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 <[email protected]>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]>
   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  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25 #include <linux/types.h>
  26 #include <linux/mutex.h>
  27 #include <linux/pm.h>
  28 #include <linux/pm_runtime.h>
  29 #include <linux/pci.h>
  30 #include <linux/pci-acpi.h>
  31 #include <linux/pci-aspm.h>
  32 #include <linux/dmar.h>
  33 #include <linux/acpi.h>
  34 #include <linux/slab.h>
  35 #include <linux/dmi.h>
  36 #include <linux/platform_data/x86/apple.h>
  37 #include <acpi/apei.h>  /* for acpi_hest_init() */
  38
  39 #include "internal.h"
  40
  41 #define _COMPONENT              ACPI_PCI_COMPONENT
  42 ACPI_MODULE_NAME("pci_root");
  43 #define ACPI_PCI_ROOT_CLASS             "pci_bridge"
  44 #define ACPI_PCI_ROOT_DEVICE_NAME       "PCI Root Bridge"
  45 static int acpi_pci_root_add(struct acpi_device *device,
  46                              const struct acpi_device_id *not_used);
  47 static void acpi_pci_root_remove(struct acpi_device *device);
  48
  49 static int acpi_pci_root_scan_dependent(struct acpi_device *adev)
  50 {
  51         acpiphp_check_host_bridge(adev);
  52         return 0;
  53 }
  54
  55 #define ACPI_PCIE_REQ_SUPPORT (OSC_PCI_EXT_CONFIG_SUPPORT \
  56                                 | OSC_PCI_ASPM_SUPPORT \
  57                                 | OSC_PCI_CLOCK_PM_SUPPORT \
  58                                 | OSC_PCI_MSI_SUPPORT)
  59
  60 static const struct acpi_device_id root_device_ids[] = {
  61         {"PNP0A03", 0},
  62         {"", 0},
  63 };
  64
  65 static struct acpi_scan_handler pci_root_handler = {
  66         .ids = root_device_ids,
  67         .attach = acpi_pci_root_add,
  68         .detach = acpi_pci_root_remove,
  69         .hotplug = {
  70                 .enabled = true,
  71                 .scan_dependent = acpi_pci_root_scan_dependent,
  72         },
  73 };
  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         acpi_status status;
 107
 108         status = acpi_resource_to_address64(resource, &address);
 109         if (ACPI_FAILURE(status))
 110                 return AE_OK;
 111
 112         if ((address.address.address_length > 0) &&
 113             (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
 114                 res->start = address.address.minimum;
 115                 res->end = address.address.minimum + address.address.address_length - 1;
 116         }
 117
 118         return AE_OK;
 119 }
 120
 121 static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
 122                                              struct resource *res)
 123 {
 124         acpi_status status;
 125
 126         res->start = -1;
 127         status =
 128             acpi_walk_resources(handle, METHOD_NAME__CRS,
 129                                 get_root_bridge_busnr_callback, res);
 130         if (ACPI_FAILURE(status))
 131                 return status;
 132         if (res->start == -1)
 133                 return AE_ERROR;
 134         return AE_OK;
 135 }
 136
 137 struct pci_osc_bit_struct {
 138         u32 bit;
 139         char *desc;
 140 };
 141
 142 static struct pci_osc_bit_struct pci_osc_support_bit[] = {
 143         { OSC_PCI_EXT_CONFIG_SUPPORT, "ExtendedConfig" },
 144         { OSC_PCI_ASPM_SUPPORT, "ASPM" },
 145         { OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" },
 146         { OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" },
 147         { OSC_PCI_MSI_SUPPORT, "MSI" },
 148 };
 149
 150 static struct pci_osc_bit_struct pci_osc_control_bit[] = {
 151         { OSC_PCI_EXPRESS_NATIVE_HP_CONTROL, "PCIeHotplug" },
 152         { OSC_PCI_SHPC_NATIVE_HP_CONTROL, "SHPCHotplug" },
 153         { OSC_PCI_EXPRESS_PME_CONTROL, "PME" },
 154         { OSC_PCI_EXPRESS_AER_CONTROL, "AER" },
 155         { OSC_PCI_EXPRESS_CAPABILITY_CONTROL, "PCIeCapability" },
 156         { OSC_PCI_EXPRESS_LTR_CONTROL, "LTR" },
 157 };
 158
 159 static void decode_osc_bits(struct acpi_pci_root *root, char *msg, u32 word,
 160                             struct pci_osc_bit_struct *table, int size)
 161 {
 162         char buf[80];
 163         int i, len = 0;
 164         struct pci_osc_bit_struct *entry;
 165
 166         buf[0] = '\0';
 167         for (i = 0, entry = table; i < size; i++, entry++)
 168                 if (word & entry->bit)
 169                         len += snprintf(buf + len, sizeof(buf) - len, "%s%s",
 170                                         len ? " " : "", entry->desc);
 171
 172         dev_info(&root->device->dev, "_OSC: %s [%s]\n", msg, buf);
 173 }
 174
 175 static void decode_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
 176 {
 177         decode_osc_bits(root, msg, word, pci_osc_support_bit,
 178                         ARRAY_SIZE(pci_osc_support_bit));
 179 }
 180
 181 static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
 182 {
 183         decode_osc_bits(root, msg, word, pci_osc_control_bit,
 184                         ARRAY_SIZE(pci_osc_control_bit));
 185 }
 186
 187 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
 188
 189 static acpi_status acpi_pci_run_osc(acpi_handle handle,
 190                                     const u32 *capbuf, u32 *retval)
 191 {
 192         struct acpi_osc_context context = {
 193                 .uuid_str = pci_osc_uuid_str,
 194                 .rev = 1,
 195                 .cap.length = 12,
 196                 .cap.pointer = (void *)capbuf,
 197         };
 198         acpi_status status;
 199
 200         status = acpi_run_osc(handle, &context);
 201         if (ACPI_SUCCESS(status)) {
 202                 *retval = *((u32 *)(context.ret.pointer + 8));
 203                 kfree(context.ret.pointer);
 204         }
 205         return status;
 206 }
 207
 208 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
 209                                         u32 support,
 210                                         u32 *control)
 211 {
 212         acpi_status status;
 213         u32 result, capbuf[3];
 214
 215         support &= OSC_PCI_SUPPORT_MASKS;
 216         support |= root->osc_support_set;
 217
 218         capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
 219         capbuf[OSC_SUPPORT_DWORD] = support;
 220         if (control) {
 221                 *control &= OSC_PCI_CONTROL_MASKS;
 222                 capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
 223         } else {
 224                 /* Run _OSC query only with existing controls. */
 225                 capbuf[OSC_CONTROL_DWORD] = root->osc_control_set;
 226         }
 227
 228         status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
 229         if (ACPI_SUCCESS(status)) {
 230                 root->osc_support_set = support;
 231                 if (control)
 232                         *control = result;
 233         }
 234         return status;
 235 }
 236
 237 static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
 238 {
 239         acpi_status status;
 240
 241         mutex_lock(&osc_lock);
 242         status = acpi_pci_query_osc(root, flags, NULL);
 243         mutex_unlock(&osc_lock);
 244         return status;
 245 }
 246
 247 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
 248 {
 249         struct acpi_pci_root *root;
 250         struct acpi_device *device;
 251
 252         if (acpi_bus_get_device(handle, &device) ||
 253             acpi_match_device_ids(device, root_device_ids))
 254                 return NULL;
 255
 256         root = acpi_driver_data(device);
 257
 258         return root;
 259 }
 260 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
 261
 262 struct acpi_handle_node {
 263         struct list_head node;
 264         acpi_handle handle;
 265 };
 266
 267 /**
 268  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
 269  * @handle: the handle in question
 270  *
 271  * Given an ACPI CA handle, the desired PCI device is located in the
 272  * list of PCI devices.
 273  *
 274  * If the device is found, its reference count is increased and this
 275  * function returns a pointer to its data structure.  The caller must
 276  * decrement the reference count by calling pci_dev_put().
 277  * If no device is found, %NULL is returned.
 278  */
 279 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
 280 {
 281         int dev, fn;
 282         unsigned long long adr;
 283         acpi_status status;
 284         acpi_handle phandle;
 285         struct pci_bus *pbus;
 286         struct pci_dev *pdev = NULL;
 287         struct acpi_handle_node *node, *tmp;
 288         struct acpi_pci_root *root;
 289         LIST_HEAD(device_list);
 290
 291         /*
 292          * Walk up the ACPI CA namespace until we reach a PCI root bridge.
 293          */
 294         phandle = handle;
 295         while (!acpi_is_root_bridge(phandle)) {
 296                 node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
 297                 if (!node)
 298                         goto out;
 299
 300                 INIT_LIST_HEAD(&node->node);
 301                 node->handle = phandle;
 302                 list_add(&node->node, &device_list);
 303
 304                 status = acpi_get_parent(phandle, &phandle);
 305                 if (ACPI_FAILURE(status))
 306                         goto out;
 307         }
 308
 309         root = acpi_pci_find_root(phandle);
 310         if (!root)
 311                 goto out;
 312
 313         pbus = root->bus;
 314
 315         /*
 316          * Now, walk back down the PCI device tree until we return to our
 317          * original handle. Assumes that everything between the PCI root
 318          * bridge and the device we're looking for must be a P2P bridge.
 319          */
 320         list_for_each_entry(node, &device_list, node) {
 321                 acpi_handle hnd = node->handle;
 322                 status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
 323                 if (ACPI_FAILURE(status))
 324                         goto out;
 325                 dev = (adr >> 16) & 0xffff;
 326                 fn  = adr & 0xffff;
 327
 328                 pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
 329                 if (!pdev || hnd == handle)
 330                         break;
 331
 332                 pbus = pdev->subordinate;
 333                 pci_dev_put(pdev);
 334
 335                 /*
 336                  * This function may be called for a non-PCI device that has a
 337                  * PCI parent (eg. a disk under a PCI SATA controller).  In that
 338                  * case pdev->subordinate will be NULL for the parent.
 339                  */
 340                 if (!pbus) {
 341                         dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
 342                         pdev = NULL;
 343                         break;
 344                 }
 345         }
 346 out:
 347         list_for_each_entry_safe(node, tmp, &device_list, node)
 348                 kfree(node);
 349
 350         return pdev;
 351 }
 352 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
 353
 354 /**
 355  * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
 356  * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
 357  * @mask: Mask of _OSC bits to request control of, place to store control mask.
 358  * @req: Mask of _OSC bits the control of is essential to the caller.
 359  *
 360  * Run _OSC query for @mask and if that is successful, compare the returned
 361  * mask of control bits with @req.  If all of the @req bits are set in the
 362  * returned mask, run _OSC request for it.
 363  *
 364  * The variable at the @mask address may be modified regardless of whether or
 365  * not the function returns success.  On success it will contain the mask of
 366  * _OSC bits the BIOS has granted control of, but its contents are meaningless
 367  * on failure.
 368  **/
 369 acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
 370 {
 371         struct acpi_pci_root *root;
 372         acpi_status status = AE_OK;
 373         u32 ctrl, capbuf[3];
 374
 375         if (!mask)
 376                 return AE_BAD_PARAMETER;
 377
 378         ctrl = *mask & OSC_PCI_CONTROL_MASKS;
 379         if ((ctrl & req) != req)
 380                 return AE_TYPE;
 381
 382         root = acpi_pci_find_root(handle);
 383         if (!root)
 384                 return AE_NOT_EXIST;
 385
 386         mutex_lock(&osc_lock);
 387
 388         *mask = ctrl | root->osc_control_set;
 389         /* No need to evaluate _OSC if the control was already granted. */
 390         if ((root->osc_control_set & ctrl) == ctrl)
 391                 goto out;
 392
 393         /* Need to check the available controls bits before requesting them. */
 394         while (*mask) {
 395                 status = acpi_pci_query_osc(root, root->osc_support_set, mask);
 396                 if (ACPI_FAILURE(status))
 397                         goto out;
 398                 if (ctrl == *mask)
 399                         break;
 400                 decode_osc_control(root, "platform does not support",
 401                                    ctrl & ~(*mask));
 402                 ctrl = *mask;
 403         }
 404
 405         if ((ctrl & req) != req) {
 406                 decode_osc_control(root, "not requesting control; platform does not support",
 407                                    req & ~(ctrl));
 408                 status = AE_SUPPORT;
 409                 goto out;
 410         }
 411
 412         capbuf[OSC_QUERY_DWORD] = 0;
 413         capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set;
 414         capbuf[OSC_CONTROL_DWORD] = ctrl;
 415         status = acpi_pci_run_osc(handle, capbuf, mask);
 416         if (ACPI_SUCCESS(status))
 417                 root->osc_control_set = *mask;
 418 out:
 419         mutex_unlock(&osc_lock);
 420         return status;
 421 }
 422 EXPORT_SYMBOL(acpi_pci_osc_control_set);
 423
 424 static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
 425 {
 426         u32 support, control, requested;
 427         acpi_status status;
 428         struct acpi_device *device = root->device;
 429         acpi_handle handle = device->handle;
 430
 431         /*
 432          * Apple always return failure on _OSC calls when _OSI("Darwin") has
 433          * been called successfully. We know the feature set supported by the
 434          * platform, so avoid calling _OSC at all
 435          */
 436         if (x86_apple_machine) {
 437                 root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;
 438                 decode_osc_control(root, "OS assumes control of",
 439                                    root->osc_control_set);
 440                 return;
 441         }
 442
 443         /*
 444          * All supported architectures that use ACPI have support for
 445          * PCI domains, so we indicate this in _OSC support capabilities.
 446          */
 447         support = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
 448         if (pci_ext_cfg_avail())
 449                 support |= OSC_PCI_EXT_CONFIG_SUPPORT;
 450         if (pcie_aspm_support_enabled())
 451                 support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
 452         if (pci_msi_enabled())
 453                 support |= OSC_PCI_MSI_SUPPORT;
 454
 455         decode_osc_support(root, "OS supports", support);
 456         status = acpi_pci_osc_support(root, support);
 457         if (ACPI_FAILURE(status)) {
 458                 dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
 459                          acpi_format_exception(status));
 460                 *no_aspm = 1;
 461                 return;
 462         }
 463
 464         if (pcie_ports_disabled) {
 465                 dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
 466                 return;
 467         }
 468
 469         if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
 470                 decode_osc_support(root, "not requesting OS control; OS requires",
 471                                    ACPI_PCIE_REQ_SUPPORT);
 472                 return;
 473         }
 474
 475         control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
 476                 | OSC_PCI_EXPRESS_PME_CONTROL;
 477
 478         if (IS_ENABLED(CONFIG_PCIEASPM))
 479                 control |= OSC_PCI_EXPRESS_LTR_CONTROL;
 480
 481         if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
 482                 control |= OSC_PCI_EXPRESS_NATIVE_HP_CONTROL;
 483
 484         if (IS_ENABLED(CONFIG_HOTPLUG_PCI_SHPC))
 485                 control |= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
 486
 487         if (pci_aer_available()) {
 488                 if (aer_acpi_firmware_first())
 489                         dev_info(&device->dev,
 490                                  "PCIe AER handled by firmware\n");
 491                 else
 492                         control |= OSC_PCI_EXPRESS_AER_CONTROL;
 493         }
 494
 495         requested = control;
 496         status = acpi_pci_osc_control_set(handle, &control,
 497                                           OSC_PCI_EXPRESS_CAPABILITY_CONTROL);
 498         if (ACPI_SUCCESS(status)) {
 499                 decode_osc_control(root, "OS now controls", control);
 500                 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 501                         /*
 502                          * We have ASPM control, but the FADT indicates that
 503                          * it's unsupported. Leave existing configuration
 504                          * intact and prevent the OS from touching it.
 505                          */
 506                         dev_info(&device->dev, "FADT indicates ASPM is unsupported, using BIOS configuration\n");
 507                         *no_aspm = 1;
 508                 }
 509         } else {
 510                 decode_osc_control(root, "OS requested", requested);
 511                 decode_osc_control(root, "platform willing to grant", control);
 512                 dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
 513                         acpi_format_exception(status));
 514
 515                 /*
 516                  * We want to disable ASPM here, but aspm_disabled
 517                  * needs to remain in its state from boot so that we
 518                  * properly handle PCIe 1.1 devices.  So we set this
 519                  * flag here, to defer the action until after the ACPI
 520                  * root scan.
 521                  */
 522                 *no_aspm = 1;
 523         }
 524 }
 525
 526 static int acpi_pci_root_add(struct acpi_device *device,
 527                              const struct acpi_device_id *not_used)
 528 {
 529         unsigned long long segment, bus;
 530         acpi_status status;
 531         int result;
 532         struct acpi_pci_root *root;
 533         acpi_handle handle = device->handle;
 534         int no_aspm = 0;
 535         bool hotadd = system_state == SYSTEM_RUNNING;
 536
 537         root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 538         if (!root)
 539                 return -ENOMEM;
 540
 541         segment = 0;
 542         status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL,
 543                                        &segment);
 544         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 545                 dev_err(&device->dev,  "can't evaluate _SEG\n");
 546                 result = -ENODEV;
 547                 goto end;
 548         }
 549
 550         /* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
 551         root->secondary.flags = IORESOURCE_BUS;
 552         status = try_get_root_bridge_busnr(handle, &root->secondary);
 553         if (ACPI_FAILURE(status)) {
 554                 /*
 555                  * We need both the start and end of the downstream bus range
 556                  * to interpret _CBA (MMCONFIG base address), so it really is
 557                  * supposed to be in _CRS.  If we don't find it there, all we
 558                  * can do is assume [_BBN-0xFF] or [0-0xFF].
 559                  */
 560                 root->secondary.end = 0xFF;
 561                 dev_warn(&device->dev,
 562                          FW_BUG "no secondary bus range in _CRS\n");
 563                 status = acpi_evaluate_integer(handle, METHOD_NAME__BBN,
 564                                                NULL, &bus);
 565                 if (ACPI_SUCCESS(status))
 566                         root->secondary.start = bus;
 567                 else if (status == AE_NOT_FOUND)
 568                         root->secondary.start = 0;
 569                 else {
 570                         dev_err(&device->dev, "can't evaluate _BBN\n");
 571                         result = -ENODEV;
 572                         goto end;
 573                 }
 574         }
 575
 576         root->device = device;
 577         root->segment = segment & 0xFFFF;
 578         strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
 579         strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 580         device->driver_data = root;
 581
 582         if (hotadd && dmar_device_add(handle)) {
 583                 result = -ENXIO;
 584                 goto end;
 585         }
 586
 587         pr_info(PREFIX "%s [%s] (domain %04x %pR)\n",
 588                acpi_device_name(device), acpi_device_bid(device),
 589                root->segment, &root->secondary);
 590
 591         root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
 592
 593         negotiate_os_control(root, &no_aspm);
 594
 595         /*
 596          * TBD: Need PCI interface for enumeration/configuration of roots.
 597          */
 598
 599         /*
 600          * Scan the Root Bridge
 601          * --------------------
 602          * Must do this prior to any attempt to bind the root device, as the
 603          * PCI namespace does not get created until this call is made (and
 604          * thus the root bridge's pci_dev does not exist).
 605          */
 606         root->bus = pci_acpi_scan_root(root);
 607         if (!root->bus) {
 608                 dev_err(&device->dev,
 609                         "Bus %04x:%02x not present in PCI namespace\n",
 610                         root->segment, (unsigned int)root->secondary.start);
 611                 device->driver_data = NULL;
 612                 result = -ENODEV;
 613                 goto remove_dmar;
 614         }
 615
 616         if (no_aspm)
 617                 pcie_no_aspm();
 618
 619         pci_acpi_add_bus_pm_notifier(device);
 620         device_set_wakeup_capable(root->bus->bridge, device->wakeup.flags.valid);
 621
 622         if (hotadd) {
 623                 pcibios_resource_survey_bus(root->bus);
 624                 pci_assign_unassigned_root_bus_resources(root->bus);
 625                 /*
 626                  * This is only called for the hotadd case. For the boot-time
 627                  * case, we need to wait until after PCI initialization in
 628                  * order to deal with IOAPICs mapped in on a PCI BAR.
 629                  *
 630                  * This is currently x86-specific, because acpi_ioapic_add()
 631                  * is an empty function without CONFIG_ACPI_HOTPLUG_IOAPIC.
 632                  * And CONFIG_ACPI_HOTPLUG_IOAPIC depends on CONFIG_X86_IO_APIC
 633                  * (see drivers/acpi/Kconfig).
 634                  */
 635                 acpi_ioapic_add(root->device->handle);
 636         }
 637
 638         pci_lock_rescan_remove();
 639         pci_bus_add_devices(root->bus);
 640         pci_unlock_rescan_remove();
 641         return 1;
 642
 643 remove_dmar:
 644         if (hotadd)
 645                 dmar_device_remove(handle);
 646 end:
 647         kfree(root);
 648         return result;
 649 }
 650
 651 static void acpi_pci_root_remove(struct acpi_device *device)
 652 {
 653         struct acpi_pci_root *root = acpi_driver_data(device);
 654
 655         pci_lock_rescan_remove();
 656
 657         pci_stop_root_bus(root->bus);
 658
 659         pci_ioapic_remove(root);
 660         device_set_wakeup_capable(root->bus->bridge, false);
 661         pci_acpi_remove_bus_pm_notifier(device);
 662
 663         pci_remove_root_bus(root->bus);
 664         WARN_ON(acpi_ioapic_remove(root));
 665
 666         dmar_device_remove(device->handle);
 667
 668         pci_unlock_rescan_remove();
 669
 670         kfree(root);
 671 }
 672
 673 /*
 674  * Following code to support acpi_pci_root_create() is copied from
 675  * arch/x86/pci/acpi.c and modified so it could be reused by x86, IA64
 676  * and ARM64.
 677  */
 678 static void acpi_pci_root_validate_resources(struct device *dev,
 679                                              struct list_head *resources,
 680                                              unsigned long type)
 681 {
 682         LIST_HEAD(list);
 683         struct resource *res1, *res2, *root = NULL;
 684         struct resource_entry *tmp, *entry, *entry2;
 685
 686         BUG_ON((type & (IORESOURCE_MEM | IORESOURCE_IO)) == 0);
 687         root = (type & IORESOURCE_MEM) ? &iomem_resource : &ioport_resource;
 688
 689         list_splice_init(resources, &list);
 690         resource_list_for_each_entry_safe(entry, tmp, &list) {
 691                 bool free = false;
 692                 resource_size_t end;
 693
 694                 res1 = entry->res;
 695                 if (!(res1->flags & type))
 696                         goto next;
 697
 698                 /* Exclude non-addressable range or non-addressable portion */
 699                 end = min(res1->end, root->end);
 700                 if (end <= res1->start) {
 701                         dev_info(dev, "host bridge window %pR (ignored, not CPU addressable)\n",
 702                                  res1);
 703                         free = true;
 704                         goto next;
 705                 } else if (res1->end != end) {
 706                         dev_info(dev, "host bridge window %pR ([%#llx-%#llx] ignored, not CPU addressable)\n",
 707                                  res1, (unsigned long long)end + 1,
 708                                  (unsigned long long)res1->end);
 709                         res1->end = end;
 710                 }
 711
 712                 resource_list_for_each_entry(entry2, resources) {
 713                         res2 = entry2->res;
 714                         if (!(res2->flags & type))
 715                                 continue;
 716
 717                         /*
 718                          * I don't like throwing away windows because then
 719                          * our resources no longer match the ACPI _CRS, but
 720                          * the kernel resource tree doesn't allow overlaps.
 721                          */
 722                         if (resource_overlaps(res1, res2)) {
 723                                 res2->start = min(res1->start, res2->start);
 724                                 res2->end = max(res1->end, res2->end);
 725                                 dev_info(dev, "host bridge window expanded to %pR; %pR ignored\n",
 726                                          res2, res1);
 727                                 free = true;
 728                                 goto next;
 729                         }
 730                 }
 731
 732 next:
 733                 resource_list_del(entry);
 734                 if (free)
 735                         resource_list_free_entry(entry);
 736                 else
 737                         resource_list_add_tail(entry, resources);
 738         }
 739 }
 740
 741 static void acpi_pci_root_remap_iospace(struct fwnode_handle *fwnode,
 742                         struct resource_entry *entry)
 743 {
 744 #ifdef PCI_IOBASE
 745         struct resource *res = entry->res;
 746         resource_size_t cpu_addr = res->start;
 747         resource_size_t pci_addr = cpu_addr - entry->offset;
 748         resource_size_t length = resource_size(res);
 749         unsigned long port;
 750
 751         if (pci_register_io_range(fwnode, cpu_addr, length))
 752                 goto err;
 753
 754         port = pci_address_to_pio(cpu_addr);
 755         if (port == (unsigned long)-1)
 756                 goto err;
 757
 758         res->start = port;
 759         res->end = port + length - 1;
 760         entry->offset = port - pci_addr;
 761
 762         if (pci_remap_iospace(res, cpu_addr) < 0)
 763                 goto err;
 764
 765         pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res);
 766         return;
 767 err:
 768         res->flags |= IORESOURCE_DISABLED;
 769 #endif
 770 }
 771
 772 int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
 773 {
 774         int ret;
 775         struct list_head *list = &info->resources;
 776         struct acpi_device *device = info->bridge;
 777         struct resource_entry *entry, *tmp;
 778         unsigned long flags;
 779
 780         flags = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_MEM_8AND16BIT;
 781         ret = acpi_dev_get_resources(device, list,
 782                                      acpi_dev_filter_resource_type_cb,
 783                                      (void *)flags);
 784         if (ret < 0)
 785                 dev_warn(&device->dev,
 786                          "failed to parse _CRS method, error code %d\n", ret);
 787         else if (ret == 0)
 788                 dev_dbg(&device->dev,
 789                         "no IO and memory resources present in _CRS\n");
 790         else {
 791                 resource_list_for_each_entry_safe(entry, tmp, list) {
 792                         if (entry->res->flags & IORESOURCE_IO)
 793                                 acpi_pci_root_remap_iospace(&device->fwnode,
 794                                                 entry);
 795
 796                         if (entry->res->flags & IORESOURCE_DISABLED)
 797                                 resource_list_destroy_entry(entry);
 798                         else
 799                                 entry->res->name = info->name;
 800                 }
 801                 acpi_pci_root_validate_resources(&device->dev, list,
 802                                                  IORESOURCE_MEM);
 803                 acpi_pci_root_validate_resources(&device->dev, list,
 804                                                  IORESOURCE_IO);
 805         }
 806
 807         return ret;
 808 }
 809
 810 static void pci_acpi_root_add_resources(struct acpi_pci_root_info *info)
 811 {
 812         struct resource_entry *entry, *tmp;
 813         struct resource *res, *conflict, *root = NULL;
 814
 815         resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
 816                 res = entry->res;
 817                 if (res->flags & IORESOURCE_MEM)
 818                         root = &iomem_resource;
 819                 else if (res->flags & IORESOURCE_IO)
 820                         root = &ioport_resource;
 821                 else
 822                         continue;
 823
 824                 /*
 825                  * Some legacy x86 host bridge drivers use iomem_resource and
 826                  * ioport_resource as default resource pool, skip it.
 827                  */
 828                 if (res == root)
 829                         continue;
 830
 831                 conflict = insert_resource_conflict(root, res);
 832                 if (conflict) {
 833                         dev_info(&info->bridge->dev,
 834                                  "ignoring host bridge window %pR (conflicts with %s %pR)\n",
 835                                  res, conflict->name, conflict);
 836                         resource_list_destroy_entry(entry);
 837                 }
 838         }
 839 }
 840
 841 static void __acpi_pci_root_release_info(struct acpi_pci_root_info *info)
 842 {
 843         struct resource *res;
 844         struct resource_entry *entry, *tmp;
 845
 846         if (!info)
 847                 return;
 848
 849         resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
 850                 res = entry->res;
 851                 if (res->parent &&
 852                     (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
 853                         release_resource(res);
 854                 resource_list_destroy_entry(entry);
 855         }
 856
 857         info->ops->release_info(info);
 858 }
 859
 860 static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
 861 {
 862         struct resource *res;
 863         struct resource_entry *entry;
 864
 865         resource_list_for_each_entry(entry, &bridge->windows) {
 866                 res = entry->res;
 867                 if (res->flags & IORESOURCE_IO)
 868                         pci_unmap_iospace(res);
 869                 if (res->parent &&
 870                     (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
 871                         release_resource(res);
 872         }
 873         __acpi_pci_root_release_info(bridge->release_data);
 874 }
 875
 876 struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
 877                                      struct acpi_pci_root_ops *ops,
 878                                      struct acpi_pci_root_info *info,
 879                                      void *sysdata)
 880 {
 881         int ret, busnum = root->secondary.start;
 882         struct acpi_device *device = root->device;
 883         int node = acpi_get_node(device->handle);
 884         struct pci_bus *bus;
 885         struct pci_host_bridge *host_bridge;
 886
 887         info->root = root;
 888         info->bridge = device;
 889         info->ops = ops;
 890         INIT_LIST_HEAD(&info->resources);
 891         snprintf(info->name, sizeof(info->name), "PCI Bus %04x:%02x",
 892                  root->segment, busnum);
 893
 894         if (ops->init_info && ops->init_info(info))
 895                 goto out_release_info;
 896         if (ops->prepare_resources)
 897                 ret = ops->prepare_resources(info);
 898         else
 899                 ret = acpi_pci_probe_root_resources(info);
 900         if (ret < 0)
 901                 goto out_release_info;
 902
 903         pci_acpi_root_add_resources(info);
 904         pci_add_resource(&info->resources, &root->secondary);
 905         bus = pci_create_root_bus(NULL, busnum, ops->pci_ops,
 906                                   sysdata, &info->resources);
 907         if (!bus)
 908                 goto out_release_info;
 909
 910         host_bridge = to_pci_host_bridge(bus->bridge);
 911         if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
 912                 host_bridge->native_pcie_hotplug = 0;
 913         if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL))
 914                 host_bridge->native_shpc_hotplug = 0;
 915         if (!(root->osc_control_set & OSC_PCI_EXPRESS_AER_CONTROL))
 916                 host_bridge->native_aer = 0;
 917         if (!(root->osc_control_set & OSC_PCI_EXPRESS_PME_CONTROL))
 918                 host_bridge->native_pme = 0;
 919         if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL))
 920                 host_bridge->native_ltr = 0;
 921
 922         pci_scan_child_bus(bus);
 923         pci_set_host_bridge_release(host_bridge, acpi_pci_root_release_info,
 924                                     info);
 925         if (node != NUMA_NO_NODE)
 926                 dev_printk(KERN_DEBUG, &bus->dev, "on NUMA node %d\n", node);
 927         return bus;
 928
 929 out_release_info:
 930         __acpi_pci_root_release_info(info);
 931         return NULL;
 932 }
 933
 934 void __init acpi_pci_root_init(void)
 935 {
 936         acpi_hest_init();
 937         if (acpi_pci_disabled)
 938                 return;
 939
 940         pci_acpi_crs_quirks();
 941         acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root");
 942 }