linux/drivers/pci/pci-acpi.c

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/*
* File: pci-acpi.c
* Purpose: Provide PCI support in ACPI
*
* Copyright (C) 2005 David Shaohua Li <shaohua.li@intel.com>
* Copyright (C) 2004 Tom Long Nguyen <tom.l.nguyen@intel.com>
* Copyright (C) 2004 Intel Corp.
*/
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/module.h>
#include <linux/pci-aspm.h>
#include <acpi/acpi.h>
#include <acpi/acpi_bus.h>
#include <linux/pci-acpi.h>
PCI / ACPI / PM: Platform support for PCI PME wake-up Although the majority of PCI devices can generate PMEs that in principle may be used to wake up devices suspended at run time, platform support is generally necessary to convert PMEs into wake-up events that can be delivered to the kernel. If ACPI is used for this purpose, PME signals generated by a PCI device will trigger the ACPI GPE associated with the device to generate an ACPI wake-up event that we can set up a handler for, provided that everything is configured correctly. Unfortunately, the subset of PCI devices that have GPEs associated with them is quite limited. The devices without dedicated GPEs have to rely on the GPEs associated with other devices (in the majority of cases their upstream bridges and, possibly, the root bridge) to generate ACPI wake-up events in response to PME signals from them. Add ACPI platform support for PCI PME wake-up: o Add a framework making is possible to use ACPI system notify handlers for run-time PM. o Add new PCI platform callback ->run_wake() to struct pci_platform_pm_ops allowing us to enable/disable the platform to generate wake-up events for given device. Implemet this callback for the ACPI platform. o Define ACPI wake-up handlers for PCI devices and PCI root buses and make the PCI-ACPI binding code register wake-up notifiers for all PCI devices present in the ACPI tables. o Add function pci_dev_run_wake() which can be used by PCI drivers to check if given device is capable of generating wake-up events at run time. Developed in cooperation with Matthew Garrett <mjg@redhat.com>. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-02-17 23:44:09 +01:00
#include <linux/pm_runtime.h>
#include "pci.h"
PCI / ACPI / PM: Platform support for PCI PME wake-up Although the majority of PCI devices can generate PMEs that in principle may be used to wake up devices suspended at run time, platform support is generally necessary to convert PMEs into wake-up events that can be delivered to the kernel. If ACPI is used for this purpose, PME signals generated by a PCI device will trigger the ACPI GPE associated with the device to generate an ACPI wake-up event that we can set up a handler for, provided that everything is configured correctly. Unfortunately, the subset of PCI devices that have GPEs associated with them is quite limited. The devices without dedicated GPEs have to rely on the GPEs associated with other devices (in the majority of cases their upstream bridges and, possibly, the root bridge) to generate ACPI wake-up events in response to PME signals from them. Add ACPI platform support for PCI PME wake-up: o Add a framework making is possible to use ACPI system notify handlers for run-time PM. o Add new PCI platform callback ->run_wake() to struct pci_platform_pm_ops allowing us to enable/disable the platform to generate wake-up events for given device. Implemet this callback for the ACPI platform. o Define ACPI wake-up handlers for PCI devices and PCI root buses and make the PCI-ACPI binding code register wake-up notifiers for all PCI devices present in the ACPI tables. o Add function pci_dev_run_wake() which can be used by PCI drivers to check if given device is capable of generating wake-up events at run time. Developed in cooperation with Matthew Garrett <mjg@redhat.com>. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-02-17 23:44:09 +01:00
static DEFINE_MUTEX(pci_acpi_pm_notify_mtx);
/**
* pci_acpi_wake_bus - Wake-up notification handler for root buses.
* @handle: ACPI handle of a device the notification is for.
* @event: Type of the signaled event.
* @context: PCI root bus to wake up devices on.
*/
static void pci_acpi_wake_bus(acpi_handle handle, u32 event, void *context)
{
struct pci_bus *pci_bus = context;
if (event == ACPI_NOTIFY_DEVICE_WAKE && pci_bus)
pci_pme_wakeup_bus(pci_bus);
}
/**
* pci_acpi_wake_dev - Wake-up notification handler for PCI devices.
* @handle: ACPI handle of a device the notification is for.
* @event: Type of the signaled event.
* @context: PCI device object to wake up.
*/
static void pci_acpi_wake_dev(acpi_handle handle, u32 event, void *context)
{
struct pci_dev *pci_dev = context;
if (event == ACPI_NOTIFY_DEVICE_WAKE && pci_dev) {
pci_check_pme_status(pci_dev);
pm_runtime_resume(&pci_dev->dev);
if (pci_dev->subordinate)
pci_pme_wakeup_bus(pci_dev->subordinate);
}
}
/**
* add_pm_notifier - Register PM notifier for given ACPI device.
* @dev: ACPI device to add the notifier for.
* @context: PCI device or bus to check for PME status if an event is signaled.
*
* NOTE: @dev need not be a run-wake or wake-up device to be a valid source of
* PM wake-up events. For example, wake-up events may be generated for bridges
* if one of the devices below the bridge is signaling PME, even if the bridge
* itself doesn't have a wake-up GPE associated with it.
*/
static acpi_status add_pm_notifier(struct acpi_device *dev,
acpi_notify_handler handler,
void *context)
{
acpi_status status = AE_ALREADY_EXISTS;
mutex_lock(&pci_acpi_pm_notify_mtx);
if (dev->wakeup.flags.notifier_present)
goto out;
status = acpi_install_notify_handler(dev->handle,
ACPI_SYSTEM_NOTIFY,
handler, context);
if (ACPI_FAILURE(status))
goto out;
dev->wakeup.flags.notifier_present = true;
out:
mutex_unlock(&pci_acpi_pm_notify_mtx);
return status;
}
/**
* remove_pm_notifier - Unregister PM notifier from given ACPI device.
* @dev: ACPI device to remove the notifier from.
*/
static acpi_status remove_pm_notifier(struct acpi_device *dev,
acpi_notify_handler handler)
{
acpi_status status = AE_BAD_PARAMETER;
mutex_lock(&pci_acpi_pm_notify_mtx);
if (!dev->wakeup.flags.notifier_present)
goto out;
status = acpi_remove_notify_handler(dev->handle,
ACPI_SYSTEM_NOTIFY,
handler);
if (ACPI_FAILURE(status))
goto out;
dev->wakeup.flags.notifier_present = false;
out:
mutex_unlock(&pci_acpi_pm_notify_mtx);
return status;
}
/**
* pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus.
* @dev: ACPI device to add the notifier for.
* @pci_bus: PCI bus to walk checking for PME status if an event is signaled.
*/
acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev,
struct pci_bus *pci_bus)
{
return add_pm_notifier(dev, pci_acpi_wake_bus, pci_bus);
}
/**
* pci_acpi_remove_bus_pm_notifier - Unregister PCI bus PM notifier.
* @dev: ACPI device to remove the notifier from.
*/
acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev)
{
return remove_pm_notifier(dev, pci_acpi_wake_bus);
}
/**
* pci_acpi_add_pm_notifier - Register PM notifier for given PCI device.
* @dev: ACPI device to add the notifier for.
* @pci_dev: PCI device to check for the PME status if an event is signaled.
*/
acpi_status pci_acpi_add_pm_notifier(struct acpi_device *dev,
struct pci_dev *pci_dev)
{
return add_pm_notifier(dev, pci_acpi_wake_dev, pci_dev);
}
/**
* pci_acpi_remove_pm_notifier - Unregister PCI device PM notifier.
* @dev: ACPI device to remove the notifier from.
*/
acpi_status pci_acpi_remove_pm_notifier(struct acpi_device *dev)
{
return remove_pm_notifier(dev, pci_acpi_wake_dev);
}
/*
* _SxD returns the D-state with the highest power
* (lowest D-state number) supported in the S-state "x".
*
* If the devices does not have a _PRW
* (Power Resources for Wake) supporting system wakeup from "x"
* then the OS is free to choose a lower power (higher number
* D-state) than the return value from _SxD.
*
* But if _PRW is enabled at S-state "x", the OS
* must not choose a power lower than _SxD --
* unless the device has an _SxW method specifying
* the lowest power (highest D-state number) the device
* may enter while still able to wake the system.
*
* ie. depending on global OS policy:
*
* if (_PRW at S-state x)
* choose from highest power _SxD to lowest power _SxW
* else // no _PRW at S-state x
* choose highest power _SxD or any lower power
*/
static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
{
int acpi_state;
acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL);
if (acpi_state < 0)
return PCI_POWER_ERROR;
switch (acpi_state) {
case ACPI_STATE_D0:
return PCI_D0;
case ACPI_STATE_D1:
return PCI_D1;
case ACPI_STATE_D2:
return PCI_D2;
case ACPI_STATE_D3:
return PCI_D3hot;
}
return PCI_POWER_ERROR;
}
static bool acpi_pci_power_manageable(struct pci_dev *dev)
{
acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
return handle ? acpi_bus_power_manageable(handle) : false;
}
static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
{
acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
acpi_handle tmp;
static const u8 state_conv[] = {
[PCI_D0] = ACPI_STATE_D0,
[PCI_D1] = ACPI_STATE_D1,
[PCI_D2] = ACPI_STATE_D2,
[PCI_D3hot] = ACPI_STATE_D3,
[PCI_D3cold] = ACPI_STATE_D3
};
int error = -EINVAL;
/* If the ACPI device has _EJ0, ignore the device */
if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
return -ENODEV;
switch (state) {
case PCI_D0:
case PCI_D1:
case PCI_D2:
case PCI_D3hot:
case PCI_D3cold:
error = acpi_bus_set_power(handle, state_conv[state]);
}
if (!error)
dev_printk(KERN_INFO, &dev->dev,
"power state changed by ACPI to D%d\n", state);
return error;
}
PCI ACPI: Rework PCI handling of wake-up * Introduce function acpi_pm_device_sleep_wake() for enabling and disabling the system wake-up capability of devices that are power manageable by ACPI. * Introduce function acpi_bus_can_wakeup() allowing other (dependent) subsystems to check if ACPI is able to enable the system wake-up capability of given device. * Introduce callback .sleep_wake() in struct pci_platform_pm_ops and for the ACPI PCI 'driver' make it use acpi_pm_device_sleep_wake(). * Introduce callback .can_wakeup() in struct pci_platform_pm_ops and for the ACPI 'driver' make it use acpi_bus_can_wakeup(). * Move the PME# handlig code out of pci_enable_wake() and split it into two functions, pci_pme_capable() and pci_pme_active(), allowing the caller to check if given device is capable of generating PME# from given power state and to enable/disable the device's PME# functionality, respectively. * Modify pci_enable_wake() to use the new ACPI callbacks and the new PME#-related functions. * Drop the generic .platform_enable_wakeup() callback that is not used any more. * Introduce device_set_wakeup_capable() that will set the power.can_wakeup flag of given device. * Rework PCI device PM initialization so that, if given device is capable of generating wake-up events, either natively through the PME# mechanism, or with the help of the platform, its power.can_wakeup flag is set and its power.should_wakeup flag is unset as appropriate. * Make ACPI set the power.can_wakeup flag for devices found to be wake-up capable by it. * Make the ACPI wake-up code enable/disable GPEs for devices that have the wakeup.flags.prepared flag set (which means that their wake-up power has been enabled). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-07-07 03:34:48 +02:00
static bool acpi_pci_can_wakeup(struct pci_dev *dev)
{
acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
return handle ? acpi_bus_can_wakeup(handle) : false;
}
static void acpi_pci_propagate_wakeup_enable(struct pci_bus *bus, bool enable)
{
while (bus->parent) {
if (!acpi_pm_device_sleep_wake(&bus->self->dev, enable))
return;
bus = bus->parent;
}
/* We have reached the root bus. */
if (bus->bridge)
acpi_pm_device_sleep_wake(bus->bridge, enable);
}
PCI ACPI: Rework PCI handling of wake-up * Introduce function acpi_pm_device_sleep_wake() for enabling and disabling the system wake-up capability of devices that are power manageable by ACPI. * Introduce function acpi_bus_can_wakeup() allowing other (dependent) subsystems to check if ACPI is able to enable the system wake-up capability of given device. * Introduce callback .sleep_wake() in struct pci_platform_pm_ops and for the ACPI PCI 'driver' make it use acpi_pm_device_sleep_wake(). * Introduce callback .can_wakeup() in struct pci_platform_pm_ops and for the ACPI 'driver' make it use acpi_bus_can_wakeup(). * Move the PME# handlig code out of pci_enable_wake() and split it into two functions, pci_pme_capable() and pci_pme_active(), allowing the caller to check if given device is capable of generating PME# from given power state and to enable/disable the device's PME# functionality, respectively. * Modify pci_enable_wake() to use the new ACPI callbacks and the new PME#-related functions. * Drop the generic .platform_enable_wakeup() callback that is not used any more. * Introduce device_set_wakeup_capable() that will set the power.can_wakeup flag of given device. * Rework PCI device PM initialization so that, if given device is capable of generating wake-up events, either natively through the PME# mechanism, or with the help of the platform, its power.can_wakeup flag is set and its power.should_wakeup flag is unset as appropriate. * Make ACPI set the power.can_wakeup flag for devices found to be wake-up capable by it. * Make the ACPI wake-up code enable/disable GPEs for devices that have the wakeup.flags.prepared flag set (which means that their wake-up power has been enabled). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-07-07 03:34:48 +02:00
static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
{
if (acpi_pci_can_wakeup(dev))
return acpi_pm_device_sleep_wake(&dev->dev, enable);
acpi_pci_propagate_wakeup_enable(dev->bus, enable);
return 0;
PCI ACPI: Rework PCI handling of wake-up * Introduce function acpi_pm_device_sleep_wake() for enabling and disabling the system wake-up capability of devices that are power manageable by ACPI. * Introduce function acpi_bus_can_wakeup() allowing other (dependent) subsystems to check if ACPI is able to enable the system wake-up capability of given device. * Introduce callback .sleep_wake() in struct pci_platform_pm_ops and for the ACPI PCI 'driver' make it use acpi_pm_device_sleep_wake(). * Introduce callback .can_wakeup() in struct pci_platform_pm_ops and for the ACPI 'driver' make it use acpi_bus_can_wakeup(). * Move the PME# handlig code out of pci_enable_wake() and split it into two functions, pci_pme_capable() and pci_pme_active(), allowing the caller to check if given device is capable of generating PME# from given power state and to enable/disable the device's PME# functionality, respectively. * Modify pci_enable_wake() to use the new ACPI callbacks and the new PME#-related functions. * Drop the generic .platform_enable_wakeup() callback that is not used any more. * Introduce device_set_wakeup_capable() that will set the power.can_wakeup flag of given device. * Rework PCI device PM initialization so that, if given device is capable of generating wake-up events, either natively through the PME# mechanism, or with the help of the platform, its power.can_wakeup flag is set and its power.should_wakeup flag is unset as appropriate. * Make ACPI set the power.can_wakeup flag for devices found to be wake-up capable by it. * Make the ACPI wake-up code enable/disable GPEs for devices that have the wakeup.flags.prepared flag set (which means that their wake-up power has been enabled). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-07-07 03:34:48 +02:00
}
PCI / ACPI / PM: Platform support for PCI PME wake-up Although the majority of PCI devices can generate PMEs that in principle may be used to wake up devices suspended at run time, platform support is generally necessary to convert PMEs into wake-up events that can be delivered to the kernel. If ACPI is used for this purpose, PME signals generated by a PCI device will trigger the ACPI GPE associated with the device to generate an ACPI wake-up event that we can set up a handler for, provided that everything is configured correctly. Unfortunately, the subset of PCI devices that have GPEs associated with them is quite limited. The devices without dedicated GPEs have to rely on the GPEs associated with other devices (in the majority of cases their upstream bridges and, possibly, the root bridge) to generate ACPI wake-up events in response to PME signals from them. Add ACPI platform support for PCI PME wake-up: o Add a framework making is possible to use ACPI system notify handlers for run-time PM. o Add new PCI platform callback ->run_wake() to struct pci_platform_pm_ops allowing us to enable/disable the platform to generate wake-up events for given device. Implemet this callback for the ACPI platform. o Define ACPI wake-up handlers for PCI devices and PCI root buses and make the PCI-ACPI binding code register wake-up notifiers for all PCI devices present in the ACPI tables. o Add function pci_dev_run_wake() which can be used by PCI drivers to check if given device is capable of generating wake-up events at run time. Developed in cooperation with Matthew Garrett <mjg@redhat.com>. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-02-17 23:44:09 +01:00
/**
* acpi_dev_run_wake - Enable/disable wake-up for given device.
* @phys_dev: Device to enable/disable the platform to wake-up the system for.
* @enable: Whether enable or disable the wake-up functionality.
*
* Find the ACPI device object corresponding to @pci_dev and try to
* enable/disable the GPE associated with it.
*/
static int acpi_dev_run_wake(struct device *phys_dev, bool enable)
{
struct acpi_device *dev;
acpi_handle handle;
int error = -ENODEV;
if (!device_run_wake(phys_dev))
return -EINVAL;
handle = DEVICE_ACPI_HANDLE(phys_dev);
if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &dev))) {
dev_dbg(phys_dev, "ACPI handle has no context in %s!\n",
__func__);
return -ENODEV;
}
if (enable) {
if (!dev->wakeup.run_wake_count++) {
acpi_enable_wakeup_device_power(dev, ACPI_STATE_S0);
acpi_enable_gpe(dev->wakeup.gpe_device,
dev->wakeup.gpe_number,
ACPI_GPE_TYPE_RUNTIME);
}
} else if (dev->wakeup.run_wake_count > 0) {
if (!--dev->wakeup.run_wake_count) {
acpi_disable_gpe(dev->wakeup.gpe_device,
dev->wakeup.gpe_number,
ACPI_GPE_TYPE_RUNTIME);
acpi_disable_wakeup_device_power(dev);
}
} else {
error = -EALREADY;
}
return error;
}
static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable)
{
while (bus->parent) {
struct pci_dev *bridge = bus->self;
if (bridge->pme_interrupt)
return;
if (!acpi_dev_run_wake(&bridge->dev, enable))
return;
bus = bus->parent;
}
/* We have reached the root bus. */
if (bus->bridge)
acpi_dev_run_wake(bus->bridge, enable);
}
static int acpi_pci_run_wake(struct pci_dev *dev, bool enable)
{
if (dev->pme_interrupt)
return 0;
if (!acpi_dev_run_wake(&dev->dev, enable))
return 0;
acpi_pci_propagate_run_wake(dev->bus, enable);
return 0;
}
static struct pci_platform_pm_ops acpi_pci_platform_pm = {
.is_manageable = acpi_pci_power_manageable,
.set_state = acpi_pci_set_power_state,
.choose_state = acpi_pci_choose_state,
PCI ACPI: Rework PCI handling of wake-up * Introduce function acpi_pm_device_sleep_wake() for enabling and disabling the system wake-up capability of devices that are power manageable by ACPI. * Introduce function acpi_bus_can_wakeup() allowing other (dependent) subsystems to check if ACPI is able to enable the system wake-up capability of given device. * Introduce callback .sleep_wake() in struct pci_platform_pm_ops and for the ACPI PCI 'driver' make it use acpi_pm_device_sleep_wake(). * Introduce callback .can_wakeup() in struct pci_platform_pm_ops and for the ACPI 'driver' make it use acpi_bus_can_wakeup(). * Move the PME# handlig code out of pci_enable_wake() and split it into two functions, pci_pme_capable() and pci_pme_active(), allowing the caller to check if given device is capable of generating PME# from given power state and to enable/disable the device's PME# functionality, respectively. * Modify pci_enable_wake() to use the new ACPI callbacks and the new PME#-related functions. * Drop the generic .platform_enable_wakeup() callback that is not used any more. * Introduce device_set_wakeup_capable() that will set the power.can_wakeup flag of given device. * Rework PCI device PM initialization so that, if given device is capable of generating wake-up events, either natively through the PME# mechanism, or with the help of the platform, its power.can_wakeup flag is set and its power.should_wakeup flag is unset as appropriate. * Make ACPI set the power.can_wakeup flag for devices found to be wake-up capable by it. * Make the ACPI wake-up code enable/disable GPEs for devices that have the wakeup.flags.prepared flag set (which means that their wake-up power has been enabled). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-07-07 03:34:48 +02:00
.can_wakeup = acpi_pci_can_wakeup,
.sleep_wake = acpi_pci_sleep_wake,
PCI / ACPI / PM: Platform support for PCI PME wake-up Although the majority of PCI devices can generate PMEs that in principle may be used to wake up devices suspended at run time, platform support is generally necessary to convert PMEs into wake-up events that can be delivered to the kernel. If ACPI is used for this purpose, PME signals generated by a PCI device will trigger the ACPI GPE associated with the device to generate an ACPI wake-up event that we can set up a handler for, provided that everything is configured correctly. Unfortunately, the subset of PCI devices that have GPEs associated with them is quite limited. The devices without dedicated GPEs have to rely on the GPEs associated with other devices (in the majority of cases their upstream bridges and, possibly, the root bridge) to generate ACPI wake-up events in response to PME signals from them. Add ACPI platform support for PCI PME wake-up: o Add a framework making is possible to use ACPI system notify handlers for run-time PM. o Add new PCI platform callback ->run_wake() to struct pci_platform_pm_ops allowing us to enable/disable the platform to generate wake-up events for given device. Implemet this callback for the ACPI platform. o Define ACPI wake-up handlers for PCI devices and PCI root buses and make the PCI-ACPI binding code register wake-up notifiers for all PCI devices present in the ACPI tables. o Add function pci_dev_run_wake() which can be used by PCI drivers to check if given device is capable of generating wake-up events at run time. Developed in cooperation with Matthew Garrett <mjg@redhat.com>. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-02-17 23:44:09 +01:00
.run_wake = acpi_pci_run_wake,
};
/* ACPI bus type */
static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
{
struct pci_dev * pci_dev;
u64 addr;
pci_dev = to_pci_dev(dev);
/* Please ref to ACPI spec for the syntax of _ADR */
addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
*handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr);
if (!*handle)
return -ENODEV;
return 0;
}
static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle)
{
int num;
unsigned int seg, bus;
/*
* The string should be the same as root bridge's name
* Please look at 'pci_scan_bus_parented'
*/
num = sscanf(dev_name(dev), "pci%04x:%02x", &seg, &bus);
if (num != 2)
return -ENODEV;
*handle = acpi_get_pci_rootbridge_handle(seg, bus);
if (!*handle)
return -ENODEV;
return 0;
}
static struct acpi_bus_type acpi_pci_bus = {
.bus = &pci_bus_type,
.find_device = acpi_pci_find_device,
.find_bridge = acpi_pci_find_root_bridge,
};
static int __init acpi_pci_init(void)
{
int ret;
if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_MSI) {
printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
pci_no_msi();
}
if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
pcie_no_aspm();
}
ret = register_acpi_bus_type(&acpi_pci_bus);
if (ret)
return 0;
pci_set_platform_pm(&acpi_pci_platform_pm);
return 0;
}
arch_initcall(acpi_pci_init);