1/*
2 * ACPI PCI HotPlug glue functions to ACPI CA subsystem
3 *
4 * Copyright (C) 2002,2003 Takayoshi Kochi (t-kochi@bq.jp.nec.com)
5 * Copyright (C) 2002 Hiroshi Aono (h-aono@ap.jp.nec.com)
6 * Copyright (C) 2002,2003 NEC Corporation
7 * Copyright (C) 2003-2005 Matthew Wilcox (matthew.wilcox@hp.com)
8 * Copyright (C) 2003-2005 Hewlett Packard
9 * Copyright (C) 2005 Rajesh Shah (rajesh.shah@intel.com)
10 * Copyright (C) 2005 Intel Corporation
11 *
12 * All rights reserved.
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or (at
17 * your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful, but
20 * WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
22 * NON INFRINGEMENT.  See the GNU General Public License for more
23 * details.
24 *
25 * You should have received a copy of the GNU General Public License
26 * along with this program; if not, write to the Free Software
27 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
28 *
29 * Send feedback to <kristen.c.accardi@intel.com>
30 *
31 */
32
33/*
34 * Lifetime rules for pci_dev:
35 *  - The one in acpiphp_bridge has its refcount elevated by pci_get_slot()
36 *    when the bridge is scanned and it loses a refcount when the bridge
37 *    is removed.
38 *  - When a P2P bridge is present, we elevate the refcount on the subordinate
39 *    bus. It loses the refcount when the the driver unloads.
40 */
41
42#define pr_fmt(fmt) "acpiphp_glue: " fmt
43
44#include <linux/module.h>
45
46#include <linux/kernel.h>
47#include <linux/pci.h>
48#include <linux/pci_hotplug.h>
49#include <linux/pci-acpi.h>
50#include <linux/pm_runtime.h>
51#include <linux/mutex.h>
52#include <linux/slab.h>
53#include <linux/acpi.h>
54
55#include "../pci.h"
56#include "acpiphp.h"
57
58static LIST_HEAD(bridge_list);
59static DEFINE_MUTEX(bridge_mutex);
60
61static int acpiphp_hotplug_notify(struct acpi_device *adev, u32 type);
62static void acpiphp_post_dock_fixup(struct acpi_device *adev);
63static void acpiphp_sanitize_bus(struct pci_bus *bus);
64static void hotplug_event(u32 type, struct acpiphp_context *context);
65static void free_bridge(struct kref *kref);
66
67/**
68 * acpiphp_init_context - Create hotplug context and grab a reference to it.
69 * @adev: ACPI device object to create the context for.
70 *
71 * Call under acpi_hp_context_lock.
72 */
73static struct acpiphp_context *acpiphp_init_context(struct acpi_device *adev)
74{
75	struct acpiphp_context *context;
76
77	context = kzalloc(sizeof(*context), GFP_KERNEL);
78	if (!context)
79		return NULL;
80
81	context->refcount = 1;
82	context->hp.notify = acpiphp_hotplug_notify;
83	context->hp.fixup = acpiphp_post_dock_fixup;
84	acpi_set_hp_context(adev, &context->hp);
85	return context;
86}
87
88/**
89 * acpiphp_get_context - Get hotplug context and grab a reference to it.
90 * @adev: ACPI device object to get the context for.
91 *
92 * Call under acpi_hp_context_lock.
93 */
94static struct acpiphp_context *acpiphp_get_context(struct acpi_device *adev)
95{
96	struct acpiphp_context *context;
97
98	if (!adev->hp)
99		return NULL;
100
101	context = to_acpiphp_context(adev->hp);
102	context->refcount++;
103	return context;
104}
105
106/**
107 * acpiphp_put_context - Drop a reference to ACPI hotplug context.
108 * @context: ACPI hotplug context to drop a reference to.
109 *
110 * The context object is removed if there are no more references to it.
111 *
112 * Call under acpi_hp_context_lock.
113 */
114static void acpiphp_put_context(struct acpiphp_context *context)
115{
116	if (--context->refcount)
117		return;
118
119	WARN_ON(context->bridge);
120	context->hp.self->hp = NULL;
121	kfree(context);
122}
123
124static inline void get_bridge(struct acpiphp_bridge *bridge)
125{
126	kref_get(&bridge->ref);
127}
128
129static inline void put_bridge(struct acpiphp_bridge *bridge)
130{
131	kref_put(&bridge->ref, free_bridge);
132}
133
134static struct acpiphp_context *acpiphp_grab_context(struct acpi_device *adev)
135{
136	struct acpiphp_context *context;
137
138	acpi_lock_hp_context();
139	context = acpiphp_get_context(adev);
140	if (!context || context->func.parent->is_going_away) {
141		acpi_unlock_hp_context();
142		return NULL;
143	}
144	get_bridge(context->func.parent);
145	acpiphp_put_context(context);
146	acpi_unlock_hp_context();
147	return context;
148}
149
150static void acpiphp_let_context_go(struct acpiphp_context *context)
151{
152	put_bridge(context->func.parent);
153}
154
155static void free_bridge(struct kref *kref)
156{
157	struct acpiphp_context *context;
158	struct acpiphp_bridge *bridge;
159	struct acpiphp_slot *slot, *next;
160	struct acpiphp_func *func, *tmp;
161
162	acpi_lock_hp_context();
163
164	bridge = container_of(kref, struct acpiphp_bridge, ref);
165
166	list_for_each_entry_safe(slot, next, &bridge->slots, node) {
167		list_for_each_entry_safe(func, tmp, &slot->funcs, sibling)
168			acpiphp_put_context(func_to_context(func));
169
170		kfree(slot);
171	}
172
173	context = bridge->context;
174	/* Root bridges will not have hotplug context. */
175	if (context) {
176		/* Release the reference taken by acpiphp_enumerate_slots(). */
177		put_bridge(context->func.parent);
178		context->bridge = NULL;
179		acpiphp_put_context(context);
180	}
181
182	put_device(&bridge->pci_bus->dev);
183	pci_dev_put(bridge->pci_dev);
184	kfree(bridge);
185
186	acpi_unlock_hp_context();
187}
188
189/**
190 * acpiphp_post_dock_fixup - Post-dock fixups for PCI devices.
191 * @adev: ACPI device object corresponding to a PCI device.
192 *
193 * TBD - figure out a way to only call fixups for systems that require them.
194 */
195static void acpiphp_post_dock_fixup(struct acpi_device *adev)
196{
197	struct acpiphp_context *context = acpiphp_grab_context(adev);
198	struct pci_bus *bus;
199	u32 buses;
200
201	if (!context)
202		return;
203
204	bus = context->func.slot->bus;
205	if (!bus->self)
206		goto out;
207
208	/* fixup bad _DCK function that rewrites
209	 * secondary bridge on slot
210	 */
211	pci_read_config_dword(bus->self, PCI_PRIMARY_BUS, &buses);
212
213	if (((buses >> 8) & 0xff) != bus->busn_res.start) {
214		buses = (buses & 0xff000000)
215			| ((unsigned int)(bus->primary)     <<  0)
216			| ((unsigned int)(bus->busn_res.start)   <<  8)
217			| ((unsigned int)(bus->busn_res.end) << 16);
218		pci_write_config_dword(bus->self, PCI_PRIMARY_BUS, buses);
219	}
220
221 out:
222	acpiphp_let_context_go(context);
223}
224
225/* Check whether the PCI device is managed by native PCIe hotplug driver */
226static bool device_is_managed_by_native_pciehp(struct pci_dev *pdev)
227{
228	u32 reg32;
229	acpi_handle tmp;
230	struct acpi_pci_root *root;
231
232	/* Check whether the PCIe port supports native PCIe hotplug */
233	if (pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &reg32))
234		return false;
235	if (!(reg32 & PCI_EXP_SLTCAP_HPC))
236		return false;
237
238	/*
239	 * Check whether native PCIe hotplug has been enabled for
240	 * this PCIe hierarchy.
241	 */
242	tmp = acpi_find_root_bridge_handle(pdev);
243	if (!tmp)
244		return false;
245	root = acpi_pci_find_root(tmp);
246	if (!root)
247		return false;
248	if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
249		return false;
250
251	return true;
252}
253
254/**
255 * acpiphp_add_context - Add ACPIPHP context to an ACPI device object.
256 * @handle: ACPI handle of the object to add a context to.
257 * @lvl: Not used.
258 * @data: The object's parent ACPIPHP bridge.
259 * @rv: Not used.
260 */
261static acpi_status acpiphp_add_context(acpi_handle handle, u32 lvl, void *data,
262				       void **rv)
263{
264	struct acpiphp_bridge *bridge = data;
265	struct acpiphp_context *context;
266	struct acpi_device *adev;
267	struct acpiphp_slot *slot;
268	struct acpiphp_func *newfunc;
269	acpi_status status = AE_OK;
270	unsigned long long adr;
271	int device, function;
272	struct pci_bus *pbus = bridge->pci_bus;
273	struct pci_dev *pdev = bridge->pci_dev;
274	u32 val;
275
276	status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
277	if (ACPI_FAILURE(status)) {
278		if (status != AE_NOT_FOUND)
279			acpi_handle_warn(handle,
280				"can't evaluate _ADR (%#x)\n", status);
281		return AE_OK;
282	}
283	if (acpi_bus_get_device(handle, &adev))
284		return AE_OK;
285
286	device = (adr >> 16) & 0xffff;
287	function = adr & 0xffff;
288
289	acpi_lock_hp_context();
290	context = acpiphp_init_context(adev);
291	if (!context) {
292		acpi_unlock_hp_context();
293		acpi_handle_err(handle, "No hotplug context\n");
294		return AE_NOT_EXIST;
295	}
296	newfunc = &context->func;
297	newfunc->function = function;
298	newfunc->parent = bridge;
299	acpi_unlock_hp_context();
300
301	/*
302	 * If this is a dock device, its _EJ0 should be executed by the dock
303	 * notify handler after calling _DCK.
304	 */
305	if (!is_dock_device(adev) && acpi_has_method(handle, "_EJ0"))
306		newfunc->flags = FUNC_HAS_EJ0;
307
308	if (acpi_has_method(handle, "_STA"))
309		newfunc->flags |= FUNC_HAS_STA;
310
311	/* search for objects that share the same slot */
312	list_for_each_entry(slot, &bridge->slots, node)
313		if (slot->device == device)
314			goto slot_found;
315
316	slot = kzalloc(sizeof(struct acpiphp_slot), GFP_KERNEL);
317	if (!slot) {
318		acpi_lock_hp_context();
319		acpiphp_put_context(context);
320		acpi_unlock_hp_context();
321		return AE_NO_MEMORY;
322	}
323
324	slot->bus = bridge->pci_bus;
325	slot->device = device;
326	INIT_LIST_HEAD(&slot->funcs);
327
328	list_add_tail(&slot->node, &bridge->slots);
329
330	/*
331	 * Expose slots to user space for functions that have _EJ0 or _RMV or
332	 * are located in dock stations.  Do not expose them for devices handled
333	 * by the native PCIe hotplug (PCIeHP), becuase that code is supposed to
334	 * expose slots to user space in those cases.
335	 */
336	if ((acpi_pci_check_ejectable(pbus, handle) || is_dock_device(adev))
337	    && !(pdev && device_is_managed_by_native_pciehp(pdev))) {
338		unsigned long long sun;
339		int retval;
340
341		bridge->nr_slots++;
342		status = acpi_evaluate_integer(handle, "_SUN", NULL, &sun);
343		if (ACPI_FAILURE(status))
344			sun = bridge->nr_slots;
345
346		pr_debug("found ACPI PCI Hotplug slot %llu at PCI %04x:%02x:%02x\n",
347		    sun, pci_domain_nr(pbus), pbus->number, device);
348
349		retval = acpiphp_register_hotplug_slot(slot, sun);
350		if (retval) {
351			slot->slot = NULL;
352			bridge->nr_slots--;
353			if (retval == -EBUSY)
354				pr_warn("Slot %llu already registered by another hotplug driver\n", sun);
355			else
356				pr_warn("acpiphp_register_hotplug_slot failed (err code = 0x%x)\n", retval);
357		}
358		/* Even if the slot registration fails, we can still use it. */
359	}
360
361 slot_found:
362	newfunc->slot = slot;
363	list_add_tail(&newfunc->sibling, &slot->funcs);
364
365	if (pci_bus_read_dev_vendor_id(pbus, PCI_DEVFN(device, function),
366				       &val, 60*1000))
367		slot->flags |= SLOT_ENABLED;
368
369	return AE_OK;
370}
371
372static void cleanup_bridge(struct acpiphp_bridge *bridge)
373{
374	struct acpiphp_slot *slot;
375	struct acpiphp_func *func;
376
377	list_for_each_entry(slot, &bridge->slots, node) {
378		list_for_each_entry(func, &slot->funcs, sibling) {
379			struct acpi_device *adev = func_to_acpi_device(func);
380
381			acpi_lock_hp_context();
382			adev->hp->notify = NULL;
383			adev->hp->fixup = NULL;
384			acpi_unlock_hp_context();
385		}
386		slot->flags |= SLOT_IS_GOING_AWAY;
387		if (slot->slot)
388			acpiphp_unregister_hotplug_slot(slot);
389	}
390
391	mutex_lock(&bridge_mutex);
392	list_del(&bridge->list);
393	mutex_unlock(&bridge_mutex);
394
395	acpi_lock_hp_context();
396	bridge->is_going_away = true;
397	acpi_unlock_hp_context();
398}
399
400/**
401 * acpiphp_max_busnr - return the highest reserved bus number under the given bus.
402 * @bus: bus to start search with
403 */
404static unsigned char acpiphp_max_busnr(struct pci_bus *bus)
405{
406	struct pci_bus *tmp;
407	unsigned char max, n;
408
409	/*
410	 * pci_bus_max_busnr will return the highest
411	 * reserved busnr for all these children.
412	 * that is equivalent to the bus->subordinate
413	 * value.  We don't want to use the parent's
414	 * bus->subordinate value because it could have
415	 * padding in it.
416	 */
417	max = bus->busn_res.start;
418
419	list_for_each_entry(tmp, &bus->children, node) {
420		n = pci_bus_max_busnr(tmp);
421		if (n > max)
422			max = n;
423	}
424	return max;
425}
426
427static void acpiphp_set_acpi_region(struct acpiphp_slot *slot)
428{
429	struct acpiphp_func *func;
430	union acpi_object params[2];
431	struct acpi_object_list arg_list;
432
433	list_for_each_entry(func, &slot->funcs, sibling) {
434		arg_list.count = 2;
435		arg_list.pointer = params;
436		params[0].type = ACPI_TYPE_INTEGER;
437		params[0].integer.value = ACPI_ADR_SPACE_PCI_CONFIG;
438		params[1].type = ACPI_TYPE_INTEGER;
439		params[1].integer.value = 1;
440		/* _REG is optional, we don't care about if there is failure */
441		acpi_evaluate_object(func_to_handle(func), "_REG", &arg_list,
442				     NULL);
443	}
444}
445
446static void check_hotplug_bridge(struct acpiphp_slot *slot, struct pci_dev *dev)
447{
448	struct acpiphp_func *func;
449
450	/* quirk, or pcie could set it already */
451	if (dev->is_hotplug_bridge)
452		return;
453
454	list_for_each_entry(func, &slot->funcs, sibling) {
455		if (PCI_FUNC(dev->devfn) == func->function) {
456			dev->is_hotplug_bridge = 1;
457			break;
458		}
459	}
460}
461
462static int acpiphp_rescan_slot(struct acpiphp_slot *slot)
463{
464	struct acpiphp_func *func;
465
466	list_for_each_entry(func, &slot->funcs, sibling) {
467		struct acpi_device *adev = func_to_acpi_device(func);
468
469		acpi_bus_scan(adev->handle);
470		if (acpi_device_enumerated(adev))
471			acpi_device_set_power(adev, ACPI_STATE_D0);
472	}
473	return pci_scan_slot(slot->bus, PCI_DEVFN(slot->device, 0));
474}
475
476/**
477 * enable_slot - enable, configure a slot
478 * @slot: slot to be enabled
479 *
480 * This function should be called per *physical slot*,
481 * not per each slot object in ACPI namespace.
482 */
483static void enable_slot(struct acpiphp_slot *slot)
484{
485	struct pci_dev *dev;
486	struct pci_bus *bus = slot->bus;
487	struct acpiphp_func *func;
488	int max, pass;
489	LIST_HEAD(add_list);
490
491	acpiphp_rescan_slot(slot);
492	max = acpiphp_max_busnr(bus);
493	for (pass = 0; pass < 2; pass++) {
494		list_for_each_entry(dev, &bus->devices, bus_list) {
495			if (PCI_SLOT(dev->devfn) != slot->device)
496				continue;
497
498			if (pci_is_bridge(dev)) {
499				max = pci_scan_bridge(bus, dev, max, pass);
500				if (pass && dev->subordinate) {
501					check_hotplug_bridge(slot, dev);
502					pcibios_resource_survey_bus(dev->subordinate);
503					__pci_bus_size_bridges(dev->subordinate,
504							       &add_list);
505				}
506			}
507		}
508	}
509	__pci_bus_assign_resources(bus, &add_list, NULL);
510
511	acpiphp_sanitize_bus(bus);
512	pcie_bus_configure_settings(bus);
513	acpiphp_set_acpi_region(slot);
514
515	list_for_each_entry(dev, &bus->devices, bus_list) {
516		/* Assume that newly added devices are powered on already. */
517		if (!dev->is_added)
518			dev->current_state = PCI_D0;
519	}
520
521	pci_bus_add_devices(bus);
522
523	slot->flags |= SLOT_ENABLED;
524	list_for_each_entry(func, &slot->funcs, sibling) {
525		dev = pci_get_slot(bus, PCI_DEVFN(slot->device,
526						  func->function));
527		if (!dev) {
528			/* Do not set SLOT_ENABLED flag if some funcs
529			   are not added. */
530			slot->flags &= (~SLOT_ENABLED);
531			continue;
532		}
533	}
534}
535
536/**
537 * disable_slot - disable a slot
538 * @slot: ACPI PHP slot
539 */
540static void disable_slot(struct acpiphp_slot *slot)
541{
542	struct pci_bus *bus = slot->bus;
543	struct pci_dev *dev, *prev;
544	struct acpiphp_func *func;
545
546	/*
547	 * enable_slot() enumerates all functions in this device via
548	 * pci_scan_slot(), whether they have associated ACPI hotplug
549	 * methods (_EJ0, etc.) or not.  Therefore, we remove all functions
550	 * here.
551	 */
552	list_for_each_entry_safe_reverse(dev, prev, &bus->devices, bus_list)
553		if (PCI_SLOT(dev->devfn) == slot->device)
554			pci_stop_and_remove_bus_device(dev);
555
556	list_for_each_entry(func, &slot->funcs, sibling)
557		acpi_bus_trim(func_to_acpi_device(func));
558
559	slot->flags &= (~SLOT_ENABLED);
560}
561
562static bool slot_no_hotplug(struct acpiphp_slot *slot)
563{
564	struct pci_bus *bus = slot->bus;
565	struct pci_dev *dev;
566
567	list_for_each_entry(dev, &bus->devices, bus_list) {
568		if (PCI_SLOT(dev->devfn) == slot->device && dev->ignore_hotplug)
569			return true;
570	}
571	return false;
572}
573
574/**
575 * get_slot_status - get ACPI slot status
576 * @slot: ACPI PHP slot
577 *
578 * If a slot has _STA for each function and if any one of them
579 * returned non-zero status, return it.
580 *
581 * If a slot doesn't have _STA and if any one of its functions'
582 * configuration space is configured, return 0x0f as a _STA.
583 *
584 * Otherwise return 0.
585 */
586static unsigned int get_slot_status(struct acpiphp_slot *slot)
587{
588	unsigned long long sta = 0;
589	struct acpiphp_func *func;
590
591	list_for_each_entry(func, &slot->funcs, sibling) {
592		if (func->flags & FUNC_HAS_STA) {
593			acpi_status status;
594
595			status = acpi_evaluate_integer(func_to_handle(func),
596						       "_STA", NULL, &sta);
597			if (ACPI_SUCCESS(status) && sta)
598				break;
599		} else {
600			u32 dvid;
601
602			pci_bus_read_config_dword(slot->bus,
603						  PCI_DEVFN(slot->device,
604							    func->function),
605						  PCI_VENDOR_ID, &dvid);
606			if (dvid != 0xffffffff) {
607				sta = ACPI_STA_ALL;
608				break;
609			}
610		}
611	}
612
613	return (unsigned int)sta;
614}
615
616static inline bool device_status_valid(unsigned int sta)
617{
618	/*
619	 * ACPI spec says that _STA may return bit 0 clear with bit 3 set
620	 * if the device is valid but does not require a device driver to be
621	 * loaded (Section 6.3.7 of ACPI 5.0A).
622	 */
623	unsigned int mask = ACPI_STA_DEVICE_ENABLED | ACPI_STA_DEVICE_FUNCTIONING;
624	return (sta & mask) == mask;
625}
626
627/**
628 * trim_stale_devices - remove PCI devices that are not responding.
629 * @dev: PCI device to start walking the hierarchy from.
630 */
631static void trim_stale_devices(struct pci_dev *dev)
632{
633	struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
634	struct pci_bus *bus = dev->subordinate;
635	bool alive = dev->ignore_hotplug;
636
637	if (adev) {
638		acpi_status status;
639		unsigned long long sta;
640
641		status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
642		alive = alive || (ACPI_SUCCESS(status) && device_status_valid(sta));
643	}
644	if (!alive)
645		alive = pci_device_is_present(dev);
646
647	if (!alive) {
648		pci_stop_and_remove_bus_device(dev);
649		if (adev)
650			acpi_bus_trim(adev);
651	} else if (bus) {
652		struct pci_dev *child, *tmp;
653
654		/* The device is a bridge. so check the bus below it. */
655		pm_runtime_get_sync(&dev->dev);
656		list_for_each_entry_safe_reverse(child, tmp, &bus->devices, bus_list)
657			trim_stale_devices(child);
658
659		pm_runtime_put(&dev->dev);
660	}
661}
662
663/**
664 * acpiphp_check_bridge - re-enumerate devices
665 * @bridge: where to begin re-enumeration
666 *
667 * Iterate over all slots under this bridge and make sure that if a
668 * card is present they are enabled, and if not they are disabled.
669 */
670static void acpiphp_check_bridge(struct acpiphp_bridge *bridge)
671{
672	struct acpiphp_slot *slot;
673
674	/* Bail out if the bridge is going away. */
675	if (bridge->is_going_away)
676		return;
677
678	list_for_each_entry(slot, &bridge->slots, node) {
679		struct pci_bus *bus = slot->bus;
680		struct pci_dev *dev, *tmp;
681
682		if (slot_no_hotplug(slot)) {
683			; /* do nothing */
684		} else if (device_status_valid(get_slot_status(slot))) {
685			/* remove stale devices if any */
686			list_for_each_entry_safe_reverse(dev, tmp,
687							 &bus->devices, bus_list)
688				if (PCI_SLOT(dev->devfn) == slot->device)
689					trim_stale_devices(dev);
690
691			/* configure all functions */
692			enable_slot(slot);
693		} else {
694			disable_slot(slot);
695		}
696	}
697}
698
699/*
700 * Remove devices for which we could not assign resources, call
701 * arch specific code to fix-up the bus
702 */
703static void acpiphp_sanitize_bus(struct pci_bus *bus)
704{
705	struct pci_dev *dev, *tmp;
706	int i;
707	unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM;
708
709	list_for_each_entry_safe_reverse(dev, tmp, &bus->devices, bus_list) {
710		for (i=0; i<PCI_BRIDGE_RESOURCES; i++) {
711			struct resource *res = &dev->resource[i];
712			if ((res->flags & type_mask) && !res->start &&
713					res->end) {
714				/* Could not assign a required resources
715				 * for this device, remove it */
716				pci_stop_and_remove_bus_device(dev);
717				break;
718			}
719		}
720	}
721}
722
723/*
724 * ACPI event handlers
725 */
726
727void acpiphp_check_host_bridge(struct acpi_device *adev)
728{
729	struct acpiphp_bridge *bridge = NULL;
730
731	acpi_lock_hp_context();
732	if (adev->hp) {
733		bridge = to_acpiphp_root_context(adev->hp)->root_bridge;
734		if (bridge)
735			get_bridge(bridge);
736	}
737	acpi_unlock_hp_context();
738	if (bridge) {
739		pci_lock_rescan_remove();
740
741		acpiphp_check_bridge(bridge);
742
743		pci_unlock_rescan_remove();
744		put_bridge(bridge);
745	}
746}
747
748static int acpiphp_disable_and_eject_slot(struct acpiphp_slot *slot);
749
750static void hotplug_event(u32 type, struct acpiphp_context *context)
751{
752	acpi_handle handle = context->hp.self->handle;
753	struct acpiphp_func *func = &context->func;
754	struct acpiphp_slot *slot = func->slot;
755	struct acpiphp_bridge *bridge;
756
757	acpi_lock_hp_context();
758	bridge = context->bridge;
759	if (bridge)
760		get_bridge(bridge);
761
762	acpi_unlock_hp_context();
763
764	pci_lock_rescan_remove();
765
766	switch (type) {
767	case ACPI_NOTIFY_BUS_CHECK:
768		/* bus re-enumerate */
769		acpi_handle_debug(handle, "Bus check in %s()\n", __func__);
770		if (bridge)
771			acpiphp_check_bridge(bridge);
772		else if (!(slot->flags & SLOT_IS_GOING_AWAY))
773			enable_slot(slot);
774
775		break;
776
777	case ACPI_NOTIFY_DEVICE_CHECK:
778		/* device check */
779		acpi_handle_debug(handle, "Device check in %s()\n", __func__);
780		if (bridge) {
781			acpiphp_check_bridge(bridge);
782		} else if (!(slot->flags & SLOT_IS_GOING_AWAY)) {
783			/*
784			 * Check if anything has changed in the slot and rescan
785			 * from the parent if that's the case.
786			 */
787			if (acpiphp_rescan_slot(slot))
788				acpiphp_check_bridge(func->parent);
789		}
790		break;
791
792	case ACPI_NOTIFY_EJECT_REQUEST:
793		/* request device eject */
794		acpi_handle_debug(handle, "Eject request in %s()\n", __func__);
795		acpiphp_disable_and_eject_slot(slot);
796		break;
797	}
798
799	pci_unlock_rescan_remove();
800	if (bridge)
801		put_bridge(bridge);
802}
803
804static int acpiphp_hotplug_notify(struct acpi_device *adev, u32 type)
805{
806	struct acpiphp_context *context;
807
808	context = acpiphp_grab_context(adev);
809	if (!context)
810		return -ENODATA;
811
812	hotplug_event(type, context);
813	acpiphp_let_context_go(context);
814	return 0;
815}
816
817/**
818 * acpiphp_enumerate_slots - Enumerate PCI slots for a given bus.
819 * @bus: PCI bus to enumerate the slots for.
820 *
821 * A "slot" is an object associated with a PCI device number.  All functions
822 * (PCI devices) with the same bus and device number belong to the same slot.
823 */
824void acpiphp_enumerate_slots(struct pci_bus *bus)
825{
826	struct acpiphp_bridge *bridge;
827	struct acpi_device *adev;
828	acpi_handle handle;
829	acpi_status status;
830
831	if (acpiphp_disabled)
832		return;
833
834	adev = ACPI_COMPANION(bus->bridge);
835	if (!adev)
836		return;
837
838	handle = adev->handle;
839	bridge = kzalloc(sizeof(struct acpiphp_bridge), GFP_KERNEL);
840	if (!bridge) {
841		acpi_handle_err(handle, "No memory for bridge object\n");
842		return;
843	}
844
845	INIT_LIST_HEAD(&bridge->slots);
846	kref_init(&bridge->ref);
847	bridge->pci_dev = pci_dev_get(bus->self);
848	bridge->pci_bus = bus;
849
850	/*
851	 * Grab a ref to the subordinate PCI bus in case the bus is
852	 * removed via PCI core logical hotplug. The ref pins the bus
853	 * (which we access during module unload).
854	 */
855	get_device(&bus->dev);
856
857	acpi_lock_hp_context();
858	if (pci_is_root_bus(bridge->pci_bus)) {
859		struct acpiphp_root_context *root_context;
860
861		root_context = kzalloc(sizeof(*root_context), GFP_KERNEL);
862		if (!root_context)
863			goto err;
864
865		root_context->root_bridge = bridge;
866		acpi_set_hp_context(adev, &root_context->hp);
867	} else {
868		struct acpiphp_context *context;
869
870		/*
871		 * This bridge should have been registered as a hotplug function
872		 * under its parent, so the context should be there, unless the
873		 * parent is going to be handled by pciehp, in which case this
874		 * bridge is not interesting to us either.
875		 */
876		context = acpiphp_get_context(adev);
877		if (!context)
878			goto err;
879
880		bridge->context = context;
881		context->bridge = bridge;
882		/* Get a reference to the parent bridge. */
883		get_bridge(context->func.parent);
884	}
885	acpi_unlock_hp_context();
886
887	/* Must be added to the list prior to calling acpiphp_add_context(). */
888	mutex_lock(&bridge_mutex);
889	list_add(&bridge->list, &bridge_list);
890	mutex_unlock(&bridge_mutex);
891
892	/* register all slot objects under this bridge */
893	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
894				     acpiphp_add_context, NULL, bridge, NULL);
895	if (ACPI_FAILURE(status)) {
896		acpi_handle_err(handle, "failed to register slots\n");
897		cleanup_bridge(bridge);
898		put_bridge(bridge);
899	}
900	return;
901
902 err:
903	acpi_unlock_hp_context();
904	put_device(&bus->dev);
905	pci_dev_put(bridge->pci_dev);
906	kfree(bridge);
907}
908
909static void acpiphp_drop_bridge(struct acpiphp_bridge *bridge)
910{
911	if (pci_is_root_bus(bridge->pci_bus)) {
912		struct acpiphp_root_context *root_context;
913		struct acpi_device *adev;
914
915		acpi_lock_hp_context();
916		adev = ACPI_COMPANION(bridge->pci_bus->bridge);
917		root_context = to_acpiphp_root_context(adev->hp);
918		adev->hp = NULL;
919		acpi_unlock_hp_context();
920		kfree(root_context);
921	}
922	cleanup_bridge(bridge);
923	put_bridge(bridge);
924}
925
926/**
927 * acpiphp_remove_slots - Remove slot objects associated with a given bus.
928 * @bus: PCI bus to remove the slot objects for.
929 */
930void acpiphp_remove_slots(struct pci_bus *bus)
931{
932	struct acpiphp_bridge *bridge;
933
934	if (acpiphp_disabled)
935		return;
936
937	mutex_lock(&bridge_mutex);
938	list_for_each_entry(bridge, &bridge_list, list)
939		if (bridge->pci_bus == bus) {
940			mutex_unlock(&bridge_mutex);
941			acpiphp_drop_bridge(bridge);
942			return;
943		}
944
945	mutex_unlock(&bridge_mutex);
946}
947
948/**
949 * acpiphp_enable_slot - power on slot
950 * @slot: ACPI PHP slot
951 */
952int acpiphp_enable_slot(struct acpiphp_slot *slot)
953{
954	pci_lock_rescan_remove();
955
956	if (slot->flags & SLOT_IS_GOING_AWAY) {
957		pci_unlock_rescan_remove();
958		return -ENODEV;
959	}
960
961	/* configure all functions */
962	if (!(slot->flags & SLOT_ENABLED))
963		enable_slot(slot);
964
965	pci_unlock_rescan_remove();
966	return 0;
967}
968
969/**
970 * acpiphp_disable_and_eject_slot - power off and eject slot
971 * @slot: ACPI PHP slot
972 */
973static int acpiphp_disable_and_eject_slot(struct acpiphp_slot *slot)
974{
975	struct acpiphp_func *func;
976
977	if (slot->flags & SLOT_IS_GOING_AWAY)
978		return -ENODEV;
979
980	/* unconfigure all functions */
981	disable_slot(slot);
982
983	list_for_each_entry(func, &slot->funcs, sibling)
984		if (func->flags & FUNC_HAS_EJ0) {
985			acpi_handle handle = func_to_handle(func);
986
987			if (ACPI_FAILURE(acpi_evaluate_ej0(handle)))
988				acpi_handle_err(handle, "_EJ0 failed\n");
989
990			break;
991		}
992
993	return 0;
994}
995
996int acpiphp_disable_slot(struct acpiphp_slot *slot)
997{
998	int ret;
999
1000	/*
1001	 * Acquire acpi_scan_lock to ensure that the execution of _EJ0 in
1002	 * acpiphp_disable_and_eject_slot() will be synchronized properly.
1003	 */
1004	acpi_scan_lock_acquire();
1005	pci_lock_rescan_remove();
1006	ret = acpiphp_disable_and_eject_slot(slot);
1007	pci_unlock_rescan_remove();
1008	acpi_scan_lock_release();
1009	return ret;
1010}
1011
1012/*
1013 * slot enabled:  1
1014 * slot disabled: 0
1015 */
1016u8 acpiphp_get_power_status(struct acpiphp_slot *slot)
1017{
1018	return (slot->flags & SLOT_ENABLED);
1019}
1020
1021/*
1022 * latch   open:  1
1023 * latch closed:  0
1024 */
1025u8 acpiphp_get_latch_status(struct acpiphp_slot *slot)
1026{
1027	return !(get_slot_status(slot) & ACPI_STA_DEVICE_UI);
1028}
1029
1030/*
1031 * adapter presence : 1
1032 *          absence : 0
1033 */
1034u8 acpiphp_get_adapter_status(struct acpiphp_slot *slot)
1035{
1036	return !!get_slot_status(slot);
1037}
1038