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 #include <linux/init.h>
  43 #include <linux/module.h>
  44
  45 #include <linux/kernel.h>
  46 #include <linux/pci.h>
  47 #include <linux/pci_hotplug.h>
  48 #include <linux/pci-acpi.h>
  49 #include <linux/pm_runtime.h>
  50 #include <linux/mutex.h>
  51 #include <linux/slab.h>
  52 #include <linux/acpi.h>
  53
  54 #include "../pci.h"
  55 #include "acpiphp.h"
  56
  57 static LIST_HEAD(bridge_list);
  58 static DEFINE_MUTEX(bridge_mutex);
  59 static DEFINE_MUTEX(acpiphp_context_lock);
  60
  61 #define MY_NAME "acpiphp_glue"
  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
 214 static const struct acpi_dock_ops acpiphp_dock_ops = {
 215         .fixup = post_dock_fixups,
 216         .handler = hotplug_event,
 217 };
 218
 219 /* Check whether the PCI device is managed by native PCIe hotplug driver */
 220 static bool device_is_managed_by_native_pciehp(struct pci_dev *pdev)
 221 {
 222         u32 reg32;
 223         acpi_handle tmp;
 224         struct acpi_pci_root *root;
 225
 226         /* Check whether the PCIe port supports native PCIe hotplug */
 227         if (pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &reg32))
 228                 return false;
 229         if (!(reg32 & PCI_EXP_SLTCAP_HPC))
 230                 return false;
 231
 232         /*
 233          * Check whether native PCIe hotplug has been enabled for
 234          * this PCIe hierarchy.
 235          */
 236         tmp = acpi_find_root_bridge_handle(pdev);
 237         if (!tmp)
 238                 return false;
 239         root = acpi_pci_find_root(tmp);
 240         if (!root)
 241                 return false;
 242         if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
 243                 return false;
 244
 245         return true;
 246 }
 247
 248 static void acpiphp_dock_init(void *data)
 249 {
 250         struct acpiphp_context *context = data;
 251
 252         get_bridge(context->func.parent);
 253 }
 254
 255 static void acpiphp_dock_release(void *data)
 256 {
 257         struct acpiphp_context *context = data;
 258
 259         put_bridge(context->func.parent);
 260 }
 261
 262 /* callback routine to register each ACPI PCI slot object */
 263 static acpi_status register_slot(acpi_handle handle, u32 lvl, void *data,
 264                                  void **rv)
 265 {
 266         struct acpiphp_bridge *bridge = data;
 267         struct acpiphp_context *context;
 268         struct acpiphp_slot *slot;
 269         struct acpiphp_func *newfunc;
 270         acpi_status status = AE_OK;
 271         unsigned long long adr;
 272         int device, function;
 273         struct pci_bus *pbus = bridge->pci_bus;
 274         struct pci_dev *pdev = bridge->pci_dev;
 275         u32 val;
 276
 277         if (pdev && device_is_managed_by_native_pciehp(pdev))
 278                 return AE_OK;
 279
 280         status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
 281         if (ACPI_FAILURE(status)) {
 282                 acpi_handle_warn(handle, "can't evaluate _ADR (%#x)\n", status);
 283                 return AE_OK;
 284         }
 285
 286         device = (adr >> 16) & 0xffff;
 287         function = adr & 0xffff;
 288
 289         mutex_lock(&acpiphp_context_lock);
 290         context = acpiphp_init_context(handle);
 291         if (!context) {
 292                 mutex_unlock(&acpiphp_context_lock);
 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         mutex_unlock(&acpiphp_context_lock);
 300
 301         if (acpi_has_method(handle, "_EJ0"))
 302                 newfunc->flags = FUNC_HAS_EJ0;
 303
 304         if (acpi_has_method(handle, "_STA"))
 305                 newfunc->flags |= FUNC_HAS_STA;
 306
 307         if (acpi_has_method(handle, "_DCK"))
 308                 newfunc->flags |= FUNC_HAS_DCK;
 309
 310         /* search for objects that share the same slot */
 311         list_for_each_entry(slot, &bridge->slots, node)
 312                 if (slot->device == device)
 313                         goto slot_found;
 314
 315         slot = kzalloc(sizeof(struct acpiphp_slot), GFP_KERNEL);
 316         if (!slot) {
 317                 status = AE_NO_MEMORY;
 318                 goto err;
 319         }
 320
 321         slot->bus = bridge->pci_bus;
 322         slot->device = device;
 323         INIT_LIST_HEAD(&slot->funcs);
 324         mutex_init(&slot->crit_sect);
 325
 326         list_add_tail(&slot->node, &bridge->slots);
 327
 328         /* Register slots for ejectable funtions only. */
 329         if (acpi_pci_check_ejectable(pbus, handle)  || is_dock_device(handle)) {
 330                 unsigned long long sun;
 331                 int retval;
 332
 333                 bridge->nr_slots++;
 334                 status = acpi_evaluate_integer(handle, "_SUN", NULL, &sun);
 335                 if (ACPI_FAILURE(status))
 336                         sun = bridge->nr_slots;
 337
 338                 dbg("found ACPI PCI Hotplug slot %llu at PCI %04x:%02x:%02x\n",
 339                     sun, pci_domain_nr(pbus), pbus->number, device);
 340
 341                 retval = acpiphp_register_hotplug_slot(slot, sun);
 342                 if (retval) {
 343                         slot->slot = NULL;
 344                         bridge->nr_slots--;
 345                         if (retval == -EBUSY)
 346                                 warn("Slot %llu already registered by another "
 347                                         "hotplug driver\n", sun);
 348                         else
 349                                 warn("acpiphp_register_hotplug_slot failed "
 350                                         "(err code = 0x%x)\n", retval);
 351                 }
 352                 /* Even if the slot registration fails, we can still use it. */
 353         }
 354
 355  slot_found:
 356         newfunc->slot = slot;
 357         list_add_tail(&newfunc->sibling, &slot->funcs);
 358
 359         if (pci_bus_read_dev_vendor_id(pbus, PCI_DEVFN(device, function),
 360                                        &val, 60*1000))
 361                 slot->flags |= SLOT_ENABLED;
 362
 363         if (is_dock_device(handle)) {
 364                 /* we don't want to call this device's _EJ0
 365                  * because we want the dock notify handler
 366                  * to call it after it calls _DCK
 367                  */
 368                 newfunc->flags &= ~FUNC_HAS_EJ0;
 369                 if (register_hotplug_dock_device(handle,
 370                         &acpiphp_dock_ops, context,
 371                         acpiphp_dock_init, acpiphp_dock_release))
 372                         dbg("failed to register dock device\n");
 373         }
 374
 375         /* install notify handler */
 376         if (!(newfunc->flags & FUNC_HAS_DCK)) {
 377                 status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 378                                                      handle_hotplug_event,
 379                                                      context);
 380                 if (ACPI_FAILURE(status))
 381                         acpi_handle_err(handle,
 382                                         "failed to install notify handler\n");
 383         }
 384
 385         return AE_OK;
 386
 387  err:
 388         mutex_lock(&acpiphp_context_lock);
 389         acpiphp_put_context(context);
 390         mutex_unlock(&acpiphp_context_lock);
 391         return status;
 392 }
 393
 394 static struct acpiphp_bridge *acpiphp_handle_to_bridge(acpi_handle handle)
 395 {
 396         struct acpiphp_context *context;
 397         struct acpiphp_bridge *bridge = NULL;
 398
 399         mutex_lock(&acpiphp_context_lock);
 400         context = acpiphp_get_context(handle);
 401         if (context) {
 402                 bridge = context->bridge;
 403                 if (bridge)
 404                         get_bridge(bridge);
 405
 406                 acpiphp_put_context(context);
 407         }
 408         mutex_unlock(&acpiphp_context_lock);
 409         return bridge;
 410 }
 411
 412 static void cleanup_bridge(struct acpiphp_bridge *bridge)
 413 {
 414         struct acpiphp_slot *slot;
 415         struct acpiphp_func *func;
 416         acpi_status status;
 417
 418         list_for_each_entry(slot, &bridge->slots, node) {
 419                 list_for_each_entry(func, &slot->funcs, sibling) {
 420                         acpi_handle handle = func_to_handle(func);
 421
 422                         if (is_dock_device(handle))
 423                                 unregister_hotplug_dock_device(handle);
 424
 425                         if (!(func->flags & FUNC_HAS_DCK)) {
 426                                 status = acpi_remove_notify_handler(handle,
 427                                                         ACPI_SYSTEM_NOTIFY,
 428                                                         handle_hotplug_event);
 429                                 if (ACPI_FAILURE(status))
 430                                         err("failed to remove notify handler\n");
 431                         }
 432                 }
 433                 if (slot->slot)
 434                         acpiphp_unregister_hotplug_slot(slot);
 435         }
 436
 437         mutex_lock(&bridge_mutex);
 438         list_del(&bridge->list);
 439         mutex_unlock(&bridge_mutex);
 440 }
 441
 442 /**
 443  * acpiphp_max_busnr - return the highest reserved bus number under the given bus.
 444  * @bus: bus to start search with
 445  */
 446 static unsigned char acpiphp_max_busnr(struct pci_bus *bus)
 447 {
 448         struct list_head *tmp;
 449         unsigned char max, n;
 450
 451         /*
 452          * pci_bus_max_busnr will return the highest
 453          * reserved busnr for all these children.
 454          * that is equivalent to the bus->subordinate
 455          * value.  We don't want to use the parent's
 456          * bus->subordinate value because it could have
 457          * padding in it.
 458          */
 459         max = bus->busn_res.start;
 460
 461         list_for_each(tmp, &bus->children) {
 462                 n = pci_bus_max_busnr(pci_bus_b(tmp));
 463                 if (n > max)
 464                         max = n;
 465         }
 466         return max;
 467 }
 468
 469 /**
 470  * acpiphp_bus_trim - Trim device objects in an ACPI namespace subtree.
 471  * @handle: ACPI device object handle to start from.
 472  */
 473 static void acpiphp_bus_trim(acpi_handle handle)
 474 {
 475         struct acpi_device *adev = NULL;
 476
 477         acpi_bus_get_device(handle, &adev);
 478         if (adev)
 479                 acpi_bus_trim(adev);
 480 }
 481
 482 /**
 483  * acpiphp_bus_add - Scan ACPI namespace subtree.
 484  * @handle: ACPI object handle to start the scan from.
 485  */
 486 static void acpiphp_bus_add(acpi_handle handle)
 487 {
 488         struct acpi_device *adev = NULL;
 489
 490         acpi_bus_scan(handle);
 491         acpi_bus_get_device(handle, &adev);
 492         if (adev)
 493                 acpi_device_set_power(adev, ACPI_STATE_D0);
 494 }
 495
 496 static void acpiphp_set_acpi_region(struct acpiphp_slot *slot)
 497 {
 498         struct acpiphp_func *func;
 499         union acpi_object params[2];
 500         struct acpi_object_list arg_list;
 501
 502         list_for_each_entry(func, &slot->funcs, sibling) {
 503                 arg_list.count = 2;
 504                 arg_list.pointer = params;
 505                 params[0].type = ACPI_TYPE_INTEGER;
 506                 params[0].integer.value = ACPI_ADR_SPACE_PCI_CONFIG;
 507                 params[1].type = ACPI_TYPE_INTEGER;
 508                 params[1].integer.value = 1;
 509                 /* _REG is optional, we don't care about if there is failure */
 510                 acpi_evaluate_object(func_to_handle(func), "_REG", &arg_list,
 511                                      NULL);
 512         }
 513 }
 514
 515 static void check_hotplug_bridge(struct acpiphp_slot *slot, struct pci_dev *dev)
 516 {
 517         struct acpiphp_func *func;
 518
 519         /* quirk, or pcie could set it already */
 520         if (dev->is_hotplug_bridge)
 521                 return;
 522
 523         list_for_each_entry(func, &slot->funcs, sibling) {
 524                 if (PCI_FUNC(dev->devfn) == func->function) {
 525                         dev->is_hotplug_bridge = 1;
 526                         break;
 527                 }
 528         }
 529 }
 530
 531 static int acpiphp_rescan_slot(struct acpiphp_slot *slot)
 532 {
 533         struct acpiphp_func *func;
 534
 535         list_for_each_entry(func, &slot->funcs, sibling)
 536                 acpiphp_bus_add(func_to_handle(func));
 537
 538         return pci_scan_slot(slot->bus, PCI_DEVFN(slot->device, 0));
 539 }
 540
 541 /**
 542  * enable_slot - enable, configure a slot
 543  * @slot: slot to be enabled
 544  *
 545  * This function should be called per *physical slot*,
 546  * not per each slot object in ACPI namespace.
 547  */
 548 static void __ref enable_slot(struct acpiphp_slot *slot)
 549 {
 550         struct pci_dev *dev;
 551         struct pci_bus *bus = slot->bus;
 552         struct acpiphp_func *func;
 553         int max, pass;
 554         LIST_HEAD(add_list);
 555
 556         acpiphp_rescan_slot(slot);
 557         max = acpiphp_max_busnr(bus);
 558         for (pass = 0; pass < 2; pass++) {
 559                 list_for_each_entry(dev, &bus->devices, bus_list) {
 560                         if (PCI_SLOT(dev->devfn) != slot->device)
 561                                 continue;
 562
 563                         if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
 564                             dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
 565                                 max = pci_scan_bridge(bus, dev, max, pass);
 566                                 if (pass && dev->subordinate) {
 567                                         check_hotplug_bridge(slot, dev);
 568                                         pcibios_resource_survey_bus(dev->subordinate);
 569                                         __pci_bus_size_bridges(dev->subordinate,
 570                                                                &add_list);
 571                                 }
 572                         }
 573                 }
 574         }
 575         __pci_bus_assign_resources(bus, &add_list, NULL);
 576
 577         acpiphp_sanitize_bus(bus);
 578         acpiphp_set_hpp_values(bus);
 579         acpiphp_set_acpi_region(slot);
 580
 581         list_for_each_entry(dev, &bus->devices, bus_list) {
 582                 /* Assume that newly added devices are powered on already. */
 583                 if (!dev->is_added)
 584                         dev->current_state = PCI_D0;
 585         }
 586
 587         pci_bus_add_devices(bus);
 588
 589         slot->flags |= SLOT_ENABLED;
 590         list_for_each_entry(func, &slot->funcs, sibling) {
 591                 dev = pci_get_slot(bus, PCI_DEVFN(slot->device,
 592                                                   func->function));
 593                 if (!dev) {
 594                         /* Do not set SLOT_ENABLED flag if some funcs
 595                            are not added. */
 596                         slot->flags &= (~SLOT_ENABLED);
 597                         continue;
 598                 }
 599         }
 600 }
 601
 602 /* return first device in slot, acquiring a reference on it */
 603 static struct pci_dev *dev_in_slot(struct acpiphp_slot *slot)
 604 {
 605         struct pci_bus *bus = slot->bus;
 606         struct pci_dev *dev;
 607         struct pci_dev *ret = NULL;
 608
 609         down_read(&pci_bus_sem);
 610         list_for_each_entry(dev, &bus->devices, bus_list)
 611                 if (PCI_SLOT(dev->devfn) == slot->device) {
 612                         ret = pci_dev_get(dev);
 613                         break;
 614                 }
 615         up_read(&pci_bus_sem);
 616
 617         return ret;
 618 }
 619
 620 /**
 621  * disable_slot - disable a slot
 622  * @slot: ACPI PHP slot
 623  */
 624 static void disable_slot(struct acpiphp_slot *slot)
 625 {
 626         struct acpiphp_func *func;
 627         struct pci_dev *pdev;
 628
 629         /*
 630          * enable_slot() enumerates all functions in this device via
 631          * pci_scan_slot(), whether they have associated ACPI hotplug
 632          * methods (_EJ0, etc.) or not.  Therefore, we remove all functions
 633          * here.
 634          */
 635         while ((pdev = dev_in_slot(slot))) {
 636                 pci_stop_and_remove_bus_device(pdev);
 637                 pci_dev_put(pdev);
 638         }
 639
 640         list_for_each_entry(func, &slot->funcs, sibling)
 641                 acpiphp_bus_trim(func_to_handle(func));
 642
 643         slot->flags &= (~SLOT_ENABLED);
 644 }
 645
 646
 647 /**
 648  * get_slot_status - get ACPI slot status
 649  * @slot: ACPI PHP slot
 650  *
 651  * If a slot has _STA for each function and if any one of them
 652  * returned non-zero status, return it.
 653  *
 654  * If a slot doesn't have _STA and if any one of its functions'
 655  * configuration space is configured, return 0x0f as a _STA.
 656  *
 657  * Otherwise return 0.
 658  */
 659 static unsigned int get_slot_status(struct acpiphp_slot *slot)
 660 {
 661         unsigned long long sta = 0;
 662         struct acpiphp_func *func;
 663
 664         list_for_each_entry(func, &slot->funcs, sibling) {
 665                 if (func->flags & FUNC_HAS_STA) {
 666                         acpi_status status;
 667
 668                         status = acpi_evaluate_integer(func_to_handle(func),
 669                                                        "_STA", NULL, &sta);
 670                         if (ACPI_SUCCESS(status) && sta)
 671                                 break;
 672                 } else {
 673                         u32 dvid;
 674
 675                         pci_bus_read_config_dword(slot->bus,
 676                                                   PCI_DEVFN(slot->device,
 677                                                             func->function),
 678                                                   PCI_VENDOR_ID, &dvid);
 679                         if (dvid != 0xffffffff) {
 680                                 sta = ACPI_STA_ALL;
 681                                 break;
 682                         }
 683                 }
 684         }
 685
 686         return (unsigned int)sta;
 687 }
 688
 689 /**
 690  * trim_stale_devices - remove PCI devices that are not responding.
 691  * @dev: PCI device to start walking the hierarchy from.
 692  */
 693 static void trim_stale_devices(struct pci_dev *dev)
 694 {
 695         acpi_handle handle = ACPI_HANDLE(&dev->dev);
 696         struct pci_bus *bus = dev->subordinate;
 697         bool alive = false;
 698
 699         if (handle) {
 700                 acpi_status status;
 701                 unsigned long long sta;
 702
 703                 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
 704                 alive = ACPI_SUCCESS(status) && sta == ACPI_STA_ALL;
 705         }
 706         if (!alive) {
 707                 u32 v;
 708
 709                 /* Check if the device responds. */
 710                 alive = pci_bus_read_dev_vendor_id(dev->bus, dev->devfn, &v, 0);
 711         }
 712         if (!alive) {
 713                 pci_stop_and_remove_bus_device(dev);
 714                 if (handle)
 715                         acpiphp_bus_trim(handle);
 716         } else if (bus) {
 717                 struct pci_dev *child, *tmp;
 718
 719                 /* The device is a bridge. so check the bus below it. */
 720                 pm_runtime_get_sync(&dev->dev);
 721                 list_for_each_entry_safe(child, tmp, &bus->devices, bus_list)
 722                         trim_stale_devices(child);
 723
 724                 pm_runtime_put(&dev->dev);
 725         }
 726 }
 727
 728 /**
 729  * acpiphp_check_bridge - re-enumerate devices
 730  * @bridge: where to begin re-enumeration
 731  *
 732  * Iterate over all slots under this bridge and make sure that if a
 733  * card is present they are enabled, and if not they are disabled.
 734  */
 735 static void acpiphp_check_bridge(struct acpiphp_bridge *bridge)
 736 {
 737         struct acpiphp_slot *slot;
 738
 739         list_for_each_entry(slot, &bridge->slots, node) {
 740                 struct pci_bus *bus = slot->bus;
 741                 struct pci_dev *dev, *tmp;
 742
 743                 mutex_lock(&slot->crit_sect);
 744                 /* wake up all functions */
 745                 if (get_slot_status(slot) == ACPI_STA_ALL) {
 746                         /* remove stale devices if any */
 747                         list_for_each_entry_safe(dev, tmp, &bus->devices,
 748                                                  bus_list)
 749                                 if (PCI_SLOT(dev->devfn) == slot->device)
 750                                         trim_stale_devices(dev);
 751
 752                         /* configure all functions */
 753                         enable_slot(slot);
 754                 } else {
 755                         disable_slot(slot);
 756                 }
 757                 mutex_unlock(&slot->crit_sect);
 758         }
 759 }
 760
 761 static void acpiphp_set_hpp_values(struct pci_bus *bus)
 762 {
 763         struct pci_dev *dev;
 764
 765         list_for_each_entry(dev, &bus->devices, bus_list)
 766                 pci_configure_slot(dev);
 767 }
 768
 769 /*
 770  * Remove devices for which we could not assign resources, call
 771  * arch specific code to fix-up the bus
 772  */
 773 static void acpiphp_sanitize_bus(struct pci_bus *bus)
 774 {
 775         struct pci_dev *dev, *tmp;
 776         int i;
 777         unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM;
 778
 779         list_for_each_entry_safe(dev, tmp, &bus->devices, bus_list) {
 780                 for (i=0; i<PCI_BRIDGE_RESOURCES; i++) {
 781                         struct resource *res = &dev->resource[i];
 782                         if ((res->flags & type_mask) && !res->start &&
 783                                         res->end) {
 784                                 /* Could not assign a required resources
 785                                  * for this device, remove it */
 786                                 pci_stop_and_remove_bus_device(dev);
 787                                 break;
 788                         }
 789                 }
 790         }
 791 }
 792
 793 /*
 794  * ACPI event handlers
 795  */
 796
 797 void acpiphp_check_host_bridge(acpi_handle handle)
 798 {
 799         struct acpiphp_bridge *bridge;
 800
 801         bridge = acpiphp_handle_to_bridge(handle);
 802         if (bridge) {
 803                 acpiphp_check_bridge(bridge);
 804                 put_bridge(bridge);
 805         }
 806 }
 807
 808 static void hotplug_event(acpi_handle handle, u32 type, void *data)
 809 {
 810         struct acpiphp_context *context = data;
 811         struct acpiphp_func *func = &context->func;
 812         struct acpiphp_bridge *bridge;
 813         char objname[64];
 814         struct acpi_buffer buffer = { .length = sizeof(objname),
 815                                       .pointer = objname };
 816
 817         mutex_lock(&acpiphp_context_lock);
 818         bridge = context->bridge;
 819         if (bridge)
 820                 get_bridge(bridge);
 821
 822         mutex_unlock(&acpiphp_context_lock);
 823
 824         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
 825
 826         switch (type) {
 827         case ACPI_NOTIFY_BUS_CHECK:
 828                 /* bus re-enumerate */
 829                 dbg("%s: Bus check notify on %s\n", __func__, objname);
 830                 dbg("%s: re-enumerating slots under %s\n", __func__, objname);
 831                 if (bridge) {
 832                         acpiphp_check_bridge(bridge);
 833                 } else {
 834                         struct acpiphp_slot *slot = func->slot;
 835
 836                         mutex_lock(&slot->crit_sect);
 837                         enable_slot(slot);
 838                         mutex_unlock(&slot->crit_sect);
 839                 }
 840                 break;
 841
 842         case ACPI_NOTIFY_DEVICE_CHECK:
 843                 /* device check */
 844                 dbg("%s: Device check notify on %s\n", __func__, objname);
 845                 if (bridge) {
 846                         acpiphp_check_bridge(bridge);
 847                 } else {
 848                         struct acpiphp_slot *slot = func->slot;
 849                         int ret;
 850
 851                         /*
 852                          * Check if anything has changed in the slot and rescan
 853                          * from the parent if that's the case.
 854                          */
 855                         mutex_lock(&slot->crit_sect);
 856                         ret = acpiphp_rescan_slot(slot);
 857                         mutex_unlock(&slot->crit_sect);
 858                         if (ret)
 859                                 acpiphp_check_bridge(func->parent);
 860                 }
 861                 break;
 862
 863         case ACPI_NOTIFY_EJECT_REQUEST:
 864                 /* request device eject */
 865                 dbg("%s: Device eject notify on %s\n", __func__, objname);
 866                 acpiphp_disable_and_eject_slot(func->slot);
 867                 break;
 868         }
 869
 870         if (bridge)
 871                 put_bridge(bridge);
 872 }
 873
 874 static void hotplug_event_work(struct work_struct *work)
 875 {
 876         struct acpiphp_context *context;
 877         struct acpi_hp_work *hp_work;
 878
 879         hp_work = container_of(work, struct acpi_hp_work, work);
 880         context = hp_work->context;
 881         acpi_scan_lock_acquire();
 882
 883         hotplug_event(hp_work->handle, hp_work->type, context);
 884
 885         acpi_scan_lock_release();
 886         acpi_evaluate_hotplug_ost(hp_work->handle, hp_work->type,
 887                                   ACPI_OST_SC_SUCCESS, NULL);
 888         kfree(hp_work); /* allocated in handle_hotplug_event() */
 889         put_bridge(context->func.parent);
 890 }
 891
 892 /**
 893  * handle_hotplug_event - handle ACPI hotplug event
 894  * @handle: Notify()'ed acpi_handle
 895  * @type: Notify code
 896  * @data: pointer to acpiphp_context structure
 897  *
 898  * Handles ACPI event notification on slots.
 899  */
 900 static void handle_hotplug_event(acpi_handle handle, u32 type, void *data)
 901 {
 902         struct acpiphp_context *context;
 903         u32 ost_code = ACPI_OST_SC_SUCCESS;
 904
 905         switch (type) {
 906         case ACPI_NOTIFY_BUS_CHECK:
 907         case ACPI_NOTIFY_DEVICE_CHECK:
 908                 break;
 909         case ACPI_NOTIFY_EJECT_REQUEST:
 910                 ost_code = ACPI_OST_SC_EJECT_IN_PROGRESS;
 911                 acpi_evaluate_hotplug_ost(handle, type, ost_code, NULL);
 912                 break;
 913
 914         case ACPI_NOTIFY_DEVICE_WAKE:
 915                 return;
 916
 917         case ACPI_NOTIFY_FREQUENCY_MISMATCH:
 918                 acpi_handle_err(handle, "Device cannot be configured due "
 919                                 "to a frequency mismatch\n");
 920                 goto out;
 921
 922         case ACPI_NOTIFY_BUS_MODE_MISMATCH:
 923                 acpi_handle_err(handle, "Device cannot be configured due "
 924                                 "to a bus mode mismatch\n");
 925                 goto out;
 926
 927         case ACPI_NOTIFY_POWER_FAULT:
 928                 acpi_handle_err(handle, "Device has suffered a power fault\n");
 929                 goto out;
 930
 931         default:
 932                 acpi_handle_warn(handle, "Unsupported event type 0x%x\n", type);
 933                 ost_code = ACPI_OST_SC_UNRECOGNIZED_NOTIFY;
 934                 goto out;
 935         }
 936
 937         mutex_lock(&acpiphp_context_lock);
 938         context = acpiphp_get_context(handle);
 939         if (context) {
 940                 get_bridge(context->func.parent);
 941                 acpiphp_put_context(context);
 942                 alloc_acpi_hp_work(handle, type, context, hotplug_event_work);
 943                 mutex_unlock(&acpiphp_context_lock);
 944                 return;
 945         }
 946         mutex_unlock(&acpiphp_context_lock);
 947         ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE;
 948
 949  out:
 950         acpi_evaluate_hotplug_ost(handle, type, ost_code, NULL);
 951 }
 952
 953 /*
 954  * Create hotplug slots for the PCI bus.
 955  * It should always return 0 to avoid skipping following notifiers.
 956  */
 957 void acpiphp_enumerate_slots(struct pci_bus *bus)
 958 {
 959         struct acpiphp_bridge *bridge;
 960         acpi_handle handle;
 961         acpi_status status;
 962
 963         if (acpiphp_disabled)
 964                 return;
 965
 966         handle = ACPI_HANDLE(bus->bridge);
 967         if (!handle)
 968                 return;
 969
 970         bridge = kzalloc(sizeof(struct acpiphp_bridge), GFP_KERNEL);
 971         if (!bridge) {
 972                 acpi_handle_err(handle, "No memory for bridge object\n");
 973                 return;
 974         }
 975
 976         INIT_LIST_HEAD(&bridge->slots);
 977         kref_init(&bridge->ref);
 978         bridge->pci_dev = pci_dev_get(bus->self);
 979         bridge->pci_bus = bus;
 980
 981         /*
 982          * Grab a ref to the subordinate PCI bus in case the bus is
 983          * removed via PCI core logical hotplug. The ref pins the bus
 984          * (which we access during module unload).
 985          */
 986         get_device(&bus->dev);
 987
 988         if (!pci_is_root_bus(bridge->pci_bus)) {
 989                 struct acpiphp_context *context;
 990
 991                 /*
 992                  * This bridge should have been registered as a hotplug function
 993                  * under its parent, so the context should be there, unless the
 994                  * parent is going to be handled by pciehp, in which case this
 995                  * bridge is not interesting to us either.
 996                  */
 997                 mutex_lock(&acpiphp_context_lock);
 998                 context = acpiphp_get_context(handle);
 999                 if (!context) {
1000                         mutex_unlock(&acpiphp_context_lock);
1001                         put_device(&bus->dev);
1002                         pci_dev_put(bridge->pci_dev);
1003                         kfree(bridge);
1004                         return;
1005                 }
1006                 bridge->context = context;
1007                 context->bridge = bridge;
1008                 /* Get a reference to the parent bridge. */
1009                 get_bridge(context->func.parent);
1010                 mutex_unlock(&acpiphp_context_lock);
1011         }
1012
1013         /* must be added to the list prior to calling register_slot */
1014         mutex_lock(&bridge_mutex);
1015         list_add(&bridge->list, &bridge_list);
1016         mutex_unlock(&bridge_mutex);
1017
1018         /* register all slot objects under this bridge */
1019         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
1020                                      register_slot, NULL, bridge, NULL);
1021         if (ACPI_FAILURE(status)) {
1022                 acpi_handle_err(handle, "failed to register slots\n");
1023                 cleanup_bridge(bridge);
1024                 put_bridge(bridge);
1025         }
1026 }
1027
1028 /* Destroy hotplug slots associated with the PCI bus */
1029 void acpiphp_remove_slots(struct pci_bus *bus)
1030 {
1031         struct acpiphp_bridge *bridge;
1032
1033         if (acpiphp_disabled)
1034                 return;
1035
1036         mutex_lock(&bridge_mutex);
1037         list_for_each_entry(bridge, &bridge_list, list)
1038                 if (bridge->pci_bus == bus) {
1039                         mutex_unlock(&bridge_mutex);
1040                         cleanup_bridge(bridge);
1041                         put_bridge(bridge);
1042                         return;
1043                 }
1044
1045         mutex_unlock(&bridge_mutex);
1046 }
1047
1048 /**
1049  * acpiphp_enable_slot - power on slot
1050  * @slot: ACPI PHP slot
1051  */
1052 int acpiphp_enable_slot(struct acpiphp_slot *slot)
1053 {
1054         mutex_lock(&slot->crit_sect);
1055         /* configure all functions */
1056         if (!(slot->flags & SLOT_ENABLED))
1057                 enable_slot(slot);
1058
1059         mutex_unlock(&slot->crit_sect);
1060         return 0;
1061 }
1062
1063 /**
1064  * acpiphp_disable_and_eject_slot - power off and eject slot
1065  * @slot: ACPI PHP slot
1066  */
1067 int acpiphp_disable_and_eject_slot(struct acpiphp_slot *slot)
1068 {
1069         struct acpiphp_func *func;
1070         int retval = 0;
1071
1072         mutex_lock(&slot->crit_sect);
1073
1074         /* unconfigure all functions */
1075         disable_slot(slot);
1076
1077         list_for_each_entry(func, &slot->funcs, sibling)
1078                 if (func->flags & FUNC_HAS_EJ0) {
1079                         acpi_handle handle = func_to_handle(func);
1080
1081                         if (ACPI_FAILURE(acpi_evaluate_ej0(handle)))
1082                                 acpi_handle_err(handle, "_EJ0 failed\n");
1083
1084                         break;
1085                 }
1086
1087         mutex_unlock(&slot->crit_sect);
1088         return retval;
1089 }
1090
1091
1092 /*
1093  * slot enabled:  1
1094  * slot disabled: 0
1095  */
1096 u8 acpiphp_get_power_status(struct acpiphp_slot *slot)
1097 {
1098         return (slot->flags & SLOT_ENABLED);
1099 }
1100
1101
1102 /*
1103  * latch   open:  1
1104  * latch closed:  0
1105  */
1106 u8 acpiphp_get_latch_status(struct acpiphp_slot *slot)
1107 {
1108         return !(get_slot_status(slot) & ACPI_STA_DEVICE_UI);
1109 }
1110
1111
1112 /*
1113  * adapter presence : 1
1114  *          absence : 0
1115  */
1116 u8 acpiphp_get_adapter_status(struct acpiphp_slot *slot)
1117 {
1118         return !!get_slot_status(slot);
1119 }