Merge tag 'pm+acpi-3.10-late' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull late power management and ACPI fixes from Rafael Wysocki:
 "Sorry about the timing of this, but ACPI-based docking stations with
  PCI devices on them and ATA bays would be hardly usable with 3.10
  without it.  We've been working on these fixes for the last couple of
  weeks and everyone involved appears to be reasonably comfortable with
  them now.

  The PM part is one fix for a cpufreq regression introduced recently

   - Fix for an ACPI dock regression introduced by the recent rework of
     the ACPI-based PCI hotplug code (acpiphp) that caused it to be
     initialized before the ACPI dock driver, which is incorrect (ACPI
     dock has to be initialized before acpiphp so that acpiphp can
     register PCI devices on docking stations with it for PCI hotplug on
     re-dock to work).  From Jiang Liu.

   - Fix for PCI resources allocation in the ACPI-based PCI hotplug code
     (acpiphp) that makes it use the same PCI resources assignment rules
     during runtime hotplug that are used during boot (the BIOS' choices
     are now respected in both cases).  This prevents PCI resource
     allocation failures during hotplug from happening in some cases.
     From Jiang Liu.

   - Fix for ordering and synchronization issues during hot-removal of
     PCI devices on docking stations.  It makes the ACPI dock code carry
     out the PCI devices removal synchronously during undock instead of
     spawning a separate asynchronous work item to remove each of them
     without even bothering to wait for all those work items to
     complete.  The hot-addition part is changed analogously.

   - Fix for a regression (introduced a few releases ago) that removed
     the code to register a hotplug notificaion handler for for ATA
     ports/devices inadvertently which prevented ATA bays hotplug from
     working.  The missing code is added back with some improvements.
     From Aaron Lu.

   - Fix for a recent cpufreq regression causing a NULL pointer
     dereference to trigger in od_set_powersave_bias() in some
     situations from Jacob Shin"

* tag 'pm+acpi-3.10-late' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: fix NULL pointer deference at od_set_powersave_bias()
  libata-acpi: add back ACPI based hotplug functionality
  ACPI / dock / PCI: Synchronous handling of dock events for PCI devices
  PCI / ACPI: Use boot-time resource allocation rules during hotplug
  ACPI / dock: Initialize ACPI dock subsystem upfront

1 files changed, 96 insertions, 83 deletions

diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index ec117c6c996..14de9f46972 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -66,20 +66,21 @@ struct dock_station {
 	spinlock_t dd_lock;
 	struct mutex hp_lock;
 	struct list_head dependent_devices;
-	struct list_head hotplug_devices;
 
 	struct list_head sibling;
 	struct platform_device *dock_device;
 };
 static LIST_HEAD(dock_stations);
 static int dock_station_count;
+static DEFINE_MUTEX(hotplug_lock);
 
 struct dock_dependent_device {
 	struct list_head list;
-	struct list_head hotplug_list;
 	acpi_handle handle;
-	const struct acpi_dock_ops *ops;
-	void *context;
+	const struct acpi_dock_ops *hp_ops;
+	void *hp_context;
+	unsigned int hp_refcount;
+	void (*hp_release)(void *);
 };
 
 #define DOCK_DOCKING	0x00000001
@@ -111,7 +112,6 @@ add_dock_dependent_device(struct dock_station *ds, acpi_handle handle)
 
 	dd->handle = handle;
 	INIT_LIST_HEAD(&dd->list);
-	INIT_LIST_HEAD(&dd->hotplug_list);
 
 	spin_lock(&ds->dd_lock);
 	list_add_tail(&dd->list, &ds->dependent_devices);
@@ -121,35 +121,90 @@ add_dock_dependent_device(struct dock_station *ds, acpi_handle handle)
 }
 
 /**
- * dock_add_hotplug_device - associate a hotplug handler with the dock station
- * @ds: The dock station
- * @dd: The dependent device struct
- *
- * Add the dependent device to the dock's hotplug device list
+ * dock_init_hotplug - Initialize a hotplug device on a docking station.
+ * @dd: Dock-dependent device.
+ * @ops: Dock operations to attach to the dependent device.
+ * @context: Data to pass to the @ops callbacks and @release.
+ * @init: Optional initialization routine to run after setting up context.
+ * @release: Optional release routine to run on removal.
  */
-static void
-dock_add_hotplug_device(struct dock_station *ds,
-			struct dock_dependent_device *dd)
+static int dock_init_hotplug(struct dock_dependent_device *dd,
+			     const struct acpi_dock_ops *ops, void *context,
+			     void (*init)(void *), void (*release)(void *))
 {
-	mutex_lock(&ds->hp_lock);
-	list_add_tail(&dd->hotplug_list, &ds->hotplug_devices);
-	mutex_unlock(&ds->hp_lock);
+	int ret = 0;
+
+	mutex_lock(&hotplug_lock);
+
+	if (dd->hp_context) {
+		ret = -EEXIST;
+	} else {
+		dd->hp_refcount = 1;
+		dd->hp_ops = ops;
+		dd->hp_context = context;
+		dd->hp_release = release;
+	}
+
+	if (!WARN_ON(ret) && init)
+		init(context);
+
+	mutex_unlock(&hotplug_lock);
+	return ret;
 }
 
 /**
- * dock_del_hotplug_device - remove a hotplug handler from the dock station
- * @ds: The dock station
- * @dd: the dependent device struct
+ * dock_release_hotplug - Decrement hotplug reference counter of dock device.
+ * @dd: Dock-dependent device.
  *
- * Delete the dependent device from the dock's hotplug device list
+ * Decrement the reference counter of @dd and if 0, detach its hotplug
+ * operations from it, reset its context pointer and run the optional release
+ * routine if present.
  */
-static void
-dock_del_hotplug_device(struct dock_station *ds,
-			struct dock_dependent_device *dd)
+static void dock_release_hotplug(struct dock_dependent_device *dd)
 {
-	mutex_lock(&ds->hp_lock);
-	list_del(&dd->hotplug_list);
-	mutex_unlock(&ds->hp_lock);
+	void (*release)(void *) = NULL;
+	void *context = NULL;
+
+	mutex_lock(&hotplug_lock);
+
+	if (dd->hp_context && !--dd->hp_refcount) {
+		dd->hp_ops = NULL;
+		context = dd->hp_context;
+		dd->hp_context = NULL;
+		release = dd->hp_release;
+		dd->hp_release = NULL;
+	}
+
+	if (release && context)
+		release(context);
+
+	mutex_unlock(&hotplug_lock);
+}
+
+static void dock_hotplug_event(struct dock_dependent_device *dd, u32 event,
+			       bool uevent)
+{
+	acpi_notify_handler cb = NULL;
+	bool run = false;
+
+	mutex_lock(&hotplug_lock);
+
+	if (dd->hp_context) {
+		run = true;
+		dd->hp_refcount++;
+		if (dd->hp_ops)
+			cb = uevent ? dd->hp_ops->uevent : dd->hp_ops->handler;
+	}
+
+	mutex_unlock(&hotplug_lock);
+
+	if (!run)
+		return;
+
+	if (cb)
+		cb(dd->handle, event, dd->hp_context);
+
+	dock_release_hotplug(dd);
 }
 
 /**
@@ -360,9 +415,8 @@ static void hotplug_dock_devices(struct dock_station *ds, u32 event)
 	/*
 	 * First call driver specific hotplug functions
 	 */
-	list_for_each_entry(dd, &ds->hotplug_devices, hotplug_list)
-		if (dd->ops && dd->ops->handler)
-			dd->ops->handler(dd->handle, event, dd->context);
+	list_for_each_entry(dd, &ds->dependent_devices, list)
+		dock_hotplug_event(dd, event, false);
 
 	/*
 	 * Now make sure that an acpi_device is created for each
@@ -398,9 +452,8 @@ static void dock_event(struct dock_station *ds, u32 event, int num)
 	if (num == DOCK_EVENT)
 		kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
 
-	list_for_each_entry(dd, &ds->hotplug_devices, hotplug_list)
-		if (dd->ops && dd->ops->uevent)
-			dd->ops->uevent(dd->handle, event, dd->context);
+	list_for_each_entry(dd, &ds->dependent_devices, list)
+		dock_hotplug_event(dd, event, true);
 
 	if (num != DOCK_EVENT)
 		kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
@@ -570,19 +623,24 @@ EXPORT_SYMBOL_GPL(unregister_dock_notifier);
  * @handle: the handle of the device
  * @ops: handlers to call after docking
  * @context: device specific data
+ * @init: Optional initialization routine to run after registration
+ * @release: Optional release routine to run on unregistration
  *
  * If a driver would like to perform a hotplug operation after a dock
  * event, they can register an acpi_notifiy_handler to be called by
  * the dock driver after _DCK is executed.
  */
-int
-register_hotplug_dock_device(acpi_handle handle, const struct acpi_dock_ops *ops,
-			     void *context)
+int register_hotplug_dock_device(acpi_handle handle,
+				 const struct acpi_dock_ops *ops, void *context,
+				 void (*init)(void *), void (*release)(void *))
 {
 	struct dock_dependent_device *dd;
 	struct dock_station *dock_station;
 	int ret = -EINVAL;
 
+	if (WARN_ON(!context))
+		return -EINVAL;
+
 	if (!dock_station_count)
 		return -ENODEV;
 
@@ -597,12 +655,8 @@ register_hotplug_dock_device(acpi_handle handle, const struct acpi_dock_ops *ops
 		 * ops
 		 */
 		dd = find_dock_dependent_device(dock_station, handle);
-		if (dd) {
-			dd->ops = ops;
-			dd->context = context;
-			dock_add_hotplug_device(dock_station, dd);
+		if (dd && !dock_init_hotplug(dd, ops, context, init, release))
 			ret = 0;
-		}
 	}
 
 	return ret;
@@ -624,7 +678,7 @@ void unregister_hotplug_dock_device(acpi_handle handle)
 	list_for_each_entry(dock_station, &dock_stations, sibling) {
 		dd = find_dock_dependent_device(dock_station, handle);
 		if (dd)
-			dock_del_hotplug_device(dock_station, dd);
+			dock_release_hotplug(dd);
 	}
 }
 EXPORT_SYMBOL_GPL(unregister_hotplug_dock_device);
@@ -953,7 +1007,6 @@ static int __init dock_add(acpi_handle handle)
 	mutex_init(&dock_station->hp_lock);
 	spin_lock_init(&dock_station->dd_lock);
 	INIT_LIST_HEAD(&dock_station->sibling);
-	INIT_LIST_HEAD(&dock_station->hotplug_devices);
 	ATOMIC_INIT_NOTIFIER_HEAD(&dock_notifier_list);
 	INIT_LIST_HEAD(&dock_station->dependent_devices);
 
@@ -994,30 +1047,6 @@ err_unregister:
 }
 
 /**
- * dock_remove - free up resources related to the dock station
- */
-static int dock_remove(struct dock_station *ds)
-{
-	struct dock_dependent_device *dd, *tmp;
-	struct platform_device *dock_device = ds->dock_device;
-
-	if (!dock_station_count)
-		return 0;
-
-	/* remove dependent devices */
-	list_for_each_entry_safe(dd, tmp, &ds->dependent_devices, list)
-		kfree(dd);
-
-	list_del(&ds->sibling);
-
-	/* cleanup sysfs */
-	sysfs_remove_group(&dock_device->dev.kobj, &dock_attribute_group);
-	platform_device_unregister(dock_device);
-
-	return 0;
-}
-
-/**
  * find_dock_and_bay - look for dock stations and bays
  * @handle: acpi handle of a device
  * @lvl: unused
@@ -1035,7 +1064,7 @@ find_dock_and_bay(acpi_handle handle, u32 lvl, void *context, void **rv)
 	return AE_OK;
 }
 
-static int __init dock_init(void)
+int __init acpi_dock_init(void)
 {
 	if (acpi_disabled)
 		return 0;
@@ -1054,19 +1083,3 @@ static int __init dock_init(void)
 		ACPI_DOCK_DRIVER_DESCRIPTION, dock_station_count);
 	return 0;
 }
-
-static void __exit dock_exit(void)
-{
-	struct dock_station *tmp, *dock_station;
-
-	unregister_acpi_bus_notifier(&dock_acpi_notifier);
-	list_for_each_entry_safe(dock_station, tmp, &dock_stations, sibling)
-		dock_remove(dock_station);
-}
-
-/*
- * Must be called before drivers of devices in dock, otherwise we can't know
- * which devices are in a dock
- */
-subsys_initcall(dock_init);
-module_exit(dock_exit);