linux/drivers/pci/pci-acpi.c
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   1/*
   2 * File:        pci-acpi.c
   3 * Purpose:     Provide PCI support in ACPI
   4 *
   5 * Copyright (C) 2005 David Shaohua Li <shaohua.li@intel.com>
   6 * Copyright (C) 2004 Tom Long Nguyen <tom.l.nguyen@intel.com>
   7 * Copyright (C) 2004 Intel Corp.
   8 */
   9
  10#include <linux/delay.h>
  11#include <linux/init.h>
  12#include <linux/pci.h>
  13#include <linux/module.h>
  14#include <linux/pci-aspm.h>
  15#include <acpi/acpi.h>
  16#include <acpi/acpi_bus.h>
  17
  18#include <linux/pci-acpi.h>
  19#include <linux/pm_runtime.h>
  20#include <linux/pm_qos.h>
  21#include "pci.h"
  22
  23/**
  24 * pci_acpi_wake_bus - Wake-up notification handler for root buses.
  25 * @handle: ACPI handle of a device the notification is for.
  26 * @event: Type of the signaled event.
  27 * @context: PCI root bus to wake up devices on.
  28 */
  29static void pci_acpi_wake_bus(acpi_handle handle, u32 event, void *context)
  30{
  31        struct pci_bus *pci_bus = context;
  32
  33        if (event == ACPI_NOTIFY_DEVICE_WAKE && pci_bus)
  34                pci_pme_wakeup_bus(pci_bus);
  35}
  36
  37/**
  38 * pci_acpi_wake_dev - Wake-up notification handler for PCI devices.
  39 * @handle: ACPI handle of a device the notification is for.
  40 * @event: Type of the signaled event.
  41 * @context: PCI device object to wake up.
  42 */
  43static void pci_acpi_wake_dev(acpi_handle handle, u32 event, void *context)
  44{
  45        struct pci_dev *pci_dev = context;
  46
  47        if (event != ACPI_NOTIFY_DEVICE_WAKE || !pci_dev)
  48                return;
  49
  50        if (pci_dev->current_state == PCI_D3cold) {
  51                pci_wakeup_event(pci_dev);
  52                pm_runtime_resume(&pci_dev->dev);
  53                return;
  54        }
  55
  56        /* Clear PME Status if set. */
  57        if (pci_dev->pme_support)
  58                pci_check_pme_status(pci_dev);
  59
  60        if (pci_dev->pme_poll)
  61                pci_dev->pme_poll = false;
  62
  63        pci_wakeup_event(pci_dev);
  64        pm_runtime_resume(&pci_dev->dev);
  65
  66        if (pci_dev->subordinate)
  67                pci_pme_wakeup_bus(pci_dev->subordinate);
  68}
  69
  70/**
  71 * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus.
  72 * @dev: ACPI device to add the notifier for.
  73 * @pci_bus: PCI bus to walk checking for PME status if an event is signaled.
  74 */
  75acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev,
  76                                         struct pci_bus *pci_bus)
  77{
  78        return acpi_add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus);
  79}
  80
  81/**
  82 * pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier.
  83 * @dev: ACPI device to remove the notifier from.
  84 */
  85acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev)
  86{
  87        return acpi_remove_pm_notifier(dev, pci_acpi_wake_bus);
  88}
  89
  90/**
  91 * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
  92 * @dev: ACPI device to add the notifier for.
  93 * @pci_dev: PCI device to check for the PME status if an event is signaled.
  94 */
  95acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
  96                                     struct pci_dev *pci_dev)
  97{
  98        return acpi_add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev);
  99}
 100
 101/**
 102 * pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier.
 103 * @dev: ACPI device to remove the notifier from.
 104 */
 105acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev)
 106{
 107        return acpi_remove_pm_notifier(dev, pci_acpi_wake_dev);
 108}
 109
 110phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle)
 111{
 112        acpi_status status = AE_NOT_EXIST;
 113        unsigned long long mcfg_addr;
 114
 115        if (handle)
 116                status = acpi_evaluate_integer(handle, METHOD_NAME__CBA,
 117                                               NULL, &mcfg_addr);
 118        if (ACPI_FAILURE(status))
 119                return 0;
 120
 121        return (phys_addr_t)mcfg_addr;
 122}
 123
 124/*
 125 * _SxD returns the D-state with the highest power
 126 * (lowest D-state number) supported in the S-state "x".
 127 *
 128 * If the devices does not have a _PRW
 129 * (Power Resources for Wake) supporting system wakeup from "x"
 130 * then the OS is free to choose a lower power (higher number
 131 * D-state) than the return value from _SxD.
 132 *
 133 * But if _PRW is enabled at S-state "x", the OS
 134 * must not choose a power lower than _SxD --
 135 * unless the device has an _SxW method specifying
 136 * the lowest power (highest D-state number) the device
 137 * may enter while still able to wake the system.
 138 *
 139 * ie. depending on global OS policy:
 140 *
 141 * if (_PRW at S-state x)
 142 *      choose from highest power _SxD to lowest power _SxW
 143 * else // no _PRW at S-state x
 144 *      choose highest power _SxD or any lower power
 145 */
 146
 147static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
 148{
 149        int acpi_state, d_max;
 150
 151        if (pdev->no_d3cold)
 152                d_max = ACPI_STATE_D3_HOT;
 153        else
 154                d_max = ACPI_STATE_D3_COLD;
 155        acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max);
 156        if (acpi_state < 0)
 157                return PCI_POWER_ERROR;
 158
 159        switch (acpi_state) {
 160        case ACPI_STATE_D0:
 161                return PCI_D0;
 162        case ACPI_STATE_D1:
 163                return PCI_D1;
 164        case ACPI_STATE_D2:
 165                return PCI_D2;
 166        case ACPI_STATE_D3_HOT:
 167                return PCI_D3hot;
 168        case ACPI_STATE_D3_COLD:
 169                return PCI_D3cold;
 170        }
 171        return PCI_POWER_ERROR;
 172}
 173
 174static bool acpi_pci_power_manageable(struct pci_dev *dev)
 175{
 176        acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 177
 178        return handle ? acpi_bus_power_manageable(handle) : false;
 179}
 180
 181static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 182{
 183        acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 184        acpi_handle tmp;
 185        static const u8 state_conv[] = {
 186                [PCI_D0] = ACPI_STATE_D0,
 187                [PCI_D1] = ACPI_STATE_D1,
 188                [PCI_D2] = ACPI_STATE_D2,
 189                [PCI_D3hot] = ACPI_STATE_D3,
 190                [PCI_D3cold] = ACPI_STATE_D3
 191        };
 192        int error = -EINVAL;
 193
 194        /* If the ACPI device has _EJ0, ignore the device */
 195        if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
 196                return -ENODEV;
 197
 198        switch (state) {
 199        case PCI_D3cold:
 200                if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
 201                                PM_QOS_FLAGS_ALL) {
 202                        error = -EBUSY;
 203                        break;
 204                }
 205        case PCI_D0:
 206        case PCI_D1:
 207        case PCI_D2:
 208        case PCI_D3hot:
 209                error = acpi_bus_set_power(handle, state_conv[state]);
 210        }
 211
 212        if (!error)
 213                dev_info(&dev->dev, "power state changed by ACPI to %s\n",
 214                         pci_power_name(state));
 215
 216        return error;
 217}
 218
 219static bool acpi_pci_can_wakeup(struct pci_dev *dev)
 220{
 221        acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 222
 223        return handle ? acpi_bus_can_wakeup(handle) : false;
 224}
 225
 226static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable)
 227{
 228        while (bus->parent) {
 229                if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable))
 230                        return;
 231                bus = bus->parent;
 232        }
 233
 234        /* We have reached the root bus. */
 235        if (bus->bridge)
 236                acpi_pm_device_sleep_wake(bus->bridge, enable);
 237}
 238
 239static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
 240{
 241        if (acpi_pci_can_wakeup(dev))
 242                return acpi_pm_device_sleep_wake(&dev->dev, enable);
 243
 244        acpi_pci_propagate_wakeup_enable(dev->bus, enable);
 245        return 0;
 246}
 247
 248static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable)
 249{
 250        while (bus->parent) {
 251                struct pci_dev *bridge = bus->self;
 252
 253                if (bridge->pme_interrupt)
 254                        return;
 255                if (!acpi_pm_device_run_wake(&bridge->dev, enable))
 256                        return;
 257                bus = bus->parent;
 258        }
 259
 260        /* We have reached the root bus. */
 261        if (bus->bridge)
 262                acpi_pm_device_run_wake(bus->bridge, enable);
 263}
 264
 265static int acpi_pci_run_wake(struct pci_dev *dev, bool enable)
 266{
 267        /*
 268         * Per PCI Express Base Specification Revision 2.0 section
 269         * 5.3.3.2 Link Wakeup, platform support is needed for D3cold
 270         * waking up to power on the main link even if there is PME
 271         * support for D3cold
 272         */
 273        if (dev->pme_interrupt && !dev->runtime_d3cold)
 274                return 0;
 275
 276        if (!acpi_pm_device_run_wake(&dev->dev, enable))
 277                return 0;
 278
 279        acpi_pci_propagate_run_wake(dev->bus, enable);
 280        return 0;
 281}
 282
 283static struct pci_platform_pm_ops acpi_pci_platform_pm = {
 284        .is_manageable = acpi_pci_power_manageable,
 285        .set_state = acpi_pci_set_power_state,
 286        .choose_state = acpi_pci_choose_state,
 287        .sleep_wake = acpi_pci_sleep_wake,
 288        .run_wake = acpi_pci_run_wake,
 289};
 290
 291void acpi_pci_add_bus(struct pci_bus *bus)
 292{
 293        acpi_handle handle = NULL;
 294
 295        if (bus->bridge)
 296                handle = ACPI_HANDLE(bus->bridge);
 297        if (acpi_pci_disabled || handle == NULL)
 298                return;
 299
 300        acpi_pci_slot_enumerate(bus, handle);
 301        acpiphp_enumerate_slots(bus, handle);
 302}
 303
 304void acpi_pci_remove_bus(struct pci_bus *bus)
 305{
 306        /*
 307         * bus->bridge->acpi_node.handle has already been reset to NULL
 308         * when acpi_pci_remove_bus() is called, so don't check ACPI handle.
 309         */
 310        if (acpi_pci_disabled)
 311                return;
 312
 313        acpiphp_remove_slots(bus);
 314        acpi_pci_slot_remove(bus);
 315}
 316
 317/* ACPI bus type */
 318static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
 319{
 320        struct pci_dev * pci_dev;
 321        u64     addr;
 322
 323        pci_dev = to_pci_dev(dev);
 324        /* Please ref to ACPI spec for the syntax of _ADR */
 325        addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
 326        *handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr);
 327        if (!*handle)
 328                return -ENODEV;
 329        return 0;
 330}
 331
 332static void pci_acpi_setup(struct device *dev)
 333{
 334        struct pci_dev *pci_dev = to_pci_dev(dev);
 335        acpi_handle handle = ACPI_HANDLE(dev);
 336        struct acpi_device *adev;
 337
 338        if (acpi_bus_get_device(handle, &adev) || !adev->wakeup.flags.valid)
 339                return;
 340
 341        device_set_wakeup_capable(dev, true);
 342        acpi_pci_sleep_wake(pci_dev, false);
 343
 344        pci_acpi_add_pm_notifier(adev, pci_dev);
 345        if (adev->wakeup.flags.run_wake)
 346                device_set_run_wake(dev, true);
 347}
 348
 349static void pci_acpi_cleanup(struct device *dev)
 350{
 351        acpi_handle handle = ACPI_HANDLE(dev);
 352        struct acpi_device *adev;
 353
 354        if (!acpi_bus_get_device(handle, &adev) && adev->wakeup.flags.valid) {
 355                device_set_wakeup_capable(dev, false);
 356                device_set_run_wake(dev, false);
 357                pci_acpi_remove_pm_notifier(adev);
 358        }
 359}
 360
 361static bool pci_acpi_bus_match(struct device *dev)
 362{
 363        return dev->bus == &pci_bus_type;
 364}
 365
 366static struct acpi_bus_type acpi_pci_bus = {
 367        .name = "PCI",
 368        .match = pci_acpi_bus_match,
 369        .find_device = acpi_pci_find_device,
 370        .setup = pci_acpi_setup,
 371        .cleanup = pci_acpi_cleanup,
 372};
 373
 374static int __init acpi_pci_init(void)
 375{
 376        int ret;
 377
 378        if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
 379                printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
 380                pci_no_msi();
 381        }
 382
 383        if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 384                printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
 385                pcie_no_aspm();
 386        }
 387
 388        ret = register_acpi_bus_type(&acpi_pci_bus);
 389        if (ret)
 390                return 0;
 391
 392        pci_set_platform_pm(&acpi_pci_platform_pm);
 393        acpi_pci_slot_init();
 394        acpiphp_init();
 395
 396        return 0;
 397}
 398arch_initcall(acpi_pci_init);
 399
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