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 <linux/pm_qos.h>
  21 #include "pci.h"
  22
  23 /**
  24  * pci_acpi_wake_bus - Wake-up notification handler for root buses.
  25  * @handle: ACPI handle of a device the notification is for.
  26  * @event: Type of the signaled event.
  27  * @context: PCI root bus to wake up devices on.
  28  */
  29 static void pci_acpi_wake_bus(acpi_handle handle, u32 event, void *context)
  30 {
  31         struct pci_bus *pci_bus = context;
  32
  33         if (event == ACPI_NOTIFY_DEVICE_WAKE && pci_bus)
  34                 pci_pme_wakeup_bus(pci_bus);
  35 }
  36
  37 /**
  38  * pci_acpi_wake_dev - Wake-up notification handler for PCI devices.
  39  * @handle: ACPI handle of a device the notification is for.
  40  * @event: Type of the signaled event.
  41  * @context: PCI device object to wake up.
  42  */
  43 static void pci_acpi_wake_dev(acpi_handle handle, u32 event, void *context)
  44 {
  45         struct pci_dev *pci_dev = context;
  46
  47         if (event != ACPI_NOTIFY_DEVICE_WAKE || !pci_dev)
  48                 return;
  49
  50         if (pci_dev->pme_poll)
  51                 pci_dev->pme_poll = false;
  52
  53         if (pci_dev->current_state == PCI_D3cold) {
  54                 pci_wakeup_event(pci_dev);
  55                 pm_runtime_resume(&pci_dev->dev);
  56                 return;
  57         }
  58
  59         /* Clear PME Status if set. */
  60         if (pci_dev->pme_support)
  61                 pci_check_pme_status(pci_dev);
  62
  63         pci_wakeup_event(pci_dev);
  64         pm_runtime_resume(&pci_dev->dev);
  65
  66         if (pci_dev->subordinate)
  67                 pci_pme_wakeup_bus(pci_dev->subordinate);
  68 }
  69
  70 /**
  71  * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus.
  72  * @dev: ACPI device to add the notifier for.
  73  * @pci_bus: PCI bus to walk checking for PME status if an event is signaled.
  74  */
  75 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev,
  76                                          struct pci_bus *pci_bus)
  77 {
  78         return acpi_add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus);
  79 }
  80
  81 /**
  82  * pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier.
  83  * @dev: ACPI device to remove the notifier from.
  84  */
  85 acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev)
  86 {
  87         return acpi_remove_pm_notifier(dev, pci_acpi_wake_bus);
  88 }
  89
  90 /**
  91  * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
  92  * @dev: ACPI device to add the notifier for.
  93  * @pci_dev: PCI device to check for the PME status if an event is signaled.
  94  */
  95 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
  96                                      struct pci_dev *pci_dev)
  97 {
  98         return acpi_add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev);
  99 }
 100
 101 /**
 102  * pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier.
 103  * @dev: ACPI device to remove the notifier from.
 104  */
 105 acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev)
 106 {
 107         return acpi_remove_pm_notifier(dev, pci_acpi_wake_dev);
 108 }
 109
 110 phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle)
 111 {
 112         acpi_status status = AE_NOT_EXIST;
 113         unsigned long long mcfg_addr;
 114
 115         if (handle)
 116                 status = acpi_evaluate_integer(handle, METHOD_NAME__CBA,
 117                                                NULL, &mcfg_addr);
 118         if (ACPI_FAILURE(status))
 119                 return 0;
 120
 121         return (phys_addr_t)mcfg_addr;
 122 }
 123
 124 /*
 125  * _SxD returns the D-state with the highest power
 126  * (lowest D-state number) supported in the S-state "x".
 127  *
 128  * If the devices does not have a _PRW
 129  * (Power Resources for Wake) supporting system wakeup from "x"
 130  * then the OS is free to choose a lower power (higher number
 131  * D-state) than the return value from _SxD.
 132  *
 133  * But if _PRW is enabled at S-state "x", the OS
 134  * must not choose a power lower than _SxD --
 135  * unless the device has an _SxW method specifying
 136  * the lowest power (highest D-state number) the device
 137  * may enter while still able to wake the system.
 138  *
 139  * ie. depending on global OS policy:
 140  *
 141  * if (_PRW at S-state x)
 142  *      choose from highest power _SxD to lowest power _SxW
 143  * else // no _PRW at S-state x
 144  *      choose highest power _SxD or any lower power
 145  */
 146
 147 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
 148 {
 149         int acpi_state, d_max;
 150
 151         if (pdev->no_d3cold)
 152                 d_max = ACPI_STATE_D3_HOT;
 153         else
 154                 d_max = ACPI_STATE_D3_COLD;
 155         acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max);
 156         if (acpi_state < 0)
 157                 return PCI_POWER_ERROR;
 158
 159         switch (acpi_state) {
 160         case ACPI_STATE_D0:
 161                 return PCI_D0;
 162         case ACPI_STATE_D1:
 163                 return PCI_D1;
 164         case ACPI_STATE_D2:
 165                 return PCI_D2;
 166         case ACPI_STATE_D3_HOT:
 167                 return PCI_D3hot;
 168         case ACPI_STATE_D3_COLD:
 169                 return PCI_D3cold;
 170         }
 171         return PCI_POWER_ERROR;
 172 }
 173
 174 static bool acpi_pci_power_manageable(struct pci_dev *dev)
 175 {
 176         acpi_handle handle = ACPI_HANDLE(&dev->dev);
 177
 178         return handle ? acpi_bus_power_manageable(handle) : false;
 179 }
 180
 181 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 182 {
 183         acpi_handle handle = ACPI_HANDLE(&dev->dev);
 184         static const u8 state_conv[] = {
 185                 [PCI_D0] = ACPI_STATE_D0,
 186                 [PCI_D1] = ACPI_STATE_D1,
 187                 [PCI_D2] = ACPI_STATE_D2,
 188                 [PCI_D3hot] = ACPI_STATE_D3_COLD,
 189                 [PCI_D3cold] = ACPI_STATE_D3_COLD,
 190         };
 191         int error = -EINVAL;
 192
 193         /* If the ACPI device has _EJ0, ignore the device */
 194         if (!handle || acpi_has_method(handle, "_EJ0"))
 195                 return -ENODEV;
 196
 197         switch (state) {
 198         case PCI_D3cold:
 199                 if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
 200                                 PM_QOS_FLAGS_ALL) {
 201                         error = -EBUSY;
 202                         break;
 203                 }
 204         case PCI_D0:
 205         case PCI_D1:
 206         case PCI_D2:
 207         case PCI_D3hot:
 208                 error = acpi_bus_set_power(handle, state_conv[state]);
 209         }
 210
 211         if (!error)
 212                 dev_dbg(&dev->dev, "power state changed by ACPI to %s\n",
 213                          acpi_power_state_string(state_conv[state]));
 214
 215         return error;
 216 }
 217
 218 static bool acpi_pci_can_wakeup(struct pci_dev *dev)
 219 {
 220         acpi_handle handle = ACPI_HANDLE(&dev->dev);
 221
 222         return handle ? acpi_bus_can_wakeup(handle) : false;
 223 }
 224
 225 static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable)
 226 {
 227         while (bus->parent) {
 228                 if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable))
 229                         return;
 230                 bus = bus->parent;
 231         }
 232
 233         /* We have reached the root bus. */
 234         if (bus->bridge)
 235                 acpi_pm_device_sleep_wake(bus->bridge, enable);
 236 }
 237
 238 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
 239 {
 240         if (acpi_pci_can_wakeup(dev))
 241                 return acpi_pm_device_sleep_wake(&dev->dev, enable);
 242
 243         acpi_pci_propagate_wakeup_enable(dev->bus, enable);
 244         return 0;
 245 }
 246
 247 static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable)
 248 {
 249         while (bus->parent) {
 250                 struct pci_dev *bridge = bus->self;
 251
 252                 if (bridge->pme_interrupt)
 253                         return;
 254                 if (!acpi_pm_device_run_wake(&bridge->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_run_wake(bus->bridge, enable);
 262 }
 263
 264 static int acpi_pci_run_wake(struct pci_dev *dev, bool enable)
 265 {
 266         /*
 267          * Per PCI Express Base Specification Revision 2.0 section
 268          * 5.3.3.2 Link Wakeup, platform support is needed for D3cold
 269          * waking up to power on the main link even if there is PME
 270          * support for D3cold
 271          */
 272         if (dev->pme_interrupt && !dev->runtime_d3cold)
 273                 return 0;
 274
 275         if (!acpi_pm_device_run_wake(&dev->dev, enable))
 276                 return 0;
 277
 278         acpi_pci_propagate_run_wake(dev->bus, enable);
 279         return 0;
 280 }
 281
 282 static struct pci_platform_pm_ops acpi_pci_platform_pm = {
 283         .is_manageable = acpi_pci_power_manageable,
 284         .set_state = acpi_pci_set_power_state,
 285         .choose_state = acpi_pci_choose_state,
 286         .sleep_wake = acpi_pci_sleep_wake,
 287         .run_wake = acpi_pci_run_wake,
 288 };
 289
 290 void acpi_pci_add_bus(struct pci_bus *bus)
 291 {
 292         if (acpi_pci_disabled || !bus->bridge)
 293                 return;
 294
 295         acpi_pci_slot_enumerate(bus);
 296         acpiphp_enumerate_slots(bus);
 297 }
 298
 299 void acpi_pci_remove_bus(struct pci_bus *bus)
 300 {
 301         if (acpi_pci_disabled || !bus->bridge)
 302                 return;
 303
 304         acpiphp_remove_slots(bus);
 305         acpi_pci_slot_remove(bus);
 306 }
 307
 308 /* ACPI bus type */
 309 static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
 310 {
 311         struct pci_dev *pci_dev = to_pci_dev(dev);
 312         bool is_bridge;
 313         u64 addr;
 314
 315         /*
 316          * pci_is_bridge() is not suitable here, because pci_dev->subordinate
 317          * is set only after acpi_pci_find_device() has been called for the
 318          * given device.
 319          */
 320         is_bridge = pci_dev->hdr_type == PCI_HEADER_TYPE_BRIDGE
 321                         || pci_dev->hdr_type == PCI_HEADER_TYPE_CARDBUS;
 322         /* Please ref to ACPI spec for the syntax of _ADR */
 323         addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
 324         *handle = acpi_find_child(ACPI_HANDLE(dev->parent), addr, is_bridge);
 325         if (!*handle)
 326                 return -ENODEV;
 327         return 0;
 328 }
 329
 330 static void pci_acpi_setup(struct device *dev)
 331 {
 332         struct pci_dev *pci_dev = to_pci_dev(dev);
 333         acpi_handle handle = ACPI_HANDLE(dev);
 334         struct acpi_device *adev;
 335
 336         if (acpi_bus_get_device(handle, &adev) || !adev->wakeup.flags.valid)
 337                 return;
 338
 339         device_set_wakeup_capable(dev, true);
 340         acpi_pci_sleep_wake(pci_dev, false);
 341
 342         pci_acpi_add_pm_notifier(adev, pci_dev);
 343         if (adev->wakeup.flags.run_wake)
 344                 device_set_run_wake(dev, true);
 345 }
 346
 347 static void pci_acpi_cleanup(struct device *dev)
 348 {
 349         acpi_handle handle = ACPI_HANDLE(dev);
 350         struct acpi_device *adev;
 351
 352         if (!acpi_bus_get_device(handle, &adev) && adev->wakeup.flags.valid) {
 353                 device_set_wakeup_capable(dev, false);
 354                 device_set_run_wake(dev, false);
 355                 pci_acpi_remove_pm_notifier(adev);
 356         }
 357 }
 358
 359 static bool pci_acpi_bus_match(struct device *dev)
 360 {
 361         return dev->bus == &pci_bus_type;
 362 }
 363
 364 static struct acpi_bus_type acpi_pci_bus = {
 365         .name = "PCI",
 366         .match = pci_acpi_bus_match,
 367         .find_device = acpi_pci_find_device,
 368         .setup = pci_acpi_setup,
 369         .cleanup = pci_acpi_cleanup,
 370 };
 371
 372 static int __init acpi_pci_init(void)
 373 {
 374         int ret;
 375
 376         if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
 377                 pr_info("ACPI FADT declares the system doesn't support MSI, so disable it\n");
 378                 pci_no_msi();
 379         }
 380
 381         if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 382                 pr_info("ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
 383                 pcie_no_aspm();
 384         }
 385
 386         ret = register_acpi_bus_type(&acpi_pci_bus);
 387         if (ret)
 388                 return 0;
 389
 390         pci_set_platform_pm(&acpi_pci_platform_pm);
 391         acpi_pci_slot_init();
 392         acpiphp_init();
 393
 394         return 0;
 395 }
 396 arch_initcall(acpi_pci_init);