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
  68static 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 */
  77int 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}
  92EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
  93
  94static acpi_status
  95get_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
 114static 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
 130static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
 131
 132static 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
 151static 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
 180static 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
 194struct 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}
 207EXPORT_SYMBOL_GPL(acpi_pci_find_root);
 208
 209struct 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 */
 226struct 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        }
 293out:
 294        list_for_each_entry_safe(node, tmp, &device_list, node)
 295                kfree(node);
 296
 297        return pdev;
 298}
 299EXPORT_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 **/
 316acpi_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;
 366out:
 367        mutex_unlock(&osc_lock);
 368        return status;
 369}
 370EXPORT_SYMBOL(acpi_pci_osc_control_set);
 371
 372static 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        bool no_aspm = false, clear_aspm = false;
 382
 383        root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 384        if (!root)
 385                return -ENOMEM;
 386
 387        segment = 0;
 388        status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL,
 389                                       &segment);
 390        if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 391                dev_err(&device->dev,  "can't evaluate _SEG\n");
 392                result = -ENODEV;
 393                goto end;
 394        }
 395
 396        /* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
 397        root->secondary.flags = IORESOURCE_BUS;
 398        status = try_get_root_bridge_busnr(handle, &root->secondary);
 399        if (ACPI_FAILURE(status)) {
 400                /*
 401                 * We need both the start and end of the downstream bus range
 402                 * to interpret _CBA (MMCONFIG base address), so it really is
 403                 * supposed to be in _CRS.  If we don't find it there, all we
 404                 * can do is assume [_BBN-0xFF] or [0-0xFF].
 405                 */
 406                root->secondary.end = 0xFF;
 407                dev_warn(&device->dev,
 408                         FW_BUG "no secondary bus range in _CRS\n");
 409                status = acpi_evaluate_integer(handle, METHOD_NAME__BBN,
 410                                               NULL, &bus);
 411                if (ACPI_SUCCESS(status))
 412                        root->secondary.start = bus;
 413                else if (status == AE_NOT_FOUND)
 414                        root->secondary.start = 0;
 415                else {
 416                        dev_err(&device->dev, "can't evaluate _BBN\n");
 417                        result = -ENODEV;
 418                        goto end;
 419                }
 420        }
 421
 422        root->device = device;
 423        root->segment = segment & 0xFFFF;
 424        strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
 425        strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 426        device->driver_data = root;
 427
 428        pr_info(PREFIX "%s [%s] (domain %04x %pR)\n",
 429               acpi_device_name(device), acpi_device_bid(device),
 430               root->segment, &root->secondary);
 431
 432        root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
 433
 434        /*
 435         * All supported architectures that use ACPI have support for
 436         * PCI domains, so we indicate this in _OSC support capabilities.
 437         */
 438        flags = base_flags = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
 439        acpi_pci_osc_support(root, flags);
 440
 441        if (pci_ext_cfg_avail())
 442                flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
 443        if (pcie_aspm_support_enabled()) {
 444                flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
 445                OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
 446        }
 447        if (pci_msi_enabled())
 448                flags |= OSC_MSI_SUPPORT;
 449        if (flags != base_flags) {
 450                status = acpi_pci_osc_support(root, flags);
 451                if (ACPI_FAILURE(status)) {
 452                        dev_info(&device->dev, "ACPI _OSC support "
 453                                "notification failed, disabling PCIe ASPM\n");
 454                        no_aspm = true;
 455                        flags = base_flags;
 456                }
 457        }
 458
 459        if (!pcie_ports_disabled
 460            && (flags & ACPI_PCIE_REQ_SUPPORT) == ACPI_PCIE_REQ_SUPPORT) {
 461                flags = OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL
 462                        | OSC_PCI_EXPRESS_NATIVE_HP_CONTROL
 463                        | OSC_PCI_EXPRESS_PME_CONTROL;
 464
 465                if (pci_aer_available()) {
 466                        if (aer_acpi_firmware_first())
 467                                dev_dbg(&device->dev,
 468                                        "PCIe errors handled by BIOS.\n");
 469                        else
 470                                flags |= OSC_PCI_EXPRESS_AER_CONTROL;
 471                }
 472
 473                dev_info(&device->dev,
 474                        "Requesting ACPI _OSC control (0x%02x)\n", flags);
 475
 476                status = acpi_pci_osc_control_set(handle, &flags,
 477                                       OSC_PCI_EXPRESS_CAP_STRUCTURE_CONTROL);
 478                if (ACPI_SUCCESS(status)) {
 479                        dev_info(&device->dev,
 480                                "ACPI _OSC control (0x%02x) granted\n", flags);
 481                        if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 482                                /*
 483                                 * We have ASPM control, but the FADT indicates
 484                                 * that it's unsupported. Clear it.
 485                                 */
 486                                clear_aspm = true;
 487                        }
 488                } else {
 489                        dev_info(&device->dev,
 490                                "ACPI _OSC request failed (%s), "
 491                                "returned control mask: 0x%02x\n",
 492                                acpi_format_exception(status), flags);
 493                        dev_info(&device->dev,
 494                                 "ACPI _OSC control for PCIe not granted, disabling ASPM\n");
 495                        /*
 496                         * We want to disable ASPM here, but aspm_disabled
 497                         * needs to remain in its state from boot so that we
 498                         * properly handle PCIe 1.1 devices.  So we set this
 499                         * flag here, to defer the action until after the ACPI
 500                         * root scan.
 501                         */
 502                        no_aspm = true;
 503                }
 504        } else {
 505                dev_info(&device->dev,
 506                         "Unable to request _OSC control "
 507                         "(_OSC support mask: 0x%02x)\n", flags);
 508        }
 509
 510        /*
 511         * TBD: Need PCI interface for enumeration/configuration of roots.
 512         */
 513
 514        /*
 515         * Scan the Root Bridge
 516         * --------------------
 517         * Must do this prior to any attempt to bind the root device, as the
 518         * PCI namespace does not get created until this call is made (and
 519         * thus the root bridge's pci_dev does not exist).
 520         */
 521        root->bus = pci_acpi_scan_root(root);
 522        if (!root->bus) {
 523                dev_err(&device->dev,
 524                        "Bus %04x:%02x not present in PCI namespace\n",
 525                        root->segment, (unsigned int)root->secondary.start);
 526                result = -ENODEV;
 527                goto end;
 528        }
 529
 530        if (clear_aspm) {
 531                dev_info(&device->dev, "Disabling ASPM (FADT indicates it is unsupported)\n");
 532                pcie_clear_aspm(root->bus);
 533        }
 534        if (no_aspm)
 535                pcie_no_aspm();
 536
 537        pci_acpi_add_bus_pm_notifier(device, root->bus);
 538        if (device->wakeup.flags.run_wake)
 539                device_set_run_wake(root->bus->bridge, true);
 540
 541        if (system_state != SYSTEM_BOOTING) {
 542                pcibios_resource_survey_bus(root->bus);
 543                pci_assign_unassigned_root_bus_resources(root->bus);
 544        }
 545
 546        pci_bus_add_devices(root->bus);
 547        return 1;
 548
 549end:
 550        kfree(root);
 551        return result;
 552}
 553
 554static void acpi_pci_root_remove(struct acpi_device *device)
 555{
 556        struct acpi_pci_root *root = acpi_driver_data(device);
 557
 558        pci_stop_root_bus(root->bus);
 559
 560        device_set_run_wake(root->bus->bridge, false);
 561        pci_acpi_remove_bus_pm_notifier(device);
 562
 563        pci_remove_root_bus(root->bus);
 564
 565        kfree(root);
 566}
 567
 568void __init acpi_pci_root_init(void)
 569{
 570        acpi_hest_init();
 571
 572        if (!acpi_pci_disabled) {
 573                pci_acpi_crs_quirks();
 574                acpi_scan_add_handler(&pci_root_handler);
 575        }
 576}
 577/* Support root bridge hotplug */
 578
 579static void handle_root_bridge_insertion(acpi_handle handle)
 580{
 581        struct acpi_device *device;
 582
 583        if (!acpi_bus_get_device(handle, &device)) {
 584                dev_printk(KERN_DEBUG, &device->dev,
 585                           "acpi device already exists; ignoring notify\n");
 586                return;
 587        }
 588
 589        if (acpi_bus_scan(handle))
 590                acpi_handle_err(handle, "cannot add bridge to acpi list\n");
 591}
 592
 593static void handle_root_bridge_removal(struct acpi_device *device)
 594{
 595        acpi_status status;
 596        struct acpi_eject_event *ej_event;
 597
 598        ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
 599        if (!ej_event) {
 600                /* Inform firmware the hot-remove operation has error */
 601                (void) acpi_evaluate_hotplug_ost(device->handle,
 602                                        ACPI_NOTIFY_EJECT_REQUEST,
 603                                        ACPI_OST_SC_NON_SPECIFIC_FAILURE,
 604                                        NULL);
 605                return;
 606        }
 607
 608        ej_event->device = device;
 609        ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
 610
 611        status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device, ej_event);
 612        if (ACPI_FAILURE(status))
 613                kfree(ej_event);
 614}
 615
 616static void _handle_hotplug_event_root(struct work_struct *work)
 617{
 618        struct acpi_pci_root *root;
 619        struct acpi_hp_work *hp_work;
 620        acpi_handle handle;
 621        u32 type;
 622
 623        hp_work = container_of(work, struct acpi_hp_work, work);
 624        handle = hp_work->handle;
 625        type = hp_work->type;
 626
 627        acpi_scan_lock_acquire();
 628
 629        root = acpi_pci_find_root(handle);
 630
 631        switch (type) {
 632        case ACPI_NOTIFY_BUS_CHECK:
 633                /* bus enumerate */
 634                acpi_handle_printk(KERN_DEBUG, handle,
 635                                   "Bus check notify on %s\n", __func__);
 636                if (root)
 637                        acpiphp_check_host_bridge(handle);
 638                else
 639                        handle_root_bridge_insertion(handle);
 640
 641                break;
 642
 643        case ACPI_NOTIFY_DEVICE_CHECK:
 644                /* device check */
 645                acpi_handle_printk(KERN_DEBUG, handle,
 646                                   "Device check notify on %s\n", __func__);
 647                if (!root)
 648                        handle_root_bridge_insertion(handle);
 649                break;
 650
 651        case ACPI_NOTIFY_EJECT_REQUEST:
 652                /* request device eject */
 653                acpi_handle_printk(KERN_DEBUG, handle,
 654                                   "Device eject notify on %s\n", __func__);
 655                if (root)
 656                        handle_root_bridge_removal(root->device);
 657                break;
 658        default:
 659                acpi_handle_warn(handle,
 660                                 "notify_handler: unknown event type 0x%x\n",
 661                                 type);
 662                break;
 663        }
 664
 665        acpi_scan_lock_release();
 666        kfree(hp_work); /* allocated in handle_hotplug_event_bridge */
 667}
 668
 669static void handle_hotplug_event_root(acpi_handle handle, u32 type,
 670                                        void *context)
 671{
 672        alloc_acpi_hp_work(handle, type, context,
 673                                _handle_hotplug_event_root);
 674}
 675
 676static acpi_status __init
 677find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
 678{
 679        acpi_status status;
 680        int *count = (int *)context;
 681
 682        if (!acpi_is_root_bridge(handle))
 683                return AE_OK;
 684
 685        (*count)++;
 686
 687        status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 688                                        handle_hotplug_event_root, NULL);
 689        if (ACPI_FAILURE(status))
 690                acpi_handle_printk(KERN_DEBUG, handle,
 691                        "notify handler is not installed, exit status: %u\n",
 692                         (unsigned int)status);
 693        else
 694                acpi_handle_printk(KERN_DEBUG, handle,
 695                                   "notify handler is installed\n");
 696
 697        return AE_OK;
 698}
 699
 700void __init acpi_pci_root_hp_init(void)
 701{
 702        int num = 0;
 703
 704        acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 705                ACPI_UINT32_MAX, find_root_bridges, NULL, &num, NULL);
 706
 707        printk(KERN_DEBUG "Found %d acpi root devices\n", num);
 708}
 709
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