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
296struct 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 */
313struct 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(dev: pn->dev);
327 pci_dev = to_pci_dev(pn->dev);
328 break;
329 }
330 }
331
332 mutex_unlock(lock: &adev->physical_node_lock);
333
334 return pci_dev;
335}
336EXPORT_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 **/
355static 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, control: mask, cxl_support,
384 cxl_control: 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, msg: "platform does not support",
399 word: pci_missing);
400 if (cxl_missing)
401 decode_cxl_osc_control(root, msg: "CXL platform does not support",
402 word: 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, msg: "not requesting control; platform does not support",
414 word: 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, pci_control: mask, cxl_control: 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
435static 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 */
491static 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
505static 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
536static 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
546static 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, msg: "not requesting OS control; OS requires",
557 ACPI_PCIE_REQ_SUPPORT);
558 return false;
559 }
560
561 return true;
562}
563
564static 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, msg: "OS assumes control of",
580 word: root->osc_control_set);
581 return;
582 }
583
584 support = calculate_support();
585
586 decode_osc_support(root, msg: "OS supports", word: 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, msg: "OS supports", word: cxl_support);
594 cxl_requested = cxl_control = calculate_cxl_control();
595 }
596
597 status = acpi_pci_osc_control_set(handle, mask: &control, support,
598 cxl_mask: &cxl_control, cxl_support);
599 if (ACPI_SUCCESS(status)) {
600 if (control)
601 decode_osc_control(root, msg: "OS now controls", word: control);
602 if (cxl_control)
603 decode_cxl_osc_control(root, msg: "OS now controls",
604 word: 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, msg: "OS requested", word: requested);
631 decode_osc_control(root, msg: "platform willing to grant", word: control);
632 }
633 if (cxl_control) {
634 decode_cxl_osc_control(root, msg: "OS requested", word: cxl_requested);
635 decode_cxl_osc_control(root, msg: "platform willing to grant",
636 word: 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
644static 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(size: 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 data: &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, res: &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, data: &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(device: 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: &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(dev: device);
747 device_set_wakeup_capable(dev: root->bus->bridge, capable: device->wakeup.flags.valid);
748
749 if (hotadd) {
750 pcibios_resource_survey_bus(bus: root->bus);
751 pci_assign_unassigned_root_bus_resources(bus: 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: root->device->handle);
763 }
764
765 pci_lock_rescan_remove();
766 pci_bus_add_devices(bus: root->bus);
767 pci_unlock_rescan_remove();
768 return 1;
769
770remove_dmar:
771 if (hotadd)
772 dmar_device_remove(handle);
773end:
774 kfree(objp: root);
775 return result;
776}
777
778static void acpi_pci_root_remove(struct acpi_device *device)
779{
780 struct acpi_pci_root *root = acpi_driver_data(d: device);
781
782 pci_lock_rescan_remove();
783
784 pci_stop_root_bus(bus: root->bus);
785
786 pci_ioapic_remove(root);
787 device_set_wakeup_capable(dev: root->bus->bridge, capable: false);
788 pci_acpi_remove_bus_pm_notifier(dev: device);
789
790 pci_remove_root_bus(bus: root->bus);
791 WARN_ON(acpi_ioapic_remove(root));
792
793 dmar_device_remove(handle: device->handle);
794
795 pci_unlock_rescan_remove();
796
797 kfree(objp: 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 */
805static 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(list: resources, head: &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(r1: res1, r2: res2, r: 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
857next:
858 resource_list_del(entry);
859 if (free)
860 resource_list_free_entry(entry);
861 else
862 resource_list_add_tail(entry, head: resources);
863 }
864}
865
866static 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;
892err:
893 res->flags |= IORESOURCE_DISABLED;
894#endif
895}
896
897int 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(adev: device, list,
907 preproc: acpi_dev_filter_resource_type_cb,
908 preproc_data: (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(fwnode: &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(dev: &device->dev, resources: list,
927 IORESOURCE_MEM);
928 acpi_pci_root_validate_resources(dev: &device->dev, resources: list,
929 IORESOURCE_IO);
930 }
931
932 return ret;
933}
934
935static 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(parent: root, new: 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
966static 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(new: res);
979 resource_list_destroy_entry(entry);
980 }
981
982 info->ops->release_info(info);
983}
984
985static 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(new: res);
997 }
998 __acpi_pci_root_release_info(info: bridge->release_data);
999}
1000
1001struct 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(handle: 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(list: &info->resources);
1017 snprintf(buf: info->name, size: sizeof(info->name), fmt: "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(resources: &info->resources, res: &root->secondary);
1031 bus = pci_create_root_bus(NULL, bus: busnum, ops: ops->pci_ops,
1032 sysdata, resources: &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 if (!(root->osc_ext_control_set & OSC_CXL_ERROR_REPORTING_CONTROL))
1051 host_bridge->native_cxl_error = 0;
1052
1053 /*
1054 * Evaluate the "PCI Boot Configuration" _DSM Function. If it
1055 * exists and returns 0, we must preserve any PCI resource
1056 * assignments made by firmware for this host bridge.
1057 */
1058 obj = acpi_evaluate_dsm_typed(ACPI_HANDLE(bus->bridge), guid: &pci_acpi_dsm_guid, rev: 1,
1059 DSM_PCI_PRESERVE_BOOT_CONFIG, NULL, ACPI_TYPE_INTEGER);
1060 if (obj && obj->integer.value == 0)
1061 host_bridge->preserve_config = 1;
1062 ACPI_FREE(obj);
1063
1064 acpi_dev_power_up_children_with_adr(adev: device);
1065
1066 pci_scan_child_bus(bus);
1067 pci_set_host_bridge_release(bridge: host_bridge, release_fn: acpi_pci_root_release_info,
1068 release_data: info);
1069 if (node != NUMA_NO_NODE)
1070 dev_printk(KERN_DEBUG, &bus->dev, "on NUMA node %d\n", node);
1071 return bus;
1072
1073out_release_info:
1074 __acpi_pci_root_release_info(info);
1075 return NULL;
1076}
1077
1078void __init acpi_pci_root_init(void)
1079{
1080 if (acpi_pci_disabled)
1081 return;
1082
1083 pci_acpi_crs_quirks();
1084 acpi_scan_add_handler_with_hotplug(handler: &pci_root_handler, hotplug_profile_name: "pci_root");
1085}
1086

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