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"
29static int acpi_pci_root_add(struct acpi_device *device,
30 const struct acpi_device_id *not_used);
31static void acpi_pci_root_remove(struct acpi_device *device);
32
33static 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
44static const struct acpi_device_id root_device_ids[] = {
45 {"PNP0A03", 0},
46 {"", 0},
47};
48
49static 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 */
66int 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, ids: root_device_ids);
75 if (ret)
76 return 0;
77 else
78 return 1;
79}
80EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
81
82static acpi_status
83get_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, out: &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
102static 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(device: handle, METHOD_NAME__CRS,
110 user_function: get_root_bridge_busnr_callback, context: res);
111 if (ACPI_FAILURE(status))
112 return status;
113 if (res->start == -1)
114 return AE_ERROR;
115 return AE_OK;
116}
117
118struct pci_osc_bit_struct {
119 u32 bit;
120 char *desc;
121};
122
123static 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
133static 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
143static 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
150static struct pci_osc_bit_struct cxl_osc_control_bit[] = {
151 { OSC_CXL_ERROR_REPORTING_CONTROL, "CXLMemErrorReporting" },
152};
153
154static 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: buf + len, size: sizeof(buf) - len, fmt: "%s%s",
165 len ? " " : "", entry->desc);
166
167 dev_info(&root->device->dev, "_OSC: %s [%s]\n", msg, buf);
168}
169
170static void decode_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
171{
172 decode_osc_bits(root, msg, word, table: pci_osc_support_bit,
173 ARRAY_SIZE(pci_osc_support_bit));
174}
175
176static void decode_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
177{
178 decode_osc_bits(root, msg, word, table: pci_osc_control_bit,
179 ARRAY_SIZE(pci_osc_control_bit));
180}
181
182static void decode_cxl_osc_support(struct acpi_pci_root *root, char *msg, u32 word)
183{
184 decode_osc_bits(root, msg, word, table: cxl_osc_support_bit,
185 ARRAY_SIZE(cxl_osc_support_bit));
186}
187
188static void decode_cxl_osc_control(struct acpi_pci_root *root, char *msg, u32 word)
189{
190 decode_osc_bits(root, msg, word, table: cxl_osc_control_bit,
191 ARRAY_SIZE(cxl_osc_control_bit));
192}
193
194static inline bool is_pcie(struct acpi_pci_root *root)
195{
196 return root->bridge_type == ACPI_BRIDGE_TYPE_PCIE;
197}
198
199static inline bool is_cxl(struct acpi_pci_root *root)
200{
201 return root->bridge_type == ACPI_BRIDGE_TYPE_CXL;
202}
203
204static u8 pci_osc_uuid_str[] = "33DB4D5B-1FF7-401C-9657-7441C03DD766";
205static u8 cxl_osc_uuid_str[] = "68F2D50B-C469-4d8A-BD3D-941A103FD3FC";
206
207static 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
214static 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
221static 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(handle: root->device->handle, context: &context);
234 if (ACPI_SUCCESS(status)) {
235 *pci_control = acpi_osc_ctx_get_pci_control(context: &context);
236 if (is_cxl(root))
237 *cxl_control = acpi_osc_ctx_get_cxl_control(context: &context);
238 kfree(objp: context.ret.pointer);
239 }
240 return status;
241}
242
243static 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
262retry:
263 status = acpi_pci_run_osc(root, capbuf, pci_control: &pci_result, cxl_control: &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
282struct 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, ids: root_device_ids))
288 return NULL;
289
290 root = acpi_driver_data(d: device);
291
292 return root;
293}
294EXPORT_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 */
308struct 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(dev: pn->dev);
322 pci_dev = to_pci_dev(pn->dev);
323 break;
324 }
325 }
326
327 mutex_unlock(lock: &adev->physical_node_lock);
328
329 return pci_dev;
330}
331EXPORT_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 **/
350static 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, control: mask, cxl_support,
379 cxl_control: 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, msg: "platform does not support",
394 word: pci_missing);
395 if (cxl_missing)
396 decode_cxl_osc_control(root, msg: "CXL platform does not support",
397 word: 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, msg: "not requesting control; platform does not support",
409 word: 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, pci_control: mask, cxl_control: 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
430static 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/20201122014203.4706-1-ashok.raj@intel.com/
485 */
486static 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
500static 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
531static 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
541static 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, msg: "not requesting OS control; OS requires",
552 ACPI_PCIE_REQ_SUPPORT);
553 return false;
554 }
555
556 return true;
557}
558
559static 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, msg: "OS assumes control of",
575 word: root->osc_control_set);
576 return;
577 }
578
579 support = calculate_support();
580
581 decode_osc_support(root, msg: "OS supports", word: 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, msg: "OS supports", word: cxl_support);
589 cxl_requested = cxl_control = calculate_cxl_control();
590 }
591
592 status = acpi_pci_osc_control_set(handle, mask: &control, support,
593 cxl_mask: &cxl_control, cxl_support);
594 if (ACPI_SUCCESS(status)) {
595 if (control)
596 decode_osc_control(root, msg: "OS now controls", word: control);
597 if (cxl_control)
598 decode_cxl_osc_control(root, msg: "OS now controls",
599 word: 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, msg: "OS requested", word: requested);
626 decode_osc_control(root, msg: "platform willing to grant", word: control);
627 }
628 if (cxl_control) {
629 decode_cxl_osc_control(root, msg: "OS requested", word: cxl_requested);
630 decode_cxl_osc_control(root, msg: "platform willing to grant",
631 word: 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
639static 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 data: &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, res: &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, data: &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(device: 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: &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(dev: device);
742 device_set_wakeup_capable(dev: root->bus->bridge, capable: device->wakeup.flags.valid);
743
744 if (hotadd) {
745 pcibios_resource_survey_bus(bus: root->bus);
746 pci_assign_unassigned_root_bus_resources(bus: 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: root->device->handle);
758 }
759
760 pci_lock_rescan_remove();
761 pci_bus_add_devices(bus: root->bus);
762 pci_unlock_rescan_remove();
763 return 1;
764
765remove_dmar:
766 if (hotadd)
767 dmar_device_remove(handle);
768end:
769 kfree(objp: root);
770 return result;
771}
772
773static void acpi_pci_root_remove(struct acpi_device *device)
774{
775 struct acpi_pci_root *root = acpi_driver_data(d: device);
776
777 pci_lock_rescan_remove();
778
779 pci_stop_root_bus(bus: root->bus);
780
781 pci_ioapic_remove(root);
782 device_set_wakeup_capable(dev: root->bus->bridge, capable: false);
783 pci_acpi_remove_bus_pm_notifier(dev: device);
784
785 pci_remove_root_bus(bus: root->bus);
786 WARN_ON(acpi_ioapic_remove(root));
787
788 dmar_device_remove(handle: device->handle);
789
790 pci_unlock_rescan_remove();
791
792 kfree(objp: 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 */
800static 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(list: resources, head: &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(r1: res1, r2: res2, r: 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
852next:
853 resource_list_del(entry);
854 if (free)
855 resource_list_free_entry(entry);
856 else
857 resource_list_add_tail(entry, head: resources);
858 }
859}
860
861static void acpi_pci_root_remap_iospace(const 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;
887err:
888 res->flags |= IORESOURCE_DISABLED;
889#endif
890}
891
892int 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(adev: device, list,
902 preproc: acpi_dev_filter_resource_type_cb,
903 preproc_data: (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(fwnode: &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(dev: &device->dev, resources: list,
922 IORESOURCE_MEM);
923 acpi_pci_root_validate_resources(dev: &device->dev, resources: list,
924 IORESOURCE_IO);
925 }
926
927 return ret;
928}
929
930static 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(parent: root, new: 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
961static 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(new: res);
974 resource_list_destroy_entry(entry);
975 }
976
977 info->ops->release_info(info);
978}
979
980static 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(new: res);
992 }
993 __acpi_pci_root_release_info(info: bridge->release_data);
994}
995
996struct 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(handle: 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(list: &info->resources);
1011 snprintf(buf: info->name, size: sizeof(info->name), fmt: "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(resources: &info->resources, res: &root->secondary);
1025 bus = pci_create_root_bus(NULL, bus: busnum, ops: ops->pci_ops,
1026 sysdata, resources: &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(adev: device);
1048
1049 pci_scan_child_bus(bus);
1050 pci_set_host_bridge_release(bridge: host_bridge, release_fn: acpi_pci_root_release_info,
1051 release_data: info);
1052 if (node != NUMA_NO_NODE)
1053 dev_printk(KERN_DEBUG, &bus->dev, "on NUMA node %d\n", node);
1054 return bus;
1055
1056out_release_info:
1057 __acpi_pci_root_release_info(info);
1058 return NULL;
1059}
1060
1061void __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(handler: &pci_root_handler, hotplug_profile_name: "pci_root");
1068}
1069

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source code of linux/drivers/acpi/pci_root.c