Re: [RFC][PATCH 3/4] PCI / ACPI PM: Platform support for PCI PME wake-up

[Rafael J. Wysocki]

On Monday 14 September 2009, Matthew Garrett wrote:
> On Mon, Sep 14, 2009 at 12:53:05AM +0200, Rafael J. Wysocki wrote:
> > On Monday 14 September 2009, Matthew Garrett wrote:
> > > On Sun, Sep 13, 2009 at 11:24:03PM +0200, Rafael J. Wysocki wrote:
> > > > +	} else if (!dev->wakeup.flags.run_wake) {
> > > > +		acpi_set_gpe_type(dev->wakeup.gpe_device,
> > > > +					dev->wakeup.gpe_number,
> > > > +					ACPI_GPE_TYPE_WAKE);
> > > 
> > > Is this going to work for cases where we have multiple devices attached 
> > > to the same GPE? The common one is EHCI, where both EHCI HCDs will be 
> > > one a single GPE. If we wake one, that'll then disable the GPE for the 
> > > other. Further wakeup events will then be lost.
> > 
> > You're right, I overlooked that.  Some kind of refcounting is needed here.
> 
> I've sent patches to implement this at the GPE level, which also change 
> the API for requesting them. I'm waiting on feedback from Bob Moore.

In the meantime I realized there's one more thing we need to take care of.
Namely, if a wake-up GPE is shared between multiple devices, it need not be
necessary to install notify handlers for all of them.  For example, if one of
these devices is the root bridge, we will walk all of the hierarchy under it
looking for devices that have PME set, so we need not install notify handlers
for any devices that share the wake-up GPE with the root bridge.  Similarly,
there's no need to install a notify handler for a device that shares the
wake-up GPE with a bridge (non-root) it is under.

Taking that into account I have prepared another version of the @subject
patch which is appended below.  It also takes the PM vs hotplug issue into
account.  The idea is pretty straightforward, everything should be clear from
the changelog and the comments within the patch.

Thanks,
Rafael

---
From: Rafael J. Wysocki <rjw@xxxxxxx>
Subject: PCI / ACPI PM: Platform support for PCI PME wake-up (rev. 2)

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, a PME 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 and the other devices have to rely on
the GPEs associated with their upstream bridges and, possibly, the
root bridge to generate ACPI wake-up events in response to PMEs from
them.  Moreover, ACPI devices tend to share wake-up GPEs, in which
cases it makes sense to install an ACPI notify handler for only one
of them and "bind" the other devices to it.  Furthermore, ACPI-based
PCI hotplug also uses ACPI notify handlers that in general may
conflict with the PM notify handlers, unless this issue is
specifically taken care of.

Add ACPI platform support for PCI PME wake-up:
o Add a framework making is possible to use ACPI system notify
  handlers for both PM and hotplug at the same time and to take
  the wake-up GPE sharing into account.
o Add function acpi_device_run_wake() allowing us to enable or
  disable the GPE associated with given device to generate run-time
  wake-up events.
o Add a new PCI platform callback ->run_wake() to struct
  pci_platform_pm_ops allowing us to enable the platform to generate
  wake-up events for given device and implemet that callback for the
  ACPI platform.
o Define ACPI wake-up handlers for PCI devices and PCI buses and make
  the PCI-ACPI binding code register wake-up notifiers for devices
  associated with wake-up GPEs.
o Add function pci_platform_run_wake() that can be used to enable (or
  disable) the platform to generate wake-up events for given PCI
  device using the ->run_wake() platform callback.

Based on a patch from Matthew Garrett.

Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
---
 drivers/acpi/pci_bind.c            |   19 
 drivers/acpi/pci_root.c            |    5 
 drivers/acpi/sleep.c               |    4 
 drivers/acpi/wakeup.c              |   50 ++
 drivers/pci/hotplug/acpiphp_glue.c |   23 -
 drivers/pci/pci-acpi.c             |  706 +++++++++++++++++++++++++++++++++++++
 drivers/pci/pci.c                  |   32 +
 drivers/pci/pci.h                  |   19 
 include/acpi/acpi_bus.h            |   20 -
 include/linux/pci-acpi.h           |   14 
 kernel/power/Kconfig               |    5 
 11 files changed, 874 insertions(+), 23 deletions(-)

Index: linux-2.6/drivers/pci/pci.h
===================================================================
--- linux-2.6.orig/drivers/pci/pci.h
+++ linux-2.6/drivers/pci/pci.h
@@ -30,10 +30,14 @@ int pci_probe_reset_function(struct pci_
  *                platform; to be used during system-wide transitions from a
  *                sleeping state to the working state and vice versa
  *
- * @can_wakeup: returns 'true' if given device is capable of waking up the
- *              system from a sleeping state
+ * @can_wakeup: returns 'true' if the plaform can generate wake-up events for
+ *		given device.
  *
- * @sleep_wake: enables/disables the system wake up capability of given device
+ * @sleep_wake: enables/disables the wake-up capability of given device
+ *
+ * @run_wake: enables/disables the platform to generate run-time wake-up events
+ *		for given device (the device's wake-up capability has to be
+ *		enabled by @sleep_wake for this feature to work)
  *
  * If given platform is generally capable of power managing PCI devices, all of
  * these callbacks are mandatory.
@@ -44,16 +48,25 @@ struct pci_platform_pm_ops {
 	pci_power_t (*choose_state)(struct pci_dev *dev);
 	bool (*can_wakeup)(struct pci_dev *dev);
 	int (*sleep_wake)(struct pci_dev *dev, bool enable);
+	int (*run_wake)(struct pci_dev *dev, bool enable);
 };
 
 extern int pci_set_platform_pm(struct pci_platform_pm_ops *ops);
+extern int pci_platform_run_wake(struct pci_dev *dev, bool enable);
 extern void pci_update_current_state(struct pci_dev *dev, pci_power_t state);
 extern void pci_disable_enabled_device(struct pci_dev *dev);
 extern bool pci_check_pme_status(struct pci_dev *dev);
+extern int __pci_pme_wakeup(struct pci_dev *dev, void *ign);
+extern void pci_pme_wakeup_bus(struct pci_bus *bus);
 extern void pci_pm_init(struct pci_dev *dev);
 extern void platform_pci_wakeup_init(struct pci_dev *dev);
 extern void pci_allocate_cap_save_buffers(struct pci_dev *dev);
 
+static inline void pci_pme_wakeup(struct pci_dev *dev)
+{
+	__pci_pme_wakeup(dev, NULL);
+}
+
 static inline bool pci_is_bridge(struct pci_dev *pci_dev)
 {
 	return !!(pci_dev->subordinate);
Index: linux-2.6/drivers/pci/pci-acpi.c
===================================================================
--- linux-2.6.orig/drivers/pci/pci-acpi.c
+++ linux-2.6/drivers/pci/pci-acpi.c
@@ -19,6 +19,682 @@
 #include "pci.h"
 
 /*
+ * ACPI-based PCI run-time power management uses ACPI system notify handlers,
+ * which are also used by ACPI-based PCI hotplug.  Unfortunately, however, there
+ * can be only one ACPI system notify handler installed for an ACPI device
+ * handle.  For this reason there has to be a way to use the same notify handler
+ * for both ACPI-based hotplug and ACPI-based run-time PM.
+ *
+ * Moreover, there may be many PCI devices, including bridges, that share one
+ * wake-up GPE and if a wake-up event is signaled for a bridge, we will check
+ * the PME status of all devices below it, so if a device below a bridge shares
+ * a wake-up GPE with the bridge, it only makes sense to install a notify
+ * handled for the bridge, because the device is going to be checked anyway in
+ * the process of handling the bridge notification.  In particular, if any
+ * devices share a wake-up GPE with the root bridge, there only need to be a
+ * notify handler for the root bridge, because the other devices will be checked
+ * in the process of handling the root bridge wake-up.
+ *
+ * Furthermore, if many devices share one wake-up GPE, we only need to install
+ * a notify handler for one of them as long as we know which devices to check
+ * in the process of handling the notification.  The purpose of the data
+ * structures and helper functions below is to arrange things in accordance with
+ * these observations.
+ *
+ * pci_acpi_runtime_notifiers is a list of struct pci_acpi_notifier_block
+ * objects that each represent ACPI devices that have ACPI system notify
+ * handlers installed.  For each of them, there is a ACPI-based hotplug notifier
+ * to execute for hotplug events, hp_cb, and a pointer to the data to pass to it
+ * hp_data, as well as a list of PCI buses and a list of PCI devices for which
+ * to execute PME handlers in the case of ACPI-based PM events.  Since every
+ * object may represent multiple PCI devices and/or buses to handle if power
+ * management event is signaled via the GPE associated with it, there are
+ * reference counters for tracking the usage of each object.
+ */
+
+static LIST_HEAD(pci_acpi_runtime_notifiers);
+static DEFINE_MUTEX(pci_acpi_notifier_mtx);
+
+struct pci_acpi_notifier_block
+{
+	struct list_head entry;
+	struct acpi_device *dev;
+	acpi_notify_handler hp_cb;
+	void *hp_data;
+	struct list_head pm_buses;
+	struct list_head pm_devices;
+	int pm_enable_count;
+};
+
+struct pci_bus_notifier_entry
+{
+	struct list_head entry;
+	struct pci_bus *bus;
+	int enable_count;
+};
+
+struct pci_dev_notifier_entry
+{
+	struct list_head entry;
+	struct pci_dev *dev;
+	bool enabled;
+};
+
+/**
+ * pci_acpi_event_fn - Universal system notification handler.
+ * @handle: ACPI handle of a device the notification is for.
+ * @event: Type of the signaled event.
+ * @data: Context data, should be a pointer to a notifier object.
+ *
+ * Take the address on a notifier object from @data and use it to extract the
+ * information needed for handling the event.  If this is a wake-up event,
+ * check if PM notification is enabled for this notifier object and, if so,
+ * execute the appropriate PME handler for each bus and for each devices that
+ * should be checked for the PME status.  If this is not a wake-up event,
+ * execute the hotplug notify handler for @handle.
+ */
+static void pci_acpi_event_fn(acpi_handle handle, u32 event, void *data)
+{
+	struct pci_acpi_notifier_block *nb = data;
+
+	if (!nb)
+		return;
+
+	mutex_lock(&pci_acpi_notifier_mtx);
+
+	if (event == ACPI_NOTIFY_DEVICE_WAKE && nb->pm_enable_count) {
+		if (!list_empty(&nb->pm_buses)) {
+			struct pci_bus_notifier_entry *bne;
+
+			list_for_each_entry(bne, &nb->pm_buses, entry)
+				if (bne->enable_count)
+					pci_pme_wakeup_bus(bne->bus);
+		}
+		if (!list_empty(&nb->pm_devices)) {
+			struct pci_dev_notifier_entry *dne;
+
+			list_for_each_entry(dne, &nb->pm_devices, entry)
+				if (dne->enabled)
+					pci_pme_wakeup(dne->dev);
+		}
+	} else if (nb->hp_cb) {
+		nb->hp_cb(handle, event, nb->hp_data);
+	}
+
+	mutex_unlock(&pci_acpi_notifier_mtx);
+}
+
+/**
+ * new_notifier - Create a new notifier object for given ACPI device.
+ * @dev: Device to create the notifier object for.
+ */
+static struct pci_acpi_notifier_block *new_notifier(struct acpi_device *dev)
+{
+	struct pci_acpi_notifier_block *nb;
+
+	nb = kzalloc(sizeof(*nb), GFP_KERNEL);
+	if (!nb)
+		return NULL;
+
+	nb->dev = dev;
+	INIT_LIST_HEAD(&nb->pm_buses);
+	INIT_LIST_HEAD(&nb->pm_devices);
+
+	return nb;
+}
+
+/**
+ * pci_acpi_add_hp_notifier - Register a hotplug notifier for given device.
+ * @handle: ACPI handle of the device to register the notifier for.
+ * @handler: Callback to execute for hotplug events related to @handle.
+ * @context: Pointer to the context data to pass to @handler.
+ *
+ * Use @handle to get an ACPI device object and check if there is a notifier
+ * object for it.  If this is the case, add @handler and @context to the
+ * existing notifier object, unless there already is a hotplug handler in this
+ * notifier object.  Otherwise, create a new notifier object for the ACPI device
+ * associated with @handle and add @handler and @context to it.
+ */
+acpi_status pci_acpi_add_hp_notifier(acpi_handle handle,
+				     acpi_notify_handler handler, void *context)
+{
+	struct pci_acpi_notifier_block *nb;
+	struct acpi_device *dev;
+	acpi_status status = AE_OK;
+
+	if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &dev)))
+		return AE_NOT_FOUND;
+
+	mutex_lock(&pci_acpi_notifier_mtx);
+
+	list_for_each_entry(nb, &pci_acpi_runtime_notifiers, entry) {
+		if (nb->dev != dev)
+			continue;
+
+		if (!nb->hp_cb) {
+			nb->hp_cb = handler;
+			nb->hp_data = context;
+		} else {
+			status = AE_ALREADY_EXISTS;
+		}
+		goto out;
+	}
+
+	nb = new_notifier(dev);
+	if (!nb) {
+		status = AE_NO_MEMORY;
+		goto out;
+	}
+	nb->hp_cb = handler;
+	nb->hp_data = context;
+
+	list_add_tail(&nb->entry, &pci_acpi_runtime_notifiers);
+
+	status = acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
+						pci_acpi_event_fn, nb);
+	if (ACPI_FAILURE(status)) {
+		list_del(&nb->entry);
+		kfree(nb);
+	}
+
+ out:
+	mutex_unlock(&pci_acpi_notifier_mtx);
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(pci_acpi_add_hp_notifier);
+
+/**
+ * pci_acpi_remove_hp_notifier - Unregister a hotplug notifier for given device.
+ * @handle: ACPI handle of the device to unregister the notifier for.
+ * @handler: Callback executed for hotplug events related to @handle.
+ *
+ * Find the notifier object associated with @handle and remove the hotplug
+ * callback and the pointer to the hotplug context data from it.  If the
+ * notifier object is not necessary any more, remove it altogether.
+ */
+acpi_status pci_acpi_remove_hp_notifier(acpi_handle handle,
+					acpi_notify_handler handler)
+{
+	struct pci_acpi_notifier_block *nb;
+	struct acpi_device *dev;
+	acpi_status status = AE_OK;
+
+	if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &dev)))
+		return AE_NOT_FOUND;
+
+	mutex_lock(&pci_acpi_notifier_mtx);
+
+	list_for_each_entry(nb, &pci_acpi_runtime_notifiers, entry)
+		if (nb->dev == dev)
+			goto found;
+
+	mutex_unlock(&pci_acpi_notifier_mtx);
+	return AE_NOT_FOUND;
+
+ found:
+	if (list_empty(&nb->pm_buses) && list_empty(&nb->pm_devices)) {
+		status = acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
+							pci_acpi_event_fn);
+		list_del(&nb->entry);
+		kfree(nb);
+	} else {
+		nb->hp_data = NULL;
+		nb->hp_cb = NULL;
+	}
+
+	mutex_unlock(&pci_acpi_notifier_mtx);
+	return status;
+}
+EXPORT_SYMBOL_GPL(pci_acpi_remove_hp_notifier);
+
+/**
+ * bus_match - Check if one PCI bus is upstream from another.
+ * @target: PCI bus expected to be upstream from the other.
+ * @bus: PCI bus expected to be downstream from the other.
+ *
+ * Return 'ture' if @target is upstream with respect to @bus.
+ */
+static inline bool bus_match(struct pci_bus *target, struct pci_bus *bus)
+{
+	return pci_domain_nr(target) == pci_domain_nr(bus)
+		&& (pci_is_root_bus(target) || (bus->number >= target->number
+		    && bus->number <= target->subordinate));
+}
+
+/**
+ * new_dev_entry - Create a new device notifier entry.
+ * @dev: PCI device to create the entry for.
+ * @list: List to add the new entry to.
+ */
+static struct pci_dev_notifier_entry *new_dev_entry(struct pci_dev *dev,
+						    struct list_head *list)
+{
+	struct pci_dev_notifier_entry *dne;
+
+	dne = kzalloc(sizeof(*dne), GFP_KERNEL);
+	if (!dne)
+		return NULL;
+
+	dne->dev = dev;
+	list_add_tail(&dne->entry, list);
+
+	return dne;
+}
+
+/**
+ * pci_acpi_add_device_pm_notifier - Register PM notifier for given device.
+ * @dev: ACPI device to add the notifier for.
+ * @pci_dev: PCI device to check for the PME status if an event is signaled.
+ *
+ * Check if there is a notifier object for @dev and if that is the case, add
+ * @pci_dev to its list of devices whose PME status should be checked if a PM
+ * event is signaled for @dev, unless @pci_dev is covered by one of the buses
+ * in the notifier's bus list.  Otherwise, create a new notifier object for @dev
+ * and add @pci_dev to its list of devices whose PME status to check.
+ */
+acpi_status pci_acpi_add_device_pm_notifier(struct acpi_device *dev,
+					    struct pci_dev *pci_dev)
+{
+	struct pci_acpi_notifier_block *nb;
+	struct pci_dev_notifier_entry *dne;
+	struct pci_bus *bus = pci_dev->bus;
+	acpi_status status = AE_OK;
+
+	if (!dev->wakeup.flags.valid)
+		return AE_BAD_PARAMETER;
+
+	mutex_lock(&pci_acpi_notifier_mtx);
+
+	list_for_each_entry(nb, &pci_acpi_runtime_notifiers, entry) {
+		struct pci_bus_notifier_entry *bne;
+
+		if (!acpi_wakeup_gpe_shared(nb->dev, dev))
+			continue;
+
+		list_for_each_entry(bne, &nb->pm_buses, entry)
+			if (bus_match(bne->bus, bus))
+				goto out;
+
+		list_for_each_entry(dne, &nb->pm_devices, entry)
+			if (dne->dev == pci_dev)
+				goto out;
+
+		if (!new_dev_entry(pci_dev, &nb->pm_devices))
+			status = AE_NO_MEMORY;
+		goto out;
+	}
+
+	nb = new_notifier(dev);
+	if (!nb) {
+		status = AE_NO_MEMORY;
+		goto out;
+	}
+
+	dne = new_dev_entry(pci_dev, &nb->pm_devices);
+	if (!dne) {
+		kfree(nb);
+		status = AE_NO_MEMORY;
+		goto out;
+	}
+
+	list_add_tail(&nb->entry, &pci_acpi_runtime_notifiers);
+
+	status = acpi_install_notify_handler(dev->handle, ACPI_SYSTEM_NOTIFY,
+						pci_acpi_event_fn, nb);
+	if (ACPI_FAILURE(status)) {
+		list_del(&dne->entry);
+		kfree(dne);
+		list_del(&nb->entry);
+		kfree(nb);
+	}
+
+ out:
+	mutex_unlock(&pci_acpi_notifier_mtx);
+	return status;
+}
+
+/**
+ * pci_acpi_remove_device_pm_notifier - Unregister PM notifier for given device.
+ * @dev: ACPI device to remove the notifier from.
+ * @pci_dev: PCI device whose PME status is checked if an event is signaled.
+ *
+ * Find the notifier object for @dev and remove @pci_dev from its list of
+ * devices whose PME status to check when wake-up event is signaled.  If the
+ * notifier object is not necessary any more after that, remove it too.
+ */
+acpi_status pci_acpi_remove_device_pm_notifier(struct acpi_device *dev,
+					       struct pci_dev *pci_dev)
+{
+	struct pci_acpi_notifier_block *nb;
+	struct pci_dev_notifier_entry *dne = NULL;
+	acpi_status status = AE_OK;
+
+	mutex_lock(&pci_acpi_notifier_mtx);
+
+	list_for_each_entry(nb, &pci_acpi_runtime_notifiers, entry) {
+		if (!acpi_wakeup_gpe_shared(nb->dev, dev))
+			continue;
+
+		list_for_each_entry(dne, &nb->pm_devices, entry)
+			if (dne->dev == pci_dev)
+				goto found;
+	}
+
+	mutex_unlock(&pci_acpi_notifier_mtx);
+	return AE_NOT_FOUND;
+
+ found:
+	if (dne->enabled) {
+		if (!--nb->pm_enable_count)
+			acpi_device_run_wake(nb->dev, false);
+	}
+	list_del(&dne->entry);
+	kfree(dne);
+
+	if (list_empty(&nb->pm_devices) && list_empty(&nb->pm_buses)
+	    && !nb->hp_cb) {
+		status = acpi_remove_notify_handler(nb->dev->handle,
+							ACPI_SYSTEM_NOTIFY,
+							pci_acpi_event_fn);
+		list_del(&nb->entry);
+		kfree(nb);
+	}
+
+	mutex_unlock(&pci_acpi_notifier_mtx);
+	return status;
+}
+
+/**
+ * new_bus_entry - Create a new bus notifier entry.
+ * @bus: PCI bus to create the entry for.
+ * @list: List to add the new entry to.
+ */
+static struct pci_bus_notifier_entry *new_bus_entry(struct pci_bus *bus,
+						    struct list_head *list)
+{
+	struct pci_bus_notifier_entry *bne;
+
+	bne = kzalloc(sizeof(*bne), GFP_KERNEL);
+	if (!bne)
+		return NULL;
+
+	bne->bus = bus;
+	list_add_tail(&bne->entry, list);
+
+	return bne;
+}
+
+/**
+ * pci_acpi_add_bus_pm_notifier - Register PM notifier for given PCI bus.
+ * @dev: ACPI device to add the notifier for.
+ * @bus: PCI bus to walk if an event is signaled.
+ *
+ * Check if there is a notifier object for @dev and if that is the case, add
+ * @bus to its list of buses to walk, checking the PME status of all devices on
+ * them, if a PM event is signaled for @dev, unless @bus or a PCI bus upstream
+ * with respect to it is in the list already.  Otherwise, create a new notifier
+ * object for @dev and add @bus to its list of buses to walk if a PM event is
+ * signaled.
+ */
+acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev,
+					 struct pci_bus *bus)
+{
+	struct pci_acpi_notifier_block *nb;
+	struct pci_bus_notifier_entry *bne;
+	acpi_status status = AE_OK;
+
+	if (!dev->wakeup.flags.valid)
+		return AE_BAD_PARAMETER;
+
+	mutex_lock(&pci_acpi_notifier_mtx);
+
+	list_for_each_entry(nb, &pci_acpi_runtime_notifiers, entry) {
+		if (!acpi_wakeup_gpe_shared(nb->dev, dev))
+			continue;
+
+		list_for_each_entry(bne, &nb->pm_buses, entry)
+			if (bus_match(bne->bus, bus))
+				goto out;
+
+		if (!new_bus_entry(bus, &nb->pm_buses))
+			status = AE_NO_MEMORY;
+		goto out;
+	}
+
+	nb = new_notifier(dev);
+	if (!nb) {
+		status = AE_NO_MEMORY;
+		goto out;
+	}
+
+	bne = new_bus_entry(bus, &nb->pm_buses);
+	if (!bne) {
+		kfree(nb);
+		status = AE_NO_MEMORY;
+		goto out;
+	}
+
+	list_add_tail(&nb->entry, &pci_acpi_runtime_notifiers);
+
+	status = acpi_install_notify_handler(dev->handle, ACPI_SYSTEM_NOTIFY,
+						pci_acpi_event_fn, nb);
+	if (ACPI_FAILURE(status)) {
+		list_del(&bne->entry);
+		kfree(bne);
+		list_del(&nb->entry);
+		kfree(nb);
+	}
+
+ out:
+	mutex_unlock(&pci_acpi_notifier_mtx);
+	return status;
+}
+
+/**
+ * pci_acpi_remove_bus_pm_notifier - Unregister PM notifier for given PCI bus.
+ * @dev: ACPI device to remove the notifier from.
+ * @bus: PCI bus that is walked if an event is signaled.
+ *
+ * Find the notifier object for @dev and remove @bus from its list of buses to
+ * walk when wake-up event is signaled.  If the notifier object is not necessary
+ * any more after that, remove it too.
+ */
+acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev,
+					    struct pci_bus *bus)
+{
+	struct pci_acpi_notifier_block *nb;
+	struct pci_bus_notifier_entry *bne = NULL;
+	acpi_status status = AE_OK;
+
+	mutex_lock(&pci_acpi_notifier_mtx);
+
+	list_for_each_entry(nb, &pci_acpi_runtime_notifiers, entry) {
+		if (!acpi_wakeup_gpe_shared(nb->dev, dev))
+			continue;
+
+		list_for_each_entry(bne, &nb->pm_buses, entry)
+			if (bne->bus == bus)
+				goto found;
+	}
+
+	mutex_unlock(&pci_acpi_notifier_mtx);
+	return AE_NOT_FOUND;
+
+ found:
+	if (bne->enable_count) {
+		nb->pm_enable_count -= bne->enable_count;
+		if (!nb->pm_enable_count)
+			acpi_device_run_wake(nb->dev, false);
+	}
+	list_del(&bne->entry);
+	kfree(bne);
+
+	if (list_empty(&nb->pm_devices) && list_empty(&nb->pm_buses)
+	    && !nb->hp_cb) {
+		status = acpi_remove_notify_handler(nb->dev->handle,
+							ACPI_SYSTEM_NOTIFY,
+							pci_acpi_event_fn);
+		list_del(&nb->entry);
+		kfree(nb);
+	}
+
+	mutex_unlock(&pci_acpi_notifier_mtx);
+	return status;
+}
+
+/**
+ * dev_run_wake - Enable/disable the GPE associated with given notifier.
+ * @nb: Notifier to enable/disable the GPE for.
+ * @dne: Device notifier entry for the device being enabled/disabled to wake-up.
+ * @enable: Whether to enable or disable the GPE.
+ */
+static int dev_run_wake(struct pci_acpi_notifier_block *nb,
+			struct pci_dev_notifier_entry *dne, bool enable)
+{
+	int error = 0;
+
+	if (enable) {
+		dne->enabled = true;
+		if (!nb->pm_enable_count++)
+			acpi_device_run_wake(nb->dev, true);
+	} else if (dne->enabled) {
+		dne->enabled = false;
+		if (!--nb->pm_enable_count)
+			acpi_device_run_wake(nb->dev, false);
+	} else {
+		error = -EALREADY;
+	}
+
+	return error;
+}
+
+/**
+ * bus_run_wake - Enable/disable the GPE associated with given notifier.
+ * @nb: Notifier to enable/disable the GPE for.
+ * @bne: Bus notifier entry for a bridge being enabled/disabled to wake-up.
+ * @enable: Whether to enable or disable the GPE.
+ */
+static int bus_run_wake(struct pci_acpi_notifier_block *nb,
+			struct pci_bus_notifier_entry *bne, bool enable)
+{
+	int error = 0;
+
+	if (enable) {
+		bne->enable_count++;
+		if (!nb->pm_enable_count++)
+			acpi_device_run_wake(nb->dev, true);
+	} else if (bne->enable_count) {
+		bne->enable_count--;
+		if (!--nb->pm_enable_count)
+			acpi_device_run_wake(nb->dev, false);
+	} else {
+		error = -EALREADY;
+	}
+
+	return error;
+}
+
+/**
+ * __acpi_dev_run_wake - Enable/disable wake-up for given PCI device.
+ * @pci_dev: Device to enable/disable the platform to wake-up the system for.
+ * @enable: Whether enable or disable the wake-up functionality.
+ *
+ * Find the notifier object corresponding to @pci_dev and try to enable/disable
+ * the GPE associated with it.
+ */
+static int __acpi_dev_run_wake(struct pci_dev *pci_dev, bool enable)
+{
+	struct pci_acpi_notifier_block *nb;
+	struct pci_bus *bus = pci_dev->bus;
+	struct acpi_device *dev;
+	acpi_handle handle;
+	int error = -ENODEV;
+
+	if (!device_can_wakeup(&pci_dev->dev))
+		return -EINVAL;
+
+	handle = DEVICE_ACPI_HANDLE(&pci_dev->dev);
+	if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &dev))) {
+		dev_dbg(&pci_dev->dev, "ACPI handle has no context in %s!\n",
+			__func__);
+		return -ENODEV;
+	}
+
+	mutex_lock(&pci_acpi_notifier_mtx);
+
+	list_for_each_entry(nb, &pci_acpi_runtime_notifiers, entry) {
+		struct pci_bus_notifier_entry *bne;
+		struct pci_dev_notifier_entry *dne;
+
+		if (!acpi_wakeup_gpe_shared(nb->dev, dev))
+			continue;
+
+		list_for_each_entry(bne, &nb->pm_buses, entry)
+			if (bus_match(bne->bus, bus)) {
+				error = bus_run_wake(nb, bne, enable);
+				goto out;
+			}
+
+		list_for_each_entry(dne, &nb->pm_devices, entry)
+			if (dne->dev == pci_dev) {
+				error = dev_run_wake(nb, dne, enable);
+				goto out;
+			}
+	}
+
+ out:
+	mutex_unlock(&pci_acpi_notifier_mtx);
+	return error;
+}
+
+/**
+ * __acpi_bridge_run_wake - Enable/disable wake-up for given bridge.
+ * @bridge: Bridge to enable/disable the platform to wake-up the system for.
+ * @enable: Whether enable or disable the wake-up functionality.
+ *
+ * Find the notifier object corresponding to @bridge and try to enable/disable
+ * the GPE associated with it, under the assumption that @bridge may be a PCI
+ * root bridge.
+ */
+static int __acpi_bridge_run_wake(struct device *bridge, bool enable)
+{
+	struct pci_acpi_notifier_block *nb;
+	struct acpi_device *dev;
+	acpi_handle handle;
+	int error = -ENODEV;
+
+	if (!device_can_wakeup(bridge))
+		return -EINVAL;
+
+	handle = DEVICE_ACPI_HANDLE(bridge);
+	if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &dev))) {
+		dev_dbg(bridge, "ACPI handle has no context in %s!\n",
+			__func__);
+		return -ENODEV;
+	}
+
+	mutex_lock(&pci_acpi_notifier_mtx);
+
+	list_for_each_entry(nb, &pci_acpi_runtime_notifiers, entry) {
+		struct pci_bus_notifier_entry *bne;
+
+		if (!acpi_wakeup_gpe_shared(nb->dev, dev))
+			continue;
+
+		list_for_each_entry(bne, &nb->pm_buses, entry)
+			if (bne->bus->bridge == bridge) {
+				error = bus_run_wake(nb, bne, enable);
+				goto out;
+			}
+	}
+
+ out:
+	mutex_unlock(&pci_acpi_notifier_mtx);
+	return error;
+}
+
+/*
  * _SxD returns the D-state with the highest power
  * (lowest D-state number) supported in the S-state "x".
  *
@@ -137,12 +813,42 @@ static int acpi_pci_sleep_wake(struct pc
 	return 0;
 }
 
+static void acpi_pci_propagate_run_wake(struct pci_bus *bus, bool enable)
+{
+	while (bus->parent) {
+		struct pci_dev *bridge = bus->self;
+
+		if (pcie_pme_enabled(bridge))
+			return;
+		if (!__acpi_dev_run_wake(bridge, enable))
+			return;
+		bus = bus->parent;
+	}
+
+	/* We have reached the root bus. */
+	if (bus->bridge)
+		__acpi_bridge_run_wake(bus->bridge, enable);
+}
+
+static int acpi_pci_run_wake(struct pci_dev *dev, bool enable)
+{
+	if (pcie_pme_enabled(dev))
+		return 0;
+
+	if (acpi_pci_can_wakeup(dev))
+		return __acpi_dev_run_wake(dev, enable);
+
+	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,
 	.can_wakeup = acpi_pci_can_wakeup,
 	.sleep_wake = acpi_pci_sleep_wake,
+	.run_wake = acpi_pci_run_wake,
 };
 
 /* ACPI bus type */
Index: linux-2.6/drivers/pci/pci.c
===================================================================
--- linux-2.6.orig/drivers/pci/pci.c
+++ linux-2.6/drivers/pci/pci.c
@@ -21,6 +21,7 @@
 #include <linux/interrupt.h>
 #include <asm/dma.h>	/* isa_dma_bridge_buggy */
 #include <linux/device.h>
+#include <linux/pm_runtime.h>
 #include <asm/setup.h>
 #include "pci.h"
 
@@ -434,6 +435,12 @@ static inline int platform_pci_sleep_wak
 			pci_platform_pm->sleep_wake(dev, enable) : -ENODEV;
 }
 
+int pci_platform_run_wake(struct pci_dev *dev, bool enable)
+{
+	return pci_platform_pm ?
+			pci_platform_pm->run_wake(dev, enable) : -ENODEV;
+}
+
 /**
  * pci_raw_set_power_state - Use PCI PM registers to set the power state of
  *                           given PCI device
@@ -1202,6 +1209,31 @@ bool pci_check_pme_status(struct pci_dev
 }
 
 /**
+ * pci_pme_wakeup - Wake up a PCI device if its PME Status bit is set.
+ * @dev: Device to handle.
+ * @ign: Ignored.
+ *
+ * Check if @dev has generated PME and queue a resume request for it in that
+ * case.
+ */
+int __pci_pme_wakeup(struct pci_dev *dev, void *ign)
+{
+	if (pci_check_pme_status(dev))
+		pm_request_resume(&dev->dev);
+	return 0;
+}
+
+/**
+ * pci_pme_wakeup_bus - Walk given bus and wake up devices on it, if necessary.
+ * @bus: Top bus of the subtree to walk.
+ */
+void pci_pme_wakeup_bus(struct pci_bus *bus)
+{
+	if (bus)
+		pci_walk_bus(bus, __pci_pme_wakeup, NULL);
+}
+
+/**
  * pci_pme_capable - check the capability of PCI device to generate PME#
  * @dev: PCI device to handle.
  * @state: PCI state from which device will issue PME#.
Index: linux-2.6/drivers/acpi/wakeup.c
===================================================================
--- linux-2.6.orig/drivers/acpi/wakeup.c
+++ linux-2.6/drivers/acpi/wakeup.c
@@ -124,6 +124,56 @@ void acpi_disable_wakeup_device(u8 sleep
 	}
 }
 
+#ifdef CONFIG_PM_WAKEUP
+/**
+ * acpi_device_run_wake - Enable/disable ACPI BIOS to generate wake-up events.
+ * @dev: Device to generate the wake-up events for.
+ * @enable: Desired action.
+ *
+ * If @enable is set, set up the GPE associated with @phys_dev to generate
+ * wake-up events at run time.  If @enable is unset, disable the GPE associated
+ * with @phys_dev (unless it is marked as a run-wake device).
+ */
+int acpi_device_run_wake(struct acpi_device *dev, bool enable)
+{
+	if (!dev || !dev->wakeup.flags.valid)
+		return -EINVAL;
+
+	if (enable) {
+		if (!dev->wakeup.state.enabled && !dev->wakeup.prepare_count)
+			return -EINVAL;
+
+		acpi_set_gpe_type(dev->wakeup.gpe_device,
+					dev->wakeup.gpe_number,
+					ACPI_GPE_TYPE_WAKE_RUN);
+		acpi_enable_gpe(dev->wakeup.gpe_device,
+					dev->wakeup.gpe_number);
+	} else if (!dev->wakeup.flags.run_wake) {
+		acpi_set_gpe_type(dev->wakeup.gpe_device,
+					dev->wakeup.gpe_number,
+					ACPI_GPE_TYPE_WAKE);
+		acpi_disable_gpe(dev->wakeup.gpe_device,
+					dev->wakeup.gpe_number);
+		acpi_clear_gpe(dev->wakeup.gpe_device,
+					dev->wakeup.gpe_number, ACPI_NOT_ISR);
+	}
+
+	return 0;
+}
+
+/**
+ * acpi_wakeup_gpes_shared - Check if given ACPI devices share a wake-up GPE.
+ * @deva: First ACPI device to check.
+ * @devb: Second ACPI device to check.
+ */
+bool acpi_wakeup_gpe_shared(struct acpi_device *deva, struct acpi_device *devb)
+{
+	return deva->wakeup.flags.valid && devb->wakeup.flags.valid
+		&& deva->wakeup.gpe_device == devb->wakeup.gpe_device
+		&& deva->wakeup.gpe_number == devb->wakeup.gpe_number;
+}
+#endif /* CONFIG_PM_WAKEUP */
+
 int __init acpi_wakeup_device_init(void)
 {
 	struct list_head *node, *next;
Index: linux-2.6/include/acpi/acpi_bus.h
===================================================================
--- linux-2.6.orig/include/acpi/acpi_bus.h
+++ linux-2.6/include/acpi/acpi_bus.h
@@ -391,21 +391,35 @@ acpi_handle acpi_get_pci_rootbridge_hand
 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle);
 #define DEVICE_ACPI_HANDLE(dev) ((acpi_handle)((dev)->archdata.acpi_handle))
 
-#ifdef CONFIG_PM_SLEEP
+#ifdef CONFIG_PM_WAKEUP
 int acpi_pm_device_sleep_state(struct device *, int *);
 int acpi_pm_device_sleep_wake(struct device *, bool);
-#else /* !CONFIG_PM_SLEEP */
+int acpi_device_run_wake(struct acpi_device *, bool);
+bool acpi_wakeup_gpe_shared(struct acpi_device *, struct acpi_device *);
+#else /* !CONFIG_PM_WAKEUP */
 static inline int acpi_pm_device_sleep_state(struct device *d, int *p)
 {
 	if (p)
 		*p = ACPI_STATE_D0;
 	return ACPI_STATE_D3;
 }
+
 static inline int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
 {
 	return -ENODEV;
 }
-#endif /* !CONFIG_PM_SLEEP */
+
+static inline int acpi_device_run_wake(struct device *dev, bool enable)
+{
+	return -ENODEV;
+}
+
+static inline bool acpi_wakeup_gpe_shared(struct acpi_device *a,
+					   struct acpi_device *b)
+{
+	return false;
+}
+#endif /* !CONFIG_PM_WAKEUP */
 
 #endif				/* CONFIG_ACPI */
 
Index: linux-2.6/kernel/power/Kconfig
===================================================================
--- linux-2.6.orig/kernel/power/Kconfig
+++ linux-2.6/kernel/power/Kconfig
@@ -236,3 +236,8 @@ config PM_RUNTIME
 	  and the bus type drivers of the buses the devices are on are
 	  responsible for the actual handling of the autosuspend requests and
 	  wake-up events.
+
+config PM_WAKEUP
+	bool
+	depends on SUSPEND || HIBERNATION || PM_RUNTIME
+	default y
Index: linux-2.6/drivers/acpi/sleep.c
===================================================================
--- linux-2.6.orig/drivers/acpi/sleep.c
+++ linux-2.6/drivers/acpi/sleep.c
@@ -594,7 +594,7 @@ int acpi_suspend(u32 acpi_state)
 	return -EINVAL;
 }
 
-#ifdef CONFIG_PM_SLEEP
+#ifdef CONFIG_PM_WAKEUP
 /**
  *	acpi_pm_device_sleep_state - return preferred power state of ACPI device
  *		in the system sleep state given by %acpi_target_sleep_state
@@ -709,7 +709,7 @@ int acpi_pm_device_sleep_wake(struct dev
 
 	return error;
 }
-#endif
+#endif /* CONFIG_PM_WAKEUP */
 
 static void acpi_power_off_prepare(void)
 {
Index: linux-2.6/drivers/acpi/pci_root.c
===================================================================
--- linux-2.6.orig/drivers/acpi/pci_root.c
+++ linux-2.6/drivers/acpi/pci_root.c
@@ -563,6 +563,9 @@ static int __devinit acpi_pci_root_add(s
 	if (flags != base_flags)
 		acpi_pci_osc_support(root, flags);
 
+	if (device->wakeup.flags.valid)
+		pci_acpi_add_bus_pm_notifier(device, root->bus);
+
 	return 0;
 
 end:
@@ -584,6 +587,8 @@ static int acpi_pci_root_remove(struct a
 {
 	struct acpi_pci_root *root = acpi_driver_data(device);
 
+	if (device->wakeup.flags.valid)
+		pci_acpi_remove_bus_pm_notifier(device, root->bus);
 	kfree(root);
 	return 0;
 }
Index: linux-2.6/include/linux/pci-acpi.h
===================================================================
--- linux-2.6.orig/include/linux/pci-acpi.h
+++ linux-2.6/include/linux/pci-acpi.h
@@ -11,6 +11,20 @@
 #include <linux/acpi.h>
 
 #ifdef CONFIG_ACPI
+extern acpi_status pci_acpi_add_hp_notifier(acpi_handle handle,
+					     acpi_notify_handler handler,
+					     void *context);
+extern acpi_status pci_acpi_remove_hp_notifier(acpi_handle handle,
+					       acpi_notify_handler handler);
+extern acpi_status pci_acpi_add_device_pm_notifier(struct acpi_device *dev,
+						   struct pci_dev *pci_dev);
+extern acpi_status pci_acpi_remove_device_pm_notifier(struct acpi_device *dev,
+						      struct pci_dev *pci_dev);
+extern acpi_status pci_acpi_add_bus_pm_notifier(struct acpi_device *dev,
+						struct pci_bus *bus);
+extern acpi_status pci_acpi_remove_bus_pm_notifier(struct acpi_device *dev,
+						   struct pci_bus *bus);
+
 static inline acpi_handle acpi_find_root_bridge_handle(struct pci_dev *pdev)
 {
 	struct pci_bus *pbus = pdev->bus;
Index: linux-2.6/drivers/acpi/pci_bind.c
===================================================================
--- linux-2.6.orig/drivers/acpi/pci_bind.c
+++ linux-2.6/drivers/acpi/pci_bind.c
@@ -26,6 +26,7 @@
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/pci.h>
+#include <linux/pci-acpi.h>
 #include <linux/acpi.h>
 #include <acpi/acpi_bus.h>
 #include <acpi/acpi_drivers.h>
@@ -38,7 +39,17 @@ static int acpi_pci_unbind(struct acpi_d
 	struct pci_dev *dev;
 
 	dev = acpi_get_pci_dev(device->handle);
-	if (!dev || !dev->subordinate)
+	if (!dev)
+		goto out;
+
+	if (device->wakeup.flags.valid) {
+		if (dev->subordinate)
+			pci_acpi_remove_bus_pm_notifier(device,
+							dev->subordinate);
+		pci_acpi_remove_device_pm_notifier(device, dev);
+	}
+
+	if (!dev->subordinate)
 		goto out;
 
 	acpi_pci_irq_del_prt(dev->subordinate);
@@ -94,6 +105,12 @@ static int acpi_pci_bind(struct acpi_dev
 
 	acpi_pci_irq_add_prt(device->handle, bus);
 
+	if (device->wakeup.flags.valid) {
+		pci_acpi_add_device_pm_notifier(device, dev);
+		if (dev->subordinate)
+			pci_acpi_add_bus_pm_notifier(device, dev->subordinate);
+	}
+
 out:
 	pci_dev_put(dev);
 	return 0;
Index: linux-2.6/drivers/pci/hotplug/acpiphp_glue.c
===================================================================
--- linux-2.6.orig/drivers/pci/hotplug/acpiphp_glue.c
+++ linux-2.6/drivers/pci/hotplug/acpiphp_glue.c
@@ -238,8 +238,7 @@ register_slot(acpi_handle handle, u32 lv
 
 	/* install notify handler */
 	if (!(newfunc->flags & FUNC_HAS_DCK)) {
-		status = acpi_install_notify_handler(handle,
-					     ACPI_SYSTEM_NOTIFY,
+		status = pci_acpi_add_hp_notifier(handle,
 					     handle_hotplug_event_func,
 					     newfunc);
 
@@ -290,14 +289,12 @@ static void init_bridge_misc(struct acpi
 	/* install notify handler */
 	if (bridge->type != BRIDGE_TYPE_HOST) {
 		if ((bridge->flags & BRIDGE_HAS_EJ0) && bridge->func) {
-			status = acpi_remove_notify_handler(bridge->func->handle,
-						ACPI_SYSTEM_NOTIFY,
+			status = pci_acpi_remove_hp_notifier(bridge->func->handle,
 						handle_hotplug_event_func);
 			if (ACPI_FAILURE(status))
 				err("failed to remove notify handler\n");
 		}
-		status = acpi_install_notify_handler(bridge->handle,
-					     ACPI_SYSTEM_NOTIFY,
+		status = pci_acpi_add_hp_notifier(bridge->handle,
 					     handle_hotplug_event_bridge,
 					     bridge);
 
@@ -513,15 +510,14 @@ static void cleanup_bridge(struct acpiph
 	acpi_status status;
 	acpi_handle handle = bridge->handle;
 
-	status = acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
+	status = pci_acpi_remove_hp_notifier(handle,
 					    handle_hotplug_event_bridge);
 	if (ACPI_FAILURE(status))
 		err("failed to remove notify handler\n");
 
 	if ((bridge->type != BRIDGE_TYPE_HOST) &&
 	    ((bridge->flags & BRIDGE_HAS_EJ0) && bridge->func)) {
-		status = acpi_install_notify_handler(bridge->func->handle,
-						ACPI_SYSTEM_NOTIFY,
+		status = pci_acpi_add_hp_notifier(bridge->func->handle,
 						handle_hotplug_event_func,
 						bridge->func);
 		if (ACPI_FAILURE(status))
@@ -539,8 +535,7 @@ static void cleanup_bridge(struct acpiph
 				unregister_dock_notifier(&func->nb);
 			}
 			if (!(func->flags & FUNC_HAS_DCK)) {
-				status = acpi_remove_notify_handler(func->handle,
-						ACPI_SYSTEM_NOTIFY,
+				status = pci_acpi_remove_hp_notifier(func->handle,
 						handle_hotplug_event_func);
 				if (ACPI_FAILURE(status))
 					err("failed to remove notify handler\n");
@@ -602,7 +597,7 @@ static void remove_bridge(acpi_handle ha
 	if (bridge)
 		cleanup_bridge(bridge);
 	else
-		acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
+		pci_acpi_remove_hp_notifier(handle,
 					   handle_hotplug_event_bridge);
 }
 
@@ -1492,8 +1487,8 @@ find_root_bridges(acpi_handle handle, u3
 	int *count = (int *)context;
 
 	if (acpi_is_root_bridge(handle)) {
-		acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
-				handle_hotplug_event_bridge, NULL);
+		pci_acpi_add_hp_notifier(handle,
+					handle_hotplug_event_bridge, NULL);
 			(*count)++;
 	}
 	return AE_OK ;
--
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