linux/drivers/acpi/pci_root.c
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   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
  45ACPI_MODULE_NAME("pci_root");
  46#define ACPI_PCI_ROOT_CLASS             "pci_bridge"
  47#define ACPI_PCI_ROOT_DEVICE_NAME       "PCI Root Bridge"
  48static int acpi_pci_root_add(struct acpi_device *device,
  49                             const struct acpi_device_id *not_used);
  50static 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
  57static const struct acpi_device_id root_device_ids[] = {
  58        {"PNP0A03", 0},
  59        {"", 0},
  60};
  61
  62static 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/* Lock to protect both acpi_pci_roots lists */
  69static DEFINE_MUTEX(acpi_pci_root_lock);
  70static LIST_HEAD(acpi_pci_roots);
  71
  72static DEFINE_MUTEX(osc_lock);
  73
  74/**
  75 * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
  76 * @handle - the ACPI CA node in question.
  77 *
  78 * Note: we could make this API take a struct acpi_device * instead, but
  79 * for now, it's more convenient to operate on an acpi_handle.
  80 */
  81int acpi_is_root_bridge(acpi_handle handle)
  82{
  83        int ret;
  84        struct acpi_device *device;
  85
  86        ret = acpi_bus_get_device(handle, &device);
  87        if (ret)
  88                return 0;
  89
  90        ret = acpi_match_device_ids(device, root_device_ids);
  91        if (ret)
  92                return 0;
  93        else
  94                return 1;
  95}
  96EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
  97
  98static acpi_status
  99get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
 100{
 101        struct resource *res = data;
 102        struct acpi_resource_address64 address;
 103
 104        if (resource->type != ACPI_RESOURCE_TYPE_ADDRESS16 &&
 105            resource->type != ACPI_RESOURCE_TYPE_ADDRESS32 &&
 106            resource->type != ACPI_RESOURCE_TYPE_ADDRESS64)
 107                return AE_OK;
 108
 109        acpi_resource_to_address64(resource, &address);
 110        if ((address.address_length > 0) &&
 111            (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
 112                res->start = address.minimum;
 113                res->end = address.minimum + address.address_length - 1;
 114        }
 115
 116        return AE_OK;
 117}
 118
 119static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
 120                                             struct resource *res)
 121{
 122        acpi_status status;
 123
 124        res->start = -1;
 125        status =
 126            acpi_walk_resources(handle, METHOD_NAME__CRS,
 127                                get_root_bridge_busnr_callback, res);
 128        if (ACPI_FAILURE(status))
 129                return status;
 130        if (res->start == -1)
 131                return AE_ERROR;
 132        return AE_OK;
 133}
 134
 135static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
 136
 137static acpi_status acpi_pci_run_osc(acpi_handle handle,
 138                                    const u32 *capbuf, u32 *retval)
 139{
 140        struct acpi_osc_context context = {
 141                .uuid_str = pci_osc_uuid_str,
 142                .rev = 1,
 143                .cap.length = 12,
 144                .cap.pointer = (void *)capbuf,
 145        };
 146        acpi_status status;
 147
 148        status = acpi_run_osc(handle, &context);
 149        if (ACPI_SUCCESS(status)) {
 150                *retval = *((u32 *)(context.ret.pointer + 8));
 151                kfree(context.ret.pointer);
 152        }
 153        return status;
 154}
 155
 156static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
 157                                        u32 support,
 158                                        u32 *control)
 159{
 160        acpi_status status;
 161        u32 result, capbuf[3];
 162
 163        support &= OSC_PCI_SUPPORT_MASKS;
 164        support |= root->osc_support_set;
 165
 166        capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
 167        capbuf[OSC_SUPPORT_TYPE] = support;
 168        if (control) {
 169                *control &= OSC_PCI_CONTROL_MASKS;
 170                capbuf[OSC_CONTROL_TYPE] = *control | root->osc_control_set;
 171        } else {
 172                /* Run _OSC query only with existing controls. */
 173                capbuf[OSC_CONTROL_TYPE] = root->osc_control_set;
 174        }
 175
 176        status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
 177        if (ACPI_SUCCESS(status)) {
 178                root->osc_support_set = support;
 179                if (control)
 180                        *control = result;
 181        }
 182        return status;
 183}
 184
 185static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
 186{
 187        acpi_status status;
 188        acpi_handle tmp;
 189
 190        status = acpi_get_handle(root->device->handle, "_OSC", &tmp);
 191        if (ACPI_FAILURE(status))
 192                return status;
 193        mutex_lock(&osc_lock);
 194        status = acpi_pci_query_osc(root, flags, NULL);
 195        mutex_unlock(&osc_lock);
 196        return status;
 197}
 198
 199struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
 200{
 201        struct acpi_pci_root *root;
 202        struct acpi_device *device;
 203
 204        if (acpi_bus_get_device(handle, &device) ||
 205            acpi_match_device_ids(device, root_device_ids))
 206                return NULL;
 207
 208        root = acpi_driver_data(device);
 209
 210        return root;
 211}
 212EXPORT_SYMBOL_GPL(acpi_pci_find_root);
 213
 214struct acpi_handle_node {
 215        struct list_head node;
 216        acpi_handle handle;
 217};
 218
 219/**
 220 * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
 221 * @handle: the handle in question
 222 *
 223 * Given an ACPI CA handle, the desired PCI device is located in the
 224 * list of PCI devices.
 225 *
 226 * If the device is found, its reference count is increased and this
 227 * function returns a pointer to its data structure.  The caller must
 228 * decrement the reference count by calling pci_dev_put().
 229 * If no device is found, %NULL is returned.
 230 */
 231struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
 232{
 233        int dev, fn;
 234        unsigned long long adr;
 235        acpi_status status;
 236        acpi_handle phandle;
 237        struct pci_bus *pbus;
 238        struct pci_dev *pdev = NULL;
 239        struct acpi_handle_node *node, *tmp;
 240        struct acpi_pci_root *root;
 241        LIST_HEAD(device_list);
 242
 243        /*
 244         * Walk up the ACPI CA namespace until we reach a PCI root bridge.
 245         */
 246        phandle = handle;
 247        while (!acpi_is_root_bridge(phandle)) {
 248                node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
 249                if (!node)
 250                        goto out;
 251
 252                INIT_LIST_HEAD(&node->node);
 253                node->handle = phandle;
 254                list_add(&node->node, &device_list);
 255
 256                status = acpi_get_parent(phandle, &phandle);
 257                if (ACPI_FAILURE(status))
 258                        goto out;
 259        }
 260
 261        root = acpi_pci_find_root(phandle);
 262        if (!root)
 263                goto out;
 264
 265        pbus = root->bus;
 266
 267        /*
 268         * Now, walk back down the PCI device tree until we return to our
 269         * original handle. Assumes that everything between the PCI root
 270         * bridge and the device we're looking for must be a P2P bridge.
 271         */
 272        list_for_each_entry(node, &device_list, node) {
 273                acpi_handle hnd = node->handle;
 274                status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
 275                if (ACPI_FAILURE(status))
 276                        goto out;
 277                dev = (adr >> 16) & 0xffff;
 278                fn  = adr & 0xffff;
 279
 280                pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
 281                if (!pdev || hnd == handle)
 282                        break;
 283
 284                pbus = pdev->subordinate;
 285                pci_dev_put(pdev);
 286
 287                /*
 288                 * This function may be called for a non-PCI device that has a
 289                 * PCI parent (eg. a disk under a PCI SATA controller).  In that
 290                 * case pdev->subordinate will be NULL for the parent.
 291                 */
 292                if (!pbus) {
 293                        dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
 294                        pdev = NULL;
 295                        break;
 296                }
 297        }
 298out:
 299        list_for_each_entry_safe(node, tmp, &device_list, node)
 300                kfree(node);
 301
 302        return pdev;
 303}
 304EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
 305
 306/**
 307 * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
 308 * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
 309 * @mask: Mask of _OSC bits to request control of, place to store control mask.
 310 * @req: Mask of _OSC bits the control of is essential to the caller.
 311 *
 312 * Run _OSC query for @mask and if that is successful, compare the returned
 313 * mask of control bits with @req.  If all of the @req bits are set in the
 314 * returned mask, run _OSC request for it.
 315 *
 316 * The variable at the @mask address may be modified regardless of whether or
 317 * not the function returns success.  On success it will contain the mask of
 318 * _OSC bits the BIOS has granted control of, but its contents are meaningless
 319 * on failure.
 320 **/
 321acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
 322{
 323        struct acpi_pci_root *root;
 324        acpi_status status;
 325        u32 ctrl, capbuf[3];
 326        acpi_handle tmp;
 327
 328        if (!mask)
 329                return AE_BAD_PARAMETER;
 330
 331        ctrl = *mask & OSC_PCI_CONTROL_MASKS;
 332        if ((ctrl & req) != req)
 333                return AE_TYPE;
 334
 335        root = acpi_pci_find_root(handle);
 336        if (!root)
 337                return AE_NOT_EXIST;
 338
 339        status = acpi_get_handle(handle, "_OSC", &tmp);
 340        if (ACPI_FAILURE(status))
 341                return status;
 342
 343        mutex_lock(&osc_lock);
 344
 345        *mask = ctrl | root->osc_control_set;
 346        /* No need to evaluate _OSC if the control was already granted. */
 347        if ((root->osc_control_set & ctrl) == ctrl)
 348                goto out;
 349
 350        /* Need to check the available controls bits before requesting them. */
 351        while (*mask) {
 352                status = acpi_pci_query_osc(root, root->osc_support_set, mask);
 353                if (ACPI_FAILURE(status))
 354                        goto out;
 355                if (ctrl == *mask)
 356                        break;
 357                ctrl = *mask;
 358        }
 359
 360        if ((ctrl & req) != req) {
 361                status = AE_SUPPORT;
 362                goto out;
 363        }
 364
 365        capbuf[OSC_QUERY_TYPE] = 0;
 366        capbuf[OSC_SUPPORT_TYPE] = root->osc_support_set;
 367        capbuf[OSC_CONTROL_TYPE] = ctrl;
 368        status = acpi_pci_run_osc(handle, capbuf, mask);
 369        if (ACPI_SUCCESS(status))
 370                root->osc_control_set = *mask;
 371out:
 372        mutex_unlock(&osc_lock);
 373        return status;
 374}
 375EXPORT_SYMBOL(acpi_pci_osc_control_set);
 376
 377static int acpi_pci_root_add(struct acpi_device *device,
 378                             const struct acpi_device_id *not_used)
 379{
 380        unsigned long long segment, bus;
 381        acpi_status status;
 382        int result;
 383        struct acpi_pci_root *root;
 384        u32 flags, base_flags;
 385
 386        root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 387        if (!root)
 388                return -ENOMEM;
 389
 390        segment = 0;
 391        status = acpi_evaluate_integer(device->handle, METHOD_NAME__SEG, NULL,
 392                                       &segment);
 393        if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 394                printk(KERN_ERR PREFIX "can't evaluate _SEG\n");
 395                result = -ENODEV;
 396                goto end;
 397        }
 398
 399        /* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
 400        root->secondary.flags = IORESOURCE_BUS;
 401        status = try_get_root_bridge_busnr(device->handle, &root->secondary);
 402        if (ACPI_FAILURE(status)) {
 403                /*
 404                 * We need both the start and end of the downstream bus range
 405                 * to interpret _CBA (MMCONFIG base address), so it really is
 406                 * supposed to be in _CRS.  If we don't find it there, all we
 407                 * can do is assume [_BBN-0xFF] or [0-0xFF].
 408                 */
 409                root->secondary.end = 0xFF;
 410                printk(KERN_WARNING FW_BUG PREFIX
 411                       "no secondary bus range in _CRS\n");
 412                status = acpi_evaluate_integer(device->handle, METHOD_NAME__BBN,
 413                                               NULL, &bus);
 414                if (ACPI_SUCCESS(status))
 415                        root->secondary.start = bus;
 416                else if (status == AE_NOT_FOUND)
 417                        root->secondary.start = 0;
 418                else {
 419                        printk(KERN_ERR PREFIX "can't evaluate _BBN\n");
 420                        result = -ENODEV;
 421                        goto end;
 422                }
 423        }
 424
 425        INIT_LIST_HEAD(&root->node);
 426        root->device = device;
 427        root->segment = segment & 0xFFFF;
 428        strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
 429        strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 430        device->driver_data = root;
 431
 432        printk(KERN_INFO PREFIX "%s [%s] (domain %04x %pR)\n",
 433               acpi_device_name(device), acpi_device_bid(device),
 434               root->segment, &root->secondary);
 435
 436        root->mcfg_addr = acpi_pci_root_get_mcfg_addr(device->handle);
 437
 438        /*
 439         * All supported architectures that use ACPI have support for
 440         * PCI domains, so we indicate this in _OSC support capabilities.
 441         */
 442        flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
 443        acpi_pci_osc_support(root, flags);
 444
 445        /*
 446         * TBD: Need PCI interface for enumeration/configuration of roots.
 447         */
 448
 449        mutex_lock(&acpi_pci_root_lock);
 450        list_add_tail(&root->node, &acpi_pci_roots);
 451        mutex_unlock(&acpi_pci_root_lock);
 452
 453        /*
 454         * Scan the Root Bridge
 455         * --------------------
 456         * Must do this prior to any attempt to bind the root device, as the
 457         * PCI namespace does not get created until this call is made (and
 458         * thus the root bridge's pci_dev does not exist).
 459         */
 460        root->bus = pci_acpi_scan_root(root);
 461        if (!root->bus) {
 462                printk(KERN_ERR PREFIX
 463                            "Bus %04x:%02x not present in PCI namespace\n",
 464                            root->segment, (unsigned int)root->secondary.start);
 465                result = -ENODEV;
 466                goto out_del_root;
 467        }
 468
 469        /* Indicate support for various _OSC capabilities. */
 470        if (pci_ext_cfg_avail())
 471                flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
 472        if (pcie_aspm_support_enabled()) {
 473                flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
 474                OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
 475        }
 476        if (pci_msi_enabled())
 477                flags |= OSC_MSI_SUPPORT;
 478        if (flags != base_flags) {
 479                status = acpi_pci_osc_support(root, flags);
 480                if (ACPI_FAILURE(status)) {
 481                        dev_info(&device->dev, "ACPI _OSC support "
 482                                "notification failed, disabling PCIe ASPM\n");
 483                        pcie_no_aspm();
 484                        flags = base_flags;
 485                }
 486        }
 487
 488        if (!pcie_ports_disabled
 489            && (flags & ACPI_PCIE_REQ_SUPPORT) == ACPI_PCIE_REQ_SUPPORT) {
 490                flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL
 491                        | OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
 492                        | OSC_PCI_EXPRESS_PME_CONTROL;
 493
 494                if (pci_aer_available()) {
 495                        if (aer_acpi_firmware_first())
 496                                dev_dbg(&device->dev,
 497                                        "PCIe errors handled by BIOS.\n");
 498                        else
 499                                flags |= OSC_PCI_EXPRESS_AER_CONTROL;
 500                }
 501
 502                dev_info(&device->dev,
 503                        "Requesting ACPI _OSC control (0x%02x)\n", flags);
 504
 505                status = acpi_pci_osc_control_set(device->handle, &flags,
 506                                       OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
 507                if (ACPI_SUCCESS(status)) {
 508                        dev_info(&device->dev,
 509                                "ACPI _OSC control (0x%02x) granted\n", flags);
 510                        if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 511                                /*
 512                                 * We have ASPM control, but the FADT indicates
 513                                 * that it's unsupported. Clear it.
 514                                 */
 515                                pcie_clear_aspm(root->bus);
 516                        }
 517                } else {
 518                        dev_info(&device->dev,
 519                                "ACPI _OSC request failed (%s), "
 520                                "returned control mask: 0x%02x\n",
 521                                acpi_format_exception(status), flags);
 522                        pr_info("ACPI _OSC control for PCIe not granted, "
 523                                "disabling ASPM\n");
 524                        pcie_no_aspm();
 525                }
 526        } else {
 527                dev_info(&device->dev,
 528                         "Unable to request _OSC control "
 529                         "(_OSC support mask: 0x%02x)\n", flags);
 530        }
 531
 532        pci_acpi_add_bus_pm_notifier(device, root->bus);
 533        if (device->wakeup.flags.run_wake)
 534                device_set_run_wake(root->bus->bridge, true);
 535
 536        if (system_state != SYSTEM_BOOTING) {
 537                pcibios_resource_survey_bus(root->bus);
 538                pci_assign_unassigned_bus_resources(root->bus);
 539        }
 540
 541        /* need to after hot-added ioapic is registered */
 542        if (system_state != SYSTEM_BOOTING)
 543                pci_enable_bridges(root->bus);
 544
 545        pci_bus_add_devices(root->bus);
 546        return 1;
 547
 548out_del_root:
 549        mutex_lock(&acpi_pci_root_lock);
 550        list_del(&root->node);
 551        mutex_unlock(&acpi_pci_root_lock);
 552
 553end:
 554        kfree(root);
 555        return result;
 556}
 557
 558static void acpi_pci_root_remove(struct acpi_device *device)
 559{
 560        struct acpi_pci_root *root = acpi_driver_data(device);
 561
 562        pci_stop_root_bus(root->bus);
 563
 564        device_set_run_wake(root->bus->bridge, false);
 565        pci_acpi_remove_bus_pm_notifier(device);
 566
 567        pci_remove_root_bus(root->bus);
 568
 569        mutex_lock(&acpi_pci_root_lock);
 570        list_del(&root->node);
 571        mutex_unlock(&acpi_pci_root_lock);
 572        kfree(root);
 573}
 574
 575void __init acpi_pci_root_init(void)
 576{
 577        acpi_hest_init();
 578
 579        if (!acpi_pci_disabled) {
 580                pci_acpi_crs_quirks();
 581                acpi_scan_add_handler(&pci_root_handler);
 582        }
 583}
 584/* Support root bridge hotplug */
 585
 586static void handle_root_bridge_insertion(acpi_handle handle)
 587{
 588        struct acpi_device *device;
 589
 590        if (!acpi_bus_get_device(handle, &device)) {
 591                printk(KERN_DEBUG "acpi device exists...\n");
 592                return;
 593        }
 594
 595        if (acpi_bus_scan(handle))
 596                printk(KERN_ERR "cannot add bridge to acpi list\n");
 597}
 598
 599static void handle_root_bridge_removal(struct acpi_device *device)
 600{
 601        acpi_status status;
 602        struct acpi_eject_event *ej_event;
 603
 604        ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
 605        if (!ej_event) {
 606                /* Inform firmware the hot-remove operation has error */
 607                (void) acpi_evaluate_hotplug_ost(device->handle,
 608                                        ACPI_NOTIFY_EJECT_REQUEST,
 609                                        ACPI_OST_SC_NON_SPECIFIC_FAILURE,
 610                                        NULL);
 611                return;
 612        }
 613
 614        ej_event->device = device;
 615        ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
 616
 617        status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device, ej_event);
 618        if (ACPI_FAILURE(status))
 619                kfree(ej_event);
 620}
 621
 622static void _handle_hotplug_event_root(struct work_struct *work)
 623{
 624        struct acpi_pci_root *root;
 625        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER };
 626        struct acpi_hp_work *hp_work;
 627        acpi_handle handle;
 628        u32 type;
 629
 630        hp_work = container_of(work, struct acpi_hp_work, work);
 631        handle = hp_work->handle;
 632        type = hp_work->type;
 633
 634        acpi_scan_lock_acquire();
 635
 636        root = acpi_pci_find_root(handle);
 637        acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 638
 639        switch (type) {
 640        case ACPI_NOTIFY_BUS_CHECK:
 641                /* bus enumerate */
 642                printk(KERN_DEBUG "%s: Bus check notify on %s\n", __func__,
 643                                 (char *)buffer.pointer);
 644                if (root)
 645                        acpiphp_check_host_bridge(handle);
 646                else
 647                        handle_root_bridge_insertion(handle);
 648
 649                break;
 650
 651        case ACPI_NOTIFY_DEVICE_CHECK:
 652                /* device check */
 653                printk(KERN_DEBUG "%s: Device check notify on %s\n", __func__,
 654                                 (char *)buffer.pointer);
 655                if (!root)
 656                        handle_root_bridge_insertion(handle);
 657                break;
 658
 659        case ACPI_NOTIFY_EJECT_REQUEST:
 660                /* request device eject */
 661                printk(KERN_DEBUG "%s: Device eject notify on %s\n", __func__,
 662                                 (char *)buffer.pointer);
 663                if (root)
 664                        handle_root_bridge_removal(root->device);
 665                break;
 666        default:
 667                printk(KERN_WARNING "notify_handler: unknown event type 0x%x for %s\n",
 668                                 type, (char *)buffer.pointer);
 669                break;
 670        }
 671
 672        acpi_scan_lock_release();
 673        kfree(hp_work); /* allocated in handle_hotplug_event_bridge */
 674        kfree(buffer.pointer);
 675}
 676
 677static void handle_hotplug_event_root(acpi_handle handle, u32 type,
 678                                        void *context)
 679{
 680        alloc_acpi_hp_work(handle, type, context,
 681                                _handle_hotplug_event_root);
 682}
 683
 684static acpi_status __init
 685find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
 686{
 687        acpi_status status;
 688        char objname[64];
 689        struct acpi_buffer buffer = { .length = sizeof(objname),
 690                                      .pointer = objname };
 691        int *count = (int *)context;
 692
 693        if (!acpi_is_root_bridge(handle))
 694                return AE_OK;
 695
 696        (*count)++;
 697
 698        acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 699
 700        status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 701                                        handle_hotplug_event_root, NULL);
 702        if (ACPI_FAILURE(status))
 703                printk(KERN_DEBUG "acpi root: %s notify handler is not installed, exit status: %u\n",
 704                                  objname, (unsigned int)status);
 705        else
 706                printk(KERN_DEBUG "acpi root: %s notify handler is installed\n",
 707                                 objname);
 708
 709        return AE_OK;
 710}
 711
 712void __init acpi_pci_root_hp_init(void)
 713{
 714        int num = 0;
 715
 716        acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 717                ACPI_UINT32_MAX, find_root_bridges, NULL, &num, NULL);
 718
 719        printk(KERN_DEBUG "Found %d acpi root devices\n", num);
 720}
 721
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