From 683058e315f00a216fd6c79df4f63bc9945ca434 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 3 May 2013 00:26:16 +0200 Subject: ACPI / hotplug: Use device offline/online for graceful hot-removal Modify the generic ACPI hotplug code to be able to check if devices scheduled for hot-removal may be gracefully removed from the system using the device offline/online mechanism introduced previously. Namely, make acpi_scan_hot_remove() handling device hot-removal call device_offline() for all physical companions of the ACPI device nodes involved in the operation and check the results. If any of the device_offline() calls fails, the function will not progress to the removal phase (which cannot be aborted), unless its (new) force argument is set (in case of a failing offline it will put the devices offlined by it back online). In support of 'forced' device hot-removal, add a new sysfs attribute 'force_remove' that will reside under /sys/firmware/acpi/hotplug/. Signed-off-by: Rafael J. Wysocki Reviewed-by: Toshi Kani --- drivers/acpi/internal.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/acpi/internal.h') diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index 6f1afd9118c8..4548f0a114ce 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -47,6 +47,8 @@ void acpi_memory_hotplug_init(void); static inline void acpi_memory_hotplug_init(void) {} #endif +extern bool acpi_force_hot_remove; + void acpi_sysfs_add_hotplug_profile(struct acpi_hotplug_profile *hotplug, const char *name); int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler, -- cgit v1.2.3 From ac212b6980d8d5eda705864fc5a8ecddc6d6eacc Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 3 May 2013 00:26:22 +0200 Subject: ACPI / processor: Use common hotplug infrastructure Split the ACPI processor driver into two parts, one that is non-modular, resides in the ACPI core and handles the enumeration and hotplug of processors and one that implements the rest of the existing processor driver functionality. The non-modular part uses an ACPI scan handler object to enumerate processors on the basis of information provided by the ACPI namespace and to hook up with the common ACPI hotplug infrastructure. It also populates the ACPI handle of each processor device having a corresponding object in the ACPI namespace, which allows the driver proper to bind to those devices, and makes the driver bind to them if it is readily available (i.e. loaded) when the scan handler's .attach() routine is running. There are a few reasons to make this change. First, switching the ACPI processor driver to using the common ACPI hotplug infrastructure reduces code duplication and size considerably, even though a new file is created along with a header comment etc. Second, since the common hotplug code attempts to offline devices before starting the (non-reversible) removal procedure, it will abort (and possibly roll back) hot-remove operations involving processors if cpu_down() returns an error code for one of them instead of continuing them blindly (if /sys/firmware/acpi/hotplug/force_remove is unset). That is a more desirable behavior than what the current code does. Finally, the separation of the scan/hotplug part from the driver proper makes it possible to simplify the driver's .remove() routine, because it doesn't need to worry about the possible cleanup related to processor removal any more (the scan/hotplug part is responsible for that now) and can handle device removal and driver removal symmetricaly (i.e. as appropriate). Some user-visible changes in sysfs are made (for example, the 'sysdev' link from the ACPI device node to the processor device's directory is gone and a 'physical_node' link is present instead and a corresponding 'firmware_node' is present in the processor device's directory, the processor driver is now visible under /sys/bus/cpu/drivers/ and bound to the processor device), but that shouldn't affect the functionality that users care about (frequency scaling, C-states and thermal management). Tested on my venerable Toshiba Portege R500. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Reviewed-by: Toshi Kani --- drivers/acpi/internal.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/acpi/internal.h') diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index 4548f0a114ce..bf792595132c 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -33,6 +33,7 @@ static inline void acpi_pci_slot_init(void) { } void acpi_pci_root_init(void); void acpi_pci_link_init(void); void acpi_pci_root_hp_init(void); +void acpi_processor_init(void); void acpi_platform_init(void); int acpi_sysfs_init(void); void acpi_csrt_init(void); @@ -79,6 +80,8 @@ void acpi_init_device_object(struct acpi_device *device, acpi_handle handle, int type, unsigned long long sta); void acpi_device_add_finalize(struct acpi_device *device); void acpi_free_pnp_ids(struct acpi_device_pnp *pnp); +int acpi_bind_one(struct device *dev, acpi_handle handle); +int acpi_unbind_one(struct device *dev); /* -------------------------------------------------------------------------- Power Resource -- cgit v1.2.3