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 support |= OSC_CXL_1_1_PORT_REG_ACCESS_SUPPORT; 497 if (pci_aer_available()) 498 support |= OSC_CXL_PROTOCOL_ERR_REPORTING_SUPPORT; 499 if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE)) 500 support |= OSC_CXL_NATIVE_HP_SUPPORT; 501 502 return support; 503 } 504 505 static u32 calculate_control(void) 506 { 507 u32 control; 508 509 control = OSC_PCI_EXPRESS_CAPABILITY_CONTROL 510 | OSC_PCI_EXPRESS_PME_CONTROL; 511 512 if (IS_ENABLED(CONFIG_PCIEASPM)) 513 control |= OSC_PCI_EXPRESS_LTR_CONTROL; 514 515 if (IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE)) 516 control |= OSC_PCI_EXPRESS_NATIVE_HP_CONTROL; 517 518 if (IS_ENABLED(CONFIG_HOTPLUG_PCI_SHPC)) 519 control |= OSC_PCI_SHPC_NATIVE_HP_CONTROL; 520 521 if (pci_aer_available()) 522 control |= OSC_PCI_EXPRESS_AER_CONTROL; 523 524 /* 525 * Per the Downstream Port Containment Related Enhancements ECN to 526 * the PCI Firmware Spec, r3.2, sec 4.5.1, table 4-5, 527 * OSC_PCI_EXPRESS_DPC_CONTROL indicates the OS supports both DPC 528 * and EDR. 529 */ 530 if (IS_ENABLED(CONFIG_PCIE_DPC) && IS_ENABLED(CONFIG_PCIE_EDR)) 531 control |= OSC_PCI_EXPRESS_DPC_CONTROL; 532 533 return control; 534 } 535 536 static u32 calculate_cxl_control(void) 537 { 538 u32 control = 0; 539 540 if (IS_ENABLED(CONFIG_MEMORY_FAILURE)) 541 control |= OSC_CXL_ERROR_REPORTING_CONTROL; 542 543 return control; 544 } 545 546 static bool os_control_query_checks(struct acpi_pci_root *root, u32 support) 547 { 548 struct acpi_device *device = root->device; 549 550 if (pcie_ports_disabled) { 551 dev_info(&device->dev, "PCIe port services disabled; not requesting _OSC control\n"); 552 return false; 553 } 554 555 if ((support & ACPI_PCIE_REQ_SUPPORT) != ACPI_PCIE_REQ_SUPPORT) { 556 decode_osc_support(root, "not requesting OS control; OS requires", 557 ACPI_PCIE_REQ_SUPPORT); 558 return false; 559 } 560 561 return true; 562 } 563 564 static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm) 565 { 566 u32 support, control = 0, requested = 0; 567 u32 cxl_support = 0, cxl_control = 0, cxl_requested = 0; 568 acpi_status status; 569 struct acpi_device *device = root->device; 570 acpi_handle handle = device->handle; 571 572 /* 573 * Apple always return failure on _OSC calls when _OSI("Darwin") has 574 * been called successfully. We know the feature set supported by the 575 * platform, so avoid calling _OSC at all 576 */ 577 if (x86_apple_machine) { 578 root->osc_control_set = ~OSC_PCI_EXPRESS_PME_CONTROL; 579 decode_osc_control(root, "OS assumes control of", 580 root->osc_control_set); 581 return; 582 } 583 584 support = calculate_support(); 585 586 decode_osc_support(root, "OS supports", support); 587 588 if (os_control_query_checks(root, support)) 589 requested = control = calculate_control(); 590 591 if (is_cxl(root)) { 592 cxl_support = calculate_cxl_support(); 593 decode_cxl_osc_support(root, "OS supports", cxl_support); 594 cxl_requested = cxl_control = calculate_cxl_control(); 595 } 596 597 status = acpi_pci_osc_control_set(handle, &control, support, 598 &cxl_control, cxl_support); 599 if (ACPI_SUCCESS(status)) { 600 if (control) 601 decode_osc_control(root, "OS now controls", control); 602 if (cxl_control) 603 decode_cxl_osc_control(root, "OS now controls", 604 cxl_control); 605 606 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) { 607 /* 608 * We have ASPM control, but the FADT indicates that 609 * it's unsupported. Leave existing configuration 610 * intact and prevent the OS from touching it. 611 */ 612 dev_info(&device->dev, "FADT indicates ASPM is unsupported, using BIOS configuration\n"); 613 *no_aspm = 1; 614 } 615 } else { 616 /* 617 * We want to disable ASPM here, but aspm_disabled 618 * needs to remain in its state from boot so that we 619 * properly handle PCIe 1.1 devices. So we set this 620 * flag here, to defer the action until after the ACPI 621 * root scan. 622 */ 623 *no_aspm = 1; 624 625 /* _OSC is optional for PCI host bridges */ 626 if (status == AE_NOT_FOUND && !is_pcie(root)) 627 return; 628 629 if (control) { 630 decode_osc_control(root, "OS requested", requested); 631 decode_osc_control(root, "platform willing to grant", control); 632 } 633 if (cxl_control) { 634 decode_cxl_osc_control(root, "OS requested", cxl_requested); 635 decode_cxl_osc_control(root, "platform willing to grant", 636 cxl_control); 637 } 638 639 dev_info(&device->dev, "_OSC: platform retains control of PCIe features (%s)\n", 640 acpi_format_exception(status)); 641 } 642 } 643 644 static int acpi_pci_root_add(struct acpi_device *device, 645 const struct acpi_device_id *not_used) 646 { 647 unsigned long long segment, bus; 648 acpi_status status; 649 int result; 650 struct acpi_pci_root *root; 651 acpi_handle handle = device->handle; 652 int no_aspm = 0; 653 bool hotadd = system_state == SYSTEM_RUNNING; 654 const char *acpi_hid; 655 656 root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL); 657 if (!root) 658 return -ENOMEM; 659 660 segment = 0; 661 status = acpi_evaluate_integer(handle, METHOD_NAME__SEG, NULL, 662 &segment); 663 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) { 664 dev_err(&device->dev, "can't evaluate _SEG\n"); 665 result = -ENODEV; 666 goto end; 667 } 668 669 /* Check _CRS first, then _BBN. If no _BBN, default to zero. */ 670 root->secondary.flags = IORESOURCE_BUS; 671 status = try_get_root_bridge_busnr(handle, &root->secondary); 672 if (ACPI_FAILURE(status)) { 673 /* 674 * We need both the start and end of the downstream bus range 675 * to interpret _CBA (MMCONFIG base address), so it really is 676 * supposed to be in _CRS. If we don't find it there, all we 677 * can do is assume [_BBN-0xFF] or [0-0xFF]. 678 */ 679 root->secondary.end = 0xFF; 680 dev_warn(&device->dev, 681 FW_BUG "no secondary bus range in _CRS\n"); 682 status = acpi_evaluate_integer(handle, METHOD_NAME__BBN, 683 NULL, &bus); 684 if (ACPI_SUCCESS(status)) 685 root->secondary.start = bus; 686 else if (status == AE_NOT_FOUND) 687 root->secondary.start = 0; 688 else { 689 dev_err(&device->dev, "can't evaluate _BBN\n"); 690 result = -ENODEV; 691 goto end; 692 } 693 } 694 695 root->device = device; 696 root->segment = segment & 0xFFFF; 697 strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME); 698 strcpy(acpi_device_class(device), ACPI_PCI_ROOT_CLASS); 699 device->driver_data = root; 700 701 if (hotadd && dmar_device_add(handle)) { 702 result = -ENXIO; 703 goto end; 704 } 705 706 pr_info("%s [%s] (domain %04x %pR)\n", 707 acpi_device_name(device), acpi_device_bid(device), 708 root->segment, &root->secondary); 709 710 root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle); 711 712 acpi_hid = acpi_device_hid(root->device); 713 if (strcmp(acpi_hid, "PNP0A08") == 0) 714 root->bridge_type = ACPI_BRIDGE_TYPE_PCIE; 715 else if (strcmp(acpi_hid, "ACPI0016") == 0) 716 root->bridge_type = ACPI_BRIDGE_TYPE_CXL; 717 else 718 dev_dbg(&device->dev, "Assuming non-PCIe host bridge\n"); 719 720 negotiate_os_control(root, &no_aspm); 721 722 /* 723 * TBD: Need PCI interface for enumeration/configuration of roots. 724 */ 725 726 /* 727 * Scan the Root Bridge 728 * -------------------- 729 * Must do this prior to any attempt to bind the root device, as the 730 * PCI namespace does not get created until this call is made (and 731 * thus the root bridge's pci_dev does not exist). 732 */ 733 root->bus = pci_acpi_scan_root(root); 734 if (!root->bus) { 735 dev_err(&device->dev, 736 "Bus %04x:%02x not present in PCI namespace\n", 737 root->segment, (unsigned int)root->secondary.start); 738 device->driver_data = NULL; 739 result = -ENODEV; 740 goto remove_dmar; 741 } 742 743 if (no_aspm) 744 pcie_no_aspm(); 745 746 pci_acpi_add_bus_pm_notifier(device); 747 device_set_wakeup_capable(root->bus->bridge, device->wakeup.flags.valid); 748 749 if (hotadd) { 750 pcibios_resource_survey_bus(root->bus); 751 pci_assign_unassigned_root_bus_resources(root->bus); 752 /* 753 * This is only called for the hotadd case. For the boot-time 754 * case, we need to wait until after PCI initialization in 755 * order to deal with IOAPICs mapped in on a PCI BAR. 756 * 757 * This is currently x86-specific, because acpi_ioapic_add() 758 * is an empty function without CONFIG_ACPI_HOTPLUG_IOAPIC. 759 * And CONFIG_ACPI_HOTPLUG_IOAPIC depends on CONFIG_X86_IO_APIC 760 * (see drivers/acpi/Kconfig). 761 */ 762 acpi_ioapic_add(root->device->handle); 763 } 764 765 pci_lock_rescan_remove(); 766 pci_bus_add_devices(root->bus); 767 pci_unlock_rescan_remove(); 768 return 1; 769 770 remove_dmar: 771 if (hotadd) 772 dmar_device_remove(handle); 773 end: 774 kfree(root); 775 return result; 776 } 777 778 static void acpi_pci_root_remove(struct acpi_device *device) 779 { 780 struct acpi_pci_root *root = acpi_driver_data(device); 781 782 pci_lock_rescan_remove(); 783 784 pci_stop_root_bus(root->bus); 785 786 pci_ioapic_remove(root); 787 device_set_wakeup_capable(root->bus->bridge, false); 788 pci_acpi_remove_bus_pm_notifier(device); 789 790 pci_remove_root_bus(root->bus); 791 WARN_ON(acpi_ioapic_remove(root)); 792 793 dmar_device_remove(device->handle); 794 795 pci_unlock_rescan_remove(); 796 797 kfree(root); 798 } 799 800 /* 801 * Following code to support acpi_pci_root_create() is copied from 802 * arch/x86/pci/acpi.c and modified so it could be reused by x86, IA64 803 * and ARM64. 804 */ 805 static void acpi_pci_root_validate_resources(struct device *dev, 806 struct list_head *resources, 807 unsigned long type) 808 { 809 LIST_HEAD(list); 810 struct resource *res1, *res2, *root = NULL; 811 struct resource_entry *tmp, *entry, *entry2; 812 813 BUG_ON((type & (IORESOURCE_MEM | IORESOURCE_IO)) == 0); 814 root = (type & IORESOURCE_MEM) ? &iomem_resource : &ioport_resource; 815 816 list_splice_init(resources, &list); 817 resource_list_for_each_entry_safe(entry, tmp, &list) { 818 bool free = false; 819 resource_size_t end; 820 821 res1 = entry->res; 822 if (!(res1->flags & type)) 823 goto next; 824 825 /* Exclude non-addressable range or non-addressable portion */ 826 end = min(res1->end, root->end); 827 if (end <= res1->start) { 828 dev_info(dev, "host bridge window %pR (ignored, not CPU addressable)\n", 829 res1); 830 free = true; 831 goto next; 832 } else if (res1->end != end) { 833 dev_info(dev, "host bridge window %pR ([%#llx-%#llx] ignored, not CPU addressable)\n", 834 res1, (unsigned long long)end + 1, 835 (unsigned long long)res1->end); 836 res1->end = end; 837 } 838 839 resource_list_for_each_entry(entry2, resources) { 840 res2 = entry2->res; 841 if (!(res2->flags & type)) 842 continue; 843 844 /* 845 * I don't like throwing away windows because then 846 * our resources no longer match the ACPI _CRS, but 847 * the kernel resource tree doesn't allow overlaps. 848 */ 849 if (resource_union(res1, res2, res2)) { 850 dev_info(dev, "host bridge window expanded to %pR; %pR ignored\n", 851 res2, res1); 852 free = true; 853 goto next; 854 } 855 } 856 857 next: 858 resource_list_del(entry); 859 if (free) 860 resource_list_free_entry(entry); 861 else 862 resource_list_add_tail(entry, resources); 863 } 864 } 865 866 static void acpi_pci_root_remap_iospace(struct fwnode_handle *fwnode, 867 struct resource_entry *entry) 868 { 869 #ifdef PCI_IOBASE 870 struct resource *res = entry->res; 871 resource_size_t cpu_addr = res->start; 872 resource_size_t pci_addr = cpu_addr - entry->offset; 873 resource_size_t length = resource_size(res); 874 unsigned long port; 875 876 if (pci_register_io_range(fwnode, cpu_addr, length)) 877 goto err; 878 879 port = pci_address_to_pio(cpu_addr); 880 if (port == (unsigned long)-1) 881 goto err; 882 883 res->start = port; 884 res->end = port + length - 1; 885 entry->offset = port - pci_addr; 886 887 if (pci_remap_iospace(res, cpu_addr) < 0) 888 goto err; 889 890 pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res); 891 return; 892 err: 893 res->flags |= IORESOURCE_DISABLED; 894 #endif 895 } 896 897 int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info) 898 { 899 int ret; 900 struct list_head *list = &info->resources; 901 struct acpi_device *device = info->bridge; 902 struct resource_entry *entry, *tmp; 903 unsigned long flags; 904 905 flags = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_MEM_8AND16BIT; 906 ret = acpi_dev_get_resources(device, list, 907 acpi_dev_filter_resource_type_cb, 908 (void *)flags); 909 if (ret < 0) 910 dev_warn(&device->dev, 911 "failed to parse _CRS method, error code %d\n", ret); 912 else if (ret == 0) 913 dev_dbg(&device->dev, 914 "no IO and memory resources present in _CRS\n"); 915 else { 916 resource_list_for_each_entry_safe(entry, tmp, list) { 917 if (entry->res->flags & IORESOURCE_IO) 918 acpi_pci_root_remap_iospace(&device->fwnode, 919 entry); 920 921 if (entry->res->flags & IORESOURCE_DISABLED) 922 resource_list_destroy_entry(entry); 923 else 924 entry->res->name = info->name; 925 } 926 acpi_pci_root_validate_resources(&device->dev, list, 927 IORESOURCE_MEM); 928 acpi_pci_root_validate_resources(&device->dev, list, 929 IORESOURCE_IO); 930 } 931 932 return ret; 933 } 934 935 static void pci_acpi_root_add_resources(struct acpi_pci_root_info *info) 936 { 937 struct resource_entry *entry, *tmp; 938 struct resource *res, *conflict, *root = NULL; 939 940 resource_list_for_each_entry_safe(entry, tmp, &info->resources) { 941 res = entry->res; 942 if (res->flags & IORESOURCE_MEM) 943 root = &iomem_resource; 944 else if (res->flags & IORESOURCE_IO) 945 root = &ioport_resource; 946 else 947 continue; 948 949 /* 950 * Some legacy x86 host bridge drivers use iomem_resource and 951 * ioport_resource as default resource pool, skip it. 952 */ 953 if (res == root) 954 continue; 955 956 conflict = insert_resource_conflict(root, res); 957 if (conflict) { 958 dev_info(&info->bridge->dev, 959 "ignoring host bridge window %pR (conflicts with %s %pR)\n", 960 res, conflict->name, conflict); 961 resource_list_destroy_entry(entry); 962 } 963 } 964 } 965 966 static void __acpi_pci_root_release_info(struct acpi_pci_root_info *info) 967 { 968 struct resource *res; 969 struct resource_entry *entry, *tmp; 970 971 if (!info) 972 return; 973 974 resource_list_for_each_entry_safe(entry, tmp, &info->resources) { 975 res = entry->res; 976 if (res->parent && 977 (res->flags & (IORESOURCE_MEM | IORESOURCE_IO))) 978 release_resource(res); 979 resource_list_destroy_entry(entry); 980 } 981 982 info->ops->release_info(info); 983 } 984 985 static void acpi_pci_root_release_info(struct pci_host_bridge *bridge) 986 { 987 struct resource *res; 988 struct resource_entry *entry; 989 990 resource_list_for_each_entry(entry, &bridge->windows) { 991 res = entry->res; 992 if (res->flags & IORESOURCE_IO) 993 pci_unmap_iospace(res); 994 if (res->parent && 995 (res->flags & (IORESOURCE_MEM | IORESOURCE_IO))) 996 release_resource(res); 997 } 998 __acpi_pci_root_release_info(bridge->release_data); 999 } 1000 1001 struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root, 1002 struct acpi_pci_root_ops *ops, 1003 struct acpi_pci_root_info *info, 1004 void *sysdata) 1005 { 1006 int ret, busnum = root->secondary.start; 1007 struct acpi_device *device = root->device; 1008 int node = acpi_get_node(device->handle); 1009 struct pci_bus *bus; 1010 struct pci_host_bridge *host_bridge; 1011 union acpi_object *obj; 1012 1013 info->root = root; 1014 info->bridge = device; 1015 info->ops = ops; 1016 INIT_LIST_HEAD(&info->resources); 1017 snprintf(info->name, sizeof(info->name), "PCI Bus %04x:%02x", 1018 root->segment, busnum); 1019 1020 if (ops->init_info && ops->init_info(info)) 1021 goto out_release_info; 1022 if (ops->prepare_resources) 1023 ret = ops->prepare_resources(info); 1024 else 1025 ret = acpi_pci_probe_root_resources(info); 1026 if (ret < 0) 1027 goto out_release_info; 1028 1029 pci_acpi_root_add_resources(info); 1030 pci_add_resource(&info->resources, &root->secondary); 1031 bus = pci_create_root_bus(NULL, busnum, ops->pci_ops, 1032 sysdata, &info->resources); 1033 if (!bus) 1034 goto out_release_info; 1035 1036 host_bridge = to_pci_host_bridge(bus->bridge); 1037 if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL)) 1038 host_bridge->native_pcie_hotplug = 0; 1039 if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL)) 1040 host_bridge->native_shpc_hotplug = 0; 1041 if (!(root->osc_control_set & OSC_PCI_EXPRESS_AER_CONTROL)) 1042 host_bridge->native_aer = 0; 1043 if (!(root->osc_control_set & OSC_PCI_EXPRESS_PME_CONTROL)) 1044 host_bridge->native_pme = 0; 1045 if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL)) 1046 host_bridge->native_ltr = 0; 1047 if (!(root->osc_control_set & OSC_PCI_EXPRESS_DPC_CONTROL)) 1048 host_bridge->native_dpc = 0; 1049 1050 /* 1051 * Evaluate the "PCI Boot Configuration" _DSM Function. If it 1052 * exists and returns 0, we must preserve any PCI resource 1053 * assignments made by firmware for this host bridge. 1054 */ 1055 obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), &pci_acpi_dsm_guid, 1, 1056 DSM_PCI_PRESERVE_BOOT_CONFIG, NULL); 1057 if (obj && obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 0) 1058 host_bridge->preserve_config = 1; 1059 ACPI_FREE(obj); 1060 1061 acpi_dev_power_up_children_with_adr(device); 1062 1063 pci_scan_child_bus(bus); 1064 pci_set_host_bridge_release(host_bridge, acpi_pci_root_release_info, 1065 info); 1066 if (node != NUMA_NO_NODE) 1067 dev_printk(KERN_DEBUG, &bus->dev, "on NUMA node %d\n", node); 1068 return bus; 1069 1070 out_release_info: 1071 __acpi_pci_root_release_info(info); 1072 return NULL; 1073 } 1074 1075 void __init acpi_pci_root_init(void) 1076 { 1077 if (acpi_pci_disabled) 1078 return; 1079 1080 pci_acpi_crs_quirks(); 1081 acpi_scan_add_handler_with_hotplug(&pci_root_handler, "pci_root"); 1082 } 1083