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->current_state == PCI_D3cold) {
  51                 pci_wakeup_event(pci_dev);
  52                 pm_runtime_resume(&pci_dev->dev);
  53                 return;
  54         }
  55
  56         if (!pci_dev->pm_cap || !pci_dev->pme_support
  57              || pci_check_pme_status(pci_dev)) {
  58                 if (pci_dev->pme_poll)
  59                         pci_dev->pme_poll = false;
  60
  61                 pci_wakeup_event(pci_dev);
  62                 pm_runtime_resume(&pci_dev->dev);
  63         }
  64
  65         if (pci_dev->subordinate)
  66                 pci_pme_wakeup_bus(pci_dev->subordinate);
  67 }
  68
  69 /**
  70  * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus.
  71  * @dev: ACPI device to add the notifier for.
  72  * @pci_bus: PCI bus to walk checking for PME status if an event is signaled.
  73  */
  74 acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev,
  75                                          struct pci_bus *pci_bus)
  76 {
  77         return acpi_add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus);
  78 }
  79
  80 /**
  81  * pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier.
  82  * @dev: ACPI device to remove the notifier from.
  83  */
  84 acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev)
  85 {
  86         return acpi_remove_pm_notifier(dev, pci_acpi_wake_bus);
  87 }
  88
  89 /**
  90  * pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
  91  * @dev: ACPI device to add the notifier for.
  92  * @pci_dev: PCI device to check for the PME status if an event is signaled.
  93  */
  94 acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
  95                                      struct pci_dev *pci_dev)
  96 {
  97         return acpi_add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev);
  98 }
  99
 100 /**
 101  * pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier.
 102  * @dev: ACPI device to remove the notifier from.
 103  */
 104 acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev)
 105 {
 106         return acpi_remove_pm_notifier(dev, pci_acpi_wake_dev);
 107 }
 108
 109 phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle)
 110 {
 111         acpi_status status = AE_NOT_EXIST;
 112         unsigned long long mcfg_addr;
 113
 114         if (handle)
 115                 status = acpi_evaluate_integer(handle, METHOD_NAME__CBA,
 116                                                NULL, &mcfg_addr);
 117         if (ACPI_FAILURE(status))
 118                 return 0;
 119
 120         return (phys_addr_t)mcfg_addr;
 121 }
 122
 123 /*
 124  * _SxD returns the D-state with the highest power
 125  * (lowest D-state number) supported in the S-state "x".
 126  *
 127  * If the devices does not have a _PRW
 128  * (Power Resources for Wake) supporting system wakeup from "x"
 129  * then the OS is free to choose a lower power (higher number
 130  * D-state) than the return value from _SxD.
 131  *
 132  * But if _PRW is enabled at S-state "x", the OS
 133  * must not choose a power lower than _SxD --
 134  * unless the device has an _SxW method specifying
 135  * the lowest power (highest D-state number) the device
 136  * may enter while still able to wake the system.
 137  *
 138  * ie. depending on global OS policy:
 139  *
 140  * if (_PRW at S-state x)
 141  *      choose from highest power _SxD to lowest power _SxW
 142  * else // no _PRW at S-state x
 143  *      choose highest power _SxD or any lower power
 144  */
 145
 146 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
 147 {
 148         int acpi_state, d_max;
 149
 150         if (pdev->no_d3cold)
 151                 d_max = ACPI_STATE_D3_HOT;
 152         else
 153                 d_max = ACPI_STATE_D3_COLD;
 154         acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max);
 155         if (acpi_state < 0)
 156                 return PCI_POWER_ERROR;
 157
 158         switch (acpi_state) {
 159         case ACPI_STATE_D0:
 160                 return PCI_D0;
 161         case ACPI_STATE_D1:
 162                 return PCI_D1;
 163         case ACPI_STATE_D2:
 164                 return PCI_D2;
 165         case ACPI_STATE_D3_HOT:
 166                 return PCI_D3hot;
 167         case ACPI_STATE_D3_COLD:
 168                 return PCI_D3cold;
 169         }
 170         return PCI_POWER_ERROR;
 171 }
 172
 173 static bool acpi_pci_power_manageable(struct pci_dev *dev)
 174 {
 175         acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 176
 177         return handle ? acpi_bus_power_manageable(handle) : false;
 178 }
 179
 180 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 181 {
 182         acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
 183         acpi_handle tmp;
 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,
 189                 [PCI_D3cold] = ACPI_STATE_D3
 190         };
 191         int error = -EINVAL;
 192
 193         /* If the ACPI device has _EJ0, ignore the device */
 194         if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
 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_info(&dev->dev, "power state changed by ACPI to %s\n",
 213                          pci_power_name(state));
 214
 215         return error;
 216 }
 217
 218 static bool acpi_pci_can_wakeup(struct pci_dev *dev)
 219 {
 220         acpi_handle handle = DEVICE_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         .can_wakeup = acpi_pci_can_wakeup,
 287         .sleep_wake = acpi_pci_sleep_wake,
 288         .run_wake = acpi_pci_run_wake,
 289 };
 290
 291 /* ACPI bus type */
 292 static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
 293 {
 294         struct pci_dev * pci_dev;
 295         u64     addr;
 296
 297         pci_dev = to_pci_dev(dev);
 298         /* Please ref to ACPI spec for the syntax of _ADR */
 299         addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
 300         *handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr);
 301         if (!*handle)
 302                 return -ENODEV;
 303         return 0;
 304 }
 305
 306 static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle)
 307 {
 308         int num;
 309         unsigned int seg, bus;
 310
 311         /*
 312          * The string should be the same as root bridge's name
 313          * Please look at 'pci_scan_bus_parented'
 314          */
 315         num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus);
 316         if (num != 2)
 317                 return -ENODEV;
 318         *handle = acpi_get_pci_rootbridge_handle(seg, bus);
 319         if (!*handle)
 320                 return -ENODEV;
 321         return 0;
 322 }
 323
 324 static struct acpi_bus_type acpi_pci_bus = {
 325         .bus = &pci_bus_type,
 326         .find_device = acpi_pci_find_device,
 327         .find_bridge = acpi_pci_find_root_bridge,
 328 };
 329
 330 static int __init acpi_pci_init(void)
 331 {
 332         int ret;
 333
 334         if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
 335                 printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
 336                 pci_no_msi();
 337         }
 338
 339         if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 340                 printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
 341                 pcie_no_aspm();
 342         }
 343
 344         ret = register_acpi_bus_type(&acpi_pci_bus);
 345         if (ret)
 346                 return 0;
 347         pci_set_platform_pm(&acpi_pci_platform_pm);
 348         return 0;
 349 }
 350 arch_initcall(acpi_pci_init);