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         case ACPI_STATE_D3_COLD:
 199                 return PCI_D3cold;
 200         }
 201         return PCI_POWER_ERROR;
 202 }
 203
 204 static bool acpi_pci_power_manageable(struct pci_dev *dev)
 205 {
 206         acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 207
 208         return handle ? acpi_bus_power_manageable(handle) : false;
 209 }
 210
 211 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 212 {
 213         acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 214         acpi_handle tmp;
 215         static const u8 state_conv[] = {
 216                 [PCI_D0] = ACPI_STATE_D0,
 217                 [PCI_D1] = ACPI_STATE_D1,
 218                 [PCI_D2] = ACPI_STATE_D2,
 219                 [PCI_D3hot] = ACPI_STATE_D3,
 220                 [PCI_D3cold] = ACPI_STATE_D3
 221         };
 222         int error = -EINVAL;
 223
 224         /* If the ACPI device has _EJ0, ignore the device */
 225         if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
 226                 return -ENODEV;
 227
 228         switch (state) {
 229         case PCI_D0:
 230         case PCI_D1:
 231         case PCI_D2:
 232         case PCI_D3hot:
 233         case PCI_D3cold:
 234                 error = acpi_bus_set_power(handle, state_conv[state]);
 235         }
 236
 237         if (!error)
 238                 dev_printk(KERN_INFO, &dev->dev,
 239                                 "power state changed by ACPI to D%d\n", state);
 240
 241         return error;
 242 }
 243
 244 static bool acpi_pci_can_wakeup(struct pci_dev *dev)
 245 {
 246         acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 247
 248         return handle ? acpi_bus_can_wakeup(handle) : false;
 249 }
 250
 251 static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable)
 252 {
 253         while (bus->parent) {
 254                 if (!acpi_pm_device_sleep_wake(&bus->self->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_sleep_wake(bus->bridge, enable);
 262 }
 263
 264 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
 265 {
 266         if (acpi_pci_can_wakeup(dev))
 267                 return acpi_pm_device_sleep_wake(&dev->dev, enable);
 268
 269         acpi_pci_propagate_wakeup_enable(dev->bus, enable);
 270         return 0;
 271 }
 272
 273 /**
 274  * acpi_dev_run_wake - Enable/disable wake-up for given device.
 275  * @phys_dev: Device to enable/disable the platform to wake-up the system for.
 276  * @enable: Whether enable or disable the wake-up functionality.
 277  *
 278  * Find the ACPI device object corresponding to @pci_dev and try to
 279  * enable/disable the GPE associated with it.
 280  */
 281 static int acpi_dev_run_wake(struct device *phys_dev, bool enable)
 282 {
 283         struct acpi_device *dev;
 284         acpi_handle handle;
 285         int error = -ENODEV;
 286
 287         if (!device_run_wake(phys_dev))
 288                 return -EINVAL;
 289
 290         handle = DEVICE_ACPI_HANDLE(phys_dev);
 291         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &dev))) {
 292                 dev_dbg(phys_dev, "ACPI handle has no context in %s!\n",
 293                         __func__);
 294                 return -ENODEV;
 295         }
 296
 297         if (enable) {
 298                 acpi_enable_wakeup_device_power(dev, ACPI_STATE_S0);
 299                 acpi_enable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number);
 300         } else {
 301                 acpi_disable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number);
 302                 acpi_disable_wakeup_device_power(dev);
 303         }
 304
 305         return error;
 306 }
 307
 308 static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable)
 309 {
 310         while (bus->parent) {
 311                 struct pci_dev *bridge = bus->self;
 312
 313                 if (bridge->pme_interrupt)
 314                         return;
 315                 if (!acpi_dev_run_wake(&bridge->dev, enable))
 316                         return;
 317                 bus = bus->parent;
 318         }
 319
 320         /* We have reached the root bus. */
 321         if (bus->bridge)
 322                 acpi_dev_run_wake(bus->bridge, enable);
 323 }
 324
 325 static int acpi_pci_run_wake(struct pci_dev *dev, bool enable)
 326 {
 327         if (dev->pme_interrupt)
 328                 return 0;
 329
 330         if (!acpi_dev_run_wake(&dev->dev, enable))
 331                 return 0;
 332
 333         acpi_pci_propagate_run_wake(dev->bus, enable);
 334         return 0;
 335 }
 336
 337 static struct pci_platform_pm_ops acpi_pci_platform_pm = {
 338         .is_manageable = acpi_pci_power_manageable,
 339         .set_state = acpi_pci_set_power_state,
 340         .choose_state = acpi_pci_choose_state,
 341         .can_wakeup = acpi_pci_can_wakeup,
 342         .sleep_wake = acpi_pci_sleep_wake,
 343         .run_wake = acpi_pci_run_wake,
 344 };
 345
 346 /* ACPI bus type */
 347 static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
 348 {
 349         struct pci_dev * pci_dev;
 350         u64     addr;
 351
 352         pci_dev = to_pci_dev(dev);
 353         /* Please ref to ACPI spec for the syntax of _ADR */
 354         addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
 355         *handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr);
 356         if (!*handle)
 357                 return -ENODEV;
 358         return 0;
 359 }
 360
 361 static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle)
 362 {
 363         int num;
 364         unsigned int seg, bus;
 365
 366         /*
 367          * The string should be the same as root bridge's name
 368          * Please look at 'pci_scan_bus_parented'
 369          */
 370         num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus);
 371         if (num != 2)
 372                 return -ENODEV;
 373         *handle = acpi_get_pci_rootbridge_handle(seg, bus);
 374         if (!*handle)
 375                 return -ENODEV;
 376         return 0;
 377 }
 378
 379 static struct acpi_bus_type acpi_pci_bus = {
 380         .bus = &pci_bus_type,
 381         .find_device = acpi_pci_find_device,
 382         .find_bridge = acpi_pci_find_root_bridge,
 383 };
 384
 385 static int __init acpi_pci_init(void)
 386 {
 387         int ret;
 388
 389         if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
 390                 printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
 391                 pci_no_msi();
 392         }
 393
 394         if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 395                 printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
 396                 pcie_clear_aspm();
 397                 pcie_no_aspm();
 398         }
 399
 400         ret = register_acpi_bus_type(&acpi_pci_bus);
 401         if (ret)
 402                 return 0;
 403         pci_set_platform_pm(&acpi_pci_platform_pm);
 404         return 0;
 405 }
 406 arch_initcall(acpi_pci_init);