diff mbox

[4/4] ACPI / processor: Use common hotplug infrastructure

Message ID 4370898.CqFcWEhTiu@vostro.rjw.lan (mailing list archive)
State Accepted, archived
Headers show

Commit Message

Rafael Wysocki May 2, 2013, 12:31 p.m. UTC
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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,
a 'firmware_node' link 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>
---
 drivers/acpi/Makefile           |    1 
 drivers/acpi/acpi_processor.c   |  473 +++++++++++++++++++++++
 drivers/acpi/glue.c             |    6 
 drivers/acpi/internal.h         |    3 
 drivers/acpi/processor_driver.c |  803 +++-------------------------------------
 drivers/acpi/scan.c             |    1 
 drivers/base/cpu.c              |   11 
 include/acpi/processor.h        |    5 
 8 files changed, 574 insertions(+), 729 deletions(-)


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Comments

gregkh@linuxfoundation.org May 2, 2013, 1:59 p.m. UTC | #1
On Thu, May 02, 2013 at 02:31:51PM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> 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,
> a 'firmware_node' link 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>

For the driver core part:

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Toshi Kani May 2, 2013, 11:20 p.m. UTC | #2
On Thu, 2013-05-02 at 14:31 +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> 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,
> a 'firmware_node' link 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).

This looks very nice.  I have one question below.

> Tested on my venerable Toshiba Portege R500.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
>  drivers/acpi/Makefile           |    1 
>  drivers/acpi/acpi_processor.c   |  473 +++++++++++++++++++++++
>  drivers/acpi/glue.c             |    6 
>  drivers/acpi/internal.h         |    3 
>  drivers/acpi/processor_driver.c |  803 +++-------------------------------------
>  drivers/acpi/scan.c             |    1 
>  drivers/base/cpu.c              |   11 
>  include/acpi/processor.h        |    5 
>  8 files changed, 574 insertions(+), 729 deletions(-)

 :

> Index: linux-pm/drivers/base/cpu.c
> ===================================================================
> --- linux-pm.orig/drivers/base/cpu.c
> +++ linux-pm/drivers/base/cpu.c
> @@ -13,11 +13,21 @@
>  #include <linux/gfp.h>
>  #include <linux/slab.h>
>  #include <linux/percpu.h>
> +#include <linux/acpi.h>
>  
>  #include "base.h"
>  
>  static DEFINE_PER_CPU(struct device *, cpu_sys_devices);
>  
> +static int cpu_subsys_match(struct device *dev, struct device_driver *drv)
> +{
> +	/* ACPI style match is the only one that may succeed. */
> +	if (acpi_driver_match_device(dev, drv))

Can you explain why this change is needed?  Do CPU devices still behave
the same on non-ACPI systems?  

Thanks,
-Toshi


> +		return 1;
> +
> +	return 0;
> +}
> +
>  #ifdef CONFIG_HOTPLUG_CPU
>  static int cpu_subsys_online(struct device *dev)
>  {
> @@ -76,6 +86,7 @@ static DEVICE_ATTR(release, S_IWUSR, NUL
>  struct bus_type cpu_subsys = {
>  	.name = "cpu",
>  	.dev_name = "cpu",
> +	.match = cpu_subsys_match,
>  #ifdef CONFIG_HOTPLUG_CPU
>  	.online = cpu_subsys_online,
>  	.offline = cpu_subsys_offline,
> 


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Rafael Wysocki May 3, 2013, 12:05 p.m. UTC | #3
On Thursday, May 02, 2013 05:20:12 PM Toshi Kani wrote:
> On Thu, 2013-05-02 at 14:31 +0200, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > 
> > 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,
> > a 'firmware_node' link 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).
> 
> This looks very nice.  I have one question below.
> 
> > Tested on my venerable Toshiba Portege R500.
> > 
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > ---
> >  drivers/acpi/Makefile           |    1 
> >  drivers/acpi/acpi_processor.c   |  473 +++++++++++++++++++++++
> >  drivers/acpi/glue.c             |    6 
> >  drivers/acpi/internal.h         |    3 
> >  drivers/acpi/processor_driver.c |  803 +++-------------------------------------
> >  drivers/acpi/scan.c             |    1 
> >  drivers/base/cpu.c              |   11 
> >  include/acpi/processor.h        |    5 
> >  8 files changed, 574 insertions(+), 729 deletions(-)
> 
>  :
> 
> > Index: linux-pm/drivers/base/cpu.c
> > ===================================================================
> > --- linux-pm.orig/drivers/base/cpu.c
> > +++ linux-pm/drivers/base/cpu.c
> > @@ -13,11 +13,21 @@
> >  #include <linux/gfp.h>
> >  #include <linux/slab.h>
> >  #include <linux/percpu.h>
> > +#include <linux/acpi.h>
> >  
> >  #include "base.h"
> >  
> >  static DEFINE_PER_CPU(struct device *, cpu_sys_devices);
> >  
> > +static int cpu_subsys_match(struct device *dev, struct device_driver *drv)
> > +{
> > +	/* ACPI style match is the only one that may succeed. */
> > +	if (acpi_driver_match_device(dev, drv))
> 
> Can you explain why this change is needed?

This is the mechanism by which the driver core determines which driver to use
with a processor device passed to device_attach().

Basically, it walks the list of drivers whose bus type is cpu_subsys and
calls cpu_subsys->match(), which points to cpu_subsys_match(), for the device
and each of the drivers.  The result of that tell is whether or not to use
the given driver with the device.

Now, acpi_driver_match_device() returns 'true' if (a) the device has an ACPI
handle and (b) at least one of the IDs of the struct acpi_device associated
with that handle is in the driver's .acpi_match_table table.  Since the ACPI
processor's .acpi_match_table contains the same set of IDs as the table
of device IDs of processor_handler, this guarantees that the ACPI processor
driver will be used for the devices prepared by acpi_processor_add().

What it boils down to is that acpi_processor_start() is going to be called
for every device whose ACPI handle is populated by acpi_processor_add().

> Do CPU devices still behave the same on non-ACPI systems?

Yes, they do.  The whole driver matching/binding is irrelevant to them, because
the ACPI processor driver is the only one registering itself under cpu_subsys.

Thanks,
Rafael
Rafael Wysocki May 3, 2013, 12:21 p.m. UTC | #4
On Friday, May 03, 2013 02:05:37 PM Rafael J. Wysocki wrote:
> On Thursday, May 02, 2013 05:20:12 PM Toshi Kani wrote:
> > On Thu, 2013-05-02 at 14:31 +0200, Rafael J. Wysocki wrote:
> > > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > > 
> > > 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,
> > > a 'firmware_node' link 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).
> > 
> > This looks very nice.  I have one question below.
> > 
> > > Tested on my venerable Toshiba Portege R500.
> > > 
> > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > > ---
> > >  drivers/acpi/Makefile           |    1 
> > >  drivers/acpi/acpi_processor.c   |  473 +++++++++++++++++++++++
> > >  drivers/acpi/glue.c             |    6 
> > >  drivers/acpi/internal.h         |    3 
> > >  drivers/acpi/processor_driver.c |  803 +++-------------------------------------
> > >  drivers/acpi/scan.c             |    1 
> > >  drivers/base/cpu.c              |   11 
> > >  include/acpi/processor.h        |    5 
> > >  8 files changed, 574 insertions(+), 729 deletions(-)
> > 
> >  :
> > 
> > > Index: linux-pm/drivers/base/cpu.c
> > > ===================================================================
> > > --- linux-pm.orig/drivers/base/cpu.c
> > > +++ linux-pm/drivers/base/cpu.c
> > > @@ -13,11 +13,21 @@
> > >  #include <linux/gfp.h>
> > >  #include <linux/slab.h>
> > >  #include <linux/percpu.h>
> > > +#include <linux/acpi.h>
> > >  
> > >  #include "base.h"
> > >  
> > >  static DEFINE_PER_CPU(struct device *, cpu_sys_devices);
> > >  
> > > +static int cpu_subsys_match(struct device *dev, struct device_driver *drv)
> > > +{
> > > +	/* ACPI style match is the only one that may succeed. */
> > > +	if (acpi_driver_match_device(dev, drv))
> > 
> > Can you explain why this change is needed?
> 
> This is the mechanism by which the driver core determines which driver to use
> with a processor device passed to device_attach().
> 
> Basically, it walks the list of drivers whose bus type is cpu_subsys and
> calls cpu_subsys->match(), which points to cpu_subsys_match(), for the device
> and each of the drivers.  The result of that tell is whether or not to use
> the given driver with the device.
> 
> Now, acpi_driver_match_device() returns 'true' if (a) the device has an ACPI
> handle and (b) at least one of the IDs of the struct acpi_device associated
> with that handle is in the driver's .acpi_match_table table.  Since the ACPI
> processor's .acpi_match_table contains the same set of IDs as the table
> of device IDs of processor_handler, this guarantees that the ACPI processor
> driver will be used for the devices prepared by acpi_processor_add().
> 
> What it boils down to is that acpi_processor_start() is going to be called
> for every device whose ACPI handle is populated by acpi_processor_add().

The reason why it really is needed is because the ACPI processor driver is
modular and it may or may not be present when acpi_processor_add() is running,
but acpi_processor_start() should be called for the device once the driver has
been loaded.

Thanks,
Rafael
Toshi Kani May 3, 2013, 6:27 p.m. UTC | #5
On Fri, 2013-05-03 at 14:05 +0200, Rafael J. Wysocki wrote:
> On Thursday, May 02, 2013 05:20:12 PM Toshi Kani wrote:
> > On Thu, 2013-05-02 at 14:31 +0200, Rafael J. Wysocki wrote:
> > > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
 : 
> > > Index: linux-pm/drivers/base/cpu.c
> > > ===================================================================
> > > --- linux-pm.orig/drivers/base/cpu.c
> > > +++ linux-pm/drivers/base/cpu.c
> > > @@ -13,11 +13,21 @@
> > >  #include <linux/gfp.h>
> > >  #include <linux/slab.h>
> > >  #include <linux/percpu.h>
> > > +#include <linux/acpi.h>
> > >  
> > >  #include "base.h"
> > >  
> > >  static DEFINE_PER_CPU(struct device *, cpu_sys_devices);
> > >  
> > > +static int cpu_subsys_match(struct device *dev, struct device_driver *drv)
> > > +{
> > > +	/* ACPI style match is the only one that may succeed. */
> > > +	if (acpi_driver_match_device(dev, drv))
> > 
> > Can you explain why this change is needed?
> 
> This is the mechanism by which the driver core determines which driver to use
> with a processor device passed to device_attach().
> 
> Basically, it walks the list of drivers whose bus type is cpu_subsys and
> calls cpu_subsys->match(), which points to cpu_subsys_match(), for the device
> and each of the drivers.  The result of that tell is whether or not to use
> the given driver with the device.
> 
> Now, acpi_driver_match_device() returns 'true' if (a) the device has an ACPI
> handle and (b) at least one of the IDs of the struct acpi_device associated
> with that handle is in the driver's .acpi_match_table table.  Since the ACPI
> processor's .acpi_match_table contains the same set of IDs as the table
> of device IDs of processor_handler, this guarantees that the ACPI processor
> driver will be used for the devices prepared by acpi_processor_add().
> 
> What it boils down to is that acpi_processor_start() is going to be called
> for every device whose ACPI handle is populated by acpi_processor_add().
> 
> > Do CPU devices still behave the same on non-ACPI systems?
> 
> Yes, they do.  The whole driver matching/binding is irrelevant to them, because
> the ACPI processor driver is the only one registering itself under cpu_subsys.

Thanks for the detailed explanation!  I missed that the new processor
driver is registered to cpu_subsys.  I now see what you did.  This is
clever.

One minor comment.

+static __cpuinit int __acpi_processor_start(struct acpi_device *device)
>  {
> -	struct acpi_device *device = per_cpu(processor_device_array,
pr->id);
> +	struct acpi_processor *pr = acpi_driver_data(device);
> +	acpi_status status;
>  	int result = 0;
>  
> +	if (!pr)
> +		return -ENODEV;
> +
> +	if (pr->flags.need_hotplug_init)
> +		return 0;
> +

I felt the name of "need_hotplug_init" is a bit misleading since the
func actually skips when the need-flag is set.  It may be nice to rename
it to defer_online_init, offline or something like that.

Otherwise the changes look very good. 

Reviewed-by: Toshi Kani <toshi.kani@hp.com>

Thanks,
-Toshi




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Rafael Wysocki May 3, 2013, 7:31 p.m. UTC | #6
On Friday, May 03, 2013 12:27:54 PM Toshi Kani wrote:
> On Fri, 2013-05-03 at 14:05 +0200, Rafael J. Wysocki wrote:
> > On Thursday, May 02, 2013 05:20:12 PM Toshi Kani wrote:
> > > On Thu, 2013-05-02 at 14:31 +0200, Rafael J. Wysocki wrote:
> > > > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>  : 
> > > > Index: linux-pm/drivers/base/cpu.c
> > > > ===================================================================
> > > > --- linux-pm.orig/drivers/base/cpu.c
> > > > +++ linux-pm/drivers/base/cpu.c
> > > > @@ -13,11 +13,21 @@
> > > >  #include <linux/gfp.h>
> > > >  #include <linux/slab.h>
> > > >  #include <linux/percpu.h>
> > > > +#include <linux/acpi.h>
> > > >  
> > > >  #include "base.h"
> > > >  
> > > >  static DEFINE_PER_CPU(struct device *, cpu_sys_devices);
> > > >  
> > > > +static int cpu_subsys_match(struct device *dev, struct device_driver *drv)
> > > > +{
> > > > +	/* ACPI style match is the only one that may succeed. */
> > > > +	if (acpi_driver_match_device(dev, drv))
> > > 
> > > Can you explain why this change is needed?
> > 
> > This is the mechanism by which the driver core determines which driver to use
> > with a processor device passed to device_attach().
> > 
> > Basically, it walks the list of drivers whose bus type is cpu_subsys and
> > calls cpu_subsys->match(), which points to cpu_subsys_match(), for the device
> > and each of the drivers.  The result of that tell is whether or not to use
> > the given driver with the device.
> > 
> > Now, acpi_driver_match_device() returns 'true' if (a) the device has an ACPI
> > handle and (b) at least one of the IDs of the struct acpi_device associated
> > with that handle is in the driver's .acpi_match_table table.  Since the ACPI
> > processor's .acpi_match_table contains the same set of IDs as the table
> > of device IDs of processor_handler, this guarantees that the ACPI processor
> > driver will be used for the devices prepared by acpi_processor_add().
> > 
> > What it boils down to is that acpi_processor_start() is going to be called
> > for every device whose ACPI handle is populated by acpi_processor_add().
> > 
> > > Do CPU devices still behave the same on non-ACPI systems?
> > 
> > Yes, they do.  The whole driver matching/binding is irrelevant to them, because
> > the ACPI processor driver is the only one registering itself under cpu_subsys.
> 
> Thanks for the detailed explanation!  I missed that the new processor
> driver is registered to cpu_subsys.  I now see what you did.  This is
> clever.

Well, thanks! :-)

> One minor comment.
> 
> +static __cpuinit int __acpi_processor_start(struct acpi_device *device)
> >  {
> > -	struct acpi_device *device = per_cpu(processor_device_array,
> pr->id);
> > +	struct acpi_processor *pr = acpi_driver_data(device);
> > +	acpi_status status;
> >  	int result = 0;
> >  
> > +	if (!pr)
> > +		return -ENODEV;
> > +
> > +	if (pr->flags.need_hotplug_init)
> > +		return 0;
> > +
> 
> I felt the name of "need_hotplug_init" is a bit misleading since the
> func actually skips when the need-flag is set.  It may be nice to rename
> it to defer_online_init, offline or something like that.

I just wanted to avoid making too many non-essential changes in one patch.
We can change the name of that field at any time later.

> Otherwise the changes look very good. 
> 
> Reviewed-by: Toshi Kani <toshi.kani@hp.com>

Thank you!

Rafael
Toshi Kani May 3, 2013, 7:34 p.m. UTC | #7
On Fri, 2013-05-03 at 21:31 +0200, Rafael J. Wysocki wrote:
> On Friday, May 03, 2013 12:27:54 PM Toshi Kani wrote:
> > On Fri, 2013-05-03 at 14:05 +0200, Rafael J. Wysocki wrote:
> > > On Thursday, May 02, 2013 05:20:12 PM Toshi Kani wrote:

:

> > One minor comment.
> > 
> > +static __cpuinit int __acpi_processor_start(struct acpi_device *device)
> > >  {
> > > -	struct acpi_device *device = per_cpu(processor_device_array,
> > pr->id);
> > > +	struct acpi_processor *pr = acpi_driver_data(device);
> > > +	acpi_status status;
> > >  	int result = 0;
> > >  
> > > +	if (!pr)
> > > +		return -ENODEV;
> > > +
> > > +	if (pr->flags.need_hotplug_init)
> > > +		return 0;
> > > +
> > 
> > I felt the name of "need_hotplug_init" is a bit misleading since the
> > func actually skips when the need-flag is set.  It may be nice to rename
> > it to defer_online_init, offline or something like that.
> 
> I just wanted to avoid making too many non-essential changes in one patch.
> We can change the name of that field at any time later.

Sounds good to me.

Thanks,
-Toshi


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diff mbox

Patch

Index: linux-pm/drivers/acpi/processor_driver.c
===================================================================
--- linux-pm.orig/drivers/acpi/processor_driver.c
+++ linux-pm/drivers/acpi/processor_driver.c
@@ -1,11 +1,13 @@ 
 /*
- * acpi_processor.c - ACPI Processor Driver ($Revision: 71 $)
+ * processor_driver.c - ACPI Processor Driver
  *
  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
  *  Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
  *  			- Added processor hotplug support
+ *  Copyright (C) 2013, Intel Corporation
+ *                      Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  *
@@ -24,52 +26,29 @@ 
  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- *  TBD:
- *	1. Make # power states dynamic.
- *	2. Support duty_cycle values that span bit 4.
- *	3. Optimize by having scheduler determine business instead of
- *	   having us try to calculate it here.
- *	4. Need C1 timing -- must modify kernel (IRQ handler) to get this.
  */
 
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
-#include <linux/types.h>
-#include <linux/pci.h>
-#include <linux/pm.h>
 #include <linux/cpufreq.h>
 #include <linux/cpu.h>
-#include <linux/dmi.h>
-#include <linux/moduleparam.h>
 #include <linux/cpuidle.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
-#include <linux/memory_hotplug.h>
 
-#include <asm/io.h>
-#include <asm/cpu.h>
-#include <asm/delay.h>
-#include <asm/uaccess.h>
-#include <asm/processor.h>
-#include <asm/smp.h>
-#include <asm/acpi.h>
-
-#include <acpi/acpi_bus.h>
-#include <acpi/acpi_drivers.h>
 #include <acpi/processor.h>
 
+#include "internal.h"
+
 #define PREFIX "ACPI: "
 
-#define ACPI_PROCESSOR_CLASS		"processor"
-#define ACPI_PROCESSOR_DEVICE_NAME	"Processor"
 #define ACPI_PROCESSOR_FILE_INFO	"info"
 #define ACPI_PROCESSOR_FILE_THROTTLING	"throttling"
 #define ACPI_PROCESSOR_FILE_LIMIT	"limit"
 #define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
 #define ACPI_PROCESSOR_NOTIFY_POWER	0x81
 #define ACPI_PROCESSOR_NOTIFY_THROTTLING	0x82
-#define ACPI_PROCESSOR_DEVICE_HID	"ACPI0007"
 
 #define ACPI_PROCESSOR_LIMIT_USER	0
 #define ACPI_PROCESSOR_LIMIT_THERMAL	1
@@ -81,12 +60,8 @@  MODULE_AUTHOR("Paul Diefenbaugh");
 MODULE_DESCRIPTION("ACPI Processor Driver");
 MODULE_LICENSE("GPL");
 
-static int acpi_processor_add(struct acpi_device *device);
-static int acpi_processor_remove(struct acpi_device *device);
-static void acpi_processor_notify(struct acpi_device *device, u32 event);
-static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr);
-static int acpi_processor_handle_eject(struct acpi_processor *pr);
-static int acpi_processor_start(struct acpi_processor *pr);
+static int acpi_processor_start(struct device *dev);
+static int acpi_processor_stop(struct device *dev);
 
 static const struct acpi_device_id processor_device_ids[] = {
 	{ACPI_PROCESSOR_OBJECT_HID, 0},
@@ -95,295 +70,27 @@  static const struct acpi_device_id proce
 };
 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
 
-static struct acpi_driver acpi_processor_driver = {
+static struct device_driver acpi_processor_driver = {
 	.name = "processor",
-	.class = ACPI_PROCESSOR_CLASS,
-	.ids = processor_device_ids,
-	.ops = {
-		.add = acpi_processor_add,
-		.remove = acpi_processor_remove,
-		.notify = acpi_processor_notify,
-		},
+	.bus = &cpu_subsys,
+	.acpi_match_table = processor_device_ids,
+	.probe = acpi_processor_start,
+	.remove = acpi_processor_stop,
 };
 
-#define INSTALL_NOTIFY_HANDLER		1
-#define UNINSTALL_NOTIFY_HANDLER	2
-
 DEFINE_PER_CPU(struct acpi_processor *, processors);
 EXPORT_PER_CPU_SYMBOL(processors);
 
-struct acpi_processor_errata errata __read_mostly;
-
-/* --------------------------------------------------------------------------
-                                Errata Handling
-   -------------------------------------------------------------------------- */
-
-static int acpi_processor_errata_piix4(struct pci_dev *dev)
+static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
 {
-	u8 value1 = 0;
-	u8 value2 = 0;
-
-
-	if (!dev)
-		return -EINVAL;
-
-	/*
-	 * Note that 'dev' references the PIIX4 ACPI Controller.
-	 */
-
-	switch (dev->revision) {
-	case 0:
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 A-step\n"));
-		break;
-	case 1:
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 B-step\n"));
-		break;
-	case 2:
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4E\n"));
-		break;
-	case 3:
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4M\n"));
-		break;
-	default:
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found unknown PIIX4\n"));
-		break;
-	}
-
-	switch (dev->revision) {
-
-	case 0:		/* PIIX4 A-step */
-	case 1:		/* PIIX4 B-step */
-		/*
-		 * See specification changes #13 ("Manual Throttle Duty Cycle")
-		 * and #14 ("Enabling and Disabling Manual Throttle"), plus
-		 * erratum #5 ("STPCLK# Deassertion Time") from the January
-		 * 2002 PIIX4 specification update.  Applies to only older
-		 * PIIX4 models.
-		 */
-		errata.piix4.throttle = 1;
-
-	case 2:		/* PIIX4E */
-	case 3:		/* PIIX4M */
-		/*
-		 * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
-		 * Livelock") from the January 2002 PIIX4 specification update.
-		 * Applies to all PIIX4 models.
-		 */
-
-		/*
-		 * BM-IDE
-		 * ------
-		 * Find the PIIX4 IDE Controller and get the Bus Master IDE
-		 * Status register address.  We'll use this later to read
-		 * each IDE controller's DMA status to make sure we catch all
-		 * DMA activity.
-		 */
-		dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
-				     PCI_DEVICE_ID_INTEL_82371AB,
-				     PCI_ANY_ID, PCI_ANY_ID, NULL);
-		if (dev) {
-			errata.piix4.bmisx = pci_resource_start(dev, 4);
-			pci_dev_put(dev);
-		}
-
-		/*
-		 * Type-F DMA
-		 * ----------
-		 * Find the PIIX4 ISA Controller and read the Motherboard
-		 * DMA controller's status to see if Type-F (Fast) DMA mode
-		 * is enabled (bit 7) on either channel.  Note that we'll
-		 * disable C3 support if this is enabled, as some legacy
-		 * devices won't operate well if fast DMA is disabled.
-		 */
-		dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
-				     PCI_DEVICE_ID_INTEL_82371AB_0,
-				     PCI_ANY_ID, PCI_ANY_ID, NULL);
-		if (dev) {
-			pci_read_config_byte(dev, 0x76, &value1);
-			pci_read_config_byte(dev, 0x77, &value2);
-			if ((value1 & 0x80) || (value2 & 0x80))
-				errata.piix4.fdma = 1;
-			pci_dev_put(dev);
-		}
-
-		break;
-	}
-
-	if (errata.piix4.bmisx)
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				  "Bus master activity detection (BM-IDE) erratum enabled\n"));
-	if (errata.piix4.fdma)
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				  "Type-F DMA livelock erratum (C3 disabled)\n"));
-
-	return 0;
-}
-
-static int acpi_processor_errata(struct acpi_processor *pr)
-{
-	int result = 0;
-	struct pci_dev *dev = NULL;
-
-
-	if (!pr)
-		return -EINVAL;
-
-	/*
-	 * PIIX4
-	 */
-	dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
-			     PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
-			     PCI_ANY_ID, NULL);
-	if (dev) {
-		result = acpi_processor_errata_piix4(dev);
-		pci_dev_put(dev);
-	}
-
-	return result;
-}
-
-/* --------------------------------------------------------------------------
-                                 Driver Interface
-   -------------------------------------------------------------------------- */
-
-static int acpi_processor_get_info(struct acpi_device *device)
-{
-	acpi_status status = 0;
-	union acpi_object object = { 0 };
-	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
+	struct acpi_device *device = data;
 	struct acpi_processor *pr;
-	int cpu_index, device_declaration = 0;
-	static int cpu0_initialized;
-
-	pr = acpi_driver_data(device);
-	if (!pr)
-		return -EINVAL;
-
-	if (num_online_cpus() > 1)
-		errata.smp = TRUE;
-
-	acpi_processor_errata(pr);
-
-	/*
-	 * Check to see if we have bus mastering arbitration control.  This
-	 * is required for proper C3 usage (to maintain cache coherency).
-	 */
-	if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
-		pr->flags.bm_control = 1;
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				  "Bus mastering arbitration control present\n"));
-	} else
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				  "No bus mastering arbitration control\n"));
-
-	if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
-		/* Declared with "Processor" statement; match ProcessorID */
-		status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
-		if (ACPI_FAILURE(status)) {
-			dev_err(&device->dev,
-				"Failed to evaluate processor object (0x%x)\n",
-				status);
-			return -ENODEV;
-		}
-
-		/*
-		 * TBD: Synch processor ID (via LAPIC/LSAPIC structures) on SMP.
-		 *      >>> 'acpi_get_processor_id(acpi_id, &id)' in
-		 *      arch/xxx/acpi.c
-		 */
-		pr->acpi_id = object.processor.proc_id;
-	} else {
-		/*
-		 * Declared with "Device" statement; match _UID.
-		 * Note that we don't handle string _UIDs yet.
-		 */
-		unsigned long long value;
-		status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
-						NULL, &value);
-		if (ACPI_FAILURE(status)) {
-			dev_err(&device->dev,
-				"Failed to evaluate processor _UID (0x%x)\n",
-				status);
-			return -ENODEV;
-		}
-		device_declaration = 1;
-		pr->acpi_id = value;
-	}
-	cpu_index = acpi_get_cpuid(pr->handle, device_declaration, pr->acpi_id);
-
-	/* Handle UP system running SMP kernel, with no LAPIC in MADT */
-	if (!cpu0_initialized && (cpu_index == -1) &&
-	    (num_online_cpus() == 1)) {
-		cpu_index = 0;
-	}
-
-	cpu0_initialized = 1;
-
-	pr->id = cpu_index;
-
-	/*
-	 *  Extra Processor objects may be enumerated on MP systems with
-	 *  less than the max # of CPUs. They should be ignored _iff
-	 *  they are physically not present.
-	 */
-	if (pr->id == -1) {
-		if (ACPI_FAILURE(acpi_processor_hotadd_init(pr)))
-			return -ENODEV;
-	}
-	/*
-	 * On some boxes several processors use the same processor bus id.
-	 * But they are located in different scope. For example:
-	 * \_SB.SCK0.CPU0
-	 * \_SB.SCK1.CPU0
-	 * Rename the processor device bus id. And the new bus id will be
-	 * generated as the following format:
-	 * CPU+CPU ID.
-	 */
-	sprintf(acpi_device_bid(device), "CPU%X", pr->id);
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
-			  pr->acpi_id));
-
-	if (!object.processor.pblk_address)
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
-	else if (object.processor.pblk_length != 6)
-		dev_err(&device->dev, "Invalid PBLK length [%d]\n",
-			    object.processor.pblk_length);
-	else {
-		pr->throttling.address = object.processor.pblk_address;
-		pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
-		pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
-
-		pr->pblk = object.processor.pblk_address;
-
-		/*
-		 * We don't care about error returns - we just try to mark
-		 * these reserved so that nobody else is confused into thinking
-		 * that this region might be unused..
-		 *
-		 * (In particular, allocating the IO range for Cardbus)
-		 */
-		request_region(pr->throttling.address, 6, "ACPI CPU throttle");
-	}
-
-	/*
-	 * If ACPI describes a slot number for this CPU, we can use it
-	 * ensure we get the right value in the "physical id" field
-	 * of /proc/cpuinfo
-	 */
-	status = acpi_evaluate_object(pr->handle, "_SUN", NULL, &buffer);
-	if (ACPI_SUCCESS(status))
-		arch_fix_phys_package_id(pr->id, object.integer.value);
-
-	return 0;
-}
-
-static DEFINE_PER_CPU(void *, processor_device_array);
-
-static void acpi_processor_notify(struct acpi_device *device, u32 event)
-{
-	struct acpi_processor *pr = acpi_driver_data(device);
 	int saved;
 
+	if (device->handle != handle)
+		return;
+
+	pr = acpi_driver_data(device);
 	if (!pr)
 		return;
 
@@ -420,32 +127,40 @@  static void acpi_processor_notify(struct
 	return;
 }
 
-static int acpi_cpu_soft_notify(struct notifier_block *nfb,
-		unsigned long action, void *hcpu)
+static __cpuinit int __acpi_processor_start(struct acpi_device *device);
+
+static int __cpuinit acpi_cpu_soft_notify(struct notifier_block *nfb,
+					  unsigned long action, void *hcpu)
 {
 	unsigned int cpu = (unsigned long)hcpu;
 	struct acpi_processor *pr = per_cpu(processors, cpu);
+	struct acpi_device *device;
+
+	if (!pr || acpi_bus_get_device(pr->handle, &device))
+		return NOTIFY_DONE;
 
-	if (action == CPU_ONLINE && pr) {
-		/* CPU got physically hotplugged and onlined the first time:
-		 * Initialize missing things
+	if (action == CPU_ONLINE) {
+		/*
+		 * CPU got physically hotplugged and onlined for the first time:
+		 * Initialize missing things.
 		 */
 		if (pr->flags.need_hotplug_init) {
+			int ret;
+
 			pr_info("Will online and init hotplugged CPU: %d\n",
 				pr->id);
-			WARN(acpi_processor_start(pr), "Failed to start CPU:"
-				" %d\n", pr->id);
 			pr->flags.need_hotplug_init = 0;
-		/* Normal CPU soft online event */
+			ret = __acpi_processor_start(device);
+			WARN(ret, "Failed to start CPU: %d\n", pr->id);
 		} else {
+			/* Normal CPU soft online event. */
 			acpi_processor_ppc_has_changed(pr, 0);
 			acpi_processor_hotplug(pr);
 			acpi_processor_reevaluate_tstate(pr, action);
 			acpi_processor_tstate_has_changed(pr);
 		}
-	}
-	if (action == CPU_DEAD && pr) {
-		/* invalidate the flag.throttling after one CPU is offline */
+	} else if (action == CPU_DEAD) {
+		/* Invalidate flag.throttling after the CPU is offline. */
 		acpi_processor_reevaluate_tstate(pr, action);
 	}
 	return NOTIFY_OK;
@@ -456,19 +171,18 @@  static struct notifier_block acpi_cpu_no
 	    .notifier_call = acpi_cpu_soft_notify,
 };
 
-/*
- * acpi_processor_start() is called by the cpu_hotplug_notifier func:
- * acpi_cpu_soft_notify(). Getting it __cpuinit{data} is difficult, the
- * root cause seem to be that acpi_processor_uninstall_hotplug_notify()
- * is in the module_exit (__exit) func. Allowing acpi_processor_start()
- * to not be in __cpuinit section, but being called from __cpuinit funcs
- * via __ref looks like the right thing to do here.
- */
-static __ref int acpi_processor_start(struct acpi_processor *pr)
+static __cpuinit int __acpi_processor_start(struct acpi_device *device)
 {
-	struct acpi_device *device = per_cpu(processor_device_array, pr->id);
+	struct acpi_processor *pr = acpi_driver_data(device);
+	acpi_status status;
 	int result = 0;
 
+	if (!pr)
+		return -ENODEV;
+
+	if (pr->flags.need_hotplug_init)
+		return 0;
+
 #ifdef CONFIG_CPU_FREQ
 	acpi_processor_ppc_has_changed(pr, 0);
 	acpi_processor_load_module(pr);
@@ -506,129 +220,48 @@  static __ref int acpi_processor_start(st
 		goto err_remove_sysfs_thermal;
 	}
 
-	return 0;
+	status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
+					     acpi_processor_notify, device);
+	if (ACPI_SUCCESS(status))
+		return 0;
 
-err_remove_sysfs_thermal:
+	sysfs_remove_link(&pr->cdev->device.kobj, "device");
+ err_remove_sysfs_thermal:
 	sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
-err_thermal_unregister:
+ err_thermal_unregister:
 	thermal_cooling_device_unregister(pr->cdev);
-err_power_exit:
+ err_power_exit:
 	acpi_processor_power_exit(pr);
-
 	return result;
 }
 
-/*
- * Do not put anything in here which needs the core to be online.
- * For example MSR access or setting up things which check for cpuinfo_x86
- * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
- * Such things have to be put in and set up above in acpi_processor_start()
- */
-static int __cpuinit acpi_processor_add(struct acpi_device *device)
+static int __cpuinit acpi_processor_start(struct device *dev)
 {
-	struct acpi_processor *pr = NULL;
-	int result = 0;
-	struct device *dev;
+	struct acpi_device *device;
 
-	pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
-	if (!pr)
-		return -ENOMEM;
+	if (acpi_bus_get_device(ACPI_HANDLE(dev), &device))
+		return -ENODEV;
 
-	if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
-		result = -ENOMEM;
-		goto err_free_pr;
-	}
-
-	pr->handle = device->handle;
-	strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
-	strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
-	device->driver_data = pr;
-
-	result = acpi_processor_get_info(device);
-	if (result) {
-		/* Processor is physically not present */
-		return 0;
-	}
-
-#ifdef CONFIG_SMP
-	if (pr->id >= setup_max_cpus && pr->id != 0)
-		return 0;
-#endif
-
-	BUG_ON(pr->id >= nr_cpu_ids);
-
-	/*
-	 * Buggy BIOS check
-	 * ACPI id of processors can be reported wrongly by the BIOS.
-	 * Don't trust it blindly
-	 */
-	if (per_cpu(processor_device_array, pr->id) != NULL &&
-	    per_cpu(processor_device_array, pr->id) != device) {
-		dev_warn(&device->dev,
-			"BIOS reported wrong ACPI id %d for the processor\n",
-			pr->id);
-		result = -ENODEV;
-		goto err_free_cpumask;
-	}
-	per_cpu(processor_device_array, pr->id) = device;
-
-	per_cpu(processors, pr->id) = pr;
-
-	dev = get_cpu_device(pr->id);
-	if (sysfs_create_link(&device->dev.kobj, &dev->kobj, "sysdev")) {
-		result = -EFAULT;
-		goto err_clear_processor;
-	}
-
-	/*
-	 * Do not start hotplugged CPUs now, but when they
-	 * are onlined the first time
-	 */
-	if (pr->flags.need_hotplug_init)
-		return 0;
-
-	result = acpi_processor_start(pr);
-	if (result)
-		goto err_remove_sysfs;
-
-	return 0;
-
-err_remove_sysfs:
-	sysfs_remove_link(&device->dev.kobj, "sysdev");
-err_clear_processor:
-	/*
-	 * processor_device_array is not cleared to allow checks for buggy BIOS
-	 */ 
-	per_cpu(processors, pr->id) = NULL;
-err_free_cpumask:
-	free_cpumask_var(pr->throttling.shared_cpu_map);
-err_free_pr:
-	kfree(pr);
-	return result;
+	return __acpi_processor_start(device);
 }
 
-static int acpi_processor_remove(struct acpi_device *device)
+static int acpi_processor_stop(struct device *dev)
 {
-	struct acpi_processor *pr = NULL;
+	struct acpi_device *device;
+	struct acpi_processor *pr;
 
+	if (acpi_bus_get_device(ACPI_HANDLE(dev), &device))
+		return 0;
 
-	if (!device || !acpi_driver_data(device))
-		return -EINVAL;
+	acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
+				   acpi_processor_notify);
 
 	pr = acpi_driver_data(device);
-
-	if (pr->id >= nr_cpu_ids)
-		goto free;
-
-	if (device->removal_type == ACPI_BUS_REMOVAL_EJECT) {
-		if (acpi_processor_handle_eject(pr))
-			return -EINVAL;
-	}
+	if (!pr)
+		return 0;
 
 	acpi_processor_power_exit(pr);
 
-	sysfs_remove_link(&device->dev.kobj, "sysdev");
-
 	if (pr->cdev) {
 		sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
 		sysfs_remove_link(&pr->cdev->device.kobj, "device");
@@ -637,331 +270,47 @@  static int acpi_processor_remove(struct
 	}
 
 	per_cpu(processors, pr->id) = NULL;
-	per_cpu(processor_device_array, pr->id) = NULL;
-	try_offline_node(cpu_to_node(pr->id));
-
-free:
-	free_cpumask_var(pr->throttling.shared_cpu_map);
-	kfree(pr);
-
 	return 0;
 }
 
-#ifdef CONFIG_ACPI_HOTPLUG_CPU
-/****************************************************************************
- * 	Acpi processor hotplug support 				       	    *
- ****************************************************************************/
-
-static int is_processor_present(acpi_handle handle)
-{
-	acpi_status status;
-	unsigned long long sta = 0;
-
-
-	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
-
-	if (ACPI_SUCCESS(status) && (sta & ACPI_STA_DEVICE_PRESENT))
-		return 1;
-
-	/*
-	 * _STA is mandatory for a processor that supports hot plug
-	 */
-	if (status == AE_NOT_FOUND)
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				"Processor does not support hot plug\n"));
-	else
-		ACPI_EXCEPTION((AE_INFO, status,
-				"Processor Device is not present"));
-	return 0;
-}
-
-static void acpi_processor_hotplug_notify(acpi_handle handle,
-					  u32 event, void *data)
-{
-	struct acpi_device *device = NULL;
-	struct acpi_eject_event *ej_event = NULL;
-	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
-	acpi_status status;
-	int result;
-
-	acpi_scan_lock_acquire();
-
-	switch (event) {
-	case ACPI_NOTIFY_BUS_CHECK:
-	case ACPI_NOTIFY_DEVICE_CHECK:
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-		"Processor driver received %s event\n",
-		       (event == ACPI_NOTIFY_BUS_CHECK) ?
-		       "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK"));
-
-		if (!is_processor_present(handle))
-			break;
-
-		if (!acpi_bus_get_device(handle, &device))
-			break;
-
-		result = acpi_bus_scan(handle);
-		if (result) {
-			acpi_handle_err(handle, "Unable to add the device\n");
-			break;
-		}
-		result = acpi_bus_get_device(handle, &device);
-		if (result) {
-			acpi_handle_err(handle, "Missing device object\n");
-			break;
-		}
-		ost_code = ACPI_OST_SC_SUCCESS;
-		break;
-
-	case ACPI_NOTIFY_EJECT_REQUEST:
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				  "received ACPI_NOTIFY_EJECT_REQUEST\n"));
-
-		if (acpi_bus_get_device(handle, &device)) {
-			acpi_handle_err(handle,
-				"Device don't exist, dropping EJECT\n");
-			break;
-		}
-		if (!acpi_driver_data(device)) {
-			acpi_handle_err(handle,
-				"Driver data is NULL, dropping EJECT\n");
-			break;
-		}
-
-		ej_event = kmalloc(sizeof(*ej_event), GFP_KERNEL);
-		if (!ej_event) {
-			acpi_handle_err(handle, "No memory, dropping EJECT\n");
-			break;
-		}
-
-		get_device(&device->dev);
-		ej_event->device = device;
-		ej_event->event = ACPI_NOTIFY_EJECT_REQUEST;
-		/* The eject is carried out asynchronously. */
-		status = acpi_os_hotplug_execute(acpi_bus_hot_remove_device,
-						 ej_event);
-		if (ACPI_FAILURE(status)) {
-			put_device(&device->dev);
-			kfree(ej_event);
-			break;
-		}
-		goto out;
-
-	default:
-		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-				  "Unsupported event [0x%x]\n", event));
-
-		/* non-hotplug event; possibly handled by other handler */
-		goto out;
-	}
-
-	/* Inform firmware that the hotplug operation has completed */
-	(void) acpi_evaluate_hotplug_ost(handle, event, ost_code, NULL);
-
- out:
-	acpi_scan_lock_release();
-}
-
-static acpi_status is_processor_device(acpi_handle handle)
-{
-	struct acpi_device_info *info;
-	char *hid;
-	acpi_status status;
-
-	status = acpi_get_object_info(handle, &info);
-	if (ACPI_FAILURE(status))
-		return status;
-
-	if (info->type == ACPI_TYPE_PROCESSOR) {
-		kfree(info);
-		return AE_OK;	/* found a processor object */
-	}
-
-	if (!(info->valid & ACPI_VALID_HID)) {
-		kfree(info);
-		return AE_ERROR;
-	}
-
-	hid = info->hardware_id.string;
-	if ((hid == NULL) || strcmp(hid, ACPI_PROCESSOR_DEVICE_HID)) {
-		kfree(info);
-		return AE_ERROR;
-	}
-
-	kfree(info);
-	return AE_OK;	/* found a processor device object */
-}
-
-static acpi_status
-processor_walk_namespace_cb(acpi_handle handle,
-			    u32 lvl, void *context, void **rv)
-{
-	acpi_status status;
-	int *action = context;
-
-	status = is_processor_device(handle);
-	if (ACPI_FAILURE(status))
-		return AE_OK;	/* not a processor; continue to walk */
-
-	switch (*action) {
-	case INSTALL_NOTIFY_HANDLER:
-		acpi_install_notify_handler(handle,
-					    ACPI_SYSTEM_NOTIFY,
-					    acpi_processor_hotplug_notify,
-					    NULL);
-		break;
-	case UNINSTALL_NOTIFY_HANDLER:
-		acpi_remove_notify_handler(handle,
-					   ACPI_SYSTEM_NOTIFY,
-					   acpi_processor_hotplug_notify);
-		break;
-	default:
-		break;
-	}
-
-	/* found a processor; skip walking underneath */
-	return AE_CTRL_DEPTH;
-}
-
-static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
-{
-	acpi_handle handle = pr->handle;
-
-	if (!is_processor_present(handle)) {
-		return AE_ERROR;
-	}
-
-	if (acpi_map_lsapic(handle, &pr->id))
-		return AE_ERROR;
-
-	if (arch_register_cpu(pr->id)) {
-		acpi_unmap_lsapic(pr->id);
-		return AE_ERROR;
-	}
-
-	/* CPU got hot-plugged, but cpu_data is not initialized yet
-	 * Set flag to delay cpu_idle/throttling initialization
-	 * in:
-	 * acpi_processor_add()
-	 *   acpi_processor_get_info()
-	 * and do it when the CPU gets online the first time
-	 * TBD: Cleanup above functions and try to do this more elegant.
-	 */
-	pr_info("CPU %d got hotplugged\n", pr->id);
-	pr->flags.need_hotplug_init = 1;
-
-	return AE_OK;
-}
-
-static int acpi_processor_handle_eject(struct acpi_processor *pr)
-{
-	if (cpu_online(pr->id))
-		cpu_down(pr->id);
-
-	get_online_cpus();
-	/*
-	 * The cpu might become online again at this point. So we check whether
-	 * the cpu has been onlined or not. If the cpu became online, it means
-	 * that someone wants to use the cpu. So acpi_processor_handle_eject()
-	 * returns -EAGAIN.
-	 */
-	if (unlikely(cpu_online(pr->id))) {
-		put_online_cpus();
-		pr_warn("Failed to remove CPU %d, because other task "
-			"brought the CPU back online\n", pr->id);
-		return -EAGAIN;
-	}
-	arch_unregister_cpu(pr->id);
-	acpi_unmap_lsapic(pr->id);
-	put_online_cpus();
-	return (0);
-}
-#else
-static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
-{
-	return AE_ERROR;
-}
-static int acpi_processor_handle_eject(struct acpi_processor *pr)
-{
-	return (-EINVAL);
-}
-#endif
-
-static
-void acpi_processor_install_hotplug_notify(void)
-{
-#ifdef CONFIG_ACPI_HOTPLUG_CPU
-	int action = INSTALL_NOTIFY_HANDLER;
-	acpi_walk_namespace(ACPI_TYPE_ANY,
-			    ACPI_ROOT_OBJECT,
-			    ACPI_UINT32_MAX,
-			    processor_walk_namespace_cb, NULL, &action, NULL);
-#endif
-	register_hotcpu_notifier(&acpi_cpu_notifier);
-}
-
-static
-void acpi_processor_uninstall_hotplug_notify(void)
-{
-#ifdef CONFIG_ACPI_HOTPLUG_CPU
-	int action = UNINSTALL_NOTIFY_HANDLER;
-	acpi_walk_namespace(ACPI_TYPE_ANY,
-			    ACPI_ROOT_OBJECT,
-			    ACPI_UINT32_MAX,
-			    processor_walk_namespace_cb, NULL, &action, NULL);
-#endif
-	unregister_hotcpu_notifier(&acpi_cpu_notifier);
-}
-
 /*
  * We keep the driver loaded even when ACPI is not running.
  * This is needed for the powernow-k8 driver, that works even without
  * ACPI, but needs symbols from this driver
  */
 
-static int __init acpi_processor_init(void)
+static int __init acpi_processor_driver_init(void)
 {
 	int result = 0;
 
 	if (acpi_disabled)
 		return 0;
 
-	result = acpi_bus_register_driver(&acpi_processor_driver);
+	result = driver_register(&acpi_processor_driver);
 	if (result < 0)
 		return result;
 
 	acpi_processor_syscore_init();
-
-	acpi_processor_install_hotplug_notify();
-
+	register_hotcpu_notifier(&acpi_cpu_notifier);
 	acpi_thermal_cpufreq_init();
-
 	acpi_processor_ppc_init();
-
 	acpi_processor_throttling_init();
-
 	return 0;
 }
 
-static void __exit acpi_processor_exit(void)
+static void __exit acpi_processor_driver_exit(void)
 {
 	if (acpi_disabled)
 		return;
 
 	acpi_processor_ppc_exit();
-
 	acpi_thermal_cpufreq_exit();
-
-	acpi_processor_uninstall_hotplug_notify();
-
+	unregister_hotcpu_notifier(&acpi_cpu_notifier);
 	acpi_processor_syscore_exit();
-
-	acpi_bus_unregister_driver(&acpi_processor_driver);
-
-	return;
+	driver_unregister(&acpi_processor_driver);
 }
 
-module_init(acpi_processor_init);
-module_exit(acpi_processor_exit);
+module_init(acpi_processor_driver_init);
+module_exit(acpi_processor_driver_exit);
 
 MODULE_ALIAS("processor");
Index: linux-pm/drivers/acpi/glue.c
===================================================================
--- linux-pm.orig/drivers/acpi/glue.c
+++ linux-pm/drivers/acpi/glue.c
@@ -105,7 +105,7 @@  acpi_handle acpi_get_child(acpi_handle p
 }
 EXPORT_SYMBOL(acpi_get_child);
 
-static int acpi_bind_one(struct device *dev, acpi_handle handle)
+int acpi_bind_one(struct device *dev, acpi_handle handle)
 {
 	struct acpi_device *acpi_dev;
 	acpi_status status;
@@ -188,8 +188,9 @@  static int acpi_bind_one(struct device *
 	kfree(physical_node);
 	goto err;
 }
+EXPORT_SYMBOL_GPL(acpi_bind_one);
 
-static int acpi_unbind_one(struct device *dev)
+int acpi_unbind_one(struct device *dev)
 {
 	struct acpi_device_physical_node *entry;
 	struct acpi_device *acpi_dev;
@@ -238,6 +239,7 @@  err:
 	dev_err(dev, "Oops, 'acpi_handle' corrupt\n");
 	return -EINVAL;
 }
+EXPORT_SYMBOL_GPL(acpi_unbind_one);
 
 static int acpi_platform_notify(struct device *dev)
 {
Index: linux-pm/drivers/acpi/internal.h
===================================================================
--- linux-pm.orig/drivers/acpi/internal.h
+++ linux-pm/drivers/acpi/internal.h
@@ -33,6 +33,7 @@  static inline void acpi_pci_slot_init(vo
 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
 			     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
Index: linux-pm/drivers/acpi/acpi_processor.c
===================================================================
--- /dev/null
+++ linux-pm/drivers/acpi/acpi_processor.c
@@ -0,0 +1,473 @@ 
+/*
+ * acpi_processor.c - ACPI processor enumeration support
+ *
+ * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ * Copyright (C) 2004       Dominik Brodowski <linux@brodo.de>
+ * Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
+ * Copyright (C) 2013, Intel Corporation
+ *                     Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+#include <acpi/processor.h>
+
+#include <asm/cpu.h>
+
+#include "internal.h"
+
+#define _COMPONENT	ACPI_PROCESSOR_COMPONENT
+
+ACPI_MODULE_NAME("processor");
+
+/* --------------------------------------------------------------------------
+                                Errata Handling
+   -------------------------------------------------------------------------- */
+
+struct acpi_processor_errata errata __read_mostly;
+EXPORT_SYMBOL_GPL(errata);
+
+static int acpi_processor_errata_piix4(struct pci_dev *dev)
+{
+	u8 value1 = 0;
+	u8 value2 = 0;
+
+
+	if (!dev)
+		return -EINVAL;
+
+	/*
+	 * Note that 'dev' references the PIIX4 ACPI Controller.
+	 */
+
+	switch (dev->revision) {
+	case 0:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 A-step\n"));
+		break;
+	case 1:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4 B-step\n"));
+		break;
+	case 2:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4E\n"));
+		break;
+	case 3:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found PIIX4M\n"));
+		break;
+	default:
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found unknown PIIX4\n"));
+		break;
+	}
+
+	switch (dev->revision) {
+
+	case 0:		/* PIIX4 A-step */
+	case 1:		/* PIIX4 B-step */
+		/*
+		 * See specification changes #13 ("Manual Throttle Duty Cycle")
+		 * and #14 ("Enabling and Disabling Manual Throttle"), plus
+		 * erratum #5 ("STPCLK# Deassertion Time") from the January
+		 * 2002 PIIX4 specification update.  Applies to only older
+		 * PIIX4 models.
+		 */
+		errata.piix4.throttle = 1;
+
+	case 2:		/* PIIX4E */
+	case 3:		/* PIIX4M */
+		/*
+		 * See erratum #18 ("C3 Power State/BMIDE and Type-F DMA
+		 * Livelock") from the January 2002 PIIX4 specification update.
+		 * Applies to all PIIX4 models.
+		 */
+
+		/*
+		 * BM-IDE
+		 * ------
+		 * Find the PIIX4 IDE Controller and get the Bus Master IDE
+		 * Status register address.  We'll use this later to read
+		 * each IDE controller's DMA status to make sure we catch all
+		 * DMA activity.
+		 */
+		dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
+				     PCI_DEVICE_ID_INTEL_82371AB,
+				     PCI_ANY_ID, PCI_ANY_ID, NULL);
+		if (dev) {
+			errata.piix4.bmisx = pci_resource_start(dev, 4);
+			pci_dev_put(dev);
+		}
+
+		/*
+		 * Type-F DMA
+		 * ----------
+		 * Find the PIIX4 ISA Controller and read the Motherboard
+		 * DMA controller's status to see if Type-F (Fast) DMA mode
+		 * is enabled (bit 7) on either channel.  Note that we'll
+		 * disable C3 support if this is enabled, as some legacy
+		 * devices won't operate well if fast DMA is disabled.
+		 */
+		dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
+				     PCI_DEVICE_ID_INTEL_82371AB_0,
+				     PCI_ANY_ID, PCI_ANY_ID, NULL);
+		if (dev) {
+			pci_read_config_byte(dev, 0x76, &value1);
+			pci_read_config_byte(dev, 0x77, &value2);
+			if ((value1 & 0x80) || (value2 & 0x80))
+				errata.piix4.fdma = 1;
+			pci_dev_put(dev);
+		}
+
+		break;
+	}
+
+	if (errata.piix4.bmisx)
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+				  "Bus master activity detection (BM-IDE) erratum enabled\n"));
+	if (errata.piix4.fdma)
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+				  "Type-F DMA livelock erratum (C3 disabled)\n"));
+
+	return 0;
+}
+
+static int acpi_processor_errata(struct acpi_processor *pr)
+{
+	int result = 0;
+	struct pci_dev *dev = NULL;
+
+
+	if (!pr)
+		return -EINVAL;
+
+	/*
+	 * PIIX4
+	 */
+	dev = pci_get_subsys(PCI_VENDOR_ID_INTEL,
+			     PCI_DEVICE_ID_INTEL_82371AB_3, PCI_ANY_ID,
+			     PCI_ANY_ID, NULL);
+	if (dev) {
+		result = acpi_processor_errata_piix4(dev);
+		pci_dev_put(dev);
+	}
+
+	return result;
+}
+
+/* --------------------------------------------------------------------------
+                                Initialization
+   -------------------------------------------------------------------------- */
+
+static acpi_status acpi_processor_hotadd_init(struct acpi_processor *pr)
+{
+	unsigned long long sta;
+	acpi_status status;
+	int ret;
+
+	status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
+	if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT))
+		return -ENODEV;
+
+	ret = acpi_map_lsapic(pr->handle, &pr->id);
+	if (ret)
+		return ret;
+
+	ret = arch_register_cpu(pr->id);
+	if (ret) {
+		acpi_unmap_lsapic(pr->id);
+		return ret;
+	}
+
+	/*
+	 * CPU got hot-added, but cpu_data is not initialized yet.  Set a flag
+	 * to delay cpu_idle/throttling initialization and do it when the CPU
+	 * gets online for the first time.
+	 */
+	pr_info("CPU%d has been hot-added\n", pr->id);
+	pr->flags.need_hotplug_init = 1;
+	return 0;
+}
+
+static int acpi_processor_get_info(struct acpi_device *device)
+{
+	union acpi_object object = { 0 };
+	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
+	struct acpi_processor *pr = acpi_driver_data(device);
+	int cpu_index, device_declaration = 0;
+	acpi_status status = AE_OK;
+	static int cpu0_initialized;
+
+	if (num_online_cpus() > 1)
+		errata.smp = TRUE;
+
+	acpi_processor_errata(pr);
+
+	/*
+	 * Check to see if we have bus mastering arbitration control.  This
+	 * is required for proper C3 usage (to maintain cache coherency).
+	 */
+	if (acpi_gbl_FADT.pm2_control_block && acpi_gbl_FADT.pm2_control_length) {
+		pr->flags.bm_control = 1;
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+				  "Bus mastering arbitration control present\n"));
+	} else
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+				  "No bus mastering arbitration control\n"));
+
+	if (!strcmp(acpi_device_hid(device), ACPI_PROCESSOR_OBJECT_HID)) {
+		/* Declared with "Processor" statement; match ProcessorID */
+		status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
+		if (ACPI_FAILURE(status)) {
+			dev_err(&device->dev,
+				"Failed to evaluate processor object (0x%x)\n",
+				status);
+			return -ENODEV;
+		}
+
+		/*
+		 * TBD: Synch processor ID (via LAPIC/LSAPIC structures) on SMP.
+		 *      >>> 'acpi_get_processor_id(acpi_id, &id)' in
+		 *      arch/xxx/acpi.c
+		 */
+		pr->acpi_id = object.processor.proc_id;
+	} else {
+		/*
+		 * Declared with "Device" statement; match _UID.
+		 * Note that we don't handle string _UIDs yet.
+		 */
+		unsigned long long value;
+		status = acpi_evaluate_integer(pr->handle, METHOD_NAME__UID,
+						NULL, &value);
+		if (ACPI_FAILURE(status)) {
+			dev_err(&device->dev,
+				"Failed to evaluate processor _UID (0x%x)\n",
+				status);
+			return -ENODEV;
+		}
+		device_declaration = 1;
+		pr->acpi_id = value;
+	}
+	cpu_index = acpi_get_cpuid(pr->handle, device_declaration, pr->acpi_id);
+
+	/* Handle UP system running SMP kernel, with no LAPIC in MADT */
+	if (!cpu0_initialized && (cpu_index == -1) &&
+	    (num_online_cpus() == 1)) {
+		cpu_index = 0;
+	}
+
+	cpu0_initialized = 1;
+
+	pr->id = cpu_index;
+
+	/*
+	 *  Extra Processor objects may be enumerated on MP systems with
+	 *  less than the max # of CPUs. They should be ignored _iff
+	 *  they are physically not present.
+	 */
+	if (pr->id == -1) {
+		int ret = acpi_processor_hotadd_init(pr);
+		if (ret)
+			return ret;
+	}
+	/*
+	 * On some boxes several processors use the same processor bus id.
+	 * But they are located in different scope. For example:
+	 * \_SB.SCK0.CPU0
+	 * \_SB.SCK1.CPU0
+	 * Rename the processor device bus id. And the new bus id will be
+	 * generated as the following format:
+	 * CPU+CPU ID.
+	 */
+	sprintf(acpi_device_bid(device), "CPU%X", pr->id);
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
+			  pr->acpi_id));
+
+	if (!object.processor.pblk_address)
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
+	else if (object.processor.pblk_length != 6)
+		dev_err(&device->dev, "Invalid PBLK length [%d]\n",
+			    object.processor.pblk_length);
+	else {
+		pr->throttling.address = object.processor.pblk_address;
+		pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
+		pr->throttling.duty_width = acpi_gbl_FADT.duty_width;
+
+		pr->pblk = object.processor.pblk_address;
+
+		/*
+		 * We don't care about error returns - we just try to mark
+		 * these reserved so that nobody else is confused into thinking
+		 * that this region might be unused..
+		 *
+		 * (In particular, allocating the IO range for Cardbus)
+		 */
+		request_region(pr->throttling.address, 6, "ACPI CPU throttle");
+	}
+
+	/*
+	 * If ACPI describes a slot number for this CPU, we can use it to
+	 * ensure we get the right value in the "physical id" field
+	 * of /proc/cpuinfo
+	 */
+	status = acpi_evaluate_object(pr->handle, "_SUN", NULL, &buffer);
+	if (ACPI_SUCCESS(status))
+		arch_fix_phys_package_id(pr->id, object.integer.value);
+
+	return 0;
+}
+
+/*
+ * Do not put anything in here which needs the core to be online.
+ * For example MSR access or setting up things which check for cpuinfo_x86
+ * (cpu_data(cpu)) values, like CPU feature flags, family, model, etc.
+ * Such things have to be put in and set up by the processor driver's .probe().
+ */
+static DEFINE_PER_CPU(void *, processor_device_array);
+
+static int __cpuinit acpi_processor_add(struct acpi_device *device,
+					const struct acpi_device_id *id)
+{
+	struct acpi_processor *pr;
+	struct device *dev;
+	int result = 0;
+
+	pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
+	if (!pr)
+		return -ENOMEM;
+
+	if (!zalloc_cpumask_var(&pr->throttling.shared_cpu_map, GFP_KERNEL)) {
+		result = -ENOMEM;
+		goto err_free_pr;
+	}
+
+	pr->handle = device->handle;
+	strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
+	strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
+	device->driver_data = pr;
+
+	result = acpi_processor_get_info(device);
+	if (result) /* Processor is not physically present or unavailable */
+		return 0;
+
+#ifdef CONFIG_SMP
+	if (pr->id >= setup_max_cpus && pr->id != 0)
+		return 0;
+#endif
+
+	BUG_ON(pr->id >= nr_cpu_ids);
+
+	/*
+	 * Buggy BIOS check.
+	 * ACPI id of processors can be reported wrongly by the BIOS.
+	 * Don't trust it blindly
+	 */
+	if (per_cpu(processor_device_array, pr->id) != NULL &&
+	    per_cpu(processor_device_array, pr->id) != device) {
+		dev_warn(&device->dev,
+			"BIOS reported wrong ACPI id %d for the processor\n",
+			pr->id);
+		/* Give up, but do not abort the namespace scan. */
+		goto err;
+	}
+	/*
+	 * processor_device_array is not cleared on errors to allow buggy BIOS
+	 * checks.
+	 */
+	per_cpu(processor_device_array, pr->id) = device;
+
+	dev = get_cpu_device(pr->id);
+	ACPI_HANDLE_SET(dev, pr->handle);
+	result = acpi_bind_one(dev, NULL);
+	if (result)
+		goto err;
+
+	pr->dev = dev;
+	dev->offline = pr->flags.need_hotplug_init;
+
+	/* Trigger the processor driver's .probe() if present. */
+	if (device_attach(dev) >= 0)
+		return 1;
+
+	dev_err(dev, "Processor driver could not be attached\n");
+	acpi_unbind_one(dev);
+
+ err:
+	free_cpumask_var(pr->throttling.shared_cpu_map);
+	device->driver_data = NULL;
+ err_free_pr:
+	kfree(pr);
+	return result;
+}
+
+/* --------------------------------------------------------------------------
+                                    Removal
+   -------------------------------------------------------------------------- */
+
+static void acpi_processor_remove(struct acpi_device *device)
+{
+	struct acpi_processor *pr;
+
+	if (!device || !acpi_driver_data(device))
+		return;
+
+	pr = acpi_driver_data(device);
+	if (pr->id >= nr_cpu_ids)
+		goto out;
+
+	/*
+	 * The only reason why we ever get here is CPU hot-removal.  The CPU is
+	 * already offline and the ACPI device removal locking prevents it from
+	 * being put back online at this point.
+	 *
+	 * Unbind the driver from the processor device and detach it from the
+	 * ACPI companion object.
+	 */
+	device_release_driver(pr->dev);
+	acpi_unbind_one(pr->dev);
+
+	/* Clean up. */
+	per_cpu(processor_device_array, pr->id) = NULL;
+	try_offline_node(cpu_to_node(pr->id));
+
+	/* Remove the CPU. */
+	get_online_cpus();
+	arch_unregister_cpu(pr->id);
+	acpi_unmap_lsapic(pr->id);
+	put_online_cpus();
+
+ out:
+	free_cpumask_var(pr->throttling.shared_cpu_map);
+	kfree(pr);
+}
+
+/*
+ * The following ACPI IDs are known to be suitable for representing as
+ * processor devices.
+ */
+static const struct acpi_device_id processor_device_ids[] = {
+
+	{ ACPI_PROCESSOR_OBJECT_HID, },
+	{ ACPI_PROCESSOR_DEVICE_HID, },
+
+	{ }
+};
+
+static struct acpi_scan_handler processor_handler = {
+	.ids = processor_device_ids,
+	.attach = acpi_processor_add,
+	.detach = acpi_processor_remove,
+	.hotplug = {
+		.enabled = true,
+	},
+};
+
+void __init acpi_processor_init(void)
+{
+	acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
+}
Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -2124,6 +2124,7 @@  int __init acpi_scan_init(void)
 
 	acpi_pci_root_init();
 	acpi_pci_link_init();
+	acpi_processor_init();
 	acpi_platform_init();
 	acpi_lpss_init();
 	acpi_csrt_init();
Index: linux-pm/drivers/acpi/Makefile
===================================================================
--- linux-pm.orig/drivers/acpi/Makefile
+++ linux-pm/drivers/acpi/Makefile
@@ -34,6 +34,7 @@  acpi-$(CONFIG_ACPI_SLEEP)	+= proc.o
 acpi-y				+= bus.o glue.o
 acpi-y				+= scan.o
 acpi-y				+= resource.o
+acpi-y				+= acpi_processor.o
 acpi-y				+= processor_core.o
 acpi-y				+= ec.o
 acpi-$(CONFIG_ACPI_DOCK)	+= dock.o
Index: linux-pm/include/acpi/processor.h
===================================================================
--- linux-pm.orig/include/acpi/processor.h
+++ linux-pm/include/acpi/processor.h
@@ -6,6 +6,10 @@ 
 #include <linux/thermal.h>
 #include <asm/acpi.h>
 
+#define ACPI_PROCESSOR_CLASS		"processor"
+#define ACPI_PROCESSOR_DEVICE_NAME	"Processor"
+#define ACPI_PROCESSOR_DEVICE_HID	"ACPI0007"
+
 #define ACPI_PROCESSOR_BUSY_METRIC	10
 
 #define ACPI_PROCESSOR_MAX_POWER	8
@@ -207,6 +211,7 @@  struct acpi_processor {
 	struct acpi_processor_throttling throttling;
 	struct acpi_processor_limit limit;
 	struct thermal_cooling_device *cdev;
+	struct device *dev; /* Processor device. */
 };
 
 struct acpi_processor_errata {
Index: linux-pm/drivers/base/cpu.c
===================================================================
--- linux-pm.orig/drivers/base/cpu.c
+++ linux-pm/drivers/base/cpu.c
@@ -13,11 +13,21 @@ 
 #include <linux/gfp.h>
 #include <linux/slab.h>
 #include <linux/percpu.h>
+#include <linux/acpi.h>
 
 #include "base.h"
 
 static DEFINE_PER_CPU(struct device *, cpu_sys_devices);
 
+static int cpu_subsys_match(struct device *dev, struct device_driver *drv)
+{
+	/* ACPI style match is the only one that may succeed. */
+	if (acpi_driver_match_device(dev, drv))
+		return 1;
+
+	return 0;
+}
+
 #ifdef CONFIG_HOTPLUG_CPU
 static int cpu_subsys_online(struct device *dev)
 {
@@ -76,6 +86,7 @@  static DEVICE_ATTR(release, S_IWUSR, NUL
 struct bus_type cpu_subsys = {
 	.name = "cpu",
 	.dev_name = "cpu",
+	.match = cpu_subsys_match,
 #ifdef CONFIG_HOTPLUG_CPU
 	.online = cpu_subsys_online,
 	.offline = cpu_subsys_offline,