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 "pci.h"
  21
  22static DEFINE_MUTEX(pci_acpi_pm_notify_mtx);
  23
  24/**
  25 * pci_acpi_wake_bus - Wake-up notification handler for root buses.
  26 * @handle: ACPI handle of a device the notification is for.
  27 * @event: Type of the signaled event.
  28 * @context: PCI root bus to wake up devices on.
  29 */
  30static void pci_acpi_wake_bus(acpi_handle handle, u32 event, void *context)
  31{
  32        struct pci_bus *pci_bus = context;
  33
  34        if (event == ACPI_NOTIFY_DEVICE_WAKE && pci_bus)
  35                pci_pme_wakeup_bus(pci_bus);
  36}
  37
  38/**
  39 * pci_acpi_wake_dev - Wake-up notification handler for PCI devices.
  40 * @handle: ACPI handle of a device the notification is for.
  41 * @event: Type of the signaled event.
  42 * @context: PCI device object to wake up.
  43 */
  44static void pci_acpi_wake_dev(acpi_handle handle, u32 event, void *context)
  45{
  46        struct pci_dev *pci_dev = context;
  47
  48        if (event != ACPI_NOTIFY_DEVICE_WAKE || !pci_dev)
  49                return;
  50
  51        if (pci_dev->current_state == PCI_D3cold) {
  52                pci_wakeup_event(pci_dev);
  53                pm_runtime_resume(&pci_dev->dev);
  54                return;
  55        }
  56
  57        if (!pci_dev->pm_cap || !pci_dev->pme_support
  58             || pci_check_pme_status(pci_dev)) {
  59                if (pci_dev->pme_poll)
  60                        pci_dev->pme_poll = false;
  61
  62                pci_wakeup_event(pci_dev);
  63                pm_runtime_resume(&pci_dev->dev);
  64        }
  65
  66        if (pci_dev->subordinate)
  67                pci_pme_wakeup_bus(pci_dev->subordinate);
  68}
  69
  70/**
  71 * add_pm_notifier - Register PM notifier for given ACPI device.
  72 * @dev: ACPI device to add the notifier for.
  73 * @context: PCI device or bus to check for PME status if an event is signaled.
  74 *
  75 * NOTE: @dev need not be a run-wake or wake-up device to be a valid source of
  76 * PM wake-up events.  For example, wake-up events may be generated for bridges
  77 * if one of the devices below the bridge is signaling PME, even if the bridge
  78 * itself doesn't have a wake-up GPE associated with it.
  79 */
  80static acpi_status add_pm_notifier(struct acpi_device *dev,
  81                                   acpi_notify_handler handler,
  82                                   void *context)
  83{
  84        acpi_status status = AE_ALREADY_EXISTS;
  85
  86        mutex_lock(&pci_acpi_pm_notify_mtx);
  87
  88        if (dev->wakeup.flags.notifier_present)
  89                goto out;
  90
  91        status = acpi_install_notify_handler(dev->handle,
  92                                             ACPI_SYSTEM_NOTIFY,
  93                                             handler, context);
  94        if (ACPI_FAILURE(status))
  95                goto out;
  96
  97        dev->wakeup.flags.notifier_present = true;
  98
  99 out:
 100        mutex_unlock(&pci_acpi_pm_notify_mtx);
 101        return status;
 102}
 103
 104/**
 105 * remove_pm_notifier - Unregister PM notifier from given ACPI device.
 106 * @dev: ACPI device to remove the notifier from.
 107 */
 108static acpi_status remove_pm_notifier(struct acpi_device *dev,
 109                                      acpi_notify_handler handler)
 110{
 111        acpi_status status = AE_BAD_PARAMETER;
 112
 113        mutex_lock(&pci_acpi_pm_notify_mtx);
 114
 115        if (!dev->wakeup.flags.notifier_present)
 116                goto out;
 117
 118        status = acpi_remove_notify_handler(dev->handle,
 119                                            ACPI_SYSTEM_NOTIFY,
 120                                            handler);
 121        if (ACPI_FAILURE(status))
 122                goto out;
 123
 124        dev->wakeup.flags.notifier_present = false;
 125
 126 out:
 127        mutex_unlock(&pci_acpi_pm_notify_mtx);
 128        return status;
 129}
 130
 131/**
 132 * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus.
 133 * @dev: ACPI device to add the notifier for.
 134 * @pci_bus: PCI bus to walk checking for PME status if an event is signaled.
 135 */
 136acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev,
 137                                         struct pci_bus *pci_bus)
 138{
 139        return add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus);
 140}
 141
 142/**
 143 * pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier.
 144 * @dev: ACPI device to remove the notifier from.
 145 */
 146acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev)
 147{
 148        return remove_pm_notifier(dev, pci_acpi_wake_bus);
 149}
 150
 151/**
 152 * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
 153 * @dev: ACPI device to add the notifier for.
 154 * @pci_dev: PCI device to check for the PME status if an event is signaled.
 155 */
 156acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
 157                                     struct pci_dev *pci_dev)
 158{
 159        return add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev);
 160}
 161
 162/**
 163 * pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier.
 164 * @dev: ACPI device to remove the notifier from.
 165 */
 166acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev)
 167{
 168        return remove_pm_notifier(dev, pci_acpi_wake_dev);
 169}
 170
 171phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle)
 172{
 173        acpi_status status = AE_NOT_EXIST;
 174        unsigned long long mcfg_addr;
 175
 176        if (handle)
 177                status = acpi_evaluate_integer(handle, METHOD_NAME__CBA,
 178                                               NULL, &mcfg_addr);
 179        if (ACPI_FAILURE(status))
 180                return 0;
 181
 182        return (phys_addr_t)mcfg_addr;
 183}
 184
 185/*
 186 * _SxD returns the D-state with the highest power
 187 * (lowest D-state number) supported in the S-state "x".
 188 *
 189 * If the devices does not have a _PRW
 190 * (Power Resources for Wake) supporting system wakeup from "x"
 191 * then the OS is free to choose a lower power (higher number
 192 * D-state) than the return value from _SxD.
 193 *
 194 * But if _PRW is enabled at S-state "x", the OS
 195 * must not choose a power lower than _SxD --
 196 * unless the device has an _SxW method specifying
 197 * the lowest power (highest D-state number) the device
 198 * may enter while still able to wake the system.
 199 *
 200 * ie. depending on global OS policy:
 201 *
 202 * if (_PRW at S-state x)
 203 *      choose from highest power _SxD to lowest power _SxW
 204 * else // no _PRW at S-state x
 205 *      choose highest power _SxD or any lower power
 206 */
 207
 208static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
 209{
 210        int acpi_state, d_max;
 211
 212        if (pdev->no_d3cold)
 213                d_max = ACPI_STATE_D3_HOT;
 214        else
 215                d_max = ACPI_STATE_D3_COLD;
 216        acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max);
 217        if (acpi_state < 0)
 218                return PCI_POWER_ERROR;
 219
 220        switch (acpi_state) {
 221        case ACPI_STATE_D0:
 222                return PCI_D0;
 223        case ACPI_STATE_D1:
 224                return PCI_D1;
 225        case ACPI_STATE_D2:
 226                return PCI_D2;
 227        case ACPI_STATE_D3_HOT:
 228                return PCI_D3hot;
 229        case ACPI_STATE_D3_COLD:
 230                return PCI_D3cold;
 231        }
 232        return PCI_POWER_ERROR;
 233}
 234
 235static bool acpi_pci_power_manageable(struct pci_dev *dev)
 236{
 237        acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 238
 239        return handle ? acpi_bus_power_manageable(handle) : false;
 240}
 241
 242static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 243{
 244        acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 245        acpi_handle tmp;
 246        static const u8 state_conv[] = {
 247                [PCI_D0] = ACPI_STATE_D0,
 248                [PCI_D1] = ACPI_STATE_D1,
 249                [PCI_D2] = ACPI_STATE_D2,
 250                [PCI_D3hot] = ACPI_STATE_D3,
 251                [PCI_D3cold] = ACPI_STATE_D3
 252        };
 253        int error = -EINVAL;
 254
 255        /* If the ACPI device has _EJ0, ignore the device */
 256        if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
 257                return -ENODEV;
 258
 259        switch (state) {
 260        case PCI_D0:
 261        case PCI_D1:
 262        case PCI_D2:
 263        case PCI_D3hot:
 264        case PCI_D3cold:
 265                error = acpi_bus_set_power(handle, state_conv[state]);
 266        }
 267
 268        if (!error)
 269                dev_info(&dev->dev, "power state changed by ACPI to %s\n",
 270                         pci_power_name(state));
 271
 272        return error;
 273}
 274
 275static bool acpi_pci_can_wakeup(struct pci_dev *dev)
 276{
 277        acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 278
 279        return handle ? acpi_bus_can_wakeup(handle) : false;
 280}
 281
 282static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable)
 283{
 284        while (bus->parent) {
 285                if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable))
 286                        return;
 287                bus = bus->parent;
 288        }
 289
 290        /* We have reached the root bus. */
 291        if (bus->bridge)
 292                acpi_pm_device_sleep_wake(bus->bridge, enable);
 293}
 294
 295static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
 296{
 297        if (acpi_pci_can_wakeup(dev))
 298                return acpi_pm_device_sleep_wake(&dev->dev, enable);
 299
 300        acpi_pci_propagate_wakeup_enable(dev->bus, enable);
 301        return 0;
 302}
 303
 304static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable)
 305{
 306        while (bus->parent) {
 307                struct pci_dev *bridge = bus->self;
 308
 309                if (bridge->pme_interrupt)
 310                        return;
 311                if (!acpi_pm_device_run_wake(&bridge->dev, enable))
 312                        return;
 313                bus = bus->parent;
 314        }
 315
 316        /* We have reached the root bus. */
 317        if (bus->bridge)
 318                acpi_pm_device_run_wake(bus->bridge, enable);
 319}
 320
 321static int acpi_pci_run_wake(struct pci_dev *dev, bool enable)
 322{
 323        /*
 324         * Per PCI Express Base Specification Revision 2.0 section
 325         * 5.3.3.2 Link Wakeup, platform support is needed for D3cold
 326         * waking up to power on the main link even if there is PME
 327         * support for D3cold
 328         */
 329        if (dev->pme_interrupt && !dev->runtime_d3cold)
 330                return 0;
 331
 332        if (!acpi_pm_device_run_wake(&dev->dev, enable))
 333                return 0;
 334
 335        acpi_pci_propagate_run_wake(dev->bus, enable);
 336        return 0;
 337}
 338
 339static struct pci_platform_pm_ops acpi_pci_platform_pm = {
 340        .is_manageable = acpi_pci_power_manageable,
 341        .set_state = acpi_pci_set_power_state,
 342        .choose_state = acpi_pci_choose_state,
 343        .can_wakeup = acpi_pci_can_wakeup,
 344        .sleep_wake = acpi_pci_sleep_wake,
 345        .run_wake = acpi_pci_run_wake,
 346};
 347
 348/* ACPI bus type */
 349static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
 350{
 351        struct pci_dev * pci_dev;
 352        u64     addr;
 353
 354        pci_dev = to_pci_dev(dev);
 355        /* Please ref to ACPI spec for the syntax of _ADR */
 356        addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
 357        *handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr);
 358        if (!*handle)
 359                return -ENODEV;
 360        return 0;
 361}
 362
 363static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle)
 364{
 365        int num;
 366        unsigned int seg, bus;
 367
 368        /*
 369         * The string should be the same as root bridge's name
 370         * Please look at 'pci_scan_bus_parented'
 371         */
 372        num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus);
 373        if (num != 2)
 374                return -ENODEV;
 375        *handle = acpi_get_pci_rootbridge_handle(seg, bus);
 376        if (!*handle)
 377                return -ENODEV;
 378        return 0;
 379}
 380
 381static struct acpi_bus_type acpi_pci_bus = {
 382        .bus = &pci_bus_type,
 383        .find_device = acpi_pci_find_device,
 384        .find_bridge = acpi_pci_find_root_bridge,
 385};
 386
 387static int __init acpi_pci_init(void)
 388{
 389        int ret;
 390
 391        if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
 392                printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
 393                pci_no_msi();
 394        }
 395
 396        if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 397                printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
 398                pcie_no_aspm();
 399        }
 400
 401        ret = register_acpi_bus_type(&acpi_pci_bus);
 402        if (ret)
 403                return 0;
 404        pci_set_platform_pm(&acpi_pci_platform_pm);
 405        return 0;
 406}
 407arch_initcall(acpi_pci_init);
 408
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