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
44 static LIST_HEAD(bridge_list);
45 static DEFINE_MUTEX(bridge_mutex);
46
47 static int acpiphp_hotplug_notify(struct acpi_device *adev, u32 type);
48 static void acpiphp_post_dock_fixup(struct acpi_device *adev);
49 static void acpiphp_sanitize_bus(struct pci_bus *bus);
50 static void hotplug_event(u32 type, struct acpiphp_context *context);
51 static 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 */
acpiphp_init_context(struct acpi_device * adev)59 static struct acpiphp_context *acpiphp_init_context(struct acpi_device *adev)
60 {
61 struct acpiphp_context *context;
62
63 context = kzalloc(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, &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 */
acpiphp_get_context(struct acpi_device * adev)80 static 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(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 */
acpiphp_put_context(struct acpiphp_context * context)100 static 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(context);
108 }
109
get_bridge(struct acpiphp_bridge * bridge)110 static inline void get_bridge(struct acpiphp_bridge *bridge)
111 {
112 kref_get(&bridge->ref);
113 }
114
put_bridge(struct acpiphp_bridge * bridge)115 static inline void put_bridge(struct acpiphp_bridge *bridge)
116 {
117 kref_put(&bridge->ref, free_bridge);
118 }
119
acpiphp_grab_context(struct acpi_device * adev)120 static 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(context->func.parent);
137 acpiphp_put_context(context);
138
139 unlock:
140 acpi_unlock_hp_context();
141 return context;
142 }
143
acpiphp_let_context_go(struct acpiphp_context * context)144 static void acpiphp_let_context_go(struct acpiphp_context *context)
145 {
146 put_bridge(context->func.parent);
147 }
148
free_bridge(struct kref * kref)149 static 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(func_to_context(func));
163
164 kfree(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(context->func.parent);
172 context->bridge = NULL;
173 acpiphp_put_context(context);
174 }
175
176 put_device(&bridge->pci_bus->dev);
177 pci_dev_put(bridge->pci_dev);
178 kfree(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 */
acpiphp_post_dock_fixup(struct acpi_device * adev)189 static 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(bus->self, PCI_PRIMARY_BUS, &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(bus->self, PCI_PRIMARY_BUS, 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 */
acpiphp_add_context(acpi_handle handle,u32 lvl,void * data,void ** rv)226 static 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, "_ADR", NULL, &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, "_EJ0"))
272 newfunc->flags = FUNC_HAS_EJ0;
273
274 if (acpi_has_method(handle, "_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(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(&slot->funcs);
293
294 list_add_tail(&slot->node, &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(pdev))) {
305 unsigned long long sun;
306 int retval;
307
308 bridge->nr_slots++;
309 status = acpi_evaluate_integer(handle, "_SUN", NULL, &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(&newfunc->sibling, &slot->funcs);
331
332 if (pci_bus_read_dev_vendor_id(pbus, PCI_DEVFN(device, function),
333 &val, 60*1000))
334 slot->flags |= SLOT_ENABLED;
335
336 return AE_OK;
337 }
338
cleanup_bridge(struct acpiphp_bridge * bridge)339 static 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(&bridge->list);
360 mutex_unlock(&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 */
acpiphp_max_busnr(struct pci_bus * bus)371 static 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(tmp);
388 if (n > max)
389 max = n;
390 }
391 return max;
392 }
393
acpiphp_set_acpi_region(struct acpiphp_slot * slot)394 static 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(func_to_handle(func),
401 ACPI_ADR_SPACE_PCI_CONFIG,
402 ACPI_REG_CONNECT);
403 }
404 }
405
check_hotplug_bridge(struct acpiphp_slot * slot,struct pci_dev * dev)406 static 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
acpiphp_rescan_slot(struct acpiphp_slot * slot)430 static 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(adev->handle);
438 if (acpi_device_enumerated(adev))
439 acpi_device_set_power(adev, ACPI_STATE_D0);
440 }
441 return pci_scan_slot(slot->bus, PCI_DEVFN(slot->device, 0));
442 }
443
acpiphp_native_scan_bridge(struct pci_dev * bridge)444 static 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(dev))
457 max = pci_scan_bridge(bus, dev, max, 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(dev))
463 continue;
464
465 max = pci_scan_bridge(bus, dev, max, 1);
466 if (dev->subordinate) {
467 pcibios_resource_survey_bus(dev->subordinate);
468 pci_bus_size_bridges(dev->subordinate);
469 pci_bus_assign_resources(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 */
enable_slot(struct acpiphp_slot * slot,bool bridge)482 static 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(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(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(dev->subordinate);
515 if (pci_is_root_bus(bus))
516 __pci_bus_size_bridges(dev->subordinate, &add_list);
517 }
518 }
519 }
520 if (pci_is_root_bus(bus))
521 __pci_bus_assign_resources(bus, &add_list, NULL);
522 else
523 pci_assign_unassigned_bridge_resources(bus->self);
524 }
525
526 acpiphp_sanitize_bus(bus);
527 pcie_bus_configure_settings(bus);
528 acpiphp_set_acpi_region(slot);
529
530 list_for_each_entry(dev, &bus->devices, bus_list) {
531 /* Assume that newly added devices are powered on already. */
532 if (!pci_dev_is_added(dev))
533 dev->current_state = PCI_D0;
534 }
535
536 pci_bus_add_devices(bus);
537
538 slot->flags |= SLOT_ENABLED;
539 list_for_each_entry(func, &slot->funcs, sibling) {
540 dev = pci_get_slot(bus, PCI_DEVFN(slot->device,
541 func->function));
542 if (!dev) {
543 /* Do not set SLOT_ENABLED flag if some funcs
544 are not added. */
545 slot->flags &= ~SLOT_ENABLED;
546 continue;
547 }
548 pci_dev_put(dev);
549 }
550 }
551
552 /**
553 * disable_slot - disable a slot
554 * @slot: ACPI PHP slot
555 */
disable_slot(struct acpiphp_slot * slot)556 static void disable_slot(struct acpiphp_slot *slot)
557 {
558 struct pci_bus *bus = slot->bus;
559 struct pci_dev *dev, *prev;
560 struct acpiphp_func *func;
561
562 /*
563 * enable_slot() enumerates all functions in this device via
564 * pci_scan_slot(), whether they have associated ACPI hotplug
565 * methods (_EJ0, etc.) or not. Therefore, we remove all functions
566 * here.
567 */
568 list_for_each_entry_safe_reverse(dev, prev, &bus->devices, bus_list)
569 if (PCI_SLOT(dev->devfn) == slot->device)
570 pci_stop_and_remove_bus_device(dev);
571
572 list_for_each_entry(func, &slot->funcs, sibling)
573 acpi_bus_trim(func_to_acpi_device(func));
574
575 slot->flags &= ~SLOT_ENABLED;
576 }
577
slot_no_hotplug(struct acpiphp_slot * slot)578 static bool slot_no_hotplug(struct acpiphp_slot *slot)
579 {
580 struct pci_bus *bus = slot->bus;
581 struct pci_dev *dev;
582
583 list_for_each_entry(dev, &bus->devices, bus_list) {
584 if (PCI_SLOT(dev->devfn) == slot->device && dev->ignore_hotplug)
585 return true;
586 }
587 return false;
588 }
589
590 /**
591 * get_slot_status - get ACPI slot status
592 * @slot: ACPI PHP slot
593 *
594 * If a slot has _STA for each function and if any one of them
595 * returned non-zero status, return it.
596 *
597 * If a slot doesn't have _STA and if any one of its functions'
598 * configuration space is configured, return 0x0f as a _STA.
599 *
600 * Otherwise return 0.
601 */
get_slot_status(struct acpiphp_slot * slot)602 static unsigned int get_slot_status(struct acpiphp_slot *slot)
603 {
604 unsigned long long sta = 0;
605 struct acpiphp_func *func;
606 u32 dvid;
607
608 list_for_each_entry(func, &slot->funcs, sibling) {
609 if (func->flags & FUNC_HAS_STA) {
610 acpi_status status;
611
612 status = acpi_evaluate_integer(func_to_handle(func),
613 "_STA", NULL, &sta);
614 if (ACPI_SUCCESS(status) && sta)
615 break;
616 } else {
617 if (pci_bus_read_dev_vendor_id(slot->bus,
618 PCI_DEVFN(slot->device, func->function),
619 &dvid, 0)) {
620 sta = ACPI_STA_ALL;
621 break;
622 }
623 }
624 }
625
626 if (!sta) {
627 /*
628 * Check for the slot itself since it may be that the
629 * ACPI slot is a device below PCIe upstream port so in
630 * that case it may not even be reachable yet.
631 */
632 if (pci_bus_read_dev_vendor_id(slot->bus,
633 PCI_DEVFN(slot->device, 0), &dvid, 0)) {
634 sta = ACPI_STA_ALL;
635 }
636 }
637
638 return (unsigned int)sta;
639 }
640
device_status_valid(unsigned int sta)641 static inline bool device_status_valid(unsigned int sta)
642 {
643 /*
644 * ACPI spec says that _STA may return bit 0 clear with bit 3 set
645 * if the device is valid but does not require a device driver to be
646 * loaded (Section 6.3.7 of ACPI 5.0A).
647 */
648 unsigned int mask = ACPI_STA_DEVICE_ENABLED | ACPI_STA_DEVICE_FUNCTIONING;
649 return (sta & mask) == mask;
650 }
651
652 /**
653 * trim_stale_devices - remove PCI devices that are not responding.
654 * @dev: PCI device to start walking the hierarchy from.
655 */
trim_stale_devices(struct pci_dev * dev)656 static void trim_stale_devices(struct pci_dev *dev)
657 {
658 struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
659 struct pci_bus *bus = dev->subordinate;
660 bool alive = dev->ignore_hotplug;
661
662 if (adev) {
663 acpi_status status;
664 unsigned long long sta;
665
666 status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
667 alive = alive || (ACPI_SUCCESS(status) && device_status_valid(sta));
668 }
669 if (!alive)
670 alive = pci_device_is_present(dev);
671
672 if (!alive) {
673 pci_dev_set_disconnected(dev, NULL);
674 if (pci_has_subordinate(dev))
675 pci_walk_bus(dev->subordinate, pci_dev_set_disconnected,
676 NULL);
677
678 pci_stop_and_remove_bus_device(dev);
679 if (adev)
680 acpi_bus_trim(adev);
681 } else if (bus) {
682 struct pci_dev *child, *tmp;
683
684 /* The device is a bridge. so check the bus below it. */
685 pm_runtime_get_sync(&dev->dev);
686 list_for_each_entry_safe_reverse(child, tmp, &bus->devices, bus_list)
687 trim_stale_devices(child);
688
689 pm_runtime_put(&dev->dev);
690 }
691 }
692
693 /**
694 * acpiphp_check_bridge - re-enumerate devices
695 * @bridge: where to begin re-enumeration
696 *
697 * Iterate over all slots under this bridge and make sure that if a
698 * card is present they are enabled, and if not they are disabled.
699 */
acpiphp_check_bridge(struct acpiphp_bridge * bridge)700 static void acpiphp_check_bridge(struct acpiphp_bridge *bridge)
701 {
702 struct acpiphp_slot *slot;
703
704 /* Bail out if the bridge is going away. */
705 if (bridge->is_going_away)
706 return;
707
708 if (bridge->pci_dev)
709 pm_runtime_get_sync(&bridge->pci_dev->dev);
710
711 list_for_each_entry(slot, &bridge->slots, node) {
712 struct pci_bus *bus = slot->bus;
713 struct pci_dev *dev, *tmp;
714
715 if (slot_no_hotplug(slot)) {
716 ; /* do nothing */
717 } else if (device_status_valid(get_slot_status(slot))) {
718 /* remove stale devices if any */
719 list_for_each_entry_safe_reverse(dev, tmp,
720 &bus->devices, bus_list)
721 if (PCI_SLOT(dev->devfn) == slot->device)
722 trim_stale_devices(dev);
723
724 /* configure all functions */
725 enable_slot(slot, true);
726 } else {
727 disable_slot(slot);
728 }
729 }
730
731 if (bridge->pci_dev)
732 pm_runtime_put(&bridge->pci_dev->dev);
733 }
734
735 /*
736 * Remove devices for which we could not assign resources, call
737 * arch specific code to fix-up the bus
738 */
acpiphp_sanitize_bus(struct pci_bus * bus)739 static void acpiphp_sanitize_bus(struct pci_bus *bus)
740 {
741 struct pci_dev *dev, *tmp;
742 int i;
743 unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM;
744
745 list_for_each_entry_safe_reverse(dev, tmp, &bus->devices, bus_list) {
746 for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) {
747 struct resource *res = &dev->resource[i];
748 if ((res->flags & type_mask) && !res->start &&
749 res->end) {
750 /* Could not assign a required resources
751 * for this device, remove it */
752 pci_stop_and_remove_bus_device(dev);
753 break;
754 }
755 }
756 }
757 }
758
759 /*
760 * ACPI event handlers
761 */
762
acpiphp_check_host_bridge(struct acpi_device * adev)763 void acpiphp_check_host_bridge(struct acpi_device *adev)
764 {
765 struct acpiphp_bridge *bridge = NULL;
766
767 acpi_lock_hp_context();
768 if (adev->hp) {
769 bridge = to_acpiphp_root_context(adev->hp)->root_bridge;
770 if (bridge)
771 get_bridge(bridge);
772 }
773 acpi_unlock_hp_context();
774 if (bridge) {
775 pci_lock_rescan_remove();
776
777 acpiphp_check_bridge(bridge);
778
779 pci_unlock_rescan_remove();
780 put_bridge(bridge);
781 }
782 }
783
784 static int acpiphp_disable_and_eject_slot(struct acpiphp_slot *slot);
785
hotplug_event(u32 type,struct acpiphp_context * context)786 static void hotplug_event(u32 type, struct acpiphp_context *context)
787 {
788 acpi_handle handle = context->hp.self->handle;
789 struct acpiphp_func *func = &context->func;
790 struct acpiphp_slot *slot = func->slot;
791 struct acpiphp_bridge *bridge;
792
793 acpi_lock_hp_context();
794 bridge = context->bridge;
795 if (bridge)
796 get_bridge(bridge);
797
798 acpi_unlock_hp_context();
799
800 pci_lock_rescan_remove();
801
802 switch (type) {
803 case ACPI_NOTIFY_BUS_CHECK:
804 /* bus re-enumerate */
805 acpi_handle_debug(handle, "Bus check in %s()\n", __func__);
806 if (bridge)
807 acpiphp_check_bridge(bridge);
808 else if (!(slot->flags & SLOT_IS_GOING_AWAY))
809 enable_slot(slot, false);
810
811 break;
812
813 case ACPI_NOTIFY_DEVICE_CHECK:
814 /* device check */
815 acpi_handle_debug(handle, "Device check in %s()\n", __func__);
816 if (bridge) {
817 acpiphp_check_bridge(bridge);
818 } else if (!(slot->flags & SLOT_IS_GOING_AWAY)) {
819 /*
820 * Check if anything has changed in the slot and rescan
821 * from the parent if that's the case.
822 */
823 if (acpiphp_rescan_slot(slot))
824 acpiphp_check_bridge(func->parent);
825 }
826 break;
827
828 case ACPI_NOTIFY_EJECT_REQUEST:
829 /* request device eject */
830 acpi_handle_debug(handle, "Eject request in %s()\n", __func__);
831 acpiphp_disable_and_eject_slot(slot);
832 break;
833 }
834
835 pci_unlock_rescan_remove();
836 if (bridge)
837 put_bridge(bridge);
838 }
839
acpiphp_hotplug_notify(struct acpi_device * adev,u32 type)840 static int acpiphp_hotplug_notify(struct acpi_device *adev, u32 type)
841 {
842 struct acpiphp_context *context;
843
844 context = acpiphp_grab_context(adev);
845 if (!context)
846 return -ENODATA;
847
848 hotplug_event(type, context);
849 acpiphp_let_context_go(context);
850 return 0;
851 }
852
853 /**
854 * acpiphp_enumerate_slots - Enumerate PCI slots for a given bus.
855 * @bus: PCI bus to enumerate the slots for.
856 *
857 * A "slot" is an object associated with a PCI device number. All functions
858 * (PCI devices) with the same bus and device number belong to the same slot.
859 */
acpiphp_enumerate_slots(struct pci_bus * bus)860 void acpiphp_enumerate_slots(struct pci_bus *bus)
861 {
862 struct acpiphp_bridge *bridge;
863 struct acpi_device *adev;
864 acpi_handle handle;
865 acpi_status status;
866
867 if (acpiphp_disabled)
868 return;
869
870 adev = ACPI_COMPANION(bus->bridge);
871 if (!adev)
872 return;
873
874 handle = adev->handle;
875 bridge = kzalloc(sizeof(struct acpiphp_bridge), GFP_KERNEL);
876 if (!bridge)
877 return;
878
879 INIT_LIST_HEAD(&bridge->slots);
880 kref_init(&bridge->ref);
881 bridge->pci_dev = pci_dev_get(bus->self);
882 bridge->pci_bus = bus;
883
884 /*
885 * Grab a ref to the subordinate PCI bus in case the bus is
886 * removed via PCI core logical hotplug. The ref pins the bus
887 * (which we access during module unload).
888 */
889 get_device(&bus->dev);
890
891 acpi_lock_hp_context();
892 if (pci_is_root_bus(bridge->pci_bus)) {
893 struct acpiphp_root_context *root_context;
894
895 root_context = kzalloc(sizeof(*root_context), GFP_KERNEL);
896 if (!root_context)
897 goto err;
898
899 root_context->root_bridge = bridge;
900 acpi_set_hp_context(adev, &root_context->hp);
901 } else {
902 struct acpiphp_context *context;
903
904 /*
905 * This bridge should have been registered as a hotplug function
906 * under its parent, so the context should be there, unless the
907 * parent is going to be handled by pciehp, in which case this
908 * bridge is not interesting to us either.
909 */
910 context = acpiphp_get_context(adev);
911 if (!context)
912 goto err;
913
914 bridge->context = context;
915 context->bridge = bridge;
916 /* Get a reference to the parent bridge. */
917 get_bridge(context->func.parent);
918 }
919 acpi_unlock_hp_context();
920
921 /* Must be added to the list prior to calling acpiphp_add_context(). */
922 mutex_lock(&bridge_mutex);
923 list_add(&bridge->list, &bridge_list);
924 mutex_unlock(&bridge_mutex);
925
926 /* register all slot objects under this bridge */
927 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
928 acpiphp_add_context, NULL, bridge, NULL);
929 if (ACPI_FAILURE(status)) {
930 acpi_handle_err(handle, "failed to register slots\n");
931 cleanup_bridge(bridge);
932 put_bridge(bridge);
933 }
934 return;
935
936 err:
937 acpi_unlock_hp_context();
938 put_device(&bus->dev);
939 pci_dev_put(bridge->pci_dev);
940 kfree(bridge);
941 }
942
acpiphp_drop_bridge(struct acpiphp_bridge * bridge)943 static void acpiphp_drop_bridge(struct acpiphp_bridge *bridge)
944 {
945 if (pci_is_root_bus(bridge->pci_bus)) {
946 struct acpiphp_root_context *root_context;
947 struct acpi_device *adev;
948
949 acpi_lock_hp_context();
950 adev = ACPI_COMPANION(bridge->pci_bus->bridge);
951 root_context = to_acpiphp_root_context(adev->hp);
952 adev->hp = NULL;
953 acpi_unlock_hp_context();
954 kfree(root_context);
955 }
956 cleanup_bridge(bridge);
957 put_bridge(bridge);
958 }
959
960 /**
961 * acpiphp_remove_slots - Remove slot objects associated with a given bus.
962 * @bus: PCI bus to remove the slot objects for.
963 */
acpiphp_remove_slots(struct pci_bus * bus)964 void acpiphp_remove_slots(struct pci_bus *bus)
965 {
966 struct acpiphp_bridge *bridge;
967
968 if (acpiphp_disabled)
969 return;
970
971 mutex_lock(&bridge_mutex);
972 list_for_each_entry(bridge, &bridge_list, list)
973 if (bridge->pci_bus == bus) {
974 mutex_unlock(&bridge_mutex);
975 acpiphp_drop_bridge(bridge);
976 return;
977 }
978
979 mutex_unlock(&bridge_mutex);
980 }
981
982 /**
983 * acpiphp_enable_slot - power on slot
984 * @slot: ACPI PHP slot
985 */
acpiphp_enable_slot(struct acpiphp_slot * slot)986 int acpiphp_enable_slot(struct acpiphp_slot *slot)
987 {
988 pci_lock_rescan_remove();
989
990 if (slot->flags & SLOT_IS_GOING_AWAY) {
991 pci_unlock_rescan_remove();
992 return -ENODEV;
993 }
994
995 /* configure all functions */
996 if (!(slot->flags & SLOT_ENABLED))
997 enable_slot(slot, false);
998
999 pci_unlock_rescan_remove();
1000 return 0;
1001 }
1002
1003 /**
1004 * acpiphp_disable_and_eject_slot - power off and eject slot
1005 * @slot: ACPI PHP slot
1006 */
acpiphp_disable_and_eject_slot(struct acpiphp_slot * slot)1007 static int acpiphp_disable_and_eject_slot(struct acpiphp_slot *slot)
1008 {
1009 struct acpiphp_func *func;
1010
1011 if (slot->flags & SLOT_IS_GOING_AWAY)
1012 return -ENODEV;
1013
1014 /* unconfigure all functions */
1015 disable_slot(slot);
1016
1017 list_for_each_entry(func, &slot->funcs, sibling)
1018 if (func->flags & FUNC_HAS_EJ0) {
1019 acpi_handle handle = func_to_handle(func);
1020
1021 if (ACPI_FAILURE(acpi_evaluate_ej0(handle)))
1022 acpi_handle_err(handle, "_EJ0 failed\n");
1023
1024 break;
1025 }
1026
1027 return 0;
1028 }
1029
acpiphp_disable_slot(struct acpiphp_slot * slot)1030 int acpiphp_disable_slot(struct acpiphp_slot *slot)
1031 {
1032 int ret;
1033
1034 /*
1035 * Acquire acpi_scan_lock to ensure that the execution of _EJ0 in
1036 * acpiphp_disable_and_eject_slot() will be synchronized properly.
1037 */
1038 acpi_scan_lock_acquire();
1039 pci_lock_rescan_remove();
1040 ret = acpiphp_disable_and_eject_slot(slot);
1041 pci_unlock_rescan_remove();
1042 acpi_scan_lock_release();
1043 return ret;
1044 }
1045
1046 /*
1047 * slot enabled: 1
1048 * slot disabled: 0
1049 */
acpiphp_get_power_status(struct acpiphp_slot * slot)1050 u8 acpiphp_get_power_status(struct acpiphp_slot *slot)
1051 {
1052 return (slot->flags & SLOT_ENABLED);
1053 }
1054
1055 /*
1056 * latch open: 1
1057 * latch closed: 0
1058 */
acpiphp_get_latch_status(struct acpiphp_slot * slot)1059 u8 acpiphp_get_latch_status(struct acpiphp_slot *slot)
1060 {
1061 return !(get_slot_status(slot) & ACPI_STA_DEVICE_UI);
1062 }
1063
1064 /*
1065 * adapter presence : 1
1066 * absence : 0
1067 */
acpiphp_get_adapter_status(struct acpiphp_slot * slot)1068 u8 acpiphp_get_adapter_status(struct acpiphp_slot *slot)
1069 {
1070 return !!get_slot_status(slot);
1071 }
1072