linux/drivers/base
Rafael J. Wysocki ac212b6980 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 <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
2013-05-12 14:14:32 +02:00
..
power Merge branch 'pm-assorted' 2013-04-28 01:54:29 +02:00
regmap Merge remote-tracking branch 'regmap/topic/range' into regmap-next 2013-04-16 16:05:50 +01:00
attribute_container.c drivers: base: Convert dev_printk(KERN_<LEVEL> to dev_<level>( 2012-10-30 17:38:43 -07:00
base.h driver/base: implement subsys_virtual_register() 2013-03-12 11:36:35 -07:00
bus.c Merge branch 'for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2013-04-29 19:07:40 -07:00
class.c driver-core: constify data for class_find_device() 2013-02-06 12:18:56 -08:00
core.c Driver core: Add offline/online device operations 2013-05-12 14:14:09 +02:00
cpu.c ACPI / processor: Use common hotplug infrastructure 2013-05-12 14:14:32 +02:00
dd.c PM / Runtime: Idle devices asynchronously after probe|release 2013-04-11 12:42:52 -07:00
devres.c Linux 3.9-rc3 2013-03-17 19:40:50 -07:00
devtmpfs.c driver core: handle user namespaces properly with the uid/gid devtmpfs change 2013-04-11 11:43:29 -07:00
dma-buf.c dma-buf: Add debugfs support 2013-05-01 16:36:22 +05:30
dma-coherent.c drivers: dma-coherent: Fix typo in dma_mmap_from_coherent documentation 2012-10-23 14:05:32 +02:00
dma-contiguous.c drivers: cma: represent physical addresses as phys_addr_t 2012-12-11 09:28:09 +01:00
dma-mapping.c [media] dma-mapping: fix dma_common_get_sgtable() conditional compilation 2012-11-27 09:42:31 -02:00
driver.c driver core: don't trigger uevent after failure 2012-07-17 10:40:23 -07:00
firmware_class.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
firmware.c
hypervisor.c drivers/base: Add export.h for EXPORT_SYMBOL/THIS_MODULE as required. 2011-10-31 19:31:38 -04:00
init.c driver-core: implement 'sysdev' functionality for regular devices and buses 2011-12-14 14:29:38 -08:00
isa.c dma-mapping: replace all DMA_24BIT_MASK macro with DMA_BIT_MASK(24) 2009-04-07 08:31:12 -07:00
Kconfig firmware: Make user-mode helper optional 2013-02-03 17:57:40 -08:00
Makefile drivers/pinctrl: grab default handles from device core 2013-01-23 16:39:51 +01:00
map.c
memory.c mm: Remove unused parameter of pages_correctly_reserved() 2013-04-29 15:54:38 -07:00
module.c driver core: module.c: Use kasprintf 2010-05-21 09:37:29 -07:00
node.c drivers/base/node.c: switch to register_hotmemory_notifier() 2013-04-29 15:54:36 -07:00
pinctrl.c drivers/pinctrl: grab default handles from device core 2013-01-23 16:39:51 +01:00
platform.c driver core: platform.c: fix checkpatch errors and warnings 2013-03-29 09:10:55 -07:00
soc.c mode_t whack-a-mole: ->is_visible() returns umode_t... 2012-05-29 23:28:42 -04:00
syscore.c PM: Reintroduce dropped call to check_wakeup_irqs 2011-07-11 10:51:49 +02:00
topology.c cpu: convert 'cpu' and 'machinecheck' sysdev_class to a regular subsystem 2011-12-21 14:29:42 -08:00
transport_class.c drivers/base: transport_class explicitly requires EXPORT_SYMBOL 2011-10-31 19:31:15 -04:00