staging: iio: ad7606: fix improper setting of oversampling pins
[linux/fpc-iii.git] / drivers / pci / pci-acpi.c
blobd966d47c9e80fbccbf904ed8c546db6645ca5be5
1 /*
2 * File: pci-acpi.c
3 * Purpose: Provide PCI support in ACPI
5 * Copyright (C) 2005 David Shaohua Li <shaohua.li@intel.com>
6 * Copyright (C) 2004 Tom Long Nguyen <tom.l.nguyen@intel.com>
7 * Copyright (C) 2004 Intel Corp.
8 */
10 #include <linux/delay.h>
11 #include <linux/init.h>
12 #include <linux/irqdomain.h>
13 #include <linux/pci.h>
14 #include <linux/msi.h>
15 #include <linux/pci_hotplug.h>
16 #include <linux/module.h>
17 #include <linux/pci-aspm.h>
18 #include <linux/pci-acpi.h>
19 #include <linux/pm_runtime.h>
20 #include <linux/pm_qos.h>
21 #include "pci.h"
24 * The UUID is defined in the PCI Firmware Specification available here:
25 * https://www.pcisig.com/members/downloads/pcifw_r3_1_13Dec10.pdf
27 const u8 pci_acpi_dsm_uuid[] = {
28 0xd0, 0x37, 0xc9, 0xe5, 0x53, 0x35, 0x7a, 0x4d,
29 0x91, 0x17, 0xea, 0x4d, 0x19, 0xc3, 0x43, 0x4d
32 phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle)
34 acpi_status status = AE_NOT_EXIST;
35 unsigned long long mcfg_addr;
37 if (handle)
38 status = acpi_evaluate_integer(handle, METHOD_NAME__CBA,
39 NULL, &mcfg_addr);
40 if (ACPI_FAILURE(status))
41 return 0;
43 return (phys_addr_t)mcfg_addr;
46 static acpi_status decode_type0_hpx_record(union acpi_object *record,
47 struct hotplug_params *hpx)
49 int i;
50 union acpi_object *fields = record->package.elements;
51 u32 revision = fields[1].integer.value;
53 switch (revision) {
54 case 1:
55 if (record->package.count != 6)
56 return AE_ERROR;
57 for (i = 2; i < 6; i++)
58 if (fields[i].type != ACPI_TYPE_INTEGER)
59 return AE_ERROR;
60 hpx->t0 = &hpx->type0_data;
61 hpx->t0->revision = revision;
62 hpx->t0->cache_line_size = fields[2].integer.value;
63 hpx->t0->latency_timer = fields[3].integer.value;
64 hpx->t0->enable_serr = fields[4].integer.value;
65 hpx->t0->enable_perr = fields[5].integer.value;
66 break;
67 default:
68 printk(KERN_WARNING
69 "%s: Type 0 Revision %d record not supported\n",
70 __func__, revision);
71 return AE_ERROR;
73 return AE_OK;
76 static acpi_status decode_type1_hpx_record(union acpi_object *record,
77 struct hotplug_params *hpx)
79 int i;
80 union acpi_object *fields = record->package.elements;
81 u32 revision = fields[1].integer.value;
83 switch (revision) {
84 case 1:
85 if (record->package.count != 5)
86 return AE_ERROR;
87 for (i = 2; i < 5; i++)
88 if (fields[i].type != ACPI_TYPE_INTEGER)
89 return AE_ERROR;
90 hpx->t1 = &hpx->type1_data;
91 hpx->t1->revision = revision;
92 hpx->t1->max_mem_read = fields[2].integer.value;
93 hpx->t1->avg_max_split = fields[3].integer.value;
94 hpx->t1->tot_max_split = fields[4].integer.value;
95 break;
96 default:
97 printk(KERN_WARNING
98 "%s: Type 1 Revision %d record not supported\n",
99 __func__, revision);
100 return AE_ERROR;
102 return AE_OK;
105 static acpi_status decode_type2_hpx_record(union acpi_object *record,
106 struct hotplug_params *hpx)
108 int i;
109 union acpi_object *fields = record->package.elements;
110 u32 revision = fields[1].integer.value;
112 switch (revision) {
113 case 1:
114 if (record->package.count != 18)
115 return AE_ERROR;
116 for (i = 2; i < 18; i++)
117 if (fields[i].type != ACPI_TYPE_INTEGER)
118 return AE_ERROR;
119 hpx->t2 = &hpx->type2_data;
120 hpx->t2->revision = revision;
121 hpx->t2->unc_err_mask_and = fields[2].integer.value;
122 hpx->t2->unc_err_mask_or = fields[3].integer.value;
123 hpx->t2->unc_err_sever_and = fields[4].integer.value;
124 hpx->t2->unc_err_sever_or = fields[5].integer.value;
125 hpx->t2->cor_err_mask_and = fields[6].integer.value;
126 hpx->t2->cor_err_mask_or = fields[7].integer.value;
127 hpx->t2->adv_err_cap_and = fields[8].integer.value;
128 hpx->t2->adv_err_cap_or = fields[9].integer.value;
129 hpx->t2->pci_exp_devctl_and = fields[10].integer.value;
130 hpx->t2->pci_exp_devctl_or = fields[11].integer.value;
131 hpx->t2->pci_exp_lnkctl_and = fields[12].integer.value;
132 hpx->t2->pci_exp_lnkctl_or = fields[13].integer.value;
133 hpx->t2->sec_unc_err_sever_and = fields[14].integer.value;
134 hpx->t2->sec_unc_err_sever_or = fields[15].integer.value;
135 hpx->t2->sec_unc_err_mask_and = fields[16].integer.value;
136 hpx->t2->sec_unc_err_mask_or = fields[17].integer.value;
137 break;
138 default:
139 printk(KERN_WARNING
140 "%s: Type 2 Revision %d record not supported\n",
141 __func__, revision);
142 return AE_ERROR;
144 return AE_OK;
147 static acpi_status acpi_run_hpx(acpi_handle handle, struct hotplug_params *hpx)
149 acpi_status status;
150 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
151 union acpi_object *package, *record, *fields;
152 u32 type;
153 int i;
155 /* Clear the return buffer with zeros */
156 memset(hpx, 0, sizeof(struct hotplug_params));
158 status = acpi_evaluate_object(handle, "_HPX", NULL, &buffer);
159 if (ACPI_FAILURE(status))
160 return status;
162 package = (union acpi_object *)buffer.pointer;
163 if (package->type != ACPI_TYPE_PACKAGE) {
164 status = AE_ERROR;
165 goto exit;
168 for (i = 0; i < package->package.count; i++) {
169 record = &package->package.elements[i];
170 if (record->type != ACPI_TYPE_PACKAGE) {
171 status = AE_ERROR;
172 goto exit;
175 fields = record->package.elements;
176 if (fields[0].type != ACPI_TYPE_INTEGER ||
177 fields[1].type != ACPI_TYPE_INTEGER) {
178 status = AE_ERROR;
179 goto exit;
182 type = fields[0].integer.value;
183 switch (type) {
184 case 0:
185 status = decode_type0_hpx_record(record, hpx);
186 if (ACPI_FAILURE(status))
187 goto exit;
188 break;
189 case 1:
190 status = decode_type1_hpx_record(record, hpx);
191 if (ACPI_FAILURE(status))
192 goto exit;
193 break;
194 case 2:
195 status = decode_type2_hpx_record(record, hpx);
196 if (ACPI_FAILURE(status))
197 goto exit;
198 break;
199 default:
200 printk(KERN_ERR "%s: Type %d record not supported\n",
201 __func__, type);
202 status = AE_ERROR;
203 goto exit;
206 exit:
207 kfree(buffer.pointer);
208 return status;
211 static acpi_status acpi_run_hpp(acpi_handle handle, struct hotplug_params *hpp)
213 acpi_status status;
214 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
215 union acpi_object *package, *fields;
216 int i;
218 memset(hpp, 0, sizeof(struct hotplug_params));
220 status = acpi_evaluate_object(handle, "_HPP", NULL, &buffer);
221 if (ACPI_FAILURE(status))
222 return status;
224 package = (union acpi_object *) buffer.pointer;
225 if (package->type != ACPI_TYPE_PACKAGE ||
226 package->package.count != 4) {
227 status = AE_ERROR;
228 goto exit;
231 fields = package->package.elements;
232 for (i = 0; i < 4; i++) {
233 if (fields[i].type != ACPI_TYPE_INTEGER) {
234 status = AE_ERROR;
235 goto exit;
239 hpp->t0 = &hpp->type0_data;
240 hpp->t0->revision = 1;
241 hpp->t0->cache_line_size = fields[0].integer.value;
242 hpp->t0->latency_timer = fields[1].integer.value;
243 hpp->t0->enable_serr = fields[2].integer.value;
244 hpp->t0->enable_perr = fields[3].integer.value;
246 exit:
247 kfree(buffer.pointer);
248 return status;
251 /* pci_get_hp_params
253 * @dev - the pci_dev for which we want parameters
254 * @hpp - allocated by the caller
256 int pci_get_hp_params(struct pci_dev *dev, struct hotplug_params *hpp)
258 acpi_status status;
259 acpi_handle handle, phandle;
260 struct pci_bus *pbus;
262 if (acpi_pci_disabled)
263 return -ENODEV;
265 handle = NULL;
266 for (pbus = dev->bus; pbus; pbus = pbus->parent) {
267 handle = acpi_pci_get_bridge_handle(pbus);
268 if (handle)
269 break;
273 * _HPP settings apply to all child buses, until another _HPP is
274 * encountered. If we don't find an _HPP for the input pci dev,
275 * look for it in the parent device scope since that would apply to
276 * this pci dev.
278 while (handle) {
279 status = acpi_run_hpx(handle, hpp);
280 if (ACPI_SUCCESS(status))
281 return 0;
282 status = acpi_run_hpp(handle, hpp);
283 if (ACPI_SUCCESS(status))
284 return 0;
285 if (acpi_is_root_bridge(handle))
286 break;
287 status = acpi_get_parent(handle, &phandle);
288 if (ACPI_FAILURE(status))
289 break;
290 handle = phandle;
292 return -ENODEV;
294 EXPORT_SYMBOL_GPL(pci_get_hp_params);
297 * pci_acpi_wake_bus - Root bus wakeup notification fork function.
298 * @work: Work item to handle.
300 static void pci_acpi_wake_bus(struct work_struct *work)
302 struct acpi_device *adev;
303 struct acpi_pci_root *root;
305 adev = container_of(work, struct acpi_device, wakeup.context.work);
306 root = acpi_driver_data(adev);
307 pci_pme_wakeup_bus(root->bus);
311 * pci_acpi_wake_dev - PCI device wakeup notification work function.
312 * @handle: ACPI handle of a device the notification is for.
313 * @work: Work item to handle.
315 static void pci_acpi_wake_dev(struct work_struct *work)
317 struct acpi_device_wakeup_context *context;
318 struct pci_dev *pci_dev;
320 context = container_of(work, struct acpi_device_wakeup_context, work);
321 pci_dev = to_pci_dev(context->dev);
323 if (pci_dev->pme_poll)
324 pci_dev->pme_poll = false;
326 if (pci_dev->current_state == PCI_D3cold) {
327 pci_wakeup_event(pci_dev);
328 pm_runtime_resume(&pci_dev->dev);
329 return;
332 /* Clear PME Status if set. */
333 if (pci_dev->pme_support)
334 pci_check_pme_status(pci_dev);
336 pci_wakeup_event(pci_dev);
337 pm_runtime_resume(&pci_dev->dev);
339 pci_pme_wakeup_bus(pci_dev->subordinate);
343 * pci_acpi_add_bus_pm_notifier - Register PM notifier for root PCI bus.
344 * @dev: PCI root bridge ACPI device.
346 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev)
348 return acpi_add_pm_notifier(dev, NULL, pci_acpi_wake_bus);
352 * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
353 * @dev: ACPI device to add the notifier for.
354 * @pci_dev: PCI device to check for the PME status if an event is signaled.
356 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
357 struct pci_dev *pci_dev)
359 return acpi_add_pm_notifier(dev, &pci_dev->dev, pci_acpi_wake_dev);
363 * _SxD returns the D-state with the highest power
364 * (lowest D-state number) supported in the S-state "x".
366 * If the devices does not have a _PRW
367 * (Power Resources for Wake) supporting system wakeup from "x"
368 * then the OS is free to choose a lower power (higher number
369 * D-state) than the return value from _SxD.
371 * But if _PRW is enabled at S-state "x", the OS
372 * must not choose a power lower than _SxD --
373 * unless the device has an _SxW method specifying
374 * the lowest power (highest D-state number) the device
375 * may enter while still able to wake the system.
377 * ie. depending on global OS policy:
379 * if (_PRW at S-state x)
380 * choose from highest power _SxD to lowest power _SxW
381 * else // no _PRW at S-state x
382 * choose highest power _SxD or any lower power
385 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
387 int acpi_state, d_max;
389 if (pdev->no_d3cold)
390 d_max = ACPI_STATE_D3_HOT;
391 else
392 d_max = ACPI_STATE_D3_COLD;
393 acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max);
394 if (acpi_state < 0)
395 return PCI_POWER_ERROR;
397 switch (acpi_state) {
398 case ACPI_STATE_D0:
399 return PCI_D0;
400 case ACPI_STATE_D1:
401 return PCI_D1;
402 case ACPI_STATE_D2:
403 return PCI_D2;
404 case ACPI_STATE_D3_HOT:
405 return PCI_D3hot;
406 case ACPI_STATE_D3_COLD:
407 return PCI_D3cold;
409 return PCI_POWER_ERROR;
412 static bool acpi_pci_power_manageable(struct pci_dev *dev)
414 struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
415 return adev ? acpi_device_power_manageable(adev) : false;
418 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
420 struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
421 static const u8 state_conv[] = {
422 [PCI_D0] = ACPI_STATE_D0,
423 [PCI_D1] = ACPI_STATE_D1,
424 [PCI_D2] = ACPI_STATE_D2,
425 [PCI_D3hot] = ACPI_STATE_D3_HOT,
426 [PCI_D3cold] = ACPI_STATE_D3_COLD,
428 int error = -EINVAL;
430 /* If the ACPI device has _EJ0, ignore the device */
431 if (!adev || acpi_has_method(adev->handle, "_EJ0"))
432 return -ENODEV;
434 switch (state) {
435 case PCI_D3cold:
436 if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
437 PM_QOS_FLAGS_ALL) {
438 error = -EBUSY;
439 break;
441 case PCI_D0:
442 case PCI_D1:
443 case PCI_D2:
444 case PCI_D3hot:
445 error = acpi_device_set_power(adev, state_conv[state]);
448 if (!error)
449 dev_dbg(&dev->dev, "power state changed by ACPI to %s\n",
450 acpi_power_state_string(state_conv[state]));
452 return error;
455 static pci_power_t acpi_pci_get_power_state(struct pci_dev *dev)
457 struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
458 static const pci_power_t state_conv[] = {
459 [ACPI_STATE_D0] = PCI_D0,
460 [ACPI_STATE_D1] = PCI_D1,
461 [ACPI_STATE_D2] = PCI_D2,
462 [ACPI_STATE_D3_HOT] = PCI_D3hot,
463 [ACPI_STATE_D3_COLD] = PCI_D3cold,
465 int state;
467 if (!adev || !acpi_device_power_manageable(adev))
468 return PCI_UNKNOWN;
470 if (acpi_device_get_power(adev, &state) || state == ACPI_STATE_UNKNOWN)
471 return PCI_UNKNOWN;
473 return state_conv[state];
476 static bool acpi_pci_can_wakeup(struct pci_dev *dev)
478 struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
479 return adev ? acpi_device_can_wakeup(adev) : false;
482 static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable)
484 while (bus->parent) {
485 if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable))
486 return;
487 bus = bus->parent;
490 /* We have reached the root bus. */
491 if (bus->bridge)
492 acpi_pm_device_sleep_wake(bus->bridge, enable);
495 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
497 if (acpi_pci_can_wakeup(dev))
498 return acpi_pm_device_sleep_wake(&dev->dev, enable);
500 acpi_pci_propagate_wakeup_enable(dev->bus, enable);
501 return 0;
504 static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable)
506 while (bus->parent) {
507 struct pci_dev *bridge = bus->self;
509 if (bridge->pme_interrupt)
510 return;
511 if (!acpi_pm_device_run_wake(&bridge->dev, enable))
512 return;
513 bus = bus->parent;
516 /* We have reached the root bus. */
517 if (bus->bridge)
518 acpi_pm_device_run_wake(bus->bridge, enable);
521 static int acpi_pci_run_wake(struct pci_dev *dev, bool enable)
524 * Per PCI Express Base Specification Revision 2.0 section
525 * 5.3.3.2 Link Wakeup, platform support is needed for D3cold
526 * waking up to power on the main link even if there is PME
527 * support for D3cold
529 if (dev->pme_interrupt && !dev->runtime_d3cold)
530 return 0;
532 if (!acpi_pm_device_run_wake(&dev->dev, enable))
533 return 0;
535 acpi_pci_propagate_run_wake(dev->bus, enable);
536 return 0;
539 static bool acpi_pci_need_resume(struct pci_dev *dev)
541 struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
543 if (!adev || !acpi_device_power_manageable(adev))
544 return false;
546 if (device_may_wakeup(&dev->dev) != !!adev->wakeup.prepare_count)
547 return true;
549 if (acpi_target_system_state() == ACPI_STATE_S0)
550 return false;
552 return !!adev->power.flags.dsw_present;
555 static const struct pci_platform_pm_ops acpi_pci_platform_pm = {
556 .is_manageable = acpi_pci_power_manageable,
557 .set_state = acpi_pci_set_power_state,
558 .get_state = acpi_pci_get_power_state,
559 .choose_state = acpi_pci_choose_state,
560 .sleep_wake = acpi_pci_sleep_wake,
561 .run_wake = acpi_pci_run_wake,
562 .need_resume = acpi_pci_need_resume,
565 void acpi_pci_add_bus(struct pci_bus *bus)
567 union acpi_object *obj;
568 struct pci_host_bridge *bridge;
570 if (acpi_pci_disabled || !bus->bridge)
571 return;
573 acpi_pci_slot_enumerate(bus);
574 acpiphp_enumerate_slots(bus);
577 * For a host bridge, check its _DSM for function 8 and if
578 * that is available, mark it in pci_host_bridge.
580 if (!pci_is_root_bus(bus))
581 return;
583 obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), pci_acpi_dsm_uuid, 3,
584 RESET_DELAY_DSM, NULL);
585 if (!obj)
586 return;
588 if (obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 1) {
589 bridge = pci_find_host_bridge(bus);
590 bridge->ignore_reset_delay = 1;
592 ACPI_FREE(obj);
595 void acpi_pci_remove_bus(struct pci_bus *bus)
597 if (acpi_pci_disabled || !bus->bridge)
598 return;
600 acpiphp_remove_slots(bus);
601 acpi_pci_slot_remove(bus);
604 /* ACPI bus type */
605 static struct acpi_device *acpi_pci_find_companion(struct device *dev)
607 struct pci_dev *pci_dev = to_pci_dev(dev);
608 bool check_children;
609 u64 addr;
611 check_children = pci_is_bridge(pci_dev);
612 /* Please ref to ACPI spec for the syntax of _ADR */
613 addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
614 return acpi_find_child_device(ACPI_COMPANION(dev->parent), addr,
615 check_children);
619 * pci_acpi_optimize_delay - optimize PCI D3 and D3cold delay from ACPI
620 * @pdev: the PCI device whose delay is to be updated
621 * @handle: ACPI handle of this device
623 * Update the d3_delay and d3cold_delay of a PCI device from the ACPI _DSM
624 * control method of either the device itself or the PCI host bridge.
626 * Function 8, "Reset Delay," applies to the entire hierarchy below a PCI
627 * host bridge. If it returns one, the OS may assume that all devices in
628 * the hierarchy have already completed power-on reset delays.
630 * Function 9, "Device Readiness Durations," applies only to the object
631 * where it is located. It returns delay durations required after various
632 * events if the device requires less time than the spec requires. Delays
633 * from this function take precedence over the Reset Delay function.
635 * These _DSM functions are defined by the draft ECN of January 28, 2014,
636 * titled "ACPI additions for FW latency optimizations."
638 static void pci_acpi_optimize_delay(struct pci_dev *pdev,
639 acpi_handle handle)
641 struct pci_host_bridge *bridge = pci_find_host_bridge(pdev->bus);
642 int value;
643 union acpi_object *obj, *elements;
645 if (bridge->ignore_reset_delay)
646 pdev->d3cold_delay = 0;
648 obj = acpi_evaluate_dsm(handle, pci_acpi_dsm_uuid, 3,
649 FUNCTION_DELAY_DSM, NULL);
650 if (!obj)
651 return;
653 if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 5) {
654 elements = obj->package.elements;
655 if (elements[0].type == ACPI_TYPE_INTEGER) {
656 value = (int)elements[0].integer.value / 1000;
657 if (value < PCI_PM_D3COLD_WAIT)
658 pdev->d3cold_delay = value;
660 if (elements[3].type == ACPI_TYPE_INTEGER) {
661 value = (int)elements[3].integer.value / 1000;
662 if (value < PCI_PM_D3_WAIT)
663 pdev->d3_delay = value;
666 ACPI_FREE(obj);
669 static void pci_acpi_setup(struct device *dev)
671 struct pci_dev *pci_dev = to_pci_dev(dev);
672 struct acpi_device *adev = ACPI_COMPANION(dev);
674 if (!adev)
675 return;
677 pci_acpi_optimize_delay(pci_dev, adev->handle);
679 pci_acpi_add_pm_notifier(adev, pci_dev);
680 if (!adev->wakeup.flags.valid)
681 return;
683 device_set_wakeup_capable(dev, true);
684 acpi_pci_sleep_wake(pci_dev, false);
685 if (adev->wakeup.flags.run_wake)
686 device_set_run_wake(dev, true);
689 static void pci_acpi_cleanup(struct device *dev)
691 struct acpi_device *adev = ACPI_COMPANION(dev);
693 if (!adev)
694 return;
696 pci_acpi_remove_pm_notifier(adev);
697 if (adev->wakeup.flags.valid) {
698 device_set_wakeup_capable(dev, false);
699 device_set_run_wake(dev, false);
703 static bool pci_acpi_bus_match(struct device *dev)
705 return dev_is_pci(dev);
708 static struct acpi_bus_type acpi_pci_bus = {
709 .name = "PCI",
710 .match = pci_acpi_bus_match,
711 .find_companion = acpi_pci_find_companion,
712 .setup = pci_acpi_setup,
713 .cleanup = pci_acpi_cleanup,
717 static struct fwnode_handle *(*pci_msi_get_fwnode_cb)(struct device *dev);
720 * pci_msi_register_fwnode_provider - Register callback to retrieve fwnode
721 * @fn: Callback matching a device to a fwnode that identifies a PCI
722 * MSI domain.
724 * This should be called by irqchip driver, which is the parent of
725 * the MSI domain to provide callback interface to query fwnode.
727 void
728 pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *))
730 pci_msi_get_fwnode_cb = fn;
734 * pci_host_bridge_acpi_msi_domain - Retrieve MSI domain of a PCI host bridge
735 * @bus: The PCI host bridge bus.
737 * This function uses the callback function registered by
738 * pci_msi_register_fwnode_provider() to retrieve the irq_domain with
739 * type DOMAIN_BUS_PCI_MSI of the specified host bridge bus.
740 * This returns NULL on error or when the domain is not found.
742 struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus)
744 struct fwnode_handle *fwnode;
746 if (!pci_msi_get_fwnode_cb)
747 return NULL;
749 fwnode = pci_msi_get_fwnode_cb(&bus->dev);
750 if (!fwnode)
751 return NULL;
753 return irq_find_matching_fwnode(fwnode, DOMAIN_BUS_PCI_MSI);
756 static int __init acpi_pci_init(void)
758 int ret;
760 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
761 pr_info("ACPI FADT declares the system doesn't support MSI, so disable it\n");
762 pci_no_msi();
765 if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
766 pr_info("ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
767 pcie_no_aspm();
770 ret = register_acpi_bus_type(&acpi_pci_bus);
771 if (ret)
772 return 0;
774 pci_set_platform_pm(&acpi_pci_platform_pm);
775 acpi_pci_slot_init();
776 acpiphp_init();
778 return 0;
780 arch_initcall(acpi_pci_init);