drivers/pci/hotplug/acpiphp

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
acpiphp_init_context
acpiphp_get_context
acpiphp_put_context
get_bridge
put_bridge
acpiphp_grab_context
acpiphp_let_context_go
free_bridge
acpiphp_post_dock_fixup
acpiphp_add_context
cleanup_bridge
acpiphp_max_busnr
acpiphp_set_acpi_region
check_hotplug_bridge
acpiphp_rescan_slot
acpiphp_native_scan_bridge
enable_slot
disable_slot
slot_no_hotplug
get_slot_status
device_status_valid
trim_stale_devices
acpiphp_check_bridge
acpiphp_sanitize_bus
acpiphp_check_host_bridge
hotplug_event
acpiphp_hotplug_notify
acpiphp_enumerate_slots
acpiphp_drop_bridge
acpiphp_remove_slots
acpiphp_enable_slot
acpiphp_disable_and_eject_slot
acpiphp_disable_slot
acpiphp_get_power_status
acpiphp_get_latch_status
acpiphp_get_adapter_status
   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 the driver unloads.
  26  */
  27 
  28 #define pr_fmt(fmt) "acpiphp_glue: " fmt
  29 
  30 #include <linux/module.h>
  31 
  32 #include <linux/kernel.h>
  33 #include <linux/pci.h>
  34 #include <linux/pci_hotplug.h>
  35 #include <linux/pci-acpi.h>
  36 #include <linux/pm_runtime.h>
  37 #include <linux/mutex.h>
  38 #include <linux/slab.h>
  39 #include <linux/acpi.h>
  40 
  41 #include "../pci.h"
  42 #include "acpiphp.h"
  43 
  44 static LIST_HEAD(bridge_list);
  45 static DEFINE_MUTEX(bridge_mutex);
  46 
  47 static int acpiphp_hotplug_notify(struct acpi_device *adev, u32 type);
  48 static void acpiphp_post_dock_fixup(struct acpi_device *adev);
  49 static void acpiphp_sanitize_bus(struct pci_bus *bus);
  50 static void hotplug_event(u32 type, struct acpiphp_context *context);
  51 static void free_bridge(struct kref *kref);
  52 
  53 /**
  54  * acpiphp_init_context - Create hotplug context and grab a reference to it.
  55  * @adev: ACPI device object to create the context for.
  56  *
  57  * Call under acpi_hp_context_lock.
  58  */
  59 static struct acpiphp_context *acpiphp_init_context(struct acpi_device *adev)
  60 {
  61         struct acpiphp_context *context;
  62 
  63         context = kzalloc(sizeof(*context), GFP_KERNEL);
  64         if (!context)
  65                 return NULL;
  66 
  67         context->refcount = 1;
  68         context->hp.notify = acpiphp_hotplug_notify;
  69         context->hp.fixup = acpiphp_post_dock_fixup;
  70         acpi_set_hp_context(adev, &context->hp);
  71         return context;
  72 }
  73 
  74 /**
  75  * acpiphp_get_context - Get hotplug context and grab a reference to it.
  76  * @adev: ACPI device object to get the context for.
  77  *
  78  * Call under acpi_hp_context_lock.
  79  */
  80 static struct acpiphp_context *acpiphp_get_context(struct acpi_device *adev)
  81 {
  82         struct acpiphp_context *context;
  83 
  84         if (!adev->hp)
  85                 return NULL;
  86 
  87         context = to_acpiphp_context(adev->hp);
  88         context->refcount++;
  89         return context;
  90 }
  91 
  92 /**
  93  * acpiphp_put_context - Drop a reference to ACPI hotplug context.
  94  * @context: ACPI hotplug context to drop a reference to.
  95  *
  96  * The context object is removed if there are no more references to it.
  97  *
  98  * Call under acpi_hp_context_lock.
  99  */
 100 static void acpiphp_put_context(struct acpiphp_context *context)
 101 {
 102         if (--context->refcount)
 103                 return;
 104 
 105         WARN_ON(context->bridge);
 106         context->hp.self->hp = NULL;
 107         kfree(context);
 108 }
 109 
 110 static inline void get_bridge(struct acpiphp_bridge *bridge)
 111 {
 112         kref_get(&bridge->ref);
 113 }
 114 
 115 static inline void put_bridge(struct acpiphp_bridge *bridge)
 116 {
 117         kref_put(&bridge->ref, free_bridge);
 118 }
 119 
 120 static struct acpiphp_context *acpiphp_grab_context(struct acpi_device *adev)
 121 {
 122         struct acpiphp_context *context;
 123 
 124         acpi_lock_hp_context();
 125         context = acpiphp_get_context(adev);
 126         if (!context || context->func.parent->is_going_away) {
 127                 acpi_unlock_hp_context();
 128                 return NULL;
 129         }
 130         get_bridge(context->func.parent);
 131         acpiphp_put_context(context);
 132         acpi_unlock_hp_context();
 133         return context;
 134 }
 135 
 136 static void acpiphp_let_context_go(struct acpiphp_context *context)
 137 {
 138         put_bridge(context->func.parent);
 139 }
 140 
 141 static void free_bridge(struct kref *kref)
 142 {
 143         struct acpiphp_context *context;
 144         struct acpiphp_bridge *bridge;
 145         struct acpiphp_slot *slot, *next;
 146         struct acpiphp_func *func, *tmp;
 147 
 148         acpi_lock_hp_context();
 149 
 150         bridge = container_of(kref, struct acpiphp_bridge, ref);
 151 
 152         list_for_each_entry_safe(slot, next, &bridge->slots, node) {
 153                 list_for_each_entry_safe(func, tmp, &slot->funcs, sibling)
 154                         acpiphp_put_context(func_to_context(func));
 155 
 156                 kfree(slot);
 157         }
 158 
 159         context = bridge->context;
 160         /* Root bridges will not have hotplug context. */
 161         if (context) {
 162                 /* Release the reference taken by acpiphp_enumerate_slots(). */
 163                 put_bridge(context->func.parent);
 164                 context->bridge = NULL;
 165                 acpiphp_put_context(context);
 166         }
 167 
 168         put_device(&bridge->pci_bus->dev);
 169         pci_dev_put(bridge->pci_dev);
 170         kfree(bridge);
 171 
 172         acpi_unlock_hp_context();
 173 }
 174 
 175 /**
 176  * acpiphp_post_dock_fixup - Post-dock fixups for PCI devices.
 177  * @adev: ACPI device object corresponding to a PCI device.
 178  *
 179  * TBD - figure out a way to only call fixups for systems that require them.
 180  */
 181 static void acpiphp_post_dock_fixup(struct acpi_device *adev)
 182 {
 183         struct acpiphp_context *context = acpiphp_grab_context(adev);
 184         struct pci_bus *bus;
 185         u32 buses;
 186 
 187         if (!context)
 188                 return;
 189 
 190         bus = context->func.slot->bus;
 191         if (!bus->self)
 192                 goto out;
 193 
 194         /* fixup bad _DCK function that rewrites
 195          * secondary bridge on slot
 196          */
 197         pci_read_config_dword(bus->self, PCI_PRIMARY_BUS, &buses);
 198 
 199         if (((buses >> 8) & 0xff) != bus->busn_res.start) {
 200                 buses = (buses & 0xff000000)
 201                         | ((unsigned int)(bus->primary)     <<  0)
 202                         | ((unsigned int)(bus->busn_res.start)   <<  8)
 203                         | ((unsigned int)(bus->busn_res.end) << 16);
 204                 pci_write_config_dword(bus->self, PCI_PRIMARY_BUS, buses);
 205         }
 206 
 207  out:
 208         acpiphp_let_context_go(context);
 209 }
 210 
 211 /**
 212  * acpiphp_add_context - Add ACPIPHP context to an ACPI device object.
 213  * @handle: ACPI handle of the object to add a context to.
 214  * @lvl: Not used.
 215  * @data: The object's parent ACPIPHP bridge.
 216  * @rv: Not used.
 217  */
 218 static acpi_status acpiphp_add_context(acpi_handle handle, u32 lvl, void *data,
 219                                        void **rv)
 220 {
 221         struct acpiphp_bridge *bridge = data;
 222         struct acpiphp_context *context;
 223         struct acpi_device *adev;
 224         struct acpiphp_slot *slot;
 225         struct acpiphp_func *newfunc;
 226         acpi_status status = AE_OK;
 227         unsigned long long adr;
 228         int device, function;
 229         struct pci_bus *pbus = bridge->pci_bus;
 230         struct pci_dev *pdev = bridge->pci_dev;
 231         u32 val;
 232 
 233         status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
 234         if (ACPI_FAILURE(status)) {
 235                 if (status != AE_NOT_FOUND)
 236                         acpi_handle_warn(handle,
 237                                 "can't evaluate _ADR (%#x)\n", status);
 238                 return AE_OK;
 239         }
 240         if (acpi_bus_get_device(handle, &adev))
 241                 return AE_OK;
 242 
 243         device = (adr >> 16) & 0xffff;
 244         function = adr & 0xffff;
 245 
 246         acpi_lock_hp_context();
 247         context = acpiphp_init_context(adev);
 248         if (!context) {
 249                 acpi_unlock_hp_context();
 250                 acpi_handle_err(handle, "No hotplug context\n");
 251                 return AE_NOT_EXIST;
 252         }
 253         newfunc = &context->func;
 254         newfunc->function = function;
 255         newfunc->parent = bridge;
 256         acpi_unlock_hp_context();
 257 
 258         /*
 259          * If this is a dock device, its _EJ0 should be executed by the dock
 260          * notify handler after calling _DCK.
 261          */
 262         if (!is_dock_device(adev) && acpi_has_method(handle, "_EJ0"))
 263                 newfunc->flags = FUNC_HAS_EJ0;
 264 
 265         if (acpi_has_method(handle, "_STA"))
 266                 newfunc->flags |= FUNC_HAS_STA;
 267 
 268         /* search for objects that share the same slot */
 269         list_for_each_entry(slot, &bridge->slots, node)
 270                 if (slot->device == device)
 271                         goto slot_found;
 272 
 273         slot = kzalloc(sizeof(struct acpiphp_slot), GFP_KERNEL);
 274         if (!slot) {
 275                 acpi_lock_hp_context();
 276                 acpiphp_put_context(context);
 277                 acpi_unlock_hp_context();
 278                 return AE_NO_MEMORY;
 279         }
 280 
 281         slot->bus = bridge->pci_bus;
 282         slot->device = device;
 283         INIT_LIST_HEAD(&slot->funcs);
 284 
 285         list_add_tail(&slot->node, &bridge->slots);
 286 
 287         /*
 288          * Expose slots to user space for functions that have _EJ0 or _RMV or
 289          * are located in dock stations.  Do not expose them for devices handled
 290          * by the native PCIe hotplug (PCIeHP) or standard PCI hotplug
 291          * (SHPCHP), because that code is supposed to expose slots to user
 292          * space in those cases.
 293          */
 294         if ((acpi_pci_check_ejectable(pbus, handle) || is_dock_device(adev))
 295             && !(pdev && hotplug_is_native(pdev))) {
 296                 unsigned long long sun;
 297                 int retval;
 298 
 299                 bridge->nr_slots++;
 300                 status = acpi_evaluate_integer(handle, "_SUN", NULL, &sun);
 301                 if (ACPI_FAILURE(status))
 302                         sun = bridge->nr_slots;
 303 
 304                 pr_debug("found ACPI PCI Hotplug slot %llu at PCI %04x:%02x:%02x\n",
 305                     sun, pci_domain_nr(pbus), pbus->number, device);
 306 
 307                 retval = acpiphp_register_hotplug_slot(slot, sun);
 308                 if (retval) {
 309                         slot->slot = NULL;
 310                         bridge->nr_slots--;
 311                         if (retval == -EBUSY)
 312                                 pr_warn("Slot %llu already registered by another hotplug driver\n", sun);
 313                         else
 314                                 pr_warn("acpiphp_register_hotplug_slot failed (err code = 0x%x)\n", retval);
 315                 }
 316                 /* Even if the slot registration fails, we can still use it. */
 317         }
 318 
 319  slot_found:
 320         newfunc->slot = slot;
 321         list_add_tail(&newfunc->sibling, &slot->funcs);
 322 
 323         if (pci_bus_read_dev_vendor_id(pbus, PCI_DEVFN(device, function),
 324                                        &val, 60*1000))
 325                 slot->flags |= SLOT_ENABLED;
 326 
 327         return AE_OK;
 328 }
 329 
 330 static void cleanup_bridge(struct acpiphp_bridge *bridge)
 331 {
 332         struct acpiphp_slot *slot;
 333         struct acpiphp_func *func;
 334 
 335         list_for_each_entry(slot, &bridge->slots, node) {
 336                 list_for_each_entry(func, &slot->funcs, sibling) {
 337                         struct acpi_device *adev = func_to_acpi_device(func);
 338 
 339                         acpi_lock_hp_context();
 340                         adev->hp->notify = NULL;
 341                         adev->hp->fixup = NULL;
 342                         acpi_unlock_hp_context();
 343                 }
 344                 slot->flags |= SLOT_IS_GOING_AWAY;
 345                 if (slot->slot)
 346                         acpiphp_unregister_hotplug_slot(slot);
 347         }
 348 
 349         mutex_lock(&bridge_mutex);
 350         list_del(&bridge->list);
 351         mutex_unlock(&bridge_mutex);
 352 
 353         acpi_lock_hp_context();
 354         bridge->is_going_away = true;
 355         acpi_unlock_hp_context();
 356 }
 357 
 358 /**
 359  * acpiphp_max_busnr - return the highest reserved bus number under the given bus.
 360  * @bus: bus to start search with
 361  */
 362 static unsigned char acpiphp_max_busnr(struct pci_bus *bus)
 363 {
 364         struct pci_bus *tmp;
 365         unsigned char max, n;
 366 
 367         /*
 368          * pci_bus_max_busnr will return the highest
 369          * reserved busnr for all these children.
 370          * that is equivalent to the bus->subordinate
 371          * value.  We don't want to use the parent's
 372          * bus->subordinate value because it could have
 373          * padding in it.
 374          */
 375         max = bus->busn_res.start;
 376 
 377         list_for_each_entry(tmp, &bus->children, node) {
 378                 n = pci_bus_max_busnr(tmp);
 379                 if (n > max)
 380                         max = n;
 381         }
 382         return max;
 383 }
 384 
 385 static void acpiphp_set_acpi_region(struct acpiphp_slot *slot)
 386 {
 387         struct acpiphp_func *func;
 388         union acpi_object params[2];
 389         struct acpi_object_list arg_list;
 390 
 391         list_for_each_entry(func, &slot->funcs, sibling) {
 392                 arg_list.count = 2;
 393                 arg_list.pointer = params;
 394                 params[0].type = ACPI_TYPE_INTEGER;
 395                 params[0].integer.value = ACPI_ADR_SPACE_PCI_CONFIG;
 396                 params[1].type = ACPI_TYPE_INTEGER;
 397                 params[1].integer.value = 1;
 398                 /* _REG is optional, we don't care about if there is failure */
 399                 acpi_evaluate_object(func_to_handle(func), "_REG", &arg_list,
 400                                      NULL);
 401         }
 402 }
 403 
 404 static void check_hotplug_bridge(struct acpiphp_slot *slot, struct pci_dev *dev)
 405 {
 406         struct acpiphp_func *func;
 407 
 408         /* quirk, or pcie could set it already */
 409         if (dev->is_hotplug_bridge)
 410                 return;
 411 
 412         list_for_each_entry(func, &slot->funcs, sibling) {
 413                 if (PCI_FUNC(dev->devfn) == func->function) {
 414                         dev->is_hotplug_bridge = 1;
 415                         break;
 416                 }
 417         }
 418 }
 419 
 420 static int acpiphp_rescan_slot(struct acpiphp_slot *slot)
 421 {
 422         struct acpiphp_func *func;
 423 
 424         list_for_each_entry(func, &slot->funcs, sibling) {
 425                 struct acpi_device *adev = func_to_acpi_device(func);
 426 
 427                 acpi_bus_scan(adev->handle);
 428                 if (acpi_device_enumerated(adev))
 429                         acpi_device_set_power(adev, ACPI_STATE_D0);
 430         }
 431         return pci_scan_slot(slot->bus, PCI_DEVFN(slot->device, 0));
 432 }
 433 
 434 static void acpiphp_native_scan_bridge(struct pci_dev *bridge)
 435 {
 436         struct pci_bus *bus = bridge->subordinate;
 437         struct pci_dev *dev;
 438         int max;
 439 
 440         if (!bus)
 441                 return;
 442 
 443         max = bus->busn_res.start;
 444         /* Scan already configured non-hotplug bridges */
 445         for_each_pci_bridge(dev, bus) {
 446                 if (!hotplug_is_native(dev))
 447                         max = pci_scan_bridge(bus, dev, max, 0);
 448         }
 449 
 450         /* Scan non-hotplug bridges that need to be reconfigured */
 451         for_each_pci_bridge(dev, bus) {
 452                 if (hotplug_is_native(dev))
 453                         continue;
 454 
 455                 max = pci_scan_bridge(bus, dev, max, 1);
 456                 if (dev->subordinate) {
 457                         pcibios_resource_survey_bus(dev->subordinate);
 458                         pci_bus_size_bridges(dev->subordinate);
 459                         pci_bus_assign_resources(dev->subordinate);
 460                 }
 461         }
 462 }
 463 
 464 /**
 465  * enable_slot - enable, configure a slot
 466  * @slot: slot to be enabled
 467  * @bridge: true if enable is for the whole bridge (not a single slot)
 468  *
 469  * This function should be called per *physical slot*,
 470  * not per each slot object in ACPI namespace.
 471  */
 472 static void enable_slot(struct acpiphp_slot *slot, bool bridge)
 473 {
 474         struct pci_dev *dev;
 475         struct pci_bus *bus = slot->bus;
 476         struct acpiphp_func *func;
 477 
 478         if (bridge && bus->self && hotplug_is_native(bus->self)) {
 479                 /*
 480                  * If native hotplug is used, it will take care of hotplug
 481                  * slot management and resource allocation for hotplug
 482                  * bridges. However, ACPI hotplug may still be used for
 483                  * non-hotplug bridges to bring in additional devices such
 484                  * as a Thunderbolt host controller.
 485                  */
 486                 for_each_pci_bridge(dev, bus) {
 487                         if (PCI_SLOT(dev->devfn) == slot->device)
 488                                 acpiphp_native_scan_bridge(dev);
 489                 }
 490         } else {
 491                 LIST_HEAD(add_list);
 492                 int max, pass;
 493 
 494                 acpiphp_rescan_slot(slot);
 495                 max = acpiphp_max_busnr(bus);
 496                 for (pass = 0; pass < 2; pass++) {
 497                         for_each_pci_bridge(dev, bus) {
 498                                 if (PCI_SLOT(dev->devfn) != slot->device)
 499                                         continue;
 500 
 501                                 max = pci_scan_bridge(bus, dev, max, pass);
 502                                 if (pass && dev->subordinate) {
 503                                         check_hotplug_bridge(slot, dev);
 504                                         pcibios_resource_survey_bus(dev->subordinate);
 505                                         __pci_bus_size_bridges(dev->subordinate,
 506                                                                &add_list);
 507                                 }
 508                         }
 509                 }
 510                 __pci_bus_assign_resources(bus, &add_list, NULL);
 511         }
 512 
 513         acpiphp_sanitize_bus(bus);
 514         pcie_bus_configure_settings(bus);
 515         acpiphp_set_acpi_region(slot);
 516 
 517         list_for_each_entry(dev, &bus->devices, bus_list) {
 518                 /* Assume that newly added devices are powered on already. */
 519                 if (!pci_dev_is_added(dev))
 520                         dev->current_state = PCI_D0;
 521         }
 522 
 523         pci_bus_add_devices(bus);
 524 
 525         slot->flags |= SLOT_ENABLED;
 526         list_for_each_entry(func, &slot->funcs, sibling) {
 527                 dev = pci_get_slot(bus, PCI_DEVFN(slot->device,
 528                                                   func->function));
 529                 if (!dev) {
 530                         /* Do not set SLOT_ENABLED flag if some funcs
 531                            are not added. */
 532                         slot->flags &= ~SLOT_ENABLED;
 533                         continue;
 534                 }
 535         }
 536 }
 537 
 538 /**
 539  * disable_slot - disable a slot
 540  * @slot: ACPI PHP slot
 541  */
 542 static void disable_slot(struct acpiphp_slot *slot)
 543 {
 544         struct pci_bus *bus = slot->bus;
 545         struct pci_dev *dev, *prev;
 546         struct acpiphp_func *func;
 547 
 548         /*
 549          * enable_slot() enumerates all functions in this device via
 550          * pci_scan_slot(), whether they have associated ACPI hotplug
 551          * methods (_EJ0, etc.) or not.  Therefore, we remove all functions
 552          * here.
 553          */
 554         list_for_each_entry_safe_reverse(dev, prev, &bus->devices, bus_list)
 555                 if (PCI_SLOT(dev->devfn) == slot->device)
 556                         pci_stop_and_remove_bus_device(dev);
 557 
 558         list_for_each_entry(func, &slot->funcs, sibling)
 559                 acpi_bus_trim(func_to_acpi_device(func));
 560 
 561         slot->flags &= ~SLOT_ENABLED;
 562 }
 563 
 564 static bool slot_no_hotplug(struct acpiphp_slot *slot)
 565 {
 566         struct pci_bus *bus = slot->bus;
 567         struct pci_dev *dev;
 568 
 569         list_for_each_entry(dev, &bus->devices, bus_list) {
 570                 if (PCI_SLOT(dev->devfn) == slot->device && dev->ignore_hotplug)
 571                         return true;
 572         }
 573         return false;
 574 }
 575 
 576 /**
 577  * get_slot_status - get ACPI slot status
 578  * @slot: ACPI PHP slot
 579  *
 580  * If a slot has _STA for each function and if any one of them
 581  * returned non-zero status, return it.
 582  *
 583  * If a slot doesn't have _STA and if any one of its functions'
 584  * configuration space is configured, return 0x0f as a _STA.
 585  *
 586  * Otherwise return 0.
 587  */
 588 static unsigned int get_slot_status(struct acpiphp_slot *slot)
 589 {
 590         unsigned long long sta = 0;
 591         struct acpiphp_func *func;
 592         u32 dvid;
 593 
 594         list_for_each_entry(func, &slot->funcs, sibling) {
 595                 if (func->flags & FUNC_HAS_STA) {
 596                         acpi_status status;
 597 
 598                         status = acpi_evaluate_integer(func_to_handle(func),
 599                                                        "_STA", NULL, &sta);
 600                         if (ACPI_SUCCESS(status) && sta)
 601                                 break;
 602                 } else {
 603                         if (pci_bus_read_dev_vendor_id(slot->bus,
 604                                         PCI_DEVFN(slot->device, func->function),
 605                                         &dvid, 0)) {
 606                                 sta = ACPI_STA_ALL;
 607                                 break;
 608                         }
 609                 }
 610         }
 611 
 612         if (!sta) {
 613                 /*
 614                  * Check for the slot itself since it may be that the
 615                  * ACPI slot is a device below PCIe upstream port so in
 616                  * that case it may not even be reachable yet.
 617                  */
 618                 if (pci_bus_read_dev_vendor_id(slot->bus,
 619                                 PCI_DEVFN(slot->device, 0), &dvid, 0)) {
 620                         sta = ACPI_STA_ALL;
 621                 }
 622         }
 623 
 624         return (unsigned int)sta;
 625 }
 626 
 627 static inline bool device_status_valid(unsigned int sta)
 628 {
 629         /*
 630          * ACPI spec says that _STA may return bit 0 clear with bit 3 set
 631          * if the device is valid but does not require a device driver to be
 632          * loaded (Section 6.3.7 of ACPI 5.0A).
 633          */
 634         unsigned int mask = ACPI_STA_DEVICE_ENABLED | ACPI_STA_DEVICE_FUNCTIONING;
 635         return (sta & mask) == mask;
 636 }
 637 
 638 /**
 639  * trim_stale_devices - remove PCI devices that are not responding.
 640  * @dev: PCI device to start walking the hierarchy from.
 641  */
 642 static void trim_stale_devices(struct pci_dev *dev)
 643 {
 644         struct acpi_device *adev = ACPI_COMPANION(&dev->dev);
 645         struct pci_bus *bus = dev->subordinate;
 646         bool alive = dev->ignore_hotplug;
 647 
 648         if (adev) {
 649                 acpi_status status;
 650                 unsigned long long sta;
 651 
 652                 status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
 653                 alive = alive || (ACPI_SUCCESS(status) && device_status_valid(sta));
 654         }
 655         if (!alive)
 656                 alive = pci_device_is_present(dev);
 657 
 658         if (!alive) {
 659                 pci_dev_set_disconnected(dev, NULL);
 660                 if (pci_has_subordinate(dev))
 661                         pci_walk_bus(dev->subordinate, pci_dev_set_disconnected,
 662                                      NULL);
 663 
 664                 pci_stop_and_remove_bus_device(dev);
 665                 if (adev)
 666                         acpi_bus_trim(adev);
 667         } else if (bus) {
 668                 struct pci_dev *child, *tmp;
 669 
 670                 /* The device is a bridge. so check the bus below it. */
 671                 pm_runtime_get_sync(&dev->dev);
 672                 list_for_each_entry_safe_reverse(child, tmp, &bus->devices, bus_list)
 673                         trim_stale_devices(child);
 674 
 675                 pm_runtime_put(&dev->dev);
 676         }
 677 }
 678 
 679 /**
 680  * acpiphp_check_bridge - re-enumerate devices
 681  * @bridge: where to begin re-enumeration
 682  *
 683  * Iterate over all slots under this bridge and make sure that if a
 684  * card is present they are enabled, and if not they are disabled.
 685  */
 686 static void acpiphp_check_bridge(struct acpiphp_bridge *bridge)
 687 {
 688         struct acpiphp_slot *slot;
 689 
 690         /* Bail out if the bridge is going away. */
 691         if (bridge->is_going_away)
 692                 return;
 693 
 694         if (bridge->pci_dev)
 695                 pm_runtime_get_sync(&bridge->pci_dev->dev);
 696 
 697         list_for_each_entry(slot, &bridge->slots, node) {
 698                 struct pci_bus *bus = slot->bus;
 699                 struct pci_dev *dev, *tmp;
 700 
 701                 if (slot_no_hotplug(slot)) {
 702                         ; /* do nothing */
 703                 } else if (device_status_valid(get_slot_status(slot))) {
 704                         /* remove stale devices if any */
 705                         list_for_each_entry_safe_reverse(dev, tmp,
 706                                                          &bus->devices, bus_list)
 707                                 if (PCI_SLOT(dev->devfn) == slot->device)
 708                                         trim_stale_devices(dev);
 709 
 710                         /* configure all functions */
 711                         enable_slot(slot, true);
 712                 } else {
 713                         disable_slot(slot);
 714                 }
 715         }
 716 
 717         if (bridge->pci_dev)
 718                 pm_runtime_put(&bridge->pci_dev->dev);
 719 }
 720 
 721 /*
 722  * Remove devices for which we could not assign resources, call
 723  * arch specific code to fix-up the bus
 724  */
 725 static void acpiphp_sanitize_bus(struct pci_bus *bus)
 726 {
 727         struct pci_dev *dev, *tmp;
 728         int i;
 729         unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM;
 730 
 731         list_for_each_entry_safe_reverse(dev, tmp, &bus->devices, bus_list) {
 732                 for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) {
 733                         struct resource *res = &dev->resource[i];
 734                         if ((res->flags & type_mask) && !res->start &&
 735                                         res->end) {
 736                                 /* Could not assign a required resources
 737                                  * for this device, remove it */
 738                                 pci_stop_and_remove_bus_device(dev);
 739                                 break;
 740                         }
 741                 }
 742         }
 743 }
 744 
 745 /*
 746  * ACPI event handlers
 747  */
 748 
 749 void acpiphp_check_host_bridge(struct acpi_device *adev)
 750 {
 751         struct acpiphp_bridge *bridge = NULL;
 752 
 753         acpi_lock_hp_context();
 754         if (adev->hp) {
 755                 bridge = to_acpiphp_root_context(adev->hp)->root_bridge;
 756                 if (bridge)
 757                         get_bridge(bridge);
 758         }
 759         acpi_unlock_hp_context();
 760         if (bridge) {
 761                 pci_lock_rescan_remove();
 762 
 763                 acpiphp_check_bridge(bridge);
 764 
 765                 pci_unlock_rescan_remove();
 766                 put_bridge(bridge);
 767         }
 768 }
 769 
 770 static int acpiphp_disable_and_eject_slot(struct acpiphp_slot *slot);
 771 
 772 static void hotplug_event(u32 type, struct acpiphp_context *context)
 773 {
 774         acpi_handle handle = context->hp.self->handle;
 775         struct acpiphp_func *func = &context->func;
 776         struct acpiphp_slot *slot = func->slot;
 777         struct acpiphp_bridge *bridge;
 778 
 779         acpi_lock_hp_context();
 780         bridge = context->bridge;
 781         if (bridge)
 782                 get_bridge(bridge);
 783 
 784         acpi_unlock_hp_context();
 785 
 786         pci_lock_rescan_remove();
 787 
 788         switch (type) {
 789         case ACPI_NOTIFY_BUS_CHECK:
 790                 /* bus re-enumerate */
 791                 acpi_handle_debug(handle, "Bus check in %s()\n", __func__);
 792                 if (bridge)
 793                         acpiphp_check_bridge(bridge);
 794                 else if (!(slot->flags & SLOT_IS_GOING_AWAY))
 795                         enable_slot(slot, false);
 796 
 797                 break;
 798 
 799         case ACPI_NOTIFY_DEVICE_CHECK:
 800                 /* device check */
 801                 acpi_handle_debug(handle, "Device check in %s()\n", __func__);
 802                 if (bridge) {
 803                         acpiphp_check_bridge(bridge);
 804                 } else if (!(slot->flags & SLOT_IS_GOING_AWAY)) {
 805                         /*
 806                          * Check if anything has changed in the slot and rescan
 807                          * from the parent if that's the case.
 808                          */
 809                         if (acpiphp_rescan_slot(slot))
 810                                 acpiphp_check_bridge(func->parent);
 811                 }
 812                 break;
 813 
 814         case ACPI_NOTIFY_EJECT_REQUEST:
 815                 /* request device eject */
 816                 acpi_handle_debug(handle, "Eject request in %s()\n", __func__);
 817                 acpiphp_disable_and_eject_slot(slot);
 818                 break;
 819         }
 820 
 821         pci_unlock_rescan_remove();
 822         if (bridge)
 823                 put_bridge(bridge);
 824 }
 825 
 826 static int acpiphp_hotplug_notify(struct acpi_device *adev, u32 type)
 827 {
 828         struct acpiphp_context *context;
 829 
 830         context = acpiphp_grab_context(adev);
 831         if (!context)
 832                 return -ENODATA;
 833 
 834         hotplug_event(type, context);
 835         acpiphp_let_context_go(context);
 836         return 0;
 837 }
 838 
 839 /**
 840  * acpiphp_enumerate_slots - Enumerate PCI slots for a given bus.
 841  * @bus: PCI bus to enumerate the slots for.
 842  *
 843  * A "slot" is an object associated with a PCI device number.  All functions
 844  * (PCI devices) with the same bus and device number belong to the same slot.
 845  */
 846 void acpiphp_enumerate_slots(struct pci_bus *bus)
 847 {
 848         struct acpiphp_bridge *bridge;
 849         struct acpi_device *adev;
 850         acpi_handle handle;
 851         acpi_status status;
 852 
 853         if (acpiphp_disabled)
 854                 return;
 855 
 856         adev = ACPI_COMPANION(bus->bridge);
 857         if (!adev)
 858                 return;
 859 
 860         handle = adev->handle;
 861         bridge = kzalloc(sizeof(struct acpiphp_bridge), GFP_KERNEL);
 862         if (!bridge)
 863                 return;
 864 
 865         INIT_LIST_HEAD(&bridge->slots);
 866         kref_init(&bridge->ref);
 867         bridge->pci_dev = pci_dev_get(bus->self);
 868         bridge->pci_bus = bus;
 869 
 870         /*
 871          * Grab a ref to the subordinate PCI bus in case the bus is
 872          * removed via PCI core logical hotplug. The ref pins the bus
 873          * (which we access during module unload).
 874          */
 875         get_device(&bus->dev);
 876 
 877         acpi_lock_hp_context();
 878         if (pci_is_root_bus(bridge->pci_bus)) {
 879                 struct acpiphp_root_context *root_context;
 880 
 881                 root_context = kzalloc(sizeof(*root_context), GFP_KERNEL);
 882                 if (!root_context)
 883                         goto err;
 884 
 885                 root_context->root_bridge = bridge;
 886                 acpi_set_hp_context(adev, &root_context->hp);
 887         } else {
 888                 struct acpiphp_context *context;
 889 
 890                 /*
 891                  * This bridge should have been registered as a hotplug function
 892                  * under its parent, so the context should be there, unless the
 893                  * parent is going to be handled by pciehp, in which case this
 894                  * bridge is not interesting to us either.
 895                  */
 896                 context = acpiphp_get_context(adev);
 897                 if (!context)
 898                         goto err;
 899 
 900                 bridge->context = context;
 901                 context->bridge = bridge;
 902                 /* Get a reference to the parent bridge. */
 903                 get_bridge(context->func.parent);
 904         }
 905         acpi_unlock_hp_context();
 906 
 907         /* Must be added to the list prior to calling acpiphp_add_context(). */
 908         mutex_lock(&bridge_mutex);
 909         list_add(&bridge->list, &bridge_list);
 910         mutex_unlock(&bridge_mutex);
 911 
 912         /* register all slot objects under this bridge */
 913         status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
 914                                      acpiphp_add_context, NULL, bridge, NULL);
 915         if (ACPI_FAILURE(status)) {
 916                 acpi_handle_err(handle, "failed to register slots\n");
 917                 cleanup_bridge(bridge);
 918                 put_bridge(bridge);
 919         }
 920         return;
 921 
 922  err:
 923         acpi_unlock_hp_context();
 924         put_device(&bus->dev);
 925         pci_dev_put(bridge->pci_dev);
 926         kfree(bridge);
 927 }
 928 
 929 static void acpiphp_drop_bridge(struct acpiphp_bridge *bridge)
 930 {
 931         if (pci_is_root_bus(bridge->pci_bus)) {
 932                 struct acpiphp_root_context *root_context;
 933                 struct acpi_device *adev;
 934 
 935                 acpi_lock_hp_context();
 936                 adev = ACPI_COMPANION(bridge->pci_bus->bridge);
 937                 root_context = to_acpiphp_root_context(adev->hp);
 938                 adev->hp = NULL;
 939                 acpi_unlock_hp_context();
 940                 kfree(root_context);
 941         }
 942         cleanup_bridge(bridge);
 943         put_bridge(bridge);
 944 }
 945 
 946 /**
 947  * acpiphp_remove_slots - Remove slot objects associated with a given bus.
 948  * @bus: PCI bus to remove the slot objects for.
 949  */
 950 void acpiphp_remove_slots(struct pci_bus *bus)
 951 {
 952         struct acpiphp_bridge *bridge;
 953 
 954         if (acpiphp_disabled)
 955                 return;
 956 
 957         mutex_lock(&bridge_mutex);
 958         list_for_each_entry(bridge, &bridge_list, list)
 959                 if (bridge->pci_bus == bus) {
 960                         mutex_unlock(&bridge_mutex);
 961                         acpiphp_drop_bridge(bridge);
 962                         return;
 963                 }
 964 
 965         mutex_unlock(&bridge_mutex);
 966 }
 967 
 968 /**
 969  * acpiphp_enable_slot - power on slot
 970  * @slot: ACPI PHP slot
 971  */
 972 int acpiphp_enable_slot(struct acpiphp_slot *slot)
 973 {
 974         pci_lock_rescan_remove();
 975 
 976         if (slot->flags & SLOT_IS_GOING_AWAY) {
 977                 pci_unlock_rescan_remove();
 978                 return -ENODEV;
 979         }
 980 
 981         /* configure all functions */
 982         if (!(slot->flags & SLOT_ENABLED))
 983                 enable_slot(slot, false);
 984 
 985         pci_unlock_rescan_remove();
 986         return 0;
 987 }
 988 
 989 /**
 990  * acpiphp_disable_and_eject_slot - power off and eject slot
 991  * @slot: ACPI PHP slot
 992  */
 993 static int acpiphp_disable_and_eject_slot(struct acpiphp_slot *slot)
 994 {
 995         struct acpiphp_func *func;
 996 
 997         if (slot->flags & SLOT_IS_GOING_AWAY)
 998                 return -ENODEV;
 999 
1000         /* unconfigure all functions */
1001         disable_slot(slot);
1002 
1003         list_for_each_entry(func, &slot->funcs, sibling)
1004                 if (func->flags & FUNC_HAS_EJ0) {
1005                         acpi_handle handle = func_to_handle(func);
1006 
1007                         if (ACPI_FAILURE(acpi_evaluate_ej0(handle)))
1008                                 acpi_handle_err(handle, "_EJ0 failed\n");
1009 
1010                         break;
1011                 }
1012 
1013         return 0;
1014 }
1015 
1016 int acpiphp_disable_slot(struct acpiphp_slot *slot)
1017 {
1018         int ret;
1019 
1020         /*
1021          * Acquire acpi_scan_lock to ensure that the execution of _EJ0 in
1022          * acpiphp_disable_and_eject_slot() will be synchronized properly.
1023          */
1024         acpi_scan_lock_acquire();
1025         pci_lock_rescan_remove();
1026         ret = acpiphp_disable_and_eject_slot(slot);
1027         pci_unlock_rescan_remove();
1028         acpi_scan_lock_release();
1029         return ret;
1030 }
1031 
1032 /*
1033  * slot enabled:  1
1034  * slot disabled: 0
1035  */
1036 u8 acpiphp_get_power_status(struct acpiphp_slot *slot)
1037 {
1038         return (slot->flags & SLOT_ENABLED);
1039 }
1040 
1041 /*
1042  * latch   open:  1
1043  * latch closed:  0
1044  */
1045 u8 acpiphp_get_latch_status(struct acpiphp_slot *slot)
1046 {
1047         return !(get_slot_status(slot) & ACPI_STA_DEVICE_UI);
1048 }
1049 
1050 /*
1051  * adapter presence : 1
1052  *          absence : 0
1053  */
1054 u8 acpiphp_get_adapter_status(struct acpiphp_slot *slot)
1055 {
1056         return !!get_slot_status(slot);
1057 }
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/pci/hotplug/acpiphp_glue.c

DEFINITIONS
