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 <[email protected]>
   6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]>
   7  */
   8
   9 #define pr_fmt(fmt) "ACPI: " fmt
  10
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/types.h>
  15 #include <linux/mutex.h>
  16 #include <linux/pm.h>
  17 #include <linux/pm_runtime.h>
  18 #include <linux/pci.h>
  19 #include <linux/pci-acpi.h>
  20 #include <linux/dmar.h>
  21 #include <linux/acpi.h>
  22 #include <linux/slab.h>
  23 #include <linux/dmi.h>
  24 #include <linux/platform_data/x86/apple.h>
  25 #include "internal.h"
  26
  27 #define ACPI_PCI_ROOT_CLASS             "pci_bridge"
  28 #define ACPI_PCI_ROOT_DEVICE_NAME       "PCI Root Bridge"
  29 static int acpi_pci_root_add(struct acpi_device *device,
  30                              const struct acpi_device_id *not_used);
  31 static void acpi_pci_root_remove(struct acpi_device *device);
  32
  33 static int acpi_pci_root_scan_dependent(struct acpi_device *adev)
  34 {
  35         acpiphp_check_host_bridge(adev);
  36         return 0;
  37 }
  38
  39 #define ACPI_PCIE_REQ_SUPPORT (OSC_PCI_EXT_CONFIG_SUPPORT \
  40                                 | OSC_PCI_ASPM_SUPPORT \
  41                                 | OSC_PCI_CLOCK_PM_SUPPORT \
  42                                 | OSC_PCI_MSI_SUPPORT)
  43
  44 static const struct acpi_device_id root_device_ids[] = {
  45         {"PNP0A03", 0},
  46         {"", 0},
  47 };
  48
  49 static struct acpi_scan_handler pci_root_handler = {
  50         .ids = root_device_ids,
  51         .attach = acpi_pci_root_add,
  52         .detach = acpi_pci_root_remove,
  53         .hotplug = {
  54                 .enabled = true,
  55                 .scan_dependent = acpi_pci_root_scan_dependent,
  56         },
  57 };
  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         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
  69         int ret;
  70
  71         if (!device)
  72                 return 0;
  73
  74         ret = acpi_match_device_ids(device, root_device_ids);
  75         if (ret)
  76                 return 0;
  77         else
  78                 return 1;
  79 }
  80 EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
  81
  82 static acpi_status
  83 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
  84 {
  85         struct resource *res = data;
  86         struct acpi_resource_address64 address;
  87         acpi_status status;
  88
  89         status = acpi_resource_to_address64(resource, &address);
  90         if (ACPI_FAILURE(status))
  91                 return AE_OK;
  92
  93         if ((address.address.address_length > 0) &&
  94             (address.resource_type == ACPI_BUS_NUMBER_RANGE)) {
  95                 res->start = address.address.minimum;
  96                 res->end = address.address.minimum + address.address.address_length - 1;
  97         }
  98
  99         return AE_OK;
 100 }
 101
 102 static acpi_status try_get_root_bridge_busnr(acpi_handle handle,
 103                                              struct resource *res)
 104 {
 105         acpi_status status;
 106
 107         res->start = -1;
 108         status =
 109             acpi_walk_resources(handle, METHOD_NAME__CRS,
 110                                 get_root_bridge_busnr_callback, res);
 111         if (ACPI_FAILURE(status))
 112                 return status;
 113         if (res->start == -1)
 114                 return AE_ERROR;
 115         return AE_OK;
 116 }
 117
 118 struct pci_osc_bit_struct {
 119         u32 bit;
 120         char *desc;
 121 };
 122
 123 static struct pci_osc_bit_struct pci_osc_support_bit[] = {
 124         { OSC_PCI_EXT_CONFIG_SUPPORT, "ExtendedConfig" },
 125         { OSC_PCI_ASPM_SUPPORT, "ASPM" },
 126         { OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" },
 127         { OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" },
 128         { OSC_PCI_MSI_SUPPORT, "MSI" },
 129         { OSC_PCI_EDR_SUPPORT, "EDR" },
 130         { OSC_PCI_HPX_TYPE_3_SUPPORT, "HPX-Type3" },
 131 };
 132
 133 static struct pci_osc_bit_struct pci_osc_control_bit[] = {
 134         { OSC_PCI_EXPRESS_NATIVE_HP_CONTROL, "PCIeHotplug" },
 135         { OSC_PCI_SHPC_NATIVE_HP_CONTROL, "SHPCHotplug" },
 136         { OSC_PCI_EXPRESS_PME_CONTROL, "PME" },
 137         { OSC_PCI_EXPRESS_AER_CONTROL, "AER" },
 138         { OSC_PCI_EXPRESS_CAPABILITY_CONTROL, "PCIeCapability" },
 139         { OSC_PCI_EXPRESS_LTR_CONTROL, "LTR" },
 140         { OSC_PCI_EXPRESS_DPC_CONTROL, "DPC" },
 141 };
 142
 143 static struct pci_osc_bit_struct cxl_osc_support_bit[] = {
 144         { OSC_CXL_1_1_PORT_REG_ACCESS_SUPPORT, "CXL11PortRegAccess" },
 145         { OSC_CXL_2_0_PORT_DEV_REG_ACCESS_SUPPORT, "CXL20PortDevRegAccess" },
 146         { OSC_CXL_PROTOCOL_ERR_REPORTING_SUPPORT, "CXLProtocolErrorReporting" },
 147         { OSC_CXL_NATIVE_HP_SUPPORT, "CXLNativeHotPlug" },
 148 };
 149
 150 static struct pci_osc_bit_struct cxl_osc_control_bit[] = {
 151         { OSC_CXL_ERROR_REPORTING_CONTROL, "CXLMemErrorReporting" },
 152 };
 153
 154 static void decode_osc_bits(struct acpi_pci_root *root, char *msg, u32 word,
 155                             struct pci_osc_bit_struct *table, int size)
 156 {
 157         char buf[80];
 158         int i, len = 0;
 159         struct pci_osc_bit_struct *entry;
 160
 161         buf[0] = '\0';
 162         for (i = 0, entry = table; i < size; i++, entry++)
 163                 if (word & entry->bit)
 164                         len += scnprintf(buf + len, sizeof(buf) - len, "%s%s",
 165                                         len ? " " : "", entry->desc);
 166
 167         dev_info(&root->device->dev, "_OSC: %s [%s]\n", msg, buf);
 168 }
 169
 170 static void decode_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
 171 {
 172         decode_osc_bits(root, msg, word, pci_osc_support_bit,
 173                         ARRAY_SIZE(pci_osc_support_bit));
 174 }
 175
 176 static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
 177 {
 178         decode_osc_bits(root, msg, word, pci_osc_control_bit,
 179                         ARRAY_SIZE(pci_osc_control_bit));
 180 }
 181
 182 static void decode_cxl_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
 183 {
 184         decode_osc_bits(root, msg, word, cxl_osc_support_bit,
 185                         ARRAY_SIZE(cxl_osc_support_bit));
 186 }
 187
 188 static void decode_cxl_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
 189 {
 190         decode_osc_bits(root, msg, word, cxl_osc_control_bit,
 191                         ARRAY_SIZE(cxl_osc_control_bit));
 192 }
 193
 194 static inline bool is_pcie(struct acpi_pci_root *root)
 195 {
 196         return root->bridge_type == ACPI_BRIDGE_TYPE_PCIE;
 197 }
 198
 199 static inline bool is_cxl(struct acpi_pci_root *root)
 200 {
 201         return root->bridge_type == ACPI_BRIDGE_TYPE_CXL;
 202 }
 203
 204 static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
 205 static u8 cxl_osc_uuid_str[] = "68F2D50B-C469-4d8A-BD3D-941A103FD3FC";
 206
 207 static char *to_uuid(struct acpi_pci_root *root)
 208 {
 209         if (is_cxl(root))
 210                 return cxl_osc_uuid_str;
 211         return pci_osc_uuid_str;
 212 }
 213
 214 static int cap_length(struct acpi_pci_root *root)
 215 {
 216         if (is_cxl(root))
 217                 return sizeof(u32) * OSC_CXL_CAPABILITY_DWORDS;
 218         return sizeof(u32) * OSC_PCI_CAPABILITY_DWORDS;
 219 }
 220
 221 static acpi_status acpi_pci_run_osc(struct acpi_pci_root *root,
 222                                     const u32 *capbuf, u32 *pci_control,
 223                                     u32 *cxl_control)
 224 {
 225         struct acpi_osc_context context = {
 226                 .uuid_str = to_uuid(root),
 227                 .rev = 1,
 228                 .cap.length = cap_length(root),
 229                 .cap.pointer = (void *)capbuf,
 230         };
 231         acpi_status status;
 232
 233         status = acpi_run_osc(root->device->handle, &context);
 234         if (ACPI_SUCCESS(status)) {
 235                 *pci_control = acpi_osc_ctx_get_pci_control(&context);
 236                 if (is_cxl(root))
 237                         *cxl_control = acpi_osc_ctx_get_cxl_control(&context);
 238                 kfree(context.ret.pointer);
 239         }
 240         return status;
 241 }
 242
 243 static acpi_status acpi_pci_query_osc(struct acpi_pci_root *root, u32 support,
 244                                       u32 *control, u32 cxl_support,
 245                                       u32 *cxl_control)
 246 {
 247         acpi_status status;
 248         u32 pci_result, cxl_result, capbuf[OSC_CXL_CAPABILITY_DWORDS];
 249
 250         support |= root->osc_support_set;
 251
 252         capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
 253         capbuf[OSC_SUPPORT_DWORD] = support;
 254         capbuf[OSC_CONTROL_DWORD] = *control | root->osc_control_set;
 255
 256         if (is_cxl(root)) {
 257                 cxl_support |= root->osc_ext_support_set;
 258                 capbuf[OSC_EXT_SUPPORT_DWORD] = cxl_support;
 259                 capbuf[OSC_EXT_CONTROL_DWORD] = *cxl_control | root->osc_ext_control_set;
 260         }
 261
 262 retry:
 263         status = acpi_pci_run_osc(root, capbuf, &pci_result, &cxl_result);
 264         if (ACPI_SUCCESS(status)) {
 265                 root->osc_support_set = support;
 266                 *control = pci_result;
 267                 if (is_cxl(root)) {
 268                         root->osc_ext_support_set = cxl_support;
 269                         *cxl_control = cxl_result;
 270                 }
 271         } else if (is_cxl(root)) {
 272                 /*
 273                  * CXL _OSC is optional on CXL 1.1 hosts. Fall back to PCIe _OSC
 274                  * upon any failure using CXL _OSC.
 275                  */
 276                 root->bridge_type = ACPI_BRIDGE_TYPE_PCIE;
 277                 goto retry;
 278         }
 279         return status;
 280 }
 281
 282 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
 283 {
 284         struct acpi_device *device = acpi_fetch_acpi_dev(handle);
 285         struct acpi_pci_root *root;
 286
 287         if (!device || acpi_match_device_ids(device, root_device_ids))
 288                 return NULL;
 289
 290         root = acpi_driver_data(device);
 291
 292         return root;
 293 }
 294 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
 295
 296 /**
 297  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
 298  * @handle: the handle in question
 299  *
 300  * Given an ACPI CA handle, the desired PCI device is located in the
 301  * list of PCI devices.
 302  *
 303  * If the device is found, its reference count is increased and this
 304  * function returns a pointer to its data structure.  The caller must
 305  * decrement the reference count by calling pci_dev_put().
 306  * If no device is found, %NULL is returned.
 307  */
 308 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
 309 {
 310         struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
 311         struct acpi_device_physical_node *pn;
 312         struct pci_dev *pci_dev = NULL;
 313
 314         if (!adev)
 315                 return NULL;
 316
 317         mutex_lock(&adev->physical_node_lock);
 318
 319         list_for_each_entry(pn, &adev->physical_node_list, node) {
 320                 if (dev_is_pci(pn->dev)) {
 321                         get_device(pn->dev);
 322                         pci_dev = to_pci_dev(pn->dev);
 323                         break;
 324                 }
 325         }
 326
 327         mutex_unlock(&adev->physical_node_lock);
 328
 329         return pci_dev;
 330 }
 331 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
 332
 333 /**
 334  * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
 335  * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
 336  * @mask: Mask of _OSC bits to request control of, place to store control mask.
 337  * @support: _OSC supported capability.
 338  * @cxl_mask: Mask of CXL _OSC control bits, place to store control mask.
 339  * @cxl_support: CXL _OSC supported capability.
 340  *
 341  * Run _OSC query for @mask and if that is successful, compare the returned
 342  * mask of control bits with @req.  If all of the @req bits are set in the
 343  * returned mask, run _OSC request for it.
 344  *
 345  * The variable at the @mask address may be modified regardless of whether or
 346  * not the function returns success.  On success it will contain the mask of
 347  * _OSC bits the BIOS has granted control of, but its contents are meaningless
 348  * on failure.
 349  **/
 350 static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask,
 351                                             u32 support, u32 *cxl_mask,
 352                                             u32 cxl_support)
 353 {
 354         u32 req = OSC_PCI_EXPRESS_CAPABILITY_CONTROL;
 355         struct acpi_pci_root *root;
 356         acpi_status status;
 357         u32 ctrl, cxl_ctrl = 0, capbuf[OSC_CXL_CAPABILITY_DWORDS];
 358
 359         if (!mask)
 360                 return AE_BAD_PARAMETER;
 361
 362         root = acpi_pci_find_root(handle);
 363         if (!root)
 364                 return AE_NOT_EXIST;
 365
 366         ctrl   = *mask;
 367         *mask |= root->osc_control_set;
 368
 369         if (is_cxl(root)) {
 370                 cxl_ctrl = *cxl_mask;
 371                 *cxl_mask |= root->osc_ext_control_set;
 372         }
 373
 374         /* Need to check the available controls bits before requesting them. */
 375         do {
 376                 u32 pci_missing = 0, cxl_missing = 0;
 377
 378                 status = acpi_pci_query_osc(root, support, mask, cxl_support,
 379                                             cxl_mask);
 380                 if (ACPI_FAILURE(status))
 381                         return status;
 382                 if (is_cxl(root)) {
 383                         if (ctrl == *mask && cxl_ctrl == *cxl_mask)
 384                                 break;
 385                         pci_missing = ctrl & ~(*mask);
 386                         cxl_missing = cxl_ctrl & ~(*cxl_mask);
 387                 } else {
 388                         if (ctrl == *mask)
 389                                 break;
 390                         pci_missing = ctrl & ~(*mask);
 391                 }
 392                 if (pci_missing)
 393                         decode_osc_control(root, "platform does not support",
 394                                            pci_missing);
 395                 if (cxl_missing)
 396                         decode_cxl_osc_control(root, "CXL platform does not support",
 397                                            cxl_missing);
 398                 ctrl = *mask;
 399                 cxl_ctrl = *cxl_mask;
 400         } while (*mask || *cxl_mask);
 401
 402         /* No need to request _OSC if the control was already granted. */
 403         if ((root->osc_control_set & ctrl) == ctrl &&
 404             (root->osc_ext_control_set & cxl_ctrl) == cxl_ctrl)
 405                 return AE_OK;
 406
 407         if ((ctrl & req) != req) {
 408                 decode_osc_control(root, "not requesting control; platform does not support",
 409                                    req & ~(ctrl));
 410                 return AE_SUPPORT;
 411         }
 412
 413         capbuf[OSC_QUERY_DWORD] = 0;
 414         capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set;
 415         capbuf[OSC_CONTROL_DWORD] = ctrl;
 416         if (is_cxl(root)) {
 417                 capbuf[OSC_EXT_SUPPORT_DWORD] = root->osc_ext_support_set;
 418                 capbuf[OSC_EXT_CONTROL_DWORD] = cxl_ctrl;
 419         }
 420
 421         status = acpi_pci_run_osc(root, capbuf, mask, cxl_mask);
 422         if (ACPI_FAILURE(status))
 423                 return status;
 424
 425         root->osc_control_set = *mask;
 426         root->osc_ext_control_set = *cxl_mask;
 427         return AE_OK;
 428 }
 429
 430 static u32 calculate_support(void)
 431 {
 432         u32 support;
 433
 434         /*
 435          * All supported architectures that use ACPI have support for
 436          * PCI domains, so we indicate this in _OSC support capabilities.
 437          */
 438         support = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
 439         support |= OSC_PCI_HPX_TYPE_3_SUPPORT;
 440         if (pci_ext_cfg_avail())
 441                 support |= OSC_PCI_EXT_CONFIG_SUPPORT;
 442         if (pcie_aspm_support_enabled())
 443                 support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
 444         if (pci_msi_enabled())
 445                 support |= OSC_PCI_MSI_SUPPORT;
 446         if (IS_ENABLED(CONFIG_PCIE_EDR))
 447                 support |= OSC_PCI_EDR_SUPPORT;
 448
 449         return support;
 450 }
 451
 452 /*
 453  * Background on hotplug support, and making it depend on only
 454  * CONFIG_HOTPLUG_PCI_PCIE vs. also considering CONFIG_MEMORY_HOTPLUG:
 455  *
 456  * CONFIG_ACPI_HOTPLUG_MEMORY does depend on CONFIG_MEMORY_HOTPLUG, but
 457  * there is no existing _OSC for memory hotplug support. The reason is that
 458  * ACPI memory hotplug requires the OS to acknowledge / coordinate with
 459  * memory plug events via a scan handler. On the CXL side the equivalent
 460  * would be if Linux supported the Mechanical Retention Lock [1], or
 461  * otherwise had some coordination for the driver of a PCI device
 462  * undergoing hotplug to be consulted on whether the hotplug should
 463  * proceed or not.
 464  *
 465  * The concern is that if Linux says no to supporting CXL hotplug then
 466  * the BIOS may say no to giving the OS hotplug control of any other PCIe
 467  * device. So the question here is not whether hotplug is enabled, it's
 468  * whether it is handled natively by the at all OS, and if
 469  * CONFIG_HOTPLUG_PCI_PCIE is enabled then the answer is "yes".
 470  *
 471  * Otherwise, the plan for CXL coordinated remove, since the kernel does
 472  * not support blocking hotplug, is to require the memory device to be
 473  * disabled before hotplug is attempted. When CONFIG_MEMORY_HOTPLUG is
 474  * disabled that step will fail and the remove attempt cancelled by the
 475  * user. If that is not honored and the card is removed anyway then it
 476  * does not matter if CONFIG_MEMORY_HOTPLUG is enabled or not, it will
 477  * cause a crash and other badness.
 478  *
 479  * Therefore, just say yes to CXL hotplug and require removal to
 480  * be coordinated by userspace unless and until the kernel grows better
 481  * mechanisms for doing "managed" removal of devices in consultation with
 482  * the driver.
 483  *
 484  * [1]: https://lore.kernel.org/all/[email protected]/
 485  */
 486 static u32 calculate_cxl_support(void)
 487 {
 488         u32 support;
 489
 490         support = OSC_CXL_2_0_PORT_DEV_REG_ACCESS_SUPPORT;
 491         support |= OSC_CXL_1_1_PORT_REG_ACCESS_SUPPORT;
 492         if (pci_aer_available())
 493                 support |= OSC_CXL_PROTOCOL_ERR_REPORTING_SUPPORT;
 494         if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
 495                 support |= OSC_CXL_NATIVE_HP_SUPPORT;
 496
 497         return support;
 498 }
 499
 500 static u32 calculate_control(void)
 501 {
 502         u32 control;
 503
 504         control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
 505                 | OSC_PCI_EXPRESS_PME_CONTROL;
 506
 507         if (IS_ENABLED(CONFIG_PCIEASPM))
 508                 control |= OSC_PCI_EXPRESS_LTR_CONTROL;
 509
 510         if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
 511                 control |= OSC_PCI_EXPRESS_NATIVE_HP_CONTROL;
 512
 513         if (IS_ENABLED(CONFIG_HOTPLUG_PCI_SHPC))
 514                 control |= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
 515
 516         if (pci_aer_available())
 517                 control |= OSC_PCI_EXPRESS_AER_CONTROL;
 518
 519         /*
 520          * Per the Downstream Port Containment Related Enhancements ECN to
 521          * the PCI Firmware Spec, r3.2, sec 4.5.1, table 4-5,
 522          * OSC_PCI_EXPRESS_DPC_CONTROL indicates the OS supports both DPC
 523          * and EDR.
 524          */
 525         if (IS_ENABLED(CONFIG_PCIE_DPC) && IS_ENABLED(CONFIG_PCIE_EDR))
 526                 control |= OSC_PCI_EXPRESS_DPC_CONTROL;
 527
 528         return control;
 529 }
 530
 531 static u32 calculate_cxl_control(void)
 532 {
 533         u32 control = 0;
 534
 535         if (IS_ENABLED(CONFIG_MEMORY_FAILURE))
 536                 control |= OSC_CXL_ERROR_REPORTING_CONTROL;
 537
 538         return control;
 539 }
 540
 541 static bool os_control_query_checks(struct acpi_pci_root *root, u32 support)
 542 {
 543         struct acpi_device *device = root->device;
 544
 545         if (pcie_ports_disabled) {
 546                 dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
 547                 return false;
 548         }
 549
 550         if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
 551                 decode_osc_support(root, "not requesting OS control; OS requires",
 552                                    ACPI_PCIE_REQ_SUPPORT);
 553                 return false;
 554         }
 555
 556         return true;
 557 }
 558
 559 static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
 560 {
 561         u32 support, control = 0, requested = 0;
 562         u32 cxl_support = 0, cxl_control = 0, cxl_requested = 0;
 563         acpi_status status;
 564         struct acpi_device *device = root->device;
 565         acpi_handle handle = device->handle;
 566
 567         /*
 568          * Apple always return failure on _OSC calls when _OSI("Darwin") has
 569          * been called successfully. We know the feature set supported by the
 570          * platform, so avoid calling _OSC at all
 571          */
 572         if (x86_apple_machine) {
 573                 root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;
 574                 decode_osc_control(root, "OS assumes control of",
 575                                    root->osc_control_set);
 576                 return;
 577         }
 578
 579         support = calculate_support();
 580
 581         decode_osc_support(root, "OS supports", support);
 582
 583         if (os_control_query_checks(root, support))
 584                 requested = control = calculate_control();
 585
 586         if (is_cxl(root)) {
 587                 cxl_support = calculate_cxl_support();
 588                 decode_cxl_osc_support(root, "OS supports", cxl_support);
 589                 cxl_requested = cxl_control = calculate_cxl_control();
 590         }
 591
 592         status = acpi_pci_osc_control_set(handle, &control, support,
 593                                           &cxl_control, cxl_support);
 594         if (ACPI_SUCCESS(status)) {
 595                 if (control)
 596                         decode_osc_control(root, "OS now controls", control);
 597                 if (cxl_control)
 598                         decode_cxl_osc_control(root, "OS now controls",
 599                                            cxl_control);
 600
 601                 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 602                         /*
 603                          * We have ASPM control, but the FADT indicates that
 604                          * it's unsupported. Leave existing configuration
 605                          * intact and prevent the OS from touching it.
 606                          */
 607                         dev_info(&device->dev, "FADT indicates ASPM is unsupported, using BIOS configuration\n");
 608                         *no_aspm = 1;
 609                 }
 610         } else {
 611                 /*
 612                  * We want to disable ASPM here, but aspm_disabled
 613                  * needs to remain in its state from boot so that we
 614                  * properly handle PCIe 1.1 devices.  So we set this
 615                  * flag here, to defer the action until after the ACPI
 616                  * root scan.
 617                  */
 618                 *no_aspm = 1;
 619
 620                 /* _OSC is optional for PCI host bridges */
 621                 if (status == AE_NOT_FOUND && !is_pcie(root))
 622                         return;
 623
 624                 if (control) {
 625                         decode_osc_control(root, "OS requested", requested);
 626                         decode_osc_control(root, "platform willing to grant", control);
 627                 }
 628                 if (cxl_control) {
 629                         decode_cxl_osc_control(root, "OS requested", cxl_requested);
 630                         decode_cxl_osc_control(root, "platform willing to grant",
 631                                            cxl_control);
 632                 }
 633
 634                 dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n",
 635                          acpi_format_exception(status));
 636         }
 637 }
 638
 639 static int acpi_pci_root_add(struct acpi_device *device,
 640                              const struct acpi_device_id *not_used)
 641 {
 642         unsigned long long segment, bus;
 643         acpi_status status;
 644         int result;
 645         struct acpi_pci_root *root;
 646         acpi_handle handle = device->handle;
 647         int no_aspm = 0;
 648         bool hotadd = system_state == SYSTEM_RUNNING;
 649         const char *acpi_hid;
 650
 651         root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 652         if (!root)
 653                 return -ENOMEM;
 654
 655         segment = 0;
 656         status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL,
 657                                        &segment);
 658         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 659                 dev_err(&device->dev,  "can't evaluate _SEG\n");
 660                 result = -ENODEV;
 661                 goto end;
 662         }
 663
 664         /* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
 665         root->secondary.flags = IORESOURCE_BUS;
 666         status = try_get_root_bridge_busnr(handle, &root->secondary);
 667         if (ACPI_FAILURE(status)) {
 668                 /*
 669                  * We need both the start and end of the downstream bus range
 670                  * to interpret _CBA (MMCONFIG base address), so it really is
 671                  * supposed to be in _CRS.  If we don't find it there, all we
 672                  * can do is assume [_BBN-0xFF] or [0-0xFF].
 673                  */
 674                 root->secondary.end = 0xFF;
 675                 dev_warn(&device->dev,
 676                          FW_BUG "no secondary bus range in _CRS\n");
 677                 status = acpi_evaluate_integer(handle, METHOD_NAME__BBN,
 678                                                NULL, &bus);
 679                 if (ACPI_SUCCESS(status))
 680                         root->secondary.start = bus;
 681                 else if (status == AE_NOT_FOUND)
 682                         root->secondary.start = 0;
 683                 else {
 684                         dev_err(&device->dev, "can't evaluate _BBN\n");
 685                         result = -ENODEV;
 686                         goto end;
 687                 }
 688         }
 689
 690         root->device = device;
 691         root->segment = segment & 0xFFFF;
 692         strscpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
 693         strscpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 694         device->driver_data = root;
 695
 696         if (hotadd && dmar_device_add(handle)) {
 697                 result = -ENXIO;
 698                 goto end;
 699         }
 700
 701         pr_info("%s [%s] (domain %04x %pR)\n",
 702                acpi_device_name(device), acpi_device_bid(device),
 703                root->segment, &root->secondary);
 704
 705         root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
 706
 707         acpi_hid = acpi_device_hid(root->device);
 708         if (strcmp(acpi_hid, "PNP0A08") == 0)
 709                 root->bridge_type = ACPI_BRIDGE_TYPE_PCIE;
 710         else if (strcmp(acpi_hid, "ACPI0016") == 0)
 711                 root->bridge_type = ACPI_BRIDGE_TYPE_CXL;
 712         else
 713                 dev_dbg(&device->dev, "Assuming non-PCIe host bridge\n");
 714
 715         negotiate_os_control(root, &no_aspm);
 716
 717         /*
 718          * TBD: Need PCI interface for enumeration/configuration of roots.
 719          */
 720
 721         /*
 722          * Scan the Root Bridge
 723          * --------------------
 724          * Must do this prior to any attempt to bind the root device, as the
 725          * PCI namespace does not get created until this call is made (and
 726          * thus the root bridge's pci_dev does not exist).
 727          */
 728         root->bus = pci_acpi_scan_root(root);
 729         if (!root->bus) {
 730                 dev_err(&device->dev,
 731                         "Bus %04x:%02x not present in PCI namespace\n",
 732                         root->segment, (unsigned int)root->secondary.start);
 733                 device->driver_data = NULL;
 734                 result = -ENODEV;
 735                 goto remove_dmar;
 736         }
 737
 738         if (no_aspm)
 739                 pcie_no_aspm();
 740
 741         pci_acpi_add_bus_pm_notifier(device);
 742         device_set_wakeup_capable(root->bus->bridge, device->wakeup.flags.valid);
 743
 744         if (hotadd) {
 745                 pcibios_resource_survey_bus(root->bus);
 746                 pci_assign_unassigned_root_bus_resources(root->bus);
 747                 /*
 748                  * This is only called for the hotadd case. For the boot-time
 749                  * case, we need to wait until after PCI initialization in
 750                  * order to deal with IOAPICs mapped in on a PCI BAR.
 751                  *
 752                  * This is currently x86-specific, because acpi_ioapic_add()
 753                  * is an empty function without CONFIG_ACPI_HOTPLUG_IOAPIC.
 754                  * And CONFIG_ACPI_HOTPLUG_IOAPIC depends on CONFIG_X86_IO_APIC
 755                  * (see drivers/acpi/Kconfig).
 756                  */
 757                 acpi_ioapic_add(root->device->handle);
 758         }
 759
 760         pci_lock_rescan_remove();
 761         pci_bus_add_devices(root->bus);
 762         pci_unlock_rescan_remove();
 763         return 1;
 764
 765 remove_dmar:
 766         if (hotadd)
 767                 dmar_device_remove(handle);
 768 end:
 769         kfree(root);
 770         return result;
 771 }
 772
 773 static void acpi_pci_root_remove(struct acpi_device *device)
 774 {
 775         struct acpi_pci_root *root = acpi_driver_data(device);
 776
 777         pci_lock_rescan_remove();
 778
 779         pci_stop_root_bus(root->bus);
 780
 781         pci_ioapic_remove(root);
 782         device_set_wakeup_capable(root->bus->bridge, false);
 783         pci_acpi_remove_bus_pm_notifier(device);
 784
 785         pci_remove_root_bus(root->bus);
 786         WARN_ON(acpi_ioapic_remove(root));
 787
 788         dmar_device_remove(device->handle);
 789
 790         pci_unlock_rescan_remove();
 791
 792         kfree(root);
 793 }
 794
 795 /*
 796  * Following code to support acpi_pci_root_create() is copied from
 797  * arch/x86/pci/acpi.c and modified so it could be reused by x86, IA64
 798  * and ARM64.
 799  */
 800 static void acpi_pci_root_validate_resources(struct device *dev,
 801                                              struct list_head *resources,
 802                                              unsigned long type)
 803 {
 804         LIST_HEAD(list);
 805         struct resource *res1, *res2, *root = NULL;
 806         struct resource_entry *tmp, *entry, *entry2;
 807
 808         BUG_ON((type & (IORESOURCE_MEM | IORESOURCE_IO)) == 0);
 809         root = (type & IORESOURCE_MEM) ? &iomem_resource : &ioport_resource;
 810
 811         list_splice_init(resources, &list);
 812         resource_list_for_each_entry_safe(entry, tmp, &list) {
 813                 bool free = false;
 814                 resource_size_t end;
 815
 816                 res1 = entry->res;
 817                 if (!(res1->flags & type))
 818                         goto next;
 819
 820                 /* Exclude non-addressable range or non-addressable portion */
 821                 end = min(res1->end, root->end);
 822                 if (end <= res1->start) {
 823                         dev_info(dev, "host bridge window %pR (ignored, not CPU addressable)\n",
 824                                  res1);
 825                         free = true;
 826                         goto next;
 827                 } else if (res1->end != end) {
 828                         dev_info(dev, "host bridge window %pR ([%#llx-%#llx] ignored, not CPU addressable)\n",
 829                                  res1, (unsigned long long)end + 1,
 830                                  (unsigned long long)res1->end);
 831                         res1->end = end;
 832                 }
 833
 834                 resource_list_for_each_entry(entry2, resources) {
 835                         res2 = entry2->res;
 836                         if (!(res2->flags & type))
 837                                 continue;
 838
 839                         /*
 840                          * I don't like throwing away windows because then
 841                          * our resources no longer match the ACPI _CRS, but
 842                          * the kernel resource tree doesn't allow overlaps.
 843                          */
 844                         if (resource_union(res1, res2, res2)) {
 845                                 dev_info(dev, "host bridge window expanded to %pR; %pR ignored\n",
 846                                          res2, res1);
 847                                 free = true;
 848                                 goto next;
 849                         }
 850                 }
 851
 852 next:
 853                 resource_list_del(entry);
 854                 if (free)
 855                         resource_list_free_entry(entry);
 856                 else
 857                         resource_list_add_tail(entry, resources);
 858         }
 859 }
 860
 861 static void acpi_pci_root_remap_iospace(struct fwnode_handle *fwnode,
 862                         struct resource_entry *entry)
 863 {
 864 #ifdef PCI_IOBASE
 865         struct resource *res = entry->res;
 866         resource_size_t cpu_addr = res->start;
 867         resource_size_t pci_addr = cpu_addr - entry->offset;
 868         resource_size_t length = resource_size(res);
 869         unsigned long port;
 870
 871         if (pci_register_io_range(fwnode, cpu_addr, length))
 872                 goto err;
 873
 874         port = pci_address_to_pio(cpu_addr);
 875         if (port == (unsigned long)-1)
 876                 goto err;
 877
 878         res->start = port;
 879         res->end = port + length - 1;
 880         entry->offset = port - pci_addr;
 881
 882         if (pci_remap_iospace(res, cpu_addr) < 0)
 883                 goto err;
 884
 885         pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res);
 886         return;
 887 err:
 888         res->flags |= IORESOURCE_DISABLED;
 889 #endif
 890 }
 891
 892 int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
 893 {
 894         int ret;
 895         struct list_head *list = &info->resources;
 896         struct acpi_device *device = info->bridge;
 897         struct resource_entry *entry, *tmp;
 898         unsigned long flags;
 899
 900         flags = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_MEM_8AND16BIT;
 901         ret = acpi_dev_get_resources(device, list,
 902                                      acpi_dev_filter_resource_type_cb,
 903                                      (void *)flags);
 904         if (ret < 0)
 905                 dev_warn(&device->dev,
 906                          "failed to parse _CRS method, error code %d\n", ret);
 907         else if (ret == 0)
 908                 dev_dbg(&device->dev,
 909                         "no IO and memory resources present in _CRS\n");
 910         else {
 911                 resource_list_for_each_entry_safe(entry, tmp, list) {
 912                         if (entry->res->flags & IORESOURCE_IO)
 913                                 acpi_pci_root_remap_iospace(&device->fwnode,
 914                                                 entry);
 915
 916                         if (entry->res->flags & IORESOURCE_DISABLED)
 917                                 resource_list_destroy_entry(entry);
 918                         else
 919                                 entry->res->name = info->name;
 920                 }
 921                 acpi_pci_root_validate_resources(&device->dev, list,
 922                                                  IORESOURCE_MEM);
 923                 acpi_pci_root_validate_resources(&device->dev, list,
 924                                                  IORESOURCE_IO);
 925         }
 926
 927         return ret;
 928 }
 929
 930 static void pci_acpi_root_add_resources(struct acpi_pci_root_info *info)
 931 {
 932         struct resource_entry *entry, *tmp;
 933         struct resource *res, *conflict, *root = NULL;
 934
 935         resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
 936                 res = entry->res;
 937                 if (res->flags & IORESOURCE_MEM)
 938                         root = &iomem_resource;
 939                 else if (res->flags & IORESOURCE_IO)
 940                         root = &ioport_resource;
 941                 else
 942                         continue;
 943
 944                 /*
 945                  * Some legacy x86 host bridge drivers use iomem_resource and
 946                  * ioport_resource as default resource pool, skip it.
 947                  */
 948                 if (res == root)
 949                         continue;
 950
 951                 conflict = insert_resource_conflict(root, res);
 952                 if (conflict) {
 953                         dev_info(&info->bridge->dev,
 954                                  "ignoring host bridge window %pR (conflicts with %s %pR)\n",
 955                                  res, conflict->name, conflict);
 956                         resource_list_destroy_entry(entry);
 957                 }
 958         }
 959 }
 960
 961 static void __acpi_pci_root_release_info(struct acpi_pci_root_info *info)
 962 {
 963         struct resource *res;
 964         struct resource_entry *entry, *tmp;
 965
 966         if (!info)
 967                 return;
 968
 969         resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
 970                 res = entry->res;
 971                 if (res->parent &&
 972                     (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
 973                         release_resource(res);
 974                 resource_list_destroy_entry(entry);
 975         }
 976
 977         info->ops->release_info(info);
 978 }
 979
 980 static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
 981 {
 982         struct resource *res;
 983         struct resource_entry *entry;
 984
 985         resource_list_for_each_entry(entry, &bridge->windows) {
 986                 res = entry->res;
 987                 if (res->flags & IORESOURCE_IO)
 988                         pci_unmap_iospace(res);
 989                 if (res->parent &&
 990                     (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
 991                         release_resource(res);
 992         }
 993         __acpi_pci_root_release_info(bridge->release_data);
 994 }
 995
 996 struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
 997                                      struct acpi_pci_root_ops *ops,
 998                                      struct acpi_pci_root_info *info,
 999                                      void *sysdata)
1000 {
1001         int ret, busnum = root->secondary.start;
1002         struct acpi_device *device = root->device;
1003         int node = acpi_get_node(device->handle);
1004         struct pci_bus *bus;
1005         struct pci_host_bridge *host_bridge;
1006
1007         info->root = root;
1008         info->bridge = device;
1009         info->ops = ops;
1010         INIT_LIST_HEAD(&info->resources);
1011         snprintf(info->name, sizeof(info->name), "PCI Bus %04x:%02x",
1012                  root->segment, busnum);
1013
1014         if (ops->init_info && ops->init_info(info))
1015                 goto out_release_info;
1016         if (ops->prepare_resources)
1017                 ret = ops->prepare_resources(info);
1018         else
1019                 ret = acpi_pci_probe_root_resources(info);
1020         if (ret < 0)
1021                 goto out_release_info;
1022
1023         pci_acpi_root_add_resources(info);
1024         pci_add_resource(&info->resources, &root->secondary);
1025         bus = pci_create_root_bus(NULL, busnum, ops->pci_ops,
1026                                   sysdata, &info->resources);
1027         if (!bus)
1028                 goto out_release_info;
1029
1030         host_bridge = to_pci_host_bridge(bus->bridge);
1031         if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
1032                 host_bridge->native_pcie_hotplug = 0;
1033         if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL))
1034                 host_bridge->native_shpc_hotplug = 0;
1035         if (!(root->osc_control_set & OSC_PCI_EXPRESS_AER_CONTROL))
1036                 host_bridge->native_aer = 0;
1037         if (!(root->osc_control_set & OSC_PCI_EXPRESS_PME_CONTROL))
1038                 host_bridge->native_pme = 0;
1039         if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL))
1040                 host_bridge->native_ltr = 0;
1041         if (!(root->osc_control_set & OSC_PCI_EXPRESS_DPC_CONTROL))
1042                 host_bridge->native_dpc = 0;
1043
1044         if (!(root->osc_ext_control_set & OSC_CXL_ERROR_REPORTING_CONTROL))
1045                 host_bridge->native_cxl_error = 0;
1046
1047         acpi_dev_power_up_children_with_adr(device);
1048
1049         pci_scan_child_bus(bus);
1050         pci_set_host_bridge_release(host_bridge, acpi_pci_root_release_info,
1051                                     info);
1052         if (node != NUMA_NO_NODE)
1053                 dev_printk(KERN_DEBUG, &bus->dev, "on NUMA node %d\n", node);
1054         return bus;
1055
1056 out_release_info:
1057         __acpi_pci_root_release_info(info);
1058         return NULL;
1059 }
1060
1061 void __init acpi_pci_root_init(void)
1062 {
1063         if (acpi_pci_disabled)
1064                 return;
1065
1066         pci_acpi_crs_quirks();
1067         acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root");
1068 }