drivers/acpi/pci_root.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  pci_root.c - ACPI PCI Root Bridge Driver ($Revision: 40 $)
   4  *
   5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/types.h>
  13 #include <linux/mutex.h>
  14 #include <linux/pm.h>
  15 #include <linux/pm_runtime.h>
  16 #include <linux/pci.h>
  17 #include <linux/pci-acpi.h>
  18 #include <linux/dmar.h>
  19 #include <linux/acpi.h>
  20 #include <linux/slab.h>
  21 #include <linux/dmi.h>
  22 #include <linux/platform_data/x86/apple.h>
  23 #include "internal.h"
  24
  25 #define ACPI_PCI_ROOT_CLASS             "pci_bridge"
  26 #define ACPI_PCI_ROOT_DEVICE_NAME       "PCI Root Bridge"
  27 static int acpi_pci_root_add(struct acpi_device *device,
  28                              const struct acpi_device_id *not_used);
  29 static void acpi_pci_root_remove(struct acpi_device *device);
  30
  31 static int acpi_pci_root_scan_dependent(struct acpi_device *adev)
  32 {
  33         acpiphp_check_host_bridge(adev);
  34         return 0;
  35 }
  36
  37 #define ACPI_PCIE_REQ_SUPPORT (OSC_PCI_EXT_CONFIG_SUPPORT \
  38                                 | OSC_PCI_ASPM_SUPPORT \
  39                                 | OSC_PCI_CLOCK_PM_SUPPORT \
  40                                 | OSC_PCI_MSI_SUPPORT)
  41
  42 static const struct acpi_device_id root_device_ids[] = {
  43         {"PNP0A03", 0},
  44         {"", 0},
  45 };
  46
  47 static struct acpi_scan_handler pci_root_handler = {
  48         .ids = root_device_ids,
  49         .attach = acpi_pci_root_add,
  50         .detach = acpi_pci_root_remove,
  51         .hotplug = {
  52                 .enabled = true,
  53                 .scan_dependent = acpi_pci_root_scan_dependent,
  54         },
  55 };
  56
  57 static DEFINE_MUTEX(osc_lock);
  58
  59 /**
  60  * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
  61  * @handle:  the ACPI CA node in question.
  62  *
  63  * Note: we could make this API take a struct acpi_device * instead, but
  64  * for now, it's more convenient to operate on an acpi_handle.
  65  */
  66 int acpi_is_root_bridge(acpi_handle handle)
  67 {
  68         int ret;
  69         struct acpi_device *device;
  70
  71         ret = acpi_bus_get_device(handle, &device);
  72         if (ret)
  73                 return 0;
  74
  75         ret = acpi_match_device_ids(device, root_device_ids);
  76         if (ret)
  77                 return 0;
  78         else
  79                 return 1;
  80 }
  81 EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
  82
  83 static acpi_status
  84 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
  85 {
  86         struct resource *res = data;
  87         struct acpi_resource_address64 address;
  88         acpi_status status;
  89
  90         status = acpi_resource_to_address64(resource, &address);
  91         if (ACPI_FAILURE(status))
  92                 return AE_OK;
  93
  94         if ((address.address.address_length > 0) &&
  95             (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
  96                 res->start = address.address.minimum;
  97                 res->end = address.address.minimum + address.address.address_length - 1;
  98         }
  99
 100         return AE_OK;
 101 }
 102
 103 static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
 104                                              struct resource *res)
 105 {
 106         acpi_status status;
 107
 108         res->start = -1;
 109         status =
 110             acpi_walk_resources(handle, METHOD_NAME__CRS,
 111                                 get_root_bridge_busnr_callback, res);
 112         if (ACPI_FAILURE(status))
 113                 return status;
 114         if (res->start == -1)
 115                 return AE_ERROR;
 116         return AE_OK;
 117 }
 118
 119 struct pci_osc_bit_struct {
 120         u32 bit;
 121         char *desc;
 122 };
 123
 124 static struct pci_osc_bit_struct pci_osc_support_bit[] = {
 125         { OSC_PCI_EXT_CONFIG_SUPPORT, "ExtendedConfig" },
 126         { OSC_PCI_ASPM_SUPPORT, "ASPM" },
 127         { OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" },
 128         { OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" },
 129         { OSC_PCI_MSI_SUPPORT, "MSI" },
 130         { OSC_PCI_EDR_SUPPORT, "EDR" },
 131         { OSC_PCI_HPX_TYPE_3_SUPPORT, "HPX-Type3" },
 132 };
 133
 134 static struct pci_osc_bit_struct pci_osc_control_bit[] = {
 135         { OSC_PCI_EXPRESS_NATIVE_HP_CONTROL, "PCIeHotplug" },
 136         { OSC_PCI_SHPC_NATIVE_HP_CONTROL, "SHPCHotplug" },
 137         { OSC_PCI_EXPRESS_PME_CONTROL, "PME" },
 138         { OSC_PCI_EXPRESS_AER_CONTROL, "AER" },
 139         { OSC_PCI_EXPRESS_CAPABILITY_CONTROL, "PCIeCapability" },
 140         { OSC_PCI_EXPRESS_LTR_CONTROL, "LTR" },
 141         { OSC_PCI_EXPRESS_DPC_CONTROL, "DPC" },
 142 };
 143
 144 static void decode_osc_bits(struct acpi_pci_root *root, char *msg, u32 word,
 145                             struct pci_osc_bit_struct *table, int size)
 146 {
 147         char buf[80];
 148         int i, len = 0;
 149         struct pci_osc_bit_struct *entry;
 150
 151         buf[0] = '\0';
 152         for (i = 0, entry = table; i < size; i++, entry++)
 153                 if (word & entry->bit)
 154                         len += scnprintf(buf + len, sizeof(buf) - len, "%s%s",
 155                                         len ? " " : "", entry->desc);
 156
 157         dev_info(&root->device->dev, "_OSC: %s [%s]\n", msg, buf);
 158 }
 159
 160 static void decode_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
 161 {
 162         decode_osc_bits(root, msg, word, pci_osc_support_bit,
 163                         ARRAY_SIZE(pci_osc_support_bit));
 164 }
 165
 166 static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
 167 {
 168         decode_osc_bits(root, msg, word, pci_osc_control_bit,
 169                         ARRAY_SIZE(pci_osc_control_bit));
 170 }
 171
 172 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
 173
 174 static acpi_status acpi_pci_run_osc(acpi_handle handle,
 175                                     const u32 *capbuf, u32 *retval)
 176 {
 177         struct acpi_osc_context context = {
 178                 .uuid_str = pci_osc_uuid_str,
 179                 .rev = 1,
 180                 .cap.length = 12,
 181                 .cap.pointer = (void *)capbuf,
 182         };
 183         acpi_status status;
 184
 185         status = acpi_run_osc(handle, &context);
 186         if (ACPI_SUCCESS(status)) {
 187                 *retval = *((u32 *)(context.ret.pointer + 8));
 188                 kfree(context.ret.pointer);
 189         }
 190         return status;
 191 }
 192
 193 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
 194                                         u32 support,
 195                                         u32 *control)
 196 {
 197         acpi_status status;
 198         u32 result, capbuf[3];
 199
 200         support &= OSC_PCI_SUPPORT_MASKS;
 201         support |= root->osc_support_set;
 202
 203         capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
 204         capbuf[OSC_SUPPORT_DWORD] = support;
 205         if (control) {
 206                 *control &= OSC_PCI_CONTROL_MASKS;
 207                 capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
 208         } else {
 209                 /* Run _OSC query only with existing controls. */
 210                 capbuf[OSC_CONTROL_DWORD] = root->osc_control_set;
 211         }
 212
 213         status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
 214         if (ACPI_SUCCESS(status)) {
 215                 root->osc_support_set = support;
 216                 if (control)
 217                         *control = result;
 218         }
 219         return status;
 220 }
 221
 222 static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
 223 {
 224         acpi_status status;
 225
 226         mutex_lock(&osc_lock);
 227         status = acpi_pci_query_osc(root, flags, NULL);
 228         mutex_unlock(&osc_lock);
 229         return status;
 230 }
 231
 232 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
 233 {
 234         struct acpi_pci_root *root;
 235         struct acpi_device *device;
 236
 237         if (acpi_bus_get_device(handle, &device) ||
 238             acpi_match_device_ids(device, root_device_ids))
 239                 return NULL;
 240
 241         root = acpi_driver_data(device);
 242
 243         return root;
 244 }
 245 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
 246
 247 struct acpi_handle_node {
 248         struct list_head node;
 249         acpi_handle handle;
 250 };
 251
 252 /**
 253  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
 254  * @handle: the handle in question
 255  *
 256  * Given an ACPI CA handle, the desired PCI device is located in the
 257  * list of PCI devices.
 258  *
 259  * If the device is found, its reference count is increased and this
 260  * function returns a pointer to its data structure.  The caller must
 261  * decrement the reference count by calling pci_dev_put().
 262  * If no device is found, %NULL is returned.
 263  */
 264 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
 265 {
 266         int dev, fn;
 267         unsigned long long adr;
 268         acpi_status status;
 269         acpi_handle phandle;
 270         struct pci_bus *pbus;
 271         struct pci_dev *pdev = NULL;
 272         struct acpi_handle_node *node, *tmp;
 273         struct acpi_pci_root *root;
 274         LIST_HEAD(device_list);
 275
 276         /*
 277          * Walk up the ACPI CA namespace until we reach a PCI root bridge.
 278          */
 279         phandle = handle;
 280         while (!acpi_is_root_bridge(phandle)) {
 281                 node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
 282                 if (!node)
 283                         goto out;
 284
 285                 INIT_LIST_HEAD(&node->node);
 286                 node->handle = phandle;
 287                 list_add(&node->node, &device_list);
 288
 289                 status = acpi_get_parent(phandle, &phandle);
 290                 if (ACPI_FAILURE(status))
 291                         goto out;
 292         }
 293
 294         root = acpi_pci_find_root(phandle);
 295         if (!root)
 296                 goto out;
 297
 298         pbus = root->bus;
 299
 300         /*
 301          * Now, walk back down the PCI device tree until we return to our
 302          * original handle. Assumes that everything between the PCI root
 303          * bridge and the device we're looking for must be a P2P bridge.
 304          */
 305         list_for_each_entry(node, &device_list, node) {
 306                 acpi_handle hnd = node->handle;
 307                 status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
 308                 if (ACPI_FAILURE(status))
 309                         goto out;
 310                 dev = (adr >> 16) & 0xffff;
 311                 fn  = adr & 0xffff;
 312
 313                 pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
 314                 if (!pdev || hnd == handle)
 315                         break;
 316
 317                 pbus = pdev->subordinate;
 318                 pci_dev_put(pdev);
 319
 320                 /*
 321                  * This function may be called for a non-PCI device that has a
 322                  * PCI parent (eg. a disk under a PCI SATA controller).  In that
 323                  * case pdev->subordinate will be NULL for the parent.
 324                  */
 325                 if (!pbus) {
 326                         dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
 327                         pdev = NULL;
 328                         break;
 329                 }
 330         }
 331 out:
 332         list_for_each_entry_safe(node, tmp, &device_list, node)
 333                 kfree(node);
 334
 335         return pdev;
 336 }
 337 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
 338
 339 /**
 340  * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
 341  * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
 342  * @mask: Mask of _OSC bits to request control of, place to store control mask.
 343  * @req: Mask of _OSC bits the control of is essential to the caller.
 344  *
 345  * Run _OSC query for @mask and if that is successful, compare the returned
 346  * mask of control bits with @req.  If all of the @req bits are set in the
 347  * returned mask, run _OSC request for it.
 348  *
 349  * The variable at the @mask address may be modified regardless of whether or
 350  * not the function returns success.  On success it will contain the mask of
 351  * _OSC bits the BIOS has granted control of, but its contents are meaningless
 352  * on failure.
 353  **/
 354 acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
 355 {
 356         struct acpi_pci_root *root;
 357         acpi_status status = AE_OK;
 358         u32 ctrl, capbuf[3];
 359
 360         if (!mask)
 361                 return AE_BAD_PARAMETER;
 362
 363         ctrl = *mask & OSC_PCI_CONTROL_MASKS;
 364         if ((ctrl & req) != req)
 365                 return AE_TYPE;
 366
 367         root = acpi_pci_find_root(handle);
 368         if (!root)
 369                 return AE_NOT_EXIST;
 370
 371         mutex_lock(&osc_lock);
 372
 373         *mask = ctrl | root->osc_control_set;
 374         /* No need to evaluate _OSC if the control was already granted. */
 375         if ((root->osc_control_set & ctrl) == ctrl)
 376                 goto out;
 377
 378         /* Need to check the available controls bits before requesting them. */
 379         while (*mask) {
 380                 status = acpi_pci_query_osc(root, root->osc_support_set, mask);
 381                 if (ACPI_FAILURE(status))
 382                         goto out;
 383                 if (ctrl == *mask)
 384                         break;
 385                 decode_osc_control(root, "platform does not support",
 386                                    ctrl & ~(*mask));
 387                 ctrl = *mask;
 388         }
 389
 390         if ((ctrl & req) != req) {
 391                 decode_osc_control(root, "not requesting control; platform does not support",
 392                                    req & ~(ctrl));
 393                 status = AE_SUPPORT;
 394                 goto out;
 395         }
 396
 397         capbuf[OSC_QUERY_DWORD] = 0;
 398         capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set;
 399         capbuf[OSC_CONTROL_DWORD] = ctrl;
 400         status = acpi_pci_run_osc(handle, capbuf, mask);
 401         if (ACPI_SUCCESS(status))
 402                 root->osc_control_set = *mask;
 403 out:
 404         mutex_unlock(&osc_lock);
 405         return status;
 406 }
 407 EXPORT_SYMBOL(acpi_pci_osc_control_set);
 408
 409 static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
 410                                  bool is_pcie)
 411 {
 412         u32 support, control, requested;
 413         acpi_status status;
 414         struct acpi_device *device = root->device;
 415         acpi_handle handle = device->handle;
 416
 417         /*
 418          * Apple always return failure on _OSC calls when _OSI("Darwin") has
 419          * been called successfully. We know the feature set supported by the
 420          * platform, so avoid calling _OSC at all
 421          */
 422         if (x86_apple_machine) {
 423                 root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;
 424                 decode_osc_control(root, "OS assumes control of",
 425                                    root->osc_control_set);
 426                 return;
 427         }
 428
 429         /*
 430          * All supported architectures that use ACPI have support for
 431          * PCI domains, so we indicate this in _OSC support capabilities.
 432          */
 433         support = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
 434         support |= OSC_PCI_HPX_TYPE_3_SUPPORT;
 435         if (pci_ext_cfg_avail())
 436                 support |= OSC_PCI_EXT_CONFIG_SUPPORT;
 437         if (pcie_aspm_support_enabled())
 438                 support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
 439         if (pci_msi_enabled())
 440                 support |= OSC_PCI_MSI_SUPPORT;
 441         if (IS_ENABLED(CONFIG_PCIE_EDR))
 442                 support |= OSC_PCI_EDR_SUPPORT;
 443
 444         decode_osc_support(root, "OS supports", support);
 445         status = acpi_pci_osc_support(root, support);
 446         if (ACPI_FAILURE(status)) {
 447                 *no_aspm = 1;
 448
 449                 /* _OSC is optional for PCI host bridges */
 450                 if ((status == AE_NOT_FOUND) && !is_pcie)
 451                         return;
 452
 453                 dev_info(&device->dev, "_OSC failed (%s)%s\n",
 454                          acpi_format_exception(status),
 455                          pcie_aspm_support_enabled() ? "; disabling ASPM" : "");
 456                 return;
 457         }
 458
 459         if (pcie_ports_disabled) {
 460                 dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
 461                 return;
 462         }
 463
 464         if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
 465                 decode_osc_support(root, "not requesting OS control; OS requires",
 466                                    ACPI_PCIE_REQ_SUPPORT);
 467                 return;
 468         }
 469
 470         control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
 471                 | OSC_PCI_EXPRESS_PME_CONTROL;
 472
 473         if (IS_ENABLED(CONFIG_PCIEASPM))
 474                 control |= OSC_PCI_EXPRESS_LTR_CONTROL;
 475
 476         if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
 477                 control |= OSC_PCI_EXPRESS_NATIVE_HP_CONTROL;
 478
 479         if (IS_ENABLED(CONFIG_HOTPLUG_PCI_SHPC))
 480                 control |= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
 481
 482         if (pci_aer_available())
 483                 control |= OSC_PCI_EXPRESS_AER_CONTROL;
 484
 485         /*
 486          * Per the Downstream Port Containment Related Enhancements ECN to
 487          * the PCI Firmware Spec, r3.2, sec 4.5.1, table 4-5,
 488          * OSC_PCI_EXPRESS_DPC_CONTROL indicates the OS supports both DPC
 489          * and EDR.
 490          */
 491         if (IS_ENABLED(CONFIG_PCIE_DPC) && IS_ENABLED(CONFIG_PCIE_EDR))
 492                 control |= OSC_PCI_EXPRESS_DPC_CONTROL;
 493
 494         requested = control;
 495         status = acpi_pci_osc_control_set(handle, &control,
 496                                           OSC_PCI_EXPRESS_CAPABILITY_CONTROL);
 497         if (ACPI_SUCCESS(status)) {
 498                 decode_osc_control(root, "OS now controls", control);
 499                 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 500                         /*
 501                          * We have ASPM control, but the FADT indicates that
 502                          * it's unsupported. Leave existing configuration
 503                          * intact and prevent the OS from touching it.
 504                          */
 505                         dev_info(&device->dev, "FADT indicates ASPM is unsupported, using BIOS configuration\n");
 506                         *no_aspm = 1;
 507                 }
 508         } else {
 509                 decode_osc_control(root, "OS requested", requested);
 510                 decode_osc_control(root, "platform willing to grant", control);
 511                 dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
 512                         acpi_format_exception(status));
 513
 514                 /*
 515                  * We want to disable ASPM here, but aspm_disabled
 516                  * needs to remain in its state from boot so that we
 517                  * properly handle PCIe 1.1 devices.  So we set this
 518                  * flag here, to defer the action until after the ACPI
 519                  * root scan.
 520                  */
 521                 *no_aspm = 1;
 522         }
 523 }
 524
 525 static int acpi_pci_root_add(struct acpi_device *device,
 526                              const struct acpi_device_id *not_used)
 527 {
 528         unsigned long long segment, bus;
 529         acpi_status status;
 530         int result;
 531         struct acpi_pci_root *root;
 532         acpi_handle handle = device->handle;
 533         int no_aspm = 0;
 534         bool hotadd = system_state == SYSTEM_RUNNING;
 535         bool is_pcie;
 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         is_pcie = strcmp(acpi_device_hid(device), "PNP0A08") == 0;
 594         negotiate_os_control(root, &no_aspm, is_pcie);
 595
 596         /*
 597          * TBD: Need PCI interface for enumeration/configuration of roots.
 598          */
 599
 600         /*
 601          * Scan the Root Bridge
 602          * --------------------
 603          * Must do this prior to any attempt to bind the root device, as the
 604          * PCI namespace does not get created until this call is made (and
 605          * thus the root bridge's pci_dev does not exist).
 606          */
 607         root->bus = pci_acpi_scan_root(root);
 608         if (!root->bus) {
 609                 dev_err(&device->dev,
 610                         "Bus %04x:%02x not present in PCI namespace\n",
 611                         root->segment, (unsigned int)root->secondary.start);
 612                 device->driver_data = NULL;
 613                 result = -ENODEV;
 614                 goto remove_dmar;
 615         }
 616
 617         if (no_aspm)
 618                 pcie_no_aspm();
 619
 620         pci_acpi_add_bus_pm_notifier(device);
 621         device_set_wakeup_capable(root->bus->bridge, device->wakeup.flags.valid);
 622
 623         if (hotadd) {
 624                 pcibios_resource_survey_bus(root->bus);
 625                 pci_assign_unassigned_root_bus_resources(root->bus);
 626                 /*
 627                  * This is only called for the hotadd case. For the boot-time
 628                  * case, we need to wait until after PCI initialization in
 629                  * order to deal with IOAPICs mapped in on a PCI BAR.
 630                  *
 631                  * This is currently x86-specific, because acpi_ioapic_add()
 632                  * is an empty function without CONFIG_ACPI_HOTPLUG_IOAPIC.
 633                  * And CONFIG_ACPI_HOTPLUG_IOAPIC depends on CONFIG_X86_IO_APIC
 634                  * (see drivers/acpi/Kconfig).
 635                  */
 636                 acpi_ioapic_add(root->device->handle);
 637         }
 638
 639         pci_lock_rescan_remove();
 640         pci_bus_add_devices(root->bus);
 641         pci_unlock_rescan_remove();
 642         return 1;
 643
 644 remove_dmar:
 645         if (hotadd)
 646                 dmar_device_remove(handle);
 647 end:
 648         kfree(root);
 649         return result;
 650 }
 651
 652 static void acpi_pci_root_remove(struct acpi_device *device)
 653 {
 654         struct acpi_pci_root *root = acpi_driver_data(device);
 655
 656         pci_lock_rescan_remove();
 657
 658         pci_stop_root_bus(root->bus);
 659
 660         pci_ioapic_remove(root);
 661         device_set_wakeup_capable(root->bus->bridge, false);
 662         pci_acpi_remove_bus_pm_notifier(device);
 663
 664         pci_remove_root_bus(root->bus);
 665         WARN_ON(acpi_ioapic_remove(root));
 666
 667         dmar_device_remove(device->handle);
 668
 669         pci_unlock_rescan_remove();
 670
 671         kfree(root);
 672 }
 673
 674 /*
 675  * Following code to support acpi_pci_root_create() is copied from
 676  * arch/x86/pci/acpi.c and modified so it could be reused by x86, IA64
 677  * and ARM64.
 678  */
 679 static void acpi_pci_root_validate_resources(struct device *dev,
 680                                              struct list_head *resources,
 681                                              unsigned long type)
 682 {
 683         LIST_HEAD(list);
 684         struct resource *res1, *res2, *root = NULL;
 685         struct resource_entry *tmp, *entry, *entry2;
 686
 687         BUG_ON((type & (IORESOURCE_MEM | IORESOURCE_IO)) == 0);
 688         root = (type & IORESOURCE_MEM) ? &iomem_resource : &ioport_resource;
 689
 690         list_splice_init(resources, &list);
 691         resource_list_for_each_entry_safe(entry, tmp, &list) {
 692                 bool free = false;
 693                 resource_size_t end;
 694
 695                 res1 = entry->res;
 696                 if (!(res1->flags & type))
 697                         goto next;
 698
 699                 /* Exclude non-addressable range or non-addressable portion */
 700                 end = min(res1->end, root->end);
 701                 if (end <= res1->start) {
 702                         dev_info(dev, "host bridge window %pR (ignored, not CPU addressable)\n",
 703                                  res1);
 704                         free = true;
 705                         goto next;
 706                 } else if (res1->end != end) {
 707                         dev_info(dev, "host bridge window %pR ([%#llx-%#llx] ignored, not CPU addressable)\n",
 708                                  res1, (unsigned long long)end + 1,
 709                                  (unsigned long long)res1->end);
 710                         res1->end = end;
 711                 }
 712
 713                 resource_list_for_each_entry(entry2, resources) {
 714                         res2 = entry2->res;
 715                         if (!(res2->flags & type))
 716                                 continue;
 717
 718                         /*
 719                          * I don't like throwing away windows because then
 720                          * our resources no longer match the ACPI _CRS, but
 721                          * the kernel resource tree doesn't allow overlaps.
 722                          */
 723                         if (resource_overlaps(res1, res2)) {
 724                                 res2->start = min(res1->start, res2->start);
 725                                 res2->end = max(res1->end, res2->end);
 726                                 dev_info(dev, "host bridge window expanded to %pR; %pR ignored\n",
 727                                          res2, res1);
 728                                 free = true;
 729                                 goto next;
 730                         }
 731                 }
 732
 733 next:
 734                 resource_list_del(entry);
 735                 if (free)
 736                         resource_list_free_entry(entry);
 737                 else
 738                         resource_list_add_tail(entry, resources);
 739         }
 740 }
 741
 742 static void acpi_pci_root_remap_iospace(struct fwnode_handle *fwnode,
 743                         struct resource_entry *entry)
 744 {
 745 #ifdef PCI_IOBASE
 746         struct resource *res = entry->res;
 747         resource_size_t cpu_addr = res->start;
 748         resource_size_t pci_addr = cpu_addr - entry->offset;
 749         resource_size_t length = resource_size(res);
 750         unsigned long port;
 751
 752         if (pci_register_io_range(fwnode, cpu_addr, length))
 753                 goto err;
 754
 755         port = pci_address_to_pio(cpu_addr);
 756         if (port == (unsigned long)-1)
 757                 goto err;
 758
 759         res->start = port;
 760         res->end = port + length - 1;
 761         entry->offset = port - pci_addr;
 762
 763         if (pci_remap_iospace(res, cpu_addr) < 0)
 764                 goto err;
 765
 766         pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res);
 767         return;
 768 err:
 769         res->flags |= IORESOURCE_DISABLED;
 770 #endif
 771 }
 772
 773 int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
 774 {
 775         int ret;
 776         struct list_head *list = &info->resources;
 777         struct acpi_device *device = info->bridge;
 778         struct resource_entry *entry, *tmp;
 779         unsigned long flags;
 780
 781         flags = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_MEM_8AND16BIT;
 782         ret = acpi_dev_get_resources(device, list,
 783                                      acpi_dev_filter_resource_type_cb,
 784                                      (void *)flags);
 785         if (ret < 0)
 786                 dev_warn(&device->dev,
 787                          "failed to parse _CRS method, error code %d\n", ret);
 788         else if (ret == 0)
 789                 dev_dbg(&device->dev,
 790                         "no IO and memory resources present in _CRS\n");
 791         else {
 792                 resource_list_for_each_entry_safe(entry, tmp, list) {
 793                         if (entry->res->flags & IORESOURCE_IO)
 794                                 acpi_pci_root_remap_iospace(&device->fwnode,
 795                                                 entry);
 796
 797                         if (entry->res->flags & IORESOURCE_DISABLED)
 798                                 resource_list_destroy_entry(entry);
 799                         else
 800                                 entry->res->name = info->name;
 801                 }
 802                 acpi_pci_root_validate_resources(&device->dev, list,
 803                                                  IORESOURCE_MEM);
 804                 acpi_pci_root_validate_resources(&device->dev, list,
 805                                                  IORESOURCE_IO);
 806         }
 807
 808         return ret;
 809 }
 810
 811 static void pci_acpi_root_add_resources(struct acpi_pci_root_info *info)
 812 {
 813         struct resource_entry *entry, *tmp;
 814         struct resource *res, *conflict, *root = NULL;
 815
 816         resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
 817                 res = entry->res;
 818                 if (res->flags & IORESOURCE_MEM)
 819                         root = &iomem_resource;
 820                 else if (res->flags & IORESOURCE_IO)
 821                         root = &ioport_resource;
 822                 else
 823                         continue;
 824
 825                 /*
 826                  * Some legacy x86 host bridge drivers use iomem_resource and
 827                  * ioport_resource as default resource pool, skip it.
 828                  */
 829                 if (res == root)
 830                         continue;
 831
 832                 conflict = insert_resource_conflict(root, res);
 833                 if (conflict) {
 834                         dev_info(&info->bridge->dev,
 835                                  "ignoring host bridge window %pR (conflicts with %s %pR)\n",
 836                                  res, conflict->name, conflict);
 837                         resource_list_destroy_entry(entry);
 838                 }
 839         }
 840 }
 841
 842 static void __acpi_pci_root_release_info(struct acpi_pci_root_info *info)
 843 {
 844         struct resource *res;
 845         struct resource_entry *entry, *tmp;
 846
 847         if (!info)
 848                 return;
 849
 850         resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
 851                 res = entry->res;
 852                 if (res->parent &&
 853                     (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
 854                         release_resource(res);
 855                 resource_list_destroy_entry(entry);
 856         }
 857
 858         info->ops->release_info(info);
 859 }
 860
 861 static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
 862 {
 863         struct resource *res;
 864         struct resource_entry *entry;
 865
 866         resource_list_for_each_entry(entry, &bridge->windows) {
 867                 res = entry->res;
 868                 if (res->flags & IORESOURCE_IO)
 869                         pci_unmap_iospace(res);
 870                 if (res->parent &&
 871                     (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
 872                         release_resource(res);
 873         }
 874         __acpi_pci_root_release_info(bridge->release_data);
 875 }
 876
 877 struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
 878                                      struct acpi_pci_root_ops *ops,
 879                                      struct acpi_pci_root_info *info,
 880                                      void *sysdata)
 881 {
 882         int ret, busnum = root->secondary.start;
 883         struct acpi_device *device = root->device;
 884         int node = acpi_get_node(device->handle);
 885         struct pci_bus *bus;
 886         struct pci_host_bridge *host_bridge;
 887         union acpi_object *obj;
 888
 889         info->root = root;
 890         info->bridge = device;
 891         info->ops = ops;
 892         INIT_LIST_HEAD(&info->resources);
 893         snprintf(info->name, sizeof(info->name), "PCI Bus %04x:%02x",
 894                  root->segment, busnum);
 895
 896         if (ops->init_info && ops->init_info(info))
 897                 goto out_release_info;
 898         if (ops->prepare_resources)
 899                 ret = ops->prepare_resources(info);
 900         else
 901                 ret = acpi_pci_probe_root_resources(info);
 902         if (ret < 0)
 903                 goto out_release_info;
 904
 905         pci_acpi_root_add_resources(info);
 906         pci_add_resource(&info->resources, &root->secondary);
 907         bus = pci_create_root_bus(NULL, busnum, ops->pci_ops,
 908                                   sysdata, &info->resources);
 909         if (!bus)
 910                 goto out_release_info;
 911
 912         host_bridge = to_pci_host_bridge(bus->bridge);
 913         if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
 914                 host_bridge->native_pcie_hotplug = 0;
 915         if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL))
 916                 host_bridge->native_shpc_hotplug = 0;
 917         if (!(root->osc_control_set & OSC_PCI_EXPRESS_AER_CONTROL))
 918                 host_bridge->native_aer = 0;
 919         if (!(root->osc_control_set & OSC_PCI_EXPRESS_PME_CONTROL))
 920                 host_bridge->native_pme = 0;
 921         if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL))
 922                 host_bridge->native_ltr = 0;
 923         if (!(root->osc_control_set & OSC_PCI_EXPRESS_DPC_CONTROL))
 924                 host_bridge->native_dpc = 0;
 925
 926         /*
 927          * Evaluate the "PCI Boot Configuration" _DSM Function.  If it
 928          * exists and returns 0, we must preserve any PCI resource
 929          * assignments made by firmware for this host bridge.
 930          */
 931         obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 1,
 932                                 DSM_PCI_PRESERVE_BOOT_CONFIG, NULL);
 933         if (obj && obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 0)
 934                 host_bridge->preserve_config = 1;
 935         ACPI_FREE(obj);
 936
 937         pci_scan_child_bus(bus);
 938         pci_set_host_bridge_release(host_bridge, acpi_pci_root_release_info,
 939                                     info);
 940         if (node != NUMA_NO_NODE)
 941                 dev_printk(KERN_DEBUG, &bus->dev, "on NUMA node %d\n", node);
 942         return bus;
 943
 944 out_release_info:
 945         __acpi_pci_root_release_info(info);
 946         return NULL;
 947 }
 948
 949 void __init acpi_pci_root_init(void)
 950 {
 951         if (acpi_pci_disabled)
 952                 return;
 953
 954         pci_acpi_crs_quirks();
 955         acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root");
 956 }