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 #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 struct acpi_handle_node {
 297         struct list_head node;
 298         acpi_handle handle;
 299 };
 300
 301 /**
 302  * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
 303  * @handle: the handle in question
 304  *
 305  * Given an ACPI CA handle, the desired PCI device is located in the
 306  * list of PCI devices.
 307  *
 308  * If the device is found, its reference count is increased and this
 309  * function returns a pointer to its data structure.  The caller must
 310  * decrement the reference count by calling pci_dev_put().
 311  * If no device is found, %NULL is returned.
 312  */
 313 struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
 314 {
 315         struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
 316         struct acpi_device_physical_node *pn;
 317         struct pci_dev *pci_dev = NULL;
 318
 319         if (!adev)
 320                 return NULL;
 321
 322         mutex_lock(&adev->physical_node_lock);
 323
 324         list_for_each_entry(pn, &adev->physical_node_list, node) {
 325                 if (dev_is_pci(pn->dev)) {
 326                         get_device(pn->dev);
 327                         pci_dev = to_pci_dev(pn->dev);
 328                         break;
 329                 }
 330         }
 331
 332         mutex_unlock(&adev->physical_node_lock);
 333
 334         return pci_dev;
 335 }
 336 EXPORT_SYMBOL_GPL(acpi_get_pci_dev);
 337
 338 /**
 339  * acpi_pci_osc_control_set - Request control of PCI root _OSC features.
 340  * @handle: ACPI handle of a PCI root bridge (or PCIe Root Complex).
 341  * @mask: Mask of _OSC bits to request control of, place to store control mask.
 342  * @support: _OSC supported capability.
 343  * @cxl_mask: Mask of CXL _OSC control bits, place to store control mask.
 344  * @cxl_support: CXL _OSC supported capability.
 345  *
 346  * Run _OSC query for @mask and if that is successful, compare the returned
 347  * mask of control bits with @req.  If all of the @req bits are set in the
 348  * returned mask, run _OSC request for it.
 349  *
 350  * The variable at the @mask address may be modified regardless of whether or
 351  * not the function returns success.  On success it will contain the mask of
 352  * _OSC bits the BIOS has granted control of, but its contents are meaningless
 353  * on failure.
 354  **/
 355 static acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask,
 356                                             u32 support, u32 *cxl_mask,
 357                                             u32 cxl_support)
 358 {
 359         u32 req = OSC_PCI_EXPRESS_CAPABILITY_CONTROL;
 360         struct acpi_pci_root *root;
 361         acpi_status status;
 362         u32 ctrl, cxl_ctrl = 0, capbuf[OSC_CXL_CAPABILITY_DWORDS];
 363
 364         if (!mask)
 365                 return AE_BAD_PARAMETER;
 366
 367         root = acpi_pci_find_root(handle);
 368         if (!root)
 369                 return AE_NOT_EXIST;
 370
 371         ctrl   = *mask;
 372         *mask |= root->osc_control_set;
 373
 374         if (is_cxl(root)) {
 375                 cxl_ctrl = *cxl_mask;
 376                 *cxl_mask |= root->osc_ext_control_set;
 377         }
 378
 379         /* Need to check the available controls bits before requesting them. */
 380         do {
 381                 u32 pci_missing = 0, cxl_missing = 0;
 382
 383                 status = acpi_pci_query_osc(root, support, mask, cxl_support,
 384                                             cxl_mask);
 385                 if (ACPI_FAILURE(status))
 386                         return status;
 387                 if (is_cxl(root)) {
 388                         if (ctrl == *mask && cxl_ctrl == *cxl_mask)
 389                                 break;
 390                         pci_missing = ctrl & ~(*mask);
 391                         cxl_missing = cxl_ctrl & ~(*cxl_mask);
 392                 } else {
 393                         if (ctrl == *mask)
 394                                 break;
 395                         pci_missing = ctrl & ~(*mask);
 396                 }
 397                 if (pci_missing)
 398                         decode_osc_control(root, "platform does not support",
 399                                            pci_missing);
 400                 if (cxl_missing)
 401                         decode_cxl_osc_control(root, "CXL platform does not support",
 402                                            cxl_missing);
 403                 ctrl = *mask;
 404                 cxl_ctrl = *cxl_mask;
 405         } while (*mask || *cxl_mask);
 406
 407         /* No need to request _OSC if the control was already granted. */
 408         if ((root->osc_control_set & ctrl) == ctrl &&
 409             (root->osc_ext_control_set & cxl_ctrl) == cxl_ctrl)
 410                 return AE_OK;
 411
 412         if ((ctrl & req) != req) {
 413                 decode_osc_control(root, "not requesting control; platform does not support",
 414                                    req & ~(ctrl));
 415                 return AE_SUPPORT;
 416         }
 417
 418         capbuf[OSC_QUERY_DWORD] = 0;
 419         capbuf[OSC_SUPPORT_DWORD] = root->osc_support_set;
 420         capbuf[OSC_CONTROL_DWORD] = ctrl;
 421         if (is_cxl(root)) {
 422                 capbuf[OSC_EXT_SUPPORT_DWORD] = root->osc_ext_support_set;
 423                 capbuf[OSC_EXT_CONTROL_DWORD] = cxl_ctrl;
 424         }
 425
 426         status = acpi_pci_run_osc(root, capbuf, mask, cxl_mask);
 427         if (ACPI_FAILURE(status))
 428                 return status;
 429
 430         root->osc_control_set = *mask;
 431         root->osc_ext_control_set = *cxl_mask;
 432         return AE_OK;
 433 }
 434
 435 static u32 calculate_support(void)
 436 {
 437         u32 support;
 438
 439         /*
 440          * All supported architectures that use ACPI have support for
 441          * PCI domains, so we indicate this in _OSC support capabilities.
 442          */
 443         support = OSC_PCI_SEGMENT_GROUPS_SUPPORT;
 444         support |= OSC_PCI_HPX_TYPE_3_SUPPORT;
 445         if (pci_ext_cfg_avail())
 446                 support |= OSC_PCI_EXT_CONFIG_SUPPORT;
 447         if (pcie_aspm_support_enabled())
 448                 support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
 449         if (pci_msi_enabled())
 450                 support |= OSC_PCI_MSI_SUPPORT;
 451         if (IS_ENABLED(CONFIG_PCIE_EDR))
 452                 support |= OSC_PCI_EDR_SUPPORT;
 453
 454         return support;
 455 }
 456
 457 /*
 458  * Background on hotplug support, and making it depend on only
 459  * CONFIG_HOTPLUG_PCI_PCIE vs. also considering CONFIG_MEMORY_HOTPLUG:
 460  *
 461  * CONFIG_ACPI_HOTPLUG_MEMORY does depend on CONFIG_MEMORY_HOTPLUG, but
 462  * there is no existing _OSC for memory hotplug support. The reason is that
 463  * ACPI memory hotplug requires the OS to acknowledge / coordinate with
 464  * memory plug events via a scan handler. On the CXL side the equivalent
 465  * would be if Linux supported the Mechanical Retention Lock [1], or
 466  * otherwise had some coordination for the driver of a PCI device
 467  * undergoing hotplug to be consulted on whether the hotplug should
 468  * proceed or not.
 469  *
 470  * The concern is that if Linux says no to supporting CXL hotplug then
 471  * the BIOS may say no to giving the OS hotplug control of any other PCIe
 472  * device. So the question here is not whether hotplug is enabled, it's
 473  * whether it is handled natively by the at all OS, and if
 474  * CONFIG_HOTPLUG_PCI_PCIE is enabled then the answer is "yes".
 475  *
 476  * Otherwise, the plan for CXL coordinated remove, since the kernel does
 477  * not support blocking hotplug, is to require the memory device to be
 478  * disabled before hotplug is attempted. When CONFIG_MEMORY_HOTPLUG is
 479  * disabled that step will fail and the remove attempt cancelled by the
 480  * user. If that is not honored and the card is removed anyway then it
 481  * does not matter if CONFIG_MEMORY_HOTPLUG is enabled or not, it will
 482  * cause a crash and other badness.
 483  *
 484  * Therefore, just say yes to CXL hotplug and require removal to
 485  * be coordinated by userspace unless and until the kernel grows better
 486  * mechanisms for doing "managed" removal of devices in consultation with
 487  * the driver.
 488  *
 489  * [1]: https://lore.kernel.org/all/20201122014203.4706-1-ashok.raj@intel.com/
 490  */
 491 static u32 calculate_cxl_support(void)
 492 {
 493         u32 support;
 494
 495         support = OSC_CXL_2_0_PORT_DEV_REG_ACCESS_SUPPORT;
 496         if (pci_aer_available())
 497                 support |= OSC_CXL_PROTOCOL_ERR_REPORTING_SUPPORT;
 498         if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
 499                 support |= OSC_CXL_NATIVE_HP_SUPPORT;
 500
 501         return support;
 502 }
 503
 504 static u32 calculate_control(void)
 505 {
 506         u32 control;
 507
 508         control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL
 509                 | OSC_PCI_EXPRESS_PME_CONTROL;
 510
 511         if (IS_ENABLED(CONFIG_PCIEASPM))
 512                 control |= OSC_PCI_EXPRESS_LTR_CONTROL;
 513
 514         if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
 515                 control |= OSC_PCI_EXPRESS_NATIVE_HP_CONTROL;
 516
 517         if (IS_ENABLED(CONFIG_HOTPLUG_PCI_SHPC))
 518                 control |= OSC_PCI_SHPC_NATIVE_HP_CONTROL;
 519
 520         if (pci_aer_available())
 521                 control |= OSC_PCI_EXPRESS_AER_CONTROL;
 522
 523         /*
 524          * Per the Downstream Port Containment Related Enhancements ECN to
 525          * the PCI Firmware Spec, r3.2, sec 4.5.1, table 4-5,
 526          * OSC_PCI_EXPRESS_DPC_CONTROL indicates the OS supports both DPC
 527          * and EDR.
 528          */
 529         if (IS_ENABLED(CONFIG_PCIE_DPC) && IS_ENABLED(CONFIG_PCIE_EDR))
 530                 control |= OSC_PCI_EXPRESS_DPC_CONTROL;
 531
 532         return control;
 533 }
 534
 535 static u32 calculate_cxl_control(void)
 536 {
 537         u32 control = 0;
 538
 539         if (IS_ENABLED(CONFIG_MEMORY_FAILURE))
 540                 control |= OSC_CXL_ERROR_REPORTING_CONTROL;
 541
 542         return control;
 543 }
 544
 545 static bool os_control_query_checks(struct acpi_pci_root *root, u32 support)
 546 {
 547         struct acpi_device *device = root->device;
 548
 549         if (pcie_ports_disabled) {
 550                 dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n");
 551                 return false;
 552         }
 553
 554         if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) {
 555                 decode_osc_support(root, "not requesting OS control; OS requires",
 556                                    ACPI_PCIE_REQ_SUPPORT);
 557                 return false;
 558         }
 559
 560         return true;
 561 }
 562
 563 static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
 564 {
 565         u32 support, control = 0, requested = 0;
 566         u32 cxl_support = 0, cxl_control = 0, cxl_requested = 0;
 567         acpi_status status;
 568         struct acpi_device *device = root->device;
 569         acpi_handle handle = device->handle;
 570
 571         /*
 572          * Apple always return failure on _OSC calls when _OSI("Darwin") has
 573          * been called successfully. We know the feature set supported by the
 574          * platform, so avoid calling _OSC at all
 575          */
 576         if (x86_apple_machine) {
 577                 root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL;
 578                 decode_osc_control(root, "OS assumes control of",
 579                                    root->osc_control_set);
 580                 return;
 581         }
 582
 583         support = calculate_support();
 584
 585         decode_osc_support(root, "OS supports", support);
 586
 587         if (os_control_query_checks(root, support))
 588                 requested = control = calculate_control();
 589
 590         if (is_cxl(root)) {
 591                 cxl_support = calculate_cxl_support();
 592                 decode_cxl_osc_support(root, "OS supports", cxl_support);
 593                 cxl_requested = cxl_control = calculate_cxl_control();
 594         }
 595
 596         status = acpi_pci_osc_control_set(handle, &control, support,
 597                                           &cxl_control, cxl_support);
 598         if (ACPI_SUCCESS(status)) {
 599                 if (control)
 600                         decode_osc_control(root, "OS now controls", control);
 601                 if (cxl_control)
 602                         decode_cxl_osc_control(root, "OS now controls",
 603                                            cxl_control);
 604
 605                 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 606                         /*
 607                          * We have ASPM control, but the FADT indicates that
 608                          * it's unsupported. Leave existing configuration
 609                          * intact and prevent the OS from touching it.
 610                          */
 611                         dev_info(&device->dev, "FADT indicates ASPM is unsupported, using BIOS configuration\n");
 612                         *no_aspm = 1;
 613                 }
 614         } else {
 615                 /*
 616                  * We want to disable ASPM here, but aspm_disabled
 617                  * needs to remain in its state from boot so that we
 618                  * properly handle PCIe 1.1 devices.  So we set this
 619                  * flag here, to defer the action until after the ACPI
 620                  * root scan.
 621                  */
 622                 *no_aspm = 1;
 623
 624                 /* _OSC is optional for PCI host bridges */
 625                 if (status == AE_NOT_FOUND && !is_pcie(root))
 626                         return;
 627
 628                 if (control) {
 629                         decode_osc_control(root, "OS requested", requested);
 630                         decode_osc_control(root, "platform willing to grant", control);
 631                 }
 632                 if (cxl_control) {
 633                         decode_cxl_osc_control(root, "OS requested", cxl_requested);
 634                         decode_cxl_osc_control(root, "platform willing to grant",
 635                                            cxl_control);
 636                 }
 637
 638                 dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n",
 639                          acpi_format_exception(status));
 640         }
 641 }
 642
 643 static int acpi_pci_root_add(struct acpi_device *device,
 644                              const struct acpi_device_id *not_used)
 645 {
 646         unsigned long long segment, bus;
 647         acpi_status status;
 648         int result;
 649         struct acpi_pci_root *root;
 650         acpi_handle handle = device->handle;
 651         int no_aspm = 0;
 652         bool hotadd = system_state == SYSTEM_RUNNING;
 653         const char *acpi_hid;
 654
 655         root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 656         if (!root)
 657                 return -ENOMEM;
 658
 659         segment = 0;
 660         status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL,
 661                                        &segment);
 662         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
 663                 dev_err(&device->dev,  "can't evaluate _SEG\n");
 664                 result = -ENODEV;
 665                 goto end;
 666         }
 667
 668         /* Check _CRS first, then _BBN.  If no _BBN, default to zero. */
 669         root->secondary.flags = IORESOURCE_BUS;
 670         status = try_get_root_bridge_busnr(handle, &root->secondary);
 671         if (ACPI_FAILURE(status)) {
 672                 /*
 673                  * We need both the start and end of the downstream bus range
 674                  * to interpret _CBA (MMCONFIG base address), so it really is
 675                  * supposed to be in _CRS.  If we don't find it there, all we
 676                  * can do is assume [_BBN-0xFF] or [0-0xFF].
 677                  */
 678                 root->secondary.end = 0xFF;
 679                 dev_warn(&device->dev,
 680                          FW_BUG "no secondary bus range in _CRS\n");
 681                 status = acpi_evaluate_integer(handle, METHOD_NAME__BBN,
 682                                                NULL, &bus);
 683                 if (ACPI_SUCCESS(status))
 684                         root->secondary.start = bus;
 685                 else if (status == AE_NOT_FOUND)
 686                         root->secondary.start = 0;
 687                 else {
 688                         dev_err(&device->dev, "can't evaluate _BBN\n");
 689                         result = -ENODEV;
 690                         goto end;
 691                 }
 692         }
 693
 694         root->device = device;
 695         root->segment = segment & 0xFFFF;
 696         strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
 697         strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS);
 698         device->driver_data = root;
 699
 700         if (hotadd && dmar_device_add(handle)) {
 701                 result = -ENXIO;
 702                 goto end;
 703         }
 704
 705         pr_info("%s [%s] (domain %04x %pR)\n",
 706                acpi_device_name(device), acpi_device_bid(device),
 707                root->segment, &root->secondary);
 708
 709         root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
 710
 711         acpi_hid = acpi_device_hid(root->device);
 712         if (strcmp(acpi_hid, "PNP0A08") == 0)
 713                 root->bridge_type = ACPI_BRIDGE_TYPE_PCIE;
 714         else if (strcmp(acpi_hid, "ACPI0016") == 0)
 715                 root->bridge_type = ACPI_BRIDGE_TYPE_CXL;
 716         else
 717                 dev_dbg(&device->dev, "Assuming non-PCIe host bridge\n");
 718
 719         negotiate_os_control(root, &no_aspm);
 720
 721         /*
 722          * TBD: Need PCI interface for enumeration/configuration of roots.
 723          */
 724
 725         /*
 726          * Scan the Root Bridge
 727          * --------------------
 728          * Must do this prior to any attempt to bind the root device, as the
 729          * PCI namespace does not get created until this call is made (and
 730          * thus the root bridge's pci_dev does not exist).
 731          */
 732         root->bus = pci_acpi_scan_root(root);
 733         if (!root->bus) {
 734                 dev_err(&device->dev,
 735                         "Bus %04x:%02x not present in PCI namespace\n",
 736                         root->segment, (unsigned int)root->secondary.start);
 737                 device->driver_data = NULL;
 738                 result = -ENODEV;
 739                 goto remove_dmar;
 740         }
 741
 742         if (no_aspm)
 743                 pcie_no_aspm();
 744
 745         pci_acpi_add_bus_pm_notifier(device);
 746         device_set_wakeup_capable(root->bus->bridge, device->wakeup.flags.valid);
 747
 748         if (hotadd) {
 749                 pcibios_resource_survey_bus(root->bus);
 750                 pci_assign_unassigned_root_bus_resources(root->bus);
 751                 /*
 752                  * This is only called for the hotadd case. For the boot-time
 753                  * case, we need to wait until after PCI initialization in
 754                  * order to deal with IOAPICs mapped in on a PCI BAR.
 755                  *
 756                  * This is currently x86-specific, because acpi_ioapic_add()
 757                  * is an empty function without CONFIG_ACPI_HOTPLUG_IOAPIC.
 758                  * And CONFIG_ACPI_HOTPLUG_IOAPIC depends on CONFIG_X86_IO_APIC
 759                  * (see drivers/acpi/Kconfig).
 760                  */
 761                 acpi_ioapic_add(root->device->handle);
 762         }
 763
 764         pci_lock_rescan_remove();
 765         pci_bus_add_devices(root->bus);
 766         pci_unlock_rescan_remove();
 767         return 1;
 768
 769 remove_dmar:
 770         if (hotadd)
 771                 dmar_device_remove(handle);
 772 end:
 773         kfree(root);
 774         return result;
 775 }
 776
 777 static void acpi_pci_root_remove(struct acpi_device *device)
 778 {
 779         struct acpi_pci_root *root = acpi_driver_data(device);
 780
 781         pci_lock_rescan_remove();
 782
 783         pci_stop_root_bus(root->bus);
 784
 785         pci_ioapic_remove(root);
 786         device_set_wakeup_capable(root->bus->bridge, false);
 787         pci_acpi_remove_bus_pm_notifier(device);
 788
 789         pci_remove_root_bus(root->bus);
 790         WARN_ON(acpi_ioapic_remove(root));
 791
 792         dmar_device_remove(device->handle);
 793
 794         pci_unlock_rescan_remove();
 795
 796         kfree(root);
 797 }
 798
 799 /*
 800  * Following code to support acpi_pci_root_create() is copied from
 801  * arch/x86/pci/acpi.c and modified so it could be reused by x86, IA64
 802  * and ARM64.
 803  */
 804 static void acpi_pci_root_validate_resources(struct device *dev,
 805                                              struct list_head *resources,
 806                                              unsigned long type)
 807 {
 808         LIST_HEAD(list);
 809         struct resource *res1, *res2, *root = NULL;
 810         struct resource_entry *tmp, *entry, *entry2;
 811
 812         BUG_ON((type & (IORESOURCE_MEM | IORESOURCE_IO)) == 0);
 813         root = (type & IORESOURCE_MEM) ? &iomem_resource : &ioport_resource;
 814
 815         list_splice_init(resources, &list);
 816         resource_list_for_each_entry_safe(entry, tmp, &list) {
 817                 bool free = false;
 818                 resource_size_t end;
 819
 820                 res1 = entry->res;
 821                 if (!(res1->flags & type))
 822                         goto next;
 823
 824                 /* Exclude non-addressable range or non-addressable portion */
 825                 end = min(res1->end, root->end);
 826                 if (end <= res1->start) {
 827                         dev_info(dev, "host bridge window %pR (ignored, not CPU addressable)\n",
 828                                  res1);
 829                         free = true;
 830                         goto next;
 831                 } else if (res1->end != end) {
 832                         dev_info(dev, "host bridge window %pR ([%#llx-%#llx] ignored, not CPU addressable)\n",
 833                                  res1, (unsigned long long)end + 1,
 834                                  (unsigned long long)res1->end);
 835                         res1->end = end;
 836                 }
 837
 838                 resource_list_for_each_entry(entry2, resources) {
 839                         res2 = entry2->res;
 840                         if (!(res2->flags & type))
 841                                 continue;
 842
 843                         /*
 844                          * I don't like throwing away windows because then
 845                          * our resources no longer match the ACPI _CRS, but
 846                          * the kernel resource tree doesn't allow overlaps.
 847                          */
 848                         if (resource_union(res1, res2, res2)) {
 849                                 dev_info(dev, "host bridge window expanded to %pR; %pR ignored\n",
 850                                          res2, res1);
 851                                 free = true;
 852                                 goto next;
 853                         }
 854                 }
 855
 856 next:
 857                 resource_list_del(entry);
 858                 if (free)
 859                         resource_list_free_entry(entry);
 860                 else
 861                         resource_list_add_tail(entry, resources);
 862         }
 863 }
 864
 865 static void acpi_pci_root_remap_iospace(struct fwnode_handle *fwnode,
 866                         struct resource_entry *entry)
 867 {
 868 #ifdef PCI_IOBASE
 869         struct resource *res = entry->res;
 870         resource_size_t cpu_addr = res->start;
 871         resource_size_t pci_addr = cpu_addr - entry->offset;
 872         resource_size_t length = resource_size(res);
 873         unsigned long port;
 874
 875         if (pci_register_io_range(fwnode, cpu_addr, length))
 876                 goto err;
 877
 878         port = pci_address_to_pio(cpu_addr);
 879         if (port == (unsigned long)-1)
 880                 goto err;
 881
 882         res->start = port;
 883         res->end = port + length - 1;
 884         entry->offset = port - pci_addr;
 885
 886         if (pci_remap_iospace(res, cpu_addr) < 0)
 887                 goto err;
 888
 889         pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res);
 890         return;
 891 err:
 892         res->flags |= IORESOURCE_DISABLED;
 893 #endif
 894 }
 895
 896 int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
 897 {
 898         int ret;
 899         struct list_head *list = &info->resources;
 900         struct acpi_device *device = info->bridge;
 901         struct resource_entry *entry, *tmp;
 902         unsigned long flags;
 903
 904         flags = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_MEM_8AND16BIT;
 905         ret = acpi_dev_get_resources(device, list,
 906                                      acpi_dev_filter_resource_type_cb,
 907                                      (void *)flags);
 908         if (ret < 0)
 909                 dev_warn(&device->dev,
 910                          "failed to parse _CRS method, error code %d\n", ret);
 911         else if (ret == 0)
 912                 dev_dbg(&device->dev,
 913                         "no IO and memory resources present in _CRS\n");
 914         else {
 915                 resource_list_for_each_entry_safe(entry, tmp, list) {
 916                         if (entry->res->flags & IORESOURCE_IO)
 917                                 acpi_pci_root_remap_iospace(&device->fwnode,
 918                                                 entry);
 919
 920                         if (entry->res->flags & IORESOURCE_DISABLED)
 921                                 resource_list_destroy_entry(entry);
 922                         else
 923                                 entry->res->name = info->name;
 924                 }
 925                 acpi_pci_root_validate_resources(&device->dev, list,
 926                                                  IORESOURCE_MEM);
 927                 acpi_pci_root_validate_resources(&device->dev, list,
 928                                                  IORESOURCE_IO);
 929         }
 930
 931         return ret;
 932 }
 933
 934 static void pci_acpi_root_add_resources(struct acpi_pci_root_info *info)
 935 {
 936         struct resource_entry *entry, *tmp;
 937         struct resource *res, *conflict, *root = NULL;
 938
 939         resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
 940                 res = entry->res;
 941                 if (res->flags & IORESOURCE_MEM)
 942                         root = &iomem_resource;
 943                 else if (res->flags & IORESOURCE_IO)
 944                         root = &ioport_resource;
 945                 else
 946                         continue;
 947
 948                 /*
 949                  * Some legacy x86 host bridge drivers use iomem_resource and
 950                  * ioport_resource as default resource pool, skip it.
 951                  */
 952                 if (res == root)
 953                         continue;
 954
 955                 conflict = insert_resource_conflict(root, res);
 956                 if (conflict) {
 957                         dev_info(&info->bridge->dev,
 958                                  "ignoring host bridge window %pR (conflicts with %s %pR)\n",
 959                                  res, conflict->name, conflict);
 960                         resource_list_destroy_entry(entry);
 961                 }
 962         }
 963 }
 964
 965 static void __acpi_pci_root_release_info(struct acpi_pci_root_info *info)
 966 {
 967         struct resource *res;
 968         struct resource_entry *entry, *tmp;
 969
 970         if (!info)
 971                 return;
 972
 973         resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
 974                 res = entry->res;
 975                 if (res->parent &&
 976                     (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
 977                         release_resource(res);
 978                 resource_list_destroy_entry(entry);
 979         }
 980
 981         info->ops->release_info(info);
 982 }
 983
 984 static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
 985 {
 986         struct resource *res;
 987         struct resource_entry *entry;
 988
 989         resource_list_for_each_entry(entry, &bridge->windows) {
 990                 res = entry->res;
 991                 if (res->flags & IORESOURCE_IO)
 992                         pci_unmap_iospace(res);
 993                 if (res->parent &&
 994                     (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
 995                         release_resource(res);
 996         }
 997         __acpi_pci_root_release_info(bridge->release_data);
 998 }
 999
1000 struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
1001                                      struct acpi_pci_root_ops *ops,
1002                                      struct acpi_pci_root_info *info,
1003                                      void *sysdata)
1004 {
1005         int ret, busnum = root->secondary.start;
1006         struct acpi_device *device = root->device;
1007         int node = acpi_get_node(device->handle);
1008         struct pci_bus *bus;
1009         struct pci_host_bridge *host_bridge;
1010         union acpi_object *obj;
1011
1012         info->root = root;
1013         info->bridge = device;
1014         info->ops = ops;
1015         INIT_LIST_HEAD(&info->resources);
1016         snprintf(info->name, sizeof(info->name), "PCI Bus %04x:%02x",
1017                  root->segment, busnum);
1018
1019         if (ops->init_info && ops->init_info(info))
1020                 goto out_release_info;
1021         if (ops->prepare_resources)
1022                 ret = ops->prepare_resources(info);
1023         else
1024                 ret = acpi_pci_probe_root_resources(info);
1025         if (ret < 0)
1026                 goto out_release_info;
1027
1028         pci_acpi_root_add_resources(info);
1029         pci_add_resource(&info->resources, &root->secondary);
1030         bus = pci_create_root_bus(NULL, busnum, ops->pci_ops,
1031                                   sysdata, &info->resources);
1032         if (!bus)
1033                 goto out_release_info;
1034
1035         host_bridge = to_pci_host_bridge(bus->bridge);
1036         if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
1037                 host_bridge->native_pcie_hotplug = 0;
1038         if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL))
1039                 host_bridge->native_shpc_hotplug = 0;
1040         if (!(root->osc_control_set & OSC_PCI_EXPRESS_AER_CONTROL))
1041                 host_bridge->native_aer = 0;
1042         if (!(root->osc_control_set & OSC_PCI_EXPRESS_PME_CONTROL))
1043                 host_bridge->native_pme = 0;
1044         if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL))
1045                 host_bridge->native_ltr = 0;
1046         if (!(root->osc_control_set & OSC_PCI_EXPRESS_DPC_CONTROL))
1047                 host_bridge->native_dpc = 0;
1048
1049         /*
1050          * Evaluate the "PCI Boot Configuration" _DSM Function.  If it
1051          * exists and returns 0, we must preserve any PCI resource
1052          * assignments made by firmware for this host bridge.
1053          */
1054         obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 1,
1055                                 DSM_PCI_PRESERVE_BOOT_CONFIG, NULL);
1056         if (obj && obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 0)
1057                 host_bridge->preserve_config = 1;
1058         ACPI_FREE(obj);
1059
1060         acpi_dev_power_up_children_with_adr(device);
1061
1062         pci_scan_child_bus(bus);
1063         pci_set_host_bridge_release(host_bridge, acpi_pci_root_release_info,
1064                                     info);
1065         if (node != NUMA_NO_NODE)
1066                 dev_printk(KERN_DEBUG, &bus->dev, "on NUMA node %d\n", node);
1067         return bus;
1068
1069 out_release_info:
1070         __acpi_pci_root_release_info(info);
1071         return NULL;
1072 }
1073
1074 void __init acpi_pci_root_init(void)
1075 {
1076         if (acpi_pci_disabled)
1077                 return;
1078
1079         pci_acpi_crs_quirks();
1080         acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root");
1081 }