173                 root->osc_support_set = support;
 174                 if (control)
 175                         *control = result;
 176         }
 177         return status;
 178 }
 179
 180 static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
 181 {
 182         acpi_status status;
 183         acpi_handle tmp;
 184
 185         status = acpi_get_handle(root->device->handle, "_OSC", &tmp);
 186         if (ACPI_FAILURE(status))
 187                 return status;
 188         mutex_lock(&osc_lock);
 189         status = acpi_pci_query_osc(root, flags, NULL);
 190         mutex_unlock(&osc_lock);
 191         return status;
 192 }
 193
 194 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
 195 {
 196         struct acpi_pci_root *root;
 197         struct acpi_device *device;
 198
 199         if (acpi_bus_get_device(handle, &device) ||
 200             acpi_match_device_ids(device, root_device_ids))
 201                 return NULL;
 202
 203         root = acpi_driver_data(device);
 204
 205         return root;
 206 }
 207 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
 208
 209 struct acpi_handle_node {
 210         struct list_head node;
 211         acpi_handle handle;
 212 };
 213
 214 /**
 215  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
 216  * @handle: the handle in question
 217  *
 218  * Given an ACPI CA handle, the desired PCI device is located in the
 219  * list of PCI devices.
 220  *
 221  * If the device is found, its reference count is increased and this
 222  * function returns a pointer to its data structure.  The caller must
 223  * decrement the reference count by calling pci_dev_put().
 224  * If no device is found, %NULL is returned.
 225  */
 226 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
 227 {
 228         int dev, fn;
 229         unsigned long long adr;
 230         acpi_status status;
 231         acpi_handle phandle;
 232         struct pci_bus *pbus;
 233         struct pci_dev *pdev = NULL;
 234         struct acpi_handle_node *node, *tmp;
 235         struct acpi_pci_root *root;
 236         LIST_HEAD(device_list);
 237
 238         /*
 239          * Walk up the ACPI CA namespace until we reach a PCI root bridge.
 240          */
 241         phandle = handle;
 242         while (!acpi_is_root_bridge(phandle)) {
 243                 node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
 244                 if (!node)
 245                         goto out;
 246
 247                 INIT_LIST_HEAD(&node->node);
 248                 node->handle = phandle;
 249                 list_add(&node->node, &device_list);
 250
 251                 status = acpi_get_parent(phandle, &phandle);
 252                 if (ACPI_FAILURE(status))
 253                         goto out;
 254         }
 255
 256         root = acpi_pci_find_root(phandle);
 257         if (!root)
 258                 goto out;
 259
 260         pbus = root->bus;
 261
 262         /*
 263          * Now, walk back down the PCI device tree until we return to our
 264          * original handle. Assumes that everything between the PCI root
 265          * bridge and the device we're looking for must be a P2P bridge.
 266          */
 267         list_for_each_entry(node, &device_list, node) {
 268                 acpi_handle hnd = node->handle;
 269                 status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
 270                 if (ACPI_FAILURE(status))
 271                         goto out;
 272                 dev = (adr >> 16) & 0xffff;
 273                 fn  = adr & 0xffff;
 274
 275                 pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
 276                 if (!pdev || hnd == handle)
 277                         break;
 278
 279                 pbus = pdev->subordinate;
 280                 pci_dev_put(pdev);
 281
 282                 /*
 283                  * This function may be called for a non-PCI device that has a
 284                  * PCI parent (eg. a disk under a PCI SATA controller).  In that
 285                  * case pdev->subordinate will be NULL for the parent.
 286                  */
 287                 if (!pbus) {
 288                         dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
 289                         pdev = NULL;
 290                         break;
 291                 }
 292         }
 293 out:
 294         list_for_each_entry_safe(node, tmp, &device_list, node)
 295                 kfree(node);
 296
 297         return pdev;
 298 }
 299 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
 300
 301 /**
 302  * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
 303  * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
 304  * @mask: Mask of _OSC bits to request control of, place to store control mask.
 305  * @req: Mask of _OSC bits the control of is essential to the caller.
 306  *
 307  * Run _OSC query for @mask and if that is successful, compare the returned
 308  * mask of control bits with @req.  If all of the @req bits are set in the
 309  * returned mask, run _OSC request for it.
 310  *
 311  * The variable at the @mask address may be modified regardless of whether or
 312  * not the function returns success.  On success it will contain the mask of
 313  * _OSC bits the BIOS has granted control of, but its contents are meaningless
 314  * on failure.
 315  **/
 316 acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
 317 {
 318         struct acpi_pci_root *root;
 319         acpi_status status;
 320         u32 ctrl, capbuf[3];
 321         acpi_handle tmp;
 322
 323         if (!mask)
 324                 return AE_BAD_PARAMETER;
 325
 326         ctrl = *mask & OSC_PCI_CONTROL_MASKS;
 327         if ((ctrl & req) != req)
 328                 return AE_TYPE;
 329
 330         root = acpi_pci_find_root(handle);
 331         if (!root)
 332                 return AE_NOT_EXIST;
 333
 334         status = acpi_get_handle(handle, "_OSC", &tmp);
 335         if (ACPI_FAILURE(status))
 336                 return status;
 337
 338         mutex_lock(&osc_lock);
 339
 340         *mask = ctrl | root->osc_control_set;
 341         /* No need to evaluate _OSC if the control was already granted. */
 342         if ((root->osc_control_set & ctrl) == ctrl)
 343                 goto out;
 344
 345         /* Need to check the available controls bits before requesting them. */
 346         while (*mask) {
 347                 status = acpi_pci_query_osc(root, root->osc_support_set, mask);
 348                 if (ACPI_FAILURE(status))
 349                         goto out;
 350                 if (ctrl == *mask)
 351                         break;
 352                 ctrl = *mask;
 353         }
 354
 355         if ((ctrl & req) != req) {
 356                 status = AE_SUPPORT;
 357                 goto out;
 358         }
 359
 360         capbuf[OSC_QUERY_TYPE] = 0;
 361         capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set;
 362         capbuf[OSC_CONTROL_TYPE] = ctrl;
 363         status = acpi_pci_run_osc(handle, capbuf, mask);
 364         if (ACPI_SUCCESS(status))
 365                 root->osc_control_set = *mask;
 366 out:
 367         mutex_unlock(&osc_lock);
 368         return status;
 369 }
 370 EXPORT_SYMBOL(acpi_pci_osc_control_set);
 371
 372 static int acpi_pci_root_add(struct acpi_device *device,
 373                              const struct acpi_device_id *not_used)
 374 {
 375         unsigned long long segment, bus;
 376         acpi_status status;
 377         int result;
 378         struct acpi_pci_root *root;
 379         u32 flags, base_flags;
 380         acpi_handle handle = device->handle;
 381
 382         root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 383         if (!root)
 384                 return -ENOMEM;
 385
 386         segment = 0;
 387         status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL,
 388                                        &segment);
 389         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 390                 dev_err(&device->dev,  "can't evaluate _SEG\n");
 391                 result = -ENODEV;
 392                 goto end;
 393         }
 394
 395         /* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
 396         root->secondary.flags = IORESOURCE_BUS;
 397         status = try_get_root_bridge_busnr(handle, &root->secondary);
 398         if (ACPI_FAILURE(status)) {
 399                 /*
 400                  * We need both the start and end of the downstream bus range
 401                  * to interpret _CBA (MMCONFIG base address), so it really is
 402                  * supposed to be in _CRS.  If we don't find it there, all we
 403                  * can do is assume [_BBN-0xFF] or [0-0xFF].
 404                  */
 405                 root->secondary.end = 0xFF;
 406                 dev_warn(&device->dev,
 407                          FW_BUG "no secondary bus range in _CRS\n");
 408                 status = acpi_evaluate_integer(handle, METHOD_NAME__BBN,
 409                                                NULL, &bus);
 410                 if (ACPI_SUCCESS(status))
 411                         root->secondary.start = bus;
 412                 else if (status == AE_NOT_FOUND)
 413                         root->secondary.start = 0;
 414                 else {
 415                         dev_err(&device->dev, "can't evaluate _BBN\n");
 416                         result = -ENODEV;
 417                         goto end;
 418                 }
 419         }
 420
 421         root->device = device;
 422         root->segment = segment & 0xFFFF;
 423         strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
 424         strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 425         device->driver_data = root;
 426
 427         pr_info(PREFIX "%s [%s] (domain %04x %pR)\n",
 428                acpi_device_name(device), acpi_device_bid(device),
 429                root->segment, &root->secondary);
 430
 431         root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
 432
 433         /*
 434          * All supported architectures that use ACPI have support for
 435          * PCI domains, so we indicate this in _OSC support capabilities.
 436          */
 437         flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
 438         acpi_pci_osc_support(root, flags);
 439
 440         /*
 441          * TBD: Need PCI interface for enumeration/configuration of roots.
 442          */
 443
 444         /*
 445          * Scan the Root Bridge
 446          * --------------------
 447          * Must do this prior to any attempt to bind the root device, as the
 448          * PCI namespace does not get created until this call is made (and
 449          * thus the root bridge's pci_dev does not exist).
 450          */
 451         root->bus = pci_acpi_scan_root(root);
 452         if (!root->bus) {
 453                 dev_err(&device->dev,
 454                         "Bus %04x:%02x not present in PCI namespace\n",
 455                         root->segment, (unsigned int)root->secondary.start);
 456                 result = -ENODEV;
 457                 goto end;
 458         }
 459
 460         /* Indicate support for various _OSC capabilities. */
 461         if (pci_ext_cfg_avail())
 462                 flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
 463         if (pcie_aspm_support_enabled()) {
 464                 flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
 465                 OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
 466         }
 467         if (pci_msi_enabled())
 468                 flags |= OSC_MSI_SUPPORT;
 469         if (flags != base_flags) {
 470                 status = acpi_pci_osc_support(root, flags);
 471                 if (ACPI_FAILURE(status)) {
 472                         dev_info(&device->dev, "ACPI _OSC support "
 473                                 "notification failed, disabling PCIe ASPM\n");
 474                         pcie_no_aspm();
 475                         flags = base_flags;
 476                 }
 477         }
 478
 479         if (!pcie_ports_disabled
 480             && (flags & ACPI_PCIE_REQ_SUPPORT) == ACPI_PCIE_REQ_SUPPORT) {
 481                 flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL
 482                         | OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
 483                         | OSC_PCI_EXPRESS_PME_CONTROL;
 484
 485                 if (pci_aer_available()) {
 486                         if (aer_acpi_firmware_first())
 487                                 dev_dbg(&device->dev,
 488                                         "PCIe errors handled by BIOS.\n");
 489                         else
 490                                 flags |= OSC_PCI_EXPRESS_AER_CONTROL;
 491                 }
 492
 493                 dev_info(&device->dev,
 494                         "Requesting ACPI _OSC control (0x%02x)\n", flags);
 495
 496                 status = acpi_pci_osc_control_set(handle, &flags,
 497                                        OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
 498                 if (ACPI_SUCCESS(status)) {
 499                         dev_info(&device->dev,
 500                                 "ACPI _OSC control (0x%02x) granted\n", flags);
 501                         if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 502                                 /*
 503                                  * We have ASPM control, but the FADT indicates
 504                                  * that it's unsupported. Clear it.
 505                                  */
 506                                 pcie_clear_aspm(root->bus);
 507                         }
 508                 } else {
 509                         dev_info(&device->dev,
 510                                 "ACPI _OSC request failed (%s), "
 511                                 "returned control mask: 0x%02x\n",
 512                                 acpi_format_exception(status), flags);
 513                         dev_info(&device->dev,
 514                                  "ACPI _OSC control for PCIe not granted, disabling ASPM\n");
 515                         pcie_no_aspm();
 516                 }
 517         } else {
 518                 dev_info(&device->dev,
 519                          "Unable to request _OSC control "
 520                          "(_OSC support mask: 0x%02x)\n", flags);
 521         }
 522
 523         pci_acpi_add_bus_pm_notifier(device, root->bus);
 524         if (device->wakeup.flags.run_wake)
 525                 device_set_run_wake(root->bus->bridge, true);
 526
 527         if (system_state != SYSTEM_BOOTING) {
 528                 pcibios_resource_survey_bus(root->bus);
 529                 pci_assign_unassigned_bus_resources(root->bus);
 530
 531                 /* need to after hot-added ioapic is registered */
 532                 pci_enable_bridges(root->bus);
 533         }
 534
 535         pci_bus_add_devices(root->bus);
 536         return 1;
 537
 538 end:
 539         kfree(root);
 540         return result;
 541 }
 542
 543 static void acpi_pci_root_remove(struct acpi_device *device)
 544 {
 545         struct acpi_pci_root *root = acpi_driver_data(device);
 546
 547         pci_stop_root_bus(root->bus);
 548
 549         device_set_run_wake(root->bus->bridge, false);
 550         pci_acpi_remove_bus_pm_notifier(device);
 551
 552         pci_remove_root_bus(root->bus);
 553
 554         kfree(root);
 555 }
 556
 557 void __init acpi_pci_root_init(void)
 558 {
 559         acpi_hest_init();
 560
 561         if (!acpi_pci_disabled) {
 562                 pci_acpi_crs_quirks();
 563                 acpi_scan_add_handler(&pci_root_handler);
 564         }
 565 }
 566 /* Support root bridge hotplug */
 567
 568 static void handle_root_bridge_insertion(acpi_handle handle)
 569 {
 570         struct acpi_device *device;
 571
 572         if (!acpi_bus_get_device(handle, &device)) {
 573                 dev_printk(KERN_DEBUG, &device->dev,
 574                            "acpi device already exists; ignoring notify\n");
 575                 return;
 576         }
 577
 578         if (acpi_bus_scan(handle))
 579                 acpi_handle_err(handle, "cannot add bridge to acpi list\n");
 580 }
 581
 582 static void handle_root_bridge_removal(struct acpi_device *device)
 583 {
 584         acpi_status status;
 585         struct acpi_eject_event *ej_event;
 586
 587         ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
 588         if (!ej_event) {
 589                 /* Inform firmware the hot-remove operation has error */
 590                 (void) acpi_evaluate_hotplug_ost(device->handle,
 591                                         ACPI_NOTIFY_EJECT_REQUEST,
 592                                         ACPI_OST_SC_NON_SPECIFIC_FAILURE,
 593                                         NULL);
 594                 return;
 595         }
 596
 597         ej_event->device = device;
 598         ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
 599
 600         status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device, ej_event);
 601         if (ACPI_FAILURE(status))
 602                 kfree(ej_event);
 603 }
 604
 605 static void _handle_hotplug_event_root(struct work_struct *work)
 606 {
 607         struct acpi_pci_root *root;
 608         struct acpi_hp_work *hp_work;
 609         acpi_handle handle;
 610         u32 type;
 611
 612         hp_work = container_of(work, struct acpi_hp_work, work);
 613         handle = hp_work->handle;
 614         type = hp_work->type;
 615
 616         acpi_scan_lock_acquire();
 617
 618         root = acpi_pci_find_root(handle);
 619
 620         switch (type) {
 621         case ACPI_NOTIFY_BUS_CHECK:
 622                 /* bus enumerate */
 623                 acpi_handle_printk(KERN_DEBUG, handle,
 624                                    "Bus check notify on %s\n", __func__);
 625                 if (root)
 626                         acpiphp_check_host_bridge(handle);
 627                 else
 628                         handle_root_bridge_insertion(handle);
 629
 630                 break;
 631
 632         case ACPI_NOTIFY_DEVICE_CHECK:
 633                 /* device check */
 634                 acpi_handle_printk(KERN_DEBUG, handle,
 635                                    "Device check notify on %s\n", __func__);
 636                 if (!root)
 637                         handle_root_bridge_insertion(handle);
 638                 break;
 639
 640         case ACPI_NOTIFY_EJECT_REQUEST:
 641                 /* request device eject */
 642                 acpi_handle_printk(KERN_DEBUG, handle,
 643                                    "Device eject notify on %s\n", __func__);
 644                 if (root)
 645                         handle_root_bridge_removal(root->device);
 646                 break;
 647         default:
 648                 acpi_handle_warn(handle,
 649                                  "notify_handler: unknown event type 0x%x\n",
 650                                  type);
 651                 break;
 652         }
 653
 654         acpi_scan_lock_release();
 655         kfree(hp_work); /* allocated in handle_hotplug_event_bridge */
 656 }
 657
 658 static void handle_hotplug_event_root(acpi_handle handle, u32 type,
 659                                         void *context)
 660 {
 661         alloc_acpi_hp_work(handle, type, context,
 662                                 _handle_hotplug_event_root);
 663 }
 664
 665 static acpi_status __init
 666 find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
 667 {
 668         acpi_status status;
 669         int *count = (int *)context;
 670
 671         if (!acpi_is_root_bridge(handle))
 672                 return AE_OK;
 673
 674         (*count)++;
 675
 676         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 677                                         handle_hotplug_event_root, NULL);
 678         if (ACPI_FAILURE(status))
 679                 acpi_handle_printk(KERN_DEBUG, handle,
 680                         "notify handler is not installed, exit status: %u\n",
 681                          (unsigned int)status);
 682         else
 683                 acpi_handle_printk(KERN_DEBUG, handle,
 684                                    "notify handler is installed\n");
 685
 686         return AE_OK;
 687 }
 688
 689 void __init acpi_pci_root_hp_init(void)
 690 {
 691         int num = 0;
 692
 693         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 694                 ACPI_UINT32_MAX, find_root_bridges, NULL, &num, NULL);
 695
 696         printk(KERN_DEBUG "Found %d acpi root devices\n", num);
 697 }