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->current_state == PCI_D3cold) {
  52                 pci_wakeup_event(pci_dev);
  53                 pm_runtime_resume(&pci_dev->dev);
  54                 return;
  55         }
  56
  57         if (!pci_dev->pm_cap || !pci_dev->pme_support
  58              || pci_check_pme_status(pci_dev)) {
  59                 if (pci_dev->pme_poll)
  60                         pci_dev->pme_poll = false;
  61
  62                 pci_wakeup_event(pci_dev);
  63                 pm_runtime_resume(&pci_dev->dev);
  64         }
  65
  66         if (pci_dev->subordinate)
  67                 pci_pme_wakeup_bus(pci_dev->subordinate);
  68 }
  69
  70 /**
  71  * add_pm_notifier - Register PM notifier for given ACPI device.
  72  * @dev: ACPI device to add the notifier for.
  73  * @context: PCI device or bus to check for PME status if an event is signaled.
  74  *
  75  * NOTE: @dev need not be a run-wake or wake-up device to be a valid source of
  76  * PM wake-up events.  For example, wake-up events may be generated for bridges
  77  * if one of the devices below the bridge is signaling PME, even if the bridge
  78  * itself doesn't have a wake-up GPE associated with it.
  79  */
  80 static acpi_status add_pm_notifier(struct acpi_device *dev,
  81                                    acpi_notify_handler handler,
  82                                    void *context)
  83 {
  84         acpi_status status = AE_ALREADY_EXISTS;
  85
  86         mutex_lock(&pci_acpi_pm_notify_mtx);
  87
  88         if (dev->wakeup.flags.notifier_present)
  89                 goto out;
  90
  91         status = acpi_install_notify_handler(dev->handle,
  92                                              ACPI_SYSTEM_NOTIFY,
  93                                              handler, context);
  94         if (ACPI_FAILURE(status))
  95                 goto out;
  96
  97         dev->wakeup.flags.notifier_present = true;
  98
  99  out:
 100         mutex_unlock(&pci_acpi_pm_notify_mtx);
 101         return status;
 102 }
 103
 104 /**
 105  * remove_pm_notifier - Unregister PM notifier from given ACPI device.
 106  * @dev: ACPI device to remove the notifier from.
 107  */
 108 static acpi_status remove_pm_notifier(struct acpi_device *dev,
 109                                       acpi_notify_handler handler)
 110 {
 111         acpi_status status = AE_BAD_PARAMETER;
 112
 113         mutex_lock(&pci_acpi_pm_notify_mtx);
 114
 115         if (!dev->wakeup.flags.notifier_present)
 116                 goto out;
 117
 118         status = acpi_remove_notify_handler(dev->handle,
 119                                             ACPI_SYSTEM_NOTIFY,
 120                                             handler);
 121         if (ACPI_FAILURE(status))
 122                 goto out;
 123
 124         dev->wakeup.flags.notifier_present = false;
 125
 126  out:
 127         mutex_unlock(&pci_acpi_pm_notify_mtx);
 128         return status;
 129 }
 130
 131 /**
 132  * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus.
 133  * @dev: ACPI device to add the notifier for.
 134  * @pci_bus: PCI bus to walk checking for PME status if an event is signaled.
 135  */
 136 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev,
 137                                          struct pci_bus *pci_bus)
 138 {
 139         return add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus);
 140 }
 141
 142 /**
 143  * pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier.
 144  * @dev: ACPI device to remove the notifier from.
 145  */
 146 acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev)
 147 {
 148         return remove_pm_notifier(dev, pci_acpi_wake_bus);
 149 }
 150
 151 /**
 152  * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
 153  * @dev: ACPI device to add the notifier for.
 154  * @pci_dev: PCI device to check for the PME status if an event is signaled.
 155  */
 156 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
 157                                      struct pci_dev *pci_dev)
 158 {
 159         return add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev);
 160 }
 161
 162 /**
 163  * pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier.
 164  * @dev: ACPI device to remove the notifier from.
 165  */
 166 acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev)
 167 {
 168         return remove_pm_notifier(dev, pci_acpi_wake_dev);
 169 }
 170
 171 phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle)
 172 {
 173         acpi_status status = AE_NOT_EXIST;
 174         unsigned long long mcfg_addr;
 175
 176         if (handle)
 177                 status = acpi_evaluate_integer(handle, METHOD_NAME__CBA,
 178                                                NULL, &mcfg_addr);
 179         if (ACPI_FAILURE(status))
 180                 return 0;
 181
 182         return (phys_addr_t)mcfg_addr;
 183 }
 184
 185 /*
 186  * _SxD returns the D-state with the highest power
 187  * (lowest D-state number) supported in the S-state "x".
 188  *
 189  * If the devices does not have a _PRW
 190  * (Power Resources for Wake) supporting system wakeup from "x"
 191  * then the OS is free to choose a lower power (higher number
 192  * D-state) than the return value from _SxD.
 193  *
 194  * But if _PRW is enabled at S-state "x", the OS
 195  * must not choose a power lower than _SxD --
 196  * unless the device has an _SxW method specifying
 197  * the lowest power (highest D-state number) the device
 198  * may enter while still able to wake the system.
 199  *
 200  * ie. depending on global OS policy:
 201  *
 202  * if (_PRW at S-state x)
 203  *      choose from highest power _SxD to lowest power _SxW
 204  * else // no _PRW at S-state x
 205  *      choose highest power _SxD or any lower power
 206  */
 207
 208 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
 209 {
 210         int acpi_state, d_max;
 211
 212         if (pdev->no_d3cold)
 213                 d_max = ACPI_STATE_D3_HOT;
 214         else
 215                 d_max = ACPI_STATE_D3_COLD;
 216         acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max);
 217         if (acpi_state < 0)
 218                 return PCI_POWER_ERROR;
 219
 220         switch (acpi_state) {
 221         case ACPI_STATE_D0:
 222                 return PCI_D0;
 223         case ACPI_STATE_D1:
 224                 return PCI_D1;
 225         case ACPI_STATE_D2:
 226                 return PCI_D2;
 227         case ACPI_STATE_D3_HOT:
 228                 return PCI_D3hot;
 229         case ACPI_STATE_D3_COLD:
 230                 return PCI_D3cold;
 231         }
 232         return PCI_POWER_ERROR;
 233 }
 234
 235 static bool acpi_pci_power_manageable(struct pci_dev *dev)
 236 {
 237         acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 238
 239         return handle ? acpi_bus_power_manageable(handle) : false;
 240 }
 241
 242 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 243 {
 244         acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 245         acpi_handle tmp;
 246         static const u8 state_conv[] = {
 247                 [PCI_D0] = ACPI_STATE_D0,
 248                 [PCI_D1] = ACPI_STATE_D1,
 249                 [PCI_D2] = ACPI_STATE_D2,
 250                 [PCI_D3hot] = ACPI_STATE_D3,
 251                 [PCI_D3cold] = ACPI_STATE_D3
 252         };
 253         int error = -EINVAL;
 254
 255         /* If the ACPI device has _EJ0, ignore the device */
 256         if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
 257                 return -ENODEV;
 258
 259         switch (state) {
 260         case PCI_D0:
 261         case PCI_D1:
 262         case PCI_D2:
 263         case PCI_D3hot:
 264         case PCI_D3cold:
 265                 error = acpi_bus_set_power(handle, state_conv[state]);
 266         }
 267
 268         if (!error)
 269                 dev_printk(KERN_INFO, &dev->dev,
 270                                 "power state changed by ACPI to D%d\n", state);
 271
 272         return error;
 273 }
 274
 275 static bool acpi_pci_can_wakeup(struct pci_dev *dev)
 276 {
 277         acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 278
 279         return handle ? acpi_bus_can_wakeup(handle) : false;
 280 }
 281
 282 static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable)
 283 {
 284         while (bus->parent) {
 285                 if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable))
 286                         return;
 287                 bus = bus->parent;
 288         }
 289
 290         /* We have reached the root bus. */
 291         if (bus->bridge)
 292                 acpi_pm_device_sleep_wake(bus->bridge, enable);
 293 }
 294
 295 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
 296 {
 297         if (acpi_pci_can_wakeup(dev))
 298                 return acpi_pm_device_sleep_wake(&dev->dev, enable);
 299
 300         acpi_pci_propagate_wakeup_enable(dev->bus, enable);
 301         return 0;
 302 }
 303
 304 static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable)
 305 {
 306         while (bus->parent) {
 307                 struct pci_dev *bridge = bus->self;
 308
 309                 if (bridge->pme_interrupt)
 310                         return;
 311                 if (!acpi_pm_device_run_wake(&bridge->dev, enable))
 312                         return;
 313                 bus = bus->parent;
 314         }
 315
 316         /* We have reached the root bus. */
 317         if (bus->bridge)
 318                 acpi_pm_device_run_wake(bus->bridge, enable);
 319 }
 320
 321 static int acpi_pci_run_wake(struct pci_dev *dev, bool enable)
 322 {
 323         /*
 324          * Per PCI Express Base Specification Revision 2.0 section
 325          * 5.3.3.2 Link Wakeup, platform support is needed for D3cold
 326          * waking up to power on the main link even if there is PME
 327          * support for D3cold
 328          */
 329         if (dev->pme_interrupt && !dev->runtime_d3cold)
 330                 return 0;
 331
 332         if (!acpi_pm_device_run_wake(&dev->dev, enable))
 333                 return 0;
 334
 335         acpi_pci_propagate_run_wake(dev->bus, enable);
 336         return 0;
 337 }
 338
 339 static struct pci_platform_pm_ops acpi_pci_platform_pm = {
 340         .is_manageable = acpi_pci_power_manageable,
 341         .set_state = acpi_pci_set_power_state,
 342         .choose_state = acpi_pci_choose_state,
 343         .can_wakeup = acpi_pci_can_wakeup,
 344         .sleep_wake = acpi_pci_sleep_wake,
 345         .run_wake = acpi_pci_run_wake,
 346 };
 347
 348 /* ACPI bus type */
 349 static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
 350 {
 351         struct pci_dev * pci_dev;
 352         u64     addr;
 353
 354         pci_dev = to_pci_dev(dev);
 355         /* Please ref to ACPI spec for the syntax of _ADR */
 356         addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
 357         *handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr);
 358         if (!*handle)
 359                 return -ENODEV;
 360         return 0;
 361 }
 362
 363 static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle)
 364 {
 365         int num;
 366         unsigned int seg, bus;
 367
 368         /*
 369          * The string should be the same as root bridge's name
 370          * Please look at 'pci_scan_bus_parented'
 371          */
 372         num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus);
 373         if (num != 2)
 374                 return -ENODEV;
 375         *handle = acpi_get_pci_rootbridge_handle(seg, bus);
 376         if (!*handle)
 377                 return -ENODEV;
 378         return 0;
 379 }
 380
 381 static struct acpi_bus_type acpi_pci_bus = {
 382         .bus = &pci_bus_type,
 383         .find_device = acpi_pci_find_device,
 384         .find_bridge = acpi_pci_find_root_bridge,
 385 };
 386
 387 static int __init acpi_pci_init(void)
 388 {
 389         int ret;
 390
 391         if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
 392                 printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
 393                 pci_no_msi();
 394         }
 395
 396         if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 397                 printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
 398                 pcie_no_aspm();
 399         }
 400
 401         ret = register_acpi_bus_type(&acpi_pci_bus);
 402         if (ret)
 403                 return 0;
 404         pci_set_platform_pm(&acpi_pci_platform_pm);
 405         return 0;
 406 }
 407 arch_initcall(acpi_pci_init);