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                 return;
  50
  51         if (!pci_dev->pm_cap || !pci_dev->pme_support
  52              || pci_check_pme_status(pci_dev)) {
  53                 if (pci_dev->pme_poll)
  54                         pci_dev->pme_poll = false;
  55
  56                 pci_wakeup_event(pci_dev);
  57                 pm_runtime_resume(&pci_dev->dev);
  58         }
  59
  60         if (pci_dev->subordinate)
  61                 pci_pme_wakeup_bus(pci_dev->subordinate);
  62 }
  63
  64 /**
  65  * add_pm_notifier - Register PM notifier for given ACPI device.
  66  * @dev: ACPI device to add the notifier for.
  67  * @context: PCI device or bus to check for PME status if an event is signaled.
  68  *
  69  * NOTE: @dev need not be a run-wake or wake-up device to be a valid source of
  70  * PM wake-up events.  For example, wake-up events may be generated for bridges
  71  * if one of the devices below the bridge is signaling PME, even if the bridge
  72  * itself doesn't have a wake-up GPE associated with it.
  73  */
  74 static acpi_status add_pm_notifier(struct acpi_device *dev,
  75                                    acpi_notify_handler handler,
  76                                    void *context)
  77 {
  78         acpi_status status = AE_ALREADY_EXISTS;
  79
  80         mutex_lock(&pci_acpi_pm_notify_mtx);
  81
  82         if (dev->wakeup.flags.notifier_present)
  83                 goto out;
  84
  85         status = acpi_install_notify_handler(dev->handle,
  86                                              ACPI_SYSTEM_NOTIFY,
  87                                              handler, context);
  88         if (ACPI_FAILURE(status))
  89                 goto out;
  90
  91         dev->wakeup.flags.notifier_present = true;
  92
  93  out:
  94         mutex_unlock(&pci_acpi_pm_notify_mtx);
  95         return status;
  96 }
  97
  98 /**
  99  * remove_pm_notifier - Unregister PM notifier from given ACPI device.
 100  * @dev: ACPI device to remove the notifier from.
 101  */
 102 static acpi_status remove_pm_notifier(struct acpi_device *dev,
 103                                       acpi_notify_handler handler)
 104 {
 105         acpi_status status = AE_BAD_PARAMETER;
 106
 107         mutex_lock(&pci_acpi_pm_notify_mtx);
 108
 109         if (!dev->wakeup.flags.notifier_present)
 110                 goto out;
 111
 112         status = acpi_remove_notify_handler(dev->handle,
 113                                             ACPI_SYSTEM_NOTIFY,
 114                                             handler);
 115         if (ACPI_FAILURE(status))
 116                 goto out;
 117
 118         dev->wakeup.flags.notifier_present = false;
 119
 120  out:
 121         mutex_unlock(&pci_acpi_pm_notify_mtx);
 122         return status;
 123 }
 124
 125 /**
 126  * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus.
 127  * @dev: ACPI device to add the notifier for.
 128  * @pci_bus: PCI bus to walk checking for PME status if an event is signaled.
 129  */
 130 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev,
 131                                          struct pci_bus *pci_bus)
 132 {
 133         return add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus);
 134 }
 135
 136 /**
 137  * pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier.
 138  * @dev: ACPI device to remove the notifier from.
 139  */
 140 acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev)
 141 {
 142         return remove_pm_notifier(dev, pci_acpi_wake_bus);
 143 }
 144
 145 /**
 146  * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
 147  * @dev: ACPI device to add the notifier for.
 148  * @pci_dev: PCI device to check for the PME status if an event is signaled.
 149  */
 150 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
 151                                      struct pci_dev *pci_dev)
 152 {
 153         return add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev);
 154 }
 155
 156 /**
 157  * pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier.
 158  * @dev: ACPI device to remove the notifier from.
 159  */
 160 acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev)
 161 {
 162         return remove_pm_notifier(dev, pci_acpi_wake_dev);
 163 }
 164
 165 /*
 166  * _SxD returns the D-state with the highest power
 167  * (lowest D-state number) supported in the S-state "x".
 168  *
 169  * If the devices does not have a _PRW
 170  * (Power Resources for Wake) supporting system wakeup from "x"
 171  * then the OS is free to choose a lower power (higher number
 172  * D-state) than the return value from _SxD.
 173  *
 174  * But if _PRW is enabled at S-state "x", the OS
 175  * must not choose a power lower than _SxD --
 176  * unless the device has an _SxW method specifying
 177  * the lowest power (highest D-state number) the device
 178  * may enter while still able to wake the system.
 179  *
 180  * ie. depending on global OS policy:
 181  *
 182  * if (_PRW at S-state x)
 183  *      choose from highest power _SxD to lowest power _SxW
 184  * else // no _PRW at S-state x
 185  *      choose highest power _SxD or any lower power
 186  */
 187
 188 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
 189 {
 190         int acpi_state;
 191
 192         acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL);
 193         if (acpi_state < 0)
 194                 return PCI_POWER_ERROR;
 195
 196         switch (acpi_state) {
 197         case ACPI_STATE_D0:
 198                 return PCI_D0;
 199         case ACPI_STATE_D1:
 200                 return PCI_D1;
 201         case ACPI_STATE_D2:
 202                 return PCI_D2;
 203         case ACPI_STATE_D3:
 204                 return PCI_D3hot;
 205         case ACPI_STATE_D3_COLD:
 206                 return PCI_D3cold;
 207         }
 208         return PCI_POWER_ERROR;
 209 }
 210
 211 static bool acpi_pci_power_manageable(struct pci_dev *dev)
 212 {
 213         acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 214
 215         return handle ? acpi_bus_power_manageable(handle) : false;
 216 }
 217
 218 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 219 {
 220         acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 221         acpi_handle tmp;
 222         static const u8 state_conv[] = {
 223                 [PCI_D0] = ACPI_STATE_D0,
 224                 [PCI_D1] = ACPI_STATE_D1,
 225                 [PCI_D2] = ACPI_STATE_D2,
 226                 [PCI_D3hot] = ACPI_STATE_D3,
 227                 [PCI_D3cold] = ACPI_STATE_D3
 228         };
 229         int error = -EINVAL;
 230
 231         /* If the ACPI device has _EJ0, ignore the device */
 232         if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
 233                 return -ENODEV;
 234
 235         switch (state) {
 236         case PCI_D0:
 237         case PCI_D1:
 238         case PCI_D2:
 239         case PCI_D3hot:
 240         case PCI_D3cold:
 241                 error = acpi_bus_set_power(handle, state_conv[state]);
 242         }
 243
 244         if (!error)
 245                 dev_printk(KERN_INFO, &dev->dev,
 246                                 "power state changed by ACPI to D%d\n", state);
 247
 248         return error;
 249 }
 250
 251 static bool acpi_pci_can_wakeup(struct pci_dev *dev)
 252 {
 253         acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 254
 255         return handle ? acpi_bus_can_wakeup(handle) : false;
 256 }
 257
 258 static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable)
 259 {
 260         while (bus->parent) {
 261                 if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable))
 262                         return;
 263                 bus = bus->parent;
 264         }
 265
 266         /* We have reached the root bus. */
 267         if (bus->bridge)
 268                 acpi_pm_device_sleep_wake(bus->bridge, enable);
 269 }
 270
 271 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
 272 {
 273         if (acpi_pci_can_wakeup(dev))
 274                 return acpi_pm_device_sleep_wake(&dev->dev, enable);
 275
 276         acpi_pci_propagate_wakeup_enable(dev->bus, enable);
 277         return 0;
 278 }
 279
 280 /**
 281  * acpi_dev_run_wake - Enable/disable wake-up for given device.
 282  * @phys_dev: Device to enable/disable the platform to wake-up the system for.
 283  * @enable: Whether enable or disable the wake-up functionality.
 284  *
 285  * Find the ACPI device object corresponding to @pci_dev and try to
 286  * enable/disable the GPE associated with it.
 287  */
 288 static int acpi_dev_run_wake(struct device *phys_dev, bool enable)
 289 {
 290         struct acpi_device *dev;
 291         acpi_handle handle;
 292
 293         if (!device_run_wake(phys_dev))
 294                 return -EINVAL;
 295
 296         handle = DEVICE_ACPI_HANDLE(phys_dev);
 297         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &dev))) {
 298                 dev_dbg(phys_dev, "ACPI handle has no context in %s!\n",
 299                         __func__);
 300                 return -ENODEV;
 301         }
 302
 303         if (enable) {
 304                 acpi_enable_wakeup_device_power(dev, ACPI_STATE_S0);
 305                 acpi_enable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number);
 306         } else {
 307                 acpi_disable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number);
 308                 acpi_disable_wakeup_device_power(dev);
 309         }
 310
 311         return 0;
 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_no_aspm();
 403         }
 404
 405         ret = register_acpi_bus_type(&acpi_pci_bus);
 406         if (ret)
 407                 return 0;
 408         pci_set_platform_pm(&acpi_pci_platform_pm);
 409         return 0;
 410 }
 411 arch_initcall(acpi_pci_init);