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(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 */
  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(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(context);
 108}
 109
 110static inline void get_bridge(struct acpiphp_bridge *bridge)
 111{
 112	kref_get(&bridge->ref);
 113}
 114
 115static inline void put_bridge(struct acpiphp_bridge *bridge)
 116{
 117	kref_put(&bridge->ref, 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(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(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(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 */
 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(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 */
 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, "_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
 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(&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 */
 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(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(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(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
 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(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 */
 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(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					__pci_bus_size_bridges(dev->subordinate,
 516							       &add_list);
 517				}
 518			}
 519		}
 520		__pci_bus_assign_resources(bus, &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(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(func_to_handle(func),
 610						       "_STA", NULL, &sta);
 611			if (ACPI_SUCCESS(status) && sta)
 612				break;
 613		} else {
 614			if (pci_bus_read_dev_vendor_id(slot->bus,
 615					PCI_DEVFN(slot->device, func->function),
 616					&dvid, 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(slot->bus,
 630				PCI_DEVFN(slot->device, 0), &dvid, 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(adev->handle, "_STA", NULL, &sta);
 664		alive = alive || (ACPI_SUCCESS(status) && device_status_valid(sta));
 665	}
 666	if (!alive)
 667		alive = pci_device_is_present(dev);
 668
 669	if (!alive) {
 670		pci_dev_set_disconnected(dev, NULL);
 671		if (pci_has_subordinate(dev))
 672			pci_walk_bus(dev->subordinate, pci_dev_set_disconnected,
 673				     NULL);
 674
 675		pci_stop_and_remove_bus_device(dev);
 676		if (adev)
 677			acpi_bus_trim(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);
 683		list_for_each_entry_safe_reverse(child, tmp, &bus->devices, bus_list)
 684			trim_stale_devices(child);
 685
 686		pm_runtime_put(&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(&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(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, true);
 723		} else {
 724			disable_slot(slot);
 725		}
 726	}
 727
 728	if (bridge->pci_dev)
 729		pm_runtime_put(&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(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, 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(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(sizeof(struct acpiphp_bridge), GFP_KERNEL);
 873	if (!bridge)
 874		return;
 875
 876	INIT_LIST_HEAD(&bridge->slots);
 877	kref_init(&bridge->ref);
 878	bridge->pci_dev = pci_dev_get(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(&bus->dev);
 887
 888	acpi_lock_hp_context();
 889	if (pci_is_root_bus(bridge->pci_bus)) {
 890		struct acpiphp_root_context *root_context;
 891
 892		root_context = kzalloc(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, &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(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(&bridge->list, &bridge_list);
 921	mutex_unlock(&bridge_mutex);
 922
 923	/* register all slot objects under this bridge */
 924	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
 925				     acpiphp_add_context, NULL, 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(&bus->dev);
 936	pci_dev_put(bridge->pci_dev);
 937	kfree(bridge);
 938}
 939
 940static void acpiphp_drop_bridge(struct acpiphp_bridge *bridge)
 941{
 942	if (pci_is_root_bus(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(adev->hp);
 949		adev->hp = NULL;
 950		acpi_unlock_hp_context();
 951		kfree(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(&bridge_mutex);
 972			acpiphp_drop_bridge(bridge);
 973			return;
 974		}
 975
 976	mutex_unlock(&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, 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}