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                 pci_check_pme_status(pci_dev);
  50                 pm_runtime_resume(&pci_dev->dev);
  51                 if (pci_dev->subordinate)
  52                         pci_pme_wakeup_bus(pci_dev->subordinate);
  53         }
  54 }
  55
  56 /**
  57  * add_pm_notifier - Register PM notifier for given ACPI device.
  58  * @dev: ACPI device to add the notifier for.
  59  * @context: PCI device or bus to check for PME status if an event is signaled.
  60  *
  61  * NOTE: @dev need not be a run-wake or wake-up device to be a valid source of
  62  * PM wake-up events.  For example, wake-up events may be generated for bridges
  63  * if one of the devices below the bridge is signaling PME, even if the bridge
  64  * itself doesn't have a wake-up GPE associated with it.
  65  */
  66 static acpi_status add_pm_notifier(struct acpi_device *dev,
  67                                    acpi_notify_handler handler,
  68                                    void *context)
  69 {
  70         acpi_status status = AE_ALREADY_EXISTS;
  71
  72         mutex_lock(&pci_acpi_pm_notify_mtx);
  73
  74         if (dev->wakeup.flags.notifier_present)
  75                 goto out;
  76
  77         status = acpi_install_notify_handler(dev->handle,
  78                                              ACPI_SYSTEM_NOTIFY,
  79                                              handler, context);
  80         if (ACPI_FAILURE(status))
  81                 goto out;
  82
  83         dev->wakeup.flags.notifier_present = true;
  84
  85  out:
  86         mutex_unlock(&pci_acpi_pm_notify_mtx);
  87         return status;
  88 }
  89
  90 /**
  91  * remove_pm_notifier - Unregister PM notifier from given ACPI device.
  92  * @dev: ACPI device to remove the notifier from.
  93  */
  94 static acpi_status remove_pm_notifier(struct acpi_device *dev,
  95                                       acpi_notify_handler handler)
  96 {
  97         acpi_status status = AE_BAD_PARAMETER;
  98
  99         mutex_lock(&pci_acpi_pm_notify_mtx);
 100
 101         if (!dev->wakeup.flags.notifier_present)
 102                 goto out;
 103
 104         status = acpi_remove_notify_handler(dev->handle,
 105                                             ACPI_SYSTEM_NOTIFY,
 106                                             handler);
 107         if (ACPI_FAILURE(status))
 108                 goto out;
 109
 110         dev->wakeup.flags.notifier_present = false;
 111
 112  out:
 113         mutex_unlock(&pci_acpi_pm_notify_mtx);
 114         return status;
 115 }
 116
 117 /**
 118  * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus.
 119  * @dev: ACPI device to add the notifier for.
 120  * @pci_bus: PCI bus to walk checking for PME status if an event is signaled.
 121  */
 122 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev,
 123                                          struct pci_bus *pci_bus)
 124 {
 125         return add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus);
 126 }
 127
 128 /**
 129  * pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier.
 130  * @dev: ACPI device to remove the notifier from.
 131  */
 132 acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev)
 133 {
 134         return remove_pm_notifier(dev, pci_acpi_wake_bus);
 135 }
 136
 137 /**
 138  * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
 139  * @dev: ACPI device to add the notifier for.
 140  * @pci_dev: PCI device to check for the PME status if an event is signaled.
 141  */
 142 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
 143                                      struct pci_dev *pci_dev)
 144 {
 145         return add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev);
 146 }
 147
 148 /**
 149  * pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier.
 150  * @dev: ACPI device to remove the notifier from.
 151  */
 152 acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev)
 153 {
 154         return remove_pm_notifier(dev, pci_acpi_wake_dev);
 155 }
 156
 157 /*
 158  * _SxD returns the D-state with the highest power
 159  * (lowest D-state number) supported in the S-state "x".
 160  *
 161  * If the devices does not have a _PRW
 162  * (Power Resources for Wake) supporting system wakeup from "x"
 163  * then the OS is free to choose a lower power (higher number
 164  * D-state) than the return value from _SxD.
 165  *
 166  * But if _PRW is enabled at S-state "x", the OS
 167  * must not choose a power lower than _SxD --
 168  * unless the device has an _SxW method specifying
 169  * the lowest power (highest D-state number) the device
 170  * may enter while still able to wake the system.
 171  *
 172  * ie. depending on global OS policy:
 173  *
 174  * if (_PRW at S-state x)
 175  *      choose from highest power _SxD to lowest power _SxW
 176  * else // no _PRW at S-state x
 177  *      choose highest power _SxD or any lower power
 178  */
 179
 180 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
 181 {
 182         int acpi_state;
 183
 184         acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL);
 185         if (acpi_state < 0)
 186                 return PCI_POWER_ERROR;
 187
 188         switch (acpi_state) {
 189         case ACPI_STATE_D0:
 190                 return PCI_D0;
 191         case ACPI_STATE_D1:
 192                 return PCI_D1;
 193         case ACPI_STATE_D2:
 194                 return PCI_D2;
 195         case ACPI_STATE_D3:
 196                 return PCI_D3hot;
 197         }
 198         return PCI_POWER_ERROR;
 199 }
 200
 201 static bool acpi_pci_power_manageable(struct pci_dev *dev)
 202 {
 203         acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 204
 205         return handle ? acpi_bus_power_manageable(handle) : false;
 206 }
 207
 208 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 209 {
 210         acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 211         acpi_handle tmp;
 212         static const u8 state_conv[] = {
 213                 [PCI_D0] = ACPI_STATE_D0,
 214                 [PCI_D1] = ACPI_STATE_D1,
 215                 [PCI_D2] = ACPI_STATE_D2,
 216                 [PCI_D3hot] = ACPI_STATE_D3,
 217                 [PCI_D3cold] = ACPI_STATE_D3
 218         };
 219         int error = -EINVAL;
 220
 221         /* If the ACPI device has _EJ0, ignore the device */
 222         if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
 223                 return -ENODEV;
 224
 225         switch (state) {
 226         case PCI_D0:
 227         case PCI_D1:
 228         case PCI_D2:
 229         case PCI_D3hot:
 230         case PCI_D3cold:
 231                 error = acpi_bus_set_power(handle, state_conv[state]);
 232         }
 233
 234         if (!error)
 235                 dev_printk(KERN_INFO, &dev->dev,
 236                                 "power state changed by ACPI to D%d\n", state);
 237
 238         return error;
 239 }
 240
 241 static bool acpi_pci_can_wakeup(struct pci_dev *dev)
 242 {
 243         acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 244
 245         return handle ? acpi_bus_can_wakeup(handle) : false;
 246 }
 247
 248 static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable)
 249 {
 250         while (bus->parent) {
 251                 if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable))
 252                         return;
 253                 bus = bus->parent;
 254         }
 255
 256         /* We have reached the root bus. */
 257         if (bus->bridge)
 258                 acpi_pm_device_sleep_wake(bus->bridge, enable);
 259 }
 260
 261 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
 262 {
 263         if (acpi_pci_can_wakeup(dev))
 264                 return acpi_pm_device_sleep_wake(&dev->dev, enable);
 265
 266         acpi_pci_propagate_wakeup_enable(dev->bus, enable);
 267         return 0;
 268 }
 269
 270 /**
 271  * acpi_dev_run_wake - Enable/disable wake-up for given device.
 272  * @phys_dev: Device to enable/disable the platform to wake-up the system for.
 273  * @enable: Whether enable or disable the wake-up functionality.
 274  *
 275  * Find the ACPI device object corresponding to @pci_dev and try to
 276  * enable/disable the GPE associated with it.
 277  */
 278 static int acpi_dev_run_wake(struct device *phys_dev, bool enable)
 279 {
 280         struct acpi_device *dev;
 281         acpi_handle handle;
 282         int error = -ENODEV;
 283
 284         if (!device_run_wake(phys_dev))
 285                 return -EINVAL;
 286
 287         handle = DEVICE_ACPI_HANDLE(phys_dev);
 288         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &dev))) {
 289                 dev_dbg(phys_dev, "ACPI handle has no context in %s!\n",
 290                         __func__);
 291                 return -ENODEV;
 292         }
 293
 294         if (enable) {
 295                 if (!dev->wakeup.run_wake_count++) {
 296                         acpi_enable_wakeup_device_power(dev, ACPI_STATE_S0);
 297                         acpi_enable_gpe(dev->wakeup.gpe_device,
 298                                         dev->wakeup.gpe_number,
 299                                         ACPI_GPE_TYPE_RUNTIME);
 300                 }
 301         } else if (dev->wakeup.run_wake_count > 0) {
 302                 if (!--dev->wakeup.run_wake_count) {
 303                         acpi_disable_gpe(dev->wakeup.gpe_device,
 304                                          dev->wakeup.gpe_number,
 305                                          ACPI_GPE_TYPE_RUNTIME);
 306                         acpi_disable_wakeup_device_power(dev);
 307                 }
 308         } else {
 309                 error = -EALREADY;
 310         }
 311
 312         return error;
 313 }
 314
 315 static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable)
 316 {
 317         while (bus->parent) {
 318                 struct pci_dev *bridge = bus->self;
 319
 320                 if (bridge->pme_interrupt)
 321                         return;
 322                 if (!acpi_dev_run_wake(&bridge->dev, enable))
 323                         return;
 324                 bus = bus->parent;
 325         }
 326
 327         /* We have reached the root bus. */
 328         if (bus->bridge)
 329                 acpi_dev_run_wake(bus->bridge, enable);
 330 }
 331
 332 static int acpi_pci_run_wake(struct pci_dev *dev, bool enable)
 333 {
 334         if (dev->pme_interrupt)
 335                 return 0;
 336
 337         if (!acpi_dev_run_wake(&dev->dev, enable))
 338                 return 0;
 339
 340         acpi_pci_propagate_run_wake(dev->bus, enable);
 341         return 0;
 342 }
 343
 344 static struct pci_platform_pm_ops acpi_pci_platform_pm = {
 345         .is_manageable = acpi_pci_power_manageable,
 346         .set_state = acpi_pci_set_power_state,
 347         .choose_state = acpi_pci_choose_state,
 348         .can_wakeup = acpi_pci_can_wakeup,
 349         .sleep_wake = acpi_pci_sleep_wake,
 350         .run_wake = acpi_pci_run_wake,
 351 };
 352
 353 /* ACPI bus type */
 354 static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
 355 {
 356         struct pci_dev * pci_dev;
 357         u64     addr;
 358
 359         pci_dev = to_pci_dev(dev);
 360         /* Please ref to ACPI spec for the syntax of _ADR */
 361         addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
 362         *handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr);
 363         if (!*handle)
 364                 return -ENODEV;
 365         return 0;
 366 }
 367
 368 static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle)
 369 {
 370         int num;
 371         unsigned int seg, bus;
 372
 373         /*
 374          * The string should be the same as root bridge's name
 375          * Please look at 'pci_scan_bus_parented'
 376          */
 377         num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus);
 378         if (num != 2)
 379                 return -ENODEV;
 380         *handle = acpi_get_pci_rootbridge_handle(seg, bus);
 381         if (!*handle)
 382                 return -ENODEV;
 383         return 0;
 384 }
 385
 386 static struct acpi_bus_type acpi_pci_bus = {
 387         .bus = &pci_bus_type,
 388         .find_device = acpi_pci_find_device,
 389         .find_bridge = acpi_pci_find_root_bridge,
 390 };
 391
 392 static int __init acpi_pci_init(void)
 393 {
 394         int ret;
 395
 396         if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
 397                 printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
 398                 pci_no_msi();
 399         }
 400
 401         if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 402                 printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
 403                 pcie_no_aspm();
 404         }
 405
 406         ret = register_acpi_bus_type(&acpi_pci_bus);
 407         if (ret)
 408                 return 0;
 409         pci_set_platform_pm(&acpi_pci_platform_pm);
 410         return 0;
 411 }
 412 arch_initcall(acpi_pci_init);