1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * ACPI PCI HotPlug glue functions to ACPI CA subsystem
4 *
5 * Copyright (C) 2002,2003 Takayoshi Kochi (t-kochi@bq.jp.nec.com)
6 * Copyright (C) 2002 Hiroshi Aono (h-aono@ap.jp.nec.com)
7 * Copyright (C) 2002,2003 NEC Corporation
8 * Copyright (C) 2003-2005 Matthew Wilcox (willy@infradead.org)
9 * Copyright (C) 2003-2005 Hewlett Packard
10 * Copyright (C) 2005 Rajesh Shah (rajesh.shah@intel.com)
11 * Copyright (C) 2005 Intel Corporation
12 *
13 * All rights reserved.
14 *
15 * Send feedback to <kristen.c.accardi@intel.com>
16 *
17 */
18
19/*
20 * Lifetime rules for pci_dev:
21 * - The one in acpiphp_bridge has its refcount elevated by pci_get_slot()
22 * when the bridge is scanned and it loses a refcount when the bridge
23 * is removed.
24 * - When a P2P bridge is present, we elevate the refcount on the subordinate
25 * bus. It loses the refcount when the driver unloads.
26 */
27
28#define pr_fmt(fmt) "acpiphp_glue: " fmt
29
30#include <linux/module.h>
31
32#include <linux/kernel.h>
33#include <linux/pci.h>
34#include <linux/pci_hotplug.h>
35#include <linux/pci-acpi.h>
36#include <linux/pm_runtime.h>
37#include <linux/mutex.h>
38#include <linux/slab.h>
39#include <linux/acpi.h>
40
41#include "../pci.h"
42#include "acpiphp.h"
43
44static LIST_HEAD(bridge_list);
45static DEFINE_MUTEX(bridge_mutex);
46
47static int acpiphp_hotplug_notify(struct acpi_device *adev, u32 type);
48static void acpiphp_post_dock_fixup(struct acpi_device *adev);
49static void acpiphp_sanitize_bus(struct pci_bus *bus);
50static void hotplug_event(u32 type, struct acpiphp_context *context);
51static void free_bridge(struct kref *kref);
52
53/**
54 * acpiphp_init_context - Create hotplug context and grab a reference to it.
55 * @adev: ACPI device object to create the context for.
56 *
57 * Call under acpi_hp_context_lock.
58 */
59static struct acpiphp_context *acpiphp_init_context(struct acpi_device *adev)
60{
61 struct acpiphp_context *context;
62
63 context = kzalloc(size: sizeof(*context), GFP_KERNEL);
64 if (!context)
65 return NULL;
66
67 context->refcount = 1;
68 context->hp.notify = acpiphp_hotplug_notify;
69 context->hp.fixup = acpiphp_post_dock_fixup;
70 acpi_set_hp_context(adev, hp: &context->hp);
71 return context;
72}
73
74/**
75 * acpiphp_get_context - Get hotplug context and grab a reference to it.
76 * @adev: ACPI device object to get the context for.
77 *
78 * Call under acpi_hp_context_lock.
79 */
80static struct acpiphp_context *acpiphp_get_context(struct acpi_device *adev)
81{
82 struct acpiphp_context *context;
83
84 if (!adev->hp)
85 return NULL;
86
87 context = to_acpiphp_context(hp: adev->hp);
88 context->refcount++;
89 return context;
90}
91
92/**
93 * acpiphp_put_context - Drop a reference to ACPI hotplug context.
94 * @context: ACPI hotplug context to drop a reference to.
95 *
96 * The context object is removed if there are no more references to it.
97 *
98 * Call under acpi_hp_context_lock.
99 */
100static void acpiphp_put_context(struct acpiphp_context *context)
101{
102 if (--context->refcount)
103 return;
104
105 WARN_ON(context->bridge);
106 context->hp.self->hp = NULL;
107 kfree(objp: context);
108}
109
110static inline void get_bridge(struct acpiphp_bridge *bridge)
111{
112 kref_get(kref: &bridge->ref);
113}
114
115static inline void put_bridge(struct acpiphp_bridge *bridge)
116{
117 kref_put(kref: &bridge->ref, release: free_bridge);
118}
119
120static struct acpiphp_context *acpiphp_grab_context(struct acpi_device *adev)
121{
122 struct acpiphp_context *context;
123
124 acpi_lock_hp_context();
125
126 context = acpiphp_get_context(adev);
127 if (!context)
128 goto unlock;
129
130 if (context->func.parent->is_going_away) {
131 acpiphp_put_context(context);
132 context = NULL;
133 goto unlock;
134 }
135
136 get_bridge(bridge: context->func.parent);
137 acpiphp_put_context(context);
138
139unlock:
140 acpi_unlock_hp_context();
141 return context;
142}
143
144static void acpiphp_let_context_go(struct acpiphp_context *context)
145{
146 put_bridge(bridge: context->func.parent);
147}
148
149static void free_bridge(struct kref *kref)
150{
151 struct acpiphp_context *context;
152 struct acpiphp_bridge *bridge;
153 struct acpiphp_slot *slot, *next;
154 struct acpiphp_func *func, *tmp;
155
156 acpi_lock_hp_context();
157
158 bridge = container_of(kref, struct acpiphp_bridge, ref);
159
160 list_for_each_entry_safe(slot, next, &bridge->slots, node) {
161 list_for_each_entry_safe(func, tmp, &slot->funcs, sibling)
162 acpiphp_put_context(context: func_to_context(func));
163
164 kfree(objp: slot);
165 }
166
167 context = bridge->context;
168 /* Root bridges will not have hotplug context. */
169 if (context) {
170 /* Release the reference taken by acpiphp_enumerate_slots(). */
171 put_bridge(bridge: context->func.parent);
172 context->bridge = NULL;
173 acpiphp_put_context(context);
174 }
175
176 put_device(dev: &bridge->pci_bus->dev);
177 pci_dev_put(dev: bridge->pci_dev);
178 kfree(objp: bridge);
179
180 acpi_unlock_hp_context();
181}
182
183/**
184 * acpiphp_post_dock_fixup - Post-dock fixups for PCI devices.
185 * @adev: ACPI device object corresponding to a PCI device.
186 *
187 * TBD - figure out a way to only call fixups for systems that require them.
188 */
189static void acpiphp_post_dock_fixup(struct acpi_device *adev)
190{
191 struct acpiphp_context *context = acpiphp_grab_context(adev);
192 struct pci_bus *bus;
193 u32 buses;
194
195 if (!context)
196 return;
197
198 bus = context->func.slot->bus;
199 if (!bus->self)
200 goto out;
201
202 /* fixup bad _DCK function that rewrites
203 * secondary bridge on slot
204 */
205 pci_read_config_dword(dev: bus->self, PCI_PRIMARY_BUS, val: &buses);
206
207 if (((buses >> 8) & 0xff) != bus->busn_res.start) {
208 buses = (buses & 0xff000000)
209 | ((unsigned int)(bus->primary) << 0)
210 | ((unsigned int)(bus->busn_res.start) << 8)
211 | ((unsigned int)(bus->busn_res.end) << 16);
212 pci_write_config_dword(dev: bus->self, PCI_PRIMARY_BUS, val: buses);
213 }
214
215 out:
216 acpiphp_let_context_go(context);
217}
218
219/**
220 * acpiphp_add_context - Add ACPIPHP context to an ACPI device object.
221 * @handle: ACPI handle of the object to add a context to.
222 * @lvl: Not used.
223 * @data: The object's parent ACPIPHP bridge.
224 * @rv: Not used.
225 */
226static acpi_status acpiphp_add_context(acpi_handle handle, u32 lvl, void *data,
227 void **rv)
228{
229 struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
230 struct acpiphp_bridge *bridge = data;
231 struct acpiphp_context *context;
232 struct acpiphp_slot *slot;
233 struct acpiphp_func *newfunc;
234 acpi_status status = AE_OK;
235 unsigned long long adr;
236 int device, function;
237 struct pci_bus *pbus = bridge->pci_bus;
238 struct pci_dev *pdev = bridge->pci_dev;
239 u32 val;
240
241 if (!adev)
242 return AE_OK;
243
244 status = acpi_evaluate_integer(handle, pathname: "_ADR", NULL, data: &adr);
245 if (ACPI_FAILURE(status)) {
246 if (status != AE_NOT_FOUND)
247 acpi_handle_warn(handle,
248 "can't evaluate _ADR (%#x)\n", status);
249 return AE_OK;
250 }
251
252 device = (adr >> 16) & 0xffff;
253 function = adr & 0xffff;
254
255 acpi_lock_hp_context();
256 context = acpiphp_init_context(adev);
257 if (!context) {
258 acpi_unlock_hp_context();
259 acpi_handle_err(handle, "No hotplug context\n");
260 return AE_NOT_EXIST;
261 }
262 newfunc = &context->func;
263 newfunc->function = function;
264 newfunc->parent = bridge;
265 acpi_unlock_hp_context();
266
267 /*
268 * If this is a dock device, its _EJ0 should be executed by the dock
269 * notify handler after calling _DCK.
270 */
271 if (!is_dock_device(adev) && acpi_has_method(handle, name: "_EJ0"))
272 newfunc->flags = FUNC_HAS_EJ0;
273
274 if (acpi_has_method(handle, name: "_STA"))
275 newfunc->flags |= FUNC_HAS_STA;
276
277 /* search for objects that share the same slot */
278 list_for_each_entry(slot, &bridge->slots, node)
279 if (slot->device == device)
280 goto slot_found;
281
282 slot = kzalloc(size: sizeof(struct acpiphp_slot), GFP_KERNEL);
283 if (!slot) {
284 acpi_lock_hp_context();
285 acpiphp_put_context(context);
286 acpi_unlock_hp_context();
287 return AE_NO_MEMORY;
288 }
289
290 slot->bus = bridge->pci_bus;
291 slot->device = device;
292 INIT_LIST_HEAD(list: &slot->funcs);
293
294 list_add_tail(new: &slot->node, head: &bridge->slots);
295
296 /*
297 * Expose slots to user space for functions that have _EJ0 or _RMV or
298 * are located in dock stations. Do not expose them for devices handled
299 * by the native PCIe hotplug (PCIeHP) or standard PCI hotplug
300 * (SHPCHP), because that code is supposed to expose slots to user
301 * space in those cases.
302 */
303 if ((acpi_pci_check_ejectable(pbus, handle) || is_dock_device(adev))
304 && !(pdev && hotplug_is_native(bridge: pdev))) {
305 unsigned long long sun;
306 int retval;
307
308 bridge->nr_slots++;
309 status = acpi_evaluate_integer(handle, pathname: "_SUN", NULL, data: &sun);
310 if (ACPI_FAILURE(status))
311 sun = bridge->nr_slots;
312
313 pr_debug("found ACPI PCI Hotplug slot %llu at PCI %04x:%02x:%02x\n",
314 sun, pci_domain_nr(pbus), pbus->number, device);
315
316 retval = acpiphp_register_hotplug_slot(slot, sun);
317 if (retval) {
318 slot->slot = NULL;
319 bridge->nr_slots--;
320 if (retval == -EBUSY)
321 pr_warn("Slot %llu already registered by another hotplug driver\n", sun);
322 else
323 pr_warn("acpiphp_register_hotplug_slot failed (err code = 0x%x)\n", retval);
324 }
325 /* Even if the slot registration fails, we can still use it. */
326 }
327
328 slot_found:
329 newfunc->slot = slot;
330 list_add_tail(new: &newfunc->sibling, head: &slot->funcs);
331
332 if (pci_bus_read_dev_vendor_id(bus: pbus, PCI_DEVFN(device, function),
333 pl: &val, crs_timeout: 60*1000))
334 slot->flags |= SLOT_ENABLED;
335
336 return AE_OK;
337}
338
339static void cleanup_bridge(struct acpiphp_bridge *bridge)
340{
341 struct acpiphp_slot *slot;
342 struct acpiphp_func *func;
343
344 list_for_each_entry(slot, &bridge->slots, node) {
345 list_for_each_entry(func, &slot->funcs, sibling) {
346 struct acpi_device *adev = func_to_acpi_device(func);
347
348 acpi_lock_hp_context();
349 adev->hp->notify = NULL;
350 adev->hp->fixup = NULL;
351 acpi_unlock_hp_context();
352 }
353 slot->flags |= SLOT_IS_GOING_AWAY;
354 if (slot->slot)
355 acpiphp_unregister_hotplug_slot(slot);
356 }
357
358 mutex_lock(&bridge_mutex);
359 list_del(entry: &bridge->list);
360 mutex_unlock(lock: &bridge_mutex);
361
362 acpi_lock_hp_context();
363 bridge->is_going_away = true;
364 acpi_unlock_hp_context();
365}
366
367/**
368 * acpiphp_max_busnr - return the highest reserved bus number under the given bus.
369 * @bus: bus to start search with
370 */
371static unsigned char acpiphp_max_busnr(struct pci_bus *bus)
372{
373 struct pci_bus *tmp;
374 unsigned char max, n;
375
376 /*
377 * pci_bus_max_busnr will return the highest
378 * reserved busnr for all these children.
379 * that is equivalent to the bus->subordinate
380 * value. We don't want to use the parent's
381 * bus->subordinate value because it could have
382 * padding in it.
383 */
384 max = bus->busn_res.start;
385
386 list_for_each_entry(tmp, &bus->children, node) {
387 n = pci_bus_max_busnr(bus: tmp);
388 if (n > max)
389 max = n;
390 }
391 return max;
392}
393
394static void acpiphp_set_acpi_region(struct acpiphp_slot *slot)
395{
396 struct acpiphp_func *func;
397
398 list_for_each_entry(func, &slot->funcs, sibling) {
399 /* _REG is optional, we don't care about if there is failure */
400 acpi_evaluate_reg(handle: func_to_handle(func),
401 ACPI_ADR_SPACE_PCI_CONFIG,
402 ACPI_REG_CONNECT);
403 }
404}
405
406static void check_hotplug_bridge(struct acpiphp_slot *slot, struct pci_dev *dev)
407{
408 struct acpiphp_func *func;
409
410 /* quirk, or pcie could set it already */
411 if (dev->is_hotplug_bridge)
412 return;
413
414 /*
415 * In the PCIe case, only Root Ports and Downstream Ports are capable of
416 * accommodating hotplug devices, so avoid marking Upstream Ports as
417 * "hotplug bridges".
418 */
419 if (pci_is_pcie(dev) && pci_pcie_type(dev) == PCI_EXP_TYPE_UPSTREAM)
420 return;
421
422 list_for_each_entry(func, &slot->funcs, sibling) {
423 if (PCI_FUNC(dev->devfn) == func->function) {
424 dev->is_hotplug_bridge = 1;
425 break;
426 }
427 }
428}
429
430static int acpiphp_rescan_slot(struct acpiphp_slot *slot)
431{
432 struct acpiphp_func *func;
433
434 list_for_each_entry(func, &slot->funcs, sibling) {
435 struct acpi_device *adev = func_to_acpi_device(func);
436
437 acpi_bus_scan(handle: adev->handle);
438 if (acpi_device_enumerated(adev))
439 acpi_device_set_power(device: adev, ACPI_STATE_D0);
440 }
441 return pci_scan_slot(bus: slot->bus, PCI_DEVFN(slot->device, 0));
442}
443
444static void acpiphp_native_scan_bridge(struct pci_dev *bridge)
445{
446 struct pci_bus *bus = bridge->subordinate;
447 struct pci_dev *dev;
448 int max;
449
450 if (!bus)
451 return;
452
453 max = bus->busn_res.start;
454 /* Scan already configured non-hotplug bridges */
455 for_each_pci_bridge(dev, bus) {
456 if (!hotplug_is_native(bridge: dev))
457 max = pci_scan_bridge(bus, dev, max, pass: 0);
458 }
459
460 /* Scan non-hotplug bridges that need to be reconfigured */
461 for_each_pci_bridge(dev, bus) {
462 if (hotplug_is_native(bridge: dev))
463 continue;
464
465 max = pci_scan_bridge(bus, dev, max, pass: 1);
466 if (dev->subordinate) {
467 pcibios_resource_survey_bus(bus: dev->subordinate);
468 pci_bus_size_bridges(bus: dev->subordinate);
469 pci_bus_assign_resources(bus: dev->subordinate);
470 }
471 }
472}
473
474/**
475 * enable_slot - enable, configure a slot
476 * @slot: slot to be enabled
477 * @bridge: true if enable is for the whole bridge (not a single slot)
478 *
479 * This function should be called per *physical slot*,
480 * not per each slot object in ACPI namespace.
481 */
482static void enable_slot(struct acpiphp_slot *slot, bool bridge)
483{
484 struct pci_dev *dev;
485 struct pci_bus *bus = slot->bus;
486 struct acpiphp_func *func;
487
488 if (bridge && bus->self && hotplug_is_native(bridge: bus->self)) {
489 /*
490 * If native hotplug is used, it will take care of hotplug
491 * slot management and resource allocation for hotplug
492 * bridges. However, ACPI hotplug may still be used for
493 * non-hotplug bridges to bring in additional devices such
494 * as a Thunderbolt host controller.
495 */
496 for_each_pci_bridge(dev, bus) {
497 if (PCI_SLOT(dev->devfn) == slot->device)
498 acpiphp_native_scan_bridge(bridge: dev);
499 }
500 } else {
501 LIST_HEAD(add_list);
502 int max, pass;
503
504 acpiphp_rescan_slot(slot);
505 max = acpiphp_max_busnr(bus);
506 for (pass = 0; pass < 2; pass++) {
507 for_each_pci_bridge(dev, bus) {
508 if (PCI_SLOT(dev->devfn) != slot->device)
509 continue;
510
511 max = pci_scan_bridge(bus, dev, max, pass);
512 if (pass && dev->subordinate) {
513 check_hotplug_bridge(slot, dev);
514 pcibios_resource_survey_bus(bus: dev->subordinate);
515 __pci_bus_size_bridges(bus: dev->subordinate,
516 realloc_head: &add_list);
517 }
518 }
519 }
520 __pci_bus_assign_resources(bus, realloc_head: &add_list, NULL);
521 }
522
523 acpiphp_sanitize_bus(bus);
524 pcie_bus_configure_settings(bus);
525 acpiphp_set_acpi_region(slot);
526
527 list_for_each_entry(dev, &bus->devices, bus_list) {
528 /* Assume that newly added devices are powered on already. */
529 if (!pci_dev_is_added(dev))
530 dev->current_state = PCI_D0;
531 }
532
533 pci_bus_add_devices(bus);
534
535 slot->flags |= SLOT_ENABLED;
536 list_for_each_entry(func, &slot->funcs, sibling) {
537 dev = pci_get_slot(bus, PCI_DEVFN(slot->device,
538 func->function));
539 if (!dev) {
540 /* Do not set SLOT_ENABLED flag if some funcs
541 are not added. */
542 slot->flags &= ~SLOT_ENABLED;
543 continue;
544 }
545 pci_dev_put(dev);
546 }
547}
548
549/**
550 * disable_slot - disable a slot
551 * @slot: ACPI PHP slot
552 */
553static void disable_slot(struct acpiphp_slot *slot)
554{
555 struct pci_bus *bus = slot->bus;
556 struct pci_dev *dev, *prev;
557 struct acpiphp_func *func;
558
559 /*
560 * enable_slot() enumerates all functions in this device via
561 * pci_scan_slot(), whether they have associated ACPI hotplug
562 * methods (_EJ0, etc.) or not. Therefore, we remove all functions
563 * here.
564 */
565 list_for_each_entry_safe_reverse(dev, prev, &bus->devices, bus_list)
566 if (PCI_SLOT(dev->devfn) == slot->device)
567 pci_stop_and_remove_bus_device(dev);
568
569 list_for_each_entry(func, &slot->funcs, sibling)
570 acpi_bus_trim(start: func_to_acpi_device(func));
571
572 slot->flags &= ~SLOT_ENABLED;
573}
574
575static bool slot_no_hotplug(struct acpiphp_slot *slot)
576{
577 struct pci_bus *bus = slot->bus;
578 struct pci_dev *dev;
579
580 list_for_each_entry(dev, &bus->devices, bus_list) {
581 if (PCI_SLOT(dev->devfn) == slot->device && dev->ignore_hotplug)
582 return true;
583 }
584 return false;
585}
586
587/**
588 * get_slot_status - get ACPI slot status
589 * @slot: ACPI PHP slot
590 *
591 * If a slot has _STA for each function and if any one of them
592 * returned non-zero status, return it.
593 *
594 * If a slot doesn't have _STA and if any one of its functions'
595 * configuration space is configured, return 0x0f as a _STA.
596 *
597 * Otherwise return 0.
598 */
599static unsigned int get_slot_status(struct acpiphp_slot *slot)
600{
601 unsigned long long sta = 0;
602 struct acpiphp_func *func;
603 u32 dvid;
604
605 list_for_each_entry(func, &slot->funcs, sibling) {
606 if (func->flags & FUNC_HAS_STA) {
607 acpi_status status;
608
609 status = acpi_evaluate_integer(handle: func_to_handle(func),
610 pathname: "_STA", NULL, data: &sta);
611 if (ACPI_SUCCESS(status) && sta)
612 break;
613 } else {
614 if (pci_bus_read_dev_vendor_id(bus: slot->bus,
615 PCI_DEVFN(slot->device, func->function),
616 pl: &dvid, crs_timeout: 0)) {
617 sta = ACPI_STA_ALL;
618 break;
619 }
620 }
621 }
622
623 if (!sta) {
624 /*
625 * Check for the slot itself since it may be that the
626 * ACPI slot is a device below PCIe upstream port so in
627 * that case it may not even be reachable yet.
628 */
629 if (pci_bus_read_dev_vendor_id(bus: slot->bus,
630 PCI_DEVFN(slot->device, 0), pl: &dvid, crs_timeout: 0)) {
631 sta = ACPI_STA_ALL;
632 }
633 }
634
635 return (unsigned int)sta;
636}
637
638static inline bool device_status_valid(unsigned int sta)
639{
640 /*
641 * ACPI spec says that _STA may return bit 0 clear with bit 3 set
642 * if the device is valid but does not require a device driver to be
643 * loaded (Section 6.3.7 of ACPI 5.0A).
644 */
645 unsigned int mask = ACPI_STA_DEVICE_ENABLED | ACPI_STA_DEVICE_FUNCTIONING;
646 return (sta & mask) == mask;
647}
648
649/**
650 * trim_stale_devices - remove PCI devices that are not responding.
651 * @dev: PCI device to start walking the hierarchy from.
652 */
653static void trim_stale_devices(struct pci_dev *dev)
654{
655 struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
656 struct pci_bus *bus = dev->subordinate;
657 bool alive = dev->ignore_hotplug;
658
659 if (adev) {
660 acpi_status status;
661 unsigned long long sta;
662
663 status = acpi_evaluate_integer(handle: adev->handle, pathname: "_STA", NULL, data: &sta);
664 alive = alive || (ACPI_SUCCESS(status) && device_status_valid(sta));
665 }
666 if (!alive)
667 alive = pci_device_is_present(pdev: dev);
668
669 if (!alive) {
670 pci_dev_set_disconnected(dev, NULL);
671 if (pci_has_subordinate(pci_dev: dev))
672 pci_walk_bus(top: dev->subordinate, cb: pci_dev_set_disconnected,
673 NULL);
674
675 pci_stop_and_remove_bus_device(dev);
676 if (adev)
677 acpi_bus_trim(start: adev);
678 } else if (bus) {
679 struct pci_dev *child, *tmp;
680
681 /* The device is a bridge. so check the bus below it. */
682 pm_runtime_get_sync(dev: &dev->dev);
683 list_for_each_entry_safe_reverse(child, tmp, &bus->devices, bus_list)
684 trim_stale_devices(dev: child);
685
686 pm_runtime_put(dev: &dev->dev);
687 }
688}
689
690/**
691 * acpiphp_check_bridge - re-enumerate devices
692 * @bridge: where to begin re-enumeration
693 *
694 * Iterate over all slots under this bridge and make sure that if a
695 * card is present they are enabled, and if not they are disabled.
696 */
697static void acpiphp_check_bridge(struct acpiphp_bridge *bridge)
698{
699 struct acpiphp_slot *slot;
700
701 /* Bail out if the bridge is going away. */
702 if (bridge->is_going_away)
703 return;
704
705 if (bridge->pci_dev)
706 pm_runtime_get_sync(dev: &bridge->pci_dev->dev);
707
708 list_for_each_entry(slot, &bridge->slots, node) {
709 struct pci_bus *bus = slot->bus;
710 struct pci_dev *dev, *tmp;
711
712 if (slot_no_hotplug(slot)) {
713 ; /* do nothing */
714 } else if (device_status_valid(sta: get_slot_status(slot))) {
715 /* remove stale devices if any */
716 list_for_each_entry_safe_reverse(dev, tmp,
717 &bus->devices, bus_list)
718 if (PCI_SLOT(dev->devfn) == slot->device)
719 trim_stale_devices(dev);
720
721 /* configure all functions */
722 enable_slot(slot, bridge: true);
723 } else {
724 disable_slot(slot);
725 }
726 }
727
728 if (bridge->pci_dev)
729 pm_runtime_put(dev: &bridge->pci_dev->dev);
730}
731
732/*
733 * Remove devices for which we could not assign resources, call
734 * arch specific code to fix-up the bus
735 */
736static void acpiphp_sanitize_bus(struct pci_bus *bus)
737{
738 struct pci_dev *dev, *tmp;
739 int i;
740 unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM;
741
742 list_for_each_entry_safe_reverse(dev, tmp, &bus->devices, bus_list) {
743 for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) {
744 struct resource *res = &dev->resource[i];
745 if ((res->flags & type_mask) && !res->start &&
746 res->end) {
747 /* Could not assign a required resources
748 * for this device, remove it */
749 pci_stop_and_remove_bus_device(dev);
750 break;
751 }
752 }
753 }
754}
755
756/*
757 * ACPI event handlers
758 */
759
760void acpiphp_check_host_bridge(struct acpi_device *adev)
761{
762 struct acpiphp_bridge *bridge = NULL;
763
764 acpi_lock_hp_context();
765 if (adev->hp) {
766 bridge = to_acpiphp_root_context(hp: adev->hp)->root_bridge;
767 if (bridge)
768 get_bridge(bridge);
769 }
770 acpi_unlock_hp_context();
771 if (bridge) {
772 pci_lock_rescan_remove();
773
774 acpiphp_check_bridge(bridge);
775
776 pci_unlock_rescan_remove();
777 put_bridge(bridge);
778 }
779}
780
781static int acpiphp_disable_and_eject_slot(struct acpiphp_slot *slot);
782
783static void hotplug_event(u32 type, struct acpiphp_context *context)
784{
785 acpi_handle handle = context->hp.self->handle;
786 struct acpiphp_func *func = &context->func;
787 struct acpiphp_slot *slot = func->slot;
788 struct acpiphp_bridge *bridge;
789
790 acpi_lock_hp_context();
791 bridge = context->bridge;
792 if (bridge)
793 get_bridge(bridge);
794
795 acpi_unlock_hp_context();
796
797 pci_lock_rescan_remove();
798
799 switch (type) {
800 case ACPI_NOTIFY_BUS_CHECK:
801 /* bus re-enumerate */
802 acpi_handle_debug(handle, "Bus check in %s()\n", __func__);
803 if (bridge)
804 acpiphp_check_bridge(bridge);
805 else if (!(slot->flags & SLOT_IS_GOING_AWAY))
806 enable_slot(slot, bridge: false);
807
808 break;
809
810 case ACPI_NOTIFY_DEVICE_CHECK:
811 /* device check */
812 acpi_handle_debug(handle, "Device check in %s()\n", __func__);
813 if (bridge) {
814 acpiphp_check_bridge(bridge);
815 } else if (!(slot->flags & SLOT_IS_GOING_AWAY)) {
816 /*
817 * Check if anything has changed in the slot and rescan
818 * from the parent if that's the case.
819 */
820 if (acpiphp_rescan_slot(slot))
821 acpiphp_check_bridge(bridge: func->parent);
822 }
823 break;
824
825 case ACPI_NOTIFY_EJECT_REQUEST:
826 /* request device eject */
827 acpi_handle_debug(handle, "Eject request in %s()\n", __func__);
828 acpiphp_disable_and_eject_slot(slot);
829 break;
830 }
831
832 pci_unlock_rescan_remove();
833 if (bridge)
834 put_bridge(bridge);
835}
836
837static int acpiphp_hotplug_notify(struct acpi_device *adev, u32 type)
838{
839 struct acpiphp_context *context;
840
841 context = acpiphp_grab_context(adev);
842 if (!context)
843 return -ENODATA;
844
845 hotplug_event(type, context);
846 acpiphp_let_context_go(context);
847 return 0;
848}
849
850/**
851 * acpiphp_enumerate_slots - Enumerate PCI slots for a given bus.
852 * @bus: PCI bus to enumerate the slots for.
853 *
854 * A "slot" is an object associated with a PCI device number. All functions
855 * (PCI devices) with the same bus and device number belong to the same slot.
856 */
857void acpiphp_enumerate_slots(struct pci_bus *bus)
858{
859 struct acpiphp_bridge *bridge;
860 struct acpi_device *adev;
861 acpi_handle handle;
862 acpi_status status;
863
864 if (acpiphp_disabled)
865 return;
866
867 adev = ACPI_COMPANION(bus->bridge);
868 if (!adev)
869 return;
870
871 handle = adev->handle;
872 bridge = kzalloc(size: sizeof(struct acpiphp_bridge), GFP_KERNEL);
873 if (!bridge)
874 return;
875
876 INIT_LIST_HEAD(list: &bridge->slots);
877 kref_init(kref: &bridge->ref);
878 bridge->pci_dev = pci_dev_get(dev: bus->self);
879 bridge->pci_bus = bus;
880
881 /*
882 * Grab a ref to the subordinate PCI bus in case the bus is
883 * removed via PCI core logical hotplug. The ref pins the bus
884 * (which we access during module unload).
885 */
886 get_device(dev: &bus->dev);
887
888 acpi_lock_hp_context();
889 if (pci_is_root_bus(pbus: bridge->pci_bus)) {
890 struct acpiphp_root_context *root_context;
891
892 root_context = kzalloc(size: sizeof(*root_context), GFP_KERNEL);
893 if (!root_context)
894 goto err;
895
896 root_context->root_bridge = bridge;
897 acpi_set_hp_context(adev, hp: &root_context->hp);
898 } else {
899 struct acpiphp_context *context;
900
901 /*
902 * This bridge should have been registered as a hotplug function
903 * under its parent, so the context should be there, unless the
904 * parent is going to be handled by pciehp, in which case this
905 * bridge is not interesting to us either.
906 */
907 context = acpiphp_get_context(adev);
908 if (!context)
909 goto err;
910
911 bridge->context = context;
912 context->bridge = bridge;
913 /* Get a reference to the parent bridge. */
914 get_bridge(bridge: context->func.parent);
915 }
916 acpi_unlock_hp_context();
917
918 /* Must be added to the list prior to calling acpiphp_add_context(). */
919 mutex_lock(&bridge_mutex);
920 list_add(new: &bridge->list, head: &bridge_list);
921 mutex_unlock(lock: &bridge_mutex);
922
923 /* register all slot objects under this bridge */
924 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, start_object: handle, max_depth: 1,
925 descending_callback: acpiphp_add_context, NULL, context: bridge, NULL);
926 if (ACPI_FAILURE(status)) {
927 acpi_handle_err(handle, "failed to register slots\n");
928 cleanup_bridge(bridge);
929 put_bridge(bridge);
930 }
931 return;
932
933 err:
934 acpi_unlock_hp_context();
935 put_device(dev: &bus->dev);
936 pci_dev_put(dev: bridge->pci_dev);
937 kfree(objp: bridge);
938}
939
940static void acpiphp_drop_bridge(struct acpiphp_bridge *bridge)
941{
942 if (pci_is_root_bus(pbus: bridge->pci_bus)) {
943 struct acpiphp_root_context *root_context;
944 struct acpi_device *adev;
945
946 acpi_lock_hp_context();
947 adev = ACPI_COMPANION(bridge->pci_bus->bridge);
948 root_context = to_acpiphp_root_context(hp: adev->hp);
949 adev->hp = NULL;
950 acpi_unlock_hp_context();
951 kfree(objp: root_context);
952 }
953 cleanup_bridge(bridge);
954 put_bridge(bridge);
955}
956
957/**
958 * acpiphp_remove_slots - Remove slot objects associated with a given bus.
959 * @bus: PCI bus to remove the slot objects for.
960 */
961void acpiphp_remove_slots(struct pci_bus *bus)
962{
963 struct acpiphp_bridge *bridge;
964
965 if (acpiphp_disabled)
966 return;
967
968 mutex_lock(&bridge_mutex);
969 list_for_each_entry(bridge, &bridge_list, list)
970 if (bridge->pci_bus == bus) {
971 mutex_unlock(lock: &bridge_mutex);
972 acpiphp_drop_bridge(bridge);
973 return;
974 }
975
976 mutex_unlock(lock: &bridge_mutex);
977}
978
979/**
980 * acpiphp_enable_slot - power on slot
981 * @slot: ACPI PHP slot
982 */
983int acpiphp_enable_slot(struct acpiphp_slot *slot)
984{
985 pci_lock_rescan_remove();
986
987 if (slot->flags & SLOT_IS_GOING_AWAY) {
988 pci_unlock_rescan_remove();
989 return -ENODEV;
990 }
991
992 /* configure all functions */
993 if (!(slot->flags & SLOT_ENABLED))
994 enable_slot(slot, bridge: false);
995
996 pci_unlock_rescan_remove();
997 return 0;
998}
999
1000/**
1001 * acpiphp_disable_and_eject_slot - power off and eject slot
1002 * @slot: ACPI PHP slot
1003 */
1004static int acpiphp_disable_and_eject_slot(struct acpiphp_slot *slot)
1005{
1006 struct acpiphp_func *func;
1007
1008 if (slot->flags & SLOT_IS_GOING_AWAY)
1009 return -ENODEV;
1010
1011 /* unconfigure all functions */
1012 disable_slot(slot);
1013
1014 list_for_each_entry(func, &slot->funcs, sibling)
1015 if (func->flags & FUNC_HAS_EJ0) {
1016 acpi_handle handle = func_to_handle(func);
1017
1018 if (ACPI_FAILURE(acpi_evaluate_ej0(handle)))
1019 acpi_handle_err(handle, "_EJ0 failed\n");
1020
1021 break;
1022 }
1023
1024 return 0;
1025}
1026
1027int acpiphp_disable_slot(struct acpiphp_slot *slot)
1028{
1029 int ret;
1030
1031 /*
1032 * Acquire acpi_scan_lock to ensure that the execution of _EJ0 in
1033 * acpiphp_disable_and_eject_slot() will be synchronized properly.
1034 */
1035 acpi_scan_lock_acquire();
1036 pci_lock_rescan_remove();
1037 ret = acpiphp_disable_and_eject_slot(slot);
1038 pci_unlock_rescan_remove();
1039 acpi_scan_lock_release();
1040 return ret;
1041}
1042
1043/*
1044 * slot enabled: 1
1045 * slot disabled: 0
1046 */
1047u8 acpiphp_get_power_status(struct acpiphp_slot *slot)
1048{
1049 return (slot->flags & SLOT_ENABLED);
1050}
1051
1052/*
1053 * latch open: 1
1054 * latch closed: 0
1055 */
1056u8 acpiphp_get_latch_status(struct acpiphp_slot *slot)
1057{
1058 return !(get_slot_status(slot) & ACPI_STA_DEVICE_UI);
1059}
1060
1061/*
1062 * adapter presence : 1
1063 * absence : 0
1064 */
1065u8 acpiphp_get_adapter_status(struct acpiphp_slot *slot)
1066{
1067 return !!get_slot_status(slot);
1068}
1069

source code of linux/drivers/pci/hotplug/acpiphp_glue.c