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 <linux/pci-acpi.h>
  16 #include <linux/pm_runtime.h>
  17 #include <linux/pm_qos.h>
  18 #include "pci.h"
  19
  20 /**
  21  * pci_acpi_wake_bus - Wake-up notification handler for root buses.
  22  * @handle: ACPI handle of a device the notification is for.
  23  * @event: Type of the signaled event.
  24  * @context: PCI root bus to wake up devices on.
  25  */
  26 static void pci_acpi_wake_bus(acpi_handle handle, u32 event, void *context)
  27 {
  28         struct pci_bus *pci_bus = context;
  29
  30         if (event == ACPI_NOTIFY_DEVICE_WAKE && pci_bus)
  31                 pci_pme_wakeup_bus(pci_bus);
  32 }
  33
  34 /**
  35  * pci_acpi_wake_dev - Wake-up notification handler for PCI devices.
  36  * @handle: ACPI handle of a device the notification is for.
  37  * @event: Type of the signaled event.
  38  * @context: PCI device object to wake up.
  39  */
  40 static void pci_acpi_wake_dev(acpi_handle handle, u32 event, void *context)
  41 {
  42         struct pci_dev *pci_dev = context;
  43
  44         if (event != ACPI_NOTIFY_DEVICE_WAKE || !pci_dev)
  45                 return;
  46
  47         if (pci_dev->pme_poll)
  48                 pci_dev->pme_poll = false;
  49
  50         if (pci_dev->current_state == PCI_D3cold) {
  51                 pci_wakeup_event(pci_dev);
  52                 pm_runtime_resume(&pci_dev->dev);
  53                 return;
  54         }
  55
  56         /* Clear PME Status if set. */
  57         if (pci_dev->pme_support)
  58                 pci_check_pme_status(pci_dev);
  59
  60         pci_wakeup_event(pci_dev);
  61         pm_runtime_resume(&pci_dev->dev);
  62
  63         if (pci_dev->subordinate)
  64                 pci_pme_wakeup_bus(pci_dev->subordinate);
  65 }
  66
  67 /**
  68  * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus.
  69  * @dev: ACPI device to add the notifier for.
  70  * @pci_bus: PCI bus to walk checking for PME status if an event is signaled.
  71  */
  72 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev,
  73                                          struct pci_bus *pci_bus)
  74 {
  75         return acpi_add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus);
  76 }
  77
  78 /**
  79  * pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier.
  80  * @dev: ACPI device to remove the notifier from.
  81  */
  82 acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev)
  83 {
  84         return acpi_remove_pm_notifier(dev, pci_acpi_wake_bus);
  85 }
  86
  87 /**
  88  * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
  89  * @dev: ACPI device to add the notifier for.
  90  * @pci_dev: PCI device to check for the PME status if an event is signaled.
  91  */
  92 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
  93                                      struct pci_dev *pci_dev)
  94 {
  95         return acpi_add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev);
  96 }
  97
  98 /**
  99  * pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier.
 100  * @dev: ACPI device to remove the notifier from.
 101  */
 102 acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev)
 103 {
 104         return acpi_remove_pm_notifier(dev, pci_acpi_wake_dev);
 105 }
 106
 107 phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle)
 108 {
 109         acpi_status status = AE_NOT_EXIST;
 110         unsigned long long mcfg_addr;
 111
 112         if (handle)
 113                 status = acpi_evaluate_integer(handle, METHOD_NAME__CBA,
 114                                                NULL, &mcfg_addr);
 115         if (ACPI_FAILURE(status))
 116                 return 0;
 117
 118         return (phys_addr_t)mcfg_addr;
 119 }
 120
 121 /*
 122  * _SxD returns the D-state with the highest power
 123  * (lowest D-state number) supported in the S-state "x".
 124  *
 125  * If the devices does not have a _PRW
 126  * (Power Resources for Wake) supporting system wakeup from "x"
 127  * then the OS is free to choose a lower power (higher number
 128  * D-state) than the return value from _SxD.
 129  *
 130  * But if _PRW is enabled at S-state "x", the OS
 131  * must not choose a power lower than _SxD --
 132  * unless the device has an _SxW method specifying
 133  * the lowest power (highest D-state number) the device
 134  * may enter while still able to wake the system.
 135  *
 136  * ie. depending on global OS policy:
 137  *
 138  * if (_PRW at S-state x)
 139  *      choose from highest power _SxD to lowest power _SxW
 140  * else // no _PRW at S-state x
 141  *      choose highest power _SxD or any lower power
 142  */
 143
 144 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
 145 {
 146         int acpi_state, d_max;
 147
 148         if (pdev->no_d3cold)
 149                 d_max = ACPI_STATE_D3_HOT;
 150         else
 151                 d_max = ACPI_STATE_D3_COLD;
 152         acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max);
 153         if (acpi_state < 0)
 154                 return PCI_POWER_ERROR;
 155
 156         switch (acpi_state) {
 157         case ACPI_STATE_D0:
 158                 return PCI_D0;
 159         case ACPI_STATE_D1:
 160                 return PCI_D1;
 161         case ACPI_STATE_D2:
 162                 return PCI_D2;
 163         case ACPI_STATE_D3_HOT:
 164                 return PCI_D3hot;
 165         case ACPI_STATE_D3_COLD:
 166                 return PCI_D3cold;
 167         }
 168         return PCI_POWER_ERROR;
 169 }
 170
 171 static bool acpi_pci_power_manageable(struct pci_dev *dev)
 172 {
 173         acpi_handle handle = ACPI_HANDLE(&dev->dev);
 174
 175         return handle ? acpi_bus_power_manageable(handle) : false;
 176 }
 177
 178 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 179 {
 180         acpi_handle handle = ACPI_HANDLE(&dev->dev);
 181         static const u8 state_conv[] = {
 182                 [PCI_D0] = ACPI_STATE_D0,
 183                 [PCI_D1] = ACPI_STATE_D1,
 184                 [PCI_D2] = ACPI_STATE_D2,
 185                 [PCI_D3hot] = ACPI_STATE_D3_COLD,
 186                 [PCI_D3cold] = ACPI_STATE_D3_COLD,
 187         };
 188         int error = -EINVAL;
 189
 190         /* If the ACPI device has _EJ0, ignore the device */
 191         if (!handle || acpi_has_method(handle, "_EJ0"))
 192                 return -ENODEV;
 193
 194         switch (state) {
 195         case PCI_D3cold:
 196                 if (dev_pm_qos_flags(&dev->dev, PM_QOS_FLAG_NO_POWER_OFF) ==
 197                                 PM_QOS_FLAGS_ALL) {
 198                         error = -EBUSY;
 199                         break;
 200                 }
 201         case PCI_D0:
 202         case PCI_D1:
 203         case PCI_D2:
 204         case PCI_D3hot:
 205                 error = acpi_bus_set_power(handle, state_conv[state]);
 206         }
 207
 208         if (!error)
 209                 dev_dbg(&dev->dev, "power state changed by ACPI to %s\n",
 210                          acpi_power_state_string(state_conv[state]));
 211
 212         return error;
 213 }
 214
 215 static bool acpi_pci_can_wakeup(struct pci_dev *dev)
 216 {
 217         acpi_handle handle = ACPI_HANDLE(&dev->dev);
 218
 219         return handle ? acpi_bus_can_wakeup(handle) : false;
 220 }
 221
 222 static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable)
 223 {
 224         while (bus->parent) {
 225                 if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable))
 226                         return;
 227                 bus = bus->parent;
 228         }
 229
 230         /* We have reached the root bus. */
 231         if (bus->bridge)
 232                 acpi_pm_device_sleep_wake(bus->bridge, enable);
 233 }
 234
 235 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
 236 {
 237         if (acpi_pci_can_wakeup(dev))
 238                 return acpi_pm_device_sleep_wake(&dev->dev, enable);
 239
 240         acpi_pci_propagate_wakeup_enable(dev->bus, enable);
 241         return 0;
 242 }
 243
 244 static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable)
 245 {
 246         while (bus->parent) {
 247                 struct pci_dev *bridge = bus->self;
 248
 249                 if (bridge->pme_interrupt)
 250                         return;
 251                 if (!acpi_pm_device_run_wake(&bridge->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_run_wake(bus->bridge, enable);
 259 }
 260
 261 static int acpi_pci_run_wake(struct pci_dev *dev, bool enable)
 262 {
 263         /*
 264          * Per PCI Express Base Specification Revision 2.0 section
 265          * 5.3.3.2 Link Wakeup, platform support is needed for D3cold
 266          * waking up to power on the main link even if there is PME
 267          * support for D3cold
 268          */
 269         if (dev->pme_interrupt && !dev->runtime_d3cold)
 270                 return 0;
 271
 272         if (!acpi_pm_device_run_wake(&dev->dev, enable))
 273                 return 0;
 274
 275         acpi_pci_propagate_run_wake(dev->bus, enable);
 276         return 0;
 277 }
 278
 279 static struct pci_platform_pm_ops acpi_pci_platform_pm = {
 280         .is_manageable = acpi_pci_power_manageable,
 281         .set_state = acpi_pci_set_power_state,
 282         .choose_state = acpi_pci_choose_state,
 283         .sleep_wake = acpi_pci_sleep_wake,
 284         .run_wake = acpi_pci_run_wake,
 285 };
 286
 287 void acpi_pci_add_bus(struct pci_bus *bus)
 288 {
 289         if (acpi_pci_disabled || !bus->bridge)
 290                 return;
 291
 292         acpi_pci_slot_enumerate(bus);
 293         acpiphp_enumerate_slots(bus);
 294 }
 295
 296 void acpi_pci_remove_bus(struct pci_bus *bus)
 297 {
 298         if (acpi_pci_disabled || !bus->bridge)
 299                 return;
 300
 301         acpiphp_remove_slots(bus);
 302         acpi_pci_slot_remove(bus);
 303 }
 304
 305 /* ACPI bus type */
 306 static struct acpi_device *acpi_pci_find_companion(struct device *dev)
 307 {
 308         struct pci_dev *pci_dev = to_pci_dev(dev);
 309         bool check_children;
 310         u64 addr;
 311
 312         /*
 313          * pci_is_bridge() is not suitable here, because pci_dev->subordinate
 314          * is set only after acpi_pci_find_device() has been called for the
 315          * given device.
 316          */
 317         check_children = pci_dev->hdr_type == PCI_HEADER_TYPE_BRIDGE
 318                         || pci_dev->hdr_type == PCI_HEADER_TYPE_CARDBUS;
 319         /* Please ref to ACPI spec for the syntax of _ADR */
 320         addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
 321         return acpi_find_child_device(ACPI_COMPANION(dev->parent), addr,
 322                                       check_children);
 323 }
 324
 325 static void pci_acpi_setup(struct device *dev)
 326 {
 327         struct pci_dev *pci_dev = to_pci_dev(dev);
 328         struct acpi_device *adev = ACPI_COMPANION(dev);
 329
 330         if (!adev)
 331                 return;
 332
 333         pci_acpi_add_pm_notifier(adev, pci_dev);
 334         if (!adev->wakeup.flags.valid)
 335                 return;
 336
 337         device_set_wakeup_capable(dev, true);
 338         acpi_pci_sleep_wake(pci_dev, false);
 339         if (adev->wakeup.flags.run_wake)
 340                 device_set_run_wake(dev, true);
 341 }
 342
 343 static void pci_acpi_cleanup(struct device *dev)
 344 {
 345         struct acpi_device *adev = ACPI_COMPANION(dev);
 346
 347         if (!adev)
 348                 return;
 349
 350         pci_acpi_remove_pm_notifier(adev);
 351         if (adev->wakeup.flags.valid) {
 352                 device_set_wakeup_capable(dev, false);
 353                 device_set_run_wake(dev, false);
 354         }
 355 }
 356
 357 static bool pci_acpi_bus_match(struct device *dev)
 358 {
 359         return dev_is_pci(dev);
 360 }
 361
 362 static struct acpi_bus_type acpi_pci_bus = {
 363         .name = "PCI",
 364         .match = pci_acpi_bus_match,
 365         .find_companion = acpi_pci_find_companion,
 366         .setup = pci_acpi_setup,
 367         .cleanup = pci_acpi_cleanup,
 368 };
 369
 370 static int __init acpi_pci_init(void)
 371 {
 372         int ret;
 373
 374         if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
 375                 pr_info("ACPI FADT declares the system doesn't support MSI, so disable it\n");
 376                 pci_no_msi();
 377         }
 378
 379         if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 380                 pr_info("ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
 381                 pcie_no_aspm();
 382         }
 383
 384         ret = register_acpi_bus_type(&acpi_pci_bus);
 385         if (ret)
 386                 return 0;
 387
 388         pci_set_platform_pm(&acpi_pci_platform_pm);
 389         acpi_pci_slot_init();
 390         acpiphp_init();
 391
 392         return 0;
 393 }
 394 arch_initcall(acpi_pci_init);