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