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