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         .hotplug = {
  67                 .ignore = true,
  68         },
  69 };
  70
  71 /* Lock to protect both acpi_pci_roots lists */
  72 static DEFINE_MUTEX(acpi_pci_root_lock);
  73 static LIST_HEAD(acpi_pci_roots);
  74
  75 static DEFINE_MUTEX(osc_lock);
  76
  77 /**
  78  * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
  79  * @handle - the ACPI CA node in question.
  80  *
  81  * Note: we could make this API take a struct acpi_device * instead, but
  82  * for now, it's more convenient to operate on an acpi_handle.
  83  */
  84 int acpi_is_root_bridge(acpi_handle handle)
  85 {
  86         int ret;
  87         struct acpi_device *device;
  88
  89         ret = acpi_bus_get_device(handle, &device);
  90         if (ret)
  91                 return 0;
  92
  93         ret = acpi_match_device_ids(device, root_device_ids);
  94         if (ret)
  95                 return 0;
  96         else
  97                 return 1;
  98 }
  99 EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
 100
 101 static acpi_status
 102 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
 103 {
 104         struct resource *res = data;
 105         struct acpi_resource_address64 address;
 106
 107         if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
 108             resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
 109             resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
 110                 return AE_OK;
 111
 112         acpi_resource_to_address64(resource, &address);
 113         if ((address.address_length > 0) &&
 114             (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
 115                 res->start = address.minimum;
 116                 res->end = address.minimum + address.address_length - 1;
 117         }
 118
 119         return AE_OK;
 120 }
 121
 122 static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
 123                                              struct resource *res)
 124 {
 125         acpi_status status;
 126
 127         res->start = -1;
 128         status =
 129             acpi_walk_resources(handle, METHOD_NAME__CRS,
 130                                 get_root_bridge_busnr_callback, res);
 131         if (ACPI_FAILURE(status))
 132                 return status;
 133         if (res->start == -1)
 134                 return AE_ERROR;
 135         return AE_OK;
 136 }
 137
 138 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
 139
 140 static acpi_status acpi_pci_run_osc(acpi_handle handle,
 141                                     const u32 *capbuf, u32 *retval)
 142 {
 143         struct acpi_osc_context context = {
 144                 .uuid_str = pci_osc_uuid_str,
 145                 .rev = 1,
 146                 .cap.length = 12,
 147                 .cap.pointer = (void *)capbuf,
 148         };
 149         acpi_status status;
 150
 151         status = acpi_run_osc(handle, &context);
 152         if (ACPI_SUCCESS(status)) {
 153                 *retval = *((u32 *)(context.ret.pointer + 8));
 154                 kfree(context.ret.pointer);
 155         }
 156         return status;
 157 }
 158
 159 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
 160                                         u32 support,
 161                                         u32 *control)
 162 {
 163         acpi_status status;
 164         u32 result, capbuf[3];
 165
 166         support &= OSC_PCI_SUPPORT_MASKS;
 167         support |= root->osc_support_set;
 168
 169         capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
 170         capbuf[OSC_SUPPORT_TYPE] = support;
 171         if (control) {
 172                 *control &= OSC_PCI_CONTROL_MASKS;
 173                 capbuf[OSC_CONTROL_TYPE] = *control | root->osc_control_set;
 174         } else {
 175                 /* Run _OSC query only with existing controls. */
 176                 capbuf[OSC_CONTROL_TYPE] = root->osc_control_set;
 177         }
 178
 179         status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
 180         if (ACPI_SUCCESS(status)) {
 181                 root->osc_support_set = support;
 182                 if (control)
 183                         *control = result;
 184         }
 185         return status;
 186 }
 187
 188 static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
 189 {
 190         acpi_status status;
 191         acpi_handle tmp;
 192
 193         status = acpi_get_handle(root->device->handle, "_OSC", &tmp);
 194         if (ACPI_FAILURE(status))
 195                 return status;
 196         mutex_lock(&osc_lock);
 197         status = acpi_pci_query_osc(root, flags, NULL);
 198         mutex_unlock(&osc_lock);
 199         return status;
 200 }
 201
 202 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
 203 {
 204         struct acpi_pci_root *root;
 205         struct acpi_device *device;
 206
 207         if (acpi_bus_get_device(handle, &device) ||
 208             acpi_match_device_ids(device, root_device_ids))
 209                 return NULL;
 210
 211         root = acpi_driver_data(device);
 212
 213         return root;
 214 }
 215 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
 216
 217 struct acpi_handle_node {
 218         struct list_head node;
 219         acpi_handle handle;
 220 };
 221
 222 /**
 223  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
 224  * @handle: the handle in question
 225  *
 226  * Given an ACPI CA handle, the desired PCI device is located in the
 227  * list of PCI devices.
 228  *
 229  * If the device is found, its reference count is increased and this
 230  * function returns a pointer to its data structure.  The caller must
 231  * decrement the reference count by calling pci_dev_put().
 232  * If no device is found, %NULL is returned.
 233  */
 234 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
 235 {
 236         int dev, fn;
 237         unsigned long long adr;
 238         acpi_status status;
 239         acpi_handle phandle;
 240         struct pci_bus *pbus;
 241         struct pci_dev *pdev = NULL;
 242         struct acpi_handle_node *node, *tmp;
 243         struct acpi_pci_root *root;
 244         LIST_HEAD(device_list);
 245
 246         /*
 247          * Walk up the ACPI CA namespace until we reach a PCI root bridge.
 248          */
 249         phandle = handle;
 250         while (!acpi_is_root_bridge(phandle)) {
 251                 node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
 252                 if (!node)
 253                         goto out;
 254
 255                 INIT_LIST_HEAD(&node->node);
 256                 node->handle = phandle;
 257                 list_add(&node->node, &device_list);
 258
 259                 status = acpi_get_parent(phandle, &phandle);
 260                 if (ACPI_FAILURE(status))
 261                         goto out;
 262         }
 263
 264         root = acpi_pci_find_root(phandle);
 265         if (!root)
 266                 goto out;
 267
 268         pbus = root->bus;
 269
 270         /*
 271          * Now, walk back down the PCI device tree until we return to our
 272          * original handle. Assumes that everything between the PCI root
 273          * bridge and the device we're looking for must be a P2P bridge.
 274          */
 275         list_for_each_entry(node, &device_list, node) {
 276                 acpi_handle hnd = node->handle;
 277                 status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
 278                 if (ACPI_FAILURE(status))
 279                         goto out;
 280                 dev = (adr >> 16) & 0xffff;
 281                 fn  = adr & 0xffff;
 282
 283                 pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
 284                 if (!pdev || hnd == handle)
 285                         break;
 286
 287                 pbus = pdev->subordinate;
 288                 pci_dev_put(pdev);
 289
 290                 /*
 291                  * This function may be called for a non-PCI device that has a
 292                  * PCI parent (eg. a disk under a PCI SATA controller).  In that
 293                  * case pdev->subordinate will be NULL for the parent.
 294                  */
 295                 if (!pbus) {
 296                         dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
 297                         pdev = NULL;
 298                         break;
 299                 }
 300         }
 301 out:
 302         list_for_each_entry_safe(node, tmp, &device_list, node)
 303                 kfree(node);
 304
 305         return pdev;
 306 }
 307 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
 308
 309 /**
 310  * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
 311  * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
 312  * @mask: Mask of _OSC bits to request control of, place to store control mask.
 313  * @req: Mask of _OSC bits the control of is essential to the caller.
 314  *
 315  * Run _OSC query for @mask and if that is successful, compare the returned
 316  * mask of control bits with @req.  If all of the @req bits are set in the
 317  * returned mask, run _OSC request for it.
 318  *
 319  * The variable at the @mask address may be modified regardless of whether or
 320  * not the function returns success.  On success it will contain the mask of
 321  * _OSC bits the BIOS has granted control of, but its contents are meaningless
 322  * on failure.
 323  **/
 324 acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
 325 {
 326         struct acpi_pci_root *root;
 327         acpi_status status;
 328         u32 ctrl, capbuf[3];
 329         acpi_handle tmp;
 330
 331         if (!mask)
 332                 return AE_BAD_PARAMETER;
 333
 334         ctrl = *mask & OSC_PCI_CONTROL_MASKS;
 335         if ((ctrl & req) != req)
 336                 return AE_TYPE;
 337
 338         root = acpi_pci_find_root(handle);
 339         if (!root)
 340                 return AE_NOT_EXIST;
 341
 342         status = acpi_get_handle(handle, "_OSC", &tmp);
 343         if (ACPI_FAILURE(status))
 344                 return status;
 345
 346         mutex_lock(&osc_lock);
 347
 348         *mask = ctrl | root->osc_control_set;
 349         /* No need to evaluate _OSC if the control was already granted. */
 350         if ((root->osc_control_set & ctrl) == ctrl)
 351                 goto out;
 352
 353         /* Need to check the available controls bits before requesting them. */
 354         while (*mask) {
 355                 status = acpi_pci_query_osc(root, root->osc_support_set, mask);
 356                 if (ACPI_FAILURE(status))
 357                         goto out;
 358                 if (ctrl == *mask)
 359                         break;
 360                 ctrl = *mask;
 361         }
 362
 363         if ((ctrl & req) != req) {
 364                 status = AE_SUPPORT;
 365                 goto out;
 366         }
 367
 368         capbuf[OSC_QUERY_TYPE] = 0;
 369         capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set;
 370         capbuf[OSC_CONTROL_TYPE] = ctrl;
 371         status = acpi_pci_run_osc(handle, capbuf, mask);
 372         if (ACPI_SUCCESS(status))
 373                 root->osc_control_set = *mask;
 374 out:
 375         mutex_unlock(&osc_lock);
 376         return status;
 377 }
 378 EXPORT_SYMBOL(acpi_pci_osc_control_set);
 379
 380 static int acpi_pci_root_add(struct acpi_device *device,
 381                              const struct acpi_device_id *not_used)
 382 {
 383         unsigned long long segment, bus;
 384         acpi_status status;
 385         int result;
 386         struct acpi_pci_root *root;
 387         u32 flags, base_flags;
 388
 389         root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 390         if (!root)
 391                 return -ENOMEM;
 392
 393         segment = 0;
 394         status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
 395                                        &segment);
 396         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 397                 printk(KERN_ERR PREFIX "can't evaluate _SEG\n");
 398                 result = -ENODEV;
 399                 goto end;
 400         }
 401
 402         /* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
 403         root->secondary.flags = IORESOURCE_BUS;
 404         status = try_get_root_bridge_busnr(device->handle, &root->secondary);
 405         if (ACPI_FAILURE(status)) {
 406                 /*
 407                  * We need both the start and end of the downstream bus range
 408                  * to interpret _CBA (MMCONFIG base address), so it really is
 409                  * supposed to be in _CRS.  If we don't find it there, all we
 410                  * can do is assume [_BBN-0xFF] or [0-0xFF].
 411                  */
 412                 root->secondary.end = 0xFF;
 413                 printk(KERN_WARNING FW_BUG PREFIX
 414                        "no secondary bus range in _CRS\n");
 415                 status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN,
 416                                                NULL, &bus);
 417                 if (ACPI_SUCCESS(status))
 418                         root->secondary.start = bus;
 419                 else if (status == AE_NOT_FOUND)
 420                         root->secondary.start = 0;
 421                 else {
 422                         printk(KERN_ERR PREFIX "can't evaluate _BBN\n");
 423                         result = -ENODEV;
 424                         goto end;
 425                 }
 426         }
 427
 428         INIT_LIST_HEAD(&root->node);
 429         root->device = device;
 430         root->segment = segment & 0xFFFF;
 431         strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
 432         strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 433         device->driver_data = root;
 434
 435         printk(KERN_INFO PREFIX "%s [%s] (domain %04x %pR)\n",
 436                acpi_device_name(device), acpi_device_bid(device),
 437                root->segment, &root->secondary);
 438
 439         root->mcfg_addr = acpi_pci_root_get_mcfg_addr(device->handle);
 440
 441         /*
 442          * All supported architectures that use ACPI have support for
 443          * PCI domains, so we indicate this in _OSC support capabilities.
 444          */
 445         flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
 446         acpi_pci_osc_support(root, flags);
 447
 448         /*
 449          * TBD: Need PCI interface for enumeration/configuration of roots.
 450          */
 451
 452         mutex_lock(&acpi_pci_root_lock);
 453         list_add_tail(&root->node, &acpi_pci_roots);
 454         mutex_unlock(&acpi_pci_root_lock);
 455
 456         /*
 457          * Scan the Root Bridge
 458          * --------------------
 459          * Must do this prior to any attempt to bind the root device, as the
 460          * PCI namespace does not get created until this call is made (and
 461          * thus the root bridge's pci_dev does not exist).
 462          */
 463         root->bus = pci_acpi_scan_root(root);
 464         if (!root->bus) {
 465                 printk(KERN_ERR PREFIX
 466                             "Bus %04x:%02x not present in PCI namespace\n",
 467                             root->segment, (unsigned int)root->secondary.start);
 468                 result = -ENODEV;
 469                 goto out_del_root;
 470         }
 471
 472         /* Indicate support for various _OSC capabilities. */
 473         if (pci_ext_cfg_avail())
 474                 flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
 475         if (pcie_aspm_support_enabled()) {
 476                 flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
 477                 OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
 478         }
 479         if (pci_msi_enabled())
 480                 flags |= OSC_MSI_SUPPORT;
 481         if (flags != base_flags) {
 482                 status = acpi_pci_osc_support(root, flags);
 483                 if (ACPI_FAILURE(status)) {
 484                         dev_info(&device->dev, "ACPI _OSC support "
 485                                 "notification failed, disabling PCIe ASPM\n");
 486                         pcie_no_aspm();
 487                         flags = base_flags;
 488                 }
 489         }
 490
 491         if (!pcie_ports_disabled
 492             && (flags & ACPI_PCIE_REQ_SUPPORT) == ACPI_PCIE_REQ_SUPPORT) {
 493                 flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL
 494                         | OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
 495                         | OSC_PCI_EXPRESS_PME_CONTROL;
 496
 497                 if (pci_aer_available()) {
 498                         if (aer_acpi_firmware_first())
 499                                 dev_dbg(&device->dev,
 500                                         "PCIe errors handled by BIOS.\n");
 501                         else
 502                                 flags |= OSC_PCI_EXPRESS_AER_CONTROL;
 503                 }
 504
 505                 dev_info(&device->dev,
 506                         "Requesting ACPI _OSC control (0x%02x)\n", flags);
 507
 508                 status = acpi_pci_osc_control_set(device->handle, &flags,
 509                                        OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
 510                 if (ACPI_SUCCESS(status)) {
 511                         dev_info(&device->dev,
 512                                 "ACPI _OSC control (0x%02x) granted\n", flags);
 513                         if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 514                                 /*
 515                                  * We have ASPM control, but the FADT indicates
 516                                  * that it's unsupported. Clear it.
 517                                  */
 518                                 pcie_clear_aspm(root->bus);
 519                         }
 520                 } else {
 521                         dev_info(&device->dev,
 522                                 "ACPI _OSC request failed (%s), "
 523                                 "returned control mask: 0x%02x\n",
 524                                 acpi_format_exception(status), flags);
 525                         pr_info("ACPI _OSC control for PCIe not granted, "
 526                                 "disabling ASPM\n");
 527                         pcie_no_aspm();
 528                 }
 529         } else {
 530                 dev_info(&device->dev,
 531                          "Unable to request _OSC control "
 532                          "(_OSC support mask: 0x%02x)\n", flags);
 533         }
 534
 535         pci_acpi_add_bus_pm_notifier(device, root->bus);
 536         if (device->wakeup.flags.run_wake)
 537                 device_set_run_wake(root->bus->bridge, true);
 538
 539         if (system_state != SYSTEM_BOOTING) {
 540                 pcibios_resource_survey_bus(root->bus);
 541                 pci_assign_unassigned_bus_resources(root->bus);
 542         }
 543
 544         /* need to after hot-added ioapic is registered */
 545         if (system_state != SYSTEM_BOOTING)
 546                 pci_enable_bridges(root->bus);
 547
 548         pci_bus_add_devices(root->bus);
 549         return 1;
 550
 551 out_del_root:
 552         mutex_lock(&acpi_pci_root_lock);
 553         list_del(&root->node);
 554         mutex_unlock(&acpi_pci_root_lock);
 555
 556 end:
 557         kfree(root);
 558         return result;
 559 }
 560
 561 static void acpi_pci_root_remove(struct acpi_device *device)
 562 {
 563         struct acpi_pci_root *root = acpi_driver_data(device);
 564
 565         pci_stop_root_bus(root->bus);
 566
 567         device_set_run_wake(root->bus->bridge, false);
 568         pci_acpi_remove_bus_pm_notifier(device);
 569
 570         pci_remove_root_bus(root->bus);
 571
 572         mutex_lock(&acpi_pci_root_lock);
 573         list_del(&root->node);
 574         mutex_unlock(&acpi_pci_root_lock);
 575         kfree(root);
 576 }
 577
 578 void __init acpi_pci_root_init(void)
 579 {
 580         acpi_hest_init();
 581
 582         if (!acpi_pci_disabled) {
 583                 pci_acpi_crs_quirks();
 584                 acpi_scan_add_handler(&pci_root_handler);
 585         }
 586 }
 587 /* Support root bridge hotplug */
 588
 589 static void handle_root_bridge_insertion(acpi_handle handle)
 590 {
 591         struct acpi_device *device;
 592
 593         if (!acpi_bus_get_device(handle, &device)) {
 594                 printk(KERN_DEBUG "acpi device exists...\n");
 595                 return;
 596         }
 597
 598         if (acpi_bus_scan(handle))
 599                 printk(KERN_ERR "cannot add bridge to acpi list\n");
 600 }
 601
 602 static void handle_root_bridge_removal(struct acpi_device *device)
 603 {
 604         acpi_status status;
 605         struct acpi_eject_event *ej_event;
 606
 607         ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
 608         if (!ej_event) {
 609                 /* Inform firmware the hot-remove operation has error */
 610                 (void) acpi_evaluate_hotplug_ost(device->handle,
 611                                         ACPI_NOTIFY_EJECT_REQUEST,
 612                                         ACPI_OST_SC_NON_SPECIFIC_FAILURE,
 613                                         NULL);
 614                 return;
 615         }
 616
 617         ej_event->device = device;
 618         ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
 619
 620         get_device(&device->dev);
 621         status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device, ej_event);
 622         if (ACPI_FAILURE(status)) {
 623                 put_device(&device->dev);
 624                 kfree(ej_event);
 625         }
 626 }
 627
 628 static void _handle_hotplug_event_root(struct work_struct *work)
 629 {
 630         struct acpi_pci_root *root;
 631         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER };
 632         struct acpi_hp_work *hp_work;
 633         acpi_handle handle;
 634         u32 type;
 635
 636         hp_work = container_of(work, struct acpi_hp_work, work);
 637         handle = hp_work->handle;
 638         type = hp_work->type;
 639
 640         acpi_scan_lock_acquire();
 641
 642         root = acpi_pci_find_root(handle);
 643         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 644
 645         switch (type) {
 646         case ACPI_NOTIFY_BUS_CHECK:
 647                 /* bus enumerate */
 648                 printk(KERN_DEBUG "%s: Bus check notify on %s\n", __func__,
 649                                  (char *)buffer.pointer);
 650                 if (root)
 651                         acpiphp_check_host_bridge(handle);
 652                 else
 653                         handle_root_bridge_insertion(handle);
 654
 655                 break;
 656
 657         case ACPI_NOTIFY_DEVICE_CHECK:
 658                 /* device check */
 659                 printk(KERN_DEBUG "%s: Device check notify on %s\n", __func__,
 660                                  (char *)buffer.pointer);
 661                 if (!root)
 662                         handle_root_bridge_insertion(handle);
 663                 break;
 664
 665         case ACPI_NOTIFY_EJECT_REQUEST:
 666                 /* request device eject */
 667                 printk(KERN_DEBUG "%s: Device eject notify on %s\n", __func__,
 668                                  (char *)buffer.pointer);
 669                 if (root)
 670                         handle_root_bridge_removal(root->device);
 671                 break;
 672         default:
 673                 printk(KERN_WARNING "notify_handler: unknown event type 0x%x for %s\n",
 674                                  type, (char *)buffer.pointer);
 675                 break;
 676         }
 677
 678         acpi_scan_lock_release();
 679         kfree(hp_work); /* allocated in handle_hotplug_event_bridge */
 680         kfree(buffer.pointer);
 681 }
 682
 683 static void handle_hotplug_event_root(acpi_handle handle, u32 type,
 684                                         void *context)
 685 {
 686         alloc_acpi_hp_work(handle, type, context,
 687                                 _handle_hotplug_event_root);
 688 }
 689
 690 static acpi_status __init
 691 find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
 692 {
 693         acpi_status status;
 694         char objname[64];
 695         struct acpi_buffer buffer = { .length = sizeof(objname),
 696                                       .pointer = objname };
 697         int *count = (int *)context;
 698
 699         if (!acpi_is_root_bridge(handle))
 700                 return AE_OK;
 701
 702         (*count)++;
 703
 704         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 705
 706         status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 707                                         handle_hotplug_event_root, NULL);
 708         if (ACPI_FAILURE(status))
 709                 printk(KERN_DEBUG "acpi root: %s notify handler is not installed, exit status: %u\n",
 710                                   objname, (unsigned int)status);
 711         else
 712                 printk(KERN_DEBUG "acpi root: %s notify handler is installed\n",
 713                                  objname);
 714
 715         return AE_OK;
 716 }
 717
 718 void __init acpi_pci_root_hp_init(void)
 719 {
 720         int num = 0;
 721
 722         acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 723                 ACPI_UINT32_MAX, find_root_bridges, NULL, &num, NULL);
 724
 725         printk(KERN_DEBUG "Found %d acpi root devices\n", num);
 726 }