drivers/pci/hotplug/acpiphp_glue.c

   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/init.h>
  45 #include <linux/module.h>
  46
  47 #include <linux/kernel.h>
  48 #include <linux/pci.h>
  49 #include <linux/pci_hotplug.h>
  50 #include <linux/pci-acpi.h>
  51 #include <linux/pm_runtime.h>
  52 #include <linux/mutex.h>
  53 #include <linux/slab.h>
  54 #include <linux/acpi.h>
  55
  56 #include "../pci.h"
  57 #include "acpiphp.h"
  58
  59 static LIST_HEAD(bridge_list);
  60 static DEFINE_MUTEX(bridge_mutex);
  61 static DEFINE_MUTEX(acpiphp_context_lock);
  62
  63 static void handle_hotplug_event(acpi_handle handle, u32 type, void *data);
  64 static void acpiphp_sanitize_bus(struct pci_bus *bus);
  65 static void acpiphp_set_hpp_values(struct pci_bus *bus);
  66 static void hotplug_event(acpi_handle handle, u32 type, void *data);
  67 static void free_bridge(struct kref *kref);
  68
  69 static void acpiphp_context_handler(acpi_handle handle, void *context)
  70 {
  71         /* Intentionally empty. */
  72 }
  73
  74 /**
  75  * acpiphp_init_context - Create hotplug context and grab a reference to it.
  76  * @handle: ACPI object handle to create the context for.
  77  *
  78  * Call under acpiphp_context_lock.
  79  */
  80 static struct acpiphp_context *acpiphp_init_context(acpi_handle handle)
  81 {
  82         struct acpiphp_context *context;
  83         acpi_status status;
  84
  85         context = kzalloc(sizeof(*context), GFP_KERNEL);
  86         if (!context)
  87                 return NULL;
  88
  89         context->handle = handle;
  90         context->refcount = 1;
  91         status = acpi_attach_data(handle, acpiphp_context_handler, context);
  92         if (ACPI_FAILURE(status)) {
  93                 kfree(context);
  94                 return NULL;
  95         }
  96         return context;
  97 }
  98
  99 /**
 100  * acpiphp_get_context - Get hotplug context and grab a reference to it.
 101  * @handle: ACPI object handle to get the context for.
 102  *
 103  * Call under acpiphp_context_lock.
 104  */
 105 static struct acpiphp_context *acpiphp_get_context(acpi_handle handle)
 106 {
 107         struct acpiphp_context *context = NULL;
 108         acpi_status status;
 109         void *data;
 110
 111         status = acpi_get_data(handle, acpiphp_context_handler, &data);
 112         if (ACPI_SUCCESS(status)) {
 113                 context = data;
 114                 context->refcount++;
 115         }
 116         return context;
 117 }
 118
 119 /**
 120  * acpiphp_put_context - Drop a reference to ACPI hotplug context.
 121  * @handle: ACPI object handle to put the context for.
 122  *
 123  * The context object is removed if there are no more references to it.
 124  *
 125  * Call under acpiphp_context_lock.
 126  */
 127 static void acpiphp_put_context(struct acpiphp_context *context)
 128 {
 129         if (--context->refcount)
 130                 return;
 131
 132         WARN_ON(context->bridge);
 133         acpi_detach_data(context->handle, acpiphp_context_handler);
 134         kfree(context);
 135 }
 136
 137 static inline void get_bridge(struct acpiphp_bridge *bridge)
 138 {
 139         kref_get(&bridge->ref);
 140 }
 141
 142 static inline void put_bridge(struct acpiphp_bridge *bridge)
 143 {
 144         kref_put(&bridge->ref, free_bridge);
 145 }
 146
 147 static void free_bridge(struct kref *kref)
 148 {
 149         struct acpiphp_context *context;
 150         struct acpiphp_bridge *bridge;
 151         struct acpiphp_slot *slot, *next;
 152         struct acpiphp_func *func, *tmp;
 153
 154         mutex_lock(&acpiphp_context_lock);
 155
 156         bridge = container_of(kref, struct acpiphp_bridge, ref);
 157
 158         list_for_each_entry_safe(slot, next, &bridge->slots, node) {
 159                 list_for_each_entry_safe(func, tmp, &slot->funcs, sibling)
 160                         acpiphp_put_context(func_to_context(func));
 161
 162                 kfree(slot);
 163         }
 164
 165         context = bridge->context;
 166         /* Root bridges will not have hotplug context. */
 167         if (context) {
 168                 /* Release the reference taken by acpiphp_enumerate_slots(). */
 169                 put_bridge(context->func.parent);
 170                 context->bridge = NULL;
 171                 acpiphp_put_context(context);
 172         }
 173
 174         put_device(&bridge->pci_bus->dev);
 175         pci_dev_put(bridge->pci_dev);
 176         kfree(bridge);
 177
 178         mutex_unlock(&acpiphp_context_lock);
 179 }
 180
 181 /*
 182  * the _DCK method can do funny things... and sometimes not
 183  * hah-hah funny.
 184  *
 185  * TBD - figure out a way to only call fixups for
 186  * systems that require them.
 187  */
 188 static void post_dock_fixups(acpi_handle not_used, u32 event, void *data)
 189 {
 190         struct acpiphp_context *context = data;
 191         struct pci_bus *bus = context->func.slot->bus;
 192         u32 buses;
 193
 194         if (!bus->self)
 195                 return;
 196
 197         /* fixup bad _DCK function that rewrites
 198          * secondary bridge on slot
 199          */
 200         pci_read_config_dword(bus->self,
 201                         PCI_PRIMARY_BUS,
 202                         &buses);
 203
 204         if (((buses >> 8) & 0xff) != bus->busn_res.start) {
 205                 buses = (buses & 0xff000000)
 206                         | ((unsigned int)(bus->primary)     <<  0)
 207                         | ((unsigned int)(bus->busn_res.start)   <<  8)
 208                         | ((unsigned int)(bus->busn_res.end) << 16);
 209                 pci_write_config_dword(bus->self, PCI_PRIMARY_BUS, buses);
 210         }
 211 }
 212
 213 static void dock_event(acpi_handle handle, u32 type, void *data)
 214 {
 215         struct acpiphp_context *context;
 216
 217         mutex_lock(&acpiphp_context_lock);
 218         context = acpiphp_get_context(handle);
 219         if (!context || WARN_ON(context->handle != handle)
 220             || context->func.parent->is_going_away) {
 221                 mutex_unlock(&acpiphp_context_lock);
 222                 return;
 223         }
 224         get_bridge(context->func.parent);
 225         acpiphp_put_context(context);
 226         mutex_unlock(&acpiphp_context_lock);
 227
 228         hotplug_event(handle, type, data);
 229
 230         put_bridge(context->func.parent);
 231 }
 232
 233 static const struct acpi_dock_ops acpiphp_dock_ops = {
 234         .fixup = post_dock_fixups,
 235         .handler = dock_event,
 236 };
 237
 238 /* Check whether the PCI device is managed by native PCIe hotplug driver */
 239 static bool device_is_managed_by_native_pciehp(struct pci_dev *pdev)
 240 {
 241         u32 reg32;
 242         acpi_handle tmp;
 243         struct acpi_pci_root *root;
 244
 245         /* Check whether the PCIe port supports native PCIe hotplug */
 246         if (pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &reg32))
 247                 return false;
 248         if (!(reg32 & PCI_EXP_SLTCAP_HPC))
 249                 return false;
 250
 251         /*
 252          * Check whether native PCIe hotplug has been enabled for
 253          * this PCIe hierarchy.
 254          */
 255         tmp = acpi_find_root_bridge_handle(pdev);
 256         if (!tmp)
 257                 return false;
 258         root = acpi_pci_find_root(tmp);
 259         if (!root)
 260                 return false;
 261         if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
 262                 return false;
 263
 264         return true;
 265 }
 266
 267 static void acpiphp_dock_init(void *data)
 268 {
 269         struct acpiphp_context *context = data;
 270
 271         get_bridge(context->func.parent);
 272 }
 273
 274 static void acpiphp_dock_release(void *data)
 275 {
 276         struct acpiphp_context *context = data;
 277
 278         put_bridge(context->func.parent);
 279 }
 280
 281 /* callback routine to register each ACPI PCI slot object */
 282 static acpi_status register_slot(acpi_handle handle, u32 lvl, void *data,
 283                                  void **rv)
 284 {
 285         struct acpiphp_bridge *bridge = data;
 286         struct acpiphp_context *context;
 287         struct acpiphp_slot *slot;
 288         struct acpiphp_func *newfunc;
 289         acpi_status status = AE_OK;
 290         unsigned long long adr;
 291         int device, function;
 292         struct pci_bus *pbus = bridge->pci_bus;
 293         struct pci_dev *pdev = bridge->pci_dev;
 294         u32 val;
 295
 296         if (pdev && device_is_managed_by_native_pciehp(pdev))
 297                 return AE_OK;
 298
 299         status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
 300         if (ACPI_FAILURE(status)) {
 301                 if (status != AE_NOT_FOUND)
 302                         acpi_handle_warn(handle,
 303                                 "can't evaluate _ADR (%#x)\n", status);
 304                 return AE_OK;
 305         }
 306
 307         device = (adr >> 16) & 0xffff;
 308         function = adr & 0xffff;
 309
 310         mutex_lock(&acpiphp_context_lock);
 311         context = acpiphp_init_context(handle);
 312         if (!context) {
 313                 mutex_unlock(&acpiphp_context_lock);
 314                 acpi_handle_err(handle, "No hotplug context\n");
 315                 return AE_NOT_EXIST;
 316         }
 317         newfunc = &context->func;
 318         newfunc->function = function;
 319         newfunc->parent = bridge;
 320         mutex_unlock(&acpiphp_context_lock);
 321
 322         if (acpi_has_method(handle, "_EJ0"))
 323                 newfunc->flags = FUNC_HAS_EJ0;
 324
 325         if (acpi_has_method(handle, "_STA"))
 326                 newfunc->flags |= FUNC_HAS_STA;
 327
 328         if (acpi_has_method(handle, "_DCK"))
 329                 newfunc->flags |= FUNC_HAS_DCK;
 330
 331         /* search for objects that share the same slot */
 332         list_for_each_entry(slot, &bridge->slots, node)
 333                 if (slot->device == device)
 334                         goto slot_found;
 335
 336         slot = kzalloc(sizeof(struct acpiphp_slot), GFP_KERNEL);
 337         if (!slot) {
 338                 status = AE_NO_MEMORY;
 339                 goto err;
 340         }
 341
 342         slot->bus = bridge->pci_bus;
 343         slot->device = device;
 344         INIT_LIST_HEAD(&slot->funcs);
 345         mutex_init(&slot->crit_sect);
 346
 347         list_add_tail(&slot->node, &bridge->slots);
 348
 349         /* Register slots for ejectable functions only. */
 350         if (acpi_pci_check_ejectable(pbus, handle)  || is_dock_device(handle)) {
 351                 unsigned long long sun;
 352                 int retval;
 353
 354                 bridge->nr_slots++;
 355                 status = acpi_evaluate_integer(handle, "_SUN", NULL, &sun);
 356                 if (ACPI_FAILURE(status))
 357                         sun = bridge->nr_slots;
 358
 359                 pr_debug("found ACPI PCI Hotplug slot %llu at PCI %04x:%02x:%02x\n",
 360                     sun, pci_domain_nr(pbus), pbus->number, device);
 361
 362                 retval = acpiphp_register_hotplug_slot(slot, sun);
 363                 if (retval) {
 364                         slot->slot = NULL;
 365                         bridge->nr_slots--;
 366                         if (retval == -EBUSY)
 367                                 pr_warn("Slot %llu already registered by another "
 368                                         "hotplug driver\n", sun);
 369                         else
 370                                 pr_warn("acpiphp_register_hotplug_slot failed "
 371                                         "(err code = 0x%x)\n", retval);
 372                 }
 373                 /* Even if the slot registration fails, we can still use it. */
 374         }
 375
 376  slot_found:
 377         newfunc->slot = slot;
 378         list_add_tail(&newfunc->sibling, &slot->funcs);
 379
 380         if (pci_bus_read_dev_vendor_id(pbus, PCI_DEVFN(device, function),
 381                                        &val, 60*1000))
 382                 slot->flags |= SLOT_ENABLED;
 383
 384         if (is_dock_device(handle)) {
 385                 /* we don't want to call this device's _EJ0
 386                  * because we want the dock notify handler
 387                  * to call it after it calls _DCK
 388                  */
 389                 newfunc->flags &= ~FUNC_HAS_EJ0;
 390                 if (register_hotplug_dock_device(handle,
 391                         &acpiphp_dock_ops, context,
 392                         acpiphp_dock_init, acpiphp_dock_release))
 393                         pr_debug("failed to register dock device\n");
 394         }
 395
 396         /* install notify handler */
 397         if (!(newfunc->flags & FUNC_HAS_DCK)) {
 398                 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 399                                                      handle_hotplug_event,
 400                                                      context);
 401                 if (ACPI_FAILURE(status))
 402                         acpi_handle_err(handle,
 403                                         "failed to install notify handler\n");
 404         }
 405
 406         return AE_OK;
 407
 408  err:
 409         mutex_lock(&acpiphp_context_lock);
 410         acpiphp_put_context(context);
 411         mutex_unlock(&acpiphp_context_lock);
 412         return status;
 413 }
 414
 415 static struct acpiphp_bridge *acpiphp_handle_to_bridge(acpi_handle handle)
 416 {
 417         struct acpiphp_context *context;
 418         struct acpiphp_bridge *bridge = NULL;
 419
 420         mutex_lock(&acpiphp_context_lock);
 421         context = acpiphp_get_context(handle);
 422         if (context) {
 423                 bridge = context->bridge;
 424                 if (bridge)
 425                         get_bridge(bridge);
 426
 427                 acpiphp_put_context(context);
 428         }
 429         mutex_unlock(&acpiphp_context_lock);
 430         return bridge;
 431 }
 432
 433 static void cleanup_bridge(struct acpiphp_bridge *bridge)
 434 {
 435         struct acpiphp_slot *slot;
 436         struct acpiphp_func *func;
 437         acpi_status status;
 438
 439         list_for_each_entry(slot, &bridge->slots, node) {
 440                 list_for_each_entry(func, &slot->funcs, sibling) {
 441                         acpi_handle handle = func_to_handle(func);
 442
 443                         if (is_dock_device(handle))
 444                                 unregister_hotplug_dock_device(handle);
 445
 446                         if (!(func->flags & FUNC_HAS_DCK)) {
 447                                 status = acpi_remove_notify_handler(handle,
 448                                                         ACPI_SYSTEM_NOTIFY,
 449                                                         handle_hotplug_event);
 450                                 if (ACPI_FAILURE(status))
 451                                         pr_err("failed to remove notify handler\n");
 452                         }
 453                 }
 454                 slot->flags |= SLOT_IS_GOING_AWAY;
 455                 if (slot->slot)
 456                         acpiphp_unregister_hotplug_slot(slot);
 457         }
 458
 459         mutex_lock(&bridge_mutex);
 460         list_del(&bridge->list);
 461         mutex_unlock(&bridge_mutex);
 462
 463         mutex_lock(&acpiphp_context_lock);
 464         bridge->is_going_away = true;
 465         mutex_unlock(&acpiphp_context_lock);
 466 }
 467
 468 /**
 469  * acpiphp_max_busnr - return the highest reserved bus number under the given bus.
 470  * @bus: bus to start search with
 471  */
 472 static unsigned char acpiphp_max_busnr(struct pci_bus *bus)
 473 {
 474         struct list_head *tmp;
 475         unsigned char max, n;
 476
 477         /*
 478          * pci_bus_max_busnr will return the highest
 479          * reserved busnr for all these children.
 480          * that is equivalent to the bus->subordinate
 481          * value.  We don't want to use the parent's
 482          * bus->subordinate value because it could have
 483          * padding in it.
 484          */
 485         max = bus->busn_res.start;
 486
 487         list_for_each(tmp, &bus->children) {
 488                 n = pci_bus_max_busnr(pci_bus_b(tmp));
 489                 if (n > max)
 490                         max = n;
 491         }
 492         return max;
 493 }
 494
 495 /**
 496  * acpiphp_bus_trim - Trim device objects in an ACPI namespace subtree.
 497  * @handle: ACPI device object handle to start from.
 498  */
 499 static void acpiphp_bus_trim(acpi_handle handle)
 500 {
 501         struct acpi_device *adev = NULL;
 502
 503         acpi_bus_get_device(handle, &adev);
 504         if (adev)
 505                 acpi_bus_trim(adev);
 506 }
 507
 508 /**
 509  * acpiphp_bus_add - Scan ACPI namespace subtree.
 510  * @handle: ACPI object handle to start the scan from.
 511  */
 512 static void acpiphp_bus_add(acpi_handle handle)
 513 {
 514         struct acpi_device *adev = NULL;
 515
 516         acpi_bus_scan(handle);
 517         acpi_bus_get_device(handle, &adev);
 518         if (acpi_device_enumerated(adev))
 519                 acpi_device_set_power(adev, ACPI_STATE_D0);
 520 }
 521
 522 static void acpiphp_set_acpi_region(struct acpiphp_slot *slot)
 523 {
 524         struct acpiphp_func *func;
 525         union acpi_object params[2];
 526         struct acpi_object_list arg_list;
 527
 528         list_for_each_entry(func, &slot->funcs, sibling) {
 529                 arg_list.count = 2;
 530                 arg_list.pointer = params;
 531                 params[0].type = ACPI_TYPE_INTEGER;
 532                 params[0].integer.value = ACPI_ADR_SPACE_PCI_CONFIG;
 533                 params[1].type = ACPI_TYPE_INTEGER;
 534                 params[1].integer.value = 1;
 535                 /* _REG is optional, we don't care about if there is failure */
 536                 acpi_evaluate_object(func_to_handle(func), "_REG", &arg_list,
 537                                      NULL);
 538         }
 539 }
 540
 541 static void check_hotplug_bridge(struct acpiphp_slot *slot, struct pci_dev *dev)
 542 {
 543         struct acpiphp_func *func;
 544
 545         /* quirk, or pcie could set it already */
 546         if (dev->is_hotplug_bridge)
 547                 return;
 548
 549         list_for_each_entry(func, &slot->funcs, sibling) {
 550                 if (PCI_FUNC(dev->devfn) == func->function) {
 551                         dev->is_hotplug_bridge = 1;
 552                         break;
 553                 }
 554         }
 555 }
 556
 557 static int acpiphp_rescan_slot(struct acpiphp_slot *slot)
 558 {
 559         struct acpiphp_func *func;
 560
 561         list_for_each_entry(func, &slot->funcs, sibling)
 562                 acpiphp_bus_add(func_to_handle(func));
 563
 564         return pci_scan_slot(slot->bus, PCI_DEVFN(slot->device, 0));
 565 }
 566
 567 /**
 568  * enable_slot - enable, configure a slot
 569  * @slot: slot to be enabled
 570  *
 571  * This function should be called per *physical slot*,
 572  * not per each slot object in ACPI namespace.
 573  */
 574 static void __ref enable_slot(struct acpiphp_slot *slot)
 575 {
 576         struct pci_dev *dev;
 577         struct pci_bus *bus = slot->bus;
 578         struct acpiphp_func *func;
 579         int max, pass;
 580         LIST_HEAD(add_list);
 581
 582         acpiphp_rescan_slot(slot);
 583         max = acpiphp_max_busnr(bus);
 584         for (pass = 0; pass < 2; pass++) {
 585                 list_for_each_entry(dev, &bus->devices, bus_list) {
 586                         if (PCI_SLOT(dev->devfn) != slot->device)
 587                                 continue;
 588
 589                         if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
 590                             dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
 591                                 max = pci_scan_bridge(bus, dev, max, pass);
 592                                 if (pass && dev->subordinate) {
 593                                         check_hotplug_bridge(slot, dev);
 594                                         pcibios_resource_survey_bus(dev->subordinate);
 595                                         __pci_bus_size_bridges(dev->subordinate,
 596                                                                &add_list);
 597                                 }
 598                         }
 599                 }
 600         }
 601         __pci_bus_assign_resources(bus, &add_list, NULL);
 602
 603         acpiphp_sanitize_bus(bus);
 604         acpiphp_set_hpp_values(bus);
 605         acpiphp_set_acpi_region(slot);
 606
 607         list_for_each_entry(dev, &bus->devices, bus_list) {
 608                 /* Assume that newly added devices are powered on already. */
 609                 if (!dev->is_added)
 610                         dev->current_state = PCI_D0;
 611         }
 612
 613         pci_bus_add_devices(bus);
 614
 615         slot->flags |= SLOT_ENABLED;
 616         list_for_each_entry(func, &slot->funcs, sibling) {
 617                 dev = pci_get_slot(bus, PCI_DEVFN(slot->device,
 618                                                   func->function));
 619                 if (!dev) {
 620                         /* Do not set SLOT_ENABLED flag if some funcs
 621                            are not added. */
 622                         slot->flags &= (~SLOT_ENABLED);
 623                         continue;
 624                 }
 625         }
 626 }
 627
 628 /* return first device in slot, acquiring a reference on it */
 629 static struct pci_dev *dev_in_slot(struct acpiphp_slot *slot)
 630 {
 631         struct pci_bus *bus = slot->bus;
 632         struct pci_dev *dev;
 633         struct pci_dev *ret = NULL;
 634
 635         down_read(&pci_bus_sem);
 636         list_for_each_entry(dev, &bus->devices, bus_list)
 637                 if (PCI_SLOT(dev->devfn) == slot->device) {
 638                         ret = pci_dev_get(dev);
 639                         break;
 640                 }
 641         up_read(&pci_bus_sem);
 642
 643         return ret;
 644 }
 645
 646 /**
 647  * disable_slot - disable a slot
 648  * @slot: ACPI PHP slot
 649  */
 650 static void disable_slot(struct acpiphp_slot *slot)
 651 {
 652         struct acpiphp_func *func;
 653         struct pci_dev *pdev;
 654
 655         /*
 656          * enable_slot() enumerates all functions in this device via
 657          * pci_scan_slot(), whether they have associated ACPI hotplug
 658          * methods (_EJ0, etc.) or not.  Therefore, we remove all functions
 659          * here.
 660          */
 661         while ((pdev = dev_in_slot(slot))) {
 662                 pci_stop_and_remove_bus_device(pdev);
 663                 pci_dev_put(pdev);
 664         }
 665
 666         list_for_each_entry(func, &slot->funcs, sibling)
 667                 acpiphp_bus_trim(func_to_handle(func));
 668
 669         slot->flags &= (~SLOT_ENABLED);
 670 }
 671
 672 static bool acpiphp_no_hotplug(acpi_handle handle)
 673 {
 674         struct acpi_device *adev = NULL;
 675
 676         acpi_bus_get_device(handle, &adev);
 677         return adev && adev->flags.no_hotplug;
 678 }
 679
 680 static bool slot_no_hotplug(struct acpiphp_slot *slot)
 681 {
 682         struct acpiphp_func *func;
 683
 684         list_for_each_entry(func, &slot->funcs, sibling)
 685                 if (acpiphp_no_hotplug(func_to_handle(func)))
 686                         return true;
 687
 688         return false;
 689 }
 690
 691 /**
 692  * get_slot_status - get ACPI slot status
 693  * @slot: ACPI PHP slot
 694  *
 695  * If a slot has _STA for each function and if any one of them
 696  * returned non-zero status, return it.
 697  *
 698  * If a slot doesn't have _STA and if any one of its functions'
 699  * configuration space is configured, return 0x0f as a _STA.
 700  *
 701  * Otherwise return 0.
 702  */
 703 static unsigned int get_slot_status(struct acpiphp_slot *slot)
 704 {
 705         unsigned long long sta = 0;
 706         struct acpiphp_func *func;
 707
 708         list_for_each_entry(func, &slot->funcs, sibling) {
 709                 if (func->flags & FUNC_HAS_STA) {
 710                         acpi_status status;
 711
 712                         status = acpi_evaluate_integer(func_to_handle(func),
 713                                                        "_STA", NULL, &sta);
 714                         if (ACPI_SUCCESS(status) && sta)
 715                                 break;
 716                 } else {
 717                         u32 dvid;
 718
 719                         pci_bus_read_config_dword(slot->bus,
 720                                                   PCI_DEVFN(slot->device,
 721                                                             func->function),
 722                                                   PCI_VENDOR_ID, &dvid);
 723                         if (dvid != 0xffffffff) {
 724                                 sta = ACPI_STA_ALL;
 725                                 break;
 726                         }
 727                 }
 728         }
 729
 730         return (unsigned int)sta;
 731 }
 732
 733 static inline bool device_status_valid(unsigned int sta)
 734 {
 735         /*
 736          * ACPI spec says that _STA may return bit 0 clear with bit 3 set
 737          * if the device is valid but does not require a device driver to be
 738          * loaded (Section 6.3.7 of ACPI 5.0A).
 739          */
 740         unsigned int mask = ACPI_STA_DEVICE_ENABLED | ACPI_STA_DEVICE_FUNCTIONING;
 741         return (sta & mask) == mask;
 742 }
 743
 744 /**
 745  * trim_stale_devices - remove PCI devices that are not responding.
 746  * @dev: PCI device to start walking the hierarchy from.
 747  */
 748 static void trim_stale_devices(struct pci_dev *dev)
 749 {
 750         acpi_handle handle = ACPI_HANDLE(&dev->dev);
 751         struct pci_bus *bus = dev->subordinate;
 752         bool alive = false;
 753
 754         if (handle) {
 755                 acpi_status status;
 756                 unsigned long long sta;
 757
 758                 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 759                 alive = (ACPI_SUCCESS(status) && device_status_valid(sta))
 760                         || acpiphp_no_hotplug(handle);
 761         }
 762         if (!alive) {
 763                 u32 v;
 764
 765                 /* Check if the device responds. */
 766                 alive = pci_bus_read_dev_vendor_id(dev->bus, dev->devfn, &v, 0);
 767         }
 768         if (!alive) {
 769                 pci_stop_and_remove_bus_device(dev);
 770                 if (handle)
 771                         acpiphp_bus_trim(handle);
 772         } else if (bus) {
 773                 struct pci_dev *child, *tmp;
 774
 775                 /* The device is a bridge. so check the bus below it. */
 776                 pm_runtime_get_sync(&dev->dev);
 777                 list_for_each_entry_safe_reverse(child, tmp, &bus->devices, bus_list)
 778                         trim_stale_devices(child);
 779
 780                 pm_runtime_put(&dev->dev);
 781         }
 782 }
 783
 784 /**
 785  * acpiphp_check_bridge - re-enumerate devices
 786  * @bridge: where to begin re-enumeration
 787  *
 788  * Iterate over all slots under this bridge and make sure that if a
 789  * card is present they are enabled, and if not they are disabled.
 790  */
 791 static void acpiphp_check_bridge(struct acpiphp_bridge *bridge)
 792 {
 793         struct acpiphp_slot *slot;
 794
 795         /* Bail out if the bridge is going away. */
 796         if (bridge->is_going_away)
 797                 return;
 798
 799         list_for_each_entry(slot, &bridge->slots, node) {
 800                 struct pci_bus *bus = slot->bus;
 801                 struct pci_dev *dev, *tmp;
 802
 803                 mutex_lock(&slot->crit_sect);
 804                 if (slot_no_hotplug(slot)) {
 805                         ; /* do nothing */
 806                 } else if (device_status_valid(get_slot_status(slot))) {
 807                         /* remove stale devices if any */
 808                         list_for_each_entry_safe_reverse(dev, tmp,
 809                                                          &bus->devices, bus_list)
 810                                 if (PCI_SLOT(dev->devfn) == slot->device)
 811                                         trim_stale_devices(dev);
 812
 813                         /* configure all functions */
 814                         enable_slot(slot);
 815                 } else {
 816                         disable_slot(slot);
 817                 }
 818                 mutex_unlock(&slot->crit_sect);
 819         }
 820 }
 821
 822 static void acpiphp_set_hpp_values(struct pci_bus *bus)
 823 {
 824         struct pci_dev *dev;
 825
 826         list_for_each_entry(dev, &bus->devices, bus_list)
 827                 pci_configure_slot(dev);
 828 }
 829
 830 /*
 831  * Remove devices for which we could not assign resources, call
 832  * arch specific code to fix-up the bus
 833  */
 834 static void acpiphp_sanitize_bus(struct pci_bus *bus)
 835 {
 836         struct pci_dev *dev, *tmp;
 837         int i;
 838         unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM;
 839
 840         list_for_each_entry_safe_reverse(dev, tmp, &bus->devices, bus_list) {
 841                 for (i=0; i<PCI_BRIDGE_RESOURCES; i++) {
 842                         struct resource *res = &dev->resource[i];
 843                         if ((res->flags & type_mask) && !res->start &&
 844                                         res->end) {
 845                                 /* Could not assign a required resources
 846                                  * for this device, remove it */
 847                                 pci_stop_and_remove_bus_device(dev);
 848                                 break;
 849                         }
 850                 }
 851         }
 852 }
 853
 854 /*
 855  * ACPI event handlers
 856  */
 857
 858 void acpiphp_check_host_bridge(acpi_handle handle)
 859 {
 860         struct acpiphp_bridge *bridge;
 861
 862         bridge = acpiphp_handle_to_bridge(handle);
 863         if (bridge) {
 864                 pci_lock_rescan_remove();
 865
 866                 acpiphp_check_bridge(bridge);
 867
 868                 pci_unlock_rescan_remove();
 869                 put_bridge(bridge);
 870         }
 871 }
 872
 873 static int acpiphp_disable_and_eject_slot(struct acpiphp_slot *slot);
 874
 875 static void hotplug_event(acpi_handle handle, u32 type, void *data)
 876 {
 877         struct acpiphp_context *context = data;
 878         struct acpiphp_func *func = &context->func;
 879         struct acpiphp_bridge *bridge;
 880         char objname[64];
 881         struct acpi_buffer buffer = { .length = sizeof(objname),
 882                                       .pointer = objname };
 883
 884         mutex_lock(&acpiphp_context_lock);
 885         bridge = context->bridge;
 886         if (bridge)
 887                 get_bridge(bridge);
 888
 889         mutex_unlock(&acpiphp_context_lock);
 890
 891         pci_lock_rescan_remove();
 892         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 893
 894         switch (type) {
 895         case ACPI_NOTIFY_BUS_CHECK:
 896                 /* bus re-enumerate */
 897                 pr_debug("%s: Bus check notify on %s\n", __func__, objname);
 898                 pr_debug("%s: re-enumerating slots under %s\n",
 899                          __func__, objname);
 900                 if (bridge) {
 901                         acpiphp_check_bridge(bridge);
 902                 } else {
 903                         struct acpiphp_slot *slot = func->slot;
 904
 905                         if (slot->flags & SLOT_IS_GOING_AWAY)
 906                                 break;
 907
 908                         mutex_lock(&slot->crit_sect);
 909                         enable_slot(slot);
 910                         mutex_unlock(&slot->crit_sect);
 911                 }
 912                 break;
 913
 914         case ACPI_NOTIFY_DEVICE_CHECK:
 915                 /* device check */
 916                 pr_debug("%s: Device check notify on %s\n", __func__, objname);
 917                 if (bridge) {
 918                         acpiphp_check_bridge(bridge);
 919                 } else {
 920                         struct acpiphp_slot *slot = func->slot;
 921                         int ret;
 922
 923                         if (slot->flags & SLOT_IS_GOING_AWAY)
 924                                 break;
 925
 926                         /*
 927                          * Check if anything has changed in the slot and rescan
 928                          * from the parent if that's the case.
 929                          */
 930                         mutex_lock(&slot->crit_sect);
 931                         ret = acpiphp_rescan_slot(slot);
 932                         mutex_unlock(&slot->crit_sect);
 933                         if (ret)
 934                                 acpiphp_check_bridge(func->parent);
 935                 }
 936                 break;
 937
 938         case ACPI_NOTIFY_EJECT_REQUEST:
 939                 /* request device eject */
 940                 pr_debug("%s: Device eject notify on %s\n", __func__, objname);
 941                 acpiphp_disable_and_eject_slot(func->slot);
 942                 break;
 943         }
 944
 945         pci_unlock_rescan_remove();
 946         if (bridge)
 947                 put_bridge(bridge);
 948 }
 949
 950 static void hotplug_event_work(void *data, u32 type)
 951 {
 952         struct acpiphp_context *context = data;
 953         acpi_handle handle = context->handle;
 954
 955         acpi_scan_lock_acquire();
 956
 957         hotplug_event(handle, type, context);
 958
 959         acpi_scan_lock_release();
 960         acpi_evaluate_hotplug_ost(handle, type, ACPI_OST_SC_SUCCESS, NULL);
 961         put_bridge(context->func.parent);
 962 }
 963
 964 /**
 965  * handle_hotplug_event - handle ACPI hotplug event
 966  * @handle: Notify()'ed acpi_handle
 967  * @type: Notify code
 968  * @data: pointer to acpiphp_context structure
 969  *
 970  * Handles ACPI event notification on slots.
 971  */
 972 static void handle_hotplug_event(acpi_handle handle, u32 type, void *data)
 973 {
 974         struct acpiphp_context *context;
 975         u32 ost_code = ACPI_OST_SC_SUCCESS;
 976         acpi_status status;
 977
 978         switch (type) {
 979         case ACPI_NOTIFY_BUS_CHECK:
 980         case ACPI_NOTIFY_DEVICE_CHECK:
 981                 break;
 982         case ACPI_NOTIFY_EJECT_REQUEST:
 983                 ost_code = ACPI_OST_SC_EJECT_IN_PROGRESS;
 984                 acpi_evaluate_hotplug_ost(handle, type, ost_code, NULL);
 985                 break;
 986
 987         case ACPI_NOTIFY_DEVICE_WAKE:
 988                 return;
 989
 990         case ACPI_NOTIFY_FREQUENCY_MISMATCH:
 991                 acpi_handle_err(handle, "Device cannot be configured due "
 992                                 "to a frequency mismatch\n");
 993                 goto out;
 994
 995         case ACPI_NOTIFY_BUS_MODE_MISMATCH:
 996                 acpi_handle_err(handle, "Device cannot be configured due "
 997                                 "to a bus mode mismatch\n");
 998                 goto out;
 999
1000         case ACPI_NOTIFY_POWER_FAULT:
1001                 acpi_handle_err(handle, "Device has suffered a power fault\n");
1002                 goto out;
1003
1004         default:
1005                 acpi_handle_warn(handle, "Unsupported event type 0x%x\n", type);
1006                 ost_code = ACPI_OST_SC_UNRECOGNIZED_NOTIFY;
1007                 goto out;
1008         }
1009
1010         mutex_lock(&acpiphp_context_lock);
1011         context = acpiphp_get_context(handle);
1012         if (!context || WARN_ON(context->handle != handle)
1013             || context->func.parent->is_going_away)
1014                 goto err_out;
1015
1016         get_bridge(context->func.parent);
1017         acpiphp_put_context(context);
1018         status = acpi_hotplug_execute(hotplug_event_work, context, type);
1019         if (ACPI_SUCCESS(status)) {
1020                 mutex_unlock(&acpiphp_context_lock);
1021                 return;
1022         }
1023         put_bridge(context->func.parent);
1024
1025  err_out:
1026         mutex_unlock(&acpiphp_context_lock);
1027         ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
1028
1029  out:
1030         acpi_evaluate_hotplug_ost(handle, type, ost_code, NULL);
1031 }
1032
1033 /*
1034  * Create hotplug slots for the PCI bus.
1035  * It should always return 0 to avoid skipping following notifiers.
1036  */
1037 void acpiphp_enumerate_slots(struct pci_bus *bus)
1038 {
1039         struct acpiphp_bridge *bridge;
1040         acpi_handle handle;
1041         acpi_status status;
1042
1043         if (acpiphp_disabled)
1044                 return;
1045
1046         handle = ACPI_HANDLE(bus->bridge);
1047         if (!handle)
1048                 return;
1049
1050         bridge = kzalloc(sizeof(struct acpiphp_bridge), GFP_KERNEL);
1051         if (!bridge) {
1052                 acpi_handle_err(handle, "No memory for bridge object\n");
1053                 return;
1054         }
1055
1056         INIT_LIST_HEAD(&bridge->slots);
1057         kref_init(&bridge->ref);
1058         bridge->pci_dev = pci_dev_get(bus->self);
1059         bridge->pci_bus = bus;
1060
1061         /*
1062          * Grab a ref to the subordinate PCI bus in case the bus is
1063          * removed via PCI core logical hotplug. The ref pins the bus
1064          * (which we access during module unload).
1065          */
1066         get_device(&bus->dev);
1067
1068         if (!pci_is_root_bus(bridge->pci_bus)) {
1069                 struct acpiphp_context *context;
1070
1071                 /*
1072                  * This bridge should have been registered as a hotplug function
1073                  * under its parent, so the context should be there, unless the
1074                  * parent is going to be handled by pciehp, in which case this
1075                  * bridge is not interesting to us either.
1076                  */
1077                 mutex_lock(&acpiphp_context_lock);
1078                 context = acpiphp_get_context(handle);
1079                 if (!context) {
1080                         mutex_unlock(&acpiphp_context_lock);
1081                         put_device(&bus->dev);
1082                         pci_dev_put(bridge->pci_dev);
1083                         kfree(bridge);
1084                         return;
1085                 }
1086                 bridge->context = context;
1087                 context->bridge = bridge;
1088                 /* Get a reference to the parent bridge. */
1089                 get_bridge(context->func.parent);
1090                 mutex_unlock(&acpiphp_context_lock);
1091         }
1092
1093         /* must be added to the list prior to calling register_slot */
1094         mutex_lock(&bridge_mutex);
1095         list_add(&bridge->list, &bridge_list);
1096         mutex_unlock(&bridge_mutex);
1097
1098         /* register all slot objects under this bridge */
1099         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1100                                      register_slot, NULL, bridge, NULL);
1101         if (ACPI_FAILURE(status)) {
1102                 acpi_handle_err(handle, "failed to register slots\n");
1103                 cleanup_bridge(bridge);
1104                 put_bridge(bridge);
1105         }
1106 }
1107
1108 /* Destroy hotplug slots associated with the PCI bus */
1109 void acpiphp_remove_slots(struct pci_bus *bus)
1110 {
1111         struct acpiphp_bridge *bridge;
1112
1113         if (acpiphp_disabled)
1114                 return;
1115
1116         mutex_lock(&bridge_mutex);
1117         list_for_each_entry(bridge, &bridge_list, list)
1118                 if (bridge->pci_bus == bus) {
1119                         mutex_unlock(&bridge_mutex);
1120                         cleanup_bridge(bridge);
1121                         put_bridge(bridge);
1122                         return;
1123                 }
1124
1125         mutex_unlock(&bridge_mutex);
1126 }
1127
1128 /**
1129  * acpiphp_enable_slot - power on slot
1130  * @slot: ACPI PHP slot
1131  */
1132 int acpiphp_enable_slot(struct acpiphp_slot *slot)
1133 {
1134         pci_lock_rescan_remove();
1135
1136         if (slot->flags & SLOT_IS_GOING_AWAY)
1137                 return -ENODEV;
1138
1139         mutex_lock(&slot->crit_sect);
1140         /* configure all functions */
1141         if (!(slot->flags & SLOT_ENABLED))
1142                 enable_slot(slot);
1143
1144         mutex_unlock(&slot->crit_sect);
1145
1146         pci_unlock_rescan_remove();
1147         return 0;
1148 }
1149
1150 /**
1151  * acpiphp_disable_and_eject_slot - power off and eject slot
1152  * @slot: ACPI PHP slot
1153  */
1154 static int acpiphp_disable_and_eject_slot(struct acpiphp_slot *slot)
1155 {
1156         struct acpiphp_func *func;
1157
1158         if (slot->flags & SLOT_IS_GOING_AWAY)
1159                 return -ENODEV;
1160
1161         mutex_lock(&slot->crit_sect);
1162
1163         /* unconfigure all functions */
1164         disable_slot(slot);
1165
1166         list_for_each_entry(func, &slot->funcs, sibling)
1167                 if (func->flags & FUNC_HAS_EJ0) {
1168                         acpi_handle handle = func_to_handle(func);
1169
1170                         if (ACPI_FAILURE(acpi_evaluate_ej0(handle)))
1171                                 acpi_handle_err(handle, "_EJ0 failed\n");
1172
1173                         break;
1174                 }
1175
1176         mutex_unlock(&slot->crit_sect);
1177         return 0;
1178 }
1179
1180 int acpiphp_disable_slot(struct acpiphp_slot *slot)
1181 {
1182         int ret;
1183
1184         pci_lock_rescan_remove();
1185         ret = acpiphp_disable_and_eject_slot(slot);
1186         pci_unlock_rescan_remove();
1187         return ret;
1188 }
1189
1190 /*
1191  * slot enabled:  1
1192  * slot disabled: 0
1193  */
1194 u8 acpiphp_get_power_status(struct acpiphp_slot *slot)
1195 {
1196         return (slot->flags & SLOT_ENABLED);
1197 }
1198
1199 /*
1200  * latch   open:  1
1201  * latch closed:  0
1202  */
1203 u8 acpiphp_get_latch_status(struct acpiphp_slot *slot)
1204 {
1205         return !(get_slot_status(slot) & ACPI_STA_DEVICE_UI);
1206 }
1207
1208 /*
1209  * adapter presence : 1
1210  *          absence : 0
1211  */
1212 u8 acpiphp_get_adapter_status(struct acpiphp_slot *slot)
1213 {
1214         return !!get_slot_status(slot);
1215 }