linux.git/kernel/power/power.h, branch v2.6.24

Hibernation: Check if ACPI is enabled during restore in the right place

2007-10-18T21:37:20+00:00

The following scenario leads to total confusion of the platform firmware on
some boxes (eg. HPC nx6325):
* Hibernate with ACPI enabled
* Resume passing "acpi=off" to the boot kernel

To prevent this from happening it's necessary to check if ACPI is enabled (and
enable it if that's not the case) _right_ _after_ control has been transfered
from the boot kernel to the image kernel, before device_power_up() is called
(ie.  with interrupts disabled).   Enabling ACPI after calling
device_power_up() turns out to be insufficient.

For this reason, introduce new hibernation callback ->leave() that will be
executed before device_power_up() by the restored image kernel.   To make it
work, it also is necessary to move swsusp_suspend() from swsusp.c to disk.c
(it's name is changed to "create_image", which is more up to the point).

Signed-off-by: Rafael J. Wysocki 
Acked-by: Pavel Machek 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Hibernation: Arbitrary boot kernel support - generic code

2007-10-18T21:37:19+00:00

Add the bits needed for supporting arbitrary boot kernels to the common
hibernation code.

To support arbitrary boot kernels, make it possible to replace the 'struct
new_utsname' and the kernel version in the hibernation image header by some
architecture specific data that will be used to verify if the image is valid
and to restore the image.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Pavel Machek 
Cc: Andi Kleen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Introduce CONFIG_SUSPEND for suspend-to-Ram and standby

2007-07-29T23:45:38+00:00

Introduce CONFIG_SUSPEND representing the ability to enter system sleep
states, such as the ACPI S3 state, and allow the user to choose SUSPEND
and HIBERNATION independently of each other.

Make HOTPLUG_CPU be selected automatically if SUSPEND or HIBERNATION has
been chosen and the kernel is intended for SMP systems.

Also, introduce CONFIG_PM_SLEEP which is automatically selected if
CONFIG_SUSPEND or CONFIG_HIBERNATION is set and use it to select the
code needed for both suspend and hibernation.

The top-level power management headers and the ACPI code related to
suspend and hibernation are modified to use the new definitions (the
changes in drivers/acpi/sleep/main.c are, mostly, moving code to reduce
the number of ifdefs).

There are many other files in which CONFIG_PM can be replaced with
CONFIG_PM_SLEEP or even with CONFIG_SUSPEND, but they can be updated in
the future.

Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Linus Torvalds

Replace CONFIG_SOFTWARE_SUSPEND with CONFIG_HIBERNATION

2007-07-29T23:45:38+00:00

Replace CONFIG_SOFTWARE_SUSPEND with CONFIG_HIBERNATION to avoid
confusion (among other things, with CONFIG_SUSPEND introduced in the
next patch).

Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Linus Torvalds

PM: Reduce code duplication between main.c and user.c

2007-07-19T17:04:42+00:00

The SNAPSHOT_S2RAM ioctl code is outdated and it should not duplicate the
suspend code in kernel/power/main.c.  Fix that.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Pavel Machek 
Cc: Nigel Cunningham 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

PM: introduce hibernation and suspend notifiers

2007-07-19T17:04:42+00:00

Make it possible to register hibernation and suspend notifiers, so that
subsystems can perform hibernation-related or suspend-related operations that
should not be carried out by device drivers' .suspend() and .resume()
routines.

[akpm@linux-foundation.org: build fixes]
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Rafael J. Wysocki 
Acked-by: Pavel Machek 
Cc: Nigel Cunningham 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

swsusp: introduce restore platform operations

2007-07-19T17:04:42+00:00

At least on some machines it is necessary to prepare the ACPI firmware for the
restoration of the system memory state from the hibernation image if the
"platform" mode of hibernation has been used.  Namely, in that cases we need
to disable the GPEs before replacing the "boot" kernel with the "frozen"
kernel (cf.  http://bugzilla.kernel.org/show_bug.cgi?id=7887).  After the
restore they will be re-enabled by hibernation_ops->finish(), but if the
restore fails, they have to be re-enabled by the restore code explicitly.

For this purpose we can introduce two additional hibernation operations,
called pre_restore() and restore_cleanup() and call them from the restore code
path.  Still, they should be called if the "platform" mode of hibernation has
been used, so we need to pass the information about the hibernation mode from
the "frozen" kernel to the "boot" kernel in the image header.

Apparently, we can't drop the disabling of GPEs before the restore because of
Bug #7887 .   We also can't do it unconditionally, because the GPEs wouldn't
have been enabled after a successful restore if the suspend had been done in
the 'shutdown' or 'reboot' mode.

In principle we could (and probably should) unconditionally disable the GPEs
before each snapshot creation *and* before the restore, but then we'd have to
unconditionally enable them after the snapshot creation as well as after the
restore (or restore failure)   Still, for this purpose we'd need to modify
acpi_enter_sleep_state_prep() and acpi_leave_sleep_state() and we'd have to
introduce some mechanism synchronizing the disablind/enabling of the GPEs with
the device drivers' .suspend()/.resume() routines and with
disable_/enable_nonboot_cpus().   However, this would have affected the
suspend (ie.  s2ram) code as well as the hibernation, which I'd like to avoid
in this patch series.

Signed-off-by: Rafael J. Wysocki 
Cc: Nigel Cunningham 
Cc: Pavel Machek 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

swsusp: remove code duplication between disk.c and user.c

2007-07-19T17:04:42+00:00

Currently, much of the code in kernel/power/disk.c is duplicated in
kernel/power/user.c , mainly for historical reasons.  By eliminating this code
duplication we can reduce the size of user.c quite substantially and remove
the maintenance difficulty resulting from it.

[bunk@stusta.de: kernel/power/disk.c: make code static]
Signed-off-by: Rafael J. Wysocki 
Acked-by: Pavel Machek 
Cc: Nigel Cunningham 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

PM: Separate hibernation code from suspend code

2007-05-09T19:30:48+00:00

[ With Johannes Berg  ]

Separate the hibernation (aka suspend to disk code) from the other suspend
code.  In particular:

 * Remove the definitions related to hibernation from include/linux/pm.h
 * Introduce struct hibernation_ops and a new hibernate() function to hibernate
   the system, defined in include/linux/suspend.h
 * Separate suspend code in kernel/power/main.c from hibernation-related code
   in kernel/power/disk.c and kernel/power/user.c (with the help of
   hibernation_ops)
 * Switch ACPI (the only user of pm_ops.pm_disk_mode) to hibernation_ops

Signed-off-by: Rafael J. Wysocki 
Cc: Greg KH 
Cc: Pavel Machek 
Cc: Nigel Cunningham 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

swsusp: free more memory

2007-05-07T19:12:59+00:00

Move the definition of PAGES_FOR_IO to kernel/power/power.h and introduce
SPARE_PAGES representing the number of pages that should be freed by the
swsusp's memory shrinker in addition to PAGES_FOR_IO so that device drivers
can allocate some memory (up to 1 MB total) in their .suspend() routines
without causing the suspend to fail.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Pavel Machek 
Cc: Nigel Cunningham 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds