drivers/pci/pci-acpi.c

   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
  22 static 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  */
  30 static 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  */
  44 static 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                 if (pci_dev->pme_poll)
  50                         pci_dev->pme_poll = false;
  51
  52                 pci_wakeup_event(pci_dev);
  53                 pci_check_pme_status(pci_dev);
  54                 pm_runtime_resume(&pci_dev->dev);
  55                 if (pci_dev->subordinate)
  56                         pci_pme_wakeup_bus(pci_dev->subordinate);
  57         }
  58 }
  59
  60 /**
  61  * add_pm_notifier - Register PM notifier for given ACPI device.
  62  * @dev: ACPI device to add the notifier for.
  63  * @context: PCI device or bus to check for PME status if an event is signaled.
  64  *
  65  * NOTE: @dev need not be a run-wake or wake-up device to be a valid source of
  66  * PM wake-up events.  For example, wake-up events may be generated for bridges
  67  * if one of the devices below the bridge is signaling PME, even if the bridge
  68  * itself doesn't have a wake-up GPE associated with it.
  69  */
  70 static acpi_status add_pm_notifier(struct acpi_device *dev,
  71                                    acpi_notify_handler handler,
  72                                    void *context)
  73 {
  74         acpi_status status = AE_ALREADY_EXISTS;
  75
  76         mutex_lock(&pci_acpi_pm_notify_mtx);
  77
  78         if (dev->wakeup.flags.notifier_present)
  79                 goto out;
  80
  81         status = acpi_install_notify_handler(dev->handle,
  82                                              ACPI_SYSTEM_NOTIFY,
  83                                              handler, context);
  84         if (ACPI_FAILURE(status))
  85                 goto out;
  86
  87         dev->wakeup.flags.notifier_present = true;
  88
  89  out:
  90         mutex_unlock(&pci_acpi_pm_notify_mtx);
  91         return status;
  92 }
  93
  94 /**
  95  * remove_pm_notifier - Unregister PM notifier from given ACPI device.
  96  * @dev: ACPI device to remove the notifier from.
  97  */
  98 static acpi_status remove_pm_notifier(struct acpi_device *dev,
  99                                       acpi_notify_handler handler)
 100 {
 101         acpi_status status = AE_BAD_PARAMETER;
 102
 103         mutex_lock(&pci_acpi_pm_notify_mtx);
 104
 105         if (!dev->wakeup.flags.notifier_present)
 106                 goto out;
 107
 108         status = acpi_remove_notify_handler(dev->handle,
 109                                             ACPI_SYSTEM_NOTIFY,
 110                                             handler);
 111         if (ACPI_FAILURE(status))
 112                 goto out;
 113
 114         dev->wakeup.flags.notifier_present = false;
 115
 116  out:
 117         mutex_unlock(&pci_acpi_pm_notify_mtx);
 118         return status;
 119 }
 120
 121 /**
 122  * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus.
 123  * @dev: ACPI device to add the notifier for.
 124  * @pci_bus: PCI bus to walk checking for PME status if an event is signaled.
 125  */
 126 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev,
 127                                          struct pci_bus *pci_bus)
 128 {
 129         return add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus);
 130 }
 131
 132 /**
 133  * pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier.
 134  * @dev: ACPI device to remove the notifier from.
 135  */
 136 acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev)
 137 {
 138         return remove_pm_notifier(dev, pci_acpi_wake_bus);
 139 }
 140
 141 /**
 142  * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
 143  * @dev: ACPI device to add the notifier for.
 144  * @pci_dev: PCI device to check for the PME status if an event is signaled.
 145  */
 146 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
 147                                      struct pci_dev *pci_dev)
 148 {
 149         return add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev);
 150 }
 151
 152 /**
 153  * pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier.
 154  * @dev: ACPI device to remove the notifier from.
 155  */
 156 acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev)
 157 {
 158         return remove_pm_notifier(dev, pci_acpi_wake_dev);
 159 }
 160
 161 /*
 162  * _SxD returns the D-state with the highest power
 163  * (lowest D-state number) supported in the S-state "x".
 164  *
 165  * If the devices does not have a _PRW
 166  * (Power Resources for Wake) supporting system wakeup from "x"
 167  * then the OS is free to choose a lower power (higher number
 168  * D-state) than the return value from _SxD.
 169  *
 170  * But if _PRW is enabled at S-state "x", the OS
 171  * must not choose a power lower than _SxD --
 172  * unless the device has an _SxW method specifying
 173  * the lowest power (highest D-state number) the device
 174  * may enter while still able to wake the system.
 175  *
 176  * ie. depending on global OS policy:
 177  *
 178  * if (_PRW at S-state x)
 179  *      choose from highest power _SxD to lowest power _SxW
 180  * else // no _PRW at S-state x
 181  *      choose highest power _SxD or any lower power
 182  */
 183
 184 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
 185 {
 186         int acpi_state;
 187
 188         acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL);
 189         if (acpi_state < 0)
 190                 return PCI_POWER_ERROR;
 191
 192         switch (acpi_state) {
 193         case ACPI_STATE_D0:
 194                 return PCI_D0;
 195         case ACPI_STATE_D1:
 196                 return PCI_D1;
 197         case ACPI_STATE_D2:
 198                 return PCI_D2;
 199         case ACPI_STATE_D3:
 200                 return PCI_D3hot;
 201         case ACPI_STATE_D3_COLD:
 202                 return PCI_D3cold;
 203         }
 204         return PCI_POWER_ERROR;
 205 }
 206
 207 static bool acpi_pci_power_manageable(struct pci_dev *dev)
 208 {
 209         acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 210
 211         return handle ? acpi_bus_power_manageable(handle) : false;
 212 }
 213
 214 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 215 {
 216         acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 217         acpi_handle tmp;
 218         static const u8 state_conv[] = {
 219                 [PCI_D0] = ACPI_STATE_D0,
 220                 [PCI_D1] = ACPI_STATE_D1,
 221                 [PCI_D2] = ACPI_STATE_D2,
 222                 [PCI_D3hot] = ACPI_STATE_D3,
 223                 [PCI_D3cold] = ACPI_STATE_D3
 224         };
 225         int error = -EINVAL;
 226
 227         /* If the ACPI device has _EJ0, ignore the device */
 228         if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
 229                 return -ENODEV;
 230
 231         switch (state) {
 232         case PCI_D0:
 233         case PCI_D1:
 234         case PCI_D2:
 235         case PCI_D3hot:
 236         case PCI_D3cold:
 237                 error = acpi_bus_set_power(handle, state_conv[state]);
 238         }
 239
 240         if (!error)
 241                 dev_printk(KERN_INFO, &dev->dev,
 242                                 "power state changed by ACPI to D%d\n", state);
 243
 244         return error;
 245 }
 246
 247 static bool acpi_pci_can_wakeup(struct pci_dev *dev)
 248 {
 249         acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 250
 251         return handle ? acpi_bus_can_wakeup(handle) : false;
 252 }
 253
 254 static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable)
 255 {
 256         while (bus->parent) {
 257                 if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable))
 258                         return;
 259                 bus = bus->parent;
 260         }
 261
 262         /* We have reached the root bus. */
 263         if (bus->bridge)
 264                 acpi_pm_device_sleep_wake(bus->bridge, enable);
 265 }
 266
 267 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
 268 {
 269         if (acpi_pci_can_wakeup(dev))
 270                 return acpi_pm_device_sleep_wake(&dev->dev, enable);
 271
 272         acpi_pci_propagate_wakeup_enable(dev->bus, enable);
 273         return 0;
 274 }
 275
 276 /**
 277  * acpi_dev_run_wake - Enable/disable wake-up for given device.
 278  * @phys_dev: Device to enable/disable the platform to wake-up the system for.
 279  * @enable: Whether enable or disable the wake-up functionality.
 280  *
 281  * Find the ACPI device object corresponding to @pci_dev and try to
 282  * enable/disable the GPE associated with it.
 283  */
 284 static int acpi_dev_run_wake(struct device *phys_dev, bool enable)
 285 {
 286         struct acpi_device *dev;
 287         acpi_handle handle;
 288
 289         if (!device_run_wake(phys_dev))
 290                 return -EINVAL;
 291
 292         handle = DEVICE_ACPI_HANDLE(phys_dev);
 293         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &dev))) {
 294                 dev_dbg(phys_dev, "ACPI handle has no context in %s!\n",
 295                         __func__);
 296                 return -ENODEV;
 297         }
 298
 299         if (enable) {
 300                 acpi_enable_wakeup_device_power(dev, ACPI_STATE_S0);
 301                 acpi_enable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number);
 302         } else {
 303                 acpi_disable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number);
 304                 acpi_disable_wakeup_device_power(dev);
 305         }
 306
 307         return 0;
 308 }
 309
 310 static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable)
 311 {
 312         while (bus->parent) {
 313                 struct pci_dev *bridge = bus->self;
 314
 315                 if (bridge->pme_interrupt)
 316                         return;
 317                 if (!acpi_dev_run_wake(&bridge->dev, enable))
 318                         return;
 319                 bus = bus->parent;
 320         }
 321
 322         /* We have reached the root bus. */
 323         if (bus->bridge)
 324                 acpi_dev_run_wake(bus->bridge, enable);
 325 }
 326
 327 static int acpi_pci_run_wake(struct pci_dev *dev, bool enable)
 328 {
 329         if (dev->pme_interrupt)
 330                 return 0;
 331
 332         if (!acpi_dev_run_wake(&dev->dev, enable))
 333                 return 0;
 334
 335         acpi_pci_propagate_run_wake(dev->bus, enable);
 336         return 0;
 337 }
 338
 339 static 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 */
 349 static 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
 363 static 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
 381 static 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
 387 static 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_clear_aspm();
 399                 pcie_no_aspm();
 400         }
 401
 402         ret = register_acpi_bus_type(&acpi_pci_bus);
 403         if (ret)
 404                 return 0;
 405         pci_set_platform_pm(&acpi_pci_platform_pm);
 406         return 0;
 407 }
 408 arch_initcall(acpi_pci_init);