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 <acpi/apei.h>  /* for acpi_hest_init() */
  24
  25 #include "internal.h"
  26
  27 #define _COMPONENT              ACPI_PCI_COMPONENT
  28 ACPI_MODULE_NAME("pci_root");
  29 #define ACPI_PCI_ROOT_CLASS             "pci_bridge"
  30 #define ACPI_PCI_ROOT_DEVICE_NAME       "PCI Root Bridge"
  31 static int acpi_pci_root_add(struct acpi_device *device,
  32                              const struct acpi_device_id *not_used);
  33 static void acpi_pci_root_remove(struct acpi_device *device);
  34
  35 static int acpi_pci_root_scan_dependent(struct acpi_device *adev)
  36 {
  37         acpiphp_check_host_bridge(adev);
  38         return 0;
  39 }
  40
  41 #define ACPI_PCIE_REQ_SUPPORT (OSC_PCI_EXT_CONFIG_SUPPORT \
  42                                 | OSC_PCI_ASPM_SUPPORT \
  43                                 | OSC_PCI_CLOCK_PM_SUPPORT \
  44                                 | OSC_PCI_MSI_SUPPORT)
  45
  46 static const struct acpi_device_id root_device_ids[] = {
  47         {"PNP0A03", 0},
  48         {"", 0},
  49 };
  50
  51 static struct acpi_scan_handler pci_root_handler = {
  52         .ids = root_device_ids,
  53         .attach = acpi_pci_root_add,
  54         .detach = acpi_pci_root_remove,
  55         .hotplug = {
  56                 .enabled = true,
  57                 .scan_dependent = acpi_pci_root_scan_dependent,
  58         },
  59 };
  60
  61 static DEFINE_MUTEX(osc_lock);
  62
  63 /**
  64  * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
  65  * @handle - the ACPI CA node in question.
  66  *
  67  * Note: we could make this API take a struct acpi_device * instead, but
  68  * for now, it's more convenient to operate on an acpi_handle.
  69  */
  70 int acpi_is_root_bridge(acpi_handle handle)
  71 {
  72         int ret;
  73         struct acpi_device *device;
  74
  75         ret = acpi_bus_get_device(handle, &device);
  76         if (ret)
  77                 return 0;
  78
  79         ret = acpi_match_device_ids(device, root_device_ids);
  80         if (ret)
  81                 return 0;
  82         else
  83                 return 1;
  84 }
  85 EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
  86
  87 static acpi_status
  88 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
  89 {
  90         struct resource *res = data;
  91         struct acpi_resource_address64 address;
  92         acpi_status status;
  93
  94         status = acpi_resource_to_address64(resource, &address);
  95         if (ACPI_FAILURE(status))
  96                 return AE_OK;
  97
  98         if ((address.address.address_length > 0) &&
  99             (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
 100                 res->start = address.address.minimum;
 101                 res->end = address.address.minimum + address.address.address_length - 1;
 102         }
 103
 104         return AE_OK;
 105 }
 106
 107 static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
 108                                              struct resource *res)
 109 {
 110         acpi_status status;
 111
 112         res->start = -1;
 113         status =
 114             acpi_walk_resources(handle, METHOD_NAME__CRS,
 115                                 get_root_bridge_busnr_callback, res);
 116         if (ACPI_FAILURE(status))
 117                 return status;
 118         if (res->start == -1)
 119                 return AE_ERROR;
 120         return AE_OK;
 121 }
 122
 123 struct pci_osc_bit_struct {
 124         u32 bit;
 125         char *desc;
 126 };
 127
 128 static struct pci_osc_bit_struct pci_osc_support_bit[] = {
 129         { OSC_PCI_EXT_CONFIG_SUPPORT, "ExtendedConfig" },
 130         { OSC_PCI_ASPM_SUPPORT, "ASPM" },
 131         { OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" },
 132         { OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" },
 133         { OSC_PCI_MSI_SUPPORT, "MSI" },
 134         { OSC_PCI_EDR_SUPPORT, "EDR" },
 135         { OSC_PCI_HPX_TYPE_3_SUPPORT, "HPX-Type3" },
 136 };
 137
 138 static struct pci_osc_bit_struct pci_osc_control_bit[] = {
 139         { OSC_PCI_EXPRESS_NATIVE_HP_CONTROL, "PCIeHotplug" },
 140         { OSC_PCI_SHPC_NATIVE_HP_CONTROL, "SHPCHotplug" },
 141         { OSC_PCI_EXPRESS_PME_CONTROL, "PME" },
 142         { OSC_PCI_EXPRESS_AER_CONTROL, "AER" },
 143         { OSC_PCI_EXPRESS_CAPABILITY_CONTROL, "PCIeCapability" },
 144         { OSC_PCI_EXPRESS_LTR_CONTROL, "LTR" },
 145         { OSC_PCI_EXPRESS_DPC_CONTROL, "DPC" },
 146 };
 147
 148 static void decode_osc_bits(struct acpi_pci_root *root, char *msg, u32 word,
 149                             struct pci_osc_bit_struct *table, int size)
 150 {
 151         char buf[80];
 152         int i, len = 0;
 153         struct pci_osc_bit_struct *entry;
 154
 155         buf[0] = '\0';
 156         for (i = 0, entry = table; i < size; i++, entry++)
 157                 if (word & entry->bit)
 158                         len += scnprintf(buf + len, sizeof(buf) - len, "%s%s",
 159                                         len ? " " : "", entry->desc);
 160
 161         dev_info(&root->device->dev, "_OSC: %s [%s]\n", msg, buf);
 162 }
 163
 164 static void decode_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
 165 {
 166         decode_osc_bits(root, msg, word, pci_osc_support_bit,
 167                         ARRAY_SIZE(pci_osc_support_bit));
 168 }
 169
 170 static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
 171 {
 172         decode_osc_bits(root, msg, word, pci_osc_control_bit,
 173                         ARRAY_SIZE(pci_osc_control_bit));
 174 }
 175
 176 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
 177
 178 static acpi_status acpi_pci_run_osc(acpi_handle handle,
 179                                     const u32 *capbuf, u32 *retval)
 180 {
 181         struct acpi_osc_context context = {
 182                 .uuid_str = pci_osc_uuid_str,
 183                 .rev = 1,
 184                 .cap.length = 12,
 185                 .cap.pointer = (void *)capbuf,
 186         };
 187         acpi_status status;
 188
 189         status = acpi_run_osc(handle, &context);
 190         if (ACPI_SUCCESS(status)) {
 191                 *retval = *((u32 *)(context.ret.pointer + 8));
 192                 kfree(context.ret.pointer);
 193         }
 194         return status;
 195 }
 196
 197 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root,
 198                                         u32 support,
 199                                         u32 *control)
 200 {
 201         acpi_status status;
 202         u32 result, capbuf[3];
 203
 204         support &= OSC_PCI_SUPPORT_MASKS;
 205         support |= root->osc_support_set;
 206
 207         capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
 208         capbuf[OSC_SUPPORT_DWORD] = support;
 209         if (control) {
 210                 *control &= OSC_PCI_CONTROL_MASKS;
 211                 capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
 212         } else {
 213                 /* Run _OSC query only with existing controls. */
 214                 capbuf[OSC_CONTROL_DWORD] = root->osc_control_set;
 215         }
 216
 217         status = acpi_pci_run_osc(root->device->handle, capbuf, &result);
 218         if (ACPI_SUCCESS(status)) {
 219                 root->osc_support_set = support;
 220                 if (control)
 221                         *control = result;
 222         }
 223         return status;
 224 }
 225
 226 static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
 227 {
 228         acpi_status status;
 229
 230         mutex_lock(&osc_lock);
 231         status = acpi_pci_query_osc(root, flags, NULL);
 232         mutex_unlock(&osc_lock);
 233         return status;
 234 }
 235
 236 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
 237 {
 238         struct acpi_pci_root *root;
 239         struct acpi_device *device;
 240
 241         if (acpi_bus_get_device(handle, &device) ||
 242             acpi_match_device_ids(device, root_device_ids))
 243                 return NULL;
 244
 245         root = acpi_driver_data(device);
 246
 247         return root;
 248 }
 249 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
 250
 251 struct acpi_handle_node {
 252         struct list_head node;
 253         acpi_handle handle;
 254 };
 255
 256 /**
 257  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
 258  * @handle: the handle in question
 259  *
 260  * Given an ACPI CA handle, the desired PCI device is located in the
 261  * list of PCI devices.
 262  *
 263  * If the device is found, its reference count is increased and this
 264  * function returns a pointer to its data structure.  The caller must
 265  * decrement the reference count by calling pci_dev_put().
 266  * If no device is found, %NULL is returned.
 267  */
 268 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
 269 {
 270         int dev, fn;
 271         unsigned long long adr;
 272         acpi_status status;
 273         acpi_handle phandle;
 274         struct pci_bus *pbus;
 275         struct pci_dev *pdev = NULL;
 276         struct acpi_handle_node *node, *tmp;
 277         struct acpi_pci_root *root;
 278         LIST_HEAD(device_list);
 279
 280         /*
 281          * Walk up the ACPI CA namespace until we reach a PCI root bridge.
 282          */
 283         phandle = handle;
 284         while (!acpi_is_root_bridge(phandle)) {
 285                 node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
 286                 if (!node)
 287                         goto out;
 288
 289                 INIT_LIST_HEAD(&node->node);
 290                 node->handle = phandle;
 291                 list_add(&node->node, &device_list);
 292
 293                 status = acpi_get_parent(phandle, &phandle);
 294                 if (ACPI_FAILURE(status))
 295                         goto out;
 296         }
 297
 298         root = acpi_pci_find_root(phandle);
 299         if (!root)
 300                 goto out;
 301
 302         pbus = root->bus;
 303
 304         /*
 305          * Now, walk back down the PCI device tree until we return to our
 306          * original handle. Assumes that everything between the PCI root
 307          * bridge and the device we're looking for must be a P2P bridge.
 308          */
 309         list_for_each_entry(node, &device_list, node) {
 310                 acpi_handle hnd = node->handle;
 311                 status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
 312                 if (ACPI_FAILURE(status))
 313                         goto out;
 314                 dev = (adr >> 16) & 0xffff;
 315                 fn  = adr & 0xffff;
 316
 317                 pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
 318                 if (!pdev || hnd == handle)
 319                         break;
 320
 321                 pbus = pdev->subordinate;
 322                 pci_dev_put(pdev);
 323
 324                 /*
 325                  * This function may be called for a non-PCI device that has a
 326                  * PCI parent (eg. a disk under a PCI SATA controller).  In that
 327                  * case pdev->subordinate will be NULL for the parent.
 328                  */
 329                 if (!pbus) {
 330                         dev_dbg(&pdev->dev, "Not a PCI-to-PCI bridge\n");
 331                         pdev = NULL;
 332                         break;
 333                 }
 334         }
 335 out:
 336         list_for_each_entry_safe(node, tmp, &device_list, node)
 337                 kfree(node);
 338
 339         return pdev;
 340 }
 341 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
 342
 343 /**
 344  * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
 345  * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
 346  * @mask: Mask of _OSC bits to request control of, place to store control mask.
 347  * @req: Mask of _OSC bits the control of is essential to the caller.
 348  *
 349  * Run _OSC query for @mask and if that is successful, compare the returned
 350  * mask of control bits with @req.  If all of the @req bits are set in the
 351  * returned mask, run _OSC request for it.
 352  *
 353  * The variable at the @mask address may be modified regardless of whether or
 354  * not the function returns success.  On success it will contain the mask of
 355  * _OSC bits the BIOS has granted control of, but its contents are meaningless
 356  * on failure.
 357  **/
 358 acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
 359 {
 360         struct acpi_pci_root *root;
 361         acpi_status status = AE_OK;
 362         u32 ctrl, capbuf[3];
 363
 364         if (!mask)
 365                 return AE_BAD_PARAMETER;
 366
 367         ctrl = *mask & OSC_PCI_CONTROL_MASKS;
 368         if ((ctrl & req) != req)
 369                 return AE_TYPE;
 370
 371         root = acpi_pci_find_root(handle);
 372         if (!root)
 373                 return AE_NOT_EXIST;
 374
 375         mutex_lock(&osc_lock);
 376
 377         *mask = ctrl | root->osc_control_set;
 378         /* No need to evaluate _OSC if the control was already granted. */
 379         if ((root->osc_control_set & ctrl) == ctrl)
 380                 goto out;
 381
 382         /* Need to check the available controls bits before requesting them. */
 383         while (*mask) {
 384                 status = acpi_pci_query_osc(root, root->osc_support_set, mask);
 385                 if (ACPI_FAILURE(status))
 386                         goto out;
 387                 if (ctrl == *mask)
 388                         break;
 389                 decode_osc_control(root, "platform does not support",
 390                                    ctrl & ~(*mask));
 391                 ctrl = *mask;
 392         }
 393
 394         if ((ctrl & req) != req) {
 395                 decode_osc_control(root, "not requesting control; platform does not support",
 396                                    req & ~(ctrl));
 397                 status = AE_SUPPORT;
 398                 goto out;
 399         }
 400
 401         capbuf[OSC_QUERY_DWORD] = 0;
 402         capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set;
 403         capbuf[OSC_CONTROL_DWORD] = ctrl;
 404         status = acpi_pci_run_osc(handle, capbuf, mask);
 405         if (ACPI_SUCCESS(status))
 406                 root->osc_control_set = *mask;
 407 out:
 408         mutex_unlock(&osc_lock);
 409         return status;
 410 }
 411 EXPORT_SYMBOL(acpi_pci_osc_control_set);
 412
 413 static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
 414                                  bool is_pcie)
 415 {
 416         u32 support, control, requested;
 417         acpi_status status;
 418         struct acpi_device *device = root->device;
 419         acpi_handle handle = device->handle;
 420
 421         /*
 422          * Apple always return failure on _OSC calls when _OSI("Darwin") has
 423          * been called successfully. We know the feature set supported by the
 424          * platform, so avoid calling _OSC at all
 425          */
 426         if (x86_apple_machine) {
 427                 root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;
 428                 decode_osc_control(root, "OS assumes control of",
 429                                    root->osc_control_set);
 430                 return;
 431         }
 432
 433         /*
 434          * All supported architectures that use ACPI have support for
 435          * PCI domains, so we indicate this in _OSC support capabilities.
 436          */
 437         support = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
 438         support |= OSC_PCI_HPX_TYPE_3_SUPPORT;
 439         if (pci_ext_cfg_avail())
 440                 support |= OSC_PCI_EXT_CONFIG_SUPPORT;
 441         if (pcie_aspm_support_enabled())
 442                 support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
 443         if (pci_msi_enabled())
 444                 support |= OSC_PCI_MSI_SUPPORT;
 445         if (IS_ENABLED(CONFIG_PCIE_EDR))
 446                 support |= OSC_PCI_EDR_SUPPORT;
 447
 448         decode_osc_support(root, "OS supports", support);
 449         status = acpi_pci_osc_support(root, support);
 450         if (ACPI_FAILURE(status)) {
 451                 *no_aspm = 1;
 452
 453                 /* _OSC is optional for PCI host bridges */
 454                 if ((status == AE_NOT_FOUND) && !is_pcie)
 455                         return;
 456
 457                 dev_info(&device->dev, "_OSC failed (%s)%s\n",
 458                          acpi_format_exception(status),
 459                          pcie_aspm_support_enabled() ? "; disabling ASPM" : "");
 460                 return;
 461         }
 462
 463         if (pcie_ports_disabled) {
 464                 dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
 465                 return;
 466         }
 467
 468         if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
 469                 decode_osc_support(root, "not requesting OS control; OS requires",
 470                                    ACPI_PCIE_REQ_SUPPORT);
 471                 return;
 472         }
 473
 474         control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
 475                 | OSC_PCI_EXPRESS_PME_CONTROL;
 476
 477         if (IS_ENABLED(CONFIG_PCIEASPM))
 478                 control |= OSC_PCI_EXPRESS_LTR_CONTROL;
 479
 480         if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
 481                 control |= OSC_PCI_EXPRESS_NATIVE_HP_CONTROL;
 482
 483         if (IS_ENABLED(CONFIG_HOTPLUG_PCI_SHPC))
 484                 control |= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
 485
 486         if (pci_aer_available())
 487                 control |= OSC_PCI_EXPRESS_AER_CONTROL;
 488
 489         /*
 490          * Per the Downstream Port Containment Related Enhancements ECN to
 491          * the PCI Firmware Spec, r3.2, sec 4.5.1, table 4-5,
 492          * OSC_PCI_EXPRESS_DPC_CONTROL indicates the OS supports both DPC
 493          * and EDR.
 494          */
 495         if (IS_ENABLED(CONFIG_PCIE_DPC) && IS_ENABLED(CONFIG_PCIE_EDR))
 496                 control |= OSC_PCI_EXPRESS_DPC_CONTROL;
 497
 498         requested = control;
 499         status = acpi_pci_osc_control_set(handle, &control,
 500                                           OSC_PCI_EXPRESS_CAPABILITY_CONTROL);
 501         if (ACPI_SUCCESS(status)) {
 502                 decode_osc_control(root, "OS now controls", control);
 503                 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 504                         /*
 505                          * We have ASPM control, but the FADT indicates that
 506                          * it's unsupported. Leave existing configuration
 507                          * intact and prevent the OS from touching it.
 508                          */
 509                         dev_info(&device->dev, "FADT indicates ASPM is unsupported, using BIOS configuration\n");
 510                         *no_aspm = 1;
 511                 }
 512         } else {
 513                 decode_osc_control(root, "OS requested", requested);
 514                 decode_osc_control(root, "platform willing to grant", control);
 515                 dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
 516                         acpi_format_exception(status));
 517
 518                 /*
 519                  * We want to disable ASPM here, but aspm_disabled
 520                  * needs to remain in its state from boot so that we
 521                  * properly handle PCIe 1.1 devices.  So we set this
 522                  * flag here, to defer the action until after the ACPI
 523                  * root scan.
 524                  */
 525                 *no_aspm = 1;
 526         }
 527 }
 528
 529 static int acpi_pci_root_add(struct acpi_device *device,
 530                              const struct acpi_device_id *not_used)
 531 {
 532         unsigned long long segment, bus;
 533         acpi_status status;
 534         int result;
 535         struct acpi_pci_root *root;
 536         acpi_handle handle = device->handle;
 537         int no_aspm = 0;
 538         bool hotadd = system_state == SYSTEM_RUNNING;
 539         bool is_pcie;
 540
 541         root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 542         if (!root)
 543                 return -ENOMEM;
 544
 545         segment = 0;
 546         status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL,
 547                                        &segment);
 548         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 549                 dev_err(&device->dev,  "can't evaluate _SEG\n");
 550                 result = -ENODEV;
 551                 goto end;
 552         }
 553
 554         /* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
 555         root->secondary.flags = IORESOURCE_BUS;
 556         status = try_get_root_bridge_busnr(handle, &root->secondary);
 557         if (ACPI_FAILURE(status)) {
 558                 /*
 559                  * We need both the start and end of the downstream bus range
 560                  * to interpret _CBA (MMCONFIG base address), so it really is
 561                  * supposed to be in _CRS.  If we don't find it there, all we
 562                  * can do is assume [_BBN-0xFF] or [0-0xFF].
 563                  */
 564                 root->secondary.end = 0xFF;
 565                 dev_warn(&device->dev,
 566                          FW_BUG "no secondary bus range in _CRS\n");
 567                 status = acpi_evaluate_integer(handle, METHOD_NAME__BBN,
 568                                                NULL, &bus);
 569                 if (ACPI_SUCCESS(status))
 570                         root->secondary.start = bus;
 571                 else if (status == AE_NOT_FOUND)
 572                         root->secondary.start = 0;
 573                 else {
 574                         dev_err(&device->dev, "can't evaluate _BBN\n");
 575                         result = -ENODEV;
 576                         goto end;
 577                 }
 578         }
 579
 580         root->device = device;
 581         root->segment = segment & 0xFFFF;
 582         strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
 583         strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 584         device->driver_data = root;
 585
 586         if (hotadd && dmar_device_add(handle)) {
 587                 result = -ENXIO;
 588                 goto end;
 589         }
 590
 591         pr_info(PREFIX "%s [%s] (domain %04x %pR)\n",
 592                acpi_device_name(device), acpi_device_bid(device),
 593                root->segment, &root->secondary);
 594
 595         root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
 596
 597         is_pcie = strcmp(acpi_device_hid(device), "PNP0A08") == 0;
 598         negotiate_os_control(root, &no_aspm, is_pcie);
 599
 600         /*
 601          * TBD: Need PCI interface for enumeration/configuration of roots.
 602          */
 603
 604         /*
 605          * Scan the Root Bridge
 606          * --------------------
 607          * Must do this prior to any attempt to bind the root device, as the
 608          * PCI namespace does not get created until this call is made (and
 609          * thus the root bridge's pci_dev does not exist).
 610          */
 611         root->bus = pci_acpi_scan_root(root);
 612         if (!root->bus) {
 613                 dev_err(&device->dev,
 614                         "Bus %04x:%02x not present in PCI namespace\n",
 615                         root->segment, (unsigned int)root->secondary.start);
 616                 device->driver_data = NULL;
 617                 result = -ENODEV;
 618                 goto remove_dmar;
 619         }
 620
 621         if (no_aspm)
 622                 pcie_no_aspm();
 623
 624         pci_acpi_add_bus_pm_notifier(device);
 625         device_set_wakeup_capable(root->bus->bridge, device->wakeup.flags.valid);
 626
 627         if (hotadd) {
 628                 pcibios_resource_survey_bus(root->bus);
 629                 pci_assign_unassigned_root_bus_resources(root->bus);
 630                 /*
 631                  * This is only called for the hotadd case. For the boot-time
 632                  * case, we need to wait until after PCI initialization in
 633                  * order to deal with IOAPICs mapped in on a PCI BAR.
 634                  *
 635                  * This is currently x86-specific, because acpi_ioapic_add()
 636                  * is an empty function without CONFIG_ACPI_HOTPLUG_IOAPIC.
 637                  * And CONFIG_ACPI_HOTPLUG_IOAPIC depends on CONFIG_X86_IO_APIC
 638                  * (see drivers/acpi/Kconfig).
 639                  */
 640                 acpi_ioapic_add(root->device->handle);
 641         }
 642
 643         pci_lock_rescan_remove();
 644         pci_bus_add_devices(root->bus);
 645         pci_unlock_rescan_remove();
 646         return 1;
 647
 648 remove_dmar:
 649         if (hotadd)
 650                 dmar_device_remove(handle);
 651 end:
 652         kfree(root);
 653         return result;
 654 }
 655
 656 static void acpi_pci_root_remove(struct acpi_device *device)
 657 {
 658         struct acpi_pci_root *root = acpi_driver_data(device);
 659
 660         pci_lock_rescan_remove();
 661
 662         pci_stop_root_bus(root->bus);
 663
 664         pci_ioapic_remove(root);
 665         device_set_wakeup_capable(root->bus->bridge, false);
 666         pci_acpi_remove_bus_pm_notifier(device);
 667
 668         pci_remove_root_bus(root->bus);
 669         WARN_ON(acpi_ioapic_remove(root));
 670
 671         dmar_device_remove(device->handle);
 672
 673         pci_unlock_rescan_remove();
 674
 675         kfree(root);
 676 }
 677
 678 /*
 679  * Following code to support acpi_pci_root_create() is copied from
 680  * arch/x86/pci/acpi.c and modified so it could be reused by x86, IA64
 681  * and ARM64.
 682  */
 683 static void acpi_pci_root_validate_resources(struct device *dev,
 684                                              struct list_head *resources,
 685                                              unsigned long type)
 686 {
 687         LIST_HEAD(list);
 688         struct resource *res1, *res2, *root = NULL;
 689         struct resource_entry *tmp, *entry, *entry2;
 690
 691         BUG_ON((type & (IORESOURCE_MEM | IORESOURCE_IO)) == 0);
 692         root = (type & IORESOURCE_MEM) ? &iomem_resource : &ioport_resource;
 693
 694         list_splice_init(resources, &list);
 695         resource_list_for_each_entry_safe(entry, tmp, &list) {
 696                 bool free = false;
 697                 resource_size_t end;
 698
 699                 res1 = entry->res;
 700                 if (!(res1->flags & type))
 701                         goto next;
 702
 703                 /* Exclude non-addressable range or non-addressable portion */
 704                 end = min(res1->end, root->end);
 705                 if (end <= res1->start) {
 706                         dev_info(dev, "host bridge window %pR (ignored, not CPU addressable)\n",
 707                                  res1);
 708                         free = true;
 709                         goto next;
 710                 } else if (res1->end != end) {
 711                         dev_info(dev, "host bridge window %pR ([%#llx-%#llx] ignored, not CPU addressable)\n",
 712                                  res1, (unsigned long long)end + 1,
 713                                  (unsigned long long)res1->end);
 714                         res1->end = end;
 715                 }
 716
 717                 resource_list_for_each_entry(entry2, resources) {
 718                         res2 = entry2->res;
 719                         if (!(res2->flags & type))
 720                                 continue;
 721
 722                         /*
 723                          * I don't like throwing away windows because then
 724                          * our resources no longer match the ACPI _CRS, but
 725                          * the kernel resource tree doesn't allow overlaps.
 726                          */
 727                         if (resource_overlaps(res1, res2)) {
 728                                 res2->start = min(res1->start, res2->start);
 729                                 res2->end = max(res1->end, res2->end);
 730                                 dev_info(dev, "host bridge window expanded to %pR; %pR ignored\n",
 731                                          res2, res1);
 732                                 free = true;
 733                                 goto next;
 734                         }
 735                 }
 736
 737 next:
 738                 resource_list_del(entry);
 739                 if (free)
 740                         resource_list_free_entry(entry);
 741                 else
 742                         resource_list_add_tail(entry, resources);
 743         }
 744 }
 745
 746 static void acpi_pci_root_remap_iospace(struct fwnode_handle *fwnode,
 747                         struct resource_entry *entry)
 748 {
 749 #ifdef PCI_IOBASE
 750         struct resource *res = entry->res;
 751         resource_size_t cpu_addr = res->start;
 752         resource_size_t pci_addr = cpu_addr - entry->offset;
 753         resource_size_t length = resource_size(res);
 754         unsigned long port;
 755
 756         if (pci_register_io_range(fwnode, cpu_addr, length))
 757                 goto err;
 758
 759         port = pci_address_to_pio(cpu_addr);
 760         if (port == (unsigned long)-1)
 761                 goto err;
 762
 763         res->start = port;
 764         res->end = port + length - 1;
 765         entry->offset = port - pci_addr;
 766
 767         if (pci_remap_iospace(res, cpu_addr) < 0)
 768                 goto err;
 769
 770         pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res);
 771         return;
 772 err:
 773         res->flags |= IORESOURCE_DISABLED;
 774 #endif
 775 }
 776
 777 int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
 778 {
 779         int ret;
 780         struct list_head *list = &info->resources;
 781         struct acpi_device *device = info->bridge;
 782         struct resource_entry *entry, *tmp;
 783         unsigned long flags;
 784
 785         flags = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_MEM_8AND16BIT;
 786         ret = acpi_dev_get_resources(device, list,
 787                                      acpi_dev_filter_resource_type_cb,
 788                                      (void *)flags);
 789         if (ret < 0)
 790                 dev_warn(&device->dev,
 791                          "failed to parse _CRS method, error code %d\n", ret);
 792         else if (ret == 0)
 793                 dev_dbg(&device->dev,
 794                         "no IO and memory resources present in _CRS\n");
 795         else {
 796                 resource_list_for_each_entry_safe(entry, tmp, list) {
 797                         if (entry->res->flags & IORESOURCE_IO)
 798                                 acpi_pci_root_remap_iospace(&device->fwnode,
 799                                                 entry);
 800
 801                         if (entry->res->flags & IORESOURCE_DISABLED)
 802                                 resource_list_destroy_entry(entry);
 803                         else
 804                                 entry->res->name = info->name;
 805                 }
 806                 acpi_pci_root_validate_resources(&device->dev, list,
 807                                                  IORESOURCE_MEM);
 808                 acpi_pci_root_validate_resources(&device->dev, list,
 809                                                  IORESOURCE_IO);
 810         }
 811
 812         return ret;
 813 }
 814
 815 static void pci_acpi_root_add_resources(struct acpi_pci_root_info *info)
 816 {
 817         struct resource_entry *entry, *tmp;
 818         struct resource *res, *conflict, *root = NULL;
 819
 820         resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
 821                 res = entry->res;
 822                 if (res->flags & IORESOURCE_MEM)
 823                         root = &iomem_resource;
 824                 else if (res->flags & IORESOURCE_IO)
 825                         root = &ioport_resource;
 826                 else
 827                         continue;
 828
 829                 /*
 830                  * Some legacy x86 host bridge drivers use iomem_resource and
 831                  * ioport_resource as default resource pool, skip it.
 832                  */
 833                 if (res == root)
 834                         continue;
 835
 836                 conflict = insert_resource_conflict(root, res);
 837                 if (conflict) {
 838                         dev_info(&info->bridge->dev,
 839                                  "ignoring host bridge window %pR (conflicts with %s %pR)\n",
 840                                  res, conflict->name, conflict);
 841                         resource_list_destroy_entry(entry);
 842                 }
 843         }
 844 }
 845
 846 static void __acpi_pci_root_release_info(struct acpi_pci_root_info *info)
 847 {
 848         struct resource *res;
 849         struct resource_entry *entry, *tmp;
 850
 851         if (!info)
 852                 return;
 853
 854         resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
 855                 res = entry->res;
 856                 if (res->parent &&
 857                     (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
 858                         release_resource(res);
 859                 resource_list_destroy_entry(entry);
 860         }
 861
 862         info->ops->release_info(info);
 863 }
 864
 865 static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
 866 {
 867         struct resource *res;
 868         struct resource_entry *entry;
 869
 870         resource_list_for_each_entry(entry, &bridge->windows) {
 871                 res = entry->res;
 872                 if (res->flags & IORESOURCE_IO)
 873                         pci_unmap_iospace(res);
 874                 if (res->parent &&
 875                     (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
 876                         release_resource(res);
 877         }
 878         __acpi_pci_root_release_info(bridge->release_data);
 879 }
 880
 881 struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
 882                                      struct acpi_pci_root_ops *ops,
 883                                      struct acpi_pci_root_info *info,
 884                                      void *sysdata)
 885 {
 886         int ret, busnum = root->secondary.start;
 887         struct acpi_device *device = root->device;
 888         int node = acpi_get_node(device->handle);
 889         struct pci_bus *bus;
 890         struct pci_host_bridge *host_bridge;
 891         union acpi_object *obj;
 892
 893         info->root = root;
 894         info->bridge = device;
 895         info->ops = ops;
 896         INIT_LIST_HEAD(&info->resources);
 897         snprintf(info->name, sizeof(info->name), "PCI Bus %04x:%02x",
 898                  root->segment, busnum);
 899
 900         if (ops->init_info && ops->init_info(info))
 901                 goto out_release_info;
 902         if (ops->prepare_resources)
 903                 ret = ops->prepare_resources(info);
 904         else
 905                 ret = acpi_pci_probe_root_resources(info);
 906         if (ret < 0)
 907                 goto out_release_info;
 908
 909         pci_acpi_root_add_resources(info);
 910         pci_add_resource(&info->resources, &root->secondary);
 911         bus = pci_create_root_bus(NULL, busnum, ops->pci_ops,
 912                                   sysdata, &info->resources);
 913         if (!bus)
 914                 goto out_release_info;
 915
 916         host_bridge = to_pci_host_bridge(bus->bridge);
 917         if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
 918                 host_bridge->native_pcie_hotplug = 0;
 919         if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL))
 920                 host_bridge->native_shpc_hotplug = 0;
 921         if (!(root->osc_control_set & OSC_PCI_EXPRESS_AER_CONTROL))
 922                 host_bridge->native_aer = 0;
 923         if (!(root->osc_control_set & OSC_PCI_EXPRESS_PME_CONTROL))
 924                 host_bridge->native_pme = 0;
 925         if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL))
 926                 host_bridge->native_ltr = 0;
 927         if (!(root->osc_control_set & OSC_PCI_EXPRESS_DPC_CONTROL))
 928                 host_bridge->native_dpc = 0;
 929
 930         /*
 931          * Evaluate the "PCI Boot Configuration" _DSM Function.  If it
 932          * exists and returns 0, we must preserve any PCI resource
 933          * assignments made by firmware for this host bridge.
 934          */
 935         obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 1,
 936                                 DSM_PCI_PRESERVE_BOOT_CONFIG, NULL);
 937         if (obj && obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 0)
 938                 host_bridge->preserve_config = 1;
 939         ACPI_FREE(obj);
 940
 941         pci_scan_child_bus(bus);
 942         pci_set_host_bridge_release(host_bridge, acpi_pci_root_release_info,
 943                                     info);
 944         if (node != NUMA_NO_NODE)
 945                 dev_printk(KERN_DEBUG, &bus->dev, "on NUMA node %d\n", node);
 946         return bus;
 947
 948 out_release_info:
 949         __acpi_pci_root_release_info(info);
 950         return NULL;
 951 }
 952
 953 void __init acpi_pci_root_init(void)
 954 {
 955         acpi_hest_init();
 956         if (acpi_pci_disabled)
 957                 return;
 958
 959         pci_acpi_crs_quirks();
 960         acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root");
 961 }